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Merge branch 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block

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* 'for-2.6.40/core' of git://git.kernel.dk/linux-2.6-block: (40 commits)
  cfq-iosched: free cic_index if cfqd allocation fails
  cfq-iosched: remove unused 'group_changed' in cfq_service_tree_add()
  cfq-iosched: reduce bit operations in cfq_choose_req()
  cfq-iosched: algebraic simplification in cfq_prio_to_maxrq()
  blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time
  block: move bd_set_size() above rescan_partitions() in __blkdev_get()
  block: call elv_bio_merged() when merged
  cfq-iosched: Make IO merge related stats per cpu
  cfq-iosched: Fix a memory leak of per cpu stats for root group
  backing-dev: Kill set but not used var in  bdi_debug_stats_show()
  block: get rid of on-stack plugging debug checks
  blk-throttle: Make no throttling rule group processing lockless
  blk-cgroup: Make cgroup stat reset path blkg->lock free for dispatch stats
  blk-cgroup: Make 64bit per cpu stats safe on 32bit arch
  blk-throttle: Make dispatch stats per cpu
  blk-throttle: Free up a group only after one rcu grace period
  blk-throttle: Use helper function to add root throtl group to lists
  blk-throttle: Introduce a helper function to fill in device details
  blk-throttle: Dynamically allocate root group
  blk-cgroup: Allow sleeping while dynamically allocating a group
  ...
This commit is contained in:
Linus Torvalds 2011-05-25 09:14:07 -07:00
commit 798ce8f1cc
25 changed files with 788 additions and 320 deletions
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64
Documentation/ABI/testing/sysfs-block
View File

@ -142,3 +142,67 @@ Description:
with the previous I/O request are enabled. When set to 2,
all merge tries are disabled. The default value is 0 -
which enables all types of merge tries.
What: /sys/block/<disk>/discard_alignment
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Devices that support discard functionality may
internally allocate space in units that are bigger than
the exported logical block size. The discard_alignment
parameter indicates how many bytes the beginning of the
device is offset from the internal allocation unit's
natural alignment.
What: /sys/block/<disk>/<partition>/discard_alignment
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Devices that support discard functionality may
internally allocate space in units that are bigger than
the exported logical block size. The discard_alignment
parameter indicates how many bytes the beginning of the
partition is offset from the internal allocation unit's
natural alignment.
What: /sys/block/<disk>/queue/discard_granularity
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Devices that support discard functionality may
internally allocate space using units that are bigger
than the logical block size. The discard_granularity
parameter indicates the size of the internal allocation
unit in bytes if reported by the device. Otherwise the
discard_granularity will be set to match the device's
physical block size. A discard_granularity of 0 means
that the device does not support discard functionality.
What: /sys/block/<disk>/queue/discard_max_bytes
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Devices that support discard functionality may have
internal limits on the number of bytes that can be
trimmed or unmapped in a single operation. Some storage
protocols also have inherent limits on the number of
blocks that can be described in a single command. The
discard_max_bytes parameter is set by the device driver
to the maximum number of bytes that can be discarded in
a single operation. Discard requests issued to the
device must not exceed this limit. A discard_max_bytes
value of 0 means that the device does not support
discard functionality.
What: /sys/block/<disk>/queue/discard_zeroes_data
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Devices that support discard functionality may return
stale or random data when a previously discarded block
is read back. This can cause problems if the filesystem
expects discarded blocks to be explicitly cleared. If a
device reports that it deterministically returns zeroes
when a discarded area is read the discard_zeroes_data
parameter will be set to one. Otherwise it will be 0 and
the result of reading a discarded area is undefined.

