From 40bea431274c247425e7f5970d796ff7b37a2b22 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 4 Sep 2009 20:40:25 +0100 Subject: [PATCH] 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 Signed-off-by: Alasdair G Kergon --- drivers/md/dm-stripe.c | 13 ++++++++++++- drivers/md/dm-table.c | 4 ++++ include/linux/device-mapper.h | 4 ++++ 3 files changed, 20 insertions(+), 1 deletion(-) 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; -- 2.20.1