Re: [bisected] RAID1 direct IO redirecting sector loop since 6.0
From: Keith Busch <kbusch@kernel.org>
Date: 2022-11-01 21:21:32
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linux-block, lkml
On Tue, Nov 01, 2022 at 11:51:44PM +0300, Dmitrii Tcvetkov wrote:
It also doesn't reproduce with 4096 sector loop: # lsblk -t -a NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE RA WSAME loop0 0 4096 0 4096 4096 0 none 128 128 0B └─md2 0 4096 0 4096 4096 0 128 128 0B ├─4096lvmraid-zfs 0 4096 0 4096 4096 0 128 128 0B └─4096lvmraid-wrk 0 4096 0 4096 4096 0 128 128 0B loop1 0 4096 0 4096 4096 0 none 128 128 0B └─md2 0 4096 0 4096 4096 0 128 128 0B ├─4096lvmraid-zfs 0 4096 0 4096 4096 0 128 128 0B └─4096lvmraid-wrk 0 4096 0 4096 4096 0 128 128 0B where: # losetup --sector-size 4096 -f /dev/sdd4 # losetup --sector-size 4096 -f /dev/sde4 # mdadm --create --level=1 --metadata=1.2 \ --raid-devices=2 /dev/md2 /dev/loop0 /dev/loop1 # pvcreate /dev/md2 # vgcreate 4096lvmraid /dev/md2 Indeed then something is wrong in LUKS.
Thanks, this helps narrow down where to consider. The offending commit definitely wasn't supposed to break crypto device mappers, but it seems I may have missed a case depending on the previous behavior's implicit constraints. I'll look more into this area.
quoted
For a different experiment, it may be safer to just force all alignment for stacking drivers. Could you try the following and see if that gets it working again? ---diff --git a/block/blk-settings.c b/block/blk-settings.c index 8bb9eef5310e..5c16fdb00c6f 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c@@ -646,6 +646,7 @@ int blk_stack_limits(struct queue_limits *t,struct queue_limits *b, t->misaligned = 1; ret = -1; } + blk_queue_dma_alignment(t, t->logical_block_size - 1); t->max_sectors = blk_round_down_sectors(t->max_sectors, t->logical_block_size); t->max_hw_sectors = blk_round_down_sectors(t->max_hw_sectors, t->logical_block_size); --This doesn't compile:
Oh shoot, sorry about that! Should have been this:
@@ -703,6 +702,7 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, pr_notice("%s: Warning: Device %pg is misaligned\n", disk->disk_name, bdev); + blk_queue_dma_alignment(t, queue_logical_block_size(t) - 1); disk_update_readahead(disk); } EXPORT_SYMBOL(disk_stack_limits);