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> |
d6b29d7c | 18 | #include <linux/splice.h> |
ee0b3e67 | 19 | #include "read_write.h" |
1da177e4 LT |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/unistd.h> | |
23 | ||
4b6f5d20 | 24 | const struct file_operations generic_ro_fops = { |
1da177e4 | 25 | .llseek = generic_file_llseek, |
543ade1f BP |
26 | .read = do_sync_read, |
27 | .aio_read = generic_file_aio_read, | |
1da177e4 | 28 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 29 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
30 | }; |
31 | ||
32 | EXPORT_SYMBOL(generic_ro_fops); | |
33 | ||
3a8cff4f CH |
34 | /** |
35 | * generic_file_llseek_unlocked - lockless generic llseek implementation | |
36 | * @file: file structure to seek on | |
37 | * @offset: file offset to seek to | |
38 | * @origin: type of seek | |
39 | * | |
40 | * Updates the file offset to the value specified by @offset and @origin. | |
41 | * Locking must be provided by the caller. | |
42 | */ | |
9465efc9 AK |
43 | loff_t |
44 | generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin) | |
1da177e4 | 45 | { |
1da177e4 LT |
46 | struct inode *inode = file->f_mapping->host; |
47 | ||
1da177e4 | 48 | switch (origin) { |
3a8cff4f CH |
49 | case SEEK_END: |
50 | offset += inode->i_size; | |
51 | break; | |
52 | case SEEK_CUR: | |
53 | offset += file->f_pos; | |
54 | break; | |
1da177e4 | 55 | } |
3a8cff4f CH |
56 | |
57 | if (offset < 0 || offset > inode->i_sb->s_maxbytes) | |
58 | return -EINVAL; | |
59 | ||
60 | /* Special lock needed here? */ | |
61 | if (offset != file->f_pos) { | |
62 | file->f_pos = offset; | |
63 | file->f_version = 0; | |
1da177e4 | 64 | } |
3a8cff4f CH |
65 | |
66 | return offset; | |
1da177e4 | 67 | } |
9465efc9 | 68 | EXPORT_SYMBOL(generic_file_llseek_unlocked); |
1da177e4 | 69 | |
3a8cff4f CH |
70 | /** |
71 | * generic_file_llseek - generic llseek implementation for regular files | |
72 | * @file: file structure to seek on | |
73 | * @offset: file offset to seek to | |
74 | * @origin: type of seek | |
75 | * | |
76 | * This is a generic implemenation of ->llseek useable for all normal local | |
77 | * filesystems. It just updates the file offset to the value specified by | |
78 | * @offset and @origin under i_mutex. | |
79 | */ | |
9465efc9 | 80 | loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) |
1da177e4 | 81 | { |
3a8cff4f CH |
82 | loff_t rval; |
83 | ||
9465efc9 | 84 | mutex_lock(&file->f_dentry->d_inode->i_mutex); |
3a8cff4f | 85 | rval = generic_file_llseek_unlocked(file, offset, origin); |
9465efc9 | 86 | mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
3a8cff4f CH |
87 | |
88 | return rval; | |
1da177e4 | 89 | } |
9465efc9 | 90 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 LT |
91 | |
92 | loff_t no_llseek(struct file *file, loff_t offset, int origin) | |
93 | { | |
94 | return -ESPIPE; | |
95 | } | |
96 | EXPORT_SYMBOL(no_llseek); | |
97 | ||
98 | loff_t default_llseek(struct file *file, loff_t offset, int origin) | |
99 | { | |
16abef0e | 100 | loff_t retval; |
1da177e4 LT |
101 | |
102 | lock_kernel(); | |
103 | switch (origin) { | |
7b8e8924 | 104 | case SEEK_END: |
0f7fc9e4 | 105 | offset += i_size_read(file->f_path.dentry->d_inode); |
1da177e4 | 106 | break; |
7b8e8924 | 107 | case SEEK_CUR: |
1da177e4 LT |
108 | offset += file->f_pos; |
109 | } | |
110 | retval = -EINVAL; | |
111 | if (offset >= 0) { | |
112 | if (offset != file->f_pos) { | |
113 | file->f_pos = offset; | |
114 | file->f_version = 0; | |
115 | } | |
116 | retval = offset; | |
117 | } | |
118 | unlock_kernel(); | |
119 | return retval; | |
120 | } | |
121 | EXPORT_SYMBOL(default_llseek); | |
