client: fix potential buffer overrun in socket path
[fio.git] / blktrace.c
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  */
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  */
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  */
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  */
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
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
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
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  */
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
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
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
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  */
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
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  */
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 }