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Commit | Line | Data |
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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 | ||
34 | loff_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 | ||
1b1dcc1b | 39 | mutex_lock(&inode->i_mutex); |
1da177e4 | 40 | switch (origin) { |
7b8e8924 | 41 | case SEEK_END: |
1da177e4 LT |
42 | offset += inode->i_size; |
43 | break; | |
7b8e8924 | 44 | case SEEK_CUR: |
1da177e4 LT |
45 | 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 | } | |
1b1dcc1b | 55 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
56 | return retval; |
57 | } | |
58 | ||
59 | EXPORT_SYMBOL(generic_file_llseek); | |
60 | ||
61 | loff_t remote_llseek(struct file *file, loff_t offset, int origin) | |
62 | { | |
63 | long long retval; | |
64 | ||
65 | lock_kernel(); | |
66 | switch (origin) { | |
7b8e8924 | 67 | case SEEK_END: |
0f7fc9e4 | 68 | offset += i_size_read(file->f_path.dentry->d_inode); |
1da177e4 | 69 | break; |
7b8e8924 | 70 | case SEEK_CUR: |
1da177e4 LT |
71 | offset += file->f_pos; |
72 | } | |
73 | retval = -EINVAL; | |
0f7fc9e4 | 74 | if (offset>=0 && offset<=file->f_path.dentry->d_inode->i_sb->s_maxbytes) { |
1da177e4 LT |
75 | 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 | } | |
84 | EXPORT_SYMBOL(remote_llseek); | |
85 | ||
86 | loff_t no_llseek(struct file *file, loff_t offset, int origin) | |
87 | { | |
88 | return -ESPIPE; | |
89 | } | |
90 | EXPORT_SYMBOL(no_llseek); | |
91 | ||
92 | loff_t default_llseek(struct file *file, loff_t offset, int origin) | |
93 | { | |
94 | long long retval; | |
95 | ||
96 | lock_kernel(); | |
97 | switch (origin) { | |
7b8e8924 | 98 | case SEEK_END: |
0f7fc9e4 | 99 | offset += i_size_read(file->f_path.dentry->d_inode); |
1da177e4 | 100 | break; |
7b8e8924 | 101 | case SEEK_CUR: |
1da177e4 LT |
102 | 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 | } | |
115 | EXPORT_SYMBOL(default_llseek); | |
116 | ||
117 | loff_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 | } | |
129 | EXPORT_SYMBOL(vfs_llseek); | |
130 | ||
131 | asmlinkage 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; | |
1ae7075b | 143 | if (origin <= SEEK_MAX) { |
1da177e4 LT |
144 | 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); | |
150 | bad: | |
151 | return retval; | |
152 | } | |
153 | ||
154 | #ifdef __ARCH_WANT_SYS_LLSEEK | |
155 | asmlinkage 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; | |
1ae7075b | 170 | if (origin > SEEK_MAX) |
1da177e4 LT |
171 | 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 | } | |
182 | out_putf: | |
183 | fput_light(file, fput_needed); | |
184 | bad: | |
185 | return retval; | |
186 | } | |
187 | #endif | |
188 | ||
e28cc715 LT |
189 | /* |
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) | |
1da177e4 LT |
195 | |
196 | int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) | |
197 | { | |
198 | struct inode *inode; | |
199 | loff_t pos; | |
c43e259c | 200 | int retval = -EINVAL; |
1da177e4 | 201 | |
163da958 | 202 | inode = file->f_path.dentry->d_inode; |
e28cc715 | 203 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 204 | return retval; |
1da177e4 LT |
205 | pos = *ppos; |
206 | if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) | |
c43e259c | 207 | return retval; |
1da177e4 | 208 | |
a16877ca | 209 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
c43e259c | 210 | retval = locks_mandatory_area( |
e28cc715 LT |
211 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
212 | inode, file, pos, count); | |
213 | if (retval < 0) | |
214 | return retval; | |
215 | } | |
c43e259c JM |
216 | retval = security_file_permission(file, |
217 | read_write == READ ? MAY_READ : MAY_WRITE); | |
218 | if (retval) | |
219 | return retval; | |
