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>

1 files changed, 3 insertions, 1 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.