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/export.h>
27 #include <linux/time.h>
28 #include <linux/uaccess.h>
29 #include <linux/list.h>
30 #include <linux/blk-cgroup.h>
32 #include "../../block/blk.h"
34 #include <trace/events/block.h>
36 #include "trace_output.h"
38 #ifdef CONFIG_BLK_DEV_IO_TRACE
40 static unsigned int blktrace_seq __read_mostly = 1;
42 static struct trace_array *blk_tr;
43 static bool blk_tracer_enabled __read_mostly;
45 static LIST_HEAD(running_trace_list);
46 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock);
48 /* Select an alternative, minimalistic output than the original one */
49 #define TRACE_BLK_OPT_CLASSIC 0x1
50 #define TRACE_BLK_OPT_CGROUP 0x2
51 #define TRACE_BLK_OPT_CGNAME 0x4
53 static struct tracer_opt blk_tracer_opts[] = {
54 /* Default disable the minimalistic output */
55 { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
56 #ifdef CONFIG_BLK_CGROUP
57 { TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) },
58 { TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) },
63 static struct tracer_flags blk_tracer_flags = {
65 .opts = blk_tracer_opts,
68 /* Global reference count of probes */
69 static atomic_t blk_probes_ref = ATOMIC_INIT(0);
71 static void blk_register_tracepoints(void);
72 static void blk_unregister_tracepoints(void);
75 * Send out a notify message.
77 static void trace_note(struct blk_trace *bt, pid_t pid, int action,
78 const void *data, size_t len,
79 union kernfs_node_id *cgid)
81 struct blk_io_trace *t;
82 struct ring_buffer_event *event = NULL;
83 struct ring_buffer *buffer = NULL;
85 int cpu = smp_processor_id();
86 bool blk_tracer = blk_tracer_enabled;
87 ssize_t cgid_len = cgid ? sizeof(*cgid) : 0;
90 buffer = blk_tr->trace_buffer.buffer;
92 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
93 sizeof(*t) + len + cgid_len,
97 t = ring_buffer_event_data(event);
104 t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len);
106 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
107 t->time = ktime_to_ns(ktime_get());
110 t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
113 t->pdu_len = len + cgid_len;
115 memcpy((void *)t + sizeof(*t), cgid, cgid_len);
116 memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
119 trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
124 * Send out a notify for this process, if we haven't done so since a trace
127 static void trace_note_tsk(struct task_struct *tsk)
130 struct blk_trace *bt;
132 tsk->btrace_seq = blktrace_seq;
133 spin_lock_irqsave(&running_trace_lock, flags);
134 list_for_each_entry(bt, &running_trace_list, running_list) {
135 trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm,
136 sizeof(tsk->comm), NULL);
138 spin_unlock_irqrestore(&running_trace_lock, flags);
141 static void trace_note_time(struct blk_trace *bt)
143 struct timespec64 now;
147 /* need to check user space to see if this breaks in y2038 or y2106 */
148 ktime_get_real_ts64(&now);
149 words[0] = (u32)now.tv_sec;
150 words[1] = now.tv_nsec;
152 local_irq_save(flags);
153 trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), NULL);
154 local_irq_restore(flags);
157 void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
158 const char *fmt, ...)
165 if (unlikely(bt->trace_state != Blktrace_running &&
166 !blk_tracer_enabled))
170 * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
171 * message to the trace.
173 if (!(bt->act_mask & BLK_TC_NOTIFY))
176 local_irq_save(flags);
177 buf = this_cpu_ptr(bt->msg_data);
179 n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
182 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
184 #ifdef CONFIG_BLK_CGROUP
185 trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
186 blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL);
188 trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL);
190 local_irq_restore(flags);
192 EXPORT_SYMBOL_GPL(__trace_note_message);
194 static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
197 if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
199 if (sector && (sector < bt->start_lba || sector > bt->end_lba))
201 if (bt->pid && pid != bt->pid)
208 * Data direction bit lookup
210 static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
211 BLK_TC_ACT(BLK_TC_WRITE) };
213 #define BLK_TC_RAHEAD BLK_TC_AHEAD
214 #define BLK_TC_PREFLUSH BLK_TC_FLUSH
216 /* The ilog2() calls fall out because they're constant */
217 #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
218 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
221 * The worker for the various blk_add_trace*() types. Fills out a
222 * blk_io_trace structure and places it in a per-cpu subbuffer.
