btrfs: combine device update operations during transaction commit

We currently overload the pending_chunks list to handle updating
btrfs_device->commit_bytes used.  We don't actually care about the
extent mapping or even the device mapping for the chunk - we just need
the device, and we can end up processing it multiple times.  The
fs_devices->resized_list does more or less the same thing, but with the
disk size.  They are called consecutively during commit and have more or
less the same purpose.

We can combine the two lists into a single list that attaches to the
transaction and contains a list of devices that need updating.  Since we
always add the device to a list when we change bytes_used or
disk_total_size, there's no harm in copying both values at once.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0fa65aca56a3..de1dcccc7c9d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4479,10 +4479,17 @@ void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 				   struct btrfs_fs_info *fs_info)
 {
+	struct btrfs_device *dev, *tmp;
+
 	btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
 	ASSERT(list_empty(&cur_trans->dirty_bgs));
 	ASSERT(list_empty(&cur_trans->io_bgs));
 
+	list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
+				 post_commit_list) {
+		list_del_init(&dev->post_commit_list);
+	}
+
 	btrfs_destroy_delayed_refs(cur_trans, fs_info);
 
 	cur_trans->state = TRANS_STATE_COMMIT_START;