blob: c4d3d17923f155004fec85fd04f836a06aa585f3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Robert Love0eeca282005-07-12 17:06:03 -040013#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/security.h>
15#include <linux/module.h>
16#include <linux/syscalls.h>
Linus Torvaldse28cc712006-01-04 16:20:40 -080017#include <linux/pagemap.h>
Jens Axboed6b29d72007-06-04 09:59:47 +020018#include <linux/splice.h>
Badari Pulavartyee0b3e62006-09-30 23:28:47 -070019#include "read_write.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21#include <asm/uaccess.h>
22#include <asm/unistd.h>
23
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080024const struct file_operations generic_ro_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 .llseek = generic_file_llseek,
Badari Pulavarty543ade12006-09-30 23:28:48 -070026 .read = do_sync_read,
27 .aio_read = generic_file_aio_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 .mmap = generic_file_readonly_mmap,
Jens Axboe534f2aa2007-06-01 14:52:37 +020029 .splice_read = generic_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -070030};
31
32EXPORT_SYMBOL(generic_ro_fops);
33
34loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
35{
36 long long retval;
37 struct inode *inode = file->f_mapping->host;
38
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080039 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 switch (origin) {
Chris Snook7b8e8922007-05-08 00:24:13 -070041 case SEEK_END:
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 offset += inode->i_size;
43 break;
Chris Snook7b8e8922007-05-08 00:24:13 -070044 case SEEK_CUR:
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 offset += file->f_pos;
46 }
47 retval = -EINVAL;
48 if (offset>=0 && offset<=inode->i_sb->s_maxbytes) {
49 if (offset != file->f_pos) {
50 file->f_pos = offset;
51 file->f_version = 0;
52 }
53 retval = offset;
54 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080055 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 return retval;
57}
58
59EXPORT_SYMBOL(generic_file_llseek);
60
61loff_t remote_llseek(struct file *file, loff_t offset, int origin)
62{
63 long long retval;
64
65 lock_kernel();
66 switch (origin) {
Chris Snook7b8e8922007-05-08 00:24:13 -070067 case SEEK_END:
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -080068 offset += i_size_read(file->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 break;
Chris Snook7b8e8922007-05-08 00:24:13 -070070 case SEEK_CUR:
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 offset += file->f_pos;
72 }
73 retval = -EINVAL;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -080074 if (offset>=0 && offset<=file->f_path.dentry->d_inode->i_sb->s_maxbytes) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 if (offset != file->f_pos) {
76 file->f_pos = offset;
77 file->f_version = 0;
78 }
79 retval = offset;
80 }
81 unlock_kernel();
82 return retval;
83}
84EXPORT_SYMBOL(remote_llseek);
85
86loff_t no_llseek(struct file *file, loff_t offset, int origin)
87{
88 return -ESPIPE;
89}
90EXPORT_SYMBOL(no_llseek);
91
92loff_t default_llseek(struct file *file, loff_t offset, int origin)
93{
94 long long retval;
95
96 lock_kernel();
97 switch (origin) {
Chris Snook7b8e8922007-05-08 00:24:13 -070098 case SEEK_END:
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -080099 offset += i_size_read(file->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 break;
Chris Snook7b8e8922007-05-08 00:24:13 -0700101 case SEEK_CUR:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 offset += file->f_pos;
103 }
104 retval = -EINVAL;
105 if (offset >= 0) {
106 if (offset != file->f_pos) {
107 file->f_pos = offset;
108 file->f_version = 0;
109 }
110 retval = offset;
111 }
112 unlock_kernel();
113 return retval;
114}
115EXPORT_SYMBOL(default_llseek);
116
117loff_t vfs_llseek(struct file *file, loff_t offset, int origin)
118{
119 loff_t (*fn)(struct file *, loff_t, int);
120
121 fn = no_llseek;
122 if (file->f_mode & FMODE_LSEEK) {
