-int read_file(char *path, char *buf, int size)
-{
- FILE *fd;
-
- fd = fopen(path, "r");
- if (fd == NULL)
- return errno;
-
- /* should not ignore fgets(3)'s return value */
- if (!fgets(buf, size, fd)) {
- fprintf(stderr, "reading from %s: %s", path, strerror(errno));
- fclose(fd);
- return 1;
- }
- fclose(fd);
- return 0;
-}
-
-int write_file(char *path, char *buf)
-{
- FILE *fd;
-
- fd = fopen(path, "w");
- if (fd == NULL)
- return errno;
-
- fputs(buf, fd);
- fclose(fd);
- return 0;
-}
-
-/* This is to tune the kernel for good SCSI performance.
- * For that we set the value of /sys/block/{dev}/queue/max_sectors_kb
- * to the value of /sys/block/{dev}/queue/max_hw_sectors_kb */
-int set_blockdev_tunables(char *source, int fan_out)
-{
- glob_t glob_info = { 0 };
- struct stat stat_buf;
- char *chk_major, *chk_minor;
- char *savept = NULL, *dev;
- char *ret_path;
- char buf[PATH_MAX] = {'\0'}, path[PATH_MAX] = {'\0'};
- char real_path[PATH_MAX] = {'\0'};
- int i, rc = 0;
- int major, minor;
-
- if (!source)
- return -EINVAL;
-
- ret_path = realpath(source, real_path);
- if (ret_path == NULL) {
- if (verbose)
- fprintf(stderr, "warning: %s: cannot resolve: %s\n",
- source, strerror(errno));
- return -EINVAL;
- }
-
- if (strncmp(real_path, "/dev/loop", 9) == 0)
- return 0;
-
- if ((real_path[0] != '/') && (strpbrk(real_path, ",:") != NULL))
- return 0;
-
- snprintf(path, sizeof(path), "/sys/block%s", real_path + 4);
- if (access(path, X_OK) == 0)
- goto set_params;
-
- /* The name of the device say 'X' specified in /dev/X may not
- * match any entry under /sys/block/. In that case we need to
- * match the major/minor number to find the entry under
- * sys/block corresponding to /dev/X */
-
- /* Don't chop tail digit on /dev/mapper/xxx, LU-478 */
- if (strncmp(real_path, "/dev/mapper", 11) != 0) {
- dev = real_path + strlen(real_path);
- while (--dev > real_path && isdigit(*dev))
- *dev = 0;
-
- if (strncmp(real_path, "/dev/md_", 8) == 0)
- *dev = 0;
- }
-
- rc = stat(real_path, &stat_buf);
- if (rc) {
- if (verbose)
- fprintf(stderr, "warning: %s, device %s stat failed\n",
- strerror(errno), real_path);
- return rc;
- }
-
- major = major(stat_buf.st_rdev);
- minor = minor(stat_buf.st_rdev);
- rc = glob("/sys/block/*", GLOB_NOSORT, NULL, &glob_info);
- if (rc) {
- if (verbose)
- fprintf(stderr, "warning: failed to read entries under "
- "/sys/block\n");
- globfree(&glob_info);
- return rc;
- }
-
- for (i = 0; i < glob_info.gl_pathc; i++){
- snprintf(path, sizeof(path), "%s/dev", glob_info.gl_pathv[i]);
-
- rc = read_file(path, buf, sizeof(buf));
- if (rc)
- continue;
-
- if (buf[strlen(buf) - 1] == '\n')
- buf[strlen(buf) - 1] = '\0';
-
- chk_major = strtok_r(buf, ":", &savept);
- chk_minor = savept;
- if (major == atoi(chk_major) &&minor == atoi(chk_minor))
- break;
- }
-
- if (i == glob_info.gl_pathc) {
- if (verbose)
- fprintf(stderr,"warning: device %s does not match any "
- "entry under /sys/block\n", real_path);
- globfree(&glob_info);
- return -EINVAL;
- }
-
- /* Chop off "/dev" from path we found */
- path[strlen(glob_info.gl_pathv[i])] = '\0';
- globfree(&glob_info);
-
-set_params:
- if (strncmp(real_path, "/dev/md", 7) == 0) {
- snprintf(real_path, sizeof(real_path), "%s/%s", path,
- STRIPE_CACHE_SIZE);
-
- rc = read_file(real_path, buf, sizeof(buf));
- if (rc) {
- if (verbose)
- fprintf(stderr, "warning: opening %s: %s\n",
- real_path, strerror(errno));
- return 0;
- }
-
- if (atoi(buf) >= md_stripe_cache_size)
- return 0;
-
- if (strlen(buf) - 1 > 0) {
- snprintf(buf, sizeof(buf), "%d", md_stripe_cache_size);
- rc = write_file(real_path, buf);
- if (rc && verbose)
- fprintf(stderr, "warning: opening %s: %s\n",
- real_path, strerror(errno));
- }
- /* Return since raid and disk tunables are different */
- return rc;
- }
-
- snprintf(real_path, sizeof(real_path), "%s/%s", path,
- MAX_HW_SECTORS_KB_PATH);
- rc = read_file(real_path, buf, sizeof(buf));
- if (rc) {
- if (verbose)
- fprintf(stderr, "warning: opening %s: %s\n",
- real_path, strerror(errno));
- /* No MAX_HW_SECTORS_KB_PATH isn't necessary an
- * error for some device. */
- rc = 0;
- }
-
- if (strlen(buf) - 1 > 0) {
- snprintf(real_path, sizeof(real_path), "%s/%s", path,
- MAX_SECTORS_KB_PATH);
- rc = write_file(real_path, buf);
- if (rc) {
- if (verbose)
- fprintf(stderr, "warning: writing to %s: %s\n",
- real_path, strerror(errno));
- /* No MAX_SECTORS_KB_PATH isn't necessary an
- * error for some device. */
- rc = 0;
- }
- }
-
- if (fan_out) {
- char *slave = NULL;
- glob_info.gl_pathc = 0;
- glob_info.gl_offs = 0;
- /* if device is multipath device, tune its slave devices */
- snprintf(real_path, sizeof(real_path), "%s/slaves/*", path);
- rc = glob(real_path, GLOB_NOSORT, NULL, &glob_info);
-
- for (i = 0; rc == 0 && i < glob_info.gl_pathc; i++){
- slave = basename(glob_info.gl_pathv[i]);
- snprintf(real_path, sizeof(real_path), "/dev/%s", slave);
- rc = set_blockdev_tunables(real_path, 0);
- }
-
- if (rc == GLOB_NOMATCH) {
- /* no slave device is not an error */
- rc = 0;
- } else if (rc && verbose) {
- if (slave == NULL) {
- fprintf(stderr, "warning: %s, failed to read"
- " entries under %s/slaves\n",
- strerror(errno), path);
- } else {
- fprintf(stderr, "unable to set tunables for"
- " slave device %s (slave would be"
- " unable to handle IO request from"
- " master %s)\n",
- real_path, source);
- }
- }
- globfree(&glob_info);
- }
-
- return rc;
-}
-
git://git.whamcloud.com / fs / lustre-release.git / blobdiff