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 disk setups 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                 BIOS
  16  * Intel (Lenovo) SSDSC2BW180A3L LE1i       SandForce 2281 1 (3.5 Debian kernel)   Lenovo x230        G2ET90WW (2.50) 2012-20-12
  17  * Intel (Lenovo) SSDSC2BW180A3L LF1i       SandForce 2281 2 (3.2 Debian kernel)   Lenovo x230
  18  * Intel (Lenovo) SSDSC2BW180A3L LF1i       SandForce 2281 1 (3.7.9 Arch kernel)   Lenovo x230        G2ET86WW (2.06) 2012-11-13
  19  *
  20  * In order to narrow down the problem, we ran this test on a number of
  21  * other hardware configurations which don't show this problem:
  22  *
  23  * Vendor         Model          Firmware   Controller     # drives tested         HW                 BIOS
  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  * OCZ            OCZSSD2-2VTXE180G  1.37   SF-1200        1 (3.7.6 Arch kernel)
  31  * Intel (Lenovo) SSDSC2BW180A3L LF1i       SandForce 2281 3 (3.2 Debian kernel)   Lenovo x200
  32  *
  33  * Under Linux (Debian, Ubuntu, various kernels), after about 5 minutes,
  34  * we get this result:
  35  *
  36  * ata1.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x6 frozen
  37  * ata1.00: failed command: WRITE FPDMA QUEUED
  38  * ata1.00: cmd 61/28:00:a8:a9:7f/00:00:02:00:00/40 tag 0 ncq 20480 out
  39  *          res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
  40  * ata1.00: status: { DRDY }
  41  * ata1.00: COMRESET failed (errno=-16)
  42  * ata1.00: COMRESET failed (errno=-16)
  43  *
  44  * This happens with random data, zeroed data (-z), and has been tested
  45  * with file sizes of 1MB, 200MB, 3.1GB and 21GB. The error happens with
  46  * and without the validation (-v) option.
  47  *
  48  * Copyright 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  49  *
  50  * Permission is hereby granted, free of charge, to any person obtaining
  51  * a copy of this software and associated documentation files (the
  52  * "Software"), to deal in the Software without restriction, including
  53  * without limitation the rights to use, copy, modify, merge, publish,
  54  * distribute, sublicense, and/or sell copies of the Software, and to
  55  * permit persons to whom the Software is furnished to do so, subject to
  56  * the following conditions:
  57  *
  58  * The above copyright notice and this permission notice shall be
  59  * included in all copies or substantial portions of the Software.
  60  *
  61  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  62  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  63  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  64  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  65  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  66  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  67  * SOFTWARE.
  68  */
  69
  70 #include <stdio.h>
  71 #include <sys/types.h>
  72 #include <sys/stat.h>
  73 #include <fcntl.h>
  74 #include <assert.h>
  75 #include <stdlib.h>
  76 #include <unistd.h>
  77 #include <stdint.h>
  78 #include <inttypes.h>
  79 #include <string.h>
  80
  81 enum write_mode {
  82         WRITE_RANDOM = 0,
  83         WRITE_ZEROES,
  84 };
  85
  86 static enum write_mode write_mode;
  87 static int verify_mode;
  88
  89 #define PRINT_FREQ      100000
  90 #define VALIDATE_FREQ   10000
  91 #define BUFLEN          4096
  92
  93 static void rand_buf(char *buf, size_t buflen)
  94 {
  95         size_t i;
  96
  97         for (i = 0; i < buflen; i += sizeof(int)) {
  98                 union {
  99                         int i;
 100                         char c[sizeof(int)];
 101                 } u;
 102                 u.i = rand();
 103                 memcpy(&buf[i], u.c, sizeof(int));
 104         }
 105 }
 106
 107 static uint64_t validate(int fd, const char *validate_buf, off_t offset)
 108 {
 109         char buf[BUFLEN];
 110         ssize_t rret;
 111         off_t pos;
 112         int i;
 113         uint64_t diffcnt = 0;
 114
 115         if (!verify_mode)
 116                 return 0;
 117
 118         pos = lseek(fd, offset, SEEK_SET);
 119         if (pos < 0) {
 120                 perror("lseek");
 121                 exit(EXIT_FAILURE);
 122         }
 123         rret = read(fd, buf, BUFLEN);
 124         if (rret != BUFLEN) {
 125                 fprintf(stderr, "Error at read from offset: %zu\n",
 126                         pos);
 127                 perror("read");
 128                 exit(EXIT_FAILURE);
 129         }
 130         for (i = 0; i < BUFLEN; i++) {
 131                 if (buf[i] != validate_buf[i]) {
 132                         diffcnt++;
 133                 }
 134         }
 135         return diffcnt;
 136 }
 137
 138 static int rand_write(int fd, size_t len)
 139 {
 140         off_t pos, offset;
 141         uint64_t write_nr = 0;
 142         ssize_t wret;
 143         char buf[BUFLEN];
 144         char validate_buf[BUFLEN];
 145         off_t validate_offset = 0;
 146         uint64_t valcount;
 147         int ret;
 148
 149         memset(buf, 0, BUFLEN);
 150
 151         for (;;) {
 152                 if (len > UINT32_MAX) {
 153                         offset = (((size_t) rand() << 32) + (size_t) rand()) % len;
 154                 } else {
 155                         offset = rand() % len;
 156                 }
 157
 158                 if ((offset >= validate_offset &&
 159                         offset < validate_offset + BUFLEN)
 160                         || (validate_offset >= offset &&
 161                                 validate_offset < offset + BUFLEN)) {
 162                         /* Don't overwrite the range we want to validate. */
 163                         continue;
 164                 }
 165                 if (write_mode == WRITE_RANDOM)
 166                         rand_buf(buf, BUFLEN);
 167                 /* Save validation buffer and position */
 168                 if (write_nr % VALIDATE_FREQ == 0 && verify_mode) {
 169                         memcpy(validate_buf, buf, BUFLEN);
 170                         validate_offset = offset;
 171                 }
 172                 pos = lseek(fd, offset, SEEK_SET);
 173                 if (pos < 0) {
 174                         perror("lseek");
 175                         exit(EXIT_FAILURE);
 176                 }
 177                 wret = write(fd, buf, BUFLEN);
 178                 if (wret != BUFLEN) {
 179                         fprintf(stderr, "Error at write to offset: %zu\n",
 180                                 pos);
 181                         perror("write");
 182                         exit(EXIT_FAILURE);
 183                 }
 184
 185                 /*
 186                  * Advise that we won't be re-reading the blocks. This
 187                  * will ask the kernel to drop pages related to this
 188                  * file quickly from its page cache, thus forcing a read
 189                  * from disk.
