*
* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
* Nauman Rafique <nauman@google.com>
+ *
+ * For policy-specific per-blkcg data:
+ * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
+ * Arianna Avanzini <avanzini.arianna@gmail.com>
*/
#include <linux/ioprio.h>
#include <linux/kdev_t.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/slab.h>
#include <linux/genhd.h>
#include <linux/delay.h>
#include <linux/atomic.h>
-#include "blk-cgroup.h"
+#include <linux/ctype.h>
+#include <linux/blk-cgroup.h>
#include "blk.h"
#define MAX_KEY_LEN 100
+/*
+ * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.
+ * blkcg_pol_register_mutex nests outside of it and synchronizes entire
+ * policy [un]register operations including cgroup file additions /
+ * removals. Putting cgroup file registration outside blkcg_pol_mutex
+ * allows grabbing it from cgroup callbacks.
+ */
+static DEFINE_MUTEX(blkcg_pol_register_mutex);
static DEFINE_MUTEX(blkcg_pol_mutex);
-struct blkcg blkcg_root = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT,
- .cfq_leaf_weight = 2 * CFQ_WEIGHT_DEFAULT, };
+struct blkcg blkcg_root;
EXPORT_SYMBOL_GPL(blkcg_root);
+struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css;
+
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
+static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */
+
static bool blkcg_policy_enabled(struct request_queue *q,
const struct blkcg_policy *pol)
{
return;
for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkg->pd[i]);
+ if (blkg->pd[i])
+ blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
- blk_exit_rl(&blkg->rl);
+ if (blkg->blkcg != &blkcg_root)
+ blk_exit_rl(&blkg->rl);
+
+ blkg_rwstat_exit(&blkg->stat_ios);
+ blkg_rwstat_exit(&blkg->stat_bytes);
kfree(blkg);
}
if (!blkg)
return NULL;
+ if (blkg_rwstat_init(&blkg->stat_bytes, gfp_mask) ||
+ blkg_rwstat_init(&blkg->stat_ios, gfp_mask))
+ goto err_free;
+
blkg->q = q;
INIT_LIST_HEAD(&blkg->q_node);
blkg->blkcg = blkcg;
continue;
/* alloc per-policy data and attach it to blkg */
- pd = kzalloc_node(pol->pd_size, gfp_mask, q->node);
+ pd = pol->pd_alloc_fn(gfp_mask, q->node);
if (!pd)
goto err_free;
return NULL;
}
-/**
- * __blkg_lookup - internal version of blkg_lookup()
- * @blkcg: blkcg of interest
- * @q: request_queue of interest
- * @update_hint: whether to update lookup hint with the result or not
- *
- * This is internal version and shouldn't be used by policy
- * implementations. Looks up blkgs for the @blkcg - @q pair regardless of
- * @q's bypass state. If @update_hint is %true, the caller should be
- * holding @q->queue_lock and lookup hint is updated on success.
- */
-struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q,
- bool update_hint)
+struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
+ struct request_queue *q, bool update_hint)
{
struct blkcg_gq *blkg;
- blkg = rcu_dereference(blkcg->blkg_hint);
- if (blkg && blkg->q == q)
- return blkg;
-
/*
* Hint didn't match. Look up from the radix tree. Note that the
* hint can only be updated under queue_lock as otherwise @blkg
return NULL;
}
-
-/**
- * blkg_lookup - lookup blkg for the specified blkcg - q pair
- * @blkcg: blkcg of interest
- * @q: request_queue of interest
- *
- * Lookup blkg for the @blkcg - @q pair. This function should be called
- * under RCU read lock and is guaranteed to return %NULL if @q is bypassing
- * - see blk_queue_bypass_start() for details.
