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Jens Axboe2056a782006-03-23 20:00:26 +01001/*
Jens Axboe0fe23472006-09-04 15:41:16 +02002 * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
Jens Axboe2056a782006-03-23 20:00:26 +01003 *
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.
7 *
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.
12 *
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
16 *
17 */
Jens Axboe2056a782006-03-23 20:00:26 +010018#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
Jens Axboe2056a782006-03-23 20:00:26 +010025#include <linux/debugfs.h>
Olaf Kirchbe1c6342006-12-01 10:39:12 +010026#include <linux/time.h>
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -020027#include <linux/uaccess.h>
Li Zefan55782132009-06-09 13:43:05 +080028
29#include <trace/events/block.h>
30
Frederic Weisbecker2db270a2009-02-07 20:46:45 +010031#include "trace_output.h"
Jens Axboe2056a782006-03-23 20:00:26 +010032
Li Zefan55782132009-06-09 13:43:05 +080033#ifdef CONFIG_BLK_DEV_IO_TRACE
34
Jens Axboe2056a782006-03-23 20:00:26 +010035static unsigned int blktrace_seq __read_mostly = 1;
36
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -020037static struct trace_array *blk_tr;
Li Zefan5006ea72009-03-20 09:48:03 +080038static bool blk_tracer_enabled __read_mostly;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -020039
40/* Select an alternative, minimalistic output than the original one */
Steven Rostedtef180122009-03-10 14:10:56 -040041#define TRACE_BLK_OPT_CLASSIC 0x1
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -020042
43static struct tracer_opt blk_tracer_opts[] = {
44 /* Default disable the minimalistic output */
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -020045 { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) },
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -020046 { }
47};
48
49static struct tracer_flags blk_tracer_flags = {
50 .val = 0,
51 .opts = blk_tracer_opts,
52};
53
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +010054/* Global reference count of probes */
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +010055static atomic_t blk_probes_ref = ATOMIC_INIT(0);
56
Li Zefan3c289ba2009-03-20 09:48:26 +080057static void blk_register_tracepoints(void);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +010058static void blk_unregister_tracepoints(void);
59
Jens Axboe2056a782006-03-23 20:00:26 +010060/*
Olaf Kirchbe1c6342006-12-01 10:39:12 +010061 * Send out a notify message.
62 */
Jens Axboea8630552006-12-04 09:30:58 +010063static void trace_note(struct blk_trace *bt, pid_t pid, int action,
64 const void *data, size_t len)
Olaf Kirchbe1c6342006-12-01 10:39:12 +010065{
66 struct blk_io_trace *t;
Li Zefan18cea452009-03-27 10:21:54 +080067 struct ring_buffer_event *event = NULL;
Steven Rostedte77405a2009-09-02 14:17:06 -040068 struct ring_buffer *buffer = NULL;
Li Zefan18cea452009-03-27 10:21:54 +080069 int pc = 0;
70 int cpu = smp_processor_id();
71 bool blk_tracer = blk_tracer_enabled;
72
73 if (blk_tracer) {
Steven Rostedte77405a2009-09-02 14:17:06 -040074 buffer = blk_tr->buffer;
Li Zefan18cea452009-03-27 10:21:54 +080075 pc = preempt_count();
Steven Rostedte77405a2009-09-02 14:17:06 -040076 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
Li Zefan18cea452009-03-27 10:21:54 +080077 sizeof(*t) + len,
78 0, pc);
79 if (!event)
80 return;
81 t = ring_buffer_event_data(event);
82 goto record_it;
83 }
Olaf Kirchbe1c6342006-12-01 10:39:12 +010084
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -020085 if (!bt->rchan)
86 return;
87
Olaf Kirchbe1c6342006-12-01 10:39:12 +010088 t = relay_reserve(bt->rchan, sizeof(*t) + len);
Jens Axboed3d9d2a2006-12-04 09:27:41 +010089 if (t) {
Jens Axboed3d9d2a2006-12-04 09:27:41 +010090 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
Ingo Molnar2997c8c2008-01-11 13:35:54 +010091 t->time = ktime_to_ns(ktime_get());
Li Zefan18cea452009-03-27 10:21:54 +080092record_it:
Jens Axboed3d9d2a2006-12-04 09:27:41 +010093 t->device = bt->dev;
94 t->action = action;
95 t->pid = pid;
96 t->cpu = cpu;
97 t->pdu_len = len;
98 memcpy((void *) t + sizeof(*t), data, len);
Li Zefan18cea452009-03-27 10:21:54 +080099
100 if (blk_tracer)
Steven Rostedte77405a2009-09-02 14:17:06 -0400101 trace_buffer_unlock_commit(buffer, event, 0, pc);
Jens Axboed3d9d2a2006-12-04 09:27:41 +0100102 }
Olaf Kirchbe1c6342006-12-01 10:39:12 +0100103}
104
105/*
Jens Axboe2056a782006-03-23 20:00:26 +0100106 * Send out a notify for this process, if we haven't done so since a trace
107 * started
108 */
109static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
110{
Jens Axboea8630552006-12-04 09:30:58 +0100111 tsk->btrace_seq = blktrace_seq;
112 trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));
Olaf Kirchbe1c6342006-12-01 10:39:12 +0100113}
Jens Axboe2056a782006-03-23 20:00:26 +0100114
Olaf Kirchbe1c6342006-12-01 10:39:12 +0100115static void trace_note_time(struct blk_trace *bt)
116{
117 struct timespec now;
118 unsigned long flags;
119 u32 words[2];
120
121 getnstimeofday(&now);
122 words[0] = now.tv_sec;
123 words[1] = now.tv_nsec;
124
125 local_irq_save(flags);
126 trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words));
127 local_irq_restore(flags);
Jens Axboe2056a782006-03-23 20:00:26 +0100128}
129
Alan D. Brunelle9d5f09a2008-05-27 14:54:41 +0200130void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
131{
132 int n;
133 va_list args;
Carl Henrik Lunde14a73f52008-06-12 20:13:58 +0200134 unsigned long flags;
Jens Axboe64565912008-05-28 14:45:33 +0200135 char *buf;
Alan D. Brunelle9d5f09a2008-05-27 14:54:41 +0200136
Li Zefan18cea452009-03-27 10:21:54 +0800137 if (unlikely(bt->trace_state != Blktrace_running &&
138 !blk_tracer_enabled))
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200139 return;
140
Carl Henrik Lunde14a73f52008-06-12 20:13:58 +0200141 local_irq_save(flags);
Jens Axboe64565912008-05-28 14:45:33 +0200142 buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
Alan D. Brunelle9d5f09a2008-05-27 14:54:41 +0200143 va_start(args, fmt);
Jens Axboe64565912008-05-28 14:45:33 +0200144 n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
Alan D. Brunelle9d5f09a2008-05-27 14:54:41 +0200145 va_end(args);
146
Jens Axboe64565912008-05-28 14:45:33 +0200147 trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
Carl Henrik Lunde14a73f52008-06-12 20:13:58 +0200148 local_irq_restore(flags);
Alan D. Brunelle9d5f09a2008-05-27 14:54:41 +0200149}
150EXPORT_SYMBOL_GPL(__trace_note_message);
151
Jens Axboe2056a782006-03-23 20:00:26 +0100152static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
153 pid_t pid)
154{
155 if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0)
156 return 1;
Shawn Dud0deef52009-04-14 13:58:56 +0800157 if (sector && (sector < bt->start_lba || sector > bt->end_lba))
Jens Axboe2056a782006-03-23 20:00:26 +0100158 return 1;
159 if (bt->pid && pid != bt->pid)
160 return 1;
161
162 return 0;
163}
164
165/*
166 * Data direction bit lookup
167 */
Li Zefane4955c92009-03-24 16:04:37 +0800168static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
169 BLK_TC_ACT(BLK_TC_WRITE) };
Jens Axboe2056a782006-03-23 20:00:26 +0100170
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200171#define BLK_TC_RAHEAD BLK_TC_AHEAD
172
David Woodhouse35ba8f72008-08-10 12:33:00 +0100173/* The ilog2() calls fall out because they're constant */
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200174#define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
175 (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name))
Jens Axboe2056a782006-03-23 20:00:26 +0100176
177/*
178 * The worker for the various blk_add_trace*() types. Fills out a
179 * blk_io_trace structure and places it in a per-cpu subbuffer.
