[PATCH 3/3] Btrfs: Clean up tree search ioctl code

[Li Zefan]

- Check if the key is within specified range before checking the
  item length.
- Advance to the next key a bit more efficiently.
- Remove redundant code.

Signed-off-by: Li Zefan <l...@cn.fujitsu.com>
---
 fs/btrfs/ioctl.c |   30 ++++++++++++------------------
 1 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 08174e2..477affb 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1059,28 +1059,24 @@ static noinline int copy_to_sk(struct btrfs_root *root,
        slot = path->slots[0];
        nritems = btrfs_header_nritems(leaf);
 
-       if (btrfs_header_generation(leaf) > sk->max_transid) {
-               i = nritems;
+       if (btrfs_header_generation(leaf) > sk->max_transid)
                goto advance_key;
-       }
        found_transid = btrfs_header_generation(leaf);
 
        for (i = slot; i < nritems; i++) {
                item_off = btrfs_item_ptr_offset(leaf, i);
                item_len = btrfs_item_size_nr(leaf, i);
 
+               btrfs_item_key_to_cpu(leaf, key, i);
+               if (!key_in_sk(key, sk))
+                       continue;
+
                if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
                        item_len = 0;
 
                if (sizeof(sh) + item_len + *sk_offset >
-                   BTRFS_SEARCH_ARGS_BUFSIZE) {
-                       ret = 1;
-                       goto overflow;
-               }
-
-               btrfs_item_key_to_cpu(leaf, key, i);
-               if (!key_in_sk(key, sk))
-                       continue;
+                   BTRFS_SEARCH_ARGS_BUFSIZE)
+                       return 1;
 
                sh.objectid = key->objectid;
                sh.offset = key->offset;
@@ -1102,22 +1098,21 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 
                (*num_found)++;
                if (*num_found >= sk->nr_items)
-                       break;
+                       return 1;
        }
 advance_key:
        ret = 0;
        if (key->offset < (u64)-1 && key->offset < sk->max_offset)
                key->offset++;
        else if (key->type < (u8)-1 && key->type < sk->max_type) {
-               key->offset = 0;
+               key->offset = sk->min_offset;
                key->type++;
        } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) 
{
-               key->offset = 0;
-               key->type = 0;
+               key->offset = sk->min_offset;
+               key->type = sk->min_type;
                key->objectid++;
        } else
                ret = 1;
-overflow:
        return ret;
 }
 
@@ -1178,9 +1173,8 @@ static noinline int search_ioctl(struct inode *inode,
                ret = copy_to_sk(root, path, &key, sk, args->buf,
                                 &sk_offset, &num_found);
                btrfs_release_path(root, path);
-               if (ret || num_found >= sk->nr_items)
+               if (ret)
                        break;
-
        }
        ret = 0;
 err:
-- 
1.6.3

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html