Commit | Line | Data |
---|---|---|
5274f052 JA |
1 | /* |
2 | * "splice": joining two ropes together by interweaving their strands. | |
3 | * | |
4 | * This is the "extended pipe" functionality, where a pipe is used as | |
5 | * an arbitrary in-memory buffer. Think of a pipe as a small kernel | |
6 | * buffer that you can use to transfer data from one end to the other. | |
7 | * | |
8 | * The traditional unix read/write is extended with a "splice()" operation | |
9 | * that transfers data buffers to or from a pipe buffer. | |
10 | * | |
11 | * Named by Larry McVoy, original implementation from Linus, extended by | |
12 | * Jens to support splicing to files and fixing the initial implementation | |
13 | * bugs. | |
14 | * | |
15 | * Copyright (C) 2005 Jens Axboe <axboe@suse.de> | |
16 | * Copyright (C) 2005 Linus Torvalds <torvalds@osdl.org> | |
17 | * | |
18 | */ | |
19 | #include <linux/fs.h> | |
20 | #include <linux/file.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/pipe_fs_i.h> | |
23 | #include <linux/mm_inline.h> | |
5abc97aa | 24 | #include <linux/swap.h> |
a0f06780 | 25 | #include <linux/module.h> |
5274f052 JA |
26 | |
27 | /* | |
28 | * Passed to the actors | |
29 | */ | |
30 | struct splice_desc { | |
31 | unsigned int len, total_len; /* current and remaining length */ | |
32 | unsigned int flags; /* splice flags */ | |
33 | struct file *file; /* file to read/write */ | |
34 | loff_t pos; /* file position */ | |
35 | }; | |
36 | ||
5abc97aa JA |
37 | static int page_cache_pipe_buf_steal(struct pipe_inode_info *info, |
38 | struct pipe_buffer *buf) | |
39 | { | |
40 | struct page *page = buf->page; | |
41 | ||
42 | WARN_ON(!PageLocked(page)); | |
43 | WARN_ON(!PageUptodate(page)); | |
44 | ||
45 | if (!remove_mapping(page_mapping(page), page)) | |
46 | return 1; | |
47 | ||
48 | if (PageLRU(page)) { | |
49 | struct zone *zone = page_zone(page); | |
50 | ||
51 | spin_lock_irq(&zone->lru_lock); | |
52 | BUG_ON(!PageLRU(page)); | |
53 | __ClearPageLRU(page); | |
54 | del_page_from_lru(zone, page); | |
55 | spin_unlock_irq(&zone->lru_lock); | |
56 | } | |
57 | ||
58 | buf->stolen = 1; | |
59 | return 0; | |
60 | } | |
61 | ||
5274f052 JA |
62 | static void page_cache_pipe_buf_release(struct pipe_inode_info *info, |
63 | struct pipe_buffer *buf) | |
64 | { | |
65 | page_cache_release(buf->page); | |
66 | buf->page = NULL; | |
5abc97aa | 67 | buf->stolen = 0; |
5274f052 JA |
68 | } |
69 | ||
70 | static void *page_cache_pipe_buf_map(struct file *file, | |
71 | struct pipe_inode_info *info, | |
72 | struct pipe_buffer *buf) | |
73 | { | |
74 | struct page *page = buf->page; | |
75 | ||
76 | lock_page(page); | |
77 | ||
78 | if (!PageUptodate(page)) { | |
79 | unlock_page(page); | |
80 | return ERR_PTR(-EIO); | |
81 | } | |
82 | ||
83 | if (!page->mapping) { | |
84 | unlock_page(page); | |
85 | return ERR_PTR(-ENODATA); | |
86 | } | |
87 | ||
88 | return kmap(buf->page); | |
89 | } | |
90 | ||
91 | static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, | |
92 | struct pipe_buffer *buf) | |
93 | { | |
5abc97aa JA |
94 | if (!buf->stolen) |
95 | unlock_page(buf->page); | |
5274f052 JA |
96 | kunmap(buf->page); |
97 | } | |
98 | ||
99 | static struct pipe_buf_operations page_cache_pipe_buf_ops = { | |
100 | .can_merge = 0, | |
101 | .map = page_cache_pipe_buf_map, | |
