2 * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 #include <linux/kernel.h>
19 #include <linux/blkdev.h>
20 #include <linux/blktrace_api.h>
21 #include <linux/percpu.h>
22 #include <linux/init.h>
23 #include <linux/mutex.h>
24 #include <linux/slab.h>
25 #include <linux/debugfs.h>
26 #include <linux/time.h>
27 #include <linux/uaccess.h>
29 #include <trace/events/block.h>
31 #include "trace_output.h"
33 #ifdef CONFIG_BLK_DEV_IO_TRACE
35 static unsigned int blktrace_seq __read_mostly
= 1;
37 static struct trace_array
*blk_tr
;
38 static bool blk_tracer_enabled __read_mostly
;
40 /* Select an alternative, minimalistic output than the original one */
41 #define TRACE_BLK_OPT_CLASSIC 0x1
43 static struct tracer_opt blk_tracer_opts
[] = {
44 /* Default disable the minimalistic output */
45 { TRACER_OPT(blk_classic
, TRACE_BLK_OPT_CLASSIC
) },
49 static struct tracer_flags blk_tracer_flags
= {
51 .opts
= blk_tracer_opts
,
54 /* Global reference count of probes */
55 static atomic_t blk_probes_ref
= ATOMIC_INIT(0);
57 static void blk_register_tracepoints(void);
58 static void blk_unregister_tracepoints(void);
61 * Send out a notify message.
63 static void trace_note(struct blk_trace
*bt
, pid_t pid
, int action
,
64 const void *data
, size_t len
)
66 struct blk_io_trace
*t
;
67 struct ring_buffer_event
*event
= NULL
;
68 struct ring_buffer
*buffer
= NULL
;
70 int cpu
= smp_processor_id();
71 bool blk_tracer
= blk_tracer_enabled
;
74 buffer
= blk_tr
->buffer
;
76 event
= trace_buffer_lock_reserve(buffer
, TRACE_BLK
,
81 t
= ring_buffer_event_data(event
);
88 t
= relay_reserve(bt
->rchan
, sizeof(*t
) + len
);
90 t
->magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
;
91 t
->time
= ktime_to_ns(ktime_get());
98 memcpy((void *) t
+ sizeof(*t
), data
, len
);
101 trace_buffer_unlock_commit(buffer
, event
, 0, pc
);
106 * Send out a notify for this process, if we haven't done so since a trace
109 static void trace_note_tsk(struct blk_trace
*bt
, struct task_struct
*tsk
)
111 tsk
->btrace_seq
= blktrace_seq
;
112 trace_note(bt
, tsk
->pid
, BLK_TN_PROCESS
, tsk
->comm
, sizeof(tsk
->comm
));
115 static void trace_note_time(struct blk_trace
*bt
)
121 getnstimeofday(&now
);
122 words
[0] = now
.tv_sec
;
123 words
[1] = now
.tv_nsec
;
125 local_irq_save(flags
);
126 trace_note(bt
, 0, BLK_TN_TIMESTAMP
, words
, sizeof(words
));
127 local_irq_restore(flags
);
130 void __trace_note_message(struct blk_trace
*bt
, const char *fmt
, ...)
137 if (unlikely(bt
->trace_state
!= Blktrace_running
&&
138 !blk_tracer_enabled
))
141 local_irq_save(flags
);
142 buf
= per_cpu_ptr(bt
->msg_data
, smp_processor_id());
144 n
= vscnprintf(buf
, BLK_TN_MAX_MSG
, fmt
, args
);
147 trace_note(bt
, 0, BLK_TN_MESSAGE
, buf
, n
);
148 local_irq_restore(flags
);
150 EXPORT_SYMBOL_GPL(__trace_note_message
);
152 static int act_log_check(struct blk_trace
*bt
, u32 what
, sector_t sector
,
155 if (((bt
->act_mask
<< BLK_TC_SHIFT
) & what
) == 0)
157 if (sector
&& (sector
< bt
->start_lba
|| sector
> bt
->end_lba
))
159 if (bt
->pid
&& pid
!= bt
->pid
)
166 * Data direction bit lookup
168 static const u32 ddir_act
[2] = { BLK_TC_ACT(BLK_TC_READ
),
169 BLK_TC_ACT(BLK_TC_WRITE
) };
171 #define BLK_TC_HARDBARRIER BLK_TC_BARRIER
172 #define BLK_TC_RAHEAD BLK_TC_AHEAD
174 /* The ilog2() calls fall out because they're constant */
175 #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
176 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
179 * The worker for the various blk_add_trace*() types. Fills out a
180 * blk_io_trace structure and places it in a per-cpu subbuffer.
182 static void __blk_add_trace(struct blk_trace
*bt
, sector_t sector
, int bytes
,
183 int rw
, u32 what
, int error
, int pdu_len
, void *pdu_data
)
185 struct task_struct
*tsk
= current
;
186 struct ring_buffer_event
*event
= NULL
;
187 struct ring_buffer
*buffer
= NULL
;
188 struct blk_io_trace
*t
;
189 unsigned long flags
= 0;
190 unsigned long *sequence
;
193 bool blk_tracer
= blk_tracer_enabled
;
195 if (unlikely(bt
->trace_state
!= Blktrace_running
&& !blk_tracer
))
198 what
|= ddir_act
[rw
& WRITE
];
199 what
|= MASK_TC_BIT(rw
, HARDBARRIER
);
200 what
|= MASK_TC_BIT(rw
, SYNC
);
201 what
|= MASK_TC_BIT(rw
, RAHEAD
);
202 what
|= MASK_TC_BIT(rw
, META
);
203 what
|= MASK_TC_BIT(rw
, DISCARD
);
206 if (act_log_check(bt
, what
, sector
, pid
))
208 cpu
= raw_smp_processor_id();
211 tracing_record_cmdline(current
);
213 buffer
= blk_tr
->buffer
;
214 pc
= preempt_count();
215 event
= trace_buffer_lock_reserve(buffer
, TRACE_BLK
,
216 sizeof(*t
) + pdu_len
,
220 t
= ring_buffer_event_data(event
);
225 * A word about the locking here - we disable interrupts to reserve
226 * some space in the relay per-cpu buffer, to prevent an irq
227 * from coming in and stepping on our toes.
