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21#include <linux/bvec.h>
22#include <linux/fs.h>
23#include <linux/file.h>
24#include <linux/pagemap.h>
25#include <linux/splice.h>
26#include <linux/memcontrol.h>
27#include <linux/mm_inline.h>
28#include <linux/swap.h>
29#include <linux/writeback.h>
30#include <linux/export.h>
31#include <linux/syscalls.h>
32#include <linux/uio.h>
33#include <linux/security.h>
34#include <linux/gfp.h>
35#include <linux/socket.h>
36#include <linux/compat.h>
37#include <linux/sched/signal.h>
38
39#include "internal.h"
40
41
42
43
44
45
46
47static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
48 struct pipe_buffer *buf)
49{
50 struct page *page = buf->page;
51 struct address_space *mapping;
52
53 lock_page(page);
54
55 mapping = page_mapping(page);
56 if (mapping) {
57 WARN_ON(!PageUptodate(page));
58
59
60
61
62
63
64
65
66
67 wait_on_page_writeback(page);
68
69 if (page_has_private(page) &&
70 !try_to_release_page(page, GFP_KERNEL))
71 goto out_unlock;
72
73
74
75
76
77 if (remove_mapping(mapping, page)) {
78 buf->flags |= PIPE_BUF_FLAG_LRU;
79 return 0;
80 }
81 }
82
83
84
85
86
87out_unlock:
88 unlock_page(page);
89 return 1;
90}
91
92static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
93 struct pipe_buffer *buf)
94{
95 put_page(buf->page);
96 buf->flags &= ~PIPE_BUF_FLAG_LRU;
97}
98
99
100
101
102
103static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe,
104 struct pipe_buffer *buf)
105{
106 struct page *page = buf->page;
107 int err;
108
109 if (!PageUptodate(page)) {
110 lock_page(page);
111
112
113
114
115
116 if (!page->mapping) {
117 err = -ENODATA;
118 goto error;
119 }
120
121
122
123
124 if (!PageUptodate(page)) {
125 err = -EIO;
126 goto error;
127 }
128
129
130
131
132 unlock_page(page);
133 }
134
135 return 0;
136error:
137 unlock_page(page);
138 return err;
139}
140
141const struct pipe_buf_operations page_cache_pipe_buf_ops = {
142 .confirm = page_cache_pipe_buf_confirm,
143 .release = page_cache_pipe_buf_release,
144 .steal = page_cache_pipe_buf_steal,
145 .get = generic_pipe_buf_get,
146};
147
148static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
149 struct pipe_buffer *buf)
150{
151 if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
152 return 1;
153
154 buf->flags |= PIPE_BUF_FLAG_LRU;
155 return generic_pipe_buf_steal(pipe, buf);
156}
157
158static const struct pipe_buf_operations user_page_pipe_buf_ops = {
159 .confirm = generic_pipe_buf_confirm,
160 .release = page_cache_pipe_buf_release,
161 .steal = user_page_pipe_buf_steal,
162 .get = generic_pipe_buf_get,
163};
164
165static void wakeup_pipe_readers(struct pipe_inode_info *pipe)
166{
167 smp_mb();
168 if (waitqueue_active(&pipe->wait))
169 wake_up_interruptible(&pipe->wait);
170 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
171}
172
173
174
175
176
177
178
179
180
181
182
183
184ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
185 struct splice_pipe_desc *spd)
186{
187 unsigned int spd_pages = spd->nr_pages;
188 int ret = 0, page_nr = 0;
189
190 if (!spd_pages)
191 return 0;
192
193 if (unlikely(!pipe->readers)) {
194 send_sig(SIGPIPE, current, 0);
195 ret = -EPIPE;
196 goto out;
197 }
198
199 while (pipe->nrbufs < pipe->buffers) {
200 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
201 struct pipe_buffer *buf = pipe->bufs + newbuf;
202
203 buf->page = spd->pages[page_nr];
204 buf->offset = spd->partial[page_nr].offset;
205 buf->len = spd->partial[page_nr].len;
206 buf->private = spd->partial[page_nr].private;
207 buf->ops = spd->ops;
208 buf->flags = 0;
209
210 pipe->nrbufs++;
211 page_nr++;
212 ret += buf->len;
213
214 if (!--spd->nr_pages)
215 break;
216 }
217
218 if (!ret)
219 ret = -EAGAIN;
220
221out:
222 while (page_nr < spd_pages)
223 spd->spd_release(spd, page_nr++);
224
225 return ret;
226}
227EXPORT_SYMBOL_GPL(splice_to_pipe);
228
229ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
230{
231 int ret;
232
233 if (unlikely(!pipe->readers)) {
234 send_sig(SIGPIPE, current, 0);
235 ret = -EPIPE;
236 } else if (pipe->nrbufs == pipe->buffers) {
237 ret = -EAGAIN;
