summary refs log tree commit diff
path: root/block/blk-throttle.c
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2012-03-05 13:15:07 -0800
committerJens Axboe <axboe@kernel.dk>2012-03-06 21:27:22 +0100
commite56da7e287967667474a58c4f60c286279e3f487 (patch)
tree4ce64581888f287a25b4abdc21fc641210351612 /block/blk-throttle.c
parentcd1604fab4f95f7cfc227d3955fd7ae14da61f38 (diff)
downloadlinux-e56da7e287967667474a58c4f60c286279e3f487.tar.gz
blkcg: don't allow or retain configuration of missing devices
blkcg is very peculiar in that it allows setting and remembering
configurations for non-existent devices by maintaining separate data
structures for configuration.

This behavior is completely out of the usual norms and outright
confusing; furthermore, it uses dev_t number to match the
configuration to devices, which is unpredictable to begin with and
becomes completely unuseable if EXT_DEVT is fully used.

It is wholely unnecessary - we already have fully functional userland
mechanism to program devices being hotplugged which has full access to
device identification, connection topology and filesystem information.

Add a new struct blkio_group_conf which contains all blkcg
configurations to blkio_group and let blkio_group, which can be
created iff the associated device exists and is removed when the
associated device goes away, carry all configurations.

Note that, after this patch, all newly created blkg's will always have
the default configuration (unlimited for throttling and blkcg's weight
for propio).

This patch makes blkio_policy_node meaningless but doesn't remove it.
The next patch will.

-v2: Updated to retry after short sleep if blkg lookup/creation failed
     due to the queue being temporarily bypassed as indicated by
     -EBUSY return.  Pointed out by Vivek.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-throttle.c')
-rw-r--r--block/blk-throttle.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 2ae637b9e80c..791b10719e43 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -196,10 +196,10 @@ static struct blkio_group *throtl_alloc_blkio_group(struct request_queue *q,
 	bio_list_init(&tg->bio_lists[1]);
 	tg->limits_changed = false;
 
-	tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
-	tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
-	tg->iops[READ] = blkcg_get_read_iops(blkcg, tg->blkg.dev);
-	tg->iops[WRITE] = blkcg_get_write_iops(blkcg, tg->blkg.dev);
+	tg->bps[READ] = -1;
+	tg->bps[WRITE] = -1;
+	tg->iops[READ] = -1;
+	tg->iops[WRITE] = -1;
 
 	/*
 	 * Take the initial reference that will be released on destroy