nfsd: move name lookup out of nfsd4_list_rec_dir()

nfsd4_list_rec_dir() is called with two different callbacks.
One of the callbacks uses vfs_rmdir() to remove the directory.
The other doesn't use the dentry at all, just the name.

As only one callback needs the dentry, this patch moves the lookup into
that callback.  This prepares of changes to how directory operations
are locked.

Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: NeilBrown

fs/nfsd/nfs4recover.c

@@ -237,7 +237,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
 	nfs4_reset_creds(original_cred);
 }
 
-typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
+typedef int (recdir_func)(struct dentry *, char *, struct nfsd_net *);
 
 struct name_list {
 	char name[HEXDIR_LEN];
@@ -291,24 +291,14 @@ nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 	}
 
 	status = iterate_dir(nn->rec_file, &ctx.ctx);
-	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 
 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
-		if (!status) {
-			struct dentry *dentry;
-			dentry = lookup_one(&nop_mnt_idmap,
-					    &QSTR(entry->name), dir);
-			if (IS_ERR(dentry)) {
-				status = PTR_ERR(dentry);
-				break;
-			}
-			status = f(dir, dentry, nn);
-			dput(dentry);
-		}
+		if (!status)
+			status = f(dir, entry->name, nn);
+
 		list_del(&entry->list);
 		kfree(entry);
 	}
-	inode_unlock(d_inode(dir));
 	nfs4_reset_creds(original_cred);
 
 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
@@ -406,18 +396,19 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
 }
 
 static int
-purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
+purge_old(struct dentry *parent, char *cname, struct nfsd_net *nn)
 {
 	int status;
+	struct dentry *child;
 	struct xdr_netobj name;
 
-	if (child->d_name.len != HEXDIR_LEN - 1) {
-		printk("%s: illegal name %pd in recovery directory\n",
-				__func__, child);
+	if (strlen(cname) != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %s in recovery directory\n",
+				__func__, cname);
 		/* Keep trying; maybe the others are OK: */
 		return 0;
 	}
-	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+	name.data = kstrdup(cname, GFP_KERNEL);
 	if (!name.data) {
 		dprintk("%s: failed to allocate memory for name.data!\n",
 			__func__);
@@ -427,10 +418,17 @@ purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 	if (nfs4_has_reclaimed_state(name, nn))
 		goto out_free;
 
-	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
-	if (status)
-		printk("failed to remove client recovery directory %pd\n",
-				child);
+	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
+	child = lookup_one(&nop_mnt_idmap, &QSTR(cname), parent);
+	if (!IS_ERR(child)) {
+		status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
+		if (status)
+			printk("failed to remove client recovery directory %pd\n",
+			       child);
+		dput(child);
+	}
+	inode_unlock(d_inode(parent));
+
 out_free:
 	kfree(name.data);
 out:
@@ -461,18 +459,18 @@ nfsd4_recdir_purge_old(struct nfsd_net *nn)
 }
 
 static int
-load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
+load_recdir(struct dentry *parent, char *cname, struct nfsd_net *nn)
 {
 	struct xdr_netobj name;
 	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 
-	if (child->d_name.len != HEXDIR_LEN - 1) {
-		printk("%s: illegal name %pd in recovery directory\n",
-				__func__, child);
+	if (strlen(cname) != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %s in recovery directory\n",
+				__func__, cname);
 		/* Keep trying; maybe the others are OK: */
 		return 0;
 	}
-	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+	name.data = kstrdup(cname, GFP_KERNEL);
 	if (!name.data) {
 		dprintk("%s: failed to allocate memory for name.data!\n",
 			__func__);