200
block/blk-cgroup.c
View File

@ -385,25 +385,40 @@ void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time,
spin_lock_irqsave(&blkg->stats_lock, flags);
blkg->stats.time += time;
#ifdef CONFIG_DEBUG_BLK_CGROUP
blkg->stats.unaccounted_time += unaccounted_time;
#endif
spin_unlock_irqrestore(&blkg->stats_lock, flags);
}
EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
/*
* should be called under rcu read lock or queue lock to make sure blkg pointer
* is valid.
*/
void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
uint64_t bytes, bool direction, bool sync)
{
struct blkio_group_stats *stats;
struct blkio_group_stats_cpu *stats_cpu;
unsigned long flags;
spin_lock_irqsave(&blkg->stats_lock, flags);
stats = &blkg->stats;
stats->sectors += bytes >> 9;
blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction,
sync);
blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes,
direction, sync);
spin_unlock_irqrestore(&blkg->stats_lock, flags);
/*
* Disabling interrupts to provide mutual exclusion between two
* writes on same cpu. It probably is not needed for 64bit. Not
* optimizing that case yet.
*/
local_irq_save(flags);
stats_cpu = this_cpu_ptr(blkg->stats_cpu);
u64_stats_update_begin(&stats_cpu->syncp);
stats_cpu->sectors += bytes >> 9;
blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED],
1, direction, sync);
blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES],
bytes, direction, sync);
u64_stats_update_end(&stats_cpu->syncp);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
@ -426,18 +441,44 @@ void blkiocg_update_completion_stats(struct blkio_group *blkg,
}
EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);
/* Merged stats are per cpu. */
void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
bool sync)
{
struct blkio_group_stats_cpu *stats_cpu;
unsigned long flags;
spin_lock_irqsave(&blkg->stats_lock, flags);
blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction,
sync);
spin_unlock_irqrestore(&blkg->stats_lock, flags);
/*
* Disabling interrupts to provide mutual exclusion between two
* writes on same cpu. It probably is not needed for 64bit. Not
* optimizing that case yet.
*/
local_irq_save(flags);
stats_cpu = this_cpu_ptr(blkg->stats_cpu);
u64_stats_update_begin(&stats_cpu->syncp);
blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_MERGED], 1,
direction, sync);
u64_stats_update_end(&stats_cpu->syncp);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
/*
* This function allocates the per cpu stats for blkio_group. Should be called
* from sleepable context as alloc_per_cpu() requires that.
*/
int blkio_alloc_blkg_stats(struct blkio_group *blkg)
{
/* Allocate memory for per cpu stats */
blkg->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu);
if (!blkg->stats_cpu)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL_GPL(blkio_alloc_blkg_stats);
void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev,
enum blkio_policy_id plid)
@ -508,6 +549,30 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
}
EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
static void blkio_reset_stats_cpu(struct blkio_group *blkg)
{
struct blkio_group_stats_cpu *stats_cpu;
int i, j, k;
/*
* Note: On 64 bit arch this should not be an issue. This has the
* possibility of returning some inconsistent value on 32bit arch
* as 64bit update on 32bit is non atomic. Taking care of this
* corner case makes code very complicated, like sending IPIs to
* cpus, taking care of stats of offline cpus etc.
*
* reset stats is anyway more of a debug feature and this sounds a
* corner case. So I am not complicating the code yet until and
* unless this becomes a real issue.
*/
for_each_possible_cpu(i) {
stats_cpu = per_cpu_ptr(blkg->stats_cpu, i);
stats_cpu->sectors = 0;
for(j = 0; j < BLKIO_STAT_CPU_NR; j++)
for (k = 0; k < BLKIO_STAT_TOTAL; k++)
stats_cpu->stat_arr_cpu[j][k] = 0;
}
}
static int
blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
{
@ -552,7 +617,11 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
}
#endif
spin_unlock(&blkg->stats_lock);
/* Reset Per cpu stats which don't take blkg->stats_lock */
blkio_reset_stats_cpu(blkg);
}
spin_unlock_irq(&blkcg->lock);
return 0;
}
@ -598,6 +667,59 @@ static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val,
return val;
}
static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg,
enum stat_type_cpu type, enum stat_sub_type sub_type)
{
int cpu;
struct blkio_group_stats_cpu *stats_cpu;
u64 val = 0, tval;
for_each_possible_cpu(cpu) {
unsigned int start;
stats_cpu = per_cpu_ptr(blkg->stats_cpu, cpu);
do {
start = u64_stats_fetch_begin(&stats_cpu->syncp);
if (type == BLKIO_STAT_CPU_SECTORS)
tval = stats_cpu->sectors;
else
tval = stats_cpu->stat_arr_cpu[type][sub_type];
} while(u64_stats_fetch_retry(&stats_cpu->syncp, start));
val += tval;
}
return val;
}
static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg,
struct cgroup_map_cb *cb, dev_t dev, enum stat_type_cpu type)
{
uint64_t disk_total, val;
char key_str[MAX_KEY_LEN];
enum stat_sub_type sub_type;
if (type == BLKIO_STAT_CPU_SECTORS) {
val = blkio_read_stat_cpu(blkg, type, 0);
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, val, cb, dev);
}
for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
sub_type++) {
blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
val = blkio_read_stat_cpu(blkg, type, sub_type);
cb->fill(cb, key_str, val);
}
disk_total = blkio_read_stat_cpu(blkg, type, BLKIO_STAT_READ) +
blkio_read_stat_cpu(blkg, type, BLKIO_STAT_WRITE);
blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);
cb->fill(cb, key_str, disk_total);
return disk_total;
}
/* This should be called with blkg->stats_lock held */
static uint64_t blkio_get_stat(struct blkio_group *blkg,
struct cgroup_map_cb *cb, dev_t dev, enum stat_type type)
@ -609,9 +731,6 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg,
if (type == BLKIO_STAT_TIME)
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
blkg->stats.time, cb, dev);
if (type == BLKIO_STAT_SECTORS)
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
blkg->stats.sectors, cb, dev);
#ifdef CONFIG_DEBUG_BLK_CGROUP
if (type == BLKIO_STAT_UNACCOUNTED_TIME)
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
@ -1075,8 +1194,8 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
}
static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type,
bool show_total)
struct cftype *cft, struct cgroup_map_cb *cb,
enum stat_type type, bool show_total, bool pcpu)
{
struct blkio_group *blkg;
struct hlist_node *n;
@ -1087,10 +1206,15 @@ static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
if (blkg->dev) {
if (!cftype_blkg_same_policy(cft, blkg))
continue;
spin_lock_irq(&blkg->stats_lock);
cgroup_total += blkio_get_stat(blkg, cb, blkg->dev,
type);
spin_unlock_irq(&blkg->stats_lock);
if (pcpu)
cgroup_total += blkio_get_stat_cpu(blkg, cb,
blkg->dev, type);
else {
spin_lock_irq(&blkg->stats_lock);
cgroup_total += blkio_get_stat(blkg, cb,
blkg->dev, type);
spin_unlock_irq(&blkg->stats_lock);
}
}
}
if (show_total)
@ -1114,47 +1238,47 @@ static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
switch(name) {
case BLKIO_PROP_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_TIME, 0);
BLKIO_STAT_TIME, 0, 0);
case BLKIO_PROP_sectors:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SECTORS, 0);
BLKIO_STAT_CPU_SECTORS, 0, 1);
case BLKIO_PROP_io_service_bytes:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SERVICE_BYTES, 1);
BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
case BLKIO_PROP_io_serviced:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SERVICED, 1);
BLKIO_STAT_CPU_SERVICED, 1, 1);
case BLKIO_PROP_io_service_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SERVICE_TIME, 1);
BLKIO_STAT_SERVICE_TIME, 1, 0);
case BLKIO_PROP_io_wait_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_WAIT_TIME, 1);
BLKIO_STAT_WAIT_TIME, 1, 0);
case BLKIO_PROP_io_merged:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_MERGED, 1);
BLKIO_STAT_CPU_MERGED, 1, 1);
case BLKIO_PROP_io_queued:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_QUEUED, 1);
BLKIO_STAT_QUEUED, 1, 0);
#ifdef CONFIG_DEBUG_BLK_CGROUP
case BLKIO_PROP_unaccounted_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_UNACCOUNTED_TIME, 0);
BLKIO_STAT_UNACCOUNTED_TIME, 0, 0);
case BLKIO_PROP_dequeue:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_DEQUEUE, 0);
BLKIO_STAT_DEQUEUE, 0, 0);
case BLKIO_PROP_avg_queue_size:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_AVG_QUEUE_SIZE, 0);
BLKIO_STAT_AVG_QUEUE_SIZE, 0, 0);
case BLKIO_PROP_group_wait_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_GROUP_WAIT_TIME, 0);
BLKIO_STAT_GROUP_WAIT_TIME, 0, 0);
case BLKIO_PROP_idle_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_IDLE_TIME, 0);
BLKIO_STAT_IDLE_TIME, 0, 0);
case BLKIO_PROP_empty_time:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_EMPTY_TIME, 0);
BLKIO_STAT_EMPTY_TIME, 0, 0);
#endif
default:
BUG();
@ -1164,10 +1288,10 @@ static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
switch(name){
case BLKIO_THROTL_io_service_bytes:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SERVICE_BYTES, 1);
BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
case BLKIO_THROTL_io_serviced:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_SERVICED, 1);
BLKIO_STAT_CPU_SERVICED, 1, 1);
default:
BUG();
}

