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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; | |
150 | if (sector < bt->start_lba || sector > bt->end_lba) | |
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; | |
195 | if (unlikely(act_log_check(bt, what, sector, pid))) | |
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); |
f48fc4d3 | 265 | relay_close(bt->rchan); |
2056a782 | 266 | free_percpu(bt->sequence); |
64565911 | 267 | free_percpu(bt->msg_data); |
2056a782 | 268 | kfree(bt); |
ad5dd549 LZ |
269 | } |
270 | ||
271 | static void blk_trace_cleanup(struct blk_trace *bt) | |
272 | { | |
273 | blk_trace_free(bt); | |
5f3ea37c ACM |
274 | if (atomic_dec_and_test(&blk_probes_ref)) |
275 | blk_unregister_tracepoints(); | |
2056a782 JA |
276 | } |
277 | ||
6da127ad | 278 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
279 | { |
280 | struct blk_trace *bt; | |
281 | ||
282 | bt = xchg(&q->blk_trace, NULL); | |
283 | if (!bt) | |
284 | return -EINVAL; | |
285 | ||
55547204 | 286 | if (bt->trace_state != Blktrace_running) |
2056a782 JA |
287 | blk_trace_cleanup(bt); |
288 | ||
289 | return 0; | |
290 | } | |
6da127ad | 291 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 JA |
292 | |
293 | static int blk_dropped_open(struct inode *inode, struct file *filp) | |
294 | { | |
8e18e294 | 295 | filp->private_data = inode->i_private; |
2056a782 JA |
296 | |
297 | return 0; | |
298 | } | |
299 | ||
300 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, | |
301 | size_t count, loff_t *ppos) | |
302 | { | |
303 | struct blk_trace *bt = filp->private_data; | |
304 | char buf[16]; | |
305 | ||
306 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
307 | ||
308 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
309 | } | |
310 | ||
2b8693c0 | 311 | static const struct file_operations blk_dropped_fops = { |
2056a782 JA |
312 | .owner = THIS_MODULE, |
313 | .open = blk_dropped_open, | |
314 | .read = blk_dropped_read, | |
315 | }; | |
316 | ||
02c62304 AB |
317 | static int blk_msg_open(struct inode *inode, struct file *filp) |
318 | { | |
319 | filp->private_data = inode->i_private; | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
324 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, | |
325 | size_t count, loff_t *ppos) | |
326 | { | |
327 | char *msg; | |
328 | struct blk_trace *bt; | |
329 | ||
7635b03a | 330 | if (count >= BLK_TN_MAX_MSG) |
02c62304 AB |
331 | return -EINVAL; |
332 | ||
a4b3ada8 | 333 | msg = kmalloc(count + 1, GFP_KERNEL); |
02c62304 AB |
334 | if (msg == NULL) |
335 | return -ENOMEM; | |
336 | ||
337 | if (copy_from_user(msg, buffer, count)) { | |
338 | kfree(msg); | |
339 | return -EFAULT; | |
340 | } | |
341 | ||
a4b3ada8 | 342 | msg[count] = '\0'; |
02c62304 AB |
343 | bt = filp->private_data; |
344 | __trace_note_message(bt, "%s", msg); | |
345 | kfree(msg); | |
346 | ||
347 | return count; | |
348 | } | |
349 | ||
350 | static const struct file_operations blk_msg_fops = { | |
351 | .owner = THIS_MODULE, | |
352 | .open = blk_msg_open, | |
353 | .write = blk_msg_write, | |
354 | }; | |
355 | ||
2056a782 JA |
356 | /* |
357 | * Keep track of how many times we encountered a full subbuffer, to aid | |
358 | * the user space app in telling how many lost events there were. | |
359 | */ | |
360 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
361 | void *prev_subbuf, size_t prev_padding) | |
362 | { | |
363 | struct blk_trace *bt; | |
364 | ||
365 | if (!relay_buf_full(buf)) | |
366 | return 1; | |
367 | ||
368 | bt = buf->chan->private_data; | |
369 | atomic_inc(&bt->dropped); | |
370 | return 0; | |
371 | } | |
372 | ||
373 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
374 | { | |
f48fc4d3 | 375 | struct dentry *parent = dentry->d_parent; |
2056a782 | 376 | debugfs_remove(dentry); |
f48fc4d3 JA |
377 | |
378 | /* | |
379 | * this will fail for all but the last file, but that is ok. what we | |
380 | * care about is the top level buts->name directory going away, when | |
381 | * the last trace file is gone. Then we don't have to rmdir() that | |
382 | * manually on trace stop, so it nicely solves the issue with | |
383 | * force killing of running traces. | |
384 | */ | |
385 | ||
386 | debugfs_remove(parent); | |
2056a782 JA |
387 | return 0; |
388 | } | |
389 | ||
390 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
391 | struct dentry *parent, | |
392 | int mode, | |
393 | struct rchan_buf *buf, | |
394 | int *is_global) | |
395 | { | |
396 | return debugfs_create_file(filename, mode, parent, buf, | |
397 | &relay_file_operations); | |
398 | } | |
399 | ||
400 | static struct rchan_callbacks blk_relay_callbacks = { | |
401 | .subbuf_start = blk_subbuf_start_callback, | |
402 | .create_buf_file = blk_create_buf_file_callback, | |
403 | .remove_buf_file = blk_remove_buf_file_callback, | |
404 | }; | |
405 | ||
406 | /* | |
407 | * Setup everything required to start tracing | |
408 | */ | |
6da127ad | 409 | int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
171044d4 | 410 | struct blk_user_trace_setup *buts) |
2056a782 | 411 | { |
2056a782 JA |
412 | struct blk_trace *old_bt, *bt = NULL; |
413 | struct dentry *dir = NULL; | |
2056a782 JA |
414 | int ret, i; |
415 | ||
171044d4 | 416 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
417 | return -EINVAL; |
418 | ||
0497b345 JA |
419 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
420 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
421 | |
422 | /* | |
423 | * some device names have larger paths - convert the slashes | |
424 | * to underscores for this to work as expected | |
