[PATCH 5.13 029/351] btrfs: zoned: fix types for u64 division in btrfs_reclaim_bgs_work

Greg Kroah-Hartman
2021-07-19T17:29:00Z

From: David Sterba <dsterba@suse.com>

commit 54afaae34ee49e98c1c902b444b42832551d090c upstream.

The types in calculation of the used percentage in the reclaiming
messages are both u64, though bg->length is either 1GiB (non-zoned) or
the zone size in the zoned mode. The upper limit on zone size is 8GiB so
this could theoretically overflow in the future, right now the values
fit.

Fixes: 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.13
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/block-group.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1539,7 +1539,7 @@ void btrfs_reclaim_bgs_work(struct work_
goto next;

btrfs_info(fs_info, "reclaiming chunk %llu with %llu%% used",
- bg->start, div_u64(bg->used * 100, bg->length));
+ bg->start, div64_u64(bg->used * 100, bg->length));
trace_btrfs_reclaim_block_group(bg);
ret = btrfs_relocate_chunk(fs_info, bg->start);
if (ret)