Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback

[pandora-kernel.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c62fb84..f55aad4 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -44,24 +44,28 @@ inline struct block_device *I_BDEV(struct inode *inode)
 {
        return &BDEV_I(inode)->bdev;
 }
-
 EXPORT_SYMBOL(I_BDEV);
 
 /*
- * move the inode from it's current bdi to the a new bdi. if the inode is dirty
- * we need to move it onto the dirty list of @dst so that the inode is always
- * on the right list.
+ * Move the inode from its current bdi to a new bdi. If the inode is dirty we
+ * need to move it onto the dirty list of @dst so that the inode is always on
+ * the right list.
  */
 static void bdev_inode_switch_bdi(struct inode *inode,
                        struct backing_dev_info *dst)
 {
-       spin_lock(&inode_wb_list_lock);
+       struct backing_dev_info *old = inode->i_data.backing_dev_info;
+
+       if (unlikely(dst == old))               /* deadlock avoidance */
+               return;
+       bdi_lock_two(&old->wb, &dst->wb);
        spin_lock(&inode->i_lock);
        inode->i_data.backing_dev_info = dst;
        if (inode->i_state & I_DIRTY)
                list_move(&inode->i_wb_list, &dst->wb.b_dirty);
        spin_unlock(&inode->i_lock);
-       spin_unlock(&inode_wb_list_lock);
+       spin_unlock(&old->wb.list_lock);
+       spin_unlock(&dst->wb.list_lock);
 }
 
 static sector_t max_block(struct block_device *bdev)