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Merge branch 'rds-fixes'
[deliverable/linux.git] / fs / read_write.c
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 static inline struct fd fdget_pos(int fd)
306 {
307 return __to_fd(__fdget_pos(fd));
308 }
309
310 static inline void fdput_pos(struct fd f)
311 {
312 if (f.flags & FDPUT_POS_UNLOCK)
313 mutex_unlock(&f.file->f_pos_lock);
314 fdput(f);
315 }
316
317 SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
318 {
319 off_t retval;
320 struct fd f = fdget_pos(fd);
321 if (!f.file)
322 return -EBADF;
323
324 retval = -EINVAL;
325 if (whence <= SEEK_MAX) {
326 loff_t res = vfs_llseek(f.file, offset, whence);
327 retval = res;
328 if (res != (loff_t)retval)
329 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
330 }
331 fdput_pos(f);
332 return retval;
333 }
334
335 #ifdef CONFIG_COMPAT
336 COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
337 {
338 return sys_lseek(fd, offset, whence);
339 }
340 #endif
341
342 #ifdef __ARCH_WANT_SYS_LLSEEK
343 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
344 unsigned long, offset_low, loff_t __user *, result,
345 unsigned int, whence)
346 {
347 int retval;
348 struct fd f = fdget_pos(fd);
349 loff_t offset;
350
351 if (!f.file)
352 return -EBADF;
353
354 retval = -EINVAL;
355 if (whence > SEEK_MAX)
356 goto out_putf;
357
358 offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
359 whence);
360
361 retval = (int)offset;
362 if (offset >= 0) {
363 retval = -EFAULT;
364 if (!copy_to_user(result, &offset, sizeof(offset)))
365 retval = 0;
366 }
367 out_putf:
368 fdput_pos(f);
369 return retval;
370 }
371 #endif
372
373 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
374 {
375 struct kiocb kiocb;
376 ssize_t ret;
377
378 if (!file->f_op->read_iter)
379 return -EINVAL;
380
381 init_sync_kiocb(&kiocb, file);
382 kiocb.ki_pos = *ppos;
383
384 iter->type |= READ;
385 ret = file->f_op->read_iter(&kiocb, iter);
386 BUG_ON(ret == -EIOCBQUEUED);
387 if (ret > 0)
388 *ppos = kiocb.ki_pos;
389 return ret;
390 }
391 EXPORT_SYMBOL(vfs_iter_read);
392
393 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
394 {
395 struct kiocb kiocb;
396 ssize_t ret;
397
398 if (!file->f_op->write_iter)
399 return -EINVAL;
400
401 init_sync_kiocb(&kiocb, file);
402 kiocb.ki_pos = *ppos;
403
404 iter->type |= WRITE;
405 ret = file->f_op->write_iter(&kiocb, iter);
406 BUG_ON(ret == -EIOCBQUEUED);
407 if (ret > 0)
408 *ppos = kiocb.ki_pos;
409 return ret;
410 }
411 EXPORT_SYMBOL(vfs_iter_write);
412
413 /*
414 * rw_verify_area doesn't like huge counts. We limit
415 * them to something that fits in "int" so that others
416 * won't have to do range checks all the time.
417 */
418 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
419 {
420 struct inode *inode;
421 loff_t pos;
422 int retval = -EINVAL;
423
424 inode = file_inode(file);
425 if (unlikely((ssize_t) count < 0))
426 return retval;
427 pos = *ppos;
428 if (unlikely(pos < 0)) {
429 if (!unsigned_offsets(file))
430 return retval;
431 if (count >= -pos) /* both values are in 0..LLONG_MAX */
432 return -EOVERFLOW;
433 } else if (unlikely((loff_t) (pos + count) < 0)) {
434 if (!unsigned_offsets(file))
435 return retval;
436 }
437
438 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
439 retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
440 read_write == READ ? F_RDLCK : F_WRLCK);
441 if (retval < 0)
442 return retval;
443 }
444 retval = security_file_permission(file,
445 read_write == READ ? MAY_READ : MAY_WRITE);
446 if (retval)
447 return retval;
448 return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
449 }
450
451 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
452 {
453 struct iovec iov = { .iov_base = buf, .iov_len = len };
454 struct kiocb kiocb;
455 struct iov_iter iter;
456 ssize_t ret;
457
458 init_sync_kiocb(&kiocb, filp);
459 kiocb.ki_pos = *ppos;
460 iov_iter_init(&iter, READ, &iov, 1, len);
461
462 ret = filp->f_op->read_iter(&kiocb, &iter);
463 BUG_ON(ret == -EIOCBQUEUED);
464 *ppos = kiocb.ki_pos;
465 return ret;
466 }
467
468 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
469 loff_t *pos)
470 {
471 if (file->f_op->read)
472 return file->f_op->read(file, buf, count, pos);
473 else if (file->f_op->read_iter)
474 return new_sync_read(file, buf, count, pos);
475 else
476 return -EINVAL;
477 }
478 EXPORT_SYMBOL(__vfs_read);
479
480 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
481 {
482 ssize_t ret;
483
484 if (!(file->f_mode & FMODE_READ))
485 return -EBADF;
486 if (!(file->f_mode & FMODE_CAN_READ))
487 return -EINVAL;
488 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
489 return -EFAULT;
490
491 ret = rw_verify_area(READ, file, pos, count);
