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Commit | Line | Data |
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ea88812f FB |
1 | /* |
2 | * QEMU low level functions | |
5fafdf24 | 3 | * |
ea88812f | 4 | * Copyright (c) 2003 Fabrice Bellard |
5fafdf24 | 5 | * |
ea88812f FB |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
aafd7584 | 24 | #include "qemu/osdep.h" |
ebb3d49c | 25 | #include "qapi/error.h" |
f348b6d1 | 26 | #include "qemu/cutils.h" |
1de7afc9 | 27 | #include "qemu/sockets.h" |
d49b6836 | 28 | #include "qemu/error-report.h" |
b85ea5fa | 29 | #include "qemu/madvise.h" |
f2241d16 | 30 | #include "qemu/mprotect.h" |
15e09912 | 31 | #include "qemu/hw-version.h" |
83c9089e | 32 | #include "monitor/monitor.h" |
03ff3ca3 | 33 | |
d494352c | 34 | static const char *hw_version = QEMU_HW_VERSION; |
93bfef4c | 35 | |
128aa589 PB |
36 | int socket_set_cork(int fd, int v) |
37 | { | |
38 | #if defined(SOL_TCP) && defined(TCP_CORK) | |
e7b79428 | 39 | return setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v)); |
128aa589 PB |
40 | #else |
41 | return 0; | |
42 | #endif | |
43 | } | |
44 | ||
bf1c852a MK |
45 | int socket_set_nodelay(int fd) |
46 | { | |
47 | int v = 1; | |
e7b79428 | 48 | return setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v)); |
bf1c852a MK |
49 | } |
50 | ||
e78815a5 AF |
51 | int qemu_madvise(void *addr, size_t len, int advice) |
52 | { | |
53 | if (advice == QEMU_MADV_INVALID) { | |
54 | errno = EINVAL; | |
55 | return -1; | |
56 | } | |
57 | #if defined(CONFIG_MADVISE) | |
58 | return madvise(addr, len, advice); | |
59 | #elif defined(CONFIG_POSIX_MADVISE) | |
60 | return posix_madvise(addr, len, advice); | |
61 | #else | |
62 | errno = EINVAL; | |
63 | return -1; | |
64 | #endif | |
65 | } | |
66 | ||
5fa64b31 EC |
67 | static int qemu_mprotect__osdep(void *addr, size_t size, int prot) |
68 | { | |
8e3b0cbb MAL |
69 | g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask())); |
70 | g_assert(!(size & ~qemu_real_host_page_mask())); | |
5fa64b31 EC |
71 | |
72 | #ifdef _WIN32 | |
73 | DWORD old_protect; | |
74 | ||
75 | if (!VirtualProtect(addr, size, prot, &old_protect)) { | |
cf0c76cd PMD |
76 | g_autofree gchar *emsg = g_win32_error_message(GetLastError()); |
77 | error_report("%s: VirtualProtect failed: %s", __func__, emsg); | |
5fa64b31 EC |
78 | return -1; |
79 | } | |
80 | return 0; | |
81 | #else | |
82 | if (mprotect(addr, size, prot)) { | |
83 | error_report("%s: mprotect failed: %s", __func__, strerror(errno)); | |
84 | return -1; | |
85 | } | |
86 | return 0; | |
87 | #endif | |
88 | } | |
89 | ||
d7107fc0 RH |
90 | int qemu_mprotect_rw(void *addr, size_t size) |
91 | { | |
92 | #ifdef _WIN32 | |
93 | return qemu_mprotect__osdep(addr, size, PAGE_READWRITE); | |
94 | #else | |
95 | return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE); | |
96 | #endif | |
97 | } | |
98 | ||
5fa64b31 EC |
99 | int qemu_mprotect_rwx(void *addr, size_t size) |
100 | { | |
101 | #ifdef _WIN32 | |
