entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "object-store.h"
   4 #include "dir.h"
   5 #include "streaming.h"
   6 #include "submodule.h"
   7 #include "progress.h"
   8 #include "fsmonitor.h"
   9
  10 static void create_directories(const char *path, int path_len,
  11                                const struct checkout *state)
  12 {
  13         char *buf = xmallocz(path_len);
  14         int len = 0;
  15
  16         while (len < path_len) {
  17                 do {
  18                         buf[len] = path[len];
  19                         len++;
  20                 } while (len < path_len && path[len] != '/');
  21                 if (len >= path_len)
  22                         break;
  23                 buf[len] = 0;
  24
  25                 /*
  26                  * For 'checkout-index --prefix=<dir>', <dir> is
  27                  * allowed to be a symlink to an existing directory,
  28                  * and we set 'state->base_dir_len' below, such that
  29                  * we test the path components of the prefix with the
  30                  * stat() function instead of the lstat() function.
  31                  */
  32                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  33                         continue; /* ok, it is already a directory. */
  34
  35                 /*
  36                  * If this mkdir() would fail, it could be that there
  37                  * is already a symlink or something else exists
  38                  * there, therefore we then try to unlink it and try
  39                  * one more time to create the directory.
  40                  */
  41                 if (mkdir(buf, 0777)) {
  42                         if (errno == EEXIST && state->force &&
  43                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  44                                 continue;
  45                         die_errno("cannot create directory at '%s'", buf);
  46                 }
  47         }
  48         free(buf);
  49 }
  50
  51 static void remove_subtree(struct strbuf *path)
  52 {
  53         DIR *dir = opendir(path->buf);
  54         struct dirent *de;
  55         int origlen = path->len;
  56
  57         if (!dir)
  58                 die_errno("cannot opendir '%s'", path->buf);
  59         while ((de = readdir_skip_dot_and_dotdot(dir)) != NULL) {
  60                 struct stat st;
  61
  62                 strbuf_addch(path, '/');
  63                 strbuf_addstr(path, de->d_name);
  64                 if (lstat(path->buf, &st))
  65                         die_errno("cannot lstat '%s'", path->buf);
  66                 if (S_ISDIR(st.st_mode))
  67                         remove_subtree(path);
  68                 else if (unlink(path->buf))
  69                         die_errno("cannot unlink '%s'", path->buf);
  70                 strbuf_setlen(path, origlen);
  71         }
  72         closedir(dir);
  73         if (rmdir(path->buf))
  74                 die_errno("cannot rmdir '%s'", path->buf);
  75 }
  76
  77 static int create_file(const char *path, unsigned int mode)
  78 {
  79         mode = (mode & 0100) ? 0777 : 0666;
  80         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  81 }
  82
  83 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  84 {
  85         enum object_type type;
  86         void *blob_data = read_object_file(&ce->oid, &type, size);
  87
  88         if (blob_data) {
  89                 if (type == OBJ_BLOB)
  90                         return blob_data;
  91                 free(blob_data);
  92         }
  93         return NULL;
  94 }
  95
  96 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
  97 {
  98         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
  99         if (to_tempfile) {
 100                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
 101                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 102                 return mkstemp(path);
 103         } else {
 104                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 105         }
 106 }
 107
 108 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 109 {
 110         /* use fstat() only when path == ce->name */
 111         if (fstat_is_reliable() &&
 112             state->refresh_cache && !state->base_dir_len) {
 113                 return !fstat(fd, st);
 114         }
 115         return 0;
 116 }
 117
 118 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 119                                  struct stream_filter *filter,
 120                                  const struct checkout *state, int to_tempfile,
 121                                  int *fstat_done, struct stat *statbuf)
 122 {
 123         int result = 0;
 124         int fd;
 125
 126         fd = open_output_fd(path, ce, to_tempfile);
 127         if (fd < 0)
 128                 return -1;
 129
 130         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
 131         *fstat_done = fstat_output(fd, state, statbuf);
 132         result |= close(fd);
 133
 134         if (result)
 135                 unlink(path);
 136         return result;
 137 }
 138
 139 void enable_delayed_checkout(struct checkout *state)
 140 {
 141         if (!state->delayed_checkout) {
 142                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 143                 state->delayed_checkout->state = CE_CAN_DELAY;
 144                 string_list_init(&state->delayed_checkout->filters, 0);
 145                 string_list_init(&state->delayed_checkout->paths, 0);
 146         }
 147 }
 148
 149 static int remove_available_paths(struct string_list_item *item, void *cb_data)
 150 {
 151         struct string_list *available_paths = cb_data;
 152         struct string_list_item *available;
 153
 154         available = string_list_lookup(available_paths, item->string);
 155         if (available)
 156                 available->util = (void *)item->string;
 157         return !available;
 158 }
 159
 160 int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 161 {
 162         int errs = 0;
 163         unsigned delayed_object_count;
