Btrfs: enable discard support

[safe/jmp/linux-2.6] / fs / btrfs / inode-map.c

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 2aa7987..c56eb59 100644 (file)
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -43,9 +43,10 @@ int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
                slot = path->slots[0] - 1;
                l = path->nodes[0];
                btrfs_item_key_to_cpu(l, &found_key, slot);
-               *objectid = found_key.objectid;
+               *objectid = max_t(u64, found_key.objectid,
+                                 BTRFS_FIRST_FREE_OBJECTID - 1);
        } else {
-               *objectid = BTRFS_FIRST_FREE_OBJECTID;
+               *objectid = BTRFS_FIRST_FREE_OBJECTID - 1;
        }
        ret = 0;
 error:
@@ -53,92 +54,27 @@ error:
        return ret;
 }
 
-/*
- * walks the btree of allocated inodes and find a hole.
- */
 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             u64 dirid, u64 *objectid)
 {
-       struct btrfs_path *path;
-       struct btrfs_key key;
        int ret;
-       int slot = 0;
-       u64 last_ino = 0;
-       int start_found;
-       struct extent_buffer *l;
-       struct btrfs_key search_key;
-       u64 search_start = dirid;
-
        mutex_lock(&root->objectid_mutex);
-       if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
-           root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
-               *objectid = ++root->last_inode_alloc;
-               mutex_unlock(&root->objectid_mutex);
-               return 0;
-       }
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
-       search_key.objectid = search_start;
-       search_key.type = 0;
-       search_key.offset = 0;
-
-       btrfs_init_path(path);
-       start_found = 0;
-       ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
-       if (ret < 0)
-               goto error;
 
-       while (1) {
-               l = path->nodes[0];
-               slot = path->slots[0];
-               if (slot >= btrfs_header_nritems(l)) {
-                       ret = btrfs_next_leaf(root, path);
-                       if (ret == 0)
-                               continue;
-                       if (ret < 0)
-                               goto error;
-                       if (!start_found) {
-                               *objectid = search_start;
-                               start_found = 1;
-                               goto found;
-                       }
-                       *objectid = last_ino > search_start ?
-                               last_ino : search_start;
-                       goto found;
-               }
-               btrfs_item_key_to_cpu(l, &key, slot);
-               if (key.objectid >= search_start) {
-                       if (start_found) {
-                               if (last_ino < search_start)
-                                       last_ino = search_start;
-                               if (key.objectid > last_ino) {
-                                       *objectid = last_ino;
-                                       goto found;
-                               }
-                       } else if (key.objectid > search_start) {
-                               *objectid = search_start;
-                               goto found;
-                       }
-               }
-               if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
-                       break;
+       if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) {
+               ret = btrfs_find_highest_inode(root, &root->highest_objectid);
+               if (ret)
+                       goto out;
+       }
 
-               start_found = 1;
-               last_ino = key.objectid + 1;
-               path->slots[0]++;
+       if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
+               ret = -ENOSPC;
+               goto out;
        }
-       BUG_ON(1);
-found:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       BUG_ON(*objectid < search_start);
-       mutex_unlock(&root->objectid_mutex);
-       return 0;
-error:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
+
+       *objectid = ++root->highest_objectid;
+       ret = 0;
+out:
        mutex_unlock(&root->objectid_mutex);
        return ret;
 }