180 */
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100181static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
Jens Axboe2056a782006-03-23 20:00:26 +0100182 int rw, u32 what, int error, int pdu_len, void *pdu_data)
183{
184 struct task_struct *tsk = current;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200185 struct ring_buffer_event *event = NULL;
Steven Rostedte77405a2009-09-02 14:17:06 -0400186 struct ring_buffer *buffer = NULL;
Jens Axboe2056a782006-03-23 20:00:26 +0100187 struct blk_io_trace *t;
Arnaldo Carvalho de Melo0a987752009-02-05 16:12:56 -0200188 unsigned long flags = 0;
Jens Axboe2056a782006-03-23 20:00:26 +0100189 unsigned long *sequence;
190 pid_t pid;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200191 int cpu, pc = 0;
Li Zefan18cea452009-03-27 10:21:54 +0800192 bool blk_tracer = blk_tracer_enabled;
Jens Axboe2056a782006-03-23 20:00:26 +0100193
Li Zefan18cea452009-03-27 10:21:54 +0800194 if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer))
Jens Axboe2056a782006-03-23 20:00:26 +0100195 return;
196
197 what |= ddir_act[rw & WRITE];
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200198 what |= MASK_TC_BIT(rw, SYNC);
199 what |= MASK_TC_BIT(rw, RAHEAD);
David Woodhouse35ba8f72008-08-10 12:33:00 +0100200 what |= MASK_TC_BIT(rw, META);
201 what |= MASK_TC_BIT(rw, DISCARD);
Jens Axboe2056a782006-03-23 20:00:26 +0100202
203 pid = tsk->pid;
Shawn Dud0deef52009-04-14 13:58:56 +0800204 if (act_log_check(bt, what, sector, pid))
Jens Axboe2056a782006-03-23 20:00:26 +0100205 return;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200206 cpu = raw_smp_processor_id();
207
Li Zefan18cea452009-03-27 10:21:54 +0800208 if (blk_tracer) {
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200209 tracing_record_cmdline(current);
210
Steven Rostedte77405a2009-09-02 14:17:06 -0400211 buffer = blk_tr->buffer;
Arnaldo Carvalho de Melo51a763d2009-02-05 16:14:13 -0200212 pc = preempt_count();
Steven Rostedte77405a2009-09-02 14:17:06 -0400213 event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
Arnaldo Carvalho de Melo51a763d2009-02-05 16:14:13 -0200214 sizeof(*t) + pdu_len,
215 0, pc);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200216 if (!event)
217 return;
Arnaldo Carvalho de Melo51a763d2009-02-05 16:14:13 -0200218 t = ring_buffer_event_data(event);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200219 goto record_it;
220 }
Jens Axboe2056a782006-03-23 20:00:26 +0100221
222 /*
223 * A word about the locking here - we disable interrupts to reserve
224 * some space in the relay per-cpu buffer, to prevent an irq
Carl Henrik Lunde14a73f52008-06-12 20:13:58 +0200225 * from coming in and stepping on our toes.
Jens Axboe2056a782006-03-23 20:00:26 +0100226 */
227 local_irq_save(flags);
228
229 if (unlikely(tsk->btrace_seq != blktrace_seq))
230 trace_note_tsk(bt, tsk);
231
232 t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len);
233 if (t) {
Jens Axboe2056a782006-03-23 20:00:26 +0100234 sequence = per_cpu_ptr(bt->sequence, cpu);
235
236 t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
237 t->sequence = ++(*sequence);
Ingo Molnar2997c8c2008-01-11 13:35:54 +0100238 t->time = ktime_to_ns(ktime_get());
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200239record_it:
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -0200240 /*
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200241 * These two are not needed in ftrace as they are in the
242 * generic trace_entry, filled by tracing_generic_entry_update,
243 * but for the trace_event->bin() synthesizer benefit we do it
244 * here too.
245 */
246 t->cpu = cpu;
247 t->pid = pid;
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -0200248
Jens Axboe2056a782006-03-23 20:00:26 +0100249 t->sector = sector;
250 t->bytes = bytes;
251 t->action = what;
Jens Axboe2056a782006-03-23 20:00:26 +0100252 t->device = bt->dev;
Jens Axboe2056a782006-03-23 20:00:26 +0100253 t->error = error;
254 t->pdu_len = pdu_len;
255
256 if (pdu_len)
257 memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200258
Li Zefan18cea452009-03-27 10:21:54 +0800259 if (blk_tracer) {
Steven Rostedte77405a2009-09-02 14:17:06 -0400260 trace_buffer_unlock_commit(buffer, event, 0, pc);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -0200261 return;
262 }
Jens Axboe2056a782006-03-23 20:00:26 +0100263 }
264
265 local_irq_restore(flags);
266}
267
Jens Axboe2056a782006-03-23 20:00:26 +0100268static struct dentry *blk_tree_root;
Jens Axboe11a57152008-01-11 13:37:01 +0100269static DEFINE_MUTEX(blk_tree_mutex);
Jens Axboe2056a782006-03-23 20:00:26 +0100270
Li Zefanad5dd542009-03-27 10:20:24 +0800271static void blk_trace_free(struct blk_trace *bt)
Jens Axboe2056a782006-03-23 20:00:26 +0100272{
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200273 debugfs_remove(bt->msg_file);
Jens Axboe2056a782006-03-23 20:00:26 +0100274 debugfs_remove(bt->dropped_file);
Jens Axboef48fc4d2009-01-05 10:17:25 +0100275 relay_close(bt->rchan);
Alan D. Brunelle39cbb602009-08-07 12:01:08 -0400276 debugfs_remove(bt->dir);
Jens Axboe2056a782006-03-23 20:00:26 +0100277 free_percpu(bt->sequence);
Jens Axboe64565912008-05-28 14:45:33 +0200278 free_percpu(bt->msg_data);
Jens Axboe2056a782006-03-23 20:00:26 +0100279 kfree(bt);
Li Zefanad5dd542009-03-27 10:20:24 +0800280}
281
282static void blk_trace_cleanup(struct blk_trace *bt)
283{
284 blk_trace_free(bt);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100285 if (atomic_dec_and_test(&blk_probes_ref))
286 blk_unregister_tracepoints();
Jens Axboe2056a782006-03-23 20:00:26 +0100287}
288
Christof Schmitt6da127a2008-01-11 10:09:43 +0100289int blk_trace_remove(struct request_queue *q)
Jens Axboe2056a782006-03-23 20:00:26 +0100290{
291 struct blk_trace *bt;
292
293 bt = xchg(&q->blk_trace, NULL);
294 if (!bt)
295 return -EINVAL;
296
Li Zefan55547202009-03-25 17:21:26 +0800297 if (bt->trace_state != Blktrace_running)
Jens Axboe2056a782006-03-23 20:00:26 +0100298 blk_trace_cleanup(bt);
299
300 return 0;
301}
Christof Schmitt6da127a2008-01-11 10:09:43 +0100302EXPORT_SYMBOL_GPL(blk_trace_remove);
Jens Axboe2056a782006-03-23 20:00:26 +0100303
304static int blk_dropped_open(struct inode *inode, struct file *filp)
305{
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700306 filp->private_data = inode->i_private;
Jens Axboe2056a782006-03-23 20:00:26 +0100307
308 return 0;
309}
310
311static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
312 size_t count, loff_t *ppos)
313{
314 struct blk_trace *bt = filp->private_data;
315 char buf[16];
316
317 snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
318
319 return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
320}
321
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800322static const struct file_operations blk_dropped_fops = {
Jens Axboe2056a782006-03-23 20:00:26 +0100323 .owner = THIS_MODULE,
324 .open = blk_dropped_open,
325 .read = blk_dropped_read,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200326 .llseek = default_llseek,
Jens Axboe2056a782006-03-23 20:00:26 +0100327};
328
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200329static int blk_msg_open(struct inode *inode, struct file *filp)
330{
331 filp->private_data = inode->i_private;
332
333 return 0;
334}
335
336static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
337 size_t count, loff_t *ppos)
338{
339 char *msg;
340 struct blk_trace *bt;
341
Li Zefan7635b032009-04-03 15:31:34 +0800342 if (count >= BLK_TN_MAX_MSG)
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200343 return -EINVAL;
344
Carl Henrik Lundea4b3ada2009-04-03 14:27:15 +0200345 msg = kmalloc(count + 1, GFP_KERNEL);
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200346 if (msg == NULL)
347 return -ENOMEM;
348
349 if (copy_from_user(msg, buffer, count)) {
350 kfree(msg);
351 return -EFAULT;
352 }
353
Carl Henrik Lundea4b3ada2009-04-03 14:27:15 +0200354 msg[count] = '\0';
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200355 bt = filp->private_data;
356 __trace_note_message(bt, "%s", msg);
357 kfree(msg);
358
359 return count;
360}
361
362static const struct file_operations blk_msg_fops = {
363 .owner = THIS_MODULE,
364 .open = blk_msg_open,
365 .write = blk_msg_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200366 .llseek = noop_llseek,
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200367};
368
Jens Axboe2056a782006-03-23 20:00:26 +0100369/*
370 * Keep track of how many times we encountered a full subbuffer, to aid
371 * the user space app in telling how many lost events there were.
