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Commit | Line | Data |
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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
c6878637 | 2 | |
11c3a366 TA |
3 | #include <errno.h> |
4 | #include <fcntl.h> | |
5 | #include <stdbool.h> | |
6 | #include <stddef.h> | |
11c3a366 TA |
7 | #include <unistd.h> |
8 | ||
265e9be7 | 9 | #include "alloc-util.h" |
d9e2daaf | 10 | #include "btrfs-util.h" |
f0bef277 | 11 | #include "cgroup-util.h" |
8fb3f009 | 12 | #include "dirent-util.h" |
3ffd4af2 | 13 | #include "fd-util.h" |
93cc7779 TA |
14 | #include "log.h" |
15 | #include "macro.h" | |
049af8ad | 16 | #include "mountpoint-util.h" |
07630cea | 17 | #include "path-util.h" |
3ffd4af2 | 18 | #include "rm-rf.h" |
8fcde012 | 19 | #include "stat-util.h" |
07630cea | 20 | #include "string-util.h" |
c6878637 | 21 | |
f0bef277 EV |
22 | static bool is_physical_fs(const struct statfs *sfs) { |
23 | return !is_temporary_fs(sfs) && !is_cgroup_fs(sfs); | |
24 | } | |
25 | ||
2899fb02 LP |
26 | static int unlinkat_harder( |
27 | int dfd, | |
28 | const char *filename, | |
29 | int unlink_flags, | |
30 | RemoveFlags remove_flags) { | |
31 | ||
32 | struct stat st; | |
33 | int r; | |
34 | ||
35 | /* Like unlinkat(), but tries harder: if we get EACCESS we'll try to set the r/w/x bits on the | |
36 | * directory. This is useful if we run unprivileged and have some files where the w bit is | |
37 | * missing. */ | |
38 | ||
39 | if (unlinkat(dfd, filename, unlink_flags) >= 0) | |
40 | return 0; | |
41 | if (errno != EACCES || !FLAGS_SET(remove_flags, REMOVE_CHMOD)) | |
42 | return -errno; | |
43 | ||
44 | if (fstat(dfd, &st) < 0) | |
45 | return -errno; | |
46 | if (!S_ISDIR(st.st_mode)) | |
47 | return -ENOTDIR; | |
1d6cc5d0 | 48 | if (FLAGS_SET(st.st_mode, 0700)) /* Already set? */ |
2899fb02 LP |
49 | return -EACCES; /* original error */ |
50 | if (st.st_uid != geteuid()) /* this only works if the UID matches ours */ | |
51 | return -EACCES; | |
52 | ||
53 | if (fchmod(dfd, (st.st_mode | 0700) & 07777) < 0) | |
54 | return -errno; | |
55 | ||
56 | if (unlinkat(dfd, filename, unlink_flags) < 0) { | |
57 | r = -errno; | |
58 | /* Try to restore the original access mode if this didn't work */ | |
59 | (void) fchmod(dfd, st.st_mode & 07777); | |
60 | return r; | |
61 | } | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
c6878637 LP |
66 | int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) { |
67 | _cleanup_closedir_ DIR *d = NULL; | |
8fb3f009 | 68 | struct dirent *de; |
c6878637 | 69 | int ret = 0, r; |
f0bef277 | 70 | struct statfs sfs; |
c6878637 LP |
71 | |
72 | assert(fd >= 0); | |
73 | ||
c0ba6b92 LP |
74 | /* This returns the first error we run into, but nevertheless tries to go on. This closes the passed |
75 | * fd, in all cases, including on failure.. */ | |
c6878637 LP |
76 | |
77 | if (!(flags & REMOVE_PHYSICAL)) { | |
78 | ||
f0bef277 | 79 | r = fstatfs(fd, &sfs); |
c6878637 LP |
80 | if (r < 0) { |
81 | safe_close(fd); | |
f0bef277 | 82 | return -errno; |
c6878637 LP |
83 | } |
84 | ||
f0bef277 | 85 | if (is_physical_fs(&sfs)) { |
265e9be7 ZJS |
86 | /* We refuse to clean physical file systems with this call, |
