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Commit | Line | Data |
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18c528e9 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
18c528e9 | 2 | |
f5947a5e | 3 | #include <unistd.h> |
18c528e9 LP |
4 | |
5 | #include "alloc-util.h" | |
6 | #include "blockdev-util.h" | |
7 | #include "btrfs-util.h" | |
8 | #include "dirent-util.h" | |
9 | #include "fd-util.h" | |
10 | #include "fileio.h" | |
f5947a5e | 11 | #include "missing_magic.h" |
3a47c40d | 12 | #include "parse-util.h" |
18c528e9 LP |
13 | #include "stat-util.h" |
14 | ||
15 | int block_get_whole_disk(dev_t d, dev_t *ret) { | |
16 | char p[SYS_BLOCK_PATH_MAX("/partition")]; | |
17 | _cleanup_free_ char *s = NULL; | |
3a47c40d | 18 | dev_t devt; |
18c528e9 LP |
19 | int r; |
20 | ||
21 | assert(ret); | |
22 | ||
51f14fa1 LP |
23 | if (major(d) == 0) |
24 | return -ENODEV; | |
25 | ||
18c528e9 LP |
26 | /* If it has a queue this is good enough for us */ |
27 | xsprintf_sys_block_path(p, "/queue", d); | |
28 | if (access(p, F_OK) >= 0) { | |
29 | *ret = d; | |
30 | return 0; | |
31 | } | |
32 | ||
33 | /* If it is a partition find the originating device */ | |
34 | xsprintf_sys_block_path(p, "/partition", d); | |
35 | if (access(p, F_OK) < 0) | |
d18b3009 | 36 | return -errno; |
18c528e9 LP |
37 | |
38 | /* Get parent dev_t */ | |
39 | xsprintf_sys_block_path(p, "/../dev", d); | |
40 | r = read_one_line_file(p, &s); | |
41 | if (r < 0) | |
42 | return r; | |
43 | ||
3a47c40d LP |
44 | r = parse_dev(s, &devt); |
45 | if (r < 0) | |
46 | return r; | |
18c528e9 LP |
47 | |
48 | /* Only return this if it is really good enough for us. */ | |
3a47c40d | 49 | xsprintf_sys_block_path(p, "/queue", devt); |
18c528e9 | 50 | if (access(p, F_OK) < 0) |
d18b3009 | 51 | return -errno; |
18c528e9 | 52 | |
3a47c40d | 53 | *ret = devt; |
a0ea1dee | 54 | return 1; |
18c528e9 LP |
55 | } |
56 | ||
db8728a6 LP |
57 | int get_block_device(const char *path, dev_t *ret) { |
58 | _cleanup_close_ int fd = -1; | |
18c528e9 | 59 | struct stat st; |
db8728a6 | 60 | int r; |
18c528e9 LP |
61 | |
62 | assert(path); | |
db8728a6 | 63 | assert(ret); |
18c528e9 | 64 | |
db8728a6 LP |
65 | /* Gets the block device directly backing a file system. If the block device is encrypted, returns |
66 | * the device mapper block device. */ | |
67 | ||
68 | fd = open(path, O_NOFOLLOW|O_CLOEXEC); | |
69 | if (fd < 0) | |
70 | return -errno; | |
18c528e9 | 71 | |
db8728a6 | 72 | if (fstat(fd, &st)) |
18c528e9 LP |
73 | return -errno; |
74 | ||
75 | if (major(st.st_dev) != 0) { | |
db8728a6 | 76 | *ret = st.st_dev; |
18c528e9 LP |
77 | return 1; |
78 | } | |
79 | ||
db8728a6 LP |
80 | r = btrfs_get_block_device_fd(fd, ret); |
81 | if (r > 0) | |
82 | return 1; | |
83 | if (r != -ENOTTY) /* not btrfs */ | |
84 | return r; | |
18c528e9 | 85 | |
db8728a6 | 86 | *ret = 0; |
18c528e9 LP |
87 | return 0; |
88 | } | |
89 | ||
880f09bd | 90 | int block_get_originating(dev_t dt, dev_t *ret) { |
18c528e9 LP |
91 | _cleanup_closedir_ DIR *d = NULL; |
92 | _cleanup_free_ char *t = NULL; | |
93 | char p[SYS_BLOCK_PATH_MAX("/slaves")]; | |
94 | struct dirent *de, *found = NULL; | |
880f09bd | 95 | const char *q; |
3a47c40d | 96 | dev_t devt; |
