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Commit | Line | Data |
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2056a782 | 1 | /* |
0fe23479 | 2 | * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> |
2056a782 JA |
3 | * |
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 | */ | |
2056a782 JA |
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/debugfs.h> | |
be1c6341 | 25 | #include <linux/time.h> |
5f3ea37c | 26 | #include <trace/block.h> |
939b3669 | 27 | #include <linux/uaccess.h> |
2db270a8 | 28 | #include "trace_output.h" |
2056a782 | 29 | |
2056a782 JA |
30 | static unsigned int blktrace_seq __read_mostly = 1; |
31 | ||
c71a8961 | 32 | static struct trace_array *blk_tr; |
5006ea73 | 33 | static bool blk_tracer_enabled __read_mostly; |
c71a8961 ACM |
34 | |
35 | /* Select an alternative, minimalistic output than the original one */ | |
ef18012b | 36 | #define TRACE_BLK_OPT_CLASSIC 0x1 |
c71a8961 ACM |
37 | |
38 | static struct tracer_opt blk_tracer_opts[] = { | |
39 | /* Default disable the minimalistic output */ | |
157f9c00 | 40 | { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, |
c71a8961 ACM |
41 | { } |
42 | }; | |
43 | ||
44 | static struct tracer_flags blk_tracer_flags = { | |
45 | .val = 0, | |
46 | .opts = blk_tracer_opts, | |
47 | }; | |
48 | ||
5f3ea37c | 49 | /* Global reference count of probes */ |
5f3ea37c ACM |
50 | static atomic_t blk_probes_ref = ATOMIC_INIT(0); |
51 | ||
3c289ba7 | 52 | static void blk_register_tracepoints(void); |
5f3ea37c ACM |
53 | static void blk_unregister_tracepoints(void); |
54 | ||
be1c6341 OK |
55 | /* |
56 | * Send out a notify message. | |
57 | */ | |
a863055b JA |
58 | static void trace_note(struct blk_trace *bt, pid_t pid, int action, |
59 | const void *data, size_t len) | |
be1c6341 OK |
60 | { |
61 | struct blk_io_trace *t; | |
18cea459 LZ |
62 | struct ring_buffer_event *event = NULL; |
63 | int pc = 0; | |
64 | int cpu = smp_processor_id(); | |
65 | bool blk_tracer = blk_tracer_enabled; | |
66 | ||
67 | if (blk_tracer) { | |
68 | pc = preempt_count(); | |
69 | event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK, | |
70 | sizeof(*t) + len, | |
71 | 0, pc); | |
72 | if (!event) | |
73 | return; | |
74 | t = ring_buffer_event_data(event); | |
75 | goto record_it; | |
76 | } | |
be1c6341 | 77 | |
c71a8961 ACM |
78 | if (!bt->rchan) |
79 | return; | |
80 | ||
be1c6341 | 81 | t = relay_reserve(bt->rchan, sizeof(*t) + len); |
d3d9d2a5 | 82 | if (t) { |
d3d9d2a5 | 83 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; |
2997c8c4 | 84 | t->time = ktime_to_ns(ktime_get()); |
18cea459 | 85 | record_it: |
d3d9d2a5 JA |
86 | t->device = bt->dev; |
87 | t->action = action; | |
88 | t->pid = pid; | |
89 | t->cpu = cpu; | |
90 | t->pdu_len = len; | |
91 | memcpy((void *) t + sizeof(*t), data, len); | |
18cea459 LZ |
92 | |
93 | if (blk_tracer) | |
94 | trace_buffer_unlock_commit(blk_tr, event, 0, pc); | |
d3d9d2a5 | 95 | } |
be1c6341 OK |
96 | } |
97 | ||
2056a782 JA |
98 | /* |
99 | * Send out a notify for this process, if we haven't done so since a trace | |
100 | * started | |
101 | */ | |
102 | static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) | |
103 | { | |
a863055b JA |
104 | tsk->btrace_seq = blktrace_seq; |
105 | trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); | |
be1c6341 | 106 | } |
2056a782 | 107 | |
be1c6341 OK |
108 | static void trace_note_time(struct blk_trace *bt) |
109 | { | |
110 | struct timespec now; | |
111 | unsigned long flags; | |
112 | u32 words[2]; | |
113 | ||
114 | getnstimeofday(&now); | |
115 | words[0] = now.tv_sec; | |
116 | words[1] = now.tv_nsec; | |
117 | ||
118 | local_irq_save(flags); | |
119 | trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); | |
120 | local_irq_restore(flags); | |
2056a782 JA |
121 | } |
122 | ||
9d5f09a4 AB |
123 | void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) |
124 | { | |
125 | int n; | |
126 | va_list args; | |
14a73f54 | 127 | unsigned long flags; |
64565911 | 128 | char *buf; |
9d5f09a4 | 129 | |
18cea459 LZ |
130 | if (unlikely(bt->trace_state != Blktrace_running && |
131 | !blk_tracer_enabled)) | |
c71a8961 ACM |
132 | return; |
133 | ||
14a73f54 | 134 | local_irq_save(flags); |
64565911 | 135 | buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); |
9d5f09a4 | 136 | va_start(args, fmt); |
64565911 | 137 | n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); |
9d5f09a4 AB |
138 | va_end(args); |
139 | ||
64565911 | 140 | trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); |
14a73f54 | 141 | local_irq_restore(flags); |
9d5f09a4 AB |
142 | } |
143 | EXPORT_SYMBOL_GPL(__trace_note_message); | |
144 | ||
2056a782 JA |
145 | static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, |
146 | pid_t pid) | |
147 | { | |
148 | if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) | |
149 | return 1; | |
d0deef5b | 150 | if (sector && (sector < bt->start_lba || sector > bt->end_lba)) |
2056a782 JA |
151 | return 1; |
152 | if (bt->pid && pid != bt->pid) | |
153 | return 1; | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | /* | |
159 | * Data direction bit lookup | |
160 | */ | |
e4955c99 LZ |
161 | static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ), |
162 | BLK_TC_ACT(BLK_TC_WRITE) }; | |
2056a782 | 163 | |
35ba8f70 | 164 | /* The ilog2() calls fall out because they're constant */ |
939b3669 ACM |
165 | #define MASK_TC_BIT(rw, __name) ((rw & (1 << BIO_RW_ ## __name)) << \ |
166 | (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name)) | |
2056a782 JA |
167 | |
168 | /* | |
169 | * The worker for the various blk_add_trace*() types. Fills out a | |
170 | * blk_io_trace structure and places it in a per-cpu subbuffer. | |
171 | */ | |
5f3ea37c | 172 | static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, |
2056a782 JA |
173 | int rw, u32 what, int error, int pdu_len, void *pdu_data) |
174 | { | |
175 | struct task_struct *tsk = current; | |
c71a8961 | 176 | struct ring_buffer_event *event = NULL; |
2056a782 | 177 | struct blk_io_trace *t; |
0a987751 | 178 | unsigned long flags = 0; |
2056a782 JA |
179 | unsigned long *sequence; |
180 | pid_t pid; | |
c71a8961 | 181 | int cpu, pc = 0; |
18cea459 | 182 | bool blk_tracer = blk_tracer_enabled; |
2056a782 | 183 | |
18cea459 | 184 | if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) |
2056a782 JA |
185 | return; |
186 | ||
187 | what |= ddir_act[rw & WRITE]; | |
35ba8f70 | 188 | what |= MASK_TC_BIT(rw, BARRIER); |
93dbb393 | 189 | what |= MASK_TC_BIT(rw, SYNCIO); |
35ba8f70 DW |
190 | what |= MASK_TC_BIT(rw, AHEAD); |
191 | what |= MASK_TC_BIT(rw, META); | |
192 | what |= MASK_TC_BIT(rw, DISCARD); | |
2056a782 JA |
193 | |
194 | pid = tsk->pid; | |
d0deef5b | 195 | if (act_log_check(bt, what, sector, pid)) |
2056a782 | 196 | return; |
c71a8961 ACM |
197 | cpu = raw_smp_processor_id(); |
198 | ||
18cea459 | 199 | if (blk_tracer) { |
c71a8961 ACM |
200 | tracing_record_cmdline(current); |
201 | ||
51a763dd ACM |
202 | pc = preempt_count(); |
203 | event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK, | |
204 | sizeof(*t) + pdu_len, | |
205 | 0, pc); | |
c71a8961 ACM |