229 local_irq_save(flags
);
231 if (unlikely(tsk
->btrace_seq
!= blktrace_seq
))
232 trace_note_tsk(bt
, tsk
);
234 t
= relay_reserve(bt
->rchan
, sizeof(*t
) + pdu_len
);
236 sequence
= per_cpu_ptr(bt
->sequence
, cpu
);
238 t
->magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
;
239 t
->sequence
= ++(*sequence
);
240 t
->time
= ktime_to_ns(ktime_get());
243 * These two are not needed in ftrace as they are in the
244 * generic trace_entry, filled by tracing_generic_entry_update,
245 * but for the trace_event->bin() synthesizer benefit we do it
256 t
->pdu_len
= pdu_len
;
259 memcpy((void *) t
+ sizeof(*t
), pdu_data
, pdu_len
);
262 trace_buffer_unlock_commit(buffer
, event
, 0, pc
);
267 local_irq_restore(flags
);
270 static struct dentry
*blk_tree_root
;
271 static DEFINE_MUTEX(blk_tree_mutex
);
273 static void blk_trace_free(struct blk_trace
*bt
)
275 debugfs_remove(bt
->msg_file
);
276 debugfs_remove(bt
->dropped_file
);
277 relay_close(bt
->rchan
);
278 debugfs_remove(bt
->dir
);
279 free_percpu(bt
->sequence
);
280 free_percpu(bt
->msg_data
);
284 static void blk_trace_cleanup(struct blk_trace
*bt
)
287 if (atomic_dec_and_test(&blk_probes_ref
))
288 blk_unregister_tracepoints();
291 int blk_trace_remove(struct request_queue
*q
)
293 struct blk_trace
*bt
;
295 bt
= xchg(&q
->blk_trace
, NULL
);
299 if (bt
->trace_state
!= Blktrace_running
)
300 blk_trace_cleanup(bt
);
304 EXPORT_SYMBOL_GPL(blk_trace_remove
);
306 static int blk_dropped_open(struct inode
*inode
, struct file
*filp
)
308 filp
->private_data
= inode
->i_private
;
313 static ssize_t
blk_dropped_read(struct file
*filp
, char __user
*buffer
,
314 size_t count
, loff_t
*ppos
)
316 struct blk_trace
*bt
= filp
->private_data
;
319 snprintf(buf
, sizeof(buf
), "%u\n", atomic_read(&bt
->dropped
));
321 return simple_read_from_buffer(buffer
, count
, ppos
, buf
, strlen(buf
));
324 static const struct file_operations blk_dropped_fops
= {
325 .owner
= THIS_MODULE
,
326 .open
= blk_dropped_open
,
327 .read
= blk_dropped_read
,
328 .llseek
= default_llseek
,
331 static int blk_msg_open(struct inode
*inode
, struct file
*filp
)
333 filp
->private_data
= inode
->i_private
;
338 static ssize_t
blk_msg_write(struct file
*filp
, const char __user
*buffer
,
339 size_t count
, loff_t
*ppos
)
342 struct blk_trace
*bt
;
344 if (count
>= BLK_TN_MAX_MSG
)
347 msg
= kmalloc(count
+ 1, GFP_KERNEL
);
351 if (copy_from_user(msg
, buffer
, count
)) {
357 bt
= filp
->private_data
;
358 __trace_note_message(bt
, "%s", msg
);
364 static const struct file_operations blk_msg_fops
= {
365 .owner
= THIS_MODULE
,
366 .open
= blk_msg_open
,
367 .write
= blk_msg_write
,
368 .llseek
= noop_llseek
,
372 * Keep track of how many times we encountered a full subbuffer, to aid
373 * the user space app in telling how many lost events there were.
375 static int blk_subbuf_start_callback(struct rchan_buf
*buf
, void *subbuf
,
376 void *prev_subbuf
, size_t prev_padding
)
378 struct blk_trace
*bt
;
380 if (!relay_buf_full(buf
))
383 bt
= buf
->chan
->private_data
;
384 atomic_inc(&bt
->dropped
);
388 static int blk_remove_buf_file_callback(struct dentry
*dentry
)
390 debugfs_remove(dentry
);
395 static struct dentry
*blk_create_buf_file_callback(const char *filename
,
396 struct dentry
*parent
,
398 struct rchan_buf
*buf
,
401 return debugfs_create_file(filename
, mode
, parent
, buf
,
402 &relay_file_operations
);
405 static struct rchan_callbacks blk_relay_callbacks
= {
406 .subbuf_start
= blk_subbuf_start_callback
,
407 .create_buf_file
= blk_create_buf_file_callback
,
408 .remove_buf_file
= blk_remove_buf_file_callback
,
411 static void blk_trace_setup_lba(struct blk_trace
*bt
,
412 struct block_device
*bdev
)
414 struct hd_struct
*part
= NULL
;
417 part
= bdev
->bd_part
;
420 bt
->start_lba
= part
->start_sect
;
421 bt
->end_lba
= part
->start_sect
+ part
->nr_sects
;
429 * Setup everything required to start tracing
431 int do_blk_trace_setup(struct request_queue
*q
, char *name
, dev_t dev
,
432 struct block_device
*bdev
,
433 struct blk_user_trace_setup
*buts
)
435 struct blk_trace
*old_bt
, *bt
= NULL
;
436 struct dentry
*dir
= NULL
;
439 if (!buts
->buf_size
|| !buts
->buf_nr
)
442 strncpy(buts
->name
, name
, BLKTRACE_BDEV_SIZE
);
443 buts
->name
[BLKTRACE_BDEV_SIZE
- 1] = '\0';
446 * some device names have larger paths - convert the slashes
447 * to underscores for this to work as expected
449 for (i
= 0; i
< strlen(buts
->name
); i
++)
450 if (buts
->name
[i
] == '/')
453 bt
= kzalloc(sizeof(*bt
), GFP_KERNEL
);
458 bt
->sequence
= alloc_percpu(unsigned long);
462 bt
->msg_data
= __alloc_percpu(BLK_TN_MAX_MSG
, __alignof__(char));
468 mutex_lock(&blk_tree_mutex
);
469 if (!blk_tree_root
) {
470 blk_tree_root
= debugfs_create_dir("block", NULL
);
471 if (!blk_tree_root
) {
472 mutex_unlock(&blk_tree_mutex
);
476 mutex_unlock(&blk_tree_mutex
);
478 dir
= debugfs_create_dir(buts
->name
, blk_tree_root
);
485 atomic_set(&bt
