linux/fs/ext4/super.c
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   1/*
   2 *  linux/fs/ext4/super.c
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/fs/minix/inode.c
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 *
  15 *  Big-endian to little-endian byte-swapping/bitmaps by
  16 *        David S. Miller (davem@caip.rutgers.edu), 1995
  17 */
  18
  19#include <linux/module.h>
  20#include <linux/string.h>
  21#include <linux/fs.h>
  22#include <linux/time.h>
  23#include <linux/vmalloc.h>
  24#include <linux/jbd2.h>
  25#include <linux/slab.h>
  26#include <linux/init.h>
  27#include <linux/blkdev.h>
  28#include <linux/parser.h>
  29#include <linux/buffer_head.h>
  30#include <linux/exportfs.h>
  31#include <linux/vfs.h>
  32#include <linux/random.h>
  33#include <linux/mount.h>
  34#include <linux/namei.h>
  35#include <linux/quotaops.h>
  36#include <linux/seq_file.h>
  37#include <linux/proc_fs.h>
  38#include <linux/ctype.h>
  39#include <linux/log2.h>
  40#include <linux/crc16.h>
  41#include <linux/cleancache.h>
  42#include <asm/uaccess.h>
  43
  44#include <linux/kthread.h>
  45#include <linux/freezer.h>
  46
  47#include "ext4.h"
  48#include "ext4_extents.h"       /* Needed for trace points definition */
  49#include "ext4_jbd2.h"
  50#include "xattr.h"
  51#include "acl.h"
  52#include "mballoc.h"
  53
  54#define CREATE_TRACE_POINTS
  55#include <trace/events/ext4.h>
  56
  57static struct proc_dir_entry *ext4_proc_root;
  58static struct kset *ext4_kset;
  59static struct ext4_lazy_init *ext4_li_info;
  60static struct mutex ext4_li_mtx;
  61static struct ext4_features *ext4_feat;
  62
  63static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                             unsigned long journal_devnum);
  65static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66static int ext4_commit_super(struct super_block *sb, int sync);
  67static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                        struct ext4_super_block *es);
  69static void ext4_clear_journal_err(struct super_block *sb,
  70                                   struct ext4_super_block *es);
  71static int ext4_sync_fs(struct super_block *sb, int wait);
  72static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
  73static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75static int ext4_unfreeze(struct super_block *sb);
  76static int ext4_freeze(struct super_block *sb);
  77static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  78                       const char *dev_name, void *data);
  79static inline int ext2_feature_set_ok(struct super_block *sb);
  80static inline int ext3_feature_set_ok(struct super_block *sb);
  81static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  82static void ext4_destroy_lazyinit_thread(void);
  83static void ext4_unregister_li_request(struct super_block *sb);
  84static void ext4_clear_request_list(void);
  85static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
  86
  87#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88static struct file_system_type ext2_fs_type = {
  89        .owner          = THIS_MODULE,
  90        .name           = "ext2",
  91        .mount          = ext4_mount,
  92        .kill_sb        = kill_block_super,
  93        .fs_flags       = FS_REQUIRES_DEV,
  94};
  95MODULE_ALIAS_FS("ext2");
  96MODULE_ALIAS("ext2");
  97#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  98#else
  99#define IS_EXT2_SB(sb) (0)
 100#endif
 101
 102
 103#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 104static struct file_system_type ext3_fs_type = {
 105        .owner          = THIS_MODULE,
 106        .name           = "ext3",
 107        .mount          = ext4_mount,
 108        .kill_sb        = kill_block_super,
 109        .fs_flags       = FS_REQUIRES_DEV,
 110};
 111MODULE_ALIAS_FS("ext3");
 112MODULE_ALIAS("ext3");
 113#define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 114#else
 115#define IS_EXT3_SB(sb) (0)
 116#endif
 117
 118static int ext4_verify_csum_type(struct super_block *sb,
 119                                 struct ext4_super_block *es)
 120{
 121        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 122                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 123                return 1;
 124
 125        return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 126}
 127
 128static __le32 ext4_superblock_csum(struct super_block *sb,
 129                                   struct ext4_super_block *es)
 130{
 131        struct ext4_sb_info *sbi = EXT4_SB(sb);
 132        int offset = offsetof(struct ext4_super_block, s_checksum);
 133        __u32 csum;
 134
 135        csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 136
 137        return cpu_to_le32(csum);
 138}
 139
 140int ext4_superblock_csum_verify(struct super_block *sb,
 141                                struct ext4_super_block *es)
 142{
 143        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 144                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 145                return 1;
 146
 147        return es->s_checksum == ext4_superblock_csum(sb, es);
 148}
 149
 150void ext4_superblock_csum_set(struct super_block *sb)
 151{
 152        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 153
 154        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 155                EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 156                return;
 157
 158        es->s_checksum = ext4_superblock_csum(sb, es);
 159}
 160
 161void *ext4_kvmalloc(size_t size, gfp_t flags)
 162{
 163        void *ret;
 164
 165        ret = kmalloc(size, flags | __GFP_NOWARN);
 166        if (!ret)
 167                ret = __vmalloc(size, flags, PAGE_KERNEL);
 168        return ret;
 169}
 170
 171void *ext4_kvzalloc(size_t size, gfp_t flags)
 172{
 173        void *ret;
 174
 175        ret = kzalloc(size, flags | __GFP_NOWARN);
 176        if (!ret)
 177                ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 178        return ret;
 179}
 180
 181void ext4_kvfree(void *ptr)
 182{
 183        if (is_vmalloc_addr(ptr))
 184                vfree(ptr);
 185        else
 186                kfree(ptr);
 187
 188}
 189
 190ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 191                               struct ext4_group_desc *bg)
 192{
 193        return le32_to_cpu(bg->bg_block_bitmap_lo) |
 194                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 195                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 196}
 197
 198ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 199                               struct ext4_group_desc *bg)
 200{
 201        return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 202                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 203                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 204}
 205
 206ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 207                              struct ext4_group_desc *bg)
 208{
 209        return le32_to_cpu(bg->bg_inode_table_lo) |
 210                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 211                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 212}
 213
 214__u32 ext4_free_group_clusters(struct super_block *sb,
 215                               struct ext4_group_desc *bg)
 216{
 217        return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 218                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 219                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 220}
 221
 222__u32 ext4_free_inodes_count(struct super_block *sb,
 223                              struct ext4_group_desc *bg)
 224{
 225        return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 226                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 227                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 228}
 229
 230__u32 ext4_used_dirs_count(struct super_block *sb,
 231                              struct ext4_group_desc *bg)
 232{
 233        return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 234                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 235                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 236}
 237
 238__u32 ext4_itable_unused_count(struct super_block *sb,
 239                              struct ext4_group_desc *bg)
 240{
 241        return le16_to_cpu(bg->bg_itable_unused_lo) |
 242                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 243                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 244}
 245
 246void ext4_block_bitmap_set(struct super_block *sb,
 247                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 248{
 249        bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 250        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 251                bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 252}
 253
 254void ext4_inode_bitmap_set(struct super_block *sb,
 255                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 256{
 257        bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 258        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 259                bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 260}
 261
 262void ext4_inode_table_set(struct super_block *sb,
 263                          struct ext4_group_desc *bg, ext4_fsblk_t blk)
 264{
 265        bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 266        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 267                bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 268}
 269
 270void ext4_free_group_clusters_set(struct super_block *sb,
 271                                  struct ext4_group_desc *bg, __u32 count)
 272{
 273        bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 274        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 275                bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 276}
 277
 278void ext4_free_inodes_set(struct super_block *sb,
 279                          struct ext4_group_desc *bg, __u32 count)
 280{
 281        bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 282        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 283                bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 284}
 285
 286void ext4_used_dirs_set(struct super_block *sb,
 287                          struct ext4_group_desc *bg, __u32 count)
 288{
 289        bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 290        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 291                bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 292}
 293
 294void ext4_itable_unused_set(struct super_block *sb,
 295                          struct ext4_group_desc *bg, __u32 count)
 296{
 297        bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 298        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 299                bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 300}
 301
 302
 303static void __save_error_info(struct super_block *sb, const char *func,
 304                            unsigned int line)
 305{
 306        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 307
 308        EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 309        es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 310        es->s_last_error_time = cpu_to_le32(get_seconds());
 311        strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 312        es->s_last_error_line = cpu_to_le32(line);
 313        if (!es->s_first_error_time) {
 314                es->s_first_error_time = es->s_last_error_time;
 315                strncpy(es->s_first_error_func, func,
 316                        sizeof(es->s_first_error_func));
 317                es->s_first_error_line = cpu_to_le32(line);
 318                es->s_first_error_ino = es->s_last_error_ino;
 319                es->s_first_error_block = es->s_last_error_block;
 320        }
 321        /*
 322         * Start the daily error reporting function if it hasn't been
 323         * started already
 324         */
 325        if (!es->s_error_count)
 326                mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 327        le32_add_cpu(&es->s_error_count, 1);
 328}
 329
 330static void save_error_info(struct super_block *sb, const char *func,
 331                            unsigned int line)
 332{
 333        __save_error_info(sb, func, line);
 334        ext4_commit_super(sb, 1);
 335}
 336
 337/*
 338 * The del_gendisk() function uninitializes the disk-specific data
 339 * structures, including the bdi structure, without telling anyone
 340 * else.  Once this happens, any attempt to call mark_buffer_dirty()
 341 * (for example, by ext4_commit_super), will cause a kernel OOPS.
 342 * This is a kludge to prevent these oops until we can put in a proper
 343 * hook in del_gendisk() to inform the VFS and file system layers.
 344 */
 345static int block_device_ejected(struct super_block *sb)
 346{
 347        struct inode *bd_inode = sb->s_bdev->bd_inode;
 348        struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 349
 350        return bdi->dev == NULL;
 351}
 352
 353static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 354{
 355        struct super_block              *sb = journal->j_private;
 356        struct ext4_sb_info             *sbi = EXT4_SB(sb);
 357        int                             error = is_journal_aborted(journal);
 358        struct ext4_journal_cb_entry    *jce;
 359
 360        BUG_ON(txn->t_state == T_FINISHED);
 361        spin_lock(&sbi->s_md_lock);
 362        while (!list_empty(&txn->t_private_list)) {
 363                jce = list_entry(txn->t_private_list.next,
 364                                 struct ext4_journal_cb_entry, jce_list);
 365                list_del_init(&jce->jce_list);
 366                spin_unlock(&sbi->s_md_lock);
 367                jce->jce_func(sb, jce, error);
 368                spin_lock(&sbi->s_md_lock);
 369        }
 370        spin_unlock(&sbi->s_md_lock);
 371}
 372
 373/* Deal with the reporting of failure conditions on a filesystem such as
 374 * inconsistencies detected or read IO failures.
 375 *
 376 * On ext2, we can store the error state of the filesystem in the
 377 * superblock.  That is not possible on ext4, because we may have other
 378 * write ordering constraints on the superblock which prevent us from
 379 * writing it out straight away; and given that the journal is about to
 380 * be aborted, we can't rely on the current, or future, transactions to
 381 * write out the superblock safely.
 382 *
 383 * We'll just use the jbd2_journal_abort() error code to record an error in
 384 * the journal instead.  On recovery, the journal will complain about
 385 * that error until we've noted it down and cleared it.
 386 */
 387
 388static void ext4_handle_error(struct super_block *sb)
 389{
 390        if (sb->s_flags & MS_RDONLY)
 391                return;
 392
 393        if (!test_opt(sb, ERRORS_CONT)) {
 394                journal_t *journal = EXT4_SB(sb)->s_journal;
 395
 396                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 397                if (journal)
 398                        jbd2_journal_abort(journal, -EIO);
 399        }
 400        if (test_opt(sb, ERRORS_RO)) {
 401                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 402                /*
 403                 * Make sure updated value of ->s_mount_flags will be visible
 404                 * before ->s_flags update
 405                 */
 406                smp_wmb();
 407                sb->s_flags |= MS_RDONLY;
 408        }
 409        if (test_opt(sb, ERRORS_PANIC))
 410                panic("EXT4-fs (device %s): panic forced after error\n",
 411                        sb->s_id);
 412}
 413
 414void __ext4_error(struct super_block *sb, const char *function,
 415                  unsigned int line, const char *fmt, ...)
 416{
 417        struct va_format vaf;
 418        va_list args;
 419
 420        va_start(args, fmt);
 421        vaf.fmt = fmt;
 422        vaf.va = &args;
 423        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 424               sb->s_id, function, line, current->comm, &vaf);
 425        va_end(args);
 426        save_error_info(sb, function, line);
 427
 428        ext4_handle_error(sb);
 429}
 430
 431void __ext4_error_inode(struct inode *inode, const char *function,
 432                        unsigned int line, ext4_fsblk_t block,
 433                        const char *fmt, ...)
 434{
 435        va_list args;
 436        struct va_format vaf;
 437        struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 438
 439        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 440        es->s_last_error_block = cpu_to_le64(block);
 441        save_error_info(inode->i_sb, function, line);
 442        va_start(args, fmt);
 443        vaf.fmt = fmt;
 444        vaf.va = &args;
 445        if (block)
 446                printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 447                       "inode #%lu: block %llu: comm %s: %pV\n",
 448                       inode->i_sb->s_id, function, line, inode->i_ino,
 449                       block, current->comm, &vaf);
 450        else
 451                printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 452                       "inode #%lu: comm %s: %pV\n",
 453                       inode->i_sb->s_id, function, line, inode->i_ino,
 454                       current->comm, &vaf);
 455        va_end(args);
 456
 457        ext4_handle_error(inode->i_sb);
 458}
 459
 460void __ext4_error_file(struct file *file, const char *function,
 461                       unsigned int line, ext4_fsblk_t block,
 462                       const char *fmt, ...)
 463{
 464        va_list args;
 465        struct va_format vaf;
 466        struct ext4_super_block *es;
 467        struct inode *inode = file_inode(file);
 468        char pathname[80], *path;
 469
 470        es = EXT4_SB(inode->i_sb)->s_es;
 471        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 472        save_error_info(inode->i_sb, function, line);
 473        path = d_path(&(file->f_path), pathname, sizeof(pathname));
 474        if (IS_ERR(path))
 475                path = "(unknown)";
 476        va_start(args, fmt);
 477        vaf.fmt = fmt;
 478        vaf.va = &args;
 479        if (block)
 480                printk(KERN_CRIT
 481                       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 482                       "block %llu: comm %s: path %s: %pV\n",
 483                       inode->i_sb->s_id, function, line, inode->i_ino,
 484                       block, current->comm, path, &vaf);
 485        else
 486                printk(KERN_CRIT
 487                       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 488                       "comm %s: path %s: %pV\n",
 489                       inode->i_sb->s_id, function, line, inode->i_ino,
 490                       current->comm, path, &vaf);
 491        va_end(args);
 492
 493        ext4_handle_error(inode->i_sb);
 494}
 495
 496const char *ext4_decode_error(struct super_block *sb, int errno,
 497                              char nbuf[16])
 498{
 499        char *errstr = NULL;
 500
 501        switch (errno) {
 502        case -EIO:
 503                errstr = "IO failure";
 504                break;
 505        case -ENOMEM:
 506                errstr = "Out of memory";
 507                break;
 508        case -EROFS:
 509                if (!sb || (EXT4_SB(sb)->s_journal &&
 510                            EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 511                        errstr = "Journal has aborted";
 512                else
 513                        errstr = "Readonly filesystem";
 514                break;
 515        default:
 516                /* If the caller passed in an extra buffer for unknown
 517                 * errors, textualise them now.  Else we just return
 518                 * NULL. */
 519                if (nbuf) {
 520                        /* Check for truncated error codes... */
 521                        if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 522                                errstr = nbuf;
 523                }
 524                break;
 525        }
 526
 527        return errstr;
 528}
 529
 530/* __ext4_std_error decodes expected errors from journaling functions
 531 * automatically and invokes the appropriate error response.  */
 532
 533void __ext4_std_error(struct super_block *sb, const char *function,
 534                      unsigned int line, int errno)
 535{
 536        char nbuf[16];
 537        const char *errstr;
 538
 539        /* Special case: if the error is EROFS, and we're not already
 540         * inside a transaction, then there's really no point in logging
 541         * an error. */
 542        if (errno == -EROFS && journal_current_handle() == NULL &&
 543            (sb->s_flags & MS_RDONLY))
 544                return;
 545
 546        errstr = ext4_decode_error(sb, errno, nbuf);
 547        printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 548               sb->s_id, function, line, errstr);
 549        save_error_info(sb, function, line);
 550
 551        ext4_handle_error(sb);
 552}
 553
 554/*
 555 * ext4_abort is a much stronger failure handler than ext4_error.  The
 556 * abort function may be used to deal with unrecoverable failures such
 557 * as journal IO errors or ENOMEM at a critical moment in log management.
 558 *
 559 * We unconditionally force the filesystem into an ABORT|READONLY state,
 560 * unless the error response on the fs has been set to panic in which
 561 * case we take the easy way out and panic immediately.
 562 */
 563
 564void __ext4_abort(struct super_block *sb, const char *function,
 565                unsigned int line, const char *fmt, ...)
 566{
 567        va_list args;
 568
 569        save_error_info(sb, function, line);
 570        va_start(args, fmt);
 571        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 572               function, line);
 573        vprintk(fmt, args);
 574        printk("\n");
 575        va_end(args);
 576
 577        if ((sb->s_flags & MS_RDONLY) == 0) {
 578                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 579                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 580                /*
 581                 * Make sure updated value of ->s_mount_flags will be visible
 582                 * before ->s_flags update
 583                 */
 584                smp_wmb();
 585                sb->s_flags |= MS_RDONLY;
 586                if (EXT4_SB(sb)->s_journal)
 587                        jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 588                save_error_info(sb, function, line);
 589        }
 590        if (test_opt(sb, ERRORS_PANIC))
 591                panic("EXT4-fs panic from previous error\n");
 592}
 593
 594void __ext4_msg(struct super_block *sb,
 595                const char *prefix, const char *fmt, ...)
 596{
 597        struct va_format vaf;
 598        va_list args;
 599
 600        va_start(args, fmt);
 601        vaf.fmt = fmt;
 602        vaf.va = &args;
 603        printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 604        va_end(args);
 605}
 606
 607void __ext4_warning(struct super_block *sb, const char *function,
 608                    unsigned int line, const char *fmt, ...)
 609{
 610        struct va_format vaf;
 611        va_list args;
 612
 613        va_start(args, fmt);
 614        vaf.fmt = fmt;
 615        vaf.va = &args;
 616        printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 617               sb->s_id, function, line, &vaf);
 618        va_end(args);
 619}
 620
 621void __ext4_grp_locked_error(const char *function, unsigned int line,
 622                             struct super_block *sb, ext4_group_t grp,
 623                             unsigned long ino, ext4_fsblk_t block,
 624                             const char *fmt, ...)
 625__releases(bitlock)
 626__acquires(bitlock)
 627{
 628        struct va_format vaf;
 629        va_list args;
 630        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 631
 632        es->s_last_error_ino = cpu_to_le32(ino);
 633        es->s_last_error_block = cpu_to_le64(block);
 634        __save_error_info(sb, function, line);
 635
 636        va_start(args, fmt);
 637
 638        vaf.fmt = fmt;
 639        vaf.va = &args;
 640        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 641               sb->s_id, function, line, grp);
 642        if (ino)
 643                printk(KERN_CONT "inode %lu: ", ino);
 644        if (block)
 645                printk(KERN_CONT "block %llu:", (unsigned long long) block);
 646        printk(KERN_CONT "%pV\n", &vaf);
 647        va_end(args);
 648
 649        if (test_opt(sb, ERRORS_CONT)) {
 650                ext4_commit_super(sb, 0);
 651                return;
 652        }
 653
 654        ext4_unlock_group(sb, grp);
 655        ext4_handle_error(sb);
 656        /*
 657         * We only get here in the ERRORS_RO case; relocking the group
 658         * may be dangerous, but nothing bad will happen since the
 659         * filesystem will have already been marked read/only and the
 660         * journal has been aborted.  We return 1 as a hint to callers
 661         * who might what to use the return value from
 662         * ext4_grp_locked_error() to distinguish between the
 663         * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 664         * aggressively from the ext4 function in question, with a
 665         * more appropriate error code.
 666         */
 667        ext4_lock_group(sb, grp);
 668        return;
 669}
 670
 671void ext4_update_dynamic_rev(struct super_block *sb)
 672{
 673        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 674
 675        if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 676                return;
 677
 678        ext4_warning(sb,
 679                     "updating to rev %d because of new feature flag, "
 680                     "running e2fsck is recommended",
 681                     EXT4_DYNAMIC_REV);
 682
 683        es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 684        es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 685        es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 686        /* leave es->s_feature_*compat flags alone */
 687        /* es->s_uuid will be set by e2fsck if empty */
 688
 689        /*
 690         * The rest of the superblock fields should be zero, and if not it
 691         * means they are likely already in use, so leave them alone.  We
 692         * can leave it up to e2fsck to clean up any inconsistencies there.
