Commit | Line | Data |
---|---|---|
1da177e4 LT |
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/smp_lock.h> | |
13 | #include <linux/dnotify.h> | |
14 | #include <linux/security.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/syscalls.h> | |
17 | ||
18 | #include <asm/uaccess.h> | |
19 | #include <asm/unistd.h> | |
20 | ||
21 | struct file_operations generic_ro_fops = { | |
22 | .llseek = generic_file_llseek, | |
23 | .read = generic_file_read, | |
24 | .mmap = generic_file_readonly_mmap, | |
25 | .sendfile = generic_file_sendfile, | |
26 | }; | |
27 | ||
28 | EXPORT_SYMBOL(generic_ro_fops); | |
29 | ||
30 | loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) | |
31 | { | |
32 | long long retval; | |
33 | struct inode *inode = file->f_mapping->host; | |
34 | ||
35 | down(&inode->i_sem); | |
36 | switch (origin) { | |
37 | case 2: | |
38 | offset += inode->i_size; | |
39 | break; | |
40 | case 1: | |
41 | offset += file->f_pos; | |
42 | } | |
43 | retval = -EINVAL; | |
44 | if (offset>=0 && offset<=inode->i_sb->s_maxbytes) { | |
45 | if (offset != file->f_pos) { | |
46 | file->f_pos = offset; | |
47 | file->f_version = 0; | |
48 | } | |
49 | retval = offset; | |
50 | } | |
51 | up(&inode->i_sem); | |
52 | return retval; | |
53 | } | |
54 | ||
55 | EXPORT_SYMBOL(generic_file_llseek); | |
56 | ||
57 | loff_t remote_llseek(struct file *file, loff_t offset, int origin) | |
58 | { | |
59 | long long retval; | |
60 | ||
61 | lock_kernel(); | |
62 | switch (origin) { | |
63 | case 2: | |
64 | offset += i_size_read(file->f_dentry->d_inode); | |
65 | break; | |
66 | case 1: | |
67 | offset += file->f_pos; | |
68 | } | |
69 | retval = -EINVAL; | |
70 | if (offset>=0 && offset<=file->f_dentry->d_inode->i_sb->s_maxbytes) { | |
71 | if (offset != file->f_pos) { | |
72 | file->f_pos = offset; | |
73 | file->f_version = 0; | |
74 | } | |
75 | retval = offset; | |
76 | } | |
77 | unlock_kernel(); | |
78 | return retval; | |
79 | } | |
80 | EXPORT_SYMBOL(remote_llseek); | |
81 | ||
82 | loff_t no_llseek(struct file *file, loff_t offset, int origin) | |
83 | { | |
84 | return -ESPIPE; | |
85 | } | |
86 | EXPORT_SYMBOL(no_llseek); | |
87 | ||
88 | loff_t default_llseek(struct file *file, loff_t offset, int origin) | |
89 | { | |
90 | long long retval; | |
91 | ||
92 | lock_kernel(); | |
93 | switch (origin) { | |
94 | case 2: | |
95 | offset += i_size_read(file->f_dentry->d_inode); | |
96 | break; | |
97 | case 1: | |
98 | offset += file->f_pos; | |
99 | } | |
100 | retval = -EINVAL; | |
101 | if (offset >= 0) { | |
102 | if (offset != file->f_pos) { | |
103 | file->f_pos = offset; | |
104 | file->f_version = 0; | |
105 | } | |
106 | retval = offset; | |
107 | } | |
108 | unlock_kernel(); | |
109 | return retval; | |
110 | } | |
111 | EXPORT_SYMBOL(default_llseek); | |
112 | ||
113 | loff_t vfs_llseek(struct file *file, loff_t offset, int origin) | |
114 | { | |
115 | loff_t (*fn)(struct file *, loff_t, int); | |
116 | ||
117 | fn = no_llseek; | |
118 | if (file->f_mode & FMODE_LSEEK) { | |
119 | fn = default_llseek; | |
120 | if (file->f_op && file->f_op->llseek) | |
121 | fn = file->f_op->llseek; | |
122 | } | |
123 | return fn(file, offset, origin); | |
124 | } | |
125 | EXPORT_SYMBOL(vfs_llseek); | |
126 | ||
127 | asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin) | |
128 | { | |
129 | off_t retval; | |
130 | struct file * file; | |
131 | int fput_needed; | |
132 | ||
133 | retval = -EBADF; | |
