Btrfs: clean up resources during umount after trans is aborted

Currently if some fatal errors occur, like all IO get -EIO, resources
would be cleaned up when
a) transaction is being committed or
b) BTRFS_FS_STATE_ERROR is set

However, in some rare cases, resources may be left alone after transaction
gets aborted and umount may run into some ASSERT(), e.g.
ASSERT(list_empty(&block_group->dirty_list));

For case a), in btrfs_commit_transaciton(), there're several places at the
beginning where we just call btrfs_end_transaction() without cleaning up
resources.  For case b), it is possible that the trans handle doesn't have
any dirty stuff, then only trans hanlde is marked as aborted while
BTRFS_FS_STATE_ERROR is not set, so resources remain in memory.

This makes btrfs also check BTRFS_FS_STATE_TRANS_ABORTED to make sure that
all resources won't stay in memory after umount.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -3812,7 +3812,8 @@ void close_ctree(struct btrfs_fs_info *fs_info)
 			btrfs_err(fs_info, "commit super ret %d", ret);
 	}
 
-	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
+	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state) ||
+	    test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state))
 		btrfs_error_commit_super(fs_info);
 
 	kthread_stop(fs_info->transaction_kthread);