492 if (ret >= 0) {
493 count = ret;
494 ret = __vfs_read(file, buf, count, pos);
495 if (ret > 0) {
496 fsnotify_access(file);
497 add_rchar(current, ret);
498 }
499 inc_syscr(current);
500 }
501
502 return ret;
503 }
504
505 EXPORT_SYMBOL(vfs_read);
506
507 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
508 {
509 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
510 struct kiocb kiocb;
511 struct iov_iter iter;
512 ssize_t ret;
513
514 init_sync_kiocb(&kiocb, filp);
515 kiocb.ki_pos = *ppos;
516 iov_iter_init(&iter, WRITE, &iov, 1, len);
517
518 ret = filp->f_op->write_iter(&kiocb, &iter);
519 BUG_ON(ret == -EIOCBQUEUED);
520 if (ret > 0)
521 *ppos = kiocb.ki_pos;
522 return ret;
523 }
524
525 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
526 loff_t *pos)
527 {
528 if (file->f_op->write)
529 return file->f_op->write(file, p, count, pos);
530 else if (file->f_op->write_iter)
531 return new_sync_write(file, p, count, pos);
532 else
533 return -EINVAL;
534 }
535 EXPORT_SYMBOL(__vfs_write);
536
537 ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
538 {
539 mm_segment_t old_fs;
540 const char __user *p;
541 ssize_t ret;
542
543 if (!(file->f_mode & FMODE_CAN_WRITE))
544 return -EINVAL;
545
546 old_fs = get_fs();
547 set_fs(get_ds());
548 p = (__force const char __user *)buf;
549 if (count > MAX_RW_COUNT)
550 count = MAX_RW_COUNT;
551 ret = __vfs_write(file, p, count, pos);
552 set_fs(old_fs);
553 if (ret > 0) {
554 fsnotify_modify(file);
555 add_wchar(current, ret);
556 }
557 inc_syscw(current);
558 return ret;
559 }
560
561 EXPORT_SYMBOL(__kernel_write);
562
563 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
564 {
565 ssize_t ret;
566
567 if (!(file->f_mode & FMODE_WRITE))
568 return -EBADF;
569 if (!(file->f_mode & FMODE_CAN_WRITE))
570 return -EINVAL;
571 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
572 return -EFAULT;
573
574 ret = rw_verify_area(WRITE, file, pos, count);
575 if (ret >= 0) {
576 count = ret;
577 file_start_write(file);
578 ret = __vfs_write(file, buf, count, pos);
579 if (ret > 0) {
580 fsnotify_modify(file);
581 add_wchar(current, ret);
582 }
583 inc_syscw(current);
584 file_end_write(file);
585 }
586
587 return ret;
588 }
589
590 EXPORT_SYMBOL(vfs_write);
591
592 static inline loff_t file_pos_read(struct file *file)
593 {
594 return file->f_pos;
595 }
596
597 static inline void file_pos_write(struct file *file, loff_t pos)
598 {
599 file->f_pos = pos;
600 }
601
602 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
603 {
604 struct fd f = fdget_pos(fd);
605 ssize_t ret = -EBADF;
606
607 if (f.file) {
608 loff_t pos = file_pos_read(f.file);
609 ret = vfs_read(f.file, buf, count, &pos);
610 if (ret >= 0)
611 file_pos_write(f.file, pos);
612 fdput_pos(f);
613 }
614 return ret;
615 }
616
617 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
618 size_t, count)
619 {
620 struct fd f = fdget_pos(fd);
621 ssize_t ret = -EBADF;
622
623 if (f.file) {
624 loff_t pos = file_pos_read(f.file);
625 ret = vfs_write(f.file, buf, count, &pos);
626 if (ret >= 0)
627 file_pos_write(f.file, pos);
628 fdput_pos(f);
629 }
630
631 return ret;
632 }
633
634 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
635 size_t, count, loff_t, pos)
636 {
637 struct fd f;
638 ssize_t ret = -EBADF;
639
640 if (pos < 0)
641 return -EINVAL;
642
643 f = fdget(fd);
644 if (f.file) {
645 ret = -ESPIPE;
646 if (f.file->f_mode & FMODE_PREAD)
647 ret = vfs_read(f.file, buf, count, &pos);
648 fdput(f);
649 }
650
651 return ret;
652 }
653
654 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
655 size_t, count, loff_t, pos)
656 {
657 struct fd f;
658 ssize_t ret = -EBADF;
659
660 if (pos < 0)
661 return -EINVAL;
662
663 f = fdget(fd);
664 if (f.file) {
665 ret = -ESPIPE;
666 if (f.file->f_mode & FMODE_PWRITE)
667 ret = vfs_write(f.file, buf, count, &pos);
668 fdput(f);
669 }
670
671 return ret;
672 }
673
674 /*
675 * Reduce an iovec's length in-place. Return the resulting number of segments
676 */
677 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
678 {
679 unsigned long seg = 0;
680 size_t len = 0;
681
682 while (seg < nr_segs) {
683 seg++;
684 if (len + iov->iov_len >= to) {
685 iov->iov_len = to - len;
686 break;
687 }
688 len += iov->iov_len;
689 iov++;
690 }
691 return seg;
692 }
693 EXPORT_SYMBOL(iov_shorten);
694
695 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
696 loff_t *ppos, iter_fn_t fn, int flags)
697 {
698 struct kiocb kiocb;
699 ssize_t ret;
700
701 if (flags & ~RWF_HIPRI)
702 return -EOPNOTSUPP;
703
704 init_sync_kiocb(&kiocb, filp);
705 if (flags & RWF_HIPRI)
706 kiocb.ki_flags |= IOCB_HIPRI;
707 kiocb.ki_pos = *ppos;
708
709 ret = fn(&kiocb, iter);
710 BUG_ON(ret == -EIOCBQUEUED);