 693         */
 694}
 695
 696/*
 697 * Open the external journal device
 698 */
 699static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 700{
 701        struct block_device *bdev;
 702        char b[BDEVNAME_SIZE];
 703
 704        bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 705        if (IS_ERR(bdev))
 706                goto fail;
 707        return bdev;
 708
 709fail:
 710        ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 711                        __bdevname(dev, b), PTR_ERR(bdev));
 712        return NULL;
 713}
 714
 715/*
 716 * Release the journal device
 717 */
 718static void ext4_blkdev_put(struct block_device *bdev)
 719{
 720        blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 721}
 722
 723static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 724{
 725        struct block_device *bdev;
 726        bdev = sbi->journal_bdev;
 727        if (bdev) {
 728                ext4_blkdev_put(bdev);
 729                sbi->journal_bdev = NULL;
 730        }
 731}
 732
 733static inline struct inode *orphan_list_entry(struct list_head *l)
 734{
 735        return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 736}
 737
 738static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 739{
 740        struct list_head *l;
 741
 742        ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 743                 le32_to_cpu(sbi->s_es->s_last_orphan));
 744
 745        printk(KERN_ERR "sb_info orphan list:\n");
 746        list_for_each(l, &sbi->s_orphan) {
 747                struct inode *inode = orphan_list_entry(l);
 748                printk(KERN_ERR "  "
 749                       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 750                       inode->i_sb->s_id, inode->i_ino, inode,
 751                       inode->i_mode, inode->i_nlink,
 752                       NEXT_ORPHAN(inode));
 753        }
 754}
 755
 756static void ext4_put_super(struct super_block *sb)
 757{
 758        struct ext4_sb_info *sbi = EXT4_SB(sb);
 759        struct ext4_super_block *es = sbi->s_es;
 760        int i, err;
 761
 762        ext4_unregister_li_request(sb);
 763        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 764
 765        flush_workqueue(sbi->rsv_conversion_wq);
 766        destroy_workqueue(sbi->rsv_conversion_wq);
 767
 768        if (sbi->s_journal) {
 769                err = jbd2_journal_destroy(sbi->s_journal);
 770                sbi->s_journal = NULL;
 771                if (err < 0)
 772                        ext4_abort(sb, "Couldn't clean up the journal");
 773        }
 774
 775        ext4_es_unregister_shrinker(sbi);
 776        del_timer(&sbi->s_err_report);
 777        ext4_release_system_zone(sb);
 778        ext4_mb_release(sb);
 779        ext4_ext_release(sb);
 780        ext4_xattr_put_super(sb);
 781
 782        if (!(sb->s_flags & MS_RDONLY)) {
 783                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 784                es->s_state = cpu_to_le16(sbi->s_mount_state);
 785        }
 786        if (!(sb->s_flags & MS_RDONLY))
 787                ext4_commit_super(sb, 1);
 788
 789        if (sbi->s_proc) {
 790                remove_proc_entry("options", sbi->s_proc);
 791                remove_proc_entry(sb->s_id, ext4_proc_root);
 792        }
 793        kobject_del(&sbi->s_kobj);
 794
 795        for (i = 0; i < sbi->s_gdb_count; i++)
 796                brelse(sbi->s_group_desc[i]);
 797        ext4_kvfree(sbi->s_group_desc);
 798        ext4_kvfree(sbi->s_flex_groups);
 799        percpu_counter_destroy(&sbi->s_freeclusters_counter);
 800        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 801        percpu_counter_destroy(&sbi->s_dirs_counter);
 802        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 803        percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 804        brelse(sbi->s_sbh);
 805#ifdef CONFIG_QUOTA
 806        for (i = 0; i < MAXQUOTAS; i++)
 807                kfree(sbi->s_qf_names[i]);
 808#endif
 809
 810        /* Debugging code just in case the in-memory inode orphan list
 811         * isn't empty.  The on-disk one can be non-empty if we've
 812         * detected an error and taken the fs readonly, but the
 813         * in-memory list had better be clean by this point. */
 814        if (!list_empty(&sbi->s_orphan))
 815                dump_orphan_list(sb, sbi);
 816        J_ASSERT(list_empty(&sbi->s_orphan));
 817
 818        invalidate_bdev(sb->s_bdev);
 819        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 820                /*
 821                 * Invalidate the journal device's buffers.  We don't want them
 822                 * floating about in memory - the physical journal device may
 823                 * hotswapped, and it breaks the `ro-after' testing code.
 824                 */
 825                sync_blockdev(sbi->journal_bdev);
 826                invalidate_bdev(sbi->journal_bdev);
 827                ext4_blkdev_remove(sbi);
 828        }
 829        if (sbi->s_mmp_tsk)
 830                kthread_stop(sbi->s_mmp_tsk);
 831        sb->s_fs_info = NULL;
 832        /*
 833         * Now that we are completely done shutting down the
 834         * superblock, we need to actually destroy the kobject.
 835         */
 836        kobject_put(&sbi->s_kobj);
 837        wait_for_completion(&sbi->s_kobj_unregister);
 838        if (sbi->s_chksum_driver)
 839                crypto_free_shash(sbi->s_chksum_driver);
 840        kfree(sbi->s_blockgroup_lock);
 841        kfree(sbi);
 842}
 843
 844static struct kmem_cache *ext4_inode_cachep;
 845
 846/*
 847 * Called inside transaction, so use GFP_NOFS
 848 */
 849static struct inode *ext4_alloc_inode(struct super_block *sb)
 850{
 851        struct ext4_inode_info *ei;
 852
 853        ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 854        if (!ei)
 855                return NULL;
 856
 857        ei->vfs_inode.i_version = 1;
 858        INIT_LIST_HEAD(&ei->i_prealloc_list);
 859        spin_lock_init(&ei->i_prealloc_lock);
 860        ext4_es_init_tree(&ei->i_es_tree);
 861        rwlock_init(&ei->i_es_lock);
 862        INIT_LIST_HEAD(&ei->i_es_lru);
 863        ei->i_es_lru_nr = 0;
 864        ei->i_touch_when = 0;
 865        ei->i_reserved_data_blocks = 0;
 866        ei->i_reserved_meta_blocks = 0;
 867        ei->i_allocated_meta_blocks = 0;
 868        ei->i_da_metadata_calc_len = 0;
 869        ei->i_da_metadata_calc_last_lblock = 0;
 870        spin_lock_init(&(ei->i_block_reservation_lock));
 871#ifdef CONFIG_QUOTA
 872        ei->i_reserved_quota = 0;
 873#endif
 874        ei->jinode = NULL;
 875        INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 876        spin_lock_init(&ei->i_completed_io_lock);
 877        ei->i_sync_tid = 0;
 878        ei->i_datasync_tid = 0;
 879        atomic_set(&ei->i_ioend_count, 0);
 880        atomic_set(&ei->i_unwritten, 0);
 881        INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 882
 883        return &ei->vfs_inode;
 884}
 885
 886static int ext4_drop_inode(struct inode *inode)
 887{
 888        int drop = generic_drop_inode(inode);
 889
 890        trace_ext4_drop_inode(inode, drop);
 891        return drop;
 892}
 893
 894static void ext4_i_callback(struct rcu_head *head)
 895{
 896        struct inode *inode = container_of(head, struct inode, i_rcu);
 897        kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 898}
 899
 900static void ext4_destroy_inode(struct inode *inode)
 901{
 902        if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 903                ext4_msg(inode->i_sb, KERN_ERR,
 904                         "Inode %lu (%p): orphan list check failed!",
 905                         inode->i_ino, EXT4_I(inode));
 906                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 907                                EXT4_I(inode), sizeof(struct ext4_inode_info),
 908                                true);
 909                dump_stack();
 910        }
 911        call_rcu(&inode->i_rcu, ext4_i_callback);
 912}
 913
 914static void init_once(void *foo)
 915{
 916        struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 917
 918        INIT_LIST_HEAD(&ei->i_orphan);
 919        init_rwsem(&ei->xattr_sem);
 920        init_rwsem(&ei->i_data_sem);
 921        inode_init_once(&ei->vfs_inode);
 922}
 923
 924static int init_inodecache(void)
 925{
 926        ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 927                                             sizeof(struct ext4_inode_info),
 928                                             0, (SLAB_RECLAIM_ACCOUNT|
 929                                                SLAB_MEM_SPREAD),
 930                                             init_once);
 931        if (ext4_inode_cachep == NULL)
 932                return -ENOMEM;
 933        return 0;
 934}
 935
 936static void destroy_inodecache(void)
 937{
 938        /*
 939         * Make sure all delayed rcu free inodes are flushed before we
 940         * destroy cache.
 941         */
 942        rcu_barrier();
 943        kmem_cache_destroy(ext4_inode_cachep);
 944}
 945
 946void ext4_clear_inode(struct inode *inode)
 947{
 948        invalidate_inode_buffers(inode);
 949        clear_inode(inode);
 950        dquot_drop(inode);
 951        ext4_discard_preallocations(inode);
 952        ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 953        ext4_es_lru_del(inode);
 954        if (EXT4_I(inode)->jinode) {
 955                jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 956                                               EXT4_I(inode)->jinode);
 957                jbd2_free_inode(EXT4_I(inode)->jinode);
 958                EXT4_I(inode)->jinode = NULL;
 959        }
 960}
 961
 962static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 963                                        u64 ino, u32 generation)
 964{
 965        struct inode *inode;
 966
 967        if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 968                return ERR_PTR(-ESTALE);
 969        if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 970                return ERR_PTR(-ESTALE);
 971
 972        /* iget isn't really right if the inode is currently unallocated!!
 973         *
 974         * ext4_read_inode will return a bad_inode if the inode had been
 975         * deleted, so we should be safe.
 976         *
 977         * Currently we don't know the generation for parent directory, so
 978         * a generation of 0 means "accept any"
 979         */
 980        inode = ext4_iget(sb, ino);
 981        if (IS_ERR(inode))
 982                return ERR_CAST(inode);
 983        if (generation && inode->i_generation != generation) {
 984                iput(inode);
 985                return ERR_PTR(-ESTALE);
 986        }
 987
 988        return inode;
 989}
 990
 991static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 992                                        int fh_len, int fh_type)
 993{
 994        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 995                                    ext4_nfs_get_inode);
 996}
 997
 998static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 999                                        int fh_len, int fh_type)
1000{
1001        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1002                                    ext4_nfs_get_inode);
1003}
1004
1005/*
1006 * Try to release metadata pages (indirect blocks, directories) which are
1007 * mapped via the block device.  Since these pages could have journal heads
1008 * which would prevent try_to_free_buffers() from freeing them, we must use
1009 * jbd2 layer's try_to_free_buffers() function to release them.
1010 */
1011static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1012                                 gfp_t wait)
1013{
1014        journal_t *journal = EXT4_SB(sb)->s_journal;
1015
1016        WARN_ON(PageChecked(page));
1017        if (!page_has_buffers(page))
1018                return 0;
1019        if (journal)
1020                return jbd2_journal_try_to_free_buffers(journal, page,
1021                                                        wait & ~__GFP_WAIT);
1022        return try_to_free_buffers(page);
1023}
1024
1025#ifdef CONFIG_QUOTA
1026#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1027#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1028
1029static int ext4_write_dquot(struct dquot *dquot);
1030static int ext4_acquire_dquot(struct dquot *dquot);
1031static int ext4_release_dquot(struct dquot *dquot);
1032static int ext4_mark_dquot_dirty(struct dquot *dquot);
1033static int ext4_write_info(struct super_block *sb, int type);
1034static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1035                         struct path *path);
1036static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1037                                 int format_id);
1038static int ext4_quota_off(struct super_block *sb, int type);
1039static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1040static int ext4_quota_on_mount(struct super_block *sb, int type);
1041static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1042                               size_t len, loff_t off);
1043static ssize_t ext4_quota_write(struct super_block *sb, int type,
1044                                const char *data, size_t len, loff_t off);
1045static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1046                             unsigned int flags);
1047static int ext4_enable_quotas(struct super_block *sb);
1048
1049static const struct dquot_operations ext4_quota_operations = {
1050        .get_reserved_space = ext4_get_reserved_space,
1051        .write_dquot    = ext4_write_dquot,
1052        .acquire_dquot  = ext4_acquire_dquot,
1053        .release_dquot  = ext4_release_dquot,
1054        .mark_dirty     = ext4_mark_dquot_dirty,
1055        .write_info     = ext4_write_info,
1056        .alloc_dquot    = dquot_alloc,
1057        .destroy_dquot  = dquot_destroy,
1058};
1059
1060static const struct quotactl_ops ext4_qctl_operations = {
1061        .quota_on       = ext4_quota_on,
1062        .quota_off      = ext4_quota_off,
1063        .quota_sync     = dquot_quota_sync,
1064        .get_info       = dquot_get_dqinfo,
1065        .set_info       = dquot_set_dqinfo,
1066        .get_dqblk      = dquot_get_dqblk,
1067        .set_dqblk      = dquot_set_dqblk
1068};
1069
1070static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1071        .quota_on_meta  = ext4_quota_on_sysfile,
1072        .quota_off      = ext4_quota_off_sysfile,
1073        .quota_sync     = dquot_quota_sync,
1074        .get_info       = dquot_get_dqinfo,
1075        .set_info       = dquot_set_dqinfo,
1076        .get_dqblk      = dquot_get_dqblk,
1077        .set_dqblk      = dquot_set_dqblk
1078};
1079#endif
1080
1081static const struct super_operations ext4_sops = {
1082        .alloc_inode    = ext4_alloc_inode,
1083        .destroy_inode  = ext4_destroy_inode,
1084        .write_inode    = ext4_write_inode,
1085        .dirty_inode    = ext4_dirty_inode,
1086        .drop_inode     = ext4_drop_inode,
1087        .evict_inode    = ext4_evict_inode,
1088        .put_super      = ext4_put_super,
1089        .sync_fs        = ext4_sync_fs,
1090        .freeze_fs      = ext4_freeze,
1091        .unfreeze_fs    = ext4_unfreeze,
1092        .statfs         = ext4_statfs,
1093        .remount_fs     = ext4_remount,
1094        .show_options   = ext4_show_options,
1095#ifdef CONFIG_QUOTA
1096        .quota_read     = ext4_quota_read,
1097        .quota_write    = ext4_quota_write,
1098#endif
1099        .bdev_try_to_free_page = bdev_try_to_free_page,
1100};
1101
1102static const struct super_operations ext4_nojournal_sops = {
1103        .alloc_inode    = ext4_alloc_inode,
1104        .destroy_inode  = ext4_destroy_inode,
1105        .write_inode    = ext4_write_inode,
1106        .dirty_inode    = ext4_dirty_inode,
1107        .drop_inode     = ext4_drop_inode,
1108        .evict_inode    = ext4_evict_inode,
1109        .sync_fs        = ext4_sync_fs_nojournal,
1110        .put_super      = ext4_put_super,
1111        .statfs         = ext4_statfs,
1112        .remount_fs     = ext4_remount,
1113        .show_options   = ext4_show_options,
1114#ifdef CONFIG_QUOTA
1115        .quota_read     = ext4_quota_read,
1116        .quota_write    = ext4_quota_write,
1117#endif
1118        .bdev_try_to_free_page = bdev_try_to_free_page,
1119};
1120
1121static const struct export_operations ext4_export_ops = {
1122        .fh_to_dentry = ext4_fh_to_dentry,
1123        .fh_to_parent = ext4_fh_to_parent,
1124        .get_parent = ext4_get_parent,
1125};
1126
1127enum {
1128        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1129        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1130        Opt_nouid32, Opt_debug, Opt_removed,
1131        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1132        Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1133        Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1134        Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1135        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1136        Opt_data_err_abort, Opt_data_err_ignore,
1137        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1138        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1139        Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1140        Opt_usrquota, Opt_grpquota, Opt_i_version,
1141        Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1142        Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1143        Opt_inode_readahead_blks, Opt_journal_ioprio,
1144        Opt_dioread_nolock, Opt_dioread_lock,
1145        Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1146        Opt_max_dir_size_kb,
1147};
1148
1149static const match_table_t tokens = {
1150        {Opt_bsd_df, "bsddf"},
1151        {Opt_minix_df, "minixdf"},
1152        {Opt_grpid, "grpid"},
1153        {Opt_grpid, "bsdgroups"},
1154        {Opt_nogrpid, "nogrpid"},
1155        {Opt_nogrpid, "sysvgroups"},
1156        {Opt_resgid, "resgid=%u"},
1157        {Opt_resuid, "resuid=%u"},
1158        {Opt_sb, "sb=%u"},
1159        {Opt_err_cont, "errors=continue"},
1160        {Opt_err_panic, "errors=panic"},
1161        {Opt_err_ro, "errors=remount-ro"},
1162        {Opt_nouid32, "nouid32"},
1163        {Opt_debug, "debug"},
1164        {Opt_removed, "oldalloc"},
1165        {Opt_removed, "orlov"},
1166        {Opt_user_xattr, "user_xattr"},
1167        {Opt_nouser_xattr, "nouser_xattr"},
1168        {Opt_acl, "acl"},
1169        {Opt_noacl, "noacl"},
1170        {Opt_noload, "norecovery"},
1171        {Opt_noload, "noload"},
1172        {Opt_removed, "nobh"},
1173        {Opt_removed, "bh"},
1174        {Opt_commit, "commit=%u"},
1175        {Opt_min_batch_time, "min_batch_time=%u"},
1176        {Opt_max_batch_time, "max_batch_time=%u"},
1177        {Opt_journal_dev, "journal_dev=%u"},
1178        {Opt_journal_path, "journal_path=%s"},
1179        {Opt_journal_checksum, "journal_checksum"},
1180        {Opt_journal_async_commit, "journal_async_commit"},
1181        {Opt_abort, "abort"},
1182        {Opt_data_journal, "data=journal"},
1183        {Opt_data_ordered, "data=ordered"},
1184        {Opt_data_writeback, "data=writeback"},
1185        {Opt_data_err_abort, "data_err=abort"},
1186        {Opt_data_err_ignore, "data_err=ignore"},
1187        {Opt_offusrjquota, "usrjquota="},
1188        {Opt_usrjquota, "usrjquota=%s"},
1189        {Opt_offgrpjquota, "grpjquota="},
1190        {Opt_grpjquota, "grpjquota=%s"},
1191        {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1192        {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1193        {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1194        {Opt_grpquota, "grpquota"},
1195        {Opt_noquota, "noquota"},
1196        {Opt_quota, "quota"},
1197        {Opt_usrquota, "usrquota"},
1198        {Opt_barrier, "barrier=%u"},
1199        {Opt_barrier, "barrier"},
1200        {Opt_nobarrier, "nobarrier"},
1201        {Opt_i_version, "i_version"},
1202        {Opt_stripe, "stripe=%u"},
1203        {Opt_delalloc, "delalloc"},
1204        {Opt_nodelalloc, "nodelalloc"},
1205        {Opt_removed, "mblk_io_submit"},
1206        {Opt_removed, "nomblk_io_submit"},
1207        {Opt_block_validity, "block_validity"},
1208        {Opt_noblock_validity, "noblock_validity"},
1209        {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1210        {Opt_journal_ioprio, "journal_ioprio=%u"},
1211        {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1212        {Opt_auto_da_alloc, "auto_da_alloc"},
1213        {Opt_noauto_da_alloc, "noauto_da_alloc"},
1214        {Opt_dioread_nolock, "dioread_nolock"},
1215        {Opt_dioread_lock, "dioread_lock"},
1216        {Opt_discard, "discard"},
1217        {Opt_nodiscard, "nodiscard"},
1218        {Opt_init_itable, "init_itable=%u"},
1219        {Opt_init_itable, "init_itable"},
1220        {Opt_noinit_itable, "noinit_itable"},
1221        {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1222        {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1223        {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1224        {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1225        {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1226        {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1227        {Opt_err, NULL},
1228};
1229
1230static ext4_fsblk_t get_sb_block(void **data)
1231{
1232        ext4_fsblk_t    sb_block;
1233        char            *options = (char *) *data;
1234
1235        if (!options || strncmp(options, "sb=", 3) != 0)
1236                return 1;       /* Default location */
1237
1238        options += 3;
1239        /* TODO: use simple_strtoll with >32bit ext4 */
1240        sb_block = simple_strtoul(options, &options, 0);
1241        if (*options && *options != ',') {
1242                printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1243                       (char *) *data);
1244                return 1;
1245        }
1246        if (*options == ',')
1247                options++;
1248        *data = (void *) options;
1249
1250        return sb_block;
1251}
1252
1253#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1254static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1255        "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1256
1257#ifdef CONFIG_QUOTA
1258static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1259{
1260        struct ext4_sb_info *sbi = EXT4_SB(sb);
1261        char *qname;
1262        int ret = -1;
1263
1264        if (sb_any_quota_loaded(sb) &&
1265                !sbi->s_qf_names[qtype]) {
1266                ext4_msg(sb, KERN_ERR,
1267                        "Cannot change journaled "
1268                        "quota options when quota turned on");
1269                return -1;
1270        }
1271        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1272                ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1273                         "when QUOTA feature is enabled");
1274                return -1;
1275        }
1276        qname = match_strdup(args);
1277        if (!qname) {
1278                ext4_msg(sb, KERN_ERR,
1279                        "Not enough memory for storing quotafile name");
1280                return -1;
1281        }
1282        if (sbi->s_qf_names[qtype]) {
1283                if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1284                        ret = 1;
1285                else
1286                        ext4_msg(sb, KERN_ERR,
1287                                 "%s quota file already specified",
1288                                 QTYPE2NAME(qtype));
1289                goto errout;
1290        }
1291        if (strchr(qname, '/')) {
1292                ext4_msg(sb, KERN_ERR,
1293                        "quotafile must be on filesystem root");
1294                goto errout;
1295        }
1296        sbi->s_qf_names[qtype] = qname;
1297        set_opt(sb, QUOTA);
1298        return 1;
1299errout:
1300        kfree(qname);
1301        return ret;
1302}
1303
1304static int clear_qf_name(struct super_block *sb, int qtype)
1305{
1306
1307        struct ext4_sb_info *sbi = EXT4_SB(sb);
1308
1309        if (sb_any_quota_loaded(sb) &&
1310                sbi->s_qf_names[qtype]) {
1311                ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1312                        " when quota turned on");
1313                return -1;
1314        }
1315        kfree(sbi->s_qf_names[qtype]);
1316        sbi->s_qf_names[qtype] = NULL;
1317        return 1;
1318}
1319#endif
1320
1321#define MOPT_SET        0x0001
1322#define MOPT_CLEAR      0x0002
1323#define MOPT_NOSUPPORT  0x0004
1324#define MOPT_EXPLICIT   0x0008
1325#define MOPT_CLEAR_ERR  0x0010
1326#define MOPT_GTE0       0x0020
1327#ifdef CONFIG_QUOTA
1328#define MOPT_Q          0
1329#define MOPT_QFMT       0x0040
1330#else
1331#define MOPT_Q          MOPT_NOSUPPORT
1332#define MOPT_QFMT       MOPT_NOSUPPORT
1333#endif
1334#define MOPT_DATAJ      0x0080
1335#define MOPT_NO_EXT2    0x0100
1336#define MOPT_NO_EXT3    0x0200
1337#define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1338#define MOPT_STRING     0x0400
1339
1340static const struct mount_opts {
1341        int     token;
1342        int     mount_opt;
1343        int     flags;
1344} ext4_mount_opts[] = {
1345        {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1346        {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1347        {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1348        {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1349        {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1350        {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1351        {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1352         MOPT_EXT4_ONLY | MOPT_SET},
1353        {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1354         MOPT_EXT4_ONLY | MOPT_CLEAR},
1355        {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1356        {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1357        {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1358         MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1359        {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1360         MOPT_EXT4_ONLY | MOPT_CLEAR},
1361        {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1362         MOPT_EXT4_ONLY | MOPT_SET},
1363        {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1364                                    EXT4_MOUNT_JOURNAL_CHECKSUM),
1365         MOPT_EXT4_ONLY | MOPT_SET},
1366        {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1367        {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1368        {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1369        {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1370        {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1371         MOPT_NO_EXT2 | MOPT_SET},
1372        {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1373         MOPT_NO_EXT2 | MOPT_CLEAR},
1374        {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1375        {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1376        {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1377        {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1378        {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1379        {Opt_commit, 0, MOPT_GTE0},
1380        {Opt_max_batch_time, 0, MOPT_GTE0},
1381        {Opt_min_batch_time, 0, MOPT_GTE0},
1382        {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1383        {Opt_init_itable, 0, MOPT_GTE0},
1384        {Opt_stripe, 0, MOPT_GTE0},
1385        {Opt_resuid, 0, MOPT_GTE0},
1386        {Opt_resgid, 0, MOPT_GTE0},
1387        {Opt_journal_dev, 0, MOPT_GTE0},
1388        {Opt_journal_path, 0, MOPT_STRING},
1389        {Opt_journal_ioprio, 0, MOPT_GTE0},
1390        {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1391        {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1392        {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1393         MOPT_NO_EXT2 | MOPT_DATAJ},
1394        {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1395        {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1396#ifdef CONFIG_EXT4_FS_POSIX_ACL
1397        {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1398        {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1399#else
1400        {Opt_acl, 0, MOPT_NOSUPPORT},
1401        {Opt_noacl, 0, MOPT_NOSUPPORT},
1402#endif
1403        {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1404        {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1405        {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1406        {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1407                                                        MOPT_SET | MOPT_Q},
1408        {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1409                                                        MOPT_SET | MOPT_Q},
1410        {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1411                       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1412        {Opt_usrjquota, 0, MOPT_Q},
1413        {Opt_grpjquota, 0, MOPT_Q},
1414        {Opt_offusrjquota, 0, MOPT_Q},
1415        {Opt_offgrpjquota, 0, MOPT_Q},
1416        {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1417        {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1418        {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1419        {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1420        {Opt_err, 0, 0}
1421};
1422
1423static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1424                            substring_t *args, unsigned long *journal_devnum,
1425                            unsigned int *journal_ioprio, int is_remount)
1426{
1427        struct ext4_sb_info *sbi = EXT4_SB(sb);
1428        const struct mount_opts *m;
1429        kuid_t uid;
1430        kgid_t gid;
1431        int arg = 0;
1432
1433#ifdef CONFIG_QUOTA
1434        if (token == Opt_usrjquota)
1435                return set_qf_name(sb, USRQUOTA, &args[0]);
1436        else if (token == Opt_grpjquota)
1437                return set_qf_name(sb, GRPQUOTA, &args[0]);
1438        else if (token == Opt_offusrjquota)
1439                return clear_qf_name(sb, USRQUOTA);
