From 09e2b0b14690fb13ccfc04af49f156df3e25b152 Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Mon, 9 Nov 2015 13:24:28 +0100
Subject: [PATCH] scsi: rescan VPD attributes
The VPD page information might change, so we need to be able to update
it. This patch implements a VPD page rescan whenever the 'rescan' sysfs
attribute is triggered.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/scsi.c | 20 +++++++++++++++++---
drivers/scsi/scsi_scan.c | 4 ++++
drivers/scsi/scsi_sysfs.c | 8 ++++++--
drivers/scsi/ses.c | 12 +++++++++---
include/scsi/scsi_device.h | 5 +++--
5 files changed, 39 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d07fb653f5dc3..b1bf42b93fccb 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -782,7 +782,7 @@ void scsi_attach_vpd(struct scsi_device *sdev)
int vpd_len = SCSI_VPD_PG_LEN;
int pg80_supported = 0;
int pg83_supported = 0;
- unsigned char *vpd_buf;
+ unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL;
if (sdev->skip_vpd_pages)
return;
@@ -828,8 +828,16 @@ retry_pg80:
kfree(vpd_buf);
goto retry_pg80;
}
+ mutex_lock(&sdev->inquiry_mutex);
+ orig_vpd_buf = sdev->vpd_pg80;
sdev->vpd_pg80_len = result;
- sdev->vpd_pg80 = vpd_buf;
+ rcu_assign_pointer(sdev->vpd_pg80, vpd_buf);
+ mutex_unlock(&sdev->inquiry_mutex);
+ synchronize_rcu();
+ if (orig_vpd_buf) {
+ kfree(orig_vpd_buf);
+ orig_vpd_buf = NULL;
+ }
vpd_len = SCSI_VPD_PG_LEN;
}
@@ -849,8 +857,14 @@ retry_pg83:
kfree(vpd_buf);
goto retry_pg83;
}
+ mutex_lock(&sdev->inquiry_mutex);
+ orig_vpd_buf = sdev->vpd_pg83;
sdev->vpd_pg83_len = result;
- sdev->vpd_pg83 = vpd_buf;
+ rcu_assign_pointer(sdev->vpd_pg83, vpd_buf);
+ mutex_unlock(&sdev->inquiry_mutex);
+ 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 83245391e956b..a1c195d71fd1c 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -236,6 +236,7 @@ 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);
INIT_WORK(&sdev->event_work, scsi_evt_thread);
INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
@@ -1516,6 +1517,9 @@ EXPORT_SYMBOL(scsi_add_device);
void scsi_rescan_device(struct device *dev)
{
device_lock(dev);
+
+ scsi_attach_vpd(to_scsi_device(dev));
+
if (dev->driver && try_module_get(dev->driver->owner)) {
struct scsi_driver *drv = to_scsi_driver(dev->driver);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 8d2312239ae0c..158f1b553acff 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -760,11 +760,15 @@ show_vpd_##_page(struct file *filp, struct kobject *kobj, \
{ \
struct device *dev = container_of(kobj, struct device, kobj); \
struct scsi_device *sdev = to_scsi_device(dev); \
+ int ret; \
if (!sdev->vpd_##_page) \
return -EINVAL; \
- return memory_read_from_buffer(buf, count, &off, \
- sdev->vpd_##_page, \
+ rcu_read_lock(); \
+ ret = memory_read_from_buffer(buf, count, &off, \
+ rcu_dereference(sdev->vpd_##_page), \
sdev->vpd_##_page##_len); \
+ rcu_read_unlock(); \
+ return ret; \
} \
static struct bin_attribute dev_attr_vpd_##_page = { \
.attr = {.name = __stringify(vpd_##_page), .mode = S_IRUGO }, \
diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index dcb0d76d73128..e234da78ce6e5 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -554,17 +554,22 @@ static void ses_match_to_enclosure(struct enclosure_device *edev,
struct scsi_device *sdev)
{
unsigned char *desc;
+ unsigned char __rcu *vpd_pg83;
struct efd efd = {
.addr = 0,
};
ses_enclosure_data_process(edev, to_scsi_device(edev->edev.parent), 0);
- if (!sdev->vpd_pg83_len)
+ rcu_read_lock();
+ vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
+ if (!vpd_pg83) {
+ rcu_read_unlock();
return;
+ }
- desc = sdev->vpd_pg83 + 4;
- while (desc < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
+ desc = vpd_pg83 + 4;
+ while (desc < vpd_pg83 + sdev->vpd_pg83_len) {
enum scsi_protocol proto = desc[0] >> 4;
u8 code_set = desc[0] & 0x0f;
u8 piv = desc[1] & 0x80;
@@ -578,6 +583,7 @@ static void ses_match_to_enclosure(struct enclosure_device *edev,
desc += len + 4;
}
+ rcu_read_unlock();
if (efd.addr) {
efd.dev = &sdev->sdev_gendev;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index fe89d7cd67b9d..bde4077f2864a 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -109,6 +109,7 @@ struct scsi_device {
char type;
char scsi_level;
char inq_periph_qual; /* PQ from INQUIRY data */
+ struct mutex inquiry_mutex;
unsigned char inquiry_len; /* valid bytes in 'inquiry' */
unsigned char * inquiry; /* INQUIRY response data */
const char * vendor; /* [back_compat] point into 'inquiry' ... */
@@ -117,9 +118,9 @@ struct scsi_device {
#define SCSI_VPD_PG_LEN 255
int vpd_pg83_len;
- unsigned char *vpd_pg83;
+ unsigned char __rcu *vpd_pg83;
int vpd_pg80_len;
- unsigned char *vpd_pg80;
+ unsigned char __rcu *vpd_pg80;
unsigned char current_tag; /* current tag */
struct scsi_target *sdev_target; /* used only for single_lun */
--
2.30.2