[PATCH 3/4] nvme: fix max_discard_sectors calculation

Christoph Hellwig
2023-12-26T08:59:13Z

ctrl->max_discard_sectors stores a value that is potentially based of
the DMRSL field in Identify Controller, which is in units of LBAs and
thus dependent on the Format of a namespace.

Fix this by moving the calculation of max_discard_sectors entirely
into nvme_config_discard and replacing the ctrl->max_discard_sectors
value with a local variable so that the calculation is always
namespace-specific.

Fixes: 1a86924e4f46 ("nvme: fix interpretation of DMRSL")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/nvme/host/core.c | 20 +++++++++-----------
drivers/nvme/host/nvme.h | 1 -
2 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 6c52b0ab382c85..86b9a1c4876f5f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1727,12 +1727,13 @@ static void nvme_config_discard(struct nvme_ctrl *ctrl, struct gendisk *disk,
struct nvme_ns_head *head)
{
struct request_queue *queue = disk->queue;
+ u32 max_discard_sectors;

- if (ctrl->dmrsl && ctrl->dmrsl <= nvme_sect_to_lba(head, UINT_MAX))
- ctrl->max_discard_sectors =
- nvme_lba_to_sect(head, ctrl->dmrsl);
-
- if (ctrl->max_discard_sectors == 0) {
+ if (ctrl->dmrsl && ctrl->dmrsl <= nvme_sect_to_lba(head, UINT_MAX)) {
+ max_discard_sectors = nvme_lba_to_sect(head, ctrl->dmrsl);
+ } else if (ctrl->oncs & NVME_CTRL_ONCS_DSM) {
+ max_discard_sectors = UINT_MAX;
+ } else {
blk_queue_max_discard_sectors(queue, 0);
return;
}
@@ -1750,7 +1751,7 @@ static void nvme_config_discard(struct nvme_ctrl *ctrl, struct gendisk *disk,
if (queue->limits.max_discard_sectors)
return;

- blk_queue_max_discard_sectors(queue, ctrl->max_discard_sectors);
+ blk_queue_max_discard_sectors(queue, max_discard_sectors);
blk_queue_max_discard_segments(queue, ctrl->max_discard_segments);
queue->limits.discard_granularity = queue_logical_block_size(queue);

@@ -2911,13 +2912,10 @@ static int nvme_init_non_mdts_limits(struct nvme_ctrl *ctrl)
struct nvme_id_ctrl_nvm *id;
int ret;

- if (ctrl->oncs & NVME_CTRL_ONCS_DSM) {
- ctrl->max_discard_sectors = UINT_MAX;
+ if (ctrl->oncs & NVME_CTRL_ONCS_DSM)
ctrl->max_discard_segments = NVME_DSM_MAX_RANGES;
- } else {
- ctrl->max_discard_sectors = 0;
+ else
ctrl->max_discard_segments = 0;
- }

/*
* Even though NVMe spec explicitly states that MDTS is not applicable
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 3dbd187896d8d8..9a698c49ea0364 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -297,7 +297,6 @@ struct nvme_ctrl {
u32 max_hw_sectors;
u32 max_segments;
u32 max_integrity_segments;
- u32 max_discard_sectors;
u32 max_discard_segments;
u32 max_zeroes_sectors;
#ifdef CONFIG_BLK_DEV_ZONED
--
2.39.2