123 fn = default_llseek;
124 if (file->f_op && file->f_op->llseek)
125 fn = file->f_op->llseek;
126 }
127 return fn(file, offset, origin);
128}
129EXPORT_SYMBOL(vfs_llseek);
130
131asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
132{
133 off_t retval;
134 struct file * file;
135 int fput_needed;
136
137 retval = -EBADF;
138 file = fget_light(fd, &fput_needed);
139 if (!file)
140 goto bad;
141
142 retval = -EINVAL;
Chris Snook1ae70752007-05-08 00:24:15 -0700143 if (origin <= SEEK_MAX) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 loff_t res = vfs_llseek(file, offset, origin);
145 retval = res;
146 if (res != (loff_t)retval)
147 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
148 }
149 fput_light(file, fput_needed);
150bad:
151 return retval;
152}
153
154#ifdef __ARCH_WANT_SYS_LLSEEK
155asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high,
156 unsigned long offset_low, loff_t __user * result,
157 unsigned int origin)
158{
159 int retval;
160 struct file * file;
161 loff_t offset;
162 int fput_needed;
163
164 retval = -EBADF;
165 file = fget_light(fd, &fput_needed);
166 if (!file)
167 goto bad;
168
169 retval = -EINVAL;
Chris Snook1ae70752007-05-08 00:24:15 -0700170 if (origin > SEEK_MAX)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 goto out_putf;
172
173 offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low,
174 origin);
175
176 retval = (int)offset;
177 if (offset >= 0) {
178 retval = -EFAULT;
179 if (!copy_to_user(result, &offset, sizeof(offset)))
180 retval = 0;
181 }
182out_putf:
183 fput_light(file, fput_needed);
184bad:
185 return retval;
186}
187#endif
188
Linus Torvaldse28cc712006-01-04 16:20:40 -0800189/*
190 * rw_verify_area doesn't like huge counts. We limit
191 * them to something that fits in "int" so that others
192 * won't have to do range checks all the time.
193 */
194#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count)
197{
198 struct inode *inode;
199 loff_t pos;
James Morrisc43e2592008-01-12 22:05:48 +1100200 int retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
Eric Dumazet163da952007-02-12 00:52:24 -0800202 inode = file->f_path.dentry->d_inode;
Linus Torvaldse28cc712006-01-04 16:20:40 -0800203 if (unlikely((ssize_t) count < 0))
James Morrisc43e2592008-01-12 22:05:48 +1100204 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 pos = *ppos;
206 if (unlikely((pos < 0) || (loff_t) (pos + count) < 0))
James Morrisc43e2592008-01-12 22:05:48 +1100207 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Pavel Emelyanova16877c2007-10-01 14:41:11 -0700209 if (unlikely(inode->i_flock && mandatory_lock(inode))) {
James Morrisc43e2592008-01-12 22:05:48 +1100210 retval = locks_mandatory_area(
Linus Torvaldse28cc712006-01-04 16:20:40 -0800211 read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
212 inode, file, pos, count);
213 if (retval < 0)
214 return retval;
215 }
James Morrisc43e2592008-01-12 22:05:48 +1100216 retval = security_file_permission(file,
217 read_write == READ ? MAY_READ : MAY_WRITE);
218 if (retval)
219 return retval;
Linus Torvaldse28cc712006-01-04 16:20:40 -0800220 return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221}
222
Benjamin LaHaise63e68802005-06-23 00:10:27 -0700223static void wait_on_retry_sync_kiocb(struct kiocb *iocb)
224{
225 set_current_state(TASK_UNINTERRUPTIBLE);
226 if (!kiocbIsKicked(iocb))
227 schedule();
228 else
229 kiocbClearKicked(iocb);
230 __set_current_state(TASK_RUNNING);
231}
232
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
234{
Badari Pulavarty027445c2006-09-30 23:28:46 -0700235 struct iovec iov = { .iov_base = buf, .iov_len = len };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 struct kiocb kiocb;
237 ssize_t ret;
238
239 init_sync_kiocb(&kiocb, filp);
240 kiocb.ki_pos = *ppos;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700241 kiocb.ki_left = len;
242
243 for (;;) {
244 ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
245 if (ret != -EIOCBRETRY)
246 break;
