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;
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;
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, 0, pc);
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;
227 bool blk_tracer = blk_tracer_enabled;
228 ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
230 if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
233 what |= ddir_act[op_is_write(op) ? WRITE : READ];
234 what |= MASK_TC_BIT(op_flags, SYNC);
235 what |= MASK_TC_BIT(op_flags, RAHEAD);
236 what |= MASK_TC_BIT(op_flags, META);
237 what |= MASK_TC_BIT(op_flags, PREFLUSH);
238 what |= MASK_TC_BIT(op_flags, FUA);
239 if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)
240 what |= BLK_TC_ACT(BLK_TC_DISCARD);
241 if (op == REQ_OP_FLUSH)
242 what |= BLK_TC_ACT(BLK_TC_FLUSH);
244 what |= __BLK_TA_CGROUP;
247 if (act_log_check(bt, what, sector, pid))
249 cpu = raw_smp_processor_id();
252 tracing_record_cmdline(current);
254 buffer = blk_tr->array_buffer.buffer;
255 pc = preempt_count();
256 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
257 sizeof(*t) + pdu_len + cgid_len,
261 t = ring_buffer_event_data(event);
265 if (unlikely(tsk->btrace_seq != blktrace_seq))
269 * A word about the locking here - we disable interrupts to reserve
270 * some space in the relay per-cpu buffer, to prevent an irq
271 * from coming in and stepping on our toes.
273 local_irq_save(flags);
274 t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len);
276 sequence = per_cpu_ptr(bt->sequence, cpu);
278 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
279 t->sequence = ++(*sequence);
280 t->time = ktime_to_ns(ktime_get());
283 * These two are not needed in ftrace as they are in the
284 * generic trace_entry, filled by tracing_generic_entry_update,
285 * but for the trace_event->bin() synthesizer benefit we do it
296 t->pdu_len = pdu_len + cgid_len;
299 memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
301 memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
304 trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
309 local_irq_restore(flags);
312 static void blk_trace_free(struct blk_trace *bt)
314 debugfs_remove(bt->msg_file);
315 debugfs_remove(bt->dropped_file);
316 relay_close(bt->rchan);
317 debugfs_remove(bt->dir);
318 free_percpu(bt->sequence);
319 free_percpu(bt->msg_data);
323 static void get_probe_ref(void)
325 mutex_lock(&blk_probe_mutex);
326 if (++blk_probes_ref == 1)
327 blk_register_tracepoints();
328 mutex_unlock(&blk_probe_mutex);
331 static void put_probe_ref(void)
333 mutex_lock(&blk_probe_mutex);
334 if (!--blk_probes_ref)
335 blk_unregister_tracepoints();
336 mutex_unlock(&blk_probe_mutex);
339 static void blk_trace_cleanup(struct blk_trace *bt)
346 static int __blk_trace_remove(struct request_queue *q)
348 struct blk_trace *bt;
350 bt = rcu_replace_pointer(q->blk_trace, NULL,
351 lockdep_is_held(&q->debugfs_mutex));
355 if (bt->trace_state != Blktrace_running)
356 blk_trace_cleanup(bt);
361 int blk_trace_remove(struct request_queue *q)
365 mutex_lock(&q->debugfs_mutex);
366 ret = __blk_trace_remove(q);
367 mutex_unlock(&q->debugfs_mutex);
371 EXPORT_SYMBOL_GPL(blk_trace_remove);
373 static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
374 size_t count, loff_t *ppos)
376 struct blk_trace *bt = filp->private_data;
379 snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
381 return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
384 static const struct file_operations blk_dropped_fops = {
385 .owner = THIS_MODULE,
387 .read = blk_dropped_read,
388 .llseek = default_llseek,
391 static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
392 size_t count, loff_t *ppos)
395 struct blk_trace *bt;
397 if (count >= BLK_TN_MAX_MSG)
400 msg = memdup_user_nul(buffer, count);
404 bt = filp->private_data;
405 __trace_note_message(bt, NULL, "%s", msg);
411 static const struct file_operations blk_msg_fops = {
412 .owner = THIS_MODULE,
414 .write = blk_msg_write,
415 .llseek = noop_llseek,
419 * Keep track of how many times we encountered a full subbuffer, to aid
420 * the user space app in telling how many lost events there were.
