test-ssd-write.c

   1 /*
   2  * test-ssd-write.c
   3  *
   4  * Hard disk write workload: write random (or zeroed) data at random
   5  * locations in a file, and optionally validate by re-reading some
   6  * blocks after a while.
   7  *
   8  * Compile with:
   9  * gcc -O2 -Wall -o test-ssd-write test-ssd-write.c
  10  *
  11  * Hard disks known to stop responding with this program (requires a
  12  * warm machine reboot to get the drive to respond, as soft reset is not
  13  * enough):
  14  *
  15  * Vendor         Model          Firmware   Controller     # drives tested         HW
  16  * Intel (Lenovo) SSDSC2BW180A3L LE1i       SandForce 2281 1 (3.5 Debian kernel)   x230
  17  * Intel (Lenovo) SSDSC2BW180A3L LF1i       SandForce 2281 3 (3.2 Debian kernel)   x230
  18  *                                                           (3.7.9 Arch kernel)   x230
  19  *
  20  * We ensured that the problem is not coming from other parts by running
  21  * this test on other SSD drives, which don't show this problem:
  22  *
  23  * Vendor         Model          Firmware   Controller     # drives tested
  24  * Intel          SSDSA2M160G2GC 2CV102HD   Intel          1
  25  * Intel          SSDSA2CW300G310 ???????   Intel          1 (over USB on 3.8 kernel)
  26  * Intel          SSDSA2CT040G3  4PC10302   Intel          1 (3.2 kernel)
  27  * Intel          SSDSA2CT040G3  4PC10362   Intel          1 (3.2 kernel)
  28  * Intel          SSDSC2CT120A3K5 ???????   SandForce 2281 1 (on HP SmartArray P212 with 3.2 kernel)
  29  * OCZ            OCZ-VERTEX3        2.25   SF-2281        1 (3.7.9 Arch kernel)
  30  *
  31  * Under Linux (Debian, Ubuntu, various kernels), after about 5 minutes,
  32  * we get this result:
  33  *
  34  * ata1.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x6 frozen
  35  * ata1.00: failed command: WRITE FPDMA QUEUED
  36  * ata1.00: cmd 61/28:00:a8:a9:7f/00:00:02:00:00/40 tag 0 ncq 20480 out
  37  *          res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
  38  * ata1.00: status: { DRDY }
  39  * ata1.00: COMRESET failed (errno=-16)
  40  * ata1.00: COMRESET failed (errno=-16)
  41  *
  42  * This happens with random data, zeroed data (-z), and has been tested
  43  * with file sizes of 1MB, 200MB, 3.1GB and 21GB. The error happens with
  44  * and without the validation (-v) option.
  45  *
  46  * Copyright 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  47  *
  48  * Permission is hereby granted, free of charge, to any person obtaining
  49  * a copy of this software and associated documentation files (the
  50  * "Software"), to deal in the Software without restriction, including
  51  * without limitation the rights to use, copy, modify, merge, publish,
  52  * distribute, sublicense, and/or sell copies of the Software, and to
  53  * permit persons to whom the Software is furnished to do so, subject to
  54  * the following conditions:
  55  *
  56  * The above copyright notice and this permission notice shall be
  57  * included in all copies or substantial portions of the Software.
  58  *
  59  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  60  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  61  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  62  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  63  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  64  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  65  * SOFTWARE.
  66  */
  67
  68 #include <stdio.h>
  69 #include <sys/types.h>
  70 #include <sys/stat.h>
  71 #include <fcntl.h>
  72 #include <assert.h>
  73 #include <stdlib.h>
  74 #include <unistd.h>
  75 #include <stdint.h>
  76 #include <inttypes.h>
  77 #include <string.h>
  78
  79 enum write_mode {
  80         WRITE_RANDOM = 0,
  81         WRITE_ZEROES,
  82 };
  83
  84 static enum write_mode write_mode;
  85 static int verify_mode;
  86
  87 #define PRINT_FREQ      100000
  88 #define VALIDATE_FREQ   10000
  89 #define BUFLEN          4096
  90
  91 static void rand_buf(char *buf, size_t buflen)
  92 {
  93         size_t i;
  94
  95         for (i = 0; i < buflen; i += sizeof(int)) {
  96                 union {
  97                         int i;
  98                         char c[sizeof(int)];
  99                 } u;
 100                 u.i = rand();
 101                 memcpy(&buf[i], u.c, sizeof(int));
 102         }
 103 }
 104
 105 static uint64_t validate(int fd, const char *validate_buf, off_t offset)
 106 {
 107         char buf[BUFLEN];
 108         ssize_t rret;
 109         off_t pos;
 110         int i;
 111         uint64_t diffcnt = 0;
 112
 113         if (!verify_mode)
 114                 return 0;
 115
 116         pos = lseek(fd, offset, SEEK_SET);
 117         if (pos < 0) {
 118                 perror("lseek");
 119                 exit(EXIT_FAILURE);
 120         }
 121         rret = read(fd, buf, BUFLEN);
 122         if (rret != BUFLEN) {
 123                 fprintf(stderr, "Error at read from offset: %zu\n",
 124                         pos);
 125                 perror("read");
 126                 exit(EXIT_FAILURE);
 127         }
 128         for (i = 0; i < BUFLEN; i++) {
 129                 if (buf[i] != validate_buf[i]) {
 130                         diffcnt++;
 131                 }
 132         }
 133         return diffcnt;
 134 }
 135
 136 static int rand_write(int fd, size_t len)
 137 {
 138         off_t pos, offset;
 139         uint64_t write_nr = 0;
 140         ssize_t wret;
 141         char buf[BUFLEN];
 142         char validate_buf[BUFLEN];
 143         off_t validate_offset = 0;
 144         uint64_t valcount;
 145         int ret;
 146
 147         memset(buf, 0, BUFLEN);
 148
