linux/fs/jfs/super.c
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   1/*
   2 *   Copyright (C) International Business Machines Corp., 2000-2004
   3 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
   4 *
   5 *   This program is free software;  you can redistribute it and/or modify
   6 *   it under the terms of the GNU General Public License as published by
   7 *   the Free Software Foundation; either version 2 of the License, or
   8 *   (at your option) any later version.
   9 *
  10 *   This program is distributed in the hope that it will be useful,
  11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13 *   the GNU General Public License for more details.
  14 *
  15 *   You should have received a copy of the GNU General Public License
  16 *   along with this program;  if not, write to the Free Software
  17 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18 */
  19
  20#include <linux/fs.h>
  21#include <linux/module.h>
  22#include <linux/parser.h>
  23#include <linux/completion.h>
  24#include <linux/vfs.h>
  25#include <linux/quotaops.h>
  26#include <linux/mount.h>
  27#include <linux/moduleparam.h>
  28#include <linux/kthread.h>
  29#include <linux/posix_acl.h>
  30#include <linux/buffer_head.h>
  31#include <linux/exportfs.h>
  32#include <linux/crc32.h>
  33#include <linux/slab.h>
  34#include <asm/uaccess.h>
  35#include <linux/seq_file.h>
  36
  37#include "jfs_incore.h"
  38#include "jfs_filsys.h"
  39#include "jfs_inode.h"
  40#include "jfs_metapage.h"
  41#include "jfs_superblock.h"
  42#include "jfs_dmap.h"
  43#include "jfs_imap.h"
  44#include "jfs_acl.h"
  45#include "jfs_debug.h"
  46
  47MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
  48MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
  49MODULE_LICENSE("GPL");
  50
  51static struct kmem_cache * jfs_inode_cachep;
  52
  53static const struct super_operations jfs_super_operations;
  54static const struct export_operations jfs_export_operations;
  55static struct file_system_type jfs_fs_type;
  56
  57#define MAX_COMMIT_THREADS 64
  58static int commit_threads = 0;
  59module_param(commit_threads, int, 0);
  60MODULE_PARM_DESC(commit_threads, "Number of commit threads");
  61
  62static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
  63struct task_struct *jfsIOthread;
  64struct task_struct *jfsSyncThread;
  65
  66#ifdef CONFIG_JFS_DEBUG
  67int jfsloglevel = JFS_LOGLEVEL_WARN;
  68module_param(jfsloglevel, int, 0644);
  69MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
  70#endif
  71
  72static void jfs_handle_error(struct super_block *sb)
  73{
  74        struct jfs_sb_info *sbi = JFS_SBI(sb);
  75
  76        if (sb->s_flags & MS_RDONLY)
  77                return;
  78
  79        updateSuper(sb, FM_DIRTY);
  80
  81        if (sbi->flag & JFS_ERR_PANIC)
  82                panic("JFS (device %s): panic forced after error\n",
  83                        sb->s_id);
  84        else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
  85                jfs_err("ERROR: (device %s): remounting filesystem "
  86                        "as read-only\n",
  87                        sb->s_id);
  88                sb->s_flags |= MS_RDONLY;
  89        }
  90
  91        /* nothing is done for continue beyond marking the superblock dirty */
  92}
  93
  94void jfs_error(struct super_block *sb, const char * function, ...)
