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> | |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 LT |
14 | #include <linux/security.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/syscalls.h> | |
e28cc715 | 17 | #include <linux/pagemap.h> |
1da177e4 LT |
18 | |
19 | #include <asm/uaccess.h> | |
20 | #include <asm/unistd.h> | |
21 | ||
4b6f5d20 | 22 | const struct file_operations generic_ro_fops = { |
1da177e4 LT |
23 | .llseek = generic_file_llseek, |
24 | .read = generic_file_read, | |
25 | .mmap = generic_file_readonly_mmap, | |
26 | .sendfile = generic_file_sendfile, | |
27 | }; | |
28 | ||
29 | EXPORT_SYMBOL(generic_ro_fops); | |
30 | ||
31 | loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) | |
32 | { | |
33 | long long retval; | |
34 | struct inode *inode = file->f_mapping->host; | |
35 | ||
1b1dcc1b | 36 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
37 | switch (origin) { |
38 | case 2: | |
39 | offset += inode->i_size; | |
40 | break; | |
41 | case 1: | |
42 | offset += file->f_pos; | |
43 | } | |
44 | retval = -EINVAL; | |
45 | if (offset>=0 && offset<=inode->i_sb->s_maxbytes) { | |
46 | if (offset != file->f_pos) { | |
47 | file->f_pos = offset; | |
48 | file->f_version = 0; | |
49 | } | |
50 | retval = offset; | |
51 | } | |
1b1dcc1b | 52 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
53 | return retval; |
54 | } | |
55 | ||
56 | EXPORT_SYMBOL(generic_file_llseek); | |
57 | ||
58 | loff_t remote_llseek(struct file *file, loff_t offset, int origin) | |
59 | { | |
60 | long long retval; | |
61 | ||
62 | lock_kernel(); | |
63 | switch (origin) { | |
64 | case 2: | |
65 | offset += i_size_read(file->f_dentry->d_inode); | |
66 | break; | |
67 | case 1: | |
68 | offset += file->f_pos; | |
69 | } | |
70 | retval = -EINVAL; | |
71 | if (offset>=0 && offset<=file->f_dentry->d_inode->i_sb->s_maxbytes) { | |
72 | if (offset != file->f_pos) { | |
73 | file->f_pos = offset; | |
74 | file->f_version = 0; | |
75 | } | |
76 | retval = offset; | |
77 | } | |
78 | unlock_kernel(); | |
79 | return retval; | |
80 | } | |
81 | EXPORT_SYMBOL(remote_llseek); | |
82 | ||
83 | loff_t no_llseek(struct file *file, loff_t offset, int origin) | |
84 | { | |
85 | return -ESPIPE; | |
86 | } | |
87 | EXPORT_SYMBOL(no_llseek); | |
88 | ||
89 | loff_t default_llseek(struct file *file, loff_t offset, int origin) | |
90 | { | |
91 | long long retval; | |
92 | ||
93 | lock_kernel(); | |
94 | switch (origin) { | |
95 | case 2: | |
96 | offset += i_size_read(file->f_dentry->d_inode); | |
97 | break; | |
98 | case 1: | |
99 | offset += file->f_pos; | |
100 | } | |
101 | retval = -EINVAL; | |
102 | if (offset >= 0) { | |
103 | if (offset != file->f_pos) { | |
104 | file->f_pos = offset; | |
105 | file->f_version = 0; | |
106 | } | |
107 | retval = offset; | |
108 | } | |
109 | unlock_kernel(); | |
110 | return retval; | |
111 | } | |
112 | EXPORT_SYMBOL(default_llseek); | |
113 | ||
114 | loff_t vfs_llseek(struct file *file, loff_t offset, int origin) | |
115 | { | |
116 | loff_t (*fn)(struct file *, loff_t, int); | |
117 | ||
118 | fn = no_llseek; | |
119 | if (file->f_mode & FMODE_LSEEK) { | |
120 | fn = default_llseek; | |
121 | if (file->f_op && file->f_op->llseek) | |
122 | fn = file->f_op->llseek; | |
123 | } | |
124 | return fn(file, offset, origin); | |
125 | } | |
126 | EXPORT_SYMBOL(vfs_llseek); | |
127 | ||
128 | asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin) | |
129 | { | |
130 | off_t retval; | |
131 | struct file * file; | |
132 | int fput_needed; | |
133 | ||
134 | retval = -EBADF; | |
135 | file = fget_light(fd, &fput_needed); | |
136 | if (!file) | |
137 | goto bad; | |
138 | ||
139 | retval = -EINVAL; | |
140 | if (origin <= 2) { | |
141 | loff_t res = vfs_llseek(file, offset, origin); | |
142 | retval = res; | |
