Commit b94e8cd2 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

nvme: fix Write Zeroes limitations 



We voluntarily limit the Write Zeroes sizes to the MDTS value provided by
the hardware, but currently get the units wrong, so fix that.

Fixes: 6e02318e ("nvme: add support for the Write Zeroes command")
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <kbusch@kernel.org>
Tested-by: default avatarKlaus Jensen <k.jensen@samsung.com>
Reviewed-by: default avatarKlaus Jensen <k.jensen@samsung.com>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: default avatarHimanshu Madhani <himanshu.madhani@oracle.com>
parent 985c5a32

drivers/nvme/host/core.c

+12 −24
Original line number Diff line number Diff line
@@ -1954,30 +1954,18 @@ static void nvme_config_discard(struct gendisk *disk, struct nvme_ns *ns) 
		blk_queue_max_write_zeroes_sectors(queue, UINT_MAX);

}



static void nvme_config_write_zeroes(struct gendisk *disk, struct nvme_ns *ns)

{

	u64 max_blocks;



	if (!(ns->ctrl->oncs & NVME_CTRL_ONCS_WRITE_ZEROES) ||

	    (ns->ctrl->quirks & NVME_QUIRK_DISABLE_WRITE_ZEROES))

		return;

/*

	 * Even though NVMe spec explicitly states that MDTS is not

	 * applicable to the write-zeroes:- "The restriction does not apply to

	 * commands that do not transfer data between the host and the

	 * controller (e.g., Write Uncorrectable ro Write Zeroes command).".

	 * In order to be more cautious use controller's max_hw_sectors value

	 * to configure the maximum sectors for the write-zeroes which is

	 * configured based on the controller's MDTS field in the

	 * nvme_init_identify() if available.

 * Even though NVMe spec explicitly states that MDTS is not applicable to the

 * write-zeroes, we are cautious and limit the size to the controllers

 * max_hw_sectors value, which is based on the MDTS field and possibly other

 * limiting factors.

 */

	if (ns->ctrl->max_hw_sectors == UINT_MAX)

		max_blocks = (u64)USHRT_MAX + 1;

	else

		max_blocks = ns->ctrl->max_hw_sectors + 1;



	blk_queue_max_write_zeroes_sectors(disk->queue,

					   nvme_lba_to_sect(ns, max_blocks));

static void nvme_config_write_zeroes(struct request_queue *q,

		struct nvme_ctrl *ctrl)

{

	if ((ctrl->oncs & NVME_CTRL_ONCS_WRITE_ZEROES) &&

	    !(ctrl->quirks & NVME_QUIRK_DISABLE_WRITE_ZEROES))

		blk_queue_max_write_zeroes_sectors(q, ctrl->max_hw_sectors);

}



static bool nvme_ns_ids_valid(struct nvme_ns_ids *ids)
@@ -2149,7 +2137,7 @@ static void nvme_update_disk_info(struct gendisk *disk, 
	set_capacity_and_notify(disk, capacity);



	nvme_config_discard(disk, ns);

	nvme_config_write_zeroes(disk, ns);

	nvme_config_write_zeroes(disk->queue, ns->ctrl);



	set_disk_ro(disk, (id->nsattr & NVME_NS_ATTR_RO) ||

		test_bit(NVME_NS_FORCE_RO, &ns->flags));