3 files changed, 22 insertions, 18 deletions

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index b8a7b223b5b1..31922657e836 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -364,12 +364,11 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp,
 				  struct cb_process_state *cps)
 {
 	struct cb_devicenotifyargs *args = argp;
+	const struct pnfs_layoutdriver_type *ld = NULL;
 	uint32_t i;
 	__be32 res = 0;
-	struct nfs_client *clp = cps->clp;
-	struct nfs_server *server = NULL;
 
-	if (!clp) {
+	if (!cps->clp) {
 		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
 		goto out;
 	}
@@ -377,23 +376,15 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp,
 	for (i = 0; i < args->ndevs; i++) {
 		struct cb_devicenotifyitem *dev = &args->devs[i];
 
-		if (!server ||
-		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
-			rcu_read_lock();
-			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
-				if (server->pnfs_curr_ld &&
-				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
-					rcu_read_unlock();
-					goto found;
-				}
-			rcu_read_unlock();
-			continue;
+		if (!ld || ld->id != dev->cbd_layout_type) {
+			pnfs_put_layoutdriver(ld);
+			ld = pnfs_find_layoutdriver(dev->cbd_layout_type);
+			if (!ld)
+				continue;
 		}
-
-	found:
-		nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
+		nfs4_delete_deviceid(ld, cps->clp, &dev->cbd_dev_id);
 	}
-
+	pnfs_put_layoutdriver(ld);
 out:
 	kfree(args->devs);
 	return res;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 1b512df1003f..0471b6e0da16 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -92,6 +92,17 @@ find_pnfs_driver(u32 id)
 	return local;
 }
 
+const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
+{
+	return find_pnfs_driver(id);
+}
+
+void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
+{
+	if (ld)
+		module_put(ld->owner);
+}
+
 void
 unset_pnfs_layoutdriver(struct nfs_server *nfss)
 {
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 3d55edd6b25a..68339680bb7d 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -226,6 +226,8 @@ struct pnfs_devicelist {
 
 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
+extern const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id);
+extern void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld);
 
 /* nfs4proc.c */
 extern size_t max_response_pages(struct nfs_server *server);