tree 0ca15a8b9250337c810e18756422c17b5f651b08
parent 1d16b0f2f3edf05f12a9e3960588e0d4854157bb
author Al Viro <viro@ZenIV.linux.org.uk> 1272507043 +0100
committer Linus Torvalds <torvalds@linux-foundation.org> 1272512403 -0700

nfs d_revalidate() is too trigger-happy with d_drop()

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>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>