From: Ryusuke Konishi Date: Sun, 27 Sep 2009 16:46:11 +0000 (+0900) Subject: nilfs2: fix missing zero-fill initialization of btree node cache X-Git-Tag: MMI-PSA29.97-13-9~26263^2~1 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1f28fcd925b2b3157411bbd08f0024b55b70d8dd;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git nilfs2: fix missing zero-fill initialization of btree node cache This will fix file system corruption which infrequently happens after mount. The problem was reported from users with the title "[NILFS users] Fail to mount NILFS." (Message-ID: <200908211918.34720.yuri@itinteg.net>), and so forth. I've also experienced the corruption multiple times on kernel 2.6.30 and 2.6.31. The problem turned out to be caused due to discordance between mapping->nrpages of a btree node cache and the actual number of pages hung on the cache; if the mapping->nrpages becomes zero even as it has pages, truncate_inode_pages() returns without doing anything. Usually this is harmless except it may cause page leak, but garbage collection fairly infrequently sees a stale page remained in the btree node cache of DAT (i.e. disk address translation file of nilfs), and induces the corruption. I identified a missing initialization in btree node caches was the root cause. This corrects the bug. I've tested this for kernel 2.6.30 and 2.6.31. Reported-by: Yuri Chislov Signed-off-by: Ryusuke Konishi Cc: stable --- diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 6a2711f4c321..5941958f1e47 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -36,6 +36,7 @@ void nilfs_btnode_cache_init_once(struct address_space *btnc) { + memset(btnc, 0, sizeof(*btnc)); INIT_RADIX_TREE(&btnc->page_tree, GFP_ATOMIC); spin_lock_init(&btnc->tree_lock); INIT_LIST_HEAD(&btnc->private_list);