[dm-devel] [PATCH v3 7/8] dm raid: add iterate_devices and io_hints functions
Mike Snitzer
snitzer at redhat.com
Tue Dec 21 02:37:44 UTC 2010
From: NeilBrown <neilb at suse.de>
Add .iterate_devices function which should be implemented for all DM
targets.
Add an .io_hints function too because the provided topology information
is particularly important for a raid device.
Signed-off-by: NeilBrown <neilb at suse.de>
Signed-off-by: Jonathan Brassow <jbrassow at redhat.com>
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
drivers/md/dm-raid.c | 33 +++++++++++++++++++++++++++++++++
1 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 4db3eab..6494833 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -577,6 +577,37 @@ static int raid_status(struct dm_target *ti, status_type_t type,
return 0;
}
+static int raid_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn,
+ void *data)
+{
+ struct raid_set *rs = ti->private;
+ int ret = 0;
+ unsigned i = 0;
+
+ for (i = 0; !ret && i < rs->md.raid_disks; i++)
+ if (rs->dev[i].data_dev)
+ ret = fn(ti,
+ rs->dev[i].data_dev,
+ 0, /* No offset on data devs */
+ rs->md.dev_sectors,
+ data);
+
+ return ret;
+}
+
+static void raid_io_hints(struct dm_target *ti,
+ struct queue_limits *limits)
+{
+ struct raid_set *rs = ti->private;
+ unsigned chunk_size = rs->md.chunk_sectors << 9;
+ raid5_conf_t *conf = rs->md.private;
+
+ blk_limits_io_min(limits, chunk_size);
+ blk_limits_io_opt(limits, chunk_size *
+ (conf->raid_disks - conf->max_degraded));
+}
+
static struct target_type raid_target = {
.name = "raid",
.version = {1, 0, 0},
@@ -585,6 +616,8 @@ static struct target_type raid_target = {
.dtr = raid_dtr,
.map = raid_map,
.status = raid_status,
+ .iterate_devices = raid_iterate_devices,
+ .io_hints = raid_io_hints,
};
static int __init dm_raid_init(void)
--
1.7.2.3
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