1440        else if (token == Opt_offgrpjquota)
1441                return clear_qf_name(sb, GRPQUOTA);
1442#endif
1443        switch (token) {
1444        case Opt_noacl:
1445        case Opt_nouser_xattr:
1446                ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1447                break;
1448        case Opt_sb:
1449                return 1;       /* handled by get_sb_block() */
1450        case Opt_removed:
1451                ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1452                return 1;
1453        case Opt_abort:
1454                sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1455                return 1;
1456        case Opt_i_version:
1457                sb->s_flags |= MS_I_VERSION;
1458                return 1;
1459        }
1460
1461        for (m = ext4_mount_opts; m->token != Opt_err; m++)
1462                if (token == m->token)
1463                        break;
1464
1465        if (m->token == Opt_err) {
1466                ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1467                         "or missing value", opt);
1468                return -1;
1469        }
1470
1471        if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1472                ext4_msg(sb, KERN_ERR,
1473                         "Mount option \"%s\" incompatible with ext2", opt);
1474                return -1;
1475        }
1476        if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1477                ext4_msg(sb, KERN_ERR,
1478                         "Mount option \"%s\" incompatible with ext3", opt);
1479                return -1;
1480        }
1481
1482        if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1483                return -1;
1484        if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1485                return -1;
1486        if (m->flags & MOPT_EXPLICIT)
1487                set_opt2(sb, EXPLICIT_DELALLOC);
1488        if (m->flags & MOPT_CLEAR_ERR)
1489                clear_opt(sb, ERRORS_MASK);
1490        if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1491                ext4_msg(sb, KERN_ERR, "Cannot change quota "
1492                         "options when quota turned on");
1493                return -1;
1494        }
1495
1496        if (m->flags & MOPT_NOSUPPORT) {
1497                ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1498        } else if (token == Opt_commit) {
1499                if (arg == 0)
1500                        arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1501                sbi->s_commit_interval = HZ * arg;
1502        } else if (token == Opt_max_batch_time) {
1503                if (arg == 0)
1504                        arg = EXT4_DEF_MAX_BATCH_TIME;
1505                sbi->s_max_batch_time = arg;
1506        } else if (token == Opt_min_batch_time) {
1507                sbi->s_min_batch_time = arg;
1508        } else if (token == Opt_inode_readahead_blks) {
1509                if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1510                        ext4_msg(sb, KERN_ERR,
1511                                 "EXT4-fs: inode_readahead_blks must be "
1512                                 "0 or a power of 2 smaller than 2^31");
1513                        return -1;
1514                }
1515                sbi->s_inode_readahead_blks = arg;
1516        } else if (token == Opt_init_itable) {
1517                set_opt(sb, INIT_INODE_TABLE);
1518                if (!args->from)
1519                        arg = EXT4_DEF_LI_WAIT_MULT;
1520                sbi->s_li_wait_mult = arg;
1521        } else if (token == Opt_max_dir_size_kb) {
1522                sbi->s_max_dir_size_kb = arg;
1523        } else if (token == Opt_stripe) {
1524                sbi->s_stripe = arg;
1525        } else if (token == Opt_resuid) {
1526                uid = make_kuid(current_user_ns(), arg);
1527                if (!uid_valid(uid)) {
1528                        ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1529                        return -1;
1530                }
1531                sbi->s_resuid = uid;
1532        } else if (token == Opt_resgid) {
1533                gid = make_kgid(current_user_ns(), arg);
1534                if (!gid_valid(gid)) {
1535                        ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1536                        return -1;
1537                }
1538                sbi->s_resgid = gid;
1539        } else if (token == Opt_journal_dev) {
1540                if (is_remount) {
1541                        ext4_msg(sb, KERN_ERR,
1542                                 "Cannot specify journal on remount");
1543                        return -1;
1544                }
1545                *journal_devnum = arg;
1546        } else if (token == Opt_journal_path) {
1547                char *journal_path;
1548                struct inode *journal_inode;
1549                struct path path;
1550                int error;
1551
1552                if (is_remount) {
1553                        ext4_msg(sb, KERN_ERR,
1554                                 "Cannot specify journal on remount");
1555                        return -1;
1556                }
1557                journal_path = match_strdup(&args[0]);
1558                if (!journal_path) {
1559                        ext4_msg(sb, KERN_ERR, "error: could not dup "
1560                                "journal device string");
1561                        return -1;
1562                }
1563
1564                error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1565                if (error) {
1566                        ext4_msg(sb, KERN_ERR, "error: could not find "
1567                                "journal device path: error %d", error);
1568                        kfree(journal_path);
1569                        return -1;
1570                }
1571
1572                journal_inode = path.dentry->d_inode;
1573                if (!S_ISBLK(journal_inode->i_mode)) {
1574                        ext4_msg(sb, KERN_ERR, "error: journal path %s "
1575                                "is not a block device", journal_path);
1576                        path_put(&path);
1577                        kfree(journal_path);
1578                        return -1;
1579                }
1580
1581                *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1582                path_put(&path);
1583                kfree(journal_path);
1584        } else if (token == Opt_journal_ioprio) {
1585                if (arg > 7) {
1586                        ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1587                                 " (must be 0-7)");
1588                        return -1;
1589                }
1590                *journal_ioprio =
1591                        IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1592        } else if (m->flags & MOPT_DATAJ) {
1593                if (is_remount) {
1594                        if (!sbi->s_journal)
1595                                ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1596                        else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1597                                ext4_msg(sb, KERN_ERR,
1598                                         "Cannot change data mode on remount");
1599                                return -1;
1600                        }
1601                } else {
1602                        clear_opt(sb, DATA_FLAGS);
1603                        sbi->s_mount_opt |= m->mount_opt;
1604                }
1605#ifdef CONFIG_QUOTA
1606        } else if (m->flags & MOPT_QFMT) {
1607                if (sb_any_quota_loaded(sb) &&
1608                    sbi->s_jquota_fmt != m->mount_opt) {
1609                        ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1610                                 "quota options when quota turned on");
1611                        return -1;
1612                }
1613                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1614                                               EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1615                        ext4_msg(sb, KERN_ERR,
1616                                 "Cannot set journaled quota options "
1617                                 "when QUOTA feature is enabled");
1618                        return -1;
1619                }
1620                sbi->s_jquota_fmt = m->mount_opt;
1621#endif
1622        } else {
1623                if (!args->from)
1624                        arg = 1;
1625                if (m->flags & MOPT_CLEAR)
1626                        arg = !arg;
1627                else if (unlikely(!(m->flags & MOPT_SET))) {
1628                        ext4_msg(sb, KERN_WARNING,
1629                                 "buggy handling of option %s", opt);
1630                        WARN_ON(1);
1631                        return -1;
1632                }
1633                if (arg != 0)
1634                        sbi->s_mount_opt |= m->mount_opt;
1635                else
1636                        sbi->s_mount_opt &= ~m->mount_opt;
1637        }
1638        return 1;
1639}
1640
1641static int parse_options(char *options, struct super_block *sb,
1642                         unsigned long *journal_devnum,
1643                         unsigned int *journal_ioprio,
1644                         int is_remount)
1645{
1646        struct ext4_sb_info *sbi = EXT4_SB(sb);
1647        char *p;
1648        substring_t args[MAX_OPT_ARGS];
1649        int token;
1650
1651        if (!options)
1652                return 1;
1653
1654        while ((p = strsep(&options, ",")) != NULL) {
1655                if (!*p)
1656                        continue;
1657                /*
1658                 * Initialize args struct so we know whether arg was
1659                 * found; some options take optional arguments.
1660                 */
1661                args[0].to = args[0].from = NULL;
1662                token = match_token(p, tokens, args);
1663                if (handle_mount_opt(sb, p, token, args, journal_devnum,
1664                                     journal_ioprio, is_remount) < 0)
1665                        return 0;
1666        }
1667#ifdef CONFIG_QUOTA
1668        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1669            (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1670                ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1671                         "feature is enabled");
1672                return 0;
1673        }
1674        if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1675                if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1676                        clear_opt(sb, USRQUOTA);
1677
1678                if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1679                        clear_opt(sb, GRPQUOTA);
1680
1681                if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1682                        ext4_msg(sb, KERN_ERR, "old and new quota "
1683                                        "format mixing");
1684                        return 0;
1685                }
1686
1687                if (!sbi->s_jquota_fmt) {
1688                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1689                                        "not specified");
1690                        return 0;
1691                }
1692        } else {
1693                if (sbi->s_jquota_fmt) {
1694                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1695                                        "specified with no journaling "
1696                                        "enabled");
1697                        return 0;
1698                }
1699        }
1700#endif
1701        if (test_opt(sb, DIOREAD_NOLOCK)) {
1702                int blocksize =
1703                        BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1704
1705                if (blocksize < PAGE_CACHE_SIZE) {
1706                        ext4_msg(sb, KERN_ERR, "can't mount with "
1707                                 "dioread_nolock if block size != PAGE_SIZE");
1708                        return 0;
1709                }
1710        }
1711        return 1;
1712}
1713
1714static inline void ext4_show_quota_options(struct seq_file *seq,
1715                                           struct super_block *sb)
1716{
1717#if defined(CONFIG_QUOTA)
1718        struct ext4_sb_info *sbi = EXT4_SB(sb);
1719
1720        if (sbi->s_jquota_fmt) {
1721                char *fmtname = "";
1722
1723                switch (sbi->s_jquota_fmt) {
1724                case QFMT_VFS_OLD:
1725                        fmtname = "vfsold";
1726                        break;
1727                case QFMT_VFS_V0:
1728                        fmtname = "vfsv0";
1729                        break;
1730                case QFMT_VFS_V1:
1731                        fmtname = "vfsv1";
1732                        break;
1733                }
1734                seq_printf(seq, ",jqfmt=%s", fmtname);
1735        }
1736
1737        if (sbi->s_qf_names[USRQUOTA])
1738                seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1739
1740        if (sbi->s_qf_names[GRPQUOTA])
1741                seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1742#endif
1743}
1744
1745static const char *token2str(int token)
1746{
1747        const struct match_token *t;
1748
1749        for (t = tokens; t->token != Opt_err; t++)
1750                if (t->token == token && !strchr(t->pattern, '='))
1751                        break;
1752        return t->pattern;
1753}
1754
1755/*
1756 * Show an option if
1757 *  - it's set to a non-default value OR
1758 *  - if the per-sb default is different from the global default
1759 */
1760static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1761                              int nodefs)
1762{
1763        struct ext4_sb_info *sbi = EXT4_SB(sb);
1764        struct ext4_super_block *es = sbi->s_es;
1765        int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1766        const struct mount_opts *m;
1767        char sep = nodefs ? '\n' : ',';
1768
1769#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1770#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1771
1772        if (sbi->s_sb_block != 1)
1773                SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1774
1775        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1776                int want_set = m->flags & MOPT_SET;
1777                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1778                    (m->flags & MOPT_CLEAR_ERR))
1779                        continue;
1780                if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1781                        continue; /* skip if same as the default */
1782                if ((want_set &&
1783                     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1784                    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1785                        continue; /* select Opt_noFoo vs Opt_Foo */
1786                SEQ_OPTS_PRINT("%s", token2str(m->token));
1787        }
1788
1789        if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1790            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1791                SEQ_OPTS_PRINT("resuid=%u",
1792                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
1793        if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1794            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1795                SEQ_OPTS_PRINT("resgid=%u",
1796                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
1797        def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1798        if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1799                SEQ_OPTS_PUTS("errors=remount-ro");
1800        if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1801                SEQ_OPTS_PUTS("errors=continue");
1802        if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1803                SEQ_OPTS_PUTS("errors=panic");
1804        if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1805                SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1806        if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1807                SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1808        if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1809                SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1810        if (sb->s_flags & MS_I_VERSION)
1811                SEQ_OPTS_PUTS("i_version");
1812        if (nodefs || sbi->s_stripe)
1813                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1814        if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1815                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1816                        SEQ_OPTS_PUTS("data=journal");
1817                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1818                        SEQ_OPTS_PUTS("data=ordered");
1819                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1820                        SEQ_OPTS_PUTS("data=writeback");
1821        }
1822        if (nodefs ||
1823            sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1824                SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1825                               sbi->s_inode_readahead_blks);
1826
1827        if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1828                       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1829                SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1830        if (nodefs || sbi->s_max_dir_size_kb)
1831                SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1832
1833        ext4_show_quota_options(seq, sb);
1834        return 0;
1835}
1836
1837static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1838{
1839        return _ext4_show_options(seq, root->d_sb, 0);
1840}
1841
1842static int options_seq_show(struct seq_file *seq, void *offset)
1843{
1844        struct super_block *sb = seq->private;
1845        int rc;
1846
1847        seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1848        rc = _ext4_show_options(seq, sb, 1);
1849        seq_puts(seq, "\n");
1850        return rc;
1851}
1852
1853static int options_open_fs(struct inode *inode, struct file *file)
1854{
1855        return single_open(file, options_seq_show, PDE_DATA(inode));
1856}
1857
1858static const struct file_operations ext4_seq_options_fops = {
1859        .owner = THIS_MODULE,
1860        .open = options_open_fs,
1861        .read = seq_read,
1862        .llseek = seq_lseek,
1863        .release = single_release,
1864};
1865
1866static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1867                            int read_only)
1868{
1869        struct ext4_sb_info *sbi = EXT4_SB(sb);
1870        int res = 0;
1871
1872        if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1873                ext4_msg(sb, KERN_ERR, "revision level too high, "
1874                         "forcing read-only mode");
1875                res = MS_RDONLY;
1876        }
1877        if (read_only)
1878                goto done;
1879        if (!(sbi->s_mount_state & EXT4_VALID_FS))
1880                ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1881                         "running e2fsck is recommended");
1882        else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1883                ext4_msg(sb, KERN_WARNING,
1884                         "warning: mounting fs with errors, "
1885                         "running e2fsck is recommended");
1886        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1887                 le16_to_cpu(es->s_mnt_count) >=
1888                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1889                ext4_msg(sb, KERN_WARNING,
1890                         "warning: maximal mount count reached, "
1891                         "running e2fsck is recommended");
1892        else if (le32_to_cpu(es->s_checkinterval) &&
1893                (le32_to_cpu(es->s_lastcheck) +
1894                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1895                ext4_msg(sb, KERN_WARNING,
1896                         "warning: checktime reached, "
1897                         "running e2fsck is recommended");
1898        if (!sbi->s_journal)
1899                es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1900        if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1901                es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1902        le16_add_cpu(&es->s_mnt_count, 1);
1903        es->s_mtime = cpu_to_le32(get_seconds());
1904        ext4_update_dynamic_rev(sb);
1905        if (sbi->s_journal)
1906                EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1907
1908        ext4_commit_super(sb, 1);
1909done:
1910        if (test_opt(sb, DEBUG))
1911                printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1912                                "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1913                        sb->s_blocksize,
1914                        sbi->s_groups_count,
1915                        EXT4_BLOCKS_PER_GROUP(sb),
1916                        EXT4_INODES_PER_GROUP(sb),
1917                        sbi->s_mount_opt, sbi->s_mount_opt2);
1918
1919        cleancache_init_fs(sb);
1920        return res;
1921}
1922
1923int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1924{
1925        struct ext4_sb_info *sbi = EXT4_SB(sb);
1926        struct flex_groups *new_groups;
1927        int size;
1928
1929        if (!sbi->s_log_groups_per_flex)
1930                return 0;
1931
1932        size = ext4_flex_group(sbi, ngroup - 1) + 1;
1933        if (size <= sbi->s_flex_groups_allocated)
1934                return 0;
1935
1936        size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1937        new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1938        if (!new_groups) {
1939                ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1940                         size / (int) sizeof(struct flex_groups));
1941                return -ENOMEM;
1942        }
1943
1944        if (sbi->s_flex_groups) {
1945                memcpy(new_groups, sbi->s_flex_groups,
1946                       (sbi->s_flex_groups_allocated *
1947                        sizeof(struct flex_groups)));
1948                ext4_kvfree(sbi->s_flex_groups);
1949        }
1950        sbi->s_flex_groups = new_groups;
1951        sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1952        return 0;
1953}
1954
1955static int ext4_fill_flex_info(struct super_block *sb)
1956{
1957        struct ext4_sb_info *sbi = EXT4_SB(sb);
1958        struct ext4_group_desc *gdp = NULL;
1959        ext4_group_t flex_group;
1960        int i, err;
1961
1962        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963        if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964                sbi->s_log_groups_per_flex = 0;
1965                return 1;
1966        }
1967
1968        err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1969        if (err)
1970                goto failed;
1971
1972        for (i = 0; i < sbi->s_groups_count; i++) {
1973                gdp = ext4_get_group_desc(sb, i, NULL);
1974
1975                flex_group = ext4_flex_group(sbi, i);
1976                atomic_add(ext4_free_inodes_count(sb, gdp),
1977                           &sbi->s_flex_groups[flex_group].free_inodes);
1978                atomic64_add(ext4_free_group_clusters(sb, gdp),
1979                             &sbi->s_flex_groups[flex_group].free_clusters);
1980                atomic_add(ext4_used_dirs_count(sb, gdp),
1981                           &sbi->s_flex_groups[flex_group].used_dirs);
1982        }
1983
1984        return 1;
1985failed:
1986        return 0;
1987}
1988
1989static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1990                                   struct ext4_group_desc *gdp)
1991{
1992        int offset;
1993        __u16 crc = 0;
1994        __le32 le_group = cpu_to_le32(block_group);
1995
1996        if ((sbi->s_es->s_feature_ro_compat &
1997             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1998                /* Use new metadata_csum algorithm */
1999                __le16 save_csum;
2000                __u32 csum32;
2001
2002                save_csum = gdp->bg_checksum;
2003                gdp->bg_checksum = 0;
2004                csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2005                                     sizeof(le_group));
2006                csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2007                                     sbi->s_desc_size);
2008                gdp->bg_checksum = save_csum;
2009
2010                crc = csum32 & 0xFFFF;
2011                goto out;
2012        }
2013
2014        /* old crc16 code */
2015        offset = offsetof(struct ext4_group_desc, bg_checksum);
2016
2017        crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2018        crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2019        crc = crc16(crc, (__u8 *)gdp, offset);
2020        offset += sizeof(gdp->bg_checksum); /* skip checksum */
2021        /* for checksum of struct ext4_group_desc do the rest...*/
2022        if ((sbi->s_es->s_feature_incompat &
2023             cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2024            offset < le16_to_cpu(sbi->s_es->s_desc_size))
2025                crc = crc16(crc, (__u8 *)gdp + offset,
2026                            le16_to_cpu(sbi->s_es->s_desc_size) -
2027                                offset);
2028
2029out:
2030        return cpu_to_le16(crc);
2031}
2032
2033int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2034                                struct ext4_group_desc *gdp)
2035{
2036        if (ext4_has_group_desc_csum(sb) &&
2037            (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2038                                                      block_group, gdp)))
2039                return 0;
2040
2041        return 1;
2042}
2043
2044void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2045                              struct ext4_group_desc *gdp)
2046{
2047        if (!ext4_has_group_desc_csum(sb))
2048                return;
2049        gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2050}
2051
2052/* Called at mount-time, super-block is locked */
2053static int ext4_check_descriptors(struct super_block *sb,
2054                                  ext4_group_t *first_not_zeroed)
2055{
2056        struct ext4_sb_info *sbi = EXT4_SB(sb);
2057        ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2058        ext4_fsblk_t last_block;
2059        ext4_fsblk_t block_bitmap;
2060        ext4_fsblk_t inode_bitmap;
2061        ext4_fsblk_t inode_table;
2062        int flexbg_flag = 0;
2063        ext4_group_t i, grp = sbi->s_groups_count;
2064
2065        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2066                flexbg_flag = 1;
2067
2068        ext4_debug("Checking group descriptors");
2069
2070        for (i = 0; i < sbi->s_groups_count; i++) {
2071                struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2072
2073                if (i == sbi->s_groups_count - 1 || flexbg_flag)
2074                        last_block = ext4_blocks_count(sbi->s_es) - 1;
2075                else
2076                        last_block = first_block +
2077                                (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2078
2079                if ((grp == sbi->s_groups_count) &&
2080                   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2081                        grp = i;
2082
2083                block_bitmap = ext4_block_bitmap(sb, gdp);
2084                if (block_bitmap < first_block || block_bitmap > last_block) {
2085                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2086                               "Block bitmap for group %u not in group "
2087                               "(block %llu)!", i, block_bitmap);
2088                        return 0;
2089                }
2090                inode_bitmap = ext4_inode_bitmap(sb, gdp);
2091                if (inode_bitmap < first_block || inode_bitmap > last_block) {
2092                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2093                               "Inode bitmap for group %u not in group "
2094                               "(block %llu)!", i, inode_bitmap);
2095                        return 0;
2096                }
2097                inode_table = ext4_inode_table(sb, gdp);
2098                if (inode_table < first_block ||
2099                    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2100                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2101                               "Inode table for group %u not in group "
2102                               "(block %llu)!", i, inode_table);
2103                        return 0;
2104                }
2105                ext4_lock_group(sb, i);
2106                if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2107                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2108                                 "Checksum for group %u failed (%u!=%u)",
2109                                 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2110                                     gdp)), le16_to_cpu(gdp->bg_checksum));
2111                        if (!(sb->s_flags & MS_RDONLY)) {
2112                                ext4_unlock_group(sb, i);
2113                                return 0;
2114                        }
2115                }
2116                ext4_unlock_group(sb, i);
2117                if (!flexbg_flag)
2118                        first_block += EXT4_BLOCKS_PER_GROUP(sb);
2119        }
2120        if (NULL != first_not_zeroed)
2121                *first_not_zeroed = grp;
2122
2123        ext4_free_blocks_count_set(sbi->s_es,
2124                                   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2125        sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2126        return 1;
2127}
2128
2129/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2130 * the superblock) which were deleted from all directories, but held open by
2131 * a process at the time of a crash.  We walk the list and try to delete these
2132 * inodes at recovery time (only with a read-write filesystem).
