This may be a bad idea. I can't really think of any pros or cons,
other than a general principle of "when feasible, prefer random over
deterministic".
Index: softraid_raid1.c
===================================================================
RCS file: /cvs/src/sys/dev/softraid_raid1.c,v
retrieving revision 1.54
diff -u -p -r1.54 softraid_raid1.c
--- softraid_raid1.c 1 Nov 2013 17:36:19 -0000 1.54
+++ softraid_raid1.c 7 Nov 2013 14:32:33 -0000
@@ -350,8 +350,8 @@ sr_raid1_rw(struct sr_workunit *wu)
rt = 0;
ragain:
/* interleave reads */
- chunk = sd->mds.mdd_raid1.sr1_counter++ %
- sd->sd_meta->ssdi.ssd_chunk_no;
+ chunk =
+ arc4random_uniform(sd->sd_meta->ssdi.ssd_chunk_no);
scp = sd->sd_vol.sv_chunks[chunk];
switch (scp->src_meta.scm_status) {
case BIOC_SDONLINE:
Index: softraidvar.h
===================================================================
RCS file: /cvs/src/sys/dev/softraidvar.h,v
retrieving revision 1.140
diff -u -p -r1.140 softraidvar.h
--- softraidvar.h 4 Nov 2013 21:02:57 -0000 1.140
+++ softraidvar.h 7 Nov 2013 14:32:33 -0000
@@ -417,7 +417,7 @@ struct sr_raid0 {
/* RAID 1 */
#define SR_RAID1_NOWU 16
struct sr_raid1 {
- u_int32_t sr1_counter;
+ u_int32_t sr1_unused;
};
/* RAID 4 */
