jbd2: fix FS corruption possibility in jbd2_journal_destroy() on umount path
[ Upstream commit c0a2ad9b50
]
On umount path, jbd2_journal_destroy() writes latest transaction ID
(->j_tail_sequence) to be used at next mount.
The bug is that ->j_tail_sequence is not holding latest transaction ID
in some cases. So, at next mount, there is chance to conflict with
remaining (not overwritten yet) transactions.
mount (id=10)
write transaction (id=11)
write transaction (id=12)
umount (id=10) <= the bug doesn't write latest ID
mount (id=10)
write transaction (id=11)
crash
mount
[recovery process]
transaction (id=11)
transaction (id=12) <= valid transaction ID, but old commit
must not replay
Like above, this bug become the cause of recovery failure, or FS
corruption.
So why ->j_tail_sequence doesn't point latest ID?
Because if checkpoint transactions was reclaimed by memory pressure
(i.e. bdev_try_to_free_page()), then ->j_tail_sequence is not updated.
(And another case is, __jbd2_journal_clean_checkpoint_list() is called
with empty transaction.)
So in above cases, ->j_tail_sequence is not pointing latest
transaction ID at umount path. Plus, REQ_FLUSH for checkpoint is not
done too.
So, to fix this problem with minimum changes, this patch updates
->j_tail_sequence, and issue REQ_FLUSH. (With more complex changes,
some optimizations would be possible to avoid unnecessary REQ_FLUSH
for example though.)
BTW,
journal->j_tail_sequence =
++journal->j_transaction_sequence;
Increment of ->j_transaction_sequence seems to be unnecessary, but
ext3 does this.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
wifi-calibration
parent
6908e712e3
commit
3b6a70271a
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@ -1423,11 +1423,12 @@ out:
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/**
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* jbd2_mark_journal_empty() - Mark on disk journal as empty.
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* @journal: The journal to update.
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* @write_op: With which operation should we write the journal sb
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*
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* Update a journal's dynamic superblock fields to show that journal is empty.
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* Write updated superblock to disk waiting for IO to complete.
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*/
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static void jbd2_mark_journal_empty(journal_t *journal)
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static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
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{
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journal_superblock_t *sb = journal->j_superblock;
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@ -1445,7 +1446,7 @@ static void jbd2_mark_journal_empty(journal_t *journal)
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sb->s_start = cpu_to_be32(0);
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read_unlock(&journal->j_state_lock);
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jbd2_write_superblock(journal, WRITE_FUA);
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jbd2_write_superblock(journal, write_op);
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/* Log is no longer empty */
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write_lock(&journal->j_state_lock);
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@ -1730,7 +1731,13 @@ int jbd2_journal_destroy(journal_t *journal)
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if (journal->j_sb_buffer) {
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if (!is_journal_aborted(journal)) {
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mutex_lock(&journal->j_checkpoint_mutex);
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jbd2_mark_journal_empty(journal);
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write_lock(&journal->j_state_lock);
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journal->j_tail_sequence =
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++journal->j_transaction_sequence;
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write_unlock(&journal->j_state_lock);
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jbd2_mark_journal_empty(journal, WRITE_FLUSH_FUA);
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mutex_unlock(&journal->j_checkpoint_mutex);
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} else
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err = -EIO;
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@ -1989,7 +1996,7 @@ int jbd2_journal_flush(journal_t *journal)
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* the magic code for a fully-recovered superblock. Any future
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* commits of data to the journal will restore the current
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* s_start value. */
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jbd2_mark_journal_empty(journal);
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jbd2_mark_journal_empty(journal, WRITE_FUA);
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mutex_unlock(&journal->j_checkpoint_mutex);
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write_lock(&journal->j_state_lock);
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J_ASSERT(!journal->j_running_transaction);
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@ -2035,7 +2042,7 @@ int jbd2_journal_wipe(journal_t *journal, int write)
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if (write) {
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/* Lock to make assertions happy... */
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mutex_lock(&journal->j_checkpoint_mutex);
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jbd2_mark_journal_empty(journal);
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jbd2_mark_journal_empty(journal, WRITE_FUA);
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mutex_unlock(&journal->j_checkpoint_mutex);
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}
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