1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/kernel.h>
10 #include <linux/blkdev.h>
11 #include <linux/blktrace_api.h>
12 #include <linux/percpu.h>
13 #include <linux/init.h>
14 #include <linux/mutex.h>
15 #include <linux/slab.h>
16 #include <linux/debugfs.h>
17 #include <linux/export.h>
18 #include <linux/time.h>
19 #include <linux/uaccess.h>
20 #include <linux/list.h>
21 #include <linux/blk-cgroup.h>
23 #include "../../block/blk.h"
25 #include <trace/events/block.h>
27 #include "trace_output.h"
29 #ifdef CONFIG_BLK_DEV_IO_TRACE
31 static unsigned int blktrace_seq __read_mostly
= 1;
33 static struct trace_array
*blk_tr
;
34 static bool blk_tracer_enabled __read_mostly
;
36 static LIST_HEAD(running_trace_list
);
37 static __cacheline_aligned_in_smp
DEFINE_SPINLOCK(running_trace_lock
);
39 /* Select an alternative, minimalistic output than the original one */
40 #define TRACE_BLK_OPT_CLASSIC 0x1
41 #define TRACE_BLK_OPT_CGROUP 0x2
42 #define TRACE_BLK_OPT_CGNAME 0x4
44 static struct tracer_opt blk_tracer_opts
[] = {
45 /* Default disable the minimalistic output */
46 { TRACER_OPT(blk_classic
, TRACE_BLK_OPT_CLASSIC
) },
47 #ifdef CONFIG_BLK_CGROUP
48 { TRACER_OPT(blk_cgroup
, TRACE_BLK_OPT_CGROUP
) },
49 { TRACER_OPT(blk_cgname
, TRACE_BLK_OPT_CGNAME
) },
54 static struct tracer_flags blk_tracer_flags
= {
56 .opts
= blk_tracer_opts
,
59 /* Global reference count of probes */
60 static DEFINE_MUTEX(blk_probe_mutex
);
61 static int blk_probes_ref
;
63 static void blk_register_tracepoints(void);
64 static void blk_unregister_tracepoints(void);
67 * Send out a notify message.
69 static void trace_note(struct blk_trace
*bt
, pid_t pid
, int action
,
70 const void *data
, size_t len
, u64 cgid
)
72 struct blk_io_trace
*t
;
73 struct ring_buffer_event
*event
= NULL
;
74 struct trace_buffer
*buffer
= NULL
;
75 unsigned int trace_ctx
= 0;
76 int cpu
= smp_processor_id();
77 bool blk_tracer
= blk_tracer_enabled
;
78 ssize_t cgid_len
= cgid
? sizeof(cgid
) : 0;
81 buffer
= blk_tr
->array_buffer
.buffer
;
82 trace_ctx
= tracing_gen_ctx_flags(0);
83 event
= trace_buffer_lock_reserve(buffer
, TRACE_BLK
,
84 sizeof(*t
) + len
+ cgid_len
,
88 t
= ring_buffer_event_data(event
);
95 t
= relay_reserve(bt
->rchan
, sizeof(*t
) + len
+ cgid_len
);
97 t
->magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
;
98 t
->time
= ktime_to_ns(ktime_get());
101 t
->action
= action
| (cgid
? __BLK_TN_CGROUP
: 0);
104 t
->pdu_len
= len
+ cgid_len
;
106 memcpy((void *)t
+ sizeof(*t
), &cgid
, cgid_len
);
107 memcpy((void *) t
+ sizeof(*t
) + cgid_len
, data
, len
);
110 trace_buffer_unlock_commit(blk_tr
, buffer
, event
, trace_ctx
);
115 * Send out a notify for this process, if we haven't done so since a trace
118 static void trace_note_tsk(struct task_struct
*tsk
)
121 struct blk_trace
*bt
;
123 tsk
->btrace_seq
= blktrace_seq
;
124 spin_lock_irqsave(&running_trace_lock
, flags
);
125 list_for_each_entry(bt
, &running_trace_list
, running_list
) {
126 trace_note(bt
, tsk
->pid
, BLK_TN_PROCESS
, tsk
->comm
,
127 sizeof(tsk
->comm
), 0);
129 spin_unlock_irqrestore(&running_trace_lock
, flags
);
132 static void trace_note_time(struct blk_trace
*bt
)
134 struct timespec64 now
;
138 /* need to check user space to see if this breaks in y2038 or y2106 */
139 ktime_get_real_ts64(&now
);
140 words
[0] = (u32
)now
.tv_sec
;
141 words
[1] = now
.tv_nsec
;
143 local_irq_save(flags
);
144 trace_note(bt
, 0, BLK_TN_TIMESTAMP
, words
, sizeof(words
), 0);
145 local_irq_restore(flags
);
148 void __trace_note_message(struct blk_trace
*bt
, struct blkcg
*blkcg
,
149 const char *fmt
, ...)
156 if (unlikely(bt
->trace_state
!= Blktrace_running
&&
157 !blk_tracer_enabled
))
161 * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
162 * message to the trace.
164 if (!(bt
->act_mask
& BLK_TC_NOTIFY
))
167 local_irq_save(flags
);
168 buf
= this_cpu_ptr(bt
->msg_data
);
170 n
= vscnprintf(buf
, BLK_TN_MAX_MSG
, fmt
, args
);
173 if (!(blk_tracer_flags
.val
& TRACE_BLK_OPT_CGROUP
))
175 #ifdef CONFIG_BLK_CGROUP
176 trace_note(bt
, current
->pid
, BLK_TN_MESSAGE
, buf
, n
,
177 blkcg
? cgroup_id(blkcg
->css
.cgroup
) : 1);
179 trace_note(bt
, current
->pid
, BLK_TN_MESSAGE
, buf
, n
, 0);
181 local_irq_restore(flags
);
183 EXPORT_SYMBOL_GPL(__trace_note_message
);
185 static int act_log_check(struct blk_trace
*bt
, u32 what
, sector_t sector
,
188 if (((bt
->act_mask
<< BLK_TC_SHIFT
) & what
) == 0)
190 if (sector
&& (sector
< bt
->start_lba
|| sector
> bt
->end_lba
))
192 if (bt
->pid
&& pid
!= bt
->pid
)
199 * Data direction bit lookup
201 static const u32 ddir_act
[2] = { BLK_TC_ACT(BLK_TC_READ
),
202 BLK_TC_ACT(BLK_TC_WRITE
) };
204 #define BLK_TC_RAHEAD BLK_TC_AHEAD
205 #define BLK_TC_PREFLUSH BLK_TC_FLUSH
207 /* The ilog2() calls fall out because they're constant */
208 #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
209 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
212 * The worker for the various blk_add_trace*() types. Fills out a
213 * blk_io_trace structure and places it in a per-cpu subbuffer.
