1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017 Kyle J. Kneitinger <[email protected]>
5 * Copyright (c) 2018 Kyle Evans <[email protected]>
6 * Copyright (c) 2019 Wes Maag <[email protected]>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include "be.h"
35 #include "be_impl.h"
36
37 struct be_mountcheck_info {
38 const char *path;
39 char *name;
40 };
41
42 struct be_mount_info {
43 libbe_handle_t *lbh;
44 const char *be;
45 const char *mountpoint;
46 int mntflags;
47 int deepmount;
48 int depth;
49 };
50
51 static int
be_mountcheck_cb(zfs_handle_t * zfs_hdl,void * data)52 be_mountcheck_cb(zfs_handle_t *zfs_hdl, void *data)
53 {
54 struct be_mountcheck_info *info;
55 char *mountpoint;
56
57 if (data == NULL)
58 return (1);
59 info = (struct be_mountcheck_info *)data;
60 if (!zfs_is_mounted(zfs_hdl, &mountpoint))
61 return (0);
62 if (strcmp(mountpoint, info->path) == 0) {
63 info->name = strdup(zfs_get_name(zfs_hdl));
64 free(mountpoint);
65 return (1);
66 }
67 free(mountpoint);
68 return (0);
69 }
70
71 /*
72 * Called from be_mount, uses the given zfs_handle and attempts to
73 * mount it at the passed mountpoint. If the deepmount flag is set, continue
74 * calling the function for each child dataset.
75 */
76 static int
be_mount_iter(zfs_handle_t * zfs_hdl,void * data)77 be_mount_iter(zfs_handle_t *zfs_hdl, void *data)
78 {
79 int err;
80 char *mountpoint;
81 char tmp[BE_MAXPATHLEN], zfs_mnt[BE_MAXPATHLEN];
82 struct be_mount_info *info;
83 char opt;
84
85 info = (struct be_mount_info *)data;
86
87 if (zfs_is_mounted(zfs_hdl, &mountpoint)) {
88 free(mountpoint);
89 return (0);
90 }
91
92 /*
93 * canmount and mountpoint are both ignored for the BE dataset, because
94 * the rest of the system (kernel and loader) will effectively do the
95 * same.
96 */
97 if (info->depth == 0) {
98 snprintf(tmp, BE_MAXPATHLEN, "%s", info->mountpoint);
99 } else {
100 if (zfs_prop_get_int(zfs_hdl, ZFS_PROP_CANMOUNT) ==
101 ZFS_CANMOUNT_OFF)
102 return (0);
103
104 if (zfs_prop_get(zfs_hdl, ZFS_PROP_MOUNTPOINT, zfs_mnt,
105 BE_MAXPATHLEN, NULL, NULL, 0, 1))
106 return (1);
107
108 /*
109 * We've encountered mountpoint=none at some intermediate
110 * dataset (e.g. zroot/var) that will have children that may
111 * need to be mounted. Skip mounting it, but iterate through
112 * the children.
113 */
114 if (strcmp("none", zfs_mnt) == 0)
115 goto skipmount;
116
117 mountpoint = be_mountpoint_augmented(info->lbh, zfs_mnt);
118 snprintf(tmp, BE_MAXPATHLEN, "%s%s", info->mountpoint,
119 mountpoint);
120 }
121
122 opt = '\0';
123 if ((err = zmount(zfs_get_name(zfs_hdl), tmp, info->mntflags,
124 __DECONST(char *, MNTTYPE_ZFS), NULL, 0, &opt, 1)) != 0) {
125 switch (errno) {
126 case ENAMETOOLONG:
127 return (set_error(info->lbh, BE_ERR_PATHLEN));
128 case ELOOP:
129 case ENOENT:
130 case ENOTDIR:
131 return (set_error(info->lbh, BE_ERR_BADPATH));
132 case EPERM:
133 return (set_error(info->lbh, BE_ERR_PERMS));
134 case EBUSY:
135 return (set_error(info->lbh, BE_ERR_PATHBUSY));
136 default:
137 return (set_error(info->lbh, BE_ERR_UNKNOWN));
138 }
139 }
140
141 if (!info->deepmount)
142 return (0);
143
144 skipmount:
145 ++info->depth;
146 err = zfs_iter_filesystems(zfs_hdl, be_mount_iter, info);
147 --info->depth;
148 return (err);
149 }
150
151
152 static int
be_umount_iter(zfs_handle_t * zfs_hdl,void * data)153 be_umount_iter(zfs_handle_t *zfs_hdl, void *data)
154 {
155
156 int err;
157 char *mountpoint;
158 struct be_mount_info *info;
159
160 info = (struct be_mount_info *)data;
161
162 ++info->depth;
163 if((err = zfs_iter_filesystems(zfs_hdl, be_umount_iter, info)) != 0) {
164 return (err);
165 }
166 --info->depth;
167
168 if (!zfs_is_mounted(zfs_hdl, &mountpoint)) {
169 return (0);
170 }
171 free(mountpoint);
172
173 if (zfs_unmount(zfs_hdl, NULL, info->mntflags) != 0) {
174 switch (errno) {
175 case ENAMETOOLONG:
176 return (set_error(info->lbh, BE_ERR_PATHLEN));
177 case ELOOP:
178 case ENOENT:
179 case ENOTDIR:
180 return (set_error(info->lbh, BE_ERR_BADPATH));
181 case EPERM:
182 return (set_error(info->lbh, BE_ERR_PERMS));
183 case EBUSY:
184 return (set_error(info->lbh, BE_ERR_PATHBUSY));
185 default:
186 return (set_error(info->lbh, BE_ERR_UNKNOWN));
