linux-scsi.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Douglas Gilbert <dgilbert@interlog.com>
To: linux-scsi@vger.kernel.org
Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com,
	hare@suse.de, bvanassche@acm.org
Subject: [PATCH v2 2/9] scsi_debug: strengthen defer_t accesses
Date: Sat,  8 Jan 2022 20:28:46 -0500	[thread overview]
Message-ID: <20220109012853.301953-3-dgilbert@interlog.com> (raw)
In-Reply-To: <20220109012853.301953-1-dgilbert@interlog.com>

Use READ_ONCE() and WRITE_ONCE() macros when accessing the
sdebug_defer::defer_t value.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
 drivers/scsi/scsi_debug.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 24f3905f054f..40f698e331ee 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4782,7 +4782,7 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
 		return;
 	}
 	spin_lock_irqsave(&sqp->qc_lock, iflags);
-	sd_dp->defer_t = SDEB_DEFER_NONE;
+	WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);
 	sqcp = &sqp->qc_arr[qc_idx];
 	scp = sqcp->a_cmnd;
 	if (unlikely(scp == NULL)) {
@@ -5103,8 +5103,8 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd)
 				sqcp->a_cmnd = NULL;
 				sd_dp = sqcp->sd_dp;
 				if (sd_dp) {
-					l_defer_t = sd_dp->defer_t;
-					sd_dp->defer_t = SDEB_DEFER_NONE;
+					l_defer_t = READ_ONCE(sd_dp->defer_t);
+					WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);
 				} else
 					l_defer_t = SDEB_DEFER_NONE;
 				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
@@ -5145,8 +5145,8 @@ static void stop_all_queued(bool done_with_no_conn)
 				sqcp->a_cmnd = NULL;
 				sd_dp = sqcp->sd_dp;
 				if (sd_dp) {
-					l_defer_t = sd_dp->defer_t;
-					sd_dp->defer_t = SDEB_DEFER_NONE;
+					l_defer_t = READ_ONCE(sd_dp->defer_t);
+					WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);
 				} else
 					l_defer_t = SDEB_DEFER_NONE;
 				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
@@ -5627,7 +5627,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 				sd_dp->sqa_idx = sqp - sdebug_q_arr;
 				sd_dp->qc_idx = k;
 			}
-			sd_dp->defer_t = SDEB_DEFER_POLL;
+			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);
 			spin_unlock_irqrestore(&sqp->qc_lock, iflags);
 		} else {
 			if (!sd_dp->init_hrt) {
@@ -5639,7 +5639,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 				sd_dp->sqa_idx = sqp - sdebug_q_arr;
 				sd_dp->qc_idx = k;
 			}
-			sd_dp->defer_t = SDEB_DEFER_HRT;
+			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_HRT);
 			/* schedule the invocation of scsi_done() for a later time */
 			hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);
 		}
@@ -5658,7 +5658,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 				sd_dp->sqa_idx = sqp - sdebug_q_arr;
 				sd_dp->qc_idx = k;
 			}
-			sd_dp->defer_t = SDEB_DEFER_POLL;
+			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);
 			spin_unlock_irqrestore(&sqp->qc_lock, iflags);
 		} else {
 			if (!sd_dp->init_wq) {
@@ -5668,7 +5668,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 				sd_dp->qc_idx = k;
 				INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);
 			}
-			sd_dp->defer_t = SDEB_DEFER_WQ;
+			WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_WQ);
 			schedule_work(&sd_dp->ew.work);
 		}
 		if (sdebug_statistics)
@@ -7436,7 +7436,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 			       queue_num, qc_idx, __func__);
 			break;
 		}
-		if (sd_dp->defer_t == SDEB_DEFER_POLL) {
+		if (READ_ONCE(sd_dp->defer_t) == SDEB_DEFER_POLL) {
 			if (kt_from_boot < sd_dp->cmpl_ts)
 				continue;
 
@@ -7470,7 +7470,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
 			else
 				atomic_set(&retired_max_queue, k + 1);
 		}
-		sd_dp->defer_t = SDEB_DEFER_NONE;
+		WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_NONE);
 		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
 		scsi_done(scp); /* callback to mid level */
 		spin_lock_irqsave(&sqp->qc_lock, iflags);
-- 
2.25.1


  parent reply	other threads:[~2022-01-09  1:29 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-09  1:28 [PATCH v2 0/9] scsi_debug: collection of additions Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 1/9] scsi_debug: address races following module load Douglas Gilbert
2022-01-09  1:28 ` Douglas Gilbert [this message]
2022-01-09  1:28 ` [PATCH v2 3/9] scsi_debug: use task set full more Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 4/9] scsi_debug: refine sdebug_blk_mq_poll Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 5/9] scsi_debug: divide power on reset unit attention Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 6/9] scsi_debug: add no_rwlock parameter Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 7/9] scsi_debug: add sdeb_sgl_copy_sgl and friends Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 8/9] scsi_debug: change store from vmalloc to sgl Douglas Gilbert
2022-01-09  1:28 ` [PATCH v2 9/9] scsi_debug: add environmental reporting log subpage Douglas Gilbert
2022-01-25  5:38 ` [PATCH v2 0/9] scsi_debug: collection of additions Martin K. Petersen
2022-02-01  2:04 ` Martin K. Petersen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220109012853.301953-3-dgilbert@interlog.com \
    --to=dgilbert@interlog.com \
    --cc=bvanassche@acm.org \
    --cc=hare@suse.de \
    --cc=jejb@linux.vnet.ibm.com \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).