#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/slab.h>
#include <linux/debugfs.h>
#include <linux/export.h>
#include <linux/time.h>
#include <linux/uaccess.h>
#include <linux/list.h>
#include <linux/blk-cgroup.h>
#include "../../block/blk.h"
#include <trace/events/block.h>
#include "trace_output.h"
#ifdef CONFIG_BLK_DEV_IO_TRACE
static unsigned int blktrace_seq __read_mostly = 1;
static struct trace_array *blk_tr;
static bool blk_tracer_enabled __read_mostly;
static LIST_HEAD(running_trace_list);
static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(running_trace_lock);
#define TRACE_BLK_OPT_CLASSIC 0x1
#define TRACE_BLK_OPT_CGROUP 0x2
#define TRACE_BLK_OPT_CGNAME 0x4
static struct tracer_opt blk_tracer_opts[] = {
{ TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
#ifdef CONFIG_BLK_CGROUP
{ TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) },
{ TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) },
#endif
{ }
};
static struct tracer_flags blk_tracer_flags = {
.val = 0,
.opts = blk_tracer_opts,
};
static DEFINE_MUTEX(blk_probe_mutex);
static int blk_probes_ref;
static void blk_register_tracepoints(void);
static void blk_unregister_tracepoints(void);
static void record_blktrace_event(struct blk_io_trace *t, pid_t pid, int cpu,
sector_t sector, int bytes, u64 what,
dev_t dev, int error, u64 cgid,
ssize_t cgid_len, void *pdu_data, int pdu_len)
{
t->cpu = cpu;
t->pid = pid;
t->sector = sector;
t->bytes = bytes;
t->action = lower_32_bits(what);
t->device = dev;
t->error = error;
t->pdu_len = pdu_len + cgid_len;
if (cgid_len)
memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
if (pdu_len)
memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
}
static void record_blktrace_event2(struct blk_io_trace2 *t2, pid_t pid, int cpu,
sector_t sector, int bytes, u64 what,
dev_t dev, int error, u64 cgid,
ssize_t cgid_len, void *pdu_data,
int pdu_len)
{
t2->pid = pid;
t2->cpu = cpu;
t2->sector = sector;
t2->bytes = bytes;
t2->action = what;
t2->device = dev;
t2->error = error;
t2->pdu_len = pdu_len + cgid_len;
if (cgid_len)
memcpy((void *)t2 + sizeof(*t2), &cgid, cgid_len);
if (pdu_len)
memcpy((void *)t2 + sizeof(*t2) + cgid_len, pdu_data, pdu_len);
}
static void relay_blktrace_event1(struct blk_trace *bt, unsigned long sequence,
pid_t pid, int cpu, sector_t sector, int bytes,
u64 what, int error, u64 cgid,
ssize_t cgid_len, void *pdu_data, int pdu_len)
{
struct blk_io_trace *t;
size_t trace_len = sizeof(*t) + pdu_len + cgid_len;
t = relay_reserve(bt->rchan, trace_len);
if (!t)
return;
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->sequence = sequence;
t->time = ktime_to_ns(ktime_get());
record_blktrace_event(t, pid, cpu, sector, bytes, what, bt->dev, error,
cgid, cgid_len, pdu_data, pdu_len);
}
static void relay_blktrace_event2(struct blk_trace *bt, unsigned long sequence,
pid_t pid, int cpu, sector_t sector,
int bytes, u64 what, int error, u64 cgid,
ssize_t cgid_len, void *pdu_data, int pdu_len)
{
struct blk_io_trace2 *t;
size_t trace_len = sizeof(struct blk_io_trace2) + pdu_len + cgid_len;
t = relay_reserve(bt->rchan, trace_len);
if (!t)
return;
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE2_VERSION;
t->sequence = sequence;
t->time = ktime_to_ns(ktime_get());
record_blktrace_event2(t, pid, cpu, sector, bytes, what, bt->dev, error,
cgid, cgid_len, pdu_data, pdu_len);
}
static void relay_blktrace_event(struct blk_trace *bt, unsigned long sequence,
pid_t pid, int cpu, sector_t sector, int bytes,
u64 what, int error, u64 cgid,
ssize_t cgid_len, void *pdu_data, int pdu_len)
{
if (bt->version == 2)
return relay_blktrace_event2(bt, sequence, pid, cpu, sector,
bytes, what, error, cgid, cgid_len,
pdu_data, pdu_len);
return relay_blktrace_event1(bt, sequence, pid, cpu, sector, bytes,
what, error, cgid, cgid_len, pdu_data,
pdu_len);
}
static void trace_note(struct blk_trace *bt, pid_t pid, u64 action,
const void *data, size_t len, u64 cgid)
{
struct ring_buffer_event *event = NULL;
struct trace_buffer *buffer = NULL;
unsigned int trace_ctx = 0;
int cpu = smp_processor_id();
bool blk_tracer = blk_tracer_enabled;
ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
action = lower_32_bits(action | (cgid ? __BLK_TN_CGROUP : 0));
if (blk_tracer) {
struct blk_io_trace2 *t;
size_t trace_len = sizeof(*t) + cgid_len + len;
buffer = blk_tr->array_buffer.buffer;
trace_ctx = tracing_gen_ctx_flags(0);
event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
trace_len, trace_ctx);
if (!event)
return;
t = ring_buffer_event_data(event);
record_blktrace_event2(t, pid, cpu, 0, 0,
action, bt->dev, 0, cgid, cgid_len,
(void *)data, len);
trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
return;
}
if (!bt->rchan)
return;
relay_blktrace_event(bt, 0, pid, cpu, 0, 0, action, 0, cgid,
cgid_len, (void *)data, len);
}
static void trace_note_tsk(struct task_struct *tsk)
{
unsigned long flags;
struct blk_trace *bt;
tsk->btrace_seq = blktrace_seq;
raw_spin_lock_irqsave(&running_trace_lock, flags);
list_for_each_entry(bt, &running_trace_list, running_list) {
trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
sizeof(tsk->comm), 0);
}
raw_spin_unlock_irqrestore(&running_trace_lock, flags);
}
static void trace_note_time(struct blk_trace *bt)
{
struct timespec64 now;
unsigned long flags;
u32 words[2];
ktime_get_real_ts64(&now);
words[0] = (u32)now.tv_sec;
words[1] = now.tv_nsec;
local_irq_save(flags);
trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0);
local_irq_restore(flags);
}
void __blk_trace_note_message(struct blk_trace *bt,
struct cgroup_subsys_state *css, const char *fmt, ...)