215 static void __blk_add_trace(struct blk_trace
*bt
, sector_t sector
, int bytes
,
216 int op
, int op_flags
, u32 what
, int error
, int pdu_len
,
217 void *pdu_data
, u64 cgid
)
219 struct task_struct
*tsk
= current
;
220 struct ring_buffer_event
*event
= NULL
;
221 struct trace_buffer
*buffer
= NULL
;
222 struct blk_io_trace
*t
;
223 unsigned long flags
= 0;
224 unsigned long *sequence
;
225 unsigned int trace_ctx
= 0;
228 bool blk_tracer
= blk_tracer_enabled
;
229 ssize_t cgid_len
= cgid
? sizeof(cgid
) : 0;
231 if (unlikely(bt
->trace_state
!= Blktrace_running
&& !blk_tracer
))
234 what
|= ddir_act
[op_is_write(op
) ? WRITE
: READ
];
235 what
|= MASK_TC_BIT(op_flags
, SYNC
);
236 what
|= MASK_TC_BIT(op_flags
, RAHEAD
);
237 what
|= MASK_TC_BIT(op_flags
, META
);
238 what
|= MASK_TC_BIT(op_flags
, PREFLUSH
);
239 what
|= MASK_TC_BIT(op_flags
, FUA
);
240 if (op
== REQ_OP_DISCARD
|| op
== REQ_OP_SECURE_ERASE
)
241 what
|= BLK_TC_ACT(BLK_TC_DISCARD
);
242 if (op
== REQ_OP_FLUSH
)
243 what
|= BLK_TC_ACT(BLK_TC_FLUSH
);
245 what
|= __BLK_TA_CGROUP
;
248 if (act_log_check(bt
, what
, sector
, pid
))
250 cpu
= raw_smp_processor_id();
253 tracing_record_cmdline(current
);
255 buffer
= blk_tr
->array_buffer
.buffer
;
256 trace_ctx
= tracing_gen_ctx_flags(0);
257 event
= trace_buffer_lock_reserve(buffer
, TRACE_BLK
,
258 sizeof(*t
) + pdu_len
+ cgid_len
,
262 t
= ring_buffer_event_data(event
);
266 if (unlikely(tsk
->btrace_seq
!= blktrace_seq
))
270 * A word about the locking here - we disable interrupts to reserve
271 * some space in the relay per-cpu buffer, to prevent an irq
272 * from coming in and stepping on our toes.
274 local_irq_save(flags
);
275 t
= relay_reserve(bt
->rchan
, sizeof(*t
) + pdu_len
+ cgid_len
);
277 sequence
= per_cpu_ptr(bt
->sequence
, cpu
);
279 t
->magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
;
280 t
->sequence
= ++(*sequence
);
281 t
->time
= ktime_to_ns(ktime_get());
284 * These two are not needed in ftrace as they are in the
285 * generic trace_entry, filled by tracing_generic_entry_update,
286 * but for the trace_event->bin() synthesizer benefit we do it
297 t
->pdu_len
= pdu_len
+ cgid_len
;
300 memcpy((void *)t
+ sizeof(*t
), &cgid
, cgid_len
);
302 memcpy((void *)t
+ sizeof(*t
) + cgid_len
, pdu_data
, pdu_len
);
305 trace_buffer_unlock_commit(blk_tr
, buffer
, event
, trace_ctx
);
310 local_irq_restore(flags
);
313 static void blk_trace_free(struct blk_trace
*bt
)
315 debugfs_remove(bt
->msg_file
);
316 debugfs_remove(bt
->dropped_file
);
317 relay_close(bt
->rchan
);
318 debugfs_remove(bt
->dir
);
319 free_percpu(bt
->sequence
);
320 free_percpu(bt
->msg_data
);
324 static void get_probe_ref(void)
326 mutex_lock(&blk_probe_mutex
);
327 if (++blk_probes_ref
== 1)
328 blk_register_tracepoints();
329 mutex_unlock(&blk_probe_mutex
);
332 static void put_probe_ref(void)
334 mutex_lock(&blk_probe_mutex
);
335 if (!--blk_probes_ref
)
336 blk_unregister_tracepoints();
337 mutex_unlock(&blk_probe_mutex
);
340 static void blk_trace_cleanup(struct blk_trace
*bt
)
347 static int __blk_trace_remove(struct request_queue
*q
)
349 struct blk_trace
*bt
;
351 bt
= rcu_replace_pointer(q
->blk_trace
, NULL
,
352 lockdep_is_held(&q
->debugfs_mutex
));
356 if (bt
->trace_state
!= Blktrace_running
)
357 blk_trace_cleanup(bt
);
362 int blk_trace_remove(struct request_queue
*q
)
366 mutex_lock(&q
->debugfs_mutex
);
367 ret
= __blk_trace_remove(q
);
368 mutex_unlock(&q
->debugfs_mutex
);
372 EXPORT_SYMBOL_GPL(blk_trace_remove
);
374 static ssize_t
blk_dropped_read(struct file
*filp
, char __user
*buffer
,
375 size_t count
, loff_t
*ppos
)
377 struct blk_trace
*bt
= filp
->private_data
;
380 snprintf(buf
, sizeof(buf
), "%u\n", atomic_read(&bt
->dropped
));
382 return simple_read_from_buffer(buffer
, count
, ppos
, buf
, strlen(buf
));
385 static const struct file_operations blk_dropped_fops
= {
386 .owner
= THIS_MODULE
,
388 .read
= blk_dropped_read
,
389 .llseek
= default_llseek
,
392 static ssize_t
blk_msg_write(struct file
*filp
, const char __user
*buffer
,
393 size_t count
, loff_t
*ppos
)
396 struct blk_trace
*bt
;
398 if (count
>= BLK_TN_MAX_MSG
)
401 msg
= memdup_user_nul(buffer
, count
);
405 bt
= filp
->private_data
;
406 __trace_note_message(bt
, NULL
, "%s", msg
);
412 static const struct file_operations blk_msg_fops
= {
413 .owner
= THIS_MODULE
,
415 .write
= blk_msg_write
,
416 .llseek
= noop_llseek
,
420 * Keep track of how many times we encountered a full subbuffer, to aid
421 * the user space app in telling how many lost events there were.
423 static int blk_subbuf_start_callback(struct rchan_buf
*buf
, void *subbuf
,
424 void *prev_subbuf
, size_t prev_padding
)
426 struct blk_trace
*bt
;
428 if (!relay_buf_full(buf
))
431 bt
= buf
->chan
->private_data
;
432 atomic_inc(&bt
->dropped
);
436 static int blk_remove_buf_file_callback(struct dentry
*dentry
)
438 debugfs_remove(dentry
);
443 static struct dentry
*blk_create_buf_file_callback(const char *filename
,
444 struct dentry
*parent
,
446 struct rchan_buf
*buf
,
449 return debugfs_create_file(filename
, mode
, parent
, buf
,
450 &relay_file_operations
);
453 static const struct rchan_callbacks blk_relay_callbacks
= {
454 .subbuf_start
= blk_subbuf_start_callback
,
455 .create_buf_file
= blk_create_buf_file_callback
,
456 .remove_buf_file
= blk_remove_buf_file_callback
,
459 static void blk_trace_setup_lba(struct blk_trace
*bt
,
460 struct block_device
*bdev
)
463 bt
->start_lba
= bdev
->bd_start_sect
;
464 bt
->end_lba
= bdev
->bd_start_sect
+ bdev_nr_sectors(bdev
);
472 * Setup everything required to start tracing
474 static int do_blk_trace_setup(struct request_queue
*q
, char *name
, dev_t dev
,
475 struct block_device
*bdev
,
476 struct blk_user_trace_setup
*buts
)
478 struct blk_trace
*bt
= NULL
;
479 struct dentry
*dir
= NULL
;
482 lockdep_assert_held(&q
->debugfs_mutex
);
484 if (!buts
->buf_size
|| !buts
->buf_nr
)
487 strncpy(buts
->name
, name
, BLKTRACE_BDEV_SIZE
);
488 buts
->name
[BLKTRACE_BDEV_SIZE
- 1] = '\0';
491 * some device names have larger paths - convert the slashes
492 * to underscores for this to work as expected
494 strreplace(buts
->name
, '/', '_');
497 * bdev can be NULL, as with scsi-generic, this is a helpful as
500 if (rcu_dereference_protected(q
->blk_trace
,
501 lockdep_is_held(&q
->debugfs_mutex
))) {
502 pr_warn("Concurrent blktraces are not allowed on %s\n",
507 bt
= kzalloc(sizeof(*bt
), GFP_KERNEL
);
512 bt
->sequence
= alloc_percpu(unsigned long);
516 bt
->msg_data
= __alloc_percpu(BLK_TN_MAX_MSG
, __alignof__(char));
521 * When tracing the whole disk reuse the existing debugfs directory
522 * created by the block layer on init. For partitions block devices,
523 * and scsi-generic block devices we create a temporary new debugfs
524 * directory that will be removed once the trace ends.