711 *ppos = kiocb.ki_pos;
712 return ret;
713 }
714
715 /* Do it by hand, with file-ops */
716 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
717 loff_t *ppos, io_fn_t fn, int flags)
718 {
719 ssize_t ret = 0;
720
721 if (flags & ~RWF_HIPRI)
722 return -EOPNOTSUPP;
723
724 while (iov_iter_count(iter)) {
725 struct iovec iovec = iov_iter_iovec(iter);
726 ssize_t nr;
727
728 nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
729
730 if (nr < 0) {
731 if (!ret)
732 ret = nr;
733 break;
734 }
735 ret += nr;
736 if (nr != iovec.iov_len)
737 break;
738 iov_iter_advance(iter, nr);
739 }
740
741 return ret;
742 }
743
744 /* A write operation does a read from user space and vice versa */
745 #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
746
747 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
748 unsigned long nr_segs, unsigned long fast_segs,
749 struct iovec *fast_pointer,
750 struct iovec **ret_pointer)
751 {
752 unsigned long seg;
753 ssize_t ret;
754 struct iovec *iov = fast_pointer;
755
756 /*
757 * SuS says "The readv() function *may* fail if the iovcnt argument
758 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
759 * traditionally returned zero for zero segments, so...
760 */
761 if (nr_segs == 0) {
762 ret = 0;
763 goto out;
764 }
765
766 /*
767 * First get the "struct iovec" from user memory and
768 * verify all the pointers
769 */
770 if (nr_segs > UIO_MAXIOV) {
771 ret = -EINVAL;
772 goto out;
773 }
774 if (nr_segs > fast_segs) {
775 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
776 if (iov == NULL) {
777 ret = -ENOMEM;
778 goto out;
779 }
780 }
781 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
782 ret = -EFAULT;
783 goto out;
784 }
785
786 /*
787 * According to the Single Unix Specification we should return EINVAL
788 * if an element length is < 0 when cast to ssize_t or if the
789 * total length would overflow the ssize_t return value of the
790 * system call.
791 *
792 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
793 * overflow case.
794 */
795 ret = 0;
796 for (seg = 0; seg < nr_segs; seg++) {
797 void __user *buf = iov[seg].iov_base;
798 ssize_t len = (ssize_t)iov[seg].iov_len;
799
800 /* see if we we're about to use an invalid len or if
801 * it's about to overflow ssize_t */
802 if (len < 0) {
803 ret = -EINVAL;
804 goto out;
805 }
806 if (type >= 0
807 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
808 ret = -EFAULT;
809 goto out;
810 }
811 if (len > MAX_RW_COUNT - ret) {
812 len = MAX_RW_COUNT - ret;
813 iov[seg].iov_len = len;
814 }
815 ret += len;
816 }
817 out:
818 *ret_pointer = iov;
819 return ret;
820 }
821
822 static ssize_t do_readv_writev(int type, struct file *file,
823 const struct iovec __user * uvector,
824 unsigned long nr_segs, loff_t *pos,
825 int flags)
826 {
827 size_t tot_len;
828 struct iovec iovstack[UIO_FASTIOV];
829 struct iovec *iov = iovstack;
830 struct iov_iter iter;
831 ssize_t ret;
832 io_fn_t fn;
833 iter_fn_t iter_fn;
834
835 ret = import_iovec(type, uvector, nr_segs,
836 ARRAY_SIZE(iovstack), &iov, &iter);
837 if (ret < 0)
838 return ret;
839
840 tot_len = iov_iter_count(&iter);
841 if (!tot_len)
842 goto out;
843 ret = rw_verify_area(type, file, pos, tot_len);
844 if (ret < 0)
845 goto out;
846
847 if (type == READ) {
848 fn = file->f_op->read;
849 iter_fn = file->f_op->read_iter;
850 } else {
851 fn = (io_fn_t)file->f_op->write;
852 iter_fn = file->f_op->write_iter;
853 file_start_write(file);
854 }
855
856 if (iter_fn)
857 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
858 else
859 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
860
861 if (type != READ)
862 file_end_write(file);
863
864 out:
865 kfree(iov);
866 if ((ret + (type == READ)) > 0) {
867 if (type == READ)
868 fsnotify_access(file);
869 else
870 fsnotify_modify(file);
871 }
872 return ret;
873 }
874
875 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
876 unsigned long vlen, loff_t *pos, int flags)
877 {
878 if (!(file->f_mode & FMODE_READ))
879 return -EBADF;
880 if (!(file->f_mode & FMODE_CAN_READ))
881 return -EINVAL;
882
883 return do_readv_writev(READ, file, vec, vlen, pos, flags);
884 }
885
886 EXPORT_SYMBOL(vfs_readv);
887
888 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
889 unsigned long vlen, loff_t *pos, int flags)
890 {
891 if (!(file->f_mode & FMODE_WRITE))
892 return -EBADF;
893 if (!(file->f_mode & FMODE_CAN_WRITE))
894 return -EINVAL;
895
896 return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
897 }
898
899 EXPORT_SYMBOL(vfs_writev);
900
901 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
902 unsigned long vlen, int flags)
903 {
904 struct fd f = fdget_pos(fd);
905 ssize_t ret = -EBADF;
906
907 if (f.file) {
908 loff_t pos = file_pos_read(f.file);
