blkcg: refine error codes returned during blkcg configuration

blkcg currently returns -EINVAL for most errors which can be pretty
confusing given that the failure modes are quite varied.  Update the
error returns so that

* -EINVAL only for syntactic errors.
* -ERANGE if the value is out of range.
* -ENODEV if the target device can't be found.
* -EOPNOTSUPP if the policy is not enabled on the target device.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tejun Heo 2015-08-18 14:55:28 -07:00 committed by Jens Axboe
parent 5332dfc364
commit 20386ce014
2 changed files with 7 additions and 7 deletions

View File

@ -179,7 +179,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
/* blkg holds a reference to blkcg */
if (!css_tryget_online(&blkcg->css)) {
ret = -EINVAL;
ret = -ENODEV;
goto err_free_blkg;
}
@ -205,7 +205,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
if (blkcg_parent(blkcg)) {
blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
if (WARN_ON_ONCE(!blkg->parent)) {
ret = -EINVAL;
ret = -ENODEV;
goto err_put_congested;
}
blkg_get(blkg->parent);
@ -279,7 +279,7 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
* we shouldn't allow anything to go through for a bypassing queue.
*/
if (unlikely(blk_queue_bypass(q)))
return ERR_PTR(blk_queue_dying(q) ? -EINVAL : -EBUSY);
return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY);
blkg = __blkg_lookup(blkcg, q, true);
if (blkg)
@ -792,10 +792,10 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
disk = get_gendisk(MKDEV(major, minor), &part);
if (!disk)
return -EINVAL;
return -ENODEV;
if (part) {
put_disk(disk);
return -EINVAL;
return -ENODEV;
}
rcu_read_lock();
@ -804,7 +804,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
if (blkcg_policy_enabled(disk->queue, pol))
blkg = blkg_lookup_create(blkcg, disk->queue);
else
blkg = ERR_PTR(-EINVAL);
blkg = ERR_PTR(-EOPNOTSUPP);
if (IS_ERR(blkg)) {
ret = PTR_ERR(blkg);

View File

@ -1755,7 +1755,7 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
cfqg = blkg_to_cfqg(ctx.blkg);
cfqgd = blkcg_to_cfqgd(blkcg);
ret = -EINVAL;
ret = -ERANGE;
if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) {
if (!is_leaf_weight) {
cfqg->dev_weight = ctx.v;