Commit d9e80b7d authored Apr 29, 2010 by Al Viro Committed by Linus Torvalds Apr 28, 2010

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>

parent 1d16b0f2

fs/nfs/dir.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -837,6 +837,8 @@ 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);

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