102 | .unmap = page_cache_pipe_buf_unmap, | |
103 | .release = page_cache_pipe_buf_release, | |
5abc97aa | 104 | .steal = page_cache_pipe_buf_steal, |
5274f052 JA |
105 | }; |
106 | ||
107 | static ssize_t move_to_pipe(struct inode *inode, struct page **pages, | |
108 | int nr_pages, unsigned long offset, | |
109 | unsigned long len) | |
110 | { | |
111 | struct pipe_inode_info *info; | |
112 | int ret, do_wakeup, i; | |
113 | ||
114 | ret = 0; | |
115 | do_wakeup = 0; | |
116 | i = 0; | |
117 | ||
118 | mutex_lock(PIPE_MUTEX(*inode)); | |
119 | ||
120 | info = inode->i_pipe; | |
121 | for (;;) { | |
122 | int bufs; | |
123 | ||
124 | if (!PIPE_READERS(*inode)) { | |
125 | send_sig(SIGPIPE, current, 0); | |
126 | if (!ret) | |
127 | ret = -EPIPE; | |
128 | break; | |
129 | } | |
130 | ||
131 | bufs = info->nrbufs; | |
132 | if (bufs < PIPE_BUFFERS) { | |
133 | int newbuf = (info->curbuf + bufs) & (PIPE_BUFFERS - 1); | |
134 | struct pipe_buffer *buf = info->bufs + newbuf; | |
135 | struct page *page = pages[i++]; | |
136 | unsigned long this_len; | |
137 | ||
138 | this_len = PAGE_CACHE_SIZE - offset; | |
139 | if (this_len > len) | |
140 | this_len = len; | |
141 | ||
142 | buf->page = page; | |
143 | buf->offset = offset; | |
144 | buf->len = this_len; | |
145 | buf->ops = &page_cache_pipe_buf_ops; | |
146 | info->nrbufs = ++bufs; | |
147 | do_wakeup = 1; | |
148 | ||
149 | ret += this_len; | |
150 | len -= this_len; | |
151 | offset = 0; | |
152 | if (!--nr_pages) | |
153 | break; | |
154 | if (!len) | |
155 | break; | |
156 | if (bufs < PIPE_BUFFERS) | |
157 | continue; | |
158 | ||
159 | break; | |
160 | } | |
161 | ||
162 | if (signal_pending(current)) { | |
163 | if (!ret) | |
164 | ret = -ERESTARTSYS; | |
165 | break; | |
166 | } | |
167 | ||
168 | if (do_wakeup) { | |
169 | wake_up_interruptible_sync(PIPE_WAIT(*inode)); | |
170 | kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, | |
171 | POLL_IN); | |
172 | do_wakeup = 0; | |
173 | } | |
174 | ||
175 | PIPE_WAITING_WRITERS(*inode)++; | |
176 | pipe_wait(inode); | |
177 | PIPE_WAITING_WRITERS(*inode)--; | |
178 | } | |
179 | ||
180 | mutex_unlock(PIPE_MUTEX(*inode)); | |
181 | ||
182 | if (do_wakeup) { | |
183 | wake_up_interruptible(PIPE_WAIT(*inode)); | |
184 | kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); | |
185 | } | |
186 | ||
187 | while (i < nr_pages) | |
188 | page_cache_release(pages[i++]); | |
189 | ||
190 | return ret; | |
191 | } | |
192 | ||
193 | static int __generic_file_splice_read(struct file *in, struct inode *pipe, | |
194 | size_t len) | |
195 | { | |
196 | struct address_space *mapping = in->f_mapping; | |
197 | unsigned int offset, nr_pages; | |
198 | struct page *pages[PIPE_BUFFERS], *shadow[PIPE_BUFFERS]; | |
199 | struct page *page; | |
200 | pgoff_t index, pidx; | |
201 | int i, j; | |
202 | ||
203 | index = in->f_pos >> PAGE_CACHE_SHIFT; | |
204 | offset = in->f_pos & ~PAGE_CACHE_MASK; | |
205 | nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
206 | ||
207 | if (nr_pages > PIPE_BUFFERS) | |
208 | nr_pages = PIPE_BUFFERS; | |
209 | ||
210 | /* | |
211 | * initiate read-ahead on this page range | |
212 | */ | |
213 | do_page_cache_readahead(mapping, in, index, nr_pages); | |
214 | ||
215 | /* | |
216 | * Get as many pages from the page cache as possible.. | |