238 } else {
239 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
240 pipe->bufs[newbuf] = *buf;
241 pipe->nrbufs++;
242 return buf->len;
243 }
244 pipe_buf_release(pipe, buf);
245 return ret;
246}
247EXPORT_SYMBOL(add_to_pipe);
248
249
250
251
252
253int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
254{
255 unsigned int buffers = READ_ONCE(pipe->buffers);
256
257 spd->nr_pages_max = buffers;
258 if (buffers <= PIPE_DEF_BUFFERS)
259 return 0;
260
261 spd->pages = kmalloc_array(buffers, sizeof(struct page *), GFP_KERNEL);
262 spd->partial = kmalloc_array(buffers, sizeof(struct partial_page),
263 GFP_KERNEL);
264
265 if (spd->pages && spd->partial)
266 return 0;
267
268 kfree(spd->pages);
269 kfree(spd->partial);
270 return -ENOMEM;
271}
272
273void splice_shrink_spd(struct splice_pipe_desc *spd)
274{
275 if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
276 return;
277
278 kfree(spd->pages);
279 kfree(spd->partial);
280}
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
296 struct pipe_inode_info *pipe, size_t len,
297 unsigned int flags)
298{
299 struct iov_iter to;
300 struct kiocb kiocb;
301 int idx, ret;
302
303 iov_iter_pipe(&to, READ, pipe, len);
304 idx = to.idx;
305 init_sync_kiocb(&kiocb, in);
306 kiocb.ki_pos = *ppos;
307 ret = call_read_iter(in, &kiocb, &to);
308 if (ret > 0) {
309 *ppos = kiocb.ki_pos;
310 file_accessed(in);
311 } else if (ret < 0) {
312 to.idx = idx;
313 to.iov_offset = 0;
314 iov_iter_advance(&to, 0);
315
316
317
318
319 if (ret == -EFAULT)
320 ret = -EAGAIN;
321 }
322
323 return ret;
324}
325EXPORT_SYMBOL(generic_file_splice_read);
326
327const struct pipe_buf_operations default_pipe_buf_ops = {
328 .confirm = generic_pipe_buf_confirm,
329 .release = generic_pipe_buf_release,
330 .steal = generic_pipe_buf_steal,
331 .get = generic_pipe_buf_get,
332};
333
334int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
335 struct pipe_buffer *buf)
336{
337 return 1;
338}
339
340
341const struct pipe_buf_operations nosteal_pipe_buf_ops = {
342 .confirm = generic_pipe_buf_confirm,
343 .release = generic_pipe_buf_release,
344 .steal = generic_pipe_buf_nosteal,
345 .get = generic_pipe_buf_get,
346};
347EXPORT_SYMBOL(nosteal_pipe_buf_ops);
348
349static ssize_t kernel_readv(struct file *file, const struct kvec *vec,
350 unsigned long vlen, loff_t offset)
351{
352 mm_segment_t old_fs;
353 loff_t pos = offset;
354 ssize_t res;
355
356 old_fs = get_fs();
357 set_fs(KERNEL_DS);
358
359 res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0);
360 set_fs(old_fs);
361
362 return res;
363}
364
365static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
366 struct pipe_inode_info *pipe, size_t len,
367 unsigned int flags)
368{
369 struct kvec *vec, __vec[PIPE_DEF_BUFFERS];
370 struct iov_iter to;
371 struct page **pages;
372 unsigned int nr_pages;
373 size_t offset, base, copied = 0;
374 ssize_t res;
375 int i;
376
377 if (pipe->nrbufs == pipe->buffers)
378 return -EAGAIN;
379
380
381
382
383
384 offset = *ppos & ~PAGE_MASK;
385
386 iov_iter_pipe(&to, READ, pipe, len + offset);
387
388 res = iov_iter_get_pages_alloc(&to, &pages, len + offset, &base);
389 if (res <= 0)
390 return -ENOMEM;
391
392 nr_pages = DIV_ROUND_UP(res + base, PAGE_SIZE);
393
394 vec = __vec;
395 if (nr_pages > PIPE_DEF_BUFFERS) {
396 vec = kmalloc_array(nr_pages, sizeof(struct kvec), GFP_KERNEL);
397 if (unlikely(!vec)) {
398 res = -ENOMEM;
399 goto out;
400 }
401 }
402
403 pipe->bufs[to.idx].offset = offset;
404 pipe->bufs[to.idx].len -= offset;
405
406 for (i = 0; i < nr_pages; i++) {
407 size_t this_len = min_t(size_t, len, PAGE_SIZE - offset);
408 vec[i].iov_base = page_address(pages[i]) + offset;
409 vec[i].iov_len = this_len;
410 len -= this_len;
411 offset = 0;
412 }
413
414 res = kernel_readv(in, vec, nr_pages, *ppos);
415 if (res > 0) {
416 copied = res;
417 *ppos += res;
418 }
419
420 if (vec != __vec)
421 kfree(vec);
422out:
423 for (i = 0; i < nr_pages; i++)
424 put_page(pages[i]);
425 kvfree(pages);
426 iov_iter_advance(&to, copied);
427 return res;
428}
429
430
431
432
433
434static int pipe_to_sendpage(struct pipe_inode_info *pipe,
