bna: check for dma mapping errors
[cascardo/linux.git] / block / cfq-iosched.c
index ea88d89..04de884 100644 (file)
@@ -68,9 +68,9 @@ static struct kmem_cache *cfq_pool;
 #define rb_entry_cfqg(node)    rb_entry((node), struct cfq_group, rb_node)
 
 /* blkio-related constants */
-#define CFQ_WEIGHT_MIN          10
-#define CFQ_WEIGHT_MAX          1000
-#define CFQ_WEIGHT_DEFAULT      500
+#define CFQ_WEIGHT_LEGACY_MIN  10
+#define CFQ_WEIGHT_LEGACY_DFL  500
+#define CFQ_WEIGHT_LEGACY_MAX  1000
 
 struct cfq_ttime {
        unsigned long last_end_request;
@@ -1522,6 +1522,9 @@ static void cfq_init_cfqg_base(struct cfq_group *cfqg)
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
+static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
+                           bool on_dfl, bool reset_dev, bool is_leaf_weight);
+
 static void cfqg_stats_exit(struct cfqg_stats *stats)
 {
        blkg_rwstat_exit(&stats->merged);
@@ -1578,14 +1581,14 @@ static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
 static void cfq_cpd_init(struct blkcg_policy_data *cpd)
 {
        struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
+       unsigned int weight = cgroup_on_dfl(blkcg_root.css.cgroup) ?
+                             CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
 
-       if (cpd_to_blkcg(cpd) == &blkcg_root) {
-               cgd->weight = 2 * CFQ_WEIGHT_DEFAULT;
-               cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
-       } else {
-               cgd->weight = CFQ_WEIGHT_DEFAULT;
-               cgd->leaf_weight = CFQ_WEIGHT_DEFAULT;
-       }
+       if (cpd_to_blkcg(cpd) == &blkcg_root)
+               weight *= 2;
+
+       cgd->weight = weight;
+       cgd->leaf_weight = weight;
 }
 
 static void cfq_cpd_free(struct blkcg_policy_data *cpd)
@@ -1593,6 +1596,19 @@ static void cfq_cpd_free(struct blkcg_policy_data *cpd)
        kfree(cpd_to_cfqgd(cpd));
 }
 
+static void cfq_cpd_bind(struct blkcg_policy_data *cpd)
+{
+       struct blkcg *blkcg = cpd_to_blkcg(cpd);
+       bool on_dfl = cgroup_on_dfl(blkcg_root.css.cgroup);
+       unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
+
+       if (blkcg == &blkcg_root)
+               weight *= 2;
+
+       WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false));
+       WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true));
+}
+
 static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
 {
        struct cfq_group *cfqg;
@@ -1740,8 +1756,10 @@ 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)
 {
+       unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
+       unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
        struct blkcg *blkcg = css_to_blkcg(of_css(of));
        struct blkg_conf_ctx ctx;
        struct cfq_group *cfqg;
@@ -1753,15 +1771,23 @@ 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);
 
        ret = -ERANGE;
-       if (!v || (v >= CFQ_WEIGHT_MIN && v <= CFQ_WEIGHT_MAX)) {
+       if (!v || (v >= min && v <= max)) {
                if (!is_leaf_weight) {
                        cfqg->dev_weight = v;
                        cfqg->new_weight = v ?: cfqgd->weight;
@@ -1779,25 +1805,27 @@ 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, struct cftype *cft,
-                           u64 val, bool is_leaf_weight)
+static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
+                           bool on_dfl, bool reset_dev, bool is_leaf_weight)
 {
+       unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
+       unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
        struct blkcg *blkcg = css_to_blkcg(css);
        struct blkcg_gq *blkg;
        struct cfq_group_data *cfqgd;
        int ret = 0;
 
-       if (val < CFQ_WEIGHT_MIN || val > CFQ_WEIGHT_MAX)
-               return -EINVAL;
+       if (val < min || val > max)
+               return -ERANGE;
 
        spin_lock_irq(&blkcg->lock);
        cfqgd = blkcg_to_cfqgd(blkcg);
@@ -1818,9 +1846,13 @@ static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
                        continue;
 
                if (!is_leaf_weight) {
+                       if (reset_dev)
+                               cfqg->dev_weight = 0;
                        if (!cfqg->dev_weight)
                                cfqg->new_weight = cfqgd->weight;
                } else {
+                       if (reset_dev)
+                               cfqg->dev_leaf_weight = 0;
                        if (!cfqg->dev_leaf_weight)
                                cfqg->new_leaf_weight = cfqgd->leaf_weight;
                }
@@ -1834,13 +1866,13 @@ out:
 static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
                          u64 val)
 {
-       return __cfq_set_weight(css, cft, val, false);
+       return __cfq_set_weight(css, val, false, false, false);
 }
 
 static int cfq_set_leaf_weight(struct cgroup_subsys_state *css,
                               struct cftype *cft, u64 val)
 {
-       return __cfq_set_weight(css, cft, val, true);
+       return __cfq_set_weight(css, val, false, false, true);
 }
 
 static int cfqg_print_stat(struct seq_file *sf, void *v)
@@ -2103,6 +2135,48 @@ 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, true, false, 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)
@@ -4462,9 +4536,9 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
                goto out_free;
 
        cfq_init_cfqg_base(cfqd->root_group);
+       cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
+       cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
 #endif
-       cfqd->root_group->weight = 2 * CFQ_WEIGHT_DEFAULT;
-       cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
 
        /*
         * Not strictly needed (since RB_ROOT just clears the node and we
@@ -4659,11 +4733,13 @@ 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,
        .cpd_init_fn            = cfq_cpd_init,
        .cpd_free_fn            = cfq_cpd_free,
+       .cpd_bind_fn            = cfq_cpd_bind,
 
        .pd_alloc_fn            = cfq_pd_alloc,
        .pd_init_fn             = cfq_pd_init,