224 static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
225 int op, int op_flags, u32 what, int error, int pdu_len,
226 void *pdu_data, union kernfs_node_id *cgid)
228 struct task_struct *tsk = current;
229 struct ring_buffer_event *event = NULL;
230 struct ring_buffer *buffer = NULL;
231 struct blk_io_trace *t;
232 unsigned long flags = 0;
233 unsigned long *sequence;
236 bool blk_tracer = blk_tracer_enabled;
237 ssize_t cgid_len = cgid ? sizeof(*cgid) : 0;
239 if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
242 what |= ddir_act[op_is_write(op) ? WRITE : READ];
243 what |= MASK_TC_BIT(op_flags, SYNC);
244 what |= MASK_TC_BIT(op_flags, RAHEAD);
245 what |= MASK_TC_BIT(op_flags, META);
246 what |= MASK_TC_BIT(op_flags, PREFLUSH);
247 what |= MASK_TC_BIT(op_flags, FUA);
248 if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)
249 what |= BLK_TC_ACT(BLK_TC_DISCARD);
250 if (op == REQ_OP_FLUSH)
251 what |= BLK_TC_ACT(BLK_TC_FLUSH);
253 what |= __BLK_TA_CGROUP;
256 if (act_log_check(bt, what, sector, pid))
258 cpu = raw_smp_processor_id();
261 tracing_record_cmdline(current);
263 buffer = blk_tr->trace_buffer.buffer;
264 pc = preempt_count();
265 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
266 sizeof(*t) + pdu_len + cgid_len,
270 t = ring_buffer_event_data(event);
274 if (unlikely(tsk->btrace_seq != blktrace_seq))
278 * A word about the locking here - we disable interrupts to reserve
279 * some space in the relay per-cpu buffer, to prevent an irq
280 * from coming in and stepping on our toes.
282 local_irq_save(flags);
283 t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len);
285 sequence = per_cpu_ptr(bt->sequence, cpu);
287 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
288 t->sequence = ++(*sequence);
289 t->time = ktime_to_ns(ktime_get());
292 * These two are not needed in ftrace as they are in the
293 * generic trace_entry, filled by tracing_generic_entry_update,
294 * but for the trace_event->bin() synthesizer benefit we do it
305 t->pdu_len = pdu_len + cgid_len;
308 memcpy((void *)t + sizeof(*t), cgid, cgid_len);
310 memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
313 trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
318 local_irq_restore(flags);
321 static void blk_trace_free(struct blk_trace *bt)
323 debugfs_remove(bt->msg_file);
324 debugfs_remove(bt->dropped_file);
325 relay_close(bt->rchan);
326 debugfs_remove(bt->dir);
327 free_percpu(bt->sequence);
328 free_percpu(bt->msg_data);
332 static void blk_trace_cleanup(struct blk_trace *bt)
335 if (atomic_dec_and_test(&blk_probes_ref))
336 blk_unregister_tracepoints();
339 int blk_trace_remove(struct request_queue *q)
341 struct blk_trace *bt;
343 bt = xchg(&q->blk_trace, NULL);
347 if (bt->trace_state != Blktrace_running)
348 blk_trace_cleanup(bt);
352 EXPORT_SYMBOL_GPL(blk_trace_remove);
354 static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
355 size_t count, loff_t *ppos)
357 struct blk_trace *bt = filp->private_data;
360 snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
362 return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
365 static const struct file_operations blk_dropped_fops = {
366 .owner = THIS_MODULE,
368 .read = blk_dropped_read,
369 .llseek = default_llseek,
372 static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
373 size_t count, loff_t *ppos)
376 struct blk_trace *bt;
378 if (count >= BLK_TN_MAX_MSG)
381 msg = memdup_user_nul(buffer, count);
385 bt = filp->private_data;
386 __trace_note_message(bt, NULL, "%s", msg);
392 static const struct file_operations blk_msg_fops = {
393 .owner = THIS_MODULE,
395 .write = blk_msg_write,
396 .llseek = noop_llseek,
400 * Keep track of how many times we encountered a full subbuffer, to aid
401 * the user space app in telling how many lost events there were.
