blk-cgroup: cgroup changes for IOPS limit support

o cgroup changes for IOPS throttling rules.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 135 insertions, 17 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index aae8c930a6f8..20ce6f584e43 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -149,6 +149,27 @@ static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
         }
 }
 
+static inline void blkio_update_group_iops(struct blkio_group *blkg,
+                        unsigned int iops, int fileid)
+{
+        struct blkio_policy_type *blkiop;
+
+        list_for_each_entry(blkiop, &blkio_list, list) {
+
+                /* If this policy does not own the blkg, do not send updates */
+                if (blkiop->plid != blkg->plid)
+                        continue;
+
+                if (fileid == BLKIO_THROTL_read_iops_device
+                    && blkiop->ops.blkio_update_group_read_iops_fn)
+                        blkiop->ops.blkio_update_group_read_iops_fn(blkg, iops);
+
+                if (fileid == BLKIO_THROTL_write_iops_device
+                    && blkiop->ops.blkio_update_group_write_iops_fn)
+                        blkiop->ops.blkio_update_group_write_iops_fn(blkg,iops);
+        }
+}
+
 /*
  * Add to the appropriate stat variable depending on the request type.
  * This should be called with the blkg->stats_lock held.
@@ -630,7 +651,7 @@ static int blkio_policy_parse_and_set(char *buf,
 {
         char *s[4], *p, *major_s = NULL, *minor_s = NULL;
         int ret;
-        unsigned long major, minor, temp;
+        unsigned long major, minor, temp, iops;
         int i = 0;
         dev_t dev;
         u64 bps;
@@ -692,13 +713,28 @@ static int blkio_policy_parse_and_set(char *buf,
                 newpn->val.weight = temp;
                 break;
         case BLKIO_POLICY_THROTL:
-                ret = strict_strtoull(s[1], 10, &bps);
-                if (ret)
-                        return -EINVAL;
+                switch(fileid) {
+                case BLKIO_THROTL_read_bps_device:
+                case BLKIO_THROTL_write_bps_device:
+                        ret = strict_strtoull(s[1], 10, &bps);
+                        if (ret)
+                                return -EINVAL;
 
-                newpn->plid = plid;
-                newpn->fileid = fileid;
-                newpn->val.bps = bps;
+                        newpn->plid = plid;
+                        newpn->fileid = fileid;
+                        newpn->val.bps = bps;
+                        break;
+                case BLKIO_THROTL_read_iops_device:
+                case BLKIO_THROTL_write_iops_device:
+                        ret = strict_strtoul(s[1], 10, &iops);
+                        if (ret)
+                                return -EINVAL;
+
+                        newpn->plid = plid;
+                        newpn->fileid = fileid;
+                        newpn->val.iops = iops;
+                        break;
+                }
                 break;
         default:
                 BUG();
@@ -744,6 +780,29 @@ uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
                 return -1;
 }
 
+unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+        struct blkio_policy_node *pn;
+
+        pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+                                BLKIO_THROTL_read_iops_device);
+        if (pn)
+                return pn->val.iops;
+        else
+                return -1;
+}
+
+unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+        struct blkio_policy_node *pn;
+        pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+                                BLKIO_THROTL_write_iops_device);
+        if (pn)
+                return pn->val.iops;
+        else
+                return -1;
+}
+
 /* Checks whether user asked for deleting a policy rule */
 static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
 {
@@ -753,8 +812,17 @@ static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
                         return 1;
                 break;
         case BLKIO_POLICY_THROTL:
-                if (pn->val.bps == 0)
-                        return 1;
+                switch(pn->fileid) {
+                case BLKIO_THROTL_read_bps_device:
+                case BLKIO_THROTL_write_bps_device:
+                        if (pn->val.bps == 0)
+                                return 1;
+                        break;
+                case BLKIO_THROTL_read_iops_device:
+                case BLKIO_THROTL_write_iops_device:
+                        if (pn->val.iops == 0)
+                                return 1;
+                }
                 break;
         default:
                 BUG();
@@ -771,7 +839,15 @@ static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
                 oldpn->val.weight = newpn->val.weight;
                 break;
         case BLKIO_POLICY_THROTL:
-                oldpn->val.bps = newpn->val.bps;
+                switch(newpn->fileid) {
+                case BLKIO_THROTL_read_bps_device:
+                case BLKIO_THROTL_write_bps_device:
+                        oldpn->val.bps = newpn->val.bps;
+                        break;
+                case BLKIO_THROTL_read_iops_device:
+                case BLKIO_THROTL_write_iops_device:
+                        oldpn->val.iops = newpn->val.iops;
+                }
                 break;
         default:
                 BUG();
@@ -785,7 +861,7 @@ static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
 static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
                 struct blkio_group *blkg, struct blkio_policy_node *pn)
 {
-        unsigned int weight;
+        unsigned int weight, iops;
         u64 bps;
 