425 | */ | |
171044d4 AB |
426 | for (i = 0; i < strlen(buts->name); i++) |
427 | if (buts->name[i] == '/') | |
428 | buts->name[i] = '_'; | |
2056a782 | 429 | |
2056a782 JA |
430 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
431 | if (!bt) | |
ad5dd549 | 432 | return -ENOMEM; |
2056a782 | 433 | |
ad5dd549 | 434 | ret = -ENOMEM; |
2056a782 JA |
435 | bt->sequence = alloc_percpu(unsigned long); |
436 | if (!bt->sequence) | |
437 | goto err; | |
438 | ||
313e458f | 439 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
64565911 JA |
440 | if (!bt->msg_data) |
441 | goto err; | |
442 | ||
2056a782 | 443 | ret = -ENOENT; |
f48fc4d3 | 444 | |
b5230b56 | 445 | mutex_lock(&blk_tree_mutex); |
f48fc4d3 JA |
446 | if (!blk_tree_root) { |
447 | blk_tree_root = debugfs_create_dir("block", NULL); | |
b5230b56 LZ |
448 | if (!blk_tree_root) { |
449 | mutex_unlock(&blk_tree_mutex); | |
1a17662e | 450 | goto err; |
b5230b56 | 451 | } |
f48fc4d3 | 452 | } |
b5230b56 | 453 | mutex_unlock(&blk_tree_mutex); |
f48fc4d3 JA |
454 | |
455 | dir = debugfs_create_dir(buts->name, blk_tree_root); | |
456 | ||
2056a782 JA |
457 | if (!dir) |
458 | goto err; | |
459 | ||
460 | bt->dir = dir; | |
6da127ad | 461 | bt->dev = dev; |
2056a782 JA |
462 | atomic_set(&bt->dropped, 0); |
463 | ||
464 | ret = -EIO; | |
939b3669 ACM |
465 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, |
466 | &blk_dropped_fops); | |
2056a782 JA |
467 | if (!bt->dropped_file) |
468 | goto err; | |
469 | ||
02c62304 AB |
470 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
471 | if (!bt->msg_file) | |
472 | goto err; | |
473 | ||
171044d4 AB |
474 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
475 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
476 | if (!bt->rchan) |
477 | goto err; | |
2056a782 | 478 | |
171044d4 | 479 | bt->act_mask = buts->act_mask; |
2056a782 JA |
480 | if (!bt->act_mask) |
481 | bt->act_mask = (u16) -1; | |
482 | ||
171044d4 AB |
483 | bt->start_lba = buts->start_lba; |
484 | bt->end_lba = buts->end_lba; | |
2056a782 JA |
485 | if (!bt->end_lba) |
486 | bt->end_lba = -1ULL; | |
487 | ||
171044d4 | 488 | bt->pid = buts->pid; |
2056a782 JA |
489 | bt->trace_state = Blktrace_setup; |
490 | ||
491 | ret = -EBUSY; | |
492 | old_bt = xchg(&q->blk_trace, bt); | |
493 | if (old_bt) { | |
494 | (void) xchg(&q->blk_trace, old_bt); | |
495 | goto err; | |
496 | } | |
497 | ||
17ba97e3 | 498 | if (atomic_inc_return(&blk_probes_ref) == 1) |
cbe28296 LZ |
499 | blk_register_tracepoints(); |
500 | ||
2056a782 JA |
501 | return 0; |
502 | err: | |
ad5dd549 | 503 | blk_trace_free(bt); |
2056a782 JA |
504 | return ret; |
505 | } | |
171044d4 | 506 | |
6da127ad CS |
507 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
508 | char __user *arg) | |
171044d4 AB |
509 | { |
510 | struct blk_user_trace_setup buts; | |
511 | int ret; | |
512 | ||
513 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
514 | if (ret) | |
515 | return -EFAULT; | |
516 | ||
6da127ad | 517 | ret = do_blk_trace_setup(q, name, dev, &buts); |
171044d4 AB |
518 | if (ret) |
519 | return ret; | |
520 | ||
521 | if (copy_to_user(arg, &buts, sizeof(buts))) | |
522 | return -EFAULT; | |
523 | ||
524 | return 0; | |
525 | } | |
6da127ad | 526 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 527 | |
6da127ad | 528 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 | 529 | { |
2056a782 | 530 | int ret; |
939b3669 | 531 | struct blk_trace *bt = q->blk_trace; |
2056a782 | 532 | |
939b3669 | 533 | if (bt == NULL) |
2056a782 JA |
534 | return -EINVAL; |
535 | ||
536 | /* | |
537 | * For starting a trace, we can transition from a setup or stopped | |
538 | * trace. For stopping a trace, the state must be running | |
539 | */ | |
540 | ret = -EINVAL; | |
541 | if (start) { | |
542 | if (bt->trace_state == Blktrace_setup || | |
543 | bt->trace_state == Blktrace_stopped) { | |
544 | blktrace_seq++; | |
545 | smp_mb(); | |
546 | bt->trace_state = Blktrace_running; | |
be1c6341 OK |
547 | |
548 | trace_note_time(bt); | |
2056a782 JA |
549 | ret = 0; |
550 | } | |
551 | } else { | |
552 | if (bt->trace_state == Blktrace_running) { | |
553 | bt->trace_state = Blktrace_stopped; | |
554 | relay_flush(bt->rchan); | |
555 | ret = 0; | |
556 | } | |
557 | } | |
558 | ||
559 | return ret; | |
560 | } | |
6da127ad | 561 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 JA |
562 | |
563 | /** | |
564 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
565 | * @bdev: the block device | |
ef18012b | 566 | * @cmd: the ioctl cmd |
2056a782 JA |
567 | * @arg: the argument data, if any |
568 | * | |
569 | **/ | |
570 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
571 | { | |
165125e1 | 572 | struct request_queue *q; |
2056a782 | 573 | int ret, start = 0; |
6da127ad | 574 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
575 | |
576 | q = bdev_get_queue(bdev); | |
577 | if (!q) | |
578 | return -ENXIO; | |
579 | ||
580 | mutex_lock(&bdev->bd_mutex); | |
581 | ||
582 | switch (cmd) { | |
583 | case BLKTRACESETUP: | |
f36f21ec | 584 | bdevname(bdev, b); |
6da127ad | 585 | ret = blk_trace_setup(q, b, bdev->bd_dev, arg); |
2056a782 JA |
586 | break; |
587 | case BLKTRACESTART: | |
588 | start = 1; | |
589 | case BLKTRACESTOP: | |
590 | ret = blk_trace_startstop(q, start); | |
591 | break; | |
592 | case BLKTRACETEARDOWN: | |
593 | ret = blk_trace_remove(q); | |
594 | break; | |
595 | default: | |
596 | ret = -ENOTTY; | |
597 | break; | |
598 | } | |
599 | ||
600 | mutex_unlock(&bdev->bd_mutex); | |
601 | return ret; | |
602 | } | |
603 | ||
