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[3.13.y-ckt,stable] Patch "SCSI: fix crashes in sd and sr runtime PM" has been added to the 3.13.y-ckt tree

Message ID 1455140392-16290-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Feb. 10, 2016, 9:39 p.m. UTC
This is a note to let you know that I have just added a patch titled

    SCSI: fix crashes in sd and sr runtime PM

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt35.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

From 1f0a778f37ba3b3422f2b6fcf8d14e4f7a151367 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Wed, 20 Jan 2016 11:26:01 -0500
Subject: SCSI: fix crashes in sd and sr runtime PM

commit 13b4389143413a1f18127c07f72c74cad5b563e8 upstream.

Runtime suspend during driver probe and removal can cause problems.
The driver's runtime_suspend or runtime_resume callbacks may invoked
before the driver has finished binding to the device or after the
driver has unbound from the device.

This problem shows up with the sd and sr drivers, and can cause disk
or CD/DVD drives to become unusable as a result.  The fix is simple.
The drivers store a pointer to the scsi_disk or scsi_cd structure as
their private device data when probing is finished, so we simply have
to be sure to clear the private data during removal and test it during
runtime suspend/resume.

This fixes <https://bugs.debian.org/801925>.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Paul Menzel <paul.menzel@giantmonkey.de>
Reported-by: Erich Schubert <erich@debian.org>
Reported-by: Alexandre Rossi <alexandre.rossi@gmail.com>
Tested-by: Paul Menzel <paul.menzel@giantmonkey.de>
Tested-by: Erich Schubert <erich@debian.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/scsi/sd.c | 7 +++++--
 drivers/scsi/sr.c | 4 ++++
 2 files changed, 9 insertions(+), 2 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 6e26021..7fee8c0 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3134,8 +3134,8 @@  static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
 	int ret = 0;

-	if (!sdkp)
-		return 0;	/* this can happen */
+	if (!sdkp)	/* E.g.: runtime suspend following sd_remove() */
+		return 0;

 	if (sdkp->WCE && sdkp->media_present) {
 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
@@ -3176,6 +3176,9 @@  static int sd_resume(struct device *dev)
 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
 	int ret = 0;

+	if (!sdkp)	/* E.g.: runtime resume at the start of sd_probe() */
+		return 0;
+
 	if (!sdkp->device->manage_start_stop)
 		goto done;

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 119d67f..1ac9943 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -142,6 +142,9 @@  static int sr_runtime_suspend(struct device *dev)
 {
 	struct scsi_cd *cd = dev_get_drvdata(dev);

+	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
+		return 0;
+
 	if (cd->media_present)
 		return -EBUSY;
 	else
@@ -1006,6 +1009,7 @@  static int sr_remove(struct device *dev)

 	blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
 	del_gendisk(cd->disk);
+	dev_set_drvdata(dev, NULL);

 	mutex_lock(&sr_ref_mutex);
 	kref_put(&cd->kref, sr_kref_release);