src/libsystemd/sd-journal/journal-vacuum.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/stat.h>
   5 #include <unistd.h>
   6
   7 #include "sd-id128.h"
   8
   9 #include "alloc-util.h"
  10 #include "dirent-util.h"
  11 #include "fd-util.h"
  12 #include "format-util.h"
  13 #include "fs-util.h"
  14 #include "journal-def.h"
  15 #include "journal-file.h"
  16 #include "journal-vacuum.h"
  17 #include "sort-util.h"
  18 #include "string-util.h"
  19 #include "time-util.h"
  20 #include "xattr-util.h"
  21
  22 struct vacuum_info {
  23         uint64_t usage;
  24         char *filename;
  25
  26         uint64_t realtime;
  27
  28         sd_id128_t seqnum_id;
  29         uint64_t seqnum;
  30         bool have_seqnum;
  31 };
  32
  33 static int vacuum_compare(const struct vacuum_info *a, const struct vacuum_info *b) {
  34         int r;
  35
  36         if (a->have_seqnum && b->have_seqnum &&
  37             sd_id128_equal(a->seqnum_id, b->seqnum_id))
  38                 return CMP(a->seqnum, b->seqnum);
  39
  40         r = CMP(a->realtime, b->realtime);
  41         if (r != 0)
  42                 return r;
  43
  44         if (a->have_seqnum && b->have_seqnum)
  45                 return memcmp(&a->seqnum_id, &b->seqnum_id, 16);
  46
  47         return strcmp(a->filename, b->filename);
  48 }
  49
  50 static void patch_realtime(
  51                 int fd,
  52                 const char *fn,
  53                 const struct stat *st,
  54                 unsigned long long *realtime) {
  55
  56         usec_t x;
  57
  58         /* The timestamp was determined by the file name, but let's see if the file might actually be older
  59          * than the file name suggested... */
  60
  61         assert(fd >= 0);
  62         assert(fn);
  63         assert(st);
  64         assert(realtime);
  65
  66         x = timespec_load(&st->st_ctim);
  67         if (x > 0 && x != USEC_INFINITY && x < *realtime)
  68                 *realtime = x;
  69
  70         x = timespec_load(&st->st_atim);
  71         if (x > 0 && x != USEC_INFINITY && x < *realtime)
  72                 *realtime = x;
  73
  74         x = timespec_load(&st->st_mtim);
  75         if (x > 0 && x != USEC_INFINITY && x < *realtime)
  76                 *realtime = x;
  77
  78         /* Let's read the original creation time, if possible. Ideally we'd just query the creation time the
  79          * FS might provide, but unfortunately there's currently no sane API to query it. Hence let's
  80          * implement this manually... */
  81
  82         if (fd_getcrtime_at(fd, fn, AT_SYMLINK_FOLLOW, &x) >= 0 && x < *realtime)
  83                 *realtime = x;
  84 }
  85
  86 static int journal_file_empty(int dir_fd, const char *name) {
  87         _cleanup_close_ int fd = -1;
  88         struct stat st;
  89         le64_t n_entries;
  90         ssize_t n;
  91
  92         fd = openat(dir_fd, name, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK|O_NOATIME);
  93         if (fd < 0) {
  94                 /* Maybe failed due to O_NOATIME and lack of privileges? */
  95                 fd = openat(dir_fd, name, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
  96                 if (fd < 0)
  97                         return -errno;
  98         }
  99
 100         if (fstat(fd, &st) < 0)
 101                 return -errno;
 102
 103         /* If an offline file doesn't even have a header we consider it empty */
 104         if (st.st_size < (off_t) sizeof(Header))
 105                 return 1;
 106
 107         /* If the number of entries is empty, we consider it empty, too */
 108         n = pread(fd, &n_entries, sizeof(n_entries), offsetof(Header, n_entries));
 109         if (n < 0)
 110                 return -errno;
 111         if (n != sizeof(n_entries))
 112                 return -EIO;
 113
 114         return le64toh(n_entries) <= 0;
 115 }
 116
 117 int journal_directory_vacuum(
 118                 const char *directory,
 119                 uint64_t max_use,
 120                 uint64_t n_max_files,
 121                 usec_t max_retention_usec,
