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

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/inode.c b/fs/btrfs/inode.c
index 55a6a0b416d769de258cddea83f00a207dcae82a..b9f7f5258343fb23183ce17001cf1cf5bf3a8e3b 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4221,10 +4221,8 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
        struct btrfs_key found_key;
        struct btrfs_path *path;
        int ret;
-       u32 nritems;
        struct extent_buffer *leaf;
        int slot;
-       int advance;
        unsigned char d_type;
        int over = 0;
        u32 di_cur;
@@ -4267,27 +4265,19 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
        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];
-               if (advance || slot >= nritems) {
-                       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 {
-                               slot++;
-                               path->slots[0]++;
-                       }
+               if (slot >= btrfs_header_nritems(leaf)) {
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret < 0)
+                               goto err;
+                       else if (ret > 0)
+                               break;
+                       continue;
                }
 
-               advance = 1;
                item = btrfs_item_nr(leaf, slot);
                btrfs_item_key_to_cpu(leaf, &found_key, slot);
 
@@ -4296,7 +4286,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
                if (btrfs_key_type(&found_key) != key_type)
                        break;
                if (found_key.offset < filp->f_pos)
-                       continue;
+                       goto next;
 
                filp->f_pos = found_key.offset;
 
@@ -4349,6 +4339,8 @@ skip:
                        di_cur += di_len;
                        di = (struct btrfs_dir_item *)((char *)di + di_len);
                }
+next:
+               path->slots[0]++;
        }
 
        /* Reached end of directory/root. Bump pos past the last item. */