Sync with 2.16.6
[git] / entry.c
1 #include "cache.h"
2 #include "blob.h"
3 #include "dir.h"
4 #include "streaming.h"
5 #include "submodule.h"
6 #include "progress.h"
7 #include "fsmonitor.h"
8
9 static void create_directories(const char *path, int path_len,
10                                const struct checkout *state)
11 {
12         char *buf = xmallocz(path_len);
13         int len = 0;
14
15         while (len < path_len) {
16                 do {
17                         buf[len] = path[len];
18                         len++;
19                 } while (len < path_len && path[len] != '/');
20                 if (len >= path_len)
21                         break;
22                 buf[len] = 0;
23
24                 /*
25                  * For 'checkout-index --prefix=<dir>', <dir> is
26                  * allowed to be a symlink to an existing directory,
27                  * and we set 'state->base_dir_len' below, such that
28                  * we test the path components of the prefix with the
29                  * stat() function instead of the lstat() function.
30                  */
31                 if (has_dirs_only_path(buf, len, state->base_dir_len))
32                         continue; /* ok, it is already a directory. */
33
34                 /*
35                  * If this mkdir() would fail, it could be that there
36                  * is already a symlink or something else exists
37                  * there, therefore we then try to unlink it and try
38                  * one more time to create the directory.
39                  */
40                 if (mkdir(buf, 0777)) {
41                         if (errno == EEXIST && state->force &&
42                             !unlink_or_warn(buf) && !mkdir(buf, 0777))
43                                 continue;
44                         die_errno("cannot create directory at '%s'", buf);
45                 }
46         }
47         free(buf);
48 }
49
50 static void remove_subtree(struct strbuf *path)
51 {
52         DIR *dir = opendir(path->buf);
53         struct dirent *de;
54         int origlen = path->len;
55
56         if (!dir)
57                 die_errno("cannot opendir '%s'", path->buf);
58         while ((de = readdir(dir)) != NULL) {
59                 struct stat st;
60
61                 if (is_dot_or_dotdot(de->d_name))
62                         continue;
63
64                 strbuf_addch(path, '/');
65                 strbuf_addstr(path, de->d_name);
66                 if (lstat(path->buf, &st))
67                         die_errno("cannot lstat '%s'", path->buf);
68                 if (S_ISDIR(st.st_mode))
69                         remove_subtree(path);
70                 else if (unlink(path->buf))
71                         die_errno("cannot unlink '%s'", path->buf);
72                 strbuf_setlen(path, origlen);
73         }
74         closedir(dir);
75         if (rmdir(path->buf))
76                 die_errno("cannot rmdir '%s'", path->buf);
77 }
78
79 static int create_file(const char *path, unsigned int mode)
80 {
81         mode = (mode & 0100) ? 0777 : 0666;
82         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
83 }
84
85 static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)
86 {
87         enum object_type type;
88         void *blob_data = read_sha1_file(ce->oid.hash, &type, size);
89
90         if (blob_data) {
91                 if (type == OBJ_BLOB)
92                         return blob_data;
93                 free(blob_data);
94         }
95         return NULL;
96 }
97
98 static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)
99 {
100         int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
101         if (to_tempfile) {
102                 xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",
103                           symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
104                 return mkstemp(path);
105         } else {
106                 return create_file(path, !symlink ? ce->ce_mode : 0666);
107         }
108 }
109
110 static int fstat_output(int fd, const struct checkout *state, struct stat *st)
111 {
112         /* use fstat() only when path == ce->name */
113         if (fstat_is_reliable() &&
114             state->refresh_cache && !state->base_dir_len) {
115                 fstat(fd, st);
116                 return 1;
117         }
118         return 0;
119 }
120
121 static int streaming_write_entry(const struct cache_entry *ce, char *path,