134 | file = fget_light(fd, &fput_needed); | |
135 | if (!file) | |
136 | goto bad; | |
137 | ||
138 | retval = -EINVAL; | |
139 | if (origin <= 2) { | |
140 | loff_t res = vfs_llseek(file, offset, origin); | |
141 | retval = res; | |
142 | if (res != (loff_t)retval) | |
143 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
144 | } | |
145 | fput_light(file, fput_needed); | |
146 | bad: | |
147 | return retval; | |
148 | } | |
149 | ||
150 | #ifdef __ARCH_WANT_SYS_LLSEEK | |
151 | asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high, | |
152 | unsigned long offset_low, loff_t __user * result, | |
153 | unsigned int origin) | |
154 | { | |
155 | int retval; | |
156 | struct file * file; | |
157 | loff_t offset; | |
158 | int fput_needed; | |
159 | ||
160 | retval = -EBADF; | |
161 | file = fget_light(fd, &fput_needed); | |
162 | if (!file) | |
163 | goto bad; | |
164 | ||
165 | retval = -EINVAL; | |
166 | if (origin > 2) | |
167 | goto out_putf; | |
168 | ||
169 | offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, | |
170 | origin); | |
171 | ||
172 | retval = (int)offset; | |
173 | if (offset >= 0) { | |
174 | retval = -EFAULT; | |
175 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
176 | retval = 0; | |
177 | } | |
178 | out_putf: | |
179 | fput_light(file, fput_needed); | |
180 | bad: | |
181 | return retval; | |
182 | } | |
183 | #endif | |
184 | ||
185 | ||
186 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) | |
187 | { | |
188 | struct inode *inode; | |
189 | loff_t pos; | |
190 | ||
191 | if (unlikely(count > file->f_maxcount)) | |
192 | goto Einval; | |
193 | pos = *ppos; | |
194 | if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) | |
195 | goto Einval; | |
196 | ||
197 | inode = file->f_dentry->d_inode; | |
198 | if (inode->i_flock && MANDATORY_LOCK(inode)) | |
199 | return locks_mandatory_area(read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, inode, file, pos, count); | |
200 | return 0; | |
201 | ||
202 | Einval: | |
203 | return -EINVAL; | |
204 | } | |
205 | ||
206 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) | |
207 | { | |
208 | struct kiocb kiocb; | |
209 | ssize_t ret; | |
210 | ||
211 | init_sync_kiocb(&kiocb, filp); | |
212 | kiocb.ki_pos = *ppos; | |
213 | ret = filp->f_op->aio_read(&kiocb, buf, len, kiocb.ki_pos); | |
214 | if (-EIOCBQUEUED == ret) | |
215 | ret = wait_on_sync_kiocb(&kiocb); | |
216 | *ppos = kiocb.ki_pos; | |
217 | return ret; | |
218 | } | |
219 | ||
220 | EXPORT_SYMBOL(do_sync_read); | |
221 | ||
222 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
223 | { | |
224 | ssize_t ret; | |
225 | ||
226 | if (!(file->f_mode & FMODE_READ)) | |
227 | return -EBADF; | |
228 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
229 | return -EINVAL; | |
230 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
231 | return -EFAULT; | |
232 | ||
233 | ret = rw_verify_area(READ, file, pos, count); | |
234 | if (!ret) { | |
235 | ret = security_file_permission (file, MAY_READ); | |
236 | if (!ret) { | |
237 | if (file->f_op->read) | |
238 | ret = file->f_op->read(file, buf, count, pos); | |
239 | else | |
240 | ret = do_sync_read(file, buf, count, pos); | |
241 | if (ret > 0) { | |
242 | dnotify_parent(file->f_dentry, DN_ACCESS); | |
243 | current->rchar += ret; | |
244 | } | |
245 | current->syscr++; | |
246 | } | |
247 | } | |
248 | ||
249 | return ret; | |
250 | } | |
251 | ||
252 | EXPORT_SYMBOL(vfs_read); | |
253 | ||
