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> | |
a27bb332 | 12 | #include <linux/aio.h> |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 | 14 | #include <linux/security.h> |
630d9c47 | 15 | #include <linux/export.h> |
1da177e4 | 16 | #include <linux/syscalls.h> |
e28cc715 | 17 | #include <linux/pagemap.h> |
d6b29d7c | 18 | #include <linux/splice.h> |
561c6731 | 19 | #include <linux/compat.h> |
06ae43f3 | 20 | #include "internal.h" |
1da177e4 LT |
21 | |
22 | #include <asm/uaccess.h> | |
23 | #include <asm/unistd.h> | |
24 | ||
c0bd14af AV |
25 | typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *); |
26 | typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *, | |
27 | unsigned long, loff_t); | |
28 | ||
4b6f5d20 | 29 | const struct file_operations generic_ro_fops = { |
1da177e4 | 30 | .llseek = generic_file_llseek, |
543ade1f BP |
31 | .read = do_sync_read, |
32 | .aio_read = generic_file_aio_read, | |
1da177e4 | 33 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 34 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
35 | }; |
36 | ||
37 | EXPORT_SYMBOL(generic_ro_fops); | |
38 | ||
cccb5a1e | 39 | static inline int unsigned_offsets(struct file *file) |
4a3956c7 | 40 | { |
cccb5a1e | 41 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
42 | } |
43 | ||
46a1c2c7 JL |
44 | /** |
45 | * vfs_setpos - update the file offset for lseek | |
46 | * @file: file structure in question | |
47 | * @offset: file offset to seek to | |
48 | * @maxsize: maximum file size | |
49 | * | |
50 | * This is a low-level filesystem helper for updating the file offset to | |
51 | * the value specified by @offset if the given offset is valid and it is | |
52 | * not equal to the current file offset. | |
53 | * | |
54 | * Return the specified offset on success and -EINVAL on invalid offset. | |
55 | */ | |
56 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
57 | { |
58 | if (offset < 0 && !unsigned_offsets(file)) | |
59 | return -EINVAL; | |
60 | if (offset > maxsize) | |
61 | return -EINVAL; | |
62 | ||
63 | if (offset != file->f_pos) { | |
64 | file->f_pos = offset; | |
65 | file->f_version = 0; | |
66 | } | |
67 | return offset; | |
68 | } | |
46a1c2c7 | 69 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 70 | |
3a8cff4f | 71 | /** |
5760495a | 72 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
73 | * @file: file structure to seek on |
74 | * @offset: file offset to seek to | |
965c8e59 | 75 | * @whence: type of seek |
e8b96eb5 ES |
76 | * @size: max size of this file in file system |
77 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 78 | * |
5760495a | 79 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 80 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
81 | * |
82 | * Synchronization: | |
5760495a | 83 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
84 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
85 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 86 | */ |
9465efc9 | 87 | loff_t |
965c8e59 | 88 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 89 | loff_t maxsize, loff_t eof) |
1da177e4 | 90 | { |
965c8e59 | 91 | switch (whence) { |
3a8cff4f | 92 | case SEEK_END: |
e8b96eb5 | 93 | offset += eof; |
3a8cff4f CH |
94 | break; |
95 | case SEEK_CUR: | |
5b6f1eb9 AK |
96 | /* |
97 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
98 | * position-querying operation. Avoid rewriting the "same" | |
99 | * f_pos value back to the file because a concurrent read(), | |
100 | * write() or lseek() might have altered it | |
101 | */ | |
102 | if (offset == 0) | |
103 | return file->f_pos; | |
ef3d0fd2 AK |
104 | /* |
105 | * f_lock protects against read/modify/write race with other | |
106 | * SEEK_CURs. Note that parallel writes and reads behave | |
107 | * like SEEK_SET. | |
108 | */ | |
109 | spin_lock(&file->f_lock); | |
46a1c2c7 | 110 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
111 | spin_unlock(&file->f_lock); |
112 | return offset; | |
982d8165 JB |
113 | case SEEK_DATA: |
114 | /* | |
115 | * In the generic case the entire file is data, so as long as | |
116 | * offset isn't at the end of the file then the offset is data. | |
117 | */ | |
e8b96eb5 | 118 | if (offset >= eof) |
982d8165 JB |
119 | return -ENXIO; |
120 | break; | |
121 | case SEEK_HOLE: | |
122 | /* | |
123 | * There is a virtual hole at the end of the file, so as long as | |
124 | * offset isn't i_size or larger, return i_size. | |
125 | */ | |
e8b96eb5 | 126 | if (offset >= eof) |
982d8165 | 127 | return -ENXIO; |
e8b96eb5 | 128 | offset = eof; |
982d8165 | 129 | break; |
1da177e4 | 130 | } |
3a8cff4f | 131 | |
46a1c2c7 | 132 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
133 | } |
134 | EXPORT_SYMBOL(generic_file_llseek_size); | |
135 | ||
136 | /** | |
137 | * generic_file_llseek - generic llseek implementation for regular files | |
138 | * @file: file structure to seek on | |
139 | * @offset: file offset to seek to | |
965c8e59 | 140 | * @whence: type of seek |
5760495a AK |
141 | * |
142 | * This is a generic implemenation of ->llseek useable for all normal local | |
143 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 144 | * @offset and @whence. |