122                                  struct stream_filter *filter,
123                                  const struct checkout *state, int to_tempfile,
124                                  int *fstat_done, struct stat *statbuf)
125 {
126         int result = 0;
127         int fd;
128
129         fd = open_output_fd(path, ce, to_tempfile);
130         if (fd < 0)
131                 return -1;
132
133         result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);
134         *fstat_done = fstat_output(fd, state, statbuf);
135         result |= close(fd);
136
137         if (result)
138                 unlink(path);
139         return result;
140 }
141
142 void enable_delayed_checkout(struct checkout *state)
143 {
144         if (!state->delayed_checkout) {
145                 state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
146                 state->delayed_checkout->state = CE_CAN_DELAY;
147                 string_list_init(&state->delayed_checkout->filters, 0);
148                 string_list_init(&state->delayed_checkout->paths, 0);
149         }
150 }
151
152 static int remove_available_paths(struct string_list_item *item, void *cb_data)
153 {
154         struct string_list *available_paths = cb_data;
155         struct string_list_item *available;
156
157         available = string_list_lookup(available_paths, item->string);
158         if (available)
159                 available->util = (void *)item->string;
160         return !available;
161 }
162
163 int finish_delayed_checkout(struct checkout *state)
164 {
165         int errs = 0;
166         unsigned delayed_object_count;
167         off_t filtered_bytes = 0;
168         struct string_list_item *filter, *path;
169         struct progress *progress;
170         struct delayed_checkout *dco = state->delayed_checkout;
171
172         if (!state->delayed_checkout)
173                 return errs;
174
175         dco->state = CE_RETRY;
176         delayed_object_count = dco->paths.nr;
177         progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
178         while (dco->filters.nr > 0) {
179                 for_each_string_list_item(filter, &dco->filters) {
180                         struct string_list available_paths = STRING_LIST_INIT_NODUP;
181                         display_progress(progress, delayed_object_count - dco->paths.nr);
182
183                         if (!async_query_available_blobs(filter->string, &available_paths)) {
184                                 /* Filter reported an error */
185                                 errs = 1;
186                                 filter->string = "";
187                                 continue;
188                         }
189                         if (available_paths.nr <= 0) {
190                                 /*
191                                  * Filter responded with no entries. That means
192                                  * the filter is done and we can remove the
193                                  * filter from the list (see
194                                  * "string_list_remove_empty_items" call below).
195                                  */
196                                 filter->string = "";
197                                 continue;
198                         }
199
200                         /*
201                          * In dco->paths we store a list of all delayed paths.
202                          * The filter just send us a list of available paths.
203                          * Remove them from the list.
204                          */
205                         filter_string_list(&dco->paths, 0,
206                                 &remove_available_paths, &available_paths);
207
208                         for_each_string_list_item(path, &available_paths) {
209                                 struct cache_entry* ce;
210
211                                 if (!path->util) {
212                                         error("external filter '%s' signaled that '%s' "
213                                               "is now available although it has not been "
214                                               "delayed earlier",
215                                               filter->string, path->string);
216                                         errs |= 1;
217
218                                         /*
219                                          * Do not ask the filter for available blobs,
220                                          * again, as the filter is likely buggy.
