[PATCH] dm table: add target flush

This patch adds support for a per-target dm_flush_fn method.  This is needed
to allow dm-loop to invalidate page cache mappings in response to BLKFLSBUF
ioctl commands.

Signed-off-by: Bryn Reeves <breeves@redhat.com>
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, 2 insertions, 0 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 7a48d428d0a1..03ef41c1eaac 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -55,6 +55,7 @@ typedef int (*dm_endio_fn) (struct dm_target *ti,
                             struct bio *bio, int error,
                             union map_info *map_context);
 
+typedef void (*dm_flush_fn) (struct dm_target *ti);
 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
 typedef int (*dm_preresume_fn) (struct dm_target *ti);
@@ -96,6 +97,7 @@ struct target_type {
         dm_dtr_fn dtr;
         dm_map_fn map;
         dm_endio_fn end_io;
+        dm_flush_fn flush;
         dm_presuspend_fn presuspend;
         dm_postsuspend_fn postsuspend;
         dm_preresume_fn preresume;