1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Lennart Poettering
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.
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.
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/>.
22 #include <sys/statvfs.h>
25 #include "time-util.h"
29 #include "coredump-vacuum.h"
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 */
36 struct vacuum_candidate {
42 static void vacuum_candidate_free(struct vacuum_candidate *c) {
50 DEFINE_TRIVIAL_CLEANUP_FUNC(struct vacuum_candidate*, vacuum_candidate_free);
52 static void vacuum_candidate_hasmap_free(Hashmap *h) {
53 struct vacuum_candidate *c;
55 while ((c = hashmap_steal_first(h)))
56 vacuum_candidate_free(c);
61 DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap*, vacuum_candidate_hasmap_free);
63 static int uid_from_file_name(const char *filename, uid_t *uid) {
64 const char *p, *e, *u;
66 p = startswith(filename, "core.");
70 /* Skip the comm field */
82 return parse_uid(u, uid);
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;
91 if (fstatvfs(fd, &sv) >= 0) {
92 fs_size = sv.f_frsize * sv.f_blocks;
93 fs_free = sv.f_frsize * sv.f_bfree;
96 if (max_use == (off_t) -1) {
99 max_use = PAGE_ALIGN(fs_size / 10); /* 10% */
101 if (max_use > DEFAULT_MAX_USE_UPPER)
102 max_use = DEFAULT_MAX_USE_UPPER;
104 if (max_use < DEFAULT_MAX_USE_LOWER)
105 max_use = DEFAULT_MAX_USE_LOWER;
108 max_use = DEFAULT_MAX_USE_LOWER;
110 max_use = PAGE_ALIGN(max_use);
112 if (max_use > 0 && sum > max_use)
115 if (keep_free == (off_t) -1) {
118 keep_free = PAGE_ALIGN((fs_size * 3) / 20); /* 15% */
120 if (keep_free > DEFAULT_KEEP_FREE_UPPER)
121 keep_free = DEFAULT_KEEP_FREE_UPPER;
123 keep_free = DEFAULT_KEEP_FREE;
125 keep_free = PAGE_ALIGN(keep_free);
127 if (keep_free > 0 && fs_free < keep_free)
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;
138 if (keep_free <= 0 && max_use <= 0)
141 if (exclude_fd >= 0) {
142 if (fstat(exclude_fd, &exclude_st) < 0)
143 return log_error_errno(errno, "Failed to fstat(): %m");
146 /* This algorithm will keep deleting the oldest file of the
147 * user with the most coredumps until we are back in the size
148 * limits. Note that vacuuming for journal files is different,
149 * because we rely on rate-limiting of the messages there,
150 * to avoid being flooded. */
152 d = opendir("/var/lib/systemd/coredump");
157 log_error_errno(errno, "Can't open coredump directory: %m");
162 _cleanup_(vacuum_candidate_hasmap_freep) Hashmap *h = NULL;
163 struct vacuum_candidate *worst = NULL;
169 FOREACH_DIRENT(de, d, goto fail) {
170 struct vacuum_candidate *c;
175 r = uid_from_file_name(de->d_name, &uid);
179 if (fstatat(dirfd(d), de->d_name, &st, AT_NO_AUTOMOUNT|AT_SYMLINK_NOFOLLOW) < 0) {
183 log_warning("Failed to stat /var/lib/systemd/coredump/%s", de->d_name);
187 if (!S_ISREG(st.st_mode))
190 if (exclude_fd >= 0 &&
191 exclude_st.st_dev == st.st_dev &&
192 exclude_st.st_ino == st.st_ino)
195 r = hashmap_ensure_allocated(&h, NULL);
199 t = timespec_load(&st.st_mtim);
201 c = hashmap_get(h, UINT32_TO_PTR(uid));
204 if (t < c->oldest_mtime) {
207 n = strdup(de->d_name);
211 free(c->oldest_file);
217 _cleanup_(vacuum_candidate_freep) struct vacuum_candidate *n = NULL;
219 n = new0(struct vacuum_candidate, 1);
223 n->oldest_file = strdup(de->d_name);
229 r = hashmap_put(h, UINT32_TO_PTR(uid), n);
240 worst->n_files < c->n_files ||
241 (worst->n_files == c->n_files && c->oldest_mtime < worst->oldest_mtime))
244 sum += st.st_blocks * 512;
250 r = vacuum_necessary(dirfd(d), sum, keep_free, max_use);
254 if (unlinkat(dirfd(d), worst->oldest_file, 0) < 0) {
259 log_error_errno(errno, "Failed to remove file %s: %m", worst->oldest_file);
262 log_info("Removed old coredump %s.", worst->oldest_file);
268 log_error_errno(errno, "Failed to read directory: %m");