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linux-next/kernel/trace/blktrace.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

1770 lines
41 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/slab.h>
#include <linux/debugfs.h>
#include <linux/smp_lock.h>
#include <linux/time.h>
#include <linux/uaccess.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;
/* 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 atomic_t blk_probes_ref = ATOMIC_INIT(0);
static void 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;
struct ring_buffer_event *event = NULL;
struct ring_buffer *buffer = NULL;
int pc = 0;
int cpu = smp_processor_id();
bool blk_tracer = blk_tracer_enabled;
if (blk_tracer) {
buffer = blk_tr->buffer;
pc = preempt_count();
event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
sizeof(*t) + len,
0, pc);
if (!event)
return;
t = ring_buffer_event_data(event);
goto record_it;
}
if (!bt->rchan)
return;
t = relay_reserve(bt->rchan, sizeof(*t) + len);
if (t) {
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
t->time = ktime_to_ns(ktime_get());
record_it:
t->device = bt->dev;
t->action = action;
t->pid = pid;
t->cpu = cpu;
t->pdu_len = len;
memcpy((void *) t + sizeof(*t), data, len);
if (blk_tracer)
trace_buffer_unlock_commit(buffer, event, 0, pc);
}
}
/*
* 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 (unlikely(bt->trace_state != Blktrace_running &&
!blk_tracer_enabled))
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 && (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 const u32 ddir_act[2] = { 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 ring_buffer *buffer = NULL;
struct blk_io_trace *t;
unsigned long flags = 0;
unsigned long *sequence;
pid_t pid;
int cpu, pc = 0;
bool blk_tracer = blk_tracer_enabled;
if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
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 (act_log_check(bt, what, sector, pid))
return;
cpu = raw_smp_processor_id();
if (blk_tracer) {
tracing_record_cmdline(current);
buffer = blk_tr->buffer;
pc = preempt_count();
event = trace_buffer_lock_reserve(buffer, 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_tracer) {
trace_buffer_unlock_commit(buffer, event, 0, pc);
return;
}
}
local_irq_restore(flags);
}
static struct dentry *blk_tree_root;
static DEFINE_MUTEX(blk_tree_mutex);
static void blk_trace_free(struct blk_trace *bt)
{
debugfs_remove(bt->msg_file);
debugfs_remove(bt->dropped_file);
relay_close(bt->rchan);
debugfs_remove(bt->dir);
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
}
static void blk_trace_cleanup(struct blk_trace *bt)
{
blk_trace_free(bt);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
}
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_running)
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 + 1, GFP_KERNEL);
if (msg == NULL)
return -ENOMEM;
if (copy_from_user(msg, buffer, count)) {
kfree(msg);
return -EFAULT;
}
msg[count] = '\0';
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,
};
static void blk_trace_setup_lba(struct blk_trace *bt,
struct block_device *bdev)
{
struct hd_struct *part = NULL;
if (bdev)
part = bdev->bd_part;
if (part) {
bt->start_lba = part->start_sect;
bt->end_lba = part->start_sect + part->nr_sects;
} else {
bt->start_lba = 0;
bt->end_lba = -1ULL;
}
}
/*
* Setup everything required to start tracing
*/
int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct block_device *bdev,
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] = '_';
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
return -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;
ret = -ENOENT;
mutex_lock(&blk_tree_mutex);
if (!blk_tree_root) {
blk_tree_root = debugfs_create_dir("block", NULL);
if (!blk_tree_root) {
mutex_unlock(&blk_tree_mutex);
goto err;
}
}
mutex_unlock(&blk_tree_mutex);
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;
blk_trace_setup_lba(bt, bdev);
/* overwrite with user settings */
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;
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
(void) xchg(&q->blk_trace, old_bt);
goto err;
}
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
return 0;
err:
blk_trace_free(bt);
return ret;
}
int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct block_device *bdev,
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, bdev, &buts);
if (ret)
return ret;
if (copy_to_user(arg, &buts, sizeof(buts))) {
blk_trace_remove(q);
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, bdev, 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, blk_rq_bytes(rq), rw,
what, rq->errors, rq->cmd_len, rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 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
*
* 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)
{
struct blk_trace *bt = q->blk_trace;
struct blk_io_trace_remap r;
if (likely(!bt))
return;
r.device_from = cpu_to_be32(dev);
r.device_to = cpu_to_be32(bio->bi_bdev->bd_dev);
r.sector_from = cpu_to_be64(from);
__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE),
sizeof(r), &r);
}
/**
* blk_add_trace_rq_remap - Add a trace for a request-remap operation
* @q: queue the io is for
* @rq: the source request
* @dev: target device
* @from: source sector
*
* Description:
* Device mapper remaps request to other devices.
