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 <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Tejun Heo 2012-03-05 13:15:08 -08:00 committed by Jens Axboe
parent e56da7e287
commit 4bfd482e73
2 changed files with 59 additions and 410 deletions

View File

@ -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 @@ static int blkio_policy_parse_and_set(char *buf,
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 @@ blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)
spin_lock_init(&blkcg->lock);
INIT_HLIST_HEAD(&blkcg->blkg_list);
INIT_LIST_HEAD(&blkcg->policy_list);
return &blkcg->css;
}

View File

@ -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,