]>
Commit | Line | Data |
---|---|---|
18c528e9 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
18c528e9 | 2 | |
ac83e5ae | 3 | #include <sys/file.h> |
f5947a5e | 4 | #include <unistd.h> |
18c528e9 LP |
5 | |
6 | #include "alloc-util.h" | |
7 | #include "blockdev-util.h" | |
8 | #include "btrfs-util.h" | |
9 | #include "dirent-util.h" | |
10 | #include "fd-util.h" | |
11 | #include "fileio.h" | |
f5947a5e | 12 | #include "missing_magic.h" |
3a47c40d | 13 | #include "parse-util.h" |
18c528e9 LP |
14 | #include "stat-util.h" |
15 | ||
16 | int block_get_whole_disk(dev_t d, dev_t *ret) { | |
17 | char p[SYS_BLOCK_PATH_MAX("/partition")]; | |
18 | _cleanup_free_ char *s = NULL; | |
3a47c40d | 19 | dev_t devt; |
18c528e9 LP |
20 | int r; |
21 | ||
22 | assert(ret); | |
23 | ||
51f14fa1 LP |
24 | if (major(d) == 0) |
25 | return -ENODEV; | |
26 | ||
18c528e9 LP |
27 | /* If it has a queue this is good enough for us */ |
28 | xsprintf_sys_block_path(p, "/queue", d); | |
29 | if (access(p, F_OK) >= 0) { | |
30 | *ret = d; | |
31 | return 0; | |
32 | } | |
6cba41ab LP |
33 | if (errno != ENOENT) |
34 | return -errno; | |
18c528e9 LP |
35 | |
36 | /* If it is a partition find the originating device */ | |
37 | xsprintf_sys_block_path(p, "/partition", d); | |
38 | if (access(p, F_OK) < 0) | |
d18b3009 | 39 | return -errno; |
18c528e9 LP |
40 | |
41 | /* Get parent dev_t */ | |
42 | xsprintf_sys_block_path(p, "/../dev", d); | |
43 | r = read_one_line_file(p, &s); | |
44 | if (r < 0) | |
45 | return r; | |
46 | ||
3a47c40d LP |
47 | r = parse_dev(s, &devt); |
48 | if (r < 0) | |
49 | return r; | |
18c528e9 LP |
50 | |
51 | /* Only return this if it is really good enough for us. */ | |
3a47c40d | 52 | xsprintf_sys_block_path(p, "/queue", devt); |
18c528e9 | 53 | if (access(p, F_OK) < 0) |
d18b3009 | 54 | return -errno; |
18c528e9 | 55 | |
3a47c40d | 56 | *ret = devt; |
a0ea1dee | 57 | return 1; |
18c528e9 LP |
58 | } |
59 | ||
db8728a6 LP |
60 | int get_block_device(const char *path, dev_t *ret) { |
61 | _cleanup_close_ int fd = -1; | |
18c528e9 | 62 | struct stat st; |
db8728a6 | 63 | int r; |
18c528e9 LP |
64 | |
65 | assert(path); | |
db8728a6 | 66 | assert(ret); |
18c528e9 | 67 | |
db8728a6 LP |
68 | /* Gets the block device directly backing a file system. If the block device is encrypted, returns |
69 | * the device mapper block device. */ | |
70 | ||
71 | fd = open(path, O_NOFOLLOW|O_CLOEXEC); | |
72 | if (fd < 0) | |
73 | return -errno; | |
18c528e9 | 74 | |
db8728a6 | 75 | if (fstat(fd, &st)) |
18c528e9 LP |
76 | return -errno; |
77 | ||
78 | if (major(st.st_dev) != 0) { | |
db8728a6 | 79 | *ret = st.st_dev; |
18c528e9 LP |
80 | return 1; |
81 | } | |
82 | ||
db8728a6 LP |
83 | r = btrfs_get_block_device_fd(fd, ret); |
84 | if (r > 0) | |
85 | return 1; | |
86 | if (r != -ENOTTY) /* not btrfs */ | |
87 | return r; | |
18c528e9 | 88 | |