5760495a | 145 | */ |
965c8e59 | 146 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
147 | { |
148 | struct inode *inode = file->f_mapping->host; | |
149 | ||
965c8e59 | 150 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
151 | inode->i_sb->s_maxbytes, |
152 | i_size_read(inode)); | |
1da177e4 | 153 | } |
9465efc9 | 154 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 155 | |
1bf9d14d AV |
156 | /** |
157 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
158 | * @file: file structure to seek on | |
159 | * @offset: file offset to seek to | |
160 | * @whence: type of seek | |
161 | * @size: size of the file | |
162 | * | |
163 | */ | |
164 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
165 | { | |
166 | switch (whence) { | |
167 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
168 | return generic_file_llseek_size(file, offset, whence, | |
169 | size, size); | |
170 | default: | |
171 | return -EINVAL; | |
172 | } | |
173 | } | |
174 | EXPORT_SYMBOL(fixed_size_llseek); | |
175 | ||
ae6afc3f B |
176 | /** |
177 | * noop_llseek - No Operation Performed llseek implementation | |
178 | * @file: file structure to seek on | |
179 | * @offset: file offset to seek to | |
965c8e59 | 180 | * @whence: type of seek |
ae6afc3f B |
181 | * |
182 | * This is an implementation of ->llseek useable for the rare special case when | |
183 | * userspace expects the seek to succeed but the (device) file is actually not | |
184 | * able to perform the seek. In this case you use noop_llseek() instead of | |
185 | * falling back to the default implementation of ->llseek. | |
186 | */ | |
965c8e59 | 187 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
188 | { |
189 | return file->f_pos; | |
190 | } | |
191 | EXPORT_SYMBOL(noop_llseek); | |
192 | ||
965c8e59 | 193 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
194 | { |
195 | return -ESPIPE; | |
196 | } | |
197 | EXPORT_SYMBOL(no_llseek); | |
198 | ||
965c8e59 | 199 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 200 | { |
496ad9aa | 201 | struct inode *inode = file_inode(file); |
16abef0e | 202 | loff_t retval; |
1da177e4 | 203 | |
982d8165 | 204 | mutex_lock(&inode->i_mutex); |
965c8e59 | 205 | switch (whence) { |
7b8e8924 | 206 | case SEEK_END: |
982d8165 | 207 | offset += i_size_read(inode); |
1da177e4 | 208 | break; |
7b8e8924 | 209 | case SEEK_CUR: |
5b6f1eb9 AK |
210 | if (offset == 0) { |
211 | retval = file->f_pos; | |
212 | goto out; | |
213 | } | |
1da177e4 | 214 | offset += file->f_pos; |
982d8165 JB |
215 | break; |
216 | case SEEK_DATA: | |
217 | /* | |
218 | * In the generic case the entire file is data, so as | |
219 | * long as offset isn't at the end of the file then the | |
220 | * offset is data. | |
221 | */ | |
bacb2d81 DC |
222 | if (offset >= inode->i_size) { |
223 | retval = -ENXIO; | |
224 | goto out; | |
225 | } | |
982d8165 JB |
226 | break; |
227 | case SEEK_HOLE: | |
228 | /* | |
229 | * There is a virtual hole at the end of the file, so | |
230 | * as long as offset isn't i_size or larger, return | |
231 | * i_size. | |
232 | */ | |
bacb2d81 DC |
233 | if (offset >= inode->i_size) { |
234 | retval = -ENXIO; | |
235 | goto out; | |
236 | } | |
982d8165 JB |
237 | offset = inode->i_size; |
238 | break; | |
1da177e4 LT |
239 | } |
240 | retval = -EINVAL; | |
cccb5a1e | 241 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
242 | if (offset != file->f_pos) { |
243 | file->f_pos = offset; | |
244 | file->f_version = 0; | |
245 | } | |
246 | retval = offset; | |
247 | } | |
5b6f1eb9 | 248 | out: |
982d8165 | 249 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
250 | return retval; |
251 | } | |
252 | EXPORT_SYMBOL(default_llseek); | |
253 | ||
965c8e59 | 254 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
255 | { |
256 | loff_t (*fn)(struct file *, loff_t, int); | |
257 | ||
258 | fn = no_llseek; | |
259 | if (file->f_mode & FMODE_LSEEK) { | |
1da177e4 LT |
260 | if (file->f_op && file->f_op->llseek) |
261 | fn = file->f_op->llseek; | |
262 | } | |
965c8e59 | 263 | return fn(file, offset, whence); |
1da177e4 LT |
264 | } |
265 | EXPORT_SYMBOL(vfs_llseek); | |
266 | ||
965c8e59 | 267 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
1da177e4 LT |
268 | { |
269 | off_t retval; | |
2903ff01 AV |
270 | struct fd f = fdget(fd); |
271 | if (!f.file) | |
272 | return -EBADF; | |
1da177e4 LT |
273 | |
274 | retval = -EINVAL; | |
965c8e59 AM |
275 | if (whence <= SEEK_MAX) { |
276 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
277 | retval = res; |
278 | if (res != (loff_t)retval) | |
279 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
280 | } | |
2903ff01 | 281 | fdput(f); |
1da177e4 LT |
282 | return retval; |
283 | } | |
284 | ||
561c6731 AV |
285 | #ifdef CONFIG_COMPAT |
286 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
287 | { | |
288 | return sys_lseek(fd, offset, whence); | |
289 | } | |
290 | #endif | |
291 | ||
1da177e4 | 292 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
293 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
294 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 295 | unsigned int, whence) |
1da177e4 LT |
296 | { |
297 | int retval; | |
