diff options
Diffstat (limited to 'drivers/md/dm-raid.c')
| -rw-r--r-- | drivers/md/dm-raid.c | 60 |
1 files changed, 58 insertions, 2 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 4880b69e2e9e..4857fa4a5484 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. */ @@ -18,6 +18,8 @@ #define DM_MSG_PREFIX "raid" +static bool devices_handle_discard_safely = false; + /* * The following flags are used by dm-raid.c to set up the array state. * They must be cleared before md_run is called. @@ -475,6 +477,8 @@ too_many: * will form the "stripe" * [[no]sync] Force or prevent recovery of the * entire array + * [devices_handle_discard_safely] Allow discards on RAID4/5/6; useful if RAID + * member device(s) properly support TRIM/UNMAP * [rebuild <idx>] Rebuild the drive indicated by the index * [daemon_sleep <ms>] Time between bitmap daemon work to * clear bits @@ -1150,6 +1154,49 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) } /* + * Enable/disable discard support on RAID set depending on + * RAID level and discard properties of underlying RAID members. + */ +static void configure_discard_support(struct dm_target *ti, struct raid_set *rs) +{ + int i; + bool raid456; + + /* Assume discards not supported until after checks below. */ + ti->discards_supported = false; + + /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */ + raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6); + + for (i = 0; i < rs->md.raid_disks; i++) { + struct request_queue *q = bdev_get_queue(rs->dev[i].rdev.bdev); + + if (!q || !blk_queue_discard(q)) + return; + + if (raid456) { + if (!q->limits.discard_zeroes_data) + return; + if (!devices_handle_discard_safely) { + DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty."); + DMERR("Set dm-raid.devices_handle_discard_safely=Y to override."); + return; + } + } + } + + /* All RAID members properly support discards */ + ti->discards_supported = true; + + /* + * RAID1 and RAID10 personalities require bio splitting, + * RAID0/4/5/6 don't and process large discard bios properly. + */ + ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10); + ti->num_discard_bios = 1; +} + +/* * Construct a RAID4/5/6 mapping: * Args: * <raid_type> <#raid_params> <raid_params> \ @@ -1231,6 +1278,11 @@ 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 +1704,7 @@ 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, @@ -1683,6 +1735,10 @@ static void __exit dm_raid_exit(void) module_init(dm_raid_init); module_exit(dm_raid_exit); +module_param(devices_handle_discard_safely, bool, 0644); +MODULE_PARM_DESC(devices_handle_discard_safely, + "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions"); + MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target"); MODULE_ALIAS("dm-raid1"); MODULE_ALIAS("dm-raid10"); |