422 static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
423 void *prev_subbuf, size_t prev_padding)
425 struct blk_trace *bt;
427 if (!relay_buf_full(buf))
430 bt = buf->chan->private_data;
431 atomic_inc(&bt->dropped);
435 static int blk_remove_buf_file_callback(struct dentry *dentry)
437 debugfs_remove(dentry);
442 static struct dentry *blk_create_buf_file_callback(const char *filename,
443 struct dentry *parent,
445 struct rchan_buf *buf,
448 return debugfs_create_file(filename, mode, parent, buf,
449 &relay_file_operations);
452 static struct rchan_callbacks blk_relay_callbacks = {
453 .subbuf_start = blk_subbuf_start_callback,
454 .create_buf_file = blk_create_buf_file_callback,
455 .remove_buf_file = blk_remove_buf_file_callback,
458 static void blk_trace_setup_lba(struct blk_trace *bt,
459 struct block_device *bdev)
461 struct hd_struct *part = NULL;
464 part = bdev->bd_part;
467 bt->start_lba = part->start_sect;
468 bt->end_lba = part->start_sect + part->nr_sects;
476 * Setup everything required to start tracing
478 static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
479 struct block_device *bdev,
480 struct blk_user_trace_setup *buts)
482 struct blk_trace *bt = NULL;
483 struct dentry *dir = NULL;
486 lockdep_assert_held(&q->debugfs_mutex);
488 if (!buts->buf_size || !buts->buf_nr)
491 strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
492 buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
495 * some device names have larger paths - convert the slashes
496 * to underscores for this to work as expected
498 strreplace(buts->name, '/', '_');
501 * bdev can be NULL, as with scsi-generic, this is a helpful as
504 if (rcu_dereference_protected(q->blk_trace,
505 lockdep_is_held(&q->debugfs_mutex))) {
506 pr_warn("Concurrent blktraces are not allowed on %s\n",
511 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
516 bt->sequence = alloc_percpu(unsigned long);
520 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
525 * When tracing the whole disk reuse the existing debugfs directory
526 * created by the block layer on init. For partitions block devices,
527 * and scsi-generic block devices we create a temporary new debugfs
528 * directory that will be removed once the trace ends.
530 if (bdev && bdev == bdev->bd_contains)
531 dir = q->debugfs_dir;
533 bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
536 * As blktrace relies on debugfs for its interface the debugfs directory
537 * is required, contrary to the usual mantra of not checking for debugfs
538 * files or directories.
540 if (IS_ERR_OR_NULL(dir)) {
541 pr_warn("debugfs_dir not present for %s so skipping\n",
548 atomic_set(&bt->dropped, 0);
549 INIT_LIST_HEAD(&bt->running_list);
552 bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
555 bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
557 bt->rchan = relay_open("trace", dir, buts->buf_size,
558 buts->buf_nr, &blk_relay_callbacks, bt);
562 bt->act_mask = buts->act_mask;
564 bt->act_mask = (u16) -1;
566 blk_trace_setup_lba(bt, bdev);
568 /* overwrite with user settings */
570 bt->start_lba = buts->start_lba;
572 bt->end_lba = buts->end_lba;
575 bt->trace_state = Blktrace_setup;
577 rcu_assign_pointer(q->blk_trace, bt);
587 static int __blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
588 struct block_device *bdev, char __user *arg)
590 struct blk_user_trace_setup buts;
593 ret = copy_from_user(&buts, arg, sizeof(buts));
597 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
601 if (copy_to_user(arg, &buts, sizeof(buts))) {
602 __blk_trace_remove(q);
608 int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
609 struct block_device *bdev,
614 mutex_lock(&q->debugfs_mutex);
615 ret = __blk_trace_setup(q, name, dev, bdev, arg);
616 mutex_unlock(&q->debugfs_mutex);
620 EXPORT_SYMBOL_GPL(blk_trace_setup);
622 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
623 static int compat_blk_trace_setup(struct request_queue *q, char *name,
624 dev_t dev, struct block_device *bdev,
627 struct blk_user_trace_setup buts;
628 struct compat_blk_user_trace_setup cbuts;
631 if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
634 buts = (struct blk_user_trace_setup) {
635 .act_mask = cbuts.act_mask,
636 .buf_size = cbuts.buf_size,
637 .buf_nr = cbuts.buf_nr,
638 .start_lba = cbuts.start_lba,
639 .end_lba = cbuts.end_lba,
643 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
647 if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
648 __blk_trace_remove(q);
656 static int __blk_trace_startstop(struct request_queue *q, int start)
659 struct blk_trace *bt;
661 bt = rcu_dereference_protected(q->blk_trace,
662 lockdep_is_held(&q->debugfs_mutex));
667 * For starting a trace, we can transition from a setup or stopped
668 * trace. For stopping a trace, the state must be running
672 if (bt->trace_state == Blktrace_setup ||
673 bt->trace_state == Blktrace_stopped) {
676 bt->trace_state = Blktrace_running;
677 spin_lock_irq(&running_trace_lock);
678 list_add(&bt->running_list, &running_trace_list);
679 spin_unlock_irq(&running_trace_lock);
685 if (bt->trace_state == Blktrace_running) {
686 bt->trace_state = Blktrace_stopped;
687 spin_lock_irq(&running_trace_lock);
688 list_del_init(&bt->running_list);
689 spin_unlock_irq(&running_trace_lock);
690 relay_flush(bt->rchan);
698 int blk_trace_startstop(struct request_queue *q, int start)
702 mutex_lock(&q->debugfs_mutex);
703 ret = __blk_trace_startstop(q, start);
704 mutex_unlock(&q->debugfs_mutex);
708 EXPORT_SYMBOL_GPL(blk_trace_startstop);
711 * When reading or writing the blktrace sysfs files, the references to the
712 * opened sysfs or device files should prevent the underlying block device
713 * from being removed. So no further delete protection is really needed.