2903ff01 | 298 | struct fd f = fdget(fd); |
1da177e4 | 299 | loff_t offset; |
1da177e4 | 300 | |
2903ff01 AV |
301 | if (!f.file) |
302 | return -EBADF; | |
1da177e4 LT |
303 | |
304 | retval = -EINVAL; | |
965c8e59 | 305 | if (whence > SEEK_MAX) |
1da177e4 LT |
306 | goto out_putf; |
307 | ||
2903ff01 | 308 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 309 | whence); |
1da177e4 LT |
310 | |
311 | retval = (int)offset; | |
312 | if (offset >= 0) { | |
313 | retval = -EFAULT; | |
314 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
315 | retval = 0; | |
316 | } | |
317 | out_putf: | |
2903ff01 | 318 | fdput(f); |
1da177e4 LT |
319 | return retval; |
320 | } | |
321 | #endif | |
322 | ||
e28cc715 LT |
323 | /* |
324 | * rw_verify_area doesn't like huge counts. We limit | |
325 | * them to something that fits in "int" so that others | |
326 | * won't have to do range checks all the time. | |
327 | */ | |
68d70d03 | 328 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
329 | { |
330 | struct inode *inode; | |
331 | loff_t pos; | |
c43e259c | 332 | int retval = -EINVAL; |
1da177e4 | 333 | |
496ad9aa | 334 | inode = file_inode(file); |
e28cc715 | 335 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 336 | return retval; |
1da177e4 | 337 | pos = *ppos; |
cccb5a1e AV |
338 | if (unlikely(pos < 0)) { |
339 | if (!unsigned_offsets(file)) | |
340 | return retval; | |
341 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
342 | return -EOVERFLOW; | |
343 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
344 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
345 | return retval; |
346 | } | |
1da177e4 | 347 | |
a16877ca | 348 | if (unlikely(inode->i_flock && mandatory_lock(inode))) { |
c43e259c | 349 | retval = locks_mandatory_area( |
e28cc715 LT |
350 | read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE, |
351 | inode, file, pos, count); | |
352 | if (retval < 0) | |
353 | return retval; | |
354 | } | |
c43e259c JM |
355 | retval = security_file_permission(file, |
356 | read_write == READ ? MAY_READ : MAY_WRITE); | |
357 | if (retval) | |
358 | return retval; | |
e28cc715 | 359 | return count > MAX_RW_COUNT ? MAX_RW_COUNT : count; |
1da177e4 LT |
360 | } |
361 | ||
362 | ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) | |
363 | { | |
027445c3 | 364 | struct iovec iov = { .iov_base = buf, .iov_len = len }; |
1da177e4 LT |
365 | struct kiocb kiocb; |
366 | ssize_t ret; | |
367 | ||
368 | init_sync_kiocb(&kiocb, filp); | |
369 | kiocb.ki_pos = *ppos; | |
027445c3 | 370 | kiocb.ki_left = len; |
61964eba | 371 | kiocb.ki_nbytes = len; |
027445c3 | 372 | |
41003a7b | 373 | ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
374 | if (-EIOCBQUEUED == ret) |
375 | ret = wait_on_sync_kiocb(&kiocb); | |
376 | *ppos = kiocb.ki_pos; | |
377 | return ret; | |
378 | } | |
379 | ||
380 | EXPORT_SYMBOL(do_sync_read); | |
381 | ||
382 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) | |
383 | { | |
384 | ssize_t ret; | |
385 | ||
386 | if (!(file->f_mode & FMODE_READ)) | |
387 | return -EBADF; | |
388 | if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read)) | |
389 | return -EINVAL; | |
390 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
391 | return -EFAULT; | |
392 | ||
393 | ret = rw_verify_area(READ, file, pos, count); | |
e28cc715 LT |
394 | if (ret >= 0) { |
395 | count = ret; | |
c43e259c JM |
396 | if (file->f_op->read) |
397 | ret = file->f_op->read(file, buf, count, pos); | |
398 | else | |
399 | ret = do_sync_read(file, buf, count, pos); | |
400 | if (ret > 0) { | |
2a12a9d7 | 401 | fsnotify_access(file); |
c43e259c | 402 | add_rchar(current, ret); |
1da177e4 | 403 | } |
c43e259c | 404 | inc_syscr(current); |
1da177e4 LT |
405 | } |
406 | ||
407 | return ret; | |
408 | } | |
409 | ||
410 | EXPORT_SYMBOL(vfs_read); | |
411 | ||
412 | ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) | |
413 | { | |
027445c3 | 414 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; |
1da177e4 LT |
415 | struct kiocb kiocb; |
416 | ssize_t ret; | |
417 | ||
418 | init_sync_kiocb(&kiocb, filp); | |
419 | kiocb.ki_pos = *ppos; | |
027445c3 | 420 | kiocb.ki_left = len; |
61964eba | 421 | kiocb.ki_nbytes = len; |
027445c3 | 422 | |
41003a7b | 423 | ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos); |
1da177e4 LT |
424 | if (-EIOCBQUEUED == ret) |
425 | ret = wait_on_sync_kiocb(&kiocb); | |
426 | *ppos = kiocb.ki_pos; | |
427 | return ret; | |
428 | } | |
429 | ||
430 | EXPORT_SYMBOL(do_sync_write); | |
431 | ||
06ae43f3 AV |
432 | ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos) |
433 | { | |
434 | mm_segment_t old_fs; | |
435 | const char __user *p; | |
436 | ssize_t ret; | |
437 | ||
3e84f48e AV |
438 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) |
439 | return -EINVAL; | |
440 | ||
06ae43f3 AV |
441 | old_fs = get_fs(); |
442 | set_fs(get_ds()); | |
443 | p = (__force const char __user *)buf; | |
444 | if (count > MAX_RW_COUNT) | |
445 | count = MAX_RW_COUNT; | |
446 | if (file->f_op->write) | |
447 | ret = file->f_op->write(file, p, count, pos); | |
448 | else | |
449 | ret = do_sync_write(file, p, count, pos); | |
450 | set_fs(old_fs); | |
