blob: e8e93c9ce6caab5d5a75433f3e14f02b92a236f6 [file] [log] [blame]
Mohan Srinivasanb707f302017-01-19 16:40:52 -08001/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdio.h>
18#include <sys/time.h>
19#include <sys/types.h>
20#include <unistd.h>
21#include <stdlib.h>
22#include <signal.h>
23#include <string.h>
24#include <sys/stat.h>
25#include <sys/errno.h>
26#include <fcntl.h>
27#include <string.h>
28#include <assert.h>
Mohan Srinivasan02f86262017-02-24 16:34:28 -080029#include <sys/vfs.h>
30#include <sys/statvfs.h>
31#include <sys/mman.h>
Mohan Srinivasanb707f302017-01-19 16:40:52 -080032#include "ioshark.h"
33#include "ioshark_bench.h"
34
35extern char *progname;
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -080036extern int verbose, summary_mode;
Mohan Srinivasanb707f302017-01-19 16:40:52 -080037
38void *
39files_db_create_handle(void)
40{
41 struct files_db_handle *h;
42 int i;
43
44 h = malloc(sizeof(struct files_db_handle));
45 for (i = 0 ; i < FILE_DB_HASHSIZE ; i++)
46 h->files_db_buckets[i] = NULL;
47 return h;
48}
49
50void *files_db_lookup_byfileno(void *handle, int fileno)
51{
52 u_int32_t hash;
53 struct files_db_handle *h = (struct files_db_handle *)handle;
54 struct files_db_s *db_node;
55
56 hash = fileno % FILE_DB_HASHSIZE;
57 db_node = h->files_db_buckets[hash];
58 while (db_node != NULL) {
59 if (db_node->fileno == fileno)
60 break;
61 db_node = db_node->next;
62 }
63 return db_node;
64}
65
Mohan Srinivasan02f86262017-02-24 16:34:28 -080066void *files_db_add_byfileno(void *handle, int fileno, int readonly)
Mohan Srinivasanb707f302017-01-19 16:40:52 -080067{
68 u_int32_t hash = fileno % FILE_DB_HASHSIZE;
69 struct files_db_handle *h = (struct files_db_handle *)handle;
70 struct files_db_s *db_node;
71
72 db_node = (struct files_db_s *)
73 files_db_lookup_byfileno(handle, fileno);
74 if (db_node == NULL) {
75 db_node = malloc(sizeof(struct files_db_s));
76 db_node->fileno = fileno;
77 db_node->filename = NULL;
Mohan Srinivasan02f86262017-02-24 16:34:28 -080078 db_node->readonly = readonly;
Mohan Srinivasanb707f302017-01-19 16:40:52 -080079 db_node->size = 0;
80 db_node->fd = -1;
81 db_node->next = h->files_db_buckets[hash];
82 h->files_db_buckets[hash] = db_node;
83 } else {
84 fprintf(stderr,
85 "%s: Node to be added already exists fileno = %d\n\n",
86 __func__, fileno);
87 exit(EXIT_FAILURE);
88 }
89 return db_node;
90}
91
92void
93files_db_fsync_discard_files(void *handle)
94{
95 struct files_db_handle *h = (struct files_db_handle *)handle;
96 struct files_db_s *db_node;
97 int i;
98
99 for (i = 0 ; i < FILE_DB_HASHSIZE ; i++) {
100 db_node = h->files_db_buckets[i];
101 while (db_node != NULL) {
102 int do_close = 0;
103
104 if (db_node->fd == -1) {
105 int fd;
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800106 int openflags;
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800107
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800108 /*n
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800109 * File was closed, let's open it so we can
110 * fsync and fadvise(DONTNEED) it.
