src/journal/journal-vacuum.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 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/types.h>
  23 #include <fcntl.h>
  24 #include <sys/stat.h>
  25 #include <sys/statvfs.h>
  26 #include <unistd.h>
  27 #include <sys/xattr.h>
  28
  29 #include "journal-def.h"
  30 #include "journal-file.h"
  31 #include "journal-vacuum.h"
  32 #include "sd-id128.h"
  33 #include "util.h"
  34
  35 struct vacuum_info {
  36         uint64_t usage;
  37         char *filename;
  38
  39         uint64_t realtime;
  40         sd_id128_t seqnum_id;
  41         uint64_t seqnum;
  42
  43         bool have_seqnum;
  44 };
  45
  46 static int vacuum_compare(const void *_a, const void *_b) {
  47         const struct vacuum_info *a, *b;
  48
  49         a = _a;
  50         b = _b;
  51
  52         if (a->have_seqnum && b->have_seqnum &&
  53             sd_id128_equal(a->seqnum_id, b->seqnum_id)) {
  54                 if (a->seqnum < b->seqnum)
  55                         return -1;
  56                 else if (a->seqnum > b->seqnum)
  57                         return 1;
  58                 else
  59                         return 0;
  60         }
  61
  62         if (a->realtime < b->realtime)
  63                 return -1;
  64         else if (a->realtime > b->realtime)
  65                 return 1;
  66         else if (a->have_seqnum && b->have_seqnum)
  67                 return memcmp(&a->seqnum_id, &b->seqnum_id, 16);
  68         else
  69                 return strcmp(a->filename, b->filename);
  70 }
  71
  72 static void patch_realtime(
  73                 const char *dir,
  74                 const char *fn,
  75                 const struct stat *st,
  76                 unsigned long long *realtime) {
  77
  78         usec_t x;
  79         uint64_t crtime;
  80         _cleanup_free_ const char *path = NULL;
  81
  82         /* The timestamp was determined by the file name, but let's
  83          * see if the file might actually be older than the file name
  84          * suggested... */
  85
  86         assert(dir);
  87         assert(fn);
  88         assert(st);
  89         assert(realtime);
  90
  91         x = timespec_load(&st->st_ctim);
  92         if (x > 0 && x != USEC_INFINITY && x < *realtime)
  93                 *realtime = x;
  94
  95         x = timespec_load(&st->st_atim);
  96         if (x > 0 && x != USEC_INFINITY && x < *realtime)
  97                 *realtime = x;
  98
  99         x = timespec_load(&st->st_mtim);
 100         if (x > 0 && x != USEC_INFINITY && x < *realtime)
 101                 *realtime = x;
 102
 103         /* Let's read the original creation time, if possible. Ideally
 104          * we'd just query the creation time the FS might provide, but
 105          * unfortunately there's currently no sane API to query
 106          * it. Hence let's implement this manually... */
 107
 108         /* Unfortunately there is is not fgetxattrat(), so we need to
 109          * go via path here. :-( */
 110
 111         path = strjoin(dir, "/", fn, NULL);
 112         if (!path)
 113                 return;
 114
 115         if (getxattr(path, "user.crtime_usec", &crtime, sizeof(crtime)) == sizeof(crtime)) {
 116                 crtime = le64toh(crtime);
 117
 118                 if (crtime > 0 && crtime != (uint64_t) -1 && crtime < *realtime)
 119                         *realtime = crtime;
 120         }
 121 }
 122
 123 static int journal_file_empty(int dir_fd, const char *name) {
 124         int r;
 125         le64_t n_entries;
 126         _cleanup_close_ int fd;
 127
 128         fd = openat(dir_fd, name, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
 129         if (fd < 0)
 130                 return -errno;
 131
 132         if (lseek(fd, offsetof(Header, n_entries), SEEK_SET) < 0)
 133                 return -errno;
 134
 135         r = read(fd, &n_entries, sizeof(n_entries));
 136         if (r != sizeof(n_entries))
 137                 return r == 0 ? -EINVAL : -errno;
 138
 139         return le64toh(n_entries) == 0;
 140 }
 141
 142 int journal_directory_vacuum(
 143                 const char *directory,
 144                 uint64_t max_use,
 145                 usec_t max_retention_usec,
 146                 usec_t *oldest_usec) {
 147
 148         _cleanup_closedir_ DIR *d = NULL;
 149         int r = 0;
 150         struct vacuum_info *list = NULL;
 151         unsigned n_list = 0, i;
 152         size_t n_allocated = 0;
 153         uint64_t sum = 0, freed = 0;
 154         usec_t retention_limit = 0;
 155
 156         assert(directory);
 157
 158         if (max_use <= 0 && max_retention_usec <= 0)
 159                 return 0;
 160
 161         if (max_retention_usec > 0) {
 162                 retention_limit = now(CLOCK_REALTIME);
 163                 if (retention_limit > max_retention_usec)
 164                         retention_limit -= max_retention_usec;
 165                 else
 166                         max_retention_usec = retention_limit = 0;
 167         }
 168
 169         d = opendir(directory);
 170         if (!d)
 171                 return -errno;
 172
 173         for (;;) {
 174                 struct dirent *de;
 175                 size_t q;
 176                 struct stat st;
 177                 char *p;
 178                 unsigned long long seqnum = 0, realtime;
 179                 sd_id128_t seqnum_id;
 180                 bool have_seqnum;
 181
 182                 errno = 0;
 183                 de = readdir(d);
 184                 if (!de && errno != 0) {
 185                         r = -errno;