526 if (bdev
&& !bdev_is_partition(bdev
))
527 dir
= q
->debugfs_dir
;
529 bt
->dir
= dir
= debugfs_create_dir(buts
->name
, blk_debugfs_root
);
532 * As blktrace relies on debugfs for its interface the debugfs directory
533 * is required, contrary to the usual mantra of not checking for debugfs
534 * files or directories.
536 if (IS_ERR_OR_NULL(dir
)) {
537 pr_warn("debugfs_dir not present for %s so skipping\n",
544 atomic_set(&bt
->dropped
, 0);
545 INIT_LIST_HEAD(&bt
->running_list
);
548 bt
->dropped_file
= debugfs_create_file("dropped", 0444, dir
, bt
,
551 bt
->msg_file
= debugfs_create_file("msg", 0222, dir
, bt
, &blk_msg_fops
);
553 bt
->rchan
= relay_open("trace", dir
, buts
->buf_size
,
554 buts
->buf_nr
, &blk_relay_callbacks
, bt
);
558 bt
->act_mask
= buts
->act_mask
;
560 bt
->act_mask
= (u16
) -1;
562 blk_trace_setup_lba(bt
, bdev
);
564 /* overwrite with user settings */
566 bt
->start_lba
= buts
->start_lba
;
568 bt
->end_lba
= buts
->end_lba
;
571 bt
->trace_state
= Blktrace_setup
;
573 rcu_assign_pointer(q
->blk_trace
, bt
);
583 static int __blk_trace_setup(struct request_queue
*q
, char *name
, dev_t dev
,
584 struct block_device
*bdev
, char __user
*arg
)
586 struct blk_user_trace_setup buts
;
589 ret
= copy_from_user(&buts
, arg
, sizeof(buts
));
593 ret
= do_blk_trace_setup(q
, name
, dev
, bdev
, &buts
);
597 if (copy_to_user(arg
, &buts
, sizeof(buts
))) {
598 __blk_trace_remove(q
);
604 int blk_trace_setup(struct request_queue
*q
, char *name
, dev_t dev
,
605 struct block_device
*bdev
,
610 mutex_lock(&q
->debugfs_mutex
);
611 ret
= __blk_trace_setup(q
, name
, dev
, bdev
, arg
);
612 mutex_unlock(&q
->debugfs_mutex
);
616 EXPORT_SYMBOL_GPL(blk_trace_setup
);
618 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
619 static int compat_blk_trace_setup(struct request_queue
*q
, char *name
,
620 dev_t dev
, struct block_device
*bdev
,
623 struct blk_user_trace_setup buts
;
624 struct compat_blk_user_trace_setup cbuts
;
627 if (copy_from_user(&cbuts
, arg
, sizeof(cbuts
)))
630 buts
= (struct blk_user_trace_setup
) {
631 .act_mask
= cbuts
.act_mask
,
632 .buf_size
= cbuts
.buf_size
,
633 .buf_nr
= cbuts
.buf_nr
,
634 .start_lba
= cbuts
.start_lba
,
635 .end_lba
= cbuts
.end_lba
,
639 ret
= do_blk_trace_setup(q
, name
, dev
, bdev
, &buts
);
643 if (copy_to_user(arg
, &buts
.name
, ARRAY_SIZE(buts
.name
))) {
644 __blk_trace_remove(q
);
652 static int __blk_trace_startstop(struct request_queue
*q
, int start
)
655 struct blk_trace
*bt
;
657 bt
= rcu_dereference_protected(q
->blk_trace
,
658 lockdep_is_held(&q
->debugfs_mutex
));
663 * For starting a trace, we can transition from a setup or stopped
664 * trace. For stopping a trace, the state must be running
668 if (bt
->trace_state
== Blktrace_setup
||
669 bt
->trace_state
== Blktrace_stopped
) {
672 bt
->trace_state
= Blktrace_running
;
673 spin_lock_irq(&running_trace_lock
);
674 list_add(&bt
->running_list
, &running_trace_list
);
675 spin_unlock_irq(&running_trace_lock
);
681 if (bt
->trace_state
== Blktrace_running
) {
682 bt
->trace_state
= Blktrace_stopped
;
683 spin_lock_irq(&running_trace_lock
);
684 list_del_init(&bt
->running_list
);
685 spin_unlock_irq(&running_trace_lock
);
686 relay_flush(bt
->rchan
);
694 int blk_trace_startstop(struct request_queue
*q
, int start
)
698 mutex_lock(&q
->debugfs_mutex
);
699 ret
= __blk_trace_startstop(q
, start
);
700 mutex_unlock(&q
->debugfs_mutex
);
704 EXPORT_SYMBOL_GPL(blk_trace_startstop
);
707 * When reading or writing the blktrace sysfs files, the references to the
708 * opened sysfs or device files should prevent the underlying block device
709 * from being removed. So no further delete protection is really needed.
713 * blk_trace_ioctl: - handle the ioctls associated with tracing
714 * @bdev: the block device
715 * @cmd: the ioctl cmd
716 * @arg: the argument data, if any
719 int blk_trace_ioctl(struct block_device
*bdev
, unsigned cmd
, char __user
*arg
)
721 struct request_queue
*q
;
723 char b
[BDEVNAME_SIZE
];
725 q
= bdev_get_queue(bdev
);
729 mutex_lock(&q
->debugfs_mutex
);
734 ret
= __blk_trace_setup(q
, b
, bdev
->bd_dev
, bdev
, arg
);
736 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
737 case BLKTRACESETUP32
:
739 ret
= compat_blk_trace_setup(q
, b
, bdev
->bd_dev
, bdev
, arg
);
746 ret
= __blk_trace_startstop(q
, start
);
748 case BLKTRACETEARDOWN
:
749 ret
= __blk_trace_remove(q
);
756 mutex_unlock(&q
->debugfs_mutex
);
761 * blk_trace_shutdown: - stop and cleanup trace structures
762 * @q: the request queue associated with the device
765 void blk_trace_shutdown(struct request_queue
*q
)
767 mutex_lock(&q
->debugfs_mutex
);
768 if (rcu_dereference_protected(q
->blk_trace
,
769 lockdep_is_held(&q
->debugfs_mutex
))) {
770 __blk_trace_startstop(q
, 0);
771 __blk_trace_remove(q
);
774 mutex_unlock(&q
->debugfs_mutex
);
777 #ifdef CONFIG_BLK_CGROUP
778 static u64
blk_trace_bio_get_cgid(struct request_queue
*q
, struct bio
*bio
)
780 struct blk_trace
*bt
;
782 /* We don't use the 'bt' value here except as an optimization... */
783 bt
= rcu_dereference_protected(q
->blk_trace
, 1);
784 if (!bt
|| !(blk_tracer_flags
.val
& TRACE_BLK_OPT_CGROUP
))
789 return cgroup_id(bio_blkcg(bio
)->css
.cgroup
);
792 static u64
blk_trace_bio_get_cgid(struct request_queue
*q
, struct bio
*bio
)
799 blk_trace_request_get_cgid(struct request
*rq
)
803 /* Use the first bio */
804 return blk_trace_bio_get_cgid(rq
->q
, rq
->bio
);
812 * blk_add_trace_rq - Add a trace for a request oriented action
813 * @rq: the source request
814 * @error: return status to log
815 * @nr_bytes: number of completed bytes
817 * @cgid: the cgroup info
820 * Records an action against a request. Will log the bio offset + size.
