[PATCH AUTOSEL for 4.15 097/124] block, scsi: Fix race between SPI domain validation and system suspend

Sasha Levin
2018-03-19T22:15:41Z

From: Bart Van Assche <bart.vanassche@wdc.com>

[ Upstream commit 203f8c250e2195371d418b1e8466e4caf1a0ed51 ]

Avoid that the following warning is reported when suspending a system
that is using the mptspi driver:

WARNING: CPU: 0 PID: 4187 at drivers/scsi/scsi_lib.c:2960 scsi_device_quiesce+0x20/0xb0
EIP: scsi_device_quiesce+0x20/0xb0
Call Trace:
spi_dv_device+0x65/0x5f0 [scsi_transport_spi]
mptspi_dv_device+0x4d/0x170 [mptspi]
mptspi_dv_renegotiate_work+0x49/0xc0 [mptspi]
process_one_work+0x190/0x2e0
worker_thread+0x37/0x3f0
kthread+0xcb/0x100
ret_from_fork+0x19/0x24

Fixes: 3a0a529971ec (block, scsi: Make SCSI quiesce and resume work reliably)
Reported-by: Woody Suwalski <terraluna977@gmail.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
[ rjw : Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/scsi/scsi_transport_spi.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c
index 10ebb213ddb3..871ea582029e 100644
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -26,6 +26,7 @@
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
+#include <linux/suspend.h>
#include <scsi/scsi.h>
#include "scsi_priv.h"
#include <scsi/scsi_device.h>
@@ -1009,11 +1010,20 @@ spi_dv_device(struct scsi_device *sdev)
u8 *buffer;
const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;

+ /*
+ * Because this function and the power management code both call
+ * scsi_device_quiesce(), it is not safe to perform domain validation
+ * while suspend or resume is in progress. Hence the
+ * lock/unlock_system_sleep() calls.
+ */
+ lock_system_sleep();
+
if (unlikely(spi_dv_in_progress(starget)))
- return;
+ goto unlock;

if (unlikely(scsi_device_get(sdev)))
- return;
+ goto unlock;
+
spi_dv_in_progress(starget) = 1;

buffer = kzalloc(len, GFP_KERNEL);
@@ -1049,6 +1059,8 @@ spi_dv_device(struct scsi_device *sdev)
out_put:
spi_dv_in_progress(starget) = 0;
scsi_device_put(sdev);
+unlock:
+ unlock_system_sleep();
}
EXPORT_SYMBOL(spi_dv_device);

--
2.14.1