fs/ext4/ext4_jbd2.c

   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
  10 int 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 */
  33 static 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 */
  49 static 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  */
  64 static 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
  89 handle_t *__ext4_journal_start_sb(struct inode *inode,
  90                                   struct super_block *sb, unsigned int line,
  91                                   int type, int blocks, int rsv_blocks,
  92                                   int revoke_creds)
  93 {
  94         journal_t *journal;
  95         int err;
  96         if (inode)
  97                 trace_ext4_journal_start_inode(inode, blocks, rsv_blocks,
  98                                         revoke_creds, type,
  99                                         _RET_IP_);
 100         else
 101                 trace_ext4_journal_start_sb(sb, blocks, rsv_blocks,
 102                                         revoke_creds, type,
 103                                         _RET_IP_);
 104         err = ext4_journal_check_start(sb);
 105         if (err < 0)
 106                 return ERR_PTR(err);
 107
 108         journal = EXT4_SB(sb)->s_journal;
 109         if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 110                 return ext4_get_nojournal();
 111         return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
 112                                    GFP_NOFS, type, line);
 113 }
 114
 115 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 116 {
 117         struct super_block *sb;
 118         int err;
 119         int rc;
 120
 121         if (!ext4_handle_valid(handle)) {
 122                 ext4_put_nojournal(handle);
 123                 return 0;
 124         }
 125
 126         err = handle->h_err;
 127         if (!handle->h_transaction) {
 128                 rc = jbd2_journal_stop(handle);
 129                 return err ? err : rc;
 130         }
 131
 132         sb = handle->h_transaction->t_journal->j_private;
 133         rc = jbd2_journal_stop(handle);
 134
 135         if (!err)
 136                 err = rc;
 137         if (err)
 138                 __ext4_std_error(sb, where, line, err);
 139         return err;
 140 }
 141
 142 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 143                                         int type)
 144 {
 145         struct super_block *sb;
 146         int err;
 147
 148         if (!ext4_handle_valid(handle))
 149                 return ext4_get_nojournal();
 150
 151         sb = handle->h_journal->j_private;
 152         trace_ext4_journal_start_reserved(sb,
 153                                 jbd2_handle_buffer_credits(handle), _RET_IP_);
 154         err = ext4_journal_check_start(sb);
 155         if (err < 0) {
 156                 jbd2_journal_free_reserved(handle);
 157                 return ERR_PTR(err);
 158         }
 159
 160         err = jbd2_journal_start_reserved(handle, type, line);
 161         if (err < 0)
 162                 return ERR_PTR(err);
 163         return handle;
 164 }
 165
 166 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 167                                   int extend_cred, int revoke_cred)
 168 {
 169         if (!ext4_handle_valid(handle))
 170                 return 0;
 171         if (is_handle_aborted(handle))
 172                 return -EROFS;
 173         if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 174             handle->h_revoke_credits >= revoke_cred)
 175                 return 0;
 176         extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 177         revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 178         return ext4_journal_extend(handle, extend_cred, revoke_cred);
 179 }
 180
 181 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 182                                       const char *err_fn,
 183                                       struct buffer_head *bh,
 184                                       handle_t *handle, int err)
 185 {
 186         char nbuf[16];
 187         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 188
 189         BUG_ON(!ext4_handle_valid(handle));
 190
 191         if (bh)
 192                 BUFFER_TRACE(bh, "abort");
 193
 194         if (!handle->h_err)
 195                 handle->h_err = err;
 196
 197         if (is_handle_aborted(handle))
 198                 return;
 199
 200         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 201                caller, line, errstr, err_fn);
 202
 203         jbd2_journal_abort_handle(handle);
 204 }
 205
 206 static void ext4_check_bdev_write_error(struct super_block *sb)
 207 {
 208         struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
 209         struct ext4_sb_info *sbi = EXT4_SB(sb);
 210         int err;
 211
 212         /*
 213          * If the block device has write error flag, it may have failed to
 214          * async write out metadata buffers in the background. In this case,
 215          * we could read old data from disk and write it out again, which
 216          * may lead to on-disk filesystem inconsistency.
 217          */
 218         if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
 219                 spin_lock(&sbi->s_bdev_wb_lock);
 220                 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
 221                 spin_unlock(&sbi->s_bdev_wb_lock);
 222                 if (err)
 223                         ext4_error_err(sb, -err,
 224                                        "Error while async write back metadata");
 225         }
 226 }
 227
 228 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 229                                     handle_t *handle, struct super_block *sb,
 230                                     struct buffer_head *bh,
 231                                     enum ext4_journal_trigger_type trigger_type)
 232 {
 233         int err;
 234
 235         might_sleep();
 236
 237         if (bh->b_bdev->bd_super)
 238                 ext4_check_bdev_write_error(bh->b_bdev->bd_super);
 239
 240         if (ext4_handle_valid(handle)) {
 241                 err = jbd2_journal_get_write_access(handle, bh);
 242                 if (err) {
 243                         ext4_journal_abort_handle(where, line, __func__, bh,
 244                                                   handle, err);
 245                         return err;
 246                 }
 247         }
 248         if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 249                 return 0;
 250         BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 251         jbd2_journal_set_triggers(bh,
 252                 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 253         return 0;
 254 }
 255
 256 /*
 257  * The ext4 forget function must perform a revoke if we are freeing data
 258  * which has been journaled.  Metadata (eg. indirect blocks) must be
 259  * revoked in all cases.