 122                 usec_t *oldest_usec,
 123                 bool verbose) {
 124
 125         uint64_t sum = 0, freed = 0, n_active_files = 0;
 126         size_t n_list = 0, i;
 127         _cleanup_closedir_ DIR *d = NULL;
 128         struct vacuum_info *list = NULL;
 129         usec_t retention_limit = 0;
 130         struct dirent *de;
 131         int r;
 132
 133         assert(directory);
 134
 135         if (max_use <= 0 && max_retention_usec <= 0 && n_max_files <= 0)
 136                 return 0;
 137
 138         if (max_retention_usec > 0)
 139                 retention_limit = usec_sub_unsigned(now(CLOCK_REALTIME), max_retention_usec);
 140
 141         d = opendir(directory);
 142         if (!d)
 143                 return -errno;
 144
 145         FOREACH_DIRENT_ALL(de, d, r = -errno; goto finish) {
 146                 unsigned long long seqnum = 0, realtime;
 147                 _cleanup_free_ char *p = NULL;
 148                 sd_id128_t seqnum_id;
 149                 bool have_seqnum;
 150                 uint64_t size;
 151                 struct stat st;
 152                 size_t q;
 153
 154                 if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
 155                         log_debug_errno(errno, "Failed to stat file %s while vacuuming, ignoring: %m", de->d_name);
 156                         continue;
 157                 }
 158
 159                 if (!S_ISREG(st.st_mode))
 160                         continue;
 161
 162                 q = strlen(de->d_name);
 163
 164                 if (endswith(de->d_name, ".journal")) {
 165
 166                         /* Vacuum archived files. Active files are
 167                          * left around */
 168
 169                         if (q < 1 + 32 + 1 + 16 + 1 + 16 + 8) {
 170                                 n_active_files++;
 171                                 continue;
 172                         }
 173
 174                         if (de->d_name[q-8-16-1] != '-' ||
 175                             de->d_name[q-8-16-1-16-1] != '-' ||
 176                             de->d_name[q-8-16-1-16-1-32-1] != '@') {
 177                                 n_active_files++;
 178                                 continue;
 179                         }
 180
 181                         p = strdup(de->d_name);
 182                         if (!p) {
 183                                 r = -ENOMEM;
 184                                 goto finish;
 185                         }
 186
 187                         de->d_name[q-8-16-1-16-1] = 0;
 188                         if (sd_id128_from_string(de->d_name + q-8-16-1-16-1-32, &seqnum_id) < 0) {
 189                                 n_active_files++;
 190                                 continue;
 191                         }
 192
 193                         if (sscanf(de->d_name + q-8-16-1-16, "%16llx-%16llx.journal", &seqnum, &realtime) != 2) {
 194                                 n_active_files++;
 195                                 continue;
 196                         }
 197
 198                         have_seqnum = true;
 199
 200                 } else if (endswith(de->d_name, ".journal~")) {
 201                         unsigned long long tmp;
 202
 203                         /* seqnum_id won't be initialised before use below, so set to 0 */
 204                         seqnum_id = SD_ID128_NULL;
 205
 206                         /* Vacuum corrupted files */
 207
 208                         if (q < 1 + 16 + 1 + 16 + 8 + 1) {
 209                                 n_active_files++;
 210                                 continue;
 211                         }
 212
 213                         if (de->d_name[q-1-8-16-1] != '-' ||
 214                             de->d_name[q-1-8-16-1-16-1] != '@') {
 215                                 n_active_files++;
 216                                 continue;
 217                         }
 218
 219                         p = strdup(de->d_name);
 220                         if (!p) {
 221                                 r = -ENOMEM;
