diff options
| author | Heinz Mauelshagen <heinzm@redhat.com> | 2014-09-24 17:47:18 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-10-05 20:03:36 -0400 |
| commit | 75b8e04bbf01bdd5c42a1d8ac54abf757196ce49 (patch) | |
| tree | aa19a10d7e0bbea56455a81fc5e47bbe60f9b05d | |
| parent | 86f1152b117a404229fd6f08ec3faca779f37b92 (diff) | |
dm raid: add discard support for RAID levels 1 and 10
Discard support is not enabled for RAID levels 4, 5, and 6 at this time
due to concerns about unreliable discard_zeroes_data support on some
hardware. Otherwise, discards could cause stripe data corruption
(classic example of bad apples spoiling the bunch).
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-raid.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 4880b69e2e9e..030e2d6bc261 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -1,6 +1,6 @@ /* * Copyright (C) 2010-2011 Neil Brown - * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved. + * Copyright (C) 2010-2014 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. */ @@ -1150,6 +1150,27 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) } /* + * Enable/disable discard support on RAID set depending on RAID level. + */ +static void configure_discard_support(struct dm_target *ti, struct raid_set *rs) +{ + /* Assume discards not supported until after checks below. */ + ti->discards_supported = false; + + /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */ + if (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6) + return; /* discard_zeroes_data cannot be trusted as reliable */ + + ti->discards_supported = true; + + /* + * RAID1 and RAID10 personalities require bio splitting, + */ + ti->split_discard_bios = true; + ti->num_discard_bios = 1; +} + +/* * Construct a RAID4/5/6 mapping: * Args: * <raid_type> <#raid_params> <raid_params> \ @@ -1231,6 +1252,11 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) ti->private = rs; ti->num_flush_bios = 1; + /* + * Disable/enable discard support on RAID set. + */ + configure_discard_support(ti, rs); + mutex_lock(&rs->md.reconfig_mutex); ret = md_run(&rs->md); rs->md.in_sync = 0; /* Assume already marked dirty */ @@ -1652,7 +1678,7 @@ static void raid_resume(struct dm_target *ti) static struct target_type raid_target = { .name = "raid", - .version = {1, 5, 2}, + .version = {1, 6, 0}, .module = THIS_MODULE, .ctr = raid_ctr, .dtr = raid_dtr, |