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Linux 4.8-rc8
[linux/fpc-iii.git] / fs / read_write.c
blob66215a7b17cf14d0b776dbb8e62b310a1571fdeb
1 /*
2 * linux/fs/read_write.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/slab.h>
8 #include <linux/stat.h>
9 #include <linux/fcntl.h>
10 #include <linux/file.h>
11 #include <linux/uio.h>
12 #include <linux/fsnotify.h>
13 #include <linux/security.h>
14 #include <linux/export.h>
15 #include <linux/syscalls.h>
16 #include <linux/pagemap.h>
17 #include <linux/splice.h>
18 #include <linux/compat.h>
19 #include <linux/mount.h>
20 #include <linux/fs.h>
21 #include "internal.h"
22
23 #include <asm/uaccess.h>
24 #include <asm/unistd.h>
25
26 typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
27 typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
28
29 const struct file_operations generic_ro_fops = {
30 .llseek = generic_file_llseek,
31 .read_iter = generic_file_read_iter,
32 .mmap = generic_file_readonly_mmap,
33 .splice_read = generic_file_splice_read,
34 };
35
36 EXPORT_SYMBOL(generic_ro_fops);
37
38 static inline int unsigned_offsets(struct file *file)
39 {
40 return file->f_mode & FMODE_UNSIGNED_OFFSET;
41 }
42
43 /**
44 * vfs_setpos - update the file offset for lseek
45 * @file: file structure in question
46 * @offset: file offset to seek to
47 * @maxsize: maximum file size
48 *
49 * This is a low-level filesystem helper for updating the file offset to
50 * the value specified by @offset if the given offset is valid and it is
51 * not equal to the current file offset.
52 *
53 * Return the specified offset on success and -EINVAL on invalid offset.
54 */
55 loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
56 {
57 if (offset < 0 && !unsigned_offsets(file))
58 return -EINVAL;
59 if (offset > maxsize)
60 return -EINVAL;
61
62 if (offset != file->f_pos) {
63 file->f_pos = offset;
64 file->f_version = 0;
65 }
66 return offset;
67 }
68 EXPORT_SYMBOL(vfs_setpos);
69
70 /**
71 * generic_file_llseek_size - generic llseek implementation for regular files
72 * @file: file structure to seek on
73 * @offset: file offset to seek to
74 * @whence: type of seek
75 * @size: max size of this file in file system
76 * @eof: offset used for SEEK_END position
77 *
78 * This is a variant of generic_file_llseek that allows passing in a custom
79 * maximum file size and a custom EOF position, for e.g. hashed directories
80 *
81 * Synchronization:
82 * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
83 * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
84 * read/writes behave like SEEK_SET against seeks.
85 */
86 loff_t
87 generic_file_llseek_size(struct file *file, loff_t offset, int whence,
88 loff_t maxsize, loff_t eof)
89 {
90 switch (whence) {
91 case SEEK_END:
92 offset += eof;
93 break;
94 case SEEK_CUR:
95 /*
96 * Here we special-case the lseek(fd, 0, SEEK_CUR)
97 * position-querying operation. Avoid rewriting the "same"
98 * f_pos value back to the file because a concurrent read(),
99 * write() or lseek() might have altered it
100 */
101 if (offset == 0)
102 return file->f_pos;
103 /*
104 * f_lock protects against read/modify/write race with other
105 * SEEK_CURs. Note that parallel writes and reads behave
106 * like SEEK_SET.
107 */
108 spin_lock(&file->f_lock);
109 offset = vfs_setpos(file, file->f_pos + offset, maxsize);
110 spin_unlock(&file->f_lock);
111 return offset;
112 case SEEK_DATA:
113 /*
114 * In the generic case the entire file is data, so as long as
115 * offset isn't at the end of the file then the offset is data.
116 */
117 if (offset >= eof)
118 return -ENXIO;
119 break;
120 case SEEK_HOLE:
121 /*
122 * There is a virtual hole at the end of the file, so as long as
123 * offset isn't i_size or larger, return i_size.
124 */
125 if (offset >= eof)
126 return -ENXIO;
127 offset = eof;
128 break;
129 }
130
131 return vfs_setpos(file, offset, maxsize);
132 }
133 EXPORT_SYMBOL(generic_file_llseek_size);
134
135 /**
136 * generic_file_llseek - generic llseek implementation for regular files
137 * @file: file structure to seek on
138 * @offset: file offset to seek to
139 * @whence: type of seek
140 *
141 * This is a generic implemenation of ->llseek useable for all normal local
142 * filesystems. It just updates the file offset to the value specified by
143 * @offset and @whence.
144 */
145 loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
146 {
147 struct inode *inode = file->f_mapping->host;
148
149 return generic_file_llseek_size(file, offset, whence,
150 inode->i_sb->s_maxbytes,
151 i_size_read(inode));
152 }
153 EXPORT_SYMBOL(generic_file_llseek);
154
155 /**
156 * fixed_size_llseek - llseek implementation for fixed-sized devices
157 * @file: file structure to seek on
158 * @offset: file offset to seek to
159 * @whence: type of seek
160 * @size: size of the file
161 *
162 */
163 loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
164 {
165 switch (whence) {
166 case SEEK_SET: case SEEK_CUR: case SEEK_END:
167 return generic_file_llseek_size(file, offset, whence,
168 size, size);
169 default:
170 return -EINVAL;
171 }
172 }
173 EXPORT_SYMBOL(fixed_size_llseek);
174
175 /**
176 * no_seek_end_llseek - llseek implementation for fixed-sized devices
177 * @file: file structure to seek on
178 * @offset: file offset to seek to
179 * @whence: type of seek
180 *
181 */
182 loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
183 {
184 switch (whence) {
185 case SEEK_SET: case SEEK_CUR:
186 return generic_file_llseek_size(file, offset, whence,
187 OFFSET_MAX, 0);
188 default:
189 return -EINVAL;
190 }
191 }
192 EXPORT_SYMBOL(no_seek_end_llseek);
193
194 /**
195 * no_seek_end_llseek_size - llseek implementation for fixed-sized devices
196 * @file: file structure to seek on
197 * @offset: file offset to seek to
198 * @whence: type of seek
199 * @size: maximal offset allowed
200 *
201 */
202 loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
203 {
204 switch (whence) {
205 case SEEK_SET: case SEEK_CUR:
206 return generic_file_llseek_size(file, offset, whence,
207 size, 0);
208 default:
209 return -EINVAL;
210 }
211 }
212 EXPORT_SYMBOL(no_seek_end_llseek_size);
213
214 /**
215 * noop_llseek - No Operation Performed llseek implementation
216 * @file: file structure to seek on
217 * @offset: file offset to seek to
218 * @whence: type of seek
219 *
220 * This is an implementation of ->llseek useable for the rare special case when
221 * userspace expects the seek to succeed but the (device) file is actually not
222 * able to perform the seek. In this case you use noop_llseek() instead of
223 * falling back to the default implementation of ->llseek.
