btrfs: make sure we create all new block groups

commit 545e3366db823dc3342ca9d7fea803f829c9062f upstream.

Allocating new chunks modifies both the extent and chunk tree, which can
trigger new chunk allocations.  So instead of doing list_for_each_safe,
just do while (!list_empty()) so we make sure we don't exit with other
pending bg's still on our list.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7a863338dba135aef04c8e566e2c71820b776224..e201415edb2dc7a3ae72f1fbe9d7ec123627dd88 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10270,7 +10270,7 @@ error:
 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
                                       struct btrfs_fs_info *fs_info)
 {
-       struct btrfs_block_group_cache *block_group, *tmp;
+       struct btrfs_block_group_cache *block_group;
        struct btrfs_root *extent_root = fs_info->extent_root;
        struct btrfs_block_group_item item;
        struct btrfs_key key;
@@ -10278,7 +10278,10 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
        bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
 
        trans->can_flush_pending_bgs = false;
-       list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
+       while (!list_empty(&trans->new_bgs)) {
+               block_group = list_first_entry(&trans->new_bgs,
+                                              struct btrfs_block_group_cache,
+                                              bg_list);
                if (ret)
                        goto next;