909 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
910 if (ret >= 0)
911 file_pos_write(f.file, pos);
912 fdput_pos(f);
913 }
914
915 if (ret > 0)
916 add_rchar(current, ret);
917 inc_syscr(current);
918 return ret;
919 }
920
921 static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
922 unsigned long vlen, int flags)
923 {
924 struct fd f = fdget_pos(fd);
925 ssize_t ret = -EBADF;
926
927 if (f.file) {
928 loff_t pos = file_pos_read(f.file);
929 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
930 if (ret >= 0)
931 file_pos_write(f.file, pos);
932 fdput_pos(f);
933 }
934
935 if (ret > 0)
936 add_wchar(current, ret);
937 inc_syscw(current);
938 return ret;
939 }
940
941 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
942 {
943 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
944 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
945 }
946
947 static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
948 unsigned long vlen, loff_t pos, int flags)
949 {
950 struct fd f;
951 ssize_t ret = -EBADF;
952
953 if (pos < 0)
954 return -EINVAL;
955
956 f = fdget(fd);
957 if (f.file) {
958 ret = -ESPIPE;
959 if (f.file->f_mode & FMODE_PREAD)
960 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
961 fdput(f);
962 }
963
964 if (ret > 0)
965 add_rchar(current, ret);
966 inc_syscr(current);
967 return ret;
968 }
969
970 static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
971 unsigned long vlen, loff_t pos, int flags)
972 {
973 struct fd f;
974 ssize_t ret = -EBADF;
975
976 if (pos < 0)
977 return -EINVAL;
978
979 f = fdget(fd);
980 if (f.file) {
981 ret = -ESPIPE;
982 if (f.file->f_mode & FMODE_PWRITE)
983 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
984 fdput(f);
985 }
986
987 if (ret > 0)
988 add_wchar(current, ret);
989 inc_syscw(current);
990 return ret;
991 }
992
993 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
994 unsigned long, vlen)
995 {
996 return do_readv(fd, vec, vlen, 0);
997 }
998
999 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
1000 unsigned long, vlen)
1001 {
1002 return do_writev(fd, vec, vlen, 0);
1003 }
1004
1005 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
1006 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1007 {
1008 loff_t pos = pos_from_hilo(pos_h, pos_l);
1009
1010 return do_preadv(fd, vec, vlen, pos, 0);
1011 }
1012
1013 SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
1014 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1015 int, flags)
1016 {
1017 loff_t pos = pos_from_hilo(pos_h, pos_l);
1018
1019 if (pos == -1)
1020 return do_readv(fd, vec, vlen, flags);
1021
1022 return do_preadv(fd, vec, vlen, pos, flags);
1023 }
1024
1025 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
1026 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1027 {
1028 loff_t pos = pos_from_hilo(pos_h, pos_l);
1029
1030 return do_pwritev(fd, vec, vlen, pos, 0);
1031 }
1032
1033 SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
1034 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1035 int, flags)
1036 {
1037 loff_t pos = pos_from_hilo(pos_h, pos_l);
1038
1039 if (pos == -1)
1040 return do_writev(fd, vec, vlen, flags);
1041
1042 return do_pwritev(fd, vec, vlen, pos, flags);
1043 }
1044
1045 #ifdef CONFIG_COMPAT
1046
1047 static ssize_t compat_do_readv_writev(int type, struct file *file,
1048 const struct compat_iovec __user *uvector,
1049 unsigned long nr_segs, loff_t *pos,
1050 int flags)
1051 {
1052 compat_ssize_t tot_len;
1053 struct iovec iovstack[UIO_FASTIOV];
1054 struct iovec *iov = iovstack;
1055 struct iov_iter iter;
1056 ssize_t ret;
1057 io_fn_t fn;
1058 iter_fn_t iter_fn;
1059
1060 ret = compat_import_iovec(type, uvector, nr_segs,
1061 UIO_FASTIOV, &iov, &iter);
1062 if (ret < 0)
1063 return ret;
1064
1065 tot_len = iov_iter_count(&iter);
1066 if (!tot_len)
1067 goto out;
1068 ret = rw_verify_area(type, file, pos, tot_len);
1069 if (ret < 0)
1070 goto out;
1071
1072 if (type == READ) {
1073 fn = file->f_op->read;
1074 iter_fn = file->f_op->read_iter;
1075 } else {
1076 fn = (io_fn_t)file->f_op->write;
1077 iter_fn = file->f_op->write_iter;
1078 file_start_write(file);
1079 }
1080
1081 if (iter_fn)
1082 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
1083 else
1084 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
1085
1086 if (type != READ)
1087 file_end_write(file);
1088
1089 out:
1090 kfree(iov);
1091 if ((ret + (type == READ)) > 0) {
1092 if (type == READ)
1093 fsnotify_access(file);
1094 else
1095 fsnotify_modify(file);
1096 }
1097 return ret;
1098 }
1099
1100 static size_t compat_readv(struct file *file,
1101 const struct compat_iovec __user *vec,
1102 unsigned long vlen, loff_t *pos, int flags)
1103 {
