1#include "cache.h"
2#include "blob.h"
3#include "dir.h"
4#include "streaming.h"
5#include "submodule.h"
6
7static 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
48static 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
77static 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
83static 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
96static 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
108static 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
119static 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
140void enable_delayed_checkout(struct checkout *state)
141{
142 if (!state->delayed_checkout) {
143 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
144 state->delayed_checkout->state = CE_CAN_DELAY;
145 string_list_init(&state->delayed_checkout->filters, 0);
146 string_list_init(&state->delayed_checkout->paths, 0);
147 }
148}
149
150static int remove_available_paths(struct string_list_item *item, void *cb_data)
151{
152 struct string_list *available_paths = cb_data;
153 struct string_list_item *available;
154
155 available = string_list_lookup(available_paths, item->string);
156 if (available)
157 available->util = (void *)item->string;
158 return !available;
159}
160
161int finish_delayed_checkout(struct checkout *state)
162{
163 int errs = 0;
164 struct string_list_item *filter, *path;
165 struct delayed_checkout *dco = state->delayed_checkout;
166
167 if (!state->delayed_checkout)
168 return errs;
169
170 dco->state = CE_RETRY;
171 while (dco->filters.nr > 0) {
172 for_each_string_list_item(filter, &dco->filters) {
173 struct string_list available_paths = STRING_LIST_INIT_NODUP;
174
175 if (!async_query_available_blobs(filter->string, &available_paths)) {
176 /* Filter reported an error */
177 errs = 1;
178 filter->string = "";
179 continue;
180 }
181 if (available_paths.nr <= 0) {
182 /*
183 * Filter responded with no entries. That means
184 * the filter is done and we can remove the
185 * filter from the list (see
186 * "string_list_remove_empty_items" call below).
187 */
188 filter->string = "";
189 continue;
190 }
191
192 /*
193 * In dco->paths we store a list of all delayed paths.
194 * The filter just send us a list of available paths.
195 * Remove them from the list.
196 */
197 filter_string_list(&dco->paths, 0,
198 &remove_available_paths, &available_paths);
199
200 for_each_string_list_item(path, &available_paths) {
201 struct cache_entry* ce;
202
203 if (!path->util) {
204 error("external filter '%s' signaled that '%s' "
205 "is now available although it has not been "
206 "delayed earlier",
207 filter->string, path->string);
208 errs |= 1;
209
210 /*
211 * Do not ask the filter for available blobs,
212 * again, as the filter is likely buggy.
213 */
214 filter->string = "";
215 continue;
216 }
217 ce = index_file_exists(state->istate, path->string,
218 strlen(path->string), 0);
219 errs |= (ce ? checkout_entry(ce, state, NULL) : 1);
220 }
221 }
222 string_list_remove_empty_items(&dco->filters, 0);
223 }
224 string_list_clear(&dco->filters, 0);
225
226 /* At this point we should not have any delayed paths anymore. */
227 errs |= dco->paths.nr;
228 for_each_string_list_item(path, &dco->paths) {
229 error("'%s' was not filtered properly", path->string);
230 }
231 string_list_clear(&dco->paths, 0);
232
233 free(dco);
234 state->delayed_checkout = NULL;
235
236 return errs;
237}
238
239static int write_entry(struct cache_entry *ce,
240 char *path, const struct checkout *state, int to_tempfile)
241{
242 unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
243 int fd, ret, fstat_done = 0;
244 char *new;
245 struct strbuf buf = STRBUF_INIT;
246 unsigned long size;
247 ssize_t wrote;
248 size_t newsize = 0;
249 struct stat st;
250 const struct submodule *sub;
251
252 if (ce_mode_s_ifmt == S_IFREG) {
253 struct stream_filter *filter = get_stream_filter(ce->name,
254 ce->oid.hash);
255 if (filter &&
256 !streaming_write_entry(ce, path, filter,
257 state, to_tempfile,
258 &fstat_done, &st))
259 goto finish;
260 }
261
262 switch (ce_mode_s_ifmt) {
263 case S_IFREG:
264 case S_IFLNK:
265 new = read_blob_entry(ce, &size);
266 if (!new)
267 return error("unable to read sha1 file of %s (%s)",
268 path, oid_to_hex(&ce->oid));
269
270 if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
271 ret = symlink(new, path);
272 free(new);
273 if (ret)
274 return error_errno("unable to create symlink %s",
275 path);
276 break;
277 }
278
279 /*
280 * Convert from git internal format to working tree format
281 */
282 if (ce_mode_s_ifmt == S_IFREG) {
283 struct delayed_checkout *dco = state->delayed_checkout;
284 if (dco && dco->state != CE_NO_DELAY) {
285 /* Do not send the blob in case of a retry. */
286 if (dco->state == CE_RETRY) {
287 new = NULL;
288 size = 0;
289 }
290 ret = async_convert_to_working_tree(
291 ce->name, new, size, &buf, dco);
292 if (ret && string_list_has_string(&dco->paths, ce->name)) {
293 free(new);
294 goto finish;
295 }
296 } else
297 ret = convert_to_working_tree(
298 ce->name, new, size, &buf);
299
300 if (ret) {
301 free(new);
302 new = strbuf_detach(&buf, &newsize);
303 size = newsize;
304 }
305 /*
306 * No "else" here as errors from convert are OK at this
307 * point. If the error would have been fatal (e.g.