143 | if (res != (loff_t)retval) | |
144 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
145 | } | |
146 | fput_light(file, fput_needed); | |
147 | bad: | |
148 | return retval; | |
149 | } | |
150 | ||
151 | #ifdef __ARCH_WANT_SYS_LLSEEK | |
152 | asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high, | |
153 | unsigned long offset_low, loff_t __user * result, | |
154 | unsigned int origin) | |
155 | { | |
156 | int retval; | |
157 | struct file * file; | |
158 | loff_t offset; | |
159 | int fput_needed; | |
160 | ||
161 | retval = -EBADF; | |
162 | file = fget_light(fd, &fput_needed); | |
163 | if (!file) | |
164 | goto bad; | |
165 | ||
166 | retval = -EINVAL; | |
167 | if (origin > 2) | |
168 | goto out_putf; | |
169 | ||
170 | offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, | |
171 | origin); | |
172 | ||
173 | retval = (int)offset; | |
174 | if (offset >= 0) { | |
175 | retval = -EFAULT; | |
176 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
177 | retval = 0; | |
178 | } | |
179 | out_putf: | |
180 | fput_light(file, fput_needed); | |
181 | bad: | |
182 | return retval; | |
183 | } | |
184 | #endif | |
185 | ||
e28cc715 LT |
186 | /* |
187 | * rw_verify_area doesn't like huge counts. We limit | |
188 | * them to something that fits in "int" so that others | |
189 | * won't have to do range checks all the time. | |
190 | */ | |
191 | #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK) | |
1da177e4 LT |
192 | |
193 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) | |
194 | { | |
195 | struct inode *inode; | |
196 | loff_t pos; | |
197 | ||
e28cc715 | 198 | if (unlikely((ssize_t) count < 0)) |
1da177e4 LT |
199 | goto Einval; |
200 | pos = *ppos; | |
201 | if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) | |
202 | goto Einval; | |
203 | ||
204 | inode = file->f_dentry->d_inode; | |
49570e9b | 205 | if (unlikely(inode->i_flock && MANDATORY_LOCK(inode))) { |
e28cc715 LT |
206 | int retval = locks_mandatory_area( |
207 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, | |
208 | inode, file, pos, count); | |
209 | if (retval < 0) | |
210 | return retval; | |
211 | } | |
212 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; | |
1da177e4 LT |
213 | |
214 | Einval: | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
63e68809 BL |
218 | static void wait_on_retry_sync_kiocb(struct kiocb *iocb) |
219 | { | |
220 | set_current_state(TASK_UNINTERRUPTIBLE); | |
221 | if (!kiocbIsKicked(iocb)) | |
222 | schedule(); | |
223 | else | |
224 | kiocbClearKicked(iocb); | |
225 | __set_current_state(TASK_RUNNING); | |
226 | } | |
227 | ||
1da177e4 LT |
228 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
229 | { | |
027445c3 | 230 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
231 | struct kiocb kiocb; |
232 | ssize_t ret; | |
233 | ||
234 | init_sync_kiocb(&kiocb, filp); | |
235 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
236 | kiocb.ki_left = len; |
237 | ||
238 | for (;;) { | |
239 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); | |
240 | if (ret != -EIOCBRETRY) | |
241 | break; | |
63e68809 | 242 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 243 | } |
63e68809 | 244 | |
1da177e4 LT |
245 | if (-EIOCBQUEUED == ret) |
246 | ret = wait_on_sync_kiocb(&kiocb); | |
247 | *ppos = kiocb.ki_pos; | |
248 | return ret; | |
249 | } | |
250 | ||
251 | EXPORT_SYMBOL(do_sync_read); | |
252 | ||
253 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
254 | { | |
255 | ssize_t ret; | |
256 | ||
257 | if (!(file->f_mode & FMODE_READ)) | |
258 | return -EBADF; | |
259 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
260 | return -EINVAL; | |
261 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
262 | return -EFAULT; | |
263 | ||
264 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