403 static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
404 void *prev_subbuf, size_t prev_padding)
406 struct blk_trace *bt;
408 if (!relay_buf_full(buf))
411 bt = buf->chan->private_data;
412 atomic_inc(&bt->dropped);
416 static int blk_remove_buf_file_callback(struct dentry *dentry)
418 debugfs_remove(dentry);
423 static struct dentry *blk_create_buf_file_callback(const char *filename,
424 struct dentry *parent,
426 struct rchan_buf *buf,
429 return debugfs_create_file(filename, mode, parent, buf,
430 &relay_file_operations);
433 static struct rchan_callbacks blk_relay_callbacks = {
434 .subbuf_start = blk_subbuf_start_callback,
435 .create_buf_file = blk_create_buf_file_callback,
436 .remove_buf_file = blk_remove_buf_file_callback,
439 static void blk_trace_setup_lba(struct blk_trace *bt,
440 struct block_device *bdev)
442 struct hd_struct *part = NULL;
445 part = bdev->bd_part;
448 bt->start_lba = part->start_sect;
449 bt->end_lba = part->start_sect + part->nr_sects;
457 * Setup everything required to start tracing
459 static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
460 struct block_device *bdev,
461 struct blk_user_trace_setup *buts)
463 struct blk_trace *bt = NULL;
464 struct dentry *dir = NULL;
467 if (!buts->buf_size || !buts->buf_nr)
470 strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
471 buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
474 * some device names have larger paths - convert the slashes
475 * to underscores for this to work as expected
477 strreplace(buts->name, '/', '_');
479 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
484 bt->sequence = alloc_percpu(unsigned long);
488 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
494 if (!blk_debugfs_root)
497 dir = debugfs_lookup(buts->name, blk_debugfs_root);
499 bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
504 atomic_set(&bt->dropped, 0);
505 INIT_LIST_HEAD(&bt->running_list);
508 bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
510 if (!bt->dropped_file)
513 bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
517 bt->rchan = relay_open("trace", dir, buts->buf_size,
518 buts->buf_nr, &blk_relay_callbacks, bt);
522 bt->act_mask = buts->act_mask;
524 bt->act_mask = (u16) -1;
526 blk_trace_setup_lba(bt, bdev);
528 /* overwrite with user settings */
530 bt->start_lba = buts->start_lba;
532 bt->end_lba = buts->end_lba;
535 bt->trace_state = Blktrace_setup;
538 if (cmpxchg(&q->blk_trace, NULL, bt))
541 if (atomic_inc_return(&blk_probes_ref) == 1)
542 blk_register_tracepoints();
553 int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
554 struct block_device *bdev,
557 struct blk_user_trace_setup buts;
560 ret = copy_from_user(&buts, arg, sizeof(buts));
564 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
568 if (copy_to_user(arg, &buts, sizeof(buts))) {
574 EXPORT_SYMBOL_GPL(blk_trace_setup);
576 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
577 static int compat_blk_trace_setup(struct request_queue *q, char *name,
578 dev_t dev, struct block_device *bdev,
581 struct blk_user_trace_setup buts;
582 struct compat_blk_user_trace_setup cbuts;
585 if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
588 buts = (struct blk_user_trace_setup) {
589 .act_mask = cbuts.act_mask,
590 .buf_size = cbuts.buf_size,
591 .buf_nr = cbuts.buf_nr,
592 .start_lba = cbuts.start_lba,
593 .end_lba = cbuts.end_lba,
597 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
601 if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
610 int blk_trace_startstop(struct request_queue *q, int start)
613 struct blk_trace *bt = q->blk_trace;
619 * For starting a trace, we can transition from a setup or stopped
620 * trace. For stopping a trace, the state must be running
624 if (bt->trace_state == Blktrace_setup ||
625 bt->trace_state == Blktrace_stopped) {
628 bt->trace_state = Blktrace_running;
629 spin_lock_irq(&running_trace_lock);
630 list_add(&bt->running_list, &running_trace_list);
631 spin_unlock_irq(&running_trace_lock);
637 if (bt->trace_state == Blktrace_running) {
638 bt->trace_state = Blktrace_stopped;
639 spin_lock_irq(&running_trace_lock);
640 list_del_init(&bt->running_list);
641 spin_unlock_irq(&running_trace_lock);
642 relay_flush(bt->rchan);
649 EXPORT_SYMBOL_GPL(blk_trace_startstop);
652 * When reading or writing the blktrace sysfs files, the references to the
653 * opened sysfs or device files should prevent the underlying block device
654 * from being removed. So no further delete protection is really needed.
658 * blk_trace_ioctl: - handle the ioctls associated with tracing
659 * @bdev: the block device
660 * @cmd: the ioctl cmd
661 * @arg: the argument data, if any
664 int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
666 struct request_queue *q;
668 char b[BDEVNAME_SIZE];
670 q = bdev_get_queue(bdev);
674 mutex_lock(&q->blk_trace_mutex);
679 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
681 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
682 case BLKTRACESETUP32:
684 ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
690 ret = blk_trace_startstop(q, start);
692 case BLKTRACETEARDOWN:
693 ret = blk_trace_remove(q);
700 mutex_unlock(&q->blk_trace_mutex);
705 * blk_trace_shutdown: - stop and cleanup trace structures
706 * @q: the request queue associated with the device
709 void blk_trace_shutdown(struct request_queue *q)
712 blk_trace_startstop(q, 0);
717 #ifdef CONFIG_BLK_CGROUP
718 static union kernfs_node_id *
719 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
721 struct blk_trace *bt = q->blk_trace;
723 if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
728 return cgroup_get_kernfs_id(bio->bi_css->cgroup);
731 static union kernfs_node_id *
732 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
738 static union kernfs_node_id *
739 blk_trace_request_get_cgid(struct request_queue *q, struct request *rq)
743 /* Use the first bio */
744 return blk_trace_bio_get_cgid(q, rq->bio);
752 * blk_add_trace_rq - Add a trace for a request oriented action
753 * @rq: the source request
754 * @error: return status to log
755 * @nr_bytes: number of completed bytes
757 * @cgid: the cgroup info
760 * Records an action against a request. Will log the bio offset + size.