435 struct pipe_buffer *buf, struct splice_desc *sd)
436{
437 struct file *file = sd->u.file;
438 loff_t pos = sd->pos;
439 int more;
440
441 if (!likely(file->f_op->sendpage))
442 return -EINVAL;
443
444 more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
445
446 if (sd->len < sd->total_len && pipe->nrbufs > 1)
447 more |= MSG_SENDPAGE_NOTLAST;
448
449 return file->f_op->sendpage(file, buf->page, buf->offset,
450 sd->len, &pos, more);
451}
452
453static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
454{
455 smp_mb();
456 if (waitqueue_active(&pipe->wait))
457 wake_up_interruptible(&pipe->wait);
458 kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
459}
460
461
462
463
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475
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477
478
479
480
481static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
482 splice_actor *actor)
483{
484 int ret;
485
486 while (pipe->nrbufs) {
487 struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
488
489 sd->len = buf->len;
490 if (sd->len > sd->total_len)
491 sd->len = sd->total_len;
492
493 ret = pipe_buf_confirm(pipe, buf);
494 if (unlikely(ret)) {
495 if (ret == -ENODATA)
496 ret = 0;
497 return ret;
498 }
499
500 ret = actor(pipe, buf, sd);
501 if (ret <= 0)
502 return ret;
503
504 buf->offset += ret;
505 buf->len -= ret;
506
507 sd->num_spliced += ret;
508 sd->len -= ret;
509 sd->pos += ret;
510 sd->total_len -= ret;
511
512 if (!buf->len) {
513 pipe_buf_release(pipe, buf);
514 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
515 pipe->nrbufs--;
516 if (pipe->files)
517 sd->need_wakeup = true;
518 }
519
520 if (!sd->total_len)
521 return 0;
522 }
523
524 return 1;
525}
526
527
528
529
530
531
532
533
534
535
536
537static int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
538{
539
540
541
542
543 if (signal_pending(current))
544 return -ERESTARTSYS;
545
546 while (!pipe->nrbufs) {
547 if (!pipe->writers)
548 return 0;
549
550 if (!pipe->waiting_writers && sd->num_spliced)
551 return 0;
552
553 if (sd->flags & SPLICE_F_NONBLOCK)
554 return -EAGAIN;
555
556 if (signal_pending(current))
557 return -ERESTARTSYS;
558
559 if (sd->need_wakeup) {
560 wakeup_pipe_writers(pipe);
561 sd->need_wakeup = false;
562 }
563
564 pipe_wait(pipe);
565 }
566
567 return 1;
568}
569
570
571
572
573
574
575
576
577
578
579static void splice_from_pipe_begin(struct splice_desc *sd)
580{
581 sd->num_spliced = 0;
582 sd->need_wakeup = false;
583}
584
585
586
587
588
589
590
591
592
593
594
595static void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
596{
597 if (sd->need_wakeup)
598 wakeup_pipe_writers(pipe);
599}
600
601
602
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610
611
612
613
614ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
615 splice_actor *actor)
616{
617 int ret;
618
619 splice_from_pipe_begin(sd);
620 do {
621 cond_resched();
622 ret = splice_from_pipe_next(pipe, sd);
623 if (ret > 0)
624 ret = splice_from_pipe_feed(pipe, sd, actor);
625 } while (ret > 0);
626 splice_from_pipe_end(pipe, sd);
627
628 return sd->num_spliced ? sd->num_spliced : ret;
629}
630EXPORT_SYMBOL(__splice_from_pipe);
631
632
633
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640
641
642
643
644
645
646ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
647 loff_t *ppos, size_t len, unsigned int flags,
648 splice_actor *actor)
649{
650 ssize_t ret;
651 struct splice_desc sd = {
652 .total_len = len,
653 .flags = flags,
654 .pos = *ppos,
655 .u.file = out,
656 };
657
658 pipe_lock(pipe);
659 ret = __splice_from_pipe(pipe, &sd, actor);
660 pipe_unlock(pipe);
661
662 return ret;
663}
664
665
666
667
668
669
670
671
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673
674
675
676
677
678
679ssize_t
680iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
681 loff_t *ppos, size_t len, unsigned int flags)
682{
683 struct splice_desc sd = {
684 .total_len = len,
685 .flags = flags,
686 .pos = *ppos,
687 .u.file = out,
688 };
689 int nbufs = pipe->buffers;
690 struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),
