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authorMike Snitzer <snitzer@redhat.com>2009-09-04 20:40:25 +0100
committerAlasdair G Kergon <agk@redhat.com>2009-09-04 20:40:25 +0100
commit40bea431274c247425e7f5970d796ff7b37a2b22 (patch)
treecc9791861c01605d2dca28d3eac9182c301a832c
parenta963a956225eb0f8c4d3537f428153c30adf54b8 (diff)
downloadlinux-stericsson-40bea431274c247425e7f5970d796ff7b37a2b22.tar.gz
dm stripe: expose correct io hints
Set sensible I/O hints for striped DM devices in the topology infrastructure added for 2.6.31 for userspace tools to obtain via sysfs. Add .io_hints to 'struct target_type' to allow the I/O hints portion (io_min and io_opt) of the 'struct queue_limits' to be set by each target and implement this for dm-stripe. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r--drivers/md/dm-stripe.c13
-rw-r--r--drivers/md/dm-table.c4
-rw-r--r--include/linux/device-mapper.h4
3 files changed, 20 insertions, 1 deletions
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 4e0e5937e42a..3e563d251733 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -329,9 +329,19 @@ static int stripe_iterate_devices(struct dm_target *ti,
return ret;
}
+static void stripe_io_hints(struct dm_target *ti,
+ struct queue_limits *limits)
+{
+ struct stripe_c *sc = ti->private;
+ unsigned chunk_size = (sc->chunk_mask + 1) << 9;
+
+ blk_limits_io_min(limits, chunk_size);
+ limits->io_opt = chunk_size * sc->stripes;
+}
+
static struct target_type stripe_target = {
.name = "striped",
- .version = {1, 2, 0},
+ .version = {1, 3, 0},
.module = THIS_MODULE,
.ctr = stripe_ctr,
.dtr = stripe_dtr,
@@ -339,6 +349,7 @@ static struct target_type stripe_target = {
.end_io = stripe_end_io,
.status = stripe_status,
.iterate_devices = stripe_iterate_devices,
+ .io_hints = stripe_io_hints,
};
int __init dm_stripe_init(void)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index c90e662d2802..1a6cb3c7822e 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1007,6 +1007,10 @@ int dm_calculate_queue_limits(struct dm_table *table,
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
+ /* Set I/O hints portion of queue limits */
+ if (ti->type->io_hints)
+ ti->type->io_hints(ti, &ti_limits);
+
/*
* Check each device area is consistent with the target's
* overall queue limits.
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 655e7721580a..df7607e6dce8 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -91,6 +91,9 @@ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
iterate_devices_callout_fn fn,
void *data);
+typedef void (*dm_io_hints_fn) (struct dm_target *ti,
+ struct queue_limits *limits);
+
/*
* Returns:
* 0: The target can handle the next I/O immediately.
@@ -151,6 +154,7 @@ struct target_type {
dm_merge_fn merge;
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
+ dm_io_hints_fn io_hints;
/* For internal device-mapper use. */
struct list_head list;