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 #include "entry.h"
  10 #include "parallel-checkout.h"
  11
  12 static void create_directories(const char *path, int path_len,
  13                                const struct checkout *state)
  14 {
  15         char *buf = xmallocz(path_len);
  16         int len = 0;
  17
  18         while (len < path_len) {
  19                 do {
  20                         buf[len] = path[len];
  21                         len++;
  22                 } while (len < path_len && path[len] != '/');
  23                 if (len >= path_len)
  24                         break;
  25                 buf[len] = 0;
  26
  27                 /*
  28                  * For 'checkout-index --prefix=<dir>', <dir> is
  29                  * allowed to be a symlink to an existing directory,
  30                  * and we set 'state->base_dir_len' below, such that
  31                  * we test the path components of the prefix with the
  32                  * stat() function instead of the lstat() function.
  33                  */
  34                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  35                         continue; /* ok, it is already a directory. */
  36
  37                 /*
  38                  * If this mkdir() would fail, it could be that there
  39                  * is already a symlink or something else exists
  40                  * there, therefore we then try to unlink it and try
  41                  * one more time to create the directory.
  42                  */
  43                 if (mkdir(buf, 0777)) {
  44                         if (errno == EEXIST && state->force &&
  45                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  46                                 continue;
  47                         die_errno("cannot create directory at '%s'", buf);
  48                 }
  49         }
  50         free(buf);
  51 }
  52
  53 static void remove_subtree(struct strbuf *path)
  54 {
  55         DIR *dir = opendir(path->buf);
  56         struct dirent *de;
  57         int origlen = path->len;
  58
  59         if (!dir)
  60                 die_errno("cannot opendir '%s'", path->buf);
  61         while ((de = readdir(dir)) != NULL) {
  62                 struct stat st;
  63
  64                 if (is_dot_or_dotdot(de->d_name))
  65                         continue;
  66
  67                 strbuf_addch(path, '/');
  68                 strbuf_addstr(path, de->d_name);
  69                 if (lstat(path->buf, &st))
  70                         die_errno("cannot lstat '%s'", path->buf);
  71                 if (S_ISDIR(st.st_mode))
  72                         remove_subtree(path);
  73                 else if (unlink(path->buf))
  74                         die_errno("cannot unlink '%s'", path->buf);
  75                 strbuf_setlen(path, origlen);
  76         }
  77         closedir(dir);
  78         if (rmdir(path->buf))
  79                 die_errno("cannot rmdir '%s'", path->buf);
  80 }
  81
  82 static int create_file(const char *path, unsigned int mode)
  83 {
  84         mode = (mode & 0100) ? 0777 : 0666;
  85         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  86 }
  87
  88 void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  89 {
  90         enum object_type type;
  91         void *blob_data = read_object_file(&ce->oid, &type, size);
  92
  93         if (blob_data) {
  94                 if (type == OBJ_BLOB)
  95                         return blob_data;
  96                 free(blob_data);
  97         }
  98         return NULL;
  99 }
 100
 101 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
 102 {
 103         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
 104         if (to_tempfile) {
 105                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
 106                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 107                 return mkstemp(path);
 108         } else {
 109                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 110         }
 111 }
 112
 113 int fstat_checkout_output(int fd, const struct checkout *state, struct stat *st)
 114 {
 115         /* use fstat() only when path == ce->name */
 116         if (fstat_is_reliable() &&
 117             state->refresh_cache && !state->base_dir_len) {
 118                 return !fstat(fd, st);
 119         }
 120         return 0;
 121 }
 122
 123 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 124                                  struct stream_filter *filter,