- */
-struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q)
-{
- WARN_ON_ONCE(!rcu_read_lock_held());
-
- if (unlikely(blk_queue_bypass(q)))
- return NULL;
- return __blkg_lookup(blkcg, q, false);
-}
-EXPORT_SYMBOL_GPL(blkg_lookup);
+EXPORT_SYMBOL_GPL(blkg_lookup_slowpath);
/*
* If @new_blkg is %NULL, this function tries to allocate a new one as
- * necessary using %GFP_ATOMIC. @new_blkg is always consumed on return.
+ * necessary using %GFP_NOWAIT. @new_blkg is always consumed on return.
*/
static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
struct request_queue *q,
struct blkcg_gq *new_blkg)
{
struct blkcg_gq *blkg;
+ struct bdi_writeback_congested *wb_congested;
int i, ret;
WARN_ON_ONCE(!rcu_read_lock_held());
/* blkg holds a reference to blkcg */
if (!css_tryget_online(&blkcg->css)) {
- ret = -EINVAL;
+ ret = -ENODEV;
goto err_free_blkg;
}
+ wb_congested = wb_congested_get_create(&q->backing_dev_info,
+ blkcg->css.id, GFP_NOWAIT);
+ if (!wb_congested) {
+ ret = -ENOMEM;
+ goto err_put_css;
+ }
+
/* allocate */
if (!new_blkg) {
- new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC);
+ new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT);
if (unlikely(!new_blkg)) {
ret = -ENOMEM;
- goto err_put_css;
+ goto err_put_congested;
}
}
blkg = new_blkg;
+ blkg->wb_congested = wb_congested;
/* link parent */
if (blkcg_parent(blkcg)) {
blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
if (WARN_ON_ONCE(!blkg->parent)) {
- ret = -EINVAL;
- goto err_put_css;
+ ret = -ENODEV;
+ goto err_put_congested;
}
blkg_get(blkg->parent);
}
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_init_fn)
- pol->pd_init_fn(blkg);
+ pol->pd_init_fn(blkg->pd[i]);
}
/* insert */
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_online_fn)
- pol->pd_online_fn(blkg);
+ pol->pd_online_fn(blkg->pd[i]);
}
}
blkg->online = true;
spin_unlock(&blkcg->lock);
- if (!ret) {
- if (blkcg == &blkcg_root) {
- q->root_blkg = blkg;
- q->root_rl.blkg = blkg;
- }
+ if (!ret)
return blkg;
- }
/* @blkg failed fully initialized, use the usual release path */
blkg_put(blkg);
return ERR_PTR(ret);
+err_put_congested:
+ wb_congested_put(wb_congested);
err_put_css:
css_put(&blkcg->css);
err_free_blkg:
* we shouldn't allow anything to go through for a bypassing queue.
*/
if (unlikely(blk_queue_bypass(q)))
- return ERR_PTR(blk_queue_dying(q) ? -EINVAL : -EBUSY);
+ return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY);
blkg = __blkg_lookup(blkcg, q, true);
if (blkg)
return blkg;
}
}
-EXPORT_SYMBOL_GPL(blkg_lookup_create);
static void blkg_destroy(struct blkcg_gq *blkg)
{
struct blkcg *blkcg = blkg->blkcg;
+ struct blkcg_gq *parent = blkg->parent;
int i;
lockdep_assert_held(blkg->q->queue_lock);
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_offline_fn)
- pol->pd_offline_fn(blkg);
+ pol->pd_offline_fn(blkg->pd[i]);
}
+
+ if (parent) {
+ blkg_rwstat_add_aux(&parent->stat_bytes, &blkg->stat_bytes);
+ blkg_rwstat_add_aux(&parent->stat_ios, &blkg->stat_ios);
+ }
+
blkg->online = false;
radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
if (rcu_access_pointer(blkcg->blkg_hint) == blkg)
rcu_assign_pointer(blkcg->blkg_hint, NULL);
- /*
- * If root blkg is destroyed. Just clear the pointer since root_rl
- * does not take reference on root blkg.
