blk-settings: align max_sectors on "logical_block_size" boundary

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: [email protected] Reviewed-by: Ming Lei <[email protected]> Signed-off-by: Mikulas Patocka <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
ambv · Feb 24, 2021 · 97f433c · 97f433c
1 parent 4601b4b
commit 97f433c
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/block/blk-settings.c b/block/blk-settings.c
@@ -504,6 +504,14 @@ void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
 }
 EXPORT_SYMBOL(blk_queue_io_opt);
 
+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)
@@ -630,6 +638,10 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 		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);