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>
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 017c34d..858a8b7 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -353,6 +353,7 @@
{
unsigned i, rebuild_cnt = 0;
unsigned long value, region_size = 0;
+ sector_t max_io_len;
char *key;
/*
@@ -522,14 +523,12 @@
return -EINVAL;
if (rs->md.chunk_sectors)
- rs->ti->split_io = rs->md.chunk_sectors;
+ max_io_len = rs->md.chunk_sectors;
else
- rs->ti->split_io = region_size;
+ max_io_len = region_size;
- if (rs->md.chunk_sectors)
- rs->ti->split_io = rs->md.chunk_sectors;
- else
- rs->ti->split_io = region_size;
+ if (dm_set_target_max_io_len(rs->ti, max_io_len))
+ return -EINVAL;
/* Assume there are no metadata devices until the drives are parsed */
rs->md.persistent = 0;