[PATCH 6.6 357/396] scsi: sd: Fix TCG OPAL unlock on system resume

Greg Kroah-Hartman
2024-04-01T16:54:12Z

From: Damien Le Moal <dlemoal@kernel.org>

commit 0c76106cb97548810214def8ee22700bbbb90543 upstream.

Commit 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop
management") introduced the manage_system_start_stop scsi_device flag to
allow libata to indicate to the SCSI disk driver that nothing should be
done when resuming a disk on system resume. This change turned the
execution of sd_resume() into a no-op for ATA devices on system
resume. While this solved deadlock issues during device resume, this change
also wrongly removed the execution of opal_unlock_from_suspend(). As a
result, devices with TCG OPAL locking enabled remain locked and
inaccessible after a system resume from sleep.

To fix this issue, introduce the SCSI driver resume method and implement it
with the sd_resume() function calling opal_unlock_from_suspend(). The
former sd_resume() function is renamed to sd_resume_common() and modified
to call the new sd_resume() function. For non-ATA devices, this result in
no functional changes.

In order for libata to explicitly execute sd_resume() when a device is
resumed during system restart, the function scsi_resume_device() is
introduced. libata calls this function from the revalidation work executed
on devie resume, a state that is indicated with the new device flag
ATA_DFLAG_RESUMING. Doing so, locked TCG OPAL enabled devices are unlocked
on resume, allowing normal operation.

Fixes: 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop management")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218538
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240319071209.1179257-1-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/ata/libata-eh.c | 5 ++++-
drivers/ata/libata-scsi.c | 9 +++++++++
drivers/scsi/scsi_scan.c | 34 ++++++++++++++++++++++++++++++++++
drivers/scsi/sd.c | 23 +++++++++++++++++++----
include/linux/libata.h | 1 +
include/scsi/scsi_driver.h | 1 +
include/scsi/scsi_host.h | 1 +
7 files changed, 69 insertions(+), 5 deletions(-)

--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -700,8 +700,10 @@ void ata_scsi_port_error_handler(struct
ehc->saved_ncq_enabled |= 1 << devno;

/* If we are resuming, wake up the device */
- if (ap->pflags & ATA_PFLAG_RESUMING)
+ if (ap->pflags & ATA_PFLAG_RESUMING) {
+ dev->flags |= ATA_DFLAG_RESUMING;
ehc->i.dev_action[devno] |= ATA_EH_SET_ACTIVE;
+ }
}
}

@@ -3170,6 +3172,7 @@ static int ata_eh_revalidate_and_attach(
return 0;

err:
+ dev->flags &= ~ATA_DFLAG_RESUMING;
*r_failed_dev = dev;
return rc;
}
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4765,6 +4765,7 @@ void ata_scsi_dev_rescan(struct work_str
struct ata_link *link;
struct ata_device *dev;
unsigned long flags;
+ bool do_resume;
int ret = 0;

mutex_lock(&ap->scsi_scan_mutex);
@@ -4786,7 +4787,15 @@ void ata_scsi_dev_rescan(struct work_str
if (scsi_device_get(sdev))
continue;

+ do_resume = dev->flags & ATA_DFLAG_RESUMING;
+
spin_unlock_irqrestore(ap->lock, flags);
+ if (do_resume) {
+ ret = scsi_resume_device(sdev);
+ if (ret == -EWOULDBLOCK)
+ goto unlock;
+ dev->flags &= ~ATA_DFLAG_RESUMING;
+ }
ret = scsi_rescan_device(sdev);
scsi_device_put(sdev);
spin_lock_irqsave(ap->lock, flags);
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1619,6 +1619,40 @@ int scsi_add_device(struct Scsi_Host *ho
}
EXPORT_SYMBOL(scsi_add_device);