102 | return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE); | |
103 | #else | |
104 | return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); | |
105 | #endif | |
106 | } | |
107 | ||
108 | int qemu_mprotect_none(void *addr, size_t size) | |
109 | { | |
110 | #ifdef _WIN32 | |
111 | return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS); | |
112 | #else | |
113 | return qemu_mprotect__osdep(addr, size, PROT_NONE); | |
114 | #endif | |
115 | } | |
116 | ||
adb696f3 | 117 | #ifndef _WIN32 |
ca749954 FZ |
118 | |
119 | static int fcntl_op_setlk = -1; | |
120 | static int fcntl_op_getlk = -1; | |
121 | ||
adb696f3 CB |
122 | /* |
123 | * Dups an fd and sets the flags | |
124 | */ | |
60efffa4 | 125 | int qemu_dup_flags(int fd, int flags) |
adb696f3 CB |
126 | { |
127 | int ret; | |
128 | int serrno; | |
129 | int dup_flags; | |
adb696f3 | 130 | |
761d1ddf | 131 | ret = qemu_dup(fd); |
adb696f3 CB |
132 | if (ret == -1) { |
133 | goto fail; | |
134 | } | |
135 | ||
136 | dup_flags = fcntl(ret, F_GETFL); | |
137 | if (dup_flags == -1) { | |
138 | goto fail; | |
139 | } | |
140 | ||
141 | if ((flags & O_SYNC) != (dup_flags & O_SYNC)) { | |
142 | errno = EINVAL; | |
143 | goto fail; | |
144 | } | |
145 | ||
146 | /* Set/unset flags that we can with fcntl */ | |
3b6eda2f | 147 | if (fcntl(ret, F_SETFL, flags) == -1) { |
adb696f3 CB |
148 | goto fail; |
149 | } | |
150 | ||
151 | /* Truncate the file in the cases that open() would truncate it */ | |
152 | if (flags & O_TRUNC || | |
153 | ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) { | |
154 | if (ftruncate(ret, 0) == -1) { | |
155 | goto fail; | |
156 | } | |
157 | } | |
158 | ||
159 | return ret; | |
160 | ||
161 | fail: | |
162 | serrno = errno; | |
163 | if (ret != -1) { | |
164 | close(ret); | |
165 | } | |
166 | errno = serrno; | |
167 | return -1; | |
168 | } | |
0100fbbe | 169 | |
761d1ddf FZ |
170 | int qemu_dup(int fd) |
171 | { | |
172 | int ret; | |
173 | #ifdef F_DUPFD_CLOEXEC | |
174 | ret = fcntl(fd, F_DUPFD_CLOEXEC, 0); | |
175 | #else | |
176 | ret = dup(fd); | |
177 | if (ret != -1) { | |
178 | qemu_set_cloexec(ret); | |
179 | } | |
180 | #endif | |
181 | return ret; | |
182 | } | |
183 | ||
0100fbbe PB |
184 | static int qemu_parse_fdset(const char *param) |
185 | { | |
186 | return qemu_parse_fd(param); | |
187 | } | |
13461fdb | 188 | |
ca749954 FZ |
189 | static void qemu_probe_lock_ops(void) |
190 | { | |
191 | if (fcntl_op_setlk == -1) { | |
192 | #ifdef F_OFD_SETLK | |
193 | int fd; | |
194 | int ret; | |
195 | struct flock fl = { | |
196 | .l_whence = SEEK_SET, | |
197 | .l_start = 0, | |
198 | .l_len = 0, | |
199 | .l_type = F_WRLCK, | |
200 | }; | |
201 | ||
202 | fd = open("/dev/null", O_RDWR); | |
203 | if (fd < 0) { | |
204 | fprintf(stderr, | |
205 | "Failed to open /dev/null for OFD lock probing: %s\n", | |
206 | strerror(errno)); | |
207 | fcntl_op_setlk = F_SETLK; | |
208 | fcntl_op_getlk = F_GETLK; | |
209 | return; | |
210 | } | |
211 | ret = fcntl(fd, F_OFD_GETLK, &fl); | |