265 | if (ret >= 0) { |
266 | count = ret; | |
1da177e4 LT |
267 | ret = security_file_permission (file, MAY_READ); |
268 | if (!ret) { | |
269 | if (file->f_op->read) | |
270 | ret = file->f_op->read(file, buf, count, pos); | |
271 | else | |
272 | ret = do_sync_read(file, buf, count, pos); | |
273 | if (ret > 0) { | |
0eeca283 | 274 | fsnotify_access(file->f_dentry); |
1da177e4 LT |
275 | current->rchar += ret; |
276 | } | |
277 | current->syscr++; | |
278 | } | |
279 | } | |
280 | ||
281 | return ret; | |
282 | } | |
283 | ||
284 | EXPORT_SYMBOL(vfs_read); | |
285 | ||
286 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
287 | { | |
027445c3 | 288 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
289 | struct kiocb kiocb; |
290 | ssize_t ret; | |
291 | ||
292 | init_sync_kiocb(&kiocb, filp); | |
293 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
294 | kiocb.ki_left = len; |
295 | ||
296 | for (;;) { | |
297 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); | |
298 | if (ret != -EIOCBRETRY) | |
299 | break; | |
63e68809 | 300 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 301 | } |
63e68809 | 302 | |
1da177e4 LT |
303 | if (-EIOCBQUEUED == ret) |
304 | ret = wait_on_sync_kiocb(&kiocb); | |
305 | *ppos = kiocb.ki_pos; | |
306 | return ret; | |
307 | } | |
308 | ||
309 | EXPORT_SYMBOL(do_sync_write); | |
310 | ||
311 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) | |
312 | { | |
313 | ssize_t ret; | |
314 | ||
315 | if (!(file->f_mode & FMODE_WRITE)) | |
316 | return -EBADF; | |
317 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
318 | return -EINVAL; | |
319 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
320 | return -EFAULT; | |
321 | ||
322 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
323 | if (ret >= 0) { |
324 | count = ret; | |
1da177e4 LT |
325 | ret = security_file_permission (file, MAY_WRITE); |
326 | if (!ret) { | |
327 | if (file->f_op->write) | |
328 | ret = file->f_op->write(file, buf, count, pos); | |
329 | else | |
330 | ret = do_sync_write(file, buf, count, pos); | |
331 | if (ret > 0) { | |
0eeca283 | 332 | fsnotify_modify(file->f_dentry); |
1da177e4 LT |
333 | current->wchar += ret; |
334 | } | |
335 | current->syscw++; | |
336 | } | |
337 | } | |
338 | ||
339 | return ret; | |
340 | } | |
341 | ||
342 | EXPORT_SYMBOL(vfs_write); | |
343 | ||
344 | static inline loff_t file_pos_read(struct file *file) | |
345 | { | |
346 | return file->f_pos; | |
347 | } | |
348 | ||
349 | static inline void file_pos_write(struct file *file, loff_t pos) | |
350 | { | |
351 | file->f_pos = pos; | |
352 | } | |
353 | ||
354 | asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count) | |
355 | { | |
356 | struct file *file; | |
357 | ssize_t ret = -EBADF; | |
358 | int fput_needed; | |
359 | ||
360 | file = fget_light(fd, &fput_needed); | |
361 | if (file) { | |
362 | loff_t pos = file_pos_read(file); | |
363 | ret = vfs_read(file, buf, count, &pos); | |
364 | file_pos_write(file, pos); | |
365 | fput_light(file, fput_needed); | |
366 | } | |
367 | ||
368 | return ret; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(sys_read); | |
371 | ||
372 | asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count) | |
373 | { | |
374 | struct file *file; | |
375 | ssize_t ret = -EBADF; | |
376 | int fput_needed; | |
377 | ||
378 | file = fget_light(fd, &fput_needed); | |
379 | if (file) { | |
380 | loff_t pos = file_pos_read(file); | |
381 | ret = vfs_write(file, buf, count, &pos); | |
382 | file_pos_write(file, pos); | |
383 | fput_light(file, fput_needed); | |
384 | } | |
385 | ||
386 | return ret; | |
387 | } | |
388 | ||
389 | asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf, | |
390 | size_t count, loff_t pos) | |
391 | { | |
392 | struct file *file; | |
393 | ssize_t ret = -EBADF; | |