- */
- if (blkcg == &blkcg_root) {
- blkg->q->root_blkg = NULL;
- blkg->q->root_rl.blkg = NULL;
- }
-
/*
* Put the reference taken at the time of creation so that when all
* queues are gone, group can be destroyed.
blkg_destroy(blkg);
spin_unlock(&blkcg->lock);
}
+
+ q->root_blkg = NULL;
+ q->root_rl.blkg = NULL;
}
/*
void __blkg_release_rcu(struct rcu_head *rcu_head)
{
struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
- int i;
-
- /* tell policies that this one is being freed */
- for (i = 0; i < BLKCG_MAX_POLS; i++) {
- struct blkcg_policy *pol = blkcg_policy[i];
-
- if (blkg->pd[i] && pol->pd_exit_fn)
- pol->pd_exit_fn(blkg);
- }
/* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
if (blkg->parent)
blkg_put(blkg->parent);
+ wb_congested_put(blkg->wb_congested);
+
blkg_free(blkg);
}
EXPORT_SYMBOL_GPL(__blkg_release_rcu);
struct blkcg_gq *blkg;
int i;
- /*
- * XXX: We invoke cgroup_add/rm_cftypes() under blkcg_pol_mutex
- * which ends up putting cgroup's internal cgroup_tree_mutex under
- * it; however, cgroup_tree_mutex is nested above cgroup file
- * active protection and grabbing blkcg_pol_mutex from a cgroup
- * file operation creates a possible circular dependency. cgroup
- * internal locking is planned to go through further simplification
- * and this issue should go away soon. For now, let's trylock
- * blkcg_pol_mutex and restart the write on failure.
- *
- * http://lkml.kernel.org/g/5363C04B.4010400@oracle.com
- */
- if (!mutex_trylock(&blkcg_pol_mutex))
- return restart_syscall();
+ mutex_lock(&blkcg_pol_mutex);
spin_lock_irq(&blkcg->lock);
/*
* anyway. If you get hit by a race, retry.
*/
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
+ blkg_rwstat_reset(&blkg->stat_bytes);
+ blkg_rwstat_reset(&blkg->stat_ios);
+
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
- if (blkcg_policy_enabled(blkg->q, pol) &&
- pol->pd_reset_stats_fn)
- pol->pd_reset_stats_fn(blkg);
+ if (blkg->pd[i] && pol->pd_reset_stats_fn)
+ pol->pd_reset_stats_fn(blkg->pd[i]);
}
}
return 0;
}
-static const char *blkg_dev_name(struct blkcg_gq *blkg)
+const char *blkg_dev_name(struct blkcg_gq *blkg)
{
/* some drivers (floppy) instantiate a queue w/o disk registered */
if (blkg->q->backing_dev_info.dev)
return dev_name(blkg->q->backing_dev_info.dev);
return NULL;
}
+EXPORT_SYMBOL_GPL(blkg_dev_name);
/**
* blkcg_print_blkgs - helper for printing per-blkg data
for (i = 0; i < BLKG_RWSTAT_NR; i++)
seq_printf(sf, "%s %s %llu\n", dname, rwstr[i],
- (unsigned long long)rwstat->cnt[i]);
+ (unsigned long long)atomic64_read(&rwstat->aux_cnt[i]));
- v = rwstat->cnt[BLKG_RWSTAT_READ] + rwstat->cnt[BLKG_RWSTAT_WRITE];
+ v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) +
+ atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]);
seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
return v;
}
}
EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
+static u64 blkg_prfill_rwstat_field(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd->blkg + off);
+
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+
+/**
+ * blkg_print_stat_bytes - seq_show callback for blkg->stat_bytes
+ * @sf: seq_file to print to
+ * @v: unused
+ *
+ * To be used as cftype->seq_show to print blkg->stat_bytes.
+ * cftype->private must be set to the blkcg_policy.
