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

[karo-tx-linux.git] / drivers / md / persistent-data / dm-block-manager.h

diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h
index 924833d2dfa69f13944628eb220733a5500cd807..be5bff61be280562932906b1b182ef1d3775ea55 100644 (file)
--- a/drivers/md/persistent-data/dm-block-manager.h
+++ b/drivers/md/persistent-data/dm-block-manager.h
@@ -96,14 +96,6 @@ int dm_bm_write_lock_zero(struct dm_block_manager *bm, dm_block_t b,
 
 int dm_bm_unlock(struct dm_block *b);
 
-/*
- * An optimisation; we often want to copy a block's contents to a new
- * block.  eg, as part of the shadowing operation.  It's far better for
- * bufio to do this move behind the scenes than hold 2 locks and memcpy the
- * data.
- */
-int dm_bm_unlock_move(struct dm_block *b, dm_block_t n);
-
 /*
  * It's a common idiom to have a superblock that should be committed last.
  *
@@ -116,6 +108,19 @@ int dm_bm_unlock_move(struct dm_block *b, dm_block_t n);
 int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
                           struct dm_block *superblock);
 
+/*
+ * Switches the bm to a read only mode.  Once read-only mode
+ * has been entered the following functions will return -EPERM.
+ *
+ *   dm_bm_write_lock
+ *   dm_bm_write_lock_zero
+ *   dm_bm_flush_and_unlock
+ *
+ * Additionally you should not use dm_bm_unlock_move, however no error will
+ * be returned if you do.
+ */
+void dm_bm_set_read_only(struct dm_block_manager *bm);
+
 u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor);
 
 /*----------------------------------------------------------------*/