308 * filter is required), then we would have died already.
309 */
310 }
311
312 fd = open_output_fd(path, ce, to_tempfile);
313 if (fd < 0) {
314 free(new);
315 return error_errno("unable to create file %s", path);
316 }
317
318 wrote = write_in_full(fd, new, size);
319 if (!to_tempfile)
320 fstat_done = fstat_output(fd, state, &st);
321 close(fd);
322 free(new);
323 if (wrote < 0)
324 return error("unable to write file %s", path);
325 break;
326 case S_IFGITLINK:
327 if (to_tempfile)
328 return error("cannot create temporary submodule %s", path);
329 if (mkdir(path, 0777) < 0)
330 return error("cannot create submodule directory %s", path);
331 sub = submodule_from_ce(ce);
332 if (sub)
333 return submodule_move_head(ce->name,
334 NULL, oid_to_hex(&ce->oid),
335 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
336 break;
337 default:
338 return error("unknown file mode for %s in index", path);
339 }
340
341finish:
342 if (state->refresh_cache) {
343 assert(state->istate);
344 if (!fstat_done)
345 lstat(ce->name, &st);
346 fill_stat_cache_info(ce, &st);
347 ce->ce_flags |= CE_UPDATE_IN_BASE;
348 state->istate->cache_changed |= CE_ENTRY_CHANGED;
349 }
350 return 0;
351}
352
353/*
354 * This is like 'lstat()', except it refuses to follow symlinks
355 * in the path, after skipping "skiplen".
356 */
357static int check_path(const char *path, int len, struct stat *st, int skiplen)
358{
359 const char *slash = path + len;
360
361 while (path < slash && *slash != '/')
362 slash--;
363 if (!has_dirs_only_path(path, slash - path, skiplen)) {
364 errno = ENOENT;
365 return -1;
366 }
367 return lstat(path, st);
368}
369
370/*
371 * Write the contents from ce out to the working tree.
372 *
373 * When topath[] is not NULL, instead of writing to the working tree
374 * file named by ce, a temporary file is created by this function and
375 * its name is returned in topath[], which must be able to hold at
376 * least TEMPORARY_FILENAME_LENGTH bytes long.
377 */
378int checkout_entry(struct cache_entry *ce,
379 const struct checkout *state, char *topath)
380{
381 static struct strbuf path = STRBUF_INIT;
382 struct stat st;
383
384 if (topath)
385 return write_entry(ce, topath, state, 1);
386
387 strbuf_reset(&path);
388 strbuf_add(&path, state->base_dir, state->base_dir_len);
389 strbuf_add(&path, ce->name, ce_namelen(ce));
390
391 if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
392 const struct submodule *sub;
393 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
394 /*
395 * Needs to be checked before !changed returns early,
396 * as the possibly empty directory was not changed
397 */
398 sub = submodule_from_ce(ce);
399 if (sub) {
400 int err;
401 if (!is_submodule_populated_gently(ce->name, &err)) {
402 struct stat sb;
403 if (lstat(ce->name, &sb))
404 die(_("could not stat file '%s'"), ce->name);
405 if (!(st.st_mode & S_IFDIR))
406 unlink_or_warn(ce->name);
407
408 return submodule_move_head(ce->name,
409 NULL, oid_to_hex(&ce->oid), 0);
410 } else
411 return submodule_move_head(ce->name,
412 "HEAD", oid_to_hex(&ce->oid),
413 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
414 }
415
416 if (!changed)
417 return 0;
418 if (!state->force) {
419 if (!state->quiet)
420 fprintf(stderr,
421 "%s already exists, no checkout\n",
422 path.buf);
423 return -1;
424 }
425
426 /*
427 * We unlink the old file, to get the new one with the
428 * right permissions (including umask, which is nasty
429 * to emulate by hand - much easier to let the system
430 * just do the right thing)
431 */
432 if (S_ISDIR(st.st_mode)) {
433 /* If it is a gitlink, leave it alone! */
434 if (S_ISGITLINK(ce->ce_mode))
435 return 0;
436 if (!state->force)
437 return error("%s is a directory", path.buf);
438 remove_subtree(&path);
439 } else if (unlink(path.buf))
440 return error_errno("unable to unlink old '%s'", path.buf);
441 } else if (state->not_new)
442 return 0;
443
444 create_directories(path.buf, path.len, state);
445 return write_entry(ce, path.buf, state, 0);
446}