Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/read_write.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
b12fb7f4 | 8 | #include <linux/slab.h> |
1da177e4 | 9 | #include <linux/stat.h> |
b12fb7f4 | 10 | #include <linux/sched/xacct.h> |
1da177e4 LT |
11 | #include <linux/fcntl.h> |
12 | #include <linux/file.h> | |
13 | #include <linux/uio.h> | |
0eeca283 | 14 | #include <linux/fsnotify.h> |
1da177e4 | 15 | #include <linux/security.h> |
630d9c47 | 16 | #include <linux/export.h> |
1da177e4 | 17 | #include <linux/syscalls.h> |
e28cc715 | 18 | #include <linux/pagemap.h> |
d6b29d7c | 19 | #include <linux/splice.h> |
561c6731 | 20 | #include <linux/compat.h> |
29732938 | 21 | #include <linux/mount.h> |
2feb55f8 | 22 | #include <linux/fs.h> |
06ae43f3 | 23 | #include "internal.h" |
1da177e4 | 24 | |
7c0f6ba6 | 25 | #include <linux/uaccess.h> |
1da177e4 LT |
26 | #include <asm/unistd.h> |
27 | ||
4b6f5d20 | 28 | const struct file_operations generic_ro_fops = { |
1da177e4 | 29 | .llseek = generic_file_llseek, |
aad4f8bb | 30 | .read_iter = generic_file_read_iter, |
1da177e4 | 31 | .mmap = generic_file_readonly_mmap, |
534f2aaa | 32 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
33 | }; |
34 | ||
35 | EXPORT_SYMBOL(generic_ro_fops); | |
36 | ||
ddef7ed2 | 37 | static inline bool unsigned_offsets(struct file *file) |
4a3956c7 | 38 | { |
cccb5a1e | 39 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
40 | } |
41 | ||
46a1c2c7 JL |
42 | /** |
43 | * vfs_setpos - update the file offset for lseek | |
44 | * @file: file structure in question | |
45 | * @offset: file offset to seek to | |
46 | * @maxsize: maximum file size | |
47 | * | |
48 | * This is a low-level filesystem helper for updating the file offset to | |
49 | * the value specified by @offset if the given offset is valid and it is | |
50 | * not equal to the current file offset. | |
51 | * | |
52 | * Return the specified offset on success and -EINVAL on invalid offset. | |
53 | */ | |
54 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
55 | { |
56 | if (offset < 0 && !unsigned_offsets(file)) | |
57 | return -EINVAL; | |
58 | if (offset > maxsize) | |
59 | return -EINVAL; | |
60 | ||
61 | if (offset != file->f_pos) { | |
62 | file->f_pos = offset; | |
63 | file->f_version = 0; | |
64 | } | |
65 | return offset; | |
66 | } | |
46a1c2c7 | 67 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 68 | |
3a8cff4f | 69 | /** |
5760495a | 70 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
71 | * @file: file structure to seek on |
72 | * @offset: file offset to seek to | |
965c8e59 | 73 | * @whence: type of seek |
e8b96eb5 ES |
74 | * @size: max size of this file in file system |
75 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 76 | * |
5760495a | 77 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 78 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
79 | * |
80 | * Synchronization: | |
5760495a | 81 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
82 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
83 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 84 | */ |
9465efc9 | 85 | loff_t |
965c8e59 | 86 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 87 | loff_t maxsize, loff_t eof) |
1da177e4 | 88 | { |
965c8e59 | 89 | switch (whence) { |
3a8cff4f | 90 | case SEEK_END: |
e8b96eb5 | 91 | offset += eof; |
3a8cff4f CH |
92 | break; |
93 | case SEEK_CUR: | |
5b6f1eb9 AK |
94 | /* |
95 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
96 | * position-querying operation. Avoid rewriting the "same" | |
97 | * f_pos value back to the file because a concurrent read(), | |
