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1 /*
2  * blktrace support code for fio
3  */
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <sys/stat.h>
7 #include <sys/ioctl.h>
8 #include <linux/fs.h>
9 #include <dirent.h>
10 
11 #include "flist.h"
12 #include "fio.h"
13 #include "blktrace_api.h"
14 #include "oslib/linux-dev-lookup.h"
15 
16 #define TRACE_FIFO_SIZE	8192
17 
18 /*
19  * fifo refill frontend, to avoid reading data in trace sized bites
20  */
refill_fifo(struct thread_data * td,struct fifo * fifo,int fd)21 static int refill_fifo(struct thread_data *td, struct fifo *fifo, int fd)
22 {
23 	char buf[TRACE_FIFO_SIZE];
24 	unsigned int total;
25 	int ret;
26 
27 	total = sizeof(buf);
28 	if (total > fifo_room(fifo))
29 		total = fifo_room(fifo);
30 
31 	ret = read(fd, buf, total);
32 	if (ret < 0) {
33 		td_verror(td, errno, "read blktrace file");
34 		return -1;
35 	}
36 
37 	if (ret > 0)
38 		ret = fifo_put(fifo, buf, ret);
39 
40 	dprint(FD_BLKTRACE, "refill: filled %d bytes\n", ret);
41 	return ret;
42 }
43 
44 /*
45  * Retrieve 'len' bytes from the fifo, refilling if necessary.
46  */
trace_fifo_get(struct thread_data * td,struct fifo * fifo,int fd,void * buf,unsigned int len)47 static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd,
48 			  void *buf, unsigned int len)
49 {
50 	if (fifo_len(fifo) < len) {
51 		int ret = refill_fifo(td, fifo, fd);
52 
53 		if (ret < 0)
54 			return ret;
55 	}
56 
57 	return fifo_get(fifo, buf, len);
58 }
59 
60 /*
61  * Just discard the pdu by seeking past it.
62  */
discard_pdu(struct thread_data * td,struct fifo * fifo,int fd,struct blk_io_trace * t)63 static int discard_pdu(struct thread_data *td, struct fifo *fifo, int fd,
64 		       struct blk_io_trace *t)
65 {
66 	if (t->pdu_len == 0)
67 		return 0;
68 
69 	dprint(FD_BLKTRACE, "discard pdu len %u\n", t->pdu_len);
70 	return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len);
71 }
72 
73 /*
74  * Check if this is a blktrace binary data file. We read a single trace
75  * into memory and check for the magic signature.
76  */
is_blktrace(const char * filename,int * need_swap)77 int is_blktrace(const char *filename, int *need_swap)
78 {
79 	struct blk_io_trace t;
80 	int fd, ret;
81 
82 	fd = open(filename, O_RDONLY);
83 	if (fd < 0)
84 		return 0;
85 
86 	ret = read(fd, &t, sizeof(t));
87 	close(fd);
88 
89 	if (ret < 0) {
90 		perror("read blktrace");
91 		return 0;
92 	} else if (ret != sizeof(t)) {
93 		log_err("fio: short read on blktrace file\n");
94 		return 0;
95 	}
96 
97 	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
98 		*need_swap = 0;
99 		return 1;
100 	}
101 
102 	/*
103 	 * Maybe it needs to be endian swapped...
