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);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 1f8052b..a64d3f2 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -140,6 +140,9 @@
#define PMOPS_ENTER 2
#define PMOPS_FINISH 3
+/* If unset, the snapshot device cannot be open. */
+extern atomic_t snapshot_device_available;
+
/**
* The bitmap is used for tracing allocated swap pages
*
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index f66e441..128da11 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -723,19 +723,19 @@
BUG_ON(forbidden_pages_map || free_pages_map);
- bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_ATOMIC);
+ bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
if (!bm1)
return -ENOMEM;
- error = memory_bm_create(bm1, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+ error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
if (error)
goto Free_first_object;
- bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_ATOMIC);
+ bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
if (!bm2)
goto Free_first_bitmap;
- error = memory_bm_create(bm2, GFP_ATOMIC | __GFP_COLD, PG_ANY);
+ error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
if (error)
goto Free_second_object;
diff --git a/kernel/power/user.c b/kernel/power/user.c
index bd1771f..72dbfd0 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -40,21 +40,21 @@
char platform_suspend;
} snapshot_state;
-static atomic_t device_available = ATOMIC_INIT(1);
+atomic_t snapshot_device_available = ATOMIC_INIT(1);
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
- if (!atomic_add_unless(&device_available, -1, 0))
+ if (!atomic_add_unless(&snapshot_device_available, -1, 0))
return -EBUSY;
if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
- atomic_inc(&device_available);
+ atomic_inc(&snapshot_device_available);
return -ENOSYS;
}
if(create_basic_memory_bitmaps()) {
- atomic_inc(&device_available);
+ atomic_inc(&snapshot_device_available);
return -ENOMEM;
}
nonseekable_open(inode, filp);
@@ -92,7 +92,7 @@
enable_nonboot_cpus();
mutex_unlock(&pm_mutex);
}
- atomic_inc(&device_available);
+ atomic_inc(&snapshot_device_available);
return 0;
}