451 | if (ret > 0) { | |
452 | fsnotify_modify(file); | |
453 | add_wchar(current, ret); | |
454 | } | |
455 | inc_syscw(current); | |
456 | return ret; | |
457 | } | |
458 | ||
1da177e4 LT |
459 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
460 | { | |
461 | ssize_t ret; | |
462 | ||
463 | if (!(file->f_mode & FMODE_WRITE)) | |
464 | return -EBADF; | |
465 | if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write)) | |
466 | return -EINVAL; | |
467 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
468 | return -EFAULT; | |
469 | ||
470 | ret = rw_verify_area(WRITE, file, pos, count); | |
e28cc715 LT |
471 | if (ret >= 0) { |
472 | count = ret; | |
03d95eb2 | 473 | file_start_write(file); |
c43e259c JM |
474 | if (file->f_op->write) |
475 | ret = file->f_op->write(file, buf, count, pos); | |
476 | else | |
477 | ret = do_sync_write(file, buf, count, pos); | |
478 | if (ret > 0) { | |
2a12a9d7 | 479 | fsnotify_modify(file); |
c43e259c | 480 | add_wchar(current, ret); |
1da177e4 | 481 | } |
c43e259c | 482 | inc_syscw(current); |
03d95eb2 | 483 | file_end_write(file); |
1da177e4 LT |
484 | } |
485 | ||
486 | return ret; | |
487 | } | |
488 | ||
489 | EXPORT_SYMBOL(vfs_write); | |
490 | ||
491 | static inline loff_t file_pos_read(struct file *file) | |
492 | { | |
493 | return file->f_pos; | |
494 | } | |
495 | ||
496 | static inline void file_pos_write(struct file *file, loff_t pos) | |
497 | { | |
498 | file->f_pos = pos; | |
499 | } | |
500 | ||
3cdad428 | 501 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 502 | { |
2903ff01 | 503 | struct fd f = fdget(fd); |
1da177e4 | 504 | ssize_t ret = -EBADF; |
1da177e4 | 505 | |
2903ff01 AV |
506 | if (f.file) { |
507 | loff_t pos = file_pos_read(f.file); | |
508 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
509 | if (ret >= 0) |
510 | file_pos_write(f.file, pos); | |
2903ff01 | 511 | fdput(f); |
1da177e4 | 512 | } |
1da177e4 LT |
513 | return ret; |
514 | } | |
1da177e4 | 515 | |
3cdad428 HC |
516 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
517 | size_t, count) | |
1da177e4 | 518 | { |
2903ff01 | 519 | struct fd f = fdget(fd); |
1da177e4 | 520 | ssize_t ret = -EBADF; |
1da177e4 | 521 | |
2903ff01 AV |
522 | if (f.file) { |
523 | loff_t pos = file_pos_read(f.file); | |
524 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
525 | if (ret >= 0) |
526 | file_pos_write(f.file, pos); | |
2903ff01 | 527 | fdput(f); |
1da177e4 LT |
528 | } |
529 | ||
530 | return ret; | |
531 | } | |
532 | ||
4a0fd5bf AV |
533 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
534 | size_t, count, loff_t, pos) | |
1da177e4 | 535 | { |
2903ff01 | 536 | struct fd f; |
1da177e4 | 537 | ssize_t ret = -EBADF; |
1da177e4 LT |
538 | |
539 | if (pos < 0) | |
540 | return -EINVAL; | |
541 | ||
2903ff01 AV |
542 | f = fdget(fd); |
543 | if (f.file) { | |
1da177e4 | 544 | ret = -ESPIPE; |
2903ff01 AV |
545 | if (f.file->f_mode & FMODE_PREAD) |
546 | ret = vfs_read(f.file, buf, count, &pos); | |
547 | fdput(f); | |
1da177e4 LT |
548 | } |
549 | ||
550 | return ret; | |
551 | } | |
552 | ||
4a0fd5bf AV |
553 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
554 | size_t, count, loff_t, pos) | |
1da177e4 | 555 | { |
2903ff01 | 556 | struct fd f; |
1da177e4 | 557 | ssize_t ret = -EBADF; |
1da177e4 LT |
558 | |
559 | if (pos < 0) | |
560 | return -EINVAL; | |
561 | ||
2903ff01 AV |
562 | f = fdget(fd); |
563 | if (f.file) { | |
1da177e4 | 564 | ret = -ESPIPE; |
2903ff01 AV |
565 | if (f.file->f_mode & FMODE_PWRITE) |
566 | ret = vfs_write(f.file, buf, count, &pos); | |
567 | fdput(f); | |
1da177e4 LT |
568 | } |
569 | ||
570 | return ret; | |
571 | } | |
572 | ||
573 | /* | |
574 | * Reduce an iovec's length in-place. Return the resulting number of segments | |
575 | */ | |
576 | unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) | |
577 | { | |
578 | unsigned long seg = 0; | |
579 | size_t len = 0; | |
580 | ||
581 | while (seg < nr_segs) { | |
582 | seg++; | |
583 | if (len + iov->iov_len >= to) { | |
584 | iov->iov_len = to - len; | |
585 | break; | |
586 | } | |
587 | len += iov->iov_len; | |
588 | iov++; | |
589 | } | |
590 | return seg; | |
591 | } | |
19295529 | 592 | EXPORT_SYMBOL(iov_shorten); |
1da177e4 | 593 | |
72ec3516 | 594 | static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, |
ee0b3e67 BP |
595 | unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn) |
596 | { | |
597 | struct kiocb kiocb; | |
598 | ssize_t ret; | |
599 | ||
600 | init_sync_kiocb(&kiocb, filp); | |
601 | kiocb.ki_pos = *ppos; | |
602 | kiocb.ki_left = len; | |
603 | kiocb.ki_nbytes = len; | |
604 | ||
41003a7b | 605 | ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos); |
ee0b3e67 BP |
606 | if (ret == -EIOCBQUEUED) |
607 | ret = wait_on_sync_kiocb(&kiocb); | |
608 | *ppos = kiocb.ki_pos; | |
609 | return ret; | |
610 | } | |
611 | ||
612 | /* Do it by hand, with file-ops */ | |
72ec3516 | 613 | static ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, |
ee0b3e67 BP |
614 | unsigned long nr_segs, loff_t *ppos, io_fn_t fn) |
615 | { | |
616 | struct iovec *vector = iov; | |
617 | ssize_t ret = 0; | |
618 | ||
619 | while (nr_segs > 0) { | |
