[PATCH v6 7/8] btrfs: don't search back for dir inode item in INO_LOOKUP_USER

[Daniel Vacek <neelx@suse.com>]

From: Josef Bacik <josef@toxicpanda.com>

We don't need to search back to the inode item, the directory inode
number is in key.offset, so simply use that.  If we can't find the
directory we'll get an ENOENT at the iget.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
Since v5 resolved rebase merge conflicts due to changes in API,
dropping the sb parameter in btrfs_iget().
---
 fs/btrfs/ioctl.c | 23 +++--------------------
 1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2973230f2988..d323fc351c00 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1822,7 +1822,7 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
 	struct btrfs_root_ref *rref;
 	struct btrfs_root *root = NULL;
 	struct btrfs_path *path;
-	struct btrfs_key key, key2;
+	struct btrfs_key key;
 	struct extent_buffer *leaf;
 	char *ptr;
 	int slot;
@@ -1877,24 +1877,6 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
 			read_extent_buffer(leaf, ptr,
 					(unsigned long)(iref + 1), len);
 
-			/* Check the read+exec permission of this directory */
-			ret = btrfs_previous_item(root, path, dirid,
-						  BTRFS_INODE_ITEM_KEY);
-			if (ret < 0) {
-				goto out_put;
-			} else if (ret > 0) {
-				ret = -ENOENT;
-				goto out_put;
-			}
-
-			leaf = path->nodes[0];
-			slot = path->slots[0];
-			btrfs_item_key_to_cpu(leaf, &key2, slot);
-			if (key2.objectid != dirid) {
-				ret = -ENOENT;
-				goto out_put;
-			}
-
 			/*
 			 * We don't need the path anymore, so release it and
 			 * avoid deadlocks and lockdep warnings in case
@@ -1902,11 +1884,12 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
 			 * btree and lock the same leaf.
 			 */
 			btrfs_release_path(path);
-			temp_inode = btrfs_iget(key2.objectid, root);
+			temp_inode = btrfs_iget(key.offset, root);
 			if (IS_ERR(temp_inode)) {
 				ret = PTR_ERR(temp_inode);
 				goto out_put;
 			}
+			/* Check the read+exec permission of this directory */
 			ret = inode_permission(idmap, &temp_inode->vfs_inode,
 					       MAY_READ | MAY_EXEC);
 			iput(&temp_inode->vfs_inode);
-- 
2.51.0