206 | if (!event) |
207 | return; | |
51a763dd | 208 | t = ring_buffer_event_data(event); |
c71a8961 ACM |
209 | goto record_it; |
210 | } | |
2056a782 JA |
211 | |
212 | /* | |
213 | * A word about the locking here - we disable interrupts to reserve | |
214 | * some space in the relay per-cpu buffer, to prevent an irq | |
14a73f54 | 215 | * from coming in and stepping on our toes. |
2056a782 JA |
216 | */ |
217 | local_irq_save(flags); | |
218 | ||
219 | if (unlikely(tsk->btrace_seq != blktrace_seq)) | |
220 | trace_note_tsk(bt, tsk); | |
221 | ||
222 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); | |
223 | if (t) { | |
2056a782 JA |
224 | sequence = per_cpu_ptr(bt->sequence, cpu); |
225 | ||
226 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
227 | t->sequence = ++(*sequence); | |
2997c8c4 | 228 | t->time = ktime_to_ns(ktime_get()); |
c71a8961 | 229 | record_it: |
08a06b83 | 230 | /* |
939b3669 ACM |
231 | * These two are not needed in ftrace as they are in the |
232 | * generic trace_entry, filled by tracing_generic_entry_update, | |
233 | * but for the trace_event->bin() synthesizer benefit we do it | |
234 | * here too. | |
235 | */ | |
236 | t->cpu = cpu; | |
237 | t->pid = pid; | |
08a06b83 | 238 | |
2056a782 JA |
239 | t->sector = sector; |
240 | t->bytes = bytes; | |
241 | t->action = what; | |
2056a782 | 242 | t->device = bt->dev; |
2056a782 JA |
243 | t->error = error; |
244 | t->pdu_len = pdu_len; | |
245 | ||
246 | if (pdu_len) | |
247 | memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); | |
c71a8961 | 248 | |
18cea459 | 249 | if (blk_tracer) { |
51a763dd | 250 | trace_buffer_unlock_commit(blk_tr, event, 0, pc); |
c71a8961 ACM |
251 | return; |
252 | } | |
2056a782 JA |
253 | } |
254 | ||
255 | local_irq_restore(flags); | |
256 | } | |
257 | ||
2056a782 | 258 | static struct dentry *blk_tree_root; |
11a57153 | 259 | static DEFINE_MUTEX(blk_tree_mutex); |
2056a782 | 260 | |
ad5dd549 | 261 | static void blk_trace_free(struct blk_trace *bt) |
2056a782 | 262 | { |
02c62304 | 263 | debugfs_remove(bt->msg_file); |
2056a782 | 264 | debugfs_remove(bt->dropped_file); |
fd51d251 | 265 | debugfs_remove(bt->dir); |
f48fc4d3 | 266 | relay_close(bt->rchan); |
2056a782 | 267 | free_percpu(bt->sequence); |
64565911 | 268 | free_percpu(bt->msg_data); |
2056a782 | 269 | kfree(bt); |
ad5dd549 LZ |
270 | } |
271 | ||
272 | static void blk_trace_cleanup(struct blk_trace *bt) | |
273 | { | |
274 | blk_trace_free(bt); | |
5f3ea37c ACM |
275 | if (atomic_dec_and_test(&blk_probes_ref)) |
276 | blk_unregister_tracepoints(); | |
2056a782 JA |
277 | } |
278 | ||
6da127ad | 279 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
280 | { |
281 | struct blk_trace *bt; | |
282 | ||
283 | bt = xchg(&q->blk_trace, NULL); | |
284 | if (!bt) | |
285 | return -EINVAL; | |
286 | ||
55547204 | 287 | if (bt->trace_state != Blktrace_running) |
2056a782 JA |
288 | blk_trace_cleanup(bt); |
289 | ||
290 | return 0; | |
291 | } | |
6da127ad | 292 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 JA |
293 | |
294 | static int blk_dropped_open(struct inode *inode, struct file *filp) | |
295 | { | |
8e18e294 | 296 | filp->private_data = inode->i_private; |
2056a782 JA |
297 | |
298 | return 0; | |
299 | } | |
300 | ||
301 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, | |
302 | size_t count, loff_t *ppos) | |
303 | { | |
304 | struct blk_trace *bt = filp->private_data; | |
305 | char buf[16]; | |
306 | ||
307 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
308 | ||
309 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
310 | } | |
311 | ||
2b8693c0 | 312 | static const struct file_operations blk_dropped_fops = { |
2056a782 JA |
313 | .owner = THIS_MODULE, |
314 | .open = blk_dropped_open, | |
315 | .read = blk_dropped_read, | |
316 | }; | |
317 | ||
02c62304 AB |
318 | static int blk_msg_open(struct inode *inode, struct file *filp) |
319 | { | |
320 | filp->private_data = inode->i_private; | |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
325 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, | |
326 | size_t count, loff_t *ppos) | |
327 | { | |
328 | char *msg; | |
329 | struct blk_trace *bt; | |
330 | ||
7635b03a | 331 | if (count >= BLK_TN_MAX_MSG) |
02c62304 AB |
332 | return -EINVAL; |
333 | ||
a4b3ada8 | 334 | msg = kmalloc(count + 1, GFP_KERNEL); |
02c62304 AB |
335 | if (msg == NULL) |
336 | return -ENOMEM; | |
337 | ||
338 | if (copy_from_user(msg, buffer, count)) { | |
339 | kfree(msg); | |
340 | return -EFAULT; | |
341 | } | |
342 | ||
a4b3ada8 | 343 | msg[count] = '\0'; |
02c62304 AB |
344 | bt = filp->private_data; |
345 | __trace_note_message(bt, "%s", msg); | |
346 | kfree(msg); | |
347 | ||
348 | return count; | |
349 | } | |
350 | ||
351 | static const struct file_operations blk_msg_fops = { | |
352 | .owner = THIS_MODULE, | |
353 | .open = blk_msg_open, | |
354 | .write = blk_msg_write, | |
355 | }; | |
356 | ||
2056a782 JA |
357 | /* |
358 | * Keep track of how many times we encountered a full subbuffer, to aid | |
359 | * the user space app in telling how many lost events there were. | |
360 | */ | |
361 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
362 | void *prev_subbuf, size_t prev_padding) | |
363 | { | |
364 | struct blk_trace *bt; | |
365 | ||
366 | if (!relay_buf_full(buf)) | |
367 | return 1; | |
368 | ||
369 | bt = buf->chan->private_data; | |
370 | atomic_inc(&bt->dropped); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
375 | { | |
f48fc4d3 | 376 | struct dentry *parent = dentry->d_parent; |
2056a782 | 377 | debugfs_remove(dentry); |
f48fc4d3 JA |
378 | |
379 | /* | |
380 | * this will fail for all but the last file, but that is ok. what we | |
381 | * care about is the top level buts->name directory going away, when | |
382 | * the last trace file is gone. Then we don't have to rmdir() that | |
383 | * manually on trace stop, so it nicely solves the issue with | |
384 | * force killing of running traces. | |
385 | */ | |
386 | ||
387 | debugfs_remove(parent); | |
2056a782 JA |
388 | return 0; |
389 | } | |
390 | ||
391 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
392 | struct dentry *parent, | |
393 | int mode, | |
394 | struct rchan_buf *buf, | |
395 | int *is_global) | |
396 | { | |
397 | return debugfs_create_file(filename, mode, parent, buf, | |
398 | &relay_file_operations); | |
399 | } | |
400 | ||
401 | static struct rchan_callbacks blk_relay_callbacks = { | |
402 | .subbuf_start = blk_subbuf_start_callback, | |
403 | .create_buf_file = blk_create_buf_file_callback, | |
404 | .remove_buf_file = blk_remove_buf_file_callback, | |
405 | }; | |
406 | ||
9908c309 LZ |
407 | static void blk_trace_setup_lba(struct blk_trace *bt, |
408 | struct block_device *bdev) | |
409 | { | |
410 | struct hd_struct *part = NULL; | |
411 | ||
412 | if (bdev) | |
413 | part = bdev->bd_part; | |
414 | ||
415 | if (part) { | |
416 | bt->start_lba = part->start_sect; | |
417 | bt->end_lba = part->start_sect + part->nr_sects; | |
418 | } else { | |
419 | bt->start_lba = 0; | |
420 | bt->end_lba = -1ULL; | |
421 | } | |
422 | } | |
423 | ||
2056a782 JA |
424 | /* |