 125                                  const struct checkout *state, int to_tempfile,
 126                                  int *fstat_done, struct stat *statbuf)
 127 {
 128         int result = 0;
 129         int fd;
 130
 131         fd = open_output_fd(path, ce, to_tempfile);
 132         if (fd < 0)
 133                 return -1;
 134
 135         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
 136         *fstat_done = fstat_checkout_output(fd, state, statbuf);
 137         result |= close(fd);
 138
 139         if (result)
 140                 unlink(path);
 141         return result;
 142 }
 143
 144 void enable_delayed_checkout(struct checkout *state)
 145 {
 146         if (!state->delayed_checkout) {
 147                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 148                 state->delayed_checkout->state = CE_CAN_DELAY;
 149                 string_list_init(&state->delayed_checkout->filters, 0);
 150                 string_list_init(&state->delayed_checkout->paths, 0);
 151         }
 152 }
 153
 154 static int remove_available_paths(struct string_list_item *item, void *cb_data)
 155 {
 156         struct string_list *available_paths = cb_data;
 157         struct string_list_item *available;
 158
 159         available = string_list_lookup(available_paths, item->string);
 160         if (available)
 161                 available->util = (void *)item->string;
 162         return !available;
 163 }
 164
 165 int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 166 {
 167         int errs = 0;
 168         unsigned delayed_object_count;
 169         off_t filtered_bytes = 0;
 170         struct string_list_item *filter, *path;
 171         struct progress *progress;
 172         struct delayed_checkout *dco = state->delayed_checkout;
 173
 174         if (!state->delayed_checkout)
 175                 return errs;
 176
 177         dco->state = CE_RETRY;
 178         delayed_object_count = dco->paths.nr;
 179         progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
 180         while (dco->filters.nr > 0) {
 181                 for_each_string_list_item(filter, &dco->filters) {
 182                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
 183                         display_progress(progress, delayed_object_count - dco->paths.nr);
 184
 185                         if (!async_query_available_blobs(filter->string, &available_paths)) {
 186                                 /* Filter reported an error */
 187                                 errs = 1;
 188                                 filter->string = "";
 189                                 continue;
 190                         }
 191                         if (available_paths.nr <= 0) {
 192                                 /*
 193                                  * Filter responded with no entries. That means
 194                                  * the filter is done and we can remove the
 195                                  * filter from the list (see
 196                                  * "string_list_remove_empty_items" call below).
 197                                  */
 198                                 filter->string = "";
 199                                 continue;
 200                         }
 201
 202                         /*
 203                          * In dco->paths we store a list of all delayed paths.
 204                          * The filter just send us a list of available paths.
 205                          * Remove them from the list.
 206                          */
 207                         filter_string_list(&dco->paths, 0,
 208                                 &remove_available_paths, &available_paths);
 209
 210                         for_each_string_list_item(path, &available_paths) {
 211                                 struct cache_entry* ce;
 212
 213                                 if (!path->util) {
 214                                         error("external filter '%s' signaled that '%s' "
 215                                               "is now available although it has not been "
 216                                               "delayed earlier",
 217                                               filter->string, path->string);
 218                                         errs |= 1;
 219
 220                                         /*
 221                                          * Do not ask the filter for available blobs,
 222                                          * again, as the filter is likely buggy.