e28cc715 | 220 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
221 | } |
222 | ||
63e68809 BL |
223 | static 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 | ||
1da177e4 LT |
233 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
234 | { | |
027445c3 | 235 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
236 | struct kiocb kiocb; |
237 | ssize_t ret; | |
238 | ||
239 | init_sync_kiocb(&kiocb, filp); | |
240 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
241 | 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; | |
63e68809 | 247 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 248 | } |
63e68809 | 249 | |
1da177e4 LT |
250 | if (-EIOCBQUEUED == ret) |
251 | ret = wait_on_sync_kiocb(&kiocb); | |
252 | *ppos = kiocb.ki_pos; | |
253 | return ret; | |
254 | } | |
255 | ||
256 | EXPORT_SYMBOL(do_sync_read); | |
257 | ||
258 | ssize_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); | |
e28cc715 LT |
270 | if (ret >= 0) { |
271 | count = ret; | |
c43e259c JM |
272 | 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); | |
1da177e4 | 279 | } |
c43e259c | 280 | inc_syscr(current); |
1da177e4 LT |
281 | } |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
286 | EXPORT_SYMBOL(vfs_read); | |
287 | ||
288 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
289 | { | |
027445c3 | 290 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
291 | struct kiocb kiocb; |
292 | ssize_t ret; | |
293 | ||
294 | init_sync_kiocb(&kiocb, filp); | |
295 | kiocb.ki_pos = *ppos; | |
027445c3 BP |
296 | 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; | |
63e68809 | 302 | wait_on_retry_sync_kiocb(&kiocb); |
027445c3 | 303 | } |
63e68809 | 304 | |
1da177e4 LT |
305 | if (-EIOCBQUEUED == ret) |
306 | ret = wait_on_sync_kiocb(&kiocb); | |
307 | *ppos = kiocb.ki_pos; | |
308 | return ret; | |
309 | } | |
310 | ||
311 | EXPORT_SYMBOL(do_sync_write); | |
312 | ||
313 | ssize_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); | |
e28cc715 LT |
325 | if (ret >= 0) { |
326 | count = ret; | |
c43e259c JM |
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) { | |
332 | fsnotify_modify(file->f_path.dentry); | |
333 | add_wchar(current, ret); | |
1da177e4 | 334 | } |
c43e259c | 335 | inc_syscw(current); |
1da177e4 LT |
336 | } |
337 | ||
338 | return ret; | |
339 | } | |
340 | ||
341 | EXPORT_SYMBOL(vfs_write); | |
342 | ||
343 | static inline loff_t file_pos_read(struct file *file) | |
344 | { | |
345 | return file->f_pos; | |
346 | } | |
347 | ||
348 | static inline void file_pos_write(struct file *file, loff_t pos) | |
349 | { | |
350 | file->f_pos = pos; | |
351 | } | |
352 | ||
353 | asmlinkage 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 | } | |
cb51f973 | 369 | EXPORT_UNUSED_SYMBOL_GPL(sys_read); /* to be deleted for 2.6.25 */ |
1da177e4 LT |
370 | |
371 | asmlinkage 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 | ||
388 | asmlinkage 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 | ||
409 | asmlinkage 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 | */ | |
433 | unsigned 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 | } | |
19295529 | 449 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 450 | |
ee0b3e67 BP |
451 | ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
452 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) | |
453 | { | |
454 | struct kiocb kiocb; | |
455 | ssize_t ret; | |
456 | ||
457 | init_sync_kiocb(&kiocb, filp); | |
458 | kiocb.ki_pos = *ppos; | |
459 | kiocb.ki_left = len; | |
460 | kiocb.ki_nbytes = len; | |
461 | ||
462 | for (;;) { | |
463 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); | |
464 | if (ret != -EIOCBRETRY) | |
465 | break; | |
466 | wait_on_retry_sync_kiocb(&kiocb); | |
467 | } | |
468 | ||
