swsusp: use GFP_KERNEL for creating basic data structures
Make swsusp call create_basic_memory_bitmaps() before processes are frozen, so
that GFP_KERNEL allocations can be made in it. Additionally, ensure that the
swsusp's userland interface won't be used while either pm_suspend_disk() or
software_resume() is being executed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 403bc37..e518379 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -130,28 +130,33 @@
{
int error;
+ /* The snapshot device should not be opened while we're running */
+ if (!atomic_add_unless(&snapshot_device_available, -1, 0))
+ return -EBUSY;
+
+ /* Allocate memory management structures */
+ error = create_basic_memory_bitmaps();
+ if (error)
+ goto Exit;
+
error = prepare_processes();
if (error)
- return error;
+ goto Finish;
if (pm_disk_mode == PM_DISK_TESTPROC) {
printk("swsusp debug: Waiting for 5 seconds.\n");
mdelay(5000);
goto Thaw;
}
- /* Allocate memory management structures */
- error = create_basic_memory_bitmaps();
- if (error)
- goto Thaw;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
- goto Finish;
+ goto Thaw;
error = platform_prepare();
if (error)
- goto Finish;
+ goto Thaw;
suspend_console();
error = device_suspend(PMSG_FREEZE);
@@ -186,7 +191,7 @@
power_down();
else {
swsusp_free();
- goto Finish;
+ goto Thaw;
}
} else {
pr_debug("PM: Image restored successfully.\n");
@@ -199,10 +204,12 @@
platform_finish();
device_resume();
resume_console();
- Finish:
- free_basic_memory_bitmaps();
Thaw:
unprepare_processes();
+ Finish:
+ free_basic_memory_bitmaps();
+ Exit:
+ atomic_inc(&snapshot_device_available);
return error;
}
@@ -250,9 +257,15 @@
if (error)
goto Unlock;
+ /* The snapshot device should not be opened while we're running */
+ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ error = -EBUSY;
+ goto Unlock;
+ }
+
error = create_basic_memory_bitmaps();
if (error)
- goto Unlock;
+ goto Finish;
pr_debug("PM: Preparing processes for restore.\n");
error = prepare_processes();
@@ -290,6 +303,8 @@
unprepare_processes();
Done:
free_basic_memory_bitmaps();
+ Finish:
+ atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&pm_mutex);