From: Jan Kara Date: Mon, 16 Jul 2007 06:41:08 +0000 (-0700) Subject: ext3: fix deadlock in ext3_remount() and orphan list handling X-Git-Tag: v2.6.23-rc1~859 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=030703e49d4966bd348660e0fdc2699507efb82b;p=linux-2.6 ext3: fix deadlock in ext3_remount() and orphan list handling ext3_orphan_add() and ext3_orphan_del() functions lock sb->s_lock with a transaction started with ext3_mark_recovery_complete() waits for a transaction holding sb->s_lock, thus leading to a possible deadlock. At the moment we call ext3_mark_recovery_complete() from ext3_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 Cc: Eric Sandeen Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 6ee4a95f49..69a59d4580 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -2147,12 +2147,14 @@ static void ext3_mark_recovery_complete(struct super_block * sb, journal_lock_updates(journal); journal_flush(journal); + lock_super(sb); if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER) && sb->s_flags & MS_RDONLY) { EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER); sb->s_dirt = 0; ext3_commit_super(sb, es, 1); } + unlock_super(sb); journal_unlock_updates(journal); } @@ -2341,7 +2343,13 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data) (sbi->s_mount_state & EXT3_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); ext3_mark_recovery_complete(sb, es); + lock_super(sb); } else { __le32 ret; if ((ret = EXT3_HAS_RO_COMPAT_FEATURE(sb,