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         int fd = -1;
 127
 128         st = open_istream(ce->sha1, &type, &sz);
 129         if (!st)
 130                 return -1;
 131         if (type != OBJ_BLOB)
 132                 goto close_and_exit;
 133
 134         fd = open_output_fd(path, ce, to_tempfile);
 135         if (fd < 0)
 136                 goto close_and_exit;
 137
 138         for (;;) {
 139                 char buf[10240];
 140                 ssize_t wrote;
 141                 ssize_t readlen = read_istream(st, buf, sizeof(buf));
 142
 143                 if (!readlen)
 144                         break;
 145
 146                 wrote = write_in_full(fd, buf, readlen);
 147
 148                 if (wrote != readlen)
 149                         goto close_and_exit;
 150         }
 151         *fstat_done = fstat_output(fd, state, statbuf);
 152
 153 close_and_exit:
 154         close_istream(st);
 155         if (0 <= fd)
 156                 result = close(fd);
 157         if (result && 0 <= fd)
 158                 unlink(path);
 159         return result;
 160 }
 161
 162 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 163 {
 164         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
 165         int fd, ret, fstat_done = 0;
 166         char *new;
 167         struct strbuf buf = STRBUF_INIT;
 168         unsigned long size;
 169         size_t wrote, newsize = 0;
 170         struct stat st;
 171
 172         if ((ce_mode_s_ifmt == S_IFREG) &&
 173             can_bypass_conversion(path) &&
 174             !streaming_write_entry(ce, path, state, to_tempfile,
 175                                    &fstat_done, &st))
 176                 goto finish;
 177
 178         switch (ce_mode_s_ifmt) {
 179         case S_IFREG:
 180         case S_IFLNK:
 181                 new = read_blob_entry(ce, &size);
 182                 if (!new)
 183                         return error("unable to read sha1 file of %s (%s)",
 184                                 path, sha1_to_hex(ce->sha1));
 185
 186                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 187                         ret = symlink(new, path);
 188                         free(new);
 189                         if (ret)
 190                                 return error("unable to create symlink %s (%s)",
 191                                              path, strerror(errno));
 192                         break;
 193                 }
 194
 195                 /*
 196                  * Convert from git internal format to working tree format
 197                  */
 198                 if (ce_mode_s_ifmt == S_IFREG &&
 199                     convert_to_working_tree(ce->name, new, size, &buf)) {
 200                         free(new);
 201                         new = strbuf_detach(&buf, &newsize);
 202                         size = newsize;
 203                 }
 204
 205                 fd = open_output_fd(path, ce, to_tempfile);
 206                 if (fd < 0) {
 207                         free(new);
 208                         return error("unable to create file %s (%s)",
 209                                 path, strerror(errno));
 210                 }
 211
 212                 wrote = write_in_full(fd, new, size);
 213                 if (!to_tempfile)
 214                         fstat_done = fstat_output(fd, state, &st);
 215                 close(fd);
 216                 free(new);
 217                 if (wrote != size)
 218                         return error("unable to write file %s", path);
 219                 break;
 220         case S_IFGITLINK:
 221                 if (to_tempfile)
 222                         return error("cannot create temporary subproject %s", path);
 223                 if (mkdir(path, 0777) < 0)
 224                         return error("cannot create subproject directory %s", path);
 225                 break;
 226         default:
 227                 return error("unknown file mode for %s in index", path);
 228         }
 229
 230 finish:
 231         if (state->refresh_cache) {
 232                 if (!fstat_done)
 233                         lstat(ce->name, &st);
 234                 fill_stat_cache_info(ce, &st);
 235         }
 236         return 0;
 237 }
 238
 239 /*
 240  * This is like 'lstat()', except it refuses to follow symlinks
 241  * in the path, after skipping "skiplen".
 242  */
 243 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 244 {
 245         const char *slash = path + len;
 246
 247         while (path < slash && *slash != '/')
 248                 slash--;
 249         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 250                 errno = ENOENT;
 251                 return -1;
 252         }
 253         return lstat(path, st);
 254 }
 255
 256 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 257 {
 258         static char path[PATH_MAX + 1];
 259         struct stat st;
 260         int len = state->base_dir_len;
 261
 262         if (topath)
 263                 return write_entry(ce, topath, state, 1);
 264
 265         memcpy(path, state->base_dir, len);
 266         strcpy(path + len, ce->name);
 267         len += ce_namelen(ce);
 268
 269         if (!check_path(path, len, &st, state->base_dir_len)) {
 270                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 271                 if (!changed)
 272                         return 0;
 273                 if (!state->force) {
 274                         if (!state->quiet)
 275                                 fprintf(stderr, "%s already exists, no checkout\n", path);
 276                         return -1;
 277                 }
 278
 279                 /*
 280                  * We unlink the old file, to get the new one with the
 281                  * right permissions (including umask, which is nasty
 282                  * to emulate by hand - much easier to let the system
 283                  * just do the right thing)
 284                  */
 285                 if (S_ISDIR(st.st_mode)) {
 286                         /* If it is a gitlink, leave it alone! */
 287                         if (S_ISGITLINK(ce->ce_mode))
 288                                 return 0;
 289                         if (!state->force)
 290                                 return error("%s is a directory", path);
 291                         remove_subtree(path);
 292                 } else if (unlink(path))
 293                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 294         } else if (state->not_new)
 295                 return 0;
 296         create_directories(path, len, state);
 297         return write_entry(ce, path, state, 0);
 298 }