Commit 75b8e04b authored by Heinz Mauelshagen's avatar Heinz Mauelshagen Committed by Mike Snitzer

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: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 86f1152b
/* /*
* Copyright (C) 2010-2011 Neil Brown * 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. * This file is released under the GPL.
*/ */
...@@ -1149,6 +1149,27 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) ...@@ -1149,6 +1149,27 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
return 0; return 0;
} }
/*
* 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: * Construct a RAID4/5/6 mapping:
* Args: * Args:
...@@ -1231,6 +1252,11 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) ...@@ -1231,6 +1252,11 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->private = rs; ti->private = rs;
ti->num_flush_bios = 1; ti->num_flush_bios = 1;
/*
* Disable/enable discard support on RAID set.
*/
configure_discard_support(ti, rs);
mutex_lock(&rs->md.reconfig_mutex); mutex_lock(&rs->md.reconfig_mutex);
ret = md_run(&rs->md); ret = md_run(&rs->md);
rs->md.in_sync = 0; /* Assume already marked dirty */ rs->md.in_sync = 0; /* Assume already marked dirty */
...@@ -1652,7 +1678,7 @@ static void raid_resume(struct dm_target *ti) ...@@ -1652,7 +1678,7 @@ static void raid_resume(struct dm_target *ti)
static struct target_type raid_target = { static struct target_type raid_target = {
.name = "raid", .name = "raid",
.version = {1, 5, 2}, .version = {1, 6, 0},
.module = THIS_MODULE, .module = THIS_MODULE,
.ctr = raid_ctr, .ctr = raid_ctr,
.dtr = raid_dtr, .dtr = raid_dtr,
......
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