691 GFP_KERNEL);
692 ssize_t ret;
693
694 if (unlikely(!array))
695 return -ENOMEM;
696
697 pipe_lock(pipe);
698
699 splice_from_pipe_begin(&sd);
700 while (sd.total_len) {
701 struct iov_iter from;
702 size_t left;
703 int n, idx;
704
705 ret = splice_from_pipe_next(pipe, &sd);
706 if (ret <= 0)
707 break;
708
709 if (unlikely(nbufs < pipe->buffers)) {
710 kfree(array);
711 nbufs = pipe->buffers;
712 array = kcalloc(nbufs, sizeof(struct bio_vec),
713 GFP_KERNEL);
714 if (!array) {
715 ret = -ENOMEM;
716 break;
717 }
718 }
719
720
721 left = sd.total_len;
722 for (n = 0, idx = pipe->curbuf; left && n < pipe->nrbufs; n++, idx++) {
723 struct pipe_buffer *buf = pipe->bufs + idx;
724 size_t this_len = buf->len;
725
726 if (this_len > left)
727 this_len = left;
728
729 if (idx == pipe->buffers - 1)
730 idx = -1;
731
732 ret = pipe_buf_confirm(pipe, buf);
733 if (unlikely(ret)) {
734 if (ret == -ENODATA)
735 ret = 0;
736 goto done;
737 }
738
739 array[n].bv_page = buf->page;
740 array[n].bv_len = this_len;
741 array[n].bv_offset = buf->offset;
742 left -= this_len;
743 }
744
745 iov_iter_bvec(&from, WRITE, array, n, sd.total_len - left);
746 ret = vfs_iter_write(out, &from, &sd.pos, 0);
747 if (ret <= 0)
748 break;
749
750 sd.num_spliced += ret;
751 sd.total_len -= ret;
752 *ppos = sd.pos;
753
754
755 while (ret) {
756 struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
757 if (ret >= buf->len) {
758 ret -= buf->len;
759 buf->len = 0;
760 pipe_buf_release(pipe, buf);
761 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
762 pipe->nrbufs--;
763 if (pipe->files)
764 sd.need_wakeup = true;
765 } else {
766 buf->offset += ret;
767 buf->len -= ret;
768 ret = 0;
769 }
770 }
771 }
772done:
773 kfree(array);
774 splice_from_pipe_end(pipe, &sd);
775
776 pipe_unlock(pipe);
777
778 if (sd.num_spliced)
779 ret = sd.num_spliced;
780
781 return ret;
782}
783
784EXPORT_SYMBOL(iter_file_splice_write);
785
786static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
787 struct splice_desc *sd)
788{
789 int ret;
790 void *data;
791 loff_t tmp = sd->pos;
792
793 data = kmap(buf->page);
794 ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp);
795 kunmap(buf->page);
796
797 return ret;
798}
799
800static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
801 struct file *out, loff_t *ppos,
802 size_t len, unsigned int flags)
803{
804 ssize_t ret;
805
806 ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
807 if (ret > 0)
808 *ppos += ret;
809
810 return ret;
811}
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
827 loff_t *ppos, size_t len, unsigned int flags)
828{
829 return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
830}
831
832EXPORT_SYMBOL(generic_splice_sendpage);
833
834
835
836
837static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
838 loff_t *ppos, size_t len, unsigned int flags)
839{
840 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
841 loff_t *, size_t, unsigned int);
842
843 if (out->f_op->splice_write)
844 splice_write = out->f_op->splice_write;
845 else
846 splice_write = default_file_splice_write;
847
848 return splice_write(pipe, out, ppos, len, flags);
849}
850
851
852
853
854static long do_splice_to(struct file *in, loff_t *ppos,
855 struct pipe_inode_info *pipe, size_t len,
856 unsigned int flags)
857{
858 ssize_t (*splice_read)(struct file *, loff_t *,
859 struct pipe_inode_info *, size_t, unsigned int);
860 int ret;
861
862 if (unlikely(!(in->f_mode & FMODE_READ)))
863 return -EBADF;
864
865 ret = rw_verify_area(READ, in, ppos, len);
866 if (unlikely(ret < 0))
867 return ret;
868
869 if (unlikely(len > MAX_RW_COUNT))
870 len = MAX_RW_COUNT;
871
872 if (in->f_op->splice_read)
873 splice_read = in->f_op->splice_read;
874 else
875 splice_read = default_file_splice_read;
876
877 return splice_read(in, ppos, pipe, len, flags);
878}
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
894 splice_direct_actor *actor)
895{
896 struct pipe_inode_info *pipe;
897 long ret, bytes;
898 umode_t i_mode;
899 size_t len;
900 int i, flags, more;
901
902
903
904
905
906
907 i_mode = file_inode(in)->i_mode;