  95{
  96        static char error_buf[256];
  97        va_list args;
  98
  99        va_start(args, function);
 100        vsnprintf(error_buf, sizeof(error_buf), function, args);
 101        va_end(args);
 102
 103        printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
 104
 105        jfs_handle_error(sb);
 106}
 107
 108static struct inode *jfs_alloc_inode(struct super_block *sb)
 109{
 110        struct jfs_inode_info *jfs_inode;
 111
 112        jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
 113        if (!jfs_inode)
 114                return NULL;
 115        return &jfs_inode->vfs_inode;
 116}
 117
 118static void jfs_i_callback(struct rcu_head *head)
 119{
 120        struct inode *inode = container_of(head, struct inode, i_rcu);
 121        struct jfs_inode_info *ji = JFS_IP(inode);
 122        kmem_cache_free(jfs_inode_cachep, ji);
 123}
 124
 125static void jfs_destroy_inode(struct inode *inode)
 126{
 127        struct jfs_inode_info *ji = JFS_IP(inode);
 128
 129        BUG_ON(!list_empty(&ji->anon_inode_list));
 130
 131        spin_lock_irq(&ji->ag_lock);
 132        if (ji->active_ag != -1) {
 133                struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
 134                atomic_dec(&bmap->db_active[ji->active_ag]);
 135                ji->active_ag = -1;
 136        }
 137        spin_unlock_irq(&ji->ag_lock);
 138        call_rcu(&inode->i_rcu, jfs_i_callback);
 139}
 140
 141static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 142{
 143        struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
 144        s64 maxinodes;
 145        struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
 146
 147        jfs_info("In jfs_statfs");
 148        buf->f_type = JFS_SUPER_MAGIC;
 149        buf->f_bsize = sbi->bsize;
 150        buf->f_blocks = sbi->bmap->db_mapsize;
 151        buf->f_bfree = sbi->bmap->db_nfree;
 152        buf->f_bavail = sbi->bmap->db_nfree;
 153        /*
 154         * If we really return the number of allocated & free inodes, some
 155         * applications will fail because they won't see enough free inodes.
 156         * We'll try to calculate some guess as to how may inodes we can
 157         * really allocate
 158         *
 159         * buf->f_files = atomic_read(&imap->im_numinos);
 160         * buf->f_ffree = atomic_read(&imap->im_numfree);
 161         */
 162        maxinodes = min((s64) atomic_read(&imap->im_numinos) +
 163                        ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
 164                         << L2INOSPEREXT), (s64) 0xffffffffLL);
 165        buf->f_files = maxinodes;
 166        buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
 167                                    atomic_read(&imap->im_numfree));
 168        buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
 169        buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
 170                                        sizeof(sbi->uuid)/2);
 171
 172        buf->f_namelen = JFS_NAME_MAX;
 173        return 0;
 174}
 175
 176static void jfs_put_super(struct super_block *sb)
 177{
 178        struct jfs_sb_info *sbi = JFS_SBI(sb);
 179        int rc;
 180
 181        jfs_info("In jfs_put_super");
 182
 183        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 184
 185        rc = jfs_umount(sb);
 186        if (rc)
 187                jfs_err("jfs_umount failed with return code %d", rc);
 188
 189        unload_nls(sbi->nls_tab);
 190
 191        truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 192        iput(sbi->direct_inode);
 193
 194        kfree(sbi);
 195}
 196
 197enum {
 198        Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
 199        Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
 200        Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
 201};
 202
 203static const match_table_t tokens = {
 204        {Opt_integrity, "integrity"},
 205        {Opt_nointegrity, "nointegrity"},
 206        {Opt_iocharset, "iocharset=%s"},
 207        {Opt_resize, "resize=%u"},
 208        {Opt_resize_nosize, "resize"},
 209        {Opt_errors, "errors=%s"},
 210        {Opt_ignore, "noquota"},
 211        {Opt_ignore, "quota"},
 212        {Opt_usrquota, "usrquota"},
 213        {Opt_grpquota, "grpquota"},
 214        {Opt_uid, "uid=%u"},
 215        {Opt_gid, "gid=%u"},
 216        {Opt_umask, "umask=%u"},
 217        {Opt_err, NULL}
 218};
 219
 220static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 221                         int *flag)
 222{
 223        void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
 224        char *p;
