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Commit | Line | Data |
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1a9d15db MH |
1 | /* |
2 | * State diagram and cleanup | |
3 | * ------------------------- | |
4 | * | |
5 | * If the program exits while a temporary file is active, we want to | |
6 | * make sure that we remove it. This is done by remembering the active | |
7 | * temporary files in a linked list, `tempfile_list`. An `atexit(3)` | |
8 | * handler and a signal handler are registered, to clean up any active | |
9 | * temporary files. | |
10 | * | |
11 | * Because the signal handler can run at any time, `tempfile_list` and | |
12 | * the `tempfile` objects that comprise it must be kept in | |
13 | * self-consistent states at all times. | |
14 | * | |
15 | * The possible states of a `tempfile` object are as follows: | |
16 | * | |
17 | * - Uninitialized. In this state the object's `on_list` field must be | |
18 | * zero but the rest of its contents need not be initialized. As | |
19 | * soon as the object is used in any way, it is irrevocably | |
20 | * registered in `tempfile_list`, and `on_list` is set. | |
21 | * | |
22 | * - Active, file open (after `create_tempfile()` or | |
23 | * `reopen_tempfile()`). In this state: | |
24 | * | |
25 | * - the temporary file exists | |
26 | * - `active` is set | |
27 | * - `filename` holds the filename of the temporary file | |
28 | * - `fd` holds a file descriptor open for writing to it | |
29 | * - `fp` holds a pointer to an open `FILE` object if and only if | |
30 | * `fdopen_tempfile()` has been called on the object | |
31 | * - `owner` holds the PID of the process that created the file | |
32 | * | |
49bd0fc2 | 33 | * - Active, file closed (after `close_tempfile_gently()`). Same |
1a9d15db MH |
34 | * as the previous state, except that the temporary file is closed, |
35 | * `fd` is -1, and `fp` is `NULL`. | |
36 | * | |
49bd0fc2 JK |
37 | * - Inactive (after `delete_tempfile()`, `rename_tempfile()`, or a |
38 | * failed attempt to create a temporary file). In this state: | |
1a9d15db MH |
39 | * |
40 | * - `active` is unset | |
41 | * - `filename` is empty (usually, though there are transitory | |
42 | * states in which this condition doesn't hold). Client code should | |
43 | * *not* rely on the filename being empty in this state. | |
44 | * - `fd` is -1 and `fp` is `NULL` | |
422a21c6 | 45 | * - the object is removed from `tempfile_list` (but could be used again) |
1a9d15db MH |
46 | * |
47 | * A temporary file is owned by the process that created it. The | |
48 | * `tempfile` has an `owner` field that records the owner's PID. This | |
49 | * field is used to prevent a forked process from deleting a temporary | |
50 | * file created by its parent. | |
51 | */ | |
52 | ||
53 | #include "cache.h" | |
54 | #include "tempfile.h" | |
55 | #include "sigchain.h" | |
56 | ||
24d82185 | 57 | static VOLATILE_LIST_HEAD(tempfile_list); |
1a9d15db | 58 | |
2c2db194 RS |
59 | static void remove_template_directory(struct tempfile *tempfile, |
60 | int in_signal_handler) | |
61 | { | |
62 | if (tempfile->directorylen > 0 && | |
63 | tempfile->directorylen < tempfile->filename.len && | |
64 | tempfile->filename.buf[tempfile->directorylen] == '/') { | |
65 | strbuf_setlen(&tempfile->filename, tempfile->directorylen); | |
66 | if (in_signal_handler) | |
67 | rmdir(tempfile->filename.buf); | |
68 | else | |
69 | rmdir_or_warn(tempfile->filename.buf); | |
70 | } | |
71 | } | |
72 | ||
6b935066 | 73 | static void remove_tempfiles(int in_signal_handler) |
1a9d15db MH |
74 | { |
75 | pid_t me = getpid(); | |
24d82185 JK |
76 | volatile struct volatile_list_head *pos; |
77 | ||
78 | list_for_each(pos, &tempfile_list) { | |
