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0dc5d23c LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <sys/statvfs.h> | |
23 | ||
24 | #include "util.h" | |
25 | #include "time-util.h" | |
26 | #include "hashmap.h" | |
27 | #include "macro.h" | |
28 | ||
29 | #include "coredump-vacuum.h" | |
30 | ||
31 | #define DEFAULT_MAX_USE_LOWER (off_t) (1ULL*1024ULL*1024ULL) /* 1 MiB */ | |
32 | #define DEFAULT_MAX_USE_UPPER (off_t) (4ULL*1024ULL*1024ULL*1024ULL) /* 4 GiB */ | |
33 | #define DEFAULT_KEEP_FREE_UPPER (off_t) (4ULL*1024ULL*1024ULL*1024ULL) /* 4 GiB */ | |
34 | #define DEFAULT_KEEP_FREE (off_t) (1024ULL*1024ULL) /* 1 MB */ | |
35 | ||
36 | struct vacuum_candidate { | |
37 | unsigned n_files; | |
38 | char *oldest_file; | |
39 | usec_t oldest_mtime; | |
40 | }; | |
41 | ||
42 | static void vacuum_candidate_free(struct vacuum_candidate *c) { | |
43 | if (!c) | |
44 | return; | |
45 | ||
46 | free(c->oldest_file); | |
47 | free(c); | |
48 | } | |
49 | ||
50 | DEFINE_TRIVIAL_CLEANUP_FUNC(struct vacuum_candidate*, vacuum_candidate_free); | |
51 | ||
52 | static void vacuum_candidate_hasmap_free(Hashmap *h) { | |
53 | struct vacuum_candidate *c; | |
54 | ||
55 | while ((c = hashmap_steal_first(h))) | |
56 | vacuum_candidate_free(c); | |
57 | ||
58 | hashmap_free(h); | |
59 | } | |
60 | ||
61 | DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap*, vacuum_candidate_hasmap_free); | |
62 | ||
63 | static int uid_from_file_name(const char *filename, uid_t *uid) { | |
64 | const char *p, *e, *u; | |
65 | ||
66 | p = startswith(filename, "core."); | |
67 | if (!p) | |
68 | return -EINVAL; | |
69 | ||
70 | /* Skip the comm field */ | |
71 | p = strchr(p, '.'); | |
72 | if (!p) | |
73 | return -EINVAL; | |
74 | p++; | |
75 | ||
76 | /* Find end up UID */ | |
77 | e = strchr(p, '.'); | |
78 | if (!e) | |
79 | return -EINVAL; | |
80 | ||
81 | u = strndupa(p, e-p); | |
82 | return parse_uid(u, uid); | |
83 | } | |
84 | ||
85 | static bool vacuum_necessary(int fd, off_t sum, off_t keep_free, off_t max_use) { | |
86 | off_t fs_size = 0, fs_free = (off_t) -1; | |
87 | struct statvfs sv; | |
88 | ||
89 | assert(fd >= 0); | |
90 | ||
91 | if (fstatvfs(fd, &sv) >= 0) { | |
92 | fs_size = sv.f_frsize * sv.f_blocks; | |
93 | fs_free = sv.f_frsize * sv.f_bfree; | |
94 | } | |
95 | ||
96 | if (max_use == (off_t) -1) { | |
97 | ||
98 | if (fs_size > 0) { | |
99 | max_use = PAGE_ALIGN(fs_size / 10); /* 10% */ | |
100 | ||
101 | if (max_use > DEFAULT_MAX_USE_UPPER) | |
102 | max_use = DEFAULT_MAX_USE_UPPER; | |
103 | ||
104 | if (max_use < DEFAULT_MAX_USE_LOWER) | |
105 | max_use = DEFAULT_MAX_USE_LOWER; | |
106 | } | |
cd4ba18a TA |
107 | else |
108 | max_use = DEFAULT_MAX_USE_LOWER; | |
0dc5d23c LP |
109 | } else |
110 | max_use = PAGE_ALIGN(max_use); | |
111 | ||
112 | if (max_use > 0 && sum > max_use) | |
113 | return true; | |
114 | ||
115 | if (keep_free == (off_t) -1) { | |
116 | ||
117 | if (fs_size > 0) { | |
118 | keep_free = PAGE_ALIGN((fs_size * 3) / 20); /* 15% */ | |
119 | ||
120 | if (keep_free > DEFAULT_KEEP_FREE_UPPER) | |
121 | keep_free = DEFAULT_KEEP_FREE_UPPER; | |
122 | } else | |
123 | keep_free = DEFAULT_KEEP_FREE; | |
124 | } else | |
125 | keep_free = PAGE_ALIGN(keep_free); | |
126 | ||
127 | if (keep_free > 0 && fs_free < keep_free) | |
128 | return true; | |
129 | ||
130 | return false; | |
131 | } | |
132 | ||
133 | int coredump_vacuum(int exclude_fd, off_t keep_free, off_t max_use) { | |
134 | _cleanup_closedir_ DIR *d = NULL; | |
135 | struct stat exclude_st; | |
136 | int r; | |
137 | ||
138 | if (keep_free <= 0 && max_use <= 0) | |
139 | return 0; | |
140 | ||
141 | if (exclude_fd >= 0) { | |
142 | if (fstat(exclude_fd, &exclude_st) < 0) { | |
56f64d95 | 143 | log_error_errno(errno, "Failed to fstat(): %m"); |
0dc5d23c LP |
144 | return -errno; |
145 | } | |
146 | } | |
147 | ||
148 | /* This algorithm will keep deleting the oldest file of the | |
149 | * user with the most coredumps until we are back in the size | |
150 | * limits. Note that vacuuming for journal files is different, | |
151 | * because we rely on rate-limiting of the messages there, | |
152 | * to avoid being flooded. */ | |
153 | ||
154 | d = opendir("/var/lib/systemd/coredump"); | |
155 | if (!d) { | |
156 | if (errno == ENOENT) | |
157 | return 0; | |
158 | ||
56f64d95 | 159 | log_error_errno(errno, "Can't open coredump directory: %m"); |
0dc5d23c LP |
160 | return -errno; |
161 | } | |
162 | ||
163 | for (;;) { | |
164 | _cleanup_(vacuum_candidate_hasmap_freep) Hashmap *h = NULL; | |
165 | struct vacuum_candidate *worst = NULL; | |
166 | struct dirent *de; | |
167 | off_t sum = 0; | |
168 | ||
169 | rewinddir(d); | |
170 | ||
171 | FOREACH_DIRENT(de, d, goto fail) { | |
172 | struct vacuum_candidate *c; | |
173 | struct stat st; | |
174 | uid_t uid; | |
175 | usec_t t; | |
176 | ||
177 | r = uid_from_file_name(de->d_name, &uid); | |
178 | if (r < 0) | |
179 | continue; | |
180 | ||
181 | if (fstatat(dirfd(d), de->d_name, &st, AT_NO_AUTOMOUNT|AT_SYMLINK_NOFOLLOW) < 0) { | |
182 | if (errno == ENOENT) | |
183 | continue; | |
184 | ||
185 | log_warning("Failed to stat /var/lib/systemd/coredump/%s", de->d_name); | |
186 | continue; | |
187 | } | |
188 | ||
189 | if (!S_ISREG(st.st_mode)) | |
190 | continue; | |
191 | ||
192 | if (exclude_fd >= 0 && | |
193 | exclude_st.st_dev == st.st_dev && | |
194 | exclude_st.st_ino == st.st_ino) | |
195 | continue; | |
196 | ||
d5099efc | 197 | r = hashmap_ensure_allocated(&h, NULL); |
0dc5d23c LP |
198 | if (r < 0) |
199 | return log_oom(); | |
200 | ||
201 | t = timespec_load(&st.st_mtim); | |
202 | ||
203 | c = hashmap_get(h, UINT32_TO_PTR(uid)); | |
204 | if (c) { | |
205 | ||
206 | if (t < c->oldest_mtime) { | |
207 | char *n; | |
208 | ||
209 | n = strdup(de->d_name); | |
210 | if (!n) | |
211 | return log_oom(); | |
212 | ||
213 | free(c->oldest_file); | |
214 | c->oldest_file = n; | |
215 | c->oldest_mtime = t; | |
216 | } | |
217 | ||
218 | } else { | |
219 | _cleanup_(vacuum_candidate_freep) struct vacuum_candidate *n = NULL; | |
220 | ||
221 | n = new0(struct vacuum_candidate, 1); | |
222 | if (!n) | |
223 | return log_oom(); | |
224 | ||
225 | n->oldest_file = strdup(de->d_name); | |
226 | if (!n->oldest_file) | |
227 | return log_oom(); | |
228 | ||
229 | n->oldest_mtime = t; | |
230 | ||
231 | r = hashmap_put(h, UINT32_TO_PTR(uid), n); | |
232 | if (r < 0) | |
233 | return log_oom(); | |
234 | ||
235 | c = n; | |
236 | n = NULL; | |
237 | } | |
238 | ||
239 | c->n_files++; | |
240 | ||
241 | if (!worst || | |
242 | worst->n_files < c->n_files || | |
243 | (worst->n_files == c->n_files && c->oldest_mtime < worst->oldest_mtime)) | |
244 | worst = c; | |
245 | ||
246 | sum += st.st_blocks * 512; | |
247 | } | |
248 | ||
249 | if (!worst) | |
250 | break; | |
251 | ||
252 | r = vacuum_necessary(dirfd(d), sum, keep_free, max_use); | |
253 | if (r <= 0) | |
254 | return r; | |
255 | ||
256 | if (unlinkat(dirfd(d), worst->oldest_file, 0) < 0) { | |
257 | ||
258 | if (errno == ENOENT) | |
259 | continue; | |
260 | ||
56f64d95 | 261 | log_error_errno(errno, "Failed to remove file %s: %m", worst->oldest_file); |
0dc5d23c LP |
262 | return -errno; |
263 | } else | |
264 | log_info("Removed old coredump %s.", worst->oldest_file); | |
265 | } | |
266 | ||
267 | return 0; | |
268 | ||
269 | fail: | |
56f64d95 | 270 | log_error_errno(errno, "Failed to read directory: %m"); |
0dc5d23c LP |
271 | return -errno; |
272 | } |