 225        struct jfs_sb_info *sbi = JFS_SBI(sb);
 226
 227        *newLVSize = 0;
 228
 229        if (!options)
 230                return 1;
 231
 232        while ((p = strsep(&options, ",")) != NULL) {
 233                substring_t args[MAX_OPT_ARGS];
 234                int token;
 235                if (!*p)
 236                        continue;
 237
 238                token = match_token(p, tokens, args);
 239                switch (token) {
 240                case Opt_integrity:
 241                        *flag &= ~JFS_NOINTEGRITY;
 242                        break;
 243                case Opt_nointegrity:
 244                        *flag |= JFS_NOINTEGRITY;
 245                        break;
 246                case Opt_ignore:
 247                        /* Silently ignore the quota options */
 248                        /* Don't do anything ;-) */
 249                        break;
 250                case Opt_iocharset:
 251                        if (nls_map && nls_map != (void *) -1)
 252                                unload_nls(nls_map);
 253                        if (!strcmp(args[0].from, "none"))
 254                                nls_map = NULL;
 255                        else {
 256                                nls_map = load_nls(args[0].from);
 257                                if (!nls_map) {
 258                                        printk(KERN_ERR
 259                                               "JFS: charset not found\n");
 260                                        goto cleanup;
 261                                }
 262                        }
 263                        break;
 264                case Opt_resize:
 265                {
 266                        char *resize = args[0].from;
 267                        *newLVSize = simple_strtoull(resize, &resize, 0);
 268                        break;
 269                }
 270                case Opt_resize_nosize:
 271                {
 272                        *newLVSize = sb->s_bdev->bd_inode->i_size >>
 273                                sb->s_blocksize_bits;
 274                        if (*newLVSize == 0)
 275                                printk(KERN_ERR
 276                                       "JFS: Cannot determine volume size\n");
 277                        break;
 278                }
 279                case Opt_errors:
 280                {
 281                        char *errors = args[0].from;
 282                        if (!errors || !*errors)
 283                                goto cleanup;
 284                        if (!strcmp(errors, "continue")) {
 285                                *flag &= ~JFS_ERR_REMOUNT_RO;
 286                                *flag &= ~JFS_ERR_PANIC;
 287                                *flag |= JFS_ERR_CONTINUE;
 288                        } else if (!strcmp(errors, "remount-ro")) {
 289                                *flag &= ~JFS_ERR_CONTINUE;
 290                                *flag &= ~JFS_ERR_PANIC;
 291                                *flag |= JFS_ERR_REMOUNT_RO;
 292                        } else if (!strcmp(errors, "panic")) {
 293                                *flag &= ~JFS_ERR_CONTINUE;
 294                                *flag &= ~JFS_ERR_REMOUNT_RO;
 295                                *flag |= JFS_ERR_PANIC;
 296                        } else {
 297                                printk(KERN_ERR
 298                                       "JFS: %s is an invalid error handler\n",
 299                                       errors);
 300                                goto cleanup;
 301                        }
 302                        break;
 303                }
 304
 305#ifdef CONFIG_QUOTA
 306                case Opt_quota:
 307                case Opt_usrquota:
 308                        *flag |= JFS_USRQUOTA;
 309                        break;
 310                case Opt_grpquota:
 311                        *flag |= JFS_GRPQUOTA;
 312                        break;
 313#else
 314                case Opt_usrquota:
 315                case Opt_grpquota:
 316                case Opt_quota:
 317                        printk(KERN_ERR
 318                               "JFS: quota operations not supported\n");
 319                        break;
 320#endif
 321                case Opt_uid:
 322                {
 323                        char *uid = args[0].from;
 324                        sbi->uid = simple_strtoul(uid, &uid, 0);
 325                        break;
 326                }
 327                case Opt_gid:
 328                {
 329                        char *gid = args[0].from;
 330                        sbi->gid = simple_strtoul(gid, &gid, 0);