908 if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode)))
909 return -EINVAL;
910
911
912
913
914
915 pipe = current->splice_pipe;
916 if (unlikely(!pipe)) {
917 pipe = alloc_pipe_info();
918 if (!pipe)
919 return -ENOMEM;
920
921
922
923
924
925
926 pipe->readers = 1;
927
928 current->splice_pipe = pipe;
929 }
930
931
932
933
934 ret = 0;
935 bytes = 0;
936 len = sd->total_len;
937 flags = sd->flags;
938
939
940
941
942 sd->flags &= ~SPLICE_F_NONBLOCK;
943 more = sd->flags & SPLICE_F_MORE;
944
945 WARN_ON_ONCE(pipe->nrbufs != 0);
946
947 while (len) {
948 size_t read_len;
949 loff_t pos = sd->pos, prev_pos = pos;
950
951
952 read_len = min_t(size_t, len,
953 (pipe->buffers - pipe->nrbufs) << PAGE_SHIFT);
954 ret = do_splice_to(in, &pos, pipe, read_len, flags);
955 if (unlikely(ret <= 0))
956 goto out_release;
957
958 read_len = ret;
959 sd->total_len = read_len;
960
961
962
963
964
965
966 if (read_len < len)
967 sd->flags |= SPLICE_F_MORE;
968 else if (!more)
969 sd->flags &= ~SPLICE_F_MORE;
970
971
972
973
974
975 ret = actor(pipe, sd);
976 if (unlikely(ret <= 0)) {
977 sd->pos = prev_pos;
978 goto out_release;
979 }
980
981 bytes += ret;
982 len -= ret;
983 sd->pos = pos;
984
985 if (ret < read_len) {
986 sd->pos = prev_pos + ret;
987 goto out_release;
988 }
989 }
990
991done:
992 pipe->nrbufs = pipe->curbuf = 0;
993 file_accessed(in);
994 return bytes;
995
996out_release:
997
998
999
1000
1001 for (i = 0; i < pipe->buffers; i++) {
1002 struct pipe_buffer *buf = pipe->bufs + i;
1003
1004 if (buf->ops)
1005 pipe_buf_release(pipe, buf);
1006 }
1007
1008 if (!bytes)
1009 bytes = ret;
1010
1011 goto done;
1012}
1013EXPORT_SYMBOL(splice_direct_to_actor);
1014
1015static int direct_splice_actor(struct pipe_inode_info *pipe,
1016 struct splice_desc *sd)
1017{
1018 struct file *file = sd->u.file;
1019
1020 return do_splice_from(pipe, file, sd->opos, sd->total_len,
1021 sd->flags);
1022}
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
1041 loff_t *opos, size_t len, unsigned int flags)
1042{
1043 struct splice_desc sd = {
1044 .len = len,
1045 .total_len = len,
1046 .flags = flags,
1047 .pos = *ppos,
1048 .u.file = out,
1049 .opos = opos,
1050 };
1051 long ret;
1052
1053 if (unlikely(!(out->f_mode & FMODE_WRITE)))
1054 return -EBADF;
1055
1056 if (unlikely(out->f_flags & O_APPEND))
1057 return -EINVAL;
1058
1059 ret = rw_verify_area(WRITE, out, opos, len);
1060 if (unlikely(ret < 0))
1061 return ret;
1062
1063 ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
1064 if (ret > 0)
1065 *ppos = sd.pos;
1066
1067 return ret;
1068}
1069EXPORT_SYMBOL(do_splice_direct);
1070
1071static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags)
1072{
1073 for (;;) {
1074 if (unlikely(!pipe->readers)) {
1075 send_sig(SIGPIPE, current, 0);
1076 return -EPIPE;
1077 }
1078 if (pipe->nrbufs != pipe->buffers)
1079 return 0;
1080 if (flags & SPLICE_F_NONBLOCK)
1081 return -EAGAIN;
1082 if (signal_pending(current))
1083 return -ERESTARTSYS;
1084 pipe->waiting_writers++;
1085 pipe_wait(pipe);
1086 pipe->waiting_writers--;
1087 }
1088}
1089
1090static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1091 struct pipe_inode_info *opipe,
1092 size_t len, unsigned int flags);
1093
1094
1095
1096
1097static long do_splice(struct file *in, loff_t __user *off_in,
1098 struct file *out, loff_t __user *off_out,
1099 size_t len, unsigned int flags)
1100{
1101 struct pipe_inode_info *ipipe;
1102 struct pipe_inode_info *opipe;
1103 loff_t offset;
1104 long ret;
1105
1106 ipipe = get_pipe_info(in);
1107 opipe = get_pipe_info(out);
1108
1109 if (ipipe && opipe) {
1110 if (off_in || off_out)
1111 return -ESPIPE;
1112
1113 if (!(in->f_mode & FMODE_READ))
1114 return -EBADF;
1115
1116 if (!(out->f_mode & FMODE_WRITE))
1117 return -EBADF;
1118
1119
1120 if (ipipe == opipe)
1121 return -EINVAL;
1122
1123 if ((in->f_flags | out->f_flags) & O_NONBLOCK)
1124 flags |= SPLICE_F_NONBLOCK;
1125
1126 return splice_pipe_to_pipe(ipipe, opipe, len, flags);
1127 }
1128
1129 if (ipipe) {
1130 if (off_in)
1131 return -ESPIPE;
1132 if (off_out) {
1133 if (!(out->f_mode & FMODE_PWRITE))
