LXR linux/fs/ext4/ext4

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Interface between ext4 and JBD
   4 */
   5
   6#include "ext4_jbd2.h"
   7
   8#include <trace/events/ext4.h>
   9
  10int ext4_inode_journal_mode(struct inode *inode)
  11{
  12        if (EXT4_JOURNAL(inode) == NULL)
  13                return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
  14        /* We do not support data journalling with delayed allocation */
  15        if (!S_ISREG(inode->i_mode) ||
  16            ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE) ||
  17            test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
  18            (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
  19            !test_opt(inode->i_sb, DELALLOC))) {
  20                /* We do not support data journalling for encrypted data */
  21                if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode))
  22                        return EXT4_INODE_ORDERED_DATA_MODE;  /* ordered */
  23                return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
  24        }
  25        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
  26                return EXT4_INODE_ORDERED_DATA_MODE;    /* ordered */
  27        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
  28                return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
  29        BUG();
  30}
  31
  32/* Just increment the non-pointer handle value */
  33static handle_t *ext4_get_nojournal(void)
  34{
  35        handle_t *handle = current->journal_info;
  36        unsigned long ref_cnt = (unsigned long)handle;
  37
  38        BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
  39
  40        ref_cnt++;
  41        handle = (handle_t *)ref_cnt;
  42
  43        current->journal_info = handle;
  44        return handle;
  45}
  46
  47
  48/* Decrement the non-pointer handle value */
  49static void ext4_put_nojournal(handle_t *handle)
  50{
  51        unsigned long ref_cnt = (unsigned long)handle;
  52
  53        BUG_ON(ref_cnt == 0);
  54
  55        ref_cnt--;
  56        handle = (handle_t *)ref_cnt;
  57
  58        current->journal_info = handle;
  59}
  60
  61/*
  62 * Wrappers for jbd2_journal_start/end.
  63 */
  64static int ext4_journal_check_start(struct super_block *sb)
  65{
  66        journal_t *journal;
  67
  68        might_sleep();
  69
  70        if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
  71                return -EIO;
  72
  73        if (sb_rdonly(sb))
  74                return -EROFS;
  75        WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  76        journal = EXT4_SB(sb)->s_journal;
  77        /*
  78         * Special case here: if the journal has aborted behind our
  79         * backs (eg. EIO in the commit thread), then we still need to
  80         * take the FS itself readonly cleanly.
  81         */
  82        if (journal && is_journal_aborted(journal)) {
  83                ext4_abort(sb, -journal->j_errno, "Detected aborted journal");
  84                return -EROFS;
  85        }
  86        return 0;
  87}
  88
  89handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  90                                  int type, int blocks, int rsv_blocks,
  91                                  int revoke_creds)
  92{
  93        journal_t *journal;
  94        int err;
  95
  96        trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
  97                                 _RET_IP_);
  98        err = ext4_journal_check_start(sb);
  99        if (err < 0)
 100                return ERR_PTR(err);
 101
 102        journal = EXT4_SB(sb)->s_journal;
 103        if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 104                return ext4_get_nojournal();
 105        return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
 106                                   GFP_NOFS, type, line);
 107}
 108
 109int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 110{
 111        struct super_block *sb;
 112        int err;
 113        int rc;
 114
 115        if (!ext4_handle_valid(handle)) {
 116                ext4_put_nojournal(handle);
 117                return 0;
 118        }
 119
 120        err = handle->h_err;
 121        if (!handle->h_transaction) {
 122                rc = jbd2_journal_stop(handle);
 123                return err ? err : rc;
 124        }
 125
 126        sb = handle->h_transaction->t_journal->j_private;
 127        rc = jbd2_journal_stop(handle);
 128
 129        if (!err)
 130                err = rc;
 131        if (err)
 132                __ext4_std_error(sb, where, line, err);
 133        return err;
 134}
 135