394 | int fput_needed; | |
395 | ||
396 | if (pos < 0) | |
397 | return -EINVAL; | |
398 | ||
399 | file = fget_light(fd, &fput_needed); | |
400 | if (file) { | |
401 | ret = -ESPIPE; | |
402 | if (file->f_mode & FMODE_PREAD) | |
403 | ret = vfs_read(file, buf, count, &pos); | |
404 | fput_light(file, fput_needed); | |
405 | } | |
406 | ||
407 | return ret; | |
408 | } | |
409 | ||
410 | asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf, | |
411 | size_t count, loff_t pos) | |
412 | { | |
413 | struct file *file; | |
414 | ssize_t ret = -EBADF; | |
415 | int fput_needed; | |
416 | ||
417 | if (pos < 0) | |
418 | return -EINVAL; | |
419 | ||
420 | file = fget_light(fd, &fput_needed); | |
421 | if (file) { | |
422 | ret = -ESPIPE; | |
423 | if (file->f_mode & FMODE_PWRITE) | |
424 | ret = vfs_write(file, buf, count, &pos); | |
425 | fput_light(file, fput_needed); | |
426 | } | |
427 | ||
428 | return ret; | |
429 | } | |
430 | ||
431 | /* | |
432 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
433 | */ | |
434 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
435 | { | |
436 | unsigned long seg = 0; | |
437 | size_t len = 0; | |
438 | ||
439 | while (seg < nr_segs) { | |
440 | seg++; | |
441 | if (len + iov->iov_len >= to) { | |
442 | iov->iov_len = to - len; | |
443 | break; | |
444 | } | |
445 | len += iov->iov_len; | |
446 | iov++; | |
447 | } | |
448 | return seg; | |
449 | } | |
450 | ||
69c3a5b8 | 451 | EXPORT_UNUSED_SYMBOL(iov_shorten); /* June 2006 */ |
1da177e4 LT |
452 | |
453 | /* A write operation does a read from user space and vice versa */ | |
454 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
455 | ||
456 | static ssize_t do_readv_writev(int type, struct file *file, | |
457 | const struct iovec __user * uvector, | |
458 | unsigned long nr_segs, loff_t *pos) | |
459 | { | |
460 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); | |
461 | typedef ssize_t (*iov_fn_t)(struct file *, const struct iovec *, unsigned long, loff_t *); | |
462 | ||
463 | size_t tot_len; | |
464 | struct iovec iovstack[UIO_FASTIOV]; | |
465 | struct iovec *iov=iovstack, *vector; | |
466 | ssize_t ret; | |
467 | int seg; | |
468 | io_fn_t fn; | |
469 | iov_fn_t fnv; | |
470 | ||
471 | /* | |
472 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
473 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
474 | * traditionally returned zero for zero segments, so... | |
475 | */ | |
476 | ret = 0; | |
477 | if (nr_segs == 0) | |
478 | goto out; | |
479 | ||
480 | /* | |
481 | * First get the "struct iovec" from user memory and | |
482 | * verify all the pointers | |
483 | */ | |
484 | ret = -EINVAL; | |
6cc6b122 | 485 | if (nr_segs > UIO_MAXIOV) |
1da177e4 LT |
486 | goto out; |
487 | if (!file->f_op) | |
488 | goto out; | |
489 | if (nr_segs > UIO_FASTIOV) { | |
490 | ret = -ENOMEM; | |
491 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
492 | if (!iov) | |
493 | goto out; | |
494 | } | |
495 | ret = -EFAULT; | |
496 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) | |
497 | goto out; | |
498 | ||
499 | /* | |
500 | * Single unix specification: | |
501 | * We should -EINVAL if an element length is not >= 0 and fitting an | |
502 | * ssize_t. The total length is fitting an ssize_t | |
503 | * | |
504 | * Be careful here because iov_len is a size_t not an ssize_t | |
505 | */ | |
506 | tot_len = 0; | |
507 | ret = -EINVAL; | |
508 | for (seg = 0; seg < nr_segs; seg++) { | |
509 | void __user *buf = iov[seg].iov_base; | |
510 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
511 | ||
1da177e4 LT |
512 | if (len < 0) /* size_t not fitting an ssize_t .. */ |
513 | goto out; | |
1f08ad02 DH |
514 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) |
515 | goto Efault; | |
1da177e4 LT |
516 | tot_len += len; |
