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| author | zhangyi (F) <yi.zhang@huawei.com> | 2020-06-09 15:35:40 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-06-12 14:51:41 -0400 |
| commit | 7b97d868b7ab2448859668de9222b8af43f76e78 (patch) | |
| tree | 976e49fc89eb8cd37e653d27192d9cb5289ed884 /fs/jbd2/journal.c | |
| parent | 88ee9d571b6d8ed345f877e05f685814412e359b (diff) | |
| download | linux-7b97d868b7ab2448859668de9222b8af43f76e78.tar.bz2 | |
ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
In the ext4 filesystem with errors=panic, if one process is recording
errno in the superblock when invoking jbd2_journal_abort() due to some
error cases, it could be raced by another __ext4_abort() which is
setting the SB_RDONLY flag but missing panic because errno has not been
recorded.
jbd2_journal_commit_transaction()
jbd2_journal_abort()
journal->j_flags |= JBD2_ABORT;
jbd2_journal_update_sb_errno()
| ext4_journal_check_start()
| __ext4_abort()
| sb->s_flags |= SB_RDONLY;
| if (!JBD2_REC_ERR)
| return;
journal->j_flags |= JBD2_REC_ERR;
Finally, it will no longer trigger panic because the filesystem has
already been set read-only. Fix this by introduce j_abort_mutex to make
sure journal abort is completed before panic, and remove JBD2_REC_ERR
flag.
Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200609073540.3810702-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index a49d0e670ddf..e4944436e733 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1140,6 +1140,7 @@ static journal_t *journal_init_common(struct block_device *bdev, init_waitqueue_head(&journal->j_wait_commit); init_waitqueue_head(&journal->j_wait_updates); init_waitqueue_head(&journal->j_wait_reserved); + mutex_init(&journal->j_abort_mutex); mutex_init(&journal->j_barrier); mutex_init(&journal->j_checkpoint_mutex); spin_lock_init(&journal->j_revoke_lock); @@ -1402,7 +1403,8 @@ static int jbd2_write_superblock(journal_t *journal, int write_flags) printk(KERN_ERR "JBD2: Error %d detected when updating " "journal superblock for %s.\n", ret, journal->j_devname); - jbd2_journal_abort(journal, ret); + if (!is_journal_aborted(journal)) + jbd2_journal_abort(journal, ret); } return ret; @@ -2154,6 +2156,13 @@ void jbd2_journal_abort(journal_t *journal, int errno) transaction_t *transaction; /* + * Lock the aborting procedure until everything is done, this avoid + * races between filesystem's error handling flow (e.g. ext4_abort()), + * ensure panic after the error info is written into journal's + * superblock. + */ + mutex_lock(&journal->j_abort_mutex); + /* * ESHUTDOWN always takes precedence because a file system check * caused by any other journal abort error is not required after * a shutdown triggered. @@ -2167,6 +2176,7 @@ void jbd2_journal_abort(journal_t *journal, int errno) journal->j_errno = errno; jbd2_journal_update_sb_errno(journal); } + mutex_unlock(&journal->j_abort_mutex); return; } @@ -2188,10 +2198,7 @@ void jbd2_journal_abort(journal_t *journal, int errno) * layer could realise that a filesystem check is needed. */ jbd2_journal_update_sb_errno(journal); - - write_lock(&journal->j_state_lock); - journal->j_flags |= JBD2_REC_ERR; - write_unlock(&journal->j_state_lock); + mutex_unlock(&journal->j_abort_mutex); } /** |