18c528e9 LP |
97 | int r; |
98 | ||
880f09bd LP |
99 | /* For the specified block device tries to chase it through the layers, in case LUKS-style DM stacking is used, |
100 | * trying to find the next underlying layer. */ | |
18c528e9 LP |
101 | |
102 | xsprintf_sys_block_path(p, "/slaves", dt); | |
103 | d = opendir(p); | |
880f09bd | 104 | if (!d) |
18c528e9 | 105 | return -errno; |
18c528e9 LP |
106 | |
107 | FOREACH_DIRENT_ALL(de, d, return -errno) { | |
108 | ||
109 | if (dot_or_dot_dot(de->d_name)) | |
110 | continue; | |
111 | ||
112 | if (!IN_SET(de->d_type, DT_LNK, DT_UNKNOWN)) | |
113 | continue; | |
114 | ||
115 | if (found) { | |
116 | _cleanup_free_ char *u = NULL, *v = NULL, *a = NULL, *b = NULL; | |
117 | ||
118 | /* We found a device backed by multiple other devices. We don't really support automatic | |
119 | * discovery on such setups, with the exception of dm-verity partitions. In this case there are | |
120 | * two backing devices: the data partition and the hash partition. We are fine with such | |
121 | * setups, however, only if both partitions are on the same physical device. Hence, let's | |
122 | * verify this. */ | |
123 | ||
657ee2d8 | 124 | u = path_join(p, de->d_name, "../dev"); |
18c528e9 LP |
125 | if (!u) |
126 | return -ENOMEM; | |
127 | ||
657ee2d8 | 128 | v = path_join(p, found->d_name, "../dev"); |
18c528e9 LP |
129 | if (!v) |
130 | return -ENOMEM; | |
131 | ||
132 | r = read_one_line_file(u, &a); | |
880f09bd LP |
133 | if (r < 0) |
134 | return log_debug_errno(r, "Failed to read %s: %m", u); | |
18c528e9 LP |
135 | |
136 | r = read_one_line_file(v, &b); | |
880f09bd LP |
137 | if (r < 0) |
138 | return log_debug_errno(r, "Failed to read %s: %m", v); | |
18c528e9 LP |
139 | |
140 | /* Check if the parent device is the same. If not, then the two backing devices are on | |
141 | * different physical devices, and we don't support that. */ | |
142 | if (!streq(a, b)) | |
880f09bd | 143 | return -ENOTUNIQ; |
18c528e9 LP |
144 | } |
145 | ||
146 | found = de; | |
147 | } | |
148 | ||
149 | if (!found) | |
880f09bd | 150 | return -ENOENT; |
18c528e9 LP |
151 | |
152 | q = strjoina(p, "/", found->d_name, "/dev"); | |
153 | ||
154 | r = read_one_line_file(q, &t); | |
18c528e9 LP |
155 | if (r < 0) |
156 | return r; | |
157 | ||
3a47c40d LP |
158 | r = parse_dev(t, &devt); |
159 | if (r < 0) | |
18c528e9 LP |
160 | return -EINVAL; |
161 | ||
3a47c40d | 162 | if (major(devt) == 0) |
880f09bd | 163 | return -ENOENT; |
18c528e9 | 164 | |
3a47c40d | 165 | *ret = devt; |
18c528e9 | 166 | return 1; |
880f09bd LP |
167 | } |
168 | ||
169 | int get_block_device_harder(const char *path, dev_t *ret) { | |
170 | int r; | |
171 | ||
172 | assert(path); | |
173 | assert(ret); | |
174 | ||
175 | /* Gets the backing block device for a file system, and handles LUKS encrypted file systems, looking for its | |
176 | * immediate parent, if there is one. */ | |
177 | ||
178 | r = get_block_device(path, ret); | |
179 | if (r <= 0) | |
180 | return r; | |
181 | ||
182 | r = block_get_originating(*ret, ret); | |
183 | if (r < 0) | |
184 | log_debug_errno(r, "Failed to chase block device '%s', ignoring: %m", path); | |
18c528e9 | 185 | |
18c528e9 LP |
186 | return 1; |
187 | } |