Commit c7510859 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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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
...@@ -38,9 +38,6 @@ static inline void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) ...@@ -38,9 +38,6 @@ static inline void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{ }; { };
#endif #endif
/* scsi_scan.c */
int scsi_complete_async_scans(void);
/* scsi_devinfo.c */ /* scsi_devinfo.c */
extern int scsi_get_device_flags(struct scsi_device *sdev, extern int scsi_get_device_flags(struct scsi_device *sdev,
const unsigned char *vendor, const unsigned char *vendor,
......
...@@ -11,7 +11,7 @@ ...@@ -11,7 +11,7 @@
*/ */
#include <linux/module.h> #include <linux/module.h>
#include "scsi_priv.h" #include <scsi/scsi_scan.h>
static int __init wait_scan_init(void) static int __init wait_scan_init(void)
{ {
......
#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 */
...@@ -22,6 +22,7 @@ ...@@ -22,6 +22,7 @@
#include <linux/console.h> #include <linux/console.h>
#include <linux/cpu.h> #include <linux/cpu.h>
#include <linux/freezer.h> #include <linux/freezer.h>
#include <scsi/scsi_scan.h>
#include <asm/suspend.h> #include <asm/suspend.h>
#include "power.h" #include "power.h"
...@@ -644,6 +645,13 @@ static int software_resume(void) ...@@ -644,6 +645,13 @@ static int software_resume(void)
if (noresume) if (noresume)
return 0; 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 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
* is configured into the kernel. Since the regular hibernate * is configured into the kernel. Since the regular hibernate
......
...@@ -24,6 +24,7 @@ ...@@ -24,6 +24,7 @@
#include <linux/cpu.h> #include <linux/cpu.h>
#include <linux/freezer.h> #include <linux/freezer.h>
#include <linux/smp_lock.h> #include <linux/smp_lock.h>
#include <scsi/scsi_scan.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -92,6 +93,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) ...@@ -92,6 +93,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
filp->private_data = data; filp->private_data = data;
memset(&data->handle, 0, sizeof(struct snapshot_handle)); memset(&data->handle, 0, sizeof(struct snapshot_handle));
if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
/* Hibernating. The image device should be accessible. */
data->swap = swsusp_resume_device ? data->swap = swsusp_resume_device ?
swap_type_of(swsusp_resume_device, 0, NULL) : -1; swap_type_of(swsusp_resume_device, 0, NULL) : -1;
data->mode = O_RDONLY; data->mode = O_RDONLY;
...@@ -99,6 +101,13 @@ static int snapshot_open(struct inode *inode, struct file *filp) ...@@ -99,6 +101,13 @@ static int snapshot_open(struct inode *inode, struct file *filp)
if (error) if (error)
pm_notifier_call_chain(PM_POST_HIBERNATION); pm_notifier_call_chain(PM_POST_HIBERNATION);
} else { } 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->swap = -1;
data->mode = O_WRONLY; data->mode = O_WRONLY;
error = pm_notifier_call_chain(PM_RESTORE_PREPARE); error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
......
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