db8728a6 | 89 | *ret = 0; |
18c528e9 LP |
90 | return 0; |
91 | } | |
92 | ||
880f09bd | 93 | int block_get_originating(dev_t dt, dev_t *ret) { |
18c528e9 LP |
94 | _cleanup_closedir_ DIR *d = NULL; |
95 | _cleanup_free_ char *t = NULL; | |
96 | char p[SYS_BLOCK_PATH_MAX("/slaves")]; | |
97 | struct dirent *de, *found = NULL; | |
880f09bd | 98 | const char *q; |
3a47c40d | 99 | dev_t devt; |
18c528e9 LP |
100 | int r; |
101 | ||
880f09bd LP |
102 | /* For the specified block device tries to chase it through the layers, in case LUKS-style DM stacking is used, |
103 | * trying to find the next underlying layer. */ | |
18c528e9 LP |
104 | |
105 | xsprintf_sys_block_path(p, "/slaves", dt); | |
106 | d = opendir(p); | |
880f09bd | 107 | if (!d) |
18c528e9 | 108 | return -errno; |
18c528e9 LP |
109 | |
110 | FOREACH_DIRENT_ALL(de, d, return -errno) { | |
111 | ||
112 | if (dot_or_dot_dot(de->d_name)) | |
113 | continue; | |
114 | ||
115 | if (!IN_SET(de->d_type, DT_LNK, DT_UNKNOWN)) | |
116 | continue; | |
117 | ||
118 | if (found) { | |
119 | _cleanup_free_ char *u = NULL, *v = NULL, *a = NULL, *b = NULL; | |
120 | ||
121 | /* We found a device backed by multiple other devices. We don't really support automatic | |
122 | * discovery on such setups, with the exception of dm-verity partitions. In this case there are | |
123 | * two backing devices: the data partition and the hash partition. We are fine with such | |
124 | * setups, however, only if both partitions are on the same physical device. Hence, let's | |
125 | * verify this. */ | |
126 | ||
657ee2d8 | 127 | u = path_join(p, de->d_name, "../dev"); |
18c528e9 LP |
128 | if (!u) |
129 | return -ENOMEM; | |
130 | ||
657ee2d8 | 131 | v = path_join(p, found->d_name, "../dev"); |
18c528e9 LP |
132 | if (!v) |
133 | return -ENOMEM; | |
134 | ||
135 | r = read_one_line_file(u, &a); | |
880f09bd LP |
136 | if (r < 0) |
137 | return log_debug_errno(r, "Failed to read %s: %m", u); | |
18c528e9 LP |
138 | |
139 | r = read_one_line_file(v, &b); | |
880f09bd LP |
140 | if (r < 0) |
141 | return log_debug_errno(r, "Failed to read %s: %m", v); | |
18c528e9 LP |
142 | |
143 | /* Check if the parent device is the same. If not, then the two backing devices are on | |
144 | * different physical devices, and we don't support that. */ | |
145 | if (!streq(a, b)) | |
880f09bd | 146 | return -ENOTUNIQ; |
18c528e9 LP |
147 | } |
148 | ||
149 | found = de; | |
150 | } | |
151 | ||
152 | if (!found) | |
880f09bd | 153 | return -ENOENT; |
18c528e9 LP |
154 | |
155 | q = strjoina(p, "/", found->d_name, "/dev"); | |
156 | ||
157 | r = read_one_line_file(q, &t); | |
18c528e9 LP |
158 | if (r < 0) |
159 | return r; | |
160 | ||
3a47c40d LP |
161 | r = parse_dev(t, &devt); |
162 | if (r < 0) | |
18c528e9 LP |
163 | return -EINVAL; |
164 | ||
3a47c40d | 165 | if (major(devt) == 0) |
880f09bd | 166 | return -ENOENT; |
18c528e9 | 167 | |
3a47c40d | 168 | *ret = devt; |
18c528e9 | 169 | return 1; |
880f09bd LP |
170 | } |
171 | ||
172 | int get_block_device_harder(const char *path, dev_t *ret) { | |
173 | int r; | |
174 | ||
175 | assert(path); | |
176 | assert(ret); | |
177 | ||
178 | /* Gets the backing block device for a file system, and handles LUKS encrypted file systems, looking for its | |
179 | * immediate parent, if there is one. */ | |
180 | ||
181 | r = get_block_device(path, ret); | |
182 | if (r <= 0) | |
183 | return r; | |
184 | ||
185 | r = block_get_originating(*ret, ret); | |
186 | if (r < 0) | |
187 | log_debug_errno(r, "Failed to chase block device '%s', ignoring: %m", path); | |
18c528e9 | 188 | |
18c528e9 LP |
189 | return 1; |
190 | } | |
ac83e5ae LP |
191 | |
192 | int lock_whole_block_device(dev_t devt, int operation) { | |
193 | _cleanup_free_ char *whole_node = NULL; | |
194 | _cleanup_close_ int lock_fd = -1; | |
195 | dev_t whole_devt; | |
196 | int r; | |
197 | ||
198 | /* Let's get a BSD file lock on the whole block device, as per: https://systemd.io/BLOCK_DEVICE_LOCKING */ | |
199 | ||
200 | r = block_get_whole_disk(devt, &whole_devt); | |
201 | if (r < 0) | |
202 | return r; | |
203 | ||
204 | r = device_path_make_major_minor(S_IFBLK, whole_devt, &whole_node); | |
205 | if (r < 0) | |
206 | return r; | |
207 | ||
208 | lock_fd = open(whole_node, O_RDONLY|O_CLOEXEC|O_NONBLOCK); | |
209 | if (lock_fd < 0) | |
210 | return -errno; | |
211 | ||
212 | if (flock(lock_fd, operation) < 0) | |
213 | return -errno; | |
214 | ||
215 | return TAKE_FD(lock_fd); | |
216 | } | |
e8467cd3 LP |
217 | |
218 | int blockdev_partscan_enabled(int fd) { | |
219 | _cleanup_free_ char *p = NULL, *buf = NULL; | |
220 | unsigned long long ull; | |
221 | struct stat st; | |
222 | int r; | |
223 | ||
224 | /* Checks if partition scanning is correctly enabled on the block device */ | |
225 | ||
226 | if (fstat(fd, &st) < 0) | |
227 | return -errno; | |
228 | ||
229 | if (!S_ISBLK(st.st_mode)) | |
230 | return -ENOTBLK; | |
231 | ||
232 | if (asprintf(&p, "/sys/dev/block/%u:%u/capability", major(st.st_rdev), minor(st.st_rdev)) < 0) | |
233 | return -ENOMEM; | |
234 | ||
235 | r = read_one_line_file(p, &buf); | |
236 | if (r == -ENOENT) /* If the capability file doesn't exist then we are most likely looking at a | |
237 | * partition block device, not the whole block device. And that means we have no | |
238 | * partition scanning on for it (we do for its parent, but not for the partition | |
239 | * itself). */ | |
240 | return false; | |
241 | if (r < 0) | |
242 | return r; | |
243 | ||
244 | r = safe_atollu_full(buf, 16, &ull); | |
245 | if (r < 0) | |
246 | return r; | |
247 | ||
248 | #ifndef GENHD_FL_NO_PART_SCAN | |
249 | #define GENHD_FL_NO_PART_SCAN (0x0200) | |
250 | #endif | |
251 | ||
252 | return !FLAGS_SET(ull, GENHD_FL_NO_PART_SCAN); | |
253 | } |