425 | * Setup everything required to start tracing | |
426 | */ | |
6da127ad | 427 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
d0deef5b SD |
428 | struct block_device *bdev, |
429 | struct blk_user_trace_setup *buts) | |
2056a782 | 430 | { |
2056a782 JA |
431 | struct blk_trace *old_bt, *bt = NULL; |
432 | struct dentry *dir = NULL; | |
2056a782 JA |
433 | int ret, i; |
434 | ||
171044d4 | 435 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
436 | return -EINVAL; |
437 | ||
0497b345 JA |
438 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
439 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
440 | |
441 | /* | |
442 | * some device names have larger paths - convert the slashes | |
443 | * to underscores for this to work as expected | |
444 | */ | |
171044d4 AB |
445 | for (i = 0; i < strlen(buts->name); i++) |
446 | if (buts->name[i] == '/') | |
447 | buts->name[i] = '_'; | |
2056a782 | 448 | |
2056a782 JA |
449 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
450 | if (!bt) | |
ad5dd549 | 451 | return -ENOMEM; |
2056a782 | 452 | |
ad5dd549 | 453 | ret = -ENOMEM; |
2056a782 JA |
454 | bt->sequence = alloc_percpu(unsigned long); |
455 | if (!bt->sequence) | |
456 | goto err; | |
457 | ||
313e458f | 458 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
64565911 JA |
459 | if (!bt->msg_data) |
460 | goto err; | |
461 | ||
2056a782 | 462 | ret = -ENOENT; |
f48fc4d3 | 463 | |
b5230b56 | 464 | mutex_lock(&blk_tree_mutex); |
f48fc4d3 JA |
465 | if (!blk_tree_root) { |
466 | blk_tree_root = debugfs_create_dir("block", NULL); | |
b5230b56 LZ |
467 | if (!blk_tree_root) { |
468 | mutex_unlock(&blk_tree_mutex); | |
1a17662e | 469 | goto err; |
b5230b56 | 470 | } |
f48fc4d3 | 471 | } |
b5230b56 | 472 | mutex_unlock(&blk_tree_mutex); |
f48fc4d3 JA |
473 | |
474 | dir = debugfs_create_dir(buts->name, blk_tree_root); | |
475 | ||
2056a782 JA |
476 | if (!dir) |
477 | goto err; | |
478 | ||
479 | bt->dir = dir; | |
6da127ad | 480 | bt->dev = dev; |
2056a782 JA |
481 | atomic_set(&bt->dropped, 0); |
482 | ||
483 | ret = -EIO; | |
939b3669 ACM |
484 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, |
485 | &blk_dropped_fops); | |
2056a782 JA |
486 | if (!bt->dropped_file) |
487 | goto err; | |
488 | ||
02c62304 AB |
489 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
490 | if (!bt->msg_file) | |
491 | goto err; | |
492 | ||
171044d4 AB |
493 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
494 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
495 | if (!bt->rchan) |
496 | goto err; | |
2056a782 | 497 | |
171044d4 | 498 | bt->act_mask = buts->act_mask; |
2056a782 JA |
499 | if (!bt->act_mask) |
500 | bt->act_mask = (u16) -1; | |
501 | ||
9908c309 | 502 | blk_trace_setup_lba(bt, bdev); |
2056a782 | 503 | |
d0deef5b SD |
504 | /* overwrite with user settings */ |
505 | if (buts->start_lba) | |
506 | bt->start_lba = buts->start_lba; | |
507 | if (buts->end_lba) | |
508 | bt->end_lba = buts->end_lba; | |
509 | ||
171044d4 | 510 | bt->pid = buts->pid; |
2056a782 JA |
511 | bt->trace_state = Blktrace_setup; |
512 | ||
513 | ret = -EBUSY; | |
514 | old_bt = xchg(&q->blk_trace, bt); | |
515 | if (old_bt) { | |
516 | (void) xchg(&q->blk_trace, old_bt); | |
517 | goto err; | |
518 | } | |
519 | ||
17ba97e3 | 520 | if (atomic_inc_return(&blk_probes_ref) == 1) |
cbe28296 LZ |
521 | blk_register_tracepoints(); |
522 | ||
2056a782 JA |
523 | return 0; |
524 | err: | |
ad5dd549 | 525 | blk_trace_free(bt); |
2056a782 JA |
526 | return ret; |
527 | } | |
171044d4 | 528 | |
6da127ad | 529 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
d0deef5b | 530 | struct block_device *bdev, |
6da127ad | 531 | char __user *arg) |
171044d4 AB |
532 | { |
533 | struct blk_user_trace_setup buts; | |
534 | int ret; | |
535 | ||
536 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
537 | if (ret) | |
538 | return -EFAULT; | |
539 | ||
d0deef5b | 540 | ret = do_blk_trace_setup(q, name, dev, bdev, &buts); |
171044d4 AB |
541 | if (ret) |
542 | return ret; | |
543 | ||
544 | if (copy_to_user(arg, &buts, sizeof(buts))) | |
545 | return -EFAULT; | |
546 | ||
547 | return 0; | |
548 | } | |
6da127ad | 549 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 550 | |
6da127ad | 551 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 | 552 | { |
2056a782 | 553 | int ret; |
939b3669 | 554 | struct blk_trace *bt = q->blk_trace; |
2056a782 | 555 | |
939b3669 | 556 | if (bt == NULL) |
2056a782 JA |
557 | return -EINVAL; |
558 | ||
559 | /* | |
560 | * For starting a trace, we can transition from a setup or stopped | |
561 | * trace. For stopping a trace, the state must be running | |
562 | */ | |
563 | ret = -EINVAL; | |
564 | if (start) { | |
565 | if (bt->trace_state == Blktrace_setup || | |
566 | bt->trace_state == Blktrace_stopped) { | |
567 | blktrace_seq++; | |
568 | smp_mb(); | |
569 | bt->trace_state = Blktrace_running; | |
be1c6341 OK |
570 | |
571 | trace_note_time(bt); | |
2056a782 JA |
572 | ret = 0; |
573 | } | |
574 | } else { | |
575 | if (bt->trace_state == Blktrace_running) { | |
576 | bt->trace_state = Blktrace_stopped; | |
577 | relay_flush(bt->rchan); | |
578 | ret = 0; | |
579 | } | |
580 | } | |
581 | ||
582 | return ret; | |
583 | } | |
6da127ad | 584 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 JA |
585 | |
586 | /** | |
587 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
588 | * @bdev: the block device | |
ef18012b | 589 | * @cmd: the ioctl cmd |
2056a782 JA |
590 | * @arg: the argument data, if any |
591 | * | |
592 | **/ | |
593 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
594 | { | |
165125e1 | 595 | struct request_queue *q; |
2056a782 | 596 | int ret, start = 0; |
6da127ad | 597 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
598 | |
599 | q = bdev_get_queue(bdev); | |
600 | if (!q) | |
601 | return -ENXIO; | |
602 | ||
603 | mutex_lock(&bdev->bd_mutex); | |
604 | ||
605 | switch (cmd) { | |
606 | case BLKTRACESETUP: | |
f36f21ec | 607 | bdevname(bdev, b); |
d0deef5b | 608 | ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); |
2056a782 JA |
609 | break; |
610 | case BLKTRACESTART: | |
611 | start = 1; | |
612 | case BLKTRACESTOP: | |
613 | ret = blk_trace_startstop(q, start); | |
614 | break; | |
615 | case BLKTRACETEARDOWN: | |
616 | ret = blk_trace_remove(q); | |
617 | break; | |
618 | default: | |
619 | ret = -ENOTTY; | |
620 | break; | |
621 | } | |
622 | ||
623 | mutex_unlock(&bdev->bd_mutex); | |
624 | return ret; | |
625 | } | |
626 | ||
627 | /** | |
628 | * blk_trace_shutdown: - stop and cleanup trace structures | |
629 | * @q: the request queue associated with the device | |
630 | * | |
631 | **/ | |
165125e1 | 632 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 633 | { |
6c5c9341 AD |
634 | if (q->blk_trace) { |
635 | blk_trace_startstop(q, 0); | |
636 | blk_trace_remove(q); | |
637 | } | |
2056a782 | 638 | } |
5f3ea37c ACM |
639 | |
640 | /* | |
641 | * blktrace probes | |
642 | */ | |
643 | ||
644 | /** | |
645 | * blk_add_trace_rq - Add a trace for a request oriented action | |
646 | * @q: queue the io is for | |
647 | * @rq: the source request | |
648 | * @what: the action | |