+ */
+int blkg_print_stat_bytes(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_bytes), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_bytes);
+
+/**
+ * blkg_print_stat_bytes - seq_show callback for blkg->stat_ios
+ * @sf: seq_file to print to
+ * @v: unused
+ *
+ * To be used as cftype->seq_show to print blkg->stat_ios. cftype->private
+ * must be set to the blkcg_policy.
+ */
+int blkg_print_stat_ios(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_ios), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_ios);
+
+static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkg_rwstat rwstat = blkg_rwstat_recursive_sum(pd->blkg,
+ NULL, off);
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+
+/**
+ * blkg_print_stat_bytes_recursive - recursive version of blkg_print_stat_bytes
+ * @sf: seq_file to print to
+ * @v: unused
+ */
+int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field_recursive,
+ (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_bytes), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_bytes_recursive);
+
+/**
+ * blkg_print_stat_ios_recursive - recursive version of blkg_print_stat_ios
+ * @sf: seq_file to print to
+ * @v: unused
+ */
+int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field_recursive,
+ (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_ios), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_ios_recursive);
+
/**
* blkg_stat_recursive_sum - collect hierarchical blkg_stat
- * @pd: policy private data of interest
- * @off: offset to the blkg_stat in @pd
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_stat
+ * @off: offset to the blkg_stat in blkg_policy_data or @blkg
+ *
+ * Collect the blkg_stat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
*
- * Collect the blkg_stat specified by @off from @pd and all its online
- * descendants and return the sum. The caller must be holding the queue
- * lock for online tests.
+ * If @pol is NULL, blkg_stat is at @off bytes into @blkg; otherwise, it is
+ * at @off bytes into @blkg's blkg_policy_data of the policy.
*/
-u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off)
+u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
{
- struct blkcg_policy *pol = blkcg_policy[pd->plid];
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
u64 sum = 0;
- lockdep_assert_held(pd->blkg->q->queue_lock);
+ lockdep_assert_held(blkg->q->queue_lock);
rcu_read_lock();
- blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) {
- struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
- struct blkg_stat *stat = (void *)pos_pd + off;
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_stat *stat;
+
+ if (!pos_blkg->online)
+ continue;
- if (pos_blkg->online)
- sum += blkg_stat_read(stat);
+ if (pol)
+ stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ stat = (void *)blkg + off;
+
+ sum += blkg_stat_read(stat) + atomic64_read(&stat->aux_cnt);
}
rcu_read_unlock();
/**
* blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
- * @pd: policy private data of interest
- * @off: offset to the blkg_stat in @pd
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_rwstat
+ * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg
+ *
+ * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
*
- * Collect the blkg_rwstat specified by @off from @pd and all its online
- * descendants and return the sum. The caller must be holding the queue
- * lock for online tests.
+ * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it
+ * is at @off bytes into @blkg's blkg_policy_data of the policy.
*/
-struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd,
- int off)
+struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
{
- struct blkcg_policy *pol = blkcg_policy[pd->plid];
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
struct blkg_rwstat sum = { };
int i;
- lockdep_assert_held(pd->blkg->q->queue_lock);
+ lockdep_assert_held(blkg->q->queue_lock);
rcu_read_lock();
- blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) {
- struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
- struct blkg_rwstat *rwstat = (void *)pos_pd + off;
- struct blkg_rwstat tmp;
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_rwstat *rwstat;
if (!pos_blkg->online)
continue;
- tmp = blkg_rwstat_read(rwstat);
+ if (pol)
+ rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ rwstat = (void *)pos_blkg + off;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
- sum.cnt[i] += tmp.cnt[i];
+ atomic64_add(atomic64_read(&rwstat->aux_cnt[i]) +
+ percpu_counter_sum_positive(&rwstat->cpu_cnt[i]),
+ &sum.aux_cnt[i]);
}
rcu_read_unlock();
* @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 lock and queue lock held and
- * must be paired with blkg_conf_finish().
+ * result. @ctx->blkg points to the blkg to be updated and @ctx->body the
+ * part of @input following MAJ:MIN. This function returns with RCU read
+ * lock and queue lock held and must be paired with blkg_conf_finish().
