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                                  struct stream_filter *filter,
 120                                  const struct checkout *state, int to_tempfile,
 121                                  int *fstat_done, struct stat *statbuf)
 122 {
 123         int result = -1;
 124         int fd;
 125
 126         fd = open_output_fd(path, ce, to_tempfile);
 127         if (0 <= fd) {
 128                 result = stream_blob_to_fd(fd, ce->sha1, filter, 1);
 129                 *fstat_done = fstat_output(fd, state, statbuf);
 130                 result = close(fd);
 131         }
 132         if (result && 0 <= fd)
 133                 unlink(path);
 134         return result;
 135 }
 136
 137 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 138 {
 139         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 140         int fd, ret, fstat_done = 0;
 141         char *new;
 142         struct strbuf buf = STRBUF_INIT;
 143         unsigned long size;
 144         size_t wrote, newsize = 0;
 145         struct stat st;
 146
 147         if (ce_mode_s_ifmt == S_IFREG) {
 148                 struct stream_filter *filter = get_stream_filter(ce->name, ce->sha1);
 149                 if (filter &&
 150                     !streaming_write_entry(ce, path, filter,
 151                                            state, to_tempfile,
 152                                            &fstat_done, &st))
 153                         goto finish;
 154         }
 155
 156         switch (ce_mode_s_ifmt) {
 157         case S_IFREG:
 158         case S_IFLNK:
 159                 new = read_blob_entry(ce, &size);
 160                 if (!new)
 161                         return error("unable to read sha1 file of %s (%s)",
 162                                 path, sha1_to_hex(ce->sha1));
 163
 164                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 165                         ret = symlink(new, path);
 166                         free(new);
 167                         if (ret)
 168                                 return error("unable to create symlink %s (%s)",
 169                                              path, strerror(errno));
 170                         break;
 171                 }
 172
 173                 /*
 174                  * Convert from git internal format to working tree format
 175                  */
 176                 if (ce_mode_s_ifmt == S_IFREG &&
 177                     convert_to_working_tree(ce->name, new, size, &buf)) {
 178                         free(new);
 179                         new = strbuf_detach(&buf, &newsize);
 180                         size = newsize;
 181                 }
 182
 183                 fd = open_output_fd(path, ce, to_tempfile);
 184                 if (fd < 0) {
 185                         free(new);
 186                         return error("unable to create file %s (%s)",
 187                                 path, strerror(errno));
 188                 }
 189
 190                 wrote = write_in_full(fd, new, size);
 191                 if (!to_tempfile)
 192                         fstat_done = fstat_output(fd, state, &st);
 193                 close(fd);
 194                 free(new);
 195                 if (wrote != size)
 196                         return error("unable to write file %s", path);
 197                 break;
 198         case S_IFGITLINK:
 199                 if (to_tempfile)
 200                         return error("cannot create temporary subproject %s", path);
 201                 if (mkdir(path, 0777) < 0)
 202                         return error("cannot create subproject directory %s", path);
 203                 break;
 204         default:
 205                 return error("unknown file mode for %s in index", path);
 206         }
 207
 208 finish:
 209         if (state->refresh_cache) {
 210                 if (!fstat_done)
 211                         lstat(ce->name, &st);
 212                 fill_stat_cache_info(ce, &st);
 213         }
 214         return 0;
 215 }
 216
 217 /*
 218  * This is like 'lstat()', except it refuses to follow symlinks
 219  * in the path, after skipping "skiplen".
 220  */
 221 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 222 {
 223         const char *slash = path + len;
 224
 225         while (path < slash && *slash != '/')
 226                 slash--;
 227         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 228                 errno = ENOENT;
 229                 return -1;
 230         }
 231         return lstat(path, st);
 232 }
 233
 234 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 235 {
 236         static char path[PATH_MAX + 1];
 237         struct stat st;
 238         int len = state->base_dir_len;
 239
 240         if (topath)
 241                 return write_entry(ce, topath, state, 1);
 242
 243         memcpy(path, state->base_dir, len);
 244         strcpy(path + len, ce->name);
 245         len += ce_namelen(ce);
 246
 247         if (!check_path(path, len, &st, state->base_dir_len)) {
 248                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 249                 if (!changed)
 250                         return 0;
 251                 if (!state->force) {
 252                         if (!state->quiet)
 253                                 fprintf(stderr, "%s already exists, no checkout\n", path);
 254                         return -1;
 255                 }
 256
 257                 /*
 258                  * We unlink the old file, to get the new one with the
 259                  * right permissions (including umask, which is nasty
 260                  * to emulate by hand - much easier to let the system
 261                  * just do the right thing)
 262                  */
 263                 if (S_ISDIR(st.st_mode)) {
 264                         /* If it is a gitlink, leave it alone! */
 265                         if (S_ISGITLINK(ce->ce_mode))
 266                                 return 0;
 267                         if (!state->force)
 268                                 return error("%s is a directory", path);
 269                         remove_subtree(path);
 270                 } else if (unlink(path))
 271                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 272         } else if (state->not_new)
 273                 return 0;
 274         create_directories(path, len, state);
 275         return write_entry(ce, path, state, 0);
 276 }