649 | * | |
650 | * Description: | |
651 | * Records an action against a request. Will log the bio offset + size. | |
652 | * | |
653 | **/ | |
654 | static void blk_add_trace_rq(struct request_queue *q, struct request *rq, | |
655 | u32 what) | |
656 | { | |
657 | struct blk_trace *bt = q->blk_trace; | |
658 | int rw = rq->cmd_flags & 0x03; | |
659 | ||
660 | if (likely(!bt)) | |
661 | return; | |
662 | ||
663 | if (blk_discard_rq(rq)) | |
664 | rw |= (1 << BIO_RW_DISCARD); | |
665 | ||
666 | if (blk_pc_request(rq)) { | |
667 | what |= BLK_TC_ACT(BLK_TC_PC); | |
668 | __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, | |
e2494e1b | 669 | rq->cmd_len, rq->cmd); |
5f3ea37c ACM |
670 | } else { |
671 | what |= BLK_TC_ACT(BLK_TC_FS); | |
672 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
673 | rw, what, rq->errors, 0, NULL); | |
674 | } | |
675 | } | |
676 | ||
677 | static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) | |
678 | { | |
679 | blk_add_trace_rq(q, rq, BLK_TA_ABORT); | |
680 | } | |
681 | ||
682 | static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) | |
683 | { | |
684 | blk_add_trace_rq(q, rq, BLK_TA_INSERT); | |
685 | } | |
686 | ||
687 | static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) | |
688 | { | |
689 | blk_add_trace_rq(q, rq, BLK_TA_ISSUE); | |
690 | } | |
691 | ||
939b3669 ACM |
692 | static void blk_add_trace_rq_requeue(struct request_queue *q, |
693 | struct request *rq) | |
5f3ea37c ACM |
694 | { |
695 | blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); | |
696 | } | |
697 | ||
939b3669 ACM |
698 | static void blk_add_trace_rq_complete(struct request_queue *q, |
699 | struct request *rq) | |
5f3ea37c ACM |
700 | { |
701 | blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); | |
702 | } | |
703 | ||
704 | /** | |
705 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
706 | * @q: queue the io is for | |
707 | * @bio: the source bio | |
708 | * @what: the action | |
709 | * | |
710 | * Description: | |
711 | * Records an action against a bio. Will log the bio offset + size. | |
712 | * | |
713 | **/ | |
714 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
715 | u32 what) | |
716 | { | |
717 | struct blk_trace *bt = q->blk_trace; | |
718 | ||
719 | if (likely(!bt)) | |
720 | return; | |
721 | ||
722 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, | |
723 | !bio_flagged(bio, BIO_UPTODATE), 0, NULL); | |
724 | } | |
725 | ||
726 | static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) | |
727 | { | |
728 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); | |
729 | } | |
730 | ||
731 | static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) | |
732 | { | |
733 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); | |
734 | } | |
735 | ||
939b3669 ACM |
736 | static void blk_add_trace_bio_backmerge(struct request_queue *q, |
737 | struct bio *bio) | |
5f3ea37c ACM |
738 | { |
739 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); | |
740 | } | |
741 | ||
939b3669 ACM |
742 | static void blk_add_trace_bio_frontmerge(struct request_queue *q, |
743 | struct bio *bio) | |
5f3ea37c ACM |
744 | { |
745 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); | |
746 | } | |
747 | ||
748 | static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) | |
749 | { | |
750 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE); | |
751 | } | |
752 | ||
939b3669 ACM |
753 | static void blk_add_trace_getrq(struct request_queue *q, |
754 | struct bio *bio, int rw) | |
5f3ea37c ACM |
755 | { |
756 | if (bio) | |
757 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ); | |
758 | else { | |
759 | struct blk_trace *bt = q->blk_trace; | |
760 | ||
761 | if (bt) | |
762 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); | |
763 | } | |
764 | } | |
765 | ||
766 | ||
939b3669 ACM |
767 | static void blk_add_trace_sleeprq(struct request_queue *q, |
768 | struct bio *bio, int rw) | |
5f3ea37c ACM |
769 | { |
770 | if (bio) | |
771 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); | |
772 | else { | |
773 | struct blk_trace *bt = q->blk_trace; | |
774 | ||
775 | if (bt) | |
939b3669 ACM |
776 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, |
777 | 0, 0, NULL); | |
5f3ea37c ACM |
778 | } |
779 | } | |
780 | ||
781 | static void blk_add_trace_plug(struct request_queue *q) | |
782 | { | |
783 | struct blk_trace *bt = q->blk_trace; | |
784 | ||
785 | if (bt) | |
786 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); | |
787 | } | |
788 | ||
789 | static void blk_add_trace_unplug_io(struct request_queue *q) | |
790 | { | |
791 | struct blk_trace *bt = q->blk_trace; | |
792 | ||
793 | if (bt) { | |
794 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
795 | __be64 rpdu = cpu_to_be64(pdu); | |
796 | ||
797 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, | |
798 | sizeof(rpdu), &rpdu); | |
799 | } | |
800 | } | |
801 | ||
802 | static void blk_add_trace_unplug_timer(struct request_queue *q) | |
803 | { | |
804 | struct blk_trace *bt = q->blk_trace; | |
805 | ||
806 | if (bt) { | |
807 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
808 | __be64 rpdu = cpu_to_be64(pdu); | |
809 | ||
810 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, | |
811 | sizeof(rpdu), &rpdu); | |
812 | } | |
813 | } | |
814 | ||
815 | static void blk_add_trace_split(struct request_queue *q, struct bio *bio, | |
816 | unsigned int pdu) | |
817 | { | |
818 | struct blk_trace *bt = q->blk_trace; | |
819 | ||
820 | if (bt) { | |
821 | __be64 rpdu = cpu_to_be64(pdu); | |
822 | ||
823 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, | |
824 | BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), | |
825 | sizeof(rpdu), &rpdu); | |
826 | } | |
827 | } | |
828 | ||
829 | /** | |
830 | * blk_add_trace_remap - Add a trace for a remap operation | |
831 | * @q: queue the io is for | |
832 | * @bio: the source bio | |
833 | * @dev: target device | |
a42aaa3b | 834 | * @from: source sector |
5f3ea37c ACM |
835 | * |
836 | * Description: | |
837 | * Device mapper or raid target sometimes need to split a bio because | |
838 | * it spans a stripe (or similar). Add a trace for that action. | |
839 | * | |
840 | **/ | |
841 | static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, | |
22a7c31a | 842 | dev_t dev, sector_t from) |
5f3ea37c ACM |
843 | { |
844 | struct blk_trace *bt = q->blk_trace; | |
845 | struct blk_io_trace_remap r; | |
846 | ||
847 | if (likely(!bt)) | |
848 | return; | |
849 | ||
a42aaa3b AB |
850 | r.device_from = cpu_to_be32(dev); |
851 | r.device_to = cpu_to_be32(bio->bi_bdev->bd_dev); | |
852 | r.sector_from = cpu_to_be64(from); | |
5f3ea37c | 853 | |
22a7c31a AB |
854 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, |
855 | BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), | |
856 | sizeof(r), &r); | |
5f3ea37c ACM |
857 | } |
858 | ||
859 | /** | |
860 | * blk_add_driver_data - Add binary message with driver-specific data | |
861 | * @q: queue the io is for | |
862 | * @rq: io request | |
863 | * @data: driver-specific data | |
864 | * @len: length of driver-specific data | |
865 | * | |
866 | * Description: | |