98 | * write() or lseek() might have altered it | |
99 | */ | |
100 | if (offset == 0) | |
101 | return file->f_pos; | |
ef3d0fd2 AK |
102 | /* |
103 | * f_lock protects against read/modify/write race with other | |
104 | * SEEK_CURs. Note that parallel writes and reads behave | |
105 | * like SEEK_SET. | |
106 | */ | |
107 | spin_lock(&file->f_lock); | |
46a1c2c7 | 108 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
109 | spin_unlock(&file->f_lock); |
110 | return offset; | |
982d8165 JB |
111 | case SEEK_DATA: |
112 | /* | |
113 | * In the generic case the entire file is data, so as long as | |
114 | * offset isn't at the end of the file then the offset is data. | |
115 | */ | |
fc46820b | 116 | if ((unsigned long long)offset >= eof) |
982d8165 JB |
117 | return -ENXIO; |
118 | break; | |
119 | case SEEK_HOLE: | |
120 | /* | |
121 | * There is a virtual hole at the end of the file, so as long as | |
122 | * offset isn't i_size or larger, return i_size. | |
123 | */ | |
fc46820b | 124 | if ((unsigned long long)offset >= eof) |
982d8165 | 125 | return -ENXIO; |
e8b96eb5 | 126 | offset = eof; |
982d8165 | 127 | break; |
1da177e4 | 128 | } |
3a8cff4f | 129 | |
46a1c2c7 | 130 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
131 | } |
132 | EXPORT_SYMBOL(generic_file_llseek_size); | |
133 | ||
134 | /** | |
135 | * generic_file_llseek - generic llseek implementation for regular files | |
136 | * @file: file structure to seek on | |
137 | * @offset: file offset to seek to | |
965c8e59 | 138 | * @whence: type of seek |
5760495a AK |
139 | * |
140 | * This is a generic implemenation of ->llseek useable for all normal local | |
141 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 142 | * @offset and @whence. |
5760495a | 143 | */ |
965c8e59 | 144 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
145 | { |
146 | struct inode *inode = file->f_mapping->host; | |
147 | ||
965c8e59 | 148 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
149 | inode->i_sb->s_maxbytes, |
150 | i_size_read(inode)); | |
1da177e4 | 151 | } |
9465efc9 | 152 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 153 | |
1bf9d14d AV |
154 | /** |
155 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
156 | * @file: file structure to seek on | |
157 | * @offset: file offset to seek to | |
158 | * @whence: type of seek | |
159 | * @size: size of the file | |
160 | * | |
161 | */ | |
162 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
163 | { | |
164 | switch (whence) { | |
165 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
166 | return generic_file_llseek_size(file, offset, whence, | |
167 | size, size); | |
168 | default: | |
169 | return -EINVAL; | |
170 | } | |
171 | } | |
172 | EXPORT_SYMBOL(fixed_size_llseek); | |
173 | ||
b25472f9 AV |
174 | /** |
175 | * no_seek_end_llseek - llseek implementation for fixed-sized devices | |
176 | * @file: file structure to seek on | |
177 | * @offset: file offset to seek to | |
178 | * @whence: type of seek | |
179 | * | |
180 | */ | |
181 | loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) | |
182 | { | |
183 | switch (whence) { | |
184 | case SEEK_SET: case SEEK_CUR: | |
185 | return generic_file_llseek_size(file, offset, whence, | |
2feb55f8 | 186 | OFFSET_MAX, 0); |
b25472f9 AV |
187 | default: |
188 | return -EINVAL; | |
189 | } | |
190 | } | |
191 | EXPORT_SYMBOL(no_seek_end_llseek); | |
192 | ||
193 | /** | |
194 | * no_seek_end_llseek_size - llseek implementation for fixed-sized devices | |
195 | * @file: file structure to seek on | |
196 | * @offset: file offset to seek to | |