 331                        break;
 332                }
 333                case Opt_umask:
 334                {
 335                        char *umask = args[0].from;
 336                        sbi->umask = simple_strtoul(umask, &umask, 8);
 337                        if (sbi->umask & ~0777) {
 338                                printk(KERN_ERR
 339                                       "JFS: Invalid value of umask\n");
 340                                goto cleanup;
 341                        }
 342                        break;
 343                }
 344                default:
 345                        printk("jfs: Unrecognized mount option \"%s\" "
 346                                        " or missing value\n", p);
 347                        goto cleanup;
 348                }
 349        }
 350
 351        if (nls_map != (void *) -1) {
 352                /* Discard old (if remount) */
 353                unload_nls(sbi->nls_tab);
 354                sbi->nls_tab = nls_map;
 355        }
 356        return 1;
 357
 358cleanup:
 359        if (nls_map && nls_map != (void *) -1)
 360                unload_nls(nls_map);
 361        return 0;
 362}
 363
 364static int jfs_remount(struct super_block *sb, int *flags, char *data)
 365{
 366        s64 newLVSize = 0;
 367        int rc = 0;
 368        int flag = JFS_SBI(sb)->flag;
 369        int ret;
 370
 371        if (!parse_options(data, sb, &newLVSize, &flag)) {
 372                return -EINVAL;
 373        }
 374
 375        if (newLVSize) {
 376                if (sb->s_flags & MS_RDONLY) {
 377                        printk(KERN_ERR
 378                  "JFS: resize requires volume to be mounted read-write\n");
 379                        return -EROFS;
 380                }
 381                rc = jfs_extendfs(sb, newLVSize, 0);
 382                if (rc)
 383                        return rc;
 384        }
 385
 386        if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
 387                /*
 388                 * Invalidate any previously read metadata.  fsck may have
 389                 * changed the on-disk data since we mounted r/o
 390                 */
 391                truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
 392
 393                JFS_SBI(sb)->flag = flag;
 394                ret = jfs_mount_rw(sb, 1);
 395
 396                /* mark the fs r/w for quota activity */
 397                sb->s_flags &= ~MS_RDONLY;
 398
 399                dquot_resume(sb, -1);
 400                return ret;
 401        }
 402        if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
 403                rc = dquot_suspend(sb, -1);
 404                if (rc < 0) {
 405                        return rc;
 406                }
 407                rc = jfs_umount_rw(sb);
 408                JFS_SBI(sb)->flag = flag;
 409                return rc;
 410        }
 411        if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
 412                if (!(sb->s_flags & MS_RDONLY)) {
 413                        rc = jfs_umount_rw(sb);
 414                        if (rc)
 415                                return rc;
 416
 417                        JFS_SBI(sb)->flag = flag;
 418                        ret = jfs_mount_rw(sb, 1);
 419                        return ret;
 420                }
 421        JFS_SBI(sb)->flag = flag;
 422
 423        return 0;
 424}
 425
 426static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 427{
 428        struct jfs_sb_info *sbi;
 429        struct inode *inode;
 430        int rc;
 431        s64 newLVSize = 0;
 432        int flag, ret = -EINVAL;
 433
 434        jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
 435
 436        if (!new_valid_dev(sb->s_bdev->bd_dev))
 437                return -EOVERFLOW;
 438
 439        sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
 440        if (!sbi)
 441                return -ENOMEM;
 442
 443        sb->s_fs_info = sbi;
 444        sb->s_max_links = JFS_LINK_MAX;
 445        sbi->sb = sb;
 446        sbi->uid = sbi->gid = sbi->umask = -1;
 447
 448        /* initialize the mount flag and determine the default error handler */
 449        flag = JFS_ERR_REMOUNT_RO;
 450
 451        if (!parse_options((char *) data, sb, &newLVSize, &flag))
 452                goto out_kfree;
 453        sbi->flag = flag;
 454
 455#ifdef CONFIG_JFS_POSIX_ACL
 456        sb->s_flags |= MS_POSIXACL;
 457#endif
 458
 459        if (newLVSize) {
 460                printk(KERN_ERR "resize option for remount only\n");
 461                goto out_kfree;
 462        }
 463
 464        /*
 465         * Initialize blocksize to 4K.
