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
  28 #ifdef HAVE_XATTR
  29 #include <attr/xattr.h>
  30 #endif
  31
  32 #include "journal-def.h"
  33 #include "journal-file.h"
  34 #include "journal-vacuum.h"
  35 #include "sd-id128.h"
  36 #include "util.h"
  37
  38 struct vacuum_info {
  39         uint64_t usage;
  40         char *filename;
  41
  42         uint64_t realtime;
  43         sd_id128_t seqnum_id;
  44         uint64_t seqnum;
  45
  46         bool have_seqnum;
  47 };
  48
  49 static int vacuum_compare(const void *_a, const void *_b) {
  50         const struct vacuum_info *a, *b;
  51
  52         a = _a;
  53         b = _b;
  54
  55         if (a->have_seqnum && b->have_seqnum &&
  56             sd_id128_equal(a->seqnum_id, b->seqnum_id)) {
  57                 if (a->seqnum < b->seqnum)
  58                         return -1;
  59                 else if (a->seqnum > b->seqnum)
  60                         return 1;
  61                 else
  62                         return 0;
  63         }
  64
  65         if (a->realtime < b->realtime)
  66                 return -1;
  67         else if (a->realtime > b->realtime)
  68                 return 1;
  69         else if (a->have_seqnum && b->have_seqnum)
  70                 return memcmp(&a->seqnum_id, &b->seqnum_id, 16);
  71         else
  72                 return strcmp(a->filename, b->filename);
  73 }
  74
  75 static void patch_realtime(
  76                 const char *dir,
  77                 const char *fn,
  78                 const struct stat *st,
  79                 unsigned long long *realtime) {
  80
  81         usec_t x;
  82
  83 #ifdef HAVE_XATTR
  84         uint64_t crtime;
  85         _cleanup_free_ const char *path = NULL;
  86 #endif
  87
  88         /* The timestamp was determined by the file name, but let's
  89          * see if the file might actually be older than the file name
  90          * suggested... */
  91
  92         assert(dir);
  93         assert(fn);
  94         assert(st);
  95         assert(realtime);
  96
  97         x = timespec_load(&st->st_ctim);
  98         if (x > 0 && x != (usec_t) -1 && x < *realtime)
  99                 *realtime = x;
 100
 101         x = timespec_load(&st->st_atim);
 102         if (x > 0 && x != (usec_t) -1 && x < *realtime)
 103                 *realtime = x;
 104
 105         x = timespec_load(&st->st_mtim);
 106         if (x > 0 && x != (usec_t) -1 && x < *realtime)
 107                 *realtime = x;
 108
 109 #ifdef HAVE_XATTR
 110         /* Let's read the original creation time, if possible. Ideally
 111          * we'd just query the creation time the FS might provide, but
 112          * unfortunately there's currently no sane API to query
 113          * it. Hence let's implement this manually... */
 114
 115         /* Unfortunately there is is not fgetxattrat(), so we need to
 116          * go via path here. :-( */
 117
 118         path = strjoin(dir, "/", fn, NULL);
 119         if (!path)
 120                 return;
 121
 122         if (getxattr(path, "user.crtime_usec", &crtime, sizeof(crtime)) == sizeof(crtime)) {
 123                 crtime = le64toh(crtime);
 124
 125                 if (crtime > 0 && crtime != (uint64_t) -1 && crtime < *realtime)
 126                         *realtime = crtime;
 127         }
 128 #endif
 129 }
 130
 131 static int journal_file_empty(int dir_fd, const char *name) {
 132         int r;
 133         le64_t n_entries;
 134         _cleanup_close_ int fd;
 135
 136         fd = openat(dir_fd, name, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
 137         if (fd < 0)
 138                 return -errno;
 139
 140         if (lseek(fd, offsetof(Header, n_entries), SEEK_SET) < 0)
 141                 return -errno;
 142
 143         r = read(fd, &n_entries, sizeof(n_entries));
 144         if (r != sizeof(n_entries))
 145                 return r == 0 ? -EINVAL : -errno;
 146
 147         return le64toh(n_entries) == 0;
 148 }
 149
 150 int journal_directory_vacuum(
 151                 const char *directory,
 152                 uint64_t max_use,
 153                 uint64_t min_free,
 154                 usec_t max_retention_usec,
 155                 usec_t *oldest_usec) {
 156
 157         _cleanup_closedir_ DIR *d = NULL;
 158         int r = 0;
 159         struct vacuum_info *list = NULL;
 160         unsigned n_list = 0, i;
 161         size_t n_allocated = 0;
 162         uint64_t sum = 0, freed = 0;
 163         usec_t retention_limit = 0;
 164
 165         assert(directory);
 166
 167         if (max_use <= 0 && min_free <= 0 && max_retention_usec <= 0)
 168                 return 0;
 169
 170         if (max_retention_usec > 0) {
 171                 retention_limit = now(CLOCK_REALTIME);
 172                 if (retention_limit > max_retention_usec)
 173                         retention_limit -= max_retention_usec;
 174                 else
 175                         max_retention_usec = retention_limit = 0;
 176         }
 177
 178         d = opendir(directory);
 179         if (!d)
 180                 return -errno;
 181
 182         for (;;) {
 183                 struct dirent *de;
 184                 size_t q;
 185                 struct stat st;
 186                 char *p;
 187                 unsigned long long seqnum = 0, realtime;
 188                 sd_id128_t seqnum_id;
 189                 bool have_seqnum;
 190
 191                 errno = 0;
 192                 de = readdir(d);
 193                 if (!de && errno != 0) {
 194                         r = -errno;
 195                         goto finish;
 196                 }
 197
 198                 if (!de)
 199                         break;
 200