372 */
373static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
374 void *prev_subbuf, size_t prev_padding)
375{
376 struct blk_trace *bt;
377
378 if (!relay_buf_full(buf))
379 return 1;
380
381 bt = buf->chan->private_data;
382 atomic_inc(&bt->dropped);
383 return 0;
384}
385
386static int blk_remove_buf_file_callback(struct dentry *dentry)
387{
388 debugfs_remove(dentry);
Jens Axboef48fc4d2009-01-05 10:17:25 +0100389
Jens Axboe2056a782006-03-23 20:00:26 +0100390 return 0;
391}
392
393static struct dentry *blk_create_buf_file_callback(const char *filename,
394 struct dentry *parent,
395 int mode,
396 struct rchan_buf *buf,
397 int *is_global)
398{
399 return debugfs_create_file(filename, mode, parent, buf,
400 &relay_file_operations);
401}
402
403static struct rchan_callbacks blk_relay_callbacks = {
404 .subbuf_start = blk_subbuf_start_callback,
405 .create_buf_file = blk_create_buf_file_callback,
406 .remove_buf_file = blk_remove_buf_file_callback,
407};
408
Li Zefan9908c302009-04-14 13:59:34 +0800409static void blk_trace_setup_lba(struct blk_trace *bt,
410 struct block_device *bdev)
411{
412 struct hd_struct *part = NULL;
413
414 if (bdev)
415 part = bdev->bd_part;
416
417 if (part) {
418 bt->start_lba = part->start_sect;
419 bt->end_lba = part->start_sect + part->nr_sects;
420 } else {
421 bt->start_lba = 0;
422 bt->end_lba = -1ULL;
423 }
424}
425
Jens Axboe2056a782006-03-23 20:00:26 +0100426/*
427 * Setup everything required to start tracing
428 */
Christof Schmitt6da127a2008-01-11 10:09:43 +0100429int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
Shawn Dud0deef52009-04-14 13:58:56 +0800430 struct block_device *bdev,
431 struct blk_user_trace_setup *buts)
Jens Axboe2056a782006-03-23 20:00:26 +0100432{
Jens Axboe2056a782006-03-23 20:00:26 +0100433 struct blk_trace *old_bt, *bt = NULL;
434 struct dentry *dir = NULL;
Jens Axboe2056a782006-03-23 20:00:26 +0100435 int ret, i;
436
Arnd Bergmann171044d42007-10-09 13:23:53 +0200437 if (!buts->buf_size || !buts->buf_nr)
Jens Axboe2056a782006-03-23 20:00:26 +0100438 return -EINVAL;
439
Jens Axboe0497b342008-10-01 16:16:25 +0200440 strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
441 buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
Jens Axboe2056a782006-03-23 20:00:26 +0100442
443 /*
444 * some device names have larger paths - convert the slashes
445 * to underscores for this to work as expected
446 */
Arnd Bergmann171044d42007-10-09 13:23:53 +0200447 for (i = 0; i < strlen(buts->name); i++)
448 if (buts->name[i] == '/')
449 buts->name[i] = '_';
Jens Axboe2056a782006-03-23 20:00:26 +0100450
Jens Axboe2056a782006-03-23 20:00:26 +0100451 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
452 if (!bt)
Li Zefanad5dd542009-03-27 10:20:24 +0800453 return -ENOMEM;
Jens Axboe2056a782006-03-23 20:00:26 +0100454
Li Zefanad5dd542009-03-27 10:20:24 +0800455 ret = -ENOMEM;
Jens Axboe2056a782006-03-23 20:00:26 +0100456 bt->sequence = alloc_percpu(unsigned long);
457 if (!bt->sequence)
458 goto err;
459
Ingo Molnarf0ef0392009-03-06 16:44:14 +0100460 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
Jens Axboe64565912008-05-28 14:45:33 +0200461 if (!bt->msg_data)
462 goto err;
463
Jens Axboe2056a782006-03-23 20:00:26 +0100464 ret = -ENOENT;
Jens Axboef48fc4d2009-01-05 10:17:25 +0100465
Li Zefanb5230b52009-03-25 17:19:33 +0800466 mutex_lock(&blk_tree_mutex);
Jens Axboef48fc4d2009-01-05 10:17:25 +0100467 if (!blk_tree_root) {
468 blk_tree_root = debugfs_create_dir("block", NULL);
Li Zefanb5230b52009-03-25 17:19:33 +0800469 if (!blk_tree_root) {
470 mutex_unlock(&blk_tree_mutex);
Li Zefan1a176622009-03-20 09:47:30 +0800471 goto err;
Li Zefanb5230b52009-03-25 17:19:33 +0800472 }
Jens Axboef48fc4d2009-01-05 10:17:25 +0100473 }
Li Zefanb5230b52009-03-25 17:19:33 +0800474 mutex_unlock(&blk_tree_mutex);
Jens Axboef48fc4d2009-01-05 10:17:25 +0100475
476 dir = debugfs_create_dir(buts->name, blk_tree_root);
477
Jens Axboe2056a782006-03-23 20:00:26 +0100478 if (!dir)
479 goto err;
480
481 bt->dir = dir;
Christof Schmitt6da127a2008-01-11 10:09:43 +0100482 bt->dev = dev;
Jens Axboe2056a782006-03-23 20:00:26 +0100483 atomic_set(&bt->dropped, 0);
484
485 ret = -EIO;
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200486 bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
487 &blk_dropped_fops);
Jens Axboe2056a782006-03-23 20:00:26 +0100488 if (!bt->dropped_file)
489 goto err;
490
Alan D. Brunelle02c62302008-06-11 09:12:52 +0200491 bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
492 if (!bt->msg_file)
493 goto err;
494
Arnd Bergmann171044d42007-10-09 13:23:53 +0200495 bt->rchan = relay_open("trace", dir, buts->buf_size,
496 buts->buf_nr, &blk_relay_callbacks, bt);
Jens Axboe2056a782006-03-23 20:00:26 +0100497 if (!bt->rchan)
498 goto err;
Jens Axboe2056a782006-03-23 20:00:26 +0100499
Arnd Bergmann171044d42007-10-09 13:23:53 +0200500 bt->act_mask = buts->act_mask;
Jens Axboe2056a782006-03-23 20:00:26 +0100501 if (!bt->act_mask)
502 bt->act_mask = (u16) -1;
503
Li Zefan9908c302009-04-14 13:59:34 +0800504 blk_trace_setup_lba(bt, bdev);
Jens Axboe2056a782006-03-23 20:00:26 +0100505
Shawn Dud0deef52009-04-14 13:58:56 +0800506 /* overwrite with user settings */
507 if (buts->start_lba)
508 bt->start_lba = buts->start_lba;
509 if (buts->end_lba)
510 bt->end_lba = buts->end_lba;
511
Arnd Bergmann171044d42007-10-09 13:23:53 +0200512 bt->pid = buts->pid;
Jens Axboe2056a782006-03-23 20:00:26 +0100513 bt->trace_state = Blktrace_setup;
514
515 ret = -EBUSY;
516 old_bt = xchg(&q->blk_trace, bt);
517 if (old_bt) {
518 (void) xchg(&q->blk_trace, old_bt);
519 goto err;
520 }
521
Li Zefan17ba97e2009-03-27 10:20:09 +0800522 if (atomic_inc_return(&blk_probes_ref) == 1)
Li Zefancbe28292009-03-20 09:48:47 +0800523 blk_register_tracepoints();
524
Jens Axboe2056a782006-03-23 20:00:26 +0100525 return 0;
526err:
Li Zefanad5dd542009-03-27 10:20:24 +0800527 blk_trace_free(bt);
Jens Axboe2056a782006-03-23 20:00:26 +0100528 return ret;
529}
530
Christof Schmitt6da127a2008-01-11 10:09:43 +0100531int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
Shawn Dud0deef52009-04-14 13:58:56 +0800532 struct block_device *bdev,
Christof Schmitt6da127a2008-01-11 10:09:43 +0100533 char __user *arg)
Arnd Bergmann171044d42007-10-09 13:23:53 +0200534{
535 struct blk_user_trace_setup buts;
536 int ret;
537
538 ret = copy_from_user(&buts, arg, sizeof(buts));
539 if (ret)
540 return -EFAULT;
541
Shawn Dud0deef52009-04-14 13:58:56 +0800542 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
Arnd Bergmann171044d42007-10-09 13:23:53 +0200543 if (ret)
544 return ret;
545
Dmitry Monakhov9a8c28c2010-02-27 20:35:13 +0300546 if (copy_to_user(arg, &buts, sizeof(buts))) {
547 blk_trace_remove(q);
Arnd Bergmann171044d42007-10-09 13:23:53 +0200548 return -EFAULT;
Dmitry Monakhov9a8c28c2010-02-27 20:35:13 +0300549 }
Arnd Bergmann171044d42007-10-09 13:23:53 +0200550 return 0;
551}
Christof Schmitt6da127a2008-01-11 10:09:43 +0100552EXPORT_SYMBOL_GPL(blk_trace_setup);
Arnd Bergmann171044d42007-10-09 13:23:53 +0200553
Arnd Bergmann62c2a7d2010-07-07 16:51:26 +0200554#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
555static int compat_blk_trace_setup(struct request_queue *q, char *name,
556 dev_t dev, struct block_device *bdev,
557 char __user *arg)
558{
559 struct blk_user_trace_setup buts;
560 struct compat_blk_user_trace_setup cbuts;
561 int ret;
562
563 if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
564 return -EFAULT;
565
566 buts = (struct blk_user_trace_setup) {
567 .act_mask = cbuts.act_mask,
568 .buf_size = cbuts.buf_size,
569 .buf_nr = cbuts.buf_nr,
570 .start_lba = cbuts.start_lba,
571 .end_lba = cbuts.end_lba,
572 .pid = cbuts.pid,
573 };
574 memcpy(&buts.name, &cbuts.name, 32);
575
576 ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
577 if (ret)
578 return ret;
579
580 if (copy_to_user(arg, &buts.name, 32)) {
581 blk_trace_remove(q);
582 return -EFAULT;
583 }
584
585 return 0;
586}
587#endif
588
Christof Schmitt6da127a2008-01-11 10:09:43 +0100589int blk_trace_startstop(struct request_queue *q, int start)
Jens Axboe2056a782006-03-23 20:00:26 +0100590{
Jens Axboe2056a782006-03-23 20:00:26 +0100591 int ret;
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200592 struct blk_trace *bt = q->blk_trace;
Jens Axboe2056a782006-03-23 20:00:26 +0100593
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200594 if (bt == NULL)
Jens Axboe2056a782006-03-23 20:00:26 +0100595 return -EINVAL;
596
597 /*
598 * For starting a trace, we can transition from a setup or stopped
599 * trace. For stopping a trace, the state must be running
600 */
601 ret = -EINVAL;
602 if (start) {
603 if (bt->trace_state == Blktrace_setup ||
604 bt->trace_state == Blktrace_stopped) {
605 blktrace_seq++;
606 smp_mb();
607 bt->trace_state = Blktrace_running;
Olaf Kirchbe1c6342006-12-01 10:39:12 +0100608
609 trace_note_time(bt);
Jens Axboe2056a782006-03-23 20:00:26 +0100610 ret = 0;
611 }
612 } else {
613 if (bt->trace_state == Blktrace_running) {
614 bt->trace_state = Blktrace_stopped;
615 relay_flush(bt->rchan);
616 ret = 0;
617 }
618 }
619
620 return ret;
621}
Christof Schmitt6da127a2008-01-11 10:09:43 +0100622EXPORT_SYMBOL_GPL(blk_trace_startstop);
Jens Axboe2056a782006-03-23 20:00:26 +0100623
624/**
625 * blk_trace_ioctl: - handle the ioctls associated with tracing
626 * @bdev: the block device
Steven Rostedtef180122009-03-10 14:10:56 -0400627 * @cmd: the ioctl cmd
Jens Axboe2056a782006-03-23 20:00:26 +0100628 * @arg: the argument data, if any
629 *
630 **/
631int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
632{
Jens Axboe165125e2007-07-24 09:28:11 +0200633 struct request_queue *q;
Jens Axboe2056a782006-03-23 20:00:26 +0100634 int ret, start = 0;
Christof Schmitt6da127a2008-01-11 10:09:43 +0100635 char b[BDEVNAME_SIZE];