 466         */
 467        sb_set_blocksize(sb, PSIZE);
 468
 469        /*
 470         * Set method vectors.
 471         */
 472        sb->s_op = &jfs_super_operations;
 473        sb->s_export_op = &jfs_export_operations;
 474#ifdef CONFIG_QUOTA
 475        sb->dq_op = &dquot_operations;
 476        sb->s_qcop = &dquot_quotactl_ops;
 477#endif
 478
 479        /*
 480         * Initialize direct-mapping inode/address-space
 481         */
 482        inode = new_inode(sb);
 483        if (inode == NULL) {
 484                ret = -ENOMEM;
 485                goto out_unload;
 486        }
 487        inode->i_ino = 0;
 488        inode->i_size = sb->s_bdev->bd_inode->i_size;
 489        inode->i_mapping->a_ops = &jfs_metapage_aops;
 490        insert_inode_hash(inode);
 491        mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 492
 493        sbi->direct_inode = inode;
 494
 495        rc = jfs_mount(sb);
 496        if (rc) {
 497                if (!silent) {
 498                        jfs_err("jfs_mount failed w/return code = %d", rc);
 499                }
 500                goto out_mount_failed;
 501        }
 502        if (sb->s_flags & MS_RDONLY)
 503                sbi->log = NULL;
 504        else {
 505                rc = jfs_mount_rw(sb, 0);
 506                if (rc) {
 507                        if (!silent) {
 508                                jfs_err("jfs_mount_rw failed, return code = %d",
 509                                        rc);
 510                        }
 511                        goto out_no_rw;
 512                }
 513        }
 514
 515        sb->s_magic = JFS_SUPER_MAGIC;
 516
 517        if (sbi->mntflag & JFS_OS2)
 518                sb->s_d_op = &jfs_ci_dentry_operations;
 519
 520        inode = jfs_iget(sb, ROOT_I);
 521        if (IS_ERR(inode)) {
 522                ret = PTR_ERR(inode);
 523                goto out_no_rw;
 524        }
 525        sb->s_root = d_make_root(inode);
 526        if (!sb->s_root)
 527                goto out_no_root;
 528
 529        /* logical blocks are represented by 40 bits in pxd_t, etc. */
 530        sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 531#if BITS_PER_LONG == 32
 532        /*
 533         * Page cache is indexed by long.
 534         * I would use MAX_LFS_FILESIZE, but it's only half as big
 535         */
 536        sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
 537#endif
 538        sb->s_time_gran = 1;
 539        return 0;
 540
 541out_no_root:
 542        jfs_err("jfs_read_super: get root dentry failed");
 543
 544out_no_rw:
 545        rc = jfs_umount(sb);
 546        if (rc) {
 547                jfs_err("jfs_umount failed with return code %d", rc);
 548        }
 549out_mount_failed:
 550        filemap_write_and_wait(sbi->direct_inode->i_mapping);
 551        truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 552        make_bad_inode(sbi->direct_inode);
 553        iput(sbi->direct_inode);
 554        sbi->direct_inode = NULL;
 555out_unload:
 556        if (sbi->nls_tab)
 557                unload_nls(sbi->nls_tab);
 558out_kfree:
 559        kfree(sbi);
 560        return ret;
 561}
 562
 563static int jfs_freeze(struct super_block *sb)
 564{
 565        struct jfs_sb_info *sbi = JFS_SBI(sb);
 566        struct jfs_log *log = sbi->log;
 567
 568        if (!(sb->s_flags & MS_RDONLY)) {