*/
int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
- const char *input, struct blkg_conf_ctx *ctx)
+ char *input, struct blkg_conf_ctx *ctx)
__acquires(rcu) __acquires(disk->queue->queue_lock)
{
struct gendisk *disk;
struct blkcg_gq *blkg;
unsigned int major, minor;
- unsigned long long v;
- int part, ret;
+ int key_len, part, ret;
+ char *body;
+
+ if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2)
+ return -EINVAL;
- if (sscanf(input, "%u:%u %llu", &major, &minor, &v) != 3)
+ body = input + key_len;
+ if (!isspace(*body))
return -EINVAL;
+ body = skip_spaces(body);
disk = get_gendisk(MKDEV(major, minor), &part);
if (!disk)
- return -EINVAL;
+ return -ENODEV;
if (part) {
put_disk(disk);
- return -EINVAL;
+ return -ENODEV;
}
rcu_read_lock();
if (blkcg_policy_enabled(disk->queue, pol))
blkg = blkg_lookup_create(blkcg, disk->queue);
else
- blkg = ERR_PTR(-EINVAL);
+ blkg = ERR_PTR(-EOPNOTSUPP);
if (IS_ERR(blkg)) {
ret = PTR_ERR(blkg);
ctx->disk = disk;
ctx->blkg = blkg;
- ctx->v = v;
+ ctx->body = body;
return 0;
}
EXPORT_SYMBOL_GPL(blkg_conf_prep);
}
EXPORT_SYMBOL_GPL(blkg_conf_finish);
+static int blkcg_print_stat(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct blkcg_gq *blkg;
+
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ const char *dname;
+ struct blkg_rwstat rwstat;
+ u64 rbytes, wbytes, rios, wios;
+
+ dname = blkg_dev_name(blkg);
+ if (!dname)
+ continue;
+
+ spin_lock_irq(blkg->q->queue_lock);
+
+ rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes));
+ rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
+ wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_ios));
+ rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
+ wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ spin_unlock_irq(blkg->q->queue_lock);
+
+ if (rbytes || wbytes || rios || wios)
+ seq_printf(sf, "%s rbytes=%llu wbytes=%llu rios=%llu wios=%llu\n",
+ dname, rbytes, wbytes, rios, wios);
+ }
+
+ rcu_read_unlock();
+ return 0;
+}
+
struct cftype blkcg_files[] = {
+ {
+ .name = "stat",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = blkcg_print_stat,
+ },
+ { } /* terminate */
+};
+
+struct cftype blkcg_legacy_files[] = {
{
.name = "reset_stats",
.write_u64 = blkcg_reset_stats,
}
spin_unlock_irq(&blkcg->lock);
+
+ wb_blkcg_offline(blkcg);
}
static void blkcg_css_free(struct cgroup_subsys_state *css)
{
struct blkcg *blkcg = css_to_blkcg(css);
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ list_del(&blkcg->all_blkcgs_node);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
- if (blkcg != &blkcg_root)
- kfree(blkcg);
+ mutex_unlock(&blkcg_pol_mutex);
+
+ kfree(blkcg);
}
static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct blkcg *blkcg;
+ struct cgroup_subsys_state *ret;
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
if (!parent_css) {
blkcg = &blkcg_root;
- goto done;
+ } else {
+ blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
}
- blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg)
- return ERR_PTR(-ENOMEM);
+ for (i = 0; i < BLKCG_MAX_POLS ; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg_policy_data *cpd;
+
+ /*
+ * If the policy hasn't been attached yet, wait for it
+ * to be attached before doing anything else. Otherwise,
+ * check if the policy requires any specific per-cgroup
+ * data: if it does, allocate and initialize it.
