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| author | Jan Kara <jack@suse.cz> | 2007-07-15 23:41:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 09:05:48 -0700 |
| commit | 32c3773011a9b3522bd4abadc7fad8c27417119f (patch) | |
| tree | c3a07aecbef3cdb66a4126e2822c69166aee1c97 | |
| parent | 030703e49d4966bd348660e0fdc2699507efb82b (diff) | |
| download | linux-32c3773011a9b3522bd4abadc7fad8c27417119f.tar.gz linux-32c3773011a9b3522bd4abadc7fad8c27417119f.tar.bz2 linux-32c3773011a9b3522bd4abadc7fad8c27417119f.zip | |
ext4: fix deadlock in ext4_remount() and orphan list handling
ext4_orphan_add() and ext4_orphan_del() functions lock sb->s_lock with a
transaction started with ext4_mark_recovery_complete() waits for a transaction
holding sb->s_lock, thus leading to a possible deadlock. At the moment we
call ext4_mark_recovery_complete() from ext4_remount() we have done all the
work needed for remounting and thus we are safe to drop sb->s_lock before we
wait for transactions to commit. Note that at this moment we are still
guarded by s_umount lock against other remounts/umounts.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Sandeen <sandeen@sandeen.net>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ext4/super.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 6768c5aa3fee..bd9aff9701c0 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2222,12 +2222,14 @@ static void ext4_mark_recovery_complete(struct super_block * sb, jbd2_journal_lock_updates(journal); jbd2_journal_flush(journal); + lock_super(sb); if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) && sb->s_flags & MS_RDONLY) { EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER); sb->s_dirt = 0; ext4_commit_super(sb, es, 1); } + unlock_super(sb); jbd2_journal_unlock_updates(journal); } @@ -2416,7 +2418,13 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data) (sbi->s_mount_state & EXT4_VALID_FS)) es->s_state = cpu_to_le16(sbi->s_mount_state); + /* + * We have to unlock super so that we can wait for + * transactions. + */ + unlock_super(sb); ext4_mark_recovery_complete(sb, es); + lock_super(sb); } else { __le32 ret; if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb, |