NFS41: do not update isize if inode needs layoutcommit

commit 0f66b5984df2fe1617c05900a39a7ef493ca9de9 upstream.

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>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 57bb31ad7a5ec1c46a5533db711ee6d7d423f68e..4e0ddb3ac41a30966d91582581fa2a8e1262680a 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;
                        }