From 4db72b40fdbc706f8957e9773ae73b1574b8c694 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 28 Jan 2014 13:47:46 -0500 Subject: nfs: add memory barriers around NFS_INO_INVALID_DATA and NFS_INO_INVALIDATING If the setting of NFS_INO_INVALIDATING gets reordered to before the clearing of NFS_INO_INVALID_DATA, then another task may hit a race window where both appear to be clear, even though the inode's pages are still in need of invalidation. Fix this by adding the appropriate memory barriers. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 5511a4247190..9a3b6a4cd6b9 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -915,6 +915,7 @@ static bool nfs_write_pageuptodate(struct page *page, struct inode *inode) goto out; if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE)) return false; + smp_rmb(); if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags)) return false; out: -- cgit v1.2.2