254 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
255 | { | |
256 | struct kiocb kiocb; | |
257 | ssize_t ret; | |
258 | ||
259 | init_sync_kiocb(&kiocb, filp); | |
260 | kiocb.ki_pos = *ppos; | |
261 | ret = filp->f_op->aio_write(&kiocb, buf, len, kiocb.ki_pos); | |
262 | if (-EIOCBQUEUED == ret) | |
263 | ret = wait_on_sync_kiocb(&kiocb); | |
264 | *ppos = kiocb.ki_pos; | |
265 | return ret; | |
266 | } | |
267 | ||
268 | EXPORT_SYMBOL(do_sync_write); | |
269 | ||
270 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) | |
271 | { | |
272 | ssize_t ret; | |
273 | ||
274 | if (!(file->f_mode & FMODE_WRITE)) | |
275 | return -EBADF; | |
276 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
277 | return -EINVAL; | |
278 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
279 | return -EFAULT; | |
280 | ||
281 | ret = rw_verify_area(WRITE, file, pos, count); | |
282 | if (!ret) { | |
283 | ret = security_file_permission (file, MAY_WRITE); | |
284 | if (!ret) { | |
285 | if (file->f_op->write) | |
286 | ret = file->f_op->write(file, buf, count, pos); | |
287 | else | |
288 | ret = do_sync_write(file, buf, count, pos); | |
289 | if (ret > 0) { | |
290 | dnotify_parent(file->f_dentry, DN_MODIFY); | |
291 | current->wchar += ret; | |
292 | } | |
293 | current->syscw++; | |
294 | } | |
295 | } | |
296 | ||
297 | return ret; | |
298 | } | |
299 | ||
300 | EXPORT_SYMBOL(vfs_write); | |
301 | ||
302 | static inline loff_t file_pos_read(struct file *file) | |
303 | { | |
304 | return file->f_pos; | |
305 | } | |
306 | ||
307 | static inline void file_pos_write(struct file *file, loff_t pos) | |
308 | { | |
309 | file->f_pos = pos; | |
310 | } | |
311 | ||
312 | asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count) | |
313 | { | |
314 | struct file *file; | |
315 | ssize_t ret = -EBADF; | |
316 | int fput_needed; | |
317 | ||
318 | file = fget_light(fd, &fput_needed); | |
319 | if (file) { | |
320 | loff_t pos = file_pos_read(file); | |
321 | ret = vfs_read(file, buf, count, &pos); | |
322 | file_pos_write(file, pos); | |
323 | fput_light(file, fput_needed); | |
324 | } | |
325 | ||
326 | return ret; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(sys_read); | |
329 | ||
330 | asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count) | |
331 | { | |
332 | struct file *file; | |
333 | ssize_t ret = -EBADF; | |
334 | int fput_needed; | |
335 | ||
336 | file = fget_light(fd, &fput_needed); | |
337 | if (file) { | |
338 | loff_t pos = file_pos_read(file); | |
339 | ret = vfs_write(file, buf, count, &pos); | |
340 | file_pos_write(file, pos); | |
341 | fput_light(file, fput_needed); | |
342 | } | |
343 | ||
344 | return ret; | |
345 | } | |
346 | ||
347 | asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf, | |
348 | size_t count, loff_t pos) | |
349 | { | |
350 | struct file *file; | |
351 | ssize_t ret = -EBADF; | |
352 | int fput_needed; | |
353 | ||
354 | if (pos < 0) | |
355 | return -EINVAL; | |
356 | ||
357 | file = fget_light(fd, &fput_needed); | |
358 | if (file) { | |
359 | ret = -ESPIPE; | |
360 | if (file->f_mode & FMODE_PREAD) | |
361 | ret = vfs_read(file, buf, count, &pos); | |
362 | fput_light(file, fput_needed); | |
363 | } | |
364 | ||
365 | return ret; | |
366 | } | |
367 | ||
368 | asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf, | |
369 | size_t count, loff_t pos) | |
370 | { | |
371 | struct file *file; | |
372 | ssize_t ret = -EBADF; | |
373 | int fput_needed; | |
374 | ||
375 | if (pos < 0) | |