122 | ||
123 | loff_t vfs_llseek(struct file *file, loff_t offset, int origin) | |
124 | { | |
125 | loff_t (*fn)(struct file *, loff_t, int); | |
126 | ||
127 | fn = no_llseek; | |
128 | if (file->f_mode & FMODE_LSEEK) { | |
129 | fn = default_llseek; | |
130 | if (file->f_op && file->f_op->llseek) | |
131 | fn = file->f_op->llseek; | |
132 | } | |
133 | return fn(file, offset, origin); | |
134 | } | |
135 | EXPORT_SYMBOL(vfs_llseek); | |
136 | ||
137 | asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin) | |
138 | { | |
139 | off_t retval; | |
140 | struct file * file; | |
141 | int fput_needed; | |
142 | ||
143 | retval = -EBADF; | |
144 | file = fget_light(fd, &fput_needed); | |
145 | if (!file) | |
146 | goto bad; | |
147 | ||
148 | retval = -EINVAL; | |
1ae7075b | 149 | if (origin <= SEEK_MAX) { |
1da177e4 LT |
150 | loff_t res = vfs_llseek(file, offset, origin); |
151 | retval = res; | |
152 | if (res != (loff_t)retval) | |
153 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
154 | } | |
155 | fput_light(file, fput_needed); | |
156 | bad: | |
157 | return retval; | |
158 | } | |
159 | ||
160 | #ifdef __ARCH_WANT_SYS_LLSEEK | |
161 | asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high, | |
162 | unsigned long offset_low, loff_t __user * result, | |
163 | unsigned int origin) | |
164 | { | |
165 | int retval; | |
166 | struct file * file; | |
167 | loff_t offset; | |
168 | int fput_needed; | |
169 | ||
170 | retval = -EBADF; | |
171 | file = fget_light(fd, &fput_needed); | |
172 | if (!file) | |
173 | goto bad; | |
174 | ||
175 | retval = -EINVAL; | |
1ae7075b | 176 | if (origin > SEEK_MAX) |
1da177e4 LT |
177 | goto out_putf; |
178 | ||
179 | offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low, | |
180 | origin); | |
181 | ||
182 | retval = (int)offset; | |
183 | if (offset >= 0) { | |
184 | retval = -EFAULT; | |
185 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
186 | retval = 0; | |
187 | } | |
188 | out_putf: | |
189 | fput_light(file, fput_needed); | |
190 | bad: | |
191 | return retval; | |
192 | } | |
193 | #endif | |
194 | ||
e28cc715 LT |
195 | /* |
196 | * rw_verify_area doesn't like huge counts. We limit | |
197 | * them to something that fits in "int" so that others | |
198 | * won't have to do range checks all the time. | |
199 | */ | |
200 | #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK) | |
1da177e4 LT |
201 | |
202 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) | |
203 | { | |
204 | struct inode *inode; | |
205 | loff_t pos; | |
c43e259c | 206 | int retval = -EINVAL; |
1da177e4 | 207 | |
163da958 | 208 | inode = file->f_path.dentry->d_inode; |
e28cc715 | 209 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 210 | return retval; |
1da177e4 LT |
211 | pos = *ppos; |
212 | if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) | |
c43e259c | 213 | return retval; |
1da177e4 | 214 | |
a16877ca | 215 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
c43e259c | 216 | retval = locks_mandatory_area( |
e28cc715 LT |
217 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
218 | inode, file, pos, count); | |
219 | if (retval < 0) | |
220 | return retval; | |
221 | } | |
c43e259c JM |
222 | retval = security_file_permission(file, |
223 | read_write == READ ? MAY_READ : MAY_WRITE); | |
224 | if (retval) | |
225 | return retval; | |
e28cc715 | 226 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
227 | } |
228 | ||
63e68809 BL |
229 | static void wait_on_retry_sync_kiocb(struct kiocb *iocb) |
230 | { | |
231 | set_current_state(TASK_UNINTERRUPTIBLE); | |
232 | if (!kiocbIsKicked(iocb)) | |
233 | schedule(); | |
234 | else | |