823 static void blk_add_trace_rq(struct request
*rq
, int error
,
824 unsigned int nr_bytes
, u32 what
, u64 cgid
)
826 struct blk_trace
*bt
;
829 bt
= rcu_dereference(rq
->q
->blk_trace
);
835 if (blk_rq_is_passthrough(rq
))
836 what
|= BLK_TC_ACT(BLK_TC_PC
);
838 what
|= BLK_TC_ACT(BLK_TC_FS
);
840 __blk_add_trace(bt
, blk_rq_trace_sector(rq
), nr_bytes
, req_op(rq
),
841 rq
->cmd_flags
, what
, error
, 0, NULL
, cgid
);
845 static void blk_add_trace_rq_insert(void *ignore
, struct request
*rq
)
847 blk_add_trace_rq(rq
, 0, blk_rq_bytes(rq
), BLK_TA_INSERT
,
848 blk_trace_request_get_cgid(rq
));
851 static void blk_add_trace_rq_issue(void *ignore
, struct request
*rq
)
853 blk_add_trace_rq(rq
, 0, blk_rq_bytes(rq
), BLK_TA_ISSUE
,
854 blk_trace_request_get_cgid(rq
));
857 static void blk_add_trace_rq_merge(void *ignore
, struct request
*rq
)
859 blk_add_trace_rq(rq
, 0, blk_rq_bytes(rq
), BLK_TA_BACKMERGE
,
860 blk_trace_request_get_cgid(rq
));
863 static void blk_add_trace_rq_requeue(void *ignore
, struct request
*rq
)
865 blk_add_trace_rq(rq
, 0, blk_rq_bytes(rq
), BLK_TA_REQUEUE
,
866 blk_trace_request_get_cgid(rq
));
869 static void blk_add_trace_rq_complete(void *ignore
, struct request
*rq
,
870 int error
, unsigned int nr_bytes
)
872 blk_add_trace_rq(rq
, error
, nr_bytes
, BLK_TA_COMPLETE
,
873 blk_trace_request_get_cgid(rq
));
877 * blk_add_trace_bio - Add a trace for a bio oriented action
878 * @q: queue the io is for
879 * @bio: the source bio
881 * @error: error, if any
884 * Records an action against a bio. Will log the bio offset + size.
887 static void blk_add_trace_bio(struct request_queue
*q
, struct bio
*bio
,
890 struct blk_trace
*bt
;
893 bt
= rcu_dereference(q
->blk_trace
);
899 __blk_add_trace(bt
, bio
->bi_iter
.bi_sector
, bio
->bi_iter
.bi_size
,
900 bio_op(bio
), bio
->bi_opf
, what
, error
, 0, NULL
,
901 blk_trace_bio_get_cgid(q
, bio
));
905 static void blk_add_trace_bio_bounce(void *ignore
, struct bio
*bio
)
907 blk_add_trace_bio(bio
->bi_bdev
->bd_disk
->queue
, bio
, BLK_TA_BOUNCE
, 0);
910 static void blk_add_trace_bio_complete(void *ignore
,
911 struct request_queue
*q
, struct bio
*bio
)
913 blk_add_trace_bio(q
, bio
, BLK_TA_COMPLETE
,
914 blk_status_to_errno(bio
->bi_status
));
917 static void blk_add_trace_bio_backmerge(void *ignore
, struct bio
*bio
)
919 blk_add_trace_bio(bio
->bi_bdev
->bd_disk
->queue
, bio
, BLK_TA_BACKMERGE
,
923 static void blk_add_trace_bio_frontmerge(void *ignore
, struct bio
*bio
)
925 blk_add_trace_bio(bio
->bi_bdev
->bd_disk
->queue
, bio
, BLK_TA_FRONTMERGE
,
929 static void blk_add_trace_bio_queue(void *ignore
, struct bio
*bio
)
931 blk_add_trace_bio(bio
->bi_bdev
->bd_disk
->queue
, bio
, BLK_TA_QUEUE
, 0);
934 static void blk_add_trace_getrq(void *ignore
, struct bio
*bio
)
936 blk_add_trace_bio(bio
->bi_bdev
->bd_disk
->queue
, bio
, BLK_TA_GETRQ
, 0);
939 static void blk_add_trace_plug(void *ignore
, struct request_queue
*q
)
941 struct blk_trace
*bt
;
944 bt
= rcu_dereference(q
->blk_trace
);
946 __blk_add_trace(bt
, 0, 0, 0, 0, BLK_TA_PLUG
, 0, 0, NULL
, 0);
950 static void blk_add_trace_unplug(void *ignore
, struct request_queue
*q
,
951 unsigned int depth
, bool explicit)
953 struct blk_trace
*bt
;
956 bt
= rcu_dereference(q
->blk_trace
);
958 __be64 rpdu
= cpu_to_be64(depth
);
962 what
= BLK_TA_UNPLUG_IO
;
964 what
= BLK_TA_UNPLUG_TIMER
;
966 __blk_add_trace(bt
, 0, 0, 0, 0, what
, 0, sizeof(rpdu
), &rpdu
, 0);
971 static void blk_add_trace_split(void *ignore
, struct bio
*bio
, unsigned int pdu
)
973 struct request_queue
*q
= bio
->bi_bdev
->bd_disk
->queue
;
974 struct blk_trace
*bt
;
977 bt
= rcu_dereference(q
->blk_trace
);
979 __be64 rpdu
= cpu_to_be64(pdu
);
981 __blk_add_trace(bt
, bio
->bi_iter
.bi_sector
,
982 bio
->bi_iter
.bi_size
, bio_op(bio
), bio
->bi_opf
,
984 blk_status_to_errno(bio
->bi_status
),
986 blk_trace_bio_get_cgid(q
, bio
));
992 * blk_add_trace_bio_remap - Add a trace for a bio-remap operation
993 * @ignore: trace callback data parameter (not used)
994 * @bio: the source bio
995 * @dev: source device
996 * @from: source sector
998 * Called after a bio is remapped to a different device and/or sector.