104 	 */
105 	t.magic = fio_swap32(t.magic);
106 	if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) {
107 		*need_swap = 1;
108 		return 1;
109 	}
110 
111 	return 0;
112 }
113 
114 #define FMINORBITS	20
115 #define FMINORMASK	((1U << FMINORBITS) - 1)
116 #define FMAJOR(dev)	((unsigned int) ((dev) >> FMINORBITS))
117 #define FMINOR(dev)	((unsigned int) ((dev) & FMINORMASK))
118 
trace_add_open_close_event(struct thread_data * td,int fileno,enum file_log_act action)119 static void trace_add_open_close_event(struct thread_data *td, int fileno, enum file_log_act action)
120 {
121 	struct io_piece *ipo;
122 
123 	ipo = calloc(1, sizeof(*ipo));
124 	init_ipo(ipo);
125 
126 	ipo->ddir = DDIR_INVAL;
127 	ipo->fileno = fileno;
128 	ipo->file_action = action;
129 	flist_add_tail(&ipo->list, &td->io_log_list);
130 }
131 
get_dev_blocksize(const char * dev,unsigned int * bs)132 static int get_dev_blocksize(const char *dev, unsigned int *bs)
133 {
134 	int fd;
135 
136 	fd = open(dev, O_RDONLY);
137 	if (fd < 0)
138 		return 1;
139 
140 	if (ioctl(fd, BLKSSZGET, bs) < 0) {
141 		close(fd);
142 		return 1;
143 	}
144 
145 	close(fd);
146 	return 0;
147 }
148 
trace_add_file(struct thread_data * td,__u32 device,unsigned int * bs)149 static int trace_add_file(struct thread_data *td, __u32 device,
150 			  unsigned int *bs)
151 {
152 	static unsigned int last_maj, last_min, last_fileno, last_bs;
153 	unsigned int maj = FMAJOR(device);
154 	unsigned int min = FMINOR(device);
155 	struct fio_file *f;
156 	unsigned int i;
157 	char dev[256];
158 
159 	if (last_maj == maj && last_min == min) {
160 		*bs = last_bs;
161 		return last_fileno;
162 	}
163 
164 	last_maj = maj;
165 	last_min = min;
166 
167 	/*
168 	 * check for this file in our list
169 	 */
170 	for_each_file(td, f, i) {
171 		if (f->major == maj && f->minor == min) {
172 			last_fileno = f->fileno;
173 			last_bs = f->bs;
174 			goto out;
175 		}
176 	}
177 
178 	strcpy(dev, "/dev");
179 	if (blktrace_lookup_device(td->o.replay_redirect, dev, maj, min)) {
180 		unsigned int this_bs;
181 		int fileno;
182 
183 		if (td->o.replay_redirect)
184 			dprint(FD_BLKTRACE, "device lookup: %d/%d\n overridden"
185 					" with: %s\n", maj, min,
186 					td->o.replay_redirect);
187 		else
188 			dprint(FD_BLKTRACE, "device lookup: %d/%d\n", maj, min);
189 
190 		dprint(FD_BLKTRACE, "add devices %s\n", dev);
191 		fileno = add_file_exclusive(td, dev);
192 
193 		if (get_dev_blocksize(dev, &this_bs))
194 			this_bs = 512;
195 
196 		td->o.open_files++;
197 		td->files[fileno]->major = maj;
198 		td->files[fileno]->minor = min;
199 		td->files[fileno]->bs = this_bs;
200 		trace_add_open_close_event(td, fileno, FIO_LOG_OPEN_FILE);
201 
202 		last_fileno = fileno;
203 		last_bs = this_bs;
204 	}
205 
206 out:
207 	*bs = last_bs;
208 	return last_fileno;
209 }
210 
t_bytes_align(struct thread_options * o,struct blk_io_trace * t)211 static void t_bytes_align(struct thread_options *o, struct blk_io_trace *t)
212 {
213 	if (!o->replay_align)
214 		return;
215 
216 	t->bytes = (t->bytes + o->replay_align - 1) & ~(o->replay_align - 1);
217 }
218 
219 /*
220  * Store blk_io_trace data in an ipo for later retrieval.
