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(dir)) != NULL) {
  60                 struct stat st;
  61
  62                 if (is_dot_or_dotdot(de->d_name))
  63                         continue;
  64
  65                 strbuf_addch(path, '/');
  66                 strbuf_addstr(path, de->d_name);
  67                 if (lstat(path->buf, &st))
  68                         die_errno("cannot lstat '%s'", path->buf);
  69                 if (S_ISDIR(st.st_mode))
  70                         remove_subtree(path);
  71                 else if (unlink(path->buf))
  72                         die_errno("cannot unlink '%s'", path->buf);
  73                 strbuf_setlen(path, origlen);
  74         }
  75         closedir(dir);
  76         if (rmdir(path->buf))
  77                 die_errno("cannot rmdir '%s'", path->buf);
  78 }
  79
  80 static int create_file(const char *path, unsigned int mode)
  81 {
  82         mode = (mode & 0100) ? 0777 : 0666;
  83         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  84 }
  85
  86 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  87 {
  88         enum object_type type;
  89         void *blob_data = read_object_file(&ce->oid, &type, size);
  90
  91         if (blob_data) {
  92                 if (type == OBJ_BLOB)
  93                         return blob_data;
  94                 free(blob_data);
  95         }
  96         return NULL;
  97 }
  98
  99 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
 100 {
 101         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
 102         if (to_tempfile) {
 103                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
 104                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 105                 return mkstemp(path);
 106         } else {
 107                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 108         }
 109 }
 110
 111 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 112 {
 113         /* use fstat() only when path == ce->name */
 114         if (fstat_is_reliable() &&
 115             state->refresh_cache && !state->base_dir_len) {
 116                 return !fstat(fd, st);
 117         }
 118         return 0;
 119 }
 120
 121 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 122                                  struct stream_filter *filter,
 123                                  const struct checkout *state, int to_tempfile,
 124                                  int *fstat_done, struct stat *statbuf)
 125 {
 126         int result = 0;
 127         int fd;
 128
 129         fd = open_output_fd(path, ce, to_tempfile);
 130         if (fd < 0)
 131                 return -1;
 132
 133         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
 134         *fstat_done = fstat_output(fd, state, statbuf);
 135         result |= close(fd);
 136
 137         if (result)
 138                 unlink(path);
 139         return result;
 140 }
 141
 142 void enable_delayed_checkout(struct checkout *state)
 143 {
 144         if (!state->delayed_checkout) {
 145                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 146                 state->delayed_checkout->state = CE_CAN_DELAY;
 147                 string_list_init(&state->delayed_checkout->filters, 0);
 148                 string_list_init(&state->delayed_checkout->paths, 0);
 149         }
 150 }
 151
 152 static int remove_available_paths(struct string_list_item *item, void *cb_data)
 153 {
 154         struct string_list *available_paths = cb_data;
 155         struct string_list_item *available;
 156
 157         available = string_list_lookup(available_paths, item->string);
 158         if (available)
 159                 available->util = (void *)item->string;
 160         return !available;
 161 }
 162
 163 int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 164 {
 165         int errs = 0;
 166         unsigned delayed_object_count;
 167         off_t filtered_bytes = 0;
 168         struct string_list_item *filter, *path;
 169         struct progress *progress;
 170         struct delayed_checkout *dco = state->delayed_checkout;
 171
 172         if (!state->delayed_checkout)
 173                 return errs;
 174
 175         dco->state = CE_RETRY;
 176         delayed_object_count = dco->paths.nr;
 177         progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
 178         while (dco->filters.nr > 0) {
 179                 for_each_string_list_item(filter, &dco->filters) {
 180                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
 181                         display_progress(progress, delayed_object_count - dco->paths.nr);
 182
 183                         if (!async_query_available_blobs(filter->string, &available_paths)) {
 184                                 /* Filter reported an error */
 185                                 errs = 1;
 186                                 filter->string = "";
 187                                 continue;
 188                         }
 189                         if (available_paths.nr <= 0) {
 190                                 /*
 191                                  * Filter responded with no entries. That means
 192                                  * the filter is done and we can remove the
 193                                  * filter from the list (see
 194                                  * "string_list_remove_empty_items" call below).
