Commit c7510859 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

PM/Hibernate: Wait for SCSI devices scan to complete during resume 



There is a race between resume from hibernation and the asynchronous
scanning of SCSI devices and to prevent it from happening we need to
call scsi_complete_async_scans() during resume from hibernation.

In addition, if the resume from hibernation is userland-driven, it's
better to wait for all device probes in the kernel to complete before
attempting to open the resume device.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7b11428d

drivers/scsi/scsi_priv.h

+0 −3
Original line number Diff line number Diff line
@@ -38,9 +38,6 @@ static inline void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) 
	{ };

#endif



/* scsi_scan.c */

int scsi_complete_async_scans(void);



/* scsi_devinfo.c */

extern int scsi_get_device_flags(struct scsi_device *sdev,

				 const unsigned char *vendor,

drivers/scsi/scsi_wait_scan.c

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
 */



#include <linux/module.h>

#include "scsi_priv.h"

#include <scsi/scsi_scan.h>



static int __init wait_scan_init(void)

{

include/scsi/scsi_scan.h

0 → 100644
+11 −0
Original line number Diff line number Diff line 
#ifndef _SCSI_SCSI_SCAN_H

#define _SCSI_SCSI_SCAN_H



#ifdef CONFIG_SCSI

/* drivers/scsi/scsi_scan.c */

extern int scsi_complete_async_scans(void);

#else

static inline int scsi_complete_async_scans(void) { return 0; }

#endif



#endif /* _SCSI_SCSI_SCAN_H */

kernel/power/disk.c

+8 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/console.h>

#include <linux/cpu.h>

#include <linux/freezer.h>

#include <scsi/scsi_scan.h>

#include <asm/suspend.h>



#include "power.h"
@@ -644,6 +645,13 @@ static int software_resume(void) 
	if (noresume)

		return 0;



	/*

	 * We can't depend on SCSI devices being available after loading one of

	 * their modules if scsi_complete_async_scans() is not called and the

	 * resume device usually is a SCSI one.

	 */

	scsi_complete_async_scans();



	/*

	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs

	 * is configured into the kernel. Since the regular hibernate

kernel/power/user.c

+9 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/cpu.h>

#include <linux/freezer.h>

#include <linux/smp_lock.h>

#include <scsi/scsi_scan.h>



#include <asm/uaccess.h>
@@ -92,6 +93,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) 
	filp->private_data = data;

	memset(&data->handle, 0, sizeof(struct snapshot_handle));

	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {

		/* Hibernating.  The image device should be accessible. */

		data->swap = swsusp_resume_device ?

			swap_type_of(swsusp_resume_device, 0, NULL) : -1;

		data->mode = O_RDONLY;
@@ -99,6 +101,13 @@ static int snapshot_open(struct inode *inode, struct file *filp) 
		if (error)

			pm_notifier_call_chain(PM_POST_HIBERNATION);

	} else {

		/*

		 * Resuming.  We may need to wait for the image device to

		 * appear.

		 */

		wait_for_device_probe();

		scsi_complete_async_scans();



		data->swap = -1;

		data->mode = O_WRONLY;

		error = pm_notifier_call_chain(PM_RESTORE_PREPARE);

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