111 */
112 do_close = 1;
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800113 if (files_db_readonly(db_node))
114 openflags = O_RDONLY;
115 else
116 openflags = O_RDWR;
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800117 fd = open(files_db_get_filename(db_node),
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800118 openflags);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800119 if (fd < 0) {
120 fprintf(stderr,
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800121 "%s: open(%s %x) error %d\n",
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800122 progname, db_node->filename,
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800123 openflags,
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800124 errno);
125 exit(EXIT_FAILURE);
126 }
127 db_node->fd = fd;
128 }
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800129 if (!db_node->readonly && fsync(db_node->fd) < 0) {
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800130 fprintf(stderr, "%s: Cannot fsync %s\n",
131 __func__, db_node->filename);
132 exit(1);
133 }
134 if (posix_fadvise(db_node->fd, 0, 0,
135 POSIX_FADV_DONTNEED) < 0) {
136 fprintf(stderr,
137 "%s: Cannot fadvise(DONTNEED) %s\n",
138 __func__, db_node->filename);
139 exit(1);
140 }
141 if (do_close) {
142 close(db_node->fd);
143 db_node->fd = -1;
144 }
145 db_node = db_node->next;
146 }
147 }
148}
149
150void
151files_db_update_fd(void *node, int fd)
152{
153 struct files_db_s *db_node = (struct files_db_s *)node;
154
155 db_node->fd = fd;
156}
157
158void
159files_db_close_fd(void *node)
160{
161 struct files_db_s *db_node = (struct files_db_s *)node;
162
163 if (db_node->fd != -1)
164 close(db_node->fd);
165 db_node->fd = -1;
166}
167
168void
169files_db_close_files(void *handle)
170{
171 struct files_db_handle *h = (struct files_db_handle *)handle;
172 struct files_db_s *db_node;
173 int i;
174
175 for (i = 0 ; i < FILE_DB_HASHSIZE ; i++) {
176 db_node = h->files_db_buckets[i];
177 while (db_node != NULL) {
178 if ((db_node->fd != -1) && close(db_node->fd) < 0) {
179 fprintf(stderr, "%s: Cannot close %s\n",
180 __func__, db_node->filename);
181 exit(1);
182 }
183 db_node->fd = -1;
184 db_node = db_node->next;
185 }
186 }
187}
188
189void
190files_db_unlink_files(void *handle)
191{
192 struct files_db_handle *h = (struct files_db_handle *)handle;
193 struct files_db_s *db_node;
194 int i;
195
196 for (i = 0 ; i < FILE_DB_HASHSIZE ; i++) {
197 db_node = h->files_db_buckets[i];
198 while (db_node != NULL) {
199 if ((db_node->fd != -1) && close(db_node->fd) < 0) {
200 fprintf(stderr, "%s: Cannot close %s\n",
201 __func__, db_node->filename);
202 exit(1);
203 }
204 db_node->fd = -1;
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800205 if (is_readonly_mount(db_node->filename, db_node->size) == 0) {
206 if (unlink(db_node->filename) < 0) {
207 fprintf(stderr, "%s: Cannot unlink %s:%s\n",
208 __func__, db_node->filename,
209 strerror(errno));
210 exit(EXIT_FAILURE);
211 }
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800212 }
213 db_node = db_node->next;
214 }
215 }
216}
217
218void
219files_db_free_memory(void *handle)
220{
221 struct files_db_handle *h = (struct files_db_handle *)handle;
222 struct files_db_s *db_node, *tmp;
223 int i;
224
225 for (i = 0 ; i < FILE_DB_HASHSIZE ; i++) {
226 db_node = h->files_db_buckets[i];
227 while (db_node != NULL) {
228 tmp = db_node;
229 db_node = db_node->next;
230 free(tmp->filename);
231 free(tmp);
232 }
233 }
234 free(h);
235}
236
237char *
238get_buf(char **buf, int *buflen, int len, int do_fill __attribute__((unused)))
239{
240 if (len == 0 && *buf == NULL) {
241 /*
242 * If we ever get a zero len
243 * request, start with MINBUFLEN
244 */
245 if (*buf == NULL)
246 len = MINBUFLEN / 2;
247 }
248 if (*buflen < len) {
249 *buflen = MAX(MINBUFLEN, len * 2);
250 if (*buf)
251 free(*buf);
252 *buf = malloc(*buflen);
253 if (do_fill) {
254 u_int32_t *s;
255 int count;
256
