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 | O_EXCL, mode);
  79 }
  80
  81 static void *read_blob_entry(struct cache_entry *ce, unsigned long *size)
  82 {
  83         enum object_type type;
  84         void *new = read_sha1_file(ce->sha1, &type, size);
  85
  86         if (new) {
  87                 if (type == OBJ_BLOB)
  88                         return new;
  89                 free(new);
  90         }
  91         return NULL;
  92 }
  93
  94 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
  95 {
  96         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
  97         int fd, ret, fstat_done = 0;
  98         char *new;
  99         struct strbuf buf = STRBUF_INIT;
 100         unsigned long size;
 101         size_t wrote, newsize = 0;
 102         struct stat st;
 103
 104         switch (ce_mode_s_ifmt) {
 105         case S_IFREG:
 106         case S_IFLNK:
 107                 new = read_blob_entry(ce, &size);
 108                 if (!new)
 109                         return error("git checkout-index: unable to read sha1 file of %s (%s)",
 110                                 path, sha1_to_hex(ce->sha1));
 111
 112                 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
 113                         ret = symlink(new, path);
 114                         free(new);
 115                         if (ret)
 116                                 return error("git checkout-index: unable to create symlink %s (%s)",
 117                                              path, strerror(errno));
 118                         break;
 119                 }
 120
 121                 /*
 122                  * Convert from git internal format to working tree format
 123                  */
 124                 if (ce_mode_s_ifmt == S_IFREG &&
 125                     convert_to_working_tree(ce->name, new, size, &buf)) {
 126                         free(new);
 127                         new = strbuf_detach(&buf, &newsize);
 128                         size = newsize;
 129                 }
 130
 131                 if (to_tempfile) {
 132                         if (ce_mode_s_ifmt == S_IFREG)
 133                                 strcpy(path, ".merge_file_XXXXXX");
 134                         else
 135                                 strcpy(path, ".merge_link_XXXXXX");
 136                         fd = mkstemp(path);
 137                 } else if (ce_mode_s_ifmt == S_IFREG) {
 138                         fd = create_file(path, ce->ce_mode);
 139                 } else {
 140                         fd = create_file(path, 0666);
 141                 }
 142                 if (fd < 0) {
 143                         free(new);
 144                         return error("git checkout-index: unable to create file %s (%s)",
 145                                 path, strerror(errno));
 146                 }
 147
 148                 wrote = write_in_full(fd, new, size);
 149                 /* use fstat() only when path == ce->name */
 150                 if (fstat_is_reliable() &&
 151                     state->refresh_cache && !to_tempfile && !state->base_dir_len) {
 152                         fstat(fd, &st);
 153                         fstat_done = 1;
 154                 }
 155                 close(fd);
 156                 free(new);
 157                 if (wrote != size)
 158                         return error("git checkout-index: unable to write file %s", path);
 159                 break;
 160         case S_IFGITLINK:
 161                 if (to_tempfile)
 162                         return error("git checkout-index: cannot create temporary subproject %s", path);
 163                 if (mkdir(path, 0777) < 0)
 164                         return error("git checkout-index: cannot create subproject directory %s", path);
 165                 break;
 166         default:
 167                 return error("git checkout-index: unknown file mode for %s", path);
 168         }
 169
 170         if (state->refresh_cache) {
 171                 if (!fstat_done)
 172                         lstat(ce->name, &st);
 173                 fill_stat_cache_info(ce, &st);
 174         }
 175         return 0;
 176 }
 177
 178 /*
 179  * This is like 'lstat()', except it refuses to follow symlinks
 180  * in the path, after skipping "skiplen".
 181  */
 182 static int check_path(const char *path, int len, struct stat *st, int skiplen)
 183 {
 184         const char *slash = path + len;
 185
 186         while (path < slash && *slash != '/')
 187                 slash--;
 188         if (!has_dirs_only_path(path, slash - path, skiplen)) {
 189                 errno = ENOENT;
 190                 return -1;
 191         }
 192         return lstat(path, st);
 193 }
 194
 195 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
 196 {
 197         static char path[PATH_MAX + 1];
 198         struct stat st;
 199         int len = state->base_dir_len;
 200
 201         if (topath)
 202                 return write_entry(ce, topath, state, 1);
 203
 204         memcpy(path, state->base_dir, len);
 205         strcpy(path + len, ce->name);
 206         len += ce_namelen(ce);
 207
 208         if (!check_path(path, len, &st, state->base_dir_len)) {
 209                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 210                 if (!changed)
 211                         return 0;
 212                 if (!state->force) {
 213                         if (!state->quiet)
 214                                 fprintf(stderr, "git-checkout-index: %s already exists\n", path);
 215                         return -1;
 216                 }
 217
 218                 /*
 219                  * We unlink the old file, to get the new one with the
 220                  * right permissions (including umask, which is nasty
 221                  * to emulate by hand - much easier to let the system
 222                  * just do the right thing)
 223                  */
 224                 if (S_ISDIR(st.st_mode)) {
 225                         /* If it is a gitlink, leave it alone! */
 226                         if (S_ISGITLINK(ce->ce_mode))
 227                                 return 0;
 228                         if (!state->force)
 229                                 return error("%s is a directory", path);
 230                         remove_subtree(path);
 231                 } else if (unlink(path))
 232                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
 233         } else if (state->not_new)
 234                 return 0;
 235         create_directories(path, len, state);
 236         return write_entry(ce, path, state, 0);
 237 }