+int scsi_resume_device(struct scsi_device *sdev)
+{
+ struct device *dev = &sdev->sdev_gendev;
+ int ret = 0;
+
+ device_lock(dev);
+
+ /*
+ * Bail out if the device or its queue are not running. Otherwise,
+ * the rescan may block waiting for commands to be executed, with us
+ * holding the device lock. This can result in a potential deadlock
+ * in the power management core code when system resume is on-going.
+ */
+ if (sdev->sdev_state != SDEV_RUNNING ||
+ blk_queue_pm_only(sdev->request_queue)) {
+ ret = -EWOULDBLOCK;
+ goto unlock;
+ }
+
+ if (dev->driver && try_module_get(dev->driver->owner)) {
+ struct scsi_driver *drv = to_scsi_driver(dev->driver);
+
+ if (drv->resume)
+ ret = drv->resume(dev);
+ module_put(dev->driver->owner);
+ }
+
+unlock:
+ device_unlock(dev);
+
+ return ret;
+}
+EXPORT_SYMBOL(scsi_resume_device);
+
int scsi_rescan_device(struct scsi_device *sdev)
{
struct device *dev = &sdev->sdev_gendev;
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3942,7 +3942,21 @@ static int sd_suspend_runtime(struct dev
return sd_suspend_common(dev, true);
}

-static int sd_resume(struct device *dev, bool runtime)
+static int sd_resume(struct device *dev)
+{
+ struct scsi_disk *sdkp = dev_get_drvdata(dev);
+
+ sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
+
+ if (opal_unlock_from_suspend(sdkp->opal_dev)) {
+ sd_printk(KERN_NOTICE, sdkp, "OPAL unlock failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int sd_resume_common(struct device *dev, bool runtime)
{
struct scsi_disk *sdkp = dev_get_drvdata(dev);
int ret = 0;
@@ -3961,7 +3975,7 @@ static int sd_resume(struct device *dev,
}

if (!ret) {
- opal_unlock_from_suspend(sdkp->opal_dev);
+ sd_resume(dev);
sdkp->suspended = false;
}

@@ -3980,7 +3994,7 @@ static int sd_resume_system(struct devic
return 0;
}

- return sd_resume(dev, false);
+ return sd_resume_common(dev, false);
}

static int sd_resume_runtime(struct device *dev)
@@ -4007,7 +4021,7 @@ static int sd_resume_runtime(struct devi
"Failed to clear sense data\n");
}

- return sd_resume(dev, true);
+ return sd_resume_common(dev, true);
}

static const struct dev_pm_ops sd_pm_ops = {
@@ -4030,6 +4044,7 @@ static struct scsi_driver sd_template =
.pm = &sd_pm_ops,
},
.rescan = sd_rescan,
+ .resume = sd_resume,
.init_command = sd_init_command,
.uninit_command = sd_uninit_command,
.done = sd_done,
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -107,6 +107,7 @@ enum {

ATA_DFLAG_NCQ_PRIO_ENABLED = (1 << 20), /* Priority cmds sent to dev */
ATA_DFLAG_CDL_ENABLED = (1 << 21), /* cmd duration limits is enabled */
+ ATA_DFLAG_RESUMING = (1 << 22), /* Device is resuming */
ATA_DFLAG_DETACH = (1 << 24),
ATA_DFLAG_DETACHED = (1 << 25),
ATA_DFLAG_DA = (1 << 26), /* device supports Device Attention */
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -12,6 +12,7 @@ struct request;
struct scsi_driver {
struct device_driver gendrv;

+ int (*resume)(struct device *);
void (*rescan)(struct device *);
blk_status_t (*init_command)(struct scsi_cmnd *);
void (*uninit_command)(struct scsi_cmnd *);
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -764,6 +764,7 @@ scsi_template_proc_dir(const struct scsi
#define scsi_template_proc_dir(sht) NULL
#endif
extern void scsi_scan_host(struct Scsi_Host *);
+extern int scsi_resume_device(struct scsi_device *sdev);
extern int scsi_rescan_device(struct scsi_device *sdev);
extern void scsi_remove_host(struct Scsi_Host *);
extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);