620 | void __user *base; | |
621 | size_t len; | |
622 | ssize_t nr; | |
623 | ||
624 | base = vector->iov_base; | |
625 | len = vector->iov_len; | |
626 | vector++; | |
627 | nr_segs--; | |
628 | ||
629 | nr = fn(filp, base, len, ppos); | |
630 | ||
631 | if (nr < 0) { | |
632 | if (!ret) | |
633 | ret = nr; | |
634 | break; | |
635 | } | |
636 | ret += nr; | |
637 | if (nr != len) | |
638 | break; | |
639 | } | |
640 | ||
641 | return ret; | |
642 | } | |
643 | ||
1da177e4 LT |
644 | /* A write operation does a read from user space and vice versa */ |
645 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
646 | ||
eed4e51f BP |
647 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
648 | unsigned long nr_segs, unsigned long fast_segs, | |
649 | struct iovec *fast_pointer, | |
ac34ebb3 | 650 | struct iovec **ret_pointer) |
435f49a5 | 651 | { |
eed4e51f | 652 | unsigned long seg; |
435f49a5 | 653 | ssize_t ret; |
eed4e51f BP |
654 | struct iovec *iov = fast_pointer; |
655 | ||
435f49a5 LT |
656 | /* |
657 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
658 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
659 | * traditionally returned zero for zero segments, so... | |
660 | */ | |
eed4e51f BP |
661 | if (nr_segs == 0) { |
662 | ret = 0; | |
435f49a5 | 663 | goto out; |
eed4e51f BP |
664 | } |
665 | ||
435f49a5 LT |
666 | /* |
667 | * First get the "struct iovec" from user memory and | |
668 | * verify all the pointers | |
669 | */ | |
eed4e51f BP |
670 | if (nr_segs > UIO_MAXIOV) { |
671 | ret = -EINVAL; | |
435f49a5 | 672 | goto out; |
eed4e51f BP |
673 | } |
674 | if (nr_segs > fast_segs) { | |
435f49a5 | 675 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
676 | if (iov == NULL) { |
677 | ret = -ENOMEM; | |
435f49a5 | 678 | goto out; |
eed4e51f | 679 | } |
435f49a5 | 680 | } |
eed4e51f BP |
681 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
682 | ret = -EFAULT; | |
435f49a5 | 683 | goto out; |
eed4e51f BP |
684 | } |
685 | ||
435f49a5 | 686 | /* |
eed4e51f BP |
687 | * According to the Single Unix Specification we should return EINVAL |
688 | * if an element length is < 0 when cast to ssize_t or if the | |
689 | * total length would overflow the ssize_t return value of the | |
690 | * system call. | |
435f49a5 LT |
691 | * |
692 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
693 | * overflow case. | |
694 | */ | |
eed4e51f | 695 | ret = 0; |
435f49a5 LT |
696 | for (seg = 0; seg < nr_segs; seg++) { |
697 | void __user *buf = iov[seg].iov_base; | |
698 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
699 | |
700 | /* see if we we're about to use an invalid len or if | |
701 | * it's about to overflow ssize_t */ | |
435f49a5 | 702 | if (len < 0) { |
eed4e51f | 703 | ret = -EINVAL; |
435f49a5 | 704 | goto out; |
eed4e51f | 705 | } |
ac34ebb3 | 706 | if (type >= 0 |
fcf63409 | 707 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 708 | ret = -EFAULT; |
435f49a5 LT |
709 | goto out; |
710 | } | |
711 | if (len > MAX_RW_COUNT - ret) { | |
712 | len = MAX_RW_COUNT - ret; | |
713 | iov[seg].iov_len = len; | |
eed4e51f | 714 | } |
eed4e51f | 715 | ret += len; |
435f49a5 | 716 | } |
eed4e51f BP |
717 | out: |
718 | *ret_pointer = iov; | |
719 | return ret; | |
720 | } | |
721 | ||
1da177e4 LT |
722 | static ssize_t do_readv_writev(int type, struct file *file, |
723 | const struct iovec __user * uvector, | |
724 | unsigned long nr_segs, loff_t *pos) | |
725 | { | |
1da177e4 LT |
726 | size_t tot_len; |
727 | struct iovec iovstack[UIO_FASTIOV]; | |
ee0b3e67 | 728 | struct iovec *iov = iovstack; |
1da177e4 | 729 | ssize_t ret; |
1da177e4 LT |
730 | io_fn_t fn; |
731 | iov_fn_t fnv; | |
732 | ||
eed4e51f BP |
733 | if (!file->f_op) { |
734 | ret = -EINVAL; | |
1da177e4 | 735 | goto out; |
1da177e4 | 736 | } |
1da177e4 | 737 | |
eed4e51f | 738 | ret = rw_copy_check_uvector(type, uvector, nr_segs, |
ac34ebb3 | 739 | ARRAY_SIZE(iovstack), iovstack, &iov); |
eed4e51f | 740 | if (ret <= 0) |
1da177e4 | 741 | goto out; |
1da177e4 | 742 | |
eed4e51f | 743 | tot_len = ret; |
1da177e4 | 744 | ret = rw_verify_area(type, file, pos, tot_len); |
e28cc715 | 745 | if (ret < 0) |
411b67b4 | 746 | goto out; |
1da177e4 LT |
747 | |
748 | fnv = NULL; | |
749 | if (type == READ) { | |
750 | fn = file->f_op->read; | |
ee0b3e67 | 751 | fnv = file->f_op->aio_read; |
1da177e4 LT |
752 | } else { |
753 | fn = (io_fn_t)file->f_op->write; | |
ee0b3e67 | 754 | fnv = file->f_op->aio_write; |
03d95eb2 | 755 | file_start_write(file); |
1da177e4 LT |
756 | } |
757 | ||
ee0b3e67 BP |
758 | if (fnv) |
759 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, | |
760 | pos, fnv); | |
761 | else | |
762 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); | |
1da177e4 | 763 | |
03d95eb2 AV |
764 | if (type != READ) |
765 | file_end_write(file); | |
766 | ||
1da177e4 LT |
767 | out: |
768 | if (iov != iovstack) | |
769 | kfree(iov); | |
0eeca283 RL |
770 | if ((ret + (type == READ)) > 0) { |
771 | if (type == READ) | |
2a12a9d7 | 772 | fsnotify_access(file); |
0eeca283 | 773 | else |
2a12a9d7 | 774 | fsnotify_modify(file); |
0eeca283 | 775 | } |
1da177e4 | 776 | return ret; |
1da177e4 LT |
777 | } |
778 | ||
