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;
 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                 int k;
 184                 struct dirent *de;
 185                 union dirent_storage buf;
 186                 size_t q;
 187                 struct stat st;
 188                 char *p;
 189                 unsigned long long seqnum = 0, realtime;
 190                 sd_id128_t seqnum_id;
 191                 bool have_seqnum;
 192
 193                 k = readdir_r(d, &buf.de, &de);
 194                 if (k != 0) {
 195                         r = -k;
 196                         goto finish;
 197                 }
 198
 199                 if (!de)
 200                         break;
 201
 202                 if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
 203                         continue;
 204
 205                 if (!S_ISREG(st.st_mode))
 206                         continue;
 207
 208                 q = strlen(de->d_name);
 209
 210                 if (endswith(de->d_name, ".journal")) {
 211
 212                         /* Vacuum archived files */
 213
 214                         if (q < 1 + 32 + 1 + 16 + 1 + 16 + 8)
 215                                 continue;
 216
 217                         if (de->d_name[q-8-16-1] != '-' ||
 218                             de->d_name[q-8-16-1-16-1] != '-' ||
 219                             de->d_name[q-8-16-1-16-1-32-1] != '@')
 220                                 continue;
 221
 222                         p = strdup(de->d_name);
 223                         if (!p) {
 224                                 r = -ENOMEM;
 225                                 goto finish;
 226                         }
 227
 228                         de->d_name[q-8-16-1-16-1] = 0;
 229                         if (sd_id128_from_string(de->d_name + q-8-16-1-16-1-32, &seqnum_id) < 0) {
 230                                 free(p);
 231                                 continue;
 232                         }
 233
 234                         if (sscanf(de->d_name + q-8-16-1-16, "%16llx-%16llx.journal", &seqnum, &realtime) != 2) {
 235                                 free(p);
 236                                 continue;
 237                         }
 238
 239                         have_seqnum = true;
 240
 241                 } else if (endswith(de->d_name, ".journal~")) {
 242                         unsigned long long tmp;
 243
 244                         /* Vacuum corrupted files */
 245
 246                         if (q < 1 + 16 + 1 + 16 + 8 + 1)
 247                                 continue;
 248
 249                         if (de->d_name[q-1-8-16-1] != '-' ||
 250                             de->d_name[q-1-8-16-1-16-1] != '@')
 251                                 continue;
 252
 253                         p = strdup(de->d_name);
 254                         if (!p) {
 255                                 r = -ENOMEM;
 256                                 goto finish;
 257                         }
 258
 259                         if (sscanf(de->d_name + q-1-8-16-1-16, "%16llx-%16llx.journal~", &realtime, &tmp) != 2) {
 260                                 free(p);
 261                                 continue;
 262                         }
 263
 264                         have_seqnum = false;
 265                 } else
 266                         /* We do not vacuum active files or unknown files! */
 267                         continue;
 268
 269                 if (journal_file_empty(dirfd(d), p)) {
 270
 271                         /* Always vacuum empty non-online files. */
 272
 273                         if (unlinkat(dirfd(d), p, 0) >= 0)
 274                                 log_debug("Deleted empty journal %s/%s.", directory, p);
 275                         else if (errno != ENOENT)
 276                                 log_warning("Failed to delete %s/%s: %m", directory, p);
 277                         continue;
 278                 }
 279
 280                 patch_realtime(directory, p, &st, &realtime);
 281
 282                 GREEDY_REALLOC(list, n_allocated, n_list + 1);
 283
 284                 list[n_list].filename = p;
 285                 list[n_list].usage = 512UL * (uint64_t) st.st_blocks;
 286                 list[n_list].seqnum = seqnum;
 287                 list[n_list].realtime = realtime;
 288                 list[n_list].seqnum_id = seqnum_id;
 289                 list[n_list].have_seqnum = have_seqnum;
 290
 291                 sum += list[n_list].usage;
 292
 293                 n_list ++;
 294         }
 295
 296         if (n_list > 0)
 297                 qsort(list, n_list, sizeof(struct vacuum_info), vacuum_compare);
 298
 299         for (i = 0; i < n_list; i++) {
 300                 struct statvfs ss;
 301
 302                 if (fstatvfs(dirfd(d), &ss) < 0) {
 303                         r = -errno;
 304                         goto finish;
 305                 }
 306
 307                 if ((max_retention_usec <= 0 || list[i].realtime >= retention_limit) &&
 308                     (max_use <= 0 || sum <= max_use) &&
 309                     (min_free <= 0 || (uint64_t) ss.f_bavail * (uint64_t) ss.f_bsize >= min_free))
 310                         break;
 311
 312                 if (unlinkat(dirfd(d), list[i].filename, 0) >= 0) {
 313                         log_debug("Deleted archived journal %s/%s.", directory, list[i].filename);
 314
 315                         if (list[i].usage < sum)
 316                                 sum -= list[i].usage;
 317                         else
 318                                 sum = 0;
 319
 320                 } else if (errno != ENOENT)
 321                         log_warning("Failed to delete %s/%s: %m", directory, list[i].filename);
 322         }
 323
 324         if (oldest_usec && i < n_list && (*oldest_usec == 0 || list[i].realtime < *oldest_usec))
 325                 *oldest_usec = list[i].realtime;
 326
 327 finish:
 328         for (i = 0; i < n_list; i++)
 329                 free(list[i].filename);
 330         free(list);
 331
 332         return r;
 333 }