nfs: if we have no valid attrs, then don't declare the attribute cache valid

If we pass in an empty nfs_fattr struct to nfs_update_inode, it will
(correctly) not update any of the attributes, but it then clears the
NFS_INO_INVALID_ATTR flag, which indicates that the attributes are
up to date. Don't clear the flag if the fattr struct has no valid
attrs to apply.

Reviewed-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index eda3da3f3a7b..31b0a52223a7 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1827,7 +1827,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                 if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0)
                         nfsi->attr_gencount = fattr->gencount;
         }
-        invalid &= ~NFS_INO_INVALID_ATTR;
+
+        /* Don't declare attrcache up to date if there were no attrs! */
+        if (fattr->valid != 0)
+                invalid &= ~NFS_INO_INVALID_ATTR;
+
         /* Don't invalidate the data if we were to blame */
         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
                                 || S_ISLNK(inode->i_mode)))