224 */
225 loff_t noop_llseek(struct file *file, loff_t offset, int whence)
226 {
227 return file->f_pos;
228 }
229 EXPORT_SYMBOL(noop_llseek);
230
231 loff_t no_llseek(struct file *file, loff_t offset, int whence)
232 {
233 return -ESPIPE;
234 }
235 EXPORT_SYMBOL(no_llseek);
236
237 loff_t default_llseek(struct file *file, loff_t offset, int whence)
238 {
239 struct inode *inode = file_inode(file);
240 loff_t retval;
241
242 inode_lock(inode);
243 switch (whence) {
244 case SEEK_END:
245 offset += i_size_read(inode);
246 break;
247 case SEEK_CUR:
248 if (offset == 0) {
249 retval = file->f_pos;
250 goto out;
251 }
252 offset += file->f_pos;
253 break;
254 case SEEK_DATA:
255 /*
256 * In the generic case the entire file is data, so as
257 * long as offset isn't at the end of the file then the
258 * offset is data.
259 */
260 if (offset >= inode->i_size) {
261 retval = -ENXIO;
262 goto out;
263 }
264 break;
265 case SEEK_HOLE:
266 /*
267 * There is a virtual hole at the end of the file, so
268 * as long as offset isn't i_size or larger, return
269 * i_size.
270 */
271 if (offset >= inode->i_size) {
272 retval = -ENXIO;
273 goto out;
274 }
275 offset = inode->i_size;
276 break;
277 }
278 retval = -EINVAL;
279 if (offset >= 0 || unsigned_offsets(file)) {
280 if (offset != file->f_pos) {
281 file->f_pos = offset;
282 file->f_version = 0;
283 }
284 retval = offset;
285 }
286 out:
287 inode_unlock(inode);
288 return retval;
289 }
290 EXPORT_SYMBOL(default_llseek);
291
292 loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
293 {
294 loff_t (*fn)(struct file *, loff_t, int);
295
296 fn = no_llseek;
297 if (file->f_mode & FMODE_LSEEK) {
298 if (file->f_op->llseek)
299 fn = file->f_op->llseek;
300 }
301 return fn(file, offset, whence);
302 }
303 EXPORT_SYMBOL(vfs_llseek);
304
305 SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
306 {
307 off_t retval;
308 struct fd f = fdget_pos(fd);
309 if (!f.file)
310 return -EBADF;
311
312 retval = -EINVAL;
313 if (whence <= SEEK_MAX) {
314 loff_t res = vfs_llseek(f.file, offset, whence);
315 retval = res;
316 if (res != (loff_t)retval)
317 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
318 }
319 fdput_pos(f);
320 return retval;
321 }
322
323 #ifdef CONFIG_COMPAT
324 COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
325 {
326 return sys_lseek(fd, offset, whence);
327 }
328 #endif
329
330 #ifdef __ARCH_WANT_SYS_LLSEEK
331 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
332 unsigned long, offset_low, loff_t __user *, result,
333 unsigned int, whence)
334 {
335 int retval;
336 struct fd f = fdget_pos(fd);
337 loff_t offset;
338
339 if (!f.file)
340 return -EBADF;
341
342 retval = -EINVAL;
343 if (whence > SEEK_MAX)
344 goto out_putf;
345
346 offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
347 whence);
348
349 retval = (int)offset;
350 if (offset >= 0) {
351 retval = -EFAULT;
352 if (!copy_to_user(result, &offset, sizeof(offset)))
353 retval = 0;
354 }
355 out_putf:
356 fdput_pos(f);
357 return retval;
358 }
359 #endif
360
361 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
362 {
363 struct kiocb kiocb;
364 ssize_t ret;
365
366 if (!file->f_op->read_iter)
367 return -EINVAL;
368
369 init_sync_kiocb(&kiocb, file);
370 kiocb.ki_pos = *ppos;
371
372 iter->type |= READ;
373 ret = file->f_op->read_iter(&kiocb, iter);
374 BUG_ON(ret == -EIOCBQUEUED);
375 if (ret > 0)
376 *ppos = kiocb.ki_pos;
377 return ret;
378 }
379 EXPORT_SYMBOL(vfs_iter_read);
380
381 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
382 {
383 struct kiocb kiocb;
384 ssize_t ret;
385
386 if (!file->f_op->write_iter)
387 return -EINVAL;
388
389 init_sync_kiocb(&kiocb, file);
390 kiocb.ki_pos = *ppos;
391
392 iter->type |= WRITE;
393 ret = file->f_op->write_iter(&kiocb, iter);
394 BUG_ON(ret == -EIOCBQUEUED);
395 if (ret > 0)
396 *ppos = kiocb.ki_pos;
397 return ret;
398 }
399 EXPORT_SYMBOL(vfs_iter_write);
400
401 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
402 {
403 struct inode *inode;
404 loff_t pos;
405 int retval = -EINVAL;
406
407 inode = file_inode(file);
408 if (unlikely((ssize_t) count < 0))
409 return retval;
410 pos = *ppos;
411 if (unlikely(pos < 0)) {
412 if (!unsigned_offsets(file))
413 return retval;
414 if (count >= -pos) /* both values are in 0..LLONG_MAX */
415 return -EOVERFLOW;
416 } else if (unlikely((loff_t) (pos + count) < 0)) {
417 if (!unsigned_offsets(file))
418 return retval;
419 }
420
421 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
422 retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
423 read_write == READ ? F_RDLCK : F_WRLCK);
424 if (retval < 0)
425 return retval;
426 }
427 return security_file_permission(file,
428 read_write == READ ? MAY_READ : MAY_WRITE);
429 }
430
431 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
432 {
433 struct iovec iov = { .iov_base = buf, .iov_len = len };
434 struct kiocb kiocb;
435 struct iov_iter iter;
436 ssize_t ret;
437
438 init_sync_kiocb(&kiocb, filp);
439 kiocb.ki_pos = *ppos;
440 iov_iter_init(&iter, READ, &iov, 1, len);
441
442 ret = filp->f_op->read_iter(&kiocb, &iter);
443 BUG_ON(ret == -EIOCBQUEUED);
444 *ppos = kiocb.ki_pos;
445 return ret;
446 }
447
448 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
449 loff_t *pos)
450 {
451 if (file->f_op->read)
452 return file->f_op->read(file, buf, count, pos);
