Commit 28c97ba3 authored by Mike Christie's avatar Mike Christie Committed by Martin K. Petersen
Browse files

nvme: Add pr_ops read_reservation support 



This patch adds support for the pr_ops read_reservation callout by
calling the NVMe Reservation Report helper. It then parses that info to
detect if there is a reservation and if there is then convert the
returned info to a pr_ops pr_held_reservation struct.

Signed-off-by: default avatarMike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230407200551.12660-14-michael.christie@oracle.com


Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent be1a7cd2

drivers/nvme/host/pr.c

+83 −0
Original line number Diff line number Diff line
@@ -29,6 +29,26 @@ static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type) 
	return 0;

}



static enum pr_type block_pr_type_from_nvme(enum nvme_pr_type type)

{

	switch (type) {

	case NVME_PR_WRITE_EXCLUSIVE:

		return PR_WRITE_EXCLUSIVE;

	case NVME_PR_EXCLUSIVE_ACCESS:

		return PR_EXCLUSIVE_ACCESS;

	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:

		return PR_WRITE_EXCLUSIVE_REG_ONLY;

	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:

		return PR_EXCLUSIVE_ACCESS_REG_ONLY;

	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:

		return PR_WRITE_EXCLUSIVE_ALL_REGS;

	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:

		return PR_EXCLUSIVE_ACCESS_ALL_REGS;

	}



	return 0;

}



static int nvme_send_ns_head_pr_command(struct block_device *bdev,

		struct nvme_command *c, void *data, unsigned int data_len)

{
@@ -222,6 +242,68 @@ static int nvme_pr_read_keys(struct block_device *bdev, 
	return ret;

}



static int nvme_pr_read_reservation(struct block_device *bdev,

		struct pr_held_reservation *resv)

{

	struct nvme_reservation_status_ext tmp_rse, *rse;

	int ret, i, num_regs;

	u32 rse_len;

	bool eds;



get_num_regs:

	/*

	 * Get the number of registrations so we know how big to allocate

	 * the response buffer.

	 */

	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);

	if (ret)

		return ret;



	num_regs = get_unaligned_le16(&tmp_rse.regctl);

	if (!num_regs) {

		resv->generation = le32_to_cpu(tmp_rse.gen);

		return 0;

	}



	rse_len = struct_size(rse, regctl_eds, num_regs);

	rse = kzalloc(rse_len, GFP_KERNEL);

	if (!rse)

		return -ENOMEM;



	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);

	if (ret)

		goto free_rse;



	if (num_regs != get_unaligned_le16(&rse->regctl)) {

		kfree(rse);

		goto get_num_regs;

	}



	resv->generation = le32_to_cpu(rse->gen);

	resv->type = block_pr_type_from_nvme(rse->rtype);



	for (i = 0; i < num_regs; i++) {

		if (eds) {

			if (rse->regctl_eds[i].rcsts) {

				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);

				break;

			}

		} else {

			struct nvme_reservation_status *rs;



			rs = (struct nvme_reservation_status *)rse;

			if (rs->regctl_ds[i].rcsts) {

				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);

				break;

			}

		}

	}



free_rse:

	kfree(rse);

	return ret;

}



const struct pr_ops nvme_pr_ops = {

	.pr_register	= nvme_pr_register,

	.pr_reserve	= nvme_pr_reserve,
@@ -229,4 +311,5 @@ const struct pr_ops nvme_pr_ops = { 
	.pr_preempt	= nvme_pr_preempt,

	.pr_clear	= nvme_pr_clear,

	.pr_read_keys	= nvme_pr_read_keys,

	.pr_read_reservation = nvme_pr_read_reservation,

};