->dropped
, 0);
488 bt
->dropped_file
= debugfs_create_file("dropped", 0444, dir
, bt
,
490 if (!bt
->dropped_file
)
493 bt
->msg_file
= debugfs_create_file("msg", 0222, dir
, bt
, &blk_msg_fops
);
497 bt
->rchan
= relay_open("trace", dir
, buts
->buf_size
,
498 buts
->buf_nr
, &blk_relay_callbacks
, bt
);
502 bt
->act_mask
= buts
->act_mask
;
504 bt
->act_mask
= (u16
) -1;
506 blk_trace_setup_lba(bt
, bdev
);
508 /* overwrite with user settings */
510 bt
->start_lba
= buts
->start_lba
;
512 bt
->end_lba
= buts
->end_lba
;
515 bt
->trace_state
= Blktrace_setup
;
518 old_bt
= xchg(&q
->blk_trace
, bt
);
520 (void) xchg(&q
->blk_trace
, old_bt
);
524 if (atomic_inc_return(&blk_probes_ref
) == 1)
525 blk_register_tracepoints();
533 int blk_trace_setup(struct request_queue
*q
, char *name
, dev_t dev
,
534 struct block_device
*bdev
,
537 struct blk_user_trace_setup buts
;
540 ret
= copy_from_user(&buts
, arg
, sizeof(buts
));
544 ret
= do_blk_trace_setup(q
, name
, dev
, bdev
, &buts
);
548 if (copy_to_user(arg
, &buts
, sizeof(buts
))) {
554 EXPORT_SYMBOL_GPL(blk_trace_setup
);
556 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
557 static int compat_blk_trace_setup(struct request_queue
*q
, char *name
,
558 dev_t dev
, struct block_device
*bdev
,
561 struct blk_user_trace_setup buts
;
562 struct compat_blk_user_trace_setup cbuts
;
565 if (copy_from_user(&cbuts
, arg
, sizeof(cbuts
)))
568 buts
= (struct blk_user_trace_setup
) {
569 .act_mask
= cbuts
.act_mask
,
570 .buf_size
= cbuts
.buf_size
,
571 .buf_nr
= cbuts
.buf_nr
,
572 .start_lba
= cbuts
.start_lba
,
573 .end_lba
= cbuts
.end_lba
,
576 memcpy(&buts
.name
, &cbuts
.name
, 32);
578 ret
= do_blk_trace_setup(q
, name
, dev
, bdev
, &buts
);
582 if (copy_to_user(arg
, &buts
.name
, 32)) {
591 int blk_trace_startstop(struct request_queue
*q
, int start
)
594 struct blk_trace
*bt
= q
->blk_trace
;
600 * For starting a trace, we can transition from a setup or stopped
601 * trace. For stopping a trace, the state must be running
605 if (bt
->trace_state
== Blktrace_setup
||
606 bt
->trace_state
== Blktrace_stopped
) {
609 bt
->trace_state
= Blktrace_running
;
615 if (bt
->trace_state
== Blktrace_running
) {
616 bt
->trace_state
= Blktrace_stopped
;
617 relay_flush(bt
->rchan
);
624 EXPORT_SYMBOL_GPL(blk_trace_startstop
);
627 * blk_trace_ioctl: - handle the ioctls associated with tracing
628 * @bdev: the block device
629 * @cmd: the ioctl cmd
630 * @arg: the argument data, if any
633 int blk_trace_ioctl(struct block_device
*bdev
, unsigned cmd
, char __user
*arg
)
635 struct request_queue
*q
;
637 char b
[BDEVNAME_SIZE
];
639 q
= bdev_get_queue(bdev
);
643 mutex_lock(&bdev
->bd_mutex
);
648 ret
= blk_trace_setup(q
, b
, bdev
->bd_dev
, bdev
, arg
);
650 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
651 case BLKTRACESETUP32
:
653 ret
= compat_blk_trace_setup(q
, b
, bdev
->bd_dev
, bdev
, arg
);
659 ret
= blk_trace_startstop(q
, start
);
661 case BLKTRACETEARDOWN
:
662 ret
= blk_trace_remove(q
);
669 mutex_unlock(&bdev
->bd_mutex
);
674 * blk_trace_shutdown: - stop and cleanup trace structures
675 * @q: the request queue associated with the device
678 void blk_trace_shutdown(struct request_queue
*q
)
681 blk_trace_startstop(q
, 0);
691 * blk_add_trace_rq - Add a trace for a request oriented action
692 * @q: queue the io is for
693 * @rq: the source request
697 * Records an action against a request. Will log the bio offset + size.
700 static void blk_add_trace_rq(struct request_queue
*q
, struct request
*rq
,
703 struct blk_trace
*bt
= q
->blk_trace
;
704 int rw
= rq
->cmd_flags
& 0x03;
709 if (rq
->cmd_flags
& REQ_DISCARD
)
712 if (rq
->cmd_flags
& REQ_SECURE
)
715 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
716 what
|= BLK_TC_ACT(BLK_TC_PC
);
717 __blk_add_trace(bt
, 0, blk_rq_bytes(rq
), rw
,
718 what
, rq
->errors
, rq
->cmd_len
, rq
->cmd
);
720 what
|= BLK_TC_ACT(BLK_TC_FS
);
721 __blk_add_trace(bt
, blk_rq_pos(rq
), blk_rq_bytes(rq
), rw
,
722 what
, rq
->errors
, 0, NULL
);
726 static void blk_add_trace_rq_abort(void *ignore
,
727 struct request_queue
*q
, struct request
*rq
)
729 blk_add_trace_rq(q
, rq
, BLK_TA_ABORT
);
732 static void blk_add_trace_rq_insert(void *ignore
,
733 struct request_queue
*q
, struct request
*rq
)
735 blk_add_trace_rq(q
, rq
, BLK_TA_INSERT
);
738 static void blk_add_trace_rq_issue(void *ignore
,
739 struct request_queue
*q
, struct request
*rq
)
741 blk_add_trace_rq(q
, rq
, BLK_TA_ISSUE
);
744 static void blk_add_trace_rq_requeue(void *ignore
,
745 struct request_queue
*q
,
748 blk_add_trace_rq(q
, rq
, BLK_TA_REQUEUE
);
751 static void blk_add_trace_rq_complete(void *ignore
,
752 struct request_queue
*q
,
755 blk_add_trace_rq(q
, rq
, BLK_TA_COMPLETE
);
759 * blk_add_trace_bio - Add a trace for a bio oriented action
760 * @q: queue the io is for
761 * @bio: the source bio
765 * Records an action against a bio. Will log the bio offset + size.