717 * blk_trace_ioctl: - handle the ioctls associated with tracing
718 * @bdev: the block device
719 * @cmd: the ioctl cmd
720 * @arg: the argument data, if any
723 int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
725 struct request_queue *q;
727 char b[BDEVNAME_SIZE];
729 q = bdev_get_queue(bdev);
733 mutex_lock(&q->debugfs_mutex);
738 ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
740 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
741 case BLKTRACESETUP32:
743 ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
750 ret = __blk_trace_startstop(q, start);
752 case BLKTRACETEARDOWN:
753 ret = __blk_trace_remove(q);
760 mutex_unlock(&q->debugfs_mutex);
765 * blk_trace_shutdown: - stop and cleanup trace structures
766 * @q: the request queue associated with the device
769 void blk_trace_shutdown(struct request_queue *q)
771 mutex_lock(&q->debugfs_mutex);
772 if (rcu_dereference_protected(q->blk_trace,
773 lockdep_is_held(&q->debugfs_mutex))) {
774 __blk_trace_startstop(q, 0);
775 __blk_trace_remove(q);
778 mutex_unlock(&q->debugfs_mutex);
781 #ifdef CONFIG_BLK_CGROUP
782 static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
784 struct blk_trace *bt;
786 /* We don't use the 'bt' value here except as an optimization... */
787 bt = rcu_dereference_protected(q->blk_trace, 1);
788 if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
793 return cgroup_id(bio_blkcg(bio)->css.cgroup);
796 u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
803 blk_trace_request_get_cgid(struct request_queue *q, struct request *rq)
807 /* Use the first bio */
808 return blk_trace_bio_get_cgid(q, rq->bio);
816 * blk_add_trace_rq - Add a trace for a request oriented action
817 * @rq: the source request
818 * @error: return status to log
819 * @nr_bytes: number of completed bytes
821 * @cgid: the cgroup info
824 * Records an action against a request. Will log the bio offset + size.
827 static void blk_add_trace_rq(struct request *rq, int error,
828 unsigned int nr_bytes, u32 what, u64 cgid)
830 struct blk_trace *bt;
833 bt = rcu_dereference(rq->q->blk_trace);
839 if (blk_rq_is_passthrough(rq))
840 what |= BLK_TC_ACT(BLK_TC_PC);
842 what |= BLK_TC_ACT(BLK_TC_FS);
844 __blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
845 rq->cmd_flags, what, error, 0, NULL, cgid);
849 static void blk_add_trace_rq_insert(void *ignore,
850 struct request_queue *q, struct request *rq)
852 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
853 blk_trace_request_get_cgid(q, rq));
856 static void blk_add_trace_rq_issue(void *ignore,
857 struct request_queue *q, struct request *rq)
859 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
860 blk_trace_request_get_cgid(q, rq));
863 static void blk_add_trace_rq_merge(void *ignore,
864 struct request_queue *q, struct request *rq)
866 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
867 blk_trace_request_get_cgid(q, rq));
870 static void blk_add_trace_rq_requeue(void *ignore,
871 struct request_queue *q,
874 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
875 blk_trace_request_get_cgid(q, rq));
878 static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
879 int error, unsigned int nr_bytes)
881 blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
882 blk_trace_request_get_cgid(rq->q, rq));
886 * blk_add_trace_bio - Add a trace for a bio oriented action
887 * @q: queue the io is for
888 * @bio: the source bio
890 * @error: error, if any
893 * Records an action against a bio. Will log the bio offset + size.
