entry.c

   1 #include "cache.h"
   2 #include "blob.h"
   3 #include "dir.h"
   4
   5 static void create_directories(const char *path, int path_len,
   6                                const struct checkout *state)
   7 {
   8         char *buf = xmalloc(path_len + 1);
   9         int len = 0;
  10
  11         while (len < path_len) {
  12                 do {
  13                         buf[len] = path[len];
  14                         len++;
  15                 } while (len < path_len && path[len] != '/');
  16                 if (len >= path_len)
  17                         break;
  18                 buf[len] = 0;
  19
  20                 /*
  21                  * For 'checkout-index --prefix=<dir>', <dir> is
  22                  * allowed to be a symlink to an existing directory,
  23                  * and we set 'state->base_dir_len' below, such that
  24                  * we test the path components of the prefix with the
  25                  * stat() function instead of the lstat() function.
  26                  */
  27                 if (has_dirs_only_path(buf, len, state->base_dir_len))
  28                         continue; /* ok, it is already a directory. */
  29
  30                 /*
  31                  * If this mkdir() would fail, it could be that there
  32                  * is already a symlink or something else exists
  33                  * there, therefore we then try to unlink it and try
  34                  * one more time to create the directory.
  35                  */
  36                 if (mkdir(buf, 0777)) {
  37                         if (errno == EEXIST && state->force &&
  38                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
  39                                 continue;
  40                         die_errno("cannot create directory at '%s'", buf);
  41                 }
  42         }
  43         free(buf);
  44 }
  45
  46 static void remove_subtree(const char *path)
  47 {
  48         DIR *dir = opendir(path);
  49         struct dirent *de;
  50         char pathbuf[PATH_MAX];
  51         char *name;
  52
  53         if (!dir)
  54                 die_errno("cannot opendir '%s'", path);
  55         strcpy(pathbuf, path);
  56         name = pathbuf + strlen(path);
  57         *name++ = '/';
  58         while ((de = readdir(dir)) != NULL) {
  59                 struct stat st;
  60                 if (is_dot_or_dotdot(de->d_name))
  61                         continue;
  62                 strcpy(name, de->d_name);
  63                 if (lstat(pathbuf, &st))
  64                         die_errno("cannot lstat '%s'", pathbuf);
  65                 if (S_ISDIR(st.st_mode))
  66                         remove_subtree(pathbuf);
  67                 else if (unlink(pathbuf))
  68                         die_errno("cannot unlink '%s'", pathbuf);
  69         }
  70         closedir(dir);
  71         if (rmdir(path))
  72                 die_errno("cannot rmdir '%s'", path);
  73 }
  74
  75 static int create_file(const char *path, unsigned int mode)
  76 {
  77         mode = (mode & 0100) ? 0777 : 0666;
  78         return open(path, O_WRONLY | O_CREAT |
  79                         (keep_hard_links ? O_TRUNC : 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 write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
  96 {
  97         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
  98         int fd, ret, fstat_done = 0;
  99         char *new;
 100         struct strbuf buf = STRBUF_INIT;
 101         unsigned long size;
 102         size_t wrote, newsize = 0;
 103         struct stat st;
 104
 105         switch (ce_mode_s_ifmt) {
 106         case S_IFREG:
 107         case S_IFLNK:
 108                 new = read_blob_entry(ce, &size);
 109                 if (!new)
 110                         return error("git checkout-index: unable to read sha1 file of %s (%s)",
 111                                 path, sha1_to_hex(ce->sha1));
 112
 113                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 114                         ret = symlink(new, path);
 115                         free(new);
 116                         if (ret)
 117                                 return error("git checkout-index: unable to create symlink %s (%s)",
 118                                              path, strerror(errno));
 119                         break;
 120                 }
 121
 122                 /*
 123                  * Convert from git internal format to working tree format
 124                  */
 125                 if (ce_mode_s_ifmt == S_IFREG &&
 126                     convert_to_working_tree(ce->name, new, size, &buf)) {
 127                         free(new);
 128                         new = strbuf_detach(&buf, &newsize);
