aboutsummaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>2016-03-09 23:47:25 -0500
committerSasha Levin <sasha.levin@oracle.com>2016-04-18 08:49:27 -0400
commit44d77496ba729e62328930e9f949adb32b4c3af7 (patch)
treedb999b89757be8887afafe6c8033ae86c3b2763f /fs
parentb90a66cdab6fc988e973c7c863f475c46e465847 (diff)
downloadlinux-linaro-stable-44d77496ba729e62328930e9f949adb32b4c3af7.tar.gz
jbd2: fix FS corruption possibility in jbd2_journal_destroy() on umount path
[ Upstream commit c0a2ad9b50dd80eeccd73d9ff962234590d5ec93 ] 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>
Diffstat (limited to 'fs')
-rw-r--r--fs/jbd2/journal.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 07e87ec45709..985e95b9b4ef 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1423,11 +1423,12 @@ out:
/**
* jbd2_mark_journal_empty() - Mark on disk journal as empty.
* @journal: The journal to update.
+ * @write_op: With which operation should we write the journal sb
*
* Update a journal's dynamic superblock fields to show that journal is empty.
* Write updated superblock to disk waiting for IO to complete.
*/
-static void jbd2_mark_journal_empty(journal_t *journal)
+static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
{
journal_superblock_t *sb = journal->j_superblock;
@@ -1445,7 +1446,7 @@ static void jbd2_mark_journal_empty(journal_t *journal)
sb->s_start = cpu_to_be32(0);
read_unlock(&journal->j_state_lock);
- jbd2_write_superblock(journal, WRITE_FUA);
+ jbd2_write_superblock(journal, write_op);
/* Log is no longer empty */
write_lock(&journal->j_state_lock);
@@ -1730,7 +1731,13 @@ int jbd2_journal_destroy(journal_t *journal)
if (journal->j_sb_buffer) {
if (!is_journal_aborted(journal)) {
mutex_lock(&journal->j_checkpoint_mutex);
- jbd2_mark_journal_empty(journal);
+
+ write_lock(&journal->j_state_lock);
+ journal->j_tail_sequence =
+ ++journal->j_transaction_sequence;
+ write_unlock(&journal->j_state_lock);
+
+ jbd2_mark_journal_empty(journal, WRITE_FLUSH_FUA);
mutex_unlock(&journal->j_checkpoint_mutex);
} else
err = -EIO;
@@ -1990,7 +1997,7 @@ int jbd2_journal_flush(journal_t *journal)
* the magic code for a fully-recovered superblock. Any future
* commits of data to the journal will restore the current
* s_start value. */
- jbd2_mark_journal_empty(journal);
+ jbd2_mark_journal_empty(journal, WRITE_FUA);
mutex_unlock(&journal->j_checkpoint_mutex);
write_lock(&journal->j_state_lock);
J_ASSERT(!journal->j_running_transaction);
@@ -2036,7 +2043,7 @@ int jbd2_journal_wipe(journal_t *journal, int write)
if (write) {
/* Lock to make assertions happy... */
mutex_lock(&journal->j_checkpoint_mutex);
- jbd2_mark_journal_empty(journal);
+ jbd2_mark_journal_empty(journal, WRITE_FUA);
mutex_unlock(&journal->j_checkpoint_mutex);
}