android_kernel_xiaomi_sm8350/block/blktrace.c
Arnaldo Carvalho de Melo 5f3ea37c77 blktrace: port to tracepoints
This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26 12:13:34 +01:00

891 lines
21 KiB
C

/*
* Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/blktrace_api.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/time.h>
#include <trace/block.h>
#include <asm/uaccess.h>
static unsigned int blktrace_seq __read_mostly = 1;
/* Global reference count of probes */
static DEFINE_MUTEX(blk_probe_mutex);
static atomic_t blk_probes_ref = ATOMIC_INIT(0);
static int blk_register_tracepoints(void);
static void blk_unregister_tracepoints(void);
/*
* Send out a notify message.
*/
static void trace_note(struct blk_trace *bt, pid_t pid, int action,
const void *data, size_t len)
{
struct blk_io_trace *t;
t = relay_reserve(bt->rchan, sizeof(*t) + len);
if (t) {
const int cpu = smp_processor_id();
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->time = ktime_to_ns(ktime_get());
t->device = bt->dev;
t->action = action;
t->pid = pid;
t->cpu = cpu;
t->pdu_len = len;
memcpy((void *) t + sizeof(*t), data, len);
}
}
/*
* Send out a notify for this process, if we haven't done so since a trace
* started
*/
static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
{
tsk->btrace_seq = blktrace_seq;
trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));
}
static void trace_note_time(struct blk_trace *bt)
{
struct timespec now;
unsigned long flags;
u32 words[2];
getnstimeofday(&now);
words[0] = now.tv_sec;
words[1] = now.tv_nsec;
local_irq_save(flags);
trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words));
local_irq_restore(flags);
}
void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
{
int n;
va_list args;
unsigned long flags;
char *buf;
local_irq_save(flags);
buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
va_start(args, fmt);
n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(__trace_note_message);
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
return 1;
if (sector < bt->start_lba || sector > bt->end_lba)
return 1;
if (bt->pid && pid != bt->pid)
return 1;
return 0;
}
/*
* Data direction bit lookup
*/
static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) };
/* The ilog2() calls fall out because they're constant */
#define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \
(ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) )
/*
* The worker for the various blk_add_trace*() types. Fills out a
* blk_io_trace structure and places it in a per-cpu subbuffer.
*/
static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
int rw, u32 what, int error, int pdu_len, void *pdu_data)
{
struct task_struct *tsk = current;
struct blk_io_trace *t;
unsigned long flags;
unsigned long *sequence;
pid_t pid;
int cpu;
if (unlikely(bt->trace_state != Blktrace_running))
return;
what |= ddir_act[rw & WRITE];
what |= MASK_TC_BIT(rw, BARRIER);
what |= MASK_TC_BIT(rw, SYNC);
what |= MASK_TC_BIT(rw, AHEAD);
what |= MASK_TC_BIT(rw, META);
what |= MASK_TC_BIT(rw, DISCARD);
pid = tsk->pid;
if (unlikely(act_log_check(bt, what, sector, pid)))
return;
/*
* A word about the locking here - we disable interrupts to reserve
* some space in the relay per-cpu buffer, to prevent an irq
* from coming in and stepping on our toes.
*/
local_irq_save(flags);
if (unlikely(tsk->btrace_seq != blktrace_seq))
trace_note_tsk(bt, tsk);
t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
if (t) {
cpu = smp_processor_id();
sequence = per_cpu_ptr(bt->sequence, cpu);
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->sequence = ++(*sequence);
t->time = ktime_to_ns(ktime_get());
t->sector = sector;
t->bytes = bytes;
t->action = what;
t->pid = pid;
t->device = bt->dev;
t->cpu = cpu;
t->error = error;
t->pdu_len = pdu_len;
if (pdu_len)
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
}
local_irq_restore(flags);
}
static struct dentry *blk_tree_root;
static DEFINE_MUTEX(blk_tree_mutex);
static unsigned int root_users;
static inline void blk_remove_root(void)
{
if (blk_tree_root) {
debugfs_remove(blk_tree_root);
blk_tree_root = NULL;
}
}
static void blk_remove_tree(struct dentry *dir)
{
mutex_lock(&blk_tree_mutex);
debugfs_remove(dir);
if (--root_users == 0)