896 static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
899 struct blk_trace *bt;
902 bt = rcu_dereference(q->blk_trace);
908 __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
909 bio_op(bio), bio->bi_opf, what, error, 0, NULL,
910 blk_trace_bio_get_cgid(q, bio));
914 static void blk_add_trace_bio_bounce(void *ignore,
915 struct request_queue *q, struct bio *bio)
917 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
920 static void blk_add_trace_bio_complete(void *ignore,
921 struct request_queue *q, struct bio *bio)
923 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE,
924 blk_status_to_errno(bio->bi_status));
927 static void blk_add_trace_bio_backmerge(void *ignore,
928 struct request_queue *q,
932 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
935 static void blk_add_trace_bio_frontmerge(void *ignore,
936 struct request_queue *q,
940 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
943 static void blk_add_trace_bio_queue(void *ignore,
944 struct request_queue *q, struct bio *bio)
946 blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
949 static void blk_add_trace_getrq(void *ignore,
950 struct request_queue *q,
951 struct bio *bio, int rw)
954 blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
956 struct blk_trace *bt;
959 bt = rcu_dereference(q->blk_trace);
961 __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
968 static void blk_add_trace_sleeprq(void *ignore,
969 struct request_queue *q,
970 struct bio *bio, int rw)
973 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0);
975 struct blk_trace *bt;
978 bt = rcu_dereference(q->blk_trace);
980 __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ,
986 static void blk_add_trace_plug(void *ignore, struct request_queue *q)
988 struct blk_trace *bt;
991 bt = rcu_dereference(q->blk_trace);
993 __blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, 0);
997 static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
998 unsigned int depth, bool explicit)
1000 struct blk_trace *bt;
1003 bt = rcu_dereference(q->blk_trace);
1005 __be64 rpdu = cpu_to_be64(depth);
1009 what = BLK_TA_UNPLUG_IO;
1011 what = BLK_TA_UNPLUG_TIMER;
1013 __blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, 0);
1018 static void blk_add_trace_split(void *ignore,
1019 struct request_queue *q, struct bio *bio,
1022 struct blk_trace *bt;
1025 bt = rcu_dereference(q->blk_trace);
1027 __be64 rpdu = cpu_to_be64(pdu);
1029 __blk_add_trace(bt, bio->bi_iter.bi_sector,
1030 bio->bi_iter.bi_size, bio_op(bio), bio->bi_opf,
1032 blk_status_to_errno(bio->bi_status),
1033 sizeof(rpdu), &rpdu,
1034 blk_trace_bio_get_cgid(q, bio));
1040 * blk_add_trace_bio_remap - Add a trace for a bio-remap operation
1041 * @ignore: trace callback data parameter (not used)
1042 * @q: queue the io is for
1043 * @bio: the source bio
1044 * @dev: target device
1045 * @from: source sector
1048 * Device mapper or raid target sometimes need to split a bio because
1049 * it spans a stripe (or similar). Add a trace for that action.
1052 static void blk_add_trace_bio_remap(void *ignore,
1053 struct request_queue *q, struct bio *bio,
1054 dev_t dev, sector_t from)
1056 struct blk_trace *bt;
1057 struct blk_io_trace_remap r;
1060 bt = rcu_dereference(q->blk_trace);
1066 r.device_from = cpu_to_be32(dev);
1067 r.device_to = cpu_to_be32(bio_dev(bio));
1068 r.sector_from = cpu_to_be64(from);
1070 __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
1071 bio_op(bio), bio->bi_opf, BLK_TA_REMAP,
1072 blk_status_to_errno(bio->bi_status),
1073 sizeof(r), &r, blk_trace_bio_get_cgid(q, bio));
1078 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
1079 * @ignore: trace callback data parameter (not used)
1080 * @q: queue the io is for
1081 * @rq: the source request
1082 * @dev: target device
1083 * @from: source sector
1086 * Device mapper remaps request to other devices.
1087 * Add a trace for that action.
1090 static void blk_add_trace_rq_remap(void *ignore,
1091 struct request_queue *q,
1092 struct request *rq, dev_t dev,
1095 struct blk_trace *bt;
1096 struct blk_io_trace_remap r;
1099 bt = rcu_dereference(q->blk_trace);
1105 r.device_from = cpu_to_be32(dev);
1106 r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
1107 r.sector_from = cpu_to_be64(from);
1109 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
1110 rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
1111 sizeof(r), &r, blk_trace_request_get_cgid(q, rq));
1116 * blk_add_driver_data - Add binary message with driver-specific data
1117 * @q: queue the io is for
1119 * @data: driver-specific data
1120 * @len: length of driver-specific data
1123 * Some drivers might want to write driver-specific data per request.
