dm bufio: remove unused dm_bufio_release_move interface

Was used by multi-snapshot DM target that never went upstream.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-bufio.c

@@ -1415,83 +1415,6 @@ int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t c
 }
 EXPORT_SYMBOL_GPL(dm_bufio_issue_discard);
 
-/*
- * We first delete any other buffer that may be at that new location.
- *
- * Then, we write the buffer to the original location if it was dirty.
- *
- * Then, if we are the only one who is holding the buffer, relink the buffer
- * in the buffer tree for the new location.
- *
- * If there was someone else holding the buffer, we write it to the new
- * location but not relink it, because that other user needs to have the buffer
- * at the same place.
- */
-void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block)
-{
-	struct dm_bufio_client *c = b->c;
-	struct dm_buffer *new;
-
-	BUG_ON(dm_bufio_in_request());
-
-	dm_bufio_lock(c);
-
-retry:
-	new = __find(c, new_block);
-	if (new) {
-		if (new->hold_count) {
-			__wait_for_free_buffer(c);
-			goto retry;
-		}
-
-		/*
-		 * FIXME: Is there any point waiting for a write that's going
-		 * to be overwritten in a bit?
-		 */
-		__make_buffer_clean(new);
-		__unlink_buffer(new);
-		__free_buffer_wake(new);
-	}
-
-	BUG_ON(!b->hold_count);
-	BUG_ON(test_bit(B_READING, &b->state));
-
-	__write_dirty_buffer(b, NULL);
-	if (b->hold_count == 1) {
-		wait_on_bit_io(&b->state, B_WRITING,
-			       TASK_UNINTERRUPTIBLE);
-		set_bit(B_DIRTY, &b->state);
-		b->dirty_start = 0;
-		b->dirty_end = c->block_size;
-		__unlink_buffer(b);
-		__link_buffer(b, new_block, LIST_DIRTY);
-	} else {
-		sector_t old_block;
-
-		wait_on_bit_lock_io(&b->state, B_WRITING,
-				    TASK_UNINTERRUPTIBLE);
-		/*
-		 * Relink buffer to "new_block" so that write_callback
-		 * sees "new_block" as a block number.
-		 * After the write, link the buffer back to old_block.
-		 * All this must be done in bufio lock, so that block number
-		 * change isn't visible to other threads.
-		 */
-		old_block = b->block;
-		__unlink_buffer(b);
-		__link_buffer(b, new_block, b->list_mode);
-		submit_io(b, REQ_OP_WRITE, write_endio);
-		wait_on_bit_io(&b->state, B_WRITING,
-			       TASK_UNINTERRUPTIBLE);
-		__unlink_buffer(b);
-		__link_buffer(b, old_block, b->list_mode);
-	}
-
-	dm_bufio_unlock(c);
-	dm_bufio_release(b);
-}
-EXPORT_SYMBOL_GPL(dm_bufio_release_move);
-
 static void forget_buffer_locked(struct dm_buffer *b)
 {
 	if (likely(!b->hold_count) && likely(!smp_load_acquire(&b->state))) {

include/linux/dm-bufio.h

@@ -130,12 +130,6 @@ int dm_bufio_issue_flush(struct dm_bufio_client *c);
  */
 int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count);
 
-/*
- * Like dm_bufio_release but also move the buffer to the new
- * block. dm_bufio_write_dirty_buffers is needed to commit the new block.
- */
-void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block);
-
 /*
  * Free the given buffer.
  * This is just a hint, if the buffer is in use or dirty, this function