768 static void blk_add_trace_bio(struct request_queue
*q
, struct bio
*bio
,
771 struct blk_trace
*bt
= q
->blk_trace
;
776 __blk_add_trace(bt
, bio
->bi_sector
, bio
->bi_size
, bio
->bi_rw
, what
,
777 !bio_flagged(bio
, BIO_UPTODATE
), 0, NULL
);
780 static void blk_add_trace_bio_bounce(void *ignore
,
781 struct request_queue
*q
, struct bio
*bio
)
783 blk_add_trace_bio(q
, bio
, BLK_TA_BOUNCE
);
786 static void blk_add_trace_bio_complete(void *ignore
,
787 struct request_queue
*q
, struct bio
*bio
)
789 blk_add_trace_bio(q
, bio
, BLK_TA_COMPLETE
);
792 static void blk_add_trace_bio_backmerge(void *ignore
,
793 struct request_queue
*q
,
796 blk_add_trace_bio(q
, bio
, BLK_TA_BACKMERGE
);
799 static void blk_add_trace_bio_frontmerge(void *ignore
,
800 struct request_queue
*q
,
803 blk_add_trace_bio(q
, bio
, BLK_TA_FRONTMERGE
);
806 static void blk_add_trace_bio_queue(void *ignore
,
807 struct request_queue
*q
, struct bio
*bio
)
809 blk_add_trace_bio(q
, bio
, BLK_TA_QUEUE
);
812 static void blk_add_trace_getrq(void *ignore
,
813 struct request_queue
*q
,
814 struct bio
*bio
, int rw
)
817 blk_add_trace_bio(q
, bio
, BLK_TA_GETRQ
);
819 struct blk_trace
*bt
= q
->blk_trace
;
822 __blk_add_trace(bt
, 0, 0, rw
, BLK_TA_GETRQ
, 0, 0, NULL
);
827 static void blk_add_trace_sleeprq(void *ignore
,
828 struct request_queue
*q
,
829 struct bio
*bio
, int rw
)
832 blk_add_trace_bio(q
, bio
, BLK_TA_SLEEPRQ
);
834 struct blk_trace
*bt
= q
->blk_trace
;
837 __blk_add_trace(bt
, 0, 0, rw
, BLK_TA_SLEEPRQ
,
842 static void blk_add_trace_plug(void *ignore
, struct request_queue
*q
)
844 struct blk_trace
*bt
= q
->blk_trace
;
847 __blk_add_trace(bt
, 0, 0, 0, BLK_TA_PLUG
, 0, 0, NULL
);
850 static void blk_add_trace_unplug_io(void *ignore
, struct request_queue
*q
)
852 struct blk_trace
*bt
= q
->blk_trace
;
855 unsigned int pdu
= q
->rq
.count
[READ
] + q
->rq
.count
[WRITE
];
856 __be64 rpdu
= cpu_to_be64(pdu
);
858 __blk_add_trace(bt
, 0, 0, 0, BLK_TA_UNPLUG_IO
, 0,
859 sizeof(rpdu
), &rpdu
);
863 static void blk_add_trace_unplug_timer(void *ignore
, struct request_queue
*q
)
865 struct blk_trace
*bt
= q
->blk_trace
;
868 unsigned int pdu
= q
->rq
.count
[READ
] + q
->rq
.count
[WRITE
];
869 __be64 rpdu
= cpu_to_be64(pdu
);
871 __blk_add_trace(bt
, 0, 0, 0, BLK_TA_UNPLUG_TIMER
, 0,
872 sizeof(rpdu
), &rpdu
);
876 static void blk_add_trace_split(void *ignore
,
877 struct request_queue
*q
, struct bio
*bio
,
880 struct blk_trace
*bt
= q
->blk_trace
;
883 __be64 rpdu
= cpu_to_be64(pdu
);
885 __blk_add_trace(bt
, bio
->bi_sector
, bio
->bi_size
, bio
->bi_rw
,
886 BLK_TA_SPLIT
, !bio_flagged(bio
, BIO_UPTODATE
),
887 sizeof(rpdu
), &rpdu
);
892 * blk_add_trace_remap - Add a trace for a remap operation
893 * @ignore: trace callback data parameter (not used)
894 * @q: queue the io is for
895 * @bio: the source bio
896 * @dev: target device
897 * @from: source sector
900 * Device mapper or raid target sometimes need to split a bio because
901 * it spans a stripe (or similar). Add a trace for that action.
904 static void blk_add_trace_remap(void *ignore
,
905 struct request_queue
*q
, struct bio
*bio
,
906 dev_t dev
, sector_t from
)
908 struct blk_trace
*bt
= q
->blk_trace
;
909 struct blk_io_trace_remap r
;
914 r
.device_from
= cpu_to_be32(dev
);
915 r
.device_to
= cpu_to_be32(bio
->bi_bdev
->bd_dev
);
916 r
.sector_from
= cpu_to_be64(from
);
918 __blk_add_trace(bt
, bio
->bi_sector
, bio
->bi_size
, bio
->bi_rw
,
919 BLK_TA_REMAP
, !bio_flagged(bio
, BIO_UPTODATE
),
924 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
925 * @ignore: trace callback data parameter (not used)
926 * @q: queue the io is for
927 * @rq: the source request
928 * @dev: target device
929 * @from: source sector
932 * Device mapper remaps request to other devices.
933 * Add a trace for that action.
936 static void blk_add_trace_rq_remap(void *ignore
,
937 struct request_queue
*q
,
938 struct request
*rq
, dev_t dev
,
941 struct blk_trace
*bt
= q
->blk_trace
;
942 struct blk_io_trace_remap r
;
947 r
.device_from
= cpu_to_be32(dev
);
948 r
.device_to
= cpu_to_be32(disk_devt(rq
->rq_disk
));
949 r
.sector_from
= cpu_to_be64(from
);
951 __blk_add_trace(bt
, blk_rq_pos(rq
), blk_rq_bytes(rq
),
952 rq_data_dir(rq
), BLK_TA_REMAP
, !!rq
->errors
,
957 * blk_add_driver_data - Add binary message with driver-specific data
958 * @q: queue the io is for
960 * @data: driver-specific data
961 * @len: length of driver-specific data
964 * Some drivers might want to write driver-specific data per request.
