4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * All rights reserved. This program and the accompanying materials
7 * are made available under the terms of the GNU Lesser General Public License
8 * (LGPL) version 2.1 or (at your discretion) any later version.
9 * (LGPL) version 2.1 accompanies this distribution, and is available at
10 * http://www.gnu.org/licenses/lgpl-2.1.html
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
20 * libcfs/libcfs/utils/param.c
22 * This code handles user interaction with the configuration interface
23 * to the Lustre file system to fine tune it.
33 #include <linux/limits.h>
34 #include <libcfs/util/string.h>
37 * Get parameter path matching the pattern
39 * \param[out] paths glob_t structure used to hold the final result
40 * \param[in] pattern the pattern containing sprintf format specifiers
41 * which will be used to create the path to match
43 * The \param pattern is appended to the default path glob to complete the
44 * absolute path to the file the caller is requesting. If the results point
45 * to one or more files that exist those results are stored in the \param
46 * paths glob_t structure that is passed by the caller.
48 * Lustre tunables traditionally were in /proc/{sys,fs}/{lnet,lustre}
49 * but in upstream kernels starting with Linux 4.2 these parameters
50 * have been moved to /sys/fs/lustre and /sys/kernel/debug/{lnet,lustre}
51 * so the user tools need to check both locations.
53 * \retval 0 for success, with results stored in \param paths.
54 * \retval -1 for failure with errno set to report the reason.
57 cfs_get_param_paths(glob_t *paths, const char *pattern, ...)
59 char path[PATH_MAX] = "{/sys/{fs,kernel/debug}/{lnet,lustre}/,"
60 "/proc/{fs,sys}/{lnet,lustre}/}";
61 size_t len = strlen(path);
66 va_start(args, pattern);
67 rc = vsnprintf(buf, sizeof(buf), pattern, args);
71 } else if (rc >= sizeof(buf)) {
77 if (strlcat(path, buf, sizeof(path)) != len) {
82 rc = glob(path, GLOB_BRACE, NULL, paths);