1000 static void blk_add_trace_bio_remap(void *ignore
, struct bio
*bio
, dev_t dev
,
1003 struct request_queue
*q
= bio
->bi_bdev
->bd_disk
->queue
;
1004 struct blk_trace
*bt
;
1005 struct blk_io_trace_remap r
;
1008 bt
= rcu_dereference(q
->blk_trace
);
1014 r
.device_from
= cpu_to_be32(dev
);
1015 r
.device_to
= cpu_to_be32(bio_dev(bio
));
1016 r
.sector_from
= cpu_to_be64(from
);
1018 __blk_add_trace(bt
, bio
->bi_iter
.bi_sector
, bio
->bi_iter
.bi_size
,
1019 bio_op(bio
), bio
->bi_opf
, BLK_TA_REMAP
,
1020 blk_status_to_errno(bio
->bi_status
),
1021 sizeof(r
), &r
, blk_trace_bio_get_cgid(q
, bio
));
1026 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
1027 * @ignore: trace callback data parameter (not used)
1028 * @rq: the source request
1029 * @dev: target device
1030 * @from: source sector
1033 * Device mapper remaps request to other devices.
1034 * Add a trace for that action.
1037 static void blk_add_trace_rq_remap(void *ignore
, struct request
*rq
, dev_t dev
,
1040 struct blk_trace
*bt
;
1041 struct blk_io_trace_remap r
;
1044 bt
= rcu_dereference(rq
->q
->blk_trace
);
1050 r
.device_from
= cpu_to_be32(dev
);
1051 r
.device_to
= cpu_to_be32(disk_devt(rq
->rq_disk
));
1052 r
.sector_from
= cpu_to_be64(from
);
1054 __blk_add_trace(bt
, blk_rq_pos(rq
), blk_rq_bytes(rq
),
1055 rq_data_dir(rq
), 0, BLK_TA_REMAP
, 0,
1056 sizeof(r
), &r
, blk_trace_request_get_cgid(rq
));
1061 * blk_add_driver_data - Add binary message with driver-specific data
1063 * @data: driver-specific data
1064 * @len: length of driver-specific data
1067 * Some drivers might want to write driver-specific data per request.
1070 void blk_add_driver_data(struct request
*rq
, void *data
, size_t len
)
1072 struct blk_trace
*bt
;
1075 bt
= rcu_dereference(rq
->q
->blk_trace
);
1081 __blk_add_trace(bt
, blk_rq_trace_sector(rq
), blk_rq_bytes(rq
), 0, 0,
1082 BLK_TA_DRV_DATA
, 0, len
, data
,
1083 blk_trace_request_get_cgid(rq
));
1086 EXPORT_SYMBOL_GPL(blk_add_driver_data
);
1088 static void blk_register_tracepoints(void)
1092 ret
= register_trace_block_rq_insert(blk_add_trace_rq_insert
, NULL
);
1094 ret
= register_trace_block_rq_issue(blk_add_trace_rq_issue
, NULL
);
1096 ret
= register_trace_block_rq_merge(blk_add_trace_rq_merge
, NULL
);
1098 ret
= register_trace_block_rq_requeue(blk_add_trace_rq_requeue
, NULL
);
1100 ret
= register_trace_block_rq_complete(blk_add_trace_rq_complete
, NULL
);
1102 ret
= register_trace_block_bio_bounce(blk_add_trace_bio_bounce
, NULL
);
1104 ret
= register_trace_block_bio_complete(blk_add_trace_bio_complete
, NULL
);
1106 ret
= register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge
, NULL
);
1108 ret
= register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge
, NULL
);
1110 ret
= register_trace_block_bio_queue(blk_add_trace_bio_queue
, NULL
);
1112 ret
= register_trace_block_getrq(blk_add_trace_getrq
, NULL
);
1114 ret
= register_trace_block_plug(blk_add_trace_plug
, NULL
);
1116 ret
= register_trace_block_unplug(blk_add_trace_unplug
, NULL
);
1118 ret
= register_trace_block_split(blk_add_trace_split
, NULL
);
1120 ret
= register_trace_block_bio_remap(blk_add_trace_bio_remap
, NULL
);
1122 ret
= register_trace_block_rq_remap(blk_add_trace_rq_remap
, NULL
);
1126 static void blk_unregister_tracepoints(void)
1128 unregister_trace_block_rq_remap(blk_add_trace_rq_remap
, NULL
);
1129 unregister_trace_block_bio_remap(blk_add_trace_bio_remap
, NULL
);
1130 unregister_trace_block_split(blk_add_trace_split
, NULL
);
1131 unregister_trace_block_unplug(blk_add_trace_unplug
, NULL
);
1132 unregister_trace_block_plug(blk_add_trace_plug
, NULL
);
1133 unregister_trace_block_getrq(blk_add_trace_getrq
, NULL
);
1134 unregister_trace_block_bio_queue(blk_add_trace_bio_queue
, NULL
);
1135 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge
, NULL
);
1136 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge
, NULL
);
1137 unregister_trace_block_bio_complete(blk_add_trace_bio_complete
, NULL
);
1138 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce
, NULL
);
1139 unregister_trace_block_rq_complete(blk_add_trace_rq_complete
, NULL
);
1140 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue
, NULL
);
1141 unregister_trace_block_rq_merge(blk_add_trace_rq_merge
, NULL
);
1142 unregister_trace_block_rq_issue(blk_add_trace_rq_issue
, NULL
);
1143 unregister_trace_block_rq_insert(blk_add_trace_rq_insert
, NULL
);
1145 tracepoint_synchronize_unregister();
1149 * struct blk_io_tracer formatting routines
1152 static void fill_rwbs(char *rwbs
, const struct blk_io_trace
*t
)
1155 int tc
= t
->action
>> BLK_TC_SHIFT
;
1157 if ((t
->action
& ~__BLK_TN_CGROUP
) == BLK_TN_MESSAGE
) {
1162 if (tc
& BLK_TC_FLUSH
)
1165 if (tc
& BLK_TC_DISCARD
)
1167 else if (tc
& BLK_TC_WRITE
)
1174 if (tc
& BLK_TC_FUA
)
1176 if (tc
& BLK_TC_AHEAD
)
1178 if (tc
& BLK_TC_SYNC
)
1180 if (tc
& BLK_TC_META
)
1187 const struct blk_io_trace
*te_blk_io_trace(const struct trace_entry
*ent
)
1189 return (const struct blk_io_trace
*)ent
;
1192 static inline const void *pdu_start(const struct trace_entry
*ent
, bool has_cg
)
1194 return (void *)(te_blk_io_trace(ent
) + 1) + (has_cg
? sizeof(u64
) : 0);
1197 static inline u64
t_cgid(const struct trace_entry
*ent
)
1199 return *(u64
*)(te_blk_io_trace(ent
) + 1);
1202 static inline int pdu_real_len(const struct trace_entry
*ent
, bool has_cg
)
1204 return te_blk_io_trace(ent
)->pdu_len
- (has_cg
? sizeof(u64
) : 0);
1207 static inline u32
t_action(const struct trace_entry
*ent
)
1209 return te_blk_io_trace(ent
)->action
;
1212 static inline u32
t_bytes(const struct trace_entry
*ent
)
1214 return te_blk_io_trace(ent
)->bytes
;
1217 static inline u32
t_sec(const struct trace_entry
*ent
)
1219 return te_blk_io_trace(ent
)->bytes
>> 9;
1222 static inline unsigned long long t_sector(const struct trace_entry
*ent
)
1224 return te_blk_io_trace(ent
)->sector
;
1227 static inline __u16
t_error(const struct trace_entry
*ent
)
1229 return te_blk_io_trace(ent
)->error
;
1232 static __u64
get_pdu_int(const struct trace_entry
*ent
, bool has_cg
)
1234 const __be64
*val
= pdu_start(ent
, has_cg
);
1235 return be64_to_cpu(*val
);
1238 typedef void (blk_log_action_t
) (struct trace_iterator
*iter
, const char *act
,
1241 static void blk_log_action_classic(struct trace_iterator
*iter
, const char *act
,
1244 char rwbs
[RWBS_LEN
];
1245 unsigned long long ts
= iter
->ts
;
1246 unsigned long nsec_rem
= do_div(ts
, NSEC_PER_SEC
);
1247 unsigned secs
= (unsigned long)ts
;
1248 const struct blk_io_trace
*t
= te_blk_io_trace(iter
->ent
);
1252 trace_seq_printf(&iter
->seq
,
1253 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1254 MAJOR(t
->device
), MINOR(t
->device
), iter
->cpu
,
1255 secs
, nsec_rem
, iter
->ent
->pid
, act
, rwbs
);
1258 static void blk_log_action(struct trace_iterator
*iter
, const char *act
,
1261 char rwbs
[RWBS_LEN
];
1262 const struct blk_io_trace
*t
= te_blk_io_trace(iter
->ent
);
1266 u64 id
= t_cgid(iter
->ent
);
1268 if (blk_tracer_flags
.val
& TRACE_BLK_OPT_CGNAME
) {
1269 char blkcg_name_buf
[NAME_MAX
+ 1] = "<...>";
1271 cgroup_path_from_kernfs_id(id
, blkcg_name_buf
,
1272 sizeof(blkcg_name_buf
));
1273 trace_seq_printf(&iter
->seq
, "%3d,%-3d %s %2s %3s ",
1274 MAJOR(t
->device
), MINOR(t
->device
),
1275 blkcg_name_buf
, act
, rwbs
);
1278 * The cgid portion used to be "INO,GEN". Userland
1279 * builds a FILEID_INO32_GEN fid out of them and
1280 * opens the cgroup using open_by_handle_at(2).