967 void blk_add_driver_data(struct request_queue
*q
,
969 void *data
, size_t len
)
971 struct blk_trace
*bt
= q
->blk_trace
;
976 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
)
977 __blk_add_trace(bt
, 0, blk_rq_bytes(rq
), 0,
978 BLK_TA_DRV_DATA
, rq
->errors
, len
, data
);
980 __blk_add_trace(bt
, blk_rq_pos(rq
), blk_rq_bytes(rq
), 0,
981 BLK_TA_DRV_DATA
, rq
->errors
, len
, data
);
983 EXPORT_SYMBOL_GPL(blk_add_driver_data
);
985 static void blk_register_tracepoints(void)
989 ret
= register_trace_block_rq_abort(blk_add_trace_rq_abort
, NULL
);
991 ret
= register_trace_block_rq_insert(blk_add_trace_rq_insert
, NULL
);
993 ret
= register_trace_block_rq_issue(blk_add_trace_rq_issue
, NULL
);
995 ret
= register_trace_block_rq_requeue(blk_add_trace_rq_requeue
, NULL
);
997 ret
= register_trace_block_rq_complete(blk_add_trace_rq_complete
, NULL
);
999 ret
= register_trace_block_bio_bounce(blk_add_trace_bio_bounce
, NULL
);
1001 ret
= register_trace_block_bio_complete(blk_add_trace_bio_complete
, NULL
);
1003 ret
= register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge
, NULL
);
1005 ret
= register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge
, NULL
);
1007 ret
= register_trace_block_bio_queue(blk_add_trace_bio_queue
, NULL
);
1009 ret
= register_trace_block_getrq(blk_add_trace_getrq
, NULL
);
1011 ret
= register_trace_block_sleeprq(blk_add_trace_sleeprq
, NULL
);
1013 ret
= register_trace_block_plug(blk_add_trace_plug
, NULL
);
1015 ret
= register_trace_block_unplug_timer(blk_add_trace_unplug_timer
, NULL
);
1017 ret
= register_trace_block_unplug_io(blk_add_trace_unplug_io
, NULL
);
1019 ret
= register_trace_block_split(blk_add_trace_split
, NULL
);
1021 ret
= register_trace_block_remap(blk_add_trace_remap
, NULL
);
1023 ret
= register_trace_block_rq_remap(blk_add_trace_rq_remap
, NULL
);
1027 static void blk_unregister_tracepoints(void)
1029 unregister_trace_block_rq_remap(blk_add_trace_rq_remap
, NULL
);
1030 unregister_trace_block_remap(blk_add_trace_remap
, NULL
);
1031 unregister_trace_block_split(blk_add_trace_split
, NULL
);
1032 unregister_trace_block_unplug_io(blk_add_trace_unplug_io
, NULL
);
1033 unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer
, NULL
);
1034 unregister_trace_block_plug(blk_add_trace_plug
, NULL
);
1035 unregister_trace_block_sleeprq(blk_add_trace_sleeprq
, NULL
);
1036 unregister_trace_block_getrq(blk_add_trace_getrq
, NULL
);
1037 unregister_trace_block_bio_queue(blk_add_trace_bio_queue
, NULL
);
1038 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge
, NULL
);
1039 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge
, NULL
);
1040 unregister_trace_block_bio_complete(blk_add_trace_bio_complete
, NULL
);
1041 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce
, NULL
);
1042 unregister_trace_block_rq_complete(blk_add_trace_rq_complete
, NULL
);
1043 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue
, NULL
);
1044 unregister_trace_block_rq_issue(blk_add_trace_rq_issue
, NULL
);
1045 unregister_trace_block_rq_insert(blk_add_trace_rq_insert
, NULL
);
1046 unregister_trace_block_rq_abort(blk_add_trace_rq_abort
, NULL
);
1048 tracepoint_synchronize_unregister();
1052 * struct blk_io_tracer formatting routines
1055 static void fill_rwbs(char *rwbs
, const struct blk_io_trace
*t
)
1058 int tc
= t
->action
>> BLK_TC_SHIFT
;
1060 if (t
->action
== BLK_TN_MESSAGE
) {
1065 if (tc
& BLK_TC_DISCARD
)
1067 else if (tc
& BLK_TC_WRITE
)
1074 if (tc
& BLK_TC_AHEAD
)
1076 if (tc
& BLK_TC_BARRIER
)
1078 if (tc
& BLK_TC_SYNC
)
1080 if (tc
& BLK_TC_META
)
1087 const struct blk_io_trace
*te_blk_io_trace(const struct trace_entry
*ent
)
1089 return (const struct blk_io_trace
*)ent
;
1092 static inline const void *pdu_start(const struct trace_entry
*ent
)
1094 return te_blk_io_trace(ent
) + 1;
1097 static inline u32
t_action(const struct trace_entry
*ent
)
1099 return te_blk_io_trace(ent
)->action
;
1102 static inline u32
t_bytes(const struct trace_entry
*ent
)
1104 return te_blk_io_trace(ent
)->bytes
;
1107 static inline u32
t_sec(const struct trace_entry
*ent
)
1109 return te_blk_io_trace(ent
)->bytes
>> 9;
1112 static inline unsigned long long t_sector(const struct trace_entry
*ent
)
1114 return te_blk_io_trace(ent
)->sector
;
1117 static inline __u16
t_error(const struct trace_entry
*ent
)
1119 return te_blk_io_trace(ent
)->error
;
1122 static __u64
get_pdu_int(const struct trace_entry
*ent
)
1124 const __u64
*val
= pdu_start(ent
);
1125 return be64_to_cpu(*val
);
1128 static void get_pdu_remap(const struct trace_entry
*ent
,
1129 struct blk_io_trace_remap
*r
)
1131 const struct blk_io_trace_remap
*__r
= pdu_start(ent
);
1132 __u64 sector_from
= __r
->sector_from
;
1134 r
->device_from
= be32_to_cpu(__r
->device_from
);
1135 r
->device_to
= be32_to_cpu(__r
->device_to
);
1136 r
->sector_from
= be64_to_cpu(sector_from
);
1139 typedef int (blk_log_action_t
) (struct trace_iterator
*iter
, const char *act
);
1141 static int blk_log_action_classic(struct trace_iterator
*iter
, const char *act
)
1144 unsigned long long ts
= iter
->ts
;
1145 unsigned long nsec_rem
= do_div(ts
, NSEC_PER_SEC
);
1146 unsigned secs
= (unsigned long)ts
;
1147 const struct blk_io_trace
*t
= te_blk_io_trace(iter
->ent
);
1151 return trace_seq_printf(&iter
->seq
,
1152 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1153 MAJOR(t
->device
), MINOR(t
->device
), iter
->cpu
,
1154 secs
, nsec_rem
, iter
->ent
->pid
, act
, rwbs
);
1157 static int blk_log_action(struct trace_iterator
*iter
, const char *act
)
1160 const struct blk_io_trace
*t
= te_blk_io_trace(iter
->ent
);
1163 return trace_seq_printf(&iter
->seq
, "%3d,%-3d %2s %3s ",
1164 MAJOR(t
->device
), MINOR(t
->device
), act
, rwbs
);
1167 static int blk_log_dump_pdu(struct trace_seq
*s
, const struct trace_entry
*ent
)
1169 const unsigned char *pdu_buf
;
1173 pdu_buf
= pdu_start(ent
);
1174 pdu_len
= te_blk_io_trace(ent
)->pdu_len
;
1179 /* find the last zero that needs to be printed */