 569                txQuiesce(sb);
 570                lmLogShutdown(log);
 571                updateSuper(sb, FM_CLEAN);
 572        }
 573        return 0;
 574}
 575
 576static int jfs_unfreeze(struct super_block *sb)
 577{
 578        struct jfs_sb_info *sbi = JFS_SBI(sb);
 579        struct jfs_log *log = sbi->log;
 580        int rc = 0;
 581
 582        if (!(sb->s_flags & MS_RDONLY)) {
 583                updateSuper(sb, FM_MOUNT);
 584                if ((rc = lmLogInit(log)))
 585                        jfs_err("jfs_unlock failed with return code %d", rc);
 586                else
 587                        txResume(sb);
 588        }
 589        return 0;
 590}
 591
 592static struct dentry *jfs_do_mount(struct file_system_type *fs_type,
 593        int flags, const char *dev_name, void *data)
 594{
 595        return mount_bdev(fs_type, flags, dev_name, data, jfs_fill_super);
 596}
 597
 598static int jfs_sync_fs(struct super_block *sb, int wait)
 599{
 600        struct jfs_log *log = JFS_SBI(sb)->log;
 601
 602        /* log == NULL indicates read-only mount */
 603        if (log) {
 604                jfs_flush_journal(log, wait);
 605                jfs_syncpt(log, 0);
 606        }
 607
 608        return 0;
 609}
 610
 611static int jfs_show_options(struct seq_file *seq, struct dentry *root)
 612{
 613        struct jfs_sb_info *sbi = JFS_SBI(root->d_sb);
 614
 615        if (sbi->uid != -1)
 616                seq_printf(seq, ",uid=%d", sbi->uid);
 617        if (sbi->gid != -1)
 618                seq_printf(seq, ",gid=%d", sbi->gid);
 619        if (sbi->umask != -1)
 620                seq_printf(seq, ",umask=%03o", sbi->umask);
 621        if (sbi->flag & JFS_NOINTEGRITY)
 622                seq_puts(seq, ",nointegrity");
 623        if (sbi->nls_tab)
 624                seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
 625        if (sbi->flag & JFS_ERR_CONTINUE)
 626                seq_printf(seq, ",errors=continue");
 627        if (sbi->flag & JFS_ERR_PANIC)
 628                seq_printf(seq, ",errors=panic");
 629
 630#ifdef CONFIG_QUOTA
 631        if (sbi->flag & JFS_USRQUOTA)
 632                seq_puts(seq, ",usrquota");
 633
 634        if (sbi->flag & JFS_GRPQUOTA)
 635                seq_puts(seq, ",grpquota");
 636#endif
 637
 638        return 0;
 639}
 640
 641#ifdef CONFIG_QUOTA
 642
 643/* Read data from quotafile - avoid pagecache and such because we cannot afford
 644 * acquiring the locks... As quota files are never truncated and quota code
 645 * itself serializes the operations (and no one else should touch the files)
 646 * we don't have to be afraid of races */
 647static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
 648                              size_t len, loff_t off)
 649{
 650        struct inode *inode = sb_dqopt(sb)->files[type];
 651        sector_t blk = off >> sb->s_blocksize_bits;
 652        int err = 0;
 653        int offset = off & (sb->s_blocksize - 1);
 654        int tocopy;
 655        size_t toread;
 656        struct buffer_head tmp_bh;
 657        struct buffer_head *bh;
 658        loff_t i_size = i_size_read(inode);
 659
 660        if (off > i_size)
 661                return 0;
 662        if (off+len > i_size)
 663                len = i_size-off;
 664        toread = len;
 665        while (toread > 0) {
 666                tocopy = sb->s_blocksize - offset < toread ?
