+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, struct mount_opts *mop, 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) >= mop->mo_md_stripe_cache_size)
+ return 0;
+
+ if (strlen(buf) - 1 > 0) {
+ snprintf(buf, sizeof(buf), "%d",
+ mop->mo_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, mop, 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;
+}
+
+int ldiskfs_tune_lustre(char *dev, struct mount_opts *mop)
+{
+ return set_blockdev_tunables(dev, mop, 1);
+}
+
git://git.whamcloud.com / fs / lustre-release.git / commitdiff