 223                                          */
 224                                         filter->string = "";
 225                                         continue;
 226                                 }
 227                                 ce = index_file_exists(state->istate, path->string,
 228                                                        strlen(path->string), 0);
 229                                 if (ce) {
 230                                         errs |= checkout_entry(ce, state, NULL, nr_checkouts);
 231                                         filtered_bytes += ce->ce_stat_data.sd_size;
 232                                         display_throughput(progress, filtered_bytes);
 233                                 } else
 234                                         errs = 1;
 235                         }
 236                 }
 237                 string_list_remove_empty_items(&dco->filters, 0);
 238         }
 239         stop_progress(&progress);
 240         string_list_clear(&dco->filters, 0);
 241
 242         /* At this point we should not have any delayed paths anymore. */
 243         errs |= dco->paths.nr;
 244         for_each_string_list_item(path, &dco->paths) {
 245                 error("'%s' was not filtered properly", path->string);
 246         }
 247         string_list_clear(&dco->paths, 0);
 248
 249         free(dco);
 250         state->delayed_checkout = NULL;
 251
 252         return errs;
 253 }
 254
 255 void update_ce_after_write(const struct checkout *state, struct cache_entry *ce,
 256                            struct stat *st)
 257 {
 258         if (state->refresh_cache) {
 259                 assert(state->istate);
 260                 fill_stat_cache_info(state->istate, ce, st);
 261                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 262                 mark_fsmonitor_invalid(state->istate, ce);
 263                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 264         }
 265 }
 266
 267 /* Note: ca is used (and required) iff the entry refers to a regular file. */
 268 static int write_entry(struct cache_entry *ce, char *path, struct conv_attrs *ca,
 269                        const struct checkout *state, int to_tempfile)
 270 {
 271         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 272         struct delayed_checkout *dco = state->delayed_checkout;
 273         int fd, ret, fstat_done = 0;
 274         char *new_blob;
 275         struct strbuf buf = STRBUF_INIT;
 276         unsigned long size;
 277         ssize_t wrote;
 278         size_t newsize = 0;
 279         struct stat st;
 280         const struct submodule *sub;
 281         struct checkout_metadata meta;
 282
 283         clone_checkout_metadata(&meta, &state->meta, &ce->oid);
 284
 285         if (ce_mode_s_ifmt == S_IFREG) {
 286                 struct stream_filter *filter = get_stream_filter_ca(ca, &ce->oid);
 287                 if (filter &&
 288                     !streaming_write_entry(ce, path, filter,
 289                                            state, to_tempfile,
 290                                            &fstat_done, &st))
 291                         goto finish;
 292         }
 293
 294         switch (ce_mode_s_ifmt) {
 295         case S_IFLNK:
 296                 new_blob = read_blob_entry(ce, &size);
 297                 if (!new_blob)
 298                         return error("unable to read sha1 file of %s (%s)",
 299                                      ce->name, oid_to_hex(&ce->oid));
 300
 301                 /*
 302                  * We can't make a real symlink; write out a regular file entry
 303                  * with the symlink destination as its contents.
 304                  */
 305                 if (!has_symlinks || to_tempfile)
 306                         goto write_file_entry;
 307
 308                 ret = symlink(new_blob, path);
 309                 free(new_blob);
 310                 if (ret)
 311                         return error_errno("unable to create symlink %s", path);
 312                 break;
 313
 314         case S_IFREG:
 315                 /*
 316                  * We do not send the blob in case of a retry, so do not
 317                  * bother reading it at all.
 318                  */
 319                 if (dco && dco->state == CE_RETRY) {
 320                         new_blob = NULL;
 321                         size = 0;
 322                 } else {
 323                         new_blob = read_blob_entry(ce, &size);
 324                         if (!new_blob)
 325                                 return error("unable to read sha1 file of %s (%s)",
 326                                              ce->name, oid_to_hex(&ce->oid));
 327                 }
 328
 329                 /*
 330                  * Convert from git internal format to working tree format
 331                  */
 332                 if (dco && dco->state != CE_NO_DELAY) {
 333                         ret = async_convert_to_working_tree_ca(ca, ce->name,
 334                                                                new_blob, size,
 335                                                                &buf, &meta, dco);
 336                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
 337                                 free(new_blob);
 338                                 goto delayed;
 339                         }
 340                 } else {
 341                         ret = convert_to_working_tree_ca(ca, ce->name, new_blob,
 342                                                          size, &buf, &meta);
 343                 }
 344
 345                 if (ret) {
 346                         free(new_blob);
 347                         new_blob = strbuf_detach(&buf, &newsize);
 348                         size = newsize;
 349                 }
 350                 /*
 351                  * No "else" here as errors from convert are OK at this
 352                  * point. If the error would have been fatal (e.g.
 353                  * filter is required), then we would have died already.