453 else if (file->f_op->read_iter)
454 return new_sync_read(file, buf, count, pos);
455 else
456 return -EINVAL;
457 }
458 EXPORT_SYMBOL(__vfs_read);
459
460 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
461 {
462 ssize_t ret;
463
464 if (!(file->f_mode & FMODE_READ))
465 return -EBADF;
466 if (!(file->f_mode & FMODE_CAN_READ))
467 return -EINVAL;
468 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
469 return -EFAULT;
470
471 ret = rw_verify_area(READ, file, pos, count);
472 if (!ret) {
473 if (count > MAX_RW_COUNT)
474 count = MAX_RW_COUNT;
475 ret = __vfs_read(file, buf, count, pos);
476 if (ret > 0) {
477 fsnotify_access(file);
478 add_rchar(current, ret);
479 }
480 inc_syscr(current);
481 }
482
483 return ret;
484 }
485
486 EXPORT_SYMBOL(vfs_read);
487
488 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
489 {
490 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
491 struct kiocb kiocb;
492 struct iov_iter iter;
493 ssize_t ret;
494
495 init_sync_kiocb(&kiocb, filp);
496 kiocb.ki_pos = *ppos;
497 iov_iter_init(&iter, WRITE, &iov, 1, len);
498
499 ret = filp->f_op->write_iter(&kiocb, &iter);
500 BUG_ON(ret == -EIOCBQUEUED);
501 if (ret > 0)
502 *ppos = kiocb.ki_pos;
503 return ret;
504 }
505
506 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
507 loff_t *pos)
508 {
509 if (file->f_op->write)
510 return file->f_op->write(file, p, count, pos);
511 else if (file->f_op->write_iter)
512 return new_sync_write(file, p, count, pos);
513 else
514 return -EINVAL;
515 }
516 EXPORT_SYMBOL(__vfs_write);
517
518 ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
519 {
520 mm_segment_t old_fs;
521 const char __user *p;
522 ssize_t ret;
523
524 if (!(file->f_mode & FMODE_CAN_WRITE))
525 return -EINVAL;
526
527 old_fs = get_fs();
528 set_fs(get_ds());
529 p = (__force const char __user *)buf;
530 if (count > MAX_RW_COUNT)
531 count = MAX_RW_COUNT;
532 ret = __vfs_write(file, p, count, pos);
533 set_fs(old_fs);
534 if (ret > 0) {
535 fsnotify_modify(file);
536 add_wchar(current, ret);
537 }
538 inc_syscw(current);
539 return ret;
540 }
541
542 EXPORT_SYMBOL(__kernel_write);
543
544 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
545 {
546 ssize_t ret;
547
548 if (!(file->f_mode & FMODE_WRITE))
549 return -EBADF;
550 if (!(file->f_mode & FMODE_CAN_WRITE))
551 return -EINVAL;
552 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
553 return -EFAULT;
554
555 ret = rw_verify_area(WRITE, file, pos, count);
556 if (!ret) {
557 if (count > MAX_RW_COUNT)
558 count = MAX_RW_COUNT;
559 file_start_write(file);
560 ret = __vfs_write(file, buf, count, pos);
561 if (ret > 0) {
562 fsnotify_modify(file);
563 add_wchar(current, ret);
564 }
565 inc_syscw(current);
566 file_end_write(file);
567 }
568
569 return ret;
570 }
571
572 EXPORT_SYMBOL(vfs_write);
573
574 static inline loff_t file_pos_read(struct file *file)
575 {
576 return file->f_pos;
577 }
578
579 static inline void file_pos_write(struct file *file, loff_t pos)
580 {
581 file->f_pos = pos;
582 }
583
584 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
585 {
586 struct fd f = fdget_pos(fd);
587 ssize_t ret = -EBADF;
588
589 if (f.file) {
590 loff_t pos = file_pos_read(f.file);
591 ret = vfs_read(f.file, buf, count, &pos);
592 if (ret >= 0)
593 file_pos_write(f.file, pos);
594 fdput_pos(f);
595 }
596 return ret;
597 }
598
599 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
600 size_t, count)
601 {
602 struct fd f = fdget_pos(fd);
603 ssize_t ret = -EBADF;
604
605 if (f.file) {
606 loff_t pos = file_pos_read(f.file);
607 ret = vfs_write(f.file, buf, count, &pos);
608 if (ret >= 0)
609 file_pos_write(f.file, pos);
610 fdput_pos(f);
611 }
612
613 return ret;
614 }
615
616 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
617 size_t, count, loff_t, pos)
618 {
619 struct fd f;
620 ssize_t ret = -EBADF;
621
622 if (pos < 0)
623 return -EINVAL;
624
625 f = fdget(fd);
626 if (f.file) {
627 ret = -ESPIPE;
628 if (f.file->f_mode & FMODE_PREAD)
629 ret = vfs_read(f.file, buf, count, &pos);
630 fdput(f);
631 }
632
633 return ret;
634 }
635
636 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
637 size_t, count, loff_t, pos)
638 {
639 struct fd f;
640 ssize_t ret = -EBADF;
641
642 if (pos < 0)
643 return -EINVAL;
644
645 f = fdget(fd);
646 if (f.file) {
647 ret = -ESPIPE;
648 if (f.file->f_mode & FMODE_PWRITE)
649 ret = vfs_write(f.file, buf, count, &pos);
650 fdput(f);
651 }
652
653 return ret;
654 }
655
656 /*
657 * Reduce an iovec's length in-place. Return the resulting number of segments
658 */
659 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
660 {
661 unsigned long seg = 0;
662 size_t len = 0;
663
664 while (seg < nr_segs) {
665 seg++;
666 if (len + iov->iov_len >= to) {
667 iov->iov_len = to - len;
668 break;
669 }
670 len += iov->iov_len;
671 iov++;
672 }
673 return seg;
674 }
675 EXPORT_SYMBOL(iov_shorten);
676
677 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
678 loff_t *ppos, iter_fn_t fn, int flags)
679 {
680 struct kiocb kiocb;
681 ssize_t ret;
682
683 if (flags & ~(RWF_HIPRI | RWF_DSYNC | RWF_SYNC))
684 return -EOPNOTSUPP;
685
686 init_sync_kiocb(&kiocb, filp);
687 if (flags & RWF_HIPRI)
688 kiocb.ki_flags |= IOCB_HIPRI;
689 if (flags & RWF_DSYNC)
690 kiocb.ki_flags |= IOCB_DSYNC;
691 if (flags & RWF_SYNC)
