xref: /freebsd/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_util_os.c (revision b1c1ee4429fcca8f69873a8be66184e68e1b19d7)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (c) 2021 Klara, Inc.
25  */
26 
27 #include <alloca.h>
28 #include <errno.h>
29 #include <fcntl.h>
30 #include <libintl.h>
31 #include <math.h>
32 #include <poll.h>
33 #include <stdarg.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <strings.h>
37 #include <sys/inotify.h>
38 #include <sys/mntent.h>
39 #include <sys/mnttab.h>
40 #include <sys/stat.h>
41 #include <sys/timerfd.h>
42 #include <sys/types.h>
43 #include <sys/wait.h>
44 #include <unistd.h>
45 
46 #include <libzfs.h>
47 #include <libzfs_core.h>
48 
49 #include "../../libzfs_impl.h"
50 #include "zfs_prop.h"
51 #include <libzutil.h>
52 #include <sys/zfs_sysfs.h>
53 
54 #define	ZDIFF_SHARESDIR		"/.zfs/shares/"
55 
56 const char *
libzfs_error_init(int error)57 libzfs_error_init(int error)
58 {
59 	switch (error) {
60 	case ENXIO:
61 		return (dgettext(TEXT_DOMAIN, "The ZFS modules are not "
62 		    "loaded.\nTry running 'modprobe zfs' as root "
63 		    "to load them."));
64 	case ENOENT:
65 		return (dgettext(TEXT_DOMAIN, "/dev/zfs and /proc/self/mounts "
66 		    "are required.\nTry running 'udevadm trigger' and 'mount "
67 		    "-t proc proc /proc' as root."));
68 	case ENOEXEC:
69 		return (dgettext(TEXT_DOMAIN, "The ZFS modules cannot be "
70 		    "auto-loaded.\nTry running 'modprobe zfs' as "
71 		    "root to manually load them."));
72 	case EACCES:
73 		return (dgettext(TEXT_DOMAIN, "Permission denied the "
74 		    "ZFS utilities must be run as root."));
75 	default:
76 		return (dgettext(TEXT_DOMAIN, "Failed to initialize the "
77 		    "libzfs library."));
78 	}
79 }
80 
81 /*
82  * zfs(4) is loaded by udev if there's a fstype=zfs device present,
83  * but if there isn't, load them automatically;
84  * always wait for ZFS_DEV to appear via udev.
85  *
86  * Environment variables:
87  * - ZFS_MODULE_TIMEOUT="<seconds>" - Seconds to wait for ZFS_DEV,
88  *                                    defaults to 10, max. 10 min.
89  */
90 int
libzfs_load_module(void)91 libzfs_load_module(void)
92 {
93 	if (access(ZFS_DEV, F_OK) == 0)
94 		return (0);
95 
96 	if (access(ZFS_SYSFS_DIR, F_OK) != 0) {
97 		char *argv[] = {(char *)"modprobe", (char *)"zfs", NULL};
98 		if (libzfs_run_process("modprobe", argv, 0))
99 			return (ENOEXEC);
100 
101 		if (access(ZFS_SYSFS_DIR, F_OK) != 0)
102 			return (ENXIO);
103 	}
104 
105 	const char *timeout_str = getenv("ZFS_MODULE_TIMEOUT");
106 	int seconds = 10;
107 	if (timeout_str)
108 		seconds = MIN(strtol(timeout_str, NULL, 0), 600);
109 	struct itimerspec timeout = {.it_value.tv_sec = MAX(seconds, 0)};
110 
111 	int ino = inotify_init1(IN_CLOEXEC);
112 	if (ino == -1)
113 		return (ENOENT);
114 	inotify_add_watch(ino, ZFS_DEVDIR, IN_CREATE);
115 
116 	if (access(ZFS_DEV, F_OK) == 0) {
117 		close(ino);
118 		return (0);
119 	} else if (seconds == 0) {
120 		close(ino);
121 		return (ENOENT);
122 	}
123 
124 	size_t evsz = sizeof (struct inotify_event) + NAME_MAX + 1;
125 	struct inotify_event *ev = alloca(evsz);
126 
127 	int tout = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
128 	if (tout == -1) {
129 		close(ino);
130 		return (ENOENT);
131 	}
132 	timerfd_settime(tout, 0, &timeout, NULL);
133 
134 	int ret = ENOENT;
135 	struct pollfd pfds[] = {
136 		{.fd = ino, .events = POLLIN},
137 		{.fd = tout, .events = POLLIN},
138 	};
139 	while (poll(pfds, ARRAY_SIZE(pfds), -1) != -1) {
140 		if (pfds[0].revents & POLLIN) {
141 			verify(read(ino, ev, evsz) >
142 			    sizeof (struct inotify_event));
143 			if (strncmp(ev->name, &ZFS_DEV[sizeof (ZFS_DEVDIR)],
144 			    ev->len) == 0) {
145 				ret = 0;
146 				break;
147 			}
148 		}
149 		if (pfds[1].revents & POLLIN)
150 			break;
151 	}
152 	close(tout);
153 	close(ino);