+ */
+ if (!pol || !pol->cpd_alloc_fn)
+ continue;
+
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
+ if (!cpd) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_pd_blkcg;
+ }
+ blkcg->cpd[i] = cpd;
+ cpd->blkcg = blkcg;
+ cpd->plid = i;
+ if (pol->cpd_init_fn)
+ pol->cpd_init_fn(cpd);
+ }
- blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
- blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
-done:
spin_lock_init(&blkcg->lock);
- INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
+ INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT);
INIT_HLIST_HEAD(&blkcg->blkg_list);
+#ifdef CONFIG_CGROUP_WRITEBACK
+ INIT_LIST_HEAD(&blkcg->cgwb_list);
+#endif
+ list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs);
+ mutex_unlock(&blkcg_pol_mutex);
return &blkcg->css;
+
+free_pd_blkcg:
+ for (i--; i >= 0; i--)
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
+free_blkcg:
+ kfree(blkcg);
+ mutex_unlock(&blkcg_pol_mutex);
+ return ret;
}
/**
*/
int blkcg_init_queue(struct request_queue *q)
{
- might_sleep();
+ struct blkcg_gq *new_blkg, *blkg;
+ bool preloaded;
+ int ret;
+
+ new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
+ if (!new_blkg)
+ return -ENOMEM;
+
+ preloaded = !radix_tree_preload(GFP_KERNEL);
- return blk_throtl_init(q);
+ /*
+ * Make sure the root blkg exists and count the existing blkgs. As
+ * @q is bypassing at this point, blkg_lookup_create() can't be
+ * used. Open code insertion.
+ */
+ rcu_read_lock();
+ spin_lock_irq(q->queue_lock);
+ blkg = blkg_create(&blkcg_root, q, new_blkg);
+ spin_unlock_irq(q->queue_lock);
+ rcu_read_unlock();
+
+ if (preloaded)
+ radix_tree_preload_end();
+
+ if (IS_ERR(blkg)) {
+ blkg_free(new_blkg);
+ return PTR_ERR(blkg);
+ }
+
+ q->root_blkg = blkg;
+ q->root_rl.blkg = blkg;
+
+ ret = blk_throtl_init(q);
+ if (ret) {
+ spin_lock_irq(q->queue_lock);
+ blkg_destroy_all(q);
+ spin_unlock_irq(q->queue_lock);
+ }
+ return ret;
}
/**
* of the main cic data structures. For now we allow a task to change
* its cgroup only if it's the only owner of its ioc.
*/
-static int blkcg_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int blkcg_can_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *dst_css;
struct io_context *ioc;
int ret = 0;
/* task_lock() is needed to avoid races with exit_io_context() */
- cgroup_taskset_for_each(task, tset) {
+ cgroup_taskset_for_each(task, dst_css, tset) {
task_lock(task);
ioc = task->io_context;
if (ioc && atomic_read(&ioc->nr_tasks) > 1)
return ret;
}
-struct cgroup_subsys blkio_cgrp_subsys = {
+static void blkcg_bind(struct cgroup_subsys_state *root_css)
+{
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg *blkcg;
+
+ if (!pol || !pol->cpd_bind_fn)
+ continue;
+
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node)
+ if (blkcg->cpd[pol->plid])
+ pol->cpd_bind_fn(blkcg->cpd[pol->plid]);
+ }
+ mutex_unlock(&blkcg_pol_mutex);
+}
+
+struct cgroup_subsys io_cgrp_subsys = {
.css_alloc = blkcg_css_alloc,
.css_offline = blkcg_css_offline,
.css_free = blkcg_css_free,
.can_attach = blkcg_can_attach,
- .legacy_cftypes = blkcg_files,
+ .bind = blkcg_bind,
+ .dfl_cftypes = blkcg_files,
+ .legacy_cftypes = blkcg_legacy_files,
+ .legacy_name = "blkio",
#ifdef CONFIG_MEMCG
/*
* This ensures that, if available, memcg is automatically enabled
.depends_on = 1 << memory_cgrp_id,
#endif
};
-EXPORT_SYMBOL_GPL(blkio_cgrp_subsys);
+EXPORT_SYMBOL_GPL(io_cgrp_subsys);
/**
* blkcg_activate_policy - activate a blkcg policy on a request_queue
int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
- LIST_HEAD(pds);
- struct blkcg_gq *blkg, *new_blkg;
- struct blkg_policy_data *pd, *n;
- int cnt = 0, ret;
- bool preloaded;
+ struct blkg_policy_data *pd_prealloc = NULL;
+ struct blkcg_gq *blkg;
+ int ret;
if (blkcg_policy_enabled(q, pol))
return 0;
- /* preallocations for root blkg */
- new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
- if (!new_blkg)
- return -ENOMEM;
-
blk_queue_bypass_start(q);
-
- preloaded = !radix_tree_preload(GFP_KERNEL);
-
- /*
- * Make sure the root blkg exists and count the existing blkgs. As
- * @q is bypassing at this point, blkg_lookup_create() can't be
- * used. Open code it.