221  */
store_ipo(struct thread_data * td,unsigned long long offset,unsigned int bytes,int rw,unsigned long long ttime,int fileno,unsigned int bs)222 static void store_ipo(struct thread_data *td, unsigned long long offset,
223 		      unsigned int bytes, int rw, unsigned long long ttime,
224 		      int fileno, unsigned int bs)
225 {
226 	struct io_piece *ipo = malloc(sizeof(*ipo));
227 
228 	init_ipo(ipo);
229 
230 	ipo->offset = offset * bs;
231 	if (td->o.replay_scale)
232 		ipo->offset = ipo->offset / td->o.replay_scale;
233 	ipo_bytes_align(td->o.replay_align, ipo);
234 	ipo->len = bytes;
235 	ipo->delay = ttime / 1000;
236 	if (rw)
237 		ipo->ddir = DDIR_WRITE;
238 	else
239 		ipo->ddir = DDIR_READ;
240 	ipo->fileno = fileno;
241 
242 	dprint(FD_BLKTRACE, "store ddir=%d, off=%llu, len=%lu, delay=%lu\n",
243 							ipo->ddir, ipo->offset,
244 							ipo->len, ipo->delay);
245 	queue_io_piece(td, ipo);
246 }
247 
handle_trace_notify(struct blk_io_trace * t)248 static void handle_trace_notify(struct blk_io_trace *t)
249 {
250 	switch (t->action) {
251 	case BLK_TN_PROCESS:
252 		dprint(FD_BLKTRACE, "got process notify: %x, %d\n",
253 				t->action, t->pid);
254 		break;
255 	case BLK_TN_TIMESTAMP:
256 		dprint(FD_BLKTRACE, "got timestamp notify: %x, %d\n",
257 				t->action, t->pid);
258 		break;
259 	case BLK_TN_MESSAGE:
260 		break;
261 	default:
262 		dprint(FD_BLKTRACE, "unknown trace act %x\n", t->action);
263 		break;
264 	}
265 }
266 
handle_trace_discard(struct thread_data * td,struct blk_io_trace * t,unsigned long long ttime,unsigned long * ios,unsigned int * rw_bs)267 static void handle_trace_discard(struct thread_data *td,
268 				 struct blk_io_trace *t,
269 				 unsigned long long ttime,
270 				 unsigned long *ios, unsigned int *rw_bs)
271 {
272 	struct io_piece *ipo = malloc(sizeof(*ipo));
273 	unsigned int bs;
274 	int fileno;
275 
276 	init_ipo(ipo);
277 	fileno = trace_add_file(td, t->device, &bs);
278 
279 	ios[DDIR_TRIM]++;
280 	if (t->bytes > rw_bs[DDIR_TRIM])
281 		rw_bs[DDIR_TRIM] = t->bytes;
282 
283 	td->o.size += t->bytes;
284 
285 	memset(ipo, 0, sizeof(*ipo));
286 	INIT_FLIST_HEAD(&ipo->list);
287 
288 	ipo->offset = t->sector * bs;
289 	if (td->o.replay_scale)
290 		ipo->offset = ipo->offset / td->o.replay_scale;
291 	ipo_bytes_align(td->o.replay_align, ipo);
292 	ipo->len = t->bytes;
293 	ipo->delay = ttime / 1000;
294 	ipo->ddir = DDIR_TRIM;
295 	ipo->fileno = fileno;
296 
297 	dprint(FD_BLKTRACE, "store discard, off=%llu, len=%lu, delay=%lu\n",
298 							ipo->offset, ipo->len,
299 							ipo->delay);
300 	queue_io_piece(td, ipo);
301 }
302 
handle_trace_fs(struct thread_data * td,struct blk_io_trace * t,unsigned long long ttime,unsigned long * ios,unsigned int * rw_bs)303 static void handle_trace_fs(struct thread_data *td, struct blk_io_trace *t,
304 			    unsigned long long ttime, unsigned long *ios,
305 			    unsigned int *rw_bs)
306 {
307 	unsigned int bs;
308 	int rw;
309 	int fileno;
310 
311 	fileno = trace_add_file(td, t->device, &bs);
312 
313 	rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0;
314 
315 	if (t->bytes > rw_bs[rw])
316 		rw_bs[rw] = t->bytes;
317 
318 	ios[rw]++;
319 	td->o.size += t->bytes;
320 	store_ipo(td, t->sector, t->bytes, rw, ttime, fileno, bs);
321 }
322 
323 /*
324  * We only care for queue traces, most of the others are side effects
325  * due to internal workings of the block layer.
