entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "dir.h"
   4 #include "streaming.h"
   5
   6 static void create_directories(const char *path, int path_len,
   7                                const struct checkout *state)
   8 {
   9         char *buf = xmalloc(path_len + 1);
  10         int len = 0;
  11
  12         while (len < path_len) {
  13                 do {
  14                         buf[len] = path[len];
  15                         len++;
  16                 } while (len < path_len && path[len] != '/');
  17                 if (len >= path_len)
  18                         break;
  19                 buf[len] = 0;
  20
  21                 /*
  22                  * For 'checkout-index --prefix=<dir>', <dir> is
  23                  * allowed to be a symlink to an existing directory,
  24                  * and we set 'state->base_dir_len' below, such that
  25                  * we test the path components of the prefix with the
  26                  * stat() function instead of the lstat() function.
  27                  */
  28                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  29                         continue; /* ok, it is already a directory. */
  30
  31                 /*
  32                  * If this mkdir() would fail, it could be that there
  33                  * is already a symlink or something else exists
  34                  * there, therefore we then try to unlink it and try
  35                  * one more time to create the directory.
  36                  */
  37                 if (mkdir(buf, 0777)) {
  38                         if (errno == EEXIST && state->force &&
  39                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  40                                 continue;
  41                         die_errno("cannot create directory at '%s'", buf);
  42                 }
  43         }
  44         free(buf);
  45 }
  46
  47 static void remove_subtree(struct strbuf *path)
  48 {
  49         DIR *dir = opendir(path->buf);
  50         struct dirent *de;
  51         int origlen = path->len;
  52
  53         if (!dir)
  54                 die_errno("cannot opendir '%s'", path->buf);
  55         while ((de = readdir(dir)) != NULL) {
  56                 struct stat st;
  57
  58                 if (is_dot_or_dotdot(de->d_name))
  59                         continue;
  60
  61                 strbuf_addch(path, '/');
  62                 strbuf_addstr(path, de->d_name);
  63                 if (lstat(path->buf, &st))
  64                         die_errno("cannot lstat '%s'", path->buf);
  65                 if (S_ISDIR(st.st_mode))
  66                         remove_subtree(path);
  67                 else if (unlink(path->buf))
  68                         die_errno("cannot unlink '%s'", path->buf);
  69                 strbuf_setlen(path, origlen);
  70         }
  71         closedir(dir);
  72         if (rmdir(path->buf))
  73                 die_errno("cannot rmdir '%s'", path->buf);
  74 }
  75
  76 static int create_file(const char *path, unsigned int mode)
  77 {
  78         mode = (mode & 0100) ? 0777 : 0666;
  79         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
  80 }
  81
  82 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
  83 {
  84         enum object_type type;
  85         void *new = read_sha1_file(ce->sha1, &type, size);
  86
  87         if (new) {
  88                 if (type == OBJ_BLOB)
  89                         return new;
  90                 free(new);
  91         }
  92         return NULL;
  93 }
  94
  95 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
  96 {
  97         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
  98         if (to_tempfile) {
  99                 strcpy(path, symlink
 100                        ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
 101                 return mkstemp(path);
 102         } else {
 103                 return create_file(path, !symlink ? ce->ce_mode : 0666);
 104         }
 105 }
 106
 107 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 108 {
 109         /* use fstat() only when path == ce->name */
 110         if (fstat_is_reliable() &&
 111             state->refresh_cache && !state->base_dir_len) {
 112                 fstat(fd, st);
 113                 return 1;
 114         }
 115         return 0;
 116 }
 117
 118 static int streaming_write_entry(const struct cache_entry *ce, char *path,
 119                                  struct stream_filter *filter,
 120                                  const struct checkout *state, int to_tempfile,
 121                                  int *fstat_done, struct stat *statbuf)
 122 {
 123         int result = 0;
 124         int fd;
 125
 126         fd = open_output_fd(path, ce, to_tempfile);
 127         if (fd < 0)
 128                 return -1;
 129
 130         result |= stream_blob_to_fd(fd, ce->sha1, filter, 1);
 131         *fstat_done = fstat_output(fd, state, statbuf);
 132         result |= close(fd);
 133
 134         if (result)
 135                 unlink(path);
 136         return result;
 137 }
 138
 139 /*
 140  * Does 'match' match the given name?
 141  * A match is found if
 142  *
 143  * (1) the 'match' string is leading directory of 'name', or
 144  * (2) the 'match' string is exactly the same as 'name'.
 145  *
 146  * and the return value tells which case it was.
 147  *
 148  * It returns 0 when there is no match.
