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-rw-r--r--block/cfq-iosched.c61
1 files changed, 56 insertions, 5 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 7a7230136e43..97da5719c87a 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1740,7 +1740,7 @@ static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off,
- bool is_leaf_weight)
+ bool on_dfl, bool is_leaf_weight)
{
struct blkcg *blkcg = css_to_blkcg(of_css(of));
struct blkg_conf_ctx ctx;
@@ -1753,9 +1753,17 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
if (ret)
return ret;
- ret = -EINVAL;
- if (sscanf(ctx.body, "%llu", &v) != 1)
+ if (sscanf(ctx.body, "%llu", &v) == 1) {
+ /* require "default" on dfl */
+ ret = -ERANGE;
+ if (!v && on_dfl)
+ goto out_finish;
+ } else if (!strcmp(strim(ctx.body), "default")) {
+ v = 0;
+ } else {
+ ret = -EINVAL;
goto out_finish;
+ }
cfqg = blkg_to_cfqg(ctx.blkg);
cfqgd = blkcg_to_cfqgd(blkcg);
@@ -1779,13 +1787,13 @@ out_finish:
static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
- return __cfqg_set_weight_device(of, buf, nbytes, off, false);
+ return __cfqg_set_weight_device(of, buf, nbytes, off, false, false);
}
static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
- return __cfqg_set_weight_device(of, buf, nbytes, off, true);
+ return __cfqg_set_weight_device(of, buf, nbytes, off, false, true);
}
static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
@@ -2103,6 +2111,48 @@ static struct cftype cfq_blkcg_legacy_files[] = {
#endif /* CONFIG_DEBUG_BLK_CGROUP */
{ } /* terminate */
};
+
+static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+
+ seq_printf(sf, "default %u\n", cgd->weight);
+ blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device,
+ &blkcg_policy_cfq, 0, false);
+ return 0;
+}
+
+static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ char *endp;
+ int ret;
+ u64 v;
+
+ buf = strim(buf);
+
+ /* "WEIGHT" or "default WEIGHT" sets the default weight */
+ v = simple_strtoull(buf, &endp, 0);
+ if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
+ ret = __cfq_set_weight(of_css(of), v, false);
+ return ret ?: nbytes;
+ }
+
+ /* "MAJ:MIN WEIGHT" */
+ return __cfqg_set_weight_device(of, buf, nbytes, off, true, false);
+}
+
+static struct cftype cfq_blkcg_files[] = {
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cfq_print_weight_on_dfl,
+ .write = cfq_set_weight_on_dfl,
+ },
+ { } /* terminate */
+};
+
#else /* GROUP_IOSCHED */
static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
struct blkcg *blkcg)
@@ -4659,6 +4709,7 @@ static struct elevator_type iosched_cfq = {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static struct blkcg_policy blkcg_policy_cfq = {
+ .dfl_cftypes = cfq_blkcg_files,
.legacy_cftypes = cfq_blkcg_legacy_files,
.cpd_alloc_fn = cfq_cpd_alloc,