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