2133 *
2134 * In order to keep the orphan inode chain consistent during traversal (in
2135 * case of crash during recovery), we link each inode into the superblock
2136 * orphan list_head and handle it the same way as an inode deletion during
2137 * normal operation (which journals the operations for us).
2138 *
2139 * We only do an iget() and an iput() on each inode, which is very safe if we
2140 * accidentally point at an in-use or already deleted inode.  The worst that
2141 * can happen in this case is that we get a "bit already cleared" message from
2142 * ext4_free_inode().  The only reason we would point at a wrong inode is if
2143 * e2fsck was run on this filesystem, and it must have already done the orphan
2144 * inode cleanup for us, so we can safely abort without any further action.
2145 */
2146static void ext4_orphan_cleanup(struct super_block *sb,
2147                                struct ext4_super_block *es)
2148{
2149        unsigned int s_flags = sb->s_flags;
2150        int nr_orphans = 0, nr_truncates = 0;
2151#ifdef CONFIG_QUOTA
2152        int i;
2153#endif
2154        if (!es->s_last_orphan) {
2155                jbd_debug(4, "no orphan inodes to clean up\n");
2156                return;
2157        }
2158
2159        if (bdev_read_only(sb->s_bdev)) {
2160                ext4_msg(sb, KERN_ERR, "write access "
2161                        "unavailable, skipping orphan cleanup");
2162                return;
2163        }
2164
2165        /* Check if feature set would not allow a r/w mount */
2166        if (!ext4_feature_set_ok(sb, 0)) {
2167                ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2168                         "unknown ROCOMPAT features");
2169                return;
2170        }
2171
2172        if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2173                /* don't clear list on RO mount w/ errors */
2174                if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2175                        jbd_debug(1, "Errors on filesystem, "
2176                                  "clearing orphan list.\n");
2177                        es->s_last_orphan = 0;
2178                }
2179                jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2180                return;
2181        }
2182
2183        if (s_flags & MS_RDONLY) {
2184                ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2185                sb->s_flags &= ~MS_RDONLY;
2186        }
2187#ifdef CONFIG_QUOTA
2188        /* Needed for iput() to work correctly and not trash data */
2189        sb->s_flags |= MS_ACTIVE;
2190        /* Turn on quotas so that they are updated correctly */
2191        for (i = 0; i < MAXQUOTAS; i++) {
2192                if (EXT4_SB(sb)->s_qf_names[i]) {
2193                        int ret = ext4_quota_on_mount(sb, i);
2194                        if (ret < 0)
2195                                ext4_msg(sb, KERN_ERR,
2196                                        "Cannot turn on journaled "
2197                                        "quota: error %d", ret);
2198                }
2199        }
2200#endif
2201
2202        while (es->s_last_orphan) {
2203                struct inode *inode;
2204
2205                inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2206                if (IS_ERR(inode)) {
2207                        es->s_last_orphan = 0;
2208                        break;
2209                }
2210
2211                list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2212                dquot_initialize(inode);
2213                if (inode->i_nlink) {
2214                        if (test_opt(sb, DEBUG))
2215                                ext4_msg(sb, KERN_DEBUG,
2216                                        "%s: truncating inode %lu to %lld bytes",
2217                                        __func__, inode->i_ino, inode->i_size);
2218                        jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2219                                  inode->i_ino, inode->i_size);
2220                        mutex_lock(&inode->i_mutex);
2221                        truncate_inode_pages(inode->i_mapping, inode->i_size);
2222                        ext4_truncate(inode);
2223                        mutex_unlock(&inode->i_mutex);
2224                        nr_truncates++;
2225                } else {
2226                        if (test_opt(sb, DEBUG))
2227                                ext4_msg(sb, KERN_DEBUG,
2228                                        "%s: deleting unreferenced inode %lu",
2229                                        __func__, inode->i_ino);
2230                        jbd_debug(2, "deleting unreferenced inode %lu\n",
2231                                  inode->i_ino);
2232                        nr_orphans++;
2233                }
2234                iput(inode);  /* The delete magic happens here! */
2235        }
2236
2237#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2238
2239        if (nr_orphans)
2240                ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2241                       PLURAL(nr_orphans));
2242        if (nr_truncates)
2243                ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2244                       PLURAL(nr_truncates));
2245#ifdef CONFIG_QUOTA
2246        /* Turn quotas off */
2247        for (i = 0; i < MAXQUOTAS; i++) {
2248                if (sb_dqopt(sb)->files[i])
2249                        dquot_quota_off(sb, i);
2250        }
2251#endif
2252        sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2253}
2254
2255/*
2256 * Maximal extent format file size.
2257 * Resulting logical blkno at s_maxbytes must fit in our on-disk
2258 * extent format containers, within a sector_t, and within i_blocks
2259 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2260 * so that won't be a limiting factor.
2261 *
2262 * However there is other limiting factor. We do store extents in the form
2263 * of starting block and length, hence the resulting length of the extent
2264 * covering maximum file size must fit into on-disk format containers as
2265 * well. Given that length is always by 1 unit bigger than max unit (because
2266 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2267 *
2268 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2269 */
2270static loff_t ext4_max_size(int blkbits, int has_huge_files)
2271{
2272        loff_t res;
2273        loff_t upper_limit = MAX_LFS_FILESIZE;
2274
2275        /* small i_blocks in vfs inode? */
2276        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2277                /*
2278                 * CONFIG_LBDAF is not enabled implies the inode
2279                 * i_block represent total blocks in 512 bytes
2280                 * 32 == size of vfs inode i_blocks * 8
2281                 */
2282                upper_limit = (1LL << 32) - 1;
2283
2284                /* total blocks in file system block size */
2285                upper_limit >>= (blkbits - 9);
2286                upper_limit <<= blkbits;
2287        }
2288
2289        /*
2290         * 32-bit extent-start container, ee_block. We lower the maxbytes
2291         * by one fs block, so ee_len can cover the extent of maximum file
2292         * size
2293         */
2294        res = (1LL << 32) - 1;
2295        res <<= blkbits;
2296
2297        /* Sanity check against vm- & vfs- imposed limits */
2298        if (res > upper_limit)
2299                res = upper_limit;
2300
2301        return res;
2302}
2303
2304/*
2305 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2306 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2307 * We need to be 1 filesystem block less than the 2^48 sector limit.
2308 */
2309static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2310{
2311        loff_t res = EXT4_NDIR_BLOCKS;
2312        int meta_blocks;
2313        loff_t upper_limit;
2314        /* This is calculated to be the largest file size for a dense, block
2315         * mapped file such that the file's total number of 512-byte sectors,
2316         * including data and all indirect blocks, does not exceed (2^48 - 1).
2317         *
2318         * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2319         * number of 512-byte sectors of the file.
2320         */
2321
2322        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2323                /*
2324                 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2325                 * the inode i_block field represents total file blocks in
2326                 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2327                 */
2328                upper_limit = (1LL << 32) - 1;
2329
2330                /* total blocks in file system block size */
2331                upper_limit >>= (bits - 9);
2332
2333        } else {
2334                /*
2335                 * We use 48 bit ext4_inode i_blocks
2336                 * With EXT4_HUGE_FILE_FL set the i_blocks
2337                 * represent total number of blocks in
2338                 * file system block size
2339                 */
2340                upper_limit = (1LL << 48) - 1;
2341
2342        }
2343
2344        /* indirect blocks */
2345        meta_blocks = 1;
2346        /* double indirect blocks */
2347        meta_blocks += 1 + (1LL << (bits-2));
2348        /* tripple indirect blocks */
2349        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2350
2351        upper_limit -= meta_blocks;
2352        upper_limit <<= bits;
2353
2354        res += 1LL << (bits-2);
2355        res += 1LL << (2*(bits-2));
2356        res += 1LL << (3*(bits-2));
2357        res <<= bits;
2358        if (res > upper_limit)
2359                res = upper_limit;
2360
2361        if (res > MAX_LFS_FILESIZE)
2362                res = MAX_LFS_FILESIZE;
2363
2364        return res;
2365}
2366
2367static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2368                                   ext4_fsblk_t logical_sb_block, int nr)
2369{
2370        struct ext4_sb_info *sbi = EXT4_SB(sb);
2371        ext4_group_t bg, first_meta_bg;
2372        int has_super = 0;
2373
2374        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2375
2376        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2377            nr < first_meta_bg)
2378                return logical_sb_block + nr + 1;
2379        bg = sbi->s_desc_per_block * nr;
2380        if (ext4_bg_has_super(sb, bg))
2381                has_super = 1;
2382
2383        return (has_super + ext4_group_first_block_no(sb, bg));
2384}
2385
2386/**
2387 * ext4_get_stripe_size: Get the stripe size.
2388 * @sbi: In memory super block info
2389 *
2390 * If we have specified it via mount option, then
2391 * use the mount option value. If the value specified at mount time is
2392 * greater than the blocks per group use the super block value.
2393 * If the super block value is greater than blocks per group return 0.
2394 * Allocator needs it be less than blocks per group.
2395 *
2396 */
2397static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2398{
2399        unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2400        unsigned long stripe_width =
2401                        le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2402        int ret;
2403
2404        if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2405                ret = sbi->s_stripe;
2406        else if (stripe_width <= sbi->s_blocks_per_group)
2407                ret = stripe_width;
2408        else if (stride <= sbi->s_blocks_per_group)
2409                ret = stride;
2410        else
2411                ret = 0;
2412
2413        /*
2414         * If the stripe width is 1, this makes no sense and
2415         * we set it to 0 to turn off stripe handling code.
2416         */
2417        if (ret <= 1)
2418                ret = 0;
2419
2420        return ret;
2421}
2422
2423/* sysfs supprt */
2424
2425struct ext4_attr {
2426        struct attribute attr;
2427        ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2428        ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2429                         const char *, size_t);
2430        union {
2431                int offset;
2432                int deprecated_val;
2433        } u;
2434};
2435
2436static int parse_strtoull(const char *buf,
2437                unsigned long long max, unsigned long long *value)
2438{
2439        int ret;
2440
2441        ret = kstrtoull(skip_spaces(buf), 0, value);
2442        if (!ret && *value > max)
2443                ret = -EINVAL;
2444        return ret;
2445}
2446
2447static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2448                                              struct ext4_sb_info *sbi,
2449                                              char *buf)
2450{
2451        return snprintf(buf, PAGE_SIZE, "%llu\n",
2452                (s64) EXT4_C2B(sbi,
2453                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2454}
2455
2456static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2457                                         struct ext4_sb_info *sbi, char *buf)
2458{
2459        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2460
2461        if (!sb->s_bdev->bd_part)
2462                return snprintf(buf, PAGE_SIZE, "0\n");
2463        return snprintf(buf, PAGE_SIZE, "%lu\n",
2464                        (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2465                         sbi->s_sectors_written_start) >> 1);
2466}
2467
2468static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2469                                          struct ext4_sb_info *sbi, char *buf)
2470{
2471        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472
2473        if (!sb->s_bdev->bd_part)
2474                return snprintf(buf, PAGE_SIZE, "0\n");
2475        return snprintf(buf, PAGE_SIZE, "%llu\n",
2476                        (unsigned long long)(sbi->s_kbytes_written +
2477                        ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2478                          EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2479}
2480
2481static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2482                                          struct ext4_sb_info *sbi,
2483                                          const char *buf, size_t count)
2484{
2485        unsigned long t;
2486        int ret;
2487
2488        ret = kstrtoul(skip_spaces(buf), 0, &t);
2489        if (ret)
2490                return ret;
2491
2492        if (t && (!is_power_of_2(t) || t > 0x40000000))
2493                return -EINVAL;
2494
2495        sbi->s_inode_readahead_blks = t;
2496        return count;
2497}
2498
2499static ssize_t sbi_ui_show(struct ext4_attr *a,
2500                           struct ext4_sb_info *sbi, char *buf)
2501{
2502        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2503
2504        return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2505}
2506
2507static ssize_t sbi_ui_store(struct ext4_attr *a,
2508                            struct ext4_sb_info *sbi,
2509                            const char *buf, size_t count)
2510{
2511        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2512        unsigned long t;
2513        int ret;
2514
2515        ret = kstrtoul(skip_spaces(buf), 0, &t);
2516        if (ret)
2517                return ret;
2518        *ui = t;
2519        return count;
2520}
2521
2522static ssize_t reserved_clusters_show(struct ext4_attr *a,
2523                                  struct ext4_sb_info *sbi, char *buf)
2524{
2525        return snprintf(buf, PAGE_SIZE, "%llu\n",
2526                (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2527}
2528
2529static ssize_t reserved_clusters_store(struct ext4_attr *a,
2530                                   struct ext4_sb_info *sbi,
2531                                   const char *buf, size_t count)
2532{
2533        unsigned long long val;
2534        int ret;
2535
2536        if (parse_strtoull(buf, -1ULL, &val))
2537                return -EINVAL;
2538        ret = ext4_reserve_clusters(sbi, val);
2539
2540        return ret ? ret : count;
2541}
2542
2543static ssize_t trigger_test_error(struct ext4_attr *a,
2544                                  struct ext4_sb_info *sbi,
2545                                  const char *buf, size_t count)
2546{
2547        int len = count;
2548
2549        if (!capable(CAP_SYS_ADMIN))
2550                return -EPERM;
2551
2552        if (len && buf[len-1] == '\n')
2553                len--;
2554
2555        if (len)
2556                ext4_error(sbi->s_sb, "%.*s", len, buf);
2557        return count;
2558}
2559
2560static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2561                                   struct ext4_sb_info *sbi, char *buf)
2562{
2563        return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2564}
2565
2566#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2567static struct ext4_attr ext4_attr_##_name = {                   \
2568        .attr = {.name = __stringify(_name), .mode = _mode },   \
2569        .show   = _show,                                        \
2570        .store  = _store,                                       \
2571        .u = {                                                  \
2572                .offset = offsetof(struct ext4_sb_info, _elname),\
2573        },                                                      \
2574}
2575#define EXT4_ATTR(name, mode, show, store) \
2576static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2577
2578#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2579#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2580#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2581#define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2582        EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2583#define ATTR_LIST(name) &ext4_attr_##name.attr
2584#define EXT4_DEPRECATED_ATTR(_name, _val)       \
2585static struct ext4_attr ext4_attr_##_name = {                   \
2586        .attr = {.name = __stringify(_name), .mode = 0444 },    \
2587        .show   = sbi_deprecated_show,                          \
2588        .u = {                                                  \
2589                .deprecated_val = _val,                         \
2590        },                                                      \
2591}
2592
2593EXT4_RO_ATTR(delayed_allocation_blocks);
2594EXT4_RO_ATTR(session_write_kbytes);
2595EXT4_RO_ATTR(lifetime_write_kbytes);
2596EXT4_RW_ATTR(reserved_clusters);
2597EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2598                 inode_readahead_blks_store, s_inode_readahead_blks);
2599EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2600EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2601EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2602EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2603EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2604EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2605EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2606EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2607EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2608EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2609
2610static struct attribute *ext4_attrs[] = {
2611        ATTR_LIST(delayed_allocation_blocks),
2612        ATTR_LIST(session_write_kbytes),
2613        ATTR_LIST(lifetime_write_kbytes),
2614        ATTR_LIST(reserved_clusters),
2615        ATTR_LIST(inode_readahead_blks),
2616        ATTR_LIST(inode_goal),
2617        ATTR_LIST(mb_stats),
2618        ATTR_LIST(mb_max_to_scan),
2619        ATTR_LIST(mb_min_to_scan),
2620        ATTR_LIST(mb_order2_req),
2621        ATTR_LIST(mb_stream_req),
2622        ATTR_LIST(mb_group_prealloc),
2623        ATTR_LIST(max_writeback_mb_bump),
2624        ATTR_LIST(extent_max_zeroout_kb),
2625        ATTR_LIST(trigger_fs_error),
2626        NULL,
2627};
2628
2629/* Features this copy of ext4 supports */
2630EXT4_INFO_ATTR(lazy_itable_init);
2631EXT4_INFO_ATTR(batched_discard);
2632EXT4_INFO_ATTR(meta_bg_resize);
2633
2634static struct attribute *ext4_feat_attrs[] = {
2635        ATTR_LIST(lazy_itable_init),
2636        ATTR_LIST(batched_discard),
2637        ATTR_LIST(meta_bg_resize),
2638        NULL,
2639};
2640
2641static ssize_t ext4_attr_show(struct kobject *kobj,
2642                              struct attribute *attr, char *buf)
2643{
2644        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2645                                                s_kobj);
2646        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2647
2648        return a->show ? a->show(a, sbi, buf) : 0;
2649}
2650
2651static ssize_t ext4_attr_store(struct kobject *kobj,
2652                               struct attribute *attr,
2653                               const char *buf, size_t len)
2654{
2655        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2656                                                s_kobj);
2657        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2658
2659        return a->store ? a->store(a, sbi, buf, len) : 0;
2660}
2661
2662static void ext4_sb_release(struct kobject *kobj)
2663{
2664        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2665                                                s_kobj);
2666        complete(&sbi->s_kobj_unregister);
2667}
2668
2669static const struct sysfs_ops ext4_attr_ops = {
2670        .show   = ext4_attr_show,
2671        .store  = ext4_attr_store,
2672};
2673
2674static struct kobj_type ext4_ktype = {
2675        .default_attrs  = ext4_attrs,
2676        .sysfs_ops      = &ext4_attr_ops,
2677        .release        = ext4_sb_release,
2678};
2679
2680static void ext4_feat_release(struct kobject *kobj)
2681{
2682        complete(&ext4_feat->f_kobj_unregister);
2683}
2684
2685static struct kobj_type ext4_feat_ktype = {
2686        .default_attrs  = ext4_feat_attrs,
2687        .sysfs_ops      = &ext4_attr_ops,
2688        .release        = ext4_feat_release,
2689};
2690
2691/*
2692 * Check whether this filesystem can be mounted based on
2693 * the features present and the RDONLY/RDWR mount requested.
2694 * Returns 1 if this filesystem can be mounted as requested,
2695 * 0 if it cannot be.