1281 * While 32bit ino setups are still the same, 64bit
1282 * ones now use the 64bit ino as the whole ID and
1283 * no longer use generation.
1285 * Regardless of the content, always output
1286 * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can
1287 * be mapped back to @id on both 64 and 32bit ino
1288 * setups. See __kernfs_fh_to_dentry().
1290 trace_seq_printf(&iter
->seq
,
1291 "%3d,%-3d %llx,%-llx %2s %3s ",
1292 MAJOR(t
->device
), MINOR(t
->device
),
1293 id
& U32_MAX
, id
>> 32, act
, rwbs
);
1296 trace_seq_printf(&iter
->seq
, "%3d,%-3d %2s %3s ",
1297 MAJOR(t
->device
), MINOR(t
->device
), act
, rwbs
);
1300 static void blk_log_dump_pdu(struct trace_seq
*s
,
1301 const struct trace_entry
*ent
, bool has_cg
)
1303 const unsigned char *pdu_buf
;
1307 pdu_buf
= pdu_start(ent
, has_cg
);
1308 pdu_len
= pdu_real_len(ent
, has_cg
);
1313 /* find the last zero that needs to be printed */
1314 for (end
= pdu_len
- 1; end
>= 0; end
--)
1319 trace_seq_putc(s
, '(');
1321 for (i
= 0; i
< pdu_len
; i
++) {
1323 trace_seq_printf(s
, "%s%02x",
1324 i
== 0 ? "" : " ", pdu_buf
[i
]);
1327 * stop when the rest is just zeros and indicate so
1328 * with a ".." appended
1330 if (i
== end
&& end
!= pdu_len
- 1) {
1331 trace_seq_puts(s
, " ..) ");
1336 trace_seq_puts(s
, ") ");
1339 static void blk_log_generic(struct trace_seq
*s
, const struct trace_entry
*ent
, bool has_cg
)
1341 char cmd
[TASK_COMM_LEN
];
1343 trace_find_cmdline(ent
->pid
, cmd
);
1345 if (t_action(ent
) & BLK_TC_ACT(BLK_TC_PC
)) {
1346 trace_seq_printf(s
, "%u ", t_bytes(ent
));
1347 blk_log_dump_pdu(s
, ent
, has_cg
);
1348 trace_seq_printf(s
, "[%s]\n", cmd
);
1351 trace_seq_printf(s
, "%llu + %u [%s]\n",
1352 t_sector(ent
), t_sec(ent
), cmd
);
1354 trace_seq_printf(s
, "[%s]\n", cmd
);
1358 static void blk_log_with_error(struct trace_seq
*s
,
1359 const struct trace_entry
*ent
, bool has_cg
)
1361 if (t_action(ent
) & BLK_TC_ACT(BLK_TC_PC
)) {
1362 blk_log_dump_pdu(s
, ent
, has_cg
);
1363 trace_seq_printf(s
, "[%d]\n", t_error(ent
));
1366 trace_seq_printf(s
, "%llu + %u [%d]\n",
1368 t_sec(ent
), t_error(ent
));
1370 trace_seq_printf(s
, "%llu [%d]\n",
1371 t_sector(ent
), t_error(ent
));
1375 static void blk_log_remap(struct trace_seq
*s
, const struct trace_entry
*ent
, bool has_cg
)
1377 const struct blk_io_trace_remap
*__r
= pdu_start(ent
, has_cg
);
1379 trace_seq_printf(s
, "%llu + %u <- (%d,%d) %llu\n",
1380 t_sector(ent
), t_sec(ent
),
1381 MAJOR(be32_to_cpu(__r
->device_from
)),
1382 MINOR(be32_to_cpu(__r
->device_from
)),
1383 be64_to_cpu(__r
->sector_from
));
1386 static void blk_log_plug(struct trace_seq
*s
, const struct trace_entry
*ent
, bool has_cg
)
1388 char cmd
[TASK_COMM_LEN
];
1390 trace_find_cmdline(ent
->pid
, cmd
);
1392 trace_seq_printf(s
, "[%s]\n", cmd
);
1395 static void blk_log_unplug(struct trace_seq
*s
, const struct trace_entry
*ent
, bool has_cg
)
1397 char cmd
[TASK_COMM_LEN
];
1399 trace_find_cmdline(ent
->pid
, cmd
);
1401 trace_seq_printf(s
, "[%s] %llu\n", cmd
, get_pdu_int(ent
, has_cg
));
1404 static void blk_log_split(struct trace_seq
*s
, const struct trace_entry
*ent
, bool has_cg
)
1406 char cmd
[TASK_COMM_LEN
];
1408 trace_find_cmdline(ent
->pid
, cmd
);
1410 trace_seq_printf(s
, "%llu / %llu [%s]\n", t_sector(ent
),
1411 get_pdu_int(ent
, has_cg
), cmd
);
1414 static void blk_log_msg(struct trace_seq
*s
, const struct trace_entry
*ent
,
1418 trace_seq_putmem(s
, pdu_start(ent
, has_cg
),
1419 pdu_real_len(ent
, has_cg
));
1420 trace_seq_putc(s
, '\n');
1424 * struct tracer operations
1427 static void blk_tracer_print_header(struct seq_file
*m
)
1429 if (!(blk_tracer_flags
.val
& TRACE_BLK_OPT_CLASSIC
))
1431 seq_puts(m
, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1435 static void blk_tracer_start(struct trace_array
*tr
)
1437 blk_tracer_enabled
= true;
1440 static int blk_tracer_init(struct trace_array
*tr
)
1443 blk_tracer_start(tr
);
1447 static void blk_tracer_stop(struct trace_array
*tr
)
1449 blk_tracer_enabled
= false;
1452 static void blk_tracer_reset(struct trace_array
*tr
)
1454 blk_tracer_stop(tr
);
1457 static const struct {
1459 void (*print
)(struct trace_seq
*s
, const struct trace_entry
*ent
,
1462 [__BLK_TA_QUEUE
] = {{ "Q", "queue" }, blk_log_generic
},
1463 [__BLK_TA_BACKMERGE
] = {{ "M", "backmerge" }, blk_log_generic
},
1464 [__BLK_TA_FRONTMERGE
] = {{ "F", "frontmerge" }, blk_log_generic
},
1465 [__BLK_TA_GETRQ
] = {{ "G", "getrq" }, blk_log_generic
},
1466 [__BLK_TA_SLEEPRQ
] = {{ "S", "sleeprq" }, blk_log_generic
},
1467 [__BLK_TA_REQUEUE
] = {{ "R", "requeue" }, blk_log_with_error
},
1468 [__BLK_TA_ISSUE
] = {{ "D", "issue" }, blk_log_generic
},
1469 [__BLK_TA_COMPLETE