79 | struct tempfile *p = list_entry(pos, struct tempfile, list); | |
1a9d15db | 80 | |
6b935066 JK |
81 | if (!is_tempfile_active(p) || p->owner != me) |
82 | continue; | |
83 | ||
84 | if (p->fd >= 0) | |
85 | close(p->fd); | |
86 | ||
87 | if (in_signal_handler) | |
88 | unlink(p->filename.buf); | |
89 | else | |
90 | unlink_or_warn(p->filename.buf); | |
2c2db194 | 91 | remove_template_directory(p, in_signal_handler); |
6b935066 JK |
92 | |
93 | p->active = 0; | |
1a9d15db MH |
94 | } |
95 | } | |
96 | ||
97 | static void remove_tempfiles_on_exit(void) | |
98 | { | |
99 | remove_tempfiles(0); | |
100 | } | |
101 | ||
102 | static void remove_tempfiles_on_signal(int signo) | |
103 | { | |
104 | remove_tempfiles(1); | |
105 | sigchain_pop(signo); | |
106 | raise(signo); | |
107 | } | |
108 | ||
076aa2cb | 109 | static struct tempfile *new_tempfile(void) |
1a9d15db | 110 | { |
076aa2cb | 111 | struct tempfile *tempfile = xmalloc(sizeof(*tempfile)); |
422a21c6 JK |
112 | tempfile->fd = -1; |
113 | tempfile->fp = NULL; | |
114 | tempfile->active = 0; | |
115 | tempfile->owner = 0; | |
116 | INIT_LIST_HEAD(&tempfile->list); | |
117 | strbuf_init(&tempfile->filename, 0); | |
2c2db194 | 118 | tempfile->directorylen = 0; |
076aa2cb | 119 | return tempfile; |
7eba6ce5 MH |
120 | } |
121 | ||
2933ebba JK |
122 | static void activate_tempfile(struct tempfile *tempfile) |
123 | { | |
422a21c6 JK |
124 | static int initialized; |
125 | ||
126 | if (is_tempfile_active(tempfile)) | |
127 | BUG("activate_tempfile called for active object"); | |
128 | ||
129 | if (!initialized) { | |
130 | sigchain_push_common(remove_tempfiles_on_signal); | |
131 | atexit(remove_tempfiles_on_exit); | |
132 | initialized = 1; | |
133 | } | |
134 | ||
135 | volatile_list_add(&tempfile->list, &tempfile_list); | |
2933ebba JK |
136 | tempfile->owner = getpid(); |
137 | tempfile->active = 1; | |
138 | } | |
139 | ||
b5f4dcb5 JK |
140 | static void deactivate_tempfile(struct tempfile *tempfile) |
141 | { | |
142 | tempfile->active = 0; | |
102cf7a6 | 143 | strbuf_release(&tempfile->filename); |
422a21c6 | 144 | volatile_list_del(&tempfile->list); |
076aa2cb | 145 | free(tempfile); |
b5f4dcb5 JK |
146 | } |
147 | ||
7eba6ce5 | 148 | /* Make sure errno contains a meaningful value on error */ |
bef0413c | 149 | struct tempfile *create_tempfile_mode(const char *path, int mode) |
7eba6ce5 | 150 | { |
076aa2cb | 151 | struct tempfile *tempfile = new_tempfile(); |
1a9d15db MH |
152 | |
153 | strbuf_add_absolute_path(&tempfile->filename, path); | |
05d1ed61 | 154 | tempfile->fd = open(tempfile->filename.buf, |
bef0413c | 155 | O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, mode); |
05d1ed61 BW |
156 | if (O_CLOEXEC && tempfile->fd < 0 && errno == EINVAL) |
157 | /* Try again w/o O_CLOEXEC: the kernel might not support it */ | |
158 | tempfile->fd = open(tempfile->filename.buf, | |
bef0413c | 159 | O_RDWR | O_CREAT | O_EXCL, mode); |
1a9d15db | 160 | if (tempfile->fd < 0) { |
b5f4dcb5 | 161 | deactivate_tempfile(tempfile); |
076aa2cb | 162 | return NULL; |
1a9d15db | 163 | } |
2933ebba | 164 | activate_tempfile(tempfile); |
1a9d15db MH |
165 | if (adjust_shared_perm(tempfile->filename.buf)) { |
166 | int save_errno = errno; | |
167 | error("cannot fix permission bits on %s", tempfile->filename.buf); | |
076aa2cb | 168 | delete_tempfile(&tempfile); |
1a9d15db | 169 | errno = save_errno; |
076aa2cb | 170 | return NULL; |
1a9d15db | 171 | } |
076aa2cb JK |
172 | |
173 | return tempfile; | |
1a9d15db MH |
174 | } |
175 | ||
076aa2cb | 176 | struct tempfile *register_tempfile(const char *path) |
99397152 | 177 | { |
076aa2cb | 178 | struct tempfile *tempfile = new_tempfile(); |
99397152 | 179 | strbuf_add_absolute_path(&tempfile->filename, path); |