 149  *
 150  * Preserved and simplified from dir.c for use here (without glob special matching)
 151  */
 152 static int match_one(const char *match, const char *name, int namelen)
 153 {
 154         int matchlen;
 155
 156         /* If the match was just the prefix, we matched */
 157         if (!*match)
 158                 return MATCHED_RECURSIVELY;
 159
 160         if (ignore_case) {
 161                 for (;;) {
 162                         unsigned char c1 = tolower(*match);
 163                         unsigned char c2 = tolower(*name);
 164                         if (c1 == '\0' )
 165                                 break;
 166                         if (c1 != c2)
 167                                 return 0;
 168                         match++;
 169                         name++;
 170                         namelen--;
 171                 }
 172                 /* We don't match the matchstring exactly, */
 173                 matchlen = strlen(match);
 174                 if (strncmp_icase(match, name, matchlen))
 175                         return 0;
 176         } else {
 177                 for (;;) {
 178                         unsigned char c1 = *match;
 179                         unsigned char c2 = *name;
 180                         if (c1 == '\0' )
 181                                 break;
 182                         if (c1 != c2)
 183                                 return 0;
 184                         match++;
 185                         name++;
 186                         namelen--;
 187                 }
 188                 /* We don't match the matchstring exactly, */
 189                 matchlen = strlen(match);
 190                 if (strncmp(match, name, matchlen))
 191                         return 0;
 192         }
 193
 194         if (namelen == matchlen)
 195                 return MATCHED_EXACTLY;
 196         if (match[matchlen-1] == '/' || name[matchlen] == '/')
 197                 return MATCHED_RECURSIVELY;
 198         return 0;
 199 }
 200
 201 static enum git_target_type get_symlink_type(const char *filepath, const char *symlinkpath)
 202 {
 203         /* For certain O/S and file-systems, symlinks need to know before-hand whether it
 204          * is a directory or a file being pointed to.
 205          *
 206          * This allows us to use index information for relative paths that lie
 207          * within the working directory.
 208          *
 209          * This function is not interested in interrogating the file-system.
 210          */
 211         char *sanitized;
 212         const char *fpos, *last;
 213         enum git_target_type ret;
 214         int len, pos;
 215
 216         /* This is an absolute path, so git doesn't know.
 217          */
 218         if (is_absolute_path(symlinkpath))
 219                 return GIT_TARGET_UNKNOWN;
 220
 221         /* Work on a sanitized version of the path that can be
 222          * matched against the index.
 223          */
 224         last = NULL;
 225         for (fpos = filepath; *fpos; ++fpos)
 226                 if (is_dir_sep(*fpos))
 227                         last = fpos;
 228
 229         if (last) {
 230                 len = (1+last-filepath);
 231                 sanitized = xmalloc(len + strlen(symlinkpath)+1);
 232                 memcpy(sanitized, filepath, 1+last-filepath);
 233         } else {
 234                 len = 0;
 235                 sanitized = xmalloc(strlen(symlinkpath)+1);
 236         }
 237         strcpy(sanitized+len, symlinkpath);
 238
 239         ret = GIT_TARGET_UNKNOWN;
 240         if (!normalize_path_copy(sanitized, sanitized)) {
 241                 for (pos = 0; pos < active_nr; pos++) {
 242                         struct cache_entry *ce = active_cache[pos];
 243                         switch (match_one(sanitized, ce->name, ce_namelen(ce))) {
 244                                 case MATCHED_EXACTLY:
 245                                 case MATCHED_FNMATCH:
 246                                         ret = GIT_TARGET_ISFILE;
 247                                         break;
 248                                 case MATCHED_RECURSIVELY:
 249                                         ret = GIT_TARGET_ISDIR;
 250                                         break;
 251                         }
 252                 }
 253         }
 254
 255         free(sanitized);
 256         return ret;
 257 }
 258
 259 static int write_entry(struct cache_entry *ce,
 260                        char *path, const struct checkout *state, int to_tempfile)
 261 {
 262         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 263         int fd, ret, fstat_done = 0;
 264         char *new;
 265         struct strbuf buf = STRBUF_INIT;
 266         unsigned long size;
 267         size_t wrote, newsize = 0;
 268         struct stat st;
 269
 270         if (ce_mode_s_ifmt == S_IFREG) {
 271                 struct stream_filter *filter = get_stream_filter(ce->name, ce->sha1);
 272                 if (filter &&
 273                     !streaming_write_entry(ce, path, filter,
 274                                            state, to_tempfile,
 275                                            &fstat_done, &st))
 276                         goto finish;
 277         }
 278
 279         switch (ce_mode_s_ifmt) {
 280         case S_IFREG:
 281         case S_IFLNK:
 282                 new = read_blob_entry(ce, &size);
 283                 if (!new)
 284                         return error("unable to read sha1 file of %s (%s)",
 285                                 path, sha1_to_hex(ce->sha1));
 286
 287                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 288                         /* Note that symlink_with_type is a macro, and that for filesystems that
 289                          * don't care, get_symlink_type will not be called.
