Patch name: dm-unplug-callback.patch
In a similar manner to congestion checking, per-target
unplug support for raid456 under dm.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
Index: linux-2.6/drivers/md/dm-raid.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-raid.c
+++ linux-2.6/drivers/md/dm-raid.c
@@ -258,6 +258,14 @@ static int raid_is_congested(void *v, in
callbacks);
return md_raid5_congested(&rs->md, bits);
}
+static void raid_unplug(void *v)
+{
+ struct target_callbacks *cb = v;
+ struct raid_set *rs = container_of(cb, struct raid_set,
+ callbacks);
+ md_raid5_unplug_device(rs->md.private);
+}
+
/*
* Construct a RAID4/5/6 mapping:
* Args:
@@ -341,6 +349,7 @@ static int raid_ctr(struct dm_target *ti
if (errnum)
goto err;
+ rs->callbacks.unplug_fn = raid_unplug;
rs->callbacks.congested_fn = raid_is_congested;
dm_table_add_callbacks(ti->table, &rs->callbacks);
Index: linux-2.6/drivers/md/dm-table.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-table.c
+++ linux-2.6/drivers/md/dm-table.c
@@ -1283,6 +1283,7 @@ void dm_table_unplug_all(struct dm_table
{
struct dm_dev_internal *dd;
struct list_head *devices = dm_table_get_devices(t);
+ struct target_callbacks *cb;
list_for_each_entry(dd, devices, list) {
struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
@@ -1295,6 +1296,9 @@ void dm_table_unplug_all(struct dm_table
dm_device_name(t->md),
bdevname(dd->dm_dev.bdev, b));
}
+ list_for_each_entry(cb, &t->target_callbacks, list)
+ if (cb->unplug_fn)
+ cb->unplug_fn(cb);
}
struct mapped_device *dm_table_get_md(struct dm_table *t)
Index: linux-2.6/include/linux/device-mapper.h
===================================================================
--- linux-2.6.orig/include/linux/device-mapper.h
+++ linux-2.6/include/linux/device-mapper.h
@@ -197,6 +197,7 @@ struct dm_target {
struct target_callbacks {
struct list_head list;
congested_fn *congested_fn;
+ void (*unplug_fn)(void *);
};
int dm_register_target(struct target_type *t);
--
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