87 | * unless explicitly requested. This is extra paranoia just | |
88 | * to be sure we never ever remove non-state data. */ | |
89 | _cleanup_free_ char *path = NULL; | |
90 | ||
91 | (void) fd_get_path(fd, &path); | |
92 | log_error("Attempted to remove disk file system under \"%s\", and we can't allow that.", | |
93 | strna(path)); | |
c6878637 | 94 | |
c6878637 LP |
95 | safe_close(fd); |
96 | return -EPERM; | |
97 | } | |
98 | } | |
99 | ||
100 | d = fdopendir(fd); | |
101 | if (!d) { | |
102 | safe_close(fd); | |
103 | return errno == ENOENT ? 0 : -errno; | |
104 | } | |
105 | ||
8fb3f009 | 106 | FOREACH_DIRENT_ALL(de, d, return -errno) { |
c6878637 LP |
107 | bool is_dir; |
108 | struct stat st; | |
109 | ||
49bfc877 | 110 | if (dot_or_dot_dot(de->d_name)) |
c6878637 LP |
111 | continue; |
112 | ||
9e9b663a LP |
113 | if (de->d_type == DT_UNKNOWN || |
114 | (de->d_type == DT_DIR && (root_dev || (flags & REMOVE_SUBVOLUME)))) { | |
c6878637 LP |
115 | if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { |
116 | if (ret == 0 && errno != ENOENT) | |
117 | ret = -errno; | |
118 | continue; | |
119 | } | |
120 | ||
121 | is_dir = S_ISDIR(st.st_mode); | |
122 | } else | |
123 | is_dir = de->d_type == DT_DIR; | |
124 | ||
125 | if (is_dir) { | |
50b6eec1 | 126 | _cleanup_close_ int subdir_fd = -1; |
c6878637 | 127 | |
f25afeb6 | 128 | /* if root_dev is set, remove subdirectories only if device is same */ |
c6878637 LP |
129 | if (root_dev && st.st_dev != root_dev->st_dev) |
130 | continue; | |
131 | ||
132 | subdir_fd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); | |
133 | if (subdir_fd < 0) { | |
134 | if (ret == 0 && errno != ENOENT) | |
135 | ret = -errno; | |
136 | continue; | |
137 | } | |
138 | ||
f25afeb6 | 139 | /* Stop at mount points */ |
5d409034 | 140 | r = fd_is_mount_point(fd, de->d_name, 0); |
f25afeb6 LP |
141 | if (r < 0) { |
142 | if (ret == 0 && r != -ENOENT) | |
143 | ret = r; | |
144 | ||
f25afeb6 LP |
145 | continue; |
146 | } | |
50b6eec1 | 147 | if (r > 0) |
f25afeb6 | 148 | continue; |
f25afeb6 | 149 | |
9e9b663a | 150 | if ((flags & REMOVE_SUBVOLUME) && st.st_ino == 256) { |
9e9b663a LP |
151 | |
152 | /* This could be a subvolume, try to remove it */ | |
153 | ||
5bcd08db | 154 | r = btrfs_subvol_remove_fd(fd, de->d_name, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA); |
d9e2daaf | 155 | if (r < 0) { |
4c701096 | 156 | if (!IN_SET(r, -ENOTTY, -EINVAL)) { |
9e9b663a | 157 | if (ret == 0) |
d9e2daaf | 158 | ret = r; |
9e9b663a | 159 | |
9e9b663a LP |
160 | continue; |
161 | } | |
162 | ||
50b6eec1 LP |
163 | /* ENOTTY, then it wasn't a btrfs subvolume, continue below. */ |
164 | } else | |
9e9b663a | 165 | /* It was a subvolume, continue. */ |
9e9b663a | 166 | continue; |
9e9b663a LP |
167 | } |
168 | ||
50b6eec1 | 169 | /* We pass REMOVE_PHYSICAL here, to avoid doing the fstatfs() to check the file |
c6878637 | 170 | * system type again for each directory */ |
50b6eec1 | 171 | r = rm_rf_children(TAKE_FD(subdir_fd), flags | REMOVE_PHYSICAL, root_dev); |
c6878637 LP |
172 | if (r < 0 && ret == 0) |
173 | ret = r; | |
174 | ||
2899fb02 LP |
175 | r = unlinkat_harder(fd, de->d_name, AT_REMOVEDIR, flags); |
