From patchwork Fri Jun 3 13:49:58 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [07/10] UBIFS: fix clean znode counter corruption in error cases Date: Fri, 03 Jun 2011 03:49:58 -0000 From: Artem Bityutskiy X-Patchwork-Id: 98576 Message-Id: <1307109001-19761-8-git-send-email-dedekind1@gmail.com> To: linux-mtd@lists.infradead.org From: Artem Bityutskiy UBIFS maintains per-filesystem and global clean znode counters ('c->clean_zn_cnt' and 'ubifs_clean_zn_cnt'). It is important to maintain correct values there since the shrinker relies on 'ubifs_clean_zn_cnt'. However, in case of failures during commit the counters were corrupted. E.g., if a failure happens in the middle of 'write_index()', then some nodes in the commit list ('c->cnext') are marked as clean, and some are marked as dirty. And the 'ubifs_destroy_tnc_subtree()' frees does not retrun correct count, and we end up with non-zero 'c->clean_zn_cnt' when unmounting. This means that if we have 2 file-sytem and one of them fails, and we unmount it, 'ubifs_clean_zn_cnt' stays incorrect and confuses the shrinker. Signed-off-by: Artem Bityutskiy --- fs/ubifs/tnc.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 8119b1f..91b4213 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -2876,12 +2876,13 @@ static void tnc_destroy_cnext(struct ubifs_info *c) */ void ubifs_tnc_close(struct ubifs_info *c) { - long clean_freed; - tnc_destroy_cnext(c); if (c->zroot.znode) { - clean_freed = ubifs_destroy_tnc_subtree(c->zroot.znode); - atomic_long_sub(clean_freed, &ubifs_clean_zn_cnt); + long n; + + ubifs_destroy_tnc_subtree(c->zroot.znode); + n = atomic_long_read(&c->clean_zn_cnt); + atomic_long_sub(n, &ubifs_clean_zn_cnt); } kfree(c->gap_lebs); kfree(c->ilebs);