 149         for (;;) {
 150                 if (len > UINT32_MAX) {
 151                         offset = (((size_t) rand() << 32) + (size_t) rand()) % len;
 152                 } else {
 153                         offset = rand() % len;
 154                 }
 155
 156                 if ((offset >= validate_offset &&
 157                         offset < validate_offset + BUFLEN)
 158                         || (validate_offset >= offset &&
 159                                 validate_offset < offset + BUFLEN)) {
 160                         /* Don't overwrite the range we want to validate. */
 161                         continue;
 162                 }
 163                 if (write_mode == WRITE_RANDOM)
 164                         rand_buf(buf, BUFLEN);
 165                 /* Save validation buffer and position */
 166                 if (write_nr % VALIDATE_FREQ == 0 && verify_mode) {
 167                         memcpy(validate_buf, buf, BUFLEN);
 168                         validate_offset = offset;
 169                 }
 170                 pos = lseek(fd, offset, SEEK_SET);
 171                 if (pos < 0) {
 172                         perror("lseek");
 173                         exit(EXIT_FAILURE);
 174                 }
 175                 wret = write(fd, buf, BUFLEN);
 176                 if (wret != BUFLEN) {
 177                         fprintf(stderr, "Error at write to offset: %zu\n",
 178                                 pos);
 179                         perror("write");
 180                         exit(EXIT_FAILURE);
 181                 }
 182
 183                 /*
 184                  * Advise that we won't be re-reading the blocks. This
 185                  * will ask the kernel to drop pages related to this
 186                  * file quickly from its page cache, thus forcing a read
 187                  * from disk.
 188                  */
 189                 ret = fdatasync(fd);
 190                 if (ret) {
 191                         perror("fdatasync");
 192                         exit(EXIT_FAILURE);
 193                 }
 194                 ret = posix_fadvise(fd, offset, BUFLEN, POSIX_FADV_DONTNEED);
 195                 if (ret) {
 196                         perror("posix_fadvise");
 197                         exit(EXIT_FAILURE);
 198                 }
 199
 200                 write_nr++;
 201                 if (write_nr % PRINT_FREQ == 0) {
 202                         printf("Status: %" PRIu64 " writes.\n", write_nr);
 203                 }
 204
 205                 /*
 206                  * Use the validation buffer and position saved
 207                  * VALIDATE_FREQ operations earlier.
 208                  */
 209                 if (write_nr % VALIDATE_FREQ == 0 && verify_mode) {
 210                         valcount = validate(fd, validate_buf, validate_offset);
 211                         if (valcount) {
 212                                 printf("VALIDATION ERROR at offset %zu, %" PRIu64 " bytes differ\n",
 213                                         validate_offset, valcount);
 214                         }
 215                 }
 216         }
 217         return 0;
 218 }
 219
 220 int main(int argc, char **argv)
 221 {
 222         int fd, ret, i, seed;
 223         size_t len;
 224         off_t pos;
 225         ssize_t wret;
 226
 227         if (argc < 4) {
 228                 printf("Usage: %s <output file> <len (64-bit)> <seed (32-bit)> <-z to write zeroes> <-v to verify written data>\n", argv[0]);
 229                 exit(EXIT_FAILURE);
 230         }
 231
 232         fd = open(argv[1], O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
 233         if (fd < 0) {
 234                 perror("open");
 235                 exit(EXIT_FAILURE);
 236         }
 237
 238         len = atoll(argv[2]);
 239         seed = atoi(argv[3]);
 240         srand(seed);
 241
 242         printf("Creating file %s of length %zu, random seed %u\n", argv[1], len,
 243                 seed);
 244
 245         for (i = 4; i < argc; i++) {
 246                 if (strcmp(argv[i], "-z") == 0) {
 247                         write_mode = WRITE_ZEROES;
 248                 } else if (strcmp(argv[i], "-v") == 0) {
 249                         verify_mode = 1;
 250                 }
 251         }
 252
 253         switch (write_mode) {
 254         case WRITE_RANDOM:
 255                 printf("Generating random data\n");
 256                 break;
 257         case WRITE_ZEROES:
 258                 printf("Filling with zeroes (compressible pattern)\n");
 259                 break;
 260         default:
 261                 printf("Unsupported write-mode\n");
 262                 exit(EXIT_FAILURE);
 263         }
 264
 265         if (verify_mode) {
 266                 printf("Verification mode activated.\n");
 267         }
 268
 269         /* Grow file */
 270         pos = lseek(fd, len - 1, SEEK_SET);
 271         if (pos < 0) {
 272                 perror("lseek");
 273                 exit(EXIT_FAILURE);
 274         }
 275         wret = write(fd, "", 1);
 276         if (wret < 0) {
 277                 perror("write");
 278                 exit(EXIT_FAILURE);
 279         }
 280
 281         /* Advise the OS that we are performing random accesses */
 282         ret = posix_fadvise(fd, 0, len, POSIX_FADV_RANDOM);
 283         if (ret) {
 284                 perror("posix_fadvise");
 285                 exit(EXIT_FAILURE);
 286         }
 287
 288         ret = rand_write(fd, len);
 289         if (ret) {
 290                 exit(EXIT_FAILURE);
 291         }
 292
 293         ret = close(fd);
 294         assert(!ret);
 295         exit(EXIT_SUCCESS);
 296 }