235 | kiocbClearKicked(iocb); | |
236 | __set_current_state(TASK_RUNNING); | |
237 | } | |
238 | ||
1da177e4 LT |
239 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
240 | { | |
027445c3 | 241 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
242 | struct kiocb kiocb; |
243 | ssize_t ret; | |
244 | ||
245 | init_sync_kiocb(&kiocb, filp); | |
246 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
247 | kiocb.ki_left = len; |
248 | ||
249 | for (;;) { | |
250 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); | |
251 | if (ret != -EIOCBRETRY) | |
252 | break; | |
63e68809 | 253 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 254 | } |
63e68809 | 255 | |
1da177e4 LT |
256 | if (-EIOCBQUEUED == ret) |
257 | ret = wait_on_sync_kiocb(&kiocb); | |
258 | *ppos = kiocb.ki_pos; | |
259 | return ret; | |
260 | } | |
261 | ||
262 | EXPORT_SYMBOL(do_sync_read); | |
263 | ||
264 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
265 | { | |
266 | ssize_t ret; | |
267 | ||
268 | if (!(file->f_mode & FMODE_READ)) | |
269 | return -EBADF; | |
270 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
271 | return -EINVAL; | |
272 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
273 | return -EFAULT; | |
274 | ||
275 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
276 | if (ret >= 0) { |
277 | count = ret; | |
c43e259c JM |
278 | if (file->f_op->read) |
279 | ret = file->f_op->read(file, buf, count, pos); | |
280 | else | |
281 | ret = do_sync_read(file, buf, count, pos); | |
282 | if (ret > 0) { | |
283 | fsnotify_access(file->f_path.dentry); | |
284 | add_rchar(current, ret); | |
1da177e4 | 285 | } |
c43e259c | 286 | inc_syscr(current); |
1da177e4 LT |
287 | } |
288 | ||
289 | return ret; | |
290 | } | |
291 | ||
292 | EXPORT_SYMBOL(vfs_read); | |
293 | ||
294 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
295 | { | |
027445c3 | 296 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
297 | struct kiocb kiocb; |
298 | ssize_t ret; | |
299 | ||
300 | init_sync_kiocb(&kiocb, filp); | |
301 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
302 | kiocb.ki_left = len; |
303 | ||
304 | for (;;) { | |
305 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); | |
306 | if (ret != -EIOCBRETRY) | |
307 | break; | |
63e68809 | 308 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 309 | } |
63e68809 | 310 | |
1da177e4 LT |
311 | if (-EIOCBQUEUED == ret) |
312 | ret = wait_on_sync_kiocb(&kiocb); | |
313 | *ppos = kiocb.ki_pos; | |
314 | return ret; | |
315 | } | |
316 | ||
317 | EXPORT_SYMBOL(do_sync_write); | |
318 | ||
319 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) | |
320 | { | |
321 | ssize_t ret; | |
322 | ||
323 | if (!(file->f_mode & FMODE_WRITE)) | |
324 | return -EBADF; | |
325 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
326 | return -EINVAL; | |
327 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
328 | return -EFAULT; | |
329 | ||
330 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
331 | if (ret >= 0) { |
332 | count = ret; | |
c43e259c JM |
333 | if (file->f_op->write) |
334 | ret = file->f_op->write(file, buf, count, pos); | |
335 | else | |
336 | ret = do_sync_write(file, buf, count, pos); | |
337 | if (ret > 0) { | |
338 | fsnotify_modify(file->f_path.dentry); | |
339 | add_wchar(current, ret); | |
1da177e4 | 340 | } |
c43e259c | 341 | inc_syscw(current); |
1da177e4 LT |
342 | } |
343 | ||
344 | return ret; | |
345 | } | |
346 | ||
347 | EXPORT_SYMBOL(vfs_write); | |
348 | ||
349 | static inline loff_t file_pos_read(struct file *file) | |
350 | { | |
351 | return file->f_pos; | |
352 | } | |
353 | ||
