Btrfs: do not reuse objectid of deleted snapshot/subvol

[linux-block.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b6cfdd9164e251abc3b09e711bdf8f9a775c1b51..790f4b61a3d7815a7dc54233fc3fc8fa05f1f666 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -42,6 +42,8 @@
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
 
+static atomic_t btrfs_bdi_num = ATOMIC_INIT(0);
+
 /*
  * end_io_wq structs are used to do processing in task context when an IO is
  * complete.  This is used during reads to verify checksums, and it is used
@@ -893,8 +895,7 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
        root->fs_info = fs_info;
        root->objectid = objectid;
        root->last_trans = 0;
-       root->highest_inode = 0;
-       root->last_inode_alloc = 0;
+       root->highest_objectid = 0;
        root->name = NULL;
        root->in_sysfs = 0;
        root->inode_tree.rb_node = NULL;
@@ -1093,7 +1094,6 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
        struct btrfs_fs_info *fs_info = tree_root->fs_info;
        struct btrfs_path *path;
        struct extent_buffer *l;
-       u64 highest_inode;
        u64 generation;
        u32 blocksize;
        int ret = 0;
@@ -1108,7 +1108,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
                        kfree(root);
                        return ERR_PTR(ret);
                }
-               goto insert;
+               goto out;
        }
 
        __setup_root(tree_root->nodesize, tree_root->leafsize,
@@ -1118,39 +1118,30 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
        path = btrfs_alloc_path();
        BUG_ON(!path);
        ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
-       if (ret != 0) {
-               if (ret > 0)
-                       ret = -ENOENT;
-               goto out;
+       if (ret == 0) {
+               l = path->nodes[0];
+               read_extent_buffer(l, &root->root_item,
+                               btrfs_item_ptr_offset(l, path->slots[0]),
+                               sizeof(root->root_item));
+               memcpy(&root->root_key, location, sizeof(*location));
        }
-       l = path->nodes[0];
-       read_extent_buffer(l, &root->root_item,
-              btrfs_item_ptr_offset(l, path->slots[0]),
-              sizeof(root->root_item));
-       memcpy(&root->root_key, location, sizeof(*location));
-       ret = 0;
-out:
-       btrfs_release_path(root, path);
        btrfs_free_path(path);
        if (ret) {
-               kfree(root);
+               if (ret > 0)
+                       ret = -ENOENT;
                return ERR_PTR(ret);
        }
+
        generation = btrfs_root_generation(&root->root_item);
        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
                                     blocksize, generation);
        root->commit_root = btrfs_root_node(root);
        BUG_ON(!root->node);
-insert:
-       if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
+out:
+       if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
                root->ref_cows = 1;
-               ret = btrfs_find_highest_inode(root, &highest_inode);
-               if (ret == 0) {
-                       root->highest_inode = highest_inode;
-                       root->last_inode_alloc = highest_inode;
-               }
-       }
+
        return root;
 }
 
@@ -1342,12 +1333,25 @@ static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
        free_extent_map(em);
 }
 
+/*
+ * If this fails, caller must call bdi_destroy() to get rid of the
+ * bdi again.
+ */
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
-       bdi_init(bdi);
+       int err;
+
+       bdi->capabilities = BDI_CAP_MAP_COPY;
+       err = bdi_init(bdi);
+       if (err)
+               return err;
+
+       err = bdi_register(bdi, NULL, "btrfs-%d",
+                               atomic_inc_return(&btrfs_bdi_num));
+       if (err)
+               return err;
+
        bdi->ra_pages   = default_backing_dev_info.ra_pages;
-       bdi->state              = 0;
-       bdi->capabilities       = default_backing_dev_info.capabilities;
        bdi->unplug_io_fn       = btrfs_unplug_io_fn;
        bdi->unplug_io_data     = info;
        bdi->congested_fn       = btrfs_congested_fn;
@@ -1548,6 +1552,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        INIT_LIST_HEAD(&fs_info->hashers);
        INIT_LIST_HEAD(&fs_info->delalloc_inodes);
        INIT_LIST_HEAD(&fs_info->ordered_operations);
+       INIT_LIST_HEAD(&fs_info->caching_block_groups);
        spin_lock_init(&fs_info->delalloc_lock);
        spin_lock_init(&fs_info->new_trans_lock);
        spin_lock_init(&fs_info->ref_cache_lock);
@@ -1569,7 +1574,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->sb = sb;
        fs_info->max_extent = (u64)-1;
        fs_info->max_inline = 8192 * 1024;
-       setup_bdi(fs_info, &fs_info->bdi);
+       if (setup_bdi(fs_info, &fs_info->bdi))
+               goto fail_bdi;
        fs_info->btree_inode = new_inode(sb);
        fs_info->btree_inode->i_ino = 1;
        fs_info->btree_inode->i_nlink = 1;
@@ -1605,8 +1611,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        spin_lock_init(&fs_info->block_group_cache_lock);
        fs_info->block_group_cache_tree.rb_node = NULL;
 
-       extent_io_tree_init(&fs_info->pinned_extents,
+       extent_io_tree_init(&fs_info->freed_extents[0],
                             fs_info->btree_inode->i_mapping, GFP_NOFS);
+       extent_io_tree_init(&fs_info->freed_extents[1],
+                            fs_info->btree_inode->i_mapping, GFP_NOFS);
+       fs_info->pinned_extents = &fs_info->freed_extents[0];
        fs_info->do_barriers = 1;
 
        BTRFS_I(fs_info->btree_inode)->root = tree_root;
@@ -1959,8 +1968,8 @@ fail_iput:
 
        btrfs_close_devices(fs_info->fs_devices);
        btrfs_mapping_tree_free(&fs_info->mapping_tree);
+fail_bdi:
        bdi_destroy(&fs_info->bdi);
-
 fail:
        kfree(extent_root);
        kfree(tree_root);
@@ -2343,7 +2352,6 @@ int close_ctree(struct btrfs_root *root)
        free_extent_buffer(root->fs_info->csum_root->commit_root);
 
        btrfs_free_block_groups(root->fs_info);
-       btrfs_free_pinned_extents(root->fs_info);
 
        del_fs_roots(fs_info);