nfsd: update mtime on truncate

This fixes a failure in xfstests generic/313 because nfs doesn't update
mtime on a truncate.  The protocol requires this to be done implicity
for a size changing setattr.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 89d1ae3bcff73a4a0823fa0599a552c4eeadc566..965cffd17a0c9fb91f7162e619782b95f25575b8 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -445,6 +445,16 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
                if (err)
                        goto out;
                size_change = 1;
+
+               /*
+                * RFC5661, Section 18.30.4:
+                *   Changing the size of a file with SETATTR indirectly
+                *   changes the time_modify and change attributes.
+                *
+                * (and similar for the older RFCs)
+                */
+               if (iap->ia_size != i_size_read(inode))
+                       iap->ia_valid |= ATTR_MTIME;
        }
 
        iap->ia_valid |= ATTR_CTIME;