* Add a trace for that action.
*
**/
static void blk_add_trace_rq_remap(struct request_queue *q,
struct request *rq, dev_t dev,
sector_t from)
{
struct blk_trace *bt = q->blk_trace;
struct blk_io_trace_remap r;
if (likely(!bt))
return;
r.device_from = cpu_to_be32(dev);
r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
r.sector_from = cpu_to_be64(from);
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
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, blk_rq_bytes(rq), 0,
BLK_TA_DRV_DATA, rq->errors, len, data);
else
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 0,
BLK_TA_DRV_DATA, rq->errors, len, data);
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);
static void 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);
ret = register_trace_block_rq_remap(blk_add_trace_rq_remap);
WARN_ON(ret);
}
static void blk_unregister_tracepoints(void)
{
unregister_trace_block_rq_remap(blk_add_trace_rq_remap);
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;
int tc = t->action >> BLK_TC_SHIFT;
if (t->action == BLK_TN_MESSAGE) {
rwbs[i++] = 'N';
goto out;
}
if (tc & BLK_TC_DISCARD)
rwbs[i++] = 'D';
else if (tc & BLK_TC_WRITE)
rwbs[i++] = 'W';
else if (t->bytes)
rwbs[i++] = 'R';
else
rwbs[i++] = 'N';
if (tc & BLK_TC_AHEAD)
rwbs[i++] = 'A';
if (tc & BLK_TC_BARRIER)
rwbs[i++] = 'B';
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_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_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)
{
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_from = __r->sector_from;
r->device_from = be32_to_cpu(__r->device_from);
r->device_to = be32_to_cpu(__r->device_to);
r->sector_from = be64_to_cpu(sector_from);
}
typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
{
char rwbs[6];
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_trace *t = te_blk_io_trace(iter->ent);
fill_rwbs(rwbs, t);
return 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 int blk_log_action(struct trace_iterator *iter, const char *act)
{
char rwbs[6];
const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
fill_rwbs(rwbs, t);
return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
MAJOR(t->device), MINOR(t->device), act, rwbs);
}
static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
{
const unsigned char *pdu_buf;
int pdu_len;
int i, end, ret;
pdu_buf = pdu_start(ent);
pdu_len = te_blk_io_trace(ent)->pdu_len;
if (!pdu_len)
return 1;
/* find the last zero that needs to be printed */
for (end = pdu_len - 1; end >= 0; end--)
if (pdu_buf[end])
break;
end++;
if (!trace_seq_putc(s, '('))
return 0;
for (i = 0; i < pdu_len; i++) {
ret = trace_seq_printf(s, "%s%02x",
i == 0 ? "" : " ", pdu_buf[i]);
if (!ret)
return ret;
/*
* stop when the rest is just zeroes and indicate so
* with a ".." appended
*/
if (i == end && end != pdu_len - 1)
return trace_seq_puts(s, " ..) ");
}
return trace_seq_puts(s, ") ");
}
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_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
int ret;
ret = trace_seq_printf(s, "%u ", t_bytes(ent));
if (!ret)
return 0;
ret = blk_log_dump_pdu(s, ent);
if (!ret)
return 0;
return trace_seq_printf(s, "[%s]\n", cmd);
} else {
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_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
int ret;
ret = blk_log_dump_pdu(s, ent);
if (ret)
return trace_seq_printf(s, "[%d]\n", t_error(ent));
return 0;
} else {
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_from = 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_from), MINOR(r.device_from),
(unsigned long long)r.sector_from);
}
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);
}
static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
{
int ret;
const struct blk_io_trace *t = te_blk_io_trace(ent);
ret = trace_seq_putmem(s, t + 1, t->pdu_len);
if (ret)
return trace_seq_putc(s, '\n');
return ret;
}
/*
* 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)
{
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];
int (*print)(struct trace_seq *s, const struct trace_entry *ent);
} 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_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
[__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
};
static enum print_line_t print_one_line(struct trace_iterator *iter,
bool classic)
{
struct trace_seq *s = &iter->seq;
const struct blk_io_trace *t;
u16 what;
int ret;
bool long_act;
blk_log_action_t *log_action;
t = te_blk_io_trace(iter->ent);
what = t->action & ((1 << BLK_TC_SHIFT) - 1);
long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
log_action = classic ? &blk_log_action_classic : &blk_log_action;
if (t->action == BLK_TN_MESSAGE) {
ret = log_action(iter, long_act ? "message" : "m");
