[Fold into 2]
---
drivers/md/persistent-data/dm-block-manager.c | 30 ++++++++++++++++++++++++++
drivers/md/persistent-data/dm-block-manager.h | 12 ++++++++++
2 files changed, 42 insertions(+)
Index: linux-3.0-rc7/drivers/md/persistent-data/dm-block-manager.c
===================================================================
--- linux-3.0-rc7.orig/drivers/md/persistent-data/dm-block-manager.c
+++ linux-3.0-rc7/drivers/md/persistent-data/dm-block-manager.c
@@ -426,6 +426,14 @@ static int __wait_all_writes(struct dm_b
!bm->writing_count);
}
+static int __wait_all_io(struct dm_block_manager *bm, unsigned long *flags)
+ __retains(&bm->lock)
+{
+ unplug();
+ __wait_block(&bm->io_q, &bm->lock, *flags, io_schedule,
+ !bm->writing_count && !bm->reading_count);
+}
+
static int __wait_clean(struct dm_block_manager *bm, unsigned long *flags)
__retains(&bm->lock)
{
@@ -928,4 +936,26 @@ int dm_bm_flush_and_unlock(struct dm_blo
}
EXPORT_SYMBOL_GPL(dm_bm_flush_and_unlock);
+int dm_bm_rebind_block_device(struct dm_block_manager *bm, struct block_device *bdev)
+{
+ unsigned long flags;
+ dm_block_t nr_blocks = i_size_read(bdev->bd_inode);
+ do_div(nr_blocks, bm->block_size);
+
+ spin_lock_irqsave(&bm->lock, flags);
+ if (nr_blocks < bm->nr_blocks) {
+ spin_unlock_irqrestore(&bm->lock, flags);
+ return -EINVAL;
+ }
+
+ bm->bdev = bdev;
+ bm->nr_blocks = nr_blocks;
+
+ /* wait for any in-flight io that may be using the old bdev */
+ __wait_all_io(bm, &flags);
+ spin_unlock_irqrestore(&bm->lock, flags);
+
+ return 0;
+}
+
/*----------------------------------------------------------------*/
Index: linux-3.0-rc7/drivers/md/persistent-data/dm-block-manager.h
===================================================================
--- linux-3.0-rc7.orig/drivers/md/persistent-data/dm-block-manager.h
+++ linux-3.0-rc7/drivers/md/persistent-data/dm-block-manager.h
@@ -101,6 +101,18 @@ int dm_bm_flush_and_unlock(struct dm_blo
struct dm_block *superblock);
/*
+ * The client may wish to change which block device the block manager
+ * points at. If you use this function then the cache remains intact, so
+ * make sure your data is identical on the new device. The new device must
+ * be at least as long as the old.
+ *
+ * This function guarantees that once it returns, no further IO will occur
+ * on the old device.
+ */
+int dm_bm_rebind_block_device(struct dm_block_manager *bm,
+ struct block_device *bdev);
+
+/*
* Debug routines.
*/
unsigned dm_bm_locks_held(struct dm_block_manager *bm);