Jens Axboe2056a782006-03-23 20:00:26 +0100636
637 q = bdev_get_queue(bdev);
638 if (!q)
639 return -ENXIO;
640
641 mutex_lock(&bdev->bd_mutex);
642
643 switch (cmd) {
644 case BLKTRACESETUP:
Jean Delvaref36f21e2008-05-12 14:02:33 -0700645 bdevname(bdev, b);
Shawn Dud0deef52009-04-14 13:58:56 +0800646 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
Jens Axboe2056a782006-03-23 20:00:26 +0100647 break;
Arnd Bergmann62c2a7d2010-07-07 16:51:26 +0200648#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
649 case BLKTRACESETUP32:
650 bdevname(bdev, b);
651 ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
652 break;
653#endif
Jens Axboe2056a782006-03-23 20:00:26 +0100654 case BLKTRACESTART:
655 start = 1;
656 case BLKTRACESTOP:
657 ret = blk_trace_startstop(q, start);
658 break;
659 case BLKTRACETEARDOWN:
660 ret = blk_trace_remove(q);
661 break;
662 default:
663 ret = -ENOTTY;
664 break;
665 }
666
667 mutex_unlock(&bdev->bd_mutex);
668 return ret;
669}
670
671/**
672 * blk_trace_shutdown: - stop and cleanup trace structures
673 * @q: the request queue associated with the device
674 *
675 **/
Jens Axboe165125e2007-07-24 09:28:11 +0200676void blk_trace_shutdown(struct request_queue *q)
Jens Axboe2056a782006-03-23 20:00:26 +0100677{
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -0700678 if (q->blk_trace) {
679 blk_trace_startstop(q, 0);
680 blk_trace_remove(q);
681 }
Jens Axboe2056a782006-03-23 20:00:26 +0100682}
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100683
684/*
685 * blktrace probes
686 */
687
688/**
689 * blk_add_trace_rq - Add a trace for a request oriented action
690 * @q: queue the io is for
691 * @rq: the source request
692 * @what: the action
693 *
694 * Description:
695 * Records an action against a request. Will log the bio offset + size.
696 *
697 **/
698static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
699 u32 what)
700{
701 struct blk_trace *bt = q->blk_trace;
702 int rw = rq->cmd_flags & 0x03;
703
704 if (likely(!bt))
705 return;
706
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200707 if (rq->cmd_flags & REQ_DISCARD)
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200708 rw |= REQ_DISCARD;
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100709
Adrian Hunter8d57a982010-08-11 14:17:49 -0700710 if (rq->cmd_flags & REQ_SECURE)
711 rw |= REQ_SECURE;
712
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200713 if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100714 what |= BLK_TC_ACT(BLK_TC_PC);
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900715 __blk_add_trace(bt, 0, blk_rq_bytes(rq), rw,
716 what, rq->errors, rq->cmd_len, rq->cmd);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100717 } else {
718 what |= BLK_TC_ACT(BLK_TC_FS);
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900719 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), rw,
720 what, rq->errors, 0, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100721 }
722}
723
Steven Rostedt38516ab2010-04-20 17:04:50 -0400724static void blk_add_trace_rq_abort(void *ignore,
725 struct request_queue *q, struct request *rq)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100726{
727 blk_add_trace_rq(q, rq, BLK_TA_ABORT);
728}
729
Steven Rostedt38516ab2010-04-20 17:04:50 -0400730static void blk_add_trace_rq_insert(void *ignore,
731 struct request_queue *q, struct request *rq)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100732{
733 blk_add_trace_rq(q, rq, BLK_TA_INSERT);
734}
735
Steven Rostedt38516ab2010-04-20 17:04:50 -0400736static void blk_add_trace_rq_issue(void *ignore,
737 struct request_queue *q, struct request *rq)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100738{
739 blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
740}
741
Steven Rostedt38516ab2010-04-20 17:04:50 -0400742static void blk_add_trace_rq_requeue(void *ignore,
743 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200744 struct request *rq)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100745{
746 blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
747}
748
Steven Rostedt38516ab2010-04-20 17:04:50 -0400749static void blk_add_trace_rq_complete(void *ignore,
750 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200751 struct request *rq)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100752{
753 blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
754}
755
756/**
757 * blk_add_trace_bio - Add a trace for a bio oriented action
758 * @q: queue the io is for
759 * @bio: the source bio
760 * @what: the action
761 *
762 * Description:
763 * Records an action against a bio. Will log the bio offset + size.
764 *
765 **/
766static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
767 u32 what)
768{
769 struct blk_trace *bt = q->blk_trace;
770
771 if (likely(!bt))
772 return;
773
774 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
775 !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
776}
777
Steven Rostedt38516ab2010-04-20 17:04:50 -0400778static void blk_add_trace_bio_bounce(void *ignore,
779 struct request_queue *q, struct bio *bio)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100780{
781 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE);
782}
783
Steven Rostedt38516ab2010-04-20 17:04:50 -0400784static void blk_add_trace_bio_complete(void *ignore,
785 struct request_queue *q, struct bio *bio)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100786{
787 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
788}
789
Steven Rostedt38516ab2010-04-20 17:04:50 -0400790static void blk_add_trace_bio_backmerge(void *ignore,
791 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200792 struct bio *bio)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100793{
794 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
795}
796
Steven Rostedt38516ab2010-04-20 17:04:50 -0400797static void blk_add_trace_bio_frontmerge(void *ignore,
798 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200799 struct bio *bio)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100800{
801 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
802}
803
Steven Rostedt38516ab2010-04-20 17:04:50 -0400804static void blk_add_trace_bio_queue(void *ignore,
805 struct request_queue *q, struct bio *bio)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100806{
807 blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
808}
809
Steven Rostedt38516ab2010-04-20 17:04:50 -0400810static void blk_add_trace_getrq(void *ignore,
811 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200812 struct bio *bio, int rw)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100813{
814 if (bio)
815 blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
816 else {
817 struct blk_trace *bt = q->blk_trace;
818
819 if (bt)
820 __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
821 }
822}
823
824
Steven Rostedt38516ab2010-04-20 17:04:50 -0400825static void blk_add_trace_sleeprq(void *ignore,
826 struct request_queue *q,
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200827 struct bio *bio, int rw)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100828{
829 if (bio)
830 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
831 else {
832 struct blk_trace *bt = q->blk_trace;
833
834 if (bt)
Arnaldo Carvalho de Melo939b3662009-02-03 11:58:29 -0200835 __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ,
836 0, 0, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100837 }
838}
839
Steven Rostedt38516ab2010-04-20 17:04:50 -0400840static void blk_add_trace_plug(void *ignore, struct request_queue *q)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100841{
842 struct blk_trace *bt = q->blk_trace;
843
844 if (bt)
845 __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
846}
847
Steven Rostedt38516ab2010-04-20 17:04:50 -0400848static void blk_add_trace_unplug_io(void *ignore, struct request_queue *q)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100849{
850 struct blk_trace *bt = q->blk_trace;
851
852 if (bt) {
853 unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
854 __be64 rpdu = cpu_to_be64(pdu);
855
856 __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0,
857 sizeof(rpdu), &rpdu);
858 }
859}
860
Steven Rostedt38516ab2010-04-20 17:04:50 -0400861static void blk_add_trace_unplug_timer(void *ignore, struct request_queue *q)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100862{
863 struct blk_trace *bt = q->blk_trace;
864
865 if (bt) {
866 unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
867 __be64 rpdu = cpu_to_be64(pdu);
868
869 __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0,
870 sizeof(rpdu), &rpdu);
871 }
872}
873
Steven Rostedt38516ab2010-04-20 17:04:50 -0400874static void blk_add_trace_split(void *ignore,
875 struct request_queue *q, struct bio *bio,
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100876 unsigned int pdu)
877{
878 struct blk_trace *bt = q->blk_trace;
879
880 if (bt) {
881 __be64 rpdu = cpu_to_be64(pdu);
882
883 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
884 BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
885 sizeof(rpdu), &rpdu);
886 }
887}
888
889/**
890 * blk_add_trace_remap - Add a trace for a remap operation
Randy Dunlap546cf442010-05-29 11:45:07 -0700891 * @ignore: trace callback data parameter (not used)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100892 * @q: queue the io is for
893 * @bio: the source bio
894 * @dev: target device
Alan D. Brunellea42aaa32009-05-04 16:27:26 -0400895 * @from: source sector
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100896 *
897 * Description:
898 * Device mapper or raid target sometimes need to split a bio because
899 * it spans a stripe (or similar). Add a trace for that action.