257 s = (u_int32_t *)*buf;
258 count = *buflen / sizeof(u_int32_t);
259 while (count > 0) {
260 *s++ = rand();
261 count--;
262 }
263 }
264 }
265 assert(*buf != NULL);
266 return *buf;
267}
268
269void
270create_file(char *path, size_t size, struct rw_bytes_s *rw_bytes)
271{
272 int fd, n;
273 char *buf = NULL;
274 int buflen = 0;
275
276 fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0644);
277 if (fd < 0) {
278 fprintf(stderr, "%s Cannot create file %s, error = %d\n",
279 progname, path, errno);
280 exit(EXIT_FAILURE);
281 }
282 while (size > 0) {
283 n = MIN(size, MINBUFLEN);
284 buf = get_buf(&buf, &buflen, n, 1);
285 if (write(fd, buf, n) < n) {
286 fprintf(stderr,
287 "%s Cannot write file %s, error = %d\n",
288 progname, path, errno);
289 exit(EXIT_FAILURE);
290 }
291 rw_bytes->bytes_written += n;
292 size -= n;
293 }
294 if (fsync(fd) < 0) {
295 fprintf(stderr, "%s Cannot fsync file %s, error = %d\n",
296 progname, path, errno);
297 exit(EXIT_FAILURE);
298 }
299 if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED) < 0) {
300 fprintf(stderr,
301 "%s Cannot fadvise(DONTNEED) file %s, error = %d\n",
302 progname, path, errno);
303 exit(EXIT_FAILURE);
304 }
305 close(fd);
306}
307
308void
309print_op_stats(u_int64_t *op_counts)
310{
311 int i;
312 extern char *IO_op[];
313
314 printf("IO Operation counts :\n");
315 for (i = IOSHARK_LSEEK ; i < IOSHARK_MAX_FILE_OP ; i++) {
316 printf("%s: %ju\n",
317 IO_op[i], op_counts[i]);
318 }
319}
320
321void
322print_bytes(char *desc, struct rw_bytes_s *rw_bytes)
323{
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -0800324 if (!summary_mode)
325 printf("%s: Reads = %dMB, Writes = %dMB\n",
326 desc,
327 (int)(rw_bytes->bytes_read / (1024 * 1024)),
328 (int)(rw_bytes->bytes_written / (1024 * 1024)));
329 else
330 printf("%d %d ",
331 (int)(rw_bytes->bytes_read / (1024 * 1024)),
332 (int)(rw_bytes->bytes_written / (1024 * 1024)));
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800333}
334
335struct cpu_disk_util_stats {
336 /* CPU util */
337 u_int64_t user_cpu_ticks;
338 u_int64_t nice_cpu_ticks;
339 u_int64_t system_cpu_ticks;
340 u_int64_t idle_cpu_ticks;
341 u_int64_t iowait_cpu_ticks;
342 u_int64_t hardirq_cpu_ticks;
343 u_int64_t softirq_cpu_ticks;
344 /* disk util */
345 unsigned long long uptime;
346 unsigned int tot_ticks;
347 unsigned long rd_ios;
348 unsigned long wr_ios;
349 unsigned long rd_sec;
350 unsigned long wr_sec;
351};
352
353static struct cpu_disk_util_stats before;
354static struct cpu_disk_util_stats after;
355
356#define BUFSIZE 8192
357
358static int hz;
359
360static void
361get_HZ(void)
362{
363 if ((hz = sysconf(_SC_CLK_TCK)) == -1)
364 exit(1);
365}
366
367#if 0
368static int num_cores;
369
370static void
371get_cores(void)
372{
373 if ((num_cores = sysconf(_SC_NPROCESSORS_ONLN)) == -1)
374 exit(1);
375}
376#endif
377
Mohan Srinivasanb9d4b522017-07-12 14:03:16 -0700378extern char *blockdev_name;
379
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800380static void
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800381get_blockdev_name(char *bdev)
382{
383 char dev_name[BUFSIZE];
384 FILE *cmd;
385
386 cmd = popen("getprop ro.product.name", "r");
387 if (cmd == NULL) {
388 fprintf(stderr, "%s: Cannot popen getprop\n",
389 progname);
390 exit(1);
391 }
392 if (fgets(dev_name, BUFSIZE, cmd) == NULL) {
393 fprintf(stderr,
394 "%s: Bad output from getprop ro.product.name\n",
395 progname);
396 exit(1);
397 }
398 pclose(cmd);
399 /* strncmp needed because of the trailing '\n' */
400 if (strncmp(dev_name, "bullhead", strlen("bullhead")) == 0 ||
401 strncmp(dev_name, "angler", strlen("angler")) == 0 ||
402 strncmp(dev_name, "shamu", strlen("shamu")) == 0) {
403 strcpy(bdev, "mmcblk0");
404 } else if (strncmp(dev_name, "marlin", strlen("marlin")) == 0 ||
405 strncmp(dev_name, "sailfish", strlen("sailfish")) == 0) {
406 strcpy(bdev, "sda");
Mohan Srinivasanb9d4b522017-07-12 14:03:16 -0700407 } else if (blockdev_name != NULL) {
