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