212 | close(fd); | |
213 | if (!ret) { | |
214 | fcntl_op_setlk = F_OFD_SETLK; | |
215 | fcntl_op_getlk = F_OFD_GETLK; | |
216 | } else { | |
217 | fcntl_op_setlk = F_SETLK; | |
218 | fcntl_op_getlk = F_GETLK; | |
219 | } | |
220 | #else | |
221 | fcntl_op_setlk = F_SETLK; | |
222 | fcntl_op_getlk = F_GETLK; | |
223 | #endif | |
224 | } | |
225 | } | |
226 | ||
227 | bool qemu_has_ofd_lock(void) | |
228 | { | |
229 | qemu_probe_lock_ops(); | |
230 | #ifdef F_OFD_SETLK | |
231 | return fcntl_op_setlk == F_OFD_SETLK; | |
232 | #else | |
233 | return false; | |
234 | #endif | |
235 | } | |
236 | ||
13461fdb FZ |
237 | static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type) |
238 | { | |
13461fdb FZ |
239 | int ret; |
240 | struct flock fl = { | |
241 | .l_whence = SEEK_SET, | |
242 | .l_start = start, | |
243 | .l_len = len, | |
244 | .l_type = fl_type, | |
245 | }; | |
ca749954 | 246 | qemu_probe_lock_ops(); |
37b0b24e | 247 | ret = RETRY_ON_EINTR(fcntl(fd, fcntl_op_setlk, &fl)); |
13461fdb | 248 | return ret == -1 ? -errno : 0; |
13461fdb FZ |
249 | } |
250 | ||
251 | int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive) | |
252 | { | |
253 | return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK); | |
254 | } | |
255 | ||
256 | int qemu_unlock_fd(int fd, int64_t start, int64_t len) | |
257 | { | |
258 | return qemu_lock_fcntl(fd, start, len, F_UNLCK); | |
259 | } | |
260 | ||
261 | int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive) | |
262 | { | |
13461fdb FZ |
263 | int ret; |
264 | struct flock fl = { | |
265 | .l_whence = SEEK_SET, | |
266 | .l_start = start, | |
267 | .l_len = len, | |
268 | .l_type = exclusive ? F_WRLCK : F_RDLCK, | |
269 | }; | |
ca749954 FZ |
270 | qemu_probe_lock_ops(); |
271 | ret = fcntl(fd, fcntl_op_getlk, &fl); | |
13461fdb FZ |
272 | if (ret == -1) { |
273 | return -errno; | |
274 | } else { | |
275 | return fl.l_type == F_UNLCK ? 0 : -EAGAIN; | |
276 | } | |
13461fdb | 277 | } |
adb696f3 | 278 | #endif |
03ff3ca3 | 279 | |
c2069ff6 DB |
280 | static int qemu_open_cloexec(const char *name, int flags, mode_t mode) |
281 | { | |
282 | int ret; | |
283 | #ifdef O_CLOEXEC | |
284 | ret = open(name, flags | O_CLOEXEC, mode); | |
285 | #else | |
286 | ret = open(name, flags, mode); | |
287 | if (ret >= 0) { | |
288 | qemu_set_cloexec(ret); | |
289 | } | |
290 | #endif | |
291 | return ret; | |
292 | } | |
293 | ||
40ff6d7e KW |
294 | /* |
295 | * Opens a file with FD_CLOEXEC set | |
296 | */ | |
bf93d2ad | 297 | static int |
ebb3d49c | 298 | qemu_open_internal(const char *name, int flags, mode_t mode, Error **errp) |
40ff6d7e KW |
299 | { |
300 | int ret; | |
40ff6d7e | 301 | |
adb696f3 CB |
302 | #ifndef _WIN32 |
303 | const char *fdset_id_str; | |
304 | ||
305 | /* Attempt dup of fd from fd set */ | |
306 | if (strstart(name, "/dev/fdset/", &fdset_id_str)) { | |
307 | int64_t fdset_id; | |
60efffa4 | 308 | int dupfd; |
adb696f3 CB |
309 | |
310 | fdset_id = qemu_parse_fdset(fdset_id_str); | |
311 | if (fdset_id == -1) { | |