Benjamin LaHaise63e68802005-06-23 00:10:27 -0700247 wait_on_retry_sync_kiocb(&kiocb);
Badari Pulavarty027445c2006-09-30 23:28:46 -0700248 }
Benjamin LaHaise63e68802005-06-23 00:10:27 -0700249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 if (-EIOCBQUEUED == ret)
251 ret = wait_on_sync_kiocb(&kiocb);
252 *ppos = kiocb.ki_pos;
253 return ret;
254}
255
256EXPORT_SYMBOL(do_sync_read);
257
258ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
259{
260 ssize_t ret;
261
262 if (!(file->f_mode & FMODE_READ))
263 return -EBADF;
264 if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
265 return -EINVAL;
266 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
267 return -EFAULT;
268
269 ret = rw_verify_area(READ, file, pos, count);
Linus Torvaldse28cc712006-01-04 16:20:40 -0800270 if (ret >= 0) {
271 count = ret;
James Morrisc43e2592008-01-12 22:05:48 +1100272 if (file->f_op->read)
273 ret = file->f_op->read(file, buf, count, pos);
274 else
275 ret = do_sync_read(file, buf, count, pos);
276 if (ret > 0) {
277 fsnotify_access(file->f_path.dentry);
278 add_rchar(current, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 }
James Morrisc43e2592008-01-12 22:05:48 +1100280 inc_syscr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 }
282
283 return ret;
284}
285
286EXPORT_SYMBOL(vfs_read);
287
288ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
289{
Badari Pulavarty027445c2006-09-30 23:28:46 -0700290 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 struct kiocb kiocb;
292 ssize_t ret;
293
294 init_sync_kiocb(&kiocb, filp);
295 kiocb.ki_pos = *ppos;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700296 kiocb.ki_left = len;
297
298 for (;;) {
299 ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
300 if (ret != -EIOCBRETRY)
301 break;
Benjamin LaHaise63e68802005-06-23 00:10:27 -0700302 wait_on_retry_sync_kiocb(&kiocb);
Badari Pulavarty027445c2006-09-30 23:28:46 -0700303 }
Benjamin LaHaise63e68802005-06-23 00:10:27 -0700304
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 if (-EIOCBQUEUED == ret)
306 ret = wait_on_sync_kiocb(&kiocb);
307 *ppos = kiocb.ki_pos;
308 return ret;
309}
310
311EXPORT_SYMBOL(do_sync_write);
312
313ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
314{
315 ssize_t ret;
316
317 if (!(file->f_mode & FMODE_WRITE))
318 return -EBADF;
319 if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
320 return -EINVAL;
321 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
322 return -EFAULT;
323
324 ret = rw_verify_area(WRITE, file, pos, count);
Linus Torvaldse28cc712006-01-04 16:20:40 -0800325 if (ret >= 0) {
326 count = ret;
James Morrisc43e2592008-01-12 22:05:48 +1100327 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) {
332 fsnotify_modify(file->f_path.dentry);
333 add_wchar(current, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 }
James Morrisc43e2592008-01-12 22:05:48 +1100335 inc_syscw(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 }
337
338 return ret;
339}
340
341EXPORT_SYMBOL(vfs_write);
342
343static inline loff_t file_pos_read(struct file *file)
344{
345 return file->f_pos;
346}
347
348static inline void file_pos_write(struct file *file, loff_t pos)
349{
350 file->f_pos = pos;
351}
352
353asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)
354{
355 struct file *file;
356 ssize_t ret = -EBADF;
357 int fput_needed;
358
359 file = fget_light(fd, &fput_needed);
360 if (file) {
361 loff_t pos = file_pos_read(file);
362 ret = vfs_read(file, buf, count, &pos);
363 file_pos_write(file, pos);
364 fput_light(file, fput_needed);
365 }
366
367 return ret;
368}
Arjan van de Vencb51f972007-11-14 17:00:10 -0800369EXPORT_UNUSED_SYMBOL_GPL(sys_read); /* to be deleted for 2.6.25 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count)
372{
373 struct file *file;
374 ssize_t ret = -EBADF;
375 int fput_needed;
376
377 file = fget_light(fd, &fput_needed);
378 if (file) {
379 loff_t pos = file_pos_read(file);
380 ret = vfs_write(file, buf, count, &pos);