- */
- spin_lock_irq(q->queue_lock);
-
- rcu_read_lock();
- blkg = __blkg_lookup(&blkcg_root, q, false);
- if (blkg)
- blkg_free(new_blkg);
- else
- blkg = blkg_create(&blkcg_root, q, new_blkg);
- rcu_read_unlock();
-
- if (preloaded)
- radix_tree_preload_end();
-
- if (IS_ERR(blkg)) {
- ret = PTR_ERR(blkg);
- goto out_unlock;
- }
-
- list_for_each_entry(blkg, &q->blkg_list, q_node)
- cnt++;
-
- spin_unlock_irq(q->queue_lock);
-
- /* allocate policy_data for all existing blkgs */
- while (cnt--) {
- pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
- if (!pd) {
+pd_prealloc:
+ if (!pd_prealloc) {
+ pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q->node);
+ if (!pd_prealloc) {
ret = -ENOMEM;
- goto out_free;
+ goto out_bypass_end;
}
- list_add_tail(&pd->alloc_node, &pds);
}
- /*
- * Install the allocated pds. With @q bypassing, no new blkg
- * should have been created while the queue lock was dropped.
- */
spin_lock_irq(q->queue_lock);
list_for_each_entry(blkg, &q->blkg_list, q_node) {
- if (WARN_ON(list_empty(&pds))) {
- /* umm... this shouldn't happen, just abort */
- ret = -ENOMEM;
- goto out_unlock;
- }
- pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node);
- list_del_init(&pd->alloc_node);
+ struct blkg_policy_data *pd;
- /* grab blkcg lock too while installing @pd on @blkg */
- spin_lock(&blkg->blkcg->lock);
+ if (blkg->pd[pol->plid])
+ continue;
+
+ pd = pol->pd_alloc_fn(GFP_NOWAIT, q->node);
+ if (!pd)
+ swap(pd, pd_prealloc);
+ if (!pd) {
+ spin_unlock_irq(q->queue_lock);
+ goto pd_prealloc;
+ }
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
- pol->pd_init_fn(blkg);
-
- spin_unlock(&blkg->blkcg->lock);
+ if (pol->pd_init_fn)
+ pol->pd_init_fn(pd);
}
__set_bit(pol->plid, q->blkcg_pols);
ret = 0;
-out_unlock:
+
spin_unlock_irq(q->queue_lock);
-out_free:
+out_bypass_end:
blk_queue_bypass_end(q);
- list_for_each_entry_safe(pd, n, &pds, alloc_node)
- kfree(pd);
+ if (pd_prealloc)
+ pol->pd_free_fn(pd_prealloc);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
__clear_bit(pol->plid, q->blkcg_pols);
- /* if no policy is left, no need for blkgs - shoot them down */
- if (bitmap_empty(q->blkcg_pols, BLKCG_MAX_POLS))
- blkg_destroy_all(q);
-
list_for_each_entry(blkg, &q->blkg_list, q_node) {
/* grab blkcg lock too while removing @pd from @blkg */
spin_lock(&blkg->blkcg->lock);
- if (pol->pd_offline_fn)
- pol->pd_offline_fn(blkg);
- if (pol->pd_exit_fn)
- pol->pd_exit_fn(blkg);
-
- kfree(blkg->pd[pol->plid]);
- blkg->pd[pol->plid] = NULL;
+ if (blkg->pd[pol->plid]) {