692 kiocb.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
693 kiocb.ki_pos = *ppos;
694
695 ret = fn(&kiocb, iter);
696 BUG_ON(ret == -EIOCBQUEUED);
697 *ppos = kiocb.ki_pos;
698 return ret;
699 }
700
701 /* Do it by hand, with file-ops */
702 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
703 loff_t *ppos, io_fn_t fn, int flags)
704 {
705 ssize_t ret = 0;
706
707 if (flags & ~RWF_HIPRI)
708 return -EOPNOTSUPP;
709
710 while (iov_iter_count(iter)) {
711 struct iovec iovec = iov_iter_iovec(iter);
712 ssize_t nr;
713
714 nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
715
716 if (nr < 0) {
717 if (!ret)
718 ret = nr;
719 break;
720 }
721 ret += nr;
722 if (nr != iovec.iov_len)
723 break;
724 iov_iter_advance(iter, nr);
725 }
726
727 return ret;
728 }
729
730 /* A write operation does a read from user space and vice versa */
731 #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
732
733 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
734 unsigned long nr_segs, unsigned long fast_segs,
735 struct iovec *fast_pointer,
736 struct iovec **ret_pointer)
737 {
738 unsigned long seg;
739 ssize_t ret;
740 struct iovec *iov = fast_pointer;
741
742 /*
743 * SuS says "The readv() function *may* fail if the iovcnt argument
744 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
745 * traditionally returned zero for zero segments, so...
746 */
747 if (nr_segs == 0) {
748 ret = 0;
749 goto out;
750 }
751
752 /*
753 * First get the "struct iovec" from user memory and
754 * verify all the pointers
755 */
756 if (nr_segs > UIO_MAXIOV) {
757 ret = -EINVAL;
758 goto out;
759 }
760 if (nr_segs > fast_segs) {
761 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
762 if (iov == NULL) {
763 ret = -ENOMEM;
764 goto out;
765 }
766 }
767 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
768 ret = -EFAULT;
769 goto out;
770 }
771
772 /*
773 * According to the Single Unix Specification we should return EINVAL
774 * if an element length is < 0 when cast to ssize_t or if the
775 * total length would overflow the ssize_t return value of the
776 * system call.
777 *
778 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
779 * overflow case.
780 */
781 ret = 0;
782 for (seg = 0; seg < nr_segs; seg++) {
783 void __user *buf = iov[seg].iov_base;
784 ssize_t len = (ssize_t)iov[seg].iov_len;
785
786 /* see if we we're about to use an invalid len or if
787 * it's about to overflow ssize_t */
788 if (len < 0) {
789 ret = -EINVAL;
790 goto out;
791 }
792 if (type >= 0
793 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
794 ret = -EFAULT;
795 goto out;
796 }
797 if (len > MAX_RW_COUNT - ret) {
798 len = MAX_RW_COUNT - ret;
799 iov[seg].iov_len = len;
800 }
801 ret += len;
802 }
803 out:
804 *ret_pointer = iov;
805 return ret;
806 }
807
808 static ssize_t do_readv_writev(int type, struct file *file,
809 const struct iovec __user * uvector,
810 unsigned long nr_segs, loff_t *pos,
811 int flags)
812 {
813 size_t tot_len;
814 struct iovec iovstack[UIO_FASTIOV];
815 struct iovec *iov = iovstack;
816 struct iov_iter iter;
817 ssize_t ret;
818 io_fn_t fn;
819 iter_fn_t iter_fn;
820
821 ret = import_iovec(type, uvector, nr_segs,
822 ARRAY_SIZE(iovstack), &iov, &iter);
823 if (ret < 0)
824 return ret;
825
826 tot_len = iov_iter_count(&iter);
827 if (!tot_len)
828 goto out;
829 ret = rw_verify_area(type, file, pos, tot_len);
830 if (ret < 0)
831 goto out;
832
833 if (type == READ) {
834 fn = file->f_op->read;
835 iter_fn = file->f_op->read_iter;
836 } else {
837 fn = (io_fn_t)file->f_op->write;
838 iter_fn = file->f_op->write_iter;
839 file_start_write(file);
840 }
841
842 if (iter_fn)
843 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
844 else
845 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
846
847 if (type != READ)
848 file_end_write(file);
849
850 out:
851 kfree(iov);
852 if ((ret + (type == READ)) > 0) {
853 if (type == READ)
854 fsnotify_access(file);
855 else
856 fsnotify_modify(file);
857 }
858 return ret;
859 }
860
861 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
862 unsigned long vlen, loff_t *pos, int flags)
863 {
864 if (!(file->f_mode & FMODE_READ))
865 return -EBADF;
866 if (!(file->f_mode & FMODE_CAN_READ))
867 return -EINVAL;
868
869 return do_readv_writev(READ, file, vec, vlen, pos, flags);
870 }
871
872 EXPORT_SYMBOL(vfs_readv);
873
874 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
875 unsigned long vlen, loff_t *pos, int flags)
876 {
877 if (!(file->f_mode & FMODE_WRITE))
878 return -EBADF;
879 if (!(file->f_mode & FMODE_CAN_WRITE))
880 return -EINVAL;
881
882 return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
883 }
884
885 EXPORT_SYMBOL(vfs_writev);
886
887 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
888 unsigned long vlen, int flags)
889 {
890 struct fd f = fdget_pos(fd);
891 ssize_t ret = -EBADF;
892
893 if (f.file) {
894 loff_t pos = file_pos_read(f.file);
895 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
896 if (ret >= 0)
897 file_pos_write(f.file, pos);
898 fdput_pos(f);
899 }
900
901 if (ret > 0)
902 add_rchar(current, ret);
903 inc_syscr(current);
904 return ret;
905 }
906
907 static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
908 unsigned long vlen, int flags)
909 {
910 struct fd f = fdget_pos(fd);
911 ssize_t ret = -EBADF;
912
913 if (f.file) {
914 loff_t pos = file_pos_read(f.file);