763 static void blk_add_trace_rq(struct request *rq, int error,
764 unsigned int nr_bytes, u32 what,
765 union kernfs_node_id *cgid)
767 struct blk_trace *bt = rq->q->blk_trace;
772 if (blk_rq_is_passthrough(rq))
773 what |= BLK_TC_ACT(BLK_TC_PC);
775 what |= BLK_TC_ACT(BLK_TC_FS);
777 __blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
778 rq->cmd_flags, what, error, 0, NULL, cgid);
781 static void blk_add_trace_rq_insert(void *ignore,
782 struct request_queue *q, struct request *rq)
784 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
785 blk_trace_request_get_cgid(q, rq));
788 static void blk_add_trace_rq_issue(void *ignore,
789 struct request_queue *q, struct request *rq)
791 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
792 blk_trace_request_get_cgid(q, rq));
795 static void blk_add_trace_rq_requeue(void *ignore,
796 struct request_queue *q,
799 blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
800 blk_trace_request_get_cgid(q, rq));
803 static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
804 int error, unsigned int nr_bytes)
806 blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
807 blk_trace_request_get_cgid(rq->q, rq));
811 * blk_add_trace_bio - Add a trace for a bio oriented action
812 * @q: queue the io is for
813 * @bio: the source bio
815 * @error: error, if any
818 * Records an action against a bio. Will log the bio offset + size.
821 static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
822 u32 what, int error, union kernfs_node_id *cgid)
824 struct blk_trace *bt = q->blk_trace;
829 __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
830 bio_op(bio), bio->bi_opf, what, error, 0, NULL, cgid);
833 static void blk_add_trace_bio_bounce(void *ignore,
834 struct request_queue *q, struct bio *bio)
836 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0,
837 blk_trace_bio_get_cgid(q, bio));
840 static void blk_add_trace_bio_complete(void *ignore,
841 struct request_queue *q, struct bio *bio,
844 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error,
845 blk_trace_bio_get_cgid(q, bio));
848 static void blk_add_trace_bio_backmerge(void *ignore,
849 struct request_queue *q,
853 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0,
854 blk_trace_bio_get_cgid(q, bio));
857 static void blk_add_trace_bio_frontmerge(void *ignore,
858 struct request_queue *q,
862 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0,
863 blk_trace_bio_get_cgid(q, bio));
866 static void blk_add_trace_bio_queue(void *ignore,
867 struct request_queue *q, struct bio *bio)
869 blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0,
870 blk_trace_bio_get_cgid(q, bio));
873 static void blk_add_trace_getrq(void *ignore,
874 struct request_queue *q,
875 struct bio *bio, int rw)
878 blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0,
879 blk_trace_bio_get_cgid(q, bio));
881 struct blk_trace *bt = q->blk_trace;
884 __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
890 static void blk_add_trace_sleeprq(void *ignore,
891 struct request_queue *q,
892 struct bio *bio, int rw)
895 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0,
896 blk_trace_bio_get_cgid(q, bio));
898 struct blk_trace *bt = q->blk_trace;
901 __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ,
906 static void blk_add_trace_plug(void *ignore, struct request_queue *q)
908 struct blk_trace *bt = q->blk_trace;
911 __blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, NULL);
914 static void blk_add_trace_unplug(void *ignore, struct request_queue *q,
915 unsigned int depth, bool explicit)
917 struct blk_trace *bt = q->blk_trace;
920 __be64 rpdu = cpu_to_be64(depth);
924 what = BLK_TA_UNPLUG_IO;
926 what = BLK_TA_UNPLUG_TIMER;
928 __blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, NULL);
932 static void blk_add_trace_split(void *ignore,
933 struct request_queue *q, struct bio *bio,
936 struct blk_trace *bt = q->blk_trace;
939 __be64 rpdu = cpu_to_be64(pdu);
941 __blk_add_trace(bt, bio->bi_iter.bi_sector,
942 bio->bi_iter.bi_size, bio_op(bio), bio->bi_opf,
943 BLK_TA_SPLIT, bio->bi_status, sizeof(rpdu),
944 &rpdu, blk_trace_bio_get_cgid(q, bio));
949 * blk_add_trace_bio_remap - Add a trace for a bio-remap operation
950 * @ignore: trace callback data parameter (not used)
951 * @q: queue the io is for
952 * @bio: the source bio
953 * @dev: target device
954 * @from: source sector
957 * Device mapper or raid target sometimes need to split a bio because
958 * it spans a stripe (or similar). Add a trace for that action.
961 static void blk_add_trace_bio_remap(void *ignore,
962 struct request_queue *q, struct bio *bio,
963 dev_t dev, sector_t from)
965 struct blk_trace *bt = q->blk_trace;
966 struct blk_io_trace_remap r;
971 r.device_from = cpu_to_be32(dev);
972 r.device_to = cpu_to_be32(bio_dev(bio));
973 r.sector_from = cpu_to_be64(from);
975 __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size,
976 bio_op(bio), bio->bi_opf, BLK_TA_REMAP, bio->bi_status,
977 sizeof(r), &r, blk_trace_bio_get_cgid(q, bio));
981 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
982 * @ignore: trace callback data parameter (not used)
983 * @q: queue the io is for
984 * @rq: the source request
985 * @dev: target device
986 * @from: source sector
989 * Device mapper remaps request to other devices.
