From: Mikulas Patocka <mpato...@redhat.com>
commit 97f433c3601a24d3513d06f575a389a2ca4e11e4 upstream.
We get I/O errors when we run md-raid1 on the top of dm-integrity on the
top of ramdisk.
device-mapper: integrity: Bio not aligned on 8 sectors: 0xff00, 0xff
device-mapper: integrity: Bio not aligned on 8 sectors: 0xff00, 0xff
device-mapper: integrity: Bio not aligned on 8 sectors: 0xffff, 0x1
device-mapper: integrity: Bio not aligned on 8 sectors: 0xffff, 0x1
device-mapper: integrity: Bio not aligned on 8 sectors: 0x8048, 0xff
device-mapper: integrity: Bio not aligned on 8 sectors: 0x8147, 0xff
device-mapper: integrity: Bio not aligned on 8 sectors: 0x8246, 0xff
device-mapper: integrity: Bio not aligned on 8 sectors: 0x8345, 0xbb
The ramdisk device has logical_block_size 512 and max_sectors 255. The
dm-integrity device uses logical_block_size 4096 and it doesn't affect the
"max_sectors" value - thus, it inherits 255 from the ramdisk. So, we have
a device with max_sectors not aligned on logical_block_size.
The md-raid device sees that the underlying leg has max_sectors 255 and it
will split the bios on 255-sector boundary, making the bios unaligned on
logical_block_size.
In order to fix the bug, we round down max_sectors to logical_block_size.
Cc: sta...@vger.kernel.org
Reviewed-by: Ming Lei <ming....@redhat.com>
Signed-off-by: Mikulas Patocka <mpato...@redhat.com>
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
block/blk-settings.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -494,6 +494,14 @@ void blk_queue_stack_limits(struct reque
}
EXPORT_SYMBOL(blk_queue_stack_limits);
+static unsigned int blk_round_down_sectors(unsigned int sectors, unsigned int
lbs)
+{
+ sectors = round_down(sectors, lbs >> SECTOR_SHIFT);
+ if (sectors < PAGE_SIZE >> SECTOR_SHIFT)
+ sectors = PAGE_SIZE >> SECTOR_SHIFT;
+ return sectors;
+}
+
/**
* blk_stack_limits - adjust queue_limits for stacked devices
* @t: the stacking driver limits (top device)
@@ -606,6 +614,10 @@ int blk_stack_limits(struct queue_limits
ret = -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);
+ t->max_dev_sectors = blk_round_down_sectors(t->max_dev_sectors,
t->logical_block_size);
+
/* Discard alignment and granularity */
if (b->discard_granularity) {
alignment = queue_limit_discard_alignment(b, start);