40
block/blk-cgroup.h
View File

@ -14,6 +14,7 @@
*/
#include <linux/cgroup.h>
#include <linux/u64_stats_sync.h>
enum blkio_policy_id {
BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
@ -36,22 +37,15 @@ enum stat_type {
* request completion for IOs doen by this cgroup. This may not be
* accurate when NCQ is turned on. */
BLKIO_STAT_SERVICE_TIME = 0,
/* Total bytes transferred */
BLKIO_STAT_SERVICE_BYTES,
/* Total IOs serviced, post merge */
BLKIO_STAT_SERVICED,
/* Total time spent waiting in scheduler queue in ns */
BLKIO_STAT_WAIT_TIME,
/* Number of IOs merged */
BLKIO_STAT_MERGED,
/* Number of IOs queued up */
BLKIO_STAT_QUEUED,
/* All the single valued stats go below this */
BLKIO_STAT_TIME,
BLKIO_STAT_SECTORS,
#ifdef CONFIG_DEBUG_BLK_CGROUP
/* Time not charged to this cgroup */
BLKIO_STAT_UNACCOUNTED_TIME,
#ifdef CONFIG_DEBUG_BLK_CGROUP
BLKIO_STAT_AVG_QUEUE_SIZE,
BLKIO_STAT_IDLE_TIME,
BLKIO_STAT_EMPTY_TIME,
@ -60,6 +54,18 @@ enum stat_type {
#endif
};
/* Per cpu stats */
enum stat_type_cpu {
BLKIO_STAT_CPU_SECTORS,
/* Total bytes transferred */
BLKIO_STAT_CPU_SERVICE_BYTES,
/* Total IOs serviced, post merge */
BLKIO_STAT_CPU_SERVICED,
/* Number of IOs merged */
BLKIO_STAT_CPU_MERGED,
BLKIO_STAT_CPU_NR
};
enum stat_sub_type {
BLKIO_STAT_READ = 0,
BLKIO_STAT_WRITE,
@ -116,11 +122,11 @@ struct blkio_cgroup {
struct blkio_group_stats {
/* total disk time and nr sectors dispatched by this group */
uint64_t time;
uint64_t sectors;
/* Time not charged to this cgroup */
uint64_t unaccounted_time;
uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
#ifdef CONFIG_DEBUG_BLK_CGROUP
/* Time not charged to this cgroup */
uint64_t unaccounted_time;
/* Sum of number of IOs queued across all samples */
uint64_t avg_queue_size_sum;
/* Count of samples taken for average */
@ -145,6 +151,13 @@ struct blkio_group_stats {
#endif
};
/* Per cpu blkio group stats */
struct blkio_group_stats_cpu {
uint64_t sectors;
uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
struct u64_stats_sync syncp;
};
struct blkio_group {
/* An rcu protected unique identifier for the group */
void *key;
@ -160,6 +173,8 @@ struct blkio_group {
/* Need to serialize the stats in the case of reset/update */
spinlock_t stats_lock;
struct blkio_group_stats stats;
/* Per cpu stats pointer */
struct blkio_group_stats_cpu __percpu *stats_cpu;
};
struct blkio_policy_node {
@ -295,6 +310,7 @@ extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev,
enum blkio_policy_id plid);
extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
void *key);
@ -322,6 +338,8 @@ static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev,
enum blkio_policy_id plid) {}
static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
static inline int
blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }

32
block/blk-core.c
View File

@ -569,8 +569,6 @@ int blk_get_queue(struct request_queue *q)
static inline void blk_free_request(struct request_queue *q, struct request *rq)
{
BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
if (rq->cmd_flags & REQ_ELVPRIV)
elv_put_request(q, rq);
mempool_free(rq, q->rq.rq_pool);
@ -1110,14 +1108,6 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
{
const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
/*
* Debug stuff, kill later
*/
if (!rq_mergeable(req)) {
blk_dump_rq_flags(req, "back");
return false;
}
if (!ll_back_merge_fn(q, req, bio))
return false;
@ -1132,6 +1122,7 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
drive_stat_acct(req, 0);
elv_bio_merged(q, req, bio);
return true;
}
@ -1141,14 +1132,6 @@ static bool bio_attempt_front_merge(struct request_queue *q,
const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
sector_t sector;
/*
* Debug stuff, kill later
*/
if (!rq_mergeable(req)) {
blk_dump_rq_flags(req, "front");
return false;
}
if (!ll_front_merge_fn(q, req, bio))
return false;
@ -1173,6 +1156,7 @@ static bool bio_attempt_front_merge(struct request_queue *q,
req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
drive_stat_acct(req, 0);
elv_bio_merged(q, req, bio);
return true;
}
@ -1258,14 +1242,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
el_ret = elv_merge(q, &req, bio);
if (el_ret == ELEVATOR_BACK_MERGE) {
BUG_ON(req->cmd_flags & REQ_ON_PLUG);
if (bio_attempt_back_merge(q, req, bio)) {
if (!attempt_back_merge(q, req))
elv_merged_request(q, req, el_ret);
goto out_unlock;
}
} else if (el_ret == ELEVATOR_FRONT_MERGE) {
BUG_ON(req->cmd_flags & REQ_ON_PLUG);
if (bio_attempt_front_merge(q, req, bio)) {
if (!attempt_front_merge(q, req))
elv_merged_request(q, req, el_ret);
@ -1320,10 +1302,6 @@ get_rq:
if (__rq->q != q)
plug->should_sort = 1;
}
/*
* Debug flag, kill later
*/
req->cmd_flags |= REQ_ON_PLUG;
list_add_tail(&req->queuelist, &plug->list);
drive_stat_acct(req, 1);
} else {
@ -1550,7 +1528,8 @@ static inline void __generic_make_request(struct bio *bio)
goto end_io;
}
blk_throtl_bio(q, &bio);
if (blk_throtl_bio(q, &bio))
goto end_io;
/*
* If bio = NULL, bio has been throttled and will be submitted
@ -2748,7 +2727,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
while (!list_empty(&list)) {
rq = list_entry_rq(list.next);
list_del_init(&rq->queuelist);
BUG_ON(!(rq->cmd_flags & REQ_ON_PLUG));
BUG_ON(!rq->q);
if (rq->q != q) {
/*
@ -2760,8 +2738,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
depth = 0;
spin_lock(q->queue_lock);
}
rq->cmd_flags &= ~REQ_ON_PLUG;
/*
* rq is already accounted, so use raw insert
*/

2
block/blk-exec.c
View File

@ -56,7 +56,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
spin_lock_irq(q->queue_lock);
__elv_add_request(q, rq, where);
__blk_run_queue(q);
/* the queue is stopped so it won't be plugged+unplugged */
/* the queue is stopped so it won't be run */
if (rq->cmd_type == REQ_TYPE_PM_RESUME)
q->request_fn(q);
spin_unlock_irq(q->queue_lock);

16
block/blk-flush.c
View File

@ -212,13 +212,19 @@ static void flush_end_io(struct request *flush_rq, int error)
}
/*
* Moving a request silently to empty queue_head may stall the
* queue. Kick the queue in those cases. This function is called
* from request completion path and calling directly into
* request_fn may confuse the driver. Always use kblockd.
* Kick the queue to avoid stall for two cases:
* 1. Moving a request silently to empty queue_head may stall the
* queue.
* 2. When flush request is running in non-queueable queue, the
* queue is hold. Restart the queue after flush request is finished
* to avoid stall.
* This function is called from request completion path and calling
* directly into request_fn may confuse the driver. Always use
* kblockd.
*/
if (queued)
if (queued || q->flush_queue_delayed)
blk_run_queue_async(q);
q->flush_queue_delayed = 0;
}
/**

3
block/blk-ioc.c
View File

@ -96,6 +96,9 @@ struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
INIT_RADIX_TREE(&ret->radix_root, GFP_ATOMIC | __GFP_HIGH);
INIT_HLIST_HEAD(&ret->cic_list);
ret->ioc_data = NULL;
#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
ret->cgroup_changed = 0;
#endif
}
return ret;

