From 688545279bd97c05dd6e6b82ba180471656b29ad Mon Sep 17 00:00:00 2001
From: Nitin Gupta <ngupta@vflare.org>
Date: Mon, 17 May 2010 11:02:43 +0530
Subject: [PATCH] --- yaml --- r: 197464 b: refs/heads/master c:
 b3a27d0529c6e5206f1b60f60263e3ecfd0d77cb h: refs/heads/master v: v3

---
 [refs]                       | 2 +-
 trunk/include/linux/blkdev.h | 2 ++
 trunk/mm/swapfile.c          | 4 ++++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index c557dcb0c864..f324bc29bcb9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b27256439568950f30864ccecaeb6dfb588089d5
+refs/heads/master: b3a27d0529c6e5206f1b60f60263e3ecfd0d77cb
diff --git a/trunk/include/linux/blkdev.h b/trunk/include/linux/blkdev.h
index 6690e8bae7bb..413284a51ccc 100644
--- a/trunk/include/linux/blkdev.h
+++ b/trunk/include/linux/blkdev.h
@@ -1287,6 +1287,8 @@ struct block_device_operations {
 						unsigned long long);
 	int (*revalidate_disk) (struct gendisk *);
 	int (*getgeo)(struct block_device *, struct hd_geometry *);
+	/* this callback is with swap_lock and sometimes page table lock held */
+	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
 	struct module *owner;
 };
 
diff --git a/trunk/mm/swapfile.c b/trunk/mm/swapfile.c
index ecb069e213d0..f5ccc476aa51 100644
--- a/trunk/mm/swapfile.c
+++ b/trunk/mm/swapfile.c
@@ -574,6 +574,7 @@ static unsigned char swap_entry_free(struct swap_info_struct *p,
 
 	/* free if no reference */
 	if (!usage) {
+		struct gendisk *disk = p->bdev->bd_disk;
 		if (offset < p->lowest_bit)
 			p->lowest_bit = offset;
 		if (offset > p->highest_bit)
@@ -583,6 +584,9 @@ static unsigned char swap_entry_free(struct swap_info_struct *p,
 			swap_list.next = p->type;
 		nr_swap_pages++;
 		p->inuse_pages--;
+		if ((p->flags & SWP_BLKDEV) &&
+				disk->fops->swap_slot_free_notify)
+			disk->fops->swap_slot_free_notify(p->bdev, offset);
 	}
 
 	return usage;