867 | * Some drivers might want to write driver-specific data per request. | |
868 | * | |
869 | **/ | |
870 | void blk_add_driver_data(struct request_queue *q, | |
871 | struct request *rq, | |
872 | void *data, size_t len) | |
873 | { | |
874 | struct blk_trace *bt = q->blk_trace; | |
875 | ||
876 | if (likely(!bt)) | |
877 | return; | |
878 | ||
879 | if (blk_pc_request(rq)) | |
880 | __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, | |
881 | rq->errors, len, data); | |
882 | else | |
883 | __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, | |
884 | 0, BLK_TA_DRV_DATA, rq->errors, len, data); | |
885 | } | |
886 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
887 | ||
3c289ba7 | 888 | static void blk_register_tracepoints(void) |
5f3ea37c ACM |
889 | { |
890 | int ret; | |
891 | ||
892 | ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); | |
893 | WARN_ON(ret); | |
894 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); | |
895 | WARN_ON(ret); | |
896 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); | |
897 | WARN_ON(ret); | |
898 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
899 | WARN_ON(ret); | |
900 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); | |
901 | WARN_ON(ret); | |
902 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
903 | WARN_ON(ret); | |
904 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); | |
905 | WARN_ON(ret); | |
906 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
907 | WARN_ON(ret); | |
908 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
909 | WARN_ON(ret); | |
910 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); | |
911 | WARN_ON(ret); | |
912 | ret = register_trace_block_getrq(blk_add_trace_getrq); | |
913 | WARN_ON(ret); | |
914 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); | |
915 | WARN_ON(ret); | |
916 | ret = register_trace_block_plug(blk_add_trace_plug); | |
917 | WARN_ON(ret); | |
918 | ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
919 | WARN_ON(ret); | |
920 | ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); | |
921 | WARN_ON(ret); | |
922 | ret = register_trace_block_split(blk_add_trace_split); | |
923 | WARN_ON(ret); | |
924 | ret = register_trace_block_remap(blk_add_trace_remap); | |
925 | WARN_ON(ret); | |
5f3ea37c ACM |
926 | } |
927 | ||
928 | static void blk_unregister_tracepoints(void) | |
929 | { | |
930 | unregister_trace_block_remap(blk_add_trace_remap); | |
931 | unregister_trace_block_split(blk_add_trace_split); | |
932 | unregister_trace_block_unplug_io(blk_add_trace_unplug_io); | |
933 | unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
934 | unregister_trace_block_plug(blk_add_trace_plug); | |
935 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq); | |
936 | unregister_trace_block_getrq(blk_add_trace_getrq); | |
937 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue); | |
938 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
939 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
940 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete); | |
941 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
942 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete); | |
943 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
944 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue); | |
945 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert); | |
946 | unregister_trace_block_rq_abort(blk_add_trace_rq_abort); | |
947 | ||
948 | tracepoint_synchronize_unregister(); | |
949 | } | |
c71a8961 ACM |
950 | |
951 | /* | |
952 | * struct blk_io_tracer formatting routines | |
953 | */ | |
954 | ||
955 | static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) | |
956 | { | |
157f9c00 | 957 | int i = 0; |
65796348 | 958 | int tc = t->action >> BLK_TC_SHIFT; |
157f9c00 | 959 | |
18cea459 LZ |
960 | if (t->action == BLK_TN_MESSAGE) { |
961 | rwbs[i++] = 'N'; | |
962 | goto out; | |
963 | } | |
964 | ||
65796348 | 965 | if (tc & BLK_TC_DISCARD) |
157f9c00 | 966 | rwbs[i++] = 'D'; |
65796348 | 967 | else if (tc & BLK_TC_WRITE) |
157f9c00 ACM |
968 | rwbs[i++] = 'W'; |
969 | else if (t->bytes) | |
970 | rwbs[i++] = 'R'; | |
971 | else | |
972 | rwbs[i++] = 'N'; | |
973 | ||
65796348 | 974 | if (tc & BLK_TC_AHEAD) |
157f9c00 | 975 | rwbs[i++] = 'A'; |
65796348 | 976 | if (tc & BLK_TC_BARRIER) |
157f9c00 | 977 | rwbs[i++] = 'B'; |
65796348 | 978 | if (tc & BLK_TC_SYNC) |
157f9c00 | 979 | rwbs[i++] = 'S'; |
65796348 | 980 | if (tc & BLK_TC_META) |
157f9c00 | 981 | rwbs[i++] = 'M'; |
18cea459 | 982 | out: |
157f9c00 | 983 | rwbs[i] = '\0'; |
c71a8961 ACM |
984 | } |
985 | ||
986 | static inline | |
987 | const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) | |
988 | { | |
989 | return (const struct blk_io_trace *)ent; | |
990 | } | |
991 | ||
992 | static inline const void *pdu_start(const struct trace_entry *ent) | |
993 | { | |
994 | return te_blk_io_trace(ent) + 1; | |
995 | } | |
996 | ||
66de7792 LZ |
997 | static inline u32 t_action(const struct trace_entry *ent) |
998 | { | |
999 | return te_blk_io_trace(ent)->action; | |
1000 | } | |
1001 | ||
1002 | static inline u32 t_bytes(const struct trace_entry *ent) | |
1003 | { | |
1004 | return te_blk_io_trace(ent)->bytes; | |
1005 | } | |
1006 | ||
c71a8961 ACM |
1007 | static inline u32 t_sec(const struct trace_entry *ent) |
1008 | { | |
1009 | return te_blk_io_trace(ent)->bytes >> 9; | |
1010 | } | |
1011 | ||
1012 | static inline unsigned long long t_sector(const struct trace_entry *ent) | |
1013 | { | |
1014 | return te_blk_io_trace(ent)->sector; | |
1015 | } | |
1016 | ||
1017 | static inline __u16 t_error(const struct trace_entry *ent) | |
1018 | { | |
e0dc81be | 1019 | return te_blk_io_trace(ent)->error; |
c71a8961 ACM |
1020 | } |
1021 | ||
1022 | static __u64 get_pdu_int(const struct trace_entry *ent) | |
1023 | { | |
1024 | const __u64 *val = pdu_start(ent); | |
1025 | return be64_to_cpu(*val); | |
1026 | } | |
1027 | ||
1028 | static void get_pdu_remap(const struct trace_entry *ent, | |
1029 | struct blk_io_trace_remap *r) | |
1030 | { | |
1031 | const struct blk_io_trace_remap *__r = pdu_start(ent); | |
a42aaa3b | 1032 | __u64 sector_from = __r->sector_from; |
c71a8961 | 1033 | |
c71a8961 | 1034 | r->device_from = be32_to_cpu(__r->device_from); |
a42aaa3b AB |
1035 | r->device_to = be32_to_cpu(__r->device_to); |
1036 | r->sector_from = be64_to_cpu(sector_from); | |
c71a8961 ACM |
1037 | } |
1038 | ||
b6a4b0c3 LZ |
1039 | typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act); |
1040 | ||
1041 | static int blk_log_action_classic(struct trace_iterator *iter, const char *act) | |
c71a8961 ACM |
1042 | { |
1043 | char rwbs[6]; | |
35ac51bf LZ |
1044 | unsigned long long ts = iter->ts; |
1045 | unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC); | |
c71a8961 | 1046 | unsigned secs = (unsigned long)ts; |
b6a4b0c3 | 1047 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
c71a8961 ACM |
1048 | |
1049 | fill_rwbs(rwbs, t); | |
1050 | ||
1051 | return trace_seq_printf(&iter->seq, | |
35ac51bf | 1052 | "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ", |