990 * Add a trace for that action.
993 static void blk_add_trace_rq_remap(void *ignore,
994 struct request_queue *q,
995 struct request *rq, dev_t dev,
998 struct blk_trace *bt = q->blk_trace;
999 struct blk_io_trace_remap r;
1004 r.device_from = cpu_to_be32(dev);
1005 r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
1006 r.sector_from = cpu_to_be64(from);
1008 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
1009 rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
1010 sizeof(r), &r, blk_trace_request_get_cgid(q, rq));
1014 * blk_add_driver_data - Add binary message with driver-specific data
1015 * @q: queue the io is for
1017 * @data: driver-specific data
1018 * @len: length of driver-specific data
1021 * Some drivers might want to write driver-specific data per request.
1024 void blk_add_driver_data(struct request_queue *q,
1026 void *data, size_t len)
1028 struct blk_trace *bt = q->blk_trace;
1033 __blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
1034 BLK_TA_DRV_DATA, 0, len, data,
1035 blk_trace_request_get_cgid(q, rq));
1037 EXPORT_SYMBOL_GPL(blk_add_driver_data);
1039 static void blk_register_tracepoints(void)
1043 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1045 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1047 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1049 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1051 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1053 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1055 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1057 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1059 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1061 ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
1063 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1065 ret = register_trace_block_plug(blk_add_trace_plug, NULL);
1067 ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
1069 ret = register_trace_block_split(blk_add_trace_split, NULL);
1071 ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1073 ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1077 static void blk_unregister_tracepoints(void)
1079 unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1080 unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);
1081 unregister_trace_block_split(blk_add_trace_split, NULL);
1082 unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
1083 unregister_trace_block_plug(blk_add_trace_plug, NULL);
1084 unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1085 unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
1086 unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1087 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1088 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1089 unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1090 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1091 unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1092 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1093 unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1094 unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1096 tracepoint_synchronize_unregister();
1100 * struct blk_io_tracer formatting routines
1103 static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
1106 int tc = t->action >> BLK_TC_SHIFT;
1108 if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
1113 if (tc & BLK_TC_FLUSH)
1116 if (tc & BLK_TC_DISCARD)
1118 else if (tc & BLK_TC_WRITE)
1125 if (tc & BLK_TC_FUA)
1127 if (tc & BLK_TC_AHEAD)
1129 if (tc & BLK_TC_SYNC)
1131 if (tc & BLK_TC_META)
1138 const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
1140 return (const struct blk_io_trace *)ent;
1143 static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg)
1145 return (void *)(te_blk_io_trace(ent) + 1) +
1146 (has_cg ? sizeof(union kernfs_node_id) : 0);
1149 static inline const void *cgid_start(const struct trace_entry *ent)
1151 return (void *)(te_blk_io_trace(ent) + 1);
1154 static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg)
1156 return te_blk_io_trace(ent)->pdu_len -
1157 (has_cg ? sizeof(union kernfs_node_id) : 0);
1160 static inline u32 t_action(const struct trace_entry *ent)
1162 return te_blk_io_trace(ent)->action;
1165 static inline u32 t_bytes(const struct trace_entry *ent)
1167 return te_blk_io_trace(ent)->bytes;
1170 static inline u32 t_sec(const struct trace_entry *ent)
1172 return te_blk_io_trace(ent)->bytes >> 9;
1175 static inline unsigned long long t_sector(const struct trace_entry *ent)
1177 return te_blk_io_trace(ent)->sector;
1180 static inline __u16 t_error(const struct trace_entry *ent)
1182 return te_blk_io_trace(ent)->error;
1185 static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg)
1187 const __u64 *val = pdu_start(ent, has_cg);
1188 return be64_to_cpu(*val);
1191 static void get_pdu_remap(const struct trace_entry *ent,