 354                  */
 355
 356         write_file_entry:
 357                 fd = open_output_fd(path, ce, to_tempfile);
 358                 if (fd < 0) {
 359                         free(new_blob);
 360                         return error_errno("unable to create file %s", path);
 361                 }
 362
 363                 wrote = write_in_full(fd, new_blob, size);
 364                 if (!to_tempfile)
 365                         fstat_done = fstat_checkout_output(fd, state, &st);
 366                 close(fd);
 367                 free(new_blob);
 368                 if (wrote < 0)
 369                         return error("unable to write file %s", path);
 370                 break;
 371
 372         case S_IFGITLINK:
 373                 if (to_tempfile)
 374                         return error("cannot create temporary submodule %s", ce->name);
 375                 if (mkdir(path, 0777) < 0)
 376                         return error("cannot create submodule directory %s", path);
 377                 sub = submodule_from_ce(ce);
 378                 if (sub)
 379                         return submodule_move_head(ce->name,
 380                                 NULL, oid_to_hex(&ce->oid),
 381                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 382                 break;
 383
 384         default:
 385                 return error("unknown file mode for %s in index", ce->name);
 386         }
 387
 388 finish:
 389         if (state->refresh_cache) {
 390                 if (!fstat_done && lstat(ce->name, &st) < 0)
 391                         return error_errno("unable to stat just-written file %s",
 392                                            ce->name);
 393                 update_ce_after_write(state, ce , &st);
 394         }
 395 delayed:
 396         return 0;
 397 }
 398
 399 /*
 400  * This is like 'lstat()', except it refuses to follow symlinks
 401  * in the path, after skipping "skiplen".
 402  */
 403 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 404 {
 405         const char *slash = path + len;
 406
 407         while (path < slash && *slash != '/')
 408                 slash--;
 409         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 410                 errno = ENOENT;
 411                 return -1;
 412         }
 413         return lstat(path, st);
 414 }
 415
 416 static void mark_colliding_entries(const struct checkout *state,
 417                                    struct cache_entry *ce, struct stat *st)
 418 {
 419         int i, trust_ino = check_stat;
 420
 421 #if defined(GIT_WINDOWS_NATIVE) || defined(__CYGWIN__)
 422         trust_ino = 0;
 423 #endif
 424
 425         ce->ce_flags |= CE_MATCHED;
 426
 427         /* TODO: audit for interaction with sparse-index. */
 428         ensure_full_index(state->istate);
 429         for (i = 0; i < state->istate->cache_nr; i++) {
 430                 struct cache_entry *dup = state->istate->cache[i];
 431
 432                 if (dup == ce) {
 433                         /*
 434                          * Parallel checkout doesn't create the files in index
 435                          * order. So the other side of the collision may appear
 436                          * after the given cache_entry in the array.
 437                          */
 438                         if (parallel_checkout_status() == PC_RUNNING)
 439                                 continue;
 440                         else
 441                                 break;
 442                 }
 443
 444                 if (dup->ce_flags & (CE_MATCHED | CE_VALID | CE_SKIP_WORKTREE))
 445                         continue;
 446
 447                 if ((trust_ino && !match_stat_data(&dup->ce_stat_data, st)) ||
 448                     (!trust_ino && !fspathcmp(ce->name, dup->name))) {
 449                         dup->ce_flags |= CE_MATCHED;
 450                         break;
 451                 }
 452         }
 453 }
 454
 455 int checkout_entry_ca(struct cache_entry *ce, struct conv_attrs *ca,
 456                       const struct checkout *state, char *topath,
 457                       int *nr_checkouts)
 458 {
 459         static struct strbuf path = STRBUF_INIT;
 460         struct stat st;
 461         struct conv_attrs ca_buf;
 462
 463         if (ce->ce_flags & CE_WT_REMOVE) {
 464                 if (topath)
 465                         /*
 466                          * No content and thus no path to create, so we have
 467                          * no pathname to return.
