entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "dir.h"
   4 #include "streaming.h"
   5 #include "submodule.h"
   6
   7 static void create_directories(const char *path, int path_len,
   8                                const struct checkout *state)
   9 {
  10         char *buf = xmallocz(path_len);
  11         int len = 0;
  12
  13         while (len < path_len) {
  14                 do {
  15                         buf[len] = path[len];
  16                         len++;
  17                 } while (len < path_len && path[len] != '/');
  18                 if (len >= path_len)
  19                         break;
  20                 buf[len] = 0;
  21
  22                 /*
  23                  * For 'checkout-index --prefix=<dir>', <dir> is
  24                  * allowed to be a symlink to an existing directory,
  25                  * and we set 'state->base_dir_len' below, such that
  26                  * we test the path components of the prefix with the
  27                  * stat() function instead of the lstat() function.
  28                  */
  29                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  30                         continue; /* ok, it is already a directory. */
  31
  32                 /*
  33                  * If this mkdir() would fail, it could be that there
  34                  * is already a symlink or something else exists
  35                  * there, therefore we then try to unlink it and try
  36                  * one more time to create the directory.
  37                  */
  38                 if (mkdir(buf, 0777)) {
  39                         if (errno == EEXIST && state->force &&
  40                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  41                                 continue;
  42                         die_errno("cannot create directory at '%s'", buf);
  43                 }
  44         }
  45         free(buf);
  46 }
  47
  48 static void remove_subtree(struct strbuf *path)
  49 {
  50         DIR *dir = opendir(path->buf);
  51         struct dirent *de;
  52         int origlen = path->len;
  53
  54         if (!dir)
  55                 die_errno("cannot opendir '%s'", path->buf);
  56         while ((de = readdir(dir)) != NULL) {
  57                 struct stat st;
  58
  59                 if (is_dot_or_dotdot(de->d_name))
  60                         continue;
  61
  62                 strbuf_addch(path, '/');
  63                 strbuf_addstr(path, de->d_name);
  64                 if (lstat(path->buf, &st))
  65                         die_errno("cannot lstat '%s'", path->buf);
  66                 if (S_ISDIR(st.st_mode))
  67                         remove_subtree(path);
  68                 else if (unlink(path->buf))
  69                         die_errno("cannot unlink '%s'", path->buf);
  70                 strbuf_setlen(path, origlen);
  71         }
  72         closedir(dir);
  73         if (rmdir(path->buf))
  74                 die_errno("cannot rmdir '%s'", path->buf);
  75 }
  76
  77 static int create_file(const char *path, unsigned int mode)
  78 {
  79         mode = (mode & 0100) ? 0777 : 0666;
  80         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  81 }
  82
  83 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  84 {
  85         enum object_type type;
  86         void *new = read_sha1_file(ce->oid.hash, &type, size);
  87
  88         if (new) {
  89                 if (type == OBJ_BLOB)
  90                         return new;
  91                 free(new);
  92         }
  93         return NULL;
  94 }
  95
  96 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
  97 {
  98         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
  99         if (to_tempfile) {
 100                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
 101                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 102                 return mkstemp(path);
 103         } else {
 104                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 105         }
 106 }
 107
 108 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 109 {
 110         /* use fstat() only when path == ce->name */
 111         if (fstat_is_reliable() &&
 112             state->refresh_cache && !state->base_dir_len) {
 113                 fstat(fd, st);
 114                 return 1;
 115         }
 116         return 0;
 117 }
 118
 119 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 120                                  struct stream_filter *filter,
 121                                  const struct checkout *state, int to_tempfile,
 122                                  int *fstat_done, struct stat *statbuf)
 123 {
 124         int result = 0;
 125         int fd;
 126
 127         fd = open_output_fd(path, ce, to_tempfile);
 128         if (fd < 0)
 129                 return -1;
 130
 131         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
 132         *fstat_done = fstat_output(fd, state, statbuf);
 133         result |= close(fd);
 134
 135         if (result)
 136                 unlink(path);
 137         return result;
 138 }
 139
 140 void enable_delayed_checkout(struct checkout *state)
 141 {
 142         if (!state->delayed_checkout) {
 143                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 144                 state->delayed_checkout->state = CE_CAN_DELAY;
 145                 string_list_init(&state->delayed_checkout->filters, 0);
 146                 string_list_init(&state->delayed_checkout->paths, 0);
 147         }
 148 }
 149
 150 static int remove_available_paths(struct string_list_item *item, void *cb_data)
 151 {
 152         struct string_list *available_paths = cb_data;
 153         struct string_list_item *available;
 154
 155         available = string_list_lookup(available_paths, item->string);
 156         if (available)
 157                 available->util = (void *)item->string;
 158         return !available;
 159 }
 160
 161 int finish_delayed_checkout(struct checkout *state)
 162 {
 163         int errs = 0;
 164         struct string_list_item *filter, *path;
 165         struct delayed_checkout *dco = state->delayed_checkout;
 166
 167         if (!state->delayed_checkout)
 168                 return errs;
 169
 170         dco->state = CE_RETRY;
 171         while (dco->filters.nr > 0) {
 172                 for_each_string_list_item(filter, &dco->filters) {
 173                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
 174
 175                         if (!async_query_available_blobs(filter->string, &available_paths)) {
 176                                 /* Filter reported an error */
 177                                 errs = 1;
 178                                 filter->string = "";
 179                                 continue;
 180                         }
 181                         if (available_paths.nr <= 0) {
 182                                 /*
 183                                  * Filter responded with no entries. That means
 184                                  * the filter is done and we can remove the
 185                                  * filter from the list (see
 186                                  * "string_list_remove_empty_items" call below).