{
int n;
va_list args;
unsigned long flags;
char *buf;
u64 cgid = 0;
if (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
return;
if (!(bt->act_mask & BLK_TC_NOTIFY))
return;
local_irq_save(flags);
buf = this_cpu_ptr(bt->msg_data);
va_start(args, fmt);
n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);
#ifdef CONFIG_BLK_CGROUP
if (css && (blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
cgid = cgroup_id(css->cgroup);
else
cgid = 1;
#endif
trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, cgid);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(__blk_trace_note_message);
static int act_log_check(struct blk_trace *bt, u64 what, sector_t sector,
pid_t pid)
{
if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
return 1;
if (sector && (sector < bt->start_lba || sector > bt->end_lba))
return 1;
if (bt->pid && pid != bt->pid)
return 1;
return 0;
}
static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
BLK_TC_ACT(BLK_TC_WRITE) };
#define BLK_TC_RAHEAD BLK_TC_AHEAD
#define BLK_TC_PREFLUSH BLK_TC_FLUSH
#define MASK_TC_BIT(rw, __name) ((__force u32)(rw & REQ_ ## __name) << \
(ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
const blk_opf_t opf, u64 what, int error,
int pdu_len, void *pdu_data, u64 cgid)
{
struct task_struct *tsk = current;
struct ring_buffer_event *event = NULL;
struct trace_buffer *buffer = NULL;
unsigned long flags = 0;
unsigned long *sequence;
unsigned int trace_ctx = 0;
pid_t pid;
int cpu;
bool blk_tracer = blk_tracer_enabled;
ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
const enum req_op op = opf & REQ_OP_MASK;
size_t trace_len;
if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
return;
what |= ddir_act[op_is_write(op) ? WRITE : READ];
what |= MASK_TC_BIT(opf, SYNC);
what |= MASK_TC_BIT(opf, RAHEAD);
what |= MASK_TC_BIT(opf, META);
what |= MASK_TC_BIT(opf, PREFLUSH);
what |= MASK_TC_BIT(opf, FUA);
switch (op) {
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
what |= BLK_TC_ACT(BLK_TC_DISCARD);
break;
case REQ_OP_FLUSH:
what |= BLK_TC_ACT(BLK_TC_FLUSH);
break;
case REQ_OP_ZONE_APPEND:
what |= BLK_TC_ACT(BLK_TC_ZONE_APPEND);
break;
case REQ_OP_ZONE_RESET:
what |= BLK_TC_ACT(BLK_TC_ZONE_RESET);
break;
case REQ_OP_ZONE_RESET_ALL:
what |= BLK_TC_ACT(BLK_TC_ZONE_RESET_ALL);
break;
case REQ_OP_ZONE_FINISH:
what |= BLK_TC_ACT(BLK_TC_ZONE_FINISH);
break;
case REQ_OP_ZONE_OPEN:
what |= BLK_TC_ACT(BLK_TC_ZONE_OPEN);
break;
case REQ_OP_ZONE_CLOSE:
what |= BLK_TC_ACT(BLK_TC_ZONE_CLOSE);
break;
case REQ_OP_WRITE_ZEROES:
what |= BLK_TC_ACT(BLK_TC_WRITE_ZEROES);
break;
default:
break;
}
if (bt->version == 1 && (what >> BLK_TC_SHIFT) > BLK_TC_END_V1) {
pr_debug_ratelimited("blktrace v1 cannot trace zone operation 0x%llx\n",
(unsigned long long)what);
return;
}
if (cgid)
what |= __BLK_TA_CGROUP;
pid = tsk->pid;
if (act_log_check(bt, what, sector, pid))
return;
cpu = raw_smp_processor_id();
if (blk_tracer) {
buffer = blk_tr->array_buffer.buffer;
trace_ctx = tracing_gen_ctx_flags(0);
switch (bt->version) {
case 1:
trace_len = sizeof(struct blk_io_trace);
break;
case 2:
default:
trace_len = sizeof(struct blk_io_trace2);
if (bt->version == 0)
bt->version = 2;
break;
}
trace_len += pdu_len + cgid_len;
event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
trace_len, trace_ctx);
if (!event)
return;
tracing_record_cmdline(current);
switch (bt->version) {
case 1:
record_blktrace_event(ring_buffer_event_data(event),
pid, cpu, sector, bytes,
what, bt->dev, error, cgid, cgid_len,
pdu_data, pdu_len);
break;
case 2:
default:
record_blktrace_event2(ring_buffer_event_data(event),
pid, cpu, sector, bytes,
what, bt->dev, error, cgid, cgid_len,
pdu_data, pdu_len);
break;
}
trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
return;
}
if (unlikely(tsk->btrace_seq != blktrace_seq))
trace_note_tsk(tsk);
local_irq_save(flags);
sequence = per_cpu_ptr(bt->sequence, cpu);
(*sequence)++;
relay_blktrace_event(bt, *sequence, pid, cpu, sector, bytes,
what, error, cgid, cgid_len, pdu_data, pdu_len);
local_irq_restore(flags);
}
static void blk_trace_free(struct request_queue *q, struct blk_trace *bt)
{
relay_close(bt->rchan);
if (!bt->dir) {
debugfs_lookup_and_remove("dropped", q->debugfs_dir);
debugfs_lookup_and_remove("msg", q->debugfs_dir);
} else {
debugfs_remove(bt->dir);
}
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
}
static void get_probe_ref(void)
{
mutex_lock(&blk_probe_mutex);
if (++blk_probes_ref == 1)
blk_register_tracepoints();
mutex_unlock(&blk_probe_mutex);
}
static void put_probe_ref(void)
{
mutex_lock(&blk_probe_mutex);
if (!--blk_probes_ref)
blk_unregister_tracepoints();
mutex_unlock(&blk_probe_mutex);
}
static int blk_trace_start(struct blk_trace *bt)
{
if (bt->trace_state != Blktrace_setup &&
bt->trace_state != Blktrace_stopped)
return -EINVAL;
blktrace_seq++;
smp_mb();
bt->trace_state = Blktrace_running;
raw_spin_lock_irq(&running_trace_lock);
list_add(&bt->running_list, &running_trace_list);
raw_spin_unlock_irq(&running_trace_lock);
trace_note_time(bt);
return 0;
}
static int blk_trace_stop(struct blk_trace *bt)
{
if (bt->trace_state != Blktrace_running)
return -EINVAL;
bt->trace_state = Blktrace_stopped;
raw_spin_lock_irq(&running_trace_lock);
list_del_init(&bt->running_list);
raw_spin_unlock_irq(&running_trace_lock);
relay_flush(bt->rchan);
return 0;
}
