[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>

3 files changed, 8 insertions, 1 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 4920998efeeb..05befa91807a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1001,6 +1001,11 @@ int dm_table_flush_all(struct dm_table *t)
 {
         struct list_head *d, *devices = dm_table_get_devices(t);
         int ret = 0;
+        unsigned i;
+
+        for (i = 0; i < t->num_targets; i++)
+                if (t->targets[i].type->flush)
+                        t->targets[i].type->flush(&t->targets[i]);
 
         for (d = devices->next; d != devices; d = d->next) {
                 struct dm_dev *dd = list_entry(d, struct dm_dev, list);
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;
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index f28b5c87aa6b..8853fc4d1c5e 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -285,7 +285,7 @@ typedef char ioctl_struct[308];
 #define DM_DEV_SET_GEOMETRY     _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR        4
-#define DM_VERSION_MINOR        9
+#define DM_VERSION_MINOR        10
 #define DM_VERSION_PATCHLEVEL   0
 #define DM_VERSION_EXTRA        "-ioctl (2006-09-14)"