604 | /** | |
605 | * blk_trace_shutdown: - stop and cleanup trace structures | |
606 | * @q: the request queue associated with the device | |
607 | * | |
608 | **/ | |
165125e1 | 609 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 610 | { |
6c5c9341 AD |
611 | if (q->blk_trace) { |
612 | blk_trace_startstop(q, 0); | |
613 | blk_trace_remove(q); | |
614 | } | |
2056a782 | 615 | } |
5f3ea37c ACM |
616 | |
617 | /* | |
618 | * blktrace probes | |
619 | */ | |
620 | ||
621 | /** | |
622 | * blk_add_trace_rq - Add a trace for a request oriented action | |
623 | * @q: queue the io is for | |
624 | * @rq: the source request | |
625 | * @what: the action | |
626 | * | |
627 | * Description: | |
628 | * Records an action against a request. Will log the bio offset + size. | |
629 | * | |
630 | **/ | |
631 | static void blk_add_trace_rq(struct request_queue *q, struct request *rq, | |
632 | u32 what) | |
633 | { | |
634 | struct blk_trace *bt = q->blk_trace; | |
635 | int rw = rq->cmd_flags & 0x03; | |
636 | ||
637 | if (likely(!bt)) | |
638 | return; | |
639 | ||
640 | if (blk_discard_rq(rq)) | |
641 | rw |= (1 << BIO_RW_DISCARD); | |
642 | ||
643 | if (blk_pc_request(rq)) { | |
644 | what |= BLK_TC_ACT(BLK_TC_PC); | |
645 | __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, | |
e2494e1b | 646 | rq->cmd_len, rq->cmd); |
5f3ea37c ACM |
647 | } else { |
648 | what |= BLK_TC_ACT(BLK_TC_FS); | |
5b93629b | 649 | __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9, |
5f3ea37c ACM |
650 | rw, what, rq->errors, 0, NULL); |
651 | } | |
652 | } | |
653 | ||
654 | static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) | |
655 | { | |
656 | blk_add_trace_rq(q, rq, BLK_TA_ABORT); | |
657 | } | |
658 | ||
659 | static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) | |
660 | { | |
661 | blk_add_trace_rq(q, rq, BLK_TA_INSERT); | |
662 | } | |
663 | ||
664 | static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) | |
665 | { | |
666 | blk_add_trace_rq(q, rq, BLK_TA_ISSUE); | |
667 | } | |
668 | ||
939b3669 ACM |
669 | static void blk_add_trace_rq_requeue(struct request_queue *q, |
670 | struct request *rq) | |
5f3ea37c ACM |
671 | { |
672 | blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); | |
673 | } | |
674 | ||
939b3669 ACM |
675 | static void blk_add_trace_rq_complete(struct request_queue *q, |
676 | struct request *rq) | |
5f3ea37c ACM |
677 | { |
678 | blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); | |
679 | } | |
680 | ||
681 | /** | |
682 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
683 | * @q: queue the io is for | |
684 | * @bio: the source bio | |
685 | * @what: the action | |
686 | * | |
687 | * Description: | |
688 | * Records an action against a bio. Will log the bio offset + size. | |
689 | * | |
690 | **/ | |
691 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
692 | u32 what) | |
693 | { | |
694 | struct blk_trace *bt = q->blk_trace; | |
695 | ||
696 | if (likely(!bt)) | |
697 | return; | |
698 | ||
699 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, | |
700 | !bio_flagged(bio, BIO_UPTODATE), 0, NULL); | |
701 | } | |
702 | ||
703 | static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) | |
704 | { | |
705 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); | |
706 | } | |
707 | ||
708 | static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) | |
709 | { | |
710 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); | |
711 | } | |
712 | ||
939b3669 ACM |
713 | static void blk_add_trace_bio_backmerge(struct request_queue *q, |
714 | struct bio *bio) | |
5f3ea37c ACM |
715 | { |
716 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); | |
717 | } | |
718 | ||
939b3669 ACM |
719 | static void blk_add_trace_bio_frontmerge(struct request_queue *q, |
720 | struct bio *bio) | |
5f3ea37c ACM |
721 | { |
722 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); | |
723 | } | |
724 | ||
725 | static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) | |
726 | { | |
727 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE); | |
728 | } | |
729 | ||
939b3669 ACM |
730 | static void blk_add_trace_getrq(struct request_queue *q, |
731 | struct bio *bio, int rw) | |
5f3ea37c ACM |
732 | { |
733 | if (bio) | |
734 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ); | |
735 | else { | |
736 | struct blk_trace *bt = q->blk_trace; | |
737 | ||
738 | if (bt) | |
739 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); | |
740 | } | |
741 | } | |
742 | ||
743 | ||
939b3669 ACM |
744 | static void blk_add_trace_sleeprq(struct request_queue *q, |
745 | struct bio *bio, int rw) | |
5f3ea37c ACM |
746 | { |
747 | if (bio) | |
748 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); | |
749 | else { | |
750 | struct blk_trace *bt = q->blk_trace; | |
751 | ||
752 | if (bt) | |
939b3669 ACM |
753 | __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, |
754 | 0, 0, NULL); | |
5f3ea37c ACM |
755 | } |
756 | } | |
757 | ||
758 | static void blk_add_trace_plug(struct request_queue *q) | |
759 | { | |
760 | struct blk_trace *bt = q->blk_trace; | |
761 | ||
762 | if (bt) | |
763 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); | |
764 | } | |
765 | ||
766 | static void blk_add_trace_unplug_io(struct request_queue *q) | |
767 | { | |
768 | struct blk_trace *bt = q->blk_trace; | |
769 | ||
770 | if (bt) { | |
771 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
772 | __be64 rpdu = cpu_to_be64(pdu); | |
773 | ||
774 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, | |
775 | sizeof(rpdu), &rpdu); | |
776 | } | |
