[PATCH v2 7/7] nvme: add reserved ioq tags for cancel

[John Meneghini]

If the nvme Cancel command is supported, we need to reserve 2 tags for
each IO queue. Note that one addition tag is reserved to account for
the case where this is a fabrics controller.

Signed-off-by: John Meneghini <jmeneghi at redhat.com>
---
 drivers/nvme/host/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 691dd6ee6dc3..76554fb373a3 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4570,6 +4570,7 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
 		unsigned int cmd_size)
 {
 	int ret;
+	u32 effects = le32_to_cpu(ctrl->effects->iocs[nvme_cmd_cancel]);
 
 	memset(set, 0, sizeof(*set));
 	set->ops = ops;
@@ -4580,9 +4581,13 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
 	 */
 	if (ctrl->quirks & NVME_QUIRK_SHARED_TAGS)
 		set->reserved_tags = NVME_AQ_DEPTH;
+	else if  (effects & NVME_CMD_EFFECTS_CSUPP)
+		/* Reserve 2 X io_queue count for NVMe Cancel */
+		set->reserved_tags = (2 * ctrl->queue_count);
 	else if (ctrl->ops->flags & NVME_F_FABRICS)
 		/* Reserved for fabric connect */
 		set->reserved_tags = 1;
+
 	set->numa_node = ctrl->numa_node;
 	set->flags = BLK_MQ_F_SHOULD_MERGE;
 	if (ctrl->ops->flags & NVME_F_BLOCKING)
-- 
2.45.2