2933ebba | 180 | activate_tempfile(tempfile); |
076aa2cb | 181 | return tempfile; |
99397152 MH |
182 | } |
183 | ||
ea8ace4a | 184 | struct tempfile *mks_tempfile_sm(const char *filename_template, int suffixlen, int mode) |
354ab112 | 185 | { |
076aa2cb | 186 | struct tempfile *tempfile = new_tempfile(); |
354ab112 | 187 | |
ea8ace4a | 188 | strbuf_add_absolute_path(&tempfile->filename, filename_template); |
354ab112 MH |
189 | tempfile->fd = git_mkstemps_mode(tempfile->filename.buf, suffixlen, mode); |
190 | if (tempfile->fd < 0) { | |
b5f4dcb5 | 191 | deactivate_tempfile(tempfile); |
076aa2cb | 192 | return NULL; |
354ab112 | 193 | } |
2933ebba | 194 | activate_tempfile(tempfile); |
076aa2cb | 195 | return tempfile; |
354ab112 MH |
196 | } |
197 | ||
ea8ace4a | 198 | struct tempfile *mks_tempfile_tsm(const char *filename_template, int suffixlen, int mode) |
354ab112 | 199 | { |
076aa2cb | 200 | struct tempfile *tempfile = new_tempfile(); |
354ab112 MH |
201 | const char *tmpdir; |
202 | ||
354ab112 MH |
203 | tmpdir = getenv("TMPDIR"); |
204 | if (!tmpdir) | |
205 | tmpdir = "/tmp"; | |
206 | ||
ea8ace4a | 207 | strbuf_addf(&tempfile->filename, "%s/%s", tmpdir, filename_template); |
354ab112 MH |
208 | tempfile->fd = git_mkstemps_mode(tempfile->filename.buf, suffixlen, mode); |
209 | if (tempfile->fd < 0) { | |
b5f4dcb5 | 210 | deactivate_tempfile(tempfile); |
076aa2cb | 211 | return NULL; |
354ab112 | 212 | } |
2933ebba | 213 | activate_tempfile(tempfile); |
076aa2cb | 214 | return tempfile; |
354ab112 MH |
215 | } |
216 | ||
2c2db194 RS |
217 | struct tempfile *mks_tempfile_dt(const char *directory_template, |
218 | const char *filename) | |
219 | { | |
220 | struct tempfile *tempfile; | |
221 | const char *tmpdir; | |
222 | struct strbuf sb = STRBUF_INIT; | |
223 | int fd; | |
224 | size_t directorylen; | |
225 | ||
226 | if (!ends_with(directory_template, "XXXXXX")) { | |
227 | errno = EINVAL; | |
228 | return NULL; | |
229 | } | |
230 | ||
231 | tmpdir = getenv("TMPDIR"); | |
232 | if (!tmpdir) | |
233 | tmpdir = "/tmp"; | |
234 | ||
235 | strbuf_addf(&sb, "%s/%s", tmpdir, directory_template); | |
236 | directorylen = sb.len; | |
237 | if (!mkdtemp(sb.buf)) { | |
238 | int orig_errno = errno; | |
239 | strbuf_release(&sb); | |
240 | errno = orig_errno; | |
241 | return NULL; | |
242 | } | |
243 | ||
244 | strbuf_addf(&sb, "/%s", filename); | |
245 | fd = open(sb.buf, O_CREAT | O_EXCL | O_RDWR, 0600); | |
246 | if (fd < 0) { | |
247 | int orig_errno = errno; | |
248 | strbuf_setlen(&sb, directorylen); | |
249 | rmdir(sb.buf); | |
250 | strbuf_release(&sb); | |
251 | errno = orig_errno; | |
252 | return NULL; | |
253 | } | |
254 | ||
255 | tempfile = new_tempfile(); | |
256 | strbuf_swap(&tempfile->filename, &sb); | |
257 | tempfile->directorylen = directorylen; | |
258 | tempfile->fd = fd; | |
259 | activate_tempfile(tempfile); | |
260 | return tempfile; | |
261 | } | |
262 | ||
ea8ace4a | 263 | struct tempfile *xmks_tempfile_m(const char *filename_template, int mode) |
354ab112 | 264 | { |
076aa2cb | 265 | struct tempfile *tempfile; |
354ab112 MH |
266 | struct strbuf full_template = STRBUF_INIT; |
267 | ||
ea8ace4a | 268 | strbuf_add_absolute_path(&full_template, filename_template); |
076aa2cb JK |
269 | tempfile = mks_tempfile_m(full_template.buf, mode); |
270 | if (!tempfile) | |
354ab112 MH |
271 | die_errno("Unable to create temporary file '%s'", |
272 | full_template.buf); | |
273 | ||
274 | strbuf_release(&full_template); | |
076aa2cb | 275 | return tempfile; |
354ab112 MH |
276 | } |
277 | ||
1a9d15db MH |
278 | FILE *fdopen_tempfile(struct tempfile *tempfile, const char *mode) |
279 | { | |