517 | if ((ssize_t)tot_len < 0) /* maths overflow on the ssize_t */ | |
518 | goto out; | |
519 | } | |
520 | if (tot_len == 0) { | |
521 | ret = 0; | |
522 | goto out; | |
523 | } | |
524 | ||
525 | ret = rw_verify_area(type, file, pos, tot_len); | |
e28cc715 | 526 | if (ret < 0) |
411b67b4 KB |
527 | goto out; |
528 | ret = security_file_permission(file, type == READ ? MAY_READ : MAY_WRITE); | |
1da177e4 LT |
529 | if (ret) |
530 | goto out; | |
531 | ||
532 | fnv = NULL; | |
533 | if (type == READ) { | |
534 | fn = file->f_op->read; | |
535 | fnv = file->f_op->readv; | |
536 | } else { | |
537 | fn = (io_fn_t)file->f_op->write; | |
538 | fnv = file->f_op->writev; | |
539 | } | |
540 | if (fnv) { | |
541 | ret = fnv(file, iov, nr_segs, pos); | |
542 | goto out; | |
543 | } | |
544 | ||
545 | /* Do it by hand, with file-ops */ | |
546 | ret = 0; | |
547 | vector = iov; | |
548 | while (nr_segs > 0) { | |
549 | void __user * base; | |
550 | size_t len; | |
551 | ssize_t nr; | |
552 | ||
553 | base = vector->iov_base; | |
554 | len = vector->iov_len; | |
555 | vector++; | |
556 | nr_segs--; | |
557 | ||
558 | nr = fn(file, base, len, pos); | |
559 | ||
560 | if (nr < 0) { | |
561 | if (!ret) ret = nr; | |
562 | break; | |
563 | } | |
564 | ret += nr; | |
565 | if (nr != len) | |
566 | break; | |
567 | } | |
568 | out: | |
569 | if (iov != iovstack) | |
570 | kfree(iov); | |
0eeca283 RL |
571 | if ((ret + (type == READ)) > 0) { |
572 | if (type == READ) | |
573 | fsnotify_access(file->f_dentry); | |
574 | else | |
575 | fsnotify_modify(file->f_dentry); | |
576 | } | |
1da177e4 LT |
577 | return ret; |
578 | Efault: | |
579 | ret = -EFAULT; | |
580 | goto out; | |
581 | } | |
582 | ||
583 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
584 | unsigned long vlen, loff_t *pos) | |
585 | { | |
586 | if (!(file->f_mode & FMODE_READ)) | |
587 | return -EBADF; | |
588 | if (!file->f_op || (!file->f_op->readv && !file->f_op->read)) | |
589 | return -EINVAL; | |
590 | ||
591 | return do_readv_writev(READ, file, vec, vlen, pos); | |
592 | } | |
593 | ||
594 | EXPORT_SYMBOL(vfs_readv); | |
595 | ||
596 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
597 | unsigned long vlen, loff_t *pos) | |
598 | { | |
599 | if (!(file->f_mode & FMODE_WRITE)) | |
600 | return -EBADF; | |
601 | if (!file->f_op || (!file->f_op->writev && !file->f_op->write)) | |
602 | return -EINVAL; | |
603 | ||
604 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
605 | } | |
606 | ||
607 | EXPORT_SYMBOL(vfs_writev); | |
608 | ||
609 | asmlinkage ssize_t | |
610 | sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
611 | { | |
612 | struct file *file; | |
613 | ssize_t ret = -EBADF; | |
614 | int fput_needed; | |
615 | ||
616 | file = fget_light(fd, &fput_needed); | |
617 | if (file) { | |
618 | loff_t pos = file_pos_read(file); | |
619 | ret = vfs_readv(file, vec, vlen, &pos); | |
620 | file_pos_write(file, pos); | |
621 | fput_light(file, fput_needed); | |
622 | } | |
623 | ||
624 | if (ret > 0) | |
625 | current->rchar += ret; | |
626 | current->syscr++; | |
627 | return ret; | |
628 | } | |
629 | ||
630 | asmlinkage ssize_t | |
631 | sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
632 | { | |
633 | struct file *file; | |
634 | ssize_t ret = -EBADF; | |
635 | int fput_needed; | |
636 | ||
637 | file = fget_light(fd, &fput_needed); | |
638 | if (file) { | |
639 | loff_t pos = file_pos_read(file); | |
640 | ret = vfs_writev(file, vec, vlen, &pos); | |
641 | file_pos_write(file, pos); | |
642 | fput_light(file, fput_needed); | |
643 | } | |
644 | ||
645 | if (ret > 0) | |
646 | current->wchar += ret; | |
647 | current->syscw++; | |
648 | return ret; | |
649 | } | |
650 | ||
651 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, | |
652 | size_t count, loff_t max) | |
653 | { | |
654 | struct file * in_file, * out_file; | |