1134 return -EINVAL;
1135 if (copy_from_user(&offset, off_out, sizeof(loff_t)))
1136 return -EFAULT;
1137 } else {
1138 offset = out->f_pos;
1139 }
1140
1141 if (unlikely(!(out->f_mode & FMODE_WRITE)))
1142 return -EBADF;
1143
1144 if (unlikely(out->f_flags & O_APPEND))
1145 return -EINVAL;
1146
1147 ret = rw_verify_area(WRITE, out, &offset, len);
1148 if (unlikely(ret < 0))
1149 return ret;
1150
1151 if (in->f_flags & O_NONBLOCK)
1152 flags |= SPLICE_F_NONBLOCK;
1153
1154 file_start_write(out);
1155 ret = do_splice_from(ipipe, out, &offset, len, flags);
1156 file_end_write(out);
1157
1158 if (!off_out)
1159 out->f_pos = offset;
1160 else if (copy_to_user(off_out, &offset, sizeof(loff_t)))
1161 ret = -EFAULT;
1162
1163 return ret;
1164 }
1165
1166 if (opipe) {
1167 if (off_out)
1168 return -ESPIPE;
1169 if (off_in) {
1170 if (!(in->f_mode & FMODE_PREAD))
1171 return -EINVAL;
1172 if (copy_from_user(&offset, off_in, sizeof(loff_t)))
1173 return -EFAULT;
1174 } else {
1175 offset = in->f_pos;
1176 }
1177
1178 if (out->f_flags & O_NONBLOCK)
1179 flags |= SPLICE_F_NONBLOCK;
1180
1181 pipe_lock(opipe);
1182 ret = wait_for_space(opipe, flags);
1183 if (!ret)
1184 ret = do_splice_to(in, &offset, opipe, len, flags);
1185 pipe_unlock(opipe);
1186 if (ret > 0)
1187 wakeup_pipe_readers(opipe);
1188 if (!off_in)
1189 in->f_pos = offset;
1190 else if (copy_to_user(off_in, &offset, sizeof(loff_t)))
1191 ret = -EFAULT;
1192
1193 return ret;
1194 }
1195
1196 return -EINVAL;
1197}
1198
1199static int iter_to_pipe(struct iov_iter *from,
1200 struct pipe_inode_info *pipe,
1201 unsigned flags)
1202{
1203 struct pipe_buffer buf = {
1204 .ops = &user_page_pipe_buf_ops,
1205 .flags = flags
1206 };
1207 size_t total = 0;
1208 int ret = 0;
1209 bool failed = false;
1210
1211 while (iov_iter_count(from) && !failed) {
1212 struct page *pages[16];
1213 ssize_t copied;
1214 size_t start;
1215 int n;
1216
1217 copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start);
1218 if (copied <= 0) {
1219 ret = copied;
1220 break;
1221 }
1222
1223 for (n = 0; copied; n++, start = 0) {
1224 int size = min_t(int, copied, PAGE_SIZE - start);
1225 if (!failed) {
1226 buf.page = pages[n];
1227 buf.offset = start;
1228 buf.len = size;
1229 ret = add_to_pipe(pipe, &buf);
1230 if (unlikely(ret < 0)) {
1231 failed = true;
1232 } else {
1233 iov_iter_advance(from, ret);
1234 total += ret;
1235 }
1236 } else {
1237 put_page(pages[n]);
1238 }
1239 copied -= size;
1240 }
1241 }
1242 return total ? total : ret;
1243}
1244
1245static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
1246 struct splice_desc *sd)
1247{
1248 int n = copy_page_to_iter(buf->page, buf->offset, sd->len, sd->u.data);
1249 return n == sd->len ? n : -EFAULT;
1250}
1251
1252
1253
1254
1255
1256static long vmsplice_to_user(struct file *file, struct iov_iter *iter,
1257 unsigned int flags)
1258{
1259 struct pipe_inode_info *pipe = get_pipe_info(file);
1260 struct splice_desc sd = {
1261 .total_len = iov_iter_count(iter),
1262 .flags = flags,
1263 .u.data = iter
1264 };
1265 long ret = 0;
1266
1267 if (!pipe)
1268 return -EBADF;
1269
1270 if (sd.total_len) {
1271 pipe_lock(pipe);
1272 ret = __splice_from_pipe(pipe, &sd, pipe_to_user);
1273 pipe_unlock(pipe);
1274 }
1275
1276 return ret;
1277}
1278
1279
1280
1281
1282
1283
1284static long vmsplice_to_pipe(struct file *file, struct iov_iter *iter,
1285 unsigned int flags)
1286{
1287 struct pipe_inode_info *pipe;
1288 long ret = 0;
1289 unsigned buf_flag = 0;
1290
1291 if (flags & SPLICE_F_GIFT)
1292 buf_flag = PIPE_BUF_FLAG_GIFT;
1293
1294 pipe = get_pipe_info(file);
1295 if (!pipe)
1296 return -EBADF;
1297
1298 pipe_lock(pipe);
1299 ret = wait_for_space(pipe, flags);
1300 if (!ret)
1301 ret = iter_to_pipe(iter, pipe, buf_flag);
1302 pipe_unlock(pipe);
1303 if (ret > 0)
1304 wakeup_pipe_readers(pipe);
1305 return ret;
1306}
1307
1308static int vmsplice_type(struct fd f, int *type)
1309{
1310 if (!f.file)
1311 return -EBADF;
1312 if (f.file->f_mode & FMODE_WRITE) {
1313 *type = WRITE;
1314 } else if (f.file->f_mode & FMODE_READ) {
1315 *type = READ;
1316 } else {