221                                          */
222                                         filter->string = "";
223                                         continue;
224                                 }
225                                 ce = index_file_exists(state->istate, path->string,
226                                                        strlen(path->string), 0);
227                                 if (ce) {
228                                         errs |= checkout_entry(ce, state, NULL);
229                                         filtered_bytes += ce->ce_stat_data.sd_size;
230                                         display_throughput(progress, filtered_bytes);
231                                 } else
232                                         errs = 1;
233                         }
234                 }
235                 string_list_remove_empty_items(&dco->filters, 0);
236         }
237         stop_progress(&progress);
238         string_list_clear(&dco->filters, 0);
239
240         /* At this point we should not have any delayed paths anymore. */
241         errs |= dco->paths.nr;
242         for_each_string_list_item(path, &dco->paths) {
243                 error("'%s' was not filtered properly", path->string);
244         }
245         string_list_clear(&dco->paths, 0);
246
247         free(dco);
248         state->delayed_checkout = NULL;
249
250         return errs;
251 }
252
253 static int write_entry(struct cache_entry *ce,
254                        char *path, const struct checkout *state, int to_tempfile)
255 {
256         unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
257         struct delayed_checkout *dco = state->delayed_checkout;
258         int fd, ret, fstat_done = 0;
259         char *new_blob;
260         struct strbuf buf = STRBUF_INIT;
261         unsigned long size;
262         ssize_t wrote;
263         size_t newsize = 0;
264         struct stat st;
265         const struct submodule *sub;
266
267         if (ce_mode_s_ifmt == S_IFREG) {
268                 struct stream_filter *filter = get_stream_filter(ce->name,
269                                                                  ce->oid.hash);
270                 if (filter &&
271                     !streaming_write_entry(ce, path, filter,
272                                            state, to_tempfile,
273                                            &fstat_done, &st))
274                         goto finish;
275         }
276
277         switch (ce_mode_s_ifmt) {
278         case S_IFLNK:
279                 new_blob = read_blob_entry(ce, &size);
280                 if (!new_blob)
281                         return error("unable to read sha1 file of %s (%s)",
282                                      path, oid_to_hex(&ce->oid));
283
284                 /*
285                  * We can't make a real symlink; write out a regular file entry
286                  * with the symlink destination as its contents.
287                  */
288                 if (!has_symlinks || to_tempfile)
289                         goto write_file_entry;
290
291                 ret = symlink(new_blob, path);
292                 free(new_blob);
293                 if (ret)
294                         return error_errno("unable to create symlink %s", path);
295                 break;
296
297         case S_IFREG:
298                 /*
299                  * We do not send the blob in case of a retry, so do not
300                  * bother reading it at all.
301                  */
302                 if (dco && dco->state == CE_RETRY) {
303                         new_blob = NULL;
304                         size = 0;
305                 } else {
306                         new_blob = read_blob_entry(ce, &size);
307                         if (!new_blob)
308                                 return error("unable to read sha1 file of %s (%s)",
309                                              path, oid_to_hex(&ce->oid));
310                 }
311
312                 /*
313                  * Convert from git internal format to working tree format
314                  */
315                 if (dco && dco->state != CE_NO_DELAY) {
316                         ret = async_convert_to_working_tree(ce->name, new_blob,
317                                                             size, &buf, dco);
318                         if (ret && string_list_has_string(&dco->paths, ce->name)) {
319                                 free(new_blob);
320                                 goto delayed;
321                         }
322                 } else
323                         ret = convert_to_working_tree(ce->name, new_blob, size, &buf);
324
325                 if (ret) {
326                         free(new_blob);
327                         new_blob = strbuf_detach(&buf, &newsize);
328                         size = newsize;
329                 }
330                 /*
331                  * No "else" here as errors from convert are OK at this
332                  * point. If the error would have been fatal (e.g.
333                  * filter is required), then we would have died already.
334                  */
335
336         write_file_entry:
337                 fd = open_output_fd(path, ce, to_tempfile);
338                 if (fd < 0) {
339                         free(new_blob);
340                         return error_errno("unable to create file %s", path);
341                 }
342
343                 wrote = write_in_full(fd, new_blob, size);
344                 if (!to_tempfile)
345                         fstat_done = fstat_output(fd, state, &st);
346                 close(fd);
347                 free(new_blob);
348                 if (wrote < 0)
349                         return error("unable to write file %s", path);
350                 break;
351
352         case S_IFGITLINK:
353                 if (to_tempfile)
354                         return error("cannot create temporary submodule %s", path);
355                 if (mkdir(path, 0777) < 0)
356                         return error("cannot create submodule directory %s", path);
357                 sub = submodule_from_ce(ce);
358                 if (sub)
359                         return submodule_move_head(ce->name,
360                                 NULL, oid_to_hex(&ce->oid),
361                                 state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
362                 break;
363
364         default:
365                 return error("unknown file mode for %s in index", path);
366         }
367
368 finish:
369         if (state->refresh_cache) {
370                 assert(state->istate);
371                 if (!fstat_done)
372                         if (lstat(ce->name, &st) < 0)
373                                 return error_errno("unable to stat just-written file %s",
374                                                    ce->name);
375                 fill_stat_cache_info(ce, &st);
376                 ce->ce_flags |= CE_UPDATE_IN_BASE;
377                 mark_fsmonitor_invalid(state->istate, ce);
378                 state->istate->cache_changed |= CE_ENTRY_CHANGED;
379         }
380 delayed:
381         return 0;
382 }
383
384 /*
385  * This is like 'lstat()', except it refuses to follow symlinks
386  * in the path, after skipping "skiplen".