915 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
916 if (ret >= 0)
917 file_pos_write(f.file, pos);
918 fdput_pos(f);
919 }
920
921 if (ret > 0)
922 add_wchar(current, ret);
923 inc_syscw(current);
924 return ret;
925 }
926
927 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
928 {
929 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
930 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
931 }
932
933 static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
934 unsigned long vlen, loff_t pos, int flags)
935 {
936 struct fd f;
937 ssize_t ret = -EBADF;
938
939 if (pos < 0)
940 return -EINVAL;
941
942 f = fdget(fd);
943 if (f.file) {
944 ret = -ESPIPE;
945 if (f.file->f_mode & FMODE_PREAD)
946 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
947 fdput(f);
948 }
949
950 if (ret > 0)
951 add_rchar(current, ret);
952 inc_syscr(current);
953 return ret;
954 }
955
956 static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
957 unsigned long vlen, loff_t pos, int flags)
958 {
959 struct fd f;
960 ssize_t ret = -EBADF;
961
962 if (pos < 0)
963 return -EINVAL;
964
965 f = fdget(fd);
966 if (f.file) {
967 ret = -ESPIPE;
968 if (f.file->f_mode & FMODE_PWRITE)
969 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
970 fdput(f);
971 }
972
973 if (ret > 0)
974 add_wchar(current, ret);
975 inc_syscw(current);
976 return ret;
977 }
978
979 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
980 unsigned long, vlen)
981 {
982 return do_readv(fd, vec, vlen, 0);
983 }
984
985 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
986 unsigned long, vlen)
987 {
988 return do_writev(fd, vec, vlen, 0);
989 }
990
991 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
992 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
993 {
994 loff_t pos = pos_from_hilo(pos_h, pos_l);
995
996 return do_preadv(fd, vec, vlen, pos, 0);
997 }
998
999 SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
1000 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1001 int, flags)
1002 {
1003 loff_t pos = pos_from_hilo(pos_h, pos_l);
1004
1005 if (pos == -1)
1006 return do_readv(fd, vec, vlen, flags);
1007
1008 return do_preadv(fd, vec, vlen, pos, flags);
1009 }
1010
1011 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
1012 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1013 {
1014 loff_t pos = pos_from_hilo(pos_h, pos_l);
1015
1016 return do_pwritev(fd, vec, vlen, pos, 0);
1017 }
1018
1019 SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
1020 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1021 int, flags)
1022 {
1023 loff_t pos = pos_from_hilo(pos_h, pos_l);
1024
1025 if (pos == -1)
1026 return do_writev(fd, vec, vlen, flags);
1027
1028 return do_pwritev(fd, vec, vlen, pos, flags);
1029 }
1030
1031 #ifdef CONFIG_COMPAT
1032
1033 static ssize_t compat_do_readv_writev(int type, struct file *file,
1034 const struct compat_iovec __user *uvector,
1035 unsigned long nr_segs, loff_t *pos,
1036 int flags)
1037 {
1038 compat_ssize_t tot_len;
1039 struct iovec iovstack[UIO_FASTIOV];
1040 struct iovec *iov = iovstack;
1041 struct iov_iter iter;
1042 ssize_t ret;
1043 io_fn_t fn;
1044 iter_fn_t iter_fn;
1045
1046 ret = compat_import_iovec(type, uvector, nr_segs,
1047 UIO_FASTIOV, &iov, &iter);
1048 if (ret < 0)
1049 return ret;
1050
1051 tot_len = iov_iter_count(&iter);
1052 if (!tot_len)
1053 goto out;
1054 ret = rw_verify_area(type, file, pos, tot_len);
1055 if (ret < 0)
1056 goto out;
1057
1058 if (type == READ) {
1059 fn = file->f_op->read;
1060 iter_fn = file->f_op->read_iter;
1061 } else {
1062 fn = (io_fn_t)file->f_op->write;
1063 iter_fn = file->f_op->write_iter;
1064 file_start_write(file);
1065 }
1066
1067 if (iter_fn)
1068 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
1069 else
1070 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
1071
1072 if (type != READ)
1073 file_end_write(file);
1074
1075 out:
1076 kfree(iov);
1077 if ((ret + (type == READ)) > 0) {
1078 if (type == READ)
1079 fsnotify_access(file);
1080 else
1081 fsnotify_modify(file);
1082 }
1083 return ret;
1084 }
1085
1086 static size_t compat_readv(struct file *file,
1087 const struct compat_iovec __user *vec,
1088 unsigned long vlen, loff_t *pos, int flags)
1089 {
1090 ssize_t ret = -EBADF;
1091
1092 if (!(file->f_mode & FMODE_READ))
1093 goto out;
1094
1095 ret = -EINVAL;
1096 if (!(file->f_mode & FMODE_CAN_READ))
1097 goto out;
1098
1099 ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
1100
1101 out:
1102 if (ret > 0)
1103 add_rchar(current, ret);
1104 inc_syscr(current);
1105 return ret;
1106 }
1107
1108 static size_t do_compat_readv(compat_ulong_t fd,
1109 const struct compat_iovec __user *vec,
1110 compat_ulong_t vlen, int flags)
1111 {
1112 struct fd f = fdget_pos(fd);
1113 ssize_t ret;
1114 loff_t pos;
1115
1116 if (!f.file)
1117 return -EBADF;
1118 pos = f.file->f_pos;
1119 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1120 if (ret >= 0)
1121 f.file->f_pos = pos;
1122 fdput_pos(f);
1123 return ret;
1124
1125 }
1126
1127 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1128 const struct compat_iovec __user *,vec,
1129 compat_ulong_t, vlen)
1130 {
1131 return do_compat_readv(fd, vec, vlen, 0);
1132 }
1133
1134 static long do_compat_preadv64(unsigned long fd,
1135 const struct compat_iovec __user *vec,