 164         off_t filtered_bytes = 0;
 165         struct string_list_item *filter, *path;
 166         struct progress *progress;
 167         struct delayed_checkout *dco = state->delayed_checkout;
 168
 169         if (!state->delayed_checkout)
 170                 return errs;
 171
 172         dco->state = CE_RETRY;
 173         delayed_object_count = dco->paths.nr;
 174         progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
 175         while (dco->filters.nr > 0) {
 176                 for_each_string_list_item(filter, &dco->filters) {
 177                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
 178                         display_progress(progress, delayed_object_count - dco->paths.nr);
 179
 180                         if (!async_query_available_blobs(filter->string, &available_paths)) {
 181                                 /* Filter reported an error */
 182                                 errs = 1;
 183                                 filter->string = "";
 184                                 continue;
 185                         }
 186                         if (available_paths.nr <= 0) {
 187                                 /*
 188                                  * Filter responded with no entries. That means
 189                                  * the filter is done and we can remove the
 190                                  * filter from the list (see
 191                                  * "string_list_remove_empty_items" call below).
 192                                  */
 193                                 filter->string = "";
 194                                 continue;
 195                         }
 196
 197                         /*
 198                          * In dco->paths we store a list of all delayed paths.
 199                          * The filter just send us a list of available paths.
 200                          * Remove them from the list.
 201                          */
 202                         filter_string_list(&dco->paths, 0,
 203                                 &remove_available_paths, &available_paths);
 204
 205                         for_each_string_list_item(path, &available_paths) {
 206                                 struct cache_entry* ce;
 207
 208                                 if (!path->util) {
 209                                         error("external filter '%s' signaled that '%s' "
 210                                               "is now available although it has not been "
 211                                               "delayed earlier",
 212                                               filter->string, path->string);
 213                                         errs |= 1;
 214
 215                                         /*
 216                                          * Do not ask the filter for available blobs,
 217                                          * again, as the filter is likely buggy.
 218                                          */
 219                                         filter->string = "";
 220                                         continue;
 221                                 }
 222                                 ce = index_file_exists(state->istate, path->string,
 223                                                        strlen(path->string), 0);
 224                                 if (ce) {
 225                                         errs |= checkout_entry(ce, state, NULL, nr_checkouts);
 226                                         filtered_bytes += ce->ce_stat_data.sd_size;
 227                                         display_throughput(progress, filtered_bytes);
 228                                 } else
 229                                         errs = 1;
 230                         }
 231                 }
 232                 string_list_remove_empty_items(&dco->filters, 0);
 233         }
 234         stop_progress(&progress);
 235         string_list_clear(&dco->filters, 0);
 236
 237         /* At this point we should not have any delayed paths anymore. */
 238         errs |= dco->paths.nr;
 239         for_each_string_list_item(path, &dco->paths) {
 240                 error("'%s' was not filtered properly", path->string);
 241         }
 242         string_list_clear(&dco->paths, 0);
 243
 244         free(dco);
 245         state->delayed_checkout = NULL;
 246
 247         return errs;
 248 }
 249
 250 static int write_entry(struct cache_entry *ce,
 251                        char *path, const struct checkout *state, int to_tempfile)
 252 {
 253         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 254         struct delayed_checkout *dco = state->delayed_checkout;
 255         int fd, ret, fstat_done = 0;
 256         char *new_blob;
 257         struct strbuf buf = STRBUF_INIT;
 258         unsigned long size;
 259         ssize_t wrote;
 260         size_t newsize = 0;
 261         struct stat st;
 262         const struct submodule *sub;
 263         struct checkout_metadata meta;
 264
 265         clone_checkout_metadata(&meta, &state->meta, &ce->oid);
 266
 267         if (ce_mode_s_ifmt == S_IFREG) {
 268                 struct stream_filter *filter = get_stream_filter(state->istate, ce->name,
 269                                                                  &ce->oid);
 270                 if (filter &&
 271                     !streaming_write_entry(ce, path, filter,
 272                                            state, to_tempfile,
 273                                            &fstat_done, &st))
 274                         goto finish;
 275         }
 276
 277         switch (ce_mode_s_ifmt) {
 278         case S_IFLNK:
 279                 new_blob = read_blob_entry(ce, &size);
 280                 if (!new_blob)
 281                         return error("unable to read sha1 file of %s (%s)",
 282                                      ce->name, oid_to_hex(&ce->oid));
 283
 284                 /*
 285                  * We can't make a real symlink; write out a regular file entry
 286                  * with the symlink destination as its contents.