408 strcpy(bdev, blockdev_name);
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800409 } else {
410 fprintf(stderr,
Mohan Srinivasanb9d4b522017-07-12 14:03:16 -0700411 "%s: Unknown device %s, please specify block device name with -b\n",
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800412 progname, dev_name);
413 exit(1);
414 }
415}
416
417static void
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800418read_disk_util_state(struct cpu_disk_util_stats *state)
419{
420 FILE *fp;
421 char line[BUFSIZE], dev_name[BUFSIZE];
422 unsigned int major, minor;
423 unsigned int ios_pgr;
424 unsigned int rq_ticks;
425 unsigned int wr_ticks;
426 unsigned long rd_ticks;
427 unsigned long rd_merges;
428 unsigned long wr_merges;
429 unsigned long up_sec, up_cent;
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800430 char blockdev_name[BUFSIZE];
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800431
432 /* Read and parse /proc/uptime */
433 fp = fopen("/proc/uptime", "r");
434 if (fgets(line, sizeof(line), fp) == NULL) {
435 fprintf(stderr, "%s: Cannot read /proc/uptime\n",
436 progname);
437 exit(1);
438 }
439 fclose(fp);
440 sscanf(line, "%lu.%lu", &up_sec, &up_cent);
441 state->uptime = (unsigned long long) up_sec * hz +
442 (unsigned long long) up_cent * hz / 100;
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800443
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800444 /* Read and parse /proc/diskstats */
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800445 get_blockdev_name(blockdev_name);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800446 fp = fopen("/proc/diskstats", "r");
447 while (fgets(line, sizeof(line), fp)) {
448 sscanf(line,
449 "%u %u %s %lu %lu %lu %lu %lu %lu %lu %u %u %u %u",
450 &major, &minor, dev_name,
451 &state->rd_ios, &rd_merges, &state->rd_sec,
452 &rd_ticks, &state->wr_ios, &wr_merges,
453 &state->wr_sec, &wr_ticks,
454 &ios_pgr, &state->tot_ticks, &rq_ticks);
Mohan Srinivasan08357df2017-02-15 12:39:35 -0800455 if (strcmp(dev_name, blockdev_name) == 0) {
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800456 /*
457 * tot_ticks is "number of milliseconds spent
458 * doing I/Os". Look at Documentation/iostats.txt.
459 * Or at genhd.c:diskstats_show(), which calls
460 * jiffies_to_msecs() on this field before printing
461 * it. Convert this to hz, so we can do all our math
462 * in ticks.
463 */
464 state->tot_ticks /= 1000; /* to seconds */
465 state->tot_ticks *= hz; /* to hz */
466 fclose(fp);
467 return;
468 }
469 }
470 fprintf(stderr, "%s: Did not find device sda in /proc/diskstats\n",
471 progname);
472 exit(1);
473}
474
475static void
476read_cpu_util_state(struct cpu_disk_util_stats *state)
477{
478 FILE *fp;
479 char line[BUFSIZE], cpu[BUFSIZE];
480
481 /* Read and parse /proc/stat */
482 fp = fopen("/proc/stat", "r");
483 if (fgets(line, sizeof(line), fp) == NULL) {
484 fprintf(stderr, "%s: Cannot read /proc/stat\n",
485 progname);
486 exit(1);
487 }
488 fclose(fp);
489 sscanf(line, "%s %ju %ju %ju %ju %ju %ju %ju",
490 cpu,
491 &state->user_cpu_ticks,
492 &state->nice_cpu_ticks,
493 &state->system_cpu_ticks,
494 &state->idle_cpu_ticks,
495 &state->iowait_cpu_ticks,
496 &state->hardirq_cpu_ticks,
497 &state->softirq_cpu_ticks);
498}
499
500void
501capture_util_state_before(void)
502{
503 get_HZ();
504 read_disk_util_state(&before);
505 read_cpu_util_state(&before);
506}
507
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800508void
509report_cpu_disk_util(void)
510{
511 double disk_util, cpu_util;
512 u_int64_t tot1, tot2, delta1, delta2;
513
514 read_disk_util_state(&after);
515 read_cpu_util_state(&after);
516 /* CPU Util */
517 tot2 = after.user_cpu_ticks + after.nice_cpu_ticks +
518 after.system_cpu_ticks + after.hardirq_cpu_ticks +
519 after.softirq_cpu_ticks;
520 tot1 = before.user_cpu_ticks + before.nice_cpu_ticks +
521 before.system_cpu_ticks + before.hardirq_cpu_ticks +
522 before.softirq_cpu_ticks;