655 | struct inode * in_inode, * out_inode; | |
656 | loff_t pos; | |
657 | ssize_t retval; | |
658 | int fput_needed_in, fput_needed_out; | |
659 | ||
660 | /* | |
661 | * Get input file, and verify that it is ok.. | |
662 | */ | |
663 | retval = -EBADF; | |
664 | in_file = fget_light(in_fd, &fput_needed_in); | |
665 | if (!in_file) | |
666 | goto out; | |
667 | if (!(in_file->f_mode & FMODE_READ)) | |
668 | goto fput_in; | |
669 | retval = -EINVAL; | |
670 | in_inode = in_file->f_dentry->d_inode; | |
671 | if (!in_inode) | |
672 | goto fput_in; | |
673 | if (!in_file->f_op || !in_file->f_op->sendfile) | |
674 | goto fput_in; | |
675 | retval = -ESPIPE; | |
676 | if (!ppos) | |
677 | ppos = &in_file->f_pos; | |
678 | else | |
679 | if (!(in_file->f_mode & FMODE_PREAD)) | |
680 | goto fput_in; | |
681 | retval = rw_verify_area(READ, in_file, ppos, count); | |
e28cc715 | 682 | if (retval < 0) |
1da177e4 | 683 | goto fput_in; |
e28cc715 | 684 | count = retval; |
1da177e4 LT |
685 | |
686 | retval = security_file_permission (in_file, MAY_READ); | |
687 | if (retval) | |
688 | goto fput_in; | |
689 | ||
690 | /* | |
691 | * Get output file, and verify that it is ok.. | |
692 | */ | |
693 | retval = -EBADF; | |
694 | out_file = fget_light(out_fd, &fput_needed_out); | |
695 | if (!out_file) | |
696 | goto fput_in; | |
697 | if (!(out_file->f_mode & FMODE_WRITE)) | |
698 | goto fput_out; | |
699 | retval = -EINVAL; | |
700 | if (!out_file->f_op || !out_file->f_op->sendpage) | |
701 | goto fput_out; | |
702 | out_inode = out_file->f_dentry->d_inode; | |
703 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); | |
e28cc715 | 704 | if (retval < 0) |
1da177e4 | 705 | goto fput_out; |
e28cc715 | 706 | count = retval; |
1da177e4 LT |
707 | |
708 | retval = security_file_permission (out_file, MAY_WRITE); | |
709 | if (retval) | |
710 | goto fput_out; | |
711 | ||
712 | if (!max) | |
713 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
714 | ||
715 | pos = *ppos; | |
716 | retval = -EINVAL; | |
717 | if (unlikely(pos < 0)) | |
718 | goto fput_out; | |
719 | if (unlikely(pos + count > max)) { | |
720 | retval = -EOVERFLOW; | |
721 | if (pos >= max) | |
722 | goto fput_out; | |
723 | count = max - pos; | |
724 | } | |
725 | ||
726 | retval = in_file->f_op->sendfile(in_file, ppos, count, file_send_actor, out_file); | |
727 | ||
728 | if (retval > 0) { | |
729 | current->rchar += retval; | |
730 | current->wchar += retval; | |
731 | } | |
732 | current->syscr++; | |
733 | current->syscw++; | |
734 | ||
735 | if (*ppos > max) | |
736 | retval = -EOVERFLOW; | |
737 | ||
738 | fput_out: | |
739 | fput_light(out_file, fput_needed_out); | |
740 | fput_in: | |
741 | fput_light(in_file, fput_needed_in); | |
742 | out: | |
743 | return retval; | |
744 | } | |
745 | ||
746 | asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count) | |
747 | { | |
748 | loff_t pos; | |
749 | off_t off; | |
750 | ssize_t ret; | |
751 | ||
752 | if (offset) { | |
753 | if (unlikely(get_user(off, offset))) | |
754 | return -EFAULT; | |
755 | pos = off; | |
756 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
757 | if (unlikely(put_user(pos, offset))) | |
758 | return -EFAULT; | |
759 | return ret; | |
760 | } | |
761 | ||
762 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
763 | } | |
764 | ||
765 | asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count) | |
766 | { | |
767 | loff_t pos; | |
768 | ssize_t ret; | |
769 | ||
770 | if (offset) { | |
771 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
772 | return -EFAULT; | |
773 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
774 | if (unlikely(put_user(pos, offset))) | |
775 | return -EFAULT; | |
776 | return ret; | |
777 | } | |
778 | ||
779 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
780 | } |