217 | * Start IO on the page cache entries we create (we | |
218 | * can assume that any pre-existing ones we find have | |
219 | * already had IO started on them). | |
220 | */ | |
221 | i = find_get_pages(mapping, index, nr_pages, pages); | |
222 | ||
223 | /* | |
224 | * common case - we found all pages and they are contiguous, | |
225 | * kick them off | |
226 | */ | |
227 | if (i && (pages[i - 1]->index == index + i - 1)) | |
228 | goto splice_them; | |
229 | ||
230 | /* | |
231 | * fill shadow[] with pages at the right locations, so we only | |
232 | * have to fill holes | |
233 | */ | |
234 | memset(shadow, 0, i * sizeof(struct page *)); | |
235 | for (j = 0, pidx = index; j < i; pidx++, j++) | |
236 | shadow[pages[j]->index - pidx] = pages[j]; | |
237 | ||
238 | /* | |
239 | * now fill in the holes | |
240 | */ | |
241 | for (i = 0, pidx = index; i < nr_pages; pidx++, i++) { | |
242 | int error; | |
243 | ||
244 | if (shadow[i]) | |
245 | continue; | |
246 | ||
247 | /* | |
248 | * no page there, look one up / create it | |
249 | */ | |
250 | page = find_or_create_page(mapping, pidx, | |
251 | mapping_gfp_mask(mapping)); | |
252 | if (!page) | |
253 | break; | |
254 | ||
255 | if (PageUptodate(page)) | |
256 | unlock_page(page); | |
257 | else { | |
258 | error = mapping->a_ops->readpage(in, page); | |
259 | ||
260 | if (unlikely(error)) { | |
261 | page_cache_release(page); | |
262 | break; | |
263 | } | |
264 | } | |
265 | shadow[i] = page; | |
266 | } | |
267 | ||
268 | if (!i) { | |
269 | for (i = 0; i < nr_pages; i++) { | |
270 | if (shadow[i]) | |
271 | page_cache_release(shadow[i]); | |
272 | } | |
273 | return 0; | |
274 | } | |
275 | ||
276 | memcpy(pages, shadow, i * sizeof(struct page *)); | |
277 | ||
278 | /* | |
279 | * Now we splice them into the pipe.. | |
280 | */ | |
281 | splice_them: | |
282 | return move_to_pipe(pipe, pages, i, offset, len); | |
283 | } | |
284 | ||
285 | ssize_t generic_file_splice_read(struct file *in, struct inode *pipe, | |
286 | size_t len, unsigned int flags) | |
287 | { | |
288 | ssize_t spliced; | |
289 | int ret; | |
290 | ||
291 | ret = 0; | |
292 | spliced = 0; | |
293 | while (len) { | |
294 | ret = __generic_file_splice_read(in, pipe, len); | |
295 | ||
296 | if (ret <= 0) | |
297 | break; | |
298 | ||
299 | in->f_pos += ret; | |
300 | len -= ret; | |
301 | spliced += ret; | |
302 | } | |
303 | ||
304 | if (spliced) | |
305 | return spliced; | |
306 | ||
307 | return ret; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Send 'len' bytes to socket from 'file' at position 'pos' using sendpage(). | |
312 | */ | |
313 | static int pipe_to_sendpage(struct pipe_inode_info *info, | |
314 | struct pipe_buffer *buf, struct splice_desc *sd) | |
315 | { | |
316 | struct file *file = sd->file; | |
317 | loff_t pos = sd->pos; | |
318 | unsigned int offset; | |
319 | ssize_t ret; | |
320 | void *ptr; | |
321 | ||
322 | /* | |
323 | * sub-optimal, but we are limited by the pipe ->map. we don't | |
324 | * need a kmap'ed buffer here, we just want to make sure we | |
325 | * have the page pinned if the pipe page originates from the | |
326 | * page cache | |
327 | */ | |
328 | ptr = buf->ops->map(file, info, buf); | |
329 | if (IS_ERR(ptr)) | |
330 | return PTR_ERR(ptr); | |
331 | ||
332 | offset = pos & ~PAGE_CACHE_MASK; | |
