[PATCH] device-mapper: fix deadlocks in core

Avoid another bdget_disk which can deadlock.

Signed-Off-By: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 12 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f0cd8ea327d3..88f1f27526cc 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -825,18 +825,13 @@ static void event_callback(void *context)
         wake_up(&md->eventq);
 }
 
-static void __set_size(struct gendisk *disk, sector_t size)
+static void __set_size(struct mapped_device *md, sector_t size)
 {
-        struct block_device *bdev;
-
-        set_capacity(disk, size);
-        bdev = bdget_disk(disk, 0);
-        if (bdev) {
-                down(&bdev->bd_inode->i_sem);
-                i_size_write(bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
-                up(&bdev->bd_inode->i_sem);
-                bdput(bdev);
-        }
+        set_capacity(md->disk, size);
+
+        down(&md->frozen_bdev->bd_inode->i_sem);
+        i_size_write(md->frozen_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+        up(&md->frozen_bdev->bd_inode->i_sem);
 }
 
 static int __bind(struct mapped_device *md, struct dm_table *t)
@@ -845,7 +840,7 @@ static int __bind(struct mapped_device *md, struct dm_table *t)
         sector_t size;
 
         size = dm_table_get_size(t);
-        __set_size(md->disk, size);
+        __set_size(md, size);
         if (size == 0)
                 return 0;