[PATCH] scsi: core: cleanup request queue before releasing gendisk

Ming Lei
2021-09-15T09:26:06Z

gendisk instance has to be released after request queue is cleaned up
because bdi is referred from gendisk since commit edb0872f44ec ("block:
move the bdi from the request_queue to the gendisk").

For sd and sr, gendisk can be removed in the release handler(sd_remove/
sr_remove) of sdev->sdev_gendev, which is triggered in device_del(sdev->sdev_gendev)
in __scsi_remove_device(), when the request queue isn't cleaned up yet.

So kernel oops could be triggered when referring bdi via gendisk.

Fix the issue by moving blk_cleanup_queue() into sd_remove() and
sr_remove().

Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/scsi/scsi_priv.h | 6 ++++++
drivers/scsi/scsi_sysfs.c | 3 ++-
drivers/scsi/sd.c | 2 ++
drivers/scsi/sr.c | 4 +++-
include/scsi/scsi_device.h | 1 +
5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 6d9152031a40..6aef88d772a3 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -145,6 +145,12 @@ extern void __scsi_remove_device(struct scsi_device *);
extern struct bus_type scsi_bus_type;
extern const struct attribute_group *scsi_sysfs_shost_attr_groups[];

+static inline void scsi_sysfs_cleanup_sdev(struct scsi_device *sdev)
+{
+ sdev->request_queue_cleaned = true;
+ blk_cleanup_queue(sdev->request_queue);
+}
+
/* scsi_netlink.c */
#ifdef CONFIG_SCSI_NETLINK
extern void scsi_netlink_init(void);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 86793259e541..9d54fc9c89ea 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1463,7 +1463,8 @@ void __scsi_remove_device(struct scsi_device *sdev)
scsi_device_set_state(sdev, SDEV_DEL);
mutex_unlock(&sdev->state_mutex);

- blk_cleanup_queue(sdev->request_queue);
+ if (!sdev->request_queue_cleaned)
+ blk_cleanup_queue(sdev->request_queue);
cancel_work_sync(&sdev->requeue_work);

if (sdev->host->hostt->slave_destroy)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cbd9999f93a6..8132f9833488 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3498,6 +3498,8 @@ static int sd_remove(struct device *dev)
del_gendisk(sdkp->disk);
sd_shutdown(dev);

+ scsi_sysfs_cleanup_sdev(to_scsi_device(dev));
+
free_opal_dev(sdkp->opal_dev);

mutex_lock(&sd_ref_mutex);
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 8b17b35283aa..ef85940f3168 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -64,7 +64,7 @@

#include "scsi_logging.h"
#include "sr.h"
-
+#include "scsi_priv.h"

MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
MODULE_LICENSE("GPL");
@@ -1045,6 +1045,8 @@ static int sr_remove(struct device *dev)
del_gendisk(cd->disk);
dev_set_drvdata(dev, NULL);

+ scsi_sysfs_cleanup_sdev(to_scsi_device(dev));
+
mutex_lock(&sr_ref_mutex);
kref_put(&cd->kref, sr_kref_release);
mutex_unlock(&sr_ref_mutex);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 09a17f6e93a7..d102bc2c423b 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -207,6 +207,7 @@ struct scsi_device {
unsigned rpm_autosuspend:1; /* Enable runtime autosuspend at device
* creation time */
unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
+ unsigned request_queue_cleaned:1; /* Request queue has been cleaned up */

bool offline_already; /* Device offline message logged */

--
2.31.1