779 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, | |
780 | unsigned long vlen, loff_t *pos) | |
781 | { | |
782 | if (!(file->f_mode & FMODE_READ)) | |
783 | return -EBADF; | |
ee0b3e67 | 784 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) |
1da177e4 LT |
785 | return -EINVAL; |
786 | ||
787 | return do_readv_writev(READ, file, vec, vlen, pos); | |
788 | } | |
789 | ||
790 | EXPORT_SYMBOL(vfs_readv); | |
791 | ||
792 | ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, | |
793 | unsigned long vlen, loff_t *pos) | |
794 | { | |
795 | if (!(file->f_mode & FMODE_WRITE)) | |
796 | return -EBADF; | |
ee0b3e67 | 797 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) |
1da177e4 LT |
798 | return -EINVAL; |
799 | ||
800 | return do_readv_writev(WRITE, file, vec, vlen, pos); | |
801 | } | |
802 | ||
803 | EXPORT_SYMBOL(vfs_writev); | |
804 | ||
3cdad428 HC |
805 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
806 | unsigned long, vlen) | |
1da177e4 | 807 | { |
2903ff01 | 808 | struct fd f = fdget(fd); |
1da177e4 | 809 | ssize_t ret = -EBADF; |
1da177e4 | 810 | |
2903ff01 AV |
811 | if (f.file) { |
812 | loff_t pos = file_pos_read(f.file); | |
813 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
814 | if (ret >= 0) |
815 | file_pos_write(f.file, pos); | |
2903ff01 | 816 | fdput(f); |
1da177e4 LT |
817 | } |
818 | ||
819 | if (ret > 0) | |
4b98d11b AD |
820 | add_rchar(current, ret); |
821 | inc_syscr(current); | |
1da177e4 LT |
822 | return ret; |
823 | } | |
824 | ||
3cdad428 HC |
825 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, |
826 | unsigned long, vlen) | |
1da177e4 | 827 | { |
2903ff01 | 828 | struct fd f = fdget(fd); |
1da177e4 | 829 | ssize_t ret = -EBADF; |
1da177e4 | 830 | |
2903ff01 AV |
831 | if (f.file) { |
832 | loff_t pos = file_pos_read(f.file); | |
833 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
834 | if (ret >= 0) |
835 | file_pos_write(f.file, pos); | |
2903ff01 | 836 | fdput(f); |
1da177e4 LT |
837 | } |
838 | ||
839 | if (ret > 0) | |
4b98d11b AD |
840 | add_wchar(current, ret); |
841 | inc_syscw(current); | |
1da177e4 LT |
842 | return ret; |
843 | } | |
844 | ||
601cc11d LT |
845 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
846 | { | |
847 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
848 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
849 | } | |
850 | ||
f3554f4b | 851 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, |
601cc11d | 852 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 853 | { |
601cc11d | 854 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 855 | struct fd f; |
f3554f4b | 856 | ssize_t ret = -EBADF; |
f3554f4b GH |
857 | |
858 | if (pos < 0) | |
859 | return -EINVAL; | |
860 | ||
2903ff01 AV |
861 | f = fdget(fd); |
862 | if (f.file) { | |
f3554f4b | 863 | ret = -ESPIPE; |
2903ff01 AV |
864 | if (f.file->f_mode & FMODE_PREAD) |
865 | ret = vfs_readv(f.file, vec, vlen, &pos); | |
866 | fdput(f); | |
f3554f4b GH |
867 | } |
868 | ||
869 | if (ret > 0) | |
870 | add_rchar(current, ret); | |
871 | inc_syscr(current); | |
872 | return ret; | |
873 | } | |
874 | ||
875 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
601cc11d | 876 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) |
f3554f4b | 877 | { |
601cc11d | 878 | loff_t pos = pos_from_hilo(pos_h, pos_l); |
2903ff01 | 879 | struct fd f; |
f3554f4b | 880 | ssize_t ret = -EBADF; |
f3554f4b GH |
881 | |
882 | if (pos < 0) | |
883 | return -EINVAL; | |
884 | ||
2903ff01 AV |
885 | f = fdget(fd); |
886 | if (f.file) { | |
f3554f4b | 887 | ret = -ESPIPE; |
2903ff01 AV |
888 | if (f.file->f_mode & FMODE_PWRITE) |
889 | ret = vfs_writev(f.file, vec, vlen, &pos); | |
890 | fdput(f); | |
f3554f4b GH |
891 | } |
892 | ||
893 | if (ret > 0) | |
894 | add_wchar(current, ret); | |
895 | inc_syscw(current); | |
896 | return ret; | |
897 | } | |
898 | ||
72ec3516 AV |
899 | #ifdef CONFIG_COMPAT |
900 | ||
901 | static ssize_t compat_do_readv_writev(int type, struct file *file, | |
902 | const struct compat_iovec __user *uvector, | |
903 | unsigned long nr_segs, loff_t *pos) | |
904 | { | |
905 | compat_ssize_t tot_len; | |
906 | struct iovec iovstack[UIO_FASTIOV]; | |
907 | struct iovec *iov = iovstack; | |
908 | ssize_t ret; | |
909 | io_fn_t fn; | |
910 | iov_fn_t fnv; | |
911 | ||
912 | ret = -EINVAL; | |
913 | if (!file->f_op) | |
914 | goto out; | |
915 | ||
916 | ret = -EFAULT; | |
917 | if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) | |
918 | goto out; | |
919 | ||
920 | ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, | |
921 | UIO_FASTIOV, iovstack, &iov); | |
922 | if (ret <= 0) | |
923 | goto out; | |
924 | ||
925 | tot_len = ret; | |
926 | ret = rw_verify_area(type, file, pos, tot_len); | |
927 | if (ret < 0) | |
928 | goto out; | |
929 | ||
930 | fnv = NULL; | |
931 | if (type == READ) { | |
932 | fn = file->f_op->read; | |
933 | fnv = file->f_op->aio_read; | |
934 | } else { | |
935 | fn = (io_fn_t)file->f_op->write; | |
936 | fnv = file->f_op->aio_write; | |
03d95eb2 | 937 | file_start_write(file); |
72ec3516 AV |
938 | } |
939 | ||
03d95eb2 | 940 | if (fnv) |
72ec3516 AV |