 260  *
 261  * "bh" may be NULL: a metadata block may have been freed from memory
 262  * but there may still be a record of it in the journal, and that record
 263  * still needs to be revoked.
 264  */
 265 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 266                   int is_metadata, struct inode *inode,
 267                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 268 {
 269         int err;
 270
 271         might_sleep();
 272
 273         trace_ext4_forget(inode, is_metadata, blocknr);
 274         BUFFER_TRACE(bh, "enter");
 275
 276         ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n",
 277                   bh, is_metadata, inode->i_mode,
 278                   test_opt(inode->i_sb, DATA_FLAGS));
 279
 280         /* In the no journal case, we can just do a bforget and return */
 281         if (!ext4_handle_valid(handle)) {
 282                 bforget(bh);
 283                 return 0;
 284         }
 285
 286         /* Never use the revoke function if we are doing full data
 287          * journaling: there is no need to, and a V1 superblock won't
 288          * support it.  Otherwise, only skip the revoke on un-journaled
 289          * data blocks. */
 290
 291         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 292             (!is_metadata && !ext4_should_journal_data(inode))) {
 293                 if (bh) {
 294                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 295                         err = jbd2_journal_forget(handle, bh);
 296                         if (err)
 297                                 ext4_journal_abort_handle(where, line, __func__,
 298                                                           bh, handle, err);
 299                         return err;
 300                 }
 301                 return 0;
 302         }
 303
 304         /*
 305          * data!=journal && (is_metadata || should_journal_data(inode))
 306          */
 307         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 308         err = jbd2_journal_revoke(handle, blocknr, bh);
 309         if (err) {
 310                 ext4_journal_abort_handle(where, line, __func__,
 311                                           bh, handle, err);
 312                 __ext4_error(inode->i_sb, where, line, true, -err, 0,
 313                              "error %d when attempting revoke", err);
 314         }
 315         BUFFER_TRACE(bh, "exit");
 316         return err;
 317 }
 318
 319 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 320                                 handle_t *handle, struct super_block *sb,
 321                                 struct buffer_head *bh,
 322                                 enum ext4_journal_trigger_type trigger_type)
 323 {
 324         int err;
 325
 326         if (!ext4_handle_valid(handle))
 327                 return 0;
 328
 329         err = jbd2_journal_get_create_access(handle, bh);
 330         if (err) {
 331                 ext4_journal_abort_handle(where, line, __func__, bh, handle,
 332                                           err);
 333                 return err;
 334         }
 335         if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 336                 return 0;
 337         BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 338         jbd2_journal_set_triggers(bh,
 339                 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 340         return 0;
 341 }
 342
 343 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 344                                  handle_t *handle, struct inode *inode,
 345                                  struct buffer_head *bh)
 346 {
 347         int err = 0;
 348
 349         might_sleep();
 350
 351         set_buffer_meta(bh);
 352         set_buffer_prio(bh);
 353         set_buffer_uptodate(bh);
 354         if (ext4_handle_valid(handle)) {
 355                 err = jbd2_journal_dirty_metadata(handle, bh);
 356                 /* Errors can only happen due to aborted journal or a nasty bug */
 357                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 358                         ext4_journal_abort_handle(where, line, __func__, bh,
 359                                                   handle, err);
 360                         if (inode == NULL) {
 361                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 362                                        "failed: handle type %u started at "
 363                                        "line %u, credits %u/%u, errcode %d",
 364                                        handle->h_type,
 365                                        handle->h_line_no,
 366                                        handle->h_requested_credits,
 367                                        jbd2_handle_buffer_credits(handle), err);
 368                                 return err;
 369                         }
 370                         ext4_error_inode(inode, where, line,
 371                                          bh->b_blocknr,
 372                                          "journal_dirty_metadata failed: "
 373                                          "handle type %u started at line %u, "
 374                                          "credits %u/%u, errcode %d",
 375                                          handle->h_type,
 376                                          handle->h_line_no,
 377                                          handle->h_requested_credits,
 378                                          jbd2_handle_buffer_credits(handle),
 379                                          err);
 380                 }
 381         } else {
 382                 if (inode)
 383                         mark_buffer_dirty_inode(bh, inode);
 384                 else
 385                         mark_buffer_dirty(bh);
 386                 if (inode && inode_needs_sync(inode)) {
 387                         sync_dirty_buffer(bh);
 388                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 389                                 ext4_error_inode_err(inode, where, line,
 390                                                      bh->b_blocknr, EIO,
 391                                         "IO error syncing itable block");
 392                                 err = -EIO;
 393                         }
 394                 }
 395         }
 396         return err;
 397 }