326  */
handle_trace(struct thread_data * td,struct blk_io_trace * t,unsigned long * ios,unsigned int * bs)327 static void handle_trace(struct thread_data *td, struct blk_io_trace *t,
328 			 unsigned long *ios, unsigned int *bs)
329 {
330 	static unsigned long long last_ttime;
331 	unsigned long long delay = 0;
332 
333 	if ((t->action & 0xffff) != __BLK_TA_QUEUE)
334 		return;
335 
336 	if (!(t->action & BLK_TC_ACT(BLK_TC_NOTIFY))) {
337 		if (!last_ttime || td->o.no_stall) {
338 			last_ttime = t->time;
339 			delay = 0;
340 		} else {
341 			delay = t->time - last_ttime;
342 			last_ttime = t->time;
343 		}
344 	}
345 
346 	t_bytes_align(&td->o, t);
347 
348 	if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY))
349 		handle_trace_notify(t);
350 	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
351 		handle_trace_discard(td, t, delay, ios, bs);
352 	else
353 		handle_trace_fs(td, t, delay, ios, bs);
354 }
355 
byteswap_trace(struct blk_io_trace * t)356 static void byteswap_trace(struct blk_io_trace *t)
357 {
358 	t->magic = fio_swap32(t->magic);
359 	t->sequence = fio_swap32(t->sequence);
360 	t->time = fio_swap64(t->time);
361 	t->sector = fio_swap64(t->sector);
362 	t->bytes = fio_swap32(t->bytes);
363 	t->action = fio_swap32(t->action);
364 	t->pid = fio_swap32(t->pid);
365 	t->device = fio_swap32(t->device);
366 	t->cpu = fio_swap32(t->cpu);
367 	t->error = fio_swap16(t->error);
368 	t->pdu_len = fio_swap16(t->pdu_len);
369 }
370 
t_is_write(struct blk_io_trace * t)371 static int t_is_write(struct blk_io_trace *t)
372 {
373 	return (t->action & BLK_TC_ACT(BLK_TC_WRITE | BLK_TC_DISCARD)) != 0;
374 }
375 
t_get_ddir(struct blk_io_trace * t)376 static enum fio_ddir t_get_ddir(struct blk_io_trace *t)
377 {
378 	if (t->action & BLK_TC_ACT(BLK_TC_READ))
379 		return DDIR_READ;
380 	else if (t->action & BLK_TC_ACT(BLK_TC_WRITE))
381 		return DDIR_WRITE;
382 	else if (t->action & BLK_TC_ACT(BLK_TC_DISCARD))
383 		return DDIR_TRIM;
384 
385 	return DDIR_INVAL;
386 }
387 
depth_inc(struct blk_io_trace * t,int * depth)388 static void depth_inc(struct blk_io_trace *t, int *depth)
389 {
390 	enum fio_ddir ddir;
391 
392 	ddir = t_get_ddir(t);
393 	if (ddir != DDIR_INVAL)
394 		depth[ddir]++;
395 }
396 
depth_dec(struct blk_io_trace * t,int * depth)397 static void depth_dec(struct blk_io_trace *t, int *depth)
398 {
399 	enum fio_ddir ddir;
400 
401 	ddir = t_get_ddir(t);
402 	if (ddir != DDIR_INVAL)
403 		depth[ddir]--;
404 }
405 
depth_end(struct blk_io_trace * t,int * this_depth,int * depth)406 static void depth_end(struct blk_io_trace *t, int *this_depth, int *depth)
407 {
408 	enum fio_ddir ddir = DDIR_INVAL;
409 
410 	ddir = t_get_ddir(t);
411 	if (ddir != DDIR_INVAL) {
412 		depth[ddir] = max(depth[ddir], this_depth[ddir]);
413 		this_depth[ddir] = 0;
414 	}
415 }
416 
417 /*
418  * Load a blktrace file by reading all the blk_io_trace entries, and storing
419  * them as io_pieces like the fio text version would do.
420  */
load_blktrace(struct thread_data * td,const char * filename,int need_swap)421 int load_blktrace(struct thread_data *td, const char *filename, int need_swap)
422 {
423 	struct blk_io_trace t;
424 	unsigned long ios[DDIR_RWDIR_CNT], skipped_writes;
425 	unsigned int rw_bs[DDIR_RWDIR_CNT];
426 	struct fifo *fifo;
427 	int fd, i, old_state;
428 	struct fio_file *f;
429 	int this_depth[DDIR_RWDIR_CNT], depth[DDIR_RWDIR_CNT], max_depth;
430 
431 	fd = open(filename, O_RDONLY);
432 	if (fd < 0) {
433 		td_verror(td, errno, "open blktrace file");
434 		return 1;
435 	}
436 
437 	fifo = fifo_alloc(TRACE_FIFO_SIZE);
438 
439 	old_state = td_bump_runstate(td, TD_SETTING_UP);
440 
441 	td->o.size = 0;
442 
443 	for (i = 0; i < DDIR_RWDIR_CNT; i++) {