 287                  */
 288                 if (!has_symlinks || to_tempfile)
 289                         goto write_file_entry;
 290
 291                 ret = symlink(new_blob, path);
 292                 free(new_blob);
 293                 if (ret)
 294                         return error_errno("unable to create symlink %s", path);
 295                 break;
 296
 297         case S_IFREG:
 298                 /*
 299                  * We do not send the blob in case of a retry, so do not
 300                  * bother reading it at all.
 301                  */
 302                 if (dco && dco->state == CE_RETRY) {
 303                         new_blob = NULL;
 304                         size = 0;
 305                 } else {
 306                         new_blob = read_blob_entry(ce, &size);
 307                         if (!new_blob)
 308                                 return error("unable to read sha1 file of %s (%s)",
 309                                              ce->name, oid_to_hex(&ce->oid));
 310                 }
 311
 312                 /*
 313                  * Convert from git internal format to working tree format
 314                  */
 315                 if (dco && dco->state != CE_NO_DELAY) {
 316                         ret = async_convert_to_working_tree(state->istate, ce->name, new_blob,
 317                                                             size, &buf, &meta, dco);
 318                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
 319                                 free(new_blob);
 320                                 goto delayed;
 321                         }
 322                 } else
 323                         ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf, &meta);
 324
 325                 if (ret) {
 326                         free(new_blob);
 327                         new_blob = strbuf_detach(&buf, &newsize);
 328                         size = newsize;
 329                 }
 330                 /*
 331                  * No "else" here as errors from convert are OK at this
 332                  * point. If the error would have been fatal (e.g.
 333                  * filter is required), then we would have died already.
 334                  */
 335
 336         write_file_entry:
 337                 fd = open_output_fd(path, ce, to_tempfile);
 338                 if (fd < 0) {
 339                         free(new_blob);
 340                         return error_errno("unable to create file %s", path);
 341                 }
 342
 343                 wrote = write_in_full(fd, new_blob, size);
 344                 if (!to_tempfile)
 345                         fstat_done = fstat_output(fd, state, &st);
 346                 close(fd);
 347                 free(new_blob);
 348                 if (wrote < 0)
 349                         return error("unable to write file %s", path);
 350                 break;
 351
 352         case S_IFGITLINK:
 353                 if (to_tempfile)
 354                         return error("cannot create temporary submodule %s", ce->name);
 355                 if (mkdir(path, 0777) < 0)
 356                         return error("cannot create submodule directory %s", path);
 357                 sub = submodule_from_ce(ce);
 358                 if (sub)
 359                         return submodule_move_head(ce->name,
 360                                 NULL, oid_to_hex(&ce->oid),
 361                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 362                 break;
 363
 364         default:
 365                 return error("unknown file mode for %s in index", ce->name);
 366         }
 367
 368 finish:
 369         if (state->refresh_cache) {
 370                 assert(state->istate);
 371                 if (!fstat_done)
 372                         if (lstat(ce->name, &st) < 0)
 373                                 return error_errno("unable to stat just-written file %s",
 374                                                    ce->name);
 375                 fill_stat_cache_info(state->istate, ce, &st);
 376                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 377                 mark_fsmonitor_invalid(state->istate, ce);
 378                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 379         }
 380 delayed:
 381         return 0;
 382 }
 383
 384 /*
 385  * This is like 'lstat()', except it refuses to follow symlinks
 386  * in the path, after skipping "skiplen".
 387  */
 388 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 389 {
 390         const char *slash = path + len;
 391
 392         while (path < slash && *slash != '/')
 393                 slash--;
 394         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 395                 errno = ENOENT;
 396                 return -1;
 397         }
 398         return lstat(path, st);
 399 }
 400
 401 static void mark_colliding_entries(const struct checkout *state,
 402                                    struct cache_entry *ce, struct stat *st)
 403 {
 404         int i, trust_ino = check_stat;
 405
 406 #if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)
 407         trust_ino = 0;
 408 #endif
 409
 410         ce->ce_flags |= CE_MATCHED;
 411
 412         for (i = 0; i < state->istate->cache_nr; i++) {
 413                 struct cache_entry *dup = state->istate->cache[i];
 414
 415                 if (dup == ce)
 416                         break;
 417
 418                 if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))
 419                         continue;
 420
 421                 if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||
 422                     (!trust_ino && !fspathcmp(ce->name, dup->name))) {
 423                         dup->ce_flags |= CE_MATCHED;
 424                         break;
 425                 }
 426         }
 427 }
 428
 429 /*
 430  * Write the contents from ce out to the working tree.