354 | static inline void file_pos_write(struct file *file, loff_t pos) | |
355 | { | |
356 | file->f_pos = pos; | |
357 | } | |
358 | ||
359 | asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count) | |
360 | { | |
361 | struct file *file; | |
362 | ssize_t ret = -EBADF; | |
363 | int fput_needed; | |
364 | ||
365 | file = fget_light(fd, &fput_needed); | |
366 | if (file) { | |
367 | loff_t pos = file_pos_read(file); | |
368 | ret = vfs_read(file, buf, count, &pos); | |
369 | file_pos_write(file, pos); | |
370 | fput_light(file, fput_needed); | |
371 | } | |
372 | ||
373 | return ret; | |
374 | } | |
1da177e4 LT |
375 | |
376 | asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count) | |
377 | { | |
378 | struct file *file; | |
379 | ssize_t ret = -EBADF; | |
380 | int fput_needed; | |
381 | ||
382 | file = fget_light(fd, &fput_needed); | |
383 | if (file) { | |
384 | loff_t pos = file_pos_read(file); | |
385 | ret = vfs_write(file, buf, count, &pos); | |
386 | file_pos_write(file, pos); | |
387 | fput_light(file, fput_needed); | |
388 | } | |
389 | ||
390 | return ret; | |
391 | } | |
392 | ||
393 | asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf, | |
394 | size_t count, loff_t pos) | |
395 | { | |
396 | struct file *file; | |
397 | ssize_t ret = -EBADF; | |
398 | int fput_needed; | |
399 | ||
400 | if (pos < 0) | |
401 | return -EINVAL; | |
402 | ||
403 | file = fget_light(fd, &fput_needed); | |
404 | if (file) { | |
405 | ret = -ESPIPE; | |
406 | if (file->f_mode & FMODE_PREAD) | |
407 | ret = vfs_read(file, buf, count, &pos); | |
408 | fput_light(file, fput_needed); | |
409 | } | |
410 | ||
411 | return ret; | |
412 | } | |
413 | ||
414 | asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf, | |
415 | size_t count, loff_t pos) | |
416 | { | |
417 | struct file *file; | |
418 | ssize_t ret = -EBADF; | |
419 | int fput_needed; | |
420 | ||
421 | if (pos < 0) | |
422 | return -EINVAL; | |
423 | ||
424 | file = fget_light(fd, &fput_needed); | |
425 | if (file) { | |
426 | ret = -ESPIPE; | |
427 | if (file->f_mode & FMODE_PWRITE) | |
428 | ret = vfs_write(file, buf, count, &pos); | |
429 | fput_light(file, fput_needed); | |
430 | } | |
431 | ||
432 | return ret; | |
433 | } | |
434 | ||
435 | /* | |
436 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
437 | */ | |
438 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
439 | { | |
440 | unsigned long seg = 0; | |
441 | size_t len = 0; | |
442 | ||
443 | while (seg < nr_segs) { | |
444 | seg++; | |
445 | if (len + iov->iov_len >= to) { | |
446 | iov->iov_len = to - len; | |
447 | break; | |
448 | } | |
449 | len += iov->iov_len; | |
450 | iov++; | |
451 | } | |
452 | return seg; | |
453 | } | |
19295529 | 454 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 455 | |
ee0b3e67 BP |
456 | ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
457 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) | |
458 | { | |
459 | struct kiocb kiocb; | |
460 | ssize_t ret; | |
461 | ||
462 | init_sync_kiocb(&kiocb, filp); | |
463 | kiocb.ki_pos = *ppos; | |
464 | kiocb.ki_left = len; | |
465 | kiocb.ki_nbytes = len; | |
466 | ||
467 | for (;;) { | |
468 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); | |
469 | if (ret != -EIOCBRETRY) | |
470 | break; | |
471 | wait_on_retry_sync_kiocb(&kiocb); | |
472 | } | |
473 | ||
474 | if (ret == -EIOCBQUEUED) | |
475 | ret = wait_on_sync_kiocb(&kiocb); | |
476 | *ppos = kiocb.ki_pos; | |
477 | return ret; | |
478 | } | |
479 | ||
480 | /* Do it by hand, with file-ops */ | |
481 | ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, | |
482 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) | |
483 | { | |
