Commit 757c4f62 authored Aug 07, 2013 by Jeff Layton Committed by Steve French Aug 07, 2013

cifs: don't instantiate new dentries in readdir for inodes that need to be revalidated immediately



David reported that commit c2b93e06 (cifs: only set ops for inodes in
I_NEW state) caused a regression with mfsymlinks. Prior to that patch,
if a mfsymlink dentry was instantiated at readdir time, the inode would
get a new set of ops when it was revalidated. After that patch, this
did not occur.

This patch addresses this by simply skipping instantiating dentries in
the readdir codepath when we know that they will need to be immediately
revalidated. The next attempt to use that dentry will cause a new lookup
to occur (which is basically what we want to happen anyway).

Cc: <stable@vger.kernel.org>
Cc: "Stefan (metze) Metzmacher" <metze@samba.org>
Cc: Sachin Prabhu <sprabhu@redhat.com>
Reported-and-Tested-by: David McBride <dwm37@cam.ac.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

parent 66ffd113

fs/cifs/readdir.c

+8 −0

Original line number	Original line	Diff line number	Diff line
	@@ -111,6 +111,14 @@ cifs_prime_dcache(struct dentry parent, struct qstr name,
	return;		return;
	}		}

			/*
			* If we know that the inode will need to be revalidated immediately,
			* then don't create a new dentry for it. We'll end up doing an on
			* the wire call either way and this spares us an invalidation.
			*/
			if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
			return;

	dentry = d_alloc(parent, name);		dentry = d_alloc(parent, name);
	if (!dentry)		if (!dentry)
	return;		return;

Admin message