LU-7004 obd: make LCFG_SET_PARAM functional

[fs/lustre-release.git] / lustre / obdclass / obd_mount.c

diff --git a/lustre/obdclass/obd_mount.c b/lustre/obdclass/obd_mount.c
index e4e0d85..4ad23a0 100644 (file)
--- a/lustre/obdclass/obd_mount.c
+++ b/lustre/obdclass/obd_mount.c
@@ -674,6 +674,79 @@ int lustre_put_lsi(struct super_block *sb)
        RETURN(0);
 }
 
+/*
+ * The goal of this function is to extract the file system name
+ * from the obd name. This can come in two flavors. One is
+ * fsname-MDTXXXX or fsname-XXXXXXX were X is a hexadecimal
+ * number. In both cases we should return fsname. If it is
+ * not a valid obd name it is assumed to be the file system
+ * name itself.
+ */
+void obdname2fsname(const char *tgt, char *fsname, size_t buflen)
+{
+       const char *ptr;
+       const char *tmp;
+       size_t len = 0;
+
+       /* First we have to see if the @tgt has '-' at all. It is
+        * valid for the user to request something like
+        * lctl set_param -P llite.lustre*.xattr_cache=0
+        */
+       ptr = strrchr(tgt, '-');
+       if (!ptr) {
+               /* No '-' means it should end in '*' */
+               ptr = strchr(tgt, '*');
+               if (!ptr)
+                       goto no_fsname;
+               len = ptr - tgt;
+               goto valid_obd_name;
+       }
+
+       /* tgt format fsname-MDT0000-* */
+       if ((!strncmp(ptr, "-MDT", 4) ||
+            !strncmp(ptr, "-OST", 4)) &&
+            (isxdigit(ptr[4]) && isxdigit(ptr[5]) &&
+             isxdigit(ptr[6]) && isxdigit(ptr[7]))) {
+               len = ptr - tgt;
+               goto valid_obd_name;
+       }
+
+       /* tgt_format fsname-cli'dev'-'uuid' except for the llite case
+        * which are named fsname-'uuid'. Examples:
+        *
+        * lustre-clilov-ffff88104db5b800
+        * lustre-ffff88104db5b800  (for llite device)
+        *
+        * The length of the obd uuid can vary on different platforms.
+        * This test if any invalid characters are in string. Allow
+        * wildcards with '*' character.
+        */
+       ptr++;
+       if (!strspn(ptr, "0123456789abcdefABCDEF*")) {
+               len = 0;
+               goto no_fsname;
+       }
+
+       /* Now that we validated the device name lets extract the
+        * file system name. Most of the names in this class will
+        * have '-cli' in its name which needs to be dropped. If
+        * it doesn't have '-cli' then its a llite device which
+        * ptr already points to the start of the uuid string.
+        */
+       tmp = strstr(tgt, "-cli");
+       if (tmp)
+               ptr = tmp;
+       else
+               ptr--;
+       len = ptr - tgt;
+valid_obd_name:
+       len = min_t(size_t, len, LUSTRE_MAXFSNAME);
+       snprintf(fsname, buflen, "%.*s", (int)len, tgt);
+no_fsname:
+       fsname[len] = '\0';
+}
+EXPORT_SYMBOL(obdname2fsname);
+
 /*** SERVER NAME ***
  * <FSNAME><SEPARATOR><TYPE><INDEX>
  * FSNAME is between 1 and 8 characters (inclusive).