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authorJonathan Brassow <jbrassow@redhat.com>2011-08-02 12:32:07 +0100
committerAlasdair G Kergon <agk@redhat.com>2011-08-02 12:32:07 +0100
commit46bed2b5c16bb7c82e1088d7ae75fb958c8a8c4e (patch)
treebab932a8eec324ca470407ff54097d86a3c0e27f
parentc1084561bb85da3630540ebe951749a8cd8fc714 (diff)
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dm raid: add write_mostly parameter
Add the write_mostly parameter to RAID1 dm-raid tables. This allows the user to set the WriteMostly flag on a RAID1 device that should normally be avoided for read I/O. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r--Documentation/device-mapper/dm-raid.txt4
-rw-r--r--drivers/md/dm-raid.c26
2 files changed, 28 insertions, 2 deletions
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt
index be4419a3078..a7d1c4abc92 100644
--- a/Documentation/device-mapper/dm-raid.txt
+++ b/Documentation/device-mapper/dm-raid.txt
@@ -50,6 +50,7 @@ The target is named "raid" and it accepts the following parameters:
[min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
[max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
+ [write_mostly <idx>] Drive index is write-mostly
[max_write_behind <sectors>] See '-write-behind=' (man mdadm)
[stripe_cache <sectors>] Stripe cache size (higher RAIDs only)
[region_size <sectors>]
@@ -87,9 +88,10 @@ Example tables
5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81
'dmsetup table' displays the table used to construct the mapping.
-The optional parameters will always be printed in the order listed
+The optional parameters are always printed in the order listed
above with "sync" or "nosync" always output ahead of the other
arguments, regardless of the order used when originally loading the table.
+Arguments that can be repeated are ordered by value.
'dmsetup status' yields information on the state and health of the
array.
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index a8a1915a450..88143a0303d 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -308,6 +308,7 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
* [daemon_sleep <ms>] Time between bitmap daemon work to clear bits
* [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
* [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
+ * [write_mostly <idx>] Indicate a write mostly drive via index
* [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
* [stripe_cache <sectors>] Stripe cache size for higher RAIDs
* [region_size <sectors>] Defines granularity of bitmap
@@ -376,7 +377,21 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
clear_bit(In_sync, &rs->dev[value].rdev.flags);
rs->dev[value].rdev.recovery_offset = 0;
rs->print_flags |= DMPF_REBUILD;
+ } else if (!strcasecmp(key, "write_mostly")) {
+ if (rs->raid_type->level != 1) {
+ rs->ti->error = "write_mostly option is only valid for RAID1";
+ return -EINVAL;
+ }
+ if (value > rs->md.raid_disks) {
+ rs->ti->error = "Invalid write_mostly drive index given";
+ return -EINVAL;
+ }
+ set_bit(WriteMostly, &rs->dev[value].rdev.flags);
} else if (!strcasecmp(key, "max_write_behind")) {
+ if (rs->raid_type->level != 1) {
+ rs->ti->error = "max_write_behind option is only valid for RAID1";
+ return -EINVAL;
+ }
rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
/*
@@ -621,11 +636,15 @@ static int raid_status(struct dm_target *ti, status_type_t type,
break;
case STATUSTYPE_TABLE:
/* The string you would use to construct this array */
- for (i = 0; i < rs->md.raid_disks; i++)
+ for (i = 0; i < rs->md.raid_disks; i++) {
if ((rs->print_flags & DMPF_REBUILD) &&
rs->dev[i].data_dev &&
!test_bit(In_sync, &rs->dev[i].rdev.flags))
raid_param_cnt += 2; /* for rebuilds */
+ if (rs->dev[i].data_dev &&
+ test_bit(WriteMostly, &rs->dev[i].rdev.flags))
+ raid_param_cnt += 2;
+ }
raid_param_cnt += (hweight64(rs->print_flags & ~DMPF_REBUILD) * 2);
if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
@@ -656,6 +675,11 @@ static int raid_status(struct dm_target *ti, status_type_t type,
if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
+ for (i = 0; i < rs->md.raid_disks; i++)
+ if (rs->dev[i].data_dev &&
+ test_bit(WriteMostly, &rs->dev[i].rdev.flags))
+ DMEMIT(" write_mostly %u", i);
+
if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
DMEMIT(" max_write_behind %lu",
rs->md.bitmap_info.max_write_behind);