376 | return -EINVAL; | |
377 | ||
378 | file = fget_light(fd, &fput_needed); | |
379 | if (file) { | |
380 | ret = -ESPIPE; | |
381 | if (file->f_mode & FMODE_PWRITE) | |
382 | ret = vfs_write(file, buf, count, &pos); | |
383 | fput_light(file, fput_needed); | |
384 | } | |
385 | ||
386 | return ret; | |
387 | } | |
388 | ||
389 | /* | |
390 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
391 | */ | |
392 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
393 | { | |
394 | unsigned long seg = 0; | |
395 | size_t len = 0; | |
396 | ||
397 | while (seg < nr_segs) { | |
398 | seg++; | |
399 | if (len + iov->iov_len >= to) { | |
400 | iov->iov_len = to - len; | |
401 | break; | |
402 | } | |
403 | len += iov->iov_len; | |
404 | iov++; | |
405 | } | |
406 | return seg; | |
407 | } | |
408 | ||
409 | EXPORT_SYMBOL(iov_shorten); | |
410 | ||
411 | /* A write operation does a read from user space and vice versa */ | |
412 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
413 | ||
414 | static ssize_t do_readv_writev(int type, struct file *file, | |
415 | const struct iovec __user * uvector, | |
416 | unsigned long nr_segs, loff_t *pos) | |
417 | { | |
418 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); | |
419 | typedef ssize_t (*iov_fn_t)(struct file *, const struct iovec *, unsigned long, loff_t *); | |
420 | ||
421 | size_t tot_len; | |
422 | struct iovec iovstack[UIO_FASTIOV]; | |
423 | struct iovec *iov=iovstack, *vector; | |
424 | ssize_t ret; | |
425 | int seg; | |
426 | io_fn_t fn; | |
427 | iov_fn_t fnv; | |
428 | ||
429 | /* | |
430 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
431 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
432 | * traditionally returned zero for zero segments, so... | |
433 | */ | |
434 | ret = 0; | |
435 | if (nr_segs == 0) | |
436 | goto out; | |
437 | ||
438 | /* | |
439 | * First get the "struct iovec" from user memory and | |
440 | * verify all the pointers | |
441 | */ | |
442 | ret = -EINVAL; | |
443 | if ((nr_segs > UIO_MAXIOV) || (nr_segs <= 0)) | |
444 | goto out; | |
445 | if (!file->f_op) | |
446 | goto out; | |
447 | if (nr_segs > UIO_FASTIOV) { | |
448 | ret = -ENOMEM; | |
449 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
450 | if (!iov) | |
451 | goto out; | |
452 | } | |
453 | ret = -EFAULT; | |
454 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) | |
455 | goto out; | |
456 | ||
457 | /* | |
458 | * Single unix specification: | |
459 | * We should -EINVAL if an element length is not >= 0 and fitting an | |
460 | * ssize_t. The total length is fitting an ssize_t | |
461 | * | |
462 | * Be careful here because iov_len is a size_t not an ssize_t | |
463 | */ | |
464 | tot_len = 0; | |
465 | ret = -EINVAL; | |
466 | for (seg = 0; seg < nr_segs; seg++) { | |
467 | void __user *buf = iov[seg].iov_base; | |
468 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
469 | ||
1da177e4 LT |
470 | if (len < 0) /* size_t not fitting an ssize_t .. */ |
471 | goto out; | |
1f08ad02 DH |
472 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) |
473 | goto Efault; | |
1da177e4 LT |
474 | tot_len += len; |
475 | if ((ssize_t)tot_len < 0) /* maths overflow on the ssize_t */ | |
476 | goto out; | |
477 | } | |
478 | if (tot_len == 0) { | |
479 | ret = 0; | |
480 | goto out; | |
481 | } | |
482 | ||
483 | ret = rw_verify_area(type, file, pos, tot_len); | |
484 | if (ret) | |
485 | goto out; | |
486 | ||
487 | fnv = NULL; | |
488 | if (type == READ) { | |