] = {{ "C", "complete" }, blk_log_with_error
},
1470 [__BLK_TA_PLUG
] = {{ "P", "plug" }, blk_log_plug
},
1471 [__BLK_TA_UNPLUG_IO
] = {{ "U", "unplug_io" }, blk_log_unplug
},
1472 [__BLK_TA_UNPLUG_TIMER
] = {{ "UT", "unplug_timer" }, blk_log_unplug
},
1473 [__BLK_TA_INSERT
] = {{ "I", "insert" }, blk_log_generic
},
1474 [__BLK_TA_SPLIT
] = {{ "X", "split" }, blk_log_split
},
1475 [__BLK_TA_BOUNCE
] = {{ "B", "bounce" }, blk_log_generic
},
1476 [__BLK_TA_REMAP
] = {{ "A", "remap" }, blk_log_remap
},
1479 static enum print_line_t
print_one_line(struct trace_iterator
*iter
,
1482 struct trace_array
*tr
= iter
->tr
;
1483 struct trace_seq
*s
= &iter
->seq
;
1484 const struct blk_io_trace
*t
;
1487 blk_log_action_t
*log_action
;
1490 t
= te_blk_io_trace(iter
->ent
);
1491 what
= (t
->action
& ((1 << BLK_TC_SHIFT
) - 1)) & ~__BLK_TA_CGROUP
;
1492 long_act
= !!(tr
->trace_flags
& TRACE_ITER_VERBOSE
);
1493 log_action
= classic
? &blk_log_action_classic
: &blk_log_action
;
1494 has_cg
= t
->action
& __BLK_TA_CGROUP
;
1496 if ((t
->action
& ~__BLK_TN_CGROUP
) == BLK_TN_MESSAGE
) {
1497 log_action(iter
, long_act
? "message" : "m", has_cg
);
1498 blk_log_msg(s
, iter
->ent
, has_cg
);
1499 return trace_handle_return(s
);
1502 if (unlikely(what
== 0 || what
>= ARRAY_SIZE(what2act
)))
1503 trace_seq_printf(s
, "Unknown action %x\n", what
);
1505 log_action(iter
, what2act
[what
].act
[long_act
], has_cg
);
1506 what2act
[what
].print(s
, iter
->ent
, has_cg
);
1509 return trace_handle_return(s
);
1512 static enum print_line_t
blk_trace_event_print(struct trace_iterator
*iter
,
1513 int flags
, struct trace_event
*event
)
1515 return print_one_line(iter
, false);
1518 static void blk_trace_synthesize_old_trace(struct trace_iterator
*iter
)
1520 struct trace_seq
*s
= &iter
->seq
;
1521 struct blk_io_trace
*t
= (struct blk_io_trace
*)iter
->ent
;
1522 const int offset
= offsetof(struct blk_io_trace
, sector
);
1523 struct blk_io_trace old
= {
1524 .magic
= BLK_IO_TRACE_MAGIC
| BLK_IO_TRACE_VERSION
,
1528 trace_seq_putmem(s
, &old
, offset
);
1529 trace_seq_putmem(s
, &t
->sector
,
1530 sizeof(old
) - offset
+ t
->pdu_len
);
1533 static enum print_line_t
1534 blk_trace_event_print_binary(struct trace_iterator
*iter
, int flags
,
1535 struct trace_event
*event
)
1537 blk_trace_synthesize_old_trace(iter
);
1539 return trace_handle_return(&iter
->seq
);
1542 static enum print_line_t
blk_tracer_print_line(struct trace_iterator
*iter
)
1544 if (!(blk_tracer_flags
.val
& TRACE_BLK_OPT_CLASSIC
))
1545 return TRACE_TYPE_UNHANDLED
;
1547 return print_one_line(iter
, true);
1551 blk_tracer_set_flag(struct trace_array
*tr
, u32 old_flags
, u32 bit
, int set
)
1553 /* don't output context-info for blk_classic output */
1554 if (bit
== TRACE_BLK_OPT_CLASSIC
) {
1556 tr
->trace_flags
&= ~TRACE_ITER_CONTEXT_INFO
;
1558 tr
->trace_flags
|= TRACE_ITER_CONTEXT_INFO
;
1563 static struct tracer blk_tracer __read_mostly
= {
1565 .init
= blk_tracer_init
,
1566 .reset
= blk_tracer_reset
,
1567 .start
= blk_tracer_start
,
1568 .stop
= blk_tracer_stop
,
1569 .print_header
= blk_tracer_print_header
,
1570 .print_line
= blk_tracer_print_line
,
1571 .flags
= &blk_tracer_flags
,
1572 .set_flag
= blk_tracer_set_flag
,
1575 static struct trace_event_functions trace_blk_event_funcs
= {
1576 .trace
= blk_trace_event_print
,
1577 .binary
= blk_trace_event_print_binary
,
1580 static struct trace_event trace_blk_event
= {
1582 .funcs
= &trace_blk_event_funcs
,
1585 static int __init
init_blk_tracer(void)
1587 if (!register_trace_event(&trace_blk_event
)) {
1588 pr_warn("Warning: could not register block events\n");
1592 if (register_tracer(&blk_tracer
) != 0) {
1593 pr_warn("Warning: could not register the block tracer\n");
1594 unregister_trace_event(&trace_blk_event
);
1601 device_initcall(init_blk_tracer
);
1603 static int blk_trace_remove_queue(struct request_queue
*q
)
1605 struct blk_trace
*bt
;
1607 bt
= rcu_replace_pointer(q
->blk_trace
, NULL
,
1608 lockdep_is_held(&q
->debugfs_mutex
));
1619 * Setup everything required to start tracing
1621 static int blk_trace_setup_queue(struct request_queue
*q
,
1622 struct block_device
*bdev
)
1624 struct blk_trace
*bt
= NULL
;
1627 bt
= kzalloc(sizeof(*bt
), GFP_KERNEL
);
1631 bt
->msg_data
= __alloc_percpu(BLK_TN_MAX_MSG
, __alignof__(char));
1635 bt
->dev
= bdev
->bd_dev
;
1636 bt
->act_mask
= (u16
)-1;
1638 blk_trace_setup_lba(bt
, bdev
);
1640 rcu_assign_pointer(q
->blk_trace
, bt
);
1650 * sysfs interface to enable and configure tracing
1653 static ssize_t
sysfs_blk_trace_attr_show(struct device
*dev
,
1654 struct device_attribute
*attr
,
1656 static ssize_t
sysfs_blk_trace_attr_store(struct device
*dev
,
1657 struct device_attribute
*attr
,
1658 const char *buf