 222                                 goto finish;
 223                         }
 224
 225                         if (sscanf(de->d_name + q-1-8-16-1-16, "%16llx-%16llx.journal~", &realtime, &tmp) != 2) {
 226                                 n_active_files++;
 227                                 continue;
 228                         }
 229
 230                         have_seqnum = false;
 231                 } else {
 232                         /* We do not vacuum unknown files! */
 233                         log_debug("Not vacuuming unknown file %s.", de->d_name);
 234                         continue;
 235                 }
 236
 237                 size = 512UL * (uint64_t) st.st_blocks;
 238
 239                 r = journal_file_empty(dirfd(d), p);
 240                 if (r < 0) {
 241                         log_debug_errno(r, "Failed check if %s is empty, ignoring: %m", p);
 242                         continue;
 243                 }
 244                 if (r > 0) {
 245                         /* Always vacuum empty non-online files. */
 246
 247                         r = unlinkat_deallocate(dirfd(d), p, 0);
 248                         if (r >= 0) {
 249
 250                                 log_full(verbose ? LOG_INFO : LOG_DEBUG,
 251                                          "Deleted empty archived journal %s/%s (%s).", directory, p, FORMAT_BYTES(size));
 252
 253                                 freed += size;
 254                         } else if (r != -ENOENT)
 255                                 log_warning_errno(r, "Failed to delete empty archived journal %s/%s: %m", directory, p);
 256
 257                         continue;
 258                 }
 259
 260                 patch_realtime(dirfd(d), p, &st, &realtime);
 261
 262                 if (!GREEDY_REALLOC(list, n_list + 1)) {
 263                         r = -ENOMEM;
 264                         goto finish;
 265                 }
 266
 267                 list[n_list++] = (struct vacuum_info) {
 268                         .filename = TAKE_PTR(p),
 269                         .usage = size,
 270                         .seqnum = seqnum,
 271                         .realtime = realtime,
 272                         .seqnum_id = seqnum_id,
 273                         .have_seqnum = have_seqnum,
 274                 };
 275
 276                 sum += size;
 277         }
 278
 279         typesafe_qsort(list, n_list, vacuum_compare);
 280
 281         for (i = 0; i < n_list; i++) {
 282                 uint64_t left;
 283
 284                 left = n_active_files + n_list - i;
 285
 286                 if ((max_retention_usec <= 0 || list[i].realtime >= retention_limit) &&
 287                     (max_use <= 0 || sum <= max_use) &&
 288                     (n_max_files <= 0 || left <= n_max_files))
 289                         break;
 290
 291                 r = unlinkat_deallocate(dirfd(d), list[i].filename, 0);
 292                 if (r >= 0) {
 293                         log_full(verbose ? LOG_INFO : LOG_DEBUG, "Deleted archived journal %s/%s (%s).",
 294                                  directory, list[i].filename, FORMAT_BYTES(list[i].usage));
 295                         freed += list[i].usage;
 296
 297                         if (list[i].usage < sum)
 298                                 sum -= list[i].usage;
 299                         else
 300                                 sum = 0;
 301
 302                 } else if (r != -ENOENT)
 303                         log_warning_errno(r, "Failed to delete archived journal %s/%s: %m", directory, list[i].filename);
 304         }
 305
 306         if (oldest_usec && i < n_list && (*oldest_usec == 0 || list[i].realtime < *oldest_usec))
 307                 *oldest_usec = list[i].realtime;
 308
 309         r = 0;
 310
 311 finish:
 312         for (i = 0; i < n_list; i++)
 313                 free(list[i].filename);
 314         free(list);
 315
 316         log_full(verbose ? LOG_INFO : LOG_DEBUG, "Vacuuming done, freed %s of archived journals from %s.",
 317                  FORMAT_BYTES(freed), directory);
 318
 319         return r;
 320 }