2696 */
2697static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2698{
2699        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2700                ext4_msg(sb, KERN_ERR,
2701                        "Couldn't mount because of "
2702                        "unsupported optional features (%x)",
2703                        (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2704                        ~EXT4_FEATURE_INCOMPAT_SUPP));
2705                return 0;
2706        }
2707
2708        if (readonly)
2709                return 1;
2710
2711        /* Check that feature set is OK for a read-write mount */
2712        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2713                ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2714                         "unsupported optional features (%x)",
2715                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2716                                ~EXT4_FEATURE_RO_COMPAT_SUPP));
2717                return 0;
2718        }
2719        /*
2720         * Large file size enabled file system can only be mounted
2721         * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2722         */
2723        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2724                if (sizeof(blkcnt_t) < sizeof(u64)) {
2725                        ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2726                                 "cannot be mounted RDWR without "
2727                                 "CONFIG_LBDAF");
2728                        return 0;
2729                }
2730        }
2731        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2732            !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2733                ext4_msg(sb, KERN_ERR,
2734                         "Can't support bigalloc feature without "
2735                         "extents feature\n");
2736                return 0;
2737        }
2738
2739#ifndef CONFIG_QUOTA
2740        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2741            !readonly) {
2742                ext4_msg(sb, KERN_ERR,
2743                         "Filesystem with quota feature cannot be mounted RDWR "
2744                         "without CONFIG_QUOTA");
2745                return 0;
2746        }
2747#endif  /* CONFIG_QUOTA */
2748        return 1;
2749}
2750
2751/*
2752 * This function is called once a day if we have errors logged
2753 * on the file system
2754 */
2755static void print_daily_error_info(unsigned long arg)
2756{
2757        struct super_block *sb = (struct super_block *) arg;
2758        struct ext4_sb_info *sbi;
2759        struct ext4_super_block *es;
2760
2761        sbi = EXT4_SB(sb);
2762        es = sbi->s_es;
2763
2764        if (es->s_error_count)
2765                ext4_msg(sb, KERN_NOTICE, "error count: %u",
2766                         le32_to_cpu(es->s_error_count));
2767        if (es->s_first_error_time) {
2768                printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2769                       sb->s_id, le32_to_cpu(es->s_first_error_time),
2770                       (int) sizeof(es->s_first_error_func),
2771                       es->s_first_error_func,
2772                       le32_to_cpu(es->s_first_error_line));
2773                if (es->s_first_error_ino)
2774                        printk(": inode %u",
2775                               le32_to_cpu(es->s_first_error_ino));
2776                if (es->s_first_error_block)
2777                        printk(": block %llu", (unsigned long long)
2778                               le64_to_cpu(es->s_first_error_block));
2779                printk("\n");
2780        }
2781        if (es->s_last_error_time) {
2782                printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2783                       sb->s_id, le32_to_cpu(es->s_last_error_time),
2784                       (int) sizeof(es->s_last_error_func),
2785                       es->s_last_error_func,
2786                       le32_to_cpu(es->s_last_error_line));
2787                if (es->s_last_error_ino)
2788                        printk(": inode %u",
2789                               le32_to_cpu(es->s_last_error_ino));
2790                if (es->s_last_error_block)
2791                        printk(": block %llu", (unsigned long long)
2792                               le64_to_cpu(es->s_last_error_block));
2793                printk("\n");
2794        }
2795        mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2796}
2797
2798/* Find next suitable group and run ext4_init_inode_table */
2799static int ext4_run_li_request(struct ext4_li_request *elr)
2800{
2801        struct ext4_group_desc *gdp = NULL;
2802        ext4_group_t group, ngroups;
2803        struct super_block *sb;
2804        unsigned long timeout = 0;
2805        int ret = 0;
2806
2807        sb = elr->lr_super;
2808        ngroups = EXT4_SB(sb)->s_groups_count;
2809
2810        sb_start_write(sb);
2811        for (group = elr->lr_next_group; group < ngroups; group++) {
2812                gdp = ext4_get_group_desc(sb, group, NULL);
2813                if (!gdp) {
2814                        ret = 1;
2815                        break;
2816                }
2817
2818                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2819                        break;
2820        }
2821
2822        if (group >= ngroups)
2823                ret = 1;
2824
2825        if (!ret) {
2826                timeout = jiffies;
2827                ret = ext4_init_inode_table(sb, group,
2828                                            elr->lr_timeout ? 0 : 1);
2829                if (elr->lr_timeout == 0) {
2830                        timeout = (jiffies - timeout) *
2831                                  elr->lr_sbi->s_li_wait_mult;
2832                        elr->lr_timeout = timeout;
2833                }
2834                elr->lr_next_sched = jiffies + elr->lr_timeout;
2835                elr->lr_next_group = group + 1;
2836        }
2837        sb_end_write(sb);
2838
2839        return ret;
2840}
2841
2842/*
2843 * Remove lr_request from the list_request and free the
2844 * request structure. Should be called with li_list_mtx held
2845 */
2846static void ext4_remove_li_request(struct ext4_li_request *elr)
2847{
2848        struct ext4_sb_info *sbi;
2849
2850        if (!elr)
2851                return;
2852
2853        sbi = elr->lr_sbi;
2854
2855        list_del(&elr->lr_request);
2856        sbi->s_li_request = NULL;
2857        kfree(elr);
2858}
2859
2860static void ext4_unregister_li_request(struct super_block *sb)
2861{
2862        mutex_lock(&ext4_li_mtx);
2863        if (!ext4_li_info) {
2864                mutex_unlock(&ext4_li_mtx);
2865                return;
2866        }
2867
2868        mutex_lock(&ext4_li_info->li_list_mtx);
2869        ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2870        mutex_unlock(&ext4_li_info->li_list_mtx);
2871        mutex_unlock(&ext4_li_mtx);
2872}
2873
2874static struct task_struct *ext4_lazyinit_task;
2875
2876/*
2877 * This is the function where ext4lazyinit thread lives. It walks
2878 * through the request list searching for next scheduled filesystem.
2879 * When such a fs is found, run the lazy initialization request
2880 * (ext4_rn_li_request) and keep track of the time spend in this
2881 * function. Based on that time we compute next schedule time of
2882 * the request. When walking through the list is complete, compute
2883 * next waking time and put itself into sleep.
2884 */
2885static int ext4_lazyinit_thread(void *arg)
2886{
2887        struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2888        struct list_head *pos, *n;
2889        struct ext4_li_request *elr;
2890        unsigned long next_wakeup, cur;
2891
2892        BUG_ON(NULL == eli);
2893
2894cont_thread:
2895        while (true) {
2896                next_wakeup = MAX_JIFFY_OFFSET;
2897
2898                mutex_lock(&eli->li_list_mtx);
2899                if (list_empty(&eli->li_request_list)) {
2900                        mutex_unlock(&eli->li_list_mtx);
2901                        goto exit_thread;
2902                }
2903
2904                list_for_each_safe(pos, n, &eli->li_request_list) {
2905                        elr = list_entry(pos, struct ext4_li_request,
2906                                         lr_request);
2907
2908                        if (time_after_eq(jiffies, elr->lr_next_sched)) {
2909                                if (ext4_run_li_request(elr) != 0) {
2910                                        /* error, remove the lazy_init job */
2911                                        ext4_remove_li_request(elr);
2912                                        continue;
2913                                }
2914                        }
2915
2916                        if (time_before(elr->lr_next_sched, next_wakeup))
2917                                next_wakeup = elr->lr_next_sched;
2918                }
2919                mutex_unlock(&eli->li_list_mtx);
2920
2921                try_to_freeze();
2922
2923                cur = jiffies;
2924                if ((time_after_eq(cur, next_wakeup)) ||
2925                    (MAX_JIFFY_OFFSET == next_wakeup)) {
2926                        cond_resched();
2927                        continue;
2928                }
2929
2930                schedule_timeout_interruptible(next_wakeup - cur);
2931
2932                if (kthread_should_stop()) {
2933                        ext4_clear_request_list();
2934                        goto exit_thread;
2935                }
2936        }
2937
2938exit_thread:
2939        /*
2940         * It looks like the request list is empty, but we need
2941         * to check it under the li_list_mtx lock, to prevent any
2942         * additions into it, and of course we should lock ext4_li_mtx
2943         * to atomically free the list and ext4_li_info, because at
2944         * this point another ext4 filesystem could be registering
2945         * new one.
2946         */
2947        mutex_lock(&ext4_li_mtx);
2948        mutex_lock(&eli->li_list_mtx);
2949        if (!list_empty(&eli->li_request_list)) {
2950                mutex_unlock(&eli->li_list_mtx);
2951                mutex_unlock(&ext4_li_mtx);
2952                goto cont_thread;
2953        }
2954        mutex_unlock(&eli->li_list_mtx);
2955        kfree(ext4_li_info);
2956        ext4_li_info = NULL;
2957        mutex_unlock(&ext4_li_mtx);
2958
2959        return 0;
2960}
2961
2962static void ext4_clear_request_list(void)
2963{
2964        struct list_head *pos, *n;
2965        struct ext4_li_request *elr;
2966
2967        mutex_lock(&ext4_li_info->li_list_mtx);
2968        list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2969                elr = list_entry(pos, struct ext4_li_request,
2970                                 lr_request);
2971                ext4_remove_li_request(elr);
2972        }
2973        mutex_unlock(&ext4_li_info->li_list_mtx);
2974}
2975
2976static int ext4_run_lazyinit_thread(void)
2977{
2978        ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2979                                         ext4_li_info, "ext4lazyinit");
2980        if (IS_ERR(ext4_lazyinit_task)) {
2981                int err = PTR_ERR(ext4_lazyinit_task);
2982                ext4_clear_request_list();
2983                kfree(ext4_li_info);
2984                ext4_li_info = NULL;
2985                printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2986                                 "initialization thread\n",
2987                                 err);
2988                return err;
2989        }
2990        ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2991        return 0;
2992}
2993
2994/*
2995 * Check whether it make sense to run itable init. thread or not.
2996 * If there is at least one uninitialized inode table, return
2997 * corresponding group number, else the loop goes through all
2998 * groups and return total number of groups.
2999 */
3000static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3001{
3002        ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3003        struct ext4_group_desc *gdp = NULL;
3004
3005        for (group = 0; group < ngroups; group++) {
3006                gdp = ext4_get_group_desc(sb, group, NULL);
3007                if (!gdp)
3008                        continue;
3009
3010                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3011                        break;
3012        }
3013
3014        return group;
3015}
3016
3017static int ext4_li_info_new(void)
3018{
3019        struct ext4_lazy_init *eli = NULL;
3020
3021        eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3022        if (!eli)
3023                return -ENOMEM;
3024
3025        INIT_LIST_HEAD(&eli->li_request_list);
3026        mutex_init(&eli->li_list_mtx);
3027
3028        eli->li_state |= EXT4_LAZYINIT_QUIT;
3029
3030        ext4_li_info = eli;
3031
3032        return 0;
3033}
3034
3035static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3036                                            ext4_group_t start)
3037{
3038        struct ext4_sb_info *sbi = EXT4_SB(sb);
3039        struct ext4_li_request *elr;
3040        unsigned long rnd;
3041
3042        elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3043        if (!elr)
3044                return NULL;
3045
3046        elr->lr_super = sb;
3047        elr->lr_sbi = sbi;
3048        elr->lr_next_group = start;
3049
3050        /*
3051         * Randomize first schedule time of the request to
3052         * spread the inode table initialization requests
3053         * better.
3054         */
3055        get_random_bytes(&rnd, sizeof(rnd));
3056        elr->lr_next_sched = jiffies + (unsigned long)rnd %
3057                             (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3058
3059        return elr;
3060}
3061
3062int ext4_register_li_request(struct super_block *sb,
3063                             ext4_group_t first_not_zeroed)
3064{
3065        struct ext4_sb_info *sbi = EXT4_SB(sb);
3066        struct ext4_li_request *elr = NULL;
3067        ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3068        int ret = 0;
3069
3070        mutex_lock(&ext4_li_mtx);
3071        if (sbi->s_li_request != NULL) {
3072                /*
3073                 * Reset timeout so it can be computed again, because
3074                 * s_li_wait_mult might have changed.
3075                 */
3076                sbi->s_li_request->lr_timeout = 0;
3077                goto out;
3078        }
3079
3080        if (first_not_zeroed == ngroups ||
3081            (sb->s_flags & MS_RDONLY) ||
3082            !test_opt(sb, INIT_INODE_TABLE))
3083                goto out;
3084
3085        elr = ext4_li_request_new(sb, first_not_zeroed);
3086        if (!elr) {
3087                ret = -ENOMEM;
3088                goto out;
3089        }
3090
3091        if (NULL == ext4_li_info) {
3092                ret = ext4_li_info_new();
3093                if (ret)
3094                        goto out;
3095        }
3096
3097        mutex_lock(&ext4_li_info->li_list_mtx);
3098        list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3099        mutex_unlock(&ext4_li_info->li_list_mtx);
3100
3101        sbi->s_li_request = elr;
3102        /*
3103         * set elr to NULL here since it has been inserted to
3104         * the request_list and the removal and free of it is
3105         * handled by ext4_clear_request_list from now on.
3106         */
3107        elr = NULL;
3108
3109        if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3110                ret = ext4_run_lazyinit_thread();
3111                if (ret)
3112                        goto out;
3113        }
3114out:
3115        mutex_unlock(&ext4_li_mtx);
3116        if (ret)
3117                kfree(elr);
3118        return ret;
3119}
3120
3121/*
3122 * We do not need to lock anything since this is called on
3123 * module unload.
3124 */
3125static void ext4_destroy_lazyinit_thread(void)
3126{
3127        /*
3128         * If thread exited earlier
3129         * there's nothing to be done.
3130         */
3131        if (!ext4_li_info || !ext4_lazyinit_task)
3132                return;
3133
3134        kthread_stop(ext4_lazyinit_task);
3135}
3136
3137static int set_journal_csum_feature_set(struct super_block *sb)
3138{
3139        int ret = 1;
3140        int compat, incompat;
3141        struct ext4_sb_info *sbi = EXT4_SB(sb);
3142
3143        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3144                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3145                /* journal checksum v2 */
3146                compat = 0;
3147                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3148        } else {
3149                /* journal checksum v1 */
3150                compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3151                incompat = 0;
3152        }
3153
3154        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3155                ret = jbd2_journal_set_features(sbi->s_journal,
3156                                compat, 0,
3157                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3158                                incompat);
3159        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3160                ret = jbd2_journal_set_features(sbi->s_journal,
3161                                compat, 0,
3162                                incompat);
3163                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3164                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3165        } else {
3166                jbd2_journal_clear_features(sbi->s_journal,
3167                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3168                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3169                                JBD2_FEATURE_INCOMPAT_CSUM_V2);
3170        }
3171
3172        return ret;
3173}
3174
3175/*
3176 * Note: calculating the overhead so we can be compatible with
3177 * historical BSD practice is quite difficult in the face of
3178 * clusters/bigalloc.  This is because multiple metadata blocks from
3179 * different block group can end up in the same allocation cluster.
3180 * Calculating the exact overhead in the face of clustered allocation
3181 * requires either O(all block bitmaps) in memory or O(number of block
3182 * groups**2) in time.  We will still calculate the superblock for
3183 * older file systems --- and if we come across with a bigalloc file
3184 * system with zero in s_overhead_clusters the estimate will be close to
3185 * correct especially for very large cluster sizes --- but for newer
3186 * file systems, it's better to calculate this figure once at mkfs
3187 * time, and store it in the superblock.  If the superblock value is
3188 * present (even for non-bigalloc file systems), we will use it.
3189 */
3190static int count_overhead(struct super_block *sb, ext4_group_t grp,
3191                          char *buf)
3192{
3193        struct ext4_sb_info     *sbi = EXT4_SB(sb);
3194        struct ext4_group_desc  *gdp;
3195        ext4_fsblk_t            first_block, last_block, b;
3196        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3197        int                     s, j, count = 0;
3198
3199        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3200                return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3201                        sbi->s_itb_per_group + 2);
3202
3203        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3204                (grp * EXT4_BLOCKS_PER_GROUP(sb));
3205        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3206        for (i = 0; i < ngroups; i++) {
3207                gdp = ext4_get_group_desc(sb, i, NULL);
3208                b = ext4_block_bitmap(sb, gdp);
3209                if (b >= first_block && b <= last_block) {
3210                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3211                        count++;
3212                }
3213                b = ext4_inode_bitmap(sb, gdp);
3214                if (b >= first_block && b <= last_block) {
3215                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3216                        count++;
3217                }
3218                b = ext4_inode_table(sb, gdp);
3219                if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3220                        for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3221                                int c = EXT4_B2C(sbi, b - first_block);
3222                                ext4_set_bit(c, buf);
3223                                count++;
3224                        }
3225                if (i != grp)
3226                        continue;
3227                s = 0;
3228                if (ext4_bg_has_super(sb, grp)) {
3229                        ext4_set_bit(s++, buf);
3230                        count++;
3231                }
3232                for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3233                        ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3234                        count++;
3235                }
3236        }
3237        if (!count)
3238                return 0;
3239        return EXT4_CLUSTERS_PER_GROUP(sb) -
3240                ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3241}
3242
3243/*
3244 * Compute the overhead and stash it in sbi->s_overhead
3245 */
3246int ext4_calculate_overhead(struct super_block *sb)
3247{
3248        struct ext4_sb_info *sbi = EXT4_SB(sb);
3249        struct ext4_super_block *es = sbi->s_es;
3250        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3251        ext4_fsblk_t overhead = 0;
3252        char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3253
3254        if (!buf)
3255                return -ENOMEM;
3256
3257        /*
3258         * Compute the overhead (FS structures).  This is constant
3259         * for a given filesystem unless the number of block groups
3260         * changes so we cache the previous value until it does.
3261         */
3262
3263        /*
3264         * All of the blocks before first_data_block are overhead
3265         */
3266        overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3267
3268        /*
3269         * Add the overhead found in each block group
3270         */
3271        for (i = 0; i < ngroups; i++) {
3272                int blks;
3273
3274                blks = count_overhead(sb, i, buf);
3275                overhead += blks;
3276                if (blks)
3277                        memset(buf, 0, PAGE_SIZE);
3278                cond_resched();
3279        }
3280        /* Add the journal blocks as well */
3281        if (sbi->s_journal)
3282                overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3283
3284        sbi->s_overhead = overhead;
3285        smp_wmb();
3286        free_page((unsigned long) buf);
3287        return 0;
3288}
3289
3290
3291static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3292{
3293        ext4_fsblk_t resv_clusters;
3294
3295        /*
3296         * By default we reserve 2% or 4096 clusters, whichever is smaller.
3297         * This should cover the situations where we can not afford to run
3298         * out of space like for example punch hole, or converting
3299         * uninitialized extents in delalloc path. In most cases such
3300         * allocation would require 1, or 2 blocks, higher numbers are
3301         * very rare.
3302         */
3303        resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3304
3305        do_div(resv_clusters, 50);
3306        resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3307
3308        return resv_clusters;
3309}
3310
3311
3312static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3313{
3314        ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3315                                sbi->s_cluster_bits;
3316
3317        if (count >= clusters)
3318                return -EINVAL;
3319
3320        atomic64_set(&sbi->s_resv_clusters, count);
3321        return 0;
3322}
3323
3324static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3325{
3326        char *orig_data = kstrdup(data, GFP_KERNEL);
3327        struct buffer_head *bh;
3328        struct ext4_super_block *es = NULL;
3329        struct ext4_sb_info *sbi;
3330        ext4_fsblk_t block;
3331        ext4_fsblk_t sb_block = get_sb_block(&data);
3332        ext4_fsblk_t logical_sb_block;
3333        unsigned long offset = 0;
3334        unsigned long journal_devnum = 0;
3335        unsigned long def_mount_opts;
3336        struct inode *root;
3337        char *cp;
3338        const char *descr;
3339        int ret = -ENOMEM;
3340        int blocksize, clustersize;
3341        unsigned int db_count;
3342        unsigned int i;
3343        int needs_recovery, has_huge_files, has_bigalloc;
3344        __u64 blocks_count;
3345        int err = 0;
3346        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3347        ext4_group_t first_not_zeroed;
3348
3349        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3350        if (!sbi)
3351                goto out_free_orig;
3352
3353        sbi->s_blockgroup_lock =
3354                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3355        if (!sbi->s_blockgroup_lock) {
3356                kfree(sbi);
3357                goto out_free_orig;
3358        }
3359        sb->s_fs_info = sbi;
3360        sbi->s_sb = sb;
3361        sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3362        sbi->s_sb_block = sb_block;
3363        if (sb->s_bdev->bd_part)
3364                sbi->s_sectors_written_start =
3365                        part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3366
3367        /* Cleanup superblock name */
3368        for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3369                *cp = '!';
3370
3371        /* -EINVAL is default */
3372        ret = -EINVAL;
3373        blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3374        if (!blocksize) {
3375                ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3376                goto out_fail;
3377        }
3378
3379        /*
3380         * The ext4 superblock will not be buffer aligned for other than 1kB
3381         * block sizes.  We need to calculate the offset from buffer start.