 667                                sb->s_blocksize - offset : toread;
 668
 669                tmp_bh.b_state = 0;
 670                tmp_bh.b_size = 1 << inode->i_blkbits;
 671                err = jfs_get_block(inode, blk, &tmp_bh, 0);
 672                if (err)
 673                        return err;
 674                if (!buffer_mapped(&tmp_bh))    /* A hole? */
 675                        memset(data, 0, tocopy);
 676                else {
 677                        bh = sb_bread(sb, tmp_bh.b_blocknr);
 678                        if (!bh)
 679                                return -EIO;
 680                        memcpy(data, bh->b_data+offset, tocopy);
 681                        brelse(bh);
 682                }
 683                offset = 0;
 684                toread -= tocopy;
 685                data += tocopy;
 686                blk++;
 687        }
 688        return len;
 689}
 690
 691/* Write to quotafile */
 692static ssize_t jfs_quota_write(struct super_block *sb, int type,
 693                               const char *data, size_t len, loff_t off)
 694{
 695        struct inode *inode = sb_dqopt(sb)->files[type];
 696        sector_t blk = off >> sb->s_blocksize_bits;
 697        int err = 0;
 698        int offset = off & (sb->s_blocksize - 1);
 699        int tocopy;
 700        size_t towrite = len;
 701        struct buffer_head tmp_bh;
 702        struct buffer_head *bh;
 703
 704        mutex_lock(&inode->i_mutex);
 705        while (towrite > 0) {
 706                tocopy = sb->s_blocksize - offset < towrite ?
 707                                sb->s_blocksize - offset : towrite;
 708
 709                tmp_bh.b_state = 0;
 710                tmp_bh.b_size = 1 << inode->i_blkbits;
 711                err = jfs_get_block(inode, blk, &tmp_bh, 1);
 712                if (err)
 713                        goto out;
 714                if (offset || tocopy != sb->s_blocksize)
 715                        bh = sb_bread(sb, tmp_bh.b_blocknr);
 716                else
 717                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
 718                if (!bh) {
 719                        err = -EIO;
 720                        goto out;
 721                }
 722                lock_buffer(bh);
 723                memcpy(bh->b_data+offset, data, tocopy);
 724                flush_dcache_page(bh->b_page);
 725                set_buffer_uptodate(bh);
 726                mark_buffer_dirty(bh);
 727                unlock_buffer(bh);
 728                brelse(bh);
 729                offset = 0;
 730                towrite -= tocopy;
 731                data += tocopy;
 732                blk++;
 733        }
 734out:
 735        if (len == towrite) {
 736                mutex_unlock(&inode->i_mutex);
 737                return err;
 738        }
 739        if (inode->i_size < off+len-towrite)
 740                i_size_write(inode, off+len-towrite);
 741        inode->i_version++;
 742        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 743        mark_inode_dirty(inode);
 744        mutex_unlock(&inode->i_mutex);
 745        return len - towrite;
 746}
 747
 748#endif
 749
 750static const struct super_operations jfs_super_operations = {
 751        .alloc_inode    = jfs_alloc_inode,
 752        .destroy_inode  = jfs_destroy_inode,
 753        .dirty_inode    = jfs_dirty_inode,
 754        .write_inode    = jfs_write_inode,
 755        .evict_inode    = jfs_evict_inode,
 756        .put_super      = jfs_put_super,
 757        .sync_fs        = jfs_sync_fs,
 758        .freeze_fs      = jfs_freeze,
 759        .unfreeze_fs    = jfs_unfreeze,
 760        .statfs         = jfs_statfs,
 761        .remount_fs     = jfs_remount,
 762        .show_options   = jfs_show_options,
 763#ifdef CONFIG_QUOTA
 764        .quota_read     = jfs_quota_read,
 765        .quota_write    = jfs_quota_write,
 766#endif
 767};
 768
 769static const struct export_operations jfs_export_operations = {
 770        .fh_to_dentry   = jfs_fh_to_dentry,
 771        .fh_to_parent   = jfs_fh_to_parent,
 772        .get_parent     = jfs_get_parent,
 773};
 774
 775static struct file_system_type jfs_fs_type = {