1136 unsigned long vlen, loff_t pos, int flags)
1137 {
1138 struct fd f;
1139 ssize_t ret;
1140
1141 if (pos < 0)
1142 return -EINVAL;
1143 f = fdget(fd);
1144 if (!f.file)
1145 return -EBADF;
1146 ret = -ESPIPE;
1147 if (f.file->f_mode & FMODE_PREAD)
1148 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1149 fdput(f);
1150 return ret;
1151 }
1152
1153 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1154 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1155 const struct compat_iovec __user *,vec,
1156 unsigned long, vlen, loff_t, pos)
1157 {
1158 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1159 }
1160 #endif
1161
1162 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1163 const struct compat_iovec __user *,vec,
1164 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1165 {
1166 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1167
1168 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1169 }
1170
1171 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
1172 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
1173 const struct compat_iovec __user *,vec,
1174 unsigned long, vlen, loff_t, pos, int, flags)
1175 {
1176 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1177 }
1178 #endif
1179
1180 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
1181 const struct compat_iovec __user *,vec,
1182 compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
1183 int, flags)
1184 {
1185 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1186
1187 if (pos == -1)
1188 return do_compat_readv(fd, vec, vlen, flags);
1189
1190 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1191 }
1192
1193 static size_t compat_writev(struct file *file,
1194 const struct compat_iovec __user *vec,
1195 unsigned long vlen, loff_t *pos, int flags)
1196 {
1197 ssize_t ret = -EBADF;
1198
1199 if (!(file->f_mode & FMODE_WRITE))
1200 goto out;
1201
1202 ret = -EINVAL;
1203 if (!(file->f_mode & FMODE_CAN_WRITE))
1204 goto out;
1205
1206 ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, 0);
1207
1208 out:
1209 if (ret > 0)
1210 add_wchar(current, ret);
1211 inc_syscw(current);
1212 return ret;
1213 }
1214
1215 static size_t do_compat_writev(compat_ulong_t fd,
1216 const struct compat_iovec __user* vec,
1217 compat_ulong_t vlen, int flags)
1218 {
1219 struct fd f = fdget_pos(fd);
1220 ssize_t ret;
1221 loff_t pos;
1222
1223 if (!f.file)
1224 return -EBADF;
1225 pos = f.file->f_pos;
1226 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1227 if (ret >= 0)
1228 f.file->f_pos = pos;
1229 fdput_pos(f);
1230 return ret;
1231 }
1232
1233 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1234 const struct compat_iovec __user *, vec,
1235 compat_ulong_t, vlen)
1236 {
1237 return do_compat_writev(fd, vec, vlen, 0);
1238 }
1239
1240 static long do_compat_pwritev64(unsigned long fd,
1241 const struct compat_iovec __user *vec,
1242 unsigned long vlen, loff_t pos, int flags)
1243 {
1244 struct fd f;
1245 ssize_t ret;
1246
1247 if (pos < 0)
1248 return -EINVAL;
1249 f = fdget(fd);
1250 if (!f.file)
1251 return -EBADF;
1252 ret = -ESPIPE;
1253 if (f.file->f_mode & FMODE_PWRITE)
1254 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1255 fdput(f);
1256 return ret;
1257 }
1258
1259 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1260 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1261 const struct compat_iovec __user *,vec,
1262 unsigned long, vlen, loff_t, pos)
1263 {
1264 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1265 }
1266 #endif
1267
1268 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1269 const struct compat_iovec __user *,vec,
1270 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1271 {
1272 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1273
1274 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1275 }
1276
1277 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
1278 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
1279 const struct compat_iovec __user *,vec,
1280 unsigned long, vlen, loff_t, pos, int, flags)
1281 {
1282 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1283 }
1284 #endif
1285
1286 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
1287 const struct compat_iovec __user *,vec,
1288 compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
1289 {
1290 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1291
1292 if (pos == -1)
1293 return do_compat_writev(fd, vec, vlen, flags);
1294
1295 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1296 }
1297
1298 #endif
1299
1300 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1301 size_t count, loff_t max)
1302 {
1303 struct fd in, out;
1304 struct inode *in_inode, *out_inode;
1305 loff_t pos;
1306 loff_t out_pos;
1307 ssize_t retval;
1308 int fl;
1309
1310 /*
1311 * Get input file, and verify that it is ok..
1312 */
1313 retval = -EBADF;
1314 in = fdget(in_fd);
1315 if (!in.file)
1316 goto out;
1317 if (!(in.file->f_mode & FMODE_READ))
1318 goto fput_in;
1319 retval = -ESPIPE;
1320 if (!ppos) {
1321 pos = in.file->f_pos;
1322 } else {
1323 pos = *ppos;
1324 if (!(in.file->f_mode & FMODE_PREAD))
1325 goto fput_in;
1326 }
1327 retval = rw_verify_area(READ, in.file, &pos, count);
1328 if (retval < 0)
1329 goto fput_in;
1330 if (count > MAX_RW_COUNT)
1331 count = MAX_RW_COUNT;
1332
1333 /*
1334 * Get output file, and verify that it is ok..