941 | ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, |
942 | pos, fnv); | |
03d95eb2 | 943 | else |
72ec3516 AV |
944 | ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn); |
945 | ||
03d95eb2 AV |
946 | if (type != READ) |
947 | file_end_write(file); | |
948 | ||
72ec3516 AV |
949 | out: |
950 | if (iov != iovstack) | |
951 | kfree(iov); | |
952 | if ((ret + (type == READ)) > 0) { | |
953 | if (type == READ) | |
954 | fsnotify_access(file); | |
955 | else | |
956 | fsnotify_modify(file); | |
957 | } | |
958 | return ret; | |
959 | } | |
960 | ||
961 | static size_t compat_readv(struct file *file, | |
962 | const struct compat_iovec __user *vec, | |
963 | unsigned long vlen, loff_t *pos) | |
964 | { | |
965 | ssize_t ret = -EBADF; | |
966 | ||
967 | if (!(file->f_mode & FMODE_READ)) | |
968 | goto out; | |
969 | ||
970 | ret = -EINVAL; | |
971 | if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) | |
972 | goto out; | |
973 | ||
974 | ret = compat_do_readv_writev(READ, file, vec, vlen, pos); | |
975 | ||
976 | out: | |
977 | if (ret > 0) | |
978 | add_rchar(current, ret); | |
979 | inc_syscr(current); | |
980 | return ret; | |
981 | } | |
982 | ||
983 | COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd, | |
984 | const struct compat_iovec __user *,vec, | |
985 | unsigned long, vlen) | |
986 | { | |
987 | struct fd f = fdget(fd); | |
988 | ssize_t ret; | |
989 | loff_t pos; | |
990 | ||
991 | if (!f.file) | |
992 | return -EBADF; | |
993 | pos = f.file->f_pos; | |
994 | ret = compat_readv(f.file, vec, vlen, &pos); | |
5faf153e AV |
995 | if (ret >= 0) |
996 | f.file->f_pos = pos; | |
72ec3516 AV |
997 | fdput(f); |
998 | return ret; | |
999 | } | |
1000 | ||
1001 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1002 | const struct compat_iovec __user *,vec, | |
1003 | unsigned long, vlen, loff_t, pos) | |
1004 | { | |
1005 | struct fd f; | |
1006 | ssize_t ret; | |
1007 | ||
1008 | if (pos < 0) | |
1009 | return -EINVAL; | |
1010 | f = fdget(fd); | |
1011 | if (!f.file) | |
1012 | return -EBADF; | |
1013 | ret = -ESPIPE; | |
1014 | if (f.file->f_mode & FMODE_PREAD) | |
1015 | ret = compat_readv(f.file, vec, vlen, &pos); | |
1016 | fdput(f); | |
1017 | return ret; | |
1018 | } | |
1019 | ||
1020 | COMPAT_SYSCALL_DEFINE5(preadv, unsigned long, fd, | |
1021 | const struct compat_iovec __user *,vec, | |
1022 | unsigned long, vlen, u32, pos_low, u32, pos_high) | |
1023 | { | |
1024 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1025 | return compat_sys_preadv64(fd, vec, vlen, pos); | |
1026 | } | |
1027 | ||
1028 | static size_t compat_writev(struct file *file, | |
1029 | const struct compat_iovec __user *vec, | |
1030 | unsigned long vlen, loff_t *pos) | |
1031 | { | |
1032 | ssize_t ret = -EBADF; | |
1033 | ||
1034 | if (!(file->f_mode & FMODE_WRITE)) | |
1035 | goto out; | |
1036 | ||
1037 | ret = -EINVAL; | |
1038 | if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) | |
1039 | goto out; | |
1040 | ||
1041 | ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); | |
1042 | ||
1043 | out: | |
1044 | if (ret > 0) | |
1045 | add_wchar(current, ret); | |
1046 | inc_syscw(current); | |
1047 | return ret; | |
1048 | } | |
1049 | ||
1050 | COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd, | |
1051 | const struct compat_iovec __user *, vec, | |
1052 | unsigned long, vlen) | |
1053 | { | |
1054 | struct fd f = fdget(fd); | |
1055 | ssize_t ret; | |
1056 | loff_t pos; | |
1057 | ||
1058 | if (!f.file) | |
1059 | return -EBADF; | |
1060 | pos = f.file->f_pos; | |
1061 | ret = compat_writev(f.file, vec, vlen, &pos); | |
5faf153e AV |
1062 | if (ret >= 0) |
1063 | f.file->f_pos = pos; | |
72ec3516 AV |
1064 | fdput(f); |
1065 | return ret; | |
1066 | } | |
1067 | ||
1068 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1069 | const struct compat_iovec __user *,vec, | |
1070 | unsigned long, vlen, loff_t, pos) | |
1071 | { | |
1072 | struct fd f; | |
1073 | ssize_t ret; | |
1074 | ||
1075 | if (pos < 0) | |
1076 | return -EINVAL; | |
1077 | f = fdget(fd); | |
1078 | if (!f.file) | |
1079 | return -EBADF; | |
1080 | ret = -ESPIPE; | |
1081 | if (f.file->f_mode & FMODE_PWRITE) | |
1082 | ret = compat_writev(f.file, vec, vlen, &pos); | |
1083 | fdput(f); | |
1084 | return ret; | |
1085 | } | |
1086 | ||
1087 | COMPAT_SYSCALL_DEFINE5(pwritev, unsigned long, fd, | |
1088 | const struct compat_iovec __user *,vec, | |
1089 | unsigned long, vlen, u32, pos_low, u32, pos_high) | |
1090 | { | |
1091 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1092 | return compat_sys_pwritev64(fd, vec, vlen, pos); | |
1093 | } | |
1094 | #endif | |
1095 | ||
19f4fc3a AV |
1096 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1097 | size_t count, loff_t max) | |
1da177e4 | 1098 | { |
2903ff01 AV |
1099 | struct fd in, out; |
1100 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1101 | loff_t pos; |
7995bd28 | 1102 | loff_t out_pos; |
1da177e4 | 1103 | ssize_t retval; |
2903ff01 | 1104 | int fl; |
1da177e4 LT |
1105 | |
1106 | /* | |
1107 | * Get input file, and verify that it is ok.. | |
1108 | */ | |
1109 | retval = -EBADF; | |
2903ff01 AV |
1110 | in = fdget(in_fd); |
1111 | if (!in.file) | |
1da177e4 | 1112 | goto out; |
