NFSv4/pnfs: pnfs_set_layout_stateid() should update the layout cred

If the cred assigned to the layout that we're updating differs from
the one used to retrieve the new layout segment, then we need to
update the layout plh_lc_cred field.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/callback_proc.c

@@ -280,7 +280,7 @@ static u32 initiate_file_draining(struct nfs_client *clp,
 		goto unlock;
 	}
 
-	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
+	pnfs_set_layout_stateid(lo, &args->cbl_stateid, NULL, true);
 	switch (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
 				&args->cbl_range,
 				be32_to_cpu(args->cbl_stateid.seqid))) {

fs/nfs/pnfs.c

@@ -903,10 +903,21 @@ pnfs_destroy_all_layouts(struct nfs_client *clp)
 	pnfs_destroy_layouts_byclid(clp, false);
 }
 
+static void
+pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
+{
+	const struct cred *old;
+
+	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
+		old = xchg(&lo->plh_lc_cred, get_cred(cred));
+		put_cred(old);
+	}
+}
+
 /* update lo->plh_stateid with new if is more recent */
 void
 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
-			bool update_barrier)
+			const struct cred *cred, bool update_barrier)
 {
 	u32 oldseq, newseq, new_barrier = 0;
 
@@ -914,6 +925,7 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 	newseq = be32_to_cpu(new->seqid);
 
 	if (!pnfs_layout_is_valid(lo)) {
+		pnfs_set_layout_cred(lo, cred);
 		nfs4_stateid_copy(&lo->plh_stateid, new);
 		lo->plh_barrier = newseq;
 		pnfs_clear_layoutreturn_info(lo);
@@ -1109,7 +1121,7 @@ void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
 
 		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
 		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
-		pnfs_set_layout_stateid(lo, stateid, true);
+		pnfs_set_layout_stateid(lo, stateid, NULL, true);
 	} else
 		pnfs_mark_layout_stateid_invalid(lo, &freeme);
 out_unlock:
@@ -2323,14 +2335,14 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 
 	if (!pnfs_layout_is_valid(lo)) {
 		/* We have a completely new layout */
-		pnfs_set_layout_stateid(lo, &res->stateid, true);
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
 	} else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
 		/* existing state ID, make sure the sequence number matches. */
 		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
 			dprintk("%s forget reply due to sequence\n", __func__);
 			goto out_forget;
 		}
-		pnfs_set_layout_stateid(lo, &res->stateid, false);
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
 	} else {
 		/*
 		 * We got an entirely new state ID.  Mark all segments for the

fs/nfs/pnfs.h

@@ -267,6 +267,7 @@ bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 			     const nfs4_stateid *new,
+			     const struct cred *cred,
 			     bool update_barrier);
 int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 				struct list_head *tmp_list,