 187                                  */
 188                                 filter->string = "";
 189                                 continue;
 190                         }
 191
 192                         /*
 193                          * In dco->paths we store a list of all delayed paths.
 194                          * The filter just send us a list of available paths.
 195                          * Remove them from the list.
 196                          */
 197                         filter_string_list(&dco->paths, 0,
 198                                 &remove_available_paths, &available_paths);
 199
 200                         for_each_string_list_item(path, &available_paths) {
 201                                 struct cache_entry* ce;
 202
 203                                 if (!path->util) {
 204                                         error("external filter '%s' signaled that '%s' "
 205                                               "is now available although it has not been "
 206                                               "delayed earlier",
 207                                               filter->string, path->string);
 208                                         errs |= 1;
 209
 210                                         /*
 211                                          * Do not ask the filter for available blobs,
 212                                          * again, as the filter is likely buggy.
 213                                          */
 214                                         filter->string = "";
 215                                         continue;
 216                                 }
 217                                 ce = index_file_exists(state->istate, path->string,
 218                                                        strlen(path->string), 0);
 219                                 errs |= (ce ? checkout_entry(ce, state, NULL) : 1);
 220                         }
 221                 }
 222                 string_list_remove_empty_items(&dco->filters, 0);
 223         }
 224         string_list_clear(&dco->filters, 0);
 225
 226         /* At this point we should not have any delayed paths anymore. */
 227         errs |= dco->paths.nr;
 228         for_each_string_list_item(path, &dco->paths) {
 229                 error("'%s' was not filtered properly", path->string);
 230         }
 231         string_list_clear(&dco->paths, 0);
 232
 233         free(dco);
 234         state->delayed_checkout = NULL;
 235
 236         return errs;
 237 }
 238
 239 static int write_entry(struct cache_entry *ce,
 240                        char *path, const struct checkout *state, int to_tempfile)
 241 {
 242         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 243         struct delayed_checkout *dco = state->delayed_checkout;
 244         int fd, ret, fstat_done = 0;
 245         char *new;
 246         struct strbuf buf = STRBUF_INIT;
 247         unsigned long size;
 248         size_t wrote, newsize = 0;
 249         struct stat st;
 250         const struct submodule *sub;
 251
 252         if (ce_mode_s_ifmt == S_IFREG) {
 253                 struct stream_filter *filter = get_stream_filter(ce->name,
 254                                                                  ce->oid.hash);
 255                 if (filter &&
 256                     !streaming_write_entry(ce, path, filter,
 257                                            state, to_tempfile,
 258                                            &fstat_done, &st))
 259                         goto finish;
 260         }
 261
 262         switch (ce_mode_s_ifmt) {
 263         case S_IFREG:
 264         case S_IFLNK:
 265                 /*
 266                  * We do not send the blob in case of a retry, so do not
 267                  * bother reading it at all.
 268                  */
 269                 if (ce_mode_s_ifmt == S_IFREG && dco && dco->state == CE_RETRY) {
 270                         new = NULL;
 271                         size = 0;
 272                 } else {
 273                         new = read_blob_entry(ce, &size);
 274                         if (!new)
 275                                 return error("unable to read sha1 file of %s (%s)",
 276                                              path, oid_to_hex(&ce->oid));
 277                 }
 278
 279                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 280                         ret = symlink(new, path);
 281                         free(new);
 282                         if (ret)
 283                                 return error_errno("unable to create symlink %s",
 284                                                    path);
 285                         break;
 286                 }
 287
 288                 /*
 289                  * Convert from git internal format to working tree format
 290                  */
 291                 if (ce_mode_s_ifmt == S_IFREG) {
 292                         if (dco && dco->state != CE_NO_DELAY) {
 293                                 ret = async_convert_to_working_tree(
 294                                         ce->name, new, size, &buf, dco);
 295                                 if (ret && string_list_has_string(&dco->paths, ce->name)) {
 296                                         free(new);
 297                                         goto delayed;
 298                                 }
 299                         } else
 300                                 ret = convert_to_working_tree(
 301                                         ce->name, new, size, &buf);
 302
 303                         if (ret) {
 304                                 free(new);
 305                                 new = strbuf_detach(&buf, &newsize);
 306                                 size = newsize;
 307                         }
 308                         /*
 309                          * No "else" here as errors from convert are OK at this
 310                          * point. If the error would have been fatal (e.g.
