4ca5308523
Impact: fix to one cause of incorrect comm outputs in trace The spinlock only protected the creation of a comm <=> pid pair. But it was possible that a reader could look up a pid, and get the wrong comm because it had no locking. This also required changing trace_find_cmdline to copy the comm cache and not just send back a pointer to it. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
1550 lines
37 KiB
C
1550 lines
37 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 <linux/uaccess.h>
|
|
#include "trace_output.h"
|
|
|
|
static unsigned int blktrace_seq __read_mostly = 1;
|
|
|
|
static struct trace_array *blk_tr;
|
|
static int __read_mostly blk_tracer_enabled;
|
|
|
|
/* Select an alternative, minimalistic output than the original one */
|
|
#define TRACE_BLK_OPT_CLASSIC 0x1
|
|
|
|
static struct tracer_opt blk_tracer_opts[] = {
|
|
/* Default disable the minimalistic output */
|
|
{ TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
|
|
{ }
|
|
};
|
|
|
|
static struct tracer_flags blk_tracer_flags = {
|
|
.val = 0,
|
|
.opts = blk_tracer_opts,
|
|
};
|
|
|
|
/* 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;
|
|
|
|
if (!bt->rchan)
|
|
return;
|
|
|
|
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;
|
|
|
|
if (blk_tr) {
|
|
va_start(args, fmt);
|
|
ftrace_vprintk(fmt, args);
|
|
va_end(args);
|
|
return;
|
|
}
|
|
|
|
if (!bt->msg_data)
|
|
return;
|
|
|
|
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 ring_buffer_event *event = NULL;
|
|
struct blk_io_trace *t;
|
|
unsigned long flags = 0;
|
|
unsigned long *sequence;
|
|
pid_t pid;
|
|
int cpu, pc = 0;
|
|
|
|
if (unlikely(bt->trace_state != Blktrace_running ||
|
|
!blk_tracer_enabled))
|
|
return;
|
|
|
|
what |= ddir_act[rw & WRITE];
|
|
what |= MASK_TC_BIT(rw, BARRIER);
|
|
what |= MASK_TC_BIT(rw, SYNCIO);
|
|
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;
|
|
cpu = raw_smp_processor_id();
|
|
|
|
if (blk_tr) {
|
|
tracing_record_cmdline(current);
|
|
|
|
pc = preempt_count();
|
|
event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
|
|
sizeof(*t) + pdu_len,
|
|
0, pc);
|
|
if (!event)
|
|
return;
|
|
t = ring_buffer_event_data(event);
|
|
goto record_it;
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
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());
|
|
record_it:
|
|
/*
|
|
* These two are not needed in ftrace as they are in the
|
|
* generic trace_entry, filled by tracing_generic_entry_update,
|
|
* but for the trace_event->bin() synthesizer benefit we do it
|
|
* here too.
|
|
*/
|
|
t->cpu = cpu;
|
|
t->pid = pid;
|
|
|
|
t->sector = sector;
|
|
t->bytes = bytes;
|
|
t->action = what;
|
|
t->device = bt->dev;
|
|
t->error = error;
|
|
t->pdu_len = pdu_len;
|
|
|
|
if (pdu_len)
|
|
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
|
|
|
|
if (blk_tr) {
|
|
trace_buffer_unlock_commit(blk_tr, event, 0, pc);
|
|
return;
|
|
}
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static struct dentry *blk_tree_root;
|
|
static DEFINE_MUTEX(blk_tree_mutex);
|
|
|
|
static void blk_trace_cleanup(struct blk_trace *bt)
|
|
{
|
|
debugfs_remove(bt->msg_file);
|
|
debugfs_remove(bt->dropped_file);
|
|
relay_close(bt->rchan);
|
|
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)
|
|
{
|
|
struct dentry *parent = dentry->d_parent;
|
|
debugfs_remove(dentry);
|
|
|
|
/*
|
|
* this will fail for all but the last file, but that is ok. what we
|
|
* care about is the top level buts->name directory going away, when
|
|
* the last trace file is gone. Then we don't have to rmdir() that
|
|
* manually on trace stop, so it nicely solves the issue with
|
|
* force killing of running traces.