blk_remove_root();
mutex_unlock(&blk_tree_mutex);
}
static struct dentry *blk_create_tree(const char *blk_name)
{
struct dentry *dir = NULL;
int created = 0;
mutex_lock(&blk_tree_mutex);
if (!blk_tree_root) {
blk_tree_root = debugfs_create_dir("block", NULL);
if (!blk_tree_root)
goto err;
created = 1;
}
dir = debugfs_create_dir(blk_name, blk_tree_root);
if (dir)
root_users++;
else {
/* Delete root only if we created it */
if (created)
blk_remove_root();
}
err:
mutex_unlock(&blk_tree_mutex);
return dir;
}
static void blk_trace_cleanup(struct blk_trace *bt)
{
relay_close(bt->rchan);
debugfs_remove(bt->msg_file);
debugfs_remove(bt->dropped_file);
blk_remove_tree(bt->dir);
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
mutex_lock(&blk_probe_mutex);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
mutex_unlock(&blk_probe_mutex);
}
int blk_trace_remove(struct request_queue *q)
{
struct blk_trace *bt;
bt = xchg(&q->blk_trace, NULL);
if (!bt)
return -EINVAL;
if (bt->trace_state == Blktrace_setup ||
bt->trace_state == Blktrace_stopped)
blk_trace_cleanup(bt);
return 0;
}
EXPORT_SYMBOL_GPL(blk_trace_remove);
static int blk_dropped_open(struct inode *inode, struct file *filp)
{
filp->private_data = inode->i_private;
return 0;
}
static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
size_t count, loff_t *ppos)
{
struct blk_trace *bt = filp->private_data;
char buf[16];
snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
}
static const struct file_operations blk_dropped_fops = {
.owner = THIS_MODULE,
.open = blk_dropped_open,
.read = blk_dropped_read,
};
static int blk_msg_open(struct inode *inode, struct file *filp)
{
filp->private_data = inode->i_private;
return 0;
}
static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
size_t count, loff_t *ppos)
{
char *msg;
struct blk_trace *bt;
if (count > BLK_TN_MAX_MSG)
return -EINVAL;
msg = kmalloc(count, GFP_KERNEL);
if (msg == NULL)
return -ENOMEM;
if (copy_from_user(msg, buffer, count)) {
kfree(msg);
return -EFAULT;
}
bt = filp->private_data;
__trace_note_message(bt, "%s", msg);
kfree(msg);
return count;
}
static const struct file_operations blk_msg_fops = {
.owner = THIS_MODULE,
.open = blk_msg_open,
.write = blk_msg_write,
};
/*
* Keep track of how many times we encountered a full subbuffer, to aid
* the user space app in telling how many lost events there were.
*/
static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
void *prev_subbuf, size_t prev_padding)
{
struct blk_trace *bt;
if (!relay_buf_full(buf))
return 1;
bt = buf->chan->private_data;
atomic_inc(&bt->dropped);
return 0;
}
static int blk_remove_buf_file_callback(struct dentry *dentry)
{
debugfs_remove(dentry);
return 0;
}
static struct dentry *blk_create_buf_file_callback(const char *filename,
struct dentry *parent,
int mode,
struct rchan_buf *buf,
int *is_global)
{
return debugfs_create_file(filename, mode, parent, buf,
&relay_file_operations);
}
static struct rchan_callbacks blk_relay_callbacks = {
.subbuf_start = blk_subbuf_start_callback,
.create_buf_file = blk_create_buf_file_callback,
.remove_buf_file = blk_remove_buf_file_callback,
};
/*
* Setup everything required to start tracing
*/
int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct blk_user_trace_setup *buts)
{
struct blk_trace *old_bt, *bt = NULL;
struct dentry *dir = NULL;
int ret, i;
if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
/*
* some device names have larger paths - convert the slashes
* to underscores for this to work as expected
*/
for (i = 0; i < strlen(buts->name); i++)
if (buts->name[i] == '/')
buts->name[i] = '_';
ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
goto err;
bt->sequence = alloc_percpu(unsigned long);
if (!bt->sequence)
goto err;
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG);
if (!bt->msg_data)
goto err;
ret = -ENOENT;
dir = blk_create_tree(buts->name);
if (!dir)
goto err;
bt->dir = dir;
bt->dev = dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
if (!bt->dropped_file)
goto err;
bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
if (!bt->msg_file)
goto err;
bt->rchan = relay_open("trace", dir, buts->buf_size,
buts->buf_nr, &blk_relay_callbacks, bt);
if (!bt->rchan)
goto err;