484 | struct iovec *vector = iov; | |
485 | ssize_t ret = 0; | |
486 | ||
487 | while (nr_segs > 0) { | |
488 | void __user *base; | |
489 | size_t len; | |
490 | ssize_t nr; | |
491 | ||
492 | base = vector->iov_base; | |
493 | len = vector->iov_len; | |
494 | vector++; | |
495 | nr_segs--; | |
496 | ||
497 | nr = fn(filp, base, len, ppos); | |
498 | ||
499 | if (nr < 0) { | |
500 | if (!ret) | |
501 | ret = nr; | |
502 | break; | |
503 | } | |
504 | ret += nr; | |
505 | if (nr != len) | |
506 | break; | |
507 | } | |
508 | ||
509 | return ret; | |
510 | } | |
511 | ||
1da177e4 LT |
512 | /* A write operation does a read from user space and vice versa */ |
513 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
514 | ||
eed4e51f BP |
515 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
516 | unsigned long nr_segs, unsigned long fast_segs, | |
517 | struct iovec *fast_pointer, | |
518 | struct iovec **ret_pointer) | |
519 | { | |
520 | unsigned long seg; | |
521 | ssize_t ret; | |
522 | struct iovec *iov = fast_pointer; | |
523 | ||
524 | /* | |
525 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
526 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
527 | * traditionally returned zero for zero segments, so... | |
528 | */ | |
529 | if (nr_segs == 0) { | |
530 | ret = 0; | |
531 | goto out; | |
532 | } | |
533 | ||
534 | /* | |
535 | * First get the "struct iovec" from user memory and | |
536 | * verify all the pointers | |
537 | */ | |
538 | if (nr_segs > UIO_MAXIOV) { | |
539 | ret = -EINVAL; | |
540 | goto out; | |
541 | } | |
542 | if (nr_segs > fast_segs) { | |
543 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
544 | if (iov == NULL) { | |
545 | ret = -ENOMEM; | |
546 | goto out; | |
547 | } | |
548 | } | |
549 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { | |
550 | ret = -EFAULT; | |
551 | goto out; | |
552 | } | |
553 | ||
554 | /* | |
555 | * According to the Single Unix Specification we should return EINVAL | |
556 | * if an element length is < 0 when cast to ssize_t or if the | |
557 | * total length would overflow the ssize_t return value of the | |
558 | * system call. | |
559 | */ | |
560 | ret = 0; | |
561 | for (seg = 0; seg < nr_segs; seg++) { | |
562 | void __user *buf = iov[seg].iov_base; | |
563 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
564 | ||
565 | /* see if we we're about to use an invalid len or if | |
566 | * it's about to overflow ssize_t */ | |
567 | if (len < 0 || (ret + len < ret)) { | |
568 | ret = -EINVAL; | |
569 | goto out; | |
570 | } | |
571 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { | |
572 | ret = -EFAULT; | |
573 | goto out; | |
574 | } | |
575 | ||
576 | ret += len; | |
577 | } | |
578 | out: | |
579 | *ret_pointer = iov; | |
580 | return ret; | |
581 | } | |
582 | ||
1da177e4 LT |
583 | static ssize_t do_readv_writev(int type, struct file *file, |
584 | const struct iovec __user * uvector, | |
585 | unsigned long nr_segs, loff_t *pos) | |
586 | { | |
1da177e4 LT |
587 | size_t tot_len; |
588 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 589 | struct iovec *iov = iovstack; |
1da177e4 | 590 | ssize_t ret; |
1da177e4 LT |
591 | io_fn_t fn; |
592 | iov_fn_t fnv; | |
593 | ||
eed4e51f BP |
594 | if (!file->f_op) { |
595 | ret = -EINVAL; | |
1da177e4 | 596 | goto out; |
1da177e4 | 597 | } |
1da177e4 | 598 | |
eed4e51f BP |
599 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
600 | ARRAY_SIZE(iovstack), iovstack, &iov); | |
601 | if (ret <= 0) | |
1da177e4 | 602 | goto out; |
1da177e4 | 603 | |
eed4e51f | 604 | tot_len = ret; |
1da177e4 | 605 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 606 | if (ret < 0) |