3382         */
3383        if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3384                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3385                offset = do_div(logical_sb_block, blocksize);
3386        } else {
3387                logical_sb_block = sb_block;
3388        }
3389
3390        if (!(bh = sb_bread(sb, logical_sb_block))) {
3391                ext4_msg(sb, KERN_ERR, "unable to read superblock");
3392                goto out_fail;
3393        }
3394        /*
3395         * Note: s_es must be initialized as soon as possible because
3396         *       some ext4 macro-instructions depend on its value
3397         */
3398        es = (struct ext4_super_block *) (bh->b_data + offset);
3399        sbi->s_es = es;
3400        sb->s_magic = le16_to_cpu(es->s_magic);
3401        if (sb->s_magic != EXT4_SUPER_MAGIC)
3402                goto cantfind_ext4;
3403        sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3404
3405        /* Warn if metadata_csum and gdt_csum are both set. */
3406        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3407                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3408            EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3409                ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3410                             "redundant flags; please run fsck.");
3411
3412        /* Check for a known checksum algorithm */
3413        if (!ext4_verify_csum_type(sb, es)) {
3414                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3415                         "unknown checksum algorithm.");
3416                silent = 1;
3417                goto cantfind_ext4;
3418        }
3419
3420        /* Load the checksum driver */
3421        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3422                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3423                sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3424                if (IS_ERR(sbi->s_chksum_driver)) {
3425                        ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3426                        ret = PTR_ERR(sbi->s_chksum_driver);
3427                        sbi->s_chksum_driver = NULL;
3428                        goto failed_mount;
3429                }
3430        }
3431
3432        /* Check superblock checksum */
3433        if (!ext4_superblock_csum_verify(sb, es)) {
3434                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3435                         "invalid superblock checksum.  Run e2fsck?");
3436                silent = 1;
3437                goto cantfind_ext4;
3438        }
3439
3440        /* Precompute checksum seed for all metadata */
3441        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3442                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3443                sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3444                                               sizeof(es->s_uuid));
3445
3446        /* Set defaults before we parse the mount options */
3447        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3448        set_opt(sb, INIT_INODE_TABLE);
3449        if (def_mount_opts & EXT4_DEFM_DEBUG)
3450                set_opt(sb, DEBUG);
3451        if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3452                set_opt(sb, GRPID);
3453        if (def_mount_opts & EXT4_DEFM_UID16)
3454                set_opt(sb, NO_UID32);
3455        /* xattr user namespace & acls are now defaulted on */
3456        set_opt(sb, XATTR_USER);
3457#ifdef CONFIG_EXT4_FS_POSIX_ACL
3458        set_opt(sb, POSIX_ACL);
3459#endif
3460        if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3461                set_opt(sb, JOURNAL_DATA);
3462        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3463                set_opt(sb, ORDERED_DATA);
3464        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3465                set_opt(sb, WRITEBACK_DATA);
3466
3467        if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3468                set_opt(sb, ERRORS_PANIC);
3469        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3470                set_opt(sb, ERRORS_CONT);
3471        else
3472                set_opt(sb, ERRORS_RO);
3473        if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3474                set_opt(sb, BLOCK_VALIDITY);
3475        if (def_mount_opts & EXT4_DEFM_DISCARD)
3476                set_opt(sb, DISCARD);
3477
3478        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3479        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3480        sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3481        sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3482        sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3483
3484        if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3485                set_opt(sb, BARRIER);
3486
3487        /*
3488         * enable delayed allocation by default
3489         * Use -o nodelalloc to turn it off
3490         */
3491        if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3492            ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3493                set_opt(sb, DELALLOC);
3494
3495        /*
3496         * set default s_li_wait_mult for lazyinit, for the case there is
3497         * no mount option specified.
3498         */
3499        sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3500
3501        if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3502                           &journal_devnum, &journal_ioprio, 0)) {
3503                ext4_msg(sb, KERN_WARNING,
3504                         "failed to parse options in superblock: %s",
3505                         sbi->s_es->s_mount_opts);
3506        }
3507        sbi->s_def_mount_opt = sbi->s_mount_opt;
3508        if (!parse_options((char *) data, sb, &journal_devnum,
3509                           &journal_ioprio, 0))
3510                goto failed_mount;
3511
3512        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3513                printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3514                            "with data=journal disables delayed "
3515                            "allocation and O_DIRECT support!\n");
3516                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3517                        ext4_msg(sb, KERN_ERR, "can't mount with "
3518                                 "both data=journal and delalloc");
3519                        goto failed_mount;
3520                }
3521                if (test_opt(sb, DIOREAD_NOLOCK)) {
3522                        ext4_msg(sb, KERN_ERR, "can't mount with "
3523                                 "both data=journal and dioread_nolock");
3524                        goto failed_mount;
3525                }
3526                if (test_opt(sb, DELALLOC))
3527                        clear_opt(sb, DELALLOC);
3528        }
3529
3530        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3531                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3532
3533        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3534            (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3535             EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3536             EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3537                ext4_msg(sb, KERN_WARNING,
3538                       "feature flags set on rev 0 fs, "
3539                       "running e2fsck is recommended");
3540
3541        if (IS_EXT2_SB(sb)) {
3542                if (ext2_feature_set_ok(sb))
3543                        ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3544                                 "using the ext4 subsystem");
3545                else {
3546                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3547                                 "to feature incompatibilities");
3548                        goto failed_mount;
3549                }
3550        }
3551
3552        if (IS_EXT3_SB(sb)) {
3553                if (ext3_feature_set_ok(sb))
3554                        ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3555                                 "using the ext4 subsystem");
3556                else {
3557                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3558                                 "to feature incompatibilities");
3559                        goto failed_mount;
3560                }
3561        }
3562
3563        /*
3564         * Check feature flags regardless of the revision level, since we
3565         * previously didn't change the revision level when setting the flags,
3566         * so there is a chance incompat flags are set on a rev 0 filesystem.
3567         */
3568        if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3569                goto failed_mount;
3570
3571        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3572        if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3573            blocksize > EXT4_MAX_BLOCK_SIZE) {
3574                ext4_msg(sb, KERN_ERR,
3575                       "Unsupported filesystem blocksize %d", blocksize);
3576                goto failed_mount;
3577        }
3578
3579        if (sb->s_blocksize != blocksize) {
3580                /* Validate the filesystem blocksize */
3581                if (!sb_set_blocksize(sb, blocksize)) {
3582                        ext4_msg(sb, KERN_ERR, "bad block size %d",
3583                                        blocksize);
3584                        goto failed_mount;
3585                }
3586
3587                brelse(bh);
3588                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3589                offset = do_div(logical_sb_block, blocksize);
3590                bh = sb_bread(sb, logical_sb_block);
3591                if (!bh) {
3592                        ext4_msg(sb, KERN_ERR,
3593                               "Can't read superblock on 2nd try");
3594                        goto failed_mount;
3595                }
3596                es = (struct ext4_super_block *)(bh->b_data + offset);
3597                sbi->s_es = es;
3598                if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3599                        ext4_msg(sb, KERN_ERR,
3600                               "Magic mismatch, very weird!");
3601                        goto failed_mount;
3602                }
3603        }
3604
3605        has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3606                                EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3607        sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3608                                                      has_huge_files);
3609        sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3610
3611        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3612                sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3613                sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3614        } else {
3615                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3616                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3617                if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3618                    (!is_power_of_2(sbi->s_inode_size)) ||
3619                    (sbi->s_inode_size > blocksize)) {
3620                        ext4_msg(sb, KERN_ERR,
3621                               "unsupported inode size: %d",
3622                               sbi->s_inode_size);
3623                        goto failed_mount;
3624                }
3625                if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3626                        sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3627        }
3628
3629        sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3630        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3631                if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3632                    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3633                    !is_power_of_2(sbi->s_desc_size)) {
3634                        ext4_msg(sb, KERN_ERR,
3635                               "unsupported descriptor size %lu",
3636                               sbi->s_desc_size);
3637                        goto failed_mount;
3638                }
3639        } else
3640                sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3641
3642        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3643        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3644        if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3645                goto cantfind_ext4;
3646
3647        sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3648        if (sbi->s_inodes_per_block == 0)
3649                goto cantfind_ext4;
3650        sbi->s_itb_per_group = sbi->s_inodes_per_group /
3651                                        sbi->s_inodes_per_block;
3652        sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3653        sbi->s_sbh = bh;
3654        sbi->s_mount_state = le16_to_cpu(es->s_state);
3655        sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3656        sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3657
3658        for (i = 0; i < 4; i++)
3659                sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3660        sbi->s_def_hash_version = es->s_def_hash_version;
3661        i = le32_to_cpu(es->s_flags);
3662        if (i & EXT2_FLAGS_UNSIGNED_HASH)
3663                sbi->s_hash_unsigned = 3;
3664        else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3665#ifdef __CHAR_UNSIGNED__
3666                es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3667                sbi->s_hash_unsigned = 3;
3668#else
3669                es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3670#endif
3671        }
3672
3673        /* Handle clustersize */
3674        clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3675        has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3676                                EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3677        if (has_bigalloc) {
3678                if (clustersize < blocksize) {
3679                        ext4_msg(sb, KERN_ERR,
3680                                 "cluster size (%d) smaller than "
3681                                 "block size (%d)", clustersize, blocksize);
3682                        goto failed_mount;
3683                }
3684                sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3685                        le32_to_cpu(es->s_log_block_size);
3686                sbi->s_clusters_per_group =
3687                        le32_to_cpu(es->s_clusters_per_group);
3688                if (sbi->s_clusters_per_group > blocksize * 8) {
3689                        ext4_msg(sb, KERN_ERR,
3690                                 "#clusters per group too big: %lu",
3691                                 sbi->s_clusters_per_group);
3692                        goto failed_mount;
3693                }
3694                if (sbi->s_blocks_per_group !=
3695                    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3696                        ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3697                                 "clusters per group (%lu) inconsistent",
3698                                 sbi->s_blocks_per_group,
3699                                 sbi->s_clusters_per_group);
3700                        goto failed_mount;
3701                }
3702        } else {
3703                if (clustersize != blocksize) {
3704                        ext4_warning(sb, "fragment/cluster size (%d) != "
3705                                     "block size (%d)", clustersize,
3706                                     blocksize);
3707                        clustersize = blocksize;
3708                }
3709                if (sbi->s_blocks_per_group > blocksize * 8) {
3710                        ext4_msg(sb, KERN_ERR,
3711                                 "#blocks per group too big: %lu",
3712                                 sbi->s_blocks_per_group);
3713                        goto failed_mount;
3714                }
3715                sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3716                sbi->s_cluster_bits = 0;
3717        }
3718        sbi->s_cluster_ratio = clustersize / blocksize;
3719
3720        if (sbi->s_inodes_per_group > blocksize * 8) {
3721                ext4_msg(sb, KERN_ERR,
3722                       "#inodes per group too big: %lu",
3723                       sbi->s_inodes_per_group);
3724                goto failed_mount;
3725        }
3726
3727        /* Do we have standard group size of clustersize * 8 blocks ? */
3728        if (sbi->s_blocks_per_group == clustersize << 3)
3729                set_opt2(sb, STD_GROUP_SIZE);
3730
3731        /*
3732         * Test whether we have more sectors than will fit in sector_t,
3733         * and whether the max offset is addressable by the page cache.
3734         */
3735        err = generic_check_addressable(sb->s_blocksize_bits,
3736                                        ext4_blocks_count(es));
3737        if (err) {
3738                ext4_msg(sb, KERN_ERR, "filesystem"
3739                         " too large to mount safely on this system");
3740                if (sizeof(sector_t) < 8)
3741                        ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3742                goto failed_mount;
3743        }
3744
3745        if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3746                goto cantfind_ext4;
3747
3748        /* check blocks count against device size */
3749        blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3750        if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3751                ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3752                       "exceeds size of device (%llu blocks)",
3753                       ext4_blocks_count(es), blocks_count);
3754                goto failed_mount;
3755        }
3756
3757        /*
3758         * It makes no sense for the first data block to be beyond the end
3759         * of the filesystem.
3760         */
3761        if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3762                ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3763                         "block %u is beyond end of filesystem (%llu)",
3764                         le32_to_cpu(es->s_first_data_block),
3765                         ext4_blocks_count(es));
3766                goto failed_mount;
3767        }
3768        blocks_count = (ext4_blocks_count(es) -
3769                        le32_to_cpu(es->s_first_data_block) +
3770                        EXT4_BLOCKS_PER_GROUP(sb) - 1);
3771        do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3772        if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3773                ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3774                       "(block count %llu, first data block %u, "
3775                       "blocks per group %lu)", sbi->s_groups_count,
3776                       ext4_blocks_count(es),
3777                       le32_to_cpu(es->s_first_data_block),
3778                       EXT4_BLOCKS_PER_GROUP(sb));
3779                goto failed_mount;
3780        }
3781        sbi->s_groups_count = blocks_count;
3782        sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3783                        (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3784        db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3785                   EXT4_DESC_PER_BLOCK(sb);
3786        sbi->s_group_desc = ext4_kvmalloc(db_count *
3787                                          sizeof(struct buffer_head *),
3788                                          GFP_KERNEL);
3789        if (sbi->s_group_desc == NULL) {
3790                ext4_msg(sb, KERN_ERR, "not enough memory");
3791                ret = -ENOMEM;
3792                goto failed_mount;
3793        }
3794
3795        if (ext4_proc_root)
3796                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3797
3798        if (sbi->s_proc)
3799                proc_create_data("options", S_IRUGO, sbi->s_proc,
3800                                 &ext4_seq_options_fops, sb);
3801
3802        bgl_lock_init(sbi->s_blockgroup_lock);
3803
3804        for (i = 0; i < db_count; i++) {
3805                block = descriptor_loc(sb, logical_sb_block, i);
3806                sbi->s_group_desc[i] = sb_bread(sb, block);
3807                if (!sbi->s_group_desc[i]) {
3808                        ext4_msg(sb, KERN_ERR,
3809                               "can't read group descriptor %d", i);
3810                        db_count = i;
3811                        goto failed_mount2;
3812                }
3813        }
3814        if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3815                ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3816                goto failed_mount2;
3817        }
3818        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3819                if (!ext4_fill_flex_info(sb)) {
3820                        ext4_msg(sb, KERN_ERR,
3821                               "unable to initialize "
3822                               "flex_bg meta info!");
3823                        goto failed_mount2;
3824                }
3825
3826        sbi->s_gdb_count = db_count;
3827        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3828        spin_lock_init(&sbi->s_next_gen_lock);
3829
3830        init_timer(&sbi->s_err_report);
3831        sbi->s_err_report.function = print_daily_error_info;
3832        sbi->s_err_report.data = (unsigned long) sb;
3833
3834        /* Register extent status tree shrinker */
3835        ext4_es_register_shrinker(sbi);
3836
3837        err = percpu_counter_init(&sbi->s_freeclusters_counter,
3838                        ext4_count_free_clusters(sb));
3839        if (!err) {
3840                err = percpu_counter_init(&sbi->s_freeinodes_counter,
3841                                ext4_count_free_inodes(sb));
3842        }
3843        if (!err) {
3844                err = percpu_counter_init(&sbi->s_dirs_counter,
3845                                ext4_count_dirs(sb));
3846        }
3847        if (!err) {
3848                err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3849        }
3850        if (!err) {
3851                err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3852        }
3853        if (err) {
3854                ext4_msg(sb, KERN_ERR, "insufficient memory");
3855                goto failed_mount3;
3856        }
3857
3858        sbi->s_stripe = ext4_get_stripe_size(sbi);
3859        sbi->s_extent_max_zeroout_kb = 32;
3860
3861        /*
3862         * set up enough so that it can read an inode
3863         */
3864        if (!test_opt(sb, NOLOAD) &&
3865            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3866                sb->s_op = &ext4_sops;
3867        else
3868                sb->s_op = &ext4_nojournal_sops;
3869        sb->s_export_op = &ext4_export_ops;
3870        sb->s_xattr = ext4_xattr_handlers;
3871#ifdef CONFIG_QUOTA
3872        sb->dq_op = &ext4_quota_operations;
3873        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3874                sb->s_qcop = &ext4_qctl_sysfile_operations;
3875        else
3876                sb->s_qcop = &ext4_qctl_operations;
3877#endif
3878        memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3879
3880        INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3881        mutex_init(&sbi->s_orphan_lock);
3882
3883        sb->s_root = NULL;
3884
3885        needs_recovery = (es->s_last_orphan != 0 ||
3886                          EXT4_HAS_INCOMPAT_FEATURE(sb,
3887                                    EXT4_FEATURE_INCOMPAT_RECOVER));
3888
3889        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3890            !(sb->s_flags & MS_RDONLY))
3891                if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3892                        goto failed_mount3;
3893
3894        /*
3895         * The first inode we look at is the journal inode.  Don't try
3896         * root first: it may be modified in the journal!
3897         */
3898        if (!test_opt(sb, NOLOAD) &&
3899            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3900                if (ext4_load_journal(sb, es, journal_devnum))
3901                        goto failed_mount3;
3902        } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3903              EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3904                ext4_msg(sb, KERN_ERR, "required journal recovery "
3905                       "suppressed and not mounted read-only");
3906                goto failed_mount_wq;
3907        } else {
3908                clear_opt(sb, DATA_FLAGS);
3909                sbi->s_journal = NULL;
3910                needs_recovery = 0;
3911                goto no_journal;
3912        }
3913
3914        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3915            !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3916                                       JBD2_FEATURE_INCOMPAT_64BIT)) {
3917                ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3918                goto failed_mount_wq;
3919        }
3920
3921        if (!set_journal_csum_feature_set(sb)) {
3922                ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3923                         "feature set");
3924                goto failed_mount_wq;
3925        }
3926
3927        /* We have now updated the journal if required, so we can
3928         * validate the data journaling mode. */
3929        switch (test_opt(sb, DATA_FLAGS)) {
3930        case 0:
3931                /* No mode set, assume a default based on the journal
3932                 * capabilities: ORDERED_DATA if the journal can
3933                 * cope, else JOURNAL_DATA
3934                 */
3935                if (jbd2_journal_check_available_features
3936                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3937                        set_opt(sb, ORDERED_DATA);
3938                else
3939                        set_opt(sb, JOURNAL_DATA);
3940                break;
3941
3942        case EXT4_MOUNT_ORDERED_DATA:
3943        case EXT4_MOUNT_WRITEBACK_DATA:
3944                if (!jbd2_journal_check_available_features
3945                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3946                        ext4_msg(sb, KERN_ERR, "Journal does not support "
3947                               "requested data journaling mode");
3948                        goto failed_mount_wq;
3949                }
3950        default:
3951                break;
3952        }
3953        set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3954
3955        sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3956
3957        /*
3958         * The journal may have updated the bg summary counts, so we
3959         * need to update the global counters.
3960         */
3961        percpu_counter_set(&sbi->s_freeclusters_counter,
3962                           ext4_count_free_clusters(sb));
3963        percpu_counter_set(&sbi->s_freeinodes_counter,
3964                           ext4_count_free_inodes(sb));
3965        percpu_counter_set(&sbi->s_dirs_counter,
3966                           ext4_count_dirs(sb));
3967        percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3968
3969no_journal:
3970        /*
3971         * Get the # of file system overhead blocks from the
3972         * superblock if present.
3973         */
3974        if (es->s_overhead_clusters)
3975                sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3976        else {
3977                err = ext4_calculate_overhead(sb);
3978                if (err)
3979                        goto failed_mount_wq;
3980        }
3981
3982        /*
3983         * The maximum number of concurrent works can be high and
3984         * concurrency isn't really necessary.  Limit it to 1.
3985         */
3986        EXT4_SB(sb)->rsv_conversion_wq =
3987                alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3988        if (!EXT4_SB(sb)->rsv_conversion_wq) {
3989                printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3990                ret = -ENOMEM;
3991                goto failed_mount4;
3992        }
3993
3994        /*
3995         * The jbd2_journal_load will have done any necessary log recovery,
3996         * so we can safely mount the rest of the filesystem now.
3997         */
3998
3999        root = ext4_iget(sb, EXT4_ROOT_INO);
4000        if (IS_ERR(root)) {
4001                ext4_msg(sb, KERN_ERR, "get root inode failed");
4002                ret = PTR_ERR(root);
4003                root = NULL;
4004                goto failed_mount4;
4005        }
4006        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4007                ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4008                iput(root);
4009                goto failed_mount4;
4010        }
4011        sb->s_root = d_make_root(root);
4012        if (!sb->s_root) {
4013                ext4_msg(sb, KERN_ERR, "get root dentry failed");
4014                ret = -ENOMEM;
4015                goto failed_mount4;
4016        }
4017
4018        if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4019                sb->s_flags |= MS_RDONLY;
4020
4021        /* determine the minimum size of new large inodes, if present */
4022        if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4023                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4024                                                     EXT4_GOOD_OLD_INODE_SIZE;
4025                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4026                                       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4027                        if (sbi->s_want_extra_isize <
4028                            le16_to_cpu(es->s_want_extra_isize))
4029                                sbi->s_want_extra_isize =
4030                                        le16_to_cpu(es->s_want_extra_isize);
4031                        if (sbi->s_want_extra_isize <
4032                            le16_to_cpu(es->s_min_extra_isize))
4033                                sbi->s_want_extra_isize =
4034                                        le16_to_cpu(es->s_min_extra_isize);
4035                }
4036        }
4037        /* Check if enough inode space is available */
4038        if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4039                                                        sbi->s_inode_size) {
4040                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4041                                                       EXT4_GOOD_OLD_INODE_SIZE;
4042                ext4_msg(sb, KERN_INFO, "required extra inode space not"
4043                         "available");
4044        }
4045
4046        err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4047        if (err) {
4048                ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4049                         "reserved pool", ext4_calculate_resv_clusters(sbi));
4050                goto failed_mount4a;
4051        }
4052
4053        err = ext4_setup_system_zone(sb);
4054        if (err) {
4055                ext4_msg(sb, KERN_ERR, "failed to initialize system "
4056                         "zone (%d)", err);
4057                goto failed_mount4a;
4058        }
4059
4060        ext4_ext_init(sb);
4061        err = ext4_mb_init(sb);
4062        if (err) {
4063                ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4064                         err);
4065                goto failed_mount5;
4066        }
4067
4068        err = ext4_register_li_request(sb, first_not_zeroed);
4069        if (err)
4070                goto failed_mount6;
4071
4072        sbi->s_kobj.kset = ext4_kset;
4073        init_completion(&sbi->s_kobj_unregister);
4074        err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4075                                   "%s", sb->s_id);
4076        if (err)
4077                goto failed_mount7;
4078
4079#ifdef CONFIG_QUOTA
4080        /* Enable quota usage during mount. */
4081        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4082            !(sb->s_flags & MS_RDONLY)) {
4083                err = ext4_enable_quotas(sb);
4084                if (err)
4085                        goto failed_mount8;
4086        }
4087#endif  /* CONFIG_QUOTA */
4088
4089        EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4090        ext4_orphan_cleanup(sb, es);
4091        EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4092        if (needs_recovery) {
4093                ext4_msg(sb, KERN_INFO, "recovery complete");
4094                ext4_mark_recovery_complete(sb, es);
4095        }
4096        if (EXT4_SB(sb)->s_journal) {
4097                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4098                        descr = " journalled data mode";
4099                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4100                        descr = " ordered data mode";
4101                else
4102                        descr = " writeback data mode";
4103        } else
4104                descr = "out journal";
4105
4106        if (test_opt(sb, DISCARD)) {
4107                struct request_queue *q = bdev_get_queue(sb->s_bdev);
4108                if (!blk_queue_discard(q))
4109                        ext4_msg(sb, KERN_WARNING,
4110                                 "mounting with \"discard\" option, but "
4111                                 "the device does not support discard");
4112        }
4113
4114        ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4115                 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4116                 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4117
4118        if (es->s_error_count)
4119                mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4120
4121        kfree(orig_data);
4122        return 0;
4123
4124cantfind_ext4:
4125        if (!silent)
4126                ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4127        goto failed_mount;
4128
4129#ifdef CONFIG_QUOTA
4130failed_mount8:
4131        kobject_del(&sbi->s_kobj);
4132#endif
4133failed_mount7:
4134        ext4_unregister_li_request(sb);
4135failed_mount6:
4136        ext4_mb_release(sb);
4137failed_mount5:
4138        ext4_ext_release(sb);
4139        ext4_release_system_zone(sb);
4140failed_mount4a:
4141        dput(sb->s_root);
4142        sb->s_root = NULL;
4143failed_mount4:
4144        ext4_msg(sb, KERN_ERR, "mount failed");
4145        if (EXT4_SB(sb)->rsv_conversion_wq)
4146                destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4147failed_mount_wq:
4148        if (sbi->s_journal) {
4149                jbd2_journal_destroy(sbi->s_journal);
4150                sbi->s_journal = NULL;
4151        }
4152failed_mount3:
4153        ext4_es_unregister_shrinker(sbi);
4154        del_timer(&sbi->s_err_report);
4155        if (sbi->s_flex_groups)
4156                ext4_kvfree(sbi->s_flex_groups);
4157        percpu_counter_destroy(&sbi->s_freeclusters_counter);
4158        percpu_counter_destroy(&sbi->s_freeinodes_counter);
4159        percpu_counter_destroy(&sbi->s_dirs_counter);
4160        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4161        percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4162        if (sbi->s_mmp_tsk)
4163                kthread_stop(sbi->s_mmp_tsk);
4164failed_mount2:
4165        for (i = 0; i < db_count; i++)
4166                brelse(sbi->s_group_desc[i]);
4167        ext4_kvfree(sbi->s_group_desc);
4168failed_mount:
4169        if (sbi->s_chksum_driver)
4170                crypto_free_shash(sbi->s_chksum_driver);
4171        if (sbi->s_proc) {
4172                remove_proc_entry("options", sbi->s_proc);
4173                remove_proc_entry(sb->s_id, ext4_proc_root);
4174        }
4175#ifdef CONFIG_QUOTA
4176        for (i = 0; i < MAXQUOTAS; i++)
4177                kfree(sbi->s_qf_names[i]);
4178#endif
4179        ext4_blkdev_remove(sbi);
4180        brelse(bh);
4181out_fail:
4182        sb->s_fs_info = NULL;
4183        kfree(sbi->s_blockgroup_lock);
4184        kfree(sbi);
4185out_free_orig:
4186        kfree(orig_data);
4187        return err ? err : ret;
4188}
4189
4190/*
4191 * Setup any per-fs journal parameters now.  We'll do this both on
4192 * initial mount, once the journal has been initialised but before we've
4193 * done any recovery; and again on any subsequent remount.