1180 for (end
= pdu_len
- 1; end
>= 0; end
--)
1185 if (!trace_seq_putc(s
, '('))
1188 for (i
= 0; i
< pdu_len
; i
++) {
1190 ret
= trace_seq_printf(s
, "%s%02x",
1191 i
== 0 ? "" : " ", pdu_buf
[i
]);
1196 * stop when the rest is just zeroes and indicate so
1197 * with a ".." appended
1199 if (i
== end
&& end
!= pdu_len
- 1)
1200 return trace_seq_puts(s
, " ..) ");
1203 return trace_seq_puts(s
, ") ");
1206 static int blk_log_generic(struct trace_seq
*s
, const struct trace_entry
*ent
)
1208 char cmd
[TASK_COMM_LEN
];
1210 trace_find_cmdline(ent
->pid
, cmd
);
1212 if (t_action(ent
) & BLK_TC_ACT(BLK_TC_PC
)) {
1215 ret
= trace_seq_printf(s
, "%u ", t_bytes(ent
));
1218 ret
= blk_log_dump_pdu(s
, ent
);
1221 return trace_seq_printf(s
, "[%s]\n", cmd
);
1224 return trace_seq_printf(s
, "%llu + %u [%s]\n",
1225 t_sector(ent
), t_sec(ent
), cmd
);
1226 return trace_seq_printf(s
, "[%s]\n", cmd
);
1230 static int blk_log_with_error(struct trace_seq
*s
,
1231 const struct trace_entry
*ent
)
1233 if (t_action(ent
) & BLK_TC_ACT(BLK_TC_PC
)) {
1236 ret
= blk_log_dump_pdu(s
, ent
);
1238 return trace_seq_printf(s
, "[%d]\n", t_error(ent
));
1242 return trace_seq_printf(s
, "%llu + %u [%d]\n",
1244 t_sec(ent
), t_error(ent
));
1245 return trace_seq_printf(s
, "%llu [%d]\n",
1246 t_sector(ent
), t_error(ent
));
1250 static int blk_log_remap(struct trace_seq
*s
, const struct trace_entry
*ent
)
1252 struct blk_io_trace_remap r
= { .device_from
= 0, };
1254 get_pdu_remap(ent
, &r
);
1255 return trace_seq_printf(s
, "%llu + %u <- (%d,%d) %llu\n",
1256 t_sector(ent
), t_sec(ent
),
1257 MAJOR(r
.device_from
), MINOR(r
.device_from
),
1258 (unsigned long long)r
.sector_from
);
1261 static int blk_log_plug(struct trace_seq
*s
, const struct trace_entry
*ent
)
1263 char cmd
[TASK_COMM_LEN
];
1265 trace_find_cmdline(ent
->pid
, cmd
);
1267 return trace_seq_printf(s
, "[%s]\n", cmd
);
1270 static int blk_log_unplug(struct trace_seq
*s
, const struct trace_entry
*ent
)
1272 char cmd
[TASK_COMM_LEN
];
1274 trace_find_cmdline(ent
->pid
, cmd
);
1276 return trace_seq_printf(s
, "[%s] %llu\n", cmd
, get_pdu_int(ent
));
1279 static int blk_log_split(struct trace_seq
*s
, const struct trace_entry
*ent
)
1281 char cmd
[TASK_COMM_LEN
];
1283 trace_find_cmdline(ent
->pid
, cmd
);
1285 return trace_seq_printf(s
, "%llu / %llu [%s]\n", t_sector(ent
),
1286 get_pdu_int(ent
), cmd
);
1289 static int blk_log_msg(struct trace_seq
*s
, const struct trace_entry
*ent
)
1292 const struct blk_io_trace
*t
= te_blk_io_trace(ent
);
1294 ret
= trace_seq_putmem(s
, t
+ 1, t
->pdu_len
);
1296 return trace_seq_putc(s
, '\n');
1301 * struct tracer operations
1304 static void blk_tracer_print_header(struct seq_file
*m
)
1306 if (!(blk_tracer_flags
.val
& TRACE_BLK_OPT_CLASSIC
))
1308 seq_puts(m
, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1312 static void blk_tracer_start(struct trace_array
*tr
)
1314 blk_tracer_enabled
= true;
1317 static int blk_tracer_init(struct trace_array
*tr
)
1320 blk_tracer_start(tr
);
1324 static void blk_tracer_stop(struct trace_array
*tr
)
1326 blk_tracer_enabled
= false;
1329 static void blk_tracer_reset(struct trace_array
*tr
)
1331 blk_tracer_stop(tr
);
1334 static const struct {
1336 int (*print
)(struct trace_seq
*s
, const struct trace_entry
*ent
);
1338 [__BLK_TA_QUEUE
] = {{ "Q", "queue" }, blk_log_generic
},
1339 [__BLK_TA_BACKMERGE
] = {{ "M", "backmerge" }, blk_log_generic
},
1340 [__BLK_TA_FRONTMERGE
] = {{ "F", "frontmerge" }, blk_log_generic
},
1341 [__BLK_TA_GETRQ
] = {{ "G", "getrq" }, blk_log_generic
},
1342 [__BLK_TA_SLEEPRQ
] = {{ "S", "sleeprq" }, blk_log_generic
},
1343 [__BLK_TA_REQUEUE
] = {{ "R", "requeue" }, blk_log_with_error
},
1344 [__BLK_TA_ISSUE
] = {{ "D", "issue" }, blk_log_generic
},
1345 [__BLK_TA_COMPLETE
] = {{ "C", "complete" }, blk_log_with_error
},
1346 [__BLK_TA_PLUG
] = {{ "P", "plug" }, blk_log_plug
},
1347 [__BLK_TA_UNPLUG_IO
] = {{ "U", "unplug_io" }, blk_log_unplug
},
1348 [__BLK_TA_UNPLUG_TIMER
] = {{ "UT", "unplug_timer" }, blk_log_unplug
},
1349 [__BLK_TA_INSERT
] = {{ "I", "insert" }, blk_log_generic
},
1350 [__BLK_TA_SPLIT
] = {{ "X", "split" }, blk_log_split
},
1351 [__BLK_TA_BOUNCE
] = {{ "B", "bounce" }, blk_log_generic
},
1352 [__BLK_TA_REMAP
] = {{ "A", "remap" }, blk_log_remap
},
1355 static enum print_line_t
print_one_line(struct trace_iterator
*iter
,
1358 struct trace_seq
*s
= &iter
->seq
;
1359 const struct blk_io_trace
*t
;
1363 blk_log_action_t
*log_action
;
1365 t
= te_blk_io_trace(iter
->ent
);
1366 what
= t
->action
& ((1 << BLK_TC_SHIFT
) - 1);
1367 long_act
= !!(trace_flags
& TRACE_ITER_VERBOSE
);
1368 log_action
= classic
? &blk_log_action_classic
: &blk_log_action
;
1370 if (t
->action
== BLK_TN_MESSAGE
) {
1371 ret
= log_action(iter
, long_act
? "message" : "m");
1373 ret
= blk_log_msg(s
, iter
->ent
);
1377 if (unlikely(what
== 0 || what
>= ARRAY_SIZE(what2act
)))
1378 ret
= trace_seq_printf(s
, "Unknown action %x\n", what
);
1380 ret
= log_action(iter
, what2act
[what
].act
[long_act
]);
1382 ret
= what2act
[what
].print(s
, iter
->ent
);
1385 return ret
? TRACE_TYPE_HANDLED
: TRACE_TYPE_PARTIAL_LINE
;
1388 static enum print_line_t
blk_trace_event_print(struct trace_iterator
*iter
,
1389 int flags
, struct trace_event
*event
)
1391 return print_one_line(iter
, false);
1394 static int blk_trace_synthesize_old_trace(struct trace_iterator
*iter
)
1396 struct trace_seq
*s
= &iter
->seq
;
1397 struct blk_io_trace
*t
= (struct blk_io_trace
*)iter
->ent
;
1398 const int offset
= offsetof(struct blk_io_trace
, sector
);
1399 struct blk_io_trace old
= {
1400 .magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
,
1404 if (!trace_seq_putmem(s
, &old
, offset
))
1406 return trace_seq_putmem(s
, &t
->sector
,
1407 sizeof(old
) - offset
+ t
->pdu_len
);
1410 static enum print_line_t
1411 blk_trace_event_print_binary(struct trace_iterator
*iter
, int flags
,
1412 struct trace_event
*event
)
1414 return blk_trace_synthesize_old_trace(iter
) ?