900 *
901 **/
Steven Rostedt38516ab2010-04-20 17:04:50 -0400902static void blk_add_trace_remap(void *ignore,
903 struct request_queue *q, struct bio *bio,
904 dev_t dev, sector_t from)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100905{
906 struct blk_trace *bt = q->blk_trace;
907 struct blk_io_trace_remap r;
908
909 if (likely(!bt))
910 return;
911
Alan D. Brunellea42aaa32009-05-04 16:27:26 -0400912 r.device_from = cpu_to_be32(dev);
913 r.device_to = cpu_to_be32(bio->bi_bdev->bd_dev);
914 r.sector_from = cpu_to_be64(from);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100915
Alan D. Brunelle22a7c312009-05-04 16:35:08 -0400916 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
917 BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE),
918 sizeof(r), &r);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100919}
920
921/**
Jun'ichi Nomurab0da3f02009-10-01 21:16:13 +0200922 * blk_add_trace_rq_remap - Add a trace for a request-remap operation
Randy Dunlap546cf442010-05-29 11:45:07 -0700923 * @ignore: trace callback data parameter (not used)
Jun'ichi Nomurab0da3f02009-10-01 21:16:13 +0200924 * @q: queue the io is for
925 * @rq: the source request
926 * @dev: target device
927 * @from: source sector
928 *
929 * Description:
930 * Device mapper remaps request to other devices.
931 * Add a trace for that action.
932 *
933 **/
Steven Rostedt38516ab2010-04-20 17:04:50 -0400934static void blk_add_trace_rq_remap(void *ignore,
935 struct request_queue *q,
Jun'ichi Nomurab0da3f02009-10-01 21:16:13 +0200936 struct request *rq, dev_t dev,
937 sector_t from)
938{
939 struct blk_trace *bt = q->blk_trace;
940 struct blk_io_trace_remap r;
941
942 if (likely(!bt))
943 return;
944
945 r.device_from = cpu_to_be32(dev);
946 r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
947 r.sector_from = cpu_to_be64(from);
948
949 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
950 rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
951 sizeof(r), &r);
952}
953
954/**
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100955 * blk_add_driver_data - Add binary message with driver-specific data
956 * @q: queue the io is for
957 * @rq: io request
958 * @data: driver-specific data
959 * @len: length of driver-specific data
960 *
961 * Description:
962 * Some drivers might want to write driver-specific data per request.
963 *
964 **/
965void blk_add_driver_data(struct request_queue *q,
966 struct request *rq,
967 void *data, size_t len)
968{
969 struct blk_trace *bt = q->blk_trace;
970
971 if (likely(!bt))
972 return;
973
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200974 if (rq->cmd_type == REQ_TYPE_BLOCK_PC)
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900975 __blk_add_trace(bt, 0, blk_rq_bytes(rq), 0,
976 BLK_TA_DRV_DATA, rq->errors, len, data);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100977 else
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900978 __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 0,
979 BLK_TA_DRV_DATA, rq->errors, len, data);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100980}
981EXPORT_SYMBOL_GPL(blk_add_driver_data);
982
Li Zefan3c289ba2009-03-20 09:48:26 +0800983static void blk_register_tracepoints(void)
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100984{
985 int ret;
986
Steven Rostedt38516ab2010-04-20 17:04:50 -0400987 ret = register_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100988 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400989 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100990 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400991 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100992 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400993 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100994 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400995 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100996 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400997 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +0100998 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -0400999 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001000 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001001 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001002 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001003 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001004 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001005 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001006 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001007 ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001008 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001009 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001010 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001011 ret = register_trace_block_plug(blk_add_trace_plug, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001012 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001013 ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001014 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001015 ret = register_trace_block_unplug_io(blk_add_trace_unplug_io, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001016 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001017 ret = register_trace_block_split(blk_add_trace_split, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001018 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001019 ret = register_trace_block_remap(blk_add_trace_remap, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001020 WARN_ON(ret);
Steven Rostedt38516ab2010-04-20 17:04:50 -04001021 ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
Jun'ichi Nomurab0da3f02009-10-01 21:16:13 +02001022 WARN_ON(ret);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001023}
1024
1025static void blk_unregister_tracepoints(void)
1026{
Steven Rostedt38516ab2010-04-20 17:04:50 -04001027 unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);
1028 unregister_trace_block_remap(blk_add_trace_remap, NULL);
1029 unregister_trace_block_split(blk_add_trace_split, NULL);
1030 unregister_trace_block_unplug_io(blk_add_trace_unplug_io, NULL);
1031 unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer, NULL);
1032 unregister_trace_block_plug(blk_add_trace_plug, NULL);
1033 unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
1034 unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
1035 unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
1036 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
1037 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL);
1038 unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL);
1039 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
1040 unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
1041 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
1042 unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
1043 unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
1044 unregister_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001045
1046 tracepoint_synchronize_unregister();
1047}
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001048
1049/*
1050 * struct blk_io_tracer formatting routines
1051 */
1052
1053static void fill_rwbs(char *rwbs, const struct blk_io_trace *t)
1054{
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001055 int i = 0;
Li Zefan65796342009-03-24 16:05:06 +08001056 int tc = t->action >> BLK_TC_SHIFT;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001057
Li Zefan18cea452009-03-27 10:21:54 +08001058 if (t->action == BLK_TN_MESSAGE) {
1059 rwbs[i++] = 'N';
1060 goto out;
1061 }
1062
Li Zefan65796342009-03-24 16:05:06 +08001063 if (tc & BLK_TC_DISCARD)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001064 rwbs[i++] = 'D';
Li Zefan65796342009-03-24 16:05:06 +08001065 else if (tc & BLK_TC_WRITE)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001066 rwbs[i++] = 'W';
1067 else if (t->bytes)
1068 rwbs[i++] = 'R';
1069 else
1070 rwbs[i++] = 'N';
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001071
Li Zefan65796342009-03-24 16:05:06 +08001072 if (tc & BLK_TC_AHEAD)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001073 rwbs[i++] = 'A';
Li Zefan65796342009-03-24 16:05:06 +08001074 if (tc & BLK_TC_BARRIER)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001075 rwbs[i++] = 'B';
Li Zefan65796342009-03-24 16:05:06 +08001076 if (tc & BLK_TC_SYNC)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001077 rwbs[i++] = 'S';
Li Zefan65796342009-03-24 16:05:06 +08001078 if (tc & BLK_TC_META)
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001079 rwbs[i++] = 'M';
Li Zefan18cea452009-03-27 10:21:54 +08001080out:
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001081 rwbs[i] = '\0';
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001082}
1083
1084static inline
1085const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent)
1086{
1087 return (const struct blk_io_trace *)ent;
1088}
1089
1090static inline const void *pdu_start(const struct trace_entry *ent)
1091{
1092 return te_blk_io_trace(ent) + 1;
1093}
1094
Li Zefan66de7792009-04-01 16:19:19 +08001095static inline u32 t_action(const struct trace_entry *ent)
1096{
1097 return te_blk_io_trace(ent)->action;
1098}
1099
1100static inline u32 t_bytes(const struct trace_entry *ent)
1101{
1102 return te_blk_io_trace(ent)->bytes;
1103}
1104
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001105static inline u32 t_sec(const struct trace_entry *ent)
1106{
1107 return te_blk_io_trace(ent)->bytes >> 9;
1108}
1109
1110static inline unsigned long long t_sector(const struct trace_entry *ent)
1111{
1112 return te_blk_io_trace(ent)->sector;
1113}
1114
1115static inline __u16 t_error(const struct trace_entry *ent)
1116{
Li Zefane0dc81b2009-03-24 16:05:51 +08001117 return te_blk_io_trace(ent)->error;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001118}
1119
1120static __u64 get_pdu_int(const struct trace_entry *ent)
1121{
1122 const __u64 *val = pdu_start(ent);
1123 return be64_to_cpu(*val);
1124}
1125
1126static void get_pdu_remap(const struct trace_entry *ent,
1127 struct blk_io_trace_remap *r)
1128{
1129 const struct blk_io_trace_remap *__r = pdu_start(ent);
Alan D. Brunellea42aaa32009-05-04 16:27:26 -04001130 __u64 sector_from = __r->sector_from;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001131
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001132 r->device_from = be32_to_cpu(__r->device_from);
Alan D. Brunellea42aaa32009-05-04 16:27:26 -04001133 r->device_to = be32_to_cpu(__r->device_to);
1134 r->sector_from = be64_to_cpu(sector_from);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001135}
1136
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001137typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
1138
1139static int blk_log_action_classic(struct trace_iterator *iter, const char *act)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001140{
1141 char rwbs[6];
Li Zefan35ac51b2009-03-27 10:19:46 +08001142 unsigned long long ts = iter->ts;
1143 unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001144 unsigned secs = (unsigned long)ts;
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001145 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001146
1147 fill_rwbs(rwbs, t);
1148
1149 return trace_seq_printf(&iter->seq,
Li Zefan35ac51b2009-03-27 10:19:46 +08001150 "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ",