4194 */
4195static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4196{
4197        struct ext4_sb_info *sbi = EXT4_SB(sb);
4198
4199        journal->j_commit_interval = sbi->s_commit_interval;
4200        journal->j_min_batch_time = sbi->s_min_batch_time;
4201        journal->j_max_batch_time = sbi->s_max_batch_time;
4202
4203        write_lock(&journal->j_state_lock);
4204        if (test_opt(sb, BARRIER))
4205                journal->j_flags |= JBD2_BARRIER;
4206        else
4207                journal->j_flags &= ~JBD2_BARRIER;
4208        if (test_opt(sb, DATA_ERR_ABORT))
4209                journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4210        else
4211                journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4212        write_unlock(&journal->j_state_lock);
4213}
4214
4215static journal_t *ext4_get_journal(struct super_block *sb,
4216                                   unsigned int journal_inum)
4217{
4218        struct inode *journal_inode;
4219        journal_t *journal;
4220
4221        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4222
4223        /* First, test for the existence of a valid inode on disk.  Bad
4224         * things happen if we iget() an unused inode, as the subsequent
4225         * iput() will try to delete it. */
4226
4227        journal_inode = ext4_iget(sb, journal_inum);
4228        if (IS_ERR(journal_inode)) {
4229                ext4_msg(sb, KERN_ERR, "no journal found");
4230                return NULL;
4231        }
4232        if (!journal_inode->i_nlink) {
4233                make_bad_inode(journal_inode);
4234                iput(journal_inode);
4235                ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4236                return NULL;
4237        }
4238
4239        jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4240                  journal_inode, journal_inode->i_size);
4241        if (!S_ISREG(journal_inode->i_mode)) {
4242                ext4_msg(sb, KERN_ERR, "invalid journal inode");
4243                iput(journal_inode);
4244                return NULL;
4245        }
4246
4247        journal = jbd2_journal_init_inode(journal_inode);
4248        if (!journal) {
4249                ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4250                iput(journal_inode);
4251                return NULL;
4252        }
4253        journal->j_private = sb;
4254        ext4_init_journal_params(sb, journal);
4255        return journal;
4256}
4257
4258static journal_t *ext4_get_dev_journal(struct super_block *sb,
4259                                       dev_t j_dev)
4260{
4261        struct buffer_head *bh;
4262        journal_t *journal;
4263        ext4_fsblk_t start;
4264        ext4_fsblk_t len;
4265        int hblock, blocksize;
4266        ext4_fsblk_t sb_block;
4267        unsigned long offset;
4268        struct ext4_super_block *es;
4269        struct block_device *bdev;
4270
4271        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4272
4273        bdev = ext4_blkdev_get(j_dev, sb);
4274        if (bdev == NULL)
4275                return NULL;
4276
4277        blocksize = sb->s_blocksize;
4278        hblock = bdev_logical_block_size(bdev);
4279        if (blocksize < hblock) {
4280                ext4_msg(sb, KERN_ERR,
4281                        "blocksize too small for journal device");
4282                goto out_bdev;
4283        }
4284
4285        sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4286        offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4287        set_blocksize(bdev, blocksize);
4288        if (!(bh = __bread(bdev, sb_block, blocksize))) {
4289                ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4290                       "external journal");
4291                goto out_bdev;
4292        }
4293
4294        es = (struct ext4_super_block *) (bh->b_data + offset);
4295        if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4296            !(le32_to_cpu(es->s_feature_incompat) &
4297              EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4298                ext4_msg(sb, KERN_ERR, "external journal has "
4299                                        "bad superblock");
4300                brelse(bh);
4301                goto out_bdev;
4302        }
4303
4304        if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4305                ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4306                brelse(bh);
4307                goto out_bdev;
4308        }
4309
4310        len = ext4_blocks_count(es);
4311        start = sb_block + 1;
4312        brelse(bh);     /* we're done with the superblock */
4313
4314        journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4315                                        start, len, blocksize);
4316        if (!journal) {
4317                ext4_msg(sb, KERN_ERR, "failed to create device journal");
4318                goto out_bdev;
4319        }
4320        journal->j_private = sb;
4321        ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4322        wait_on_buffer(journal->j_sb_buffer);
4323        if (!buffer_uptodate(journal->j_sb_buffer)) {
4324                ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4325                goto out_journal;
4326        }
4327        if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4328                ext4_msg(sb, KERN_ERR, "External journal has more than one "
4329                                        "user (unsupported) - %d",
4330                        be32_to_cpu(journal->j_superblock->s_nr_users));
4331                goto out_journal;
4332        }
4333        EXT4_SB(sb)->journal_bdev = bdev;
4334        ext4_init_journal_params(sb, journal);
4335        return journal;
4336
4337out_journal:
4338        jbd2_journal_destroy(journal);
4339out_bdev:
4340        ext4_blkdev_put(bdev);
4341        return NULL;
4342}
4343
4344static int ext4_load_journal(struct super_block *sb,
4345                             struct ext4_super_block *es,
4346                             unsigned long journal_devnum)
4347{
4348        journal_t *journal;
4349        unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4350        dev_t journal_dev;
4351        int err = 0;
4352        int really_read_only;
4353
4354        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4355
4356        if (journal_devnum &&
4357            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4358                ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4359                        "numbers have changed");
4360                journal_dev = new_decode_dev(journal_devnum);
4361        } else
4362                journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4363
4364        really_read_only = bdev_read_only(sb->s_bdev);
4365
4366        /*
4367         * Are we loading a blank journal or performing recovery after a
4368         * crash?  For recovery, we need to check in advance whether we
4369         * can get read-write access to the device.
4370         */
4371        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4372                if (sb->s_flags & MS_RDONLY) {
4373                        ext4_msg(sb, KERN_INFO, "INFO: recovery "
4374                                        "required on readonly filesystem");
4375                        if (really_read_only) {
4376                                ext4_msg(sb, KERN_ERR, "write access "
4377                                        "unavailable, cannot proceed");
4378                                return -EROFS;
4379                        }
4380                        ext4_msg(sb, KERN_INFO, "write access will "
4381                               "be enabled during recovery");
4382                }
4383        }
4384
4385        if (journal_inum && journal_dev) {
4386                ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4387                       "and inode journals!");
4388                return -EINVAL;
4389        }
4390
4391        if (journal_inum) {
4392                if (!(journal = ext4_get_journal(sb, journal_inum)))
4393                        return -EINVAL;
4394        } else {
4395                if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4396                        return -EINVAL;
4397        }
4398
4399        if (!(journal->j_flags & JBD2_BARRIER))
4400                ext4_msg(sb, KERN_INFO, "barriers disabled");
4401
4402        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4403                err = jbd2_journal_wipe(journal, !really_read_only);
4404        if (!err) {
4405                char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4406                if (save)
4407                        memcpy(save, ((char *) es) +
4408                               EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4409                err = jbd2_journal_load(journal);
4410                if (save)
4411                        memcpy(((char *) es) + EXT4_S_ERR_START,
4412                               save, EXT4_S_ERR_LEN);
4413                kfree(save);
4414        }
4415
4416        if (err) {
4417                ext4_msg(sb, KERN_ERR, "error loading journal");
4418                jbd2_journal_destroy(journal);
4419                return err;
4420        }
4421
4422        EXT4_SB(sb)->s_journal = journal;
4423        ext4_clear_journal_err(sb, es);
4424
4425        if (!really_read_only && journal_devnum &&
4426            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4427                es->s_journal_dev = cpu_to_le32(journal_devnum);
4428
4429                /* Make sure we flush the recovery flag to disk. */
4430                ext4_commit_super(sb, 1);
4431        }
4432
4433        return 0;
4434}
4435
4436static int ext4_commit_super(struct super_block *sb, int sync)
4437{
4438        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4439        struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4440        int error = 0;
4441
4442        if (!sbh || block_device_ejected(sb))
4443                return error;
4444        if (buffer_write_io_error(sbh)) {
4445                /*
4446                 * Oh, dear.  A previous attempt to write the
4447                 * superblock failed.  This could happen because the
4448                 * USB device was yanked out.  Or it could happen to
4449                 * be a transient write error and maybe the block will
4450                 * be remapped.  Nothing we can do but to retry the
4451                 * write and hope for the best.
4452                 */
4453                ext4_msg(sb, KERN_ERR, "previous I/O error to "
4454                       "superblock detected");
4455                clear_buffer_write_io_error(sbh);
4456                set_buffer_uptodate(sbh);
4457        }
4458        /*
4459         * If the file system is mounted read-only, don't update the
4460         * superblock write time.  This avoids updating the superblock
4461         * write time when we are mounting the root file system
4462         * read/only but we need to replay the journal; at that point,
4463         * for people who are east of GMT and who make their clock
4464         * tick in localtime for Windows bug-for-bug compatibility,
4465         * the clock is set in the future, and this will cause e2fsck
4466         * to complain and force a full file system check.
4467         */
4468        if (!(sb->s_flags & MS_RDONLY))
4469                es->s_wtime = cpu_to_le32(get_seconds());
4470        if (sb->s_bdev->bd_part)
4471                es->s_kbytes_written =
4472                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4473                            ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4474                              EXT4_SB(sb)->s_sectors_written_start) >> 1));
4475        else
4476                es->s_kbytes_written =
4477                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4478        ext4_free_blocks_count_set(es,
4479                        EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4480                                &EXT4_SB(sb)->s_freeclusters_counter)));
4481        es->s_free_inodes_count =
4482                cpu_to_le32(percpu_counter_sum_positive(
4483                                &EXT4_SB(sb)->s_freeinodes_counter));
4484        BUFFER_TRACE(sbh, "marking dirty");
4485        ext4_superblock_csum_set(sb);
4486        mark_buffer_dirty(sbh);
4487        if (sync) {
4488                error = sync_dirty_buffer(sbh);
4489                if (error)
4490                        return error;
4491
4492                error = buffer_write_io_error(sbh);
4493                if (error) {
4494                        ext4_msg(sb, KERN_ERR, "I/O error while writing "
4495                               "superblock");
4496                        clear_buffer_write_io_error(sbh);
4497                        set_buffer_uptodate(sbh);
4498                }
4499        }
4500        return error;
4501}
4502
4503/*
4504 * Have we just finished recovery?  If so, and if we are mounting (or
4505 * remounting) the filesystem readonly, then we will end up with a
4506 * consistent fs on disk.  Record that fact.
4507 */
4508static void ext4_mark_recovery_complete(struct super_block *sb,
4509                                        struct ext4_super_block *es)
4510{
4511        journal_t *journal = EXT4_SB(sb)->s_journal;
4512
4513        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4514                BUG_ON(journal != NULL);
4515                return;
4516        }
4517        jbd2_journal_lock_updates(journal);
4518        if (jbd2_journal_flush(journal) < 0)
4519                goto out;
4520
4521        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4522            sb->s_flags & MS_RDONLY) {
4523                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4524                ext4_commit_super(sb, 1);
4525        }
4526
4527out:
4528        jbd2_journal_unlock_updates(journal);
4529}
4530
4531/*
4532 * If we are mounting (or read-write remounting) a filesystem whose journal
4533 * has recorded an error from a previous lifetime, move that error to the
4534 * main filesystem now.
4535 */
4536static void ext4_clear_journal_err(struct super_block *sb,
4537                                   struct ext4_super_block *es)
4538{
4539        journal_t *journal;
4540        int j_errno;
4541        const char *errstr;
4542
4543        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4544
4545        journal = EXT4_SB(sb)->s_journal;
4546
4547        /*
4548         * Now check for any error status which may have been recorded in the
4549         * journal by a prior ext4_error() or ext4_abort()
4550         */
4551
4552        j_errno = jbd2_journal_errno(journal);
4553        if (j_errno) {
4554                char nbuf[16];
4555
4556                errstr = ext4_decode_error(sb, j_errno, nbuf);
4557                ext4_warning(sb, "Filesystem error recorded "
4558                             "from previous mount: %s", errstr);
4559                ext4_warning(sb, "Marking fs in need of filesystem check.");
4560
4561                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4562                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4563                ext4_commit_super(sb, 1);
4564
4565                jbd2_journal_clear_err(journal);
4566                jbd2_journal_update_sb_errno(journal);
4567        }
4568}
4569
4570/*
4571 * Force the running and committing transactions to commit,
4572 * and wait on the commit.
4573 */
4574int ext4_force_commit(struct super_block *sb)
4575{
4576        journal_t *journal;
4577
4578        if (sb->s_flags & MS_RDONLY)
4579                return 0;
4580
4581        journal = EXT4_SB(sb)->s_journal;
4582        return ext4_journal_force_commit(journal);
4583}
4584
4585static int ext4_sync_fs(struct super_block *sb, int wait)
4586{
4587        int ret = 0;
4588        tid_t target;
4589        bool needs_barrier = false;
4590        struct ext4_sb_info *sbi = EXT4_SB(sb);
4591
4592        trace_ext4_sync_fs(sb, wait);
4593        flush_workqueue(sbi->rsv_conversion_wq);
4594        /*
4595         * Writeback quota in non-journalled quota case - journalled quota has
4596         * no dirty dquots
4597         */
4598        dquot_writeback_dquots(sb, -1);
4599        /*
4600         * Data writeback is possible w/o journal transaction, so barrier must
4601         * being sent at the end of the function. But we can skip it if
4602         * transaction_commit will do it for us.
4603         */
4604        target = jbd2_get_latest_transaction(sbi->s_journal);
4605        if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4606            !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4607                needs_barrier = true;
4608
4609        if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4610                if (wait)
4611                        ret = jbd2_log_wait_commit(sbi->s_journal, target);
4612        }
4613        if (needs_barrier) {
4614                int err;
4615                err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4616                if (!ret)
4617                        ret = err;
4618        }
4619
4620        return ret;
4621}
4622
4623static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4624{
4625        int ret = 0;
4626
4627        trace_ext4_sync_fs(sb, wait);
4628        flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4629        dquot_writeback_dquots(sb, -1);
4630        if (wait && test_opt(sb, BARRIER))
4631                ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4632
4633        return ret;
4634}
4635
4636/*
4637 * LVM calls this function before a (read-only) snapshot is created.  This
4638 * gives us a chance to flush the journal completely and mark the fs clean.
4639 *
4640 * Note that only this function cannot bring a filesystem to be in a clean
4641 * state independently. It relies on upper layer to stop all data & metadata
4642 * modifications.
4643 */
4644static int ext4_freeze(struct super_block *sb)
4645{
4646        int error = 0;
4647        journal_t *journal;
4648
4649        if (sb->s_flags & MS_RDONLY)
4650                return 0;
4651
4652        journal = EXT4_SB(sb)->s_journal;
4653
4654        /* Now we set up the journal barrier. */
4655        jbd2_journal_lock_updates(journal);
4656
4657        /*
4658         * Don't clear the needs_recovery flag if we failed to flush
4659         * the journal.
4660         */
4661        error = jbd2_journal_flush(journal);
4662        if (error < 0)
4663                goto out;
4664
4665        /* Journal blocked and flushed, clear needs_recovery flag. */
4666        EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4667        error = ext4_commit_super(sb, 1);
4668out:
4669        /* we rely on upper layer to stop further updates */
4670        jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4671        return error;
4672}
4673
4674/*
4675 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4676 * flag here, even though the filesystem is not technically dirty yet.
4677 */
4678static int ext4_unfreeze(struct super_block *sb)
4679{
4680        if (sb->s_flags & MS_RDONLY)
4681                return 0;
4682
4683        /* Reset the needs_recovery flag before the fs is unlocked. */
4684        EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4685        ext4_commit_super(sb, 1);
4686        return 0;
4687}
4688
4689/*
4690 * Structure to save mount options for ext4_remount's benefit
4691 */
4692struct ext4_mount_options {
4693        unsigned long s_mount_opt;
4694        unsigned long s_mount_opt2;
4695        kuid_t s_resuid;
4696        kgid_t s_resgid;
4697        unsigned long s_commit_interval;
4698        u32 s_min_batch_time, s_max_batch_time;
4699#ifdef CONFIG_QUOTA
4700        int s_jquota_fmt;
4701        char *s_qf_names[MAXQUOTAS];
4702#endif
4703};
4704
4705static int ext4_remount(struct super_block *sb, int *flags, char *data)
4706{
4707        struct ext4_super_block *es;
4708        struct ext4_sb_info *sbi = EXT4_SB(sb);
4709        unsigned long old_sb_flags;
4710        struct ext4_mount_options old_opts;
4711        int enable_quota = 0;
4712        ext4_group_t g;
4713        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4714        int err = 0;
4715#ifdef CONFIG_QUOTA
4716        int i, j;
4717#endif
4718        char *orig_data = kstrdup(data, GFP_KERNEL);
4719
4720        /* Store the original options */
4721        old_sb_flags = sb->s_flags;
4722        old_opts.s_mount_opt = sbi->s_mount_opt;
4723        old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4724        old_opts.s_resuid = sbi->s_resuid;
4725        old_opts.s_resgid = sbi->s_resgid;
4726        old_opts.s_commit_interval = sbi->s_commit_interval;
4727        old_opts.s_min_batch_time = sbi->s_min_batch_time;
4728        old_opts.s_max_batch_time = sbi->s_max_batch_time;
4729#ifdef CONFIG_QUOTA
4730        old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4731        for (i = 0; i < MAXQUOTAS; i++)
4732                if (sbi->s_qf_names[i]) {
4733                        old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4734                                                         GFP_KERNEL);
4735                        if (!old_opts.s_qf_names[i]) {
4736                                for (j = 0; j < i; j++)
4737                                        kfree(old_opts.s_qf_names[j]);
4738                                kfree(orig_data);
4739                                return -ENOMEM;
4740                        }
4741                } else
4742                        old_opts.s_qf_names[i] = NULL;
4743#endif
4744        if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4745                journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4746
4747        /*
4748         * Allow the "check" option to be passed as a remount option.
4749         */
4750        if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4751                err = -EINVAL;
4752                goto restore_opts;
4753        }
4754
4755        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4756                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4757                        ext4_msg(sb, KERN_ERR, "can't mount with "
4758                                 "both data=journal and delalloc");
4759                        err = -EINVAL;
4760                        goto restore_opts;
4761                }
4762                if (test_opt(sb, DIOREAD_NOLOCK)) {
4763                        ext4_msg(sb, KERN_ERR, "can't mount with "
4764                                 "both data=journal and dioread_nolock");
4765                        err = -EINVAL;
4766                        goto restore_opts;
4767                }
4768        }
4769
4770        if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4771                ext4_abort(sb, "Abort forced by user");
4772
4773        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4774                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4775
4776        es = sbi->s_es;
4777
4778        if (sbi->s_journal) {
4779                ext4_init_journal_params(sb, sbi->s_journal);
4780                set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4781        }
4782
4783        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4784                if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4785                        err = -EROFS;
4786                        goto restore_opts;
4787                }
4788
4789                if (*flags & MS_RDONLY) {
4790                        err = dquot_suspend(sb, -1);
4791                        if (err < 0)
4792                                goto restore_opts;
4793
4794                        /*
4795                         * First of all, the unconditional stuff we have to do
4796                         * to disable replay of the journal when we next remount
4797                         */
4798                        sb->s_flags |= MS_RDONLY;
4799
4800                        /*
4801                         * OK, test if we are remounting a valid rw partition
4802                         * readonly, and if so set the rdonly flag and then
4803                         * mark the partition as valid again.
