entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "dir.h"
   4 #include "streaming.h"
   5 #include "submodule.h"
   6 #include "progress.h"
   7 #include "fsmonitor.h"
   8
   9 static void create_directories(const char *path, int path_len,
  10                                const struct checkout *state)
  11 {
  12         char *buf = xmallocz(path_len);
  13         int len = 0;
  14
  15         while (len < path_len) {
  16                 do {
  17                         buf[len] = path[len];
  18                         len++;
  19                 } while (len < path_len && path[len] != '/');
  20                 if (len >= path_len)
  21                         break;
  22                 buf[len] = 0;
  23
  24                 /*
  25                  * For 'checkout-index --prefix=<dir>', <dir> is
  26                  * allowed to be a symlink to an existing directory,
  27                  * and we set 'state->base_dir_len' below, such that
  28                  * we test the path components of the prefix with the
  29                  * stat() function instead of the lstat() function.
  30                  */
  31                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  32                         continue; /* ok, it is already a directory. */
  33
  34                 /*
  35                  * If this mkdir() would fail, it could be that there
  36                  * is already a symlink or something else exists
  37                  * there, therefore we then try to unlink it and try
  38                  * one more time to create the directory.
  39                  */
  40                 if (mkdir(buf, 0777)) {
  41                         if (errno == EEXIST && state->force &&
  42                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  43                                 continue;
  44                         die_errno("cannot create directory at '%s'", buf);
  45                 }
  46         }
  47         free(buf);
  48 }
  49
  50 static void remove_subtree(struct strbuf *path)
  51 {
  52         DIR *dir = opendir(path->buf);
  53         struct dirent *de;
  54         int origlen = path->len;
  55
  56         if (!dir)
  57                 die_errno("cannot opendir '%s'", path->buf);
  58         while ((de = readdir(dir)) != NULL) {
  59                 struct stat st;
  60
  61                 if (is_dot_or_dotdot(de->d_name))
  62                         continue;
  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 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  86 {
  87         enum object_type type;
  88         void *new = read_sha1_file(ce->oid.hash, &type, size);
  89
  90         if (new) {
  91                 if (type == OBJ_BLOB)
  92                         return new;
  93                 free(new);
  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 static int fstat_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                 fstat(fd, st);
 116                 return 1;
 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)
 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);
 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;
 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
 267         if (ce_mode_s_ifmt == S_IFREG) {
 268                 struct stream_filter *filter = get_stream_filter(ce->name,
 269                                                                  ce->oid.hash);
 270                 if (filter &&
 271                     !streaming_write_entry(ce, path, filter,
 272                                            state, to_tempfile,
 273                                            &fstat_done, &st))
 274                         goto finish;
 275         }
 276
 277         switch (ce_mode_s_ifmt) {
 278         case S_IFLNK:
 279                 new = read_blob_entry(ce, &size);
 280                 if (!new)
 281                         return error("unable to read sha1 file of %s (%s)",
 282                                      path, oid_to_hex(&ce->oid));
 283
 284                 /*
 285                  * We can't make a real symlink; write out a regular file entry
 286                  * with the symlink destination as its contents.
 287                  */
 288                 if (!has_symlinks || to_tempfile)
 289                         goto write_file_entry;
 290
 291                 ret = symlink(new, path);
 292                 free(new);
 293                 if (ret)
 294                         return error_errno("unable to create symlink %s", path);
 295                 break;
 296
 297         case S_IFREG:
 298                 /*
 299                  * We do not send the blob in case of a retry, so do not
 300                  * bother reading it at all.
 301                  */
 302                 if (dco && dco->state == CE_RETRY) {
 303                         new = NULL;
 304                         size = 0;
 305                 } else {
 306                         new = read_blob_entry(ce, &size);
 307                         if (!new)
 308                                 return error("unable to read sha1 file of %s (%s)",
 309                                              path, oid_to_hex(&ce->oid));
 310                 }
 311
 312                 /*
 313                  * Convert from git internal format to working tree format
 314                  */
 315                 if (dco && dco->state != CE_NO_DELAY) {
 316                         ret = async_convert_to_working_tree(ce->name, new,
 317                                                             size, &buf, dco);
 318                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
 319                                 free(new);
 320                                 goto delayed;
 321                         }
 322                 } else
 323                         ret = convert_to_working_tree(ce->name, new, size, &buf);
 324
 325                 if (ret) {
 326                         free(new);
 327                         new = strbuf_detach(&buf, &newsize);
 328                         size = newsize;
 329                 }
 330                 /*
 331                  * No "else" here as errors from convert are OK at this
 332                  * point. If the error would have been fatal (e.g.
 333                  * filter is required), then we would have died already.