|
|
*/
|
|
|
|
debugfs_remove(parent);
|
|
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, __alignof__(char));
|
|
if (!bt->msg_data)
|
|
goto err;
|
|
|
|
ret = -ENOENT;
|
|
|
|
if (!blk_tree_root) {
|
|
blk_tree_root = debugfs_create_dir("block", NULL);
|
|
if (!blk_tree_root)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
dir = debugfs_create_dir(buts->name, blk_tree_root);
|
|
|
|
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 (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)
|
|
{
|
|
int ret;
|
|
struct blk_trace *bt = q->blk_trace;
|
|
|
|
if (bt == 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();
|
|
}
|
|
|
|
/*
|
|
* struct blk_io_tracer formatting routines
|
|
*/
|
|
|
|
static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
|
|
{
|
|
int i = 0;
|
|
|
|
if (t->action & BLK_TC_DISCARD)
|
|
rwbs[i++] = 'D';
|
|
else if (t->action & BLK_TC_WRITE)
|
|
rwbs[i++] = 'W';
|
|
else if (t->bytes)
|
|
rwbs[i++] = 'R';
|
|
else
|
|
rwbs[i++] = 'N';
|
|
|
|
if (t->action & BLK_TC_AHEAD)
|
|
rwbs[i++] = 'A';
|
|
if (t->action & BLK_TC_BARRIER)
|
|
rwbs[i++] = 'B';
|
|
if (t->action & BLK_TC_SYNC)
|
|
rwbs[i++] = 'S';
|
|
if (t->action & BLK_TC_META)
|
|
rwbs[i++] = 'M';
|
|
|
|
rwbs[i] = '\0';
|
|
}
|
|
|
|
static inline
|
|
const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
|
|
{
|
|
return (const struct blk_io_trace *)ent;
|
|
}
|
|
|
|
static inline const void *pdu_start(const struct trace_entry *ent)
|
|
{
|
|
return te_blk_io_trace(ent) + 1;
|
|
}
|
|
|
|
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)->sector;
|
|
}
|
|
|
|
static __u64 get_pdu_int(const struct trace_entry *ent)
|
|
{
|
|
const __u64 *val = pdu_start(ent);
|
|
return be64_to_cpu(*val);
|
|
}
|
|
|
|
static void get_pdu_remap(const struct trace_entry *ent,
|
|
struct blk_io_trace_remap *r)
|
|
{
|
|
const struct blk_io_trace_remap *__r = pdu_start(ent);
|
|
__u64 sector = __r->sector;
|
|
|
|
r->device = be32_to_cpu(__r->device);
|
|
r->device_from = be32_to_cpu(__r->device_from);
|
|
r->sector = be64_to_cpu(sector);
|
|
}
|
|
|
|
static int blk_log_action_iter(struct trace_iterator *iter, const char *act)
|
|
{
|
|
char rwbs[6];
|
|
unsigned long long ts = ns2usecs(iter->ts);
|
|
unsigned long usec_rem = do_div(ts, USEC_PER_SEC);
|
|
unsigned secs = (unsigned long)ts;
|
|
const struct trace_entry *ent = iter->ent;
|
|
const struct blk_io_trace *t = (const struct blk_io_trace *)ent;
|
|
|
|
fill_rwbs(rwbs, t);
|
|
|
|
return trace_seq_printf(&iter->seq,
|
|
"%3d,%-3d %2d %5d.%06lu %5u %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device), iter->cpu,
|
|
secs, usec_rem, ent->pid, act, rwbs);
|
|
}
|
|
|
|
static int blk_log_action_seq(struct trace_seq *s, const struct blk_io_trace *t,
|
|
const char *act)
|
|
{
|
|
char rwbs[6];
|
|
fill_rwbs(rwbs, t);
|
|
return trace_seq_printf(s, "%3d,%-3d %2s %3s ",
|
|
MAJOR(t->device), MINOR(t->device), act, rwbs);
|
|
}
|
|
|
|
static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
if (t_sec(ent))
|
|
return trace_seq_printf(s, "%llu + %u [%s]\n",
|
|
t_sector(ent), t_sec(ent), cmd);
|
|
return trace_seq_printf(s, "[%s]\n", cmd);
|
|
}
|
|
|
|
static int blk_log_with_error(struct trace_seq *s,
|
|
const struct trace_entry *ent)
|
|
{
|
|
if (t_sec(ent))
|
|
return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent),
|
|
t_sec(ent), t_error(ent));
|
|
