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LU-9132 utils: tuning max_sectors_kb on mount
[fs/lustre-release.git] / lustre / utils / mount_utils_ldiskfs.c
index a010a40..6e566ba 100644 (file)
@@ -1194,16 +1194,20 @@ set_params:
                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. */
-               goto subdevs;
+       if (mop->mo_max_sectors_kb >= 0) {
+               snprintf(buf, sizeof(buf), "%d", mop->mo_max_sectors_kb);
+       } else {
+               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. */
+                       goto subdevs;
+               }
        }
 
        if (strlen(buf) - 1 > 0) {
@@ -1228,14 +1232,15 @@ set_params:
                 * PTLRPC_MAX_BRW_SIZE, but that isn't in a public header.
                 * Note that even though the block layer allows larger values,
                 * setting max_sectors_kb = 32768 causes crashes (LU-6974). */
-               if (newval > 16 * 1024) {
+               if (mop->mo_max_sectors_kb < 0 && newval > 16 * 1024) {
                        newval = 16 * 1024;
                        snprintf(buf, sizeof(buf), "%llu", newval);
                }
 
                oldval = strtoull(oldbuf, &end, 0);
                /* Don't shrink the current limit. */
-               if (oldval != ULLONG_MAX && newval <= oldval)
+               if (mop->mo_max_sectors_kb < 0 && oldval != ULLONG_MAX &&
+                   newval <= oldval)
                        goto subdevs;
 
                rc = write_file(real_path, buf);