1317 fdput(f);
1318 return -EBADF;
1319 }
1320 return 0;
1321}
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339static long do_vmsplice(struct file *f, struct iov_iter *iter, unsigned int flags)
1340{
1341 if (unlikely(flags & ~SPLICE_F_ALL))
1342 return -EINVAL;
1343
1344 if (!iov_iter_count(iter))
1345 return 0;
1346
1347 if (iov_iter_rw(iter) == WRITE)
1348 return vmsplice_to_pipe(f, iter, flags);
1349 else
1350 return vmsplice_to_user(f, iter, flags);
1351}
1352
1353SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
1354 unsigned long, nr_segs, unsigned int, flags)
1355{
1356 struct iovec iovstack[UIO_FASTIOV];
1357 struct iovec *iov = iovstack;
1358 struct iov_iter iter;
1359 ssize_t error;
1360 struct fd f;
1361 int type;
1362
1363 f = fdget(fd);
1364 error = vmsplice_type(f, &type);
1365 if (error)
1366 return error;
1367
1368 error = import_iovec(type, uiov, nr_segs,
1369 ARRAY_SIZE(iovstack), &iov, &iter);
1370 if (error >= 0) {
1371 error = do_vmsplice(f.file, &iter, flags);
1372 kfree(iov);
1373 }
1374 fdput(f);
1375 return error;
1376}
1377
1378#ifdef CONFIG_COMPAT
1379COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32,
1380 unsigned int, nr_segs, unsigned int, flags)
1381{
1382 struct iovec iovstack[UIO_FASTIOV];
1383 struct iovec *iov = iovstack;
1384 struct iov_iter iter;
1385 ssize_t error;
1386 struct fd f;
1387 int type;
1388
1389 f = fdget(fd);
1390 error = vmsplice_type(f, &type);
1391 if (error)
1392 return error;
1393
1394 error = compat_import_iovec(type, iov32, nr_segs,
1395 ARRAY_SIZE(iovstack), &iov, &iter);
1396 if (error >= 0) {
1397 error = do_vmsplice(f.file, &iter, flags);
1398 kfree(iov);
1399 }
1400 fdput(f);
1401 return error;
1402}
1403#endif
1404
1405SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in,
1406 int, fd_out, loff_t __user *, off_out,
1407 size_t, len, unsigned int, flags)
1408{
1409 struct fd in, out;
1410 long error;
1411
1412 if (unlikely(!len))
1413 return 0;
1414
1415 if (unlikely(flags & ~SPLICE_F_ALL))
1416 return -EINVAL;
1417
1418 error = -EBADF;
1419 in = fdget(fd_in);
1420 if (in.file) {
1421 if (in.file->f_mode & FMODE_READ) {
1422 out = fdget(fd_out);
1423 if (out.file) {
1424 if (out.file->f_mode & FMODE_WRITE)
1425 error = do_splice(in.file, off_in,
1426 out.file, off_out,
1427 len, flags);
1428 fdput(out);
1429 }
1430 }
1431 fdput(in);
1432 }
1433 return error;
1434}
1435
1436
1437
1438
1439
1440static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
1441{
1442 int ret;
1443
1444
1445
1446
1447
1448 if (pipe->nrbufs)
1449 return 0;
1450
1451 ret = 0;
1452 pipe_lock(pipe);
1453
1454 while (!pipe->nrbufs) {
1455 if (signal_pending(current)) {
1456 ret = -ERESTARTSYS;
1457 break;
1458 }
1459 if (!pipe->writers)
1460 break;
1461 if (!pipe->waiting_writers) {
1462 if (flags & SPLICE_F_NONBLOCK) {
1463 ret = -EAGAIN;
1464 break;
1465 }
1466 }
1467 pipe_wait(pipe);
1468 }
1469
1470 pipe_unlock(pipe);
1471 return ret;
1472}
1473
1474
1475
1476
1477
1478static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
1479{
1480 int ret;
1481
1482
1483
1484
1485
1486 if (pipe->nrbufs < pipe->buffers)
1487 return 0;
1488
1489 ret = 0;
1490 pipe_lock(pipe);
1491
1492 while (pipe->nrbufs >= pipe->buffers) {
1493 if (!pipe->readers) {
1494 send_sig(SIGPIPE, current, 0);
1495 ret = -EPIPE;
1496 break;
1497 }
1498 if (flags & SPLICE_F_NONBLOCK) {
1499 ret = -EAGAIN;
1500 break;
1501 }
1502 if (signal_pending(current)) {
1503 ret = -ERESTARTSYS;
1504 break;
1505 }
1506 pipe->waiting_writers++;
1507 pipe_wait(pipe);
1508 pipe->waiting_writers--;
1509 }
1510
1511 pipe_unlock(pipe);
1512 return ret;
1513}
1514
1515
1516
1517
1518static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
1519 struct pipe_inode_info *opipe,
1520 size_t len, unsigned int flags)
1521{
1522 struct pipe_buffer *ibuf, *obuf;
1523 int ret = 0, nbuf;
1524 bool input_wakeup = false;
1525
1526
1527retry:
1528 ret = ipipe_prep(ipipe, flags);
1529 if (ret)
1530 return ret;
1531
1532 ret = opipe_prep(opipe, flags);
1533 if (ret)
1534 return ret;
1535
1536
1537
1538
1539
1540
1541 pipe_double_lock(ipipe, opipe);
