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(const char *path)
  48 {
  49         DIR *dir = opendir(path);
  50         struct dirent *de;
  51         char pathbuf[PATH_MAX];
  52         char *name;
  53
  54         if (!dir)
  55                 die_errno("cannot opendir '%s'", path);
  56         strcpy(pathbuf, path);
  57         name = pathbuf + strlen(path);
  58         *name++ = '/';
  59         while ((de = readdir(dir)) != NULL) {
  60                 struct stat st;
  61                 if (is_dot_or_dotdot(de->d_name))
  62                         continue;
  63                 strcpy(name, de->d_name);
  64                 if (lstat(pathbuf, &st))
  65                         die_errno("cannot lstat '%s'", pathbuf);
  66                 if (S_ISDIR(st.st_mode))
  67                         remove_subtree(pathbuf);
  68                 else if (unlink(pathbuf))
  69                         die_errno("cannot unlink '%s'", pathbuf);
  70         }
  71         closedir(dir);
  72         if (rmdir(path))
  73                 die_errno("cannot rmdir '%s'", path);
  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(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, 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(struct cache_entry *ce, char *path,
 119                                  const struct checkout *state, int to_tempfile,
 120                                  int *fstat_done, struct stat *statbuf)
 121 {
 122         struct git_istream *st;
 123         enum object_type type;
 124         unsigned long sz;
 125         int result = -1;
 126         ssize_t kept = 0;
 127         int fd = -1;
 128
 129         st = open_istream(ce->sha1, &type, &sz);
 130         if (!st)
 131                 return -1;
 132         if (type != OBJ_BLOB)
 133                 goto close_and_exit;
 134
 135         fd = open_output_fd(path, ce, to_tempfile);
 136         if (fd < 0)
 137                 goto close_and_exit;
 138
 139         for (;;) {
 140                 char buf[1024 * 16];
 141                 ssize_t wrote, holeto;
 142                 ssize_t readlen = read_istream(st, buf, sizeof(buf));
 143
 144                 if (!readlen)
 145                         break;
 146                 if (sizeof(buf) == readlen) {
 147                         for (holeto = 0; holeto < readlen; holeto++)
 148                                 if (buf[holeto])
 149                                         break;
 150                         if (readlen == holeto) {
 151                                 kept += holeto;
 152                                 continue;
 153                         }
 154                 }
 155
 156                 if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
 157                         goto close_and_exit;
 158                 else
 159                         kept = 0;
 160                 wrote = write_in_full(fd, buf, readlen);
 161
 162                 if (wrote != readlen)
 163                         goto close_and_exit;
 164         }
 165         if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
 166                      write(fd, "", 1) != 1))
 167                 goto close_and_exit;
 168         *fstat_done = fstat_output(fd, state, statbuf);
 169
 170 close_and_exit:
 171         close_istream(st);
 172         if (0 <= fd)
 173                 result = close(fd);
 174         if (result && 0 <= fd)
 175                 unlink(path);
 176         return result;
 177 }
 178
 179 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 180 {
 181         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 182         int fd, ret, fstat_done = 0;
 183         char *new;
 184         struct strbuf buf = STRBUF_INIT;
 185         unsigned long size;
 186         size_t wrote, newsize = 0;
 187         struct stat st;
 188
 189         if ((ce_mode_s_ifmt == S_IFREG) &&
 190             can_bypass_conversion(path) &&
 191             !streaming_write_entry(ce, path, state, to_tempfile,
 192                                    &fstat_done, &st))
 193                 goto finish;
 194
 195         switch (ce_mode_s_ifmt) {
 196         case S_IFREG:
 197         case S_IFLNK:
 198                 new = read_blob_entry(ce, &size);
 199                 if (!new)
 200                         return error("unable to read sha1 file of %s (%s)",
 201                                 path, sha1_to_hex(ce->sha1));
 202
 203                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 204                         ret = symlink(new, path);
 205                         free(new);
 206                         if (ret)
 207                                 return error("unable to create symlink %s (%s)",
 208                                              path, strerror(errno));
 209                         break;
 210                 }
 211
 212                 /*
 213                  * Convert from git internal format to working tree format
 214                  */
 215                 if (ce_mode_s_ifmt == S_IFREG &&
 216                     convert_to_working_tree(ce->name, new, size, &buf)) {
 217                         free(new);
 218                         new = strbuf_detach(&buf, &newsize);
 219                         size = newsize;
 220                 }
 221
 222                 fd = open_output_fd(path, ce, to_tempfile);
 223                 if (fd < 0) {
 224                         free(new);
 225                         return error("unable to create file %s (%s)",
 226                                 path, strerror(errno));
 227                 }
 228
 229                 wrote = write_in_full(fd, new, size);
 230                 if (!to_tempfile)
 231                         fstat_done = fstat_output(fd, state, &st);
 232                 close(fd);
 233                 free(new);
 234                 if (wrote != size)
 235                         return error("unable to write file %s", path);
 236                 break;
 237         case S_IFGITLINK:
 238                 if (to_tempfile)
 239                         return error("cannot create temporary subproject %s", path);
 240                 if (mkdir(path, 0777) < 0)
 241                         return error("cannot create subproject directory %s", path);
 242                 break;
 243         default:
 244                 return error("unknown file mode for %s in index", path);
 245         }
 246
 247 finish:
 248         if (state->refresh_cache) {
 249                 if (!fstat_done)
 250                         lstat(ce->name, &st);
 251                 fill_stat_cache_info(ce, &st);
 252         }
 253         return 0;
 254 }
 255
 256 /*
 257  * This is like 'lstat()', except it refuses to follow symlinks
 258  * in the path, after skipping "skiplen".
 259  */
 260 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 261 {
 262         const char *slash = path + len;
 263
 264         while (path < slash && *slash != '/')
 265                 slash--;
 266         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 267                 errno = ENOENT;
 268                 return -1;
 269         }
 270         return lstat(path, st);
 271 }
 272
 273 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 274 {
 275         static char path[PATH_MAX + 1];
 276         struct stat st;
 277         int len = state->base_dir_len;
 278
 279         if (topath)
 280                 return write_entry(ce, topath, state, 1);
 281
 282         memcpy(path, state->base_dir, len);
 283         strcpy(path + len, ce->name);
 284         len += ce_namelen(ce);
 285
 286         if (!check_path(path, len, &st, state->base_dir_len)) {
 287                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 288                 if (!changed)
 289                         return 0;
 290                 if (!state->force) {
 291                         if (!state->quiet)
 292                                 fprintf(stderr, "%s already exists, no checkout\n", path);
 293                         return -1;
 294                 }
 295
 296                 /*
 297                  * We unlink the old file, to get the new one with the
 298                  * right permissions (including umask, which is nasty
 299                  * to emulate by hand - much easier to let the system
 300                  * just do the right thing)
 301                  */
 302                 if (S_ISDIR(st.st_mode)) {
 303                         /* If it is a gitlink, leave it alone! */
 304                         if (S_ISGITLINK(ce->ce_mode))
 305                                 return 0;
 306                         if (!state->force)
 307                                 return error("%s is a directory", path);
 308                         remove_subtree(path);
 309                 } else if (unlink(path))
 310                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 311         } else if (state->not_new)
 312                 return 0;
 313         create_directories(path, len, state);
 314         return write_entry(ce, path, state, 0);
 315 }