1335 */
1336 retval = -EBADF;
1337 out = fdget(out_fd);
1338 if (!out.file)
1339 goto fput_in;
1340 if (!(out.file->f_mode & FMODE_WRITE))
1341 goto fput_out;
1342 retval = -EINVAL;
1343 in_inode = file_inode(in.file);
1344 out_inode = file_inode(out.file);
1345 out_pos = out.file->f_pos;
1346 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1347 if (retval < 0)
1348 goto fput_out;
1349
1350 if (!max)
1351 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1352
1353 if (unlikely(pos + count > max)) {
1354 retval = -EOVERFLOW;
1355 if (pos >= max)
1356 goto fput_out;
1357 count = max - pos;
1358 }
1359
1360 fl = 0;
1361 #if 0
1362 /*
1363 * We need to debate whether we can enable this or not. The
1364 * man page documents EAGAIN return for the output at least,
1365 * and the application is arguably buggy if it doesn't expect
1366 * EAGAIN on a non-blocking file descriptor.
1367 */
1368 if (in.file->f_flags & O_NONBLOCK)
1369 fl = SPLICE_F_NONBLOCK;
1370 #endif
1371 file_start_write(out.file);
1372 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1373 file_end_write(out.file);
1374
1375 if (retval > 0) {
1376 add_rchar(current, retval);
1377 add_wchar(current, retval);
1378 fsnotify_access(in.file);
1379 fsnotify_modify(out.file);
1380 out.file->f_pos = out_pos;
1381 if (ppos)
1382 *ppos = pos;
1383 else
1384 in.file->f_pos = pos;
1385 }
1386
1387 inc_syscr(current);
1388 inc_syscw(current);
1389 if (pos > max)
1390 retval = -EOVERFLOW;
1391
1392 fput_out:
1393 fdput(out);
1394 fput_in:
1395 fdput(in);
1396 out:
1397 return retval;
1398 }
1399
1400 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1401 {
1402 loff_t pos;
1403 off_t off;
1404 ssize_t ret;
1405
1406 if (offset) {
1407 if (unlikely(get_user(off, offset)))
1408 return -EFAULT;
1409 pos = off;
1410 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1411 if (unlikely(put_user(pos, offset)))
1412 return -EFAULT;
1413 return ret;
1414 }
1415
1416 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1417 }
1418
1419 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1420 {
1421 loff_t pos;
1422 ssize_t ret;
1423
1424 if (offset) {
1425 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1426 return -EFAULT;
1427 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1428 if (unlikely(put_user(pos, offset)))
1429 return -EFAULT;
1430 return ret;
1431 }
1432
1433 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1434 }
1435
1436 #ifdef CONFIG_COMPAT
1437 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1438 compat_off_t __user *, offset, compat_size_t, count)
1439 {
1440 loff_t pos;
1441 off_t off;
1442 ssize_t ret;
1443
1444 if (offset) {
1445 if (unlikely(get_user(off, offset)))
1446 return -EFAULT;
1447 pos = off;
1448 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1449 if (unlikely(put_user(pos, offset)))
1450 return -EFAULT;
1451 return ret;
1452 }
1453
1454 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1455 }
1456
1457 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1458 compat_loff_t __user *, offset, compat_size_t, count)
1459 {
1460 loff_t pos;
1461 ssize_t ret;
1462
1463 if (offset) {
1464 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1465 return -EFAULT;
1466 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1467 if (unlikely(put_user(pos, offset)))
1468 return -EFAULT;
1469 return ret;
1470 }
1471
1472 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1473 }
1474 #endif
1475
1476 /*
1477 * copy_file_range() differs from regular file read and write in that it
1478 * specifically allows return partial success. When it does so is up to
1479 * the copy_file_range method.
1480 */
1481 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
1482 struct file *file_out, loff_t pos_out,
1483 size_t len, unsigned int flags)
1484 {
1485 struct inode *inode_in = file_inode(file_in);
1486 struct inode *inode_out = file_inode(file_out);
1487 ssize_t ret;
1488
1489 if (flags != 0)
1490 return -EINVAL;
1491
1492 ret = rw_verify_area(READ, file_in, &pos_in, len);
1493 if (unlikely(ret))
1494 return ret;
1495
1496 ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1497 if (unlikely(ret))
1498 return ret;
1499
1500 if (!(file_in->f_mode & FMODE_READ) ||
1501 !(file_out->f_mode & FMODE_WRITE) ||
1502 (file_out->f_flags & O_APPEND))
1503 return -EBADF;
1504
1505 /* this could be relaxed once a method supports cross-fs copies */
1506 if (inode_in->i_sb != inode_out->i_sb)
1507 return -EXDEV;
1508
1509 if (len == 0)
1510 return 0;
1511
1512 ret = mnt_want_write_file(file_out);
1513 if (ret)
1514 return ret;
1515
1516 ret = -EOPNOTSUPP;
1517 if (file_out->f_op->copy_file_range)
1518 ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
1519 pos_out, len, flags);
1520 if (ret == -EOPNOTSUPP)
1521 ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1522 len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
1523
1524 if (ret > 0) {
1525 fsnotify_access(file_in);
1526 add_rchar(current, ret);
1527 fsnotify_modify(file_out);
1528 add_wchar(current, ret);
1529 }
1530 inc_syscr(current);
1531 inc_syscw(current);
1532
1533 mnt_drop_write_file(file_out);
1534
1535 return ret;
1536 }
1537 EXPORT_SYMBOL(vfs_copy_file_range);
1538
1539 SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
1540 int, fd_out, loff_t __user *, off_out,
1541 size_t, len, unsigned int, flags)
1542 {
1543 loff_t pos_in;
1544 loff_t pos_out;
1545 struct fd f_in;
1546 struct fd f_out;
1547 ssize_t ret = -EBADF;
1548
1549 f_in = fdget(fd_in);
1550 if (!f_in.file)
