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