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 static int write_entry(struct cache_entry *ce,
 141                        char *path, const struct checkout *state, int to_tempfile)
 142 {
 143         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 144         int fd, ret, fstat_done = 0;
 145         char *new;
 146         struct strbuf buf = STRBUF_INIT;
 147         unsigned long size;
 148         size_t wrote, newsize = 0;
 149         struct stat st;
 150         const struct submodule *sub;
 151
 152         if (ce_mode_s_ifmt == S_IFREG) {
 153                 struct stream_filter *filter = get_stream_filter(ce->name,
 154                                                                  ce->oid.hash);
 155                 if (filter &&
 156                     !streaming_write_entry(ce, path, filter,
 157                                            state, to_tempfile,
 158                                            &fstat_done, &st))
 159                         goto finish;
 160         }
 161
 162         switch (ce_mode_s_ifmt) {
 163         case S_IFREG:
 164         case S_IFLNK:
 165                 new = read_blob_entry(ce, &size);
 166                 if (!new)
 167                         return error("unable to read sha1 file of %s (%s)",
 168                                 path, oid_to_hex(&ce->oid));
 169
 170                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 171                         ret = symlink(new, path);
 172                         free(new);
 173                         if (ret)
 174                                 return error_errno("unable to create symlink %s",
 175                                                    path);
 176                         break;
 177                 }
 178
 179                 /*
 180                  * Convert from git internal format to working tree format
 181                  */
 182                 if (ce_mode_s_ifmt == S_IFREG &&
 183                     convert_to_working_tree(ce->name, new, size, &buf)) {
 184                         free(new);
 185                         new = strbuf_detach(&buf, &newsize);
 186                         size = newsize;
 187                 }
 188
 189                 fd = open_output_fd(path, ce, to_tempfile);
 190                 if (fd < 0) {
 191                         free(new);
 192                         return error_errno("unable to create file %s", path);
 193                 }
 194
 195                 wrote = write_in_full(fd, new, size);
 196                 if (!to_tempfile)
 197                         fstat_done = fstat_output(fd, state, &st);
 198                 close(fd);
 199                 free(new);
 200                 if (wrote != size)
 201                         return error("unable to write file %s", path);
 202                 break;
 203         case S_IFGITLINK:
 204                 if (to_tempfile)
 205                         return error("cannot create temporary submodule %s", path);
 206                 if (mkdir(path, 0777) < 0)
 207                         return error("cannot create submodule directory %s", path);
 208                 sub = submodule_from_ce(ce);
 209                 if (sub)
 210                         return submodule_move_head(ce->name,
 211                                 NULL, oid_to_hex(&ce->oid),
 212                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 213                 break;
 214         default:
 215                 return error("unknown file mode for %s in index", path);
 216         }
 217
 218 finish:
 219         if (state->refresh_cache) {
 220                 assert(state->istate);
 221                 if (!fstat_done)
 222                         lstat(ce->name, &st);
 223                 fill_stat_cache_info(ce, &st);
 224                 ce->ce_flags |= CE_UPDATE_IN_BASE;
 225                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
 226         }
 227         return 0;
 228 }
 229
 230 /*
 231  * This is like 'lstat()', except it refuses to follow symlinks
 232  * in the path, after skipping "skiplen".
 233  */
 234 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 235 {
 236         const char *slash = path + len;
 237
 238         while (path < slash && *slash != '/')
 239                 slash--;
 240         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 241                 errno = ENOENT;
 242                 return -1;
 243         }
 244         return lstat(path, st);
 245 }
 246
 247 /*
 248  * Write the contents from ce out to the working tree.
 249  *
 250  * When topath[] is not NULL, instead of writing to the working tree
 251  * file named by ce, a temporary file is created by this function and
 252  * its name is returned in topath[], which must be able to hold at
 253  * least TEMPORARY_FILENAME_LENGTH bytes long.
 254  */
 255 int checkout_entry(struct cache_entry *ce,
 256                    const struct checkout *state, char *topath)
 257 {
 258         static struct strbuf path = STRBUF_INIT;
 259         struct stat st;
 260
 261         if (topath)
 262                 return write_entry(ce, topath, state, 1);
 263
 264         strbuf_reset(&path);
 265         strbuf_add(&path, state->base_dir, state->base_dir_len);
 266         strbuf_add(&path, ce->name, ce_namelen(ce));
 267
 268         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
 269                 const struct submodule *sub;
 270                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 271                 /*
 272                  * Needs to be checked before !changed returns early,
 273                  * as the possibly empty directory was not changed
 274                  */
 275                 sub = submodule_from_ce(ce);
 276                 if (sub) {
 277                         int err;
 278                         if (!is_submodule_populated_gently(ce->name, &err)) {
 279                                 struct stat sb;
 280                                 if (lstat(ce->name, &sb))
 281                                         die(_("could not stat file '%s'"), ce->name);
 282                                 if (!(st.st_mode & S_IFDIR))
 283                                         unlink_or_warn(ce->name);
 284
 285                                 return submodule_move_head(ce->name,
 286                                         NULL, oid_to_hex(&ce->oid), 0);
 287                         } else
 288                                 return submodule_move_head(ce->name,
 289                                         "HEAD", oid_to_hex(&ce->oid),
 290                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
 291                 }
 292
 293                 if (!changed)
 294                         return 0;
 295                 if (!state->force) {
 296                         if (!state->quiet)
 297                                 fprintf(stderr,
 298                                         "%s already exists, no checkout\n",
 299                                         path.buf);
 300                         return -1;
 301                 }
 302
 303                 /*
 304                  * We unlink the old file, to get the new one with the
 305                  * right permissions (including umask, which is nasty
 306                  * to emulate by hand - much easier to let the system
 307                  * just do the right thing)
 308                  */
 309                 if (S_ISDIR(st.st_mode)) {
 310                         /* If it is a gitlink, leave it alone! */
 311                         if (S_ISGITLINK(ce->ce_mode))
 312                                 return 0;
 313                         if (!state->force)
 314                                 return error("%s is a directory", path.buf);
 315                         remove_subtree(&path);
 316                 } else if (unlink(path.buf))
 317                         return error_errno("unable to unlink old '%s'", path.buf);
 318         } else if (state->not_new)
 319                 return 0;
 320
 321         create_directories(path.buf, path.len, state);
 322         return write_entry(ce, path.buf, state, 0);
 323 }