From: "Ewan D. Milne" <emilne@redhat.com>
To: linux-scsi@vger.kernel.org
Subject: [PATCH] scsi: use spinlock instead of mutex for RCU-protected VPD inquiry data
Date: Fri, 20 May 2016 08:56:14 -0400 [thread overview]
Message-ID: <1463748974-31315-1-git-send-email-emilne@redhat.com> (raw)
From: "Ewan D. Milne" <emilne@redhat.com>
A spinlock is sufficient for this purpose, and much smaller.
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
---
drivers/scsi/scsi.c | 8 ++++----
drivers/scsi/scsi_scan.c | 2 +-
include/scsi/scsi_device.h | 2 +-
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 1deb6ad..330d807 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -829,11 +829,11 @@ retry_pg80:
kfree(vpd_buf);
goto retry_pg80;
}
- mutex_lock(&sdev->inquiry_mutex);
+ spin_lock(&sdev->inquiry_lock);
orig_vpd_buf = sdev->vpd_pg80;
sdev->vpd_pg80_len = result;
rcu_assign_pointer(sdev->vpd_pg80, vpd_buf);
- mutex_unlock(&sdev->inquiry_mutex);
+ spin_unlock(&sdev->inquiry_lock);
synchronize_rcu();
if (orig_vpd_buf) {
kfree(orig_vpd_buf);
@@ -858,11 +858,11 @@ retry_pg83:
kfree(vpd_buf);
goto retry_pg83;
}
- mutex_lock(&sdev->inquiry_mutex);
+ spin_lock(&sdev->inquiry_lock);
orig_vpd_buf = sdev->vpd_pg83;
sdev->vpd_pg83_len = result;
rcu_assign_pointer(sdev->vpd_pg83, vpd_buf);
- mutex_unlock(&sdev->inquiry_mutex);
+ spin_unlock(&sdev->inquiry_lock);
synchronize_rcu();
if (orig_vpd_buf)
kfree(orig_vpd_buf);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e0a78f5..f445615 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -240,7 +240,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
INIT_LIST_HEAD(&sdev->starved_entry);
INIT_LIST_HEAD(&sdev->event_list);
spin_lock_init(&sdev->list_lock);
- mutex_init(&sdev->inquiry_mutex);
+ spin_lock_init(&sdev->inquiry_lock);
INIT_WORK(&sdev->event_work, scsi_evt_thread);
INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index a6c346d..0410ed8 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -115,7 +115,7 @@ struct scsi_device {
char type;
char scsi_level;
char inq_periph_qual; /* PQ from INQUIRY data */
- struct mutex inquiry_mutex;
+ spinlock_t inquiry_lock;
unsigned char inquiry_len; /* valid bytes in 'inquiry' */
unsigned char * inquiry; /* INQUIRY response data */
const char * vendor; /* [back_compat] point into 'inquiry' ... */
--
2.1.0
next reply other threads:[~2016-05-20 12:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 12:56 Ewan D. Milne [this message]
2016-05-20 14:33 ` [PATCH] scsi: use spinlock instead of mutex for RCU-protected VPD inquiry data Laurence Oberman
2016-05-23 9:19 ` Johannes Thumshirn
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