777 | } | |
778 | ||
779 | static void blk_add_trace_unplug_timer(struct request_queue *q) | |
780 | { | |
781 | struct blk_trace *bt = q->blk_trace; | |
782 | ||
783 | if (bt) { | |
784 | unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; | |
785 | __be64 rpdu = cpu_to_be64(pdu); | |
786 | ||
787 | __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, | |
788 | sizeof(rpdu), &rpdu); | |
789 | } | |
790 | } | |
791 | ||
792 | static void blk_add_trace_split(struct request_queue *q, struct bio *bio, | |
793 | unsigned int pdu) | |
794 | { | |
795 | struct blk_trace *bt = q->blk_trace; | |
796 | ||
797 | if (bt) { | |
798 | __be64 rpdu = cpu_to_be64(pdu); | |
799 | ||
800 | __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, | |
801 | BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), | |
802 | sizeof(rpdu), &rpdu); | |
803 | } | |
804 | } | |
805 | ||
806 | /** | |
807 | * blk_add_trace_remap - Add a trace for a remap operation | |
808 | * @q: queue the io is for | |
809 | * @bio: the source bio | |
810 | * @dev: target device | |
811 | * @from: source sector | |
812 | * @to: target sector | |
813 | * | |
814 | * Description: | |
815 | * Device mapper or raid target sometimes need to split a bio because | |
816 | * it spans a stripe (or similar). Add a trace for that action. | |
817 | * | |
818 | **/ | |
819 | static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, | |
820 | dev_t dev, sector_t from, sector_t to) | |
821 | { | |
822 | struct blk_trace *bt = q->blk_trace; | |
823 | struct blk_io_trace_remap r; | |
824 | ||
825 | if (likely(!bt)) | |
826 | return; | |
827 | ||
828 | r.device = cpu_to_be32(dev); | |
829 | r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); | |
830 | r.sector = cpu_to_be64(to); | |
831 | ||
832 | __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, | |
833 | !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); | |
834 | } | |
835 | ||
836 | /** | |
837 | * blk_add_driver_data - Add binary message with driver-specific data | |
838 | * @q: queue the io is for | |
839 | * @rq: io request | |
840 | * @data: driver-specific data | |
841 | * @len: length of driver-specific data | |
842 | * | |
843 | * Description: | |
844 | * Some drivers might want to write driver-specific data per request. | |
845 | * | |
846 | **/ | |
847 | void blk_add_driver_data(struct request_queue *q, | |
848 | struct request *rq, | |
849 | void *data, size_t len) | |
850 | { | |
851 | struct blk_trace *bt = q->blk_trace; | |
852 | ||
853 | if (likely(!bt)) | |
854 | return; | |
855 | ||
856 | if (blk_pc_request(rq)) | |
857 | __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, | |
858 | rq->errors, len, data); | |
859 | else | |
5b93629b | 860 | __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9, |
5f3ea37c ACM |
861 | 0, BLK_TA_DRV_DATA, rq->errors, len, data); |
862 | } | |
863 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
864 | ||
3c289ba7 | 865 | static void blk_register_tracepoints(void) |
5f3ea37c ACM |
866 | { |
867 | int ret; | |
868 | ||
869 | ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); | |
870 | WARN_ON(ret); | |
871 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); | |
872 | WARN_ON(ret); | |
873 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); | |
874 | WARN_ON(ret); | |
875 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
876 | WARN_ON(ret); | |
877 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); | |
878 | WARN_ON(ret); | |
879 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
880 | WARN_ON(ret); | |
881 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); | |
882 | WARN_ON(ret); | |
883 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
884 | WARN_ON(ret); | |
885 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
886 | WARN_ON(ret); | |
887 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); | |
888 | WARN_ON(ret); | |
889 | ret = register_trace_block_getrq(blk_add_trace_getrq); | |
890 | WARN_ON(ret); | |
891 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); | |
892 | WARN_ON(ret); | |
893 | ret = register_trace_block_plug(blk_add_trace_plug); | |
894 | WARN_ON(ret); | |
895 | ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
896 | WARN_ON(ret); | |
897 | ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); | |
898 | WARN_ON(ret); | |
899 | ret = register_trace_block_split(blk_add_trace_split); | |
900 | WARN_ON(ret); | |
901 | ret = register_trace_block_remap(blk_add_trace_remap); | |
902 | WARN_ON(ret); | |
5f3ea37c ACM |
903 | } |
904 | ||
905 | static void blk_unregister_tracepoints(void) | |
906 | { | |
907 | unregister_trace_block_remap(blk_add_trace_remap); | |
908 | unregister_trace_block_split(blk_add_trace_split); | |
909 | unregister_trace_block_unplug_io(blk_add_trace_unplug_io); | |
910 | unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); | |
911 | unregister_trace_block_plug(blk_add_trace_plug); | |
912 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq); | |
913 | unregister_trace_block_getrq(blk_add_trace_getrq); | |
914 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue); | |
915 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); | |
916 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); | |
917 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete); | |
918 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); | |
919 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete); | |
920 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); | |
921 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue); | |