187 }
188 }
189 return (0);
190 }
191
192 /*
193 * usage
194 */
195 int
be_mounted_at(libbe_handle_t * lbh,const char * path,nvlist_t * details)196 be_mounted_at(libbe_handle_t *lbh, const char *path, nvlist_t *details)
197 {
198 char be[BE_MAXPATHLEN];
199 zfs_handle_t *root_hdl;
200 struct be_mountcheck_info info;
201 prop_data_t propinfo;
202
203 bzero(&be, BE_MAXPATHLEN);
204 if ((root_hdl = zfs_open(lbh->lzh, lbh->root,
205 ZFS_TYPE_FILESYSTEM)) == NULL)
206 return (BE_ERR_ZFSOPEN);
207
208 info.path = path;
209 info.name = NULL;
210 zfs_iter_filesystems(root_hdl, be_mountcheck_cb, &info);
211 zfs_close(root_hdl);
212
213 if (info.name != NULL) {
214 if (details != NULL) {
215 if ((root_hdl = zfs_open(lbh->lzh, lbh->root,
216 ZFS_TYPE_FILESYSTEM)) == NULL) {
217 free(info.name);
218 return (BE_ERR_ZFSOPEN);
219 }
220
221 propinfo.lbh = lbh;
222 propinfo.list = details;
223 propinfo.single_object = false;
224 prop_list_builder_cb(root_hdl, &propinfo);
225 zfs_close(root_hdl);
226 }
227 free(info.name);
228 return (0);
229 }
230 return (1);
231 }
232
233 /*
234 * usage
235 */
236 int
be_mount(libbe_handle_t * lbh,char * bootenv,char * mountpoint,int flags,char * result_loc)237 be_mount(libbe_handle_t *lbh, char *bootenv, char *mountpoint, int flags,
238 char *result_loc)
239 {
240 char be[BE_MAXPATHLEN];
241 char mnt_temp[BE_MAXPATHLEN];
242 int mntflags, mntdeep;
243 int err;
244 struct be_mount_info info;
245 zfs_handle_t *zhdl;
246
247 if ((err = be_root_concat(lbh, bootenv, be)) != 0)
248 return (set_error(lbh, err));
249
250 if ((err = be_exists(lbh, bootenv)) != 0)
251 return (set_error(lbh, err));
252
253 if (is_mounted(lbh->lzh, be, NULL))
254 return (set_error(lbh, BE_ERR_MOUNTED));
255
256 mntdeep = (flags & BE_MNT_DEEP) ? 1 : 0;
257 mntflags = (flags & BE_MNT_FORCE) ? MNT_FORCE : 0;
258
259 /* Create mountpoint if it is not specified */
260 if (mountpoint == NULL) {
261 strlcpy(mnt_temp, "/tmp/be_mount.XXXX", sizeof(mnt_temp));
262 if (mkdtemp(mnt_temp) == NULL)
263 return (set_error(lbh, BE_ERR_IO));
264 }
265
266 if ((zhdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
267 return (set_error(lbh, BE_ERR_ZFSOPEN));
268
269 info.lbh = lbh;
270 info.be = be;
271 info.mountpoint = (mountpoint == NULL) ? mnt_temp : mountpoint;
272 info.mntflags = mntflags;
273 info.deepmount = mntdeep;
274 info.depth = 0;
275
276 if((err = be_mount_iter(zhdl, &info) != 0)) {
277 zfs_close(zhdl);
278 return (err);
279 }
280 zfs_close(zhdl);
281
282 if (result_loc != NULL)
283 strlcpy(result_loc, mountpoint == NULL ? mnt_temp : mountpoint,
284 BE_MAXPATHLEN);
285
286 return (BE_ERR_SUCCESS);
287 }
288
289 /*
290 * usage
291 */
292 int
be_unmount(libbe_handle_t * lbh,char * bootenv,int flags)293 be_unmount(libbe_handle_t *lbh, char *bootenv, int flags)
294 {
295 int err;
296 char be[BE_MAXPATHLEN];
297 zfs_handle_t *root_hdl;
298 struct be_mount_info info;
299
300 if ((err = be_root_concat(lbh, bootenv, be)) != 0)
301 return (set_error(lbh, err));
302
303 if ((root_hdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
304 return (set_error(lbh, BE_ERR_ZFSOPEN));
305
306 info.lbh = lbh;
307 info.be = be;
308 info.mountpoint = NULL;
309 info.mntflags = (flags & BE_MNT_FORCE) ? MS_FORCE : 0;
310 info.depth = 0;
311
312 if ((err = be_umount_iter(root_hdl, &info)) != 0) {
313 zfs_close(root_hdl);
314 return (err);
315 }
316
317 zfs_close(root_hdl);
318 return (BE_ERR_SUCCESS);
319 }
320
321 /*
322 * This function will blow away the input buffer as needed if we're discovered
323 * to be looking at a root-mount. If the mountpoint is naturally beyond the
324 * root, however, the buffer may be left intact and a pointer to the section
325 * past altroot will be returned instead for the caller's perusal.
326 */
327 char *
be_mountpoint_augmented(libbe_handle_t * lbh,char * mountpoint)328 be_mountpoint_augmented(libbe_handle_t *lbh, char *mountpoint)
329 {
330
331 if (lbh->altroot_len == 0)
332 return (mountpoint);
333 if (mountpoint == NULL || *mountpoint == '\0')
334 return (mountpoint);
335
336 if (mountpoint[lbh->altroot_len] == '\0') {
337 *(mountpoint + 1) = '\0';
338 return (mountpoint);
339 } else
340 return (mountpoint + lbh->altroot_len);
341 }
342