static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt)
{
blk_trace_stop(bt);
synchronize_rcu();
blk_trace_free(q, bt);
put_probe_ref();
}
static int __blk_trace_remove(struct request_queue *q)
{
struct blk_trace *bt;
bt = rcu_replace_pointer(q->blk_trace, NULL,
lockdep_is_held(&q->debugfs_mutex));
if (!bt)
return -EINVAL;
blk_trace_cleanup(q, bt);
return 0;
}
int blk_trace_remove(struct request_queue *q)
{
int ret;
blk_debugfs_lock_nomemsave(q);
ret = __blk_trace_remove(q);
blk_debugfs_unlock_nomemrestore(q);
return ret;
}
EXPORT_SYMBOL_GPL(blk_trace_remove);
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;
size_t dropped = relay_stats(bt->rchan, RELAY_STATS_BUF_FULL);
char buf[16];
snprintf(buf, sizeof(buf), "%zu\n", dropped);
return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
}
static const struct file_operations blk_dropped_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = blk_dropped_read,
.llseek = default_llseek,
};
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 = memdup_user_nul(buffer, count);
if (IS_ERR(msg))
return PTR_ERR(msg);
bt = filp->private_data;
__blk_trace_note_message(bt, NULL, "%s", msg);
kfree(msg);
return count;
}
static const struct file_operations blk_msg_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.write = blk_msg_write,
.llseek = noop_llseek,
};
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,
umode_t mode,
struct rchan_buf *buf,
int *is_global)
{
return debugfs_create_file(filename, mode, parent, buf,
&relay_file_operations);
}
static const struct rchan_callbacks blk_relay_callbacks = {
.create_buf_file = blk_create_buf_file_callback,
.remove_buf_file = blk_remove_buf_file_callback,
};
static void blk_trace_setup_lba(struct blk_trace *bt,
struct block_device *bdev)
{
if (bdev) {
bt->start_lba = bdev->bd_start_sect;
bt->end_lba = bdev->bd_start_sect + bdev_nr_sectors(bdev);
} else {
bt->start_lba = 0;
bt->end_lba = -1ULL;
}
}
static struct blk_trace *blk_trace_setup_prepare(struct request_queue *q,
char *name, dev_t dev,
u32 buf_size, u32 buf_nr,
struct block_device *bdev)
{
struct blk_trace *bt = NULL;
struct dentry *dir = NULL;
int ret;
lockdep_assert_held(&q->debugfs_mutex);
if (rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex))) {
pr_warn("Concurrent blktraces are not allowed on %s\n", name);
return ERR_PTR(-EBUSY);
}
bt = kzalloc_obj(*bt);
if (!bt)
return ERR_PTR(-ENOMEM);
ret = -ENOMEM;
bt->sequence = alloc_percpu(unsigned long);
if (!bt->sequence)
goto err;
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
if (!bt->msg_data)
goto err;
if (bdev && !bdev_is_partition(bdev))
dir = q->debugfs_dir;
else
bt->dir = dir = debugfs_create_dir(name, blk_debugfs_root);
if (IS_ERR_OR_NULL(dir)) {
pr_warn("debugfs_dir not present for %s so skipping\n", name);
ret = -ENOENT;
goto err;
}
bt->dev = dev;
INIT_LIST_HEAD(&bt->running_list);
ret = -EIO;
debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
bt->rchan = relay_open("trace", dir, buf_size, buf_nr,
&blk_relay_callbacks, bt);
if (!bt->rchan)
goto err;
blk_trace_setup_lba(bt, bdev);
return bt;
err:
blk_trace_free(q, bt);
return ERR_PTR(ret);
}
static void blk_trace_setup_finalize(struct request_queue *q,
char *name, int version,
struct blk_trace *bt,
struct blk_user_trace_setup2 *buts)
{
strscpy_pad(buts->name, name, BLKTRACE_BDEV_SIZE2);
strreplace(buts->name, '/', '_');
bt->version = version;
bt->act_mask = buts->act_mask;
if (!bt->act_mask)
bt->act_mask = (u16) -1;
if (buts->start_lba)
bt->start_lba = buts->start_lba;
if (buts->end_lba)
bt->end_lba = buts->end_lba;
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
rcu_assign_pointer(q->blk_trace, bt);
get_probe_ref();
}
int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct block_device *bdev,
char __user *arg)
{
struct blk_user_trace_setup2 buts2;
struct blk_user_trace_setup buts;
struct blk_trace *bt;
unsigned int memflags;
int ret;
ret = copy_from_user(&buts, arg, sizeof(buts));
if (ret)
return -EFAULT;
if (!buts.buf_size || !buts.buf_nr)
return -EINVAL;
buts2 = (struct blk_user_trace_setup2) {
.act_mask = buts.act_mask,
.buf_size = buts.buf_size,
.buf_nr = buts.buf_nr,
.start_lba = buts.start_lba,
.end_lba = buts.end_lba,
.pid = buts.pid,
};
memflags = blk_debugfs_lock(q);
bt = blk_trace_setup_prepare(q, name, dev, buts.buf_size, buts.buf_nr,
bdev);
if (IS_ERR(bt)) {
blk_debugfs_unlock(q, memflags);
return PTR_ERR(bt);
}
blk_trace_setup_finalize(q, name, 1, bt, &buts2);
strscpy(buts.name, buts2.name, BLKTRACE_BDEV_SIZE);
blk_debugfs_unlock(q, memflags);
if (copy_to_user(arg, &buts, sizeof(buts))) {
blk_trace_remove(q);
return -EFAULT;
}
return 0;
}
EXPORT_SYMBOL_GPL(blk_trace_setup);
static int blk_trace_setup2(struct request_queue *q, char *name, dev_t dev,
struct block_device *bdev, char __user *arg)
{
struct blk_user_trace_setup2 buts2;
struct blk_trace *bt;
unsigned int memflags;
if (copy_from_user(&buts2, arg, sizeof(buts2)))
return -EFAULT;
if (!buts2.buf_size || !buts2.buf_nr)
return -EINVAL;
if (buts2.flags != 0)
return -EINVAL;
memflags = blk_debugfs_lock(q);
bt = blk_trace_setup_prepare(q, name, dev, buts2.buf_size, buts2.buf_nr,
bdev);
if (IS_ERR(bt)) {
blk_debugfs_unlock(q, memflags);
return PTR_ERR(bt);
}
blk_trace_setup_finalize(q, name, 2, bt, &buts2);
blk_debugfs_unlock(q, memflags);