return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent));
|
|
}
|
|
|
|
static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
|
|
{
|
|
struct blk_io_trace_remap r = { .device = 0, };
|
|
|
|
get_pdu_remap(ent, &r);
|
|
return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
|
|
t_sector(ent),
|
|
t_sec(ent), MAJOR(r.device), MINOR(r.device),
|
|
(unsigned long long)r.sector);
|
|
}
|
|
|
|
static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
return trace_seq_printf(s, "[%s]\n", cmd);
|
|
}
|
|
|
|
static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
|
|
}
|
|
|
|
static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
|
|
{
|
|
char cmd[TASK_COMM_LEN];
|
|
|
|
trace_find_cmdline(ent->pid, cmd);
|
|
|
|
return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
|
|
get_pdu_int(ent), cmd);
|
|
}
|
|
|
|
/*
|
|
* struct tracer operations
|
|
*/
|
|
|
|
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)
|
|
{
|
|
mutex_lock(&blk_probe_mutex);
|
|
if (atomic_add_return(1, &blk_probes_ref) == 1)
|
|
if (blk_register_tracepoints())
|
|
atomic_dec(&blk_probes_ref);
|
|
mutex_unlock(&blk_probe_mutex);
|
|
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
|
|
}
|
|
|
|
static int blk_tracer_init(struct trace_array *tr)
|
|
{
|
|
blk_tr = tr;
|
|
blk_tracer_start(tr);
|
|
mutex_lock(&blk_probe_mutex);
|
|
blk_tracer_enabled++;
|
|
mutex_unlock(&blk_probe_mutex);
|
|
return 0;
|
|
}
|
|
|
|
static void blk_tracer_stop(struct trace_array *tr)
|
|
{
|
|
trace_flags |= TRACE_ITER_CONTEXT_INFO;
|
|
mutex_lock(&blk_probe_mutex);
|
|
if (atomic_dec_and_test(&blk_probes_ref))
|
|
blk_unregister_tracepoints();
|
|
mutex_unlock(&blk_probe_mutex);
|
|
}
|
|
|
|
static void blk_tracer_reset(struct trace_array *tr)
|
|
{
|
|
if (!atomic_read(&blk_probes_ref))
|
|
return;
|
|
|
|
mutex_lock(&blk_probe_mutex);
|
|
blk_tracer_enabled--;
|
|
WARN_ON(blk_tracer_enabled < 0);
|
|
mutex_unlock(&blk_probe_mutex);
|
|
|
|
blk_tracer_stop(tr);
|
|
}
|
|
|
|
static struct {
|
|
const char *act[2];
|
|
int (*print)(struct trace_seq *s, const struct trace_entry *ent);
|
|
} what2act[] __read_mostly = {
|
|
[__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_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
|
|
[__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
|
|
};
|
|
|
|
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
|
|
int flags)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
const struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
|
|
const u16 what = t->action & ((1 << BLK_TC_SHIFT) - 1);
|
|
int ret;
|
|
|
|
if (!trace_print_context(iter))
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
|
|
if (unlikely(what == 0 || what > ARRAY_SIZE(what2act)))
|
|
ret = trace_seq_printf(s, "Bad pc action %x\n", what);
|
|
else {
|
|
const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
|
|
ret = blk_log_action_seq(s, t, what2act[what].act[long_act]);
|
|
if (ret)
|
|
ret = what2act[what].print(s, iter->ent);
|
|
}
|
|
|
|
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
|
|
const int offset = offsetof(struct blk_io_trace, sector);
|
|
struct blk_io_trace old = {
|
|
.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
|
|
.time = ns2usecs(iter->ts),
|
|
};
|
|
|
|
if (!trace_seq_putmem(s, &old, offset))
|
|
return 0;
|
|
return 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)
|
|
{
|
|
return blk_trace_synthesize_old_trace(iter) ?