 776        .owner          = THIS_MODULE,
 777        .name           = "jfs",
 778        .mount          = jfs_do_mount,
 779        .kill_sb        = kill_block_super,
 780        .fs_flags       = FS_REQUIRES_DEV,
 781};
 782
 783static void init_once(void *foo)
 784{
 785        struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
 786
 787        memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
 788        INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
 789        init_rwsem(&jfs_ip->rdwrlock);
 790        mutex_init(&jfs_ip->commit_mutex);
 791        init_rwsem(&jfs_ip->xattr_sem);
 792        spin_lock_init(&jfs_ip->ag_lock);
 793        jfs_ip->active_ag = -1;
 794        inode_init_once(&jfs_ip->vfs_inode);
 795}
 796
 797static int __init init_jfs_fs(void)
 798{
 799        int i;
 800        int rc;
 801
 802        jfs_inode_cachep =
 803            kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
 804                            SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 805                            init_once);
 806        if (jfs_inode_cachep == NULL)
 807                return -ENOMEM;
 808
 809        /*
 810         * Metapage initialization
 811         */
 812        rc = metapage_init();
 813        if (rc) {
 814                jfs_err("metapage_init failed w/rc = %d", rc);
 815                goto free_slab;
 816        }
 817
 818        /*
 819         * Transaction Manager initialization
 820         */
 821        rc = txInit();
 822        if (rc) {
 823                jfs_err("txInit failed w/rc = %d", rc);
 824                goto free_metapage;
 825        }
 826
 827        /*
 828         * I/O completion thread (endio)
 829         */
 830        jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
 831        if (IS_ERR(jfsIOthread)) {
 832                rc = PTR_ERR(jfsIOthread);
 833                jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 834                goto end_txmngr;
 835        }
 836
 837        if (commit_threads < 1)
 838                commit_threads = num_online_cpus();
 839        if (commit_threads > MAX_COMMIT_THREADS)
 840                commit_threads = MAX_COMMIT_THREADS;
 841
 842        for (i = 0; i < commit_threads; i++) {
 843                jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
 844                if (IS_ERR(jfsCommitThread[i])) {
 845                        rc = PTR_ERR(jfsCommitThread[i]);
 846                        jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 847                        commit_threads = i;
 848                        goto kill_committask;
 849                }
 850        }
 851
 852        jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
 853        if (IS_ERR(jfsSyncThread)) {
 854                rc = PTR_ERR(jfsSyncThread);
 855                jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 856                goto kill_committask;
 857        }
 858
 859#ifdef PROC_FS_JFS
 860        jfs_proc_init();
 861#endif
 862
 863        rc = register_filesystem(&jfs_fs_type);
 864        if (!rc)
 865                return 0;
 866
 867#ifdef PROC_FS_JFS
 868        jfs_proc_clean();
 869#endif
 870        kthread_stop(jfsSyncThread);
 871kill_committask:
 872        for (i = 0; i < commit_threads; i++)
 873                kthread_stop(jfsCommitThread[i]);
 874        kthread_stop(jfsIOthread);
 875end_txmngr:
 876        txExit();
 877free_metapage:
 878        metapage_exit();
 879free_slab:
 880        kmem_cache_destroy(jfs_inode_cachep);
 881        return rc;
 882}
 883
 884static void __exit exit_jfs_fs(void)
 885{
 886        int i;
 887
 888        jfs_info("exit_jfs_fs called");
 889
 890        txExit();
 891        metapage_exit();
 892
 893        kthread_stop(jfsIOthread);
 894        for (i = 0; i < commit_threads; i++)
 895                kthread_stop(jfsCommitThread[i]);
 896        kthread_stop(jfsSyncThread);
 897#ifdef PROC_FS_JFS
 898        jfs_proc_clean();
 899#endif
 900        unregister_filesystem(&jfs_fs_type);
 901        kmem_cache_destroy(jfs_inode_cachep);
 902}
 903
 904module_init(init_jfs_fs)
 905module_exit(exit_jfs_fs)
 906