From: Heinz Mauelshagen <heinzm@xxxxxxxxxx> Only the md raid1 personality supports setting a maximum number of "write behind" write ios on any legs set "write mostly". "write mostly" enhances throughput with slow links/disks. Technically the "write behind" value is a write intent bitmap property only being respected by the raid1 personality. It allows a maximum number of "write behind" writes to any "write mostly" raid1 mirror legs to be delayed and reads from such legs avoided. No other MD personalities supported via dm-raid types make use of "write behind", thus setting this property is superfluous; it wouldn't cause harm but it is correct to reject it. Patch removes CTR_FLAG_MAX_WRITE_BEHIND from raid4/5/6 valid flags allowed. No bz is related, I came across it during review. Signed-off-by: Heinz Mauelshagen <heinzm@xxxxxxxxxx> --- drivers/md/dm-raid.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 698b03e..9d5c6bb 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -160,7 +160,6 @@ struct raid_dev { CTR_FLAG_DAEMON_SLEEP | \ CTR_FLAG_MIN_RECOVERY_RATE | \ CTR_FLAG_MAX_RECOVERY_RATE | \ - CTR_FLAG_MAX_WRITE_BEHIND | \ CTR_FLAG_STRIPE_CACHE | \ CTR_FLAG_REGION_SIZE | \ CTR_FLAG_DELTA_DISKS | \ @@ -171,7 +170,6 @@ struct raid_dev { CTR_FLAG_DAEMON_SLEEP | \ CTR_FLAG_MIN_RECOVERY_RATE | \ CTR_FLAG_MAX_RECOVERY_RATE | \ - CTR_FLAG_MAX_WRITE_BEHIND | \ CTR_FLAG_STRIPE_CACHE | \ CTR_FLAG_REGION_SIZE | \ CTR_FLAG_DELTA_DISKS | \ -- 2.7.4 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel