Btrfs: Check if btrfs_next_leaf() returns error in btrfs_listxattr()

btrfs_next_leaf() can return -errno, and we should propagate
it to userspace.

This also simplifies how we walk the btree path.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index e5d22f280956c99a33e1f6039ca99285878fa7c4..07b9bc350d5d1d4f25af9e7f8d4bb0a64dc30678 100644 (file)
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -180,11 +180,10 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
        struct btrfs_path *path;
        struct extent_buffer *leaf;
        struct btrfs_dir_item *di;
-       int ret = 0, slot, advance;
+       int ret = 0, slot;
        size_t total_size = 0, size_left = size;
        unsigned long name_ptr;
        size_t name_len;
-       u32 nritems;
 
        /*
         * ok we want all objects associated with this id.
@@ -204,34 +203,24 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
        if (ret < 0)
                goto err;
-       advance = 0;
+
        while (1) {
                leaf = path->nodes[0];
-               nritems = btrfs_header_nritems(leaf);
                slot = path->slots[0];
 
                /* this is where we start walking through the path */
-               if (advance || slot >= nritems) {
+               if (slot >= btrfs_header_nritems(leaf)) {
                        /*
                         * if we've reached the last slot in this leaf we need
                         * to go to the next leaf and reset everything
                         */
-                       if (slot >= nritems-1) {
-                               ret = btrfs_next_leaf(root, path);
-                               if (ret)
-                                       break;
-                               leaf = path->nodes[0];
-                               nritems = btrfs_header_nritems(leaf);
-                               slot = path->slots[0];
-                       } else {
-                               /*
-                                * just walking through the slots on this leaf
-                                */
-                               slot++;
-                               path->slots[0]++;
-                       }
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret < 0)
+                               goto err;
+                       else if (ret > 0)
+                               break;
+                       continue;
                }
-               advance = 1;
 
                btrfs_item_key_to_cpu(leaf, &found_key, slot);
 
@@ -250,7 +239,7 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
                /* we are just looking for how big our buffer needs to be */
                if (!size)
-                       continue;
+                       goto next;
 
                if (!buffer || (name_len + 1) > size_left) {
                        ret = -ERANGE;
@@ -263,6 +252,8 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
                size_left -= name_len + 1;
                buffer += name_len + 1;
+next:
+               path->slots[0]++;
        }
        ret = total_size;