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001151 MAJOR(t->device), MINOR(t->device), iter->cpu,
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001152 secs, nsec_rem, iter->ent->pid, act, rwbs);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001153}
1154
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001155static int blk_log_action(struct trace_iterator *iter, const char *act)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001156{
1157 char rwbs[6];
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001158 const struct blk_io_trace *t = te_blk_io_trace(iter->ent);
1159
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001160 fill_rwbs(rwbs, t);
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001161 return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ",
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001162 MAJOR(t->device), MINOR(t->device), act, rwbs);
1163}
1164
Li Zefan66de7792009-04-01 16:19:19 +08001165static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent)
1166{
Li Zefan04986252009-05-11 14:33:23 +08001167 const unsigned char *pdu_buf;
Li Zefan66de7792009-04-01 16:19:19 +08001168 int pdu_len;
1169 int i, end, ret;
1170
1171 pdu_buf = pdu_start(ent);
1172 pdu_len = te_blk_io_trace(ent)->pdu_len;
1173
1174 if (!pdu_len)
1175 return 1;
1176
1177 /* find the last zero that needs to be printed */
1178 for (end = pdu_len - 1; end >= 0; end--)
1179 if (pdu_buf[end])
1180 break;
1181 end++;
1182
1183 if (!trace_seq_putc(s, '('))
1184 return 0;
1185
1186 for (i = 0; i < pdu_len; i++) {
1187
1188 ret = trace_seq_printf(s, "%s%02x",
1189 i == 0 ? "" : " ", pdu_buf[i]);
1190 if (!ret)
1191 return ret;
1192
1193 /*
1194 * stop when the rest is just zeroes and indicate so
1195 * with a ".." appended
1196 */
1197 if (i == end && end != pdu_len - 1)
1198 return trace_seq_puts(s, " ..) ");
1199 }
1200
1201 return trace_seq_puts(s, ") ");
1202}
1203
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001204static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent)
1205{
Steven Rostedt4ca530852009-03-16 19:20:15 -04001206 char cmd[TASK_COMM_LEN];
1207
1208 trace_find_cmdline(ent->pid, cmd);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001209
Li Zefan66de7792009-04-01 16:19:19 +08001210 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1211 int ret;
1212
1213 ret = trace_seq_printf(s, "%u ", t_bytes(ent));
1214 if (!ret)
1215 return 0;
1216 ret = blk_log_dump_pdu(s, ent);
1217 if (!ret)
1218 return 0;
1219 return trace_seq_printf(s, "[%s]\n", cmd);
1220 } else {
1221 if (t_sec(ent))
1222 return trace_seq_printf(s, "%llu + %u [%s]\n",
1223 t_sector(ent), t_sec(ent), cmd);
1224 return trace_seq_printf(s, "[%s]\n", cmd);
1225 }
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001226}
1227
Arnaldo Carvalho de Melo157f9c02009-01-26 15:00:56 -02001228static int blk_log_with_error(struct trace_seq *s,
1229 const struct trace_entry *ent)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001230{
Li Zefan66de7792009-04-01 16:19:19 +08001231 if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) {
1232 int ret;
1233
1234 ret = blk_log_dump_pdu(s, ent);
1235 if (ret)
1236 return trace_seq_printf(s, "[%d]\n", t_error(ent));
1237 return 0;
1238 } else {
1239 if (t_sec(ent))
1240 return trace_seq_printf(s, "%llu + %u [%d]\n",
1241 t_sector(ent),
1242 t_sec(ent), t_error(ent));
1243 return trace_seq_printf(s, "%llu [%d]\n",
1244 t_sector(ent), t_error(ent));
1245 }
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001246}
1247
1248static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
1249{
Alan D. Brunellea42aaa32009-05-04 16:27:26 -04001250 struct blk_io_trace_remap r = { .device_from = 0, };
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001251
1252 get_pdu_remap(ent, &r);
1253 return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
Alan D. Brunellea42aaa32009-05-04 16:27:26 -04001254 t_sector(ent), t_sec(ent),
1255 MAJOR(r.device_from), MINOR(r.device_from),
1256 (unsigned long long)r.sector_from);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001257}
1258
1259static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
1260{
Steven Rostedt4ca530852009-03-16 19:20:15 -04001261 char cmd[TASK_COMM_LEN];
1262
1263 trace_find_cmdline(ent->pid, cmd);
1264
1265 return trace_seq_printf(s, "[%s]\n", cmd);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001266}
1267
1268static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent)
1269{
Steven Rostedt4ca530852009-03-16 19:20:15 -04001270 char cmd[TASK_COMM_LEN];
1271
1272 trace_find_cmdline(ent->pid, cmd);
1273
1274 return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent));
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001275}
1276
1277static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent)
1278{
Steven Rostedt4ca530852009-03-16 19:20:15 -04001279 char cmd[TASK_COMM_LEN];
1280
1281 trace_find_cmdline(ent->pid, cmd);
1282
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001283 return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent),
Steven Rostedt4ca530852009-03-16 19:20:15 -04001284 get_pdu_int(ent), cmd);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001285}
1286
Li Zefan18cea452009-03-27 10:21:54 +08001287static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent)
1288{
1289 int ret;
1290 const struct blk_io_trace *t = te_blk_io_trace(ent);
1291
1292 ret = trace_seq_putmem(s, t + 1, t->pdu_len);
1293 if (ret)
1294 return trace_seq_putc(s, '\n');
1295 return ret;
1296}
1297
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001298/*
1299 * struct tracer operations
1300 */
1301
1302static void blk_tracer_print_header(struct seq_file *m)
1303{
1304 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1305 return;
1306 seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n"
1307 "# | | | | | |\n");
1308}
1309
1310static void blk_tracer_start(struct trace_array *tr)
1311{
Li Zefanad5dd542009-03-27 10:20:24 +08001312 blk_tracer_enabled = true;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001313}
1314
1315static int blk_tracer_init(struct trace_array *tr)
1316{
1317 blk_tr = tr;
1318 blk_tracer_start(tr);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001319 return 0;
1320}
1321
1322static void blk_tracer_stop(struct trace_array *tr)
1323{
Li Zefanad5dd542009-03-27 10:20:24 +08001324 blk_tracer_enabled = false;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001325}
1326
1327static void blk_tracer_reset(struct trace_array *tr)
1328{
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001329 blk_tracer_stop(tr);
1330}
1331
Li Zefane4955c92009-03-24 16:04:37 +08001332static const struct {
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001333 const char *act[2];
Steven Rostedtef180122009-03-10 14:10:56 -04001334 int (*print)(struct trace_seq *s, const struct trace_entry *ent);
Li Zefane4955c92009-03-24 16:04:37 +08001335} what2act[] = {
Steven Rostedtef180122009-03-10 14:10:56 -04001336 [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic },
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001337 [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic },
1338 [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic },
1339 [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic },
1340 [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic },
1341 [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error },
1342 [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic },
1343 [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error },
1344 [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug },
1345 [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug },
1346 [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug },
1347 [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic },
1348 [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split },
1349 [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic },
1350 [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap },
1351};
1352
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001353static enum print_line_t print_one_line(struct trace_iterator *iter,
1354 bool classic)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001355{
Arnaldo Carvalho de Melo2c9b2382009-02-02 20:30:12 -02001356 struct trace_seq *s = &iter->seq;
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001357 const struct blk_io_trace *t;
1358 u16 what;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001359 int ret;
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001360 bool long_act;
1361 blk_log_action_t *log_action;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001362
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001363 t = te_blk_io_trace(iter->ent);
1364 what = t->action & ((1 << BLK_TC_SHIFT) - 1);
1365 long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
1366 log_action = classic ? &blk_log_action_classic : &blk_log_action;
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -02001367
Li Zefan18cea452009-03-27 10:21:54 +08001368 if (t->action == BLK_TN_MESSAGE) {
1369 ret = log_action(iter, long_act ? "message" : "m");
1370 if (ret)
1371 ret = blk_log_msg(s, iter->ent);
1372 goto out;
1373 }
1374
Li Zefaneb08f8e2009-03-24 16:05:27 +08001375 if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
Li Zefanb78825d2009-04-01 16:18:53 +08001376 ret = trace_seq_printf(s, "Unknown action %x\n", what);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001377 else {
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001378 ret = log_action(iter, what2act[what].act[long_act]);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001379 if (ret)
Arnaldo Carvalho de Melo2c9b2382009-02-02 20:30:12 -02001380 ret = what2act[what].print(s, iter->ent);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001381 }
Li Zefan18cea452009-03-27 10:21:54 +08001382out:
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001383 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1384}
1385
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001386static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
Steven Rostedta9a57762010-04-22 18:46:14 -04001387 int flags, struct trace_event *event)
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001388{
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001389 return print_one_line(iter, false);
1390}
1391
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -02001392static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
1393{
1394 struct trace_seq *s = &iter->seq;
1395 struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
1396 const int offset = offsetof(struct blk_io_trace, sector);
1397 struct blk_io_trace old = {
1398 .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
Li Zefan6c051ce2009-03-25 17:18:56 +08001399 .time = iter->ts,
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -02001400 };
1401
1402 if (!trace_seq_putmem(s, &old, offset))
1403 return 0;
1404 return trace_seq_putmem(s, &t->sector,
1405 sizeof(old) - offset + t->pdu_len);
1406}
1407
Arnaldo Carvalho de Meloae7462b2009-02-03 22:05:50 -02001408static enum print_line_t
Steven Rostedta9a57762010-04-22 18:46:14 -04001409blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
1410 struct trace_event *event)
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -02001411{
1412 return blk_trace_synthesize_old_trace(iter) ?
