Btrfs: tweak the inode-map and free extent search starts on cold mount

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

1 files changed, 20 insertions, 7 deletions

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index b3de823eb628..329edb42897e 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -22,17 +22,31 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
         struct btrfs_key search_key;
         u64 search_start = dirid;
 
-        if (fs_root->fs_info->last_inode_alloc_dirid == dirid)
-                search_start = fs_root->fs_info->last_inode_alloc;
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+        search_key.flags = 0;
+        btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
 
+        search_start = fs_root->fs_info->last_inode_alloc;
+        if (search_start == 0) {
+                struct btrfs_disk_key *last_key;
+                btrfs_init_path(path);
+                search_key.objectid = (u64)-1;
+                search_key.offset = (u64)-1;
+                ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
+                if (ret < 0)
+                        goto error;
+                BUG_ON(ret == 0);
+                if (path->slots[0] > 0)
+                        path->slots[0]--;
+                l = btrfs_buffer_leaf(path->nodes[0]);
+                last_key = &l->items[path->slots[0]].key;
+                search_start = btrfs_disk_key_objectid(last_key);
+        }
         search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
         search_key.objectid = search_start;
-        search_key.flags = 0;
-        btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
         search_key.offset = 0;
 
-        path = btrfs_alloc_path();
-        BUG_ON(!path);
         btrfs_init_path(path);
         start_found = 0;
         ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
@@ -79,7 +93,6 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
         // FIXME -ENOSPC
 found:
         root->fs_info->last_inode_alloc = *objectid;
-        root->fs_info->last_inode_alloc_dirid = dirid;
         btrfs_release_path(root, path);
         btrfs_free_path(path);
         BUG_ON(*objectid < search_start);