e6fc2673 | 280 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 281 | BUG("fdopen_tempfile() called for inactive object"); |
1a9d15db | 282 | if (tempfile->fp) |
9b028aa4 | 283 | BUG("fdopen_tempfile() called for open object"); |
1a9d15db MH |
284 | |
285 | tempfile->fp = fdopen(tempfile->fd, mode); | |
286 | return tempfile->fp; | |
287 | } | |
288 | ||
289 | const char *get_tempfile_path(struct tempfile *tempfile) | |
290 | { | |
e6fc2673 | 291 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 292 | BUG("get_tempfile_path() called for inactive object"); |
1a9d15db MH |
293 | return tempfile->filename.buf; |
294 | } | |
295 | ||
296 | int get_tempfile_fd(struct tempfile *tempfile) | |
297 | { | |
e6fc2673 | 298 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 299 | BUG("get_tempfile_fd() called for inactive object"); |
1a9d15db MH |
300 | return tempfile->fd; |
301 | } | |
302 | ||
303 | FILE *get_tempfile_fp(struct tempfile *tempfile) | |
304 | { | |
e6fc2673 | 305 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 306 | BUG("get_tempfile_fp() called for inactive object"); |
1a9d15db MH |
307 | return tempfile->fp; |
308 | } | |
309 | ||
49bd0fc2 | 310 | int close_tempfile_gently(struct tempfile *tempfile) |
1a9d15db | 311 | { |
f5b4dc76 JK |
312 | int fd; |
313 | FILE *fp; | |
1a9d15db MH |
314 | int err; |
315 | ||
f5b4dc76 | 316 | if (!is_tempfile_active(tempfile) || tempfile->fd < 0) |
1a9d15db MH |
317 | return 0; |
318 | ||
f5b4dc76 JK |
319 | fd = tempfile->fd; |
320 | fp = tempfile->fp; | |
1a9d15db MH |
321 | tempfile->fd = -1; |
322 | if (fp) { | |
323 | tempfile->fp = NULL; | |
7e8c9355 JK |
324 | if (ferror(fp)) { |
325 | err = -1; | |
326 | if (!fclose(fp)) | |
327 | errno = EIO; | |
328 | } else { | |
329 | err = fclose(fp); | |
330 | } | |
1a9d15db MH |
331 | } else { |
332 | err = close(fd); | |
333 | } | |
334 | ||
49bd0fc2 | 335 | return err ? -1 : 0; |
1a9d15db MH |
336 | } |
337 | ||
338 | int reopen_tempfile(struct tempfile *tempfile) | |
339 | { | |
e6fc2673 | 340 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 341 | BUG("reopen_tempfile called for an inactive object"); |
f5b4dc76 | 342 | if (0 <= tempfile->fd) |
9b028aa4 | 343 | BUG("reopen_tempfile called for an open object"); |
6c003d6f | 344 | tempfile->fd = open(tempfile->filename.buf, O_WRONLY|O_TRUNC); |
1a9d15db MH |
345 | return tempfile->fd; |
346 | } | |
347 | ||
076aa2cb | 348 | int rename_tempfile(struct tempfile **tempfile_p, const char *path) |
1a9d15db | 349 | { |
076aa2cb JK |
350 | struct tempfile *tempfile = *tempfile_p; |
351 | ||
e6fc2673 | 352 | if (!is_tempfile_active(tempfile)) |
9b028aa4 | 353 | BUG("rename_tempfile called for inactive object"); |
1a9d15db | 354 | |
49bd0fc2 | 355 | if (close_tempfile_gently(tempfile)) { |
076aa2cb | 356 | delete_tempfile(tempfile_p); |
1a9d15db | 357 | return -1; |
49bd0fc2 | 358 | } |
1a9d15db MH |
359 | |
360 | if (rename(tempfile->filename.buf, path)) { | |
361 | int save_errno = errno; | |
076aa2cb | 362 | delete_tempfile(tempfile_p); |
1a9d15db MH |
363 | errno = save_errno; |
364 | return -1; | |
365 | } | |
366 | ||
b5f4dcb5 | 367 | deactivate_tempfile(tempfile); |
076aa2cb | 368 | *tempfile_p = NULL; |
1a9d15db MH |
369 | return 0; |
370 | } | |
371 | ||
076aa2cb | 372 | void delete_tempfile(struct tempfile **tempfile_p) |
1a9d15db | 373 | { |
076aa2cb JK |
374 | struct tempfile *tempfile = *tempfile_p; |
375 | ||
e6fc2673 | 376 | if (!is_tempfile_active(tempfile)) |
1a9d15db MH |
377 | return; |
378 | ||
49bd0fc2 JK |
379 | close_tempfile_gently(tempfile); |
380 | unlink_or_warn(tempfile->filename.buf); | |
2c2db194 | 381 | remove_template_directory(tempfile, 0); |
b5f4dcb5 | 382 | deactivate_tempfile(tempfile); |
076aa2cb | 383 | *tempfile_p = NULL; |
1a9d15db | 384 | } |