LU-12521 llapi: add separate fsname and instance API

[fs/lustre-release.git] / lustre / utils / liblustreapi_util.c

diff --git a/lustre/utils/liblustreapi_util.c b/lustre/utils/liblustreapi_util.c
index 59f7e98..c19674e 100644 (file)
--- a/lustre/utils/liblustreapi_util.c
+++ b/lustre/utils/liblustreapi_util.c
@@ -311,3 +311,79 @@ retry_open:
 
        return rc ? -errno : 0;
 }
+
+int llapi_get_fsname_instance(const char *path, char *fsname, size_t fsname_len,
+                             char *instance, size_t instance_len)
+{
+       struct obd_uuid uuid_buf;
+       char *uuid = uuid_buf.uuid;
+       char *ptr;
+       int rc;
+
+       memset(&uuid_buf, 0, sizeof(uuid_buf));
+       rc = llapi_file_get_lov_uuid(path, &uuid_buf);
+       if (rc)
+               return rc;
+
+       /*
+        * We want to turn fs-foo-clilov-ffff88002738bc00 into 'fs-foo' and
+        * 'ffff88002738bc00' in a portable way that doesn't depend on what is
+        * after "-clilov-" as it may change to a UUID string in the future.
+        * Unfortunately, the "fsname" part may contain a dash, so we can't
+        * just skip to the first dash, and if the "instance" is a UUID in the
+        * future we can't necessarily go to the last dash either.
+        */
+       ptr = strstr(uuid, "-clilov-");
+       if (!ptr || (!fsname && !instance)) {
+               rc = -EINVAL;
+               goto out;
+       }
+
+       *ptr = '\0';
+       ptr += strlen("-clilov-");
+       if (instance) {
+               snprintf(instance, instance_len, "%s", ptr);
+               if (strlen(ptr) >= instance_len)
+                       rc = -ENAMETOOLONG;
+       }
+
+       if (fsname) {
+               snprintf(fsname, fsname_len, "%s", uuid);
+               if (strlen(uuid) >= fsname_len)
+                       rc = -ENAMETOOLONG;
+       }
+
+out:
+       errno = -rc;
+       return rc;
+}
+
+int llapi_getname(const char *path, char *name, size_t namelen)
+{
+       char fsname[16];
+       char instance[40];
+       int rc;
+
+       rc = llapi_get_fsname_instance(path, fsname, sizeof(fsname),
+                                      instance, sizeof(instance));
+       if (rc)
+               return rc;
+
+       snprintf(name, namelen, "%s-%s", fsname, instance);
+       if (strlen(fsname) + 1 + strlen(instance) >= namelen) {
+               rc = -ENAMETOOLONG;
+               errno = -rc;
+       }
+
+       return rc;
+}
+
+int llapi_get_instance(const char *path, char *instance, size_t instance_len)
+{
+       return llapi_get_fsname_instance(path, NULL, 0, instance, instance_len);
+}
+
+int llapi_get_fsname(const char *path, char *fsname, size_t fsname_len)
+{
+       return llapi_get_fsname_instance(path, fsname, fsname_len, NULL, 0);
+}