 290                          */
 291                         ret = symlink_with_type(new, path, get_symlink_type(path, new));
 292                         free(new);
 293                         if (ret)
 294                                 return error("unable to create symlink %s (%s)",
 295                                              path, strerror(errno));
 296                         break;
 297                 }
 298
 299                 /*
 300                  * Convert from git internal format to working tree format
 301                  */
 302                 if (ce_mode_s_ifmt == S_IFREG &&
 303                     convert_to_working_tree(ce->name, new, size, &buf)) {
 304                         free(new);
 305                         new = strbuf_detach(&buf, &newsize);
 306                         size = newsize;
 307                 }
 308
 309                 fd = open_output_fd(path, ce, to_tempfile);
 310                 if (fd < 0) {
 311                         free(new);
 312                         return error("unable to create file %s (%s)",
 313                                 path, strerror(errno));
 314                 }
 315
 316                 wrote = write_in_full(fd, new, size);
 317                 if (!to_tempfile)
 318                         fstat_done = fstat_output(fd, state, &st);
 319                 close(fd);
 320                 free(new);
 321                 if (wrote != size)
 322                         return error("unable to write file %s", path);
 323                 break;
 324         case S_IFGITLINK:
 325                 if (to_tempfile)
 326                         return error("cannot create temporary submodule %s", path);
 327                 if (mkdir(path, 0777) < 0)
 328                         return error("cannot create submodule directory %s", path);
 329                 break;
 330         default:
 331                 return error("unknown file mode for %s in index", path);
 332         }
 333
 334 finish:
 335         if (state->refresh_cache) {
 336                 if (!fstat_done)
 337                         lstat(ce->name, &st);
 338                 fill_stat_cache_info(ce, &st);
 339         }
 340         return 0;
 341 }
 342
 343 /*
 344  * This is like 'lstat()', except it refuses to follow symlinks
 345  * in the path, after skipping "skiplen".
 346  */
 347 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 348 {
 349         const char *slash = path + len;
 350
 351         while (path < slash && *slash != '/')
 352                 slash--;
 353         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 354                 errno = ENOENT;
 355                 return -1;
 356         }
 357         return lstat(path, st);
 358 }
 359
 360 /*
 361  * Write the contents from ce out to the working tree.
 362  *
 363  * When topath[] is not NULL, instead of writing to the working tree
 364  * file named by ce, a temporary file is created by this function and
 365  * its name is returned in topath[], which must be able to hold at
 366  * least TEMPORARY_FILENAME_LENGTH bytes long.
 367  */
 368 int checkout_entry(struct cache_entry *ce,
 369                    const struct checkout *state, char *topath)
 370 {
 371         static struct strbuf path = STRBUF_INIT;
 372         struct stat st;
 373
 374         if (topath)
 375                 return write_entry(ce, topath, state, 1);
 376
 377         strbuf_reset(&path);
 378         strbuf_add(&path, state->base_dir, state->base_dir_len);
 379         strbuf_add(&path, ce->name, ce_namelen(ce));
 380
 381         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 382                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 383                 if (!changed)
 384                         return 0;
 385                 if (!state->force) {
 386                         if (!state->quiet)
 387                                 fprintf(stderr,
 388                                         "%s already exists, no checkout\n",
 389                                         path.buf);
 390                         return -1;
 391                 }
 392
 393                 /*
 394                  * We unlink the old file, to get the new one with the
 395                  * right permissions (including umask, which is nasty
 396                  * to emulate by hand - much easier to let the system
 397                  * just do the right thing)
 398                  */
 399                 if (S_ISDIR(st.st_mode)) {
 400                         /* If it is a gitlink, leave it alone! */
 401                         if (S_ISGITLINK(ce->ce_mode))
 402                                 return 0;
 403                         if (!state->force)
 404                                 return error("%s is a directory", path.buf);
 405                         remove_subtree(&path);
 406                 } else if (unlink(path.buf))
 407                         return error("unable to unlink old '%s' (%s)",
 408                                      path.buf, strerror(errno));
 409         } else if (state->not_new)
 410                 return 0;
 411
 412         create_directories(path.buf, path.len, state);
 413         return write_entry(ce, path.buf, state, 0);
 414 }