197 | * @whence: type of seek | |
198 | * @size: maximal offset allowed | |
199 | * | |
200 | */ | |
201 | loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size) | |
202 | { | |
203 | switch (whence) { | |
204 | case SEEK_SET: case SEEK_CUR: | |
205 | return generic_file_llseek_size(file, offset, whence, | |
206 | size, 0); | |
207 | default: | |
208 | return -EINVAL; | |
209 | } | |
210 | } | |
211 | EXPORT_SYMBOL(no_seek_end_llseek_size); | |
212 | ||
ae6afc3f B |
213 | /** |
214 | * noop_llseek - No Operation Performed llseek implementation | |
215 | * @file: file structure to seek on | |
216 | * @offset: file offset to seek to | |
965c8e59 | 217 | * @whence: type of seek |
ae6afc3f B |
218 | * |
219 | * This is an implementation of ->llseek useable for the rare special case when | |
220 | * userspace expects the seek to succeed but the (device) file is actually not | |
221 | * able to perform the seek. In this case you use noop_llseek() instead of | |
222 | * falling back to the default implementation of ->llseek. | |
223 | */ | |
965c8e59 | 224 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
225 | { |
226 | return file->f_pos; | |
227 | } | |
228 | EXPORT_SYMBOL(noop_llseek); | |
229 | ||
965c8e59 | 230 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
231 | { |
232 | return -ESPIPE; | |
233 | } | |
234 | EXPORT_SYMBOL(no_llseek); | |
235 | ||
965c8e59 | 236 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 237 | { |
496ad9aa | 238 | struct inode *inode = file_inode(file); |
16abef0e | 239 | loff_t retval; |
1da177e4 | 240 | |
5955102c | 241 | inode_lock(inode); |
965c8e59 | 242 | switch (whence) { |
7b8e8924 | 243 | case SEEK_END: |
982d8165 | 244 | offset += i_size_read(inode); |
1da177e4 | 245 | break; |
7b8e8924 | 246 | case SEEK_CUR: |
5b6f1eb9 AK |
247 | if (offset == 0) { |
248 | retval = file->f_pos; | |
249 | goto out; | |
250 | } | |
1da177e4 | 251 | offset += file->f_pos; |
982d8165 JB |
252 | break; |
253 | case SEEK_DATA: | |
254 | /* | |
255 | * In the generic case the entire file is data, so as | |
256 | * long as offset isn't at the end of the file then the | |
257 | * offset is data. | |
258 | */ | |
bacb2d81 DC |
259 | if (offset >= inode->i_size) { |
260 | retval = -ENXIO; | |
261 | goto out; | |
262 | } | |
982d8165 JB |
263 | break; |
264 | case SEEK_HOLE: | |
265 | /* | |
266 | * There is a virtual hole at the end of the file, so | |
267 | * as long as offset isn't i_size or larger, return | |
268 | * i_size. | |
269 | */ | |
bacb2d81 DC |
270 | if (offset >= inode->i_size) { |
271 | retval = -ENXIO; | |
272 | goto out; | |
273 | } | |
982d8165 JB |
274 | offset = inode->i_size; |
275 | break; | |
1da177e4 LT |
276 | } |
277 | retval = -EINVAL; | |
cccb5a1e | 278 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
279 | if (offset != file->f_pos) { |
280 | file->f_pos = offset; | |
281 | file->f_version = 0; | |
282 | } | |
283 | retval = offset; | |
284 | } | |
5b6f1eb9 | 285 | out: |
5955102c | 286 | inode_unlock(inode); |
1da177e4 LT |
287 | return retval; |
288 | } | |
289 | EXPORT_SYMBOL(default_llseek); | |
290 | ||
965c8e59 | 291 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
292 | { |
293 | loff_t (*fn)(struct file *, loff_t, int); | |
294 | ||
295 | fn = no_llseek; | |
296 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 297 | if (file->f_op->llseek) |
1da177e4 LT |
298 | fn = file->f_op->llseek; |
299 | } | |
965c8e59 | 300 | return fn(file, offset, whence); |
1da177e4 LT |
301 | } |
302 | EXPORT_SYMBOL(vfs_llseek); | |
303 | ||
bef17329 | 304 | static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) |
