[PATCH] device-mapper: rename frozen_bdev

Rename frozen_bdev to suspended_bdev and move the bdget outside lockfs.  (This
prepares for making lockfs optional.)

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, 25 insertions, 26 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 9e8c1edd89dd..fc335e09d072 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -97,7 +97,7 @@ struct mapped_device {
          * freeze/thaw support require holding onto a super block
          */
         struct super_block *frozen_sb;
-        struct block_device *frozen_bdev;
+        struct block_device *suspended_bdev;
 };
 
 #define MIN_IOS 256
@@ -836,9 +836,9 @@ static void __set_size(struct mapped_device *md, sector_t size)
 {
         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);
+        down(&md->suspended_bdev->bd_inode->i_sem);
+        i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+        up(&md->suspended_bdev->bd_inode->i_sem);
 }
 
 static int __bind(struct mapped_device *md, struct dm_table *t)
@@ -1010,43 +1010,27 @@ out:
  */
 static int lock_fs(struct mapped_device *md)
 {
-        int r = -ENOMEM;
-
-        md->frozen_bdev = bdget_disk(md->disk, 0);
-        if (!md->frozen_bdev) {
-                DMWARN("bdget failed in lock_fs");
-                goto out;
-        }
+        int r;
 
         WARN_ON(md->frozen_sb);
 
-        md->frozen_sb = freeze_bdev(md->frozen_bdev);
+        md->frozen_sb = freeze_bdev(md->suspended_bdev);
         if (IS_ERR(md->frozen_sb)) {
                 r = PTR_ERR(md->frozen_sb);
-                goto out_bdput;
+                md->frozen_sb = NULL;
+                return r;
         }
 
         /* don't bdput right now, we don't want the bdev
-         * to go away while it is locked.  We'll bdput
-         * in unlock_fs
+         * to go away while it is locked.
          */
         return 0;
-
-out_bdput:
-        bdput(md->frozen_bdev);
-        md->frozen_sb = NULL;
-        md->frozen_bdev = NULL;
-out:
-        return r;
 }
 
 static void unlock_fs(struct mapped_device *md)
 {
-        thaw_bdev(md->frozen_bdev, md->frozen_sb);
-        bdput(md->frozen_bdev);
-
+        thaw_bdev(md->suspended_bdev, md->frozen_sb);
         md->frozen_sb = NULL;
-        md->frozen_bdev = NULL;
 }
 
 /*
@@ -1072,6 +1056,13 @@ int dm_suspend(struct mapped_device *md)
         /* This does not get reverted if there's an error later. */
         dm_table_presuspend_targets(map);
 
+        md->suspended_bdev = bdget_disk(md->disk, 0);
+        if (!md->suspended_bdev) {
+                DMWARN("bdget failed in dm_suspend");
+                r = -ENOMEM;
+                goto out;
+        }
+
         /* Flush I/O to the device. */
         r = lock_fs(md);
         if (r)
@@ -1124,6 +1115,11 @@ int dm_suspend(struct mapped_device *md)
         r = 0;
 
 out:
+        if (r && md->suspended_bdev) {
+                bdput(md->suspended_bdev);
+                md->suspended_bdev = NULL;
+        }
+
         dm_table_put(map);
         up(&md->suspend_lock);
         return r;
@@ -1154,6 +1150,9 @@ int dm_resume(struct mapped_device *md)
 
         unlock_fs(md);
 
+        bdput(md->suspended_bdev);
+        md->suspended_bdev = NULL;
+
         clear_bit(DMF_SUSPENDED, &md->flags);
 
         dm_table_unplug_all(map);