, size_t count
);
1659 #define BLK_TRACE_DEVICE_ATTR(_name) \
1660 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1661 sysfs_blk_trace_attr_show, \
1662 sysfs_blk_trace_attr_store)
1664 static BLK_TRACE_DEVICE_ATTR(enable
);
1665 static BLK_TRACE_DEVICE_ATTR(act_mask
);
1666 static BLK_TRACE_DEVICE_ATTR(pid
);
1667 static BLK_TRACE_DEVICE_ATTR(start_lba
);
1668 static BLK_TRACE_DEVICE_ATTR(end_lba
);
1670 static struct attribute
*blk_trace_attrs
[] = {
1671 &dev_attr_enable
.attr
,
1672 &dev_attr_act_mask
.attr
,
1674 &dev_attr_start_lba
.attr
,
1675 &dev_attr_end_lba
.attr
,
1679 struct attribute_group blk_trace_attr_group
= {
1681 .attrs
= blk_trace_attrs
,
1684 static const struct {
1688 { BLK_TC_READ
, "read" },
1689 { BLK_TC_WRITE
, "write" },
1690 { BLK_TC_FLUSH
, "flush" },
1691 { BLK_TC_SYNC
, "sync" },
1692 { BLK_TC_QUEUE
, "queue" },
1693 { BLK_TC_REQUEUE
, "requeue" },
1694 { BLK_TC_ISSUE
, "issue" },
1695 { BLK_TC_COMPLETE
, "complete" },
1696 { BLK_TC_FS
, "fs" },
1697 { BLK_TC_PC
, "pc" },
1698 { BLK_TC_NOTIFY
, "notify" },
1699 { BLK_TC_AHEAD
, "ahead" },
1700 { BLK_TC_META
, "meta" },
1701 { BLK_TC_DISCARD
, "discard" },
1702 { BLK_TC_DRV_DATA
, "drv_data" },
1703 { BLK_TC_FUA
, "fua" },
1706 static int blk_trace_str2mask(const char *str
)
1710 char *buf
, *s
, *token
;
1712 buf
= kstrdup(str
, GFP_KERNEL
);
1718 token
= strsep(&s
, ",");
1725 for (i
= 0; i
< ARRAY_SIZE(mask_maps
); i
++) {
1726 if (strcasecmp(token
, mask_maps
[i
].str
) == 0) {
1727 mask
|= mask_maps
[i
].mask
;
1731 if (i
== ARRAY_SIZE(mask_maps
)) {
1741 static ssize_t
blk_trace_mask2str(char *buf
, int mask
)
1746 for (i
= 0; i
< ARRAY_SIZE(mask_maps
); i
++) {
1747 if (mask
& mask_maps
[i
].mask
) {
1748 p
+= sprintf(p
, "%s%s",
1749 (p
== buf
) ? "" : ",", mask_maps
[i
].str
);
1757 static ssize_t
sysfs_blk_trace_attr_show(struct device
*dev
,
1758 struct device_attribute
*attr
,
1761 struct block_device
*bdev
= dev_to_bdev(dev
);
1762 struct request_queue
*q
= bdev_get_queue(bdev
);
1763 struct blk_trace
*bt
;
1764 ssize_t ret
= -ENXIO
;
1766 mutex_lock(&q
->debugfs_mutex
);
1768 bt
= rcu_dereference_protected(q
->blk_trace
,
1769 lockdep_is_held(&q
->debugfs_mutex
));
1770 if (attr
== &dev_attr_enable
) {
1771 ret
= sprintf(buf
, "%u\n", !!bt
);
1772 goto out_unlock_bdev
;
1776 ret
= sprintf(buf
, "disabled\n");
1777 else if (attr
== &dev_attr_act_mask
)
1778 ret
= blk_trace_mask2str(buf
, bt
->act_mask
);
1779 else if (attr
== &dev_attr_pid
)
1780 ret
= sprintf(buf
, "%u\n", bt
->pid
);
1781 else if (attr
== &dev_attr_start_lba
)
1782 ret
= sprintf(buf
, "%llu\n", bt
->start_lba
);
1783 else if (attr
== &dev_attr_end_lba
)
1784 ret
= sprintf(buf
, "%llu\n", bt
->end_lba
);
1787 mutex_unlock(&q
->debugfs_mutex
);
1791 static ssize_t
sysfs_blk_trace_attr_store(struct device
*dev
,
1792 struct device_attribute
*attr
,
1793 const char *buf
, size_t count
)
1795 struct block_device
*bdev
= dev_to_bdev(dev
);
1796 struct request_queue
*q
= bdev_get_queue(bdev
);
1797 struct blk_trace
*bt
;
1799 ssize_t ret
= -EINVAL
;
1804 if (attr
== &dev_attr_act_mask
) {
1805 if (kstrtoull(buf
, 0, &value
)) {
1806 /* Assume it is a list of trace category names */
1807 ret
= blk_trace_str2mask(buf
);
1813 if (kstrtoull(buf
, 0, &value
))
1817 mutex_lock(&q
->debugfs_mutex
);
1819 bt
= rcu_dereference_protected(q
->blk_trace
,
1820 lockdep_is_held(&q
->debugfs_mutex
));
1821 if (attr
== &dev_attr_enable
) {
1822 if (!!value
== !!bt
) {
1824 goto out_unlock_bdev
;
1827 ret
= blk_trace_setup_queue(q
, bdev
);
1829 ret
= blk_trace_remove_queue(q
);
1830 goto out_unlock_bdev
;
1835 ret
= blk_trace_setup_queue(q
, bdev
);
1836 bt
= rcu_dereference_protected(q
->blk_trace
,
1837 lockdep_is_held(&q
->debugfs_mutex
));
1841 if (attr
== &dev_attr_act_mask
)
1842 bt
->act_mask
= value
;
1843 else if (attr
== &dev_attr_pid
)
1845 else if (attr
== &dev_attr_start_lba
)
1846 bt
->start_lba
= value
;
1847 else if (attr
== &dev_attr_end_lba
)
1848 bt
->end_lba
= value
;
1852 mutex_unlock(&q
->debugfs_mutex
);
1854 return ret
? ret
: count
;
1857 int blk_trace_init_sysfs(struct device
*dev
)
1859 return sysfs_create_group(&dev
->kobj
, &blk_trace_attr_group
);
1862 void blk_trace_remove_sysfs(struct device
*dev
)
1864 sysfs_remove_group(&dev
->kobj
, &blk_trace_attr_group
);
1867 #endif /* CONFIG_BLK_DEV_IO_TRACE */
1869 #ifdef CONFIG_EVENT_TRACING
1871 void blk_fill_rwbs(char *rwbs
, unsigned int op
, int bytes
)
1875 if (op
& REQ_PREFLUSH
)
1878 switch (op
& REQ_OP_MASK
) {
1880 case REQ_OP_WRITE_SAME
:
1883 case REQ_OP_DISCARD
:
1886 case REQ_OP_SECURE_ERASE
:
1902 if (op
& REQ_RAHEAD
)
1911 EXPORT_SYMBOL_GPL(blk_fill_rwbs
);
1913 #endif /* CONFIG_EVENT_TRACING */