1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
5 * Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
6 * Copyright (c) 2019 Wes Maag <wes@jwmaag.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 #include <sys/mntent.h>
32
33 #include "be.h"
34 #include "be_impl.h"
35
36 struct be_mountcheck_info {
37 const char *path;
38 char *name;
39 };
40
41 struct be_mount_info {
42 libbe_handle_t *lbh;
43 const char *be;
44 const char *mountpoint;
45 int mntflags;
46 int deepmount;
47 int depth;
48 };
49
50 static int
be_mountcheck_cb(zfs_handle_t * zfs_hdl,void * data)51 be_mountcheck_cb(zfs_handle_t *zfs_hdl, void *data)
52 {
53 struct be_mountcheck_info *info;
54 char *mountpoint;
55
56 if (data == NULL)
57 return (1);
58 info = (struct be_mountcheck_info *)data;
59 if (!zfs_is_mounted(zfs_hdl, &mountpoint))
60 return (0);
61 if (strcmp(mountpoint, info->path) == 0) {
62 info->name = strdup(zfs_get_name(zfs_hdl));
63 free(mountpoint);
64 return (1);
65 }
66 free(mountpoint);
67 return (0);
68 }
69
70 /*
71 * Called from be_mount, uses the given zfs_handle and attempts to
72 * mount it at the passed mountpoint. If the deepmount flag is set, continue
73 * calling the function for each child dataset.
74 */
75 static int
be_mount_iter(zfs_handle_t * zfs_hdl,void * data)76 be_mount_iter(zfs_handle_t *zfs_hdl, void *data)
77 {
78 int err;
79 char *mountpoint;
80 char tmp[BE_MAXPATHLEN], zfs_mnt[BE_MAXPATHLEN];
81 struct be_mount_info *info;
82
83 info = (struct be_mount_info *)data;
84
85 if (zfs_is_mounted(zfs_hdl, &mountpoint)) {
86 free(mountpoint);
87 return (0);
88 }
89
90 /*
91 * canmount and mountpoint are both ignored for the BE dataset, because
92 * the rest of the system (kernel and loader) will effectively do the
93 * same.
94 */
95 if (info->depth == 0) {
96 snprintf(tmp, BE_MAXPATHLEN, "%s", info->mountpoint);
97 } else {
98 if (zfs_prop_get_int(zfs_hdl, ZFS_PROP_CANMOUNT) ==
99 ZFS_CANMOUNT_OFF)
100 return (0);
101
102 if (zfs_prop_get(zfs_hdl, ZFS_PROP_MOUNTPOINT, zfs_mnt,
103 BE_MAXPATHLEN, NULL, NULL, 0, 1))
104 return (1);
105
106 /*
107 * We've encountered mountpoint=none at some intermediate
108 * dataset (e.g. zroot/var) that will have children that may
109 * need to be mounted. Skip mounting it, but iterate through
110 * the children.
111 */
112 if (strcmp("none", zfs_mnt) == 0)
113 goto skipmount;
114
115 mountpoint = be_mountpoint_augmented(info->lbh, zfs_mnt);
116 snprintf(tmp, BE_MAXPATHLEN, "%s%s", info->mountpoint,
117 mountpoint);
118 }
119
120 if ((err = zfs_mount_at(zfs_hdl, NULL, info->mntflags, tmp)) != 0) {
121 switch (errno) {
122 case ENAMETOOLONG:
123 return (set_error(info->lbh, BE_ERR_PATHLEN));
124 case ELOOP:
125 case ENOENT:
126 case ENOTDIR:
127 return (set_error(info->lbh, BE_ERR_BADPATH));
128 case EPERM:
129 return (set_error(info->lbh, BE_ERR_PERMS));
130 case EBUSY:
131 return (set_error(info->lbh, BE_ERR_PATHBUSY));
132 default:
133 return (set_error(info->lbh, BE_ERR_UNKNOWN));
134 }
135 }
136
137 if (!info->deepmount)
138 return (0);
139
140 skipmount:
141 ++info->depth;
142 err = zfs_iter_filesystems(zfs_hdl, be_mount_iter, info);
143 --info->depth;
144 return (err);
145 }
146
147
148 static int
be_umount_iter(zfs_handle_t * zfs_hdl,void * data)149 be_umount_iter(zfs_handle_t *zfs_hdl, void *data)
150 {
151
152 int err;
153 char *mountpoint;
154 struct be_mount_info *info;
155
156 info = (struct be_mount_info *)data;
157
158 ++info->depth;
159 if((err = zfs_iter_filesystems(zfs_hdl, be_umount_iter, info)) != 0) {
160 return (err);
161 }
162 --info->depth;
163
164 if (!zfs_is_mounted(zfs_hdl, &mountpoint)) {
165 return (0);
166 }
167 free(mountpoint);
168
169 if (zfs_unmount(zfs_hdl, NULL, info->mntflags) != 0) {
170 switch (errno) {
171 case ENAMETOOLONG:
172 return (set_error(info->lbh, BE_ERR_PATHLEN));
173 case ELOOP:
174 case ENOENT:
175 case ENOTDIR:
176 return (set_error(info->lbh, BE_ERR_BADPATH));
177 case EPERM:
178 return (set_error(info->lbh, BE_ERR_PERMS));
179 case EBUSY:
180 return (set_error(info->lbh, BE_ERR_PATHBUSY));
181 default:
182 return (set_error(info->lbh, BE_ERR_UNKNOWN));
183 }
184 }
185 return (0);
186 }
187
188 /*
189 * usage
190 */
191 int