82
block/blk-lib.c
View File

@ -9,17 +9,20 @@
#include "blk.h"
static void blkdev_discard_end_io(struct bio *bio, int err)
struct bio_batch {
atomic_t done;
unsigned long flags;
struct completion *wait;
};
static void bio_batch_end_io(struct bio *bio, int err)
{
if (err) {
if (err == -EOPNOTSUPP)
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
clear_bit(BIO_UPTODATE, &bio->bi_flags);
}
if (bio->bi_private)
complete(bio->bi_private);
struct bio_batch *bb = bio->bi_private;
if (err && (err != -EOPNOTSUPP))
clear_bit(BIO_UPTODATE, &bb->flags);
if (atomic_dec_and_test(&bb->done))
complete(bb->wait);
bio_put(bio);
}
@ -41,6 +44,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
struct request_queue *q = bdev_get_queue(bdev);
int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
struct bio_batch bb;
struct bio *bio;
int ret = 0;
@ -67,7 +71,11 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
type |= REQ_SECURE;
}
while (nr_sects && !ret) {
atomic_set(&bb.done, 1);
bb.flags = 1 << BIO_UPTODATE;
bb.wait = &wait;
while (nr_sects) {
bio = bio_alloc(gfp_mask, 1);
if (!bio) {
ret = -ENOMEM;
@ -75,9 +83,9 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
}
bio->bi_sector = sector;
bio->bi_end_io = blkdev_discard_end_io;
bio->bi_end_io = bio_batch_end_io;
bio->bi_bdev = bdev;
bio->bi_private = &wait;
bio->bi_private = &bb;
if (nr_sects > max_discard_sectors) {
bio->bi_size = max_discard_sectors << 9;
@ -88,45 +96,21 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
nr_sects = 0;
}
bio_get(bio);
atomic_inc(&bb.done);
submit_bio(type, bio);
}
/* Wait for bios in-flight */
if (!atomic_dec_and_test(&bb.done))
wait_for_completion(&wait);
if (bio_flagged(bio, BIO_EOPNOTSUPP))
ret = -EOPNOTSUPP;
else if (!bio_flagged(bio, BIO_UPTODATE))
ret = -EIO;
bio_put(bio);
}
if (!test_bit(BIO_UPTODATE, &bb.flags))
ret = -EIO;
return ret;
}
EXPORT_SYMBOL(blkdev_issue_discard);
struct bio_batch
{
atomic_t done;
unsigned long flags;
struct completion *wait;
};
static void bio_batch_end_io(struct bio *bio, int err)
{
struct bio_batch *bb = bio->bi_private;
if (err) {
if (err == -EOPNOTSUPP)
set_bit(BIO_EOPNOTSUPP, &bb->flags);
else
clear_bit(BIO_UPTODATE, &bb->flags);
}
if (bb)
if (atomic_dec_and_test(&bb->done))
complete(bb->wait);
bio_put(bio);
}
/**
* blkdev_issue_zeroout - generate number of zero filed write bios
* @bdev: blockdev to issue
@ -151,7 +135,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
bb.flags = 1 << BIO_UPTODATE;
bb.wait = &wait;
submit:
ret = 0;
while (nr_sects != 0) {
bio = bio_alloc(gfp_mask,
@ -168,9 +151,6 @@ submit:
while (nr_sects != 0) {
sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
if (sz == 0)
/* bio has maximum size possible */
break;
ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
nr_sects -= ret >> 9;
sector += ret >> 9;
@ -190,16 +170,6 @@ submit:
/* One of bios in the batch was completed with error.*/
ret = -EIO;
if (ret)
goto out;
if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
ret = -EOPNOTSUPP;
goto out;
}
if (nr_sects != 0)
goto submit;
out:
return ret;
}
EXPORT_SYMBOL(blkdev_issue_zeroout);

9
block/blk-settings.c
View File

@ -120,7 +120,7 @@ void blk_set_default_limits(struct queue_limits *lim)
lim->discard_granularity = 0;
lim->discard_alignment = 0;
lim->discard_misaligned = 0;
lim->discard_zeroes_data = -1;
lim->discard_zeroes_data = 1;
lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
lim->alignment_offset = 0;
@ -166,6 +166,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
blk_set_default_limits(&q->limits);
blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS);
q->limits.discard_zeroes_data = 0;
/*
* by default assume old behaviour and bounce for any highmem page
@ -790,6 +791,12 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush)
}
EXPORT_SYMBOL_GPL(blk_queue_flush);
void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
{
q->flush_not_queueable = !queueable;
}
EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;

3
block/blk-sysfs.c
View File

@ -152,7 +152,8 @@ static ssize_t queue_discard_granularity_show(struct request_queue *q, char *pag
static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
{
return queue_var_show(q->limits.max_discard_sectors << 9, page);
return sprintf(page, "%llu\n",
(unsigned long long)q->limits.max_discard_sectors << 9);
}
static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)