if (copy_to_user(arg, &buts2, sizeof(buts2))) {
blk_trace_remove(q);
return -EFAULT;
}
return 0;
}
#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
static int compat_blk_trace_setup(struct request_queue *q, char *name,
dev_t dev, struct block_device *bdev,
char __user *arg)
{
struct blk_user_trace_setup2 buts2;
struct compat_blk_user_trace_setup cbuts;
struct blk_trace *bt;
unsigned int memflags;
if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
return -EFAULT;
if (!cbuts.buf_size || !cbuts.buf_nr)
return -EINVAL;
buts2 = (struct blk_user_trace_setup2) {
.act_mask = cbuts.act_mask,
.buf_size = cbuts.buf_size,
.buf_nr = cbuts.buf_nr,
.start_lba = cbuts.start_lba,
.end_lba = cbuts.end_lba,
.pid = cbuts.pid,
};
memflags = blk_debugfs_lock(q);
bt = blk_trace_setup_prepare(q, name, dev, buts2.buf_size, buts2.buf_nr,
bdev);
if (IS_ERR(bt)) {
blk_debugfs_unlock(q, memflags);
return PTR_ERR(bt);
}
blk_trace_setup_finalize(q, name, 1, bt, &buts2);
blk_debugfs_unlock(q, memflags);
if (copy_to_user(arg, &buts2.name, ARRAY_SIZE(buts2.name))) {
blk_trace_remove(q);
return -EFAULT;
}
return 0;
}
#endif
static int __blk_trace_startstop(struct request_queue *q, int start)
{
struct blk_trace *bt;
bt = rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex));
if (bt == NULL)
return -EINVAL;
if (start)
return blk_trace_start(bt);
else
return blk_trace_stop(bt);
}
int blk_trace_startstop(struct request_queue *q, int start)
{
int ret;
blk_debugfs_lock_nomemsave(q);
ret = __blk_trace_startstop(q, start);
blk_debugfs_unlock_nomemrestore(q);
return ret;
}
EXPORT_SYMBOL_GPL(blk_trace_startstop);
int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
{
struct request_queue *q = bdev_get_queue(bdev);
int ret, start = 0;
char b[BDEVNAME_SIZE];
switch (cmd) {
case BLKTRACESETUP2:
snprintf(b, sizeof(b), "%pg", bdev);
ret = blk_trace_setup2(q, b, bdev->bd_dev, bdev, arg);
break;
case BLKTRACESETUP:
snprintf(b, sizeof(b), "%pg", bdev);
ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
break;
#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
case BLKTRACESETUP32:
snprintf(b, sizeof(b), "%pg", bdev);
ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
break;
#endif
case BLKTRACESTART:
start = 1;
fallthrough;
case BLKTRACESTOP:
ret = blk_trace_startstop(q, start);
break;
case BLKTRACETEARDOWN:
ret = blk_trace_remove(q);
break;
default:
ret = -ENOTTY;
break;
}
return ret;
}
void blk_trace_shutdown(struct request_queue *q)
{
if (rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex)))
__blk_trace_remove(q);
}
#ifdef CONFIG_BLK_CGROUP
static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
{
struct cgroup_subsys_state *blkcg_css;
struct blk_trace *bt;
bt = rcu_dereference_protected(q->blk_trace, 1);
if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
return 0;
blkcg_css = bio_blkcg_css(bio);
if (!blkcg_css)
return 0;
return cgroup_id(blkcg_css->cgroup);
}
#else
static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
{
return 0;
}
#endif
static u64
blk_trace_request_get_cgid(struct request *rq)
{
if (!rq->bio)
return 0;
return blk_trace_bio_get_cgid(rq->q, rq->bio);
}
static void blk_add_trace_rq(struct request *rq, blk_status_t error,
unsigned int nr_bytes, u64 what, u64 cgid)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(rq->q->blk_trace);
if (likely(!bt)) {
rcu_read_unlock();
return;
}
if (blk_rq_is_passthrough(rq))
what |= BLK_TC_ACT(BLK_TC_PC);
else
what |= BLK_TC_ACT(BLK_TC_FS);
__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, rq->cmd_flags,
what, blk_status_to_errno(error), 0, NULL, cgid);
rcu_read_unlock();
}
static void blk_add_trace_rq_insert(void *ignore, struct request *rq)
{
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_rq_issue(void *ignore, struct request *rq)
{
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_rq_merge(void *ignore, struct request *rq)
{
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_rq_requeue(void *ignore, struct request *rq)
{
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
blk_status_t error, unsigned int nr_bytes)
{
blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_zone_update_request(void *ignore, struct request *rq)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(rq->q->blk_trace);
if (likely(!bt) || bt->version < 2) {
rcu_read_unlock();
return;
}
rcu_read_unlock();
blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ZONE_APPEND,
blk_trace_request_get_cgid(rq));
}
static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
u64 what, int error)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (likely(!bt)) {
rcu_read_unlock();
return;
}
__blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
bio->bi_opf, what, error, 0, NULL,
blk_trace_bio_get_cgid(q, bio));
rcu_read_unlock();
}
static void blk_add_trace_bio_complete(void *ignore,
struct request_queue *q, struct bio *bio)
{
blk_add_trace_bio(q, bio, BLK_TA_COMPLETE,
blk_status_to_errno(bio->bi_status));
}
static void blk_add_trace_bio_backmerge(void *ignore, struct bio *bio)
{
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_BACKMERGE,
0);
}
static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio)
{
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_FRONTMERGE,
0);
}
static void blk_add_trace_bio_queue(void *ignore, struct bio *bio)
{
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_QUEUE, 0);