 136handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 137                                        int type)
 138{
 139        struct super_block *sb;
 140        int err;
 141
 142        if (!ext4_handle_valid(handle))
 143                return ext4_get_nojournal();
 144
 145        sb = handle->h_journal->j_private;
 146        trace_ext4_journal_start_reserved(sb,
 147                                jbd2_handle_buffer_credits(handle), _RET_IP_);
 148        err = ext4_journal_check_start(sb);
 149        if (err < 0) {
 150                jbd2_journal_free_reserved(handle);
 151                return ERR_PTR(err);
 152        }
 153
 154        err = jbd2_journal_start_reserved(handle, type, line);
 155        if (err < 0)
 156                return ERR_PTR(err);
 157        return handle;
 158}
 159
 160int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 161                                  int extend_cred, int revoke_cred)
 162{
 163        if (!ext4_handle_valid(handle))
 164                return 0;
 165        if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 166            handle->h_revoke_credits >= revoke_cred)
 167                return 0;
 168        extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 169        revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 170        return ext4_journal_extend(handle, extend_cred, revoke_cred);
 171}
 172
 173static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 174                                      const char *err_fn,
 175                                      struct buffer_head *bh,
 176                                      handle_t *handle, int err)
 177{
 178        char nbuf[16];
 179        const char *errstr = ext4_decode_error(NULL, err, nbuf);
 180
 181        BUG_ON(!ext4_handle_valid(handle));
 182
 183        if (bh)
 184                BUFFER_TRACE(bh, "abort");
 185
 186        if (!handle->h_err)
 187                handle->h_err = err;
 188
 189        if (is_handle_aborted(handle))
 190                return;
 191
 192        printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 193               caller, line, errstr, err_fn);
 194
 195        jbd2_journal_abort_handle(handle);
 196}
 197
 198static void ext4_check_bdev_write_error(struct super_block *sb)
 199{
 200        struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
 201        struct ext4_sb_info *sbi = EXT4_SB(sb);
 202        int err;
 203
 204        /*
 205         * If the block device has write error flag, it may have failed to
 206         * async write out metadata buffers in the background. In this case,
 207         * we could read old data from disk and write it out again, which
 208         * may lead to on-disk filesystem inconsistency.
 209         */
 210        if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
 211                spin_lock(&sbi->s_bdev_wb_lock);
 212                err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
 213                spin_unlock(&sbi->s_bdev_wb_lock);
 214                if (err)
 215                        ext4_error_err(sb, -err,
 216                                       "Error while async write back metadata");
 217        }
 218}
 219
 220int __ext4_journal_get_write_access(const char *where, unsigned int line,
 221                                    handle_t *handle, struct super_block *sb,
 222                                    struct buffer_head *bh,
 223                                    enum ext4_journal_trigger_type trigger_type)
 224{
 225        int err;
 226
 227        might_sleep();
 228
 229        if (bh->b_bdev->bd_super)
 230                ext4_check_bdev_write_error(bh->b_bdev->bd_super);
 231
 232        if (ext4_handle_valid(handle)) {
 233                err = jbd2_journal_get_write_access(handle, bh);
 234                if (err) {
 235                        ext4_journal_abort_handle(where, line, __func__, bh,
 236                                                  handle, err);
 237                        return err;
 238                }
 239        }
 240        if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 241                return 0;
 242        BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 243        jbd2_journal_set_triggers(bh,
 244                &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 245        return 0;
 246}
 247
 248/*
 249 * The ext4 forget function must perform a revoke if we are freeing data
 250 * which has been journaled.  Metadata (eg. indirect blocks) must be
 251 * revoked in all cases.
 252 *
 253 * "bh" may be NULL: a metadata block may have been freed from memory
 254 * but there may still be a record of it in the journal, and that record
 255 * still needs to be revoked.