319
block/blk-throttle.c
View File

@ -78,6 +78,8 @@ struct throtl_grp {
/* Some throttle limits got updated for the group */
int limits_changed;
struct rcu_head rcu_head;
};
struct throtl_data
@ -88,7 +90,7 @@ struct throtl_data
/* service tree for active throtl groups */
struct throtl_rb_root tg_service_tree;
struct throtl_grp root_tg;
struct throtl_grp *root_tg;
struct request_queue *queue;
/* Total Number of queued bios on READ and WRITE lists */
@ -151,56 +153,44 @@ static inline struct throtl_grp *throtl_ref_get_tg(struct throtl_grp *tg)
return tg;
}
static void throtl_free_tg(struct rcu_head *head)
{
struct throtl_grp *tg;
tg = container_of(head, struct throtl_grp, rcu_head);
free_percpu(tg->blkg.stats_cpu);
kfree(tg);
}
static void throtl_put_tg(struct throtl_grp *tg)
{
BUG_ON(atomic_read(&tg->ref) <= 0);
if (!atomic_dec_and_test(&tg->ref))
return;
kfree(tg);
/*
* A group is freed in rcu manner. But having an rcu lock does not
* mean that one can access all the fields of blkg and assume these
* are valid. For example, don't try to follow throtl_data and
* request queue links.
*
* Having a reference to blkg under an rcu allows acess to only
* values local to groups like group stats and group rate limits
*/
call_rcu(&tg->rcu_head, throtl_free_tg);
}
static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
struct blkio_cgroup *blkcg)
static void throtl_init_group(struct throtl_grp *tg)
{
struct throtl_grp *tg = NULL;
void *key = td;
struct backing_dev_info *bdi = &td->queue->backing_dev_info;
unsigned int major, minor;
/*
* TODO: Speed up blkiocg_lookup_group() by maintaining a radix
* tree of blkg (instead of traversing through hash list all
* the time.
*/
/*
* This is the common case when there are no blkio cgroups.
* Avoid lookup in this case
*/
if (blkcg == &blkio_root_cgroup)
tg = &td->root_tg;
else
tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
/* Fill in device details for root group */
if (tg && !tg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
tg->blkg.dev = MKDEV(major, minor);
goto done;
}
if (tg)
goto done;
tg = kzalloc_node(sizeof(*tg), GFP_ATOMIC, td->queue->node);
if (!tg)
goto done;
INIT_HLIST_NODE(&tg->tg_node);
RB_CLEAR_NODE(&tg->rb_node);
bio_list_init(&tg->bio_lists[0]);
bio_list_init(&tg->bio_lists[1]);
td->limits_changed = false;
tg->limits_changed = false;
/* Practically unlimited BW */
tg->bps[0] = tg->bps[1] = -1;
tg->iops[0] = tg->iops[1] = -1;
/*
* Take the initial reference that will be released on destroy
@ -209,33 +199,181 @@ static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
* exit or cgroup deletion path depending on who is exiting first.
*/
atomic_set(&tg->ref, 1);
}
/* Should be called with rcu read lock held (needed for blkcg) */
static void
throtl_add_group_to_td_list(struct throtl_data *td, struct throtl_grp *tg)
{
hlist_add_head(&tg->tg_node, &td->tg_list);
td->nr_undestroyed_grps++;
}
static void
__throtl_tg_fill_dev_details(struct throtl_data *td, struct throtl_grp *tg)
{
struct backing_dev_info *bdi = &td->queue->backing_dev_info;
unsigned int major, minor;
if (!tg || tg->blkg.dev)
return;
/*
* Fill in device details for a group which might not have been
* filled at group creation time as queue was being instantiated
* and driver had not attached a device yet
*/
if (bdi->dev && dev_name(bdi->dev)) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
tg->blkg.dev = MKDEV(major, minor);
}
}
/*
* Should be called with without queue lock held. Here queue lock will be
* taken rarely. It will be taken only once during life time of a group
* if need be
*/
static void
throtl_tg_fill_dev_details(struct throtl_data *td, struct throtl_grp *tg)
{
if (!tg || tg->blkg.dev)
return;
spin_lock_irq(td->queue->queue_lock);
__throtl_tg_fill_dev_details(td, tg);
spin_unlock_irq(td->queue->queue_lock);
}
static void throtl_init_add_tg_lists(struct throtl_data *td,
struct throtl_grp *tg, struct blkio_cgroup *blkcg)
{
__throtl_tg_fill_dev_details(td, tg);
/* Add group onto cgroup list */
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
blkiocg_add_blkio_group(blkcg, &tg->blkg, (void *)td,
MKDEV(major, minor), BLKIO_POLICY_THROTL);
tg->blkg.dev, BLKIO_POLICY_THROTL);
tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
tg->iops[READ] = blkcg_get_read_iops(blkcg, tg->blkg.dev);
tg->iops[WRITE] = blkcg_get_write_iops(blkcg, tg->blkg.dev);
hlist_add_head(&tg->tg_node, &td->tg_list);
td->nr_undestroyed_grps++;
done:
throtl_add_group_to_td_list(td, tg);
}
/* Should be called without queue lock and outside of rcu period */
static struct throtl_grp *throtl_alloc_tg(struct throtl_data *td)
{
struct throtl_grp *tg = NULL;
int ret;
tg = kzalloc_node(sizeof(*tg), GFP_ATOMIC, td->queue->node);
if (!tg)
return NULL;
ret = blkio_alloc_blkg_stats(&tg->blkg);
if (ret) {
kfree(tg);
return NULL;
}
throtl_init_group(tg);
return tg;
}
static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
static struct
throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg)
{
struct throtl_grp *tg = NULL;
void *key = td;
/*
* This is the common case when there are no blkio cgroups.
* Avoid lookup in this case
*/
if (blkcg == &blkio_root_cgroup)
tg = td->root_tg;
else
tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
__throtl_tg_fill_dev_details(td, tg);
return tg;
}
/*
* This function returns with queue lock unlocked in case of error, like
* request queue is no more
*/
static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
{
struct throtl_grp *tg = NULL, *__tg = NULL;
struct blkio_cgroup *blkcg;
struct request_queue *q = td->queue;
rcu_read_lock();
blkcg = task_blkio_cgroup(current);
tg = throtl_find_alloc_tg(td, blkcg);
if (!tg)
tg = &td->root_tg;
tg = throtl_find_tg(td, blkcg);
if (tg) {
rcu_read_unlock();
return tg;
}
/*
* Need to allocate a group. Allocation of group also needs allocation
* of per cpu stats which in-turn takes a mutex() and can block. Hence
* we need to drop rcu lock and queue_lock before we call alloc
*
* Take the request queue reference to make sure queue does not
* go away once we return from allocation.
*/
blk_get_queue(q);
rcu_read_unlock();
spin_unlock_irq(q->queue_lock);
tg = throtl_alloc_tg(td);
/*
* We might have slept in group allocation. Make sure queue is not
* dead
*/
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
blk_put_queue(q);
if (tg)
kfree(tg);
return ERR_PTR(-ENODEV);
}
blk_put_queue(q);
/* Group allocated and queue is still alive. take the lock */
spin_lock_irq(q->queue_lock);
/*
* Initialize the new group. After sleeping, read the blkcg again.
*/
rcu_read_lock();
blkcg = task_blkio_cgroup(current);
/*
* If some other thread already allocated the group while we were
* not holding queue lock, free up the group
*/
__tg = throtl_find_tg(td, blkcg);
if (__tg) {
kfree(tg);
rcu_read_unlock();
return __tg;
}
/* Group allocation failed. Account the IO to root group */
if (!tg) {
tg = td->root_tg;
return tg;
}
throtl_init_add_tg_lists(td, tg, blkcg);
rcu_read_unlock();
return tg;
}
@ -544,6 +682,12 @@ static bool tg_with_in_bps_limit(struct throtl_data *td, struct throtl_grp *tg,
return 0;
}
static bool tg_no_rule_group(struct throtl_grp *tg, bool rw) {
if (tg->bps[rw] == -1 && tg->iops[rw] == -1)
return 1;
return 0;
}
/*
* Returns whether one can dispatch a bio or not. Also returns approx number
* of jiffies to wait before this bio is with-in IO rate and can be dispatched
@ -608,10 +752,6 @@ static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
tg->bytes_disp[rw] += bio->bi_size;
tg->io_disp[rw]++;
/*
* TODO: This will take blkg->stats_lock. Figure out a way
* to avoid this cost.
*/
blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size, rw, sync);
}
@ -989,15 +1129,51 @@ int blk_throtl_bio(struct request_queue *q, struct bio **biop)
struct throtl_grp *tg;
struct bio *bio = *biop;
bool rw = bio_data_dir(bio), update_disptime = true;
struct blkio_cgroup *blkcg;
if (bio->bi_rw & REQ_THROTTLED) {
bio->bi_rw &= ~REQ_THROTTLED;
return 0;
}
/*
* A throtl_grp pointer retrieved under rcu can be used to access
* basic fields like stats and io rates. If a group has no rules,
* just update the dispatch stats in lockless manner and return.
*/
rcu_read_lock();
blkcg = task_blkio_cgroup(current);
tg = throtl_find_tg(td, blkcg);
if (tg) {
throtl_tg_fill_dev_details(td, tg);
if (tg_no_rule_group(tg, rw)) {
blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size,
rw, bio->bi_rw & REQ_SYNC);
rcu_read_unlock();
return 0;
}
}
rcu_read_unlock();
/*
* Either group has not been allocated yet or it is not an unlimited
* IO group
*/
spin_lock_irq(q->queue_lock);
tg = throtl_get_tg(td);
if (IS_ERR(tg)) {
if (PTR_ERR(tg) == -ENODEV) {
/*
* Queue is gone. No queue lock held here.
*/
return -ENODEV;
}
}
if (tg->nr_queued[rw]) {
/*
* There is already another bio queued in same dir. No
@ -1060,39 +1236,24 @@ int blk_throtl_init(struct request_queue *q)
INIT_HLIST_HEAD(&td->tg_list);
td->tg_service_tree = THROTL_RB_ROOT;
td->limits_changed = false;
/* Init root group */
tg = &td->root_tg;
INIT_HLIST_NODE(&tg->tg_node);
RB_CLEAR_NODE(&tg->rb_node);
bio_list_init(&tg->bio_lists[0]);
bio_list_init(&tg->bio_lists[1]);
/* Practically unlimited BW */
tg->bps[0] = tg->bps[1] = -1;
tg->iops[0] = tg->iops[1] = -1;
td->limits_changed = false;
/*
* Set root group reference to 2. One reference will be dropped when
* all groups on tg_list are being deleted during queue exit. Other
* reference will remain there as we don't want to delete this group
* as it is statically allocated and gets destroyed when throtl_data
* goes away.
*/
atomic_set(&tg->ref, 2);
hlist_add_head(&tg->tg_node, &td->tg_list);
td->nr_undestroyed_grps++;
INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
/* alloc and Init root group. */
td->queue = q;
tg = throtl_alloc_tg(td);
if (!tg) {
kfree(td);
return -ENOMEM;
}
td->root_tg = tg;
rcu_read_lock();
blkiocg_add_blkio_group(&blkio_root_cgroup, &tg->blkg, (void *)td,
0, BLKIO_POLICY_THROTL);
throtl_init_add_tg_lists(td, tg, &blkio_root_cgroup);
rcu_read_unlock();
/* Attach throtl data to request queue */
td->queue = q;
q->td = td;
return 0;
}