1415 TRACE_TYPE_HANDLED
: TRACE_TYPE_PARTIAL_LINE
;
1418 static enum print_line_t
blk_tracer_print_line(struct trace_iterator
*iter
)
1420 if (!(blk_tracer_flags
.val
& TRACE_BLK_OPT_CLASSIC
))
1421 return TRACE_TYPE_UNHANDLED
;
1423 return print_one_line(iter
, true);
1426 static int blk_tracer_set_flag(u32 old_flags
, u32 bit
, int set
)
1428 /* don't output context-info for blk_classic output */
1429 if (bit
== TRACE_BLK_OPT_CLASSIC
) {
1431 trace_flags
&= ~TRACE_ITER_CONTEXT_INFO
;
1433 trace_flags
|= TRACE_ITER_CONTEXT_INFO
;
1438 static struct tracer blk_tracer __read_mostly
= {
1440 .init
= blk_tracer_init
,
1441 .reset
= blk_tracer_reset
,
1442 .start
= blk_tracer_start
,
1443 .stop
= blk_tracer_stop
,
1444 .print_header
= blk_tracer_print_header
,
1445 .print_line
= blk_tracer_print_line
,
1446 .flags
= &blk_tracer_flags
,
1447 .set_flag
= blk_tracer_set_flag
,
1450 static struct trace_event_functions trace_blk_event_funcs
= {
1451 .trace
= blk_trace_event_print
,
1452 .binary
= blk_trace_event_print_binary
,
1455 static struct trace_event trace_blk_event
= {
1457 .funcs
= &trace_blk_event_funcs
,
1460 static int __init
init_blk_tracer(void)
1462 if (!register_ftrace_event(&trace_blk_event
)) {
1463 pr_warning("Warning: could not register block events\n");
1467 if (register_tracer(&blk_tracer
) != 0) {
1468 pr_warning("Warning: could not register the block tracer\n");
1469 unregister_ftrace_event(&trace_blk_event
);
1476 device_initcall(init_blk_tracer
);
1478 static int blk_trace_remove_queue(struct request_queue
*q
)
1480 struct blk_trace
*bt
;
1482 bt
= xchg(&q
->blk_trace
, NULL
);
1486 if (atomic_dec_and_test(&blk_probes_ref
))
1487 blk_unregister_tracepoints();
1494 * Setup everything required to start tracing
1496 static int blk_trace_setup_queue(struct request_queue
*q
,
1497 struct block_device
*bdev
)
1499 struct blk_trace
*old_bt
, *bt
= NULL
;
1502 bt
= kzalloc(sizeof(*bt
), GFP_KERNEL
);
1506 bt
->msg_data
= __alloc_percpu(BLK_TN_MAX_MSG
, __alignof__(char));
1510 bt
->dev
= bdev
->bd_dev
;
1511 bt
->act_mask
= (u16
)-1;
1513 blk_trace_setup_lba(bt
, bdev
);
1515 old_bt
= xchg(&q
->blk_trace
, bt
);
1516 if (old_bt
!= NULL
) {
1517 (void)xchg(&q
->blk_trace
, old_bt
);
1522 if (atomic_inc_return(&blk_probes_ref
) == 1)
1523 blk_register_tracepoints();
1532 * sysfs interface to enable and configure tracing
1535 static ssize_t
sysfs_blk_trace_attr_show(struct device
*dev
,
1536 struct device_attribute
*attr
,
1538 static ssize_t
sysfs_blk_trace_attr_store(struct device
*dev
,
1539 struct device_attribute
*attr
,
1540 const char *buf
, size_t count
);
1541 #define BLK_TRACE_DEVICE_ATTR(_name) \
1542 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1543 sysfs_blk_trace_attr_show, \
1544 sysfs_blk_trace_attr_store)
1546 static BLK_TRACE_DEVICE_ATTR(enable
);
1547 static BLK_TRACE_DEVICE_ATTR(act_mask
);
1548 static BLK_TRACE_DEVICE_ATTR(pid
);
1549 static BLK_TRACE_DEVICE_ATTR(start_lba
);
1550 static BLK_TRACE_DEVICE_ATTR(end_lba
);
1552 static struct attribute
*blk_trace_attrs
[] = {
1553 &dev_attr_enable
.attr
,
1554 &dev_attr_act_mask
.attr
,
1556 &dev_attr_start_lba
.attr
,
1557 &dev_attr_end_lba
.attr
,
1561 struct attribute_group blk_trace_attr_group
= {
1563 .attrs
= blk_trace_attrs
,
1566 static const struct {
1570 { BLK_TC_READ
, "read" },
1571 { BLK_TC_WRITE
, "write" },
1572 { BLK_TC_BARRIER
, "barrier" },
1573 { BLK_TC_SYNC
, "sync" },
1574 { BLK_TC_QUEUE
, "queue" },
1575 { BLK_TC_REQUEUE
, "requeue" },
1576 { BLK_TC_ISSUE
, "issue" },
1577 { BLK_TC_COMPLETE
, "complete" },
1578 { BLK_TC_FS
, "fs" },
1579 { BLK_TC_PC
, "pc" },
1580 { BLK_TC_AHEAD
, "ahead" },
1581 { BLK_TC_META
, "meta" },
1582 { BLK_TC_DISCARD
, "discard" },
1583 { BLK_TC_DRV_DATA
, "drv_data" },
1586 static int blk_trace_str2mask(const char *str
)
1590 char *buf
, *s
, *token
;
1592 buf
= kstrdup(str
, GFP_KERNEL
);
1598 token
= strsep(&s
, ",");
1605 for (i
= 0; i