922 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert); | |
923 | unregister_trace_block_rq_abort(blk_add_trace_rq_abort); | |
924 | ||
925 | tracepoint_synchronize_unregister(); | |
926 | } | |
c71a8961 ACM |
927 | |
928 | /* | |
929 | * struct blk_io_tracer formatting routines | |
930 | */ | |
931 | ||
932 | static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) | |
933 | { | |
157f9c00 | 934 | int i = 0; |
65796348 | 935 | int tc = t->action >> BLK_TC_SHIFT; |
157f9c00 | 936 | |
18cea459 LZ |
937 | if (t->action == BLK_TN_MESSAGE) { |
938 | rwbs[i++] = 'N'; | |
939 | goto out; | |
940 | } | |
941 | ||
65796348 | 942 | if (tc & BLK_TC_DISCARD) |
157f9c00 | 943 | rwbs[i++] = 'D'; |
65796348 | 944 | else if (tc & BLK_TC_WRITE) |
157f9c00 ACM |
945 | rwbs[i++] = 'W'; |
946 | else if (t->bytes) | |
947 | rwbs[i++] = 'R'; | |
948 | else | |
949 | rwbs[i++] = 'N'; | |
950 | ||
65796348 | 951 | if (tc & BLK_TC_AHEAD) |
157f9c00 | 952 | rwbs[i++] = 'A'; |
65796348 | 953 | if (tc & BLK_TC_BARRIER) |
157f9c00 | 954 | rwbs[i++] = 'B'; |
65796348 | 955 | if (tc & BLK_TC_SYNC) |
157f9c00 | 956 | rwbs[i++] = 'S'; |
65796348 | 957 | if (tc & BLK_TC_META) |
157f9c00 | 958 | rwbs[i++] = 'M'; |
18cea459 | 959 | out: |
157f9c00 | 960 | rwbs[i] = '\0'; |
c71a8961 ACM |
961 | } |
962 | ||
963 | static inline | |
964 | const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) | |
965 | { | |
966 | return (const struct blk_io_trace *)ent; | |
967 | } | |
968 | ||
969 | static inline const void *pdu_start(const struct trace_entry *ent) | |
970 | { | |
971 | return te_blk_io_trace(ent) + 1; | |
972 | } | |
973 | ||
974 | static inline u32 t_sec(const struct trace_entry *ent) | |
975 | { | |
976 | return te_blk_io_trace(ent)->bytes >> 9; | |
977 | } | |
978 | ||
979 | static inline unsigned long long t_sector(const struct trace_entry *ent) | |
980 | { | |
981 | return te_blk_io_trace(ent)->sector; | |
982 | } | |
983 | ||
984 | static inline __u16 t_error(const struct trace_entry *ent) | |
985 | { | |
e0dc81be | 986 | return te_blk_io_trace(ent)->error; |
c71a8961 ACM |
987 | } |
988 | ||
989 | static __u64 get_pdu_int(const struct trace_entry *ent) | |
990 | { | |
991 | const __u64 *val = pdu_start(ent); | |
992 | return be64_to_cpu(*val); | |
993 | } | |
994 | ||
995 | static void get_pdu_remap(const struct trace_entry *ent, | |
996 | struct blk_io_trace_remap *r) | |
997 | { | |
998 | const struct blk_io_trace_remap *__r = pdu_start(ent); | |
999 | __u64 sector = __r->sector; | |
1000 | ||
1001 | r->device = be32_to_cpu(__r->device); | |
1002 | r->device_from = be32_to_cpu(__r->device_from); | |
1003 | r->sector = be64_to_cpu(sector); | |
1004 | } | |
1005 | ||
b6a4b0c3 LZ |
1006 | typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act); |
1007 | ||
1008 | static int blk_log_action_classic(struct trace_iterator *iter, const char *act) | |
c71a8961 ACM |
1009 | { |
1010 | char rwbs[6]; | |
35ac51bf LZ |
1011 | unsigned long long ts = iter->ts; |
1012 | unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC); | |
c71a8961 | 1013 | unsigned secs = (unsigned long)ts; |
b6a4b0c3 | 1014 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
c71a8961 ACM |
1015 | |
1016 | fill_rwbs(rwbs, t); | |
1017 | ||
1018 | return trace_seq_printf(&iter->seq, | |
35ac51bf | 1019 | "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ", |
c71a8961 | 1020 | MAJOR(t->device), MINOR(t->device), iter->cpu, |
b6a4b0c3 | 1021 | secs, nsec_rem, iter->ent->pid, act, rwbs); |
c71a8961 ACM |
1022 | } |
1023 | ||
b6a4b0c3 | 1024 | static int blk_log_action(struct trace_iterator *iter, const char *act) |
c71a8961 ACM |
1025 | { |
1026 | char rwbs[6]; | |
b6a4b0c3 LZ |
1027 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
1028 | ||
c71a8961 | 1029 | fill_rwbs(rwbs, t); |
b6a4b0c3 | 1030 | return trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ", |
c71a8961 ACM |
1031 | MAJOR(t->device), MINOR(t->device), act, rwbs); |
1032 | } | |
1033 | ||
1034 | static int blk_log_generic(struct trace_seq *s, const struct trace_entry *ent) | |
1035 | { | |
4ca53085 SR |
1036 | char cmd[TASK_COMM_LEN]; |
1037 | ||
1038 | trace_find_cmdline(ent->pid, cmd); | |
c71a8961 ACM |
1039 | |
1040 | if (t_sec(ent)) | |
1041 | return trace_seq_printf(s, "%llu + %u [%s]\n", | |
1042 | t_sector(ent), t_sec(ent), cmd); | |
1043 | return trace_seq_printf(s, "[%s]\n", cmd); | |
1044 | } | |
1045 | ||
157f9c00 ACM |
1046 | static int blk_log_with_error(struct trace_seq *s, |
1047 | const struct trace_entry *ent) | |
c71a8961 ACM |
1048 | { |
1049 | if (t_sec(ent)) | |
1050 | return trace_seq_printf(s, "%llu + %u [%d]\n", t_sector(ent), | |
1051 | t_sec(ent), t_error(ent)); | |
1052 | return trace_seq_printf(s, "%llu [%d]\n", t_sector(ent), t_error(ent)); | |
1053 | } | |
1054 | ||
1055 | static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent) | |
1056 | { | |
1057 | struct blk_io_trace_remap r = { .device = 0, }; | |
1058 | ||
1059 | get_pdu_remap(ent, &r); | |
1060 | return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", | |
1061 | t_sector(ent), | |
1062 | t_sec(ent), MAJOR(r.device), MINOR(r.device), | |
1063 | (unsigned long long)r.sector); | |
1064 | } | |
1065 | ||
1066 | static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent) | |
1067 | { | |
4ca53085 SR |
1068 | char cmd[TASK_COMM_LEN]; |
1069 | ||
1070 | trace_find_cmdline(ent->pid, cmd); | |
1071 | ||
1072 | return trace_seq_printf(s, "[%s]\n", cmd); | |
c71a8961 ACM |
1073 | } |
1074 | ||
1075 | static int blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent) | |
1076 | { | |
4ca53085 SR |