 468                          */
 469                         BUG("Can't remove entry to a path");
 470                 unlink_entry(ce);
 471                 return 0;
 472         }
 473
 474         if (topath) {
 475                 if (S_ISREG(ce->ce_mode) && !ca) {
 476                         convert_attrs(state->istate, &ca_buf, ce->name);
 477                         ca = &ca_buf;
 478                 }
 479                 return write_entry(ce, topath, ca, state, 1);
 480         }
 481
 482         strbuf_reset(&path);
 483         strbuf_add(&path, state->base_dir, state->base_dir_len);
 484         strbuf_add(&path, ce->name, ce_namelen(ce));
 485
 486         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 487                 const struct submodule *sub;
 488                 unsigned changed = ie_match_stat(state->istate, ce, &st,
 489                                                  CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
 490                 /*
 491                  * Needs to be checked before !changed returns early,
 492                  * as the possibly empty directory was not changed
 493                  */
 494                 sub = submodule_from_ce(ce);
 495                 if (sub) {
 496                         int err;
 497                         if (!is_submodule_populated_gently(ce->name, &err)) {
 498                                 struct stat sb;
 499                                 if (lstat(ce->name, &sb))
 500                                         die(_("could not stat file '%s'"), ce->name);
 501                                 if (!(st.st_mode & S_IFDIR))
 502                                         unlink_or_warn(ce->name);
 503
 504                                 return submodule_move_head(ce->name,
 505                                         NULL, oid_to_hex(&ce->oid), 0);
 506                         } else
 507                                 return submodule_move_head(ce->name,
 508                                         "HEAD", oid_to_hex(&ce->oid),
 509                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 510                 }
 511
 512                 if (!changed)
 513                         return 0;
 514                 if (!state->force) {
 515                         if (!state->quiet)
 516                                 fprintf(stderr,
 517                                         "%s already exists, no checkout\n",
 518                                         path.buf);
 519                         return -1;
 520                 }
 521
 522                 if (state->clone)
 523                         mark_colliding_entries(state, ce, &st);
 524
 525                 /*
 526                  * We unlink the old file, to get the new one with the
 527                  * right permissions (including umask, which is nasty
 528                  * to emulate by hand - much easier to let the system
 529                  * just do the right thing)
 530                  */
 531                 if (S_ISDIR(st.st_mode)) {
 532                         /* If it is a gitlink, leave it alone! */
 533                         if (S_ISGITLINK(ce->ce_mode))
 534                                 return 0;
 535                         remove_subtree(&path);
 536                 } else if (unlink(path.buf))
 537                         return error_errno("unable to unlink old '%s'", path.buf);
 538         } else if (state->not_new)
 539                 return 0;
 540
 541         create_directories(path.buf, path.len, state);
 542
 543         if (nr_checkouts)
 544                 (*nr_checkouts)++;
 545
 546         if (S_ISREG(ce->ce_mode) && !ca) {
 547                 convert_attrs(state->istate, &ca_buf, ce->name);
 548                 ca = &ca_buf;
 549         }
 550
 551         if (!enqueue_checkout(ce, ca))
 552                 return 0;
 553
 554         return write_entry(ce, path.buf, ca, state, 0);
 555 }
 556
 557 void unlink_entry(const struct cache_entry *ce)
 558 {
 559         const struct submodule *sub = submodule_from_ce(ce);
 560         if (sub) {
 561                 /* state.force is set at the caller. */
 562                 submodule_move_head(ce->name, "HEAD", NULL,
 563                                     SUBMODULE_MOVE_HEAD_FORCE);
 564         }
 565         if (check_leading_path(ce->name, ce_namelen(ce), 1) >= 0)
 566                 return;
 567         if (remove_or_warn(ce->ce_mode, ce->name))
 568                 return;
 569         schedule_dir_for_removal(ce->name, ce_namelen(ce));
 570 }