4804                         */
4805                        if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4806                            (sbi->s_mount_state & EXT4_VALID_FS))
4807                                es->s_state = cpu_to_le16(sbi->s_mount_state);
4808
4809                        if (sbi->s_journal)
4810                                ext4_mark_recovery_complete(sb, es);
4811                } else {
4812                        /* Make sure we can mount this feature set readwrite */
4813                        if (!ext4_feature_set_ok(sb, 0)) {
4814                                err = -EROFS;
4815                                goto restore_opts;
4816                        }
4817                        /*
4818                         * Make sure the group descriptor checksums
4819                         * are sane.  If they aren't, refuse to remount r/w.
4820                         */
4821                        for (g = 0; g < sbi->s_groups_count; g++) {
4822                                struct ext4_group_desc *gdp =
4823                                        ext4_get_group_desc(sb, g, NULL);
4824
4825                                if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4826                                        ext4_msg(sb, KERN_ERR,
4827               "ext4_remount: Checksum for group %u failed (%u!=%u)",
4828                g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4829                                               le16_to_cpu(gdp->bg_checksum));
4830                                        err = -EINVAL;
4831                                        goto restore_opts;
4832                                }
4833                        }
4834
4835                        /*
4836                         * If we have an unprocessed orphan list hanging
4837                         * around from a previously readonly bdev mount,
4838                         * require a full umount/remount for now.
4839                         */
4840                        if (es->s_last_orphan) {
4841                                ext4_msg(sb, KERN_WARNING, "Couldn't "
4842                                       "remount RDWR because of unprocessed "
4843                                       "orphan inode list.  Please "
4844                                       "umount/remount instead");
4845                                err = -EINVAL;
4846                                goto restore_opts;
4847                        }
4848
4849                        /*
4850                         * Mounting a RDONLY partition read-write, so reread
4851                         * and store the current valid flag.  (It may have
4852                         * been changed by e2fsck since we originally mounted
4853                         * the partition.)
4854                         */
4855                        if (sbi->s_journal)
4856                                ext4_clear_journal_err(sb, es);
4857                        sbi->s_mount_state = le16_to_cpu(es->s_state);
4858                        if (!ext4_setup_super(sb, es, 0))
4859                                sb->s_flags &= ~MS_RDONLY;
4860                        if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4861                                                     EXT4_FEATURE_INCOMPAT_MMP))
4862                                if (ext4_multi_mount_protect(sb,
4863                                                le64_to_cpu(es->s_mmp_block))) {
4864                                        err = -EROFS;
4865                                        goto restore_opts;
4866                                }
4867                        enable_quota = 1;
4868                }
4869        }
4870
4871        /*
4872         * Reinitialize lazy itable initialization thread based on
4873         * current settings
4874         */
4875        if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4876                ext4_unregister_li_request(sb);
4877        else {
4878                ext4_group_t first_not_zeroed;
4879                first_not_zeroed = ext4_has_uninit_itable(sb);
4880                ext4_register_li_request(sb, first_not_zeroed);
4881        }
4882
4883        ext4_setup_system_zone(sb);
4884        if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4885                ext4_commit_super(sb, 1);
4886
4887#ifdef CONFIG_QUOTA
4888        /* Release old quota file names */
4889        for (i = 0; i < MAXQUOTAS; i++)
4890                kfree(old_opts.s_qf_names[i]);
4891        if (enable_quota) {
4892                if (sb_any_quota_suspended(sb))
4893                        dquot_resume(sb, -1);
4894                else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4895                                        EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4896                        err = ext4_enable_quotas(sb);
4897                        if (err)
4898                                goto restore_opts;
4899                }
4900        }
4901#endif
4902
4903        ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4904        kfree(orig_data);
4905        return 0;
4906
4907restore_opts:
4908        sb->s_flags = old_sb_flags;
4909        sbi->s_mount_opt = old_opts.s_mount_opt;
4910        sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4911        sbi->s_resuid = old_opts.s_resuid;
4912        sbi->s_resgid = old_opts.s_resgid;
4913        sbi->s_commit_interval = old_opts.s_commit_interval;
4914        sbi->s_min_batch_time = old_opts.s_min_batch_time;
4915        sbi->s_max_batch_time = old_opts.s_max_batch_time;
4916#ifdef CONFIG_QUOTA
4917        sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4918        for (i = 0; i < MAXQUOTAS; i++) {
4919                kfree(sbi->s_qf_names[i]);
4920                sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4921        }
4922#endif
4923        kfree(orig_data);
4924        return err;
4925}
4926
4927static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4928{
4929        struct super_block *sb = dentry->d_sb;
4930        struct ext4_sb_info *sbi = EXT4_SB(sb);
4931        struct ext4_super_block *es = sbi->s_es;
4932        ext4_fsblk_t overhead = 0, resv_blocks;
4933        u64 fsid;
4934        s64 bfree;
4935        resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4936
4937        if (!test_opt(sb, MINIX_DF))
4938                overhead = sbi->s_overhead;
4939
4940        buf->f_type = EXT4_SUPER_MAGIC;
4941        buf->f_bsize = sb->s_blocksize;
4942        buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4943        bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4944                percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4945        /* prevent underflow in case that few free space is available */
4946        buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4947        buf->f_bavail = buf->f_bfree -
4948                        (ext4_r_blocks_count(es) + resv_blocks);
4949        if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4950                buf->f_bavail = 0;
4951        buf->f_files = le32_to_cpu(es->s_inodes_count);
4952        buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4953        buf->f_namelen = EXT4_NAME_LEN;
4954        fsid = le64_to_cpup((void *)es->s_uuid) ^
4955               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4956        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4957        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4958
4959        return 0;
4960}
4961
4962/* Helper function for writing quotas on sync - we need to start transaction
4963 * before quota file is locked for write. Otherwise the are possible deadlocks:
4964 * Process 1                         Process 2
4965 * ext4_create()                     quota_sync()
4966 *   jbd2_journal_start()                  write_dquot()
4967 *   dquot_initialize()                         down(dqio_mutex)
4968 *     down(dqio_mutex)                    jbd2_journal_start()
4969 *
4970 */
4971
4972#ifdef CONFIG_QUOTA
4973
4974static inline struct inode *dquot_to_inode(struct dquot *dquot)
4975{
4976        return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4977}
4978
4979static int ext4_write_dquot(struct dquot *dquot)
4980{
4981        int ret, err;
4982        handle_t *handle;
4983        struct inode *inode;
4984
4985        inode = dquot_to_inode(dquot);
4986        handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4987                                    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4988        if (IS_ERR(handle))
4989                return PTR_ERR(handle);
4990        ret = dquot_commit(dquot);
4991        err = ext4_journal_stop(handle);
4992        if (!ret)
4993                ret = err;
4994        return ret;
4995}
4996
4997static int ext4_acquire_dquot(struct dquot *dquot)
4998{
4999        int ret, err;
5000        handle_t *handle;
5001
5002        handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5003                                    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5004        if (IS_ERR(handle))
5005                return PTR_ERR(handle);
5006        ret = dquot_acquire(dquot);
5007        err = ext4_journal_stop(handle);
5008        if (!ret)
5009                ret = err;
5010        return ret;
5011}
5012
5013static int ext4_release_dquot(struct dquot *dquot)
5014{
5015        int ret, err;
5016        handle_t *handle;
5017
5018        handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5019                                    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5020        if (IS_ERR(handle)) {
5021                /* Release dquot anyway to avoid endless cycle in dqput() */
5022                dquot_release(dquot);
5023                return PTR_ERR(handle);
5024        }
5025        ret = dquot_release(dquot);
5026        err = ext4_journal_stop(handle);
5027        if (!ret)
5028                ret = err;
5029        return ret;
5030}
5031
5032static int ext4_mark_dquot_dirty(struct dquot *dquot)
5033{
5034        struct super_block *sb = dquot->dq_sb;
5035        struct ext4_sb_info *sbi = EXT4_SB(sb);
5036
5037        /* Are we journaling quotas? */
5038        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5039            sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5040                dquot_mark_dquot_dirty(dquot);
5041                return ext4_write_dquot(dquot);
5042        } else {
5043                return dquot_mark_dquot_dirty(dquot);
5044        }
5045}
5046
5047static int ext4_write_info(struct super_block *sb, int type)
5048{
5049        int ret, err;
5050        handle_t *handle;
5051
5052        /* Data block + inode block */
5053        handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5054        if (IS_ERR(handle))
5055                return PTR_ERR(handle);
5056        ret = dquot_commit_info(sb, type);
5057        err = ext4_journal_stop(handle);
5058        if (!ret)
5059                ret = err;
5060        return ret;
5061}
5062
5063/*
5064 * Turn on quotas during mount time - we need to find
5065 * the quota file and such...
5066 */
5067static int ext4_quota_on_mount(struct super_block *sb, int type)
5068{
5069        return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5070                                        EXT4_SB(sb)->s_jquota_fmt, type);
5071}
5072
5073/*
5074 * Standard function to be called on quota_on
5075 */
5076static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5077                         struct path *path)
5078{
5079        int err;
5080
5081        if (!test_opt(sb, QUOTA))
5082                return -EINVAL;
5083
5084        /* Quotafile not on the same filesystem? */
5085        if (path->dentry->d_sb != sb)
5086                return -EXDEV;
5087        /* Journaling quota? */
5088        if (EXT4_SB(sb)->s_qf_names[type]) {
5089                /* Quotafile not in fs root? */
5090                if (path->dentry->d_parent != sb->s_root)
5091                        ext4_msg(sb, KERN_WARNING,
5092                                "Quota file not on filesystem root. "
5093                                "Journaled quota will not work");
5094        }
5095
5096        /*
5097         * When we journal data on quota file, we have to flush journal to see
5098         * all updates to the file when we bypass pagecache...
5099         */
5100        if (EXT4_SB(sb)->s_journal &&
5101            ext4_should_journal_data(path->dentry->d_inode)) {
5102                /*
5103                 * We don't need to lock updates but journal_flush() could
5104                 * otherwise be livelocked...
5105                 */
5106                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5107                err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5108                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5109                if (err)
5110                        return err;
5111        }
5112
5113        return dquot_quota_on(sb, type, format_id, path);
5114}
5115
5116static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5117                             unsigned int flags)
5118{
5119        int err;
5120        struct inode *qf_inode;
5121        unsigned long qf_inums[MAXQUOTAS] = {
5122                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5123                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5124        };
5125
5126        BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5127
5128        if (!qf_inums[type])
5129                return -EPERM;
5130
5131        qf_inode = ext4_iget(sb, qf_inums[type]);
5132        if (IS_ERR(qf_inode)) {
5133                ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5134                return PTR_ERR(qf_inode);
5135        }
5136
5137        /* Don't account quota for quota files to avoid recursion */
5138        qf_inode->i_flags |= S_NOQUOTA;
5139        err = dquot_enable(qf_inode, type, format_id, flags);
5140        iput(qf_inode);
5141
5142        return err;
5143}
5144
5145/* Enable usage tracking for all quota types. */
5146static int ext4_enable_quotas(struct super_block *sb)
5147{
5148        int type, err = 0;
5149        unsigned long qf_inums[MAXQUOTAS] = {
5150                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5151                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5152        };
5153
5154        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5155        for (type = 0; type < MAXQUOTAS; type++) {
5156                if (qf_inums[type]) {
5157                        err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5158                                                DQUOT_USAGE_ENABLED);
5159                        if (err) {
5160                                ext4_warning(sb,
5161                                        "Failed to enable quota tracking "
5162                                        "(type=%d, err=%d). Please run "
5163                                        "e2fsck to fix.", type, err);
5164                                return err;
5165                        }
5166                }
5167        }
5168        return 0;
5169}
5170
5171/*
5172 * quota_on function that is used when QUOTA feature is set.
5173 */
5174static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5175                                 int format_id)
5176{
5177        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5178                return -EINVAL;
5179
5180        /*
5181         * USAGE was enabled at mount time. Only need to enable LIMITS now.
5182         */
5183        return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5184}
5185
5186static int ext4_quota_off(struct super_block *sb, int type)
5187{
5188        struct inode *inode = sb_dqopt(sb)->files[type];
5189        handle_t *handle;
5190
5191        /* Force all delayed allocation blocks to be allocated.
5192         * Caller already holds s_umount sem */
5193        if (test_opt(sb, DELALLOC))
5194                sync_filesystem(sb);
5195
5196        if (!inode)
5197                goto out;
5198
5199        /* Update modification times of quota files when userspace can
5200         * start looking at them */
5201        handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5202        if (IS_ERR(handle))
5203                goto out;
5204        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5205        ext4_mark_inode_dirty(handle, inode);
5206        ext4_journal_stop(handle);
5207
5208out:
5209        return dquot_quota_off(sb, type);
5210}
5211
5212/*
5213 * quota_off function that is used when QUOTA feature is set.
5214 */
5215static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5216{
5217        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5218                return -EINVAL;
5219
5220        /* Disable only the limits. */
5221        return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5222}
5223
5224/* Read data from quotafile - avoid pagecache and such because we cannot afford
5225 * acquiring the locks... As quota files are never truncated and quota code
5226 * itself serializes the operations (and no one else should touch the files)
5227 * we don't have to be afraid of races */
5228static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5229                               size_t len, loff_t off)
5230{
5231        struct inode *inode = sb_dqopt(sb)->files[type];
5232        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5233        int err = 0;
5234        int offset = off & (sb->s_blocksize - 1);
5235        int tocopy;
5236        size_t toread;
5237        struct buffer_head *bh;
5238        loff_t i_size = i_size_read(inode);
5239
5240        if (off > i_size)
5241                return 0;
5242        if (off+len > i_size)
5243                len = i_size-off;
5244        toread = len;
5245        while (toread > 0) {
5246                tocopy = sb->s_blocksize - offset < toread ?
5247                                sb->s_blocksize - offset : toread;
5248                bh = ext4_bread(NULL, inode, blk, 0, &err);
5249                if (err)
5250                        return err;
5251                if (!bh)        /* A hole? */
5252                        memset(data, 0, tocopy);
5253                else
5254                        memcpy(data, bh->b_data+offset, tocopy);
5255                brelse(bh);
5256                offset = 0;
5257                toread -= tocopy;
5258                data += tocopy;
5259                blk++;
5260        }
5261        return len;
5262}
5263
5264/* Write to quotafile (we know the transaction is already started and has
5265 * enough credits) */
5266static ssize_t ext4_quota_write(struct super_block *sb, int type,
5267                                const char *data, size_t len, loff_t off)
5268{
5269        struct inode *inode = sb_dqopt(sb)->files[type];
5270        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5271        int err = 0;
5272        int offset = off & (sb->s_blocksize - 1);
5273        struct buffer_head *bh;
5274        handle_t *handle = journal_current_handle();
5275
5276        if (EXT4_SB(sb)->s_journal && !handle) {
5277                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5278                        " cancelled because transaction is not started",
5279                        (unsigned long long)off, (unsigned long long)len);
5280                return -EIO;
5281        }
5282        /*
5283         * Since we account only one data block in transaction credits,
5284         * then it is impossible to cross a block boundary.
5285         */
5286        if (sb->s_blocksize - offset < len) {
5287                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5288                        " cancelled because not block aligned",
5289                        (unsigned long long)off, (unsigned long long)len);
5290                return -EIO;
5291        }
5292
5293        bh = ext4_bread(handle, inode, blk, 1, &err);
5294        if (!bh)
5295                goto out;
5296        err = ext4_journal_get_write_access(handle, bh);
5297        if (err) {
5298                brelse(bh);
5299                goto out;
5300        }
5301        lock_buffer(bh);
5302        memcpy(bh->b_data+offset, data, len);
5303        flush_dcache_page(bh->b_page);
5304        unlock_buffer(bh);
5305        err = ext4_handle_dirty_metadata(handle, NULL, bh);
5306        brelse(bh);
5307out:
5308        if (err)
5309                return err;
5310        if (inode->i_size < off + len) {
5311                i_size_write(inode, off + len);
5312                EXT4_I(inode)->i_disksize = inode->i_size;
5313                ext4_mark_inode_dirty(handle, inode);
5314        }
5315        return len;
5316}
5317
5318#endif
5319
5320static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5321                       const char *dev_name, void *data)
5322{
5323        return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5324}
5325
5326#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5327static inline void register_as_ext2(void)
5328{
5329        int err = register_filesystem(&ext2_fs_type);
5330        if (err)
5331                printk(KERN_WARNING
5332                       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5333}
5334
5335static inline void unregister_as_ext2(void)
5336{
5337        unregister_filesystem(&ext2_fs_type);
5338}
5339
5340static inline int ext2_feature_set_ok(struct super_block *sb)
5341{
5342        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5343                return 0;
5344        if (sb->s_flags & MS_RDONLY)
5345                return 1;
5346        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5347                return 0;
5348        return 1;
5349}
5350#else
5351static inline void register_as_ext2(void) { }
5352static inline void unregister_as_ext2(void) { }
5353static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5354#endif
5355
5356#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5357static inline void register_as_ext3(void)
5358{
5359        int err = register_filesystem(&ext3_fs_type);
5360        if (err)
5361                printk(KERN_WARNING
5362                       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5363}
5364
5365static inline void unregister_as_ext3(void)
5366{
5367        unregister_filesystem(&ext3_fs_type);
5368}
5369
5370static inline int ext3_feature_set_ok(struct super_block *sb)
5371{
5372        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5373                return 0;
5374        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5375                return 0;
5376        if (sb->s_flags & MS_RDONLY)
5377                return 1;
5378        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5379                return 0;
5380        return 1;
5381}
5382#else
5383static inline void register_as_ext3(void) { }
5384static inline void unregister_as_ext3(void) { }
5385static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5386#endif
5387
5388static struct file_system_type ext4_fs_type = {
5389        .owner          = THIS_MODULE,
5390        .name           = "ext4",
5391        .mount          = ext4_mount,
5392        .kill_sb        = kill_block_super,
5393        .fs_flags       = FS_REQUIRES_DEV,
5394};
5395MODULE_ALIAS_FS("ext4");
5396
5397static int __init ext4_init_feat_adverts(void)
5398{
5399        struct ext4_features *ef;
5400        int ret = -ENOMEM;
5401
5402        ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5403        if (!ef)
5404                goto out;
5405
5406        ef->f_kobj.kset = ext4_kset;
5407        init_completion(&ef->f_kobj_unregister);
5408        ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5409                                   "features");
5410        if (ret) {
5411                kfree(ef);
5412                goto out;
5413        }
5414
5415        ext4_feat = ef;
5416        ret = 0;
5417out:
5418        return ret;
5419}
5420
5421static void ext4_exit_feat_adverts(void)
5422{
5423        kobject_put(&ext4_feat->f_kobj);
5424        wait_for_completion(&ext4_feat->f_kobj_unregister);
5425        kfree(ext4_feat);
5426}
5427
5428/* Shared across all ext4 file systems */
5429wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5430struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5431
5432static int __init ext4_init_fs(void)
5433{
5434        int i, err;
5435
5436        ext4_li_info = NULL;
5437        mutex_init(&ext4_li_mtx);
5438
5439        /* Build-time check for flags consistency */
5440        ext4_check_flag_values();
5441
5442        for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5443                mutex_init(&ext4__aio_mutex[i]);
5444                init_waitqueue_head(&ext4__ioend_wq[i]);
5445        }
5446
5447        err = ext4_init_es();
5448        if (err)
5449                return err;
5450
5451        err = ext4_init_pageio();
5452        if (err)
5453                goto out7;
5454
5455        err = ext4_init_system_zone();
5456        if (err)
5457                goto out6;
5458        ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5459        if (!ext4_kset) {
5460                err = -ENOMEM;
5461                goto out5;
5462        }
5463        ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5464
5465        err = ext4_init_feat_adverts();
5466        if (err)
5467                goto out4;
5468
5469        err = ext4_init_mballoc();
5470        if (err)
5471                goto out3;
5472
5473        err = ext4_init_xattr();
5474        if (err)
5475                goto out2;
5476        err = init_inodecache();
5477        if (err)
5478                goto out1;
5479        register_as_ext3();
5480        register_as_ext2();
5481        err = register_filesystem(&ext4_fs_type);
5482        if (err)
5483                goto out;
5484
5485        return 0;
5486out:
5487        unregister_as_ext2();
5488        unregister_as_ext3();
5489        destroy_inodecache();
5490out1:
5491        ext4_exit_xattr();
5492out2:
5493        ext4_exit_mballoc();
5494out3:
5495        ext4_exit_feat_adverts();
5496out4:
5497        if (ext4_proc_root)
5498                remove_proc_entry("fs/ext4", NULL);
5499        kset_unregister(ext4_kset);
5500out5:
5501        ext4_exit_system_zone();
5502out6:
5503        ext4_exit_pageio();
5504out7:
5505        ext4_exit_es();
5506
5507        return err;
5508}
5509
5510static void __exit ext4_exit_fs(void)
5511{
5512        ext4_destroy_lazyinit_thread();
5513        unregister_as_ext2();
5514        unregister_as_ext3();
5515        unregister_filesystem(&ext4_fs_type);
5516        destroy_inodecache();
5517        ext4_exit_xattr();
5518        ext4_exit_mballoc();
5519        ext4_exit_feat_adverts();
5520        remove_proc_entry("fs/ext4", NULL);
5521        kset_unregister(ext4_kset);
5522        ext4_exit_system_zone();
5523        ext4_exit_pageio();
5524        ext4_exit_es();
5525}
5526
5527MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5528MODULE_DESCRIPTION("Fourth Extended Filesystem");
5529MODULE_LICENSE("GPL");
5530module_init(ext4_init_fs)
5531module_exit(ext4_exit_fs)
5532