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authorTejun Heo <tj@kernel.org>2015-08-18 14:55:31 -0700
committerJens Axboe <axboe@fb.com>2015-08-18 15:49:18 -0700
commit36aa9e5f591e84d67aad2c5bff75e413d77660dd (patch)
tree228d8986be70359b086c30a453d1fc7ee77cfada /block/cfq-iosched.c
parent880f50e228f80626dff6327a6e281e40286f5228 (diff)
downloadlinux-0-day-36aa9e5f591e84d67aad2c5bff75e413d77660dd.tar.gz
blkcg: move body parsing from blkg_conf_prep() to its callers
Currently, blkg_conf_prep() expects input to be of the following form MAJ:MIN NUM and reads the NUM part into blkg_conf_ctx->v. This is quite restrictive and gets in the way in implementing blkcg interface for the unified hierarchy. This patch updates blkg_conf_prep() so that it expects MAJ:MIN BODY_STR where BODY_STR is an arbitrary string. blkg_conf_ctx->v is replaced with ->body which is a char pointer pointing to the start of BODY_STR. Parsing of the body is moved to blkg_conf_prep()'s callers. To allow using, for example, strsep() on blkg_conf_ctx->val, it is a non-const pointer and to accommodate that const is dropped from @input too. This doesn't cause any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r--block/cfq-iosched.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index baa8459..ea88d89 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1747,26 +1747,31 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
struct cfq_group *cfqg;
struct cfq_group_data *cfqgd;
int ret;
+ u64 v;
ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx);
if (ret)
return ret;
+ ret = -EINVAL;
+ if (sscanf(ctx.body, "%llu", &v) != 1)
+ goto out_finish;
+
cfqg = blkg_to_cfqg(ctx.blkg);
cfqgd = blkcg_to_cfqgd(blkcg);
ret = -ERANGE;
- if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) {
+ if (!v || (v >= CFQ_WEIGHT_MIN && v <= CFQ_WEIGHT_MAX)) {
if (!is_leaf_weight) {
- cfqg->dev_weight = ctx.v;
- cfqg->new_weight = ctx.v ?: cfqgd->weight;
+ cfqg->dev_weight = v;
+ cfqg->new_weight = v ?: cfqgd->weight;
} else {
- cfqg->dev_leaf_weight = ctx.v;
- cfqg->new_leaf_weight = ctx.v ?: cfqgd->leaf_weight;
+ cfqg->dev_leaf_weight = v;
+ cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight;
}
ret = 0;
}
-
+out_finish:
blkg_conf_finish(&ctx);
return ret ?: nbytes;
}