176 | if (r < 0 && r != -ENOENT && ret == 0) | |
177 | ret = r; | |
c6878637 LP |
178 | |
179 | } else if (!(flags & REMOVE_ONLY_DIRECTORIES)) { | |
180 | ||
2899fb02 LP |
181 | r = unlinkat_harder(fd, de->d_name, 0, flags); |
182 | if (r < 0 && r != -ENOENT && ret == 0) | |
183 | ret = r; | |
c6878637 LP |
184 | } |
185 | } | |
8fb3f009 | 186 | return ret; |
c6878637 LP |
187 | } |
188 | ||
189 | int rm_rf(const char *path, RemoveFlags flags) { | |
190 | int fd, r; | |
191 | struct statfs s; | |
192 | ||
193 | assert(path); | |
194 | ||
c2f64c07 LP |
195 | /* For now, don't support dropping subvols when also only dropping directories, since we can't do |
196 | * this race-freely. */ | |
197 | if (FLAGS_SET(flags, REMOVE_ONLY_DIRECTORIES|REMOVE_SUBVOLUME)) | |
198 | return -EINVAL; | |
199 | ||
c0228b4f LP |
200 | /* We refuse to clean the root file system with this call. This is extra paranoia to never cause a |
201 | * really seriously broken system. */ | |
baaa35ad ZJS |
202 | if (path_equal_or_files_same(path, "/", AT_SYMLINK_NOFOLLOW)) |
203 | return log_error_errno(SYNTHETIC_ERRNO(EPERM), | |
204 | "Attempted to remove entire root file system (\"%s\"), and we can't allow that.", | |
205 | path); | |
c6878637 | 206 | |
d94a24ca | 207 | if (FLAGS_SET(flags, REMOVE_SUBVOLUME | REMOVE_ROOT | REMOVE_PHYSICAL)) { |
d9e2daaf | 208 | /* Try to remove as subvolume first */ |
5bcd08db | 209 | r = btrfs_subvol_remove(path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA); |
d9e2daaf LP |
210 | if (r >= 0) |
211 | return r; | |
212 | ||
c0228b4f LP |
213 | if (FLAGS_SET(flags, REMOVE_MISSING_OK) && r == -ENOENT) |
214 | return 0; | |
215 | ||
4c701096 | 216 | if (!IN_SET(r, -ENOTTY, -EINVAL, -ENOTDIR)) |
d9e2daaf LP |
217 | return r; |
218 | ||
219 | /* Not btrfs or not a subvolume */ | |
220 | } | |
221 | ||
c6878637 LP |
222 | fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); |
223 | if (fd < 0) { | |
c0228b4f LP |
224 | if (FLAGS_SET(flags, REMOVE_MISSING_OK) && errno == ENOENT) |
225 | return 0; | |
226 | ||
ec2ce0c5 | 227 | if (!IN_SET(errno, ENOTDIR, ELOOP)) |
c6878637 LP |
228 | return -errno; |
229 | ||
c0228b4f LP |
230 | if (FLAGS_SET(flags, REMOVE_ONLY_DIRECTORIES)) |
231 | return 0; | |
c6878637 | 232 | |
c0228b4f LP |
233 | if (FLAGS_SET(flags, REMOVE_ROOT)) { |
234 | ||
235 | if (!FLAGS_SET(flags, REMOVE_PHYSICAL)) { | |
236 | if (statfs(path, &s) < 0) | |
237 | return -errno; | |
238 | ||
239 | if (is_physical_fs(&s)) | |
240 | return log_error_errno(SYNTHETIC_ERRNO(EPERM), | |
241 | "Attempted to remove files from a disk file system under \"%s\", refusing.", | |
242 | path); | |
243 | } | |
244 | ||
245 | if (unlink(path) < 0) { | |
246 | if (FLAGS_SET(flags, REMOVE_MISSING_OK) && errno == ENOENT) | |
247 | return 0; | |
c6878637 | 248 | |
c6878637 | 249 | return -errno; |
c0228b4f LP |
250 | } |
251 | } | |
c6878637 LP |
252 | |
253 | return 0; | |
254 | } | |
255 | ||
256 | r = rm_rf_children(fd, flags, NULL); | |
257 | ||
c0228b4f LP |
258 | if (FLAGS_SET(flags, REMOVE_ROOT) && |
259 | rmdir(path) < 0 && | |
260 | r >= 0 && | |
261 | (!FLAGS_SET(flags, REMOVE_MISSING_OK) || errno != ENOENT)) | |
262 | r = -errno; | |
c6878637 LP |
263 | |
264 | return r; | |
265 | } |