1104 ssize_t ret = -EBADF;
1105
1106 if (!(file->f_mode & FMODE_READ))
1107 goto out;
1108
1109 ret = -EINVAL;
1110 if (!(file->f_mode & FMODE_CAN_READ))
1111 goto out;
1112
1113 ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
1114
1115 out:
1116 if (ret > 0)
1117 add_rchar(current, ret);
1118 inc_syscr(current);
1119 return ret;
1120 }
1121
1122 static size_t do_compat_readv(compat_ulong_t fd,
1123 const struct compat_iovec __user *vec,
1124 compat_ulong_t vlen, int flags)
1125 {
1126 struct fd f = fdget_pos(fd);
1127 ssize_t ret;
1128 loff_t pos;
1129
1130 if (!f.file)
1131 return -EBADF;
1132 pos = f.file->f_pos;
1133 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1134 if (ret >= 0)
1135 f.file->f_pos = pos;
1136 fdput_pos(f);
1137 return ret;
1138
1139 }
1140
1141 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1142 const struct compat_iovec __user *,vec,
1143 compat_ulong_t, vlen)
1144 {
1145 return do_compat_readv(fd, vec, vlen, 0);
1146 }
1147
1148 static long do_compat_preadv64(unsigned long fd,
1149 const struct compat_iovec __user *vec,
1150 unsigned long vlen, loff_t pos, int flags)
1151 {
1152 struct fd f;
1153 ssize_t ret;
1154
1155 if (pos < 0)
1156 return -EINVAL;
1157 f = fdget(fd);
1158 if (!f.file)
1159 return -EBADF;
1160 ret = -ESPIPE;
1161 if (f.file->f_mode & FMODE_PREAD)
1162 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1163 fdput(f);
1164 return ret;
1165 }
1166
1167 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1168 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1169 const struct compat_iovec __user *,vec,
1170 unsigned long, vlen, loff_t, pos)
1171 {
1172 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1173 }
1174 #endif
1175
1176 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1177 const struct compat_iovec __user *,vec,
1178 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1179 {
1180 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1181
1182 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1183 }
1184
1185 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
1186 const struct compat_iovec __user *,vec,
1187 compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
1188 int, flags)
1189 {
1190 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1191
1192 if (pos == -1)
1193 return do_compat_readv(fd, vec, vlen, flags);
1194
1195 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1196 }
1197
1198 static size_t compat_writev(struct file *file,
1199 const struct compat_iovec __user *vec,
1200 unsigned long vlen, loff_t *pos, int flags)
1201 {
1202 ssize_t ret = -EBADF;
1203
1204 if (!(file->f_mode & FMODE_WRITE))
1205 goto out;
1206
1207 ret = -EINVAL;
1208 if (!(file->f_mode & FMODE_CAN_WRITE))
1209 goto out;
1210
1211 ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, 0);
1212
1213 out:
1214 if (ret > 0)
1215 add_wchar(current, ret);
1216 inc_syscw(current);
1217 return ret;
1218 }
1219
1220 static size_t do_compat_writev(compat_ulong_t fd,
1221 const struct compat_iovec __user* vec,
1222 compat_ulong_t vlen, int flags)
1223 {
1224 struct fd f = fdget_pos(fd);
1225 ssize_t ret;
1226 loff_t pos;
1227
1228 if (!f.file)
1229 return -EBADF;
1230 pos = f.file->f_pos;
1231 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1232 if (ret >= 0)
1233 f.file->f_pos = pos;
1234 fdput_pos(f);
1235 return ret;
1236 }
1237
1238 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1239 const struct compat_iovec __user *, vec,
1240 compat_ulong_t, vlen)
1241 {
1242 return do_compat_writev(fd, vec, vlen, 0);
1243 }
1244
1245 static long do_compat_pwritev64(unsigned long fd,
1246 const struct compat_iovec __user *vec,
1247 unsigned long vlen, loff_t pos, int flags)
1248 {
1249 struct fd f;
1250 ssize_t ret;
1251
1252 if (pos < 0)
1253 return -EINVAL;
1254 f = fdget(fd);
1255 if (!f.file)
1256 return -EBADF;
1257 ret = -ESPIPE;
1258 if (f.file->f_mode & FMODE_PWRITE)
1259 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1260 fdput(f);
1261 return ret;
1262 }
1263
1264 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1265 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1266 const struct compat_iovec __user *,vec,
1267 unsigned long, vlen, loff_t, pos)
1268 {
1269 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1270 }
1271 #endif
1272
1273 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1274 const struct compat_iovec __user *,vec,
1275 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1276 {
1277 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1278
1279 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1280 }
1281
1282 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
1283 const struct compat_iovec __user *,vec,
1284 compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