1413 TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
1414}
1415
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001416static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
1417{
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001418 if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
1419 return TRACE_TYPE_UNHANDLED;
1420
Li Zefanb6a4b0c2009-03-27 10:21:23 +08001421 return print_one_line(iter, true);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001422}
1423
Li Zefanf3948f82009-04-15 11:02:56 +08001424static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
1425{
1426 /* don't output context-info for blk_classic output */
1427 if (bit == TRACE_BLK_OPT_CLASSIC) {
1428 if (set)
1429 trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
1430 else
1431 trace_flags |= TRACE_ITER_CONTEXT_INFO;
1432 }
1433 return 0;
1434}
1435
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001436static struct tracer blk_tracer __read_mostly = {
1437 .name = "blk",
1438 .init = blk_tracer_init,
1439 .reset = blk_tracer_reset,
1440 .start = blk_tracer_start,
1441 .stop = blk_tracer_stop,
1442 .print_header = blk_tracer_print_header,
1443 .print_line = blk_tracer_print_line,
1444 .flags = &blk_tracer_flags,
Li Zefanf3948f82009-04-15 11:02:56 +08001445 .set_flag = blk_tracer_set_flag,
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001446};
1447
Steven Rostedta9a57762010-04-22 18:46:14 -04001448static struct trace_event_functions trace_blk_event_funcs = {
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001449 .trace = blk_trace_event_print,
Arnaldo Carvalho de Melo08a06b82009-02-02 20:30:40 -02001450 .binary = blk_trace_event_print_binary,
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001451};
1452
Steven Rostedta9a57762010-04-22 18:46:14 -04001453static struct trace_event trace_blk_event = {
1454 .type = TRACE_BLK,
1455 .funcs = &trace_blk_event_funcs,
1456};
1457
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001458static int __init init_blk_tracer(void)
1459{
1460 if (!register_ftrace_event(&trace_blk_event)) {
1461 pr_warning("Warning: could not register block events\n");
1462 return 1;
1463 }
1464
1465 if (register_tracer(&blk_tracer) != 0) {
1466 pr_warning("Warning: could not register the block tracer\n");
1467 unregister_ftrace_event(&trace_blk_event);
1468 return 1;
1469 }
1470
1471 return 0;
1472}
1473
1474device_initcall(init_blk_tracer);
1475
1476static int blk_trace_remove_queue(struct request_queue *q)
1477{
1478 struct blk_trace *bt;
1479
1480 bt = xchg(&q->blk_trace, NULL);
1481 if (bt == NULL)
1482 return -EINVAL;
1483
Li Zefan17ba97e2009-03-27 10:20:09 +08001484 if (atomic_dec_and_test(&blk_probes_ref))
1485 blk_unregister_tracepoints();
1486
Li Zefanad5dd542009-03-27 10:20:24 +08001487 blk_trace_free(bt);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001488 return 0;
1489}
1490
1491/*
1492 * Setup everything required to start tracing
1493 */
Li Zefan9908c302009-04-14 13:59:34 +08001494static int blk_trace_setup_queue(struct request_queue *q,
1495 struct block_device *bdev)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001496{
1497 struct blk_trace *old_bt, *bt = NULL;
Li Zefan18cea452009-03-27 10:21:54 +08001498 int ret = -ENOMEM;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001499
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001500 bt = kzalloc(sizeof(*bt), GFP_KERNEL);
1501 if (!bt)
Li Zefan15152e42009-03-20 09:49:08 +08001502 return -ENOMEM;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001503
Li Zefan18cea452009-03-27 10:21:54 +08001504 bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
1505 if (!bt->msg_data)
1506 goto free_bt;
1507
Li Zefan9908c302009-04-14 13:59:34 +08001508 bt->dev = bdev->bd_dev;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001509 bt->act_mask = (u16)-1;
Li Zefan9908c302009-04-14 13:59:34 +08001510
1511 blk_trace_setup_lba(bt, bdev);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001512
1513 old_bt = xchg(&q->blk_trace, bt);
1514 if (old_bt != NULL) {
1515 (void)xchg(&q->blk_trace, old_bt);
Li Zefan18cea452009-03-27 10:21:54 +08001516 ret = -EBUSY;
1517 goto free_bt;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001518 }
Li Zefan15152e42009-03-20 09:49:08 +08001519
Li Zefan17ba97e2009-03-27 10:20:09 +08001520 if (atomic_inc_return(&blk_probes_ref) == 1)
1521 blk_register_tracepoints();
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001522 return 0;
Li Zefan18cea452009-03-27 10:21:54 +08001523
1524free_bt:
1525 blk_trace_free(bt);
1526 return ret;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001527}
1528
1529/*
1530 * sysfs interface to enable and configure tracing
1531 */
1532
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001533static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1534 struct device_attribute *attr,
1535 char *buf);
1536static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1537 struct device_attribute *attr,
1538 const char *buf, size_t count);
1539#define BLK_TRACE_DEVICE_ATTR(_name) \
1540 DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
1541 sysfs_blk_trace_attr_show, \
1542 sysfs_blk_trace_attr_store)
1543
Li Zefancd649b82009-03-20 11:33:55 +08001544static BLK_TRACE_DEVICE_ATTR(enable);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001545static BLK_TRACE_DEVICE_ATTR(act_mask);
1546static BLK_TRACE_DEVICE_ATTR(pid);
1547static BLK_TRACE_DEVICE_ATTR(start_lba);
1548static BLK_TRACE_DEVICE_ATTR(end_lba);
1549
1550static struct attribute *blk_trace_attrs[] = {
1551 &dev_attr_enable.attr,
1552 &dev_attr_act_mask.attr,
1553 &dev_attr_pid.attr,
1554 &dev_attr_start_lba.attr,
1555 &dev_attr_end_lba.attr,
1556 NULL
1557};
1558
1559struct attribute_group blk_trace_attr_group = {
1560 .name = "trace",
1561 .attrs = blk_trace_attrs,
1562};
1563
Li Zefan09341992009-03-24 17:43:30 +08001564static const struct {
1565 int mask;
1566 const char *str;
1567} mask_maps[] = {
1568 { BLK_TC_READ, "read" },
1569 { BLK_TC_WRITE, "write" },
1570 { BLK_TC_BARRIER, "barrier" },
1571 { BLK_TC_SYNC, "sync" },
1572 { BLK_TC_QUEUE, "queue" },
1573 { BLK_TC_REQUEUE, "requeue" },
1574 { BLK_TC_ISSUE, "issue" },
1575 { BLK_TC_COMPLETE, "complete" },
1576 { BLK_TC_FS, "fs" },
1577 { BLK_TC_PC, "pc" },
1578 { BLK_TC_AHEAD, "ahead" },
1579 { BLK_TC_META, "meta" },
1580 { BLK_TC_DISCARD, "discard" },
1581 { BLK_TC_DRV_DATA, "drv_data" },
1582};
1583
1584static int blk_trace_str2mask(const char *str)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001585{
Li Zefan09341992009-03-24 17:43:30 +08001586 int i;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001587 int mask = 0;
Li Zefan9eb85122009-04-09 11:19:40 +08001588 char *buf, *s, *token;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001589
Li Zefan9eb85122009-04-09 11:19:40 +08001590 buf = kstrdup(str, GFP_KERNEL);
1591 if (buf == NULL)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001592 return -ENOMEM;
Li Zefan9eb85122009-04-09 11:19:40 +08001593 s = strstrip(buf);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001594
1595 while (1) {
Li Zefan09341992009-03-24 17:43:30 +08001596 token = strsep(&s, ",");
1597 if (token == NULL)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001598 break;
1599
Li Zefan09341992009-03-24 17:43:30 +08001600 if (*token == '\0')
1601 continue;
1602
1603 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1604 if (strcasecmp(token, mask_maps[i].str) == 0) {
1605 mask |= mask_maps[i].mask;
1606 break;
1607 }
1608 }
1609 if (i == ARRAY_SIZE(mask_maps)) {
1610 mask = -EINVAL;
1611 break;
1612 }
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001613 }
Li Zefan9eb85122009-04-09 11:19:40 +08001614 kfree(buf);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001615
1616 return mask;
1617}
1618
Li Zefan09341992009-03-24 17:43:30 +08001619static ssize_t blk_trace_mask2str(char *buf, int mask)