bt->act_mask = buts->act_mask;
if (!bt->act_mask)
bt->act_mask = (u16) -1;
bt->start_lba = buts->start_lba;
bt->end_lba = buts->end_lba;
if (!bt->end_lba)
bt->end_lba = -1ULL;
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
mutex_lock(&blk_probe_mutex);
if (atomic_add_return(1, &blk_probes_ref) == 1) {
ret = blk_register_tracepoints();
if (ret)
goto probe_err;
}
mutex_unlock(&blk_probe_mutex);
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
(void) xchg(&q->blk_trace, old_bt);
goto err;
}
return 0;
probe_err:
atomic_dec(&blk_probes_ref);
mutex_unlock(&blk_probe_mutex);
err:
if (dir)
blk_remove_tree(dir);
if (bt) {
if (bt->msg_file)
debugfs_remove(bt->msg_file);
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
}
return ret;
}
int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
char __user *arg)
{
struct blk_user_trace_setup buts;
int ret;
ret = copy_from_user(&buts, arg, sizeof(buts));
if (ret)
return -EFAULT;
ret = do_blk_trace_setup(q, name, dev, &buts);
if (ret)
return ret;
if (copy_to_user(arg, &buts, sizeof(buts)))
return -EFAULT;
return 0;
}
EXPORT_SYMBOL_GPL(blk_trace_setup);
int blk_trace_startstop(struct request_queue *q, int start)
{
struct blk_trace *bt;
int ret;
if ((bt = q->blk_trace) == NULL)
return -EINVAL;
/*
* For starting a trace, we can transition from a setup or stopped
* trace. For stopping a trace, the state must be running
*/
ret = -EINVAL;
if (start) {
if (bt->trace_state == Blktrace_setup ||
bt->trace_state == Blktrace_stopped) {
blktrace_seq++;
smp_mb();
bt->trace_state = Blktrace_running;
trace_note_time(bt);
ret = 0;
}
} else {
if (bt->trace_state == Blktrace_running) {
bt->trace_state = Blktrace_stopped;
relay_flush(bt->rchan);
ret = 0;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(blk_trace_startstop);
/**
* blk_trace_ioctl: - handle the ioctls associated with tracing
* @bdev: the block device
* @cmd: the ioctl cmd
* @arg: the argument data, if any
*
**/
int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
{
struct request_queue *q;
int ret, start = 0;
char b[BDEVNAME_SIZE];
q = bdev_get_queue(bdev);
if (!q)
return -ENXIO;
mutex_lock(&bdev->bd_mutex);
switch (cmd) {
case BLKTRACESETUP:
bdevname(bdev, b);
ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
break;
case BLKTRACESTART:
start = 1;
case BLKTRACESTOP:
ret = blk_trace_startstop(q, start);
break;
case BLKTRACETEARDOWN:
ret = blk_trace_remove(q);
break;
default:
ret = -ENOTTY;
break;
}
mutex_unlock(&bdev->bd_mutex);
return ret;
}
/**
* blk_trace_shutdown: - stop and cleanup trace structures
* @q: the request queue associated with the device
*
**/
void blk_trace_shutdown(struct request_queue *q)
{
if (q->blk_trace) {
blk_trace_startstop(q, 0);
blk_trace_remove(q);
}
}
/*
* blktrace probes
*/
/**
* blk_add_trace_rq - Add a trace for a request oriented action
* @q: queue the io is for
* @rq: the source request
* @what: the action
*
* Description:
* Records an action against a request. Will log the bio offset + size.
*
**/
static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
int rw = rq->cmd_flags & 0x03;
if (likely(!bt))
return;
if (blk_discard_rq(rq))
rw |= (1 << BIO_RW_DISCARD);
if (blk_pc_request(rq)) {
what |= BLK_TC_ACT(BLK_TC_PC);
__blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors,
sizeof(rq->cmd), rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
__blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
rw, what, rq->errors, 0, NULL);
}
}
static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq)
{
blk_add_trace_rq(q, rq, BLK_TA_ABORT);
}
static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq)
{
blk_add_trace_rq(q, rq, BLK_TA_INSERT);
}
static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq)
{
blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
}
static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq)
{
blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
}
static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq)
{
blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
}
/**
* blk_add_trace_bio - Add a trace for a bio oriented action
* @q: queue the io is for
* @bio: the source bio
* @what: the action
*
* Description:
* Records an action against a bio. Will log the bio offset + size.