444 		ios[i] = 0;
445 		rw_bs[i] = 0;
446 		this_depth[i] = 0;
447 		depth[i] = 0;
448 	}
449 
450 	skipped_writes = 0;
451 	do {
452 		int ret = trace_fifo_get(td, fifo, fd, &t, sizeof(t));
453 
454 		if (ret < 0)
455 			goto err;
456 		else if (!ret)
457 			break;
458 		else if (ret < (int) sizeof(t)) {
459 			log_err("fio: short fifo get\n");
460 			break;
461 		}
462 
463 		if (need_swap)
464 			byteswap_trace(&t);
465 
466 		if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) {
467 			log_err("fio: bad magic in blktrace data: %x\n",
468 								t.magic);
469 			goto err;
470 		}
471 		if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) {
472 			log_err("fio: bad blktrace version %d\n",
473 								t.magic & 0xff);
474 			goto err;
475 		}
476 		ret = discard_pdu(td, fifo, fd, &t);
477 		if (ret < 0) {
478 			td_verror(td, ret, "blktrace lseek");
479 			goto err;
480 		} else if (t.pdu_len != ret) {
481 			log_err("fio: discarded %d of %d\n", ret, t.pdu_len);
482 			goto err;
483 		}
484 		if ((t.action & BLK_TC_ACT(BLK_TC_NOTIFY)) == 0) {
485 			if ((t.action & 0xffff) == __BLK_TA_QUEUE)
486 				depth_inc(&t, this_depth);
487 			else if (((t.action & 0xffff) == __BLK_TA_BACKMERGE) ||
488 				((t.action & 0xffff) == __BLK_TA_FRONTMERGE))
489 				depth_dec(&t, this_depth);
490 			else if ((t.action & 0xffff) == __BLK_TA_COMPLETE)
491 				depth_end(&t, this_depth, depth);
492 
493 			if (t_is_write(&t) && read_only) {
494 				skipped_writes++;
495 				continue;
496 			}
497 		}
498 
499 		handle_trace(td, &t, ios, rw_bs);
500 	} while (1);
501 
502 	for (i = 0; i < td->files_index; i++) {
503 		f = td->files[i];
504 		trace_add_open_close_event(td, f->fileno, FIO_LOG_CLOSE_FILE);
505 	}
506 
507 	fifo_free(fifo);
508 	close(fd);
509 
510 	td_restore_runstate(td, old_state);
511 
512 	if (!td->files_index) {
513 		log_err("fio: did not find replay device(s)\n");
514 		return 1;
515 	}
516 
517 	/*
518 	 * For stacked devices, we don't always get a COMPLETE event so
519 	 * the depth grows to insane values. Limit it to something sane(r).
520 	 */
521 	max_depth = 0;
522 	for (i = 0; i < DDIR_RWDIR_CNT; i++) {
523 		if (depth[i] > 1024)
524 			depth[i] = 1024;
525 		else if (!depth[i] && ios[i])
526 			depth[i] = 1;
527 		max_depth = max(depth[i], max_depth);
528 	}
529 
530 	if (skipped_writes)
531 		log_err("fio: %s skips replay of %lu writes due to read-only\n",
532 						td->o.name, skipped_writes);
533 
534 	if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) {
535 		log_err("fio: found no ios in blktrace data\n");
536 		return 1;
537 	} else if (ios[DDIR_READ] && !ios[DDIR_WRITE]) {
538 		td->o.td_ddir = TD_DDIR_READ;
539 		td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
540 	} else if (!ios[DDIR_READ] && ios[DDIR_WRITE]) {
541 		td->o.td_ddir = TD_DDIR_WRITE;
542 		td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
543 	} else {
544 		td->o.td_ddir = TD_DDIR_RW;
545 		td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ];
546 		td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE];
547 		td->o.max_bs[DDIR_TRIM] = rw_bs[DDIR_TRIM];
548 	}
549 
550 	/*
551 	 * We need to do direct/raw ios to the device, to avoid getting
552 	 * read-ahead in our way. But only do so if the minimum block size
553 	 * is a multiple of 4k, otherwise we don't know if it's safe to do so.
554 	 */
555 	if (!fio_option_is_set(&td->o, odirect) && !(td_min_bs(td) & 4095))
556 		td->o.odirect = 1;
557 
558 	/*
559 	 * If depth wasn't manually set, use probed depth
560 	 */
561 	if (!fio_option_is_set(&td->o, iodepth))
562 		td->o.iodepth = td->o.iodepth_low = max_depth;
563 
564 	return 0;
565 err:
566 	close(fd);
567 	fifo_free(fifo);
568 	return 1;
569 }
570