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 403bc3722fee914f13d82a912739c83b1f508895..e518379b667a77a6df39321c3bed94dcafbb1f2d 100644 (file)
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -130,28 +130,33 @@ int pm_suspend_disk(void)
 {
        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 @@ int pm_suspend_disk(void)
                        power_down();
                else {
                        swsusp_free();
-                       goto Finish;
+                       goto Thaw;
                }
        } else {
                pr_debug("PM: Image restored successfully.\n");
@@ -199,10 +204,12 @@ int pm_suspend_disk(void)
        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 @@ static int software_resume(void)
        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 @@ static int software_resume(void)
        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 1f8052bda0f7aa1bbebc6f7d0c44009705a6fa9e..a64d3f22de9729e990c166db78eaea53ab24082d 100644 (file)
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -140,6 +140,9 @@ struct resume_swap_area {
 #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 f66e4411795b8618843896638f0706ac577a74d0..128da11f01c2678aedb77854af1f910870a9d7c3 100644 (file)
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -723,19 +723,19 @@ int create_basic_memory_bitmaps(void)
 
        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 bd1771f7a64ee141a2770fe202e7c724923010fd..72dbfd01408e505ab3394a0256eaec36632f6656 100644 (file)
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -40,21 +40,21 @@ static struct snapshot_data {
        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 @@ static int snapshot_release(struct inode *inode, struct file *filp)
                enable_nonboot_cpus();
                mutex_unlock(&pm_mutex);
        }
-       atomic_inc(&device_available);
+       atomic_inc(&snapshot_device_available);
        return 0;
 }