489 | fn = file->f_op->read; | |
490 | fnv = file->f_op->readv; | |
491 | } else { | |
492 | fn = (io_fn_t)file->f_op->write; | |
493 | fnv = file->f_op->writev; | |
494 | } | |
495 | if (fnv) { | |
496 | ret = fnv(file, iov, nr_segs, pos); | |
497 | goto out; | |
498 | } | |
499 | ||
500 | /* Do it by hand, with file-ops */ | |
501 | ret = 0; | |
502 | vector = iov; | |
503 | while (nr_segs > 0) { | |
504 | void __user * base; | |
505 | size_t len; | |
506 | ssize_t nr; | |
507 | ||
508 | base = vector->iov_base; | |
509 | len = vector->iov_len; | |
510 | vector++; | |
511 | nr_segs--; | |
512 | ||
513 | nr = fn(file, base, len, pos); | |
514 | ||
515 | if (nr < 0) { | |
516 | if (!ret) ret = nr; | |
517 | break; | |
518 | } | |
519 | ret += nr; | |
520 | if (nr != len) | |
521 | break; | |
522 | } | |
523 | out: | |
524 | if (iov != iovstack) | |
525 | kfree(iov); | |
526 | if ((ret + (type == READ)) > 0) | |
527 | dnotify_parent(file->f_dentry, | |
528 | (type == READ) ? DN_ACCESS : DN_MODIFY); | |
529 | return ret; | |
530 | Efault: | |
531 | ret = -EFAULT; | |
532 | goto out; | |
533 | } | |
534 | ||
535 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
536 | unsigned long vlen, loff_t *pos) | |
537 | { | |
538 | if (!(file->f_mode & FMODE_READ)) | |
539 | return -EBADF; | |
540 | if (!file->f_op || (!file->f_op->readv && !file->f_op->read)) | |
541 | return -EINVAL; | |
542 | ||
543 | return do_readv_writev(READ, file, vec, vlen, pos); | |
544 | } | |
545 | ||
546 | EXPORT_SYMBOL(vfs_readv); | |
547 | ||
548 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
549 | unsigned long vlen, loff_t *pos) | |
550 | { | |
551 | if (!(file->f_mode & FMODE_WRITE)) | |
552 | return -EBADF; | |
553 | if (!file->f_op || (!file->f_op->writev && !file->f_op->write)) | |
554 | return -EINVAL; | |
555 | ||
556 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
557 | } | |
558 | ||
559 | EXPORT_SYMBOL(vfs_writev); | |
560 | ||
561 | asmlinkage ssize_t | |
562 | sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
563 | { | |
564 | struct file *file; | |
565 | ssize_t ret = -EBADF; | |
566 | int fput_needed; | |
567 | ||
568 | file = fget_light(fd, &fput_needed); | |
569 | if (file) { | |
570 | loff_t pos = file_pos_read(file); | |
571 | ret = vfs_readv(file, vec, vlen, &pos); | |
572 | file_pos_write(file, pos); | |
573 | fput_light(file, fput_needed); | |
574 | } | |
575 | ||
576 | if (ret > 0) | |
577 | current->rchar += ret; | |
578 | current->syscr++; | |
579 | return ret; | |
580 | } | |
581 | ||
582 | asmlinkage ssize_t | |
583 | sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
584 | { | |
585 | struct file *file; | |
586 | ssize_t ret = -EBADF; | |
587 | int fput_needed; | |
588 | ||
589 | file = fget_light(fd, &fput_needed); | |
590 | if (file) { | |
591 | loff_t pos = file_pos_read(file); | |
592 | ret = vfs_writev(file, vec, vlen, &pos); | |
593 | file_pos_write(file, pos); | |
594 | fput_light(file, fput_needed); | |
595 | } | |
596 | ||
597 | if (ret > 0) | |
598 | current->wchar += ret; | |
599 | current->syscw++; | |
600 | return ret; | |
601 | } | |
602 | ||
603 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, | |
604 | size_t count, loff_t max) | |
605 | { | |
606 | struct file * in_file, * out_file; | |
607 | struct inode * in_inode, * out_inode; | |
608 | loff_t pos; | |
609 | ssize_t retval; | |
610 | int fput_needed_in, fput_needed_out; | |
611 | ||
612 | /* | |