1542
1543 do {
1544 if (!opipe->readers) {
1545 send_sig(SIGPIPE, current, 0);
1546 if (!ret)
1547 ret = -EPIPE;
1548 break;
1549 }
1550
1551 if (!ipipe->nrbufs && !ipipe->writers)
1552 break;
1553
1554
1555
1556
1557
1558 if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
1559
1560 if (ret)
1561 break;
1562
1563 if (flags & SPLICE_F_NONBLOCK) {
1564 ret = -EAGAIN;
1565 break;
1566 }
1567
1568
1569
1570
1571
1572
1573 pipe_unlock(ipipe);
1574 pipe_unlock(opipe);
1575 goto retry;
1576 }
1577
1578 ibuf = ipipe->bufs + ipipe->curbuf;
1579 nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
1580 obuf = opipe->bufs + nbuf;
1581
1582 if (len >= ibuf->len) {
1583
1584
1585
1586 *obuf = *ibuf;
1587 ibuf->ops = NULL;
1588 opipe->nrbufs++;
1589 ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
1590 ipipe->nrbufs--;
1591 input_wakeup = true;
1592 } else {
1593
1594
1595
1596
1597 if (!pipe_buf_get(ipipe, ibuf)) {
1598 if (ret == 0)
1599 ret = -EFAULT;
1600 break;
1601 }
1602 *obuf = *ibuf;
1603
1604
1605
1606
1607
1608 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1609
1610 pipe_buf_mark_unmergeable(obuf);
1611
1612 obuf->len = len;
1613 opipe->nrbufs++;
1614 ibuf->offset += obuf->len;
1615 ibuf->len -= obuf->len;
1616 }
1617 ret += obuf->len;
1618 len -= obuf->len;
1619 } while (len);
1620
1621 pipe_unlock(ipipe);
1622 pipe_unlock(opipe);
1623
1624
1625
1626
1627 if (ret > 0)
1628 wakeup_pipe_readers(opipe);
1629
1630 if (input_wakeup)
1631 wakeup_pipe_writers(ipipe);
1632
1633 return ret;
1634}
1635
1636
1637
1638
1639static int link_pipe(struct pipe_inode_info *ipipe,
1640 struct pipe_inode_info *opipe,
1641 size_t len, unsigned int flags)
1642{
1643 struct pipe_buffer *ibuf, *obuf;
1644 int ret = 0, i = 0, nbuf;
1645
1646
1647
1648
1649
1650
1651 pipe_double_lock(ipipe, opipe);
1652
1653 do {
1654 if (!opipe->readers) {
1655 send_sig(SIGPIPE, current, 0);
1656 if (!ret)
1657 ret = -EPIPE;
1658 break;
1659 }
1660
1661
1662
1663
1664
1665 if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
1666 break;
1667
1668 ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
1669 nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
1670
1671
1672
1673
1674
1675 if (!pipe_buf_get(ipipe, ibuf)) {
1676 if (ret == 0)
1677 ret = -EFAULT;
1678 break;
1679 }
1680
1681 obuf = opipe->bufs + nbuf;
1682 *obuf = *ibuf;
1683
1684
1685
1686
1687
1688 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1689
1690 pipe_buf_mark_unmergeable(obuf);
1691
1692 if (obuf->len > len)
1693 obuf->len = len;
1694
1695 opipe->nrbufs++;
1696 ret += obuf->len;
1697 len -= obuf->len;
1698 i++;
1699 } while (len);
1700
1701
1702
1703
1704
1705 if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK))
1706 ret = -EAGAIN;
1707
1708 pipe_unlock(ipipe);
1709 pipe_unlock(opipe);
1710
1711
1712
1713
1714 if (ret > 0)
1715 wakeup_pipe_readers(opipe);
1716
1717 return ret;
1718}
1719
1720
1721
1722
1723
1724
1725
1726static long do_tee(struct file *in, struct file *out, size_t len,
1727 unsigned int flags)
1728{
1729 struct pipe_inode_info *ipipe = get_pipe_info(in);
1730 struct pipe_inode_info *opipe = get_pipe_info(out);
1731 int ret = -EINVAL;
1732
1733
1734
1735
1736
1737 if (ipipe && opipe && ipipe != opipe) {
1738 if ((in->f_flags | out->f_flags) & O_NONBLOCK)
1739 flags |= SPLICE_F_NONBLOCK;
1740
1741
1742
1743
1744
1745 ret = ipipe_prep(ipipe, flags);
1746 if (!ret) {
1747 ret = opipe_prep(opipe, flags);
1748 if (!ret)
1749 ret = link_pipe(ipipe, opipe, len, flags);
1750 }
1751 }
1752
1753 return ret;
1754}
1755
1756SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
1757{
1758 struct fd in;
1759 int error;
1760
1761 if (unlikely(flags & ~SPLICE_F_ALL))
1762 return -EINVAL;
1763
1764 if (unlikely(!len))
1765 return 0;
1766
1767 error = -EBADF;
1768 in = fdget(fdin);
1769 if (in.file) {
1770 if (in.file->f_mode & FMODE_READ) {
1771 struct fd out = fdget(fdout);
1772 if (out.file) {
1773 if (out.file->f_mode & FMODE_WRITE)
1774 error = do_tee(in.file, out.file,
1775 len, flags);
1776 fdput(out);
1777 }
1778 }
1779 fdput(in);
1780 }
1781
1782 return error;
1783}
1784