 190                  */
 191                 ret = fdatasync(fd);
 192                 if (ret) {
 193                         perror("fdatasync");
 194                         exit(EXIT_FAILURE);
 195                 }
 196                 ret = posix_fadvise(fd, offset, BUFLEN, POSIX_FADV_DONTNEED);
 197                 if (ret) {
 198                         perror("posix_fadvise");
 199                         exit(EXIT_FAILURE);
 200                 }
 201
 202                 write_nr++;
 203                 if (write_nr % PRINT_FREQ == 0) {
 204                         printf("Status: %" PRIu64 " writes.\n", write_nr);
 205                 }
 206
 207                 /*
 208                  * Use the validation buffer and position saved
 209                  * VALIDATE_FREQ operations earlier.
 210                  */
 211                 if (write_nr % VALIDATE_FREQ == 0 && verify_mode) {
 212                         valcount = validate(fd, validate_buf, validate_offset);
 213                         if (valcount) {
 214                                 printf("VALIDATION ERROR at offset %zu, %" PRIu64 " bytes differ\n",
 215                                         validate_offset, valcount);
 216                         }
 217                 }
 218         }
 219         return 0;
 220 }
 221
 222 int main(int argc, char **argv)
 223 {
 224         int fd, ret, i, seed;
 225         size_t len;
 226         off_t pos;
 227         ssize_t wret;
 228
 229         if (argc < 4) {
 230                 printf("Usage: %s <output file> <len (64-bit)> <seed (32-bit)> <-z to write zeroes> <-v to verify written data>\n", argv[0]);
 231                 exit(EXIT_FAILURE);
 232         }
 233
 234         fd = open(argv[1], O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
 235         if (fd < 0) {
 236                 perror("open");
 237                 exit(EXIT_FAILURE);
 238         }
 239
 240         len = atoll(argv[2]);
 241         seed = atoi(argv[3]);
 242         srand(seed);
 243
 244         printf("Creating file %s of length %zu, random seed %u\n", argv[1], len,
 245                 seed);
 246
 247         for (i = 4; i < argc; i++) {
 248                 if (strcmp(argv[i], "-z") == 0) {
 249                         write_mode = WRITE_ZEROES;
 250                 } else if (strcmp(argv[i], "-v") == 0) {
 251                         verify_mode = 1;
 252                 }
 253         }
 254
 255         switch (write_mode) {
 256         case WRITE_RANDOM:
 257                 printf("Generating random data\n");
 258                 break;
 259         case WRITE_ZEROES:
 260                 printf("Filling with zeroes (compressible pattern)\n");
 261                 break;
 262         default:
 263                 printf("Unsupported write-mode\n");
 264                 exit(EXIT_FAILURE);
 265         }
 266
 267         if (verify_mode) {
 268                 printf("Verification mode activated.\n");
 269         }
 270
 271         /* Grow file */
 272         pos = lseek(fd, len - 1, SEEK_SET);
 273         if (pos < 0) {
 274                 perror("lseek");
 275                 exit(EXIT_FAILURE);
 276         }
 277         wret = write(fd, "", 1);
 278         if (wret < 0) {
 279                 perror("write");
 280                 exit(EXIT_FAILURE);
 281         }
 282
 283         /* Advise the OS that we are performing random accesses */
 284         ret = posix_fadvise(fd, 0, len, POSIX_FADV_RANDOM);
 285         if (ret) {
 286                 perror("posix_fadvise");
 287                 exit(EXIT_FAILURE);
 288         }
 289
 290         ret = rand_write(fd, len);
 291         if (ret) {
 292                 exit(EXIT_FAILURE);
 293         }
 294
 295         ret = close(fd);
 296         assert(!ret);
 297         exit(EXIT_SUCCESS);
 298 }