1285 {
1286 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1287
1288 if (pos == -1)
1289 return do_compat_writev(fd, vec, vlen, flags);
1290
1291 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1292 }
1293
1294 #endif
1295
1296 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1297 size_t count, loff_t max)
1298 {
1299 struct fd in, out;
1300 struct inode *in_inode, *out_inode;
1301 loff_t pos;
1302 loff_t out_pos;
1303 ssize_t retval;
1304 int fl;
1305
1306 /*
1307 * Get input file, and verify that it is ok..
1308 */
1309 retval = -EBADF;
1310 in = fdget(in_fd);
1311 if (!in.file)
1312 goto out;
1313 if (!(in.file->f_mode & FMODE_READ))
1314 goto fput_in;
1315 retval = -ESPIPE;
1316 if (!ppos) {
1317 pos = in.file->f_pos;
1318 } else {
1319 pos = *ppos;
1320 if (!(in.file->f_mode & FMODE_PREAD))
1321 goto fput_in;
1322 }
1323 retval = rw_verify_area(READ, in.file, &pos, count);
1324 if (retval < 0)
1325 goto fput_in;
1326 count = retval;
1327
1328 /*
1329 * Get output file, and verify that it is ok..
1330 */
1331 retval = -EBADF;
1332 out = fdget(out_fd);
1333 if (!out.file)
1334 goto fput_in;
1335 if (!(out.file->f_mode & FMODE_WRITE))
1336 goto fput_out;
1337 retval = -EINVAL;
1338 in_inode = file_inode(in.file);
1339 out_inode = file_inode(out.file);
1340 out_pos = out.file->f_pos;
1341 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1342 if (retval < 0)
1343 goto fput_out;
1344 count = retval;
1345
1346 if (!max)
1347 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1348
1349 if (unlikely(pos + count > max)) {
1350 retval = -EOVERFLOW;
1351 if (pos >= max)
1352 goto fput_out;
1353 count = max - pos;
1354 }
1355
1356 fl = 0;
1357 #if 0
1358 /*
1359 * We need to debate whether we can enable this or not. The
1360 * man page documents EAGAIN return for the output at least,
1361 * and the application is arguably buggy if it doesn't expect
1362 * EAGAIN on a non-blocking file descriptor.
1363 */
1364 if (in.file->f_flags & O_NONBLOCK)
1365 fl = SPLICE_F_NONBLOCK;
1366 #endif
1367 file_start_write(out.file);
1368 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1369 file_end_write(out.file);
1370
1371 if (retval > 0) {
1372 add_rchar(current, retval);
1373 add_wchar(current, retval);
1374 fsnotify_access(in.file);
1375 fsnotify_modify(out.file);
1376 out.file->f_pos = out_pos;
1377 if (ppos)
1378 *ppos = pos;
1379 else
1380 in.file->f_pos = pos;
1381 }
1382
1383 inc_syscr(current);
1384 inc_syscw(current);
1385 if (pos > max)
1386 retval = -EOVERFLOW;
1387
1388 fput_out:
1389 fdput(out);
1390 fput_in:
1391 fdput(in);
1392 out:
1393 return retval;
1394 }
1395
1396 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1397 {
1398 loff_t pos;
1399 off_t off;
1400 ssize_t ret;
1401
1402 if (offset) {
1403 if (unlikely(get_user(off, offset)))
1404 return -EFAULT;
1405 pos = off;
1406 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1407 if (unlikely(put_user(pos, offset)))
1408 return -EFAULT;
1409 return ret;
1410 }
1411
1412 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1413 }
1414
1415 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1416 {
1417 loff_t pos;
1418 ssize_t ret;
1419
1420 if (offset) {
1421 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1422 return -EFAULT;
1423 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1424 if (unlikely(put_user(pos, offset)))
1425 return -EFAULT;
1426 return ret;
1427 }
1428
1429 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1430 }
1431
1432 #ifdef CONFIG_COMPAT
1433 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1434 compat_off_t __user *, offset, compat_size_t, count)
1435 {
1436 loff_t pos;
1437 off_t off;
1438 ssize_t ret;
1439
1440 if (offset) {
1441 if (unlikely(get_user(off, offset)))
1442 return -EFAULT;
1443 pos = off;
1444 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1445 if (unlikely(put_user(pos, offset)))
1446 return -EFAULT;
1447 return ret;
1448 }
1449
1450 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1451 }
1452
1453 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1454 compat_loff_t __user *, offset, compat_size_t, count)
1455 {
1456 loff_t pos;
1457 ssize_t ret;
1458
1459 if (offset) {
1460 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1461 return -EFAULT;
1462 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1463 if (unlikely(put_user(pos, offset)))
1464 return -EFAULT;
1465 return ret;
1466 }
1467
1468 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1469 }
1470 #endif
1471
1472 /*
1473 * copy_file_range() differs from regular file read and write in that it
1474 * specifically allows return partial success. When it does so is up to
1475 * the copy_file_range method.