if (ret)
ret = blk_log_msg(s, iter->ent);
goto out;
}
if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
ret = trace_seq_printf(s, "Unknown action %x\n", what);
else {
ret = log_action(iter, what2act[what].act[long_act]);
if (ret)
ret = what2act[what].print(s, iter->ent);
}
out:
return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
}
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
int flags)
{
return print_one_line(iter, false);
}
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 = 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)
{
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
return TRACE_TYPE_UNHANDLED;
return print_one_line(iter, true);
}
static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
{
/* don't output context-info for blk_classic output */
if (bit == TRACE_BLK_OPT_CLASSIC) {
if (set)
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
else
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 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;
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
blk_trace_free(bt);
return 0;
}
/*
* Setup everything required to start tracing
*/
static int blk_trace_setup_queue(struct request_queue *q,
struct block_device *bdev)
{
struct blk_trace *old_bt, *bt = NULL;
int ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
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);
old_bt = xchg(&q->blk_trace, bt);
if (old_bt != NULL) {
(void)xchg(&q->blk_trace, old_bt);
ret = -EBUSY;
goto free_bt;
}
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
return 0;
free_bt:
blk_trace_free(bt);
return ret;
}
/*
* sysfs interface to enable and configure tracing
*/
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_BARRIER, "barrier" },
{ 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_AHEAD, "ahead" },
{ BLK_TC_META, "meta" },
{ BLK_TC_DISCARD, "discard" },
{ BLK_TC_DRV_DATA, "drv_data" },
};
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 struct request_queue *blk_trace_get_queue(struct block_device *bdev)
{
if (bdev->bd_disk == NULL)
return NULL;
return bdev_get_queue(bdev);
}
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 = blk_trace_get_queue(bdev);
if (q == NULL)
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
if (attr == &dev_attr_enable) {
ret = sprintf(buf, "%u\n", !!q->blk_trace);
goto out_unlock_bdev;
}
if (q->blk_trace == NULL)
ret = sprintf(buf, "disabled\n");
else if (attr == &dev_attr_act_mask)
ret = blk_trace_mask2str(buf, 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);
out_unlock_bdev:
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 = -EINVAL;
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 */
ret = blk_trace_str2mask(buf);
if (ret < 0)
goto out;
value = ret;
}
} else if (sscanf(buf, "%llu", &value) != 1)
goto out;
ret = -ENXIO;
lock_kernel();
p = dev_to_part(dev);
bdev = bdget(part_devt(p));
if (bdev == NULL)
goto out_unlock_kernel;
q = blk_trace_get_queue(bdev);
if (q == NULL)
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
if (attr == &dev_attr_enable) {
if (value)
ret = blk_trace_setup_queue(q, bdev);
else
ret = blk_trace_remove_queue(q);
goto out_unlock_bdev;
}
ret = 0;
if (q->blk_trace == NULL)
ret = blk_trace_setup_queue(q, bdev);
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;
}
out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
return ret ? ret : count;
}
int blk_trace_init_sysfs(struct device *dev)
{
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
}
void blk_trace_remove_sysfs(struct device *dev)
{
sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
}
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#ifdef CONFIG_EVENT_TRACING
void blk_dump_cmd(char *buf, struct request *rq)
{
int i, end;
int len = rq->cmd_len;
unsigned char *cmd = rq->cmd;
if (!blk_pc_request(rq)) {
buf[0] = '\0';
return;
}
for (end = len - 1; end >= 0; end--)
if (cmd[end])
break;
end++;
for (i = 0; i < len; i++) {
buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
if (i == end && end != len - 1) {
sprintf(buf, " ..");
break;
}
}
}
void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
{
int i = 0;
if (rw & WRITE)
rwbs[i++] = 'W';
else if (rw & 1 << BIO_RW_DISCARD)
rwbs[i++] = 'D';
else if (bytes)
rwbs[i++] = 'R';
else
rwbs[i++] = 'N';
if (rw & 1 << BIO_RW_AHEAD)
rwbs[i++] = 'A';
if (rw & 1 << BIO_RW_BARRIER)
rwbs[i++] = 'B';
if (rw & 1 << BIO_RW_SYNCIO)
rwbs[i++] = 'S';
if (rw & 1 << BIO_RW_META)
rwbs[i++] = 'M';
rwbs[i] = '\0';
}
void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
{
int rw = rq->cmd_flags & 0x03;
int bytes;
if (blk_discard_rq(rq))
rw |= (1 << BIO_RW_DISCARD);
bytes = blk_rq_bytes(rq);
blk_fill_rwbs(rwbs, rw, bytes);
}
#endif /* CONFIG_EVENT_TRACING */