411b67b4 | 607 | goto out; |
1da177e4 LT |
608 | |
609 | fnv = NULL; | |
610 | if (type == READ) { | |
611 | fn = file->f_op->read; | |
ee0b3e67 | 612 | fnv = file->f_op->aio_read; |
1da177e4 LT |
613 | } else { |
614 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 615 | fnv = file->f_op->aio_write; |
1da177e4 LT |
616 | } |
617 | ||
ee0b3e67 BP |
618 | if (fnv) |
619 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
620 | pos, fnv); | |
621 | else | |
622 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 623 | |
1da177e4 LT |
624 | out: |
625 | if (iov != iovstack) | |
626 | kfree(iov); | |
0eeca283 RL |
627 | if ((ret + (type == READ)) > 0) { |
628 | if (type == READ) | |
0f7fc9e4 | 629 | fsnotify_access(file->f_path.dentry); |
0eeca283 | 630 | else |
0f7fc9e4 | 631 | fsnotify_modify(file->f_path.dentry); |
0eeca283 | 632 | } |
1da177e4 | 633 | return ret; |
1da177e4 LT |
634 | } |
635 | ||
636 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
637 | unsigned long vlen, loff_t *pos) | |
638 | { | |
639 | if (!(file->f_mode & FMODE_READ)) | |
640 | return -EBADF; | |
ee0b3e67 | 641 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4 LT |
642 | return -EINVAL; |
643 | ||
644 | return do_readv_writev(READ, file, vec, vlen, pos); | |
645 | } | |
646 | ||
647 | EXPORT_SYMBOL(vfs_readv); | |
648 | ||
649 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
650 | unsigned long vlen, loff_t *pos) | |
651 | { | |
652 | if (!(file->f_mode & FMODE_WRITE)) | |
653 | return -EBADF; | |
ee0b3e67 | 654 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4 LT |
655 | return -EINVAL; |
656 | ||
657 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
658 | } | |
659 | ||
660 | EXPORT_SYMBOL(vfs_writev); | |
661 | ||
662 | asmlinkage ssize_t | |
663 | sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
664 | { | |
665 | struct file *file; | |
666 | ssize_t ret = -EBADF; | |
667 | int fput_needed; | |
668 | ||
669 | file = fget_light(fd, &fput_needed); | |
670 | if (file) { | |
671 | loff_t pos = file_pos_read(file); | |
672 | ret = vfs_readv(file, vec, vlen, &pos); | |
673 | file_pos_write(file, pos); | |
674 | fput_light(file, fput_needed); | |
675 | } | |
676 | ||
677 | if (ret > 0) | |
4b98d11b AD |
678 | add_rchar(current, ret); |
679 | inc_syscr(current); | |
1da177e4 LT |
680 | return ret; |
681 | } | |
682 | ||
683 | asmlinkage ssize_t | |
684 | sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
685 | { | |
686 | struct file *file; | |
687 | ssize_t ret = -EBADF; | |
688 | int fput_needed; | |
689 | ||
690 | file = fget_light(fd, &fput_needed); | |
691 | if (file) { | |
692 | loff_t pos = file_pos_read(file); | |
693 | ret = vfs_writev(file, vec, vlen, &pos); | |
694 | file_pos_write(file, pos); | |
695 | fput_light(file, fput_needed); | |
696 | } | |
697 | ||
698 | if (ret > 0) | |
4b98d11b AD |
699 | add_wchar(current, ret); |
700 | inc_syscw(current); | |
1da177e4 LT |
701 | return ret; |
702 | } | |
703 | ||
704 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, | |
705 | size_t count, loff_t max) | |
706 | { | |
707 | struct file * in_file, * out_file; | |
708 | struct inode * in_inode, * out_inode; | |
709 | loff_t pos; | |
710 | ssize_t retval; | |
534f2aaa | 711 | int fput_needed_in, fput_needed_out, fl; |
1da177e4 LT |
712 | |
713 | /* | |
714 | * Get input file, and verify that it is ok.. | |
715 | */ | |
716 | retval = -EBADF; | |
717 | in_file = fget_light(in_fd, &fput_needed_in); | |
718 | if (!in_file) | |
719 | goto out; | |
720 | if (!(in_file->f_mode & FMODE_READ)) | |
721 | goto fput_in; | |
722 | retval = -EINVAL; | |
0f7fc9e4 | 723 | in_inode = in_file->f_path.dentry->d_inode; |