333 | ||
334 | ret = file->f_op->sendpage(file, buf->page, offset, sd->len, &pos, | |
335 | sd->len < sd->total_len); | |
336 | ||
337 | buf->ops->unmap(info, buf); | |
338 | if (ret == sd->len) | |
339 | return 0; | |
340 | ||
341 | return -EIO; | |
342 | } | |
343 | ||
344 | /* | |
345 | * This is a little more tricky than the file -> pipe splicing. There are | |
346 | * basically three cases: | |
347 | * | |
348 | * - Destination page already exists in the address space and there | |
349 | * are users of it. For that case we have no other option that | |
350 | * copying the data. Tough luck. | |
351 | * - Destination page already exists in the address space, but there | |
352 | * are no users of it. Make sure it's uptodate, then drop it. Fall | |
353 | * through to last case. | |
354 | * - Destination page does not exist, we can add the pipe page to | |
355 | * the page cache and avoid the copy. | |
356 | * | |
357 | * For now we just do the slower thing and always copy pages over, it's | |
358 | * easier than migrating pages from the pipe to the target file. For the | |
359 | * case of doing file | file splicing, the migrate approach had some LRU | |
360 | * nastiness... | |
361 | */ | |
362 | static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, | |
363 | struct splice_desc *sd) | |
364 | { | |
365 | struct file *file = sd->file; | |
366 | struct address_space *mapping = file->f_mapping; | |
367 | unsigned int offset; | |
368 | struct page *page; | |
5274f052 | 369 | pgoff_t index; |
5abc97aa | 370 | char *src; |
5274f052 JA |
371 | int ret; |
372 | ||
373 | /* | |
374 | * after this, page will be locked and unmapped | |
375 | */ | |
376 | src = buf->ops->map(file, info, buf); | |
377 | if (IS_ERR(src)) | |
378 | return PTR_ERR(src); | |
379 | ||
380 | index = sd->pos >> PAGE_CACHE_SHIFT; | |
381 | offset = sd->pos & ~PAGE_CACHE_MASK; | |
382 | ||
5274f052 | 383 | /* |
5abc97aa | 384 | * reuse buf page, if SPLICE_F_MOVE is set |
5274f052 | 385 | */ |
5abc97aa JA |
386 | if (sd->flags & SPLICE_F_MOVE) { |
387 | if (buf->ops->steal(info, buf)) | |
388 | goto find_page; | |
389 | ||
390 | page = buf->page; | |
391 | if (add_to_page_cache_lru(page, mapping, index, | |
392 | mapping_gfp_mask(mapping))) | |
393 | goto find_page; | |
394 | } else { | |
395 | find_page: | |
396 | ret = -ENOMEM; | |
397 | page = find_or_create_page(mapping, index, | |
398 | mapping_gfp_mask(mapping)); | |
399 | if (!page) | |
400 | goto out; | |
401 | ||
402 | /* | |
403 | * If the page is uptodate, it is also locked. If it isn't | |
404 | * uptodate, we can mark it uptodate if we are filling the | |
405 | * full page. Otherwise we need to read it in first... | |
406 | */ | |
407 | if (!PageUptodate(page)) { | |
408 | if (sd->len < PAGE_CACHE_SIZE) { | |
409 | ret = mapping->a_ops->readpage(file, page); | |
410 | if (unlikely(ret)) | |
411 | goto out; | |
412 | ||
413 | lock_page(page); | |
414 | ||
415 | if (!PageUptodate(page)) { | |
416 | /* | |
417 | * page got invalidated, repeat | |
418 | */ | |
419 | if (!page->mapping) { | |
420 | unlock_page(page); | |
421 | page_cache_release(page); | |
422 | goto find_page; | |
423 | } | |
424 | ret = -EIO; | |
425 | goto out; | |
5274f052 | 426 | } |
5abc97aa JA |
427 | } else { |
428 | WARN_ON(!PageLocked(page)); | |