ebb3d49c | 312 | error_setg(errp, "Could not parse fdset %s", name); |
adb696f3 CB |
313 | errno = EINVAL; |
314 | return -1; | |
315 | } | |
316 | ||
60efffa4 | 317 | dupfd = monitor_fdset_dup_fd_add(fdset_id, flags); |
adb696f3 | 318 | if (dupfd == -1) { |
ebb3d49c DB |
319 | error_setg_errno(errp, errno, "Could not dup FD for %s flags %x", |
320 | name, flags); | |
adb696f3 CB |
321 | return -1; |
322 | } | |
323 | ||
adb696f3 CB |
324 | return dupfd; |
325 | } | |
326 | #endif | |
327 | ||
bf93d2ad DB |
328 | ret = qemu_open_cloexec(name, flags, mode); |
329 | ||
ebb3d49c DB |
330 | if (ret == -1) { |
331 | const char *action = flags & O_CREAT ? "create" : "open"; | |
661b3e81 DB |
332 | #ifdef O_DIRECT |
333 | /* Give more helpful error message for O_DIRECT */ | |
334 | if (errno == EINVAL && (flags & O_DIRECT)) { | |
335 | ret = open(name, flags & ~O_DIRECT, mode); | |
336 | if (ret != -1) { | |
337 | close(ret); | |
338 | error_setg(errp, "Could not %s '%s': " | |
339 | "filesystem does not support O_DIRECT", | |
340 | action, name); | |
341 | errno = EINVAL; /* restore first open()'s errno */ | |
342 | return -1; | |
343 | } | |
344 | } | |
345 | #endif /* O_DIRECT */ | |
ebb3d49c DB |
346 | error_setg_errno(errp, errno, "Could not %s '%s'", |
347 | action, name); | |
348 | } | |
349 | ||
bf93d2ad DB |
350 | return ret; |
351 | } | |
352 | ||
40ff6d7e | 353 | |
c490af57 DB |
354 | int qemu_open(const char *name, int flags, Error **errp) |
355 | { | |
356 | assert(!(flags & O_CREAT)); | |
357 | ||
358 | return qemu_open_internal(name, flags, 0, errp); | |
359 | } | |
360 | ||
361 | ||
362 | int qemu_create(const char *name, int flags, mode_t mode, Error **errp) | |
363 | { | |
364 | assert(!(flags & O_CREAT)); | |
365 | ||
366 | return qemu_open_internal(name, flags | O_CREAT, mode, errp); | |
367 | } | |
368 | ||
369 | ||
bf93d2ad DB |
370 | int qemu_open_old(const char *name, int flags, ...) |
371 | { | |
372 | va_list ap; | |
373 | mode_t mode = 0; | |
374 | int ret; | |
375 | ||
376 | va_start(ap, flags); | |
377 | if (flags & O_CREAT) { | |
40ff6d7e | 378 | mode = va_arg(ap, int); |
40ff6d7e | 379 | } |
bf93d2ad | 380 | va_end(ap); |
40ff6d7e | 381 | |
ebb3d49c | 382 | ret = qemu_open_internal(name, flags, mode, NULL); |
40ff6d7e | 383 | |
a5813077 SH |
384 | #ifdef O_DIRECT |
385 | if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) { | |
386 | error_report("file system may not support O_DIRECT"); | |
387 | errno = EINVAL; /* in case it was clobbered */ | |
388 | } | |
389 | #endif /* O_DIRECT */ | |
390 | ||
40ff6d7e KW |
391 | return ret; |
392 | } | |
393 | ||
2e1e79da CB |
394 | int qemu_close(int fd) |
395 | { | |
adb696f3 CB |
396 | int64_t fdset_id; |
397 | ||
398 | /* Close fd that was dup'd from an fdset */ | |
399 | fdset_id = monitor_fdset_dup_fd_find(fd); | |
400 | if (fdset_id != -1) { | |
401 | int ret; | |
402 | ||
403 | ret = close(fd); | |
404 | if (ret == 0) { | |
405 | monitor_fdset_dup_fd_remove(fd); | |
406 | } | |
407 | ||