1077 | char cmd[TASK_COMM_LEN]; |
1078 | ||
1079 | trace_find_cmdline(ent->pid, cmd); | |
1080 | ||
1081 | return trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent)); | |
c71a8961 ACM |
1082 | } |
1083 | ||
1084 | static int blk_log_split(struct trace_seq *s, const struct trace_entry *ent) | |
1085 | { | |
4ca53085 SR |
1086 | char cmd[TASK_COMM_LEN]; |
1087 | ||
1088 | trace_find_cmdline(ent->pid, cmd); | |
1089 | ||
c71a8961 | 1090 | return trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), |
4ca53085 | 1091 | get_pdu_int(ent), cmd); |
c71a8961 ACM |
1092 | } |
1093 | ||
18cea459 LZ |
1094 | static int blk_log_msg(struct trace_seq *s, const struct trace_entry *ent) |
1095 | { | |
1096 | int ret; | |
1097 | const struct blk_io_trace *t = te_blk_io_trace(ent); | |
1098 | ||
1099 | ret = trace_seq_putmem(s, t + 1, t->pdu_len); | |
1100 | if (ret) | |
1101 | return trace_seq_putc(s, '\n'); | |
1102 | return ret; | |
1103 | } | |
1104 | ||
c71a8961 ACM |
1105 | /* |
1106 | * struct tracer operations | |
1107 | */ | |
1108 | ||
1109 | static void blk_tracer_print_header(struct seq_file *m) | |
1110 | { | |
1111 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1112 | return; | |
1113 | seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" | |
1114 | "# | | | | | |\n"); | |
1115 | } | |
1116 | ||
1117 | static void blk_tracer_start(struct trace_array *tr) | |
1118 | { | |
ad5dd549 | 1119 | blk_tracer_enabled = true; |
08a06b83 | 1120 | trace_flags &= ~TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1121 | } |
1122 | ||
1123 | static int blk_tracer_init(struct trace_array *tr) | |
1124 | { | |
1125 | blk_tr = tr; | |
1126 | blk_tracer_start(tr); | |
c71a8961 ACM |
1127 | return 0; |
1128 | } | |
1129 | ||
1130 | static void blk_tracer_stop(struct trace_array *tr) | |
1131 | { | |
ad5dd549 | 1132 | blk_tracer_enabled = false; |
08a06b83 | 1133 | trace_flags |= TRACE_ITER_CONTEXT_INFO; |
c71a8961 ACM |
1134 | } |
1135 | ||
1136 | static void blk_tracer_reset(struct trace_array *tr) | |
1137 | { | |
c71a8961 ACM |
1138 | blk_tracer_stop(tr); |
1139 | } | |
1140 | ||
e4955c99 | 1141 | static const struct { |
c71a8961 | 1142 | const char *act[2]; |
ef18012b | 1143 | int (*print)(struct trace_seq *s, const struct trace_entry *ent); |
e4955c99 | 1144 | } what2act[] = { |
ef18012b | 1145 | [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, |
c71a8961 ACM |
1146 | [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, |
1147 | [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, | |
1148 | [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, | |
1149 | [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, | |
1150 | [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, | |
1151 | [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, | |
1152 | [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, | |
1153 | [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, | |
1154 | [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, | |
1155 | [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, | |
1156 | [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, | |
1157 | [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, | |
1158 | [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, | |
1159 | [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, | |
1160 | }; | |
1161 | ||
b6a4b0c3 LZ |
1162 | static enum print_line_t print_one_line(struct trace_iterator *iter, |
1163 | bool classic) | |
c71a8961 | 1164 | { |
2c9b238e | 1165 | struct trace_seq *s = &iter->seq; |
b6a4b0c3 LZ |
1166 | const struct blk_io_trace *t; |
1167 | u16 what; | |
c71a8961 | 1168 | int ret; |
b6a4b0c3 LZ |
1169 | bool long_act; |
1170 | blk_log_action_t *log_action; | |
c71a8961 | 1171 | |
b6a4b0c3 LZ |
1172 | t = te_blk_io_trace(iter->ent); |
1173 | what = t->action & ((1 << BLK_TC_SHIFT) - 1); | |
1174 | long_act = !!(trace_flags & TRACE_ITER_VERBOSE); | |
1175 | log_action = classic ? &blk_log_action_classic : &blk_log_action; | |
08a06b83 | 1176 | |
18cea459 LZ |
1177 | if (t->action == BLK_TN_MESSAGE) { |
1178 | ret = log_action(iter, long_act ? "message" : "m"); | |
1179 | if (ret) | |
1180 | ret = blk_log_msg(s, iter->ent); | |
1181 | goto out; | |
1182 | } | |
1183 | ||
eb08f8eb | 1184 | if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act))) |
c71a8961 ACM |
1185 | ret = trace_seq_printf(s, "Bad pc action %x\n", what); |
1186 | else { | |
b6a4b0c3 | 1187 | ret = log_action(iter, what2act[what].act[long_act]); |
c71a8961 | 1188 | if (ret) |
2c9b238e | 1189 | ret = what2act[what].print(s, iter->ent); |
c71a8961 | 1190 | } |
18cea459 | 1191 | out: |
c71a8961 ACM |
1192 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; |
1193 | } | |
1194 | ||
b6a4b0c3 LZ |
1195 | static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, |
1196 | int flags) | |
1197 | { | |
1198 | if (!trace_print_context(iter)) | |
1199 | return TRACE_TYPE_PARTIAL_LINE; | |
1200 | ||
1201 | return print_one_line(iter, false); | |
1202 | } | |
1203 | ||
08a06b83 ACM |
1204 | static int blk_trace_synthesize_old_trace(struct trace_iterator *iter) |
1205 | { | |
1206 | struct trace_seq *s = &iter->seq; | |
1207 | struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
1208 | const int offset = offsetof(struct blk_io_trace, sector); | |
1209 | struct blk_io_trace old = { | |
1210 | .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, | |
6c051ce0 | 1211 | .time = iter->ts, |
08a06b83 ACM |
1212 | }; |
1213 | ||
1214 | if (!trace_seq_putmem(s, &old, offset)) | |
1215 | return 0; | |