|
|
TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
|
|
{
|
|
const struct blk_io_trace *t;
|
|
u16 what;
|
|
int ret;
|
|
|
|
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
|
|
return TRACE_TYPE_UNHANDLED;
|
|
|
|
t = (const struct blk_io_trace *)iter->ent;
|
|
what = t->action & ((1 << BLK_TC_SHIFT) - 1);
|
|
|
|
if (unlikely(what == 0 || what > ARRAY_SIZE(what2act)))
|
|
ret = trace_seq_printf(&iter->seq, "Bad pc action %x\n", what);
|
|
else {
|
|
const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
|
|
ret = blk_log_action_iter(iter, what2act[what].act[long_act]);
|
|
if (ret)
|
|
ret = what2act[what].print(&iter->seq, iter->ent);
|
|
}
|
|
|
|
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
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,
|
|
};
|
|
|
|
static struct trace_event trace_blk_event = {
|
|
.type = TRACE_BLK,
|
|
.trace = blk_trace_event_print,
|
|
.binary = blk_trace_event_print_binary,
|
|
};
|
|
|
|
static int __init init_blk_tracer(void)
|
|
{
|
|
if (!register_ftrace_event(&trace_blk_event)) {
|
|
pr_warning("Warning: could not register block events\n");
|
|
return 1;
|
|
}
|
|
|
|
if (register_tracer(&blk_tracer) != 0) {
|
|
pr_warning("Warning: could not register the block tracer\n");
|
|
unregister_ftrace_event(&trace_blk_event);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(init_blk_tracer);
|
|
|
|
static int blk_trace_remove_queue(struct request_queue *q)
|
|
{
|
|
struct blk_trace *bt;
|
|
|
|
bt = xchg(&q->blk_trace, NULL);
|
|
if (bt == NULL)
|
|
return -EINVAL;
|
|
|
|
kfree(bt);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Setup everything required to start tracing
|
|
*/
|
|
static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
|
|
{
|
|
struct blk_trace *old_bt, *bt = NULL;
|
|
int ret;
|
|
|
|
ret = -ENOMEM;
|
|
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
|
|
if (!bt)
|
|
goto err;
|
|
|
|
bt->dev = dev;
|
|
bt->act_mask = (u16)-1;
|
|
bt->end_lba = -1ULL;
|
|
bt->trace_state = Blktrace_running;
|
|
|
|
old_bt = xchg(&q->blk_trace, bt);
|
|
if (old_bt != NULL) {
|
|
(void)xchg(&q->blk_trace, old_bt);
|
|
kfree(bt);
|
|
ret = -EBUSY;
|
|
}
|
|
return 0;
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* sysfs interface to enable and configure tracing
|
|
*/
|
|
|
|
static ssize_t sysfs_blk_trace_enable_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct hd_struct *p = dev_to_part(dev);
|
|
struct block_device *bdev;
|
|
ssize_t ret = -ENXIO;
|
|
|
|
lock_kernel();
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev != NULL) {
|
|
struct request_queue *q = bdev_get_queue(bdev);
|
|
|
|
if (q != NULL) {
|
|
mutex_lock(&bdev->bd_mutex);
|
|
ret = sprintf(buf, "%u\n", !!q->blk_trace);
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
}
|
|
|
|
bdput(bdev);
|
|
}
|
|
|
|
unlock_kernel();
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t sysfs_blk_trace_enable_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct block_device *bdev;
|
|
struct request_queue *q;
|
|
struct hd_struct *p;
|
|
int value;
|
|
ssize_t ret = -ENXIO;
|
|
|
|
if (count == 0 || sscanf(buf, "%d", &value) != 1)
|
|
goto out;
|
|
|
|
lock_kernel();
|
|
p = dev_to_part(dev);
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev == NULL)
|
|
goto out_unlock_kernel;
|
|
|
|
q = bdev_get_queue(bdev);
|
|
if (q == NULL)
|
|
goto out_bdput;
|
|
|
|
mutex_lock(&bdev->bd_mutex);
|
|
if (value)
|
|
ret = blk_trace_setup_queue(q, bdev->bd_dev);
|
|
else
|
|
ret = blk_trace_remove_queue(q);
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
|
|
if (ret == 0)