1da177e4 LT |
305 | { |
306 | off_t retval; | |
9c225f26 | 307 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
308 | if (!f.file) |
309 | return -EBADF; | |
1da177e4 LT |
310 | |
311 | retval = -EINVAL; | |
965c8e59 AM |
312 | if (whence <= SEEK_MAX) { |
313 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
314 | retval = res; |
315 | if (res != (loff_t)retval) | |
316 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
317 | } | |
9c225f26 | 318 | fdput_pos(f); |
1da177e4 LT |
319 | return retval; |
320 | } | |
321 | ||
76847e43 DB |
322 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
323 | { | |
324 | return ksys_lseek(fd, offset, whence); | |
325 | } | |
326 | ||
561c6731 AV |
327 | #ifdef CONFIG_COMPAT |
328 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
329 | { | |
76847e43 | 330 | return ksys_lseek(fd, offset, whence); |
561c6731 AV |
331 | } |
332 | #endif | |
333 | ||
9e62ccec MS |
334 | #if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \ |
335 | defined(__ARCH_WANT_SYS_LLSEEK) | |
003d7ab4 HC |
336 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
337 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 338 | unsigned int, whence) |
1da177e4 LT |
339 | { |
340 | int retval; | |
d7a15f8d | 341 | struct fd f = fdget_pos(fd); |
1da177e4 | 342 | loff_t offset; |
1da177e4 | 343 | |
2903ff01 AV |
344 | if (!f.file) |
345 | return -EBADF; | |
1da177e4 LT |
346 | |
347 | retval = -EINVAL; | |
965c8e59 | 348 | if (whence > SEEK_MAX) |
1da177e4 LT |
349 | goto out_putf; |
350 | ||
2903ff01 | 351 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 352 | whence); |
1da177e4 LT |
353 | |
354 | retval = (int)offset; | |
355 | if (offset >= 0) { | |
356 | retval = -EFAULT; | |
357 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
358 | retval = 0; | |
359 | } | |
360 | out_putf: | |
d7a15f8d | 361 | fdput_pos(f); |
1da177e4 LT |
362 | return retval; |
363 | } | |
364 | #endif | |
365 | ||
68d70d03 | 366 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 | 367 | { |
e28cc715 | 368 | if (unlikely((ssize_t) count < 0)) |
2949e842 | 369 | return -EINVAL; |
1da177e4 | 370 | |
438ab720 KS |
371 | if (ppos) { |
372 | loff_t pos = *ppos; | |
373 | ||
374 | if (unlikely(pos < 0)) { | |
375 | if (!unsigned_offsets(file)) | |
2949e842 | 376 | return -EINVAL; |
438ab720 KS |
377 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
378 | return -EOVERFLOW; | |
379 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
380 | if (!unsigned_offsets(file)) | |
2949e842 | 381 | return -EINVAL; |
438ab720 | 382 | } |
e28cc715 | 383 | } |
438ab720 | 384 | |
bc61384d | 385 | return security_file_permission(file, |
c43e259c | 386 | read_write == READ ? MAY_READ : MAY_WRITE); |
1da177e4 | 387 | } |
87112933 | 388 | EXPORT_SYMBOL(rw_verify_area); |
1da177e4 | 389 | |
5d5d5689 | 390 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
391 | { |
392 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
393 | struct kiocb kiocb; | |
394 | struct iov_iter iter; | |
395 | ssize_t ret; | |
396 | ||
397 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 398 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 AV |
399 | iov_iter_init(&iter, READ, &iov, 1, len); |
400 | ||
bb7462b6 | 401 | ret = call_read_iter(filp, &kiocb, &iter); |
599bd19b | 402 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
403 | if (ppos) |
404 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
405 | return ret; |
406 | } | |
407 | ||
4d03e3cc CH |
408 | static int warn_unsupported(struct file *file, const char *op) |
409 | { | |
410 | pr_warn_ratelimited( | |