523 delta1 = tot2 - tot1;
524 tot2 += after.iowait_cpu_ticks + after.idle_cpu_ticks;
525 tot1 += before.iowait_cpu_ticks + before.idle_cpu_ticks;
526 delta2 = tot2 - tot1;
527 cpu_util = delta1 * 100.0 / delta2;
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -0800528 if (!summary_mode)
529 printf("CPU util = %.2f%%\n", cpu_util);
530 else
531 printf("%.2f ", cpu_util);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800532 /* Next compute system (incl irq/softirq) and user cpu util */
533 delta1 = (after.user_cpu_ticks + after.nice_cpu_ticks) -
534 (before.user_cpu_ticks + before.nice_cpu_ticks);
535 cpu_util = delta1 * 100.0 / delta2;
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -0800536 if (!summary_mode)
537 printf("User CPU util = %.2f%%\n", cpu_util);
538 else
539 printf("%.2f ", cpu_util);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800540 delta1 = (after.system_cpu_ticks + after.hardirq_cpu_ticks +
541 after.softirq_cpu_ticks) -
542 (before.system_cpu_ticks + before.hardirq_cpu_ticks +
543 before.softirq_cpu_ticks);
544 cpu_util = delta1 * 100.0 / delta2;
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -0800545 if (!summary_mode)
546 printf("System CPU util = %.2f%%\n", cpu_util);
547 else
548 printf("%.2f ", cpu_util);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800549 /* Disk Util */
550 disk_util = (after.tot_ticks - before.tot_ticks) * 100.0 /
551 (after.uptime - before.uptime);
552 if (verbose) {
553 printf("Reads : nr_ios %lu, MB read %lu\n",
554 (after.rd_ios - before.rd_ios),
555 (after.rd_sec - before.rd_sec) / 2048);
556 printf("Writes : nr_ios %lu, MB written %lu\n",
557 (after.wr_ios - before.wr_ios),
558 (after.wr_sec - before.wr_sec) / 2048);
559 }
Mohan Srinivasan2aa6e6f2017-02-22 16:19:25 -0800560 if (!summary_mode)
561 printf("Disk util = %.2f%%\n", disk_util);
562 else
563 printf("%.2f", disk_util);
Mohan Srinivasanb707f302017-01-19 16:40:52 -0800564}
Mohan Srinivasan02f86262017-02-24 16:34:28 -0800565
566
567static struct ioshark_filename_struct *filename_cache;
568static int filename_cache_num_entries;
569
570char *
571get_ro_filename(int ix)
572{
573 if (ix >= filename_cache_num_entries)
574 return NULL;
575 return filename_cache[ix].path;
576}
577
578void
579init_filename_cache(void)
580{
581 int fd;
582 struct stat st;
583
584 fd = open("ioshark_filenames", O_RDONLY);
585 if (fd < 0) {
586 fprintf(stderr, "%s Can't open ioshark_filenames file\n",
587 progname);
588 exit(EXIT_FAILURE);
589 }
590 if (fstat(fd, &st) < 0) {
591 fprintf(stderr, "%s Can't fstat ioshark_filenames file\n",
592 progname);
593 exit(EXIT_FAILURE);
594 }
595 filename_cache_num_entries = st.st_size /
596 sizeof(struct ioshark_filename_struct);
597 filename_cache = mmap(NULL, st.st_size, PROT_READ,
598 MAP_SHARED | MAP_LOCKED | MAP_POPULATE,
599 fd, 0);
600 if (filename_cache == MAP_FAILED) {
601 fprintf(stderr, "%s Can't fstat ioshark_filenames file: %s\n",
602 progname, strerror(errno));
603 exit(EXIT_FAILURE);
604 }
605 close(fd);
606}
607
608void
609free_filename_cache(void)
610{
611 size_t mmap_size;
612
613 mmap_size = filename_cache_num_entries *
614 sizeof(struct ioshark_filename_struct);
615 munmap(filename_cache, mmap_size);
616}
617
618/*
619 * Is the passed in filename a regular file ? (eg. not a directory).
620 * Second, is it in a read-only partition ?
621 */
622int
623is_readonly_mount(char *filename, size_t size)
624{
625 struct statfs statfsbuf;
626 struct stat statbuf;
627
628 if (stat(filename, &statbuf) < 0) {
629 /* File possibly deleted */
630 return 0;
631 }
632 if (!S_ISREG(statbuf.st_mode)) {
633 /* Is it a regular file ? */
634 return 0;
635 }
636 if ((size_t)statbuf.st_size < size) {
637 /* Size of existing file is smaller than we expect */
638 return 0;
639 }
640 if (statfs(filename, &statfsbuf) < 0) {
641 /* This shouldn't happen */
642 return 0;
643 }
644 if ((statfsbuf.f_flags & ST_RDONLY) == 0)
645 return 0;
646 else
647 return 1;
648}