154 	return (ret);
155 }
156 
157 int
find_shares_object(differ_info_t * di)158 find_shares_object(differ_info_t *di)
159 {
160 	char fullpath[MAXPATHLEN];
161 	struct stat64 sb = { 0 };
162 
163 	(void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN);
164 	(void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN);
165 
166 	if (stat64(fullpath, &sb) != 0) {
167 		(void) snprintf(di->errbuf, sizeof (di->errbuf),
168 		    dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath);
169 		return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf));
170 	}
171 
172 	di->shares = (uint64_t)sb.st_ino;
173 	return (0);
174 }
175 
176 int
zfs_destroy_snaps_nvl_os(libzfs_handle_t * hdl,nvlist_t * snaps)177 zfs_destroy_snaps_nvl_os(libzfs_handle_t *hdl, nvlist_t *snaps)
178 {
179 	(void) hdl, (void) snaps;
180 	return (0);
181 }
182 
183 /*
184  * Return allocated loaded module version, or NULL on error (with errno set)
185  */
186 char *
zfs_version_kernel(void)187 zfs_version_kernel(void)
188 {
189 	FILE *f = fopen(ZFS_SYSFS_DIR "/version", "re");
190 	if (f == NULL)
191 		return (NULL);
192 
193 	char *ret = NULL;
194 	size_t l;
195 	ssize_t read;
196 	if ((read = getline(&ret, &l, f)) == -1) {
197 		int err = errno;
198 		fclose(f);
199 		errno = err;
200 		return (NULL);
201 	}
202 
203 	fclose(f);
204 	if (ret[read - 1] == '\n')
205 		ret[read - 1] = '\0';
206 	return (ret);
207 }
208 
209 /*
210  * Add or delete the given filesystem to/from the given user namespace.
211  */
212 int
zfs_userns(zfs_handle_t * zhp,const char * nspath,int attach)213 zfs_userns(zfs_handle_t *zhp, const char *nspath, int attach)
214 {
215 	libzfs_handle_t *hdl = zhp->zfs_hdl;
216 	zfs_cmd_t zc = {"\0"};
217 	char errbuf[1024];
218 	unsigned long cmd;
219 	int ret;
220 
221 	if (attach) {
222 		(void) snprintf(errbuf, sizeof (errbuf),
223 		    dgettext(TEXT_DOMAIN, "cannot add '%s' to namespace"),
224 		    zhp->zfs_name);
225 	} else {
226 		(void) snprintf(errbuf, sizeof (errbuf),
227 		    dgettext(TEXT_DOMAIN, "cannot remove '%s' from namespace"),
228 		    zhp->zfs_name);
229 	}
230 
231 	switch (zhp->zfs_type) {
232 	case ZFS_TYPE_VOLUME:
233 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
234 		    "volumes can not be namespaced"));
235 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
236 	case ZFS_TYPE_SNAPSHOT:
237 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
238 		    "snapshots can not be namespaced"));
239 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
240 	case ZFS_TYPE_BOOKMARK:
241 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
242 		    "bookmarks can not be namespaced"));
243 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
244 	case ZFS_TYPE_VDEV:
245 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
246 		    "vdevs can not be namespaced"));
247 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
248 	case ZFS_TYPE_INVALID:
249 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
250 		    "invalid zfs_type_t: ZFS_TYPE_INVALID"));
251 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
252 	case ZFS_TYPE_POOL:
253 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
254 		    "pools can not be namespaced"));
255 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
256 	case ZFS_TYPE_FILESYSTEM:
257 		break;
258 	}
259 	assert(zhp->zfs_type == ZFS_TYPE_FILESYSTEM);
260 
261 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
262 	zc.zc_objset_type = DMU_OST_ZFS;
263 	zc.zc_cleanup_fd = open(nspath, O_RDONLY);
264 	if (zc.zc_cleanup_fd < 0) {
265 		return (zfs_error(hdl, EZFS_NOT_USER_NAMESPACE, errbuf));
266 	}
267 
268 	cmd = attach ? ZFS_IOC_USERNS_ATTACH : ZFS_IOC_USERNS_DETACH;
269 	if ((ret = zfs_ioctl(hdl, cmd, &zc)) != 0)
270 		zfs_standard_error(hdl, errno, errbuf);
271 
272 	(void) close(zc.zc_cleanup_fd);
273 
274 	return (ret);
275 }
276