23
block/blk.h
View File

@ -62,7 +62,28 @@ static inline struct request *__elv_next_request(struct request_queue *q)
return rq;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
/*
* Flush request is running and flush request isn't queueable
* in the drive, we can hold the queue till flush request is
* finished. Even we don't do this, driver can't dispatch next
* requests and will requeue them. And this can improve
* throughput too. For example, we have request flush1, write1,
* flush 2. flush1 is dispatched, then queue is hold, write1
* isn't inserted to queue. After flush1 is finished, flush2
* will be dispatched. Since disk cache is already clean,
* flush2 will be finished very soon, so looks like flush2 is
* folded to flush1.
* Since the queue is hold, a flag is set to indicate the queue
* should be restarted later. Please see flush_end_io() for
* details.
*/
if (q->flush_pending_idx != q->flush_running_idx &&
!queue_flush_queueable(q)) {
q->flush_queue_delayed = 1;
return NULL;
}
if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
!q->elevator->ops->elevator_dispatch_fn(q, 0))
return NULL;
}
}

232
block/cfq-iosched.c
View File

@ -300,7 +300,9 @@ struct cfq_data {
/* List of cfq groups being managed on this device*/
struct hlist_head cfqg_list;
struct rcu_head rcu;
/* Number of groups which are on blkcg->blkg_list */
unsigned int nr_blkcg_linked_grps;
};
static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
@ -665,15 +667,11 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2,
if (rq2 == NULL)
return rq1;
if (rq_is_sync(rq1) && !rq_is_sync(rq2))
return rq1;
else if (rq_is_sync(rq2) && !rq_is_sync(rq1))
return rq2;
if ((rq1->cmd_flags & REQ_META) && !(rq2->cmd_flags & REQ_META))
return rq1;
else if ((rq2->cmd_flags & REQ_META) &&
!(rq1->cmd_flags & REQ_META))
return rq2;
if (rq_is_sync(rq1) != rq_is_sync(rq2))
return rq_is_sync(rq1) ? rq1 : rq2;
if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_META)
return rq1->cmd_flags & REQ_META ? rq1 : rq2;
s1 = blk_rq_pos(rq1);
s2 = blk_rq_pos(rq2);
@ -1014,28 +1012,47 @@ void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg,
cfqg->needs_update = true;
}
static struct cfq_group * cfq_find_alloc_cfqg(struct cfq_data *cfqd,
struct blkio_cgroup *blkcg, int create)
static void cfq_init_add_cfqg_lists(struct cfq_data *cfqd,
struct cfq_group *cfqg, struct blkio_cgroup *blkcg)
{
struct cfq_group *cfqg = NULL;
void *key = cfqd;
int i, j;
struct cfq_rb_root *st;
struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
unsigned int major, minor;
cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
/*
* Add group onto cgroup list. It might happen that bdi->dev is
* not initialized yet. Initialize this new group without major
* and minor info and this info will be filled in once a new thread
* comes for IO.
*/
if (bdi->dev) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
cfqg->blkg.dev = MKDEV(major, minor);
goto done;
}
if (cfqg || !create)
goto done;
cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg,
(void *)cfqd, MKDEV(major, minor));
} else
cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg,
(void *)cfqd, 0);
cfqd->nr_blkcg_linked_grps++;
cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
/* Add group on cfqd list */
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
}
/*
* Should be called from sleepable context. No request queue lock as per
* cpu stats are allocated dynamically and alloc_percpu needs to be called
* from sleepable context.
*/
static struct cfq_group * cfq_alloc_cfqg(struct cfq_data *cfqd)
{
struct cfq_group *cfqg = NULL;
int i, j, ret;
struct cfq_rb_root *st;
cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node);
if (!cfqg)
goto done;
return NULL;
for_each_cfqg_st(cfqg, i, j, st)
*st = CFQ_RB_ROOT;
@ -1049,43 +1066,94 @@ static struct cfq_group * cfq_find_alloc_cfqg(struct cfq_data *cfqd,
*/
cfqg->ref = 1;
ret = blkio_alloc_blkg_stats(&cfqg->blkg);
if (ret) {
kfree(cfqg);
return NULL;
}
return cfqg;
}
static struct cfq_group *
cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg)
{
struct cfq_group *cfqg = NULL;
void *key = cfqd;
struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
unsigned int major, minor;
/*
* Add group onto cgroup list. It might happen that bdi->dev is
* not initialized yet. Initialize this new group without major
* and minor info and this info will be filled in once a new thread
* comes for IO. See code above.
* This is the common case when there are no blkio cgroups.
* Avoid lookup in this case
*/
if (bdi->dev) {
if (blkcg == &blkio_root_cgroup)
cfqg = &cfqd->root_group;
else
cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
MKDEV(major, minor));
} else
cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
0);
cfqg->blkg.dev = MKDEV(major, minor);
}
cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
/* Add group on cfqd list */
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
done:
return cfqg;
}
/*
* Search for the cfq group current task belongs to. If create = 1, then also
* create the cfq group if it does not exist. request_queue lock must be held.
* Search for the cfq group current task belongs to. request_queue lock must
* be held.
*/
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd)
{
struct blkio_cgroup *blkcg;
struct cfq_group *cfqg = NULL;
struct cfq_group *cfqg = NULL, *__cfqg = NULL;
struct request_queue *q = cfqd->queue;
rcu_read_lock();
blkcg = task_blkio_cgroup(current);
cfqg = cfq_find_alloc_cfqg(cfqd, blkcg, create);
if (!cfqg && create)
cfqg = cfq_find_cfqg(cfqd, blkcg);
if (cfqg) {
rcu_read_unlock();
return cfqg;
}
/*
* Need to allocate a group. Allocation of group also needs allocation
* of per cpu stats which in-turn takes a mutex() and can block. Hence
* we need to drop rcu lock and queue_lock before we call alloc.
*
* Not taking any queue reference here and assuming that queue is
