[2.6.27.stable][patch 6/6] NFS: Close page_mkwrite() races

[npiggin@suse.de]

[-- Attachment #1: 7fdf523067666b0eaff330f362401ee50ce187c4 --]
[-- Type: text/plain, Size: 954 bytes --]

    NFS: Close page_mkwrite() races
    
    Follow up to Nick Piggin's patches to ensure that nfs_vm_page_mkwrite
    returns with the page lock held, and sets the VM_FAULT_LOCKED flag.
    
    See http://bugzilla.kernel.org/show_bug.cgi?id=12913
    
    Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

---
 fs/nfs/file.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-2.6/fs/nfs/file.c
===================================================================
--- linux-2.6.orig/fs/nfs/file.c
+++ linux-2.6/fs/nfs/file.c
@@ -478,10 +478,10 @@ static int nfs_vm_page_mkwrite(struct vm
 
 	ret = nfs_updatepage(filp, page, 0, pagelen);
 out_unlock:
+	if (!ret)
+		return VM_FAULT_LOCKED;
 	unlock_page(page);
-	if (ret)
-		ret = VM_FAULT_SIGBUS;
-	return ret;
+	return VM_FAULT_SIGBUS;
 }
 
 static struct vm_operations_struct nfs_file_vm_ops = {