469 | if (ret == -EIOCBQUEUED) | |
470 | ret = wait_on_sync_kiocb(&kiocb); | |
471 | *ppos = kiocb.ki_pos; | |
472 | return ret; | |
473 | } | |
474 | ||
475 | /* Do it by hand, with file-ops */ | |
476 | ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, | |
477 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) | |
478 | { | |
479 | struct iovec *vector = iov; | |
480 | ssize_t ret = 0; | |
481 | ||
482 | while (nr_segs > 0) { | |
483 | void __user *base; | |
484 | size_t len; | |
485 | ssize_t nr; | |
486 | ||
487 | base = vector->iov_base; | |
488 | len = vector->iov_len; | |
489 | vector++; | |
490 | nr_segs--; | |
491 | ||
492 | nr = fn(filp, base, len, ppos); | |
493 | ||
494 | if (nr < 0) { | |
495 | if (!ret) | |
496 | ret = nr; | |
497 | break; | |
498 | } | |
499 | ret += nr; | |
500 | if (nr != len) | |
501 | break; | |
502 | } | |
503 | ||
504 | return ret; | |
505 | } | |
506 | ||
1da177e4 LT |
507 | /* A write operation does a read from user space and vice versa */ |
508 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
509 | ||
eed4e51f BP |
510 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
511 | unsigned long nr_segs, unsigned long fast_segs, | |
512 | struct iovec *fast_pointer, | |
513 | struct iovec **ret_pointer) | |
514 | { | |
515 | unsigned long seg; | |
516 | ssize_t ret; | |
517 | struct iovec *iov = fast_pointer; | |
518 | ||
519 | /* | |
520 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
521 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
522 | * traditionally returned zero for zero segments, so... | |
523 | */ | |
524 | if (nr_segs == 0) { | |
525 | ret = 0; | |
526 | goto out; | |
527 | } | |
528 | ||
529 | /* | |
530 | * First get the "struct iovec" from user memory and | |
531 | * verify all the pointers | |
532 | */ | |
533 | if (nr_segs > UIO_MAXIOV) { | |
534 | ret = -EINVAL; | |
535 | goto out; | |
536 | } | |
537 | if (nr_segs > fast_segs) { | |
538 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
539 | if (iov == NULL) { | |
540 | ret = -ENOMEM; | |
541 | goto out; | |
542 | } | |
543 | } | |
544 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { | |
545 | ret = -EFAULT; | |
546 | goto out; | |
547 | } | |
548 | ||
549 | /* | |
550 | * According to the Single Unix Specification we should return EINVAL | |
551 | * if an element length is < 0 when cast to ssize_t or if the | |
552 | * total length would overflow the ssize_t return value of the | |
553 | * system call. | |
554 | */ | |
555 | ret = 0; | |
556 | for (seg = 0; seg < nr_segs; seg++) { | |
557 | void __user *buf = iov[seg].iov_base; | |
558 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
559 | ||
560 | /* see if we we're about to use an invalid len or if | |
561 | * it's about to overflow ssize_t */ | |
562 | if (len < 0 || (ret + len < ret)) { | |
563 | ret = -EINVAL; | |
564 | goto out; | |
565 | } | |
566 | if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { | |
567 | ret = -EFAULT; | |
568 | goto out; | |
569 | } | |
570 | ||
571 | ret += len; | |
572 | } | |
573 | out: | |
574 | *ret_pointer = iov; | |
575 | return ret; | |
576 | } | |
577 | ||
1da177e4 LT |
578 | static ssize_t do_readv_writev(int type, struct file *file, |
579 | const struct iovec __user * uvector, | |
580 | unsigned long nr_segs, loff_t *pos) | |
581 | { | |
1da177e4 LT |
582 | size_t tot_len; |
583 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 584 | struct iovec *iov = iovstack; |
1da177e4 | 585 | ssize_t ret; |
1da177e4 LT |
586 | io_fn_t fn; |
587 | iov_fn_t fnv; | |
588 | ||
eed4e51f BP |
589 | if (!file->f_op) { |
590 | ret = -EINVAL; | |
1da177e4 | 591 | goto out; |
1da177e4 | 592 | } |
1da177e4 | 593 | |
eed4e51f BP |
594 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