1126 void blk_add_driver_data(struct request_queue *q,
1128 void *data, size_t len)
1130 struct blk_trace *bt;
1133 bt = rcu_dereference(q->blk_trace);
1139 __blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
1140 BLK_TA_DRV_DATA, 0, len, data,
1141 blk_trace_request_get_cgid(q, rq));
1144 EXPORT_SYMBOL_GPL(blk_add_driver_data);
1146 static void blk_register_tracepoints(void)
1150 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1152 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1154 ret = register_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
1156 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1158 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1160 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1162 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1164 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1166 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1168 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1170 ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
1172 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1174 ret = register_trace_block_plug(blk_add_trace_plug, NULL);
1176 ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
1178 ret = register_trace_block_split(blk_add_trace_split, NULL);
1180 ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1182 ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1186 static void blk_unregister_tracepoints(void)
1188 unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1189 unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1190 unregister_trace_block_split(blk_add_trace_split, NULL);
1191 unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
1192 unregister_trace_block_plug(blk_add_trace_plug, NULL);
1193 unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1194 unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
1195 unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1196 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1197 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1198 unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1199 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1200 unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1201 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1202 unregister_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
1203 unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1204 unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1206 tracepoint_synchronize_unregister();
1210 * struct blk_io_tracer formatting routines
1213 static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
1216 int tc = t->action >> BLK_TC_SHIFT;
1218 if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
1223 if (tc & BLK_TC_FLUSH)
1226 if (tc & BLK_TC_DISCARD)
1228 else if (tc & BLK_TC_WRITE)
1235 if (tc & BLK_TC_FUA)
1237 if (tc & BLK_TC_AHEAD)
1239 if (tc & BLK_TC_SYNC)
1241 if (tc & BLK_TC_META)
1248 const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
1250 return (const struct blk_io_trace *)ent;
1253 static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg)
1255 return (void *)(te_blk_io_trace(ent) + 1) + (has_cg ? sizeof(u64) : 0);
1258 static inline u64 t_cgid(const struct trace_entry *ent)
1260 return *(u64 *)(te_blk_io_trace(ent) + 1);
1263 static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
1265 return te_blk_io_trace(ent)->pdu_len - (has_cg ? sizeof(u64) : 0);
1268 static inline u32 t_action(const struct trace_entry *ent)
1270 return te_blk_io_trace(ent)->action;
1273 static inline u32 t_bytes(const struct trace_entry *ent)
1275 return te_blk_io_trace(ent)->bytes;
1278 static inline u32 t_sec(const struct trace_entry *ent)
1280 return te_blk_io_trace(ent)->bytes >> 9;
1283 static inline unsigned long long t_sector(const struct trace_entry *ent)
1285 return te_blk_io_trace(ent)->sector;
1288 static inline __u16 t_error(const struct trace_entry *ent)
1290 return te_blk_io_trace(ent)->error;
1293 static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg)
1295 const __be64 *val = pdu_start(ent, has_cg);
1296 return be64_to_cpu(*val);
1299 typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act,
1302 static void blk_log_action_classic(struct trace_iterator *iter, const char *act,
1305 char rwbs[RWBS_LEN];
1306 unsigned long long ts = iter->ts;
1307 unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
1308 unsigned secs = (unsigned long)ts;
1309 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1313 trace_seq_printf(&iter->seq,
1314 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1315 MAJOR(t->device), MINOR(t->device), iter->cpu,
1316 secs, nsec_rem, iter->ent->pid, act, rwbs);
1319 static void blk_log_action(struct trace_iterator *iter, const char *act,
1322 char rwbs[RWBS_LEN];
1323 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1327 u64 id = t_cgid(iter->ent);
1329 if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
1330 char blkcg_name_buf[NAME_MAX + 1] = "<...>";
1332 cgroup_path_from_kernfs_id(id, blkcg_name_buf,
1333 sizeof(blkcg_name_buf));
1334 trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
1335 MAJOR(t->device), MINOR(t->device),
1336 blkcg_name_buf, act, rwbs);
1339 * The cgid portion used to be "INO,GEN". Userland
1340 * builds a FILEID_INO32_GEN fid out of them and
1341 * opens the cgroup using open_by_handle_at(2).
1342 * While 32bit ino setups are still the same, 64bit
1343 * ones now use the 64bit ino as the whole ID and
1344 * no longer use generation.
1346 * Regarldess of the content, always output
1347 * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can
1348 * be mapped back to @id on both 64 and 32bit ino
1349 * setups. See __kernfs_fh_to_dentry().
