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 static int write_entry(struct cache_entry *ce,
 140                        char *path, const struct checkout *state, int to_tempfile)
 141 {
 142         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 143         int fd, ret, fstat_done = 0;
 144         char *new;
 145         struct strbuf buf = STRBUF_INIT;
 146         unsigned long size;
 147         size_t wrote, newsize = 0;
 148         struct stat st;
 149
 150         if (ce_mode_s_ifmt == S_IFREG) {
 151                 struct stream_filter *filter = get_stream_filter(ce->name, ce->sha1);
 152                 if (filter &&
 153                     !streaming_write_entry(ce, path, filter,
 154                                            state, to_tempfile,
 155                                            &fstat_done, &st))
 156                         goto finish;
 157         }
 158
 159         switch (ce_mode_s_ifmt) {
 160         case S_IFREG:
 161         case S_IFLNK:
 162                 new = read_blob_entry(ce, &size);
 163                 if (!new)
 164                         return error("unable to read sha1 file of %s (%s)",
 165                                 path, sha1_to_hex(ce->sha1));
 166
 167                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 168                         ret = symlink(new, path);
 169                         free(new);
 170                         if (ret)
 171                                 return error("unable to create symlink %s (%s)",
 172                                              path, strerror(errno));
 173                         break;
 174                 }
 175
 176                 /*
 177                  * Convert from git internal format to working tree format
 178                  */
 179                 if (ce_mode_s_ifmt == S_IFREG &&
 180                     convert_to_working_tree(ce->name, new, size, &buf)) {
 181                         free(new);
 182                         new = strbuf_detach(&buf, &newsize);
 183                         size = newsize;
 184                 }
 185
 186                 fd = open_output_fd(path, ce, to_tempfile);
 187                 if (fd < 0) {
 188                         free(new);
 189                         return error("unable to create file %s (%s)",
 190                                 path, strerror(errno));
 191                 }
 192
 193                 wrote = write_in_full(fd, new, size);
 194                 if (!to_tempfile)
 195                         fstat_done = fstat_output(fd, state, &st);
 196                 close(fd);
 197                 free(new);
 198                 if (wrote != size)
 199                         return error("unable to write file %s", path);
 200                 break;
 201         case S_IFGITLINK:
 202                 if (to_tempfile)
 203                         return error("cannot create temporary submodule %s", path);
 204                 if (mkdir(path, 0777) < 0)
 205                         return error("cannot create submodule directory %s", path);
 206                 break;
 207         default:
 208                 return error("unknown file mode for %s in index", path);
 209         }
 210
 211 finish:
 212         if (state->refresh_cache) {
 213                 if (!fstat_done)
 214                         lstat(ce->name, &st);
 215                 fill_stat_cache_info(ce, &st);
 216         }
 217         return 0;
 218 }
 219
 220 /*
 221  * This is like 'lstat()', except it refuses to follow symlinks
 222  * in the path, after skipping "skiplen".
 223  */
 224 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 225 {
 226         const char *slash = path + len;
 227
 228         while (path < slash && *slash != '/')
 229                 slash--;
 230         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 231                 errno = ENOENT;
 232                 return -1;
 233         }
 234         return lstat(path, st);
 235 }
 236
 237 int checkout_entry(struct cache_entry *ce,
 238                    const struct checkout *state, char *topath)
 239 {
 240         static struct strbuf path = STRBUF_INIT;
 241         struct stat st;
 242
 243         if (topath)
 244                 return write_entry(ce, topath, state, 1);
 245
 246         strbuf_reset(&path);
 247         strbuf_add(&path, state->base_dir, state->base_dir_len);
 248         strbuf_add(&path, ce->name, ce_namelen(ce));
 249
 250         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 251                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 252                 if (!changed)
 253                         return 0;
 254                 if (!state->force) {
 255                         if (!state->quiet)
 256                                 fprintf(stderr,
 257                                         "%s already exists, no checkout\n",
 258                                         path.buf);
 259                         return -1;
 260                 }
 261
 262                 /*
 263                  * We unlink the old file, to get the new one with the
 264                  * right permissions (including umask, which is nasty
 265                  * to emulate by hand - much easier to let the system
 266                  * just do the right thing)
 267                  */
 268                 if (S_ISDIR(st.st_mode)) {
 269                         /* If it is a gitlink, leave it alone! */
 270                         if (S_ISGITLINK(ce->ce_mode))
 271                                 return 0;
 272                         if (!state->force)
 273                                 return error("%s is a directory", path.buf);
 274                         remove_subtree(&path);
 275                 } else if (unlink(path.buf))
 276                         return error("unable to unlink old '%s' (%s)",
 277                                      path.buf, strerror(errno));
 278         } else if (state->not_new)
 279                 return 0;
 280
 281         create_directories(path.buf, path.len, state);
 282         return write_entry(ce, path.buf, state, 0);
 283 }