1192 struct blk_io_trace_remap *r, bool has_cg)
1194 const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg);
1195 __u64 sector_from = __r->sector_from;
1197 r->device_from = be32_to_cpu(__r->device_from);
1198 r->device_to = be32_to_cpu(__r->device_to);
1199 r->sector_from = be64_to_cpu(sector_from);
1202 typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act,
1205 static void blk_log_action_classic(struct trace_iterator *iter, const char *act,
1208 char rwbs[RWBS_LEN];
1209 unsigned long long ts = iter->ts;
1210 unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
1211 unsigned secs = (unsigned long)ts;
1212 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1216 trace_seq_printf(&iter->seq,
1217 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
1218 MAJOR(t->device), MINOR(t->device), iter->cpu,
1219 secs, nsec_rem, iter->ent->pid, act, rwbs);
1222 static void blk_log_action(struct trace_iterator *iter, const char *act,
1225 char rwbs[RWBS_LEN];
1226 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1230 const union kernfs_node_id *id = cgid_start(iter->ent);
1232 if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) {
1233 char blkcg_name_buf[NAME_MAX + 1] = "<...>";
1235 cgroup_path_from_kernfs_id(id, blkcg_name_buf,
1236 sizeof(blkcg_name_buf));
1237 trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ",
1238 MAJOR(t->device), MINOR(t->device),
1239 blkcg_name_buf, act, rwbs);
1241 trace_seq_printf(&iter->seq,
1242 "%3d,%-3d %x,%-x %2s %3s ",
1243 MAJOR(t->device), MINOR(t->device),
1244 id->ino, id->generation, act, rwbs);
1246 trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
1247 MAJOR(t->device), MINOR(t->device), act, rwbs);
1250 static void blk_log_dump_pdu(struct trace_seq *s,
1251 const struct trace_entry *ent, bool has_cg)
1253 const unsigned char *pdu_buf;
1257 pdu_buf = pdu_start(ent, has_cg);
1258 pdu_len = pdu_real_len(ent, has_cg);
1263 /* find the last zero that needs to be printed */
1264 for (end = pdu_len - 1; end >= 0; end--)
1269 trace_seq_putc(s, '(');
1271 for (i = 0; i < pdu_len; i++) {
1273 trace_seq_printf(s, "%s%02x",
1274 i == 0 ? "" : " ", pdu_buf[i]);
1277 * stop when the rest is just zeroes and indicate so
1278 * with a ".." appended
1280 if (i == end && end != pdu_len - 1) {
1281 trace_seq_puts(s, " ..) ");
1286 trace_seq_puts(s, ") ");
1289 static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1291 char cmd[TASK_COMM_LEN];
1293 trace_find_cmdline(ent->pid, cmd);
1295 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1296 trace_seq_printf(s, "%u ", t_bytes(ent));
1297 blk_log_dump_pdu(s, ent, has_cg);
1298 trace_seq_printf(s, "[%s]\n", cmd);
1301 trace_seq_printf(s, "%llu + %u [%s]\n",
1302 t_sector(ent), t_sec(ent), cmd);
1304 trace_seq_printf(s, "[%s]\n", cmd);
1308 static void blk_log_with_error(struct trace_seq *s,
1309 const struct trace_entry *ent, bool has_cg)
1311 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1312 blk_log_dump_pdu(s, ent, has_cg);
1313 trace_seq_printf(s, "[%d]\n", t_error(ent));
1316 trace_seq_printf(s, "%llu + %u [%d]\n",
1318 t_sec(ent), t_error(ent));
1320 trace_seq_printf(s, "%llu [%d]\n",
1321 t_sector(ent), t_error(ent));
1325 static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1327 struct blk_io_trace_remap r = { .device_from = 0, };
1329 get_pdu_remap(ent, &r, has_cg);
1330 trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
1331 t_sector(ent), t_sec(ent),
1332 MAJOR(r.device_from), MINOR(r.device_from),
1333 (unsigned long long)r.sector_from);
1336 static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1338 char cmd[TASK_COMM_LEN];
1340 trace_find_cmdline(ent->pid, cmd);
1342 trace_seq_printf(s, "[%s]\n", cmd);
1345 static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1347 char cmd[TASK_COMM_LEN];
1349 trace_find_cmdline(ent->pid, cmd);
1351 trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg));
1354 static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg)
1356 char cmd[TASK_COMM_LEN];
1358 trace_find_cmdline(ent->pid, cmd);
1360 trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
1361 get_pdu_int(ent, has_cg), cmd);
1364 static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent,
1368 trace_seq_putmem(s, pdu_start(ent, has_cg),
1369 pdu_real_len(ent, has_cg));
1370 trace_seq_putc(s, '\n');
1374 * struct tracer operations
1377 static void blk_tracer_print_header(struct seq_file *m)
1379 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1381 seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1385 static void blk_tracer_start(struct trace_array *tr)
1387 blk_tracer_enabled = true;
1390 static int blk_tracer_init(struct trace_array *tr)
1393 blk_tracer_start(tr);
1397 static void blk_tracer_stop(struct trace_array *tr)
1399 blk_tracer_enabled = false;
1402 static void blk_tracer_reset(struct trace_array *tr)
1404 blk_tracer_stop(tr);
1407 static const struct {