c71a8961 | 1053 | MAJOR(t->device), MINOR(t->device), iter->cpu, |
b6a4b0c3 | 1054 | secs, nsec_rem, iter->ent->pid, act, rwbs); |
c71a8961 ACM |
1055 | } |
1056 | ||
b6a4b0c3 | 1057 | static int blk_log_action(struct trace_iterator *iter, const char *act) |
c71a8961 ACM |
1058 | { |
1059 | char rwbs[6]; | |
b6a4b0c3 LZ |
1060 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
1061 | ||
c71a8961 | 1062 | fill_rwbs(rwbs, t); |
b6a4b0c3 | 1063 | return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ", |
c71a8961 ACM |
1064 | MAJOR(t->device), MINOR(t->device), act, rwbs); |
1065 | } | |
1066 | ||
66de7792 LZ |
1067 | static int blk_log_dump_pdu(struct trace_seq *s, const struct trace_entry *ent) |
1068 | { | |
04986257 | 1069 | const unsigned char *pdu_buf; |
66de7792 LZ |
1070 | int pdu_len; |
1071 | int i, end, ret; | |
1072 | ||
1073 | pdu_buf = pdu_start(ent); | |
1074 | pdu_len = te_blk_io_trace(ent)->pdu_len; | |
1075 | ||
1076 | if (!pdu_len) | |
1077 | return 1; | |
1078 | ||
1079 | /* find the last zero that needs to be printed */ | |
1080 | for (end = pdu_len - 1; end >= 0; end--) | |
1081 | if (pdu_buf[end]) | |
1082 | break; | |
1083 | end++; | |
1084 | ||
1085 | if (!trace_seq_putc(s, '(')) | |
1086 | return 0; | |
1087 | ||
1088 | for (i = 0; i < pdu_len; i++) { | |
1089 | ||
1090 | ret = trace_seq_printf(s, "%s%02x", | |
1091 | i == 0 ? "" : " ", pdu_buf[i]); | |
1092 | if (!ret) | |
1093 | return ret; | |
1094 | ||
1095 | /* | |
1096 | * stop when the rest is just zeroes and indicate so | |
1097 | * with a ".." appended | |
1098 | */ | |
1099 | if (i == end && end != pdu_len - 1) | |
1100 | return trace_seq_puts(s, " ..) "); | |
1101 | } | |
1102 | ||
1103 | return trace_seq_puts(s, ") "); | |
1104 | } | |
1105 | ||
c71a8961 ACM |
1106 | static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent) |
1107 | { | |
4ca53085 SR |
1108 | char cmd[TASK_COMM_LEN]; |
1109 | ||
1110 | trace_find_cmdline(ent->pid, cmd); | |
c71a8961 | 1111 | |
66de7792 LZ |
1112 | if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) { |
1113 | int ret; | |
1114 | ||
1115 | ret = trace_seq_printf(s, "%u ", t_bytes(ent)); | |
1116 | if (!ret) | |
1117 | return 0; | |
1118 | ret = blk_log_dump_pdu(s, ent); | |
1119 | if (!ret) | |
1120 | return 0; | |
1121 | return trace_seq_printf(s, "[%s]\n", cmd); | |
1122 | } else { | |
1123 | if (t_sec(ent)) | |
1124 | return trace_seq_printf(s, "%llu + %u [%s]\n", | |
1125 | t_sector(ent), t_sec(ent), cmd); | |
1126 | return trace_seq_printf(s, "[%s]\n", cmd); | |
1127 | } | |
c71a8961 ACM |
1128 | } |
1129 | ||
157f9c00 ACM |
1130 | static int blk_log_with_error(struct trace_seq *s, |
1131 | const struct trace_entry *ent) | |
c71a8961 | 1132 | { |
66de7792 LZ |
1133 | if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) { |
1134 | int ret; | |
1135 | ||
1136 | ret = blk_log_dump_pdu(s, ent); | |
1137 | if (ret) | |
1138 | return trace_seq_printf(s, "[%d]\n", t_error(ent)); | |
1139 | return 0; | |
1140 | } else { | |
1141 | if (t_sec(ent)) | |
1142 | return trace_seq_printf(s, "%llu + %u [%d]\n", | |
1143 | t_sector(ent), | |
1144 | t_sec(ent), t_error(ent)); | |
1145 | return trace_seq_printf(s, "%llu [%d]\n", | |
1146 | t_sector(ent), t_error(ent)); | |
1147 | } | |
c71a8961 ACM |
1148 | } |
1149 | ||
1150 | static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent) | |
1151 | { | |
a42aaa3b | 1152 | struct blk_io_trace_remap r = { .device_from = 0, }; |
c71a8961 ACM |
1153 | |
1154 | get_pdu_remap(ent, &r); | |
1155 | return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", | |
a42aaa3b AB |
1156 | t_sector(ent), t_sec(ent), |
1157 | MAJOR(r.device_from), MINOR(r.device_from), | |
1158 | (unsigned long long)r.sector_from); | |
c71a8961 ACM |
1159 | } |
1160 | ||
1161 | static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent) | |
1162 | { | |
4ca53085 SR |
1163 | char cmd[TASK_COMM_LEN]; |
1164 | ||
1165 | trace_find_cmdline(ent->pid, cmd); | |
1166 | ||
1167 | return trace_seq_printf(s, "[%s]\n", cmd); | |
c71a8961 ACM |
1168 | } |
1169 | ||
1170 | static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent) | |
1171 | { | |
4ca53085 SR |
1172 | char cmd[TASK_COMM_LEN]; |
1173 | ||
1174 | trace_find_cmdline(ent->pid, cmd); | |
1175 | ||
1176 | return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent)); | |
c71a8961 ACM |
1177 | } |
1178 | ||
1179 | static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent) | |
1180 | { | |
4ca53085 SR |
1181 | char cmd[TASK_COMM_LEN]; |
1182 | ||
1183 | trace_find_cmdline(ent->pid, cmd); | |
1184 | ||
c71a8961 | 1185 | return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), |
4ca53085 | 1186 | get_pdu_int(ent), cmd); |
c71a8961 ACM |
1187 | } |
1188 | ||
18cea459 LZ |
1189 | static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent) |
1190 | { | |
1191 | int ret; | |
1192 | const struct blk_io_trace *t = te_blk_io_trace(ent); | |
1193 | ||
1194 | ret = trace_seq_putmem(s, t + 1, t->pdu_len); | |
1195 | if (ret) | |
1196 | return trace_seq_putc(s, '\n'); | |
1197 | return ret; | |
1198 | } | |
1199 | ||
c71a8961 ACM |
1200 | /* |
1201 | * struct tracer operations | |
1202 | */ | |
1203 | ||
1204 | static void blk_tracer_print_header(struct seq_file *m) | |
1205 | { | |
1206 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1207 | return; | |
1208 | seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" | |
1209 | "# | | | | | |\n"); | |
1210 | } | |
1211 | ||
1212 | static void blk_tracer_start(struct trace_array *tr) | |
1213 | { | |
ad5dd549 | 1214 | blk_tracer_enabled = true; |
c71a8961 ACM |
1215 | } |
1216 | ||
1217 | static int blk_tracer_init(struct trace_array *tr) | |
1218 | { | |
1219 | blk_tr = tr; | |
1220 | blk_tracer_start(tr); | |
c71a8961 ACM |
1221 | return 0; |
1222 | } | |
1223 | ||
1224 | static void blk_tracer_stop(struct trace_array *tr) | |
1225 | { | |
ad5dd549 | 1226 | blk_tracer_enabled = false; |
c71a8961 ACM |
1227 | } |
1228 | ||
1229 | static void blk_tracer_reset(struct trace_array *tr) | |
1230 | { | |
c71a8961 ACM |
1231 | blk_tracer_stop(tr); |
1232 | } | |
1233 | ||
e4955c99 | 1234 | static const struct { |
c71a8961 | 1235 | const char *act[2]; |
ef18012b | 1236 | int (*print)(struct trace_seq *s, const struct trace_entry *ent); |
e4955c99 | 1237 | } what2act[] = { |
ef18012b | 1238 | [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, |
c71a8961 ACM |
1239 | [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, |
1240 | [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, | |
1241 | [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, | |
1242 | [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, | |
1243 | [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, | |
1244 | [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, | |
1245 | [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, | |
1246 | [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, | |
1247 | [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, | |
1248 | [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, | |
1249 | [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, | |
1250 | [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, | |
