dm: support non power of two target max_io_len

Remove the restriction that limits a target's specified maximum incoming
I/O size to be a power of 2.

Rename this setting from 'split_io' to the less-ambiguous 'max_io_len'.
Change it from sector_t to uint32_t, which is plenty big enough, and
introduce a wrapper function dm_set_target_max_io_len() to set it.
Use sector_div() to process it now that it is not necessarily a power of 2.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 75fd5573516..3ece4eee84c 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -268,8 +268,8 @@ enum {
 
 #define DM_VERSION_MAJOR        4
 #define DM_VERSION_MINOR        22
-#define DM_VERSION_PATCHLEVEL   0
-#define DM_VERSION_EXTRA        "-ioctl (2011-10-19)"
+#define DM_VERSION_PATCHLEVEL   1
+#define DM_VERSION_EXTRA        "-ioctl (2012-06-01)"
 
 /* Status bits */
 #define DM_READONLY_FLAG        (1 << 0) /* In/Out */