*
**/
static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
if (likely(!bt))
return;
__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
!bio_flagged(bio, BIO_UPTODATE), 0, NULL);
}
static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_BOUNCE);
}
static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
}
static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
}
static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
}
static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
}
static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw)
{
if (bio)
blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
else {
struct blk_trace *bt = q->blk_trace;
if (bt)
__blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
}
}
static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw)
{
if (bio)
blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
else {
struct blk_trace *bt = q->blk_trace;
if (bt)
__blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL);
}
}
static void blk_add_trace_plug(struct request_queue *q)
{
struct blk_trace *bt = q->blk_trace;
if (bt)
__blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
}
static void blk_add_trace_unplug_io(struct request_queue *q)
{
struct blk_trace *bt = q->blk_trace;
if (bt) {
unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
__be64 rpdu = cpu_to_be64(pdu);
__blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0,
sizeof(rpdu), &rpdu);
}
}
static void blk_add_trace_unplug_timer(struct request_queue *q)
{
struct blk_trace *bt = q->blk_trace;
if (bt) {
unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
__be64 rpdu = cpu_to_be64(pdu);
__blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0,
sizeof(rpdu), &rpdu);
}
}
static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
unsigned int pdu)
{
struct blk_trace *bt = q->blk_trace;
if (bt) {
__be64 rpdu = cpu_to_be64(pdu);
__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
sizeof(rpdu), &rpdu);
}
}
/**
* blk_add_trace_remap - Add a trace for a remap operation
* @q: queue the io is for
* @bio: the source bio
* @dev: target device
* @from: source sector
* @to: target sector
*
* Description:
* Device mapper or raid target sometimes need to split a bio because
* it spans a stripe (or similar). Add a trace for that action.
*
**/
static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
dev_t dev, sector_t from, sector_t to)
{
struct blk_trace *bt = q->blk_trace;
struct blk_io_trace_remap r;
if (likely(!bt))
return;
r.device = cpu_to_be32(dev);
r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
r.sector = cpu_to_be64(to);
__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP,
!bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
}
/**
* blk_add_driver_data - Add binary message with driver-specific data
* @q: queue the io is for
* @rq: io request
* @data: driver-specific data
* @len: length of driver-specific data
*
* Description:
* Some drivers might want to write driver-specific data per request.
*
**/
void blk_add_driver_data(struct request_queue *q,
struct request *rq,
void *data, size_t len)
{
struct blk_trace *bt = q->blk_trace;
if (likely(!bt))
return;
if (blk_pc_request(rq))
__blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
rq->errors, len, data);
else
__blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
0, BLK_TA_DRV_DATA, rq->errors, len, data);
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);
static int blk_register_tracepoints(void)
{
int ret;
ret = register_trace_block_rq_abort(blk_add_trace_rq_abort);
WARN_ON(ret);
ret = register_trace_block_rq_insert(blk_add_trace_rq_insert);
WARN_ON(ret);
ret = register_trace_block_rq_issue(blk_add_trace_rq_issue);
WARN_ON(ret);
ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue);
WARN_ON(ret);
ret = register_trace_block_rq_complete(blk_add_trace_rq_complete);
WARN_ON(ret);
ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce);
WARN_ON(ret);
ret = register_trace_block_bio_complete(blk_add_trace_bio_complete);
WARN_ON(ret);
ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
WARN_ON(ret);
ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
WARN_ON(ret);
ret = register_trace_block_bio_queue(blk_add_trace_bio_queue);
WARN_ON(ret);
ret = register_trace_block_getrq(blk_add_trace_getrq);
WARN_ON(ret);
ret = register_trace_block_sleeprq(blk_add_trace_sleeprq);
WARN_ON(ret);
ret = register_trace_block_plug(blk_add_trace_plug);
WARN_ON(ret);
ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer);
WARN_ON(ret);
ret = register_trace_block_unplug_io(blk_add_trace_unplug_io);
WARN_ON(ret);
ret = register_trace_block_split(blk_add_trace_split);
WARN_ON(ret);
ret = register_trace_block_remap(blk_add_trace_remap);
WARN_ON(ret);
return 0;
}
static void blk_unregister_tracepoints(void)
{
unregister_trace_block_remap(blk_add_trace_remap);
unregister_trace_block_split(blk_add_trace_split);
unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer);
unregister_trace_block_plug(blk_add_trace_plug);
unregister_trace_block_sleeprq(blk_add_trace_sleeprq);
unregister_trace_block_getrq(blk_add_trace_getrq);
unregister_trace_block_bio_queue(blk_add_trace_bio_queue);
unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
unregister_trace_block_bio_complete(blk_add_trace_bio_complete);
unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce);
unregister_trace_block_rq_complete(blk_add_trace_rq_complete);
unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue);
unregister_trace_block_rq_issue(blk_add_trace_rq_issue);
unregister_trace_block_rq_insert(blk_add_trace_rq_insert);
unregister_trace_block_rq_abort(blk_add_trace_rq_abort);
tracepoint_synchronize_unregister();
}