This is a note to let you know that I've just added the patch titled
scsi: core: Use a structure member to track the SCSI command submitter
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-core-use-a-structure-member-to-track-the-scsi-c.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ddd5d8cbd4e1f51f73857d43cf83a8145b0a5d72
Author: Bart Van Assche <bvanassche@xxxxxxx>
Date: Thu Oct 7 13:27:56 2021 -0700
scsi: core: Use a structure member to track the SCSI command submitter
[ Upstream commit bf23e619039d360d503b7282d030daf2277a5d47 ]
Conditional statements are faster than indirect calls. Use a structure
member to track the SCSI command submitter such that later patches can call
scsi_done(scmd) instead of scmd->scsi_done(scmd).
The asymmetric behavior that scsi_send_eh_cmnd() sets the submission
context to the SCSI error handler and that it does not restore the
submission context to the SCSI core is retained.
Link: https://lore.kernel.org/r/20211007202923.2174984-2-bvanassche@xxxxxxx
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Stable-dep-of: e193b7955dfa ("RDMA/srp: Do not call scsi_done() from srp_abort()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index dd9f5778f687d..18b99240a9062 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -50,8 +50,6 @@
#include <asm/unaligned.h>
-static void scsi_eh_done(struct scsi_cmnd *scmd);
-
/*
* These should *probably* be handled by the host itself.
* Since it is allowed to sleep, it probably should.
@@ -542,7 +540,8 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
/* handler does not care. Drop down to default handling */
}
- if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
+ if (scmd->cmnd[0] == TEST_UNIT_READY &&
+ scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER)
/*
* nasty: for mid-layer issued TURs, we need to return the
* actual sense data without any recovery attempt. For eh
@@ -804,7 +803,7 @@ static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
* scsi_eh_done - Completion function for error handling.
* @scmd: Cmd that is done.
*/
-static void scsi_eh_done(struct scsi_cmnd *scmd)
+void scsi_eh_done(struct scsi_cmnd *scmd)
{
struct completion *eh_action;
@@ -1104,7 +1103,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,
shost->eh_action = &done;
scsi_log_send(scmd);
- scmd->scsi_done = scsi_eh_done;
+ scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER;
/*
* Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
@@ -1131,6 +1130,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,
if (rtn) {
if (timeleft > stall_for) {
scsi_eh_restore_cmnd(scmd, &ses);
+
timeleft -= stall_for;
msleep(jiffies_to_msecs(stall_for));
goto retry;
@@ -2360,11 +2360,6 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
}
EXPORT_SYMBOL(scsi_report_device_reset);
-static void
-scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
-{
-}
-
/**
* scsi_ioctl_reset: explicitly reset a host/bus/target/device
* @dev: scsi_device to operate on
@@ -2401,7 +2396,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
scsi_init_command(dev, scmd);
scmd->cmnd = scsi_req(rq)->cmd;
- scmd->scsi_done = scsi_reset_provider_done_command;
+ scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL;
memset(&scmd->sdb, 0, sizeof(scmd->sdb));
scmd->cmd_len = 0;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 5525e6ffee537..7bdaa6b757cd4 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1578,6 +1578,15 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
static void scsi_mq_done(struct scsi_cmnd *cmd)
{
+ switch (cmd->submitter) {
+ case SUBMITTED_BY_BLOCK_LAYER:
+ break;
+ case SUBMITTED_BY_SCSI_ERROR_HANDLER:
+ return scsi_eh_done(cmd);
+ case SUBMITTED_BY_SCSI_RESET_IOCTL:
+ return;
+ }
+
if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q)))
return;
if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
@@ -1684,6 +1693,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
scsi_set_resid(cmd, 0);
memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+ cmd->submitter = SUBMITTED_BY_BLOCK_LAYER;
cmd->scsi_done = scsi_mq_done;
blk_mq_start_request(req);
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 6d9152031a403..b7f9631493522 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -84,6 +84,7 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost,
int scsi_eh_get_sense(struct list_head *work_q,
struct list_head *done_q);
int scsi_noretry_cmd(struct scsi_cmnd *scmd);
+void scsi_eh_done(struct scsi_cmnd *scmd);
/* scsi_lib.c */
extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 685249233f2fe..0823bad7b0c90 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -65,6 +65,12 @@ struct scsi_pointer {
#define SCMD_STATE_COMPLETE 0
#define SCMD_STATE_INFLIGHT 1
+enum scsi_cmnd_submitter {
+ SUBMITTED_BY_BLOCK_LAYER = 0,
+ SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
+ SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
+} __packed;
+
struct scsi_cmnd {
struct scsi_request req;
struct scsi_device *device;
@@ -90,6 +96,7 @@ struct scsi_cmnd {
unsigned char prot_op;
unsigned char prot_type;
unsigned char prot_flags;
+ enum scsi_cmnd_submitter submitter;
unsigned short cmd_len;
enum dma_data_direction sc_data_direction;