408 | return ret; | |
409 | } | |
410 | ||
2e1e79da CB |
411 | return close(fd); |
412 | } | |
413 | ||
ee13240e MAL |
414 | /* |
415 | * Delete a file from the filesystem, unless the filename is /dev/fdset/... | |
416 | * | |
417 | * Returns: On success, zero is returned. On error, -1 is returned, | |
418 | * and errno is set appropriately. | |
419 | */ | |
420 | int qemu_unlink(const char *name) | |
421 | { | |
422 | if (g_str_has_prefix(name, "/dev/fdset/")) { | |
423 | return 0; | |
424 | } | |
425 | ||
426 | return unlink(name); | |
427 | } | |
428 | ||
7b5f699d KS |
429 | /* |
430 | * A variant of write(2) which handles partial write. | |
431 | * | |
432 | * Return the number of bytes transferred. | |
433 | * Set errno if fewer than `count' bytes are written. | |
1298cb68 JQ |
434 | * |
435 | * This function don't work with non-blocking fd's. | |
8cc360b9 | 436 | * Any of the possibilities with non-blocking fd's is bad: |
1298cb68 JQ |
437 | * - return a short write (then name is wrong) |
438 | * - busy wait adding (errno == EAGAIN) to the loop | |
7b5f699d KS |
439 | */ |
440 | ssize_t qemu_write_full(int fd, const void *buf, size_t count) | |
441 | { | |
442 | ssize_t ret = 0; | |
443 | ssize_t total = 0; | |
444 | ||
445 | while (count) { | |
446 | ret = write(fd, buf, count); | |
447 | if (ret < 0) { | |
448 | if (errno == EINTR) | |
449 | continue; | |
450 | break; | |
451 | } | |
452 | ||
453 | count -= ret; | |
454 | buf += ret; | |
455 | total += ret; | |
456 | } | |
457 | ||
458 | return total; | |
459 | } | |
460 | ||
40ff6d7e KW |
461 | /* |
462 | * Opens a socket with FD_CLOEXEC set | |
463 | */ | |
464 | int qemu_socket(int domain, int type, int protocol) | |
465 | { | |
466 | int ret; | |
467 | ||
468 | #ifdef SOCK_CLOEXEC | |
469 | ret = socket(domain, type | SOCK_CLOEXEC, protocol); | |
3a03bfa5 AP |
470 | if (ret != -1 || errno != EINVAL) { |
471 | return ret; | |
472 | } | |
473 | #endif | |
40ff6d7e KW |
474 | ret = socket(domain, type, protocol); |
475 | if (ret >= 0) { | |
476 | qemu_set_cloexec(ret); | |
477 | } | |
40ff6d7e KW |
478 | |
479 | return ret; | |
480 | } | |
481 | ||
482 | /* | |
483 | * Accept a connection and set FD_CLOEXEC | |
484 | */ | |
485 | int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen) | |
486 | { | |
487 | int ret; | |
488 | ||
489 | #ifdef CONFIG_ACCEPT4 | |
490 | ret = accept4(s, addr, addrlen, SOCK_CLOEXEC); | |
347ed55c | 491 | if (ret != -1 || errno != ENOSYS) { |
3a03bfa5 AP |
492 | return ret; |
493 | } | |
494 | #endif | |
40ff6d7e KW |
495 | ret = accept(s, addr, addrlen); |
496 | if (ret >= 0) { | |
497 | qemu_set_cloexec(ret); | |
498 | } | |
40ff6d7e KW |
499 | |
500 | return ret; | |
501 | } | |
993295fe | 502 | |
84c662d2 XC |
503 | ssize_t qemu_send_full(int s, const void *buf, size_t count) |
504 | { | |
505 | ssize_t ret = 0; | |
506 | ssize_t total = 0; | |
507 | ||
508 | while (count) { | |
509 | ret = send(s, buf, count, 0); | |
510 | if (ret < 0) { | |
511 | if (errno == EINTR) { | |
512 | continue; | |