 201                 if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
 202                         continue;
 203
 204                 if (!S_ISREG(st.st_mode))
 205                         continue;
 206
 207                 q = strlen(de->d_name);
 208
 209                 if (endswith(de->d_name, ".journal")) {
 210
 211                         /* Vacuum archived files */
 212
 213                         if (q < 1 + 32 + 1 + 16 + 1 + 16 + 8)
 214                                 continue;
 215
 216                         if (de->d_name[q-8-16-1] != '-' ||
 217                             de->d_name[q-8-16-1-16-1] != '-' ||
 218                             de->d_name[q-8-16-1-16-1-32-1] != '@')
 219                                 continue;
 220
 221                         p = strdup(de->d_name);
 222                         if (!p) {
 223                                 r = -ENOMEM;
 224                                 goto finish;
 225                         }
 226
 227                         de->d_name[q-8-16-1-16-1] = 0;
 228                         if (sd_id128_from_string(de->d_name + q-8-16-1-16-1-32, &seqnum_id) < 0) {
 229                                 free(p);
 230                                 continue;
 231                         }
 232
 233                         if (sscanf(de->d_name + q-8-16-1-16, "%16llx-%16llx.journal", &seqnum, &realtime) != 2) {
 234                                 free(p);
 235                                 continue;
 236                         }
 237
 238                         have_seqnum = true;
 239
 240                 } else if (endswith(de->d_name, ".journal~")) {
 241                         unsigned long long tmp;
 242
 243                         /* Vacuum corrupted files */
 244
 245                         if (q < 1 + 16 + 1 + 16 + 8 + 1)
 246                                 continue;
 247
 248                         if (de->d_name[q-1-8-16-1] != '-' ||
 249                             de->d_name[q-1-8-16-1-16-1] != '@')
 250                                 continue;
 251
 252                         p = strdup(de->d_name);
 253                         if (!p) {
 254                                 r = -ENOMEM;
 255                                 goto finish;
 256                         }
 257
 258                         if (sscanf(de->d_name + q-1-8-16-1-16, "%16llx-%16llx.journal~", &realtime, &tmp) != 2) {
 259                                 free(p);
 260                                 continue;
 261                         }
 262
 263                         have_seqnum = false;
 264                 } else
 265                         /* We do not vacuum active files or unknown files! */
 266                         continue;
 267
 268                 if (journal_file_empty(dirfd(d), p)) {
 269                         /* Always vacuum empty non-online files. */
 270
 271                         uint64_t size = 512UL * (uint64_t) st.st_blocks;
 272
 273                         if (unlinkat(dirfd(d), p, 0) >= 0) {
 274                                 log_info("Deleted empty journal %s/%s (%"PRIu64" bytes).",
 275                                          directory, p, size);
 276                                 freed += size;
 277                         } else if (errno != ENOENT)
 278                                 log_warning("Failed to delete %s/%s: %m", directory, p);
 279
 280                         free(p);
 281
 282                         continue;
 283                 }
 284
 285                 patch_realtime(directory, p, &st, &realtime);
 286
 287                 GREEDY_REALLOC(list, n_allocated, n_list + 1);
 288
 289                 list[n_list].filename = p;
 290                 list[n_list].usage = 512UL * (uint64_t) st.st_blocks;
 291                 list[n_list].seqnum = seqnum;
 292                 list[n_list].realtime = realtime;
 293                 list[n_list].seqnum_id = seqnum_id;
 294                 list[n_list].have_seqnum = have_seqnum;
 295
 296                 sum += list[n_list].usage;
 297
 298                 n_list ++;
 299         }
 300
 301         qsort_safe(list, n_list, sizeof(struct vacuum_info), vacuum_compare);
 302
 303         for (i = 0; i < n_list; i++) {
 304                 struct statvfs ss;
 305
 306                 if (fstatvfs(dirfd(d), &ss) < 0) {
 307                         r = -errno;
 308                         goto finish;
 309                 }
 310
 311                 if ((max_retention_usec <= 0 || list[i].realtime >= retention_limit) &&
 312                     (max_use <= 0 || sum <= max_use) &&
 313                     (min_free <= 0 || (uint64_t) ss.f_bavail * (uint64_t) ss.f_bsize >= min_free))
 314                         break;
 315
 316                 if (unlinkat(dirfd(d), list[i].filename, 0) >= 0) {
 317                         log_debug("Deleted archived journal %s/%s (%"PRIu64" bytes).",
 318                                   directory, list[i].filename, list[i].usage);
 319                         freed += list[i].usage;
 320
 321                         if (list[i].usage < sum)
 322                                 sum -= list[i].usage;
 323                         else
 324                                 sum = 0;
 325
 326                 } else if (errno != ENOENT)
 327                         log_warning("Failed to delete %s/%s: %m", directory, list[i].filename);
 328         }
 329
 330         if (oldest_usec && i < n_list && (*oldest_usec == 0 || list[i].realtime < *oldest_usec))
 331                 *oldest_usec = list[i].realtime;
 332
 333 finish:
 334         for (i = 0; i < n_list; i++)
 335                 free(list[i].filename);
 336         free(list);
 337
 338         log_info("Vacuuming done, freed %"PRIu64" bytes", freed);
 339
 340         return r;
 341 }