 334                  */
 335
 336         write_file_entry:
 337                 fd = open_output_fd(path, ce, to_tempfile);
 338                 if (fd < 0) {
 339                         free(new);
 340                         return error_errno("unable to create file %s", path);
 341                 }
 342
 343                 wrote = write_in_full(fd, new, size);
 344                 if (!to_tempfile)
 345                         fstat_done = fstat_output(fd, state, &st);
 346                 close(fd);
 347                 free(new);
 348                 if (wrote < 0)
 349                         return error("unable to write file %s", path);
 350                 break;
 351
 352         case S_IFGITLINK:
 353                 if (to_tempfile)
 354                         return error("cannot create temporary submodule %s", path);
 355                 if (mkdir(path, 0777) < 0)
 356                         return error("cannot create submodule directory %s", path);
 357                 sub = submodule_from_ce(ce);
 358                 if (sub)
 359                         return submodule_move_head(ce->name,
 360                                 NULL, oid_to_hex(&ce->oid),
 361                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 362                 break;
 363
 364         default:
 365                 return error("unknown file mode for %s in index", path);
 366         }
 367
 368 finish:
 369         if (state->refresh_cache) {
 370                 assert(state->istate);
 371                 if (!fstat_done)
 372                         if (lstat(ce->name, &st) < 0)
 373                                 return error_errno("unable to stat just-written file %s",
 374                                                    ce->name);
 375                 fill_stat_cache_info(ce, &st);
 376                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 377                 mark_fsmonitor_invalid(state->istate, ce);
 378                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 379         }
 380 delayed:
 381         return 0;
 382 }
 383
 384 /*
 385  * This is like 'lstat()', except it refuses to follow symlinks
 386  * in the path, after skipping "skiplen".
 387  */
 388 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 389 {
 390         const char *slash = path + len;
 391
 392         while (path < slash && *slash != '/')
 393                 slash--;
 394         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 395                 errno = ENOENT;
 396                 return -1;
 397         }
 398         return lstat(path, st);
 399 }
 400
 401 /*
 402  * Write the contents from ce out to the working tree.
 403  *
 404  * When topath[] is not NULL, instead of writing to the working tree
 405  * file named by ce, a temporary file is created by this function and
 406  * its name is returned in topath[], which must be able to hold at
 407  * least TEMPORARY_FILENAME_LENGTH bytes long.
 408  */
 409 int checkout_entry(struct cache_entry *ce,
 410                    const struct checkout *state, char *topath)
 411 {
 412         static struct strbuf path = STRBUF_INIT;
 413         struct stat st;
 414
 415         if (topath)
 416                 return write_entry(ce, topath, state, 1);
 417
 418         strbuf_reset(&path);
 419         strbuf_add(&path, state->base_dir, state->base_dir_len);
 420         strbuf_add(&path, ce->name, ce_namelen(ce));
 421
 422         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 423                 const struct submodule *sub;
 424                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 425                 /*
 426                  * Needs to be checked before !changed returns early,
 427                  * as the possibly empty directory was not changed
 428                  */
 429                 sub = submodule_from_ce(ce);
 430                 if (sub) {
 431                         int err;
 432                         if (!is_submodule_populated_gently(ce->name, &err)) {
 433                                 struct stat sb;
 434                                 if (lstat(ce->name, &sb))
 435                                         die(_("could not stat file '%s'"), ce->name);
 436                                 if (!(st.st_mode & S_IFDIR))
 437                                         unlink_or_warn(ce->name);
 438
 439                                 return submodule_move_head(ce->name,
 440                                         NULL, oid_to_hex(&ce->oid), 0);
 441                         } else
 442                                 return submodule_move_head(ce->name,
 443                                         "HEAD", oid_to_hex(&ce->oid),
 444                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 445                 }
 446
 447                 if (!changed)
 448                         return 0;
 449                 if (!state->force) {
 450                         if (!state->quiet)
 451                                 fprintf(stderr,
 452                                         "%s already exists, no checkout\n",
 453                                         path.buf);
 454                         return -1;
 455                 }
 456
 457                 /*
 458                  * We unlink the old file, to get the new one with the
 459                  * right permissions (including umask, which is nasty
 460                  * to emulate by hand - much easier to let the system
 461                  * just do the right thing)
 462                  */
 463                 if (S_ISDIR(st.st_mode)) {
 464                         /* If it is a gitlink, leave it alone! */
 465                         if (S_ISGITLINK(ce->ce_mode))
 466                                 return 0;
 467                         if (!state->force)
 468                                 return error("%s is a directory", path.buf);
 469                         remove_subtree(&path);
 470                 } else if (unlink(path.buf))
 471                         return error_errno("unable to unlink old '%s'", path.buf);
 472         } else if (state->not_new)
 473                 return 0;
 474
 475         create_directories(path.buf, path.len, state);
 476         return write_entry(ce, path.buf, state, 0);
 477 }