595 | ARRAY_SIZE(iovstack), iovstack, &iov); | |
596 | if (ret <= 0) | |
1da177e4 | 597 | goto out; |
1da177e4 | 598 | |
eed4e51f | 599 | tot_len = ret; |
1da177e4 | 600 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 601 | if (ret < 0) |
411b67b4 | 602 | goto out; |
1da177e4 LT |
603 | |
604 | fnv = NULL; | |
605 | if (type == READ) { | |
606 | fn = file->f_op->read; | |
ee0b3e67 | 607 | fnv = file->f_op->aio_read; |
1da177e4 LT |
608 | } else { |
609 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 610 | fnv = file->f_op->aio_write; |
1da177e4 LT |
611 | } |
612 | ||
ee0b3e67 BP |
613 | if (fnv) |
614 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
615 | pos, fnv); | |
616 | else | |
617 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 618 | |
1da177e4 LT |
619 | out: |
620 | if (iov != iovstack) | |
621 | kfree(iov); | |
0eeca283 RL |
622 | if ((ret + (type == READ)) > 0) { |
623 | if (type == READ) | |
0f7fc9e4 | 624 | fsnotify_access(file->f_path.dentry); |
0eeca283 | 625 | else |
0f7fc9e4 | 626 | fsnotify_modify(file->f_path.dentry); |
0eeca283 | 627 | } |
1da177e4 | 628 | return ret; |
1da177e4 LT |
629 | } |
630 | ||
631 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
632 | unsigned long vlen, loff_t *pos) | |
633 | { | |
634 | if (!(file->f_mode & FMODE_READ)) | |
635 | return -EBADF; | |
ee0b3e67 | 636 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4 LT |
637 | return -EINVAL; |
638 | ||
639 | return do_readv_writev(READ, file, vec, vlen, pos); | |
640 | } | |
641 | ||
642 | EXPORT_SYMBOL(vfs_readv); | |
643 | ||
644 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
645 | unsigned long vlen, loff_t *pos) | |
646 | { | |
647 | if (!(file->f_mode & FMODE_WRITE)) | |
648 | return -EBADF; | |
ee0b3e67 | 649 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4 LT |
650 | return -EINVAL; |
651 | ||
652 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
653 | } | |
654 | ||
655 | EXPORT_SYMBOL(vfs_writev); | |
656 | ||
657 | asmlinkage ssize_t | |
658 | sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
659 | { | |
660 | struct file *file; | |
661 | ssize_t ret = -EBADF; | |
662 | int fput_needed; | |
663 | ||
664 | file = fget_light(fd, &fput_needed); | |
665 | if (file) { | |
666 | loff_t pos = file_pos_read(file); | |
667 | ret = vfs_readv(file, vec, vlen, &pos); | |
668 | file_pos_write(file, pos); | |
669 | fput_light(file, fput_needed); | |
670 | } | |
671 | ||
672 | if (ret > 0) | |
4b98d11b AD |
673 | add_rchar(current, ret); |
674 | inc_syscr(current); | |
1da177e4 LT |
675 | return ret; |
676 | } | |
677 | ||
678 | asmlinkage ssize_t | |
679 | sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) | |
680 | { | |
681 | struct file *file; | |
682 | ssize_t ret = -EBADF; | |
683 | int fput_needed; | |
684 | ||
685 | file = fget_light(fd, &fput_needed); | |
686 | if (file) { | |
687 | loff_t pos = file_pos_read(file); | |
688 | ret = vfs_writev(file, vec, vlen, &pos); | |
689 | file_pos_write(file, pos); | |
690 | fput_light(file, fput_needed); | |
691 | } | |
692 | ||
693 | if (ret > 0) | |
4b98d11b AD |
694 | add_wchar(current, ret); |
695 | inc_syscw(current); | |
1da177e4 LT |
696 | return ret; |
697 | } | |
698 | ||
699 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, | |
700 | size_t count, loff_t max) | |
701 | { | |
702 | struct file * in_file, * out_file; | |
703 | struct inode * in_inode, * out_inode; | |
704 | loff_t pos; | |
705 | ssize_t retval; | |
534f2aaa | 706 | int fput_needed_in, fput_needed_out, fl; |
1da177e4 LT |
707 | |
708 | /* | |
709 | * Get input file, and verify that it is ok.. | |
710 | */ | |
711 | retval = -EBADF; | |
712 | in_file = fget_light(in_fd, &fput_needed_in); | |
713 | if (!in_file) | |
714 | goto out; | |
715 | if (!(in_file->f_mode & FMODE_READ)) | |
