From 9c0ba14828d64744ccd195c610594ba254a1a9ab Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 18 Nov 2024 15:52:50 +0100 Subject: [PATCH] blk-settings: round down io_opt to physical_block_size There was a bug report [1] where the user got a warning alignment inconsistency. The user has optimal I/O 16776704 (0xFFFE00) and physical block size 4096. Note that the optimal I/O size may be set by the DMA engines or SCSI controllers and they have no knowledge about the disks attached to them, so the situation with optimal I/O not aligned to physical block size may happen. This commit makes blk_validate_limits round down optimal I/O size to the physical block size of the block device. Closes: https://lore.kernel.org/dm-devel/1426ad71-79b4-4062-b2bf-84278be66a5d@redhat.com/T/ [1] Signed-off-by: Mikulas Patocka Fixes: a23634644afc ("block: take io_opt and io_min into account for max_sectors") Cc: stable@vger.kernel.org # v6.11+ Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/3dc0014b-9690-dc38-81c9-4a316a2d4fb2@redhat.com Signed-off-by: Jens Axboe --- block/blk-settings.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/blk-settings.c b/block/blk-settings.c index f1d4dfdc37a7..0fe16f987cde 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -248,6 +248,13 @@ int blk_validate_limits(struct queue_limits *lim) if (lim->io_min < lim->physical_block_size) lim->io_min = lim->physical_block_size; + /* + * The optimal I/O size may not be aligned to physical block size + * (because it may be limited by dma engines which have no clue about + * block size of the disks attached to them), so we round it down here. + */ + lim->io_opt = round_down(lim->io_opt, lim->physical_block_size); + /* * max_hw_sectors has a somewhat weird default for historical reason, * but driver really should set their own instead of relying on this