381 file_pos_write(file, pos);
382 fput_light(file, fput_needed);
383 }
384
385 return ret;
386}
387
388asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf,
389 size_t count, loff_t pos)
390{
391 struct file *file;
392 ssize_t ret = -EBADF;
393 int fput_needed;
394
395 if (pos < 0)
396 return -EINVAL;
397
398 file = fget_light(fd, &fput_needed);
399 if (file) {
400 ret = -ESPIPE;
401 if (file->f_mode & FMODE_PREAD)
402 ret = vfs_read(file, buf, count, &pos);
403 fput_light(file, fput_needed);
404 }
405
406 return ret;
407}
408
409asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf,
410 size_t count, loff_t pos)
411{
412 struct file *file;
413 ssize_t ret = -EBADF;
414 int fput_needed;
415
416 if (pos < 0)
417 return -EINVAL;
418
419 file = fget_light(fd, &fput_needed);
420 if (file) {
421 ret = -ESPIPE;
422 if (file->f_mode & FMODE_PWRITE)
423 ret = vfs_write(file, buf, count, &pos);
424 fput_light(file, fput_needed);
425 }
426
427 return ret;
428}
429
430/*
431 * Reduce an iovec's length in-place. Return the resulting number of segments
432 */
433unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
434{
435 unsigned long seg = 0;
436 size_t len = 0;
437
438 while (seg < nr_segs) {
439 seg++;
440 if (len + iov->iov_len >= to) {
441 iov->iov_len = to - len;
442 break;
443 }
444 len += iov->iov_len;
445 iov++;
446 }
447 return seg;
448}
449
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700450ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
451 unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn)
452{
453 struct kiocb kiocb;
454 ssize_t ret;
455
456 init_sync_kiocb(&kiocb, filp);
457 kiocb.ki_pos = *ppos;
458 kiocb.ki_left = len;
459 kiocb.ki_nbytes = len;
460
461 for (;;) {
462 ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
463 if (ret != -EIOCBRETRY)
464 break;
465 wait_on_retry_sync_kiocb(&kiocb);
466 }
467
468 if (ret == -EIOCBQUEUED)
469 ret = wait_on_sync_kiocb(&kiocb);
470 *ppos = kiocb.ki_pos;
471 return ret;
472}
473
474/* Do it by hand, with file-ops */
475ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
476 unsigned long nr_segs, loff_t *ppos, io_fn_t fn)
477{
478 struct iovec *vector = iov;
479 ssize_t ret = 0;
480
481 while (nr_segs > 0) {
482 void __user *base;
483 size_t len;
484 ssize_t nr;
485
486 base = vector->iov_base;
487 len = vector->iov_len;
488 vector++;
489 nr_segs--;
490
491 nr = fn(filp, base, len, ppos);
492
493 if (nr < 0) {
494 if (!ret)
495 ret = nr;
496 break;
497 }
498 ret += nr;
499 if (nr != len)
500 break;
501 }
502
503 return ret;
504}
505
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506/* A write operation does a read from user space and vice versa */
507#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
508
Badari Pulavartyeed4e512006-09-30 23:28:49 -0700509ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
510 unsigned long nr_segs, unsigned long fast_segs,
511 struct iovec *fast_pointer,
512 struct iovec **ret_pointer)
513 {
514 unsigned long seg;
515 ssize_t ret;
516 struct iovec *iov = fast_pointer;
517
518 /*
519 * SuS says "The readv() function *may* fail if the iovcnt argument
520 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
521 * traditionally returned zero for zero segments, so...
522 */
523 if (nr_segs == 0) {
524 ret = 0;
525 goto out;
526 }
527
528 /*
529 * First get the "struct iovec" from user memory and
530 * verify all the pointers
531 */
532 if (nr_segs > UIO_MAXIOV) {
533 ret = -EINVAL;
534 goto out;
535 }
536 if (nr_segs > fast_segs) {
537 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
538 if (iov == NULL) {
539 ret = -ENOMEM;
540 goto out;
541 }
542 }
543 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
544 ret = -EFAULT;
545 goto out;
546 }
547
548 /*
549 * According to the Single Unix Specification we should return EINVAL
550 * if an element length is < 0 when cast to ssize_t or if the
551 * total length would overflow the ssize_t return value of the
552 * system call.