         switch(pn->plid) {
@@ -801,6 +877,11 @@ static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
                         bps = pn->val.bps ? pn->val.bps : (-1);
                         blkio_update_group_bps(blkg, bps, pn->fileid);
                         break;
+                case BLKIO_THROTL_read_iops_device:
+                case BLKIO_THROTL_write_iops_device:
+                        iops = pn->val.iops ? pn->val.iops : (-1);
+                        blkio_update_group_iops(blkg, iops, pn->fileid);
+                        break;
                 }
                 break;
         default:
@@ -900,14 +981,18 @@ blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
                                         MINOR(pn->dev), pn->val.weight);
                         break;
                 case BLKIO_POLICY_THROTL:
-                        if (pn->fileid == BLKIO_THROTL_read_bps_device)
+                        switch(pn->fileid) {
+                        case BLKIO_THROTL_read_bps_device:
+                        case BLKIO_THROTL_write_bps_device:
                                 seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
                                         MINOR(pn->dev), pn->val.bps);
-                        else if (pn->fileid == BLKIO_THROTL_write_bps_device)
-                                seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
-                                        MINOR(pn->dev), pn->val.bps);
-                        else
-                                BUG();
+                                break;
+                        case BLKIO_THROTL_read_iops_device:
+                        case BLKIO_THROTL_write_iops_device:
+                                seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
+                                        MINOR(pn->dev), pn->val.iops);
+                                break;
+                        }
                         break;
                 default:
                         BUG();
@@ -954,6 +1039,8 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
                 switch(name){
                 case BLKIO_THROTL_read_bps_device:
                 case BLKIO_THROTL_write_bps_device:
+                case BLKIO_THROTL_read_iops_device:
+                case BLKIO_THROTL_write_iops_device:
                         blkio_read_policy_node_files(cft, blkcg, m);
                         return 0;
                 default:
@@ -1171,6 +1258,24 @@ struct cftype blkio_files[] = {
                 .write_string = blkiocg_file_write,
                 .max_write_len = 256,
         },
+
+        {
+                .name = "throttle.read_iops_device",
+                .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+                                BLKIO_THROTL_read_iops_device),
+                .read_seq_string = blkiocg_file_read,
+                .write_string = blkiocg_file_write,
+                .max_write_len = 256,
+        },
+
+        {
+                .name = "throttle.write_iops_device",
+                .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+                                BLKIO_THROTL_write_iops_device),
+                .read_seq_string = blkiocg_file_read,
+                .write_string = blkiocg_file_write,
+                .max_write_len = 256,
+        },
         {
                 .name = "time",
                 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 1b738827b2f6..2070053a30b1 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -93,6 +93,8 @@ enum blkcg_file_name_prop {
 enum blkcg_file_name_throtl {
         BLKIO_THROTL_read_bps_device,
         BLKIO_THROTL_write_bps_device,
+        BLKIO_THROTL_read_iops_device,
+        BLKIO_THROTL_write_iops_device,
         BLKIO_THROTL_io_service_bytes,
         BLKIO_THROTL_io_serviced,
 };
@@ -168,6 +170,7 @@ struct blkio_policy_node {
                  * by file type "fileid".
                  */
                 u64 bps;
+                unsigned int iops;
         } val;
 };
 
@@ -177,6 +180,10 @@ extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
                                      dev_t dev);
 extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
                                      dev_t dev);
+extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
+                                     dev_t dev);
+extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
+                                     dev_t dev);
 
 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
@@ -185,12 +192,18 @@ typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
                                                 u64 read_bps);
 typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
                                                 u64 write_bps);
+typedef void (blkio_update_group_read_iops_fn) (struct blkio_group *blkg,
+                                                unsigned int read_iops);
+typedef void (blkio_update_group_write_iops_fn) (struct blkio_group *blkg,
+                                                unsigned int write_iops);
 
 struct blkio_policy_ops {
         blkio_unlink_group_fn *blkio_unlink_group_fn;
         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
         blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
         blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
+        blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
+        blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
 };
 
 struct blkio_policy_type {