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Diffstat (limited to 'fs/btrfs/block-group.c')
-rw-r--r--fs/btrfs/block-group.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 176e8a292fd1..c037ef514b64 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -940,7 +940,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
- goto out_put_group;
+ goto out;
}
/*
@@ -978,7 +978,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret) {
btrfs_add_delayed_iput(inode);
- goto out_put_group;
+ goto out;
}
clear_nlink(inode);
/* One for the block groups ref */
@@ -1001,13 +1001,13 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
- goto out_put_group;
+ goto out;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
- goto out_put_group;
+ goto out;
btrfs_release_path(path);
}
@@ -1016,6 +1016,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
&fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
+ /* Once for the block groups rbtree */
+ btrfs_put_block_group(block_group);
+
if (fs_info->first_logical_byte == block_group->start)
fs_info->first_logical_byte = (u64)-1;
spin_unlock(&fs_info->block_group_cache_lock);
@@ -1089,6 +1092,25 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
spin_unlock(&block_group->space_info->lock);
+ /*
+ * Remove the free space for the block group from the free space tree
+ * and the block group's item from the extent tree before marking the
+ * block group as removed. This is to prevent races with tasks that
+ * freeze and unfreeze a block group, this task and another task
+ * allocating a new block group - the unfreeze task ends up removing
+ * the block group's extent map before the task calling this function
+ * deletes the block group item from the extent tree, allowing for
+ * another task to attempt to create another block group with the same
+ * item key (and failing with -EEXIST and a transaction abort).
+ */
+ ret = remove_block_group_free_space(trans, block_group);
+ if (ret)
+ goto out;
+
+ ret = remove_block_group_item(trans, path, block_group);
+ if (ret < 0)
+ goto out;
+
mutex_lock(&fs_info->chunk_mutex);
spin_lock(&block_group->lock);
block_group->removed = 1;
@@ -1123,17 +1145,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
mutex_unlock(&fs_info->chunk_mutex);
- ret = remove_block_group_free_space(trans, block_group);
- if (ret)
- goto out_put_group;
-
- /* Once for the block groups rbtree */
- btrfs_put_block_group(block_group);
-
- ret = remove_block_group_item(trans, path, block_group);
- if (ret < 0)
- goto out;
-
if (remove_em) {
struct extent_map_tree *em_tree;
@@ -1145,10 +1156,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
free_extent_map(em);
}
-out_put_group:
+out:
/* Once for the lookup reference */
btrfs_put_block_group(block_group);
-out:
if (remove_rsv)
btrfs_delayed_refs_rsv_release(fs_info, 1);
btrfs_free_path(path);