1551 goto out2;
1552
1553 f_out = fdget(fd_out);
1554 if (!f_out.file)
1555 goto out1;
1556
1557 ret = -EFAULT;
1558 if (off_in) {
1559 if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
1560 goto out;
1561 } else {
1562 pos_in = f_in.file->f_pos;
1563 }
1564
1565 if (off_out) {
1566 if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
1567 goto out;
1568 } else {
1569 pos_out = f_out.file->f_pos;
1570 }
1571
1572 ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
1573 flags);
1574 if (ret > 0) {
1575 pos_in += ret;
1576 pos_out += ret;
1577
1578 if (off_in) {
1579 if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
1580 ret = -EFAULT;
1581 } else {
1582 f_in.file->f_pos = pos_in;
1583 }
1584
1585 if (off_out) {
1586 if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
1587 ret = -EFAULT;
1588 } else {
1589 f_out.file->f_pos = pos_out;
1590 }
1591 }
1592
1593 out:
1594 fdput(f_out);
1595 out1:
1596 fdput(f_in);
1597 out2:
1598 return ret;
1599 }
1600
1601 static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
1602 {
1603 struct inode *inode = file_inode(file);
1604
1605 if (unlikely(pos < 0))
1606 return -EINVAL;
1607
1608 if (unlikely((loff_t) (pos + len) < 0))
1609 return -EINVAL;
1610
1611 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
1612 loff_t end = len ? pos + len - 1 : OFFSET_MAX;
1613 int retval;
1614
1615 retval = locks_mandatory_area(inode, file, pos, end,
1616 write ? F_WRLCK : F_RDLCK);
1617 if (retval < 0)
1618 return retval;
1619 }
1620
1621 return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
1622 }
1623
1624 int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1625 struct file *file_out, loff_t pos_out, u64 len)
1626 {
1627 struct inode *inode_in = file_inode(file_in);
1628 struct inode *inode_out = file_inode(file_out);
1629 int ret;
1630
1631 if (inode_in->i_sb != inode_out->i_sb ||
1632 file_in->f_path.mnt != file_out->f_path.mnt)
1633 return -EXDEV;
1634
1635 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1636 return -EISDIR;
1637 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1638 return -EINVAL;
1639
1640 if (!(file_in->f_mode & FMODE_READ) ||
1641 !(file_out->f_mode & FMODE_WRITE) ||
1642 (file_out->f_flags & O_APPEND))
1643 return -EBADF;
1644
1645 if (!file_in->f_op->clone_file_range)
1646 return -EOPNOTSUPP;
1647
1648 ret = clone_verify_area(file_in, pos_in, len, false);
1649 if (ret)
1650 return ret;
1651
1652 ret = clone_verify_area(file_out, pos_out, len, true);
1653 if (ret)
1654 return ret;
1655
1656 if (pos_in + len > i_size_read(inode_in))
1657 return -EINVAL;
1658
1659 ret = mnt_want_write_file(file_out);
1660 if (ret)
1661 return ret;
1662
1663 ret = file_in->f_op->clone_file_range(file_in, pos_in,
1664 file_out, pos_out, len);
1665 if (!ret) {
1666 fsnotify_access(file_in);
1667 fsnotify_modify(file_out);
1668 }
1669
1670 mnt_drop_write_file(file_out);
1671 return ret;
1672 }
1673 EXPORT_SYMBOL(vfs_clone_file_range);
1674
1675 int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
1676 {
1677 struct file_dedupe_range_info *info;
1678 struct inode *src = file_inode(file);
1679 u64 off;
1680 u64 len;
1681 int i;
1682 int ret;
1683 bool is_admin = capable(CAP_SYS_ADMIN);
1684 u16 count = same->dest_count;
1685 struct file *dst_file;
1686 loff_t dst_off;
1687 ssize_t deduped;
1688
1689 if (!(file->f_mode & FMODE_READ))
1690 return -EINVAL;
1691
1692 if (same->reserved1 || same->reserved2)
1693 return -EINVAL;
1694
1695 off = same->src_offset;
1696 len = same->src_length;
1697
1698 ret = -EISDIR;
1699 if (S_ISDIR(src->i_mode))
1700 goto out;
1701
1702 ret = -EINVAL;
1703 if (!S_ISREG(src->i_mode))
1704 goto out;
1705
1706 ret = clone_verify_area(file, off, len, false);
1707 if (ret < 0)
1708 goto out;
1709 ret = 0;
1710
1711 /* pre-format output fields to sane values */
1712 for (i = 0; i < count; i++) {
1713 same->info[i].bytes_deduped = 0ULL;
1714 same->info[i].status = FILE_DEDUPE_RANGE_SAME;
1715 }
1716
1717 for (i = 0, info = same->info; i < count; i++, info++) {
1718 struct inode *dst;
1719 struct fd dst_fd = fdget(info->dest_fd);
1720
1721 dst_file = dst_fd.file;
1722 if (!dst_file) {
1723 info->status = -EBADF;
1724 goto next_loop;
1725 }
1726 dst = file_inode(dst_file);
1727
1728 ret = mnt_want_write_file(dst_file);
1729 if (ret) {
1730 info->status = ret;
1731 goto next_loop;
1732 }
1733
1734 dst_off = info->dest_offset;
1735 ret = clone_verify_area(dst_file, dst_off, len, true);
1736 if (ret < 0) {
1737 info->status = ret;
1738 goto next_file;
1739 }
1740 ret = 0;
1741
1742 if (info->reserved) {
1743 info->status = -EINVAL;
1744 } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
1745 info->status = -EINVAL;
1746 } else if (file->f_path.mnt != dst_file->f_path.mnt) {
1747 info->status = -EXDEV;
1748 } else if (S_ISDIR(dst->i_mode)) {
1749 info->status = -EISDIR;
1750 } else if (dst_file->f_op->dedupe_file_range == NULL) {
1751 info->status = -EINVAL;
1752 } else {
1753 deduped = dst_file->f_op->dedupe_file_range(file, off,
1754 len, dst_file,
1755 info->dest_offset);
1756 if (deduped == -EBADE)
1757 info->status = FILE_DEDUPE_RANGE_DIFFERS;
1758 else if (deduped < 0)
1759 info->status = deduped;
1760 else
1761 info->bytes_deduped += deduped;
1762 }
1763
1764 next_file:
1765 mnt_drop_write_file(dst_file);
1766 next_loop:
1767 fdput(dst_fd);
1768
1769 if (fatal_signal_pending(current))
1770 goto out;
1771 }
1772
1773 out:
1774 return ret;
1775 }
1776 EXPORT_SYMBOL(vfs_dedupe_file_range);
Linux with added FPC-III support