2903ff01 | 1113 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1114 | goto fput_in; |
1da177e4 | 1115 | retval = -ESPIPE; |
7995bd28 AV |
1116 | if (!ppos) { |
1117 | pos = in.file->f_pos; | |
1118 | } else { | |
1119 | pos = *ppos; | |
2903ff01 | 1120 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1121 | goto fput_in; |
7995bd28 AV |
1122 | } |
1123 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1124 | if (retval < 0) |
1da177e4 | 1125 | goto fput_in; |
e28cc715 | 1126 | count = retval; |
1da177e4 | 1127 | |
1da177e4 LT |
1128 | /* |
1129 | * Get output file, and verify that it is ok.. | |
1130 | */ | |
1131 | retval = -EBADF; | |
2903ff01 AV |
1132 | out = fdget(out_fd); |
1133 | if (!out.file) | |
1da177e4 | 1134 | goto fput_in; |
2903ff01 | 1135 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1136 | goto fput_out; |
1137 | retval = -EINVAL; | |
496ad9aa AV |
1138 | in_inode = file_inode(in.file); |
1139 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1140 | out_pos = out.file->f_pos; |
1141 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1142 | if (retval < 0) |
1da177e4 | 1143 | goto fput_out; |
e28cc715 | 1144 | count = retval; |
1da177e4 | 1145 | |
1da177e4 LT |
1146 | if (!max) |
1147 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1148 | ||
1da177e4 LT |
1149 | if (unlikely(pos + count > max)) { |
1150 | retval = -EOVERFLOW; | |
1151 | if (pos >= max) | |
1152 | goto fput_out; | |
1153 | count = max - pos; | |
1154 | } | |
1155 | ||
d96e6e71 | 1156 | fl = 0; |
534f2aaa | 1157 | #if 0 |
d96e6e71 JA |
1158 | /* |
1159 | * We need to debate whether we can enable this or not. The | |
1160 | * man page documents EAGAIN return for the output at least, | |
1161 | * and the application is arguably buggy if it doesn't expect | |
1162 | * EAGAIN on a non-blocking file descriptor. | |
1163 | */ | |
2903ff01 | 1164 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1165 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1166 | #endif |
50cd2c57 | 1167 | file_start_write(out.file); |
7995bd28 | 1168 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1169 | file_end_write(out.file); |
1da177e4 LT |
1170 | |
1171 | if (retval > 0) { | |
4b98d11b AD |
1172 | add_rchar(current, retval); |
1173 | add_wchar(current, retval); | |
a68c2f12 SW |
1174 | fsnotify_access(in.file); |
1175 | fsnotify_modify(out.file); | |
7995bd28 AV |
1176 | out.file->f_pos = out_pos; |
1177 | if (ppos) | |
1178 | *ppos = pos; | |
1179 | else | |
1180 | in.file->f_pos = pos; | |
1da177e4 | 1181 | } |
1da177e4 | 1182 | |
4b98d11b AD |
1183 | inc_syscr(current); |
1184 | inc_syscw(current); | |
7995bd28 | 1185 | if (pos > max) |
1da177e4 LT |
1186 | retval = -EOVERFLOW; |
1187 | ||
1188 | fput_out: | |
2903ff01 | 1189 | fdput(out); |
1da177e4 | 1190 | fput_in: |
2903ff01 | 1191 | fdput(in); |
1da177e4 LT |
1192 | out: |
1193 | return retval; | |
1194 | } | |
1195 | ||
002c8976 | 1196 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1197 | { |
1198 | loff_t pos; | |
1199 | off_t off; | |
1200 | ssize_t ret; | |
1201 | ||
1202 | if (offset) { | |
1203 | if (unlikely(get_user(off, offset))) | |
1204 | return -EFAULT; | |
1205 | pos = off; | |
1206 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1207 | if (unlikely(put_user(pos, offset))) | |
1208 | return -EFAULT; | |
1209 | return ret; | |
1210 | } | |
1211 | ||
1212 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1213 | } | |
1214 | ||
002c8976 | 1215 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1216 | { |
1217 | loff_t pos; | |
1218 | ssize_t ret; | |
1219 | ||
1220 | if (offset) { | |
1221 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1222 | return -EFAULT; | |
1223 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1224 | if (unlikely(put_user(pos, offset))) | |
1225 | return -EFAULT; | |
1226 | return ret; | |
1227 | } | |
1228 | ||
1229 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1230 | } | |
19f4fc3a AV |
1231 | |
1232 | #ifdef CONFIG_COMPAT | |
1233 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1234 | compat_off_t __user *, offset, compat_size_t, count) | |
1235 | { | |
1236 | loff_t pos; | |
1237 | off_t off; | |
1238 | ssize_t ret; | |
1239 | ||
1240 | if (offset) { | |
1241 | if (unlikely(get_user(off, offset))) | |
1242 | return -EFAULT; | |
1243 | pos = off; | |
1244 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1245 | if (unlikely(put_user(pos, offset))) | |
1246 | return -EFAULT; | |
1247 | return ret; | |
1248 | } | |
1249 | ||
1250 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1251 | } | |
1252 | ||
1253 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1254 | compat_loff_t __user *, offset, compat_size_t, count) | |
1255 | { | |
1256 | loff_t pos; | |
1257 | ssize_t ret; | |
1258 | ||
1259 | if (offset) { | |
1260 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1261 | return -EFAULT; | |
1262 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1263 | if (unlikely(put_user(pos, offset))) | |
1264 | return -EFAULT; | |
1265 | return ret; | |
1266 | } | |
1267 | ||
1268 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1269 | } | |
1270 | #endif |