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| author | Johannes Thumshirn <johannes.thumshirn@wdc.com> | 2023-02-21 10:11:24 -0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-03-06 19:28:19 +0100 |
| commit | 95cd356ca23c3807b5f3503687161e216b1c520d (patch) | |
| tree | 9003d6497b7c456801954b39430a896b6b201e67 /fs/btrfs/block-group.c | |
| parent | 98e8d36a26c2ed22f78316df7d4bf33e554b9f9f (diff) | |
| download | lwn-95cd356ca23c3807b5f3503687161e216b1c520d.tar.gz lwn-95cd356ca23c3807b5f3503687161e216b1c520d.zip | |
btrfs: fix percent calculation for bg reclaim message
We have a report, that the info message for block-group reclaim is
crossing the 100% used mark.
This is happening as we were truncating the divisor for the division
(the block_group->length) to a 32bit value.
Fix this by using div64_u64() to not truncate the divisor.
In the worst case, it can lead to a div by zero error and should be
possible to trigger on 4 disks RAID0, and each device is large enough:
$ mkfs.btrfs -f /dev/test/scratch[1234] -m raid1 -d raid0
btrfs-progs v6.1
[...]
Filesystem size: 40.00GiB
Block group profiles:
Data: RAID0 4.00GiB <<<
Metadata: RAID1 256.00MiB
System: RAID1 8.00MiB
Reported-by: Forza <forza@tnonline.net>
Link: https://lore.kernel.org/linux-btrfs/e99483.c11a58d.1863591ca52@tnonline.net/
Fixes: 5f93e776c673 ("btrfs: zoned: print unusable percentage when reclaiming block groups")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add Qu's note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/block-group.c')
| -rw-r--r-- | fs/btrfs/block-group.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index 05102a55710c..0eec3084fb00 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1826,7 +1826,8 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) btrfs_info(fs_info, "reclaiming chunk %llu with %llu%% used %llu%% unusable", - bg->start, div_u64(bg->used * 100, bg->length), + bg->start, + div64_u64(bg->used * 100, bg->length), div64_u64(zone_unusable * 100, bg->length)); trace_btrfs_reclaim_block_group(bg); ret = btrfs_relocate_chunk(fs_info, bg->start); |