 129                         size = newsize;
 130                 }
 131
 132                 if (to_tempfile) {
 133                         if (ce_mode_s_ifmt == S_IFREG)
 134                                 strcpy(path, ".merge_file_XXXXXX");
 135                         else
 136                                 strcpy(path, ".merge_link_XXXXXX");
 137                         fd = mkstemp(path);
 138                 } else if (ce_mode_s_ifmt == S_IFREG) {
 139                         fd = create_file(path, ce->ce_mode);
 140                 } else {
 141                         fd = create_file(path, 0666);
 142                 }
 143                 if (fd < 0) {
 144                         free(new);
 145                         return error("git checkout-index: unable to create file %s (%s)",
 146                                 path, strerror(errno));
 147                 }
 148
 149                 wrote = write_in_full(fd, new, size);
 150                 /* use fstat() only when path == ce->name */
 151                 if (fstat_is_reliable() &&
 152                     state->refresh_cache && !to_tempfile && !state->base_dir_len) {
 153                         fstat(fd, &st);
 154                         fstat_done = 1;
 155                 }
 156                 close(fd);
 157                 free(new);
 158                 if (wrote != size)
 159                         return error("git checkout-index: unable to write file %s", path);
 160                 break;
 161         case S_IFGITLINK:
 162                 if (to_tempfile)
 163                         return error("git checkout-index: cannot create temporary subproject %s", path);
 164                 if (mkdir(path, 0777) < 0)
 165                         return error("git checkout-index: cannot create subproject directory %s", path);
 166                 break;
 167         default:
 168                 return error("git checkout-index: unknown file mode for %s", path);
 169         }
 170
 171         if (state->refresh_cache) {
 172                 if (!fstat_done)
 173                         lstat(ce->name, &st);
 174                 fill_stat_cache_info(ce, &st);
 175         }
 176         return 0;
 177 }
 178
 179 /*
 180  * This is like 'lstat()', except it refuses to follow symlinks
 181  * in the path, after skipping "skiplen".
 182  */
 183 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 184 {
 185         const char *slash = path + len;
 186
 187         while (path < slash && *slash != '/')
 188                 slash--;
 189         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 190                 errno = ENOENT;
 191                 return -1;
 192         }
 193         return lstat(path, st);
 194 }
 195
 196 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 197 {
 198         static char path[PATH_MAX + 1];
 199         struct stat st;
 200         int len = state->base_dir_len;
 201
 202         if (topath)
 203                 return write_entry(ce, topath, state, 1);
 204
 205         memcpy(path, state->base_dir, len);
 206         strcpy(path + len, ce->name);
 207         len += ce_namelen(ce);
 208
 209         if (!check_path(path, len, &st, state->base_dir_len)) {
 210                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 211                 if (!changed)
 212                         return 0;
 213                 if (!state->force) {
 214                         if (!state->quiet)
 215                                 fprintf(stderr, "git-checkout-index: %s already exists\n", path);
 216                         return -1;
 217                 }
 218
 219                 /*
 220                  * We unlink the old file, to get the new one with the
 221                  * right permissions (including umask, which is nasty
 222                  * to emulate by hand - much easier to let the system
 223                  * just do the right thing)
 224                  */
 225                 if (S_ISDIR(st.st_mode)) {
 226                         /* If it is a gitlink, leave it alone! */
 227                         if (S_ISGITLINK(ce->ce_mode))
 228                                 return 0;
 229                         if (!state->force)
 230                                 return error("%s is a directory", path);
 231                         remove_subtree(path);
 232                 } else if ((!keep_hard_links || !S_ISREG(st.st_mode) ||
 233                                         st.st_mode != ce->ce_mode) &&
 234                                 unlink(path))
 235                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 236         } else if (state->not_new)
 237                 return 0;
 238         create_directories(path, len, state);
 239         return write_entry(ce, path, state, 0);
 240 }