NFSv4: Warn once about servers that incorrectly apply open mode to setattr

Debugging aid to help identify servers that incorrectly apply open mode
checks to setattr requests that are not changing the file size.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 982b4527551d136fae8db1e6ee06e9ef1ccb8526..9da4bd55eb3019a964f8a7a7b0f89e2bab4c8b42 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2184,6 +2184,13 @@ static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
                err = _nfs4_do_setattr(inode, cred, fattr, sattr, state);
                switch (err) {
                case -NFS4ERR_OPENMODE:
+                       if (!(sattr->ia_valid & ATTR_SIZE)) {
+                               pr_warn_once("NFSv4: server %s is incorrectly "
+                                               "applying open mode checks to "
+                                               "a SETATTR that is not "
+                                               "changing file size.\n",
+                                               server->nfs_client->cl_hostname);
+                       }
                        if (state && !(state->state & FMODE_WRITE)) {
                                err = -EBADF;
                                if (sattr->ia_valid & ATTR_OPEN)