From 3a8b31d396b296df4b8594429d86d415d3409432 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 1 Apr 2012 14:38:43 -0700 Subject: [PATCH] blkcg: restructure blkio_group configruation setting As part of userland interface restructuring, this patch updates per-blkio_group configuration setting. Instead of funneling everything through a master function which has hard-coded cases for each config file it may handle, the common part is factored into blkg_conf_prep() and blkg_conf_finish() and different configuration setters are implemented using the helpers. While this doesn't result in immediate LOC reduction, this enables further cleanups and more modular implementation. Signed-off-by: Tejun Heo --- block/blk-cgroup.c | 274 ++++++++++++++++++++++++++++------------------------- block/blk-cgroup.h | 13 --- 2 files changed, 147 insertions(+), 140 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index a9723a8..1e1ee2a 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -43,12 +43,6 @@ EXPORT_SYMBOL_GPL(blkio_root_cgroup); static struct blkio_policy_type *blkio_policy[BLKIO_NR_POLICIES]; -/* for encoding cft->private value on file */ -#define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val)) -/* What policy owns the file, proportional or throttle */ -#define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff) -#define BLKIOFILE_ATTR(val) ((val) & 0xffff) - struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), @@ -86,7 +80,7 @@ static inline void blkio_update_group_weight(struct blkio_group *blkg, } static inline void blkio_update_group_bps(struct blkio_group *blkg, int plid, - u64 bps, int fileid) + u64 bps, int rw) { struct blkio_policy_type *blkiop; @@ -96,21 +90,18 @@ static inline void blkio_update_group_bps(struct blkio_group *blkg, int plid, if (blkiop->plid != plid) continue; - if (fileid == BLKIO_THROTL_read_bps_device - && blkiop->ops.blkio_update_group_read_bps_fn) + if (rw == READ && blkiop->ops.blkio_update_group_read_bps_fn) blkiop->ops.blkio_update_group_read_bps_fn(blkg->q, blkg, bps); - if (fileid == BLKIO_THROTL_write_bps_device - && blkiop->ops.blkio_update_group_write_bps_fn) + if (rw == WRITE && blkiop->ops.blkio_update_group_write_bps_fn) blkiop->ops.blkio_update_group_write_bps_fn(blkg->q, blkg, bps); } } -static inline void blkio_update_group_iops(struct blkio_group *blkg, - int plid, unsigned int iops, - int fileid) +static inline void blkio_update_group_iops(struct blkio_group *blkg, int plid, + u64 iops, int rw) { struct blkio_policy_type *blkiop; @@ -120,13 +111,11 @@ static inline void blkio_update_group_iops(struct blkio_group *blkg, if (blkiop->plid != plid) continue; - if (fileid == BLKIO_THROTL_read_iops_device - && blkiop->ops.blkio_update_group_read_iops_fn) + if (rw == READ && blkiop->ops.blkio_update_group_read_iops_fn) blkiop->ops.blkio_update_group_read_iops_fn(blkg->q, blkg, iops); - if (fileid == BLKIO_THROTL_write_iops_device - && blkiop->ops.blkio_update_group_write_iops_fn) + if (rw == WRITE && blkiop->ops.blkio_update_group_write_iops_fn) blkiop->ops.blkio_update_group_write_iops_fn(blkg->q, blkg,iops); } @@ -975,19 +964,40 @@ static int blkcg_print_avg_queue_size(struct cgroup *cgrp, struct cftype *cft, } #endif /* CONFIG_DEBUG_BLK_CGROUP */ -static int blkio_policy_parse_and_set(char *buf, enum blkio_policy_id plid, - int fileid, struct blkio_cgroup *blkcg) +struct blkg_conf_ctx { + struct gendisk *disk; + struct blkio_group *blkg; + u64 v; +}; + +/** + * blkg_conf_prep - parse and prepare for per-blkg config update + * @blkcg: target block cgroup + * @input: input string + * @ctx: blkg_conf_ctx to be filled + * + * Parse per-blkg config update from @input and initialize @ctx with the + * result. @ctx->blkg points to the blkg to be updated and @ctx->v the new + * value. This function returns with RCU read locked and must be paired + * with blkg_conf_finish(). + */ +static int blkg_conf_prep(struct blkio_cgroup *blkcg, const char *input, + struct blkg_conf_ctx *ctx) + __acquires(rcu) { - struct gendisk *disk = NULL; - struct blkio_group *blkg = NULL; - struct blkg_policy_data *pd; - char *s[4], *p, *major_s = NULL, *minor_s = NULL; + struct gendisk *disk; + struct blkio_group *blkg; + char *buf, *s[4], *p, *major_s, *minor_s; unsigned long major, minor; int i = 0, ret = -EINVAL; int part; dev_t dev; u64 temp; + buf = kstrdup(input, GFP_KERNEL); + if (!buf) + return -ENOMEM; + memset(s, 0, sizeof(s)); while ((p = strsep(&buf, " ")) != NULL) { @@ -1037,82 +1047,42 @@ static int blkio_policy_parse_and_set(char *buf, enum blkio_policy_id plid, if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); - goto out_unlock; - } - - pd = blkg->pd[plid]; - - switch (plid) { - case BLKIO_POLICY_PROP: - if ((temp < BLKIO_WEIGHT_MIN && temp > 0) || - temp > BLKIO_WEIGHT_MAX) - goto out_unlock; - - pd->conf.weight = temp; - blkio_update_group_weight(blkg, plid, temp ?: blkcg->weight); - break; - case BLKIO_POLICY_THROTL: - switch(fileid) { - case BLKIO_THROTL_read_bps_device: - pd->conf.bps[READ] = temp; - blkio_update_group_bps(blkg, plid, temp ?: -1, fileid); - break; - case BLKIO_THROTL_write_bps_device: - pd->conf.bps[WRITE] = temp; - blkio_update_group_bps(blkg, plid, temp ?: -1, fileid); - break; - case BLKIO_THROTL_read_iops_device: - if (temp > THROTL_IOPS_MAX) - goto out_unlock; - pd->conf.iops[READ] = temp; - blkio_update_group_iops(blkg, plid, temp ?: -1, fileid); - break; - case BLKIO_THROTL_write_iops_device: - if (temp > THROTL_IOPS_MAX) - goto out_unlock; - pd->conf.iops[WRITE] = temp; - blkio_update_group_iops(blkg, plid, temp ?: -1, fileid); - break; + rcu_read_unlock(); + put_disk(disk); + /* + * If queue was bypassing, we should retry. Do so after a + * short msleep(). It isn't strictly necessary but queue + * can be bypassing for some time and it's always nice to + * avoid busy looping. + */ + if (ret == -EBUSY) { + msleep(10); + ret = restart_syscall(); } - break; - default: - BUG(); + goto out; } + + ctx->disk = disk; + ctx->blkg = blkg; + ctx->v = temp; ret = 0; -out_unlock: - rcu_read_unlock(); out: - put_disk(disk); - - /* - * If queue was bypassing, we should retry. Do so after a short - * msleep(). It isn't strictly necessary but queue can be - * bypassing for some time and it's always nice to avoid busy - * looping. - */ - if (ret == -EBUSY) { - msleep(10); - return restart_syscall(); - } + kfree(buf); return ret; } -static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, - const char *buffer) +/** + * blkg_conf_finish - finish up per-blkg config update + * @ctx: blkg_conf_ctx intiailized by blkg_conf_prep() + * + * Finish up after per-blkg config update. This function must be paired + * with blkg_conf_prep(). + */ +static void blkg_conf_finish(struct blkg_conf_ctx *ctx) + __releases(rcu) { - int ret = 0; - char *buf; - struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp); - enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); - int fileid = BLKIOFILE_ATTR(cft->private); - - buf = kstrdup(buffer, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - ret = blkio_policy_parse_and_set(buf, plid, fileid, blkcg); - kfree(buf); - return ret; + rcu_read_unlock(); + put_disk(ctx->disk); } /* for propio conf */ @@ -1140,6 +1110,32 @@ static int blkcg_print_weight(struct cgroup *cgrp, struct cftype *cft, return 0; } +static int blkcg_set_weight_device(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp); + struct blkg_policy_data *pd; + struct blkg_conf_ctx ctx; + int ret; + + ret = blkg_conf_prep(blkcg, buf, &ctx); + if (ret) + return ret; + + ret = -EINVAL; + pd = ctx.blkg->pd[BLKIO_POLICY_PROP]; + if (pd && (!ctx.v || (ctx.v >= BLKIO_WEIGHT_MIN && + ctx.v <= BLKIO_WEIGHT_MAX))) { + pd->conf.weight = ctx.v; + blkio_update_group_weight(ctx.blkg, BLKIO_POLICY_PROP, + ctx.v ?: blkcg->weight); + ret = 0; + } + + blkg_conf_finish(&ctx); + return ret; +} + static int blkcg_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val) { struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp); @@ -1181,39 +1177,67 @@ static u64 blkg_prfill_conf_u64(struct seq_file *sf, static int blkcg_print_conf_u64(struct cgroup *cgrp, struct cftype *cft, struct seq_file *sf) { - int off; - - switch (BLKIOFILE_ATTR(cft->private)) { - case BLKIO_THROTL_read_bps_device: - off = offsetof(struct blkio_group_conf, bps[READ]); - break; - case BLKIO_THROTL_write_bps_device: - off = offsetof(struct blkio_group_conf, bps[WRITE]); - break; - case BLKIO_THROTL_read_iops_device: - off = offsetof(struct blkio_group_conf, iops[READ]); - break; - case BLKIO_THROTL_write_iops_device: - off = offsetof(struct blkio_group_conf, iops[WRITE]); - break; - default: - return -EINVAL; - } - blkcg_print_blkgs(sf, cgroup_to_blkio_cgroup(cgrp), blkg_prfill_conf_u64, BLKIO_POLICY_THROTL, - off, false); + cft->private, false); return 0; } + +static int blkcg_set_conf_u64(struct cgroup *cgrp, struct cftype *cft, + const char *buf, int rw, + void (*update)(struct blkio_group *, int, u64, int)) +{ + struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp); + struct blkg_policy_data *pd; + struct blkg_conf_ctx ctx; + int ret; + + ret = blkg_conf_prep(blkcg, buf, &ctx); + if (ret) + return ret; + + ret = -EINVAL; + pd = ctx.blkg->pd[BLKIO_POLICY_THROTL]; + if (pd) { + *(u64 *)((void *)&pd->conf + cft->private) = ctx.v; + update(ctx.blkg, BLKIO_POLICY_THROTL, ctx.v ?: -1, rw); + ret = 0; + } + + blkg_conf_finish(&ctx); + return ret; +} + +static int blkcg_set_conf_bps_r(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + return blkcg_set_conf_u64(cgrp, cft, buf, READ, blkio_update_group_bps); +} + +static int blkcg_set_conf_bps_w(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + return blkcg_set_conf_u64(cgrp, cft, buf, WRITE, blkio_update_group_bps); +} + +static int blkcg_set_conf_iops_r(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + return blkcg_set_conf_u64(cgrp, cft, buf, READ, blkio_update_group_iops); +} + +static int blkcg_set_conf_iops_w(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + return blkcg_set_conf_u64(cgrp, cft, buf, WRITE, blkio_update_group_iops); +} #endif struct cftype blkio_files[] = { { .name = "weight_device", - .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, - BLKIO_PROP_weight_device), .read_seq_string = blkcg_print_weight_device, - .write_string = blkiocg_file_write, + .write_string = blkcg_set_weight_device, .max_write_len = 256, }, { @@ -1276,37 +1300,33 @@ struct cftype blkio_files[] = { #ifdef CONFIG_BLK_DEV_THROTTLING { .name = "throttle.read_bps_device", - .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, - BLKIO_THROTL_read_bps_device), + .private = offsetof(struct blkio_group_conf, bps[READ]), .read_seq_string = blkcg_print_conf_u64, - .write_string = blkiocg_file_write, + .write_string = blkcg_set_conf_bps_r, .max_write_len = 256, }, { .name = "throttle.write_bps_device", - .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, - BLKIO_THROTL_write_bps_device), + .private = offsetof(struct blkio_group_conf, bps[WRITE]), .read_seq_string = blkcg_print_conf_u64, - .write_string = blkiocg_file_write, + .write_string = blkcg_set_conf_bps_w, .max_write_len = 256, }, { .name = "throttle.read_iops_device", - .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, - BLKIO_THROTL_read_iops_device), + .private = offsetof(struct blkio_group_conf, iops[READ]), .read_seq_string = blkcg_print_conf_u64, - .write_string = blkiocg_file_write, + .write_string = blkcg_set_conf_iops_r, .max_write_len = 256, }, { .name = "throttle.write_iops_device", - .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, - BLKIO_THROTL_write_iops_device), + .private = offsetof(struct blkio_group_conf, iops[WRITE]), .read_seq_string = blkcg_print_conf_u64, - .write_string = blkiocg_file_write, + .write_string = blkcg_set_conf_iops_w, .max_write_len = 256, }, { diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index b67eefa..108ffbf 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -50,19 +50,6 @@ enum blkg_state_flags { BLKG_empty, }; -/* cgroup files owned by proportional weight policy */ -enum blkcg_file_name_prop { - BLKIO_PROP_weight_device, -}; - -/* cgroup files owned by throttle policy */ -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, -}; - struct blkio_cgroup { struct cgroup_subsys_state css; unsigned int weight; -- 2.7.4