1216 | return trace_seq_putmem(s, &t->sector, | |
1217 | sizeof(old) - offset + t->pdu_len); | |
1218 | } | |
1219 | ||
ae7462b4 ACM |
1220 | static enum print_line_t |
1221 | blk_trace_event_print_binary(struct trace_iterator *iter, int flags) | |
08a06b83 ACM |
1222 | { |
1223 | return blk_trace_synthesize_old_trace(iter) ? | |
1224 | TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; | |
1225 | } | |
1226 | ||
c71a8961 ACM |
1227 | static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) |
1228 | { | |
c71a8961 ACM |
1229 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) |
1230 | return TRACE_TYPE_UNHANDLED; | |
1231 | ||
b6a4b0c3 | 1232 | return print_one_line(iter, true); |
c71a8961 ACM |
1233 | } |
1234 | ||
1235 | static struct tracer blk_tracer __read_mostly = { | |
1236 | .name = "blk", | |
1237 | .init = blk_tracer_init, | |
1238 | .reset = blk_tracer_reset, | |
1239 | .start = blk_tracer_start, | |
1240 | .stop = blk_tracer_stop, | |
1241 | .print_header = blk_tracer_print_header, | |
1242 | .print_line = blk_tracer_print_line, | |
1243 | .flags = &blk_tracer_flags, | |
1244 | }; | |
1245 | ||
1246 | static struct trace_event trace_blk_event = { | |
ef18012b | 1247 | .type = TRACE_BLK, |
c71a8961 | 1248 | .trace = blk_trace_event_print, |
08a06b83 | 1249 | .binary = blk_trace_event_print_binary, |
c71a8961 ACM |
1250 | }; |
1251 | ||
1252 | static int __init init_blk_tracer(void) | |
1253 | { | |
1254 | if (!register_ftrace_event(&trace_blk_event)) { | |
1255 | pr_warning("Warning: could not register block events\n"); | |
1256 | return 1; | |
1257 | } | |
1258 | ||
1259 | if (register_tracer(&blk_tracer) != 0) { | |
1260 | pr_warning("Warning: could not register the block tracer\n"); | |
1261 | unregister_ftrace_event(&trace_blk_event); | |
1262 | return 1; | |
1263 | } | |
1264 | ||
1265 | return 0; | |
1266 | } | |
1267 | ||
1268 | device_initcall(init_blk_tracer); | |
1269 | ||
1270 | static int blk_trace_remove_queue(struct request_queue *q) | |
1271 | { | |
1272 | struct blk_trace *bt; | |
1273 | ||
1274 | bt = xchg(&q->blk_trace, NULL); | |
1275 | if (bt == NULL) | |
1276 | return -EINVAL; | |
1277 | ||
17ba97e3 LZ |
1278 | if (atomic_dec_and_test(&blk_probes_ref)) |
1279 | blk_unregister_tracepoints(); | |
1280 | ||
ad5dd549 | 1281 | blk_trace_free(bt); |
c71a8961 ACM |
1282 | return 0; |
1283 | } | |
1284 | ||
1285 | /* | |
1286 | * Setup everything required to start tracing | |
1287 | */ | |
1288 | static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) | |
1289 | { | |
1290 | struct blk_trace *old_bt, *bt = NULL; | |
18cea459 | 1291 | int ret = -ENOMEM; |
c71a8961 | 1292 | |
c71a8961 ACM |
1293 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
1294 | if (!bt) | |
15152e44 | 1295 | return -ENOMEM; |
c71a8961 | 1296 | |
18cea459 LZ |
1297 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
1298 | if (!bt->msg_data) | |
1299 | goto free_bt; | |
1300 | ||
c71a8961 ACM |
1301 | bt->dev = dev; |
1302 | bt->act_mask = (u16)-1; | |
1303 | bt->end_lba = -1ULL; | |
c71a8961 ACM |
1304 | |
1305 | old_bt = xchg(&q->blk_trace, bt); | |
1306 | if (old_bt != NULL) { | |
1307 | (void)xchg(&q->blk_trace, old_bt); | |
18cea459 LZ |
1308 | ret = -EBUSY; |
1309 | goto free_bt; | |
c71a8961 | 1310 | } |
15152e44 | 1311 | |
17ba97e3 LZ |
1312 | if (atomic_inc_return(&blk_probes_ref) == 1) |
1313 | blk_register_tracepoints(); | |
c71a8961 | 1314 | return 0; |
18cea459 LZ |
1315 | |
1316 | free_bt: | |
1317 | blk_trace_free(bt); | |
1318 | return ret; | |
c71a8961 ACM |
1319 | } |
1320 | ||
1321 | /* | |
1322 | * sysfs interface to enable and configure tracing | |
1323 | */ | |
1324 | ||
c71a8961 ACM |
1325 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1326 | struct device_attribute *attr, | |
1327 | char *buf); | |
1328 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1329 | struct device_attribute *attr, | |
1330 | const char *buf, size_t count); | |
1331 | #define BLK_TRACE_DEVICE_ATTR(_name) \ | |
1332 | DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ | |
1333 | sysfs_blk_trace_attr_show, \ | |
1334 | sysfs_blk_trace_attr_store) | |
1335 | ||
cd649b8b | 1336 | static BLK_TRACE_DEVICE_ATTR(enable); |
c71a8961 ACM |
1337 | static BLK_TRACE_DEVICE_ATTR(act_mask); |
1338 | static BLK_TRACE_DEVICE_ATTR(pid); | |
1339 | static BLK_TRACE_DEVICE_ATTR(start_lba); | |
1340 | static BLK_TRACE_DEVICE_ATTR(end_lba); | |
1341 | ||
1342 | static struct attribute *blk_trace_attrs[] = { | |
1343 | &dev_attr_enable.attr, | |
1344 | &dev_attr_act_mask.attr, | |
1345 | &dev_attr_pid.attr, | |
1346 | &dev_attr_start_lba.attr, | |
1347 | &dev_attr_end_lba.attr, | |
1348 | NULL | |
1349 | }; | |
1350 | ||
1351 | struct attribute_group blk_trace_attr_group = { | |
1352 | .name = "trace", | |
1353 | .attrs = blk_trace_attrs, | |
1354 | }; | |
1355 | ||
09341997 LZ |
1356 | static const struct { |
1357 | int mask; | |
1358 | const char *str; | |
1359 | } mask_maps[] = { | |
1360 | { BLK_TC_READ, "read" }, | |
1361 | { BLK_TC_WRITE, "write" }, | |
1362 | { BLK_TC_BARRIER, "barrier" }, | |
1363 | { BLK_TC_SYNC, "sync" }, | |
1364 | { BLK_TC_QUEUE, "queue" }, | |
1365 | { BLK_TC_REQUEUE, "requeue" }, | |
1366 | { BLK_TC_ISSUE, "issue" }, | |
1367 | { BLK_TC_COMPLETE, "complete" }, | |
1368 | { BLK_TC_FS, "fs" }, | |
1369 | { BLK_TC_PC, "pc" }, | |
1370 | { BLK_TC_AHEAD, "ahead" }, | |
1371 | { BLK_TC_META, "meta" }, | |
1372 | { BLK_TC_DISCARD, "discard" }, | |
1373 | { BLK_TC_DRV_DATA, "drv_data" }, | |
1374 | }; | |
1375 | ||
1376 | static int blk_trace_str2mask(const char *str) | |
c71a8961 | 1377 | { |