 256 */
 257int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 258                  int is_metadata, struct inode *inode,
 259                  struct buffer_head *bh, ext4_fsblk_t blocknr)
 260{
 261        int err;
 262
 263        might_sleep();
 264
 265        trace_ext4_forget(inode, is_metadata, blocknr);
 266        BUFFER_TRACE(bh, "enter");
 267
 268        jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 269                  "data mode %x\n",
 270                  bh, is_metadata, inode->i_mode,
 271                  test_opt(inode->i_sb, DATA_FLAGS));
 272
 273        /* In the no journal case, we can just do a bforget and return */
 274        if (!ext4_handle_valid(handle)) {
 275                bforget(bh);
 276                return 0;
 277        }
 278
 279        /* Never use the revoke function if we are doing full data
 280         * journaling: there is no need to, and a V1 superblock won't
 281         * support it.  Otherwise, only skip the revoke on un-journaled
 282         * data blocks. */
 283
 284        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 285            (!is_metadata && !ext4_should_journal_data(inode))) {
 286                if (bh) {
 287                        BUFFER_TRACE(bh, "call jbd2_journal_forget");
 288                        err = jbd2_journal_forget(handle, bh);
 289                        if (err)
 290                                ext4_journal_abort_handle(where, line, __func__,
 291                                                          bh, handle, err);
 292                        return err;
 293                }
 294                return 0;
 295        }
 296
 297        /*
 298         * data!=journal && (is_metadata || should_journal_data(inode))
 299         */
 300        BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 301        err = jbd2_journal_revoke(handle, blocknr, bh);
 302        if (err) {
 303                ext4_journal_abort_handle(where, line, __func__,
 304                                          bh, handle, err);
 305                __ext4_error(inode->i_sb, where, line, true, -err, 0,
 306                             "error %d when attempting revoke", err);
 307        }
 308        BUFFER_TRACE(bh, "exit");
 309        return err;
 310}
 311
 312int __ext4_journal_get_create_access(const char *where, unsigned int line,
 313                                handle_t *handle, struct super_block *sb,
 314                                struct buffer_head *bh,
 315                                enum ext4_journal_trigger_type trigger_type)
 316{
 317        int err;
 318
 319        if (!ext4_handle_valid(handle))
 320                return 0;
 321
 322        err = jbd2_journal_get_create_access(handle, bh);
 323        if (err) {
 324                ext4_journal_abort_handle(where, line, __func__, bh, handle,
 325                                          err);
 326                return err;
 327        }
 328        if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 329                return 0;
 330        BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 331        jbd2_journal_set_triggers(bh,
 332                &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 333        return 0;
 334}
 335
 336int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 337                                 handle_t *handle, struct inode *inode,
 338                                 struct buffer_head *bh)
 339{
 340        int err = 0;
 341
 342        might_sleep();
 343
 344        set_buffer_meta(bh);
 345        set_buffer_prio(bh);
 346        set_buffer_uptodate(bh);
 347        if (ext4_handle_valid(handle)) {
 348                err = jbd2_journal_dirty_metadata(handle, bh);
 349                /* Errors can only happen due to aborted journal or a nasty bug */
 350                if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 351                        ext4_journal_abort_handle(where, line, __func__, bh,
 352                                                  handle, err);
 353                        if (inode == NULL) {
 354                                pr_err("EXT4: jbd2_journal_dirty_metadata "
 355                                       "failed: handle type %u started at "
 356                                       "line %u, credits %u/%u, errcode %d",
 357                                       handle->h_type,
 358                                       handle->h_line_no,
 359                                       handle->h_requested_credits,
 360                                       jbd2_handle_buffer_credits(handle), err);
 361                                return err;
 362                        }
 363                        ext4_error_inode(inode, where, line,
 364                                         bh->b_blocknr,
 365                                         "journal_dirty_metadata failed: "
 366                                         "handle type %u started at line %u, "
 367                                         "credits %u/%u, errcode %d",
 368                                         handle->h_type,
 369                                         handle->h_line_no,
 370                                         handle->h_requested_credits,
 371                                         jbd2_handle_buffer_credits(handle),
 372                                         err);
 373                }
 374        } else {
 375                if (inode)
 376                        mark_buffer_dirty_inode(bh, inode);
 377                else
 378                        mark_buffer_dirty(bh);
 379                if (inode && inode_needs_sync(inode)) {
 380                        sync_dirty_buffer(bh);
 381                        if (buffer_req(bh) && !buffer_uptodate(bh)) {
 382                                ext4_error_inode_err(inode, where, line,
 383                                                     bh->b_blocknr, EIO,
 384                                        "IO error syncing itable block");
 385                                err = -EIO;
 386                        }
 387                }
 388        }
 389        return err;
 390}
 391