1476 */
1477 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
1478 struct file *file_out, loff_t pos_out,
1479 size_t len, unsigned int flags)
1480 {
1481 struct inode *inode_in = file_inode(file_in);
1482 struct inode *inode_out = file_inode(file_out);
1483 ssize_t ret;
1484
1485 if (flags != 0)
1486 return -EINVAL;
1487
1488 /* copy_file_range allows full ssize_t len, ignoring MAX_RW_COUNT */
1489 ret = rw_verify_area(READ, file_in, &pos_in, len);
1490 if (ret >= 0)
1491 ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1492 if (ret < 0)
1493 return ret;
1494
1495 if (!(file_in->f_mode & FMODE_READ) ||
1496 !(file_out->f_mode & FMODE_WRITE) ||
1497 (file_out->f_flags & O_APPEND))
1498 return -EBADF;
1499
1500 /* this could be relaxed once a method supports cross-fs copies */
1501 if (inode_in->i_sb != inode_out->i_sb)
1502 return -EXDEV;
1503
1504 if (len == 0)
1505 return 0;
1506
1507 ret = mnt_want_write_file(file_out);
1508 if (ret)
1509 return ret;
1510
1511 ret = -EOPNOTSUPP;
1512 if (file_out->f_op->copy_file_range)
1513 ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
1514 pos_out, len, flags);
1515 if (ret == -EOPNOTSUPP)
1516 ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1517 len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
1518
1519 if (ret > 0) {
1520 fsnotify_access(file_in);
1521 add_rchar(current, ret);
1522 fsnotify_modify(file_out);
1523 add_wchar(current, ret);
1524 }
1525 inc_syscr(current);
1526 inc_syscw(current);
1527
1528 mnt_drop_write_file(file_out);
1529
1530 return ret;
1531 }
1532 EXPORT_SYMBOL(vfs_copy_file_range);
1533
1534 SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
1535 int, fd_out, loff_t __user *, off_out,
1536 size_t, len, unsigned int, flags)
1537 {
1538 loff_t pos_in;
1539 loff_t pos_out;
1540 struct fd f_in;
1541 struct fd f_out;
1542 ssize_t ret = -EBADF;
1543
1544 f_in = fdget(fd_in);
1545 if (!f_in.file)
1546 goto out2;
1547
1548 f_out = fdget(fd_out);
1549 if (!f_out.file)
1550 goto out1;
1551
1552 ret = -EFAULT;
1553 if (off_in) {
1554 if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
1555 goto out;
1556 } else {
1557 pos_in = f_in.file->f_pos;
1558 }
1559
1560 if (off_out) {
1561 if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
1562 goto out;
1563 } else {
1564 pos_out = f_out.file->f_pos;
1565 }
1566
1567 ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
1568 flags);
1569 if (ret > 0) {
1570 pos_in += ret;
1571 pos_out += ret;
1572
1573 if (off_in) {
1574 if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
1575 ret = -EFAULT;
1576 } else {
1577 f_in.file->f_pos = pos_in;
1578 }
1579
1580 if (off_out) {
1581 if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
1582 ret = -EFAULT;
1583 } else {
1584 f_out.file->f_pos = pos_out;
1585 }
1586 }
1587
1588 out:
1589 fdput(f_out);
1590 out1:
1591 fdput(f_in);
1592 out2:
1593 return ret;
1594 }
1595
1596 static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
1597 {
1598 struct inode *inode = file_inode(file);
1599
1600 if (unlikely(pos < 0))
1601 return -EINVAL;
1602
1603 if (unlikely((loff_t) (pos + len) < 0))
1604 return -EINVAL;
1605
1606 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
1607 loff_t end = len ? pos + len - 1 : OFFSET_MAX;
1608 int retval;
1609
1610 retval = locks_mandatory_area(inode, file, pos, end,
1611 write ? F_WRLCK : F_RDLCK);
1612 if (retval < 0)
1613 return retval;
1614 }
1615
1616 return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
1617 }
1618
1619 int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1620 struct file *file_out, loff_t pos_out, u64 len)
1621 {
1622 struct inode *inode_in = file_inode(file_in);
1623 struct inode *inode_out = file_inode(file_out);
1624 int ret;
1625
