[patch 35/51] NFS: Close page_mkwrite() races

Greg KH
2009-05-14T22:55:08Z

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2.6.29-stable review patch. If anyone has any objections, please let us know.

------------------

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit 7fdf523067666b0eaff330f362401ee50ce187c4 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

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

--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -481,10 +481,10 @@ 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 = {