 431  *
 432  * When topath[] is not NULL, instead of writing to the working tree
 433  * file named by ce, a temporary file is created by this function and
 434  * its name is returned in topath[], which must be able to hold at
 435  * least TEMPORARY_FILENAME_LENGTH bytes long.
 436  */
 437 int checkout_entry(struct cache_entry *ce, const struct checkout *state,
 438                    char *topath, int *nr_checkouts)
 439 {
 440         static struct strbuf path = STRBUF_INIT;
 441         struct stat st;
 442
 443         if (ce->ce_flags & CE_WT_REMOVE) {
 444                 if (topath)
 445                         /*
 446                          * No content and thus no path to create, so we have
 447                          * no pathname to return.
 448                          */
 449                         BUG("Can't remove entry to a path");
 450                 unlink_entry(ce);
 451                 return 0;
 452         }
 453
 454         if (topath)
 455                 return write_entry(ce, topath, state, 1);
 456
 457         strbuf_reset(&path);
 458         strbuf_add(&path, state->base_dir, state->base_dir_len);
 459         strbuf_add(&path, ce->name, ce_namelen(ce));
 460
 461         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 462                 const struct submodule *sub;
 463                 unsigned changed = ie_match_stat(state->istate, ce, &st,
 464                                                  CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
 465                 /*
 466                  * Needs to be checked before !changed returns early,
 467                  * as the possibly empty directory was not changed
 468                  */
 469                 sub = submodule_from_ce(ce);
 470                 if (sub) {
 471                         int err;
 472                         if (!is_submodule_populated_gently(ce->name, &err)) {
 473                                 struct stat sb;
 474                                 if (lstat(ce->name, &sb))
 475                                         die(_("could not stat file '%s'"), ce->name);
 476                                 if (!(st.st_mode & S_IFDIR))
 477                                         unlink_or_warn(ce->name);
 478
 479                                 return submodule_move_head(ce->name,
 480                                         NULL, oid_to_hex(&ce->oid), 0);
 481                         } else
 482                                 return submodule_move_head(ce->name,
 483                                         "HEAD", oid_to_hex(&ce->oid),
 484                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 485                 }
 486
 487                 if (!changed)
 488                         return 0;
 489                 if (!state->force) {
 490                         if (!state->quiet)
 491                                 fprintf(stderr,
 492                                         "%s already exists, no checkout\n",
 493                                         path.buf);
 494                         return -1;
 495                 }
 496
 497                 if (state->clone)
 498                         mark_colliding_entries(state, ce, &st);
 499
 500                 /*
 501                  * We unlink the old file, to get the new one with the
 502                  * right permissions (including umask, which is nasty
 503                  * to emulate by hand - much easier to let the system
 504                  * just do the right thing)
 505                  */
 506                 if (S_ISDIR(st.st_mode)) {
 507                         /* If it is a gitlink, leave it alone! */
 508                         if (S_ISGITLINK(ce->ce_mode))
 509                                 return 0;
 510                         remove_subtree(&path);
 511                 } else if (unlink(path.buf))
 512                         return error_errno("unable to unlink old '%s'", path.buf);
 513         } else if (state->not_new)
 514                 return 0;
 515
 516         create_directories(path.buf, path.len, state);
 517         if (nr_checkouts)
 518                 (*nr_checkouts)++;
 519         return write_entry(ce, path.buf, state, 0);
 520 }
 521
 522 void unlink_entry(const struct cache_entry *ce)
 523 {
 524         const struct submodule *sub = submodule_from_ce(ce);
 525         if (sub) {
 526                 /* state.force is set at the caller. */
 527                 submodule_move_head(ce->name, "HEAD", NULL,
 528                                     SUBMODULE_MOVE_HEAD_FORCE);
 529         }
 530         if (!check_leading_path(ce->name, ce_namelen(ce)))
 531                 return;
 532         if (remove_or_warn(ce->ce_mode, ce->name))
 533                 return;
 534         schedule_dir_for_removal(ce->name, ce_namelen(ce));
 535 }