 195                                  */
 196                                 filter->string = "";
 197                                 continue;
 198                         }
 199
 200                         /*
 201                          * In dco->paths we store a list of all delayed paths.
 202                          * The filter just send us a list of available paths.
 203                          * Remove them from the list.
 204                          */
 205                         filter_string_list(&dco->paths, 0,
 206                                 &remove_available_paths, &available_paths);
 207
 208                         for_each_string_list_item(path, &available_paths) {
 209                                 struct cache_entry* ce;
 210
 211                                 if (!path->util) {
 212                                         error("external filter '%s' signaled that '%s' "
 213                                               "is now available although it has not been "
 214                                               "delayed earlier",
 215                                               filter->string, path->string);
 216                                         errs |= 1;
 217
 218                                         /*
 219                                          * Do not ask the filter for available blobs,
 220                                          * again, as the filter is likely buggy.
 221                                          */
 222                                         filter->string = "";
 223                                         continue;
 224                                 }
 225                                 ce = index_file_exists(state->istate, path->string,
 226                                                        strlen(path->string), 0);
 227                                 if (ce) {
 228                                         errs |= checkout_entry(ce, state, NULL, nr_checkouts);
 229                                         filtered_bytes += ce->ce_stat_data.sd_size;
 230                                         display_throughput(progress, filtered_bytes);
 231                                 } else
 232                                         errs = 1;
 233                         }
 234                 }
 235                 string_list_remove_empty_items(&dco->filters, 0);
 236         }
 237         stop_progress(&progress);
 238         string_list_clear(&dco->filters, 0);
 239
 240         /* At this point we should not have any delayed paths anymore. */
 241         errs |= dco->paths.nr;
 242         for_each_string_list_item(path, &dco->paths) {
 243                 error("'%s' was not filtered properly", path->string);
 244         }
 245         string_list_clear(&dco->paths, 0);
 246
 247         free(dco);
 248         state->delayed_checkout = NULL;
 249
 250         return errs;
 251 }
 252
 253 static int write_entry(struct cache_entry *ce,
 254                        char *path, const struct checkout *state, int to_tempfile)
 255 {
 256         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 257         struct delayed_checkout *dco = state->delayed_checkout;
 258         int fd, ret, fstat_done = 0;
 259         char *new_blob;
 260         struct strbuf buf = STRBUF_INIT;
 261         unsigned long size;
 262         ssize_t wrote;
 263         size_t newsize = 0;
 264         struct stat st;
 265         const struct submodule *sub;
 266         struct checkout_metadata meta;
 267
 268         clone_checkout_metadata(&meta, &state->meta, &ce->oid);
 269
 270         if (ce_mode_s_ifmt == S_IFREG) {
 271                 struct stream_filter *filter = get_stream_filter(state->istate, ce->name,
 272                                                                  &ce->oid);
 273                 if (filter &&
 274                     !streaming_write_entry(ce, path, filter,
 275                                            state, to_tempfile,
 276                                            &fstat_done, &st))
 277                         goto finish;
 278         }
 279
 280         switch (ce_mode_s_ifmt) {
 281         case S_IFLNK:
 282                 new_blob = read_blob_entry(ce, &size);
 283                 if (!new_blob)
 284                         return error("unable to read sha1 file of %s (%s)",
 285                                      ce->name, oid_to_hex(&ce->oid));
 286
 287                 /*
 288                  * We can't make a real symlink; write out a regular file entry
 289                  * with the symlink destination as its contents.
 290                  */
 291                 if (!has_symlinks || to_tempfile)
 292                         goto write_file_entry;
 293
 294                 ret = symlink(new_blob, path);
 295                 free(new_blob);
 296                 if (ret)
 297                         return error_errno("unable to create symlink %s", path);
 298                 break;
 299
 300         case S_IFREG:
 301                 /*
 302                  * We do not send the blob in case of a retry, so do not
 303                  * bother reading it at all.
