LU-5969 lustreapi: replace llapi_get_version()

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

diff --git a/lustre/utils/liblustreapi_util.c b/lustre/utils/liblustreapi_util.c
index efd9d3c..db84f98 100644 (file)
--- a/lustre/utils/liblustreapi_util.c
+++ b/lustre/utils/liblustreapi_util.c
@@ -5,6 +5,8 @@
  *
  * (C) Copyright (c) 2015, Cray Inc, all rights reserved.
  *
+ * Copyright (c) 2016 Intel Corporation.
+ *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the GNU Lesser General Public License
  * LGPL version 2.1 or (at your discretion) any later version.
@@ -26,26 +28,39 @@
  * Author: Frank Zago <fzago@cray.com>
  */
 
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
-#include <stdbool.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <fcntl.h>
 #include <sys/syscall.h>
+#include <lustre/lustreapi.h>
+#include <libcfs/util/string.h>        /* only needed for compat strlcpy() */
+#include <lustre_ver.h>                /* only until LUSTRE_VERSION_CODE is gone */
+#include "lustreapi_internal.h"
 
 /*
  * Indicate whether the liblustreapi_init() constructor below has run or not.
  *
- * This can be used by external programs to ensure if the initialization
+ * This can be used by external programs to ensure that the initialization
  * mechanism has actually worked.
  */
 bool liblustreapi_initialized;
 
 
-/*
- * Initializes the library
+/**
+ * Initialize the library once at startup.
+ *
+ * Initializes the random number generator (random()). Get
+ * data from different places in case one of them fails. This
+ * is enough to get reasonably random numbers, but is not
+ * strong enough to be used for cryptography.
  */
 static __attribute__ ((constructor)) void liblustreapi_init(void)
 {
@@ -53,10 +68,6 @@ static __attribute__ ((constructor)) void liblustreapi_init(void)
        struct timeval  tv;
        int             fd;
 
-       /* Initializes the random number generator (random()). Get
-        * data from different places in case one of them fails. This
-        * is enough to get reasonably random numbers, but is not
-        * strong enough to be used for cryptography. */
        seed = syscall(SYS_gettid);
 
        if (gettimeofday(&tv, NULL) == 0) {
@@ -77,3 +88,94 @@ static __attribute__ ((constructor)) void liblustreapi_init(void)
        srandom(seed);
        liblustreapi_initialized = true;
 }
+
+/**
+ * Return the release version for the Lustre modules, e.g. 2.6.92.
+ *
+ * The "version" file in /proc currently returns only the line:
+ * lustre: 2.8.52
+ *
+ * but in the past it also returned more lines that should be ignored:
+ * kernel: patchless_client
+ * build: v2_6_92_0-gadb3ee4-2.6.32-431.29.2.el6_lustre.g36cd22b.x86_64
+ *
+ * \param version[in,out]      buffer to store build version string
+ * \param version_size[in]     size of \a version
+ *
+ * \retval                     0 on success
+ * \retval                     -1 on failure, errno set
+ */
+int llapi_get_version_string(char *version, unsigned int version_size)
+{
+       char buffer[4096];
+       char *ptr;
+       int rc;
+
+       if (version == NULL || version_size == 0) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       rc = get_lustre_param_value(NULL, NULL, FILTER_BY_NONE, buffer,
+                                   "version", sizeof(buffer));
+       if (rc < 0) {
+               errno = -rc;
+               return -1;
+       }
+
+       ptr = strstr(buffer, "lustre:");
+       if (ptr != NULL) {
+               llapi_chomp_string(ptr);
+               ptr += strlen("lustre:");
+               while (*ptr == ' ' || *ptr == '\t')
+                       ptr++;
+
+               if (strlcpy(version, ptr, version_size) >= version_size) {
+                       errno = EOVERFLOW;
+                       return -1;
+               }
+       } else {
+               errno = ENODATA;
+               return -1;
+       }
+
+       return 0;
+}
+
+#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 4, 53, 0)
+/**
+ * Return the build version of the Lustre code.
+ *
+ * The **version argument is pointless, so llapi_get_version_string() is
+ * better to use in the future, but give users a few versions to fix * it.
+ *
+ * \param buffer[in]           temporary buffer to hold version string
+ * \param buffer_size[in]      length of the \a buffer
+ * \param version[out]         pointer to the start of build version string
+ *
+ * \retval                     0 on success
+ * \retval                     -ve errno on failure
+ */
+int llapi_get_version(char *buffer, int buffer_size, char **version)
+{
+       int rc;
+#if LUSTRE_VERSION_CODE > OBD_OCD_VERSION(2, 8, 53, 0)
+       static bool printed;
+       if (!printed) {
+               fprintf(stderr,
+                       "%s deprecated, use llapi_get_version_string()\n",
+                       __func__);
+               printed = true;
+       }
+#endif
+
+       rc = llapi_get_version_string(buffer, buffer_size);
+       /* keep old return style for this legacy function */
+       if (rc == -1)
+               rc = -errno;
+       else
+               *version = buffer;
+
+       return rc;
+}
+#endif /* LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 4, 53, 0) */