429 | SetPageUptodate(page); | |
5274f052 | 430 | } |
5274f052 JA |
431 | } |
432 | } | |
433 | ||
434 | ret = mapping->a_ops->prepare_write(file, page, 0, sd->len); | |
435 | if (ret) | |
436 | goto out; | |
437 | ||
5abc97aa JA |
438 | if (!buf->stolen) { |
439 | char *dst = kmap_atomic(page, KM_USER0); | |
440 | ||
441 | memcpy(dst + offset, src + buf->offset, sd->len); | |
442 | flush_dcache_page(page); | |
443 | kunmap_atomic(dst, KM_USER0); | |
444 | } | |
5274f052 JA |
445 | |
446 | ret = mapping->a_ops->commit_write(file, page, 0, sd->len); | |
447 | if (ret < 0) | |
448 | goto out; | |
449 | ||
450 | set_page_dirty(page); | |
451 | ret = write_one_page(page, 0); | |
452 | out: | |
453 | if (ret < 0) | |
454 | unlock_page(page); | |
5abc97aa JA |
455 | if (!buf->stolen) |
456 | page_cache_release(page); | |
5274f052 JA |
457 | buf->ops->unmap(info, buf); |
458 | return ret; | |
459 | } | |
460 | ||
461 | typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, | |
462 | struct splice_desc *); | |
463 | ||
464 | static ssize_t move_from_pipe(struct inode *inode, struct file *out, | |
465 | size_t len, unsigned int flags, | |
466 | splice_actor *actor) | |
467 | { | |
468 | struct pipe_inode_info *info; | |
469 | int ret, do_wakeup, err; | |
470 | struct splice_desc sd; | |
471 | ||
472 | ret = 0; | |
473 | do_wakeup = 0; | |
474 | ||
475 | sd.total_len = len; | |
476 | sd.flags = flags; | |
477 | sd.file = out; | |
478 | sd.pos = out->f_pos; | |
479 | ||
480 | mutex_lock(PIPE_MUTEX(*inode)); | |
481 | ||
482 | info = inode->i_pipe; | |
483 | for (;;) { | |
484 | int bufs = info->nrbufs; | |
485 | ||
486 | if (bufs) { | |
487 | int curbuf = info->curbuf; | |
488 | struct pipe_buffer *buf = info->bufs + curbuf; | |
489 | struct pipe_buf_operations *ops = buf->ops; | |
490 | ||
491 | sd.len = buf->len; | |
492 | if (sd.len > sd.total_len) | |
493 | sd.len = sd.total_len; | |
494 | ||
495 | err = actor(info, buf, &sd); | |
496 | if (err) { | |
497 | if (!ret && err != -ENODATA) | |
498 | ret = err; | |
499 | ||
500 | break; | |
501 | } | |
502 | ||
503 | ret += sd.len; | |
504 | buf->offset += sd.len; | |
505 | buf->len -= sd.len; | |
506 | if (!buf->len) { | |
507 | buf->ops = NULL; | |
508 | ops->release(info, buf); | |
509 | curbuf = (curbuf + 1) & (PIPE_BUFFERS - 1); | |
510 | info->curbuf = curbuf; | |
511 | info->nrbufs = --bufs; | |
512 | do_wakeup = 1; | |
513 | } | |
514 | ||
515 | sd.pos += sd.len; | |
516 | sd.total_len -= sd.len; | |
517 | if (!sd.total_len) | |
518 | break; | |
519 | } | |
520 | ||
521 | if (bufs) | |
522 | continue; | |
523 | if (!PIPE_WRITERS(*inode)) | |
524 | break; | |
525 | if (!PIPE_WAITING_WRITERS(*inode)) { | |
526 | if (ret) | |
527 | break; | |
528 | } | |
529 | ||
530 | if (signal_pending(current)) { | |
531 | if (!ret) | |
532 | ret = -ERESTARTSYS; | |
533 | break; | |
534 | } | |
535 | ||
536 | if (do_wakeup) { | |
537 | wake_up_interruptible_sync(PIPE_WAIT(*inode)); | |
538 | kill_fasync(PIPE_FASYNC_WRITERS(*inode),SIGIO,POLL_OUT); | |
539 | do_wakeup = 0; | |
540 | } | |
541 | ||
542 | pipe_wait(inode); | |
543 | } | |
544 | ||
545 | mutex_unlock(PIPE_MUTEX(*inode)); | |
546 | ||
547 | if (do_wakeup) { | |
548 | wake_up_interruptible(PIPE_WAIT(*inode)); | |
549 | kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); | |
550 | } | |