 311                          * filter is required), then we would have died already.
 312                          */
 313                 }
 314
 315                 fd = open_output_fd(path, ce, to_tempfile);
 316                 if (fd < 0) {
 317                         free(new);
 318                         return error_errno("unable to create file %s", path);
 319                 }
 320
 321                 wrote = write_in_full(fd, new, size);
 322                 if (!to_tempfile)
 323                         fstat_done = fstat_output(fd, state, &st);
 324                 close(fd);
 325                 free(new);
 326                 if (wrote != size)
 327                         return error("unable to write file %s", path);
 328                 break;
 329         case S_IFGITLINK:
 330                 if (to_tempfile)
 331                         return error("cannot create temporary submodule %s", path);
 332                 if (mkdir(path, 0777) < 0)
 333                         return error("cannot create submodule directory %s", path);
 334                 sub = submodule_from_ce(ce);
 335                 if (sub)
 336                         return submodule_move_head(ce->name,
 337                                 NULL, oid_to_hex(&ce->oid),
 338                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 339                 break;
 340         default:
 341                 return error("unknown file mode for %s in index", path);
 342         }
 343
 344 finish:
 345         if (state->refresh_cache) {
 346                 assert(state->istate);
 347                 if (!fstat_done)
 348                         if (lstat(ce->name, &st) < 0)
 349                                 return error_errno("unable to stat just-written file %s",
 350                                                    ce->name);
 351                 fill_stat_cache_info(ce, &st);
 352                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 353                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 354         }
 355 delayed:
 356         return 0;
 357 }
 358
 359 /*
 360  * This is like 'lstat()', except it refuses to follow symlinks
 361  * in the path, after skipping "skiplen".
 362  */
 363 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 364 {
 365         const char *slash = path + len;
 366
 367         while (path < slash && *slash != '/')
 368                 slash--;
 369         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 370                 errno = ENOENT;
 371                 return -1;
 372         }
 373         return lstat(path, st);
 374 }
 375
 376 /*
 377  * Write the contents from ce out to the working tree.
 378  *
 379  * When topath[] is not NULL, instead of writing to the working tree
 380  * file named by ce, a temporary file is created by this function and
 381  * its name is returned in topath[], which must be able to hold at
 382  * least TEMPORARY_FILENAME_LENGTH bytes long.
 383  */
 384 int checkout_entry(struct cache_entry *ce,
 385                    const struct checkout *state, char *topath)
 386 {
 387         static struct strbuf path = STRBUF_INIT;
 388         struct stat st;
 389
 390         if (topath)
 391                 return write_entry(ce, topath, state, 1);
 392
 393         strbuf_reset(&path);
 394         strbuf_add(&path, state->base_dir, state->base_dir_len);
 395         strbuf_add(&path, ce->name, ce_namelen(ce));
 396
 397         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 398                 const struct submodule *sub;
 399                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 400                 /*
 401                  * Needs to be checked before !changed returns early,
 402                  * as the possibly empty directory was not changed
 403                  */
 404                 sub = submodule_from_ce(ce);
 405                 if (sub) {
 406                         int err;
 407                         if (!is_submodule_populated_gently(ce->name, &err)) {
 408                                 struct stat sb;
 409                                 if (lstat(ce->name, &sb))
 410                                         die(_("could not stat file '%s'"), ce->name);
 411                                 if (!(st.st_mode & S_IFDIR))
 412                                         unlink_or_warn(ce->name);
 413
 414                                 return submodule_move_head(ce->name,
 415                                         NULL, oid_to_hex(&ce->oid), 0);
 416                         } else
 417                                 return submodule_move_head(ce->name,
 418                                         "HEAD", oid_to_hex(&ce->oid),
 419                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 420                 }
 421
 422                 if (!changed)
 423                         return 0;
 424                 if (!state->force) {
 425                         if (!state->quiet)
 426                                 fprintf(stderr,
 427                                         "%s already exists, no checkout\n",
 428                                         path.buf);
 429                         return -1;
 430                 }
 431
 432                 /*
 433                  * We unlink the old file, to get the new one with the
 434                  * right permissions (including umask, which is nasty
 435                  * to emulate by hand - much easier to let the system
 436                  * just do the right thing)
 437                  */
 438                 if (S_ISDIR(st.st_mode)) {
 439                         /* If it is a gitlink, leave it alone! */
 440                         if (S_ISGITLINK(ce->ce_mode))
 441                                 return 0;
 442                         if (!state->force)
 443                                 return error("%s is a directory", path.buf);
 444                         remove_subtree(&path);
 445                 } else if (unlink(path.buf))
 446                         return error_errno("unable to unlink old '%s'", path.buf);
 447         } else if (state->not_new)
 448                 return 0;
 449
 450         create_directories(path.buf, path.len, state);
 451         return write_entry(ce, path.buf, state, 0);
 452 }