716 | goto fput_in; | |
717 | retval = -EINVAL; | |
0f7fc9e4 | 718 | in_inode = in_file->f_path.dentry->d_inode; |
1da177e4 LT |
719 | if (!in_inode) |
720 | goto fput_in; | |
d96e6e71 | 721 | if (!in_file->f_op || !in_file->f_op->splice_read) |
1da177e4 LT |
722 | goto fput_in; |
723 | retval = -ESPIPE; | |
724 | if (!ppos) | |
725 | ppos = &in_file->f_pos; | |
726 | else | |
727 | if (!(in_file->f_mode & FMODE_PREAD)) | |
728 | goto fput_in; | |
729 | retval = rw_verify_area(READ, in_file, ppos, count); | |
e28cc715 | 730 | if (retval < 0) |
1da177e4 | 731 | goto fput_in; |
e28cc715 | 732 | count = retval; |
1da177e4 | 733 | |
1da177e4 LT |
734 | /* |
735 | * Get output file, and verify that it is ok.. | |
736 | */ | |
737 | retval = -EBADF; | |
738 | out_file = fget_light(out_fd, &fput_needed_out); | |
739 | if (!out_file) | |
740 | goto fput_in; | |
741 | if (!(out_file->f_mode & FMODE_WRITE)) | |
742 | goto fput_out; | |
743 | retval = -EINVAL; | |
744 | if (!out_file->f_op || !out_file->f_op->sendpage) | |
745 | goto fput_out; | |
0f7fc9e4 | 746 | out_inode = out_file->f_path.dentry->d_inode; |
1da177e4 | 747 | retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); |
e28cc715 | 748 | if (retval < 0) |
1da177e4 | 749 | goto fput_out; |
e28cc715 | 750 | count = retval; |
1da177e4 | 751 | |
1da177e4 LT |
752 | if (!max) |
753 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
754 | ||
755 | pos = *ppos; | |
756 | retval = -EINVAL; | |
757 | if (unlikely(pos < 0)) | |
758 | goto fput_out; | |
759 | if (unlikely(pos + count > max)) { | |
760 | retval = -EOVERFLOW; | |
761 | if (pos >= max) | |
762 | goto fput_out; | |
763 | count = max - pos; | |
764 | } | |
765 | ||
d96e6e71 | 766 | fl = 0; |
534f2aaa | 767 | #if 0 |
d96e6e71 JA |
768 | /* |
769 | * We need to debate whether we can enable this or not. The | |
770 | * man page documents EAGAIN return for the output at least, | |
771 | * and the application is arguably buggy if it doesn't expect | |
772 | * EAGAIN on a non-blocking file descriptor. | |
773 | */ | |
774 | if (in_file->f_flags & O_NONBLOCK) | |
775 | fl = SPLICE_F_NONBLOCK; | |
534f2aaa | 776 | #endif |
d96e6e71 | 777 | retval = do_splice_direct(in_file, ppos, out_file, count, fl); |
1da177e4 LT |
778 | |
779 | if (retval > 0) { | |
4b98d11b AD |
780 | add_rchar(current, retval); |
781 | add_wchar(current, retval); | |
1da177e4 | 782 | } |
1da177e4 | 783 | |
4b98d11b AD |
784 | inc_syscr(current); |
785 | inc_syscw(current); | |
1da177e4 LT |
786 | if (*ppos > max) |
787 | retval = -EOVERFLOW; | |
788 | ||
789 | fput_out: | |
790 | fput_light(out_file, fput_needed_out); | |
791 | fput_in: | |
792 | fput_light(in_file, fput_needed_in); | |
793 | out: | |
794 | return retval; | |
795 | } | |
796 | ||
797 | asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count) | |
798 | { | |
799 | loff_t pos; | |
800 | off_t off; | |
801 | ssize_t ret; | |
802 | ||
803 | if (offset) { | |
804 | if (unlikely(get_user(off, offset))) | |
805 | return -EFAULT; | |
806 | pos = off; | |
807 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
808 | if (unlikely(put_user(pos, offset))) | |
809 | return -EFAULT; | |
810 | return ret; | |
811 | } | |
812 | ||
813 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
814 | } | |
815 | ||
816 | asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count) | |
817 | { | |
818 | loff_t pos; | |
819 | ssize_t ret; | |
820 | ||
821 | if (offset) { | |
822 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
823 | return -EFAULT; | |
824 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
825 | if (unlikely(put_user(pos, offset))) | |
826 | return -EFAULT; | |
827 | return ret; | |
828 | } | |
829 | ||
830 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
831 | } |