NFS41: do not update isize if inode needs layoutcommit

nfs_update_inode will update isize if there is no queued pages. For pNFS,
layoutcommit is supposed to change file size on server, the same effect as queued
pages. nfs_update_inode may be called when dirty pages are written back (nfsi->npages==0)
but layoutcommit is not sent, and it will change client file size according to server
file size. Then client ends up losing what it just writes back in pNFS path.
So we should skip updating client file size if file needs layoutcommit.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Cc: stable@kernel.org   [2.6.39]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 144f2a3c718575cf0b3448118cd881600339e5b6..3f1eb8180373dd7dd55e83cfbf201a87e009230f 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1294,7 +1294,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                if (new_isize != cur_isize) {
                        /* Do we perhaps have any outstanding writes, or has
                         * the file grown beyond our last write? */
-                       if (nfsi->npages == 0 || new_isize > cur_isize) {
+                       if ((nfsi->npages == 0 && !test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) ||
+                            new_isize > cur_isize) {
                                i_size_write(inode, new_isize);
                                invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
                        }