}
static void blk_add_trace_getrq(void *ignore, struct bio *bio)
{
blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_GETRQ, 0);
}
static void blk_add_trace_plug(void *ignore, struct request_queue *q)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (bt)
__blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0);
rcu_read_unlock();
}
static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
unsigned int depth, bool explicit)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (bt) {
__be64 rpdu = cpu_to_be64(depth);
u64 what;
if (explicit)
what = BLK_TA_UNPLUG_IO;
else
what = BLK_TA_UNPLUG_TIMER;
__blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0);
}
rcu_read_unlock();
}
static void blk_add_trace_zone_plug(void *ignore, struct request_queue *q,
unsigned int zno, sector_t sector,
unsigned int sectors)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (bt && bt->version >= 2)
__blk_add_trace(bt, sector, sectors << SECTOR_SHIFT, 0,
BLK_TA_ZONE_PLUG, 0, 0, NULL, 0);
rcu_read_unlock();
return;
}
static void blk_add_trace_zone_unplug(void *ignore, struct request_queue *q,
unsigned int zno, sector_t sector,
unsigned int sectors)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (bt && bt->version >= 2)
__blk_add_trace(bt, sector, sectors << SECTOR_SHIFT, 0,
BLK_TA_ZONE_UNPLUG, 0, 0, NULL, 0);
rcu_read_unlock();
return;
}
static void blk_add_trace_split(void *ignore, struct bio *bio, unsigned int pdu)
{
struct request_queue *q = bio->bi_bdev->bd_disk->queue;
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (bt) {
__be64 rpdu = cpu_to_be64(pdu);
__blk_add_trace(bt, bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, bio->bi_opf, BLK_TA_SPLIT,
blk_status_to_errno(bio->bi_status),
sizeof(rpdu), &rpdu,
blk_trace_bio_get_cgid(q, bio));
}
rcu_read_unlock();
}
static void blk_add_trace_bio_remap(void *ignore, struct bio *bio, dev_t dev,
sector_t from)
{
struct request_queue *q = bio->bi_bdev->bd_disk->queue;
struct blk_trace *bt;
struct blk_io_trace_remap r;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
if (likely(!bt)) {
rcu_read_unlock();
return;
}
r.device_from = cpu_to_be32(dev);
r.device_to = cpu_to_be32(bio_dev(bio));
r.sector_from = cpu_to_be64(from);
__blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
bio->bi_opf, BLK_TA_REMAP,
blk_status_to_errno(bio->bi_status),
sizeof(r), &r, blk_trace_bio_get_cgid(q, bio));
rcu_read_unlock();
}
static void blk_add_trace_rq_remap(void *ignore, struct request *rq, dev_t dev,
sector_t from)
{
struct blk_trace *bt;
struct blk_io_trace_remap r;
rcu_read_lock();
bt = rcu_dereference(rq->q->blk_trace);
if (likely(!bt)) {
rcu_read_unlock();
return;
}
r.device_from = cpu_to_be32(dev);
r.device_to = cpu_to_be32(disk_devt(rq->q->disk));
r.sector_from = cpu_to_be64(from);
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
rq->cmd_flags, BLK_TA_REMAP, 0,
sizeof(r), &r, blk_trace_request_get_cgid(rq));
rcu_read_unlock();
}
void blk_add_driver_data(struct request *rq, void *data, size_t len)
{
struct blk_trace *bt;
rcu_read_lock();
bt = rcu_dereference(rq->q->blk_trace);
if (likely(!bt)) {
rcu_read_unlock();
return;
}
__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0,
BLK_TA_DRV_DATA, 0, len, data,
blk_trace_request_get_cgid(rq));
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);
static void blk_register_tracepoints(void)
{
int ret;
ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
WARN_ON(ret);
ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
WARN_ON(ret);
ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
WARN_ON(ret);
ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
WARN_ON(ret);
ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
WARN_ON(ret);
ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
WARN_ON(ret);
ret = register_trace_blk_zone_append_update_request_bio(
blk_add_trace_zone_update_request, NULL);
WARN_ON(ret);
ret = register_trace_disk_zone_wplug_add_bio(blk_add_trace_zone_plug,
NULL);
WARN_ON(ret);
ret = register_trace_blk_zone_wplug_bio(blk_add_trace_zone_unplug,
NULL);
WARN_ON(ret);
ret = register_trace_block_plug(blk_add_trace_plug, NULL);
WARN_ON(ret);
ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
WARN_ON(ret);
ret = register_trace_block_split(blk_add_trace_split, NULL);
WARN_ON(ret);
ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
WARN_ON(ret);
}
static void blk_unregister_tracepoints(void)
{
unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
unregister_trace_block_split(blk_add_trace_split, NULL);
unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
unregister_trace_block_plug(blk_add_trace_plug, NULL);
unregister_trace_blk_zone_wplug_bio(blk_add_trace_zone_unplug, NULL);
unregister_trace_disk_zone_wplug_add_bio(blk_add_trace_zone_plug, NULL);
unregister_trace_blk_zone_append_update_request_bio(
blk_add_trace_zone_update_request, NULL);
unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
unregister_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
tracepoint_synchronize_unregister();
}
static void fill_rwbs(char *rwbs, const struct blk_io_trace2 *t)
{
int i = 0;
int tc = t->action >> BLK_TC_SHIFT;
if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
rwbs[i++] = 'N';
goto out;
}
if (tc & BLK_TC_FLUSH)
rwbs[i++] = 'F';
if (tc & BLK_TC_DISCARD)
rwbs[i++] = 'D';
else if (tc & BLK_TC_WRITE_ZEROES) {
rwbs[i++] = 'W';
rwbs[i++] = 'Z';
} else if (tc & BLK_TC_WRITE)
rwbs[i++] = 'W';
else if (t->bytes)
rwbs[i++] = 'R';
else
rwbs[i++] = 'N';
if (tc & BLK_TC_FUA)
rwbs[i++] = 'F';
if (tc & BLK_TC_AHEAD)
rwbs[i++] = 'A';
if (tc & BLK_TC_SYNC)
rwbs[i++] = 'S';
if (tc & BLK_TC_META)
rwbs[i++] = 'M';
out:
rwbs[i] = '\0';
}
static inline
const struct blk_io_trace2 *te_blk_io_trace(const struct trace_entry *ent)
{
return (const struct blk_io_trace2 *)ent;
}
static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg)
{
return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0);
}
static inline u64 t_cgid(const struct trace_entry *ent)
{
return *(u64 *)(te_blk_io_trace(ent) + 1);
}
static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
{
return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0);
}
static inline u32 t_action(const struct trace_entry *ent)
{
return te_blk_io_trace(ent)->action;
}
static inline u32 t_bytes(const struct trace_entry *ent)
{
return te_blk_io_trace(ent)->bytes;
}
static inline u32 t_sec(const struct trace_entry *ent)
{
return te_blk_io_trace(ent)->bytes >> 9;
}
static inline unsigned long long t_sector(const struct trace_entry *ent)
{
return te_blk_io_trace(ent)->sector;
}
static inline __u16 t_error(const struct trace_entry *ent)
{
return te_blk_io_trace(ent)->error;
}
static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg)
{
const __be64 *val = pdu_start(ent, has_cg);
return be64_to_cpu(*val);
}
typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act,
bool has_cg);
static void blk_log_action_classic(struct trace_iterator *iter, const char *act,
bool has_cg)
{
char rwbs[RWBS_LEN];
unsigned long long ts = iter->ts;
unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
unsigned secs = (unsigned long)ts;
const struct blk_io_trace2 *t = te_blk_io_trace(iter->ent);
fill_rwbs(rwbs, t);
trace_seq_printf(&iter->seq,
"%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
MAJOR(t->device), MINOR(t->device), iter->cpu,
secs, nsec_rem, iter->ent->pid, act, rwbs);
}
static void blk_log_action(struct trace_iterator *iter, const char *act,
bool has_cg)
{
char rwbs[RWBS_LEN];
const struct blk_io_trace2 *t = te_blk_io_trace(iter->ent);
fill_rwbs(rwbs, t);
if (has_cg) {
u64 id = t_cgid(iter->ent);
if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
char blkcg_name_buf[NAME_MAX + 1] = "<...>";
cgroup_path_from_kernfs_id(id, blkcg_name_buf,
sizeof(blkcg_name_buf));
trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
MAJOR(t->device), MINOR(t->device),
blkcg_name_buf, act, rwbs);
} else {
trace_seq_printf(&iter->seq,
"%3d,%-3d %llx,%-llx %2s %3s ",
MAJOR(t->device), MINOR(t->device),
id & U32_MAX, id >> 32, act, rwbs);
}
} else
trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
MAJOR(t->device), MINOR(t->device), act, rwbs);
}
static void blk_log_dump_pdu(struct trace_seq *s,
const struct trace_entry *ent, bool has_cg)
{
const unsigned char *pdu_buf;
int pdu_len;
int i, end;
pdu_buf = pdu_start(ent, has_cg);
pdu_len = pdu_real_len(ent, has_cg);
if (!pdu_len)
return;
for (end = pdu_len - 1; end >= 0; end--)
if (pdu_buf[end])
break;
end++;
trace_seq_putc(s, '(');
for (i = 0; i < pdu_len; i++) {
trace_seq_printf(s, "%s%02x",
i == 0 ? "" : " ", pdu_buf[i]);
if (i == end && end != pdu_len - 1) {
trace_seq_puts(s, " ..) ");
return;
}
}
trace_seq_puts(s, ") ");
}
static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
trace_seq_printf(s, "%u ", t_bytes(ent));
blk_log_dump_pdu(s, ent, has_cg);
trace_seq_printf(s, "[%s]\n", cmd);
} else {
if (t_sec(ent))
trace_seq_printf(s, "%llu + %u [%s]\n",
t_sector(ent), t_sec(ent), cmd);
else
trace_seq_printf(s, "[%s]\n", cmd);
}
}
static void blk_log_with_error(struct trace_seq *s,
const struct trace_entry *ent, bool has_cg)
{
if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
blk_log_dump_pdu(s, ent, has_cg);
trace_seq_printf(s, "[%d]\n", t_error(ent));
} else {
if (t_sec(ent))
trace_seq_printf(s, "%llu + %u [%d]\n",
t_sector(ent),
t_sec(ent), t_error(ent));
else
trace_seq_printf(s, "%llu [%d]\n",
t_sector(ent), t_error(ent));
}
}
static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
{
const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg);
trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
t_sector(ent), t_sec(ent),
MAJOR(be32_to_cpu(__r->device_from)),
MINOR(be32_to_cpu(__r->device_from)),
be64_to_cpu(__r->sector_from));
}
static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
trace_seq_printf(s, "[%s]\n", cmd);
}
static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg));
}
static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
{
char cmd[TASK_COMM_LEN];
trace_find_cmdline(ent->pid, cmd);
trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
get_pdu_int(ent, has_cg), cmd);
}
static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent,
bool has_cg)
{
trace_seq_putmem(s, pdu_start(ent, has_cg),
pdu_real_len(ent, has_cg));
trace_seq_putc(s, '\n');
}
static void blk_tracer_print_header(struct seq_file *m)
{
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
return;
seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
"# | | | | | |\n");
}
static void blk_tracer_start(struct trace_array *tr)
{
blk_tracer_enabled = true;
}
static int blk_tracer_init(struct trace_array *tr)