551 | ||
552 | mutex_lock(&out->f_mapping->host->i_mutex); | |
553 | out->f_pos = sd.pos; | |
554 | mutex_unlock(&out->f_mapping->host->i_mutex); | |
555 | return ret; | |
556 | ||
557 | } | |
558 | ||
559 | ssize_t generic_file_splice_write(struct inode *inode, struct file *out, | |
560 | size_t len, unsigned int flags) | |
561 | { | |
562 | return move_from_pipe(inode, out, len, flags, pipe_to_file); | |
563 | } | |
564 | ||
565 | ssize_t generic_splice_sendpage(struct inode *inode, struct file *out, | |
566 | size_t len, unsigned int flags) | |
567 | { | |
568 | return move_from_pipe(inode, out, len, flags, pipe_to_sendpage); | |
569 | } | |
570 | ||
a0f06780 JG |
571 | EXPORT_SYMBOL(generic_file_splice_write); |
572 | EXPORT_SYMBOL(generic_file_splice_read); | |
573 | ||
5274f052 JA |
574 | static long do_splice_from(struct inode *pipe, struct file *out, size_t len, |
575 | unsigned int flags) | |
576 | { | |
577 | loff_t pos; | |
578 | int ret; | |
579 | ||
580 | if (!out->f_op || !out->f_op->splice_write) | |
581 | return -EINVAL; | |
582 | ||
583 | if (!(out->f_mode & FMODE_WRITE)) | |
584 | return -EBADF; | |
585 | ||
586 | pos = out->f_pos; | |
587 | ret = rw_verify_area(WRITE, out, &pos, len); | |
588 | if (unlikely(ret < 0)) | |
589 | return ret; | |
590 | ||
591 | return out->f_op->splice_write(pipe, out, len, flags); | |
592 | } | |
593 | ||
594 | static long do_splice_to(struct file *in, struct inode *pipe, size_t len, | |
595 | unsigned int flags) | |
596 | { | |
597 | loff_t pos, isize, left; | |
598 | int ret; | |
599 | ||
600 | if (!in->f_op || !in->f_op->splice_read) | |
601 | return -EINVAL; | |
602 | ||
603 | if (!(in->f_mode & FMODE_READ)) | |
604 | return -EBADF; | |
605 | ||
606 | pos = in->f_pos; | |
607 | ret = rw_verify_area(READ, in, &pos, len); | |
608 | if (unlikely(ret < 0)) | |
609 | return ret; | |
610 | ||
611 | isize = i_size_read(in->f_mapping->host); | |
612 | if (unlikely(in->f_pos >= isize)) | |
613 | return 0; | |
614 | ||
615 | left = isize - in->f_pos; | |
616 | if (left < len) | |
617 | len = left; | |
618 | ||
619 | return in->f_op->splice_read(in, pipe, len, flags); | |
620 | } | |
621 | ||
622 | static long do_splice(struct file *in, struct file *out, size_t len, | |
623 | unsigned int flags) | |
624 | { | |
625 | struct inode *pipe; | |
626 | ||
627 | pipe = in->f_dentry->d_inode; | |
628 | if (pipe->i_pipe) | |
629 | return do_splice_from(pipe, out, len, flags); | |
630 | ||
631 | pipe = out->f_dentry->d_inode; | |
632 | if (pipe->i_pipe) | |
633 | return do_splice_to(in, pipe, len, flags); | |
634 | ||
635 | return -EINVAL; | |
636 | } | |
637 | ||
638 | asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags) | |
639 | { | |
640 | long error; | |
641 | struct file *in, *out; | |
642 | int fput_in, fput_out; | |
643 | ||
644 | if (unlikely(!len)) | |
645 | return 0; | |
646 | ||
647 | error = -EBADF; | |
648 | in = fget_light(fdin, &fput_in); | |
649 | if (in) { | |
650 | if (in->f_mode & FMODE_READ) { | |
651 | out = fget_light(fdout, &fput_out); | |
652 | if (out) { | |
653 | if (out->f_mode & FMODE_WRITE) | |
654 | error = do_splice(in, out, len, flags); | |
655 | fput_light(out, fput_out); | |
656 | } | |
657 | } | |
658 | ||
659 | fput_light(in, fput_in); | |
660 | } | |
661 | ||
662 | return error; | |
663 | } |