1626 if (inode_in->i_sb != inode_out->i_sb ||
1627 file_in->f_path.mnt != file_out->f_path.mnt)
1628 return -EXDEV;
1629
1630 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1631 return -EISDIR;
1632 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1633 return -EINVAL;
1634
1635 if (!(file_in->f_mode & FMODE_READ) ||
1636 !(file_out->f_mode & FMODE_WRITE) ||
1637 (file_out->f_flags & O_APPEND))
1638 return -EBADF;
1639
1640 if (!file_in->f_op->clone_file_range)
1641 return -EOPNOTSUPP;
1642
1643 ret = clone_verify_area(file_in, pos_in, len, false);
1644 if (ret)
1645 return ret;
1646
1647 ret = clone_verify_area(file_out, pos_out, len, true);
1648 if (ret)
1649 return ret;
1650
1651 if (pos_in + len > i_size_read(inode_in))
1652 return -EINVAL;
1653
1654 ret = mnt_want_write_file(file_out);
1655 if (ret)
1656 return ret;
1657
1658 ret = file_in->f_op->clone_file_range(file_in, pos_in,
1659 file_out, pos_out, len);
1660 if (!ret) {
1661 fsnotify_access(file_in);
1662 fsnotify_modify(file_out);
1663 }
1664
1665 mnt_drop_write_file(file_out);
1666 return ret;
1667 }
1668 EXPORT_SYMBOL(vfs_clone_file_range);
1669
1670 int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
1671 {
1672 struct file_dedupe_range_info *info;
1673 struct inode *src = file_inode(file);
1674 u64 off;
1675 u64 len;
1676 int i;
1677 int ret;
1678 bool is_admin = capable(CAP_SYS_ADMIN);
1679 u16 count = same->dest_count;
1680 struct file *dst_file;
1681 loff_t dst_off;
1682 ssize_t deduped;
1683
1684 if (!(file->f_mode & FMODE_READ))
1685 return -EINVAL;
1686
1687 if (same->reserved1 || same->reserved2)
1688 return -EINVAL;
1689
1690 off = same->src_offset;
1691 len = same->src_length;
1692
1693 ret = -EISDIR;
1694 if (S_ISDIR(src->i_mode))
1695 goto out;
1696
1697 ret = -EINVAL;
1698 if (!S_ISREG(src->i_mode))
1699 goto out;
1700
1701 ret = clone_verify_area(file, off, len, false);
1702 if (ret < 0)
1703 goto out;
1704 ret = 0;
1705
1706 /* pre-format output fields to sane values */
1707 for (i = 0; i < count; i++) {
1708 same->info[i].bytes_deduped = 0ULL;
1709 same->info[i].status = FILE_DEDUPE_RANGE_SAME;
1710 }
1711
1712 for (i = 0, info = same->info; i < count; i++, info++) {
1713 struct inode *dst;
1714 struct fd dst_fd = fdget(info->dest_fd);
1715
1716 dst_file = dst_fd.file;
1717 if (!dst_file) {
1718 info->status = -EBADF;
1719 goto next_loop;
1720 }
1721 dst = file_inode(dst_file);
1722
1723 ret = mnt_want_write_file(dst_file);
1724 if (ret) {
1725 info->status = ret;
1726 goto next_loop;
1727 }
1728
1729 dst_off = info->dest_offset;
1730 ret = clone_verify_area(dst_file, dst_off, len, true);
1731 if (ret < 0) {
1732 info->status = ret;
1733 goto next_file;
1734 }
1735 ret = 0;
1736
1737 if (info->reserved) {
1738 info->status = -EINVAL;
1739 } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
1740 info->status = -EINVAL;
1741 } else if (file->f_path.mnt != dst_file->f_path.mnt) {
1742 info->status = -EXDEV;
1743 } else if (S_ISDIR(dst->i_mode)) {
1744 info->status = -EISDIR;
1745 } else if (dst_file->f_op->dedupe_file_range == NULL) {
1746 info->status = -EINVAL;
1747 } else {
1748 deduped = dst_file->f_op->dedupe_file_range(file, off,
1749 len, dst_file,
1750 info->dest_offset);
1751 if (deduped == -EBADE)
1752 info->status = FILE_DEDUPE_RANGE_DIFFERS;
1753 else if (deduped < 0)
1754 info->status = deduped;
1755 else
1756 info->bytes_deduped += deduped;
1757 }
1758
1759 next_file:
1760 mnt_drop_write_file(dst_file);
1761 next_loop:
1762 fdput(dst_fd);
1763
1764 if (fatal_signal_pending(current))
1765 goto out;
1766 }
1767
1768 out:
1769 return ret;
1770 }
1771 EXPORT_SYMBOL(vfs_dedupe_file_range);
Linux kernel - Deliverables
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