{
blk_tr = tr;
blk_tracer_start(tr);
return 0;
}
static void blk_tracer_stop(struct trace_array *tr)
{
blk_tracer_enabled = false;
}
static void blk_tracer_reset(struct trace_array *tr)
{
blk_tracer_stop(tr);
}
static const struct {
const char *act[2];
void (*print)(struct trace_seq *s, const struct trace_entry *ent,
bool has_cg);
} what2act[] = {
[__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
[__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
[__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
[__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
[__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
[__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
[__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
[__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
[__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
[__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
[__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
[__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
[__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
[__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
};
static enum print_line_t print_one_line(struct trace_iterator *iter,
bool classic)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
const struct blk_io_trace2 *t;
u16 what;
bool long_act;
blk_log_action_t *log_action;
bool has_cg;
t = te_blk_io_trace(iter->ent);
what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP;
long_act = !!(tr->trace_flags & TRACE_ITER(VERBOSE));
log_action = classic ? &blk_log_action_classic : &blk_log_action;
has_cg = t->action & __BLK_TA_CGROUP;
if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
log_action(iter, long_act ? "message" : "m", has_cg);
blk_log_msg(s, iter->ent, has_cg);
return trace_handle_return(s);
}
if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
trace_seq_printf(s, "Unknown action %x\n", what);
else {
log_action(iter, what2act[what].act[long_act], has_cg);
what2act[what].print(s, iter->ent, has_cg);
}
return trace_handle_return(s);
}
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
int flags, struct trace_event *event)
{
return print_one_line(iter, false);
}
static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct blk_io_trace2 *t = (struct blk_io_trace2 *)iter->ent;
const int offset = offsetof(struct blk_io_trace2, sector);
struct blk_io_trace old = {
.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
.time = iter->ts,
};
trace_seq_putmem(s, &old, offset);
trace_seq_putmem(s, &t->sector,
sizeof(old) - offset + t->pdu_len);
}
static enum print_line_t
blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
struct trace_event *event)
{
blk_trace_synthesize_old_trace(iter);
return trace_handle_return(&iter->seq);
}
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
{
if ((iter->ent->type != TRACE_BLK) ||
!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
return TRACE_TYPE_UNHANDLED;
return print_one_line(iter, true);
}
static int
blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
{
if (bit == TRACE_BLK_OPT_CLASSIC) {
if (set)
tr->trace_flags &= ~TRACE_ITER(CONTEXT_INFO);
else
tr->trace_flags |= TRACE_ITER(CONTEXT_INFO);
}
return 0;
}
static struct tracer blk_tracer __read_mostly = {
.name = "blk",
.init = blk_tracer_init,
.reset = blk_tracer_reset,
.start = blk_tracer_start,
.stop = blk_tracer_stop,
.print_header = blk_tracer_print_header,
.print_line = blk_tracer_print_line,
.flags = &blk_tracer_flags,
.set_flag = blk_tracer_set_flag,
};
static struct trace_event_functions trace_blk_event_funcs = {
.trace = blk_trace_event_print,
.binary = blk_trace_event_print_binary,
};
static struct trace_event trace_blk_event = {
.type = TRACE_BLK,
.funcs = &trace_blk_event_funcs,
};
static struct work_struct blktrace_works __initdata;
static int __init __init_blk_tracer(void)
{
if (!register_trace_event(&trace_blk_event)) {
pr_warn("Warning: could not register block events\n");
return 1;
}
if (register_tracer(&blk_tracer) != 0) {
pr_warn("Warning: could not register the block tracer\n");
unregister_trace_event(&trace_blk_event);
return 1;
}
BUILD_BUG_ON(__alignof__(struct blk_user_trace_setup2) %
__alignof__(long));
BUILD_BUG_ON(__alignof__(struct blk_io_trace2) % __alignof__(long));
return 0;
}
static void __init blktrace_works_func(struct work_struct *work)
{
__init_blk_tracer();
}
static int __init init_blk_tracer(void)
{
int ret = 0;
if (trace_init_wq) {
INIT_WORK(&blktrace_works, blktrace_works_func);
queue_work(trace_init_wq, &blktrace_works);
} else {
ret = __init_blk_tracer();
}
return ret;
}
device_initcall(init_blk_tracer);
static int blk_trace_remove_queue(struct request_queue *q)
{
struct blk_trace *bt;
bt = rcu_replace_pointer(q->blk_trace, NULL,
lockdep_is_held(&q->debugfs_mutex));
if (bt == NULL)
return -EINVAL;
blk_trace_stop(bt);
put_probe_ref();
synchronize_rcu();
blk_trace_free(q, bt);
return 0;
}
static int blk_trace_setup_queue(struct request_queue *q,
struct block_device *bdev)
{
struct blk_trace *bt = NULL;
int ret = -ENOMEM;
bt = kzalloc_obj(*bt);
if (!bt)
return -ENOMEM;
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
if (!bt->msg_data)
goto free_bt;
bt->dev = bdev->bd_dev;
bt->act_mask = (u16)-1;
blk_trace_setup_lba(bt, bdev);
rcu_assign_pointer(q->blk_trace, bt);
get_probe_ref();
