From 4bfd482e73b30284cb21e10834ce729fa81aa256 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 5 Mar 2012 13:15:08 -0800 Subject: blkcg: kill blkio_policy_node Now that blkcg configuration lives in blkg's, blkio_policy_node is no longer necessary. Kill it. blkio_policy_parse_and_set() now fails if invoked for missing device and functions to print out configurations are updated to print from blkg's. cftype_blkg_same_policy() is dropped along with other policy functions for consistency. Its one line is open coded in the only user - blkio_read_blkg_stats(). -v2: Update to reflect the retry-on-bypass logic change of the previous patch. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 437 ++++++++--------------------------------------------- block/blk-cgroup.h | 32 ---- 2 files changed, 59 insertions(+), 410 deletions(-) (limited to 'block') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index fe8ce148017..adf61c99258 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -59,54 +59,6 @@ struct cgroup_subsys blkio_subsys = { }; EXPORT_SYMBOL_GPL(blkio_subsys); -static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg, - struct blkio_policy_node *pn) -{ - list_add(&pn->node, &blkcg->policy_list); -} - -static inline bool cftype_blkg_same_policy(struct cftype *cft, - struct blkio_group *blkg) -{ - enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); - - if (blkg->plid == plid) - return 1; - - return 0; -} - -/* Determines if policy node matches cgroup file being accessed */ -static inline bool pn_matches_cftype(struct cftype *cft, - struct blkio_policy_node *pn) -{ - enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); - int fileid = BLKIOFILE_ATTR(cft->private); - - return (plid == pn->plid && fileid == pn->fileid); -} - -/* Must be called with blkcg->lock held */ -static inline void blkio_policy_delete_node(struct blkio_policy_node *pn) -{ - list_del(&pn->node); -} - -/* Must be called with blkcg->lock held */ -static struct blkio_policy_node * -blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev, - enum blkio_policy_id plid, int fileid) -{ - struct blkio_policy_node *pn; - - list_for_each_entry(pn, &blkcg->policy_list, node) { - if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid) - return pn; - } - - return NULL; -} - struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), @@ -854,10 +806,8 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg, return disk_total; } -static int blkio_policy_parse_and_set(char *buf, - struct blkio_policy_node *newpn, - enum blkio_policy_id plid, int fileid, - struct blkio_cgroup *blkcg) +static int blkio_policy_parse_and_set(char *buf, enum blkio_policy_id plid, + int fileid, struct blkio_cgroup *blkcg) { struct gendisk *disk = NULL; struct blkio_group *blkg = NULL; @@ -905,78 +855,51 @@ static int blkio_policy_parse_and_set(char *buf, if (strict_strtoull(s[1], 10, &temp)) goto out; - /* For rule removal, do not check for device presence. */ disk = get_gendisk(dev, &part); - - if ((!disk || part) && temp) { - ret = -ENODEV; + if (!disk || part) goto out; - } rcu_read_lock(); - if (disk && !part) { - spin_lock_irq(disk->queue->queue_lock); - blkg = blkg_lookup_create(blkcg, disk->queue, plid, false); - spin_unlock_irq(disk->queue->queue_lock); + spin_lock_irq(disk->queue->queue_lock); + blkg = blkg_lookup_create(blkcg, disk->queue, plid, false); + spin_unlock_irq(disk->queue->queue_lock); - if (IS_ERR(blkg)) { - ret = PTR_ERR(blkg); - if (ret == -EBUSY) - goto out_unlock; - blkg = NULL; - } + if (IS_ERR(blkg)) { + ret = PTR_ERR(blkg); + goto out_unlock; } - newpn->dev = dev; - switch (plid) { case BLKIO_POLICY_PROP: if ((temp < BLKIO_WEIGHT_MIN && temp > 0) || temp > BLKIO_WEIGHT_MAX) goto out_unlock; - newpn->plid = plid; - newpn->fileid = fileid; - newpn->val.weight = temp; - if (blkg) - blkg->conf.weight = temp; + blkg->conf.weight = temp; + blkio_update_group_weight(blkg, temp ?: blkcg->weight); break; case BLKIO_POLICY_THROTL: switch(fileid) { case BLKIO_THROTL_read_bps_device: - if (blkg) - blkg->conf.bps[READ] = temp; - newpn->plid = plid; - newpn->fileid = fileid; - newpn->val.bps = temp; + blkg->conf.bps[READ] = temp; + blkio_update_group_bps(blkg, temp ?: -1, fileid); break; case BLKIO_THROTL_write_bps_device: - if (blkg) - blkg->conf.bps[WRITE] = temp; - newpn->plid = plid; - newpn->fileid = fileid; - newpn->val.bps = temp; + blkg->conf.bps[WRITE] = temp; + blkio_update_group_bps(blkg, temp ?: -1, fileid); break; case BLKIO_THROTL_read_iops_device: if (temp > THROTL_IOPS_MAX) goto out_unlock; - - if (blkg) - blkg->conf.iops[READ] = temp; - newpn->plid = plid; - newpn->fileid = fileid; - newpn->val.iops = (unsigned int)temp; + blkg->conf.iops[READ] = temp; + blkio_update_group_iops(blkg, temp ?: -1, fileid); break; case BLKIO_THROTL_write_iops_device: if (temp > THROTL_IOPS_MAX) goto out_unlock; - - if (blkg) - blkg->conf.iops[WRITE] = temp; - newpn->plid = plid; - newpn->fileid = fileid; - newpn->val.iops = (unsigned int)temp; + blkg->conf.iops[WRITE] = temp; + blkio_update_group_iops(blkg, temp ?: -1, fileid); break; } break; @@ -1002,212 +925,12 @@ out: return ret; } -unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, - dev_t dev) -{ - struct blkio_policy_node *pn; - unsigned long flags; - unsigned int weight; - - spin_lock_irqsave(&blkcg->lock, flags); - - pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, - BLKIO_PROP_weight_device); - if (pn) - weight = pn->val.weight; - else - weight = blkcg->weight; - - spin_unlock_irqrestore(&blkcg->lock, flags); - - return weight; -} -EXPORT_SYMBOL_GPL(blkcg_get_weight); - -uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) -{ - struct blkio_policy_node *pn; - unsigned long flags; - uint64_t bps = -1; - - spin_lock_irqsave(&blkcg->lock, flags); - pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, - BLKIO_THROTL_read_bps_device); - if (pn) - bps = pn->val.bps; - spin_unlock_irqrestore(&blkcg->lock, flags); - - return bps; -} - -uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) -{ - struct blkio_policy_node *pn; - unsigned long flags; - uint64_t bps = -1; - - spin_lock_irqsave(&blkcg->lock, flags); - pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, - BLKIO_THROTL_write_bps_device); - if (pn) - bps = pn->val.bps; - spin_unlock_irqrestore(&blkcg->lock, flags); - - return bps; -} - -unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) -{ - struct blkio_policy_node *pn; - unsigned long flags; - unsigned int iops = -1; - - spin_lock_irqsave(&blkcg->lock, flags); - pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, - BLKIO_THROTL_read_iops_device); - if (pn) - iops = pn->val.iops; - spin_unlock_irqrestore(&blkcg->lock, flags); - - return iops; -} - -unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) -{ - struct blkio_policy_node *pn; - unsigned long flags; - unsigned int iops = -1; - - spin_lock_irqsave(&blkcg->lock, flags); - pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, - BLKIO_THROTL_write_iops_device); - if (pn) - iops = pn->val.iops; - spin_unlock_irqrestore(&blkcg->lock, flags); - - return iops; -} - -/* Checks whether user asked for deleting a policy rule */ -static bool blkio_delete_rule_command(struct blkio_policy_node *pn) -{ - switch(pn->plid) { - case BLKIO_POLICY_PROP: - if (pn->val.weight == 0) - return 1; - break; - case BLKIO_POLICY_THROTL: - 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(); - } - - return 0; -} - -static void blkio_update_policy_rule(struct blkio_policy_node *oldpn, - struct blkio_policy_node *newpn) -{ - switch(oldpn->plid) { - case BLKIO_POLICY_PROP: - oldpn->val.weight = newpn->val.weight; - break; - case BLKIO_POLICY_THROTL: - 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(); - } -} - -/* - * Some rules/values in blkg have changed. Propagate those to respective - * policies. - */ -static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg, - struct blkio_group *blkg, struct blkio_policy_node *pn) -{ - struct blkio_group_conf *conf = &blkg->conf; - - switch(pn->plid) { - case BLKIO_POLICY_PROP: - blkio_update_group_weight(blkg, conf->weight ?: blkcg->weight); - break; - case BLKIO_POLICY_THROTL: - switch(pn->fileid) { - case BLKIO_THROTL_read_bps_device: - blkio_update_group_bps(blkg, conf->bps[READ] ?: -1, - pn->fileid); - break; - case BLKIO_THROTL_write_bps_device: - blkio_update_group_bps(blkg, conf->bps[WRITE] ?: -1, - pn->fileid); - break; - case BLKIO_THROTL_read_iops_device: - blkio_update_group_iops(blkg, conf->iops[READ] ?: -1, - pn->fileid); - break; - case BLKIO_THROTL_write_iops_device: - blkio_update_group_iops(blkg, conf->iops[WRITE] ?: -1, - pn->fileid); - break; - } - break; - default: - BUG(); - } -} - -/* - * A policy node rule has been updated. Propagate this update to all the - * block groups which might be affected by this update. - */ -static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg, - struct blkio_policy_node *pn) -{ - struct blkio_group *blkg; - struct hlist_node *n; - - spin_lock(&blkio_list_lock); - spin_lock_irq(&blkcg->lock); - - hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { - if (pn->dev != blkg->dev || pn->plid != blkg->plid) - continue; - blkio_update_blkg_policy(blkcg, blkg, pn); - } - - spin_unlock_irq(&blkcg->lock); - spin_unlock(&blkio_list_lock); -} - static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { int ret = 0; char *buf; - struct blkio_policy_node *newpn, *pn; struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp); - int keep_newpn = 0; enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); int fileid = BLKIOFILE_ATTR(cft->private); @@ -1215,69 +938,42 @@ static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, if (!buf) return -ENOMEM; - newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); - if (!newpn) { - ret = -ENOMEM; - goto free_buf; - } - - ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid, blkcg); - if (ret) - goto free_newpn; - - spin_lock_irq(&blkcg->lock); - - pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid); - if (!pn) { - if (!blkio_delete_rule_command(newpn)) { - blkio_policy_insert_node(blkcg, newpn); - keep_newpn = 1; - } - spin_unlock_irq(&blkcg->lock); - goto update_io_group; - } - - if (blkio_delete_rule_command(newpn)) { - blkio_policy_delete_node(pn); - kfree(pn); - spin_unlock_irq(&blkcg->lock); - goto update_io_group; - } - spin_unlock_irq(&blkcg->lock); - - blkio_update_policy_rule(pn, newpn); - -update_io_group: - blkio_update_policy_node_blkg(blkcg, newpn); - -free_newpn: - if (!keep_newpn) - kfree(newpn); -free_buf: + ret = blkio_policy_parse_and_set(buf, plid, fileid, blkcg); kfree(buf); return ret; } -static void -blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) +static void blkio_print_group_conf(struct cftype *cft, struct blkio_group *blkg, + struct seq_file *m) { - switch(pn->plid) { + int fileid = BLKIOFILE_ATTR(cft->private); + int rw = WRITE; + + switch (blkg->plid) { case BLKIO_POLICY_PROP: - if (pn->fileid == BLKIO_PROP_weight_device) - seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), - MINOR(pn->dev), pn->val.weight); + if (blkg->conf.weight) + seq_printf(m, "%u:%u\t%u\n", MAJOR(blkg->dev), + MINOR(blkg->dev), blkg->conf.weight); break; case BLKIO_POLICY_THROTL: - switch(pn->fileid) { + switch (fileid) { case BLKIO_THROTL_read_bps_device: + rw = READ; case BLKIO_THROTL_write_bps_device: - seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev), - MINOR(pn->dev), pn->val.bps); + if (blkg->conf.bps[rw]) + seq_printf(m, "%u:%u\t%llu\n", + MAJOR(blkg->dev), + MINOR(blkg->dev), + blkg->conf.bps[rw]); break; case BLKIO_THROTL_read_iops_device: + rw = READ; case BLKIO_THROTL_write_iops_device: - seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), - MINOR(pn->dev), pn->val.iops); + if (blkg->conf.iops[rw]) + seq_printf(m, "%u:%u\t%u\n", + MAJOR(blkg->dev), + MINOR(blkg->dev), + blkg->conf.iops[rw]); break; } break; @@ -1287,20 +983,17 @@ blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) } /* cgroup files which read their data from policy nodes end up here */ -static void blkio_read_policy_node_files(struct cftype *cft, - struct blkio_cgroup *blkcg, struct seq_file *m) +static void blkio_read_conf(struct cftype *cft, struct blkio_cgroup *blkcg, + struct seq_file *m) { - struct blkio_policy_node *pn; + struct blkio_group *blkg; + struct hlist_node *n; - if (!list_empty(&blkcg->policy_list)) { - spin_lock_irq(&blkcg->lock); - list_for_each_entry(pn, &blkcg->policy_list, node) { - if (!pn_matches_cftype(cft, pn)) - continue; - blkio_print_policy_node(m, pn); - } - spin_unlock_irq(&blkcg->lock); - } + spin_lock_irq(&blkcg->lock); + hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) + if (BLKIOFILE_POLICY(cft->private) == blkg->plid) + blkio_print_group_conf(cft, blkg, m); + spin_unlock_irq(&blkcg->lock); } static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, @@ -1316,7 +1009,7 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, case BLKIO_POLICY_PROP: switch(name) { case BLKIO_PROP_weight_device: - blkio_read_policy_node_files(cft, blkcg, m); + blkio_read_conf(cft, blkcg, m); return 0; default: BUG(); @@ -1328,7 +1021,7 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, 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); + blkio_read_conf(cft, blkcg, m); return 0; default: BUG(); @@ -1352,7 +1045,7 @@ static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg, rcu_read_lock(); hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { if (blkg->dev) { - if (!cftype_blkg_same_policy(cft, blkg)) + if (BLKIOFILE_POLICY(cft->private) != blkg->plid) continue; if (pcpu) cgroup_total += blkio_get_stat_cpu(blkg, cb, @@ -1451,11 +1144,10 @@ static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, return 0; } -static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) +static int blkio_weight_write(struct blkio_cgroup *blkcg, int plid, u64 val) { struct blkio_group *blkg; struct hlist_node *n; - struct blkio_policy_node *pn; if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) return -EINVAL; @@ -1464,14 +1156,10 @@ static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) spin_lock_irq(&blkcg->lock); blkcg->weight = (unsigned int)val; - hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { - pn = blkio_policy_search_node(blkcg, blkg->dev, - BLKIO_POLICY_PROP, BLKIO_PROP_weight_device); - if (pn) - continue; + hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) + if (blkg->plid == plid && !blkg->conf.weight) + blkio_update_group_weight(blkg, blkcg->weight); - blkio_update_group_weight(blkg, blkcg->weight); - } spin_unlock_irq(&blkcg->lock); spin_unlock(&blkio_list_lock); return 0; @@ -1510,7 +1198,7 @@ blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) case BLKIO_POLICY_PROP: switch(name) { case BLKIO_PROP_weight: - return blkio_weight_write(blkcg, val); + return blkio_weight_write(blkcg, plid, val); } break; default: @@ -1691,7 +1379,6 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) struct blkio_group *blkg; struct request_queue *q; struct blkio_policy_type *blkiop; - struct blkio_policy_node *pn, *pntmp; rcu_read_lock(); do { @@ -1723,11 +1410,6 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) spin_unlock(&blkio_list_lock); } while (1); - list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { - blkio_policy_delete_node(pn); - kfree(pn); - } - free_css_id(&blkio_subsys, &blkcg->css); rcu_read_unlock(); if (blkcg != &blkio_root_cgroup) @@ -1754,7 +1436,6 @@ done: spin_lock_init(&blkcg->lock); INIT_HLIST_HEAD(&blkcg->blkg_list); - INIT_LIST_HEAD(&blkcg->policy_list); return &blkcg->css; } diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 81efe718a1c..9a5c68d7cc9 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -112,7 +112,6 @@ struct blkio_cgroup { unsigned int weight; spinlock_t lock; struct hlist_head blkg_list; - struct list_head policy_list; /* list of blkio_policy_node */ }; struct blkio_group_stats { @@ -182,37 +181,6 @@ struct blkio_group { struct blkio_group_stats_cpu __percpu *stats_cpu; }; -struct blkio_policy_node { - struct list_head node; - dev_t dev; - /* This node belongs to max bw policy or porportional weight policy */ - enum blkio_policy_id plid; - /* cgroup file to which this rule belongs to */ - int fileid; - - union { - unsigned int weight; - /* - * Rate read/write in terms of bytes per second - * Whether this rate represents read or write is determined - * by file type "fileid". - */ - u64 bps; - unsigned int iops; - } val; -}; - -extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, - dev_t dev); -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 struct blkio_group *(blkio_alloc_group_fn)(struct request_queue *q, struct blkio_cgroup *blkcg); typedef void (blkio_link_group_fn)(struct request_queue *q, -- cgit v1.2.3-70-g09d2