1409 void (*print)(struct trace_seq *s, const struct trace_entry *ent,
1412 [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
1413 [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
1414 [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
1415 [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
1416 [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
1417 [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
1418 [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
1419 [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
1420 [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
1421 [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
1422 [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
1423 [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
1424 [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
1425 [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
1426 [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
1429 static enum print_line_t print_one_line(struct trace_iterator *iter,
1432 struct trace_array *tr = iter->tr;
1433 struct trace_seq *s = &iter->seq;
1434 const struct blk_io_trace *t;
1437 blk_log_action_t *log_action;
1440 t = te_blk_io_trace(iter->ent);
1441 what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP;
1442 long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE);
1443 log_action = classic ? &blk_log_action_classic : &blk_log_action;
1444 has_cg = t->action & __BLK_TA_CGROUP;
1446 if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) {
1447 log_action(iter, long_act ? "message" : "m", has_cg);
1448 blk_log_msg(s, iter->ent, has_cg);
1449 return trace_handle_return(s);
1452 if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
1453 trace_seq_printf(s, "Unknown action %x\n", what);
1455 log_action(iter, what2act[what].act[long_act], has_cg);
1456 what2act[what].print(s, iter->ent, has_cg);
1459 return trace_handle_return(s);
1462 static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
1463 int flags, struct trace_event *event)
1465 return print_one_line(iter, false);
1468 static void blk_trace_synthesize_old_trace(struct trace_iterator *iter)
1470 struct trace_seq *s = &iter->seq;
1471 struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
1472 const int offset = offsetof(struct blk_io_trace, sector);
1473 struct blk_io_trace old = {
1474 .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
1478 trace_seq_putmem(s, &old, offset);
1479 trace_seq_putmem(s, &t->sector,
1480 sizeof(old) - offset + t->pdu_len);
1483 static enum print_line_t
1484 blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
1485 struct trace_event *event)
1487 blk_trace_synthesize_old_trace(iter);
1489 return trace_handle_return(&iter->seq);
1492 static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
1494 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1495 return TRACE_TYPE_UNHANDLED;
1497 return print_one_line(iter, true);
1501 blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1503 /* don't output context-info for blk_classic output */
1504 if (bit == TRACE_BLK_OPT_CLASSIC) {
1506 tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
1508 tr->trace_flags |= TRACE_ITER_CONTEXT_INFO;
1513 static struct tracer blk_tracer __read_mostly = {
1515 .init = blk_tracer_init,
1516 .reset = blk_tracer_reset,
1517 .start = blk_tracer_start,
1518 .stop = blk_tracer_stop,
1519 .print_header = blk_tracer_print_header,
1520 .print_line = blk_tracer_print_line,
1521 .flags = &blk_tracer_flags,
1522 .set_flag = blk_tracer_set_flag,
1525 static struct trace_event_functions trace_blk_event_funcs = {
1526 .trace = blk_trace_event_print,
1527 .binary = blk_trace_event_print_binary,
1530 static struct trace_event trace_blk_event = {
1532 .funcs = &trace_blk_event_funcs,
1535 static int __init init_blk_tracer(void)
1537 if (!register_trace_event(&trace_blk_event)) {
1538 pr_warn("Warning: could not register block events\n");
1542 if (register_tracer(&blk_tracer) != 0) {
1543 pr_warn("Warning: could not register the block tracer\n");
1544 unregister_trace_event(&trace_blk_event);
1551 device_initcall(init_blk_tracer);
1553 static int blk_trace_remove_queue(struct request_queue *q)
1555 struct blk_trace *bt;
1557 bt = xchg(&q->blk_trace, NULL);
1561 if (atomic_dec_and_test(&blk_probes_ref))
1562 blk_unregister_tracepoints();
1569 * Setup everything required to start tracing
1571 static int blk_trace_setup_queue(struct request_queue *q,
1572 struct block_device *bdev)
1574 struct blk_trace *bt = NULL;
1577 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
1581 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
1585 bt->dev = bdev->bd_dev;
1586 bt->act_mask = (u16)-1;
1588 blk_trace_setup_lba(bt, bdev);
1591 if (cmpxchg(&q->blk_trace, NULL, bt))
1594 if (atomic_inc_return(&blk_probes_ref) == 1)
1595 blk_register_tracepoints();