613 | * Get input file, and verify that it is ok.. | |
614 | */ | |
615 | retval = -EBADF; | |
616 | in_file = fget_light(in_fd, &fput_needed_in); | |
617 | if (!in_file) | |
618 | goto out; | |
619 | if (!(in_file->f_mode & FMODE_READ)) | |
620 | goto fput_in; | |
621 | retval = -EINVAL; | |
622 | in_inode = in_file->f_dentry->d_inode; | |
623 | if (!in_inode) | |
624 | goto fput_in; | |
625 | if (!in_file->f_op || !in_file->f_op->sendfile) | |
626 | goto fput_in; | |
627 | retval = -ESPIPE; | |
628 | if (!ppos) | |
629 | ppos = &in_file->f_pos; | |
630 | else | |
631 | if (!(in_file->f_mode & FMODE_PREAD)) | |
632 | goto fput_in; | |
633 | retval = rw_verify_area(READ, in_file, ppos, count); | |
634 | if (retval) | |
635 | goto fput_in; | |
636 | ||
637 | retval = security_file_permission (in_file, MAY_READ); | |
638 | if (retval) | |
639 | goto fput_in; | |
640 | ||
641 | /* | |
642 | * Get output file, and verify that it is ok.. | |
643 | */ | |
644 | retval = -EBADF; | |
645 | out_file = fget_light(out_fd, &fput_needed_out); | |
646 | if (!out_file) | |
647 | goto fput_in; | |
648 | if (!(out_file->f_mode & FMODE_WRITE)) | |
649 | goto fput_out; | |
650 | retval = -EINVAL; | |
651 | if (!out_file->f_op || !out_file->f_op->sendpage) | |
652 | goto fput_out; | |
653 | out_inode = out_file->f_dentry->d_inode; | |
654 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); | |
655 | if (retval) | |
656 | goto fput_out; | |
657 | ||
658 | retval = security_file_permission (out_file, MAY_WRITE); | |
659 | if (retval) | |
660 | goto fput_out; | |
661 | ||
662 | if (!max) | |
663 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
664 | ||
665 | pos = *ppos; | |
666 | retval = -EINVAL; | |
667 | if (unlikely(pos < 0)) | |
668 | goto fput_out; | |
669 | if (unlikely(pos + count > max)) { | |
670 | retval = -EOVERFLOW; | |
671 | if (pos >= max) | |
672 | goto fput_out; | |
673 | count = max - pos; | |
674 | } | |
675 | ||
676 | retval = in_file->f_op->sendfile(in_file, ppos, count, file_send_actor, out_file); | |
677 | ||
678 | if (retval > 0) { | |
679 | current->rchar += retval; | |
680 | current->wchar += retval; | |
681 | } | |
682 | current->syscr++; | |
683 | current->syscw++; | |
684 | ||
685 | if (*ppos > max) | |
686 | retval = -EOVERFLOW; | |
687 | ||
688 | fput_out: | |
689 | fput_light(out_file, fput_needed_out); | |
690 | fput_in: | |
691 | fput_light(in_file, fput_needed_in); | |
692 | out: | |
693 | return retval; | |
694 | } | |
695 | ||
696 | asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count) | |
697 | { | |
698 | loff_t pos; | |
699 | off_t off; | |
700 | ssize_t ret; | |
701 | ||
702 | if (offset) { | |
703 | if (unlikely(get_user(off, offset))) | |
704 | return -EFAULT; | |
705 | pos = off; | |
706 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
707 | if (unlikely(put_user(pos, offset))) | |
708 | return -EFAULT; | |
709 | return ret; | |
710 | } | |
711 | ||
712 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
713 | } | |
714 | ||
715 | asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count) | |
716 | { | |
717 | loff_t pos; | |
718 | ssize_t ret; | |
719 | ||
720 | if (offset) { | |
721 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
722 | return -EFAULT; | |
723 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
724 | if (unlikely(put_user(pos, offset))) | |
725 | return -EFAULT; | |
726 | return ret; | |
727 | } | |
728 | ||
729 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
730 | } |