From: Zhang Yi yi.zhang@huawei.com
mainline inclusion from mainline-v5.14-rc1 commit fcf37549ae19e904bc6a5eadf5c25eca36100c5e category: bugfix bugzilla: 50788 https://gitee.com/openeuler/kernel/issues/I4DDEL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
---------------------------
Although we merged c044f3d8360 ("jbd2: abort journal if free a async write error metadata buffer"), there is a race between jbd2_journal_try_to_free_buffers() and jbd2_journal_destroy(), so the jbd2_log_do_checkpoint() may still fail to detect the buffer write io error flag which may lead to filesystem inconsistency.
jbd2_journal_try_to_free_buffers() ext4_put_super() jbd2_journal_destroy() __jbd2_journal_remove_checkpoint() detect buffer write error jbd2_log_do_checkpoint() jbd2_cleanup_journal_tail() <--- lead to inconsistency jbd2_journal_abort()
Fix this issue by introducing a new atomic flag which only have one JBD2_CHECKPOINT_IO_ERROR bit now, and set it in __jbd2_journal_remove_checkpoint() when freeing a checkpoint buffer which has write_io_error flag. Then jbd2_journal_destroy() will detect this mark and abort the journal to prevent updating log tail.
Signed-off-by: Zhang Yi yi.zhang@huawei.com Reviewed-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20210610112440.3438139-3-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Reviewed-by: Yang Erkun yangerkun@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- fs/jbd2/checkpoint.c | 12 ++++++++++++ fs/jbd2/journal.c | 14 ++++++++++++++ include/linux/jbd2.h | 11 +++++++++++ 3 files changed, 37 insertions(+)
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 96a5713b466a..172a5ad64071 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -564,6 +564,7 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) struct transaction_chp_stats_s *stats; transaction_t *transaction; journal_t *journal; + struct buffer_head *bh = jh2bh(jh);
JBUFFER_TRACE(jh, "entry");
@@ -575,6 +576,17 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) journal = transaction->t_journal;
JBUFFER_TRACE(jh, "removing from transaction"); + + /* + * If we have failed to write the buffer out to disk, the filesystem + * may become inconsistent. We cannot abort the journal here since + * we hold j_list_lock and we have to be careful about races with + * jbd2_journal_destroy(). So mark the writeback IO error in the + * journal here and we abort the journal later from a better context. + */ + if (buffer_write_io_error(bh)) + set_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags); + __buffer_unlink(jh); jh->b_cp_transaction = NULL; jbd2_journal_put_journal_head(jh); diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 188f79d76988..1a11b06b9de9 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1618,6 +1618,10 @@ int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
if (is_journal_aborted(journal)) return -EIO; + if (test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags)) { + jbd2_journal_abort(journal, -EIO); + return -EIO; + }
BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", @@ -1997,6 +2001,16 @@ int jbd2_journal_destroy(journal_t *journal) J_ASSERT(journal->j_checkpoint_transactions == NULL); spin_unlock(&journal->j_list_lock);
+ /* + * OK, all checkpoint transactions have been checked, now check the + * write out io error flag and abort the journal if some buffer failed + * to write back to the original location, otherwise the filesystem + * may become inconsistent. + */ + if (!is_journal_aborted(journal) && + test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags)) + jbd2_journal_abort(journal, -EIO); + if (journal->j_sb_buffer) { if (!is_journal_aborted(journal)) { mutex_lock_io(&journal->j_checkpoint_mutex); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 578ff196b3ce..b737024b4b9c 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -771,6 +771,11 @@ struct journal_s */ unsigned long j_flags;
+ /** + * @j_atomic_flags: Atomic journaling state flags. + */ + unsigned long j_atomic_flags; + /** * @j_errno: * @@ -1361,6 +1366,12 @@ JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT) #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */ #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
+/* + * Journal atomic flag definitions + */ +#define JBD2_CHECKPOINT_IO_ERROR 0x001 /* Detect io error while writing + * buffer back to disk */ + /* * Function declarations for the journaling transaction and buffer * management