1351 trace_seq_printf(&iter->seq,
1352 "%3d,%-3d %llx,%-llx %2s %3s ",
1353 MAJOR(t->device), MINOR(t->device),
1354 id & U32_MAX, id >> 32, act, rwbs);
1357 trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
1358 MAJOR(t->device), MINOR(t->device), act, rwbs);
1361 static void blk_log_dump_pdu(struct trace_seq *s,
1362 const struct trace_entry *ent, bool has_cg)
1364 const unsigned char *pdu_buf;
1368 pdu_buf = pdu_start(ent, has_cg);
1369 pdu_len = pdu_real_len(ent, has_cg);
1374 /* find the last zero that needs to be printed */
1375 for (end = pdu_len - 1; end >= 0; end--)
1380 trace_seq_putc(s, '(');
1382 for (i = 0; i < pdu_len; i++) {
1384 trace_seq_printf(s, "%s%02x",
1385 i == 0 ? "" : " ", pdu_buf[i]);
1388 * stop when the rest is just zeroes and indicate so
1389 * with a ".." appended
1391 if (i == end && end != pdu_len - 1) {
1392 trace_seq_puts(s, " ..) ");
1397 trace_seq_puts(s, ") ");
1400 static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1402 char cmd[TASK_COMM_LEN];
1404 trace_find_cmdline(ent->pid, cmd);
1406 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1407 trace_seq_printf(s, "%u ", t_bytes(ent));
1408 blk_log_dump_pdu(s, ent, has_cg);
1409 trace_seq_printf(s, "[%s]\n", cmd);
1412 trace_seq_printf(s, "%llu + %u [%s]\n",
1413 t_sector(ent), t_sec(ent), cmd);
1415 trace_seq_printf(s, "[%s]\n", cmd);
1419 static void blk_log_with_error(struct trace_seq *s,
1420 const struct trace_entry *ent, bool has_cg)
1422 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1423 blk_log_dump_pdu(s, ent, has_cg);
1424 trace_seq_printf(s, "[%d]\n", t_error(ent));
1427 trace_seq_printf(s, "%llu + %u [%d]\n",
1429 t_sec(ent), t_error(ent));
1431 trace_seq_printf(s, "%llu [%d]\n",
1432 t_sector(ent), t_error(ent));
1436 static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1438 const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg);
1440 trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
1441 t_sector(ent), t_sec(ent),
1442 MAJOR(be32_to_cpu(__r->device_from)),
1443 MINOR(be32_to_cpu(__r->device_from)),
1444 be64_to_cpu(__r->sector_from));
1447 static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1449 char cmd[TASK_COMM_LEN];
1451 trace_find_cmdline(ent->pid, cmd);
1453 trace_seq_printf(s, "[%s]\n", cmd);
1456 static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1458 char cmd[TASK_COMM_LEN];
1460 trace_find_cmdline(ent->pid, cmd);
1462 trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg));
1465 static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1467 char cmd[TASK_COMM_LEN];
1469 trace_find_cmdline(ent->pid, cmd);
1471 trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
1472 get_pdu_int(ent, has_cg), cmd);
1475 static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent,
1479 trace_seq_putmem(s, pdu_start(ent, has_cg),
1480 pdu_real_len(ent, has_cg));
1481 trace_seq_putc(s, '\n');
1485 * struct tracer operations
1488 static void blk_tracer_print_header(struct seq_file *m)
1490 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1492 seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1496 static void blk_tracer_start(struct trace_array *tr)
1498 blk_tracer_enabled = true;
1501 static int blk_tracer_init(struct trace_array *tr)
1504 blk_tracer_start(tr);
1508 static void blk_tracer_stop(struct trace_array *tr)
1510 blk_tracer_enabled = false;
1513 static void blk_tracer_reset(struct trace_array *tr)
1515 blk_tracer_stop(tr);
1518 static const struct {
1520 void (*print)(struct trace_seq *s, const struct trace_entry *ent,
1523 [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
1524 [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
1525 [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
1526 [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
1527 [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
1528 [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
1529 [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
1530 [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
1531 [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
1532 [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
1533 [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
1534 [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
1535 [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
1536 [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
1537 [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