513 | } | |
514 | break; | |
515 | } | |
516 | ||
517 | count -= ret; | |
518 | buf += ret; | |
519 | total += ret; | |
520 | } | |
521 | ||
522 | return total; | |
523 | } | |
524 | ||
35c2c8dc | 525 | void qemu_set_hw_version(const char *version) |
93bfef4c | 526 | { |
35c2c8dc | 527 | hw_version = version; |
93bfef4c CV |
528 | } |
529 | ||
35c2c8dc | 530 | const char *qemu_hw_version(void) |
93bfef4c | 531 | { |
35c2c8dc | 532 | return hw_version; |
93bfef4c | 533 | } |
0f66998f | 534 | |
d3bf825e MAL |
535 | #ifdef _WIN32 |
536 | static void socket_cleanup(void) | |
537 | { | |
538 | WSACleanup(); | |
539 | } | |
540 | #endif | |
541 | ||
542 | int socket_init(void) | |
543 | { | |
544 | #ifdef _WIN32 | |
545 | WSADATA Data; | |
546 | int ret, err; | |
547 | ||
548 | ret = WSAStartup(MAKEWORD(2, 2), &Data); | |
549 | if (ret != 0) { | |
550 | err = WSAGetLastError(); | |
551 | fprintf(stderr, "WSAStartup: %d\n", err); | |
552 | return -1; | |
553 | } | |
554 | atexit(socket_cleanup); | |
555 | #endif | |
556 | return 0; | |
557 | } | |
9adea5f7 | 558 | |
ae2990c2 | 559 | |
9adea5f7 | 560 | #ifndef CONFIG_IOVEC |
9adea5f7 PB |
561 | static ssize_t |
562 | readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write) | |
563 | { | |
564 | unsigned i = 0; | |
565 | ssize_t ret = 0; | |
c1f79809 | 566 | ssize_t off = 0; |
9adea5f7 PB |
567 | while (i < iov_cnt) { |
568 | ssize_t r = do_write | |
c1f79809 MAL |
569 | ? write(fd, iov[i].iov_base + off, iov[i].iov_len - off) |
570 | : read(fd, iov[i].iov_base + off, iov[i].iov_len - off); | |
9adea5f7 PB |
571 | if (r > 0) { |
572 | ret += r; | |
c1f79809 MAL |
573 | off += r; |
574 | if (off < iov[i].iov_len) { | |
575 | continue; | |
576 | } | |
9adea5f7 PB |
577 | } else if (!r) { |
578 | break; | |
579 | } else if (errno == EINTR) { | |
580 | continue; | |
581 | } else { | |
582 | /* else it is some "other" error, | |
583 | * only return if there was no data processed. */ | |
584 | if (ret == 0) { | |
585 | ret = -1; | |
586 | } | |
587 | break; | |
588 | } | |
c1f79809 | 589 | off = 0; |
9adea5f7 PB |
590 | i++; |
591 | } | |
592 | return ret; | |
593 | } | |
594 | ||
595 | ssize_t | |
596 | readv(int fd, const struct iovec *iov, int iov_cnt) | |
597 | { | |
598 | return readv_writev(fd, iov, iov_cnt, false); | |
599 | } | |
600 | ||
601 | ssize_t | |
602 | writev(int fd, const struct iovec *iov, int iov_cnt) | |
603 | { | |
604 | return readv_writev(fd, iov, iov_cnt, true); | |
605 | } | |
606 | #endif | |
282468c7 MAL |
607 | |
608 | /* | |
609 | * Make sure data goes on disk, but if possible do not bother to | |
610 | * write out the inode just for timestamp updates. | |
611 | * | |
612 | * Unfortunately even in 2009 many operating systems do not support | |
613 | * fdatasync and have to fall back to fsync. | |
614 | */ | |
615 | int qemu_fdatasync(int fd) | |
616 | { | |
617 | #ifdef CONFIG_FDATASYNC | |
618 | return fdatasync(fd); | |
619 | #else | |
620 | return fsync(fd); | |
621 | #endif | |
622 | } |