1251 | [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, | |
1252 | [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, | |
1253 | }; | |
1254 | ||
b6a4b0c3 LZ |
1255 | static enum print_line_t print_one_line(struct trace_iterator *iter, |
1256 | bool classic) | |
c71a8961 | 1257 | { |
2c9b238e | 1258 | struct trace_seq *s = &iter->seq; |
b6a4b0c3 LZ |
1259 | const struct blk_io_trace *t; |
1260 | u16 what; | |
c71a8961 | 1261 | int ret; |
b6a4b0c3 LZ |
1262 | bool long_act; |
1263 | blk_log_action_t *log_action; | |
c71a8961 | 1264 | |
b6a4b0c3 LZ |
1265 | t = te_blk_io_trace(iter->ent); |
1266 | what = t->action & ((1 << BLK_TC_SHIFT) - 1); | |
1267 | long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1268 | log_action = classic ? &blk_log_action_classic : &blk_log_action; | |
08a06b83 | 1269 | |
18cea459 LZ |
1270 | if (t->action == BLK_TN_MESSAGE) { |
1271 | ret = log_action(iter, long_act ? "message" : "m"); | |
1272 | if (ret) | |
1273 | ret = blk_log_msg(s, iter->ent); | |
1274 | goto out; | |
1275 | } | |
1276 | ||
eb08f8eb | 1277 | if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act))) |
b78825d6 | 1278 | ret = trace_seq_printf(s, "Unknown action %x\n", what); |
c71a8961 | 1279 | else { |
b6a4b0c3 | 1280 | ret = log_action(iter, what2act[what].act[long_act]); |
c71a8961 | 1281 | if (ret) |
2c9b238e | 1282 | ret = what2act[what].print(s, iter->ent); |
c71a8961 | 1283 | } |
18cea459 | 1284 | out: |
c71a8961 ACM |
1285 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; |
1286 | } | |
1287 | ||
b6a4b0c3 LZ |
1288 | static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, |
1289 | int flags) | |
1290 | { | |
b6a4b0c3 LZ |
1291 | return print_one_line(iter, false); |
1292 | } | |
1293 | ||
08a06b83 ACM |
1294 | static int blk_trace_synthesize_old_trace(struct trace_iterator *iter) |
1295 | { | |
1296 | struct trace_seq *s = &iter->seq; | |
1297 | struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
1298 | const int offset = offsetof(struct blk_io_trace, sector); | |
1299 | struct blk_io_trace old = { | |
1300 | .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, | |
6c051ce0 | 1301 | .time = iter->ts, |
08a06b83 ACM |
1302 | }; |
1303 | ||
1304 | if (!trace_seq_putmem(s, &old, offset)) | |
1305 | return 0; | |
1306 | return trace_seq_putmem(s, &t->sector, | |
1307 | sizeof(old) - offset + t->pdu_len); | |
1308 | } | |
1309 | ||
ae7462b4 ACM |
1310 | static enum print_line_t |
1311 | blk_trace_event_print_binary(struct trace_iterator *iter, int flags) | |
08a06b83 ACM |
1312 | { |
1313 | return blk_trace_synthesize_old_trace(iter) ? | |
1314 | TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1315 | } | |
1316 | ||
c71a8961 ACM |
1317 | static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) |
1318 | { | |
c71a8961 ACM |
1319 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) |
1320 | return TRACE_TYPE_UNHANDLED; | |
1321 | ||
b6a4b0c3 | 1322 | return print_one_line(iter, true); |
c71a8961 ACM |
1323 | } |
1324 | ||
f3948f88 LZ |
1325 | static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set) |
1326 | { | |
1327 | /* don't output context-info for blk_classic output */ | |
1328 | if (bit == TRACE_BLK_OPT_CLASSIC) { | |
1329 | if (set) | |
1330 | trace_flags &= ~TRACE_ITER_CONTEXT_INFO; | |
1331 | else | |
1332 | trace_flags |= TRACE_ITER_CONTEXT_INFO; | |
1333 | } | |
1334 | return 0; | |
1335 | } | |
1336 | ||
c71a8961 ACM |
1337 | static struct tracer blk_tracer __read_mostly = { |
1338 | .name = "blk", | |
1339 | .init = blk_tracer_init, | |
1340 | .reset = blk_tracer_reset, | |
1341 | .start = blk_tracer_start, | |
1342 | .stop = blk_tracer_stop, | |
1343 | .print_header = blk_tracer_print_header, | |
1344 | .print_line = blk_tracer_print_line, | |
1345 | .flags = &blk_tracer_flags, | |
f3948f88 | 1346 | .set_flag = blk_tracer_set_flag, |
c71a8961 ACM |
1347 | }; |
1348 | ||
1349 | static struct trace_event trace_blk_event = { | |
ef18012b | 1350 | .type = TRACE_BLK, |
c71a8961 | 1351 | .trace = blk_trace_event_print, |
08a06b83 | 1352 | .binary = blk_trace_event_print_binary, |
c71a8961 ACM |
1353 | }; |
1354 | ||
1355 | static int __init init_blk_tracer(void) | |
1356 | { | |
1357 | if (!register_ftrace_event(&trace_blk_event)) { | |
1358 | pr_warning("Warning: could not register block events\n"); | |
1359 | return 1; | |
1360 | } | |
1361 | ||
1362 | if (register_tracer(&blk_tracer) != 0) { | |
1363 | pr_warning("Warning: could not register the block tracer\n"); | |
1364 | unregister_ftrace_event(&trace_blk_event); | |
1365 | return 1; | |
1366 | } | |
1367 | ||
1368 | return 0; | |
1369 | } | |
1370 | ||
1371 | device_initcall(init_blk_tracer); | |
1372 | ||
1373 | static int blk_trace_remove_queue(struct request_queue *q) | |
1374 | { | |
1375 | struct blk_trace *bt; | |
1376 | ||
1377 | bt = xchg(&q->blk_trace, NULL); | |
1378 | if (bt == NULL) | |
1379 | return -EINVAL; | |
1380 | ||
17ba97e3 LZ |
1381 | if (atomic_dec_and_test(&blk_probes_ref)) |
1382 | blk_unregister_tracepoints(); | |
1383 | ||
ad5dd549 | 1384 | blk_trace_free(bt); |
c71a8961 ACM |
1385 | return 0; |
1386 | } | |
1387 | ||
1388 | /* | |
1389 | * Setup everything required to start tracing | |
1390 | */ | |
9908c309 LZ |
1391 | static int blk_trace_setup_queue(struct request_queue *q, |
1392 | struct block_device *bdev) | |
c71a8961 ACM |
1393 | { |
1394 | struct blk_trace *old_bt, *bt = NULL; | |
18cea459 | 1395 | int ret = -ENOMEM; |
c71a8961 | 1396 | |
c71a8961 ACM |
1397 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
1398 | if (!bt) | |
15152e44 | 1399 | return -ENOMEM; |
c71a8961 | 1400 | |
18cea459 LZ |
1401 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
1402 | if (!bt->msg_data) | |
1403 | goto free_bt; | |
1404 | ||
9908c309 | 1405 | bt->dev = bdev->bd_dev; |
c71a8961 | 1406 | bt->act_mask = (u16)-1; |
9908c309 LZ |
1407 | |
1408 | blk_trace_setup_lba(bt, bdev); | |
c71a8961 ACM |
1409 | |
1410 | old_bt = xchg(&q->blk_trace, bt); | |
1411 | if (old_bt != NULL) { | |
1412 | (void)xchg(&q->blk_trace, old_bt); | |
18cea459 LZ |
1413 | ret = -EBUSY; |
1414 | goto free_bt; | |
c71a8961 | 1415 | } |
15152e44 | 1416 | |
17ba97e3 LZ |
1417 | if (atomic_inc_return(&blk_probes_ref) == 1) |
1418 | blk_register_tracepoints(); | |
c71a8961 | 1419 | return 0; |
18cea459 LZ |
1420 | |
1421 | free_bt: | |
1422 | blk_trace_free(bt); | |
1423 | return ret; | |
c71a8961 ACM |
1424 | } |
1425 | ||
1426 | /* | |
1427 | * sysfs interface to enable and configure tracing | |
1428 | */ | |
1429 | ||
c71a8961 ACM |
1430 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1431 | struct device_attribute *attr, | |
1432 | char *buf); | |
1433 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1434 | struct device_attribute *attr, | |
1435 | const char *buf, size_t count); | |
1436 | #define BLK_TRACE_DEVICE_ATTR(_name) \ | |
1437 | DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ | |
1438 | sysfs_blk_trace_attr_show, \ | |
1439 | sysfs_blk_trace_attr_store) | |
1440 | ||
cd649b8b | 1441 | static BLK_TRACE_DEVICE_ATTR(enable); |
c71a8961 ACM |
1442 | static BLK_TRACE_DEVICE_ATTR(act_mask); |