387  */
388 static int check_path(const char *path, int len, struct stat *st, int skiplen)
389 {
390         const char *slash = path + len;
391
392         while (path < slash && *slash != '/')
393                 slash--;
394         if (!has_dirs_only_path(path, slash - path, skiplen)) {
395                 errno = ENOENT;
396                 return -1;
397         }
398         return lstat(path, st);
399 }
400
401 /*
402  * Write the contents from ce out to the working tree.
403  *
404  * When topath[] is not NULL, instead of writing to the working tree
405  * file named by ce, a temporary file is created by this function and
406  * its name is returned in topath[], which must be able to hold at
407  * least TEMPORARY_FILENAME_LENGTH bytes long.
408  */
409 int checkout_entry(struct cache_entry *ce,
410                    const struct checkout *state, char *topath)
411 {
412         static struct strbuf path = STRBUF_INIT;
413         struct stat st;
414
415         if (topath)
416                 return write_entry(ce, topath, state, 1);
417
418         strbuf_reset(&path);
419         strbuf_add(&path, state->base_dir, state->base_dir_len);
420         strbuf_add(&path, ce->name, ce_namelen(ce));
421
422         if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {
423                 const struct submodule *sub;
424                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
425                 /*
426                  * Needs to be checked before !changed returns early,
427                  * as the possibly empty directory was not changed
428                  */
429                 sub = submodule_from_ce(ce);
430                 if (sub) {
431                         int err;
432                         if (!is_submodule_populated_gently(ce->name, &err)) {
433                                 struct stat sb;
434                                 if (lstat(ce->name, &sb))
435                                         die(_("could not stat file '%s'"), ce->name);
436                                 if (!(st.st_mode & S_IFDIR))
437                                         unlink_or_warn(ce->name);
438
439                                 return submodule_move_head(ce->name,
440                                         NULL, oid_to_hex(&ce->oid), 0);
441                         } else
442                                 return submodule_move_head(ce->name,
443                                         "HEAD", oid_to_hex(&ce->oid),
444                                         state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);
445                 }
446
447                 if (!changed)
448                         return 0;
449                 if (!state->force) {
450                         if (!state->quiet)
451                                 fprintf(stderr,
452                                         "%s already exists, no checkout\n",
453                                         path.buf);
454                         return -1;
455                 }
456
457                 /*
458                  * We unlink the old file, to get the new one with the
459                  * right permissions (including umask, which is nasty
460                  * to emulate by hand - much easier to let the system
461                  * just do the right thing)
462                  */
463                 if (S_ISDIR(st.st_mode)) {
464                         /* If it is a gitlink, leave it alone! */
465                         if (S_ISGITLINK(ce->ce_mode))
466                                 return 0;
467                         if (!state->force)
468                                 return error("%s is a directory", path.buf);
469                         remove_subtree(&path);
470                 } else if (unlink(path.buf))
471                         return error_errno("unable to unlink old '%s'", path.buf);
472         } else if (state->not_new)
473                 return 0;
474
475         create_directories(path.buf, path.len, state);
476         return write_entry(ce, path.buf, state, 0);
477 }