return 0;
free_bt:
blk_trace_free(q, bt);
return ret;
}
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf);
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count);
#define BLK_TRACE_DEVICE_ATTR(_name) \
DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
sysfs_blk_trace_attr_show, \
sysfs_blk_trace_attr_store)
static BLK_TRACE_DEVICE_ATTR(enable);
static BLK_TRACE_DEVICE_ATTR(act_mask);
static BLK_TRACE_DEVICE_ATTR(pid);
static BLK_TRACE_DEVICE_ATTR(start_lba);
static BLK_TRACE_DEVICE_ATTR(end_lba);
static struct attribute *blk_trace_attrs[] = {
&dev_attr_enable.attr,
&dev_attr_act_mask.attr,
&dev_attr_pid.attr,
&dev_attr_start_lba.attr,
&dev_attr_end_lba.attr,
NULL
};
struct attribute_group blk_trace_attr_group = {
.name = "trace",
.attrs = blk_trace_attrs,
};
static const struct {
int mask;
const char *str;
} mask_maps[] = {
{ BLK_TC_READ, "read" },
{ BLK_TC_WRITE, "write" },
{ BLK_TC_FLUSH, "flush" },
{ BLK_TC_SYNC, "sync" },
{ BLK_TC_QUEUE, "queue" },
{ BLK_TC_REQUEUE, "requeue" },
{ BLK_TC_ISSUE, "issue" },
{ BLK_TC_COMPLETE, "complete" },
{ BLK_TC_FS, "fs" },
{ BLK_TC_PC, "pc" },
{ BLK_TC_NOTIFY, "notify" },
{ BLK_TC_AHEAD, "ahead" },
{ BLK_TC_META, "meta" },
{ BLK_TC_DISCARD, "discard" },
{ BLK_TC_DRV_DATA, "drv_data" },
{ BLK_TC_FUA, "fua" },
{ BLK_TC_WRITE_ZEROES, "write-zeroes" },
};
static int blk_trace_str2mask(const char *str)
{
int i;
int mask = 0;
char *buf, *s, *token;
buf = kstrdup(str, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
s = strstrip(buf);
while (1) {
token = strsep(&s, ",");
if (token == NULL)
break;
if (*token == '\0')
continue;
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
if (strcasecmp(token, mask_maps[i].str) == 0) {
mask |= mask_maps[i].mask;
break;
}
}
if (i == ARRAY_SIZE(mask_maps)) {
mask = -EINVAL;
break;
}
}
kfree(buf);
return mask;
}
static ssize_t blk_trace_mask2str(char *buf, int mask)
{
int i;
char *p = buf;
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
if (mask & mask_maps[i].mask) {
p += sprintf(p, "%s%s",
(p == buf) ? "" : ",", mask_maps[i].str);
}
}
*p++ = '\n';
return p - buf;
}
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct block_device *bdev = dev_to_bdev(dev);
struct request_queue *q = bdev_get_queue(bdev);
struct blk_trace *bt;
ssize_t ret = -ENXIO;
blk_debugfs_lock_nomemsave(q);
bt = rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex));
if (attr == &dev_attr_enable) {
ret = sprintf(buf, "%u\n", !!bt);
goto out_unlock_bdev;
}
if (bt == NULL)
ret = sprintf(buf, "disabled\n");
else if (attr == &dev_attr_act_mask)
ret = blk_trace_mask2str(buf, bt->act_mask);
else if (attr == &dev_attr_pid)
ret = sprintf(buf, "%u\n", bt->pid);
else if (attr == &dev_attr_start_lba)
ret = sprintf(buf, "%llu\n", bt->start_lba);
else if (attr == &dev_attr_end_lba)
ret = sprintf(buf, "%llu\n", bt->end_lba);
out_unlock_bdev:
blk_debugfs_unlock_nomemrestore(q);
return ret;
}
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct block_device *bdev = dev_to_bdev(dev);
struct request_queue *q = bdev_get_queue(bdev);
struct blk_trace *bt;
unsigned int memflags;
u64 value;
ssize_t ret = -EINVAL;
if (count == 0)
goto out;
if (attr == &dev_attr_act_mask) {
if (kstrtoull(buf, 0, &value)) {
ret = blk_trace_str2mask(buf);
if (ret < 0)
goto out;
value = ret;
}
} else {
if (kstrtoull(buf, 0, &value))
goto out;
}
memflags = blk_debugfs_lock(q);
bt = rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex));
if (attr == &dev_attr_enable) {
if (!!value == !!bt) {
ret = 0;
goto out_unlock_bdev;
}
if (value)
ret = blk_trace_setup_queue(q, bdev);
else
ret = blk_trace_remove_queue(q);
goto out_unlock_bdev;
}
ret = 0;
if (bt == NULL) {
ret = blk_trace_setup_queue(q, bdev);
bt = rcu_dereference_protected(q->blk_trace,
lockdep_is_held(&q->debugfs_mutex));
}
if (ret == 0) {
if (attr == &dev_attr_act_mask)
bt->act_mask = value;
else if (attr == &dev_attr_pid)
bt->pid = value;
else if (attr == &dev_attr_start_lba)
bt->start_lba = value;
else if (attr == &dev_attr_end_lba)
bt->end_lba = value;
}
out_unlock_bdev:
blk_debugfs_unlock(q, memflags);
out:
return ret ? ret : count;
}
#endif
#ifdef CONFIG_EVENT_TRACING
void blk_fill_rwbs(char *rwbs, blk_opf_t opf)
{
int i = 0;
if (opf & REQ_PREFLUSH)
rwbs[i++] = 'F';
switch (opf & REQ_OP_MASK) {
case REQ_OP_WRITE:
rwbs[i++] = 'W';
break;
case REQ_OP_DISCARD:
rwbs[i++] = 'D';
break;
case REQ_OP_SECURE_ERASE:
rwbs[i++] = 'D';
rwbs[i++] = 'E';
break;
case REQ_OP_FLUSH:
rwbs[i++] = 'F';
break;
case REQ_OP_READ:
rwbs[i++] = 'R';
break;
case REQ_OP_ZONE_APPEND:
rwbs[i++] = 'Z';
rwbs[i++] = 'A';
break;
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_RESET_ALL:
rwbs[i++] = 'Z';
rwbs[i++] = 'R';
if ((opf & REQ_OP_MASK) == REQ_OP_ZONE_RESET_ALL)
rwbs[i++] = 'A';
break;
case REQ_OP_ZONE_FINISH:
rwbs[i++] = 'Z';
rwbs[i++] = 'F';
break;
case REQ_OP_ZONE_OPEN:
rwbs[i++] = 'Z';
rwbs[i++] = 'O';
break;
case REQ_OP_ZONE_CLOSE:
rwbs[i++] = 'Z';
rwbs[i++] = 'C';
break;
case REQ_OP_WRITE_ZEROES:
rwbs[i++] = 'W';
rwbs[i++] = 'Z';
break;
default:
rwbs[i++] = 'N';
}
if (opf & REQ_FUA)
rwbs[i++] = 'F';
if (opf & REQ_RAHEAD)
rwbs[i++] = 'A';
if (opf & REQ_SYNC)
rwbs[i++] = 'S';
if (opf & REQ_META)
rwbs[i++] = 'M';
if (opf & REQ_ATOMIC)
rwbs[i++] = 'U';
WARN_ON_ONCE(i >= RWBS_LEN);
rwbs[i] = '\0';
}
EXPORT_SYMBOL_GPL(blk_fill_rwbs);
#endif