1da177e4 LT |
724 | if (!in_inode) |
725 | goto fput_in; | |
d96e6e71 | 726 | if (!in_file->f_op || !in_file->f_op->splice_read) |
1da177e4 LT |
727 | goto fput_in; |
728 | retval = -ESPIPE; | |
729 | if (!ppos) | |
730 | ppos = &in_file->f_pos; | |
731 | else | |
732 | if (!(in_file->f_mode & FMODE_PREAD)) | |
733 | goto fput_in; | |
734 | retval = rw_verify_area(READ, in_file, ppos, count); | |
e28cc715 | 735 | if (retval < 0) |
1da177e4 | 736 | goto fput_in; |
e28cc715 | 737 | count = retval; |
1da177e4 | 738 | |
1da177e4 LT |
739 | /* |
740 | * Get output file, and verify that it is ok.. | |
741 | */ | |
742 | retval = -EBADF; | |
743 | out_file = fget_light(out_fd, &fput_needed_out); | |
744 | if (!out_file) | |
745 | goto fput_in; | |
746 | if (!(out_file->f_mode & FMODE_WRITE)) | |
747 | goto fput_out; | |
748 | retval = -EINVAL; | |
749 | if (!out_file->f_op || !out_file->f_op->sendpage) | |
750 | goto fput_out; | |
0f7fc9e4 | 751 | out_inode = out_file->f_path.dentry->d_inode; |
1da177e4 | 752 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); |
e28cc715 | 753 | if (retval < 0) |
1da177e4 | 754 | goto fput_out; |
e28cc715 | 755 | count = retval; |
1da177e4 | 756 | |
1da177e4 LT |
757 | if (!max) |
758 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
759 | ||
760 | pos = *ppos; | |
761 | retval = -EINVAL; | |
762 | if (unlikely(pos < 0)) | |
763 | goto fput_out; | |
764 | if (unlikely(pos + count > max)) { | |
765 | retval = -EOVERFLOW; | |
766 | if (pos >= max) | |
767 | goto fput_out; | |
768 | count = max - pos; | |
769 | } | |
770 | ||
d96e6e71 | 771 | fl = 0; |
534f2aaa | 772 | #if 0 |
d96e6e71 JA |
773 | /* |
774 | * We need to debate whether we can enable this or not. The | |
775 | * man page documents EAGAIN return for the output at least, | |
776 | * and the application is arguably buggy if it doesn't expect | |
777 | * EAGAIN on a non-blocking file descriptor. | |
778 | */ | |
779 | if (in_file->f_flags & O_NONBLOCK) | |
780 | fl = SPLICE_F_NONBLOCK; | |
534f2aaa | 781 | #endif |
d96e6e71 | 782 | retval = do_splice_direct(in_file, ppos, out_file, count, fl); |
1da177e4 LT |
783 | |
784 | if (retval > 0) { | |
4b98d11b AD |
785 | add_rchar(current, retval); |
786 | add_wchar(current, retval); | |
1da177e4 | 787 | } |
1da177e4 | 788 | |
4b98d11b AD |
789 | inc_syscr(current); |
790 | inc_syscw(current); | |
1da177e4 LT |
791 | if (*ppos > max) |
792 | retval = -EOVERFLOW; | |
793 | ||
794 | fput_out: | |
795 | fput_light(out_file, fput_needed_out); | |
796 | fput_in: | |
797 | fput_light(in_file, fput_needed_in); | |
798 | out: | |
799 | return retval; | |
800 | } | |
801 | ||
802 | asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count) | |
803 | { | |
804 | loff_t pos; | |
805 | off_t off; | |
806 | ssize_t ret; | |
807 | ||
808 | if (offset) { | |
809 | if (unlikely(get_user(off, offset))) | |
810 | return -EFAULT; | |
811 | pos = off; | |
812 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
813 | if (unlikely(put_user(pos, offset))) | |
814 | return -EFAULT; | |
815 | return ret; | |
816 | } | |
817 | ||
818 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
819 | } | |
820 | ||
821 | asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count) | |
822 | { | |
823 | loff_t pos; | |
824 | ssize_t ret; | |
825 | ||
826 | if (offset) { | |
827 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
828 | return -EFAULT; | |
829 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
830 | if (unlikely(put_user(pos, offset))) | |
831 | return -EFAULT; | |
832 | return ret; | |
833 | } | |
834 | ||
835 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
836 | } |