553 */
554 ret = 0;
555 for (seg = 0; seg < nr_segs; seg++) {
556 void __user *buf = iov[seg].iov_base;
557 ssize_t len = (ssize_t)iov[seg].iov_len;
558
559 /* see if we we're about to use an invalid len or if
560 * it's about to overflow ssize_t */
561 if (len < 0 || (ret + len < ret)) {
562 ret = -EINVAL;
563 goto out;
564 }
565 if (unlikely(!access_ok(vrfy_dir(type), buf, len))) {
566 ret = -EFAULT;
567 goto out;
568 }
569
570 ret += len;
571 }
572out:
573 *ret_pointer = iov;
574 return ret;
575}
576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577static ssize_t do_readv_writev(int type, struct file *file,
578 const struct iovec __user * uvector,
579 unsigned long nr_segs, loff_t *pos)
580{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 size_t tot_len;
582 struct iovec iovstack[UIO_FASTIOV];
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700583 struct iovec *iov = iovstack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 io_fn_t fn;
586 iov_fn_t fnv;
587
Badari Pulavartyeed4e512006-09-30 23:28:49 -0700588 if (!file->f_op) {
589 ret = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 goto out;
591 }
592
Badari Pulavartyeed4e512006-09-30 23:28:49 -0700593 ret = rw_copy_check_uvector(type, uvector, nr_segs,
594 ARRAY_SIZE(iovstack), iovstack, &iov);
595 if (ret <= 0)
596 goto out;
597
598 tot_len = ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 ret = rw_verify_area(type, file, pos, tot_len);
Linus Torvaldse28cc712006-01-04 16:20:40 -0800600 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 goto out;
602
603 fnv = NULL;
604 if (type == READ) {
605 fn = file->f_op->read;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700606 fnv = file->f_op->aio_read;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 } else {
608 fn = (io_fn_t)file->f_op->write;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700609 fnv = file->f_op->aio_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 }
611
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700612 if (fnv)
613 ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
614 pos, fnv);
615 else
616 ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618out:
619 if (iov != iovstack)
620 kfree(iov);
Robert Love0eeca282005-07-12 17:06:03 -0400621 if ((ret + (type == READ)) > 0) {
622 if (type == READ)
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800623 fsnotify_access(file->f_path.dentry);
Robert Love0eeca282005-07-12 17:06:03 -0400624 else
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800625 fsnotify_modify(file->f_path.dentry);
Robert Love0eeca282005-07-12 17:06:03 -0400626 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628}
629
630ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
631 unsigned long vlen, loff_t *pos)
632{
633 if (!(file->f_mode & FMODE_READ))
634 return -EBADF;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700635 if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 return -EINVAL;
637
638 return do_readv_writev(READ, file, vec, vlen, pos);
639}
640
641EXPORT_SYMBOL(vfs_readv);
642
643ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
644 unsigned long vlen, loff_t *pos)
645{
646 if (!(file->f_mode & FMODE_WRITE))
647 return -EBADF;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700648 if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 return -EINVAL;
650
651 return do_readv_writev(WRITE, file, vec, vlen, pos);
652}
653
654EXPORT_SYMBOL(vfs_writev);
655
656asmlinkage ssize_t
657sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
658{
659 struct file *file;
660 ssize_t ret = -EBADF;
661 int fput_needed;
662
663 file = fget_light(fd, &fput_needed);
664 if (file) {
665 loff_t pos = file_pos_read(file);
666 ret = vfs_readv(file, vec, vlen, &pos);
667 file_pos_write(file, pos);
668 fput_light(file, fput_needed);
669 }
670
671 if (ret > 0)
Alexey Dobriyan4b98d112007-02-10 01:46:45 -0800672 add_rchar(current, ret);
673 inc_syscr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 return ret;
675}
676
677asmlinkage ssize_t
678sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
679{
680 struct file *file;
681 ssize_t ret = -EBADF;
682 int fput_needed;
683
684 file = fget_light(fd, &fput_needed);
685 if (file) {
686 loff_t pos = file_pos_read(file);
687 ret = vfs_writev(file, vec, vlen, &pos);
688 file_pos_write(file, pos);
689 fput_light(file, fput_needed);
690 }
691
692 if (ret > 0)
Alexey Dobriyan4b98d112007-02-10 01:46:45 -0800693 add_wchar(current, ret);
694 inc_syscw(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 return ret;
696}
697
698static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
699 size_t count, loff_t max)
700{
701 struct file * in_file, * out_file;
702 struct inode * in_inode, * out_inode;
703 loff_t pos;
704 ssize_t retval;
Jens Axboe534f2aa2007-06-01 14:52:37 +0200705 int fput_needed_in, fput_needed_out, fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
707 /*
708 * Get input file, and verify that it is ok..