09341997 | 1378 | int i; |
c71a8961 | 1379 | int mask = 0; |
9eb85125 | 1380 | char *buf, *s, *token; |
c71a8961 | 1381 | |
9eb85125 LZ |
1382 | buf = kstrdup(str, GFP_KERNEL); |
1383 | if (buf == NULL) | |
c71a8961 | 1384 | return -ENOMEM; |
9eb85125 | 1385 | s = strstrip(buf); |
c71a8961 ACM |
1386 | |
1387 | while (1) { | |
09341997 LZ |
1388 | token = strsep(&s, ","); |
1389 | if (token == NULL) | |
c71a8961 ACM |
1390 | break; |
1391 | ||
09341997 LZ |
1392 | if (*token == '\0') |
1393 | continue; | |
1394 | ||
1395 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1396 | if (strcasecmp(token, mask_maps[i].str) == 0) { | |
1397 | mask |= mask_maps[i].mask; | |
1398 | break; | |
1399 | } | |
1400 | } | |
1401 | if (i == ARRAY_SIZE(mask_maps)) { | |
1402 | mask = -EINVAL; | |
1403 | break; | |
1404 | } | |
c71a8961 | 1405 | } |
9eb85125 | 1406 | kfree(buf); |
c71a8961 ACM |
1407 | |
1408 | return mask; | |
1409 | } | |
1410 | ||
09341997 LZ |
1411 | static ssize_t blk_trace_mask2str(char *buf, int mask) |
1412 | { | |
1413 | int i; | |
1414 | char *p = buf; | |
1415 | ||
1416 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1417 | if (mask & mask_maps[i].mask) { | |
1418 | p += sprintf(p, "%s%s", | |
1419 | (p == buf) ? "" : ",", mask_maps[i].str); | |
1420 | } | |
1421 | } | |
1422 | *p++ = '\n'; | |
1423 | ||
1424 | return p - buf; | |
1425 | } | |
1426 | ||
b125130b LZ |
1427 | static struct request_queue *blk_trace_get_queue(struct block_device *bdev) |
1428 | { | |
1429 | if (bdev->bd_disk == NULL) | |
1430 | return NULL; | |
1431 | ||
1432 | return bdev_get_queue(bdev); | |
1433 | } | |
1434 | ||
c71a8961 ACM |
1435 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1436 | struct device_attribute *attr, | |
1437 | char *buf) | |
1438 | { | |
1439 | struct hd_struct *p = dev_to_part(dev); | |
1440 | struct request_queue *q; | |
1441 | struct block_device *bdev; | |
1442 | ssize_t ret = -ENXIO; | |
1443 | ||
1444 | lock_kernel(); | |
1445 | bdev = bdget(part_devt(p)); | |
1446 | if (bdev == NULL) | |
1447 | goto out_unlock_kernel; | |
1448 | ||
b125130b | 1449 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1450 | if (q == NULL) |
1451 | goto out_bdput; | |
b125130b | 1452 | |
c71a8961 | 1453 | mutex_lock(&bdev->bd_mutex); |
cd649b8b LZ |
1454 | |
1455 | if (attr == &dev_attr_enable) { | |
1456 | ret = sprintf(buf, "%u\n", !!q->blk_trace); | |
1457 | goto out_unlock_bdev; | |
1458 | } | |
1459 | ||
c71a8961 ACM |
1460 | if (q->blk_trace == NULL) |
1461 | ret = sprintf(buf, "disabled\n"); | |
1462 | else if (attr == &dev_attr_act_mask) | |
09341997 | 1463 | ret = blk_trace_mask2str(buf, q->blk_trace->act_mask); |
c71a8961 ACM |
1464 | else if (attr == &dev_attr_pid) |
1465 | ret = sprintf(buf, "%u\n", q->blk_trace->pid); | |
1466 | else if (attr == &dev_attr_start_lba) | |
1467 | ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); | |
1468 | else if (attr == &dev_attr_end_lba) | |
1469 | ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); | |
cd649b8b LZ |
1470 | |
1471 | out_unlock_bdev: | |
c71a8961 ACM |
1472 | mutex_unlock(&bdev->bd_mutex); |
1473 | out_bdput: | |
1474 | bdput(bdev); | |
1475 | out_unlock_kernel: | |
1476 | unlock_kernel(); | |
1477 | return ret; | |
1478 | } | |
1479 | ||
1480 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1481 | struct device_attribute *attr, | |
1482 | const char *buf, size_t count) | |
1483 | { | |
1484 | struct block_device *bdev; | |
1485 | struct request_queue *q; | |
1486 | struct hd_struct *p; | |
1487 | u64 value; | |
09341997 | 1488 | ssize_t ret = -EINVAL; |
c71a8961 ACM |
1489 | |
1490 | if (count == 0) | |
1491 | goto out; | |
1492 | ||
1493 | if (attr == &dev_attr_act_mask) { | |
1494 | if (sscanf(buf, "%llx", &value) != 1) { | |
1495 | /* Assume it is a list of trace category names */ | |
09341997 LZ |
1496 | ret = blk_trace_str2mask(buf); |
1497 | if (ret < 0) | |
c71a8961 | 1498 | goto out; |
09341997 | 1499 | value = ret; |
c71a8961 ACM |
1500 | } |
1501 | } else if (sscanf(buf, "%llu", &value) != 1) | |
1502 | goto out; | |
1503 | ||
09341997 LZ |
1504 | ret = -ENXIO; |
1505 | ||
c71a8961 ACM |
1506 | lock_kernel(); |
1507 | p = dev_to_part(dev); | |
1508 | bdev = bdget(part_devt(p)); | |
1509 | if (bdev == NULL) | |
1510 | goto out_unlock_kernel; | |
1511 | ||
b125130b | 1512 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1513 | if (q == NULL) |
1514 | goto out_bdput; | |
1515 | ||
1516 | mutex_lock(&bdev->bd_mutex); | |
cd649b8b LZ |
1517 | |
1518 | if (attr == &dev_attr_enable) { | |
1519 | if (value) | |
1520 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1521 | else | |
1522 | ret = blk_trace_remove_queue(q); | |
1523 | goto out_unlock_bdev; | |
1524 | } | |
1525 | ||
c71a8961 ACM |
1526 | ret = 0; |
1527 | if (q->blk_trace == NULL) | |
1528 | ret = blk_trace_setup_queue(q, bdev->bd_dev); | |
1529 | ||
1530 | if (ret == 0) { | |
1531 | if (attr == &dev_attr_act_mask) | |
1532 | q->blk_trace->act_mask = value; | |
1533 | else if (attr == &dev_attr_pid) | |
1534 | q->blk_trace->pid = value; | |
1535 | else if (attr == &dev_attr_start_lba) | |
1536 | q->blk_trace->start_lba = value; | |
1537 | else if (attr == &dev_attr_end_lba) | |
1538 | q->blk_trace->end_lba = value; | |
c71a8961 | 1539 | } |
cd649b8b LZ |
1540 | |
1541 | out_unlock_bdev: | |
c71a8961 ACM |
1542 | mutex_unlock(&bdev->bd_mutex); |
1543 | out_bdput: | |
1544 | bdput(bdev); | |
1545 | out_unlock_kernel: | |
1546 | unlock_kernel(); | |
1547 | out: | |
cd649b8b | 1548 | return ret ? ret : count; |
c71a8961 | 1549 | } |
cd649b8b | 1550 |