 186                         goto finish;
 187                 }
 188
 189                 if (!de)
 190                         break;
 191
 192                 if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
 193                         continue;
 194
 195                 if (!S_ISREG(st.st_mode))
 196                         continue;
 197
 198                 q = strlen(de->d_name);
 199
 200                 if (endswith(de->d_name, ".journal")) {
 201
 202                         /* Vacuum archived files */
 203
 204                         if (q < 1 + 32 + 1 + 16 + 1 + 16 + 8)
 205                                 continue;
 206
 207                         if (de->d_name[q-8-16-1] != '-' ||
 208                             de->d_name[q-8-16-1-16-1] != '-' ||
 209                             de->d_name[q-8-16-1-16-1-32-1] != '@')
 210                                 continue;
 211
 212                         p = strdup(de->d_name);
 213                         if (!p) {
 214                                 r = -ENOMEM;
 215                                 goto finish;
 216                         }
 217
 218                         de->d_name[q-8-16-1-16-1] = 0;
 219                         if (sd_id128_from_string(de->d_name + q-8-16-1-16-1-32, &seqnum_id) < 0) {
 220                                 free(p);
 221                                 continue;
 222                         }
 223
 224                         if (sscanf(de->d_name + q-8-16-1-16, "%16llx-%16llx.journal", &seqnum, &realtime) != 2) {
 225                                 free(p);
 226                                 continue;
 227                         }
 228
 229                         have_seqnum = true;
 230
 231                 } else if (endswith(de->d_name, ".journal~")) {
 232                         unsigned long long tmp;
 233
 234                         /* Vacuum corrupted files */
 235
 236                         if (q < 1 + 16 + 1 + 16 + 8 + 1)
 237                                 continue;
 238
 239                         if (de->d_name[q-1-8-16-1] != '-' ||
 240                             de->d_name[q-1-8-16-1-16-1] != '@')
 241                                 continue;
 242
 243                         p = strdup(de->d_name);
 244                         if (!p) {
 245                                 r = -ENOMEM;
 246                                 goto finish;
 247                         }
 248
 249                         if (sscanf(de->d_name + q-1-8-16-1-16, "%16llx-%16llx.journal~", &realtime, &tmp) != 2) {
 250                                 free(p);
 251                                 continue;
 252                         }
 253
 254                         have_seqnum = false;
 255                 } else
 256                         /* We do not vacuum active files or unknown files! */
 257                         continue;
 258
 259                 if (journal_file_empty(dirfd(d), p)) {
 260                         /* Always vacuum empty non-online files. */
 261
 262                         uint64_t size = 512UL * (uint64_t) st.st_blocks;
 263
 264                         if (unlinkat(dirfd(d), p, 0) >= 0) {
 265                                 log_info("Deleted empty journal %s/%s (%"PRIu64" bytes).",
 266                                          directory, p, size);
 267                                 freed += size;
 268                         } else if (errno != ENOENT)
 269                                 log_warning("Failed to delete %s/%s: %m", directory, p);
 270
 271                         free(p);
 272
 273                         continue;
 274                 }
 275
 276                 patch_realtime(directory, p, &st, &realtime);
 277
 278                 GREEDY_REALLOC(list, n_allocated, n_list + 1);
 279
 280                 list[n_list].filename = p;
 281                 list[n_list].usage = 512UL * (uint64_t) st.st_blocks;
 282                 list[n_list].seqnum = seqnum;
 283                 list[n_list].realtime = realtime;
 284                 list[n_list].seqnum_id = seqnum_id;
 285                 list[n_list].have_seqnum = have_seqnum;
 286
 287                 sum += list[n_list].usage;
 288
 289                 n_list ++;
 290         }
 291
 292         qsort_safe(list, n_list, sizeof(struct vacuum_info), vacuum_compare);
 293
 294         for (i = 0; i < n_list; i++) {
 295                 if ((max_retention_usec <= 0 || list[i].realtime >= retention_limit) &&
 296                     (max_use <= 0 || sum <= max_use))
 297                         break;
 298
 299                 if (unlinkat(dirfd(d), list[i].filename, 0) >= 0) {
 300                         log_debug("Deleted archived journal %s/%s (%"PRIu64" bytes).",
 301                                   directory, list[i].filename, list[i].usage);
 302                         freed += list[i].usage;
 303
 304                         if (list[i].usage < sum)
 305                                 sum -= list[i].usage;
 306                         else
 307                                 sum = 0;
 308
 309                 } else if (errno != ENOENT)
 310                         log_warning("Failed to delete %s/%s: %m", directory, list[i].filename);
 311         }
 312
 313         if (oldest_usec && i < n_list && (*oldest_usec == 0 || list[i].realtime < *oldest_usec))
 314                 *oldest_usec = list[i].realtime;
 315
 316 finish:
 317         for (i = 0; i < n_list; i++)
 318                 free(list[i].filename);
 319         free(list);
 320
 321         log_debug("Vacuuming done, freed %"PRIu64" bytes", freed);
 322
 323         return r;
 324 }