1620{
1621 int i;
1622 char *p = buf;
1623
1624 for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
1625 if (mask & mask_maps[i].mask) {
1626 p += sprintf(p, "%s%s",
1627 (p == buf) ? "" : ",", mask_maps[i].str);
1628 }
1629 }
1630 *p++ = '\n';
1631
1632 return p - buf;
1633}
1634
Li Zefanb1251302009-03-20 10:34:00 +08001635static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
1636{
1637 if (bdev->bd_disk == NULL)
1638 return NULL;
1639
1640 return bdev_get_queue(bdev);
1641}
1642
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001643static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
1644 struct device_attribute *attr,
1645 char *buf)
1646{
1647 struct hd_struct *p = dev_to_part(dev);
1648 struct request_queue *q;
1649 struct block_device *bdev;
1650 ssize_t ret = -ENXIO;
1651
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001652 bdev = bdget(part_devt(p));
1653 if (bdev == NULL)
Arnd Bergmann01b284f2010-09-17 20:39:22 +02001654 goto out;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001655
Li Zefanb1251302009-03-20 10:34:00 +08001656 q = blk_trace_get_queue(bdev);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001657 if (q == NULL)
1658 goto out_bdput;
Li Zefanb1251302009-03-20 10:34:00 +08001659
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001660 mutex_lock(&bdev->bd_mutex);
Li Zefancd649b82009-03-20 11:33:55 +08001661
1662 if (attr == &dev_attr_enable) {
1663 ret = sprintf(buf, "%u\n", !!q->blk_trace);
1664 goto out_unlock_bdev;
1665 }
1666
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001667 if (q->blk_trace == NULL)
1668 ret = sprintf(buf, "disabled\n");
1669 else if (attr == &dev_attr_act_mask)
Li Zefan09341992009-03-24 17:43:30 +08001670 ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001671 else if (attr == &dev_attr_pid)
1672 ret = sprintf(buf, "%u\n", q->blk_trace->pid);
1673 else if (attr == &dev_attr_start_lba)
1674 ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
1675 else if (attr == &dev_attr_end_lba)
1676 ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
Li Zefancd649b82009-03-20 11:33:55 +08001677
1678out_unlock_bdev:
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001679 mutex_unlock(&bdev->bd_mutex);
1680out_bdput:
1681 bdput(bdev);
Arnd Bergmann01b284f2010-09-17 20:39:22 +02001682out:
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001683 return ret;
1684}
1685
1686static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
1687 struct device_attribute *attr,
1688 const char *buf, size_t count)
1689{
1690 struct block_device *bdev;
1691 struct request_queue *q;
1692 struct hd_struct *p;
1693 u64 value;
Li Zefan09341992009-03-24 17:43:30 +08001694 ssize_t ret = -EINVAL;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001695
1696 if (count == 0)
1697 goto out;
1698
1699 if (attr == &dev_attr_act_mask) {
1700 if (sscanf(buf, "%llx", &value) != 1) {
1701 /* Assume it is a list of trace category names */
Li Zefan09341992009-03-24 17:43:30 +08001702 ret = blk_trace_str2mask(buf);
1703 if (ret < 0)
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001704 goto out;
Li Zefan09341992009-03-24 17:43:30 +08001705 value = ret;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001706 }
1707 } else if (sscanf(buf, "%llu", &value) != 1)
1708 goto out;
1709
Li Zefan09341992009-03-24 17:43:30 +08001710 ret = -ENXIO;
1711
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001712 p = dev_to_part(dev);
1713 bdev = bdget(part_devt(p));
1714 if (bdev == NULL)
Arnd Bergmann01b284f2010-09-17 20:39:22 +02001715 goto out;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001716
Li Zefanb1251302009-03-20 10:34:00 +08001717 q = blk_trace_get_queue(bdev);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001718 if (q == NULL)
1719 goto out_bdput;
1720
1721 mutex_lock(&bdev->bd_mutex);
Li Zefancd649b82009-03-20 11:33:55 +08001722
1723 if (attr == &dev_attr_enable) {
1724 if (value)
Li Zefan9908c302009-04-14 13:59:34 +08001725 ret = blk_trace_setup_queue(q, bdev);
Li Zefancd649b82009-03-20 11:33:55 +08001726 else
1727 ret = blk_trace_remove_queue(q);
1728 goto out_unlock_bdev;
1729 }
1730
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001731 ret = 0;
1732 if (q->blk_trace == NULL)
Li Zefan9908c302009-04-14 13:59:34 +08001733 ret = blk_trace_setup_queue(q, bdev);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001734
1735 if (ret == 0) {
1736 if (attr == &dev_attr_act_mask)
1737 q->blk_trace->act_mask = value;
1738 else if (attr == &dev_attr_pid)
1739 q->blk_trace->pid = value;
1740 else if (attr == &dev_attr_start_lba)
1741 q->blk_trace->start_lba = value;
1742 else if (attr == &dev_attr_end_lba)
1743 q->blk_trace->end_lba = value;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001744 }
Li Zefancd649b82009-03-20 11:33:55 +08001745
1746out_unlock_bdev:
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001747 mutex_unlock(&bdev->bd_mutex);
1748out_bdput:
1749 bdput(bdev);
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001750out:
Li Zefancd649b82009-03-20 11:33:55 +08001751 return ret ? ret : count;
Arnaldo Carvalho de Meloc71a8962009-01-23 12:06:27 -02001752}
Li Zefancd649b82009-03-20 11:33:55 +08001753
Li Zefan1d54ad62009-04-14 14:00:05 +08001754int blk_trace_init_sysfs(struct device *dev)
1755{
1756 return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
1757}
1758
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +02001759void blk_trace_remove_sysfs(struct device *dev)
1760{
1761 sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
1762}
1763
Li Zefan55782132009-06-09 13:43:05 +08001764#endif /* CONFIG_BLK_DEV_IO_TRACE */
1765
1766#ifdef CONFIG_EVENT_TRACING
1767
1768void blk_dump_cmd(char *buf, struct request *rq)
1769{
1770 int i, end;
1771 int len = rq->cmd_len;
1772 unsigned char *cmd = rq->cmd;
1773
Christoph Hellwig33659eb2010-08-07 18:17:56 +02001774 if (rq->cmd_type != REQ_TYPE_BLOCK_PC) {
Li Zefan55782132009-06-09 13:43:05 +08001775 buf[0] = '\0';
1776 return;
1777 }
1778
1779 for (end = len - 1; end >= 0; end--)
1780 if (cmd[end])
1781 break;
1782 end++;
1783
1784 for (i = 0; i < len; i++) {
1785 buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
1786 if (i == end && end != len - 1) {
1787 sprintf(buf, " ..");
1788 break;
1789 }
1790 }
1791}
1792
1793void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
1794{
1795 int i = 0;
1796
1797 if (rw & WRITE)
1798 rwbs[i++] = 'W';
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001799 else if (rw & REQ_DISCARD)
Li Zefan55782132009-06-09 13:43:05 +08001800 rwbs[i++] = 'D';
1801 else if (bytes)
1802 rwbs[i++] = 'R';
1803 else
1804 rwbs[i++] = 'N';
1805
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001806 if (rw & REQ_RAHEAD)
Li Zefan55782132009-06-09 13:43:05 +08001807 rwbs[i++] = 'A';
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001808 if (rw & REQ_SYNC)
Li Zefan55782132009-06-09 13:43:05 +08001809 rwbs[i++] = 'S';
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001810 if (rw & REQ_META)
Li Zefan55782132009-06-09 13:43:05 +08001811 rwbs[i++] = 'M';
Adrian Hunter8d57a982010-08-11 14:17:49 -07001812 if (rw & REQ_SECURE)
1813 rwbs[i++] = 'E';
Li Zefan55782132009-06-09 13:43:05 +08001814
1815 rwbs[i] = '\0';
1816}
1817
1818void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
1819{
1820 int rw = rq->cmd_flags & 0x03;
1821 int bytes;
1822
Christoph Hellwig33659eb2010-08-07 18:17:56 +02001823 if (rq->cmd_flags & REQ_DISCARD)
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +02001824 rw |= REQ_DISCARD;
Li Zefan55782132009-06-09 13:43:05 +08001825
Adrian Hunter8d57a982010-08-11 14:17:49 -07001826 if (rq->cmd_flags & REQ_SECURE)
1827 rw |= REQ_SECURE;
1828
Linus Torvaldsc9059592009-06-11 10:52:27 -07001829 bytes = blk_rq_bytes(rq);
Li Zefan55782132009-06-09 13:43:05 +08001830
1831 blk_fill_rwbs(rwbs, rw, bytes);
1832}
1833
1834#endif /* CONFIG_EVENT_TRACING */
1835