* around by the time we return. CFQ queue allocation code does
* the same. It might be racy though.
*/
rcu_read_unlock();
spin_unlock_irq(q->queue_lock);
cfqg = cfq_alloc_cfqg(cfqd);
spin_lock_irq(q->queue_lock);
rcu_read_lock();
blkcg = task_blkio_cgroup(current);
/*
* If some other thread already allocated the group while we were
* not holding queue lock, free up the group
*/
__cfqg = cfq_find_cfqg(cfqd, blkcg);
if (__cfqg) {
kfree(cfqg);
rcu_read_unlock();
return __cfqg;
}
if (!cfqg)
cfqg = &cfqd->root_group;
cfq_init_add_cfqg_lists(cfqd, cfqg, blkcg);
rcu_read_unlock();
return cfqg;
}
@ -1118,6 +1186,7 @@ static void cfq_put_cfqg(struct cfq_group *cfqg)
return;
for_each_cfqg_st(cfqg, i, j, st)
BUG_ON(!RB_EMPTY_ROOT(&st->rb));
free_percpu(cfqg->blkg.stats_cpu);
kfree(cfqg);
}
@ -1176,7 +1245,7 @@ void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg)
}
#else /* GROUP_IOSCHED */
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd)
{
return &cfqd->root_group;
}
@ -1210,7 +1279,6 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct cfq_rb_root *service_tree;
int left;
int new_cfqq = 1;
int group_changed = 0;
service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq),
cfqq_type(cfqq));
@ -1281,7 +1349,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
rb_link_node(&cfqq->rb_node, parent, p);
rb_insert_color(&cfqq->rb_node, &service_tree->rb);
service_tree->count++;
if ((add_front || !new_cfqq) && !group_changed)
if (add_front || !new_cfqq)
return;
cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
}
@ -2029,7 +2097,7 @@ cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);
return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio));
return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio);
}
/*
@ -2911,7 +2979,7 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync,
struct cfq_group *cfqg;
retry:
cfqg = cfq_get_cfqg(cfqd, 1);
cfqg = cfq_get_cfqg(cfqd);
cic = cfq_cic_lookup(cfqd, ioc);
/* cic always exists here */
cfqq = cic_to_cfqq(cic, is_sync);
@ -3815,15 +3883,11 @@ static void cfq_put_async_queues(struct cfq_data *cfqd)
cfq_put_queue(cfqd->async_idle_cfqq);
}
static void cfq_cfqd_free(struct rcu_head *head)
{
kfree(container_of(head, struct cfq_data, rcu));
}
static void cfq_exit_queue(struct elevator_queue *e)
{
struct cfq_data *cfqd = e->elevator_data;
struct request_queue *q = cfqd->queue;
bool wait = false;
cfq_shutdown_timer_wq(cfqd);
@ -3842,7 +3906,13 @@ static void cfq_exit_queue(struct elevator_queue *e)
cfq_put_async_queues(cfqd);
cfq_release_cfq_groups(cfqd);
cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg);
/*
* If there are groups which we could not unlink from blkcg list,
* wait for a rcu period for them to be freed.
*/
if (cfqd->nr_blkcg_linked_grps)
wait = true;
spin_unlock_irq(q->queue_lock);
@ -3852,8 +3922,25 @@ static void cfq_exit_queue(struct elevator_queue *e)
ida_remove(&cic_index_ida, cfqd->cic_index);
spin_unlock(&cic_index_lock);
/* Wait for cfqg->blkg->key accessors to exit their grace periods. */
call_rcu(&cfqd->rcu, cfq_cfqd_free);
/*
* Wait for cfqg->blkg->key accessors to exit their grace periods.
* Do this wait only if there are other unlinked groups out
* there. This can happen if cgroup deletion path claimed the
* responsibility of cleaning up a group before queue cleanup code
* get to the group.
*
* Do not call synchronize_rcu() unconditionally as there are drivers
* which create/delete request queue hundreds of times during scan/boot
* and synchronize_rcu() can take significant time and slow down boot.
*/
if (wait)
synchronize_rcu();
#ifdef CONFIG_CFQ_GROUP_IOSCHED
/* Free up per cpu stats for root group */
free_percpu(cfqd->root_group.blkg.stats_cpu);
#endif
kfree(cfqd);
}
static int cfq_alloc_cic_index(void)
@ -3886,8 +3973,12 @@ static void *cfq_init_queue(struct request_queue *q)
return NULL;
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!cfqd)
if (!cfqd) {
spin_lock(&cic_index_lock);
ida_remove(&cic_index_ida, i);
spin_unlock(&cic_index_lock);
return NULL;
}
/*
* Don't need take queue_lock in the routine, since we are
@ -3909,14 +4000,29 @@ static void *cfq_init_queue(struct request_queue *q)
#ifdef CONFIG_CFQ_GROUP_IOSCHED
/*
* Take a reference to root group which we never drop. This is just
* to make sure that cfq_put_cfqg() does not try to kfree root group
* Set root group reference to 2. One reference will be dropped when
* all groups on cfqd->cfqg_list are being deleted during queue exit.
* Other reference will remain there as we don't want to delete this
* group as it is statically allocated and gets destroyed when
* throtl_data goes away.
*/
cfqg->ref = 1;
cfqg->ref = 2;
if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
kfree(cfqg);
kfree(cfqd);
return NULL;
}
rcu_read_lock();
cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
(void *)cfqd, 0);
rcu_read_unlock();
cfqd->nr_blkcg_linked_grps++;
/* Add group on cfqd->cfqg_list */
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
#endif
/*
* Not strictly needed (since RB_ROOT just clears the node and we

11
block/elevator.c
View File

@ -155,13 +155,8 @@ static struct elevator_type *elevator_get(const char *name)
e = elevator_find(name);
if (!e) {
char elv[ELV_NAME_MAX + strlen("-iosched")];
spin_unlock(&elv_list_lock);
snprintf(elv, sizeof(elv), "%s-iosched", name);
request_module("%s", elv);
request_module("%s-iosched", name);
spin_lock(&elv_list_lock);
e = elevator_find(name);
}
@ -421,8 +416,6 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
struct list_head *entry;
int stop_flags;
BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
if (q->last_merge == rq)
q->last_merge = NULL;
@ -661,8 +654,6 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
rq->q = q;
BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
if (rq->cmd_flags & REQ_SOFTBARRIER) {
/* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||