be_mounted_at(libbe_handle_t * lbh,const char * path,nvlist_t * details)192 be_mounted_at(libbe_handle_t *lbh, const char *path, nvlist_t *details)
193 {
194 char be[BE_MAXPATHLEN];
195 zfs_handle_t *root_hdl;
196 struct be_mountcheck_info info;
197 prop_data_t propinfo;
198
199 bzero(&be, BE_MAXPATHLEN);
200 if ((root_hdl = zfs_open(lbh->lzh, lbh->root,
201 ZFS_TYPE_FILESYSTEM)) == NULL)
202 return (BE_ERR_ZFSOPEN);
203
204 info.path = path;
205 info.name = NULL;
206 zfs_iter_filesystems(root_hdl, be_mountcheck_cb, &info);
207 zfs_close(root_hdl);
208
209 if (info.name != NULL) {
210 if (details != NULL) {
211 if ((root_hdl = zfs_open(lbh->lzh, info.name,
212 ZFS_TYPE_FILESYSTEM)) == NULL) {
213 free(info.name);
214 return (BE_ERR_ZFSOPEN);
215 }
216
217 propinfo.lbh = lbh;
218 propinfo.list = details;
219 propinfo.single_object = false;
220 propinfo.bootonce = NULL;
221 prop_list_builder_cb(root_hdl, &propinfo);
222 zfs_close(root_hdl);
223 }
224 free(info.name);
225 return (0);
226 }
227 return (1);
228 }
229
230 /*
231 * usage
232 */
233 int
be_mount(libbe_handle_t * lbh,const char * bootenv,const char * mountpoint,int flags,char * result_loc)234 be_mount(libbe_handle_t *lbh, const char *bootenv, const char *mountpoint,
235 int flags, char *result_loc)
236 {
237 char be[BE_MAXPATHLEN];
238 char mnt_temp[BE_MAXPATHLEN];
239 int mntflags, mntdeep;
240 int err;
241 struct be_mount_info info;
242 zfs_handle_t *zhdl;
243
244 if ((err = be_root_concat(lbh, bootenv, be)) != 0)
245 return (set_error(lbh, err));
246
247 if ((err = be_exists(lbh, bootenv)) != 0)
248 return (set_error(lbh, err));
249
250 if (is_mounted(lbh->lzh, be, NULL))
251 return (set_error(lbh, BE_ERR_MOUNTED));
252
253 mntdeep = (flags & BE_MNT_DEEP) ? 1 : 0;
254 mntflags = (flags & BE_MNT_FORCE) ? MNT_FORCE : 0;
255
256 /* Create mountpoint if it is not specified */
257 if (mountpoint == NULL) {
258 strlcpy(mnt_temp, "/tmp/be_mount.XXXX", sizeof(mnt_temp));
259 if (mkdtemp(mnt_temp) == NULL)
260 return (set_error(lbh, BE_ERR_IO));
261 }
262
263 if ((zhdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
264 return (set_error(lbh, BE_ERR_ZFSOPEN));
265
266 info.lbh = lbh;
267 info.be = be;
268 info.mountpoint = (mountpoint == NULL) ? mnt_temp : mountpoint;
269 info.mntflags = mntflags;
270 info.deepmount = mntdeep;
271 info.depth = 0;
272
273 if((err = be_mount_iter(zhdl, &info) != 0)) {
274 zfs_close(zhdl);
275 return (err);
276 }
277 zfs_close(zhdl);
278
279 if (result_loc != NULL)
280 strlcpy(result_loc, mountpoint == NULL ? mnt_temp : mountpoint,
281 BE_MAXPATHLEN);
282
283 return (BE_ERR_SUCCESS);
284 }
285
286 /*
287 * usage
288 */
289 int
be_unmount(libbe_handle_t * lbh,const char * bootenv,int flags)290 be_unmount(libbe_handle_t *lbh, const char *bootenv, int flags)
291 {
292 int err;
293 char be[BE_MAXPATHLEN];
294 zfs_handle_t *root_hdl;
295 struct be_mount_info info;
296
297 if ((err = be_root_concat(lbh, bootenv, be)) != 0)
298 return (set_error(lbh, err));
299
300 if ((root_hdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
301 return (set_error(lbh, BE_ERR_ZFSOPEN));
302
303 info.lbh = lbh;
304 info.be = be;
305 info.mountpoint = NULL;
306 info.mntflags = (flags & BE_MNT_FORCE) ? MS_FORCE : 0;
307 info.depth = 0;
308
309 if ((err = be_umount_iter(root_hdl, &info)) != 0) {
310 zfs_close(root_hdl);
311 return (err);
312 }
313
314 zfs_close(root_hdl);
315 return (BE_ERR_SUCCESS);
316 }
317
318 /*
319 * This function will blow away the input buffer as needed if we're discovered
320 * to be looking at a root-mount. If the mountpoint is naturally beyond the
321 * root, however, the buffer may be left intact and a pointer to the section
322 * past altroot will be returned instead for the caller's perusal.
323 */
324 char *
be_mountpoint_augmented(libbe_handle_t * lbh,char * mountpoint)325 be_mountpoint_augmented(libbe_handle_t *lbh, char *mountpoint)
326 {
327
328 if (lbh->altroot_len == 0)
329 return (mountpoint);
330 if (mountpoint == NULL || *mountpoint == '\0')
331 return (mountpoint);
332
333 if (mountpoint[lbh->altroot_len] == '\0') {
334 *(mountpoint + 1) = '\0';
335 return (mountpoint);
336 } else
337 return (mountpoint + lbh->altroot_len);
338 }
339