1540 static enum print_line_t print_one_line(struct trace_iterator *iter,
1543 struct trace_array *tr = iter->tr;
1544 struct trace_seq *s = &iter->seq;
1545 const struct blk_io_trace *t;
1548 blk_log_action_t *log_action;
1551 t = te_blk_io_trace(iter->ent);
1552 what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP;
1553 long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE);
1554 log_action = classic ? &blk_log_action_classic : &blk_log_action;
1555 has_cg = t->action & __BLK_TA_CGROUP;
1557 if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
1558 log_action(iter, long_act ? "message" : "m", has_cg);
1559 blk_log_msg(s, iter->ent, has_cg);
1560 return trace_handle_return(s);
1563 if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
1564 trace_seq_printf(s, "Unknown action %x\n", what);
1566 log_action(iter, what2act[what].act[long_act], has_cg);
1567 what2act[what].print(s, iter->ent, has_cg);
1570 return trace_handle_return(s);
1573 static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
1574 int flags, struct trace_event *event)
1576 return print_one_line(iter, false);
1579 static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
1581 struct trace_seq *s = &iter->seq;
1582 struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
1583 const int offset = offsetof(struct blk_io_trace, sector);
1584 struct blk_io_trace old = {
1585 .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
1589 trace_seq_putmem(s, &old, offset);
1590 trace_seq_putmem(s, &t->sector,
1591 sizeof(old) - offset + t->pdu_len);
1594 static enum print_line_t
1595 blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
1596 struct trace_event *event)
1598 blk_trace_synthesize_old_trace(iter);
1600 return trace_handle_return(&iter->seq);
1603 static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
1605 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1606 return TRACE_TYPE_UNHANDLED;
1608 return print_one_line(iter, true);
1612 blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1614 /* don't output context-info for blk_classic output */
1615 if (bit == TRACE_BLK_OPT_CLASSIC) {
1617 tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
1619 tr->trace_flags |= TRACE_ITER_CONTEXT_INFO;
1624 static struct tracer blk_tracer __read_mostly = {
1626 .init = blk_tracer_init,
1627 .reset = blk_tracer_reset,
1628 .start = blk_tracer_start,
1629 .stop = blk_tracer_stop,
1630 .print_header = blk_tracer_print_header,
1631 .print_line = blk_tracer_print_line,
1632 .flags = &blk_tracer_flags,
1633 .set_flag = blk_tracer_set_flag,
1636 static struct trace_event_functions trace_blk_event_funcs = {
1637 .trace = blk_trace_event_print,
1638 .binary = blk_trace_event_print_binary,
1641 static struct trace_event trace_blk_event = {
1643 .funcs = &trace_blk_event_funcs,
1646 static int __init init_blk_tracer(void)
1648 if (!register_trace_event(&trace_blk_event)) {
1649 pr_warn("Warning: could not register block events\n");
1653 if (register_tracer(&blk_tracer) != 0) {
1654 pr_warn("Warning: could not register the block tracer\n");
1655 unregister_trace_event(&trace_blk_event);
1662 device_initcall(init_blk_tracer);
1664 static int blk_trace_remove_queue(struct request_queue *q)
1666 struct blk_trace *bt;
1668 bt = rcu_replace_pointer(q->blk_trace, NULL,
1669 lockdep_is_held(&q->debugfs_mutex));
1680 * Setup everything required to start tracing
1682 static int blk_trace_setup_queue(struct request_queue *q,
1683 struct block_device *bdev)
1685 struct blk_trace *bt = NULL;
1688 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
1692 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
1696 bt->dev = bdev->bd_dev;
1697 bt->act_mask = (u16)-1;
1699 blk_trace_setup_lba(bt, bdev);
1701 rcu_assign_pointer(q->blk_trace, bt);
1711 * sysfs interface to enable and configure tracing
1714 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1715 struct device_attribute *attr,
1717 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1718 struct device_attribute *attr,
1719 const char *buf, size_t count);
1720 #define BLK_TRACE_DEVICE_ATTR(_name) \
1721 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1722 sysfs_blk_trace_attr_show, \
1723 sysfs_blk_trace_attr_store)
1725 static BLK_TRACE_DEVICE_ATTR(enable);
1726 static BLK_TRACE_DEVICE_ATTR(act_mask);
1727 static BLK_TRACE_DEVICE_ATTR(pid);
1728 static BLK_TRACE_DEVICE_ATTR(start_lba);
1729 static BLK_TRACE_DEVICE_ATTR(end_lba);
