Btrfs: start of support for many FS volumes

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 19 insertions, 7 deletions

diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 6bfa980790c2..b276a3b40a66 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -26,15 +26,27 @@ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
 }
 
 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
-                       *root, struct btrfs_path *path, u64 objectid, int mod)
+                       *root, struct btrfs_path *path,
+                       struct btrfs_key *location, int mod)
 {
-        struct btrfs_key key;
         int ins_len = mod < 0 ? -1 : 0;
         int cow = mod != 0;
+        int ret;
+        int slot;
+        struct btrfs_leaf *leaf;
+        struct btrfs_key found_key;
 
-        key.objectid = objectid;
-        key.flags = 0;
-        btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-        key.offset = 0;
-        return btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+        ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
+        if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
+            location->offset == (u64)-1 && path->slots[0] != 0) {
+                slot = path->slots[0] - 1;
+                leaf = btrfs_buffer_leaf(path->nodes[0]);
+                btrfs_disk_key_to_cpu(&found_key, &leaf->items[slot].key);
+                if (found_key.objectid == location->objectid &&
+                    btrfs_key_type(&found_key) == btrfs_key_type(location)) {
+                        path->slots[0]--;
+                        return 0;
+                }
+        }
+        return ret;
 }