diff mbox series

[v4,1/3] nvme: return BLK_STS_DO_NOT_RETRY if the DNR bit is set

Message ID 20210416235329.49234-2-snitzer@redhat.com (mailing list archive)
State New
Headers show
Series nvme: improve error handling and ana_state to work well with dm-multipath | expand

Commit Message

Mike Snitzer April 16, 2021, 11:53 p.m. UTC
If the DNR bit is set we should not retry the command.

We care about the retryable vs not retryable distinction at the block
layer so propagate the equivalent of the DNR bit by introducing
BLK_STS_DO_NOT_RETRY. Update blk_path_error() to _not_ retry if it
is set.

This change runs with the suggestion made here:
https://lore.kernel.org/linux-nvme/20190813170144.GA10269@lst.de/

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/core.c  | 3 +++
 include/linux/blk_types.h | 8 ++++++++
 2 files changed, 11 insertions(+)

Comments

Christoph Hellwig April 20, 2021, 9:34 a.m. UTC | #1
I don't think this works at all.  We lose way too much information here.
The proposal you linked was to literally propagate the DNR bit.  We'd
still need to make sure drivers for protocols don't support it have
a somewhat sensible options when to set or clear the bit.
diff mbox series

Patch

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0896e21642be..540d6fd8ffef 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -237,6 +237,9 @@  static void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)
 
 static blk_status_t nvme_error_status(u16 status)
 {
+	if (unlikely(status & NVME_SC_DNR))
+		return BLK_STS_DO_NOT_RETRY;
+
 	switch (status & 0x7ff) {
 	case NVME_SC_SUCCESS:
 		return BLK_STS_OK;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index db026b6ec15a..1ca724948c56 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -142,6 +142,13 @@  typedef u8 __bitwise blk_status_t;
  */
 #define BLK_STS_ZONE_ACTIVE_RESOURCE	((__force blk_status_t)16)
 
+/*
+ * BLK_STS_DO_NOT_RETRY is returned from the driver in the completion path
+ * if the device returns a status indicating that if the same command is
+ * re-submitted it is expected to fail.
+ */
+#define BLK_STS_DO_NOT_RETRY	((__force blk_status_t)17)
+
 /**
  * blk_path_error - returns true if error may be path related
  * @error: status the request was completed with
@@ -157,6 +164,7 @@  typedef u8 __bitwise blk_status_t;
 static inline bool blk_path_error(blk_status_t error)
 {
 	switch (error) {
+	case BLK_STS_DO_NOT_RETRY:
 	case BLK_STS_NOTSUPP:
 	case BLK_STS_NOSPC:
 	case BLK_STS_TARGET: