1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2014 Lennart Poettering
7 systemd is free software; you can redistribute it and/or modify it
8 under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 2.1 of the License, or
10 (at your option) any later version.
12 systemd is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with systemd; If not, see <http://www.gnu.org/licenses/>.
21 #include <sys/statvfs.h>
23 #include "alloc-util.h"
24 #include "coredump-vacuum.h"
25 #include "dirent-util.h"
30 #include "string-util.h"
31 #include "time-util.h"
32 #include "user-util.h"
35 #define DEFAULT_MAX_USE_LOWER (uint64_t) (1ULL*1024ULL*1024ULL) /* 1 MiB */
36 #define DEFAULT_MAX_USE_UPPER (uint64_t) (4ULL*1024ULL*1024ULL*1024ULL) /* 4 GiB */
37 #define DEFAULT_KEEP_FREE_UPPER (uint64_t) (4ULL*1024ULL*1024ULL*1024ULL) /* 4 GiB */
38 #define DEFAULT_KEEP_FREE (uint64_t) (1024ULL*1024ULL) /* 1 MB */
40 struct vacuum_candidate
{
46 static void vacuum_candidate_free(struct vacuum_candidate
*c
) {
54 DEFINE_TRIVIAL_CLEANUP_FUNC(struct vacuum_candidate
*, vacuum_candidate_free
);
56 static void vacuum_candidate_hashmap_free(Hashmap
*h
) {
57 hashmap_free_with_destructor(h
, vacuum_candidate_free
);
60 DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap
*, vacuum_candidate_hashmap_free
);
62 static int uid_from_file_name(const char *filename
, uid_t
*uid
) {
63 const char *p
, *e
, *u
;
65 p
= startswith(filename
, "core.");
69 /* Skip the comm field */
81 return parse_uid(u
, uid
);
84 static bool vacuum_necessary(int fd
, uint64_t sum
, uint64_t keep_free
, uint64_t max_use
) {
85 uint64_t fs_size
= 0, fs_free
= (uint64_t) -1;
90 if (fstatvfs(fd
, &sv
) >= 0) {
91 fs_size
= sv
.f_frsize
* sv
.f_blocks
;
92 fs_free
= sv
.f_frsize
* sv
.f_bfree
;
95 if (max_use
== (uint64_t) -1) {
98 max_use
= PAGE_ALIGN(fs_size
/ 10); /* 10% */
100 if (max_use
> DEFAULT_MAX_USE_UPPER
)
101 max_use
= DEFAULT_MAX_USE_UPPER
;
103 if (max_use
< DEFAULT_MAX_USE_LOWER
)
104 max_use
= DEFAULT_MAX_USE_LOWER
;
106 max_use
= DEFAULT_MAX_USE_LOWER
;
108 max_use
= PAGE_ALIGN(max_use
);
110 if (max_use
> 0 && sum
> max_use
)
113 if (keep_free
== (uint64_t) -1) {
116 keep_free
= PAGE_ALIGN((fs_size
* 3) / 20); /* 15% */
118 if (keep_free
> DEFAULT_KEEP_FREE_UPPER
)
119 keep_free
= DEFAULT_KEEP_FREE_UPPER
;
121 keep_free
= DEFAULT_KEEP_FREE
;
123 keep_free
= PAGE_ALIGN(keep_free
);
125 if (keep_free
> 0 && fs_free
< keep_free
)
131 int coredump_vacuum(int exclude_fd
, uint64_t keep_free
, uint64_t max_use
) {
132 _cleanup_closedir_
DIR *d
= NULL
;
133 struct stat exclude_st
;
136 if (keep_free
== 0 && max_use
== 0)
139 if (exclude_fd
>= 0) {
140 if (fstat(exclude_fd
, &exclude_st
) < 0)
141 return log_error_errno(errno
, "Failed to fstat(): %m");
144 /* This algorithm will keep deleting the oldest file of the
145 * user with the most coredumps until we are back in the size
146 * limits. Note that vacuuming for journal files is different,
147 * because we rely on rate-limiting of the messages there,
148 * to avoid being flooded. */
150 d
= opendir("/var/lib/systemd/coredump");
155 return log_error_errno(errno
, "Can't open coredump directory: %m");
159 _cleanup_(vacuum_candidate_hashmap_freep
) Hashmap
*h
= NULL
;
160 struct vacuum_candidate
*worst
= NULL
;
166 FOREACH_DIRENT(de
, d
, goto fail
) {
167 struct vacuum_candidate
*c
;
172 r
= uid_from_file_name(de
->d_name
, &uid
);
176 if (fstatat(dirfd(d
), de
->d_name
, &st
, AT_NO_AUTOMOUNT
|AT_SYMLINK_NOFOLLOW
) < 0) {
180 log_warning_errno(errno
, "Failed to stat /var/lib/systemd/coredump/%s: %m", de
->d_name
);
184 if (!S_ISREG(st
.st_mode
))
187 if (exclude_fd
>= 0 &&
188 exclude_st
.st_dev
== st
.st_dev
&&
189 exclude_st
.st_ino
== st
.st_ino
)
192 r
= hashmap_ensure_allocated(&h
, NULL
);
196 t
= timespec_load(&st
.st_mtim
);
198 c
= hashmap_get(h
, UID_TO_PTR(uid
));
201 if (t
< c
->oldest_mtime
) {
204 n
= strdup(de
->d_name
);
208 free(c
->oldest_file
);
214 _cleanup_(vacuum_candidate_freep
) struct vacuum_candidate
*n
= NULL
;
216 n
= new0(struct vacuum_candidate
, 1);
220 n
->oldest_file
= strdup(de
->d_name
);
226 r
= hashmap_put(h
, UID_TO_PTR(uid
), n
);
237 worst
->n_files
< c
->n_files
||
238 (worst
->n_files
== c
->n_files
&& c
->oldest_mtime
< worst
->oldest_mtime
))
241 sum
+= st
.st_blocks
* 512;
247 r
= vacuum_necessary(dirfd(d
), sum
, keep_free
, max_use
);
251 r
= unlinkat_deallocate(dirfd(d
), worst
->oldest_file
, 0);
255 return log_error_errno(r
, "Failed to remove file %s: %m", worst
->oldest_file
);
257 log_info("Removed old coredump %s.", worst
->oldest_file
);
263 return log_error_errno(errno
, "Failed to read directory: %m");