< ARRAY_SIZE(mask_maps
); i
++) {
1606 if (strcasecmp(token
, mask_maps
[i
].str
) == 0) {
1607 mask
|= mask_maps
[i
].mask
;
1611 if (i
== ARRAY_SIZE(mask_maps
)) {
1621 static ssize_t
blk_trace_mask2str(char *buf
, int mask
)
1626 for (i
= 0; i
< ARRAY_SIZE(mask_maps
); i
++) {
1627 if (mask
& mask_maps
[i
].mask
) {
1628 p
+= sprintf(p
, "%s%s",
1629 (p
== buf
) ? "" : ",", mask_maps
[i
].str
);
1637 static struct request_queue
*blk_trace_get_queue(struct block_device
*bdev
)
1639 if (bdev
->bd_disk
== NULL
)
1642 return bdev_get_queue(bdev
);
1645 static ssize_t
sysfs_blk_trace_attr_show(struct device
*dev
,
1646 struct device_attribute
*attr
,
1649 struct hd_struct
*p
= dev_to_part(dev
);
1650 struct request_queue
*q
;
1651 struct block_device
*bdev
;
1652 ssize_t ret
= -ENXIO
;
1654 bdev
= bdget(part_devt(p
));
1658 q
= blk_trace_get_queue(bdev
);
1662 mutex_lock(&bdev
->bd_mutex
);
1664 if (attr
== &dev_attr_enable
) {
1665 ret
= sprintf(buf
, "%u\n", !!q
->blk_trace
);
1666 goto out_unlock_bdev
;
1669 if (q
->blk_trace
== NULL
)
1670 ret
= sprintf(buf
, "disabled\n");
1671 else if (attr
== &dev_attr_act_mask
)
1672 ret
= blk_trace_mask2str(buf
, q
->blk_trace
->act_mask
);
1673 else if (attr
== &dev_attr_pid
)
1674 ret
= sprintf(buf
, "%u\n", q
->blk_trace
->pid
);
1675 else if (attr
== &dev_attr_start_lba
)
1676 ret
= sprintf(buf
, "%llu\n", q
->blk_trace
->start_lba
);
1677 else if (attr
== &dev_attr_end_lba
)
1678 ret
= sprintf(buf
, "%llu\n", q
->blk_trace
->end_lba
);
1681 mutex_unlock(&bdev
->bd_mutex
);
1688 static ssize_t
sysfs_blk_trace_attr_store(struct device
*dev
,
1689 struct device_attribute
*attr
,
1690 const char *buf
, size_t count
)
1692 struct block_device
*bdev
;
1693 struct request_queue
*q
;
1694 struct hd_struct
*p
;
1696 ssize_t ret
= -EINVAL
;
1701 if (attr
== &dev_attr_act_mask
) {
1702 if (sscanf(buf
, "%llx", &value
) != 1) {
1703 /* Assume it is a list of trace category names */
1704 ret
= blk_trace_str2mask(buf
);
1709 } else if (sscanf(buf
, "%llu", &value
) != 1)
1714 p
= dev_to_part(dev
);
1715 bdev
= bdget(part_devt(p
));
1719 q
= blk_trace_get_queue(bdev
);
1723 mutex_lock(&bdev
->bd_mutex
);
1725 if (attr
== &dev_attr_enable
) {
1727 ret
= blk_trace_setup_queue(q
, bdev
);
1729 ret
= blk_trace_remove_queue(q
);
1730 goto out_unlock_bdev
;
1734 if (q
->blk_trace
== NULL
)
1735 ret
= blk_trace_setup_queue(q
, bdev
);
1738 if (attr
== &dev_attr_act_mask
)
1739 q
->blk_trace
->act_mask
= value
;
1740 else if (attr
== &dev_attr_pid
)
1741 q
->blk_trace
->pid
= value
;
1742 else if (attr
== &dev_attr_start_lba
)
1743 q
->blk_trace
->start_lba
= value
;
1744 else if (attr
== &dev_attr_end_lba
)
1745 q
->blk_trace
->end_lba
= value
;
1749 mutex_unlock(&bdev
->bd_mutex
);
1753 return ret
? ret
: count
;
1756 int blk_trace_init_sysfs(struct device
*dev
)
1758 return sysfs_create_group(&dev
->kobj
, &blk_trace_attr_group
);
1761 void blk_trace_remove_sysfs(struct device
*dev
)
1763 sysfs_remove_group(&dev
->kobj
, &blk_trace_attr_group
);
1766 #endif /* CONFIG_BLK_DEV_IO_TRACE */
1768 #ifdef CONFIG_EVENT_TRACING
1770 void blk_dump_cmd(char *buf
, struct request
*rq
)
1773 int len
= rq
->cmd_len
;
1774 unsigned char *cmd
= rq
->cmd
;
1776 if (rq
->cmd_type
!= REQ_TYPE_BLOCK_PC
) {
1781 for (end
= len
- 1; end
>= 0; end
--)
1786 for (i
= 0; i
< len
; i
++) {
1787 buf
+= sprintf(buf
, "%s%02x", i
== 0 ? "" : " ", cmd
[i
]);
1788 if (i
== end
&& end
!= len
- 1) {
1789 sprintf(buf
, " ..");
1795 void blk_fill_rwbs(char *rwbs
, u32 rw
, int bytes
)
1801 else if (rw
& REQ_DISCARD
)
1808 if (rw
& REQ_RAHEAD
)
1810 if (rw
& REQ_HARDBARRIER
)
1816 if (rw
& REQ_SECURE
)
1822 void blk_fill_rwbs_rq(char *rwbs
, struct request
*rq
)
1824 int rw
= rq
->cmd_flags
& 0x03;
1827 if (rq
->cmd_flags
& REQ_DISCARD
)
1830 if (rq
->cmd_flags
& REQ_SECURE
)
1833 bytes
= blk_rq_bytes(rq
);
1835 blk_fill_rwbs(rwbs
, rw
, bytes
);
1838 #endif /* CONFIG_EVENT_TRACING */