1443 | static BLK_TRACE_DEVICE_ATTR(pid); | |
1444 | static BLK_TRACE_DEVICE_ATTR(start_lba); | |
1445 | static BLK_TRACE_DEVICE_ATTR(end_lba); | |
1446 | ||
1447 | static struct attribute *blk_trace_attrs[] = { | |
1448 | &dev_attr_enable.attr, | |
1449 | &dev_attr_act_mask.attr, | |
1450 | &dev_attr_pid.attr, | |
1451 | &dev_attr_start_lba.attr, | |
1452 | &dev_attr_end_lba.attr, | |
1453 | NULL | |
1454 | }; | |
1455 | ||
1456 | struct attribute_group blk_trace_attr_group = { | |
1457 | .name = "trace", | |
1458 | .attrs = blk_trace_attrs, | |
1459 | }; | |
1460 | ||
09341997 LZ |
1461 | static const struct { |
1462 | int mask; | |
1463 | const char *str; | |
1464 | } mask_maps[] = { | |
1465 | { BLK_TC_READ, "read" }, | |
1466 | { BLK_TC_WRITE, "write" }, | |
1467 | { BLK_TC_BARRIER, "barrier" }, | |
1468 | { BLK_TC_SYNC, "sync" }, | |
1469 | { BLK_TC_QUEUE, "queue" }, | |
1470 | { BLK_TC_REQUEUE, "requeue" }, | |
1471 | { BLK_TC_ISSUE, "issue" }, | |
1472 | { BLK_TC_COMPLETE, "complete" }, | |
1473 | { BLK_TC_FS, "fs" }, | |
1474 | { BLK_TC_PC, "pc" }, | |
1475 | { BLK_TC_AHEAD, "ahead" }, | |
1476 | { BLK_TC_META, "meta" }, | |
1477 | { BLK_TC_DISCARD, "discard" }, | |
1478 | { BLK_TC_DRV_DATA, "drv_data" }, | |
1479 | }; | |
1480 | ||
1481 | static int blk_trace_str2mask(const char *str) | |
c71a8961 | 1482 | { |
09341997 | 1483 | int i; |
c71a8961 | 1484 | int mask = 0; |
9eb85125 | 1485 | char *buf, *s, *token; |
c71a8961 | 1486 | |
9eb85125 LZ |
1487 | buf = kstrdup(str, GFP_KERNEL); |
1488 | if (buf == NULL) | |
c71a8961 | 1489 | return -ENOMEM; |
9eb85125 | 1490 | s = strstrip(buf); |
c71a8961 ACM |
1491 | |
1492 | while (1) { | |
09341997 LZ |
1493 | token = strsep(&s, ","); |
1494 | if (token == NULL) | |
c71a8961 ACM |
1495 | break; |
1496 | ||
09341997 LZ |
1497 | if (*token == '\0') |
1498 | continue; | |
1499 | ||
1500 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1501 | if (strcasecmp(token, mask_maps[i].str) == 0) { | |
1502 | mask |= mask_maps[i].mask; | |
1503 | break; | |
1504 | } | |
1505 | } | |
1506 | if (i == ARRAY_SIZE(mask_maps)) { | |
1507 | mask = -EINVAL; | |
1508 | break; | |
1509 | } | |
c71a8961 | 1510 | } |
9eb85125 | 1511 | kfree(buf); |
c71a8961 ACM |
1512 | |
1513 | return mask; | |
1514 | } | |
1515 | ||
09341997 LZ |
1516 | static ssize_t blk_trace_mask2str(char *buf, int mask) |
1517 | { | |
1518 | int i; | |
1519 | char *p = buf; | |
1520 | ||
1521 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1522 | if (mask & mask_maps[i].mask) { | |
1523 | p += sprintf(p, "%s%s", | |
1524 | (p == buf) ? "" : ",", mask_maps[i].str); | |
1525 | } | |
1526 | } | |
1527 | *p++ = '\n'; | |
1528 | ||
1529 | return p - buf; | |
1530 | } | |
1531 | ||
b125130b LZ |
1532 | static struct request_queue *blk_trace_get_queue(struct block_device *bdev) |
1533 | { | |
1534 | if (bdev->bd_disk == NULL) | |
1535 | return NULL; | |
1536 | ||
1537 | return bdev_get_queue(bdev); | |
1538 | } | |
1539 | ||
c71a8961 ACM |
1540 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1541 | struct device_attribute *attr, | |
1542 | char *buf) | |
1543 | { | |
1544 | struct hd_struct *p = dev_to_part(dev); | |
1545 | struct request_queue *q; | |
1546 | struct block_device *bdev; | |
1547 | ssize_t ret = -ENXIO; | |
1548 | ||
1549 | lock_kernel(); | |
1550 | bdev = bdget(part_devt(p)); | |
1551 | if (bdev == NULL) | |
1552 | goto out_unlock_kernel; | |
1553 | ||
b125130b | 1554 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1555 | if (q == NULL) |
1556 | goto out_bdput; | |
b125130b | 1557 | |
c71a8961 | 1558 | mutex_lock(&bdev->bd_mutex); |
cd649b8b LZ |
1559 | |
1560 | if (attr == &dev_attr_enable) { | |
1561 | ret = sprintf(buf, "%u\n", !!q->blk_trace); | |
1562 | goto out_unlock_bdev; | |
1563 | } | |
1564 | ||
c71a8961 ACM |
1565 | if (q->blk_trace == NULL) |
1566 | ret = sprintf(buf, "disabled\n"); | |
1567 | else if (attr == &dev_attr_act_mask) | |
09341997 | 1568 | ret = blk_trace_mask2str(buf, q->blk_trace->act_mask); |
c71a8961 ACM |
1569 | else if (attr == &dev_attr_pid) |
1570 | ret = sprintf(buf, "%u\n", q->blk_trace->pid); | |
1571 | else if (attr == &dev_attr_start_lba) | |
1572 | ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); | |
1573 | else if (attr == &dev_attr_end_lba) | |
1574 | ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); | |
cd649b8b LZ |
1575 | |
1576 | out_unlock_bdev: | |
c71a8961 ACM |
1577 | mutex_unlock(&bdev->bd_mutex); |
1578 | out_bdput: | |
1579 | bdput(bdev); | |
1580 | out_unlock_kernel: | |
1581 | unlock_kernel(); | |
1582 | return ret; | |
1583 | } | |
1584 | ||
1585 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1586 | struct device_attribute *attr, | |
1587 | const char *buf, size_t count) | |
1588 | { | |
1589 | struct block_device *bdev; | |
1590 | struct request_queue *q; | |
1591 | struct hd_struct *p; | |
1592 | u64 value; | |
09341997 | 1593 | ssize_t ret = -EINVAL; |
c71a8961 ACM |
1594 | |
1595 | if (count == 0) | |
1596 | goto out; | |
1597 | ||
1598 | if (attr == &dev_attr_act_mask) { | |
1599 | if (sscanf(buf, "%llx", &value) != 1) { | |
1600 | /* Assume it is a list of trace category names */ | |
09341997 LZ |
1601 | ret = blk_trace_str2mask(buf); |
1602 | if (ret < 0) | |
c71a8961 | 1603 | goto out; |
09341997 | 1604 | value = ret; |
c71a8961 ACM |
1605 | } |
1606 | } else if (sscanf(buf, "%llu", &value) != 1) | |
1607 | goto out; | |
1608 | ||
09341997 LZ |
1609 | ret = -ENXIO; |
1610 | ||
c71a8961 ACM |
1611 | lock_kernel(); |
1612 | p = dev_to_part(dev); | |
1613 | bdev = bdget(part_devt(p)); | |
1614 | if (bdev == NULL) | |
1615 | goto out_unlock_kernel; | |
1616 | ||
b125130b | 1617 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1618 | if (q == NULL) |
1619 | goto out_bdput; | |
1620 | ||
1621 | mutex_lock(&bdev->bd_mutex); | |
cd649b8b LZ |
1622 | |
1623 | if (attr == &dev_attr_enable) { | |
1624 | if (value) | |
9908c309 | 1625 | ret = blk_trace_setup_queue(q, bdev); |
cd649b8b LZ |
1626 | else |
1627 | ret = blk_trace_remove_queue(q); | |
1628 | goto out_unlock_bdev; | |
1629 | } | |
1630 | ||
c71a8961 ACM |
1631 | ret = 0; |
1632 | if (q->blk_trace == NULL) | |
9908c309 | 1633 | ret = blk_trace_setup_queue(q, bdev); |
c71a8961 ACM |
1634 | |
1635 | if (ret == 0) { | |
1636 | if (attr == &dev_attr_act_mask) | |
1637 | q->blk_trace->act_mask = value; | |
1638 | else if (attr == &dev_attr_pid) | |
1639 | q->blk_trace->pid = value; | |
1640 | else if (attr == &dev_attr_start_lba) | |
1641 | q->blk_trace->start_lba = value; | |
1642 | else if (attr == &dev_attr_end_lba) | |
1643 | q->blk_trace->end_lba = value; | |
c71a8961 | 1644 | } |
cd649b8b LZ |
1645 | |
1646 | out_unlock_bdev: | |
c71a8961 ACM |
1647 | mutex_unlock(&bdev->bd_mutex); |
1648 | out_bdput: | |
1649 | bdput(bdev); | |
1650 | out_unlock_kernel: | |
1651 | unlock_kernel(); | |
1652 | out: | |
cd649b8b | 1653 | return ret ? ret : count; |
c71a8961 | 1654 | } |
cd649b8b | 1655 | |
1d54ad6d LZ |
1656 | int blk_trace_init_sysfs(struct device *dev) |
1657 | { | |
1658 | return sysfs_create_group(&dev->kobj, &blk_trace_attr_group); | |
1659 | } | |
1660 |