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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-04-14 00:10:35 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-09-14 07:18:01 +0200 |
| commit | a412f9efdd6424bf4bf28c8e8c92060b5e975482 (patch) | |
| tree | b290d38a85c4b675af426dbd8593768bc5339fa1 /fs/reiserfs/journal.c | |
| parent | reiserfs: kill-the-BKL (diff) | |
| download | linux-a412f9efdd6424bf4bf28c8e8c92060b5e975482.tar.xz linux-a412f9efdd6424bf4bf28c8e8c92060b5e975482.zip | |
reiserfs, kill-the-BKL: fix unsafe j_flush_mutex lock
Impact: fix a deadlock
The j_flush_mutex is acquired safely in journal.c:
if we can't take it, we free the reiserfs per superblock lock
and wait a bit.
But we have a remaining place in kupdate_transactions() where
j_flush_mutex is still acquired traditionnaly. Thus the following
scenario (warned by lockdep) can happen:
A B
mutex_lock(&write_lock) mutex_lock(&write_lock)
mutex_lock(&j_flush_mutex) mutex_lock(&j_flush_mutex) //block
mutex_unlock(&write_lock)
sleep...
mutex_lock(&write_lock) //deadlock
Fix this by using reiserfs_mutex_lock_safe() in kupdate_transactions().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Jeff Mahoney <jeffm@suse.com>
LKML-Reference: <1239660635-12940-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'fs/reiserfs/journal.c')
| -rw-r--r-- | fs/reiserfs/journal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index 438c71f0bc91..0ba98ca367c7 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -1826,7 +1826,7 @@ static int kupdate_transactions(struct super_block *s, struct reiserfs_journal *journal = SB_JOURNAL(s); chunk.nr = 0; - mutex_lock(&journal->j_flush_mutex); + reiserfs_mutex_lock_safe(&journal->j_flush_mutex, s); if (!journal_list_still_alive(s, orig_trans_id)) { goto done; } |