+ if (pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg->pd[pol->plid]);
+ pol->pd_free_fn(blkg->pd[pol->plid]);
+ blkg->pd[pol->plid] = NULL;
+ }
spin_unlock(&blkg->blkcg->lock);
}
*/
int blkcg_policy_register(struct blkcg_policy *pol)
{
+ struct blkcg *blkcg;
int i, ret;
- if (WARN_ON(pol->pd_size < sizeof(struct blkg_policy_data)))
- return -EINVAL;
-
+ mutex_lock(&blkcg_pol_register_mutex);
mutex_lock(&blkcg_pol_mutex);
/* find an empty slot */
if (!blkcg_policy[i])
break;
if (i >= BLKCG_MAX_POLS)
- goto out_unlock;
+ goto err_unlock;
- /* register and update blkgs */
+ /* register @pol */
pol->plid = i;
- blkcg_policy[i] = pol;
+ blkcg_policy[pol->plid] = pol;
+
+ /* allocate and install cpd's */
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ struct blkcg_policy_data *cpd;
+
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
+ if (!cpd) {
+ mutex_unlock(&blkcg_pol_mutex);
+ goto err_free_cpds;
+ }
+
+ blkcg->cpd[pol->plid] = cpd;
+ cpd->blkcg = blkcg;
+ cpd->plid = pol->plid;
+ pol->cpd_init_fn(cpd);
+ }
+ }
+
+ mutex_unlock(&blkcg_pol_mutex);
/* everything is in place, add intf files for the new policy */
- if (pol->cftypes)
- WARN_ON(cgroup_add_legacy_cftypes(&blkio_cgrp_subsys,
- pol->cftypes));
- ret = 0;
-out_unlock:
+ if (pol->dfl_cftypes)
+ WARN_ON(cgroup_add_dfl_cftypes(&io_cgrp_subsys,
+ pol->dfl_cftypes));
+ if (pol->legacy_cftypes)
+ WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys,
+ pol->legacy_cftypes));
+ mutex_unlock(&blkcg_pol_register_mutex);
+ return 0;
+
+err_free_cpds:
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
+ }
+ }
+ blkcg_policy[pol->plid] = NULL;
+err_unlock:
mutex_unlock(&blkcg_pol_mutex);
+ mutex_unlock(&blkcg_pol_register_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_policy_register);
*/
void blkcg_policy_unregister(struct blkcg_policy *pol)
{
- mutex_lock(&blkcg_pol_mutex);
+ struct blkcg *blkcg;
+
+ mutex_lock(&blkcg_pol_register_mutex);
if (WARN_ON(blkcg_policy[pol->plid] != pol))
goto out_unlock;
/* kill the intf files first */
- if (pol->cftypes)
- cgroup_rm_cftypes(pol->cftypes);
+ if (pol->dfl_cftypes)
+ cgroup_rm_cftypes(pol->dfl_cftypes);
+ if (pol->legacy_cftypes)
+ cgroup_rm_cftypes(pol->legacy_cftypes);
+
+ /* remove cpds and unregister */
+ mutex_lock(&blkcg_pol_mutex);
- /* unregister and update blkgs */
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
+ }
+ }
blkcg_policy[pol->plid] = NULL;
-out_unlock:
+
mutex_unlock(&blkcg_pol_mutex);
+out_unlock:
+ mutex_unlock(&blkcg_pol_register_mutex);
}
EXPORT_SYMBOL_GPL(blkcg_policy_unregister);
Code Review / kvmfornfv.git / blobdiff