1604 * sysfs interface to enable and configure tracing
1607 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1608 struct device_attribute *attr,
1610 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1611 struct device_attribute *attr,
1612 const char *buf, size_t count);
1613 #define BLK_TRACE_DEVICE_ATTR(_name) \
1614 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1615 sysfs_blk_trace_attr_show, \
1616 sysfs_blk_trace_attr_store)
1618 static BLK_TRACE_DEVICE_ATTR(enable);
1619 static BLK_TRACE_DEVICE_ATTR(act_mask);
1620 static BLK_TRACE_DEVICE_ATTR(pid);
1621 static BLK_TRACE_DEVICE_ATTR(start_lba);
1622 static BLK_TRACE_DEVICE_ATTR(end_lba);
1624 static struct attribute *blk_trace_attrs[] = {
1625 &dev_attr_enable.attr,
1626 &dev_attr_act_mask.attr,
1628 &dev_attr_start_lba.attr,
1629 &dev_attr_end_lba.attr,
1633 struct attribute_group blk_trace_attr_group = {
1635 .attrs = blk_trace_attrs,
1638 static const struct {
1642 { BLK_TC_READ, "read" },
1643 { BLK_TC_WRITE, "write" },
1644 { BLK_TC_FLUSH, "flush" },
1645 { BLK_TC_SYNC, "sync" },
1646 { BLK_TC_QUEUE, "queue" },
1647 { BLK_TC_REQUEUE, "requeue" },
1648 { BLK_TC_ISSUE, "issue" },
1649 { BLK_TC_COMPLETE, "complete" },
1650 { BLK_TC_FS, "fs" },
1651 { BLK_TC_PC, "pc" },
1652 { BLK_TC_NOTIFY, "notify" },
1653 { BLK_TC_AHEAD, "ahead" },
1654 { BLK_TC_META, "meta" },
1655 { BLK_TC_DISCARD, "discard" },
1656 { BLK_TC_DRV_DATA, "drv_data" },
1657 { BLK_TC_FUA, "fua" },
1660 static int blk_trace_str2mask(const char *str)
1664 char *buf, *s, *token;
1666 buf = kstrdup(str, GFP_KERNEL);
1672 token = strsep(&s, ",");
1679 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1680 if (strcasecmp(token, mask_maps[i].str) == 0) {
1681 mask |= mask_maps[i].mask;
1685 if (i == ARRAY_SIZE(mask_maps)) {
1695 static ssize_t blk_trace_mask2str(char *buf, int mask)
1700 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1701 if (mask & mask_maps[i].mask) {
1702 p += sprintf(p, "%s%s",
1703 (p == buf) ? "" : ",", mask_maps[i].str);
1711 static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
1713 if (bdev->bd_disk == NULL)
1716 return bdev_get_queue(bdev);
1719 static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1720 struct device_attribute *attr,
1723 struct hd_struct *p = dev_to_part(dev);
1724 struct request_queue *q;
1725 struct block_device *bdev;
1726 ssize_t ret = -ENXIO;
1728 bdev = bdget(part_devt(p));
1732 q = blk_trace_get_queue(bdev);
1736 mutex_lock(&q->blk_trace_mutex);
1738 if (attr == &dev_attr_enable) {
1739 ret = sprintf(buf, "%u\n", !!q->blk_trace);
1740 goto out_unlock_bdev;
1743 if (q->blk_trace == NULL)
1744 ret = sprintf(buf, "disabled\n");
1745 else if (attr == &dev_attr_act_mask)
1746 ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
1747 else if (attr == &dev_attr_pid)
1748 ret = sprintf(buf, "%u\n", q->blk_trace->pid);
1749 else if (attr == &dev_attr_start_lba)
1750 ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
1751 else if (attr == &dev_attr_end_lba)
1752 ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
1755 mutex_unlock(&q->blk_trace_mutex);
1762 static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1763 struct device_attribute *attr,
1764 const char *buf, size_t count)
1766 struct block_device *bdev;
1767 struct request_queue *q;
1768 struct hd_struct *p;
1770 ssize_t ret = -EINVAL;
1775 if (attr == &dev_attr_act_mask) {
1776 if (kstrtoull(buf, 0, &value)) {
1777 /* Assume it is a list of trace category names */
1778 ret = blk_trace_str2mask(buf);
1783 } else if (kstrtoull(buf, 0, &value))
1788 p = dev_to_part(dev);
1789 bdev = bdget(part_devt(p));
1793 q = blk_trace_get_queue(bdev);
1797 mutex_lock(&q->blk_trace_mutex);
1799 if (attr == &dev_attr_enable) {
1801 ret = blk_trace_setup_queue(q, bdev);
1803 ret = blk_trace_remove_queue(q);
1804 goto out_unlock_bdev;
1808 if (q->blk_trace == NULL)
1809 ret = blk_trace_setup_queue(q, bdev);
1812 if (attr == &dev_attr_act_mask)
1813 q->blk_trace->act_mask = value;
1814 else if (attr == &dev_attr_pid)
1815 q->blk_trace->pid = value;
1816 else if (attr == &dev_attr_start_lba)
1817 q->blk_trace->start_lba = value;
1818 else if (attr == &dev_attr_end_lba)
1819 q->blk_trace->end_lba = value;
1823 mutex_unlock(&q->blk_trace_mutex);
1827 return ret ? ret : count;
1830 int blk_trace_init_sysfs(struct device *dev)
1832 return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
1835 void blk_trace_remove_sysfs(struct device *dev)
1837 sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
1840 #endif /* CONFIG_BLK_DEV_IO_TRACE */
1842 #ifdef CONFIG_EVENT_TRACING
1844 void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
1848 if (op & REQ_PREFLUSH)
1851 switch (op & REQ_OP_MASK) {
1853 case REQ_OP_WRITE_SAME:
1856 case REQ_OP_DISCARD:
1859 case REQ_OP_SECURE_ERASE:
1875 if (op & REQ_RAHEAD)
1884 EXPORT_SYMBOL_GPL(blk_fill_rwbs);
1886 #endif /* CONFIG_EVENT_TRACING */