| From d9e80b7de91db05c1c4d2e5ebbfd70b3b3ba0e0f Mon Sep 17 00:00:00 2001 |
| From: Al Viro <viro@ZenIV.linux.org.uk> |
| Date: Thu, 29 Apr 2010 03:10:43 +0100 |
| Subject: nfs d_revalidate() is too trigger-happy with d_drop() |
| |
| From: Al Viro <viro@ZenIV.linux.org.uk> |
| |
| commit d9e80b7de91db05c1c4d2e5ebbfd70b3b3ba0e0f upstream. |
| |
| If dentry found stale happens to be a root of disconnected tree, we |
| can't d_drop() it; its d_hash is actually part of s_anon and d_drop() |
| would simply hide it from shrink_dcache_for_umount(), leading to |
| all sorts of fun, including busy inodes on umount and oopsen after |
| that. |
| |
| Bug had been there since at least 2006 (commit c636eb already has it), |
| so it's definitely -stable fodder. |
| |
| Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| fs/nfs/dir.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/fs/nfs/dir.c |
| +++ b/fs/nfs/dir.c |
| @@ -826,6 +826,8 @@ out_zap_parent: |
| /* If we have submounts, don't unhash ! */ |
| if (have_submounts(dentry)) |
| goto out_valid; |
| + if (dentry->d_flags & DCACHE_DISCONNECTED) |
| + goto out_valid; |
| shrink_dcache_parent(dentry); |
| } |
| d_drop(dentry); |