|
|
ret = count;
|
|
out_bdput:
|
|
bdput(bdev);
|
|
out_unlock_kernel:
|
|
unlock_kernel();
|
|
out:
|
|
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 DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
|
|
sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_store);
|
|
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 int blk_str2act_mask(const char *str)
|
|
{
|
|
int mask = 0;
|
|
char *copy = kstrdup(str, GFP_KERNEL), *s;
|
|
|
|
if (copy == NULL)
|
|
return -ENOMEM;
|
|
|
|
s = strstrip(copy);
|
|
|
|
while (1) {
|
|
char *sep = strchr(s, ',');
|
|
|
|
if (sep != NULL)
|
|
*sep = '\0';
|
|
|
|
if (strcasecmp(s, "barrier") == 0)
|
|
mask |= BLK_TC_BARRIER;
|
|
else if (strcasecmp(s, "complete") == 0)
|
|
mask |= BLK_TC_COMPLETE;
|
|
else if (strcasecmp(s, "fs") == 0)
|
|
mask |= BLK_TC_FS;
|
|
else if (strcasecmp(s, "issue") == 0)
|
|
mask |= BLK_TC_ISSUE;
|
|
else if (strcasecmp(s, "pc") == 0)
|
|
mask |= BLK_TC_PC;
|
|
else if (strcasecmp(s, "queue") == 0)
|
|
mask |= BLK_TC_QUEUE;
|
|
else if (strcasecmp(s, "read") == 0)
|
|
mask |= BLK_TC_READ;
|
|
else if (strcasecmp(s, "requeue") == 0)
|
|
mask |= BLK_TC_REQUEUE;
|
|
else if (strcasecmp(s, "sync") == 0)
|
|
mask |= BLK_TC_SYNC;
|
|
else if (strcasecmp(s, "write") == 0)
|
|
mask |= BLK_TC_WRITE;
|
|
|
|
if (sep == NULL)
|
|
break;
|
|
|
|
s = sep + 1;
|
|
}
|
|
kfree(copy);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct hd_struct *p = dev_to_part(dev);
|
|
struct request_queue *q;
|
|
struct block_device *bdev;
|
|
ssize_t ret = -ENXIO;
|
|
|
|
lock_kernel();
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev == NULL)
|
|
goto out_unlock_kernel;
|
|
|
|
q = bdev_get_queue(bdev);
|
|
if (q == NULL)
|
|
goto out_bdput;
|
|
mutex_lock(&bdev->bd_mutex);
|
|
if (q->blk_trace == NULL)
|
|
ret = sprintf(buf, "disabled\n");
|
|
else if (attr == &dev_attr_act_mask)
|
|
ret = sprintf(buf, "%#x\n", q->blk_trace->act_mask);
|
|
else if (attr == &dev_attr_pid)
|
|
ret = sprintf(buf, "%u\n", q->blk_trace->pid);
|
|
else if (attr == &dev_attr_start_lba)
|
|
ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
|
|
else if (attr == &dev_attr_end_lba)
|
|
ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
out_bdput:
|
|
bdput(bdev);
|
|
out_unlock_kernel:
|
|
unlock_kernel();
|
|
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;
|
|
struct request_queue *q;
|
|
struct hd_struct *p;
|
|
u64 value;
|
|
ssize_t ret = -ENXIO;
|
|
|
|
if (count == 0)
|
|
goto out;
|
|
|
|
if (attr == &dev_attr_act_mask) {
|
|
if (sscanf(buf, "%llx", &value) != 1) {
|
|
/* Assume it is a list of trace category names */
|
|
value = blk_str2act_mask(buf);
|
|
if (value < 0)
|
|
goto out;
|
|
}
|
|
} else if (sscanf(buf, "%llu", &value) != 1)
|
|
goto out;
|
|
|
|
lock_kernel();
|
|
p = dev_to_part(dev);
|
|
bdev = bdget(part_devt(p));
|
|
if (bdev == NULL)
|
|
goto out_unlock_kernel;
|
|
|
|
q = bdev_get_queue(bdev);
|
|
if (q == NULL)
|
|
goto out_bdput;
|
|
|
|
mutex_lock(&bdev->bd_mutex);
|
|
ret = 0;
|
|
if (q->blk_trace == NULL)
|
|
ret = blk_trace_setup_queue(q, bdev->bd_dev);
|
|
|
|
if (ret == 0) {
|
|
if (attr == &dev_attr_act_mask)
|
|
q->blk_trace->act_mask = value;
|
|
else if (attr == &dev_attr_pid)
|
|
q->blk_trace->pid = value;
|
|
else if (attr == &dev_attr_start_lba)
|
|
q->blk_trace->start_lba = value;
|
|
else if (attr == &dev_attr_end_lba)
|
|
q->blk_trace->end_lba = value;
|
|
ret = count;
|
|
}
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
out_bdput:
|
|
bdput(bdev);
|
|
out_unlock_kernel:
|
|
unlock_kernel();
|
|
out:
|
|
return ret;
|
|
}
|