 304                  */
 305                 if (dco && dco->state == CE_RETRY) {
 306                         new_blob = NULL;
 307                         size = 0;
 308                 } else {
 309                         new_blob = read_blob_entry(ce, &size);
 310                         if (!new_blob)
 311                                 return error("unable to read sha1 file of %s (%s)",
 312                                              ce->name, oid_to_hex(&ce->oid));
 313                 }
 314
 315                 /*
 316                  * Convert from git internal format to working tree format
 317                  */
 318                 if (dco && dco->state != CE_NO_DELAY) {
 319                         ret = async_convert_to_working_tree(state->istate, ce->name, new_blob,
 320                                                             size, &buf, &meta, dco);
 321                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
 322                                 free(new_blob);
 323                                 goto delayed;
 324                         }
 325                 } else
 326                         ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf, &meta);
 327
 328                 if (ret) {
 329                         free(new_blob);
 330                         new_blob = strbuf_detach(&buf, &newsize);
 331                         size = newsize;
 332                 }
 333                 /*
 334                  * No "else" here as errors from convert are OK at this
 335                  * point. If the error would have been fatal (e.g.
 336                  * filter is required), then we would have died already.
 337                  */
 338
 339         write_file_entry:
 340                 fd = open_output_fd(path, ce, to_tempfile);
 341                 if (fd < 0) {
 342                         free(new_blob);
 343                         return error_errno("unable to create file %s", path);
 344                 }
 345
 346                 wrote = write_in_full(fd, new_blob, size);
 347                 if (!to_tempfile)
 348                         fstat_done = fstat_output(fd, state, &st);
 349                 close(fd);
 350                 free(new_blob);
 351                 if (wrote < 0)
 352                         return error("unable to write file %s", path);
 353                 break;
 354
 355         case S_IFGITLINK:
 356                 if (to_tempfile)
 357                         return error("cannot create temporary submodule %s", ce->name);
 358                 if (mkdir(path, 0777) < 0)
 359                         return error("cannot create submodule directory %s", path);
 360                 sub = submodule_from_ce(ce);
 361                 if (sub)
 362                         return submodule_move_head(ce->name,
 363                                 NULL, oid_to_hex(&ce->oid),
 364                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 365                 break;
 366
 367         default:
 368                 return error("unknown file mode for %s in index", ce->name);
 369         }
 370
 371 finish:
 372         if (state->refresh_cache) {
 373                 assert(state->istate);
 374                 if (!fstat_done)
 375                         if (lstat(ce->name, &st) < 0)
 376                                 return error_errno("unable to stat just-written file %s",
 377                                                    ce->name);
 378                 fill_stat_cache_info(state->istate, ce, &st);
 379                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 380                 mark_fsmonitor_invalid(state->istate, ce);
 381                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 382         }
 383 delayed:
 384         return 0;
 385 }
 386
 387 /*
 388  * This is like 'lstat()', except it refuses to follow symlinks
 389  * in the path, after skipping "skiplen".
 390  */
 391 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 392 {
 393         const char *slash = path + len;
 394
 395         while (path < slash && *slash != '/')
 396                 slash--;
 397         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 398                 errno = ENOENT;
 399                 return -1;
 400         }
 401         return lstat(path, st);
 402 }
 403
 404 static void mark_colliding_entries(const struct checkout *state,
 405                                    struct cache_entry *ce, struct stat *st)
 406 {
 407         int i, trust_ino = check_stat;
 408
 409 #if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)
 410         trust_ino = 0;
 411 #endif
 412
 413         ce->ce_flags |= CE_MATCHED;
 414
 415         for (i = 0; i < state->istate->cache_nr; i++) {
 416                 struct cache_entry *dup = state->istate->cache[i];
 417
 418                 if (dup == ce)
 419                         break;
 420
 421                 if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))
 422                         continue;
 423
 424                 if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||
 425                     (!trust_ino && !fspathcmp(ce->name, dup->name))) {
 426                         dup->ce_flags |= CE_MATCHED;
 427                         break;
 428                 }
 429         }
 430 }
 431
 432 /*
 433  * Write the contents from ce out to the working tree.