709 */
710 retval = -EBADF;
711 in_file = fget_light(in_fd, &fput_needed_in);
712 if (!in_file)
713 goto out;
714 if (!(in_file->f_mode & FMODE_READ))
715 goto fput_in;
716 retval = -EINVAL;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800717 in_inode = in_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 if (!in_inode)
719 goto fput_in;
Jens Axboed96e6e72007-06-11 12:18:52 +0200720 if (!in_file->f_op || !in_file->f_op->splice_read)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 goto fput_in;
722 retval = -ESPIPE;
723 if (!ppos)
724 ppos = &in_file->f_pos;
725 else
726 if (!(in_file->f_mode & FMODE_PREAD))
727 goto fput_in;
728 retval = rw_verify_area(READ, in_file, ppos, count);
Linus Torvaldse28cc712006-01-04 16:20:40 -0800729 if (retval < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 goto fput_in;
Linus Torvaldse28cc712006-01-04 16:20:40 -0800731 count = retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 /*
734 * Get output file, and verify that it is ok..
735 */
736 retval = -EBADF;
737 out_file = fget_light(out_fd, &fput_needed_out);
738 if (!out_file)
739 goto fput_in;
740 if (!(out_file->f_mode & FMODE_WRITE))
741 goto fput_out;
742 retval = -EINVAL;
743 if (!out_file->f_op || !out_file->f_op->sendpage)
744 goto fput_out;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800745 out_inode = out_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);
Linus Torvaldse28cc712006-01-04 16:20:40 -0800747 if (retval < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 goto fput_out;
Linus Torvaldse28cc712006-01-04 16:20:40 -0800749 count = retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 if (!max)
752 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
753
754 pos = *ppos;
755 retval = -EINVAL;
756 if (unlikely(pos < 0))
757 goto fput_out;
758 if (unlikely(pos + count > max)) {
759 retval = -EOVERFLOW;
760 if (pos >= max)
761 goto fput_out;
762 count = max - pos;
763 }
764
Jens Axboed96e6e72007-06-11 12:18:52 +0200765 fl = 0;
Jens Axboe534f2aa2007-06-01 14:52:37 +0200766#if 0
Jens Axboed96e6e72007-06-11 12:18:52 +0200767 /*
768 * We need to debate whether we can enable this or not. The
769 * man page documents EAGAIN return for the output at least,
770 * and the application is arguably buggy if it doesn't expect
771 * EAGAIN on a non-blocking file descriptor.
772 */
773 if (in_file->f_flags & O_NONBLOCK)
774 fl = SPLICE_F_NONBLOCK;
Jens Axboe534f2aa2007-06-01 14:52:37 +0200775#endif
Jens Axboed96e6e72007-06-11 12:18:52 +0200776 retval = do_splice_direct(in_file, ppos, out_file, count, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
778 if (retval > 0) {
Alexey Dobriyan4b98d112007-02-10 01:46:45 -0800779 add_rchar(current, retval);
780 add_wchar(current, retval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
Alexey Dobriyan4b98d112007-02-10 01:46:45 -0800783 inc_syscr(current);
784 inc_syscw(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 if (*ppos > max)
786 retval = -EOVERFLOW;
787
788fput_out:
789 fput_light(out_file, fput_needed_out);
790fput_in:
791 fput_light(in_file, fput_needed_in);
792out:
793 return retval;
794}
795
796asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count)
797{
798 loff_t pos;
799 off_t off;
800 ssize_t ret;
801
802 if (offset) {
803 if (unlikely(get_user(off, offset)))
804 return -EFAULT;
805 pos = off;
806 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
807 if (unlikely(put_user(pos, offset)))
808 return -EFAULT;
809 return ret;
810 }
811
812 return do_sendfile(out_fd, in_fd, NULL, count, 0);
813}
814
815asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count)
816{
817 loff_t pos;
818 ssize_t ret;
819
820 if (offset) {
821 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
822 return -EFAULT;
823 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
824 if (unlikely(put_user(pos, offset)))
825 return -EFAULT;
826 return ret;
827 }
828
829 return do_sendfile(out_fd, in_fd, NULL, count, 0);
830}