From 5cb502f4ab6469c3d02bd787a3ff58a7b624ba67 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Mon, 13 Jul 2020 09:03:19 +0800
Patch-mainline: v5.9-rc1
Git-commit: 5cb502f4ab6469c3d02bd787a3ff58a7b624ba67
References: bsc#1174354
Subject: [PATCH] btrfs: relocation: allow signal to cancel balance

Although btrfs balance can be canceled with "btrfs balance cancel"
command, it's still almost muscle memory to press Ctrl-C to cancel a
long running btrfs balance.

So allow btrfs balance to check signal to determine if it should exit.
The cancellation points are in known location and we're only adding one
more reason, so this should be safe.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/relocation.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3322,7 +3322,8 @@ int setup_extent_mapping(struct inode *i
  */
 int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info)
 {
-	return atomic_read(&fs_info->balance_cancel_req);
+	return atomic_read(&fs_info->balance_cancel_req) ||
+		fatal_signal_pending(current);
 }
 
 static int relocate_file_extent_cluster(struct inode *inode,