 434  *
 435  * When topath[] is not NULL, instead of writing to the working tree
 436  * file named by ce, a temporary file is created by this function and
 437  * its name is returned in topath[], which must be able to hold at
 438  * least TEMPORARY_FILENAME_LENGTH bytes long.
 439  */
 440 int checkout_entry(struct cache_entry *ce, const struct checkout *state,
 441                    char *topath, int *nr_checkouts)
 442 {
 443         static struct strbuf path = STRBUF_INIT;
 444         struct stat st;
 445
 446         if (ce->ce_flags & CE_WT_REMOVE) {
 447                 if (topath)
 448                         /*
 449                          * No content and thus no path to create, so we have
 450                          * no pathname to return.
 451                          */
 452                         BUG("Can't remove entry to a path");
 453                 unlink_entry(ce);
 454                 return 0;
 455         }
 456
 457         if (topath)
 458                 return write_entry(ce, topath, state, 1);
 459
 460         strbuf_reset(&path);
 461         strbuf_add(&path, state->base_dir, state->base_dir_len);
 462         strbuf_add(&path, ce->name, ce_namelen(ce));
 463
 464         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 465                 const struct submodule *sub;
 466                 unsigned changed = ie_match_stat(state->istate, ce, &st,
 467                                                  CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
 468                 /*
 469                  * Needs to be checked before !changed returns early,
 470                  * as the possibly empty directory was not changed
 471                  */
 472                 sub = submodule_from_ce(ce);
 473                 if (sub) {
 474                         int err;
 475                         if (!is_submodule_populated_gently(ce->name, &err)) {
 476                                 struct stat sb;
 477                                 if (lstat(ce->name, &sb))
 478                                         die(_("could not stat file '%s'"), ce->name);
 479                                 if (!(st.st_mode & S_IFDIR))
 480                                         unlink_or_warn(ce->name);
 481
 482                                 return submodule_move_head(ce->name,
 483                                         NULL, oid_to_hex(&ce->oid), 0);
 484                         } else
 485                                 return submodule_move_head(ce->name,
 486                                         "HEAD", oid_to_hex(&ce->oid),
 487                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 488                 }
 489
 490                 if (!changed)
 491                         return 0;
 492                 if (!state->force) {
 493                         if (!state->quiet)
 494                                 fprintf(stderr,
 495                                         "%s already exists, no checkout\n",
 496                                         path.buf);
 497                         return -1;
 498                 }
 499
 500                 if (state->clone)
 501                         mark_colliding_entries(state, ce, &st);
 502
 503                 /*
 504                  * We unlink the old file, to get the new one with the
 505                  * right permissions (including umask, which is nasty
 506                  * to emulate by hand - much easier to let the system
 507                  * just do the right thing)
 508                  */
 509                 if (S_ISDIR(st.st_mode)) {
 510                         /* If it is a gitlink, leave it alone! */
 511                         if (S_ISGITLINK(ce->ce_mode))
 512                                 return 0;
 513                         remove_subtree(&path);
 514                 } else if (unlink(path.buf))
 515                         return error_errno("unable to unlink old '%s'", path.buf);
 516         } else if (state->not_new)
 517                 return 0;
 518
 519         create_directories(path.buf, path.len, state);
 520         if (nr_checkouts)
 521                 (*nr_checkouts)++;
 522         return write_entry(ce, path.buf, state, 0);
 523 }
 524
 525 void unlink_entry(const struct cache_entry *ce)
 526 {
 527         const struct submodule *sub = submodule_from_ce(ce);
 528         if (sub) {
 529                 /* state.force is set at the caller. */
 530                 submodule_move_head(ce->name, "HEAD", NULL,
 531                                     SUBMODULE_MOVE_HEAD_FORCE);
 532         }
 533         if (!check_leading_path(ce->name, ce_namelen(ce)))
 534                 return;
 535         if (remove_or_warn(ce->ce_mode, ce->name))
 536                 return;
 537         schedule_dir_for_removal(ce->name, ce_namelen(ce));
 538 }