1 files changed, 17 insertions, 19 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 5889f70d4d27..2853acd64482 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -180,6 +180,7 @@ static int afs_dir_open(struct inode *inode, struct file *file)
  * get reclaimed during the iteration.
  */
 static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
+	__acquires(&dvnode->validate_lock)
 {
 	struct afs_read *req;
 	loff_t i_size;
@@ -261,18 +262,21 @@ retry:
 	/* If we're going to reload, we need to lock all the pages to prevent
 	 * races.
 	 */
-	if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
-		ret = -ERESTARTSYS;
-		for (i = 0; i < req->nr_pages; i++)
-			if (lock_page_killable(req->pages[i]) < 0)
-				goto error_unlock;
+	ret = -ERESTARTSYS;
+	if (down_read_killable(&dvnode->validate_lock) < 0)
+		goto error;
 
-		if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
-			goto success;
+	if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+		goto success;
+
+	up_read(&dvnode->validate_lock);
+	if (down_write_killable(&dvnode->validate_lock) < 0)
+		goto error;
 
+	if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
 		ret = afs_fetch_data(dvnode, key, req);
 		if (ret < 0)
-			goto error_unlock_all;
+			goto error_unlock;
 
 		task_io_account_read(PAGE_SIZE * req->nr_pages);
 
@@ -284,33 +288,26 @@ retry:
 		for (i = 0; i < req->nr_pages; i++)
 			if (!afs_dir_check_page(dvnode, req->pages[i],
 						req->actual_len))
-				goto error_unlock_all;
+				goto error_unlock;
 
 		// TODO: Trim excess pages
 
 		set_bit(AFS_VNODE_DIR_VALID, &dvnode->flags);
 	}
 
+	downgrade_write(&dvnode->validate_lock);
 success:
-	i = req->nr_pages;
-	while (i > 0)
-		unlock_page(req->pages[--i]);
 	return req;
 
-error_unlock_all:
-	i = req->nr_pages;
 error_unlock:
-	while (i > 0)
-		unlock_page(req->pages[--i]);
+	up_write(&dvnode->validate_lock);
 error:
 	afs_put_read(req);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
 
 content_has_grown:
-	i = req->nr_pages;
-	while (i > 0)
-		unlock_page(req->pages[--i]);
+	up_write(&dvnode->validate_lock);
 	afs_put_read(req);
 	goto retry;
 }
@@ -473,6 +470,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 	}
 
 out:
+	up_read(&dvnode->validate_lock);
 	afs_put_read(req);
 	_leave(" = %d", ret);
 	return ret;