1731 static struct attribute *blk_trace_attrs[] = {
1732 &dev_attr_enable.attr,
1733 &dev_attr_act_mask.attr,
1735 &dev_attr_start_lba.attr,
1736 &dev_attr_end_lba.attr,
1740 struct attribute_group blk_trace_attr_group = {
1742 .attrs = blk_trace_attrs,
1745 static const struct {
1749 { BLK_TC_READ, "read" },
1750 { BLK_TC_WRITE, "write" },
1751 { BLK_TC_FLUSH, "flush" },
1752 { BLK_TC_SYNC, "sync" },
1753 { BLK_TC_QUEUE, "queue" },
1754 { BLK_TC_REQUEUE, "requeue" },
1755 { BLK_TC_ISSUE, "issue" },
1756 { BLK_TC_COMPLETE, "complete" },
1757 { BLK_TC_FS, "fs" },
1758 { BLK_TC_PC, "pc" },
1759 { BLK_TC_NOTIFY, "notify" },
1760 { BLK_TC_AHEAD, "ahead" },
1761 { BLK_TC_META, "meta" },
1762 { BLK_TC_DISCARD, "discard" },
1763 { BLK_TC_DRV_DATA, "drv_data" },
1764 { BLK_TC_FUA, "fua" },
1767 static int blk_trace_str2mask(const char *str)
1771 char *buf, *s, *token;
1773 buf = kstrdup(str, GFP_KERNEL);
1779 token = strsep(&s, ",");
1786 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1787 if (strcasecmp(token, mask_maps[i].str) == 0) {
1788 mask |= mask_maps[i].mask;
1792 if (i == ARRAY_SIZE(mask_maps)) {
1802 static ssize_t blk_trace_mask2str(char *buf, int mask)
1807 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1808 if (mask & mask_maps[i].mask) {
1809 p += sprintf(p, "%s%s",
1810 (p == buf) ? "" : ",", mask_maps[i].str);
1818 static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
1820 if (bdev->bd_disk == NULL)
1823 return bdev_get_queue(bdev);
1826 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1827 struct device_attribute *attr,
1830 struct hd_struct *p = dev_to_part(dev);
1831 struct request_queue *q;
1832 struct block_device *bdev;
1833 struct blk_trace *bt;
1834 ssize_t ret = -ENXIO;
1836 bdev = bdget(part_devt(p));
1840 q = blk_trace_get_queue(bdev);
1844 mutex_lock(&q->debugfs_mutex);
1846 bt = rcu_dereference_protected(q->blk_trace,
1847 lockdep_is_held(&q->debugfs_mutex));
1848 if (attr == &dev_attr_enable) {
1849 ret = sprintf(buf, "%u\n", !!bt);
1850 goto out_unlock_bdev;
1854 ret = sprintf(buf, "disabled\n");
1855 else if (attr == &dev_attr_act_mask)
1856 ret = blk_trace_mask2str(buf, bt->act_mask);
1857 else if (attr == &dev_attr_pid)
1858 ret = sprintf(buf, "%u\n", bt->pid);
1859 else if (attr == &dev_attr_start_lba)
1860 ret = sprintf(buf, "%llu\n", bt->start_lba);
1861 else if (attr == &dev_attr_end_lba)
1862 ret = sprintf(buf, "%llu\n", bt->end_lba);
1865 mutex_unlock(&q->debugfs_mutex);
1872 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1873 struct device_attribute *attr,
1874 const char *buf, size_t count)
1876 struct block_device *bdev;
1877 struct request_queue *q;
1878 struct hd_struct *p;
1879 struct blk_trace *bt;
1881 ssize_t ret = -EINVAL;
1886 if (attr == &dev_attr_act_mask) {
1887 if (kstrtoull(buf, 0, &value)) {
1888 /* Assume it is a list of trace category names */
1889 ret = blk_trace_str2mask(buf);
1894 } else if (kstrtoull(buf, 0, &value))
1899 p = dev_to_part(dev);
1900 bdev = bdget(part_devt(p));
1904 q = blk_trace_get_queue(bdev);
1908 mutex_lock(&q->debugfs_mutex);
1910 bt = rcu_dereference_protected(q->blk_trace,
1911 lockdep_is_held(&q->debugfs_mutex));
1912 if (attr == &dev_attr_enable) {
1913 if (!!value == !!bt) {
1915 goto out_unlock_bdev;
1918 ret = blk_trace_setup_queue(q, bdev);
1920 ret = blk_trace_remove_queue(q);
1921 goto out_unlock_bdev;
1926 ret = blk_trace_setup_queue(q, bdev);
1927 bt = rcu_dereference_protected(q->blk_trace,
1928 lockdep_is_held(&q->debugfs_mutex));
1932 if (attr == &dev_attr_act_mask)
1933 bt->act_mask = value;
1934 else if (attr == &dev_attr_pid)
1936 else if (attr == &dev_attr_start_lba)
1937 bt->start_lba = value;
1938 else if (attr == &dev_attr_end_lba)
1939 bt->end_lba = value;
1943 mutex_unlock(&q->debugfs_mutex);
1947 return ret ? ret : count;
1950 int blk_trace_init_sysfs(struct device *dev)
1952 return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
1955 void blk_trace_remove_sysfs(struct device *dev)
1957 sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
1960 #endif /* CONFIG_BLK_DEV_IO_TRACE */
1962 #ifdef CONFIG_EVENT_TRACING
1964 void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
1968 if (op & REQ_PREFLUSH)
1971 switch (op & REQ_OP_MASK) {
1973 case REQ_OP_WRITE_SAME:
1976 case REQ_OP_DISCARD:
1979 case REQ_OP_SECURE_ERASE:
1995 if (op & REQ_RAHEAD)
2004 EXPORT_SYMBOL_GPL(blk_fill_rwbs);
2006 #endif /* CONFIG_EVENT_TRACING */