13
drivers/ata/libata-scsi.c
View File

@ -1089,21 +1089,21 @@ static int atapi_drain_needed(struct request *rq)
static int ata_scsi_dev_config(struct scsi_device *sdev,
struct ata_device *dev)
{
struct request_queue *q = sdev->request_queue;
if (!ata_id_has_unload(dev->id))
dev->flags |= ATA_DFLAG_NO_UNLOAD;
/* configure max sectors */
blk_queue_max_hw_sectors(sdev->request_queue, dev->max_sectors);
blk_queue_max_hw_sectors(q, dev->max_sectors);
if (dev->class == ATA_DEV_ATAPI) {
struct request_queue *q = sdev->request_queue;
void *buf;
sdev->sector_size = ATA_SECT_SIZE;
/* set DMA padding */
blk_queue_update_dma_pad(sdev->request_queue,
ATA_DMA_PAD_SZ - 1);
blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);
/* configure draining */
buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
@ -1131,8 +1131,7 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
"sector_size=%u > PAGE_SIZE, PIO may malfunction\n",
sdev->sector_size);
blk_queue_update_dma_alignment(sdev->request_queue,
sdev->sector_size - 1);
blk_queue_update_dma_alignment(q, sdev->sector_size - 1);
if (dev->flags & ATA_DFLAG_AN)
set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
@ -1145,6 +1144,8 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
}
blk_queue_flush_queueable(q, false);
dev->sdev = sdev;
return 0;
}

2
drivers/block/paride/pcd.c
View File

@ -320,6 +320,8 @@ static void pcd_init_units(void)
disk->first_minor = unit;
strcpy(disk->disk_name, cd->name); /* umm... */
disk->fops = &pcd_bdops;
disk->flags = GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
disk->events = DISK_EVENT_MEDIA_CHANGE;
}
}

4
drivers/cdrom/viocd.c
View File

@ -625,7 +625,9 @@ static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
blk_queue_max_hw_sectors(q, 4096 / 512);
gendisk->queue = q;
gendisk->fops = &viocd_fops;
gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE;
gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
gendisk->events = DISK_EVENT_MEDIA_CHANGE;
set_capacity(gendisk, 0);
gendisk->private_data = d;
d->viocd_disk = gendisk;

3
drivers/ide/ide-cd.c
View File

@ -1781,7 +1781,8 @@ static int ide_cd_probe(ide_drive_t *drive)
ide_cd_read_toc(drive, &sense);
g->fops = &idecd_ops;
g->flags |= GENHD_FL_REMOVABLE;
g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
g->events = DISK_EVENT_MEDIA_CHANGE;
add_disk(g);
return 0;

2
drivers/scsi/sr.c
View File

@ -636,7 +636,7 @@ static int sr_probe(struct device *dev)
disk->first_minor = minor;
sprintf(disk->disk_name, "sr%d", minor);
disk->fops = &sr_bdops;
disk->flags = GENHD_FL_CD;
disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);

17
fs/block_dev.c
View File

@ -1238,6 +1238,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
res = __blkdev_get(bdev, mode, 0);
if (whole) {
struct gendisk *disk = whole->bd_disk;
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
@ -1264,15 +1266,16 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
spin_unlock(&bdev_lock);
/*
* Block event polling for write claims. Any write
* holder makes the write_holder state stick until all
* are released. This is good enough and tracking
* individual writeable reference is too fragile given
* the way @mode is used in blkdev_get/put().
* Block event polling for write claims if requested. Any
* write holder makes the write_holder state stick until
* all are released. This is good enough and tracking
* individual writeable reference is too fragile given the
* way @mode is used in blkdev_get/put().
*/
if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
bdev->bd_write_holder = true;
disk_block_events(bdev->bd_disk);
disk_block_events(disk);
}
mutex_unlock(&bdev->bd_mutex);

8
fs/partitions/check.c
View File

@ -255,7 +255,11 @@ ssize_t part_discard_alignment_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
return sprintf(buf, "%u\n", p->discard_alignment);
struct gendisk *disk = dev_to_disk(dev);
return sprintf(buf, "%u\n",
queue_limit_discard_alignment(&disk->queue->limits,
p->start_sect));
}
ssize_t part_stat_show(struct device *dev,
@ -449,8 +453,6 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
p->start_sect = start;
p->alignment_offset =
queue_limit_alignment_offset(&disk->queue->limits, start);
p->discard_alignment =
queue_limit_discard_alignment(&disk->queue->limits, start);
p->nr_sects = len;
p->partno = partno;
p->policy = get_disk_ro(disk);

2
include/linux/blk_types.h
View File

@ -151,7 +151,6 @@ enum rq_flag_bits {
__REQ_IO_STAT, /* account I/O stat */
__REQ_MIXED_MERGE, /* merge of different types, fail separately */
__REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */
__REQ_ON_PLUG, /* on plug list */
__REQ_NR_BITS, /* stops here */
};
@ -192,6 +191,5 @@ enum rq_flag_bits {
#define REQ_IO_STAT (1 << __REQ_IO_STAT)
#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
#define REQ_SECURE (1 << __REQ_SECURE)
#define REQ_ON_PLUG (1 << __REQ_ON_PLUG)
#endif /* __LINUX_BLK_TYPES_H */

15
include/linux/blkdev.h
View File

@ -257,7 +257,7 @@ struct queue_limits {
unsigned char misaligned;
unsigned char discard_misaligned;
unsigned char cluster;
signed char discard_zeroes_data;
unsigned char discard_zeroes_data;
};
struct request_queue
@ -364,6 +364,8 @@ struct request_queue
* for flush operations
*/
unsigned int flush_flags;
unsigned int flush_not_queueable:1;
unsigned int flush_queue_delayed:1;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
unsigned long flush_pending_since;
@ -843,6 +845,7 @@ extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
@ -1066,13 +1069,16 @@ static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector
{
unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
if (!lim->max_discard_sectors)
return 0;
return (lim->discard_granularity + lim->discard_alignment - alignment)
& (lim->discard_granularity - 1);
}
static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
{
if (q->limits.discard_zeroes_data == 1)
if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
return 1;
return 0;
@ -1111,6 +1117,11 @@ static inline unsigned int block_size(struct block_device *bdev)
return bdev->bd_block_size;
}
static inline bool queue_flush_queueable(struct request_queue *q)
{
return !q->flush_not_queueable;
}
typedef struct {struct page *v;} Sector;
unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);

2
include/linux/genhd.h
View File

@ -100,7 +100,6 @@ struct hd_struct {
sector_t start_sect;
sector_t nr_sects;
sector_t alignment_offset;
unsigned int discard_alignment;
struct device __dev;
struct kobject *holder_dir;
int policy, partno;
@ -127,6 +126,7 @@ struct hd_struct {
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY 128
#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
enum {
DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */

4
mm/backing-dev.c
View File

@ -63,10 +63,10 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
unsigned long background_thresh;
unsigned long dirty_thresh;
unsigned long bdi_thresh;
unsigned long nr_dirty, nr_io, nr_more_io, nr_wb;
unsigned long nr_dirty, nr_io, nr_more_io;
struct inode *inode;
nr_wb = nr_dirty = nr_io = nr_more_io = 0;
nr_dirty = nr_io = nr_more_io = 0;
spin_lock(&inode_wb_list_lock);
list_for_each_entry(inode, &wb->b_dirty, i_wb_list)
nr_dirty++;