411 | "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n", | |
412 | op, file, current->pid, current->comm); | |
413 | return -EINVAL; | |
414 | } | |
415 | ||
61a707c5 CH |
416 | ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
417 | { | |
4d03e3cc CH |
418 | struct kvec iov = { |
419 | .iov_base = buf, | |
420 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
421 | }; | |
422 | struct kiocb kiocb; | |
423 | struct iov_iter iter; | |
61a707c5 CH |
424 | ssize_t ret; |
425 | ||
426 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ))) | |
427 | return -EINVAL; | |
428 | if (!(file->f_mode & FMODE_CAN_READ)) | |
429 | return -EINVAL; | |
4d03e3cc CH |
430 | /* |
431 | * Also fail if ->read_iter and ->read are both wired up as that | |
432 | * implies very convoluted semantics. | |
433 | */ | |
434 | if (unlikely(!file->f_op->read_iter || file->f_op->read)) | |
435 | return warn_unsupported(file, "read"); | |
61a707c5 | 436 | |
4d03e3cc | 437 | init_sync_kiocb(&kiocb, file); |
7b84b665 | 438 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
439 | iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len); |
440 | ret = file->f_op->read_iter(&kiocb, &iter); | |
61a707c5 | 441 | if (ret > 0) { |
7b84b665 MWO |
442 | if (pos) |
443 | *pos = kiocb.ki_pos; | |
61a707c5 CH |
444 | fsnotify_access(file); |
445 | add_rchar(current, ret); | |
446 | } | |
447 | inc_syscr(current); | |
448 | return ret; | |
449 | } | |
450 | ||
bdd1d2d3 | 451 | ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
c41fbad0 | 452 | { |
6209dd91 | 453 | ssize_t ret; |
c41fbad0 | 454 | |
6209dd91 CH |
455 | ret = rw_verify_area(READ, file, pos, count); |
456 | if (ret) | |
457 | return ret; | |
458 | return __kernel_read(file, buf, count, pos); | |
c41fbad0 CH |
459 | } |
460 | EXPORT_SYMBOL(kernel_read); | |
6fb5032e | 461 | |
1da177e4 LT |
462 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
463 | { | |
464 | ssize_t ret; | |
465 | ||
466 | if (!(file->f_mode & FMODE_READ)) | |
467 | return -EBADF; | |
7f7f25e8 | 468 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 | 469 | return -EINVAL; |
96d4f267 | 470 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
471 | return -EFAULT; |
472 | ||
473 | ret = rw_verify_area(READ, file, pos, count); | |
775802c0 CH |
474 | if (ret) |
475 | return ret; | |
476 | if (count > MAX_RW_COUNT) | |
477 | count = MAX_RW_COUNT; | |
1da177e4 | 478 | |
775802c0 CH |
479 | if (file->f_op->read) |
480 | ret = file->f_op->read(file, buf, count, pos); | |
481 | else if (file->f_op->read_iter) | |
482 | ret = new_sync_read(file, buf, count, pos); | |
483 | else | |
484 | ret = -EINVAL; | |
485 | if (ret > 0) { | |
486 | fsnotify_access(file); | |
487 | add_rchar(current, ret); | |
488 | } | |
489 | inc_syscr(current); | |
1da177e4 LT |
490 | return ret; |
491 | } | |
492 | ||
5d5d5689 | 493 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
494 | { |
495 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
496 | struct kiocb kiocb; | |
497 | struct iov_iter iter; | |
498 | ssize_t ret; | |
499 | ||
500 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 501 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 AV |
502 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
503 | ||
bb7462b6 | 504 | ret = call_write_iter(filp, &kiocb, &iter); |
599bd19b | 505 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 | 506 | if (ret > 0 && ppos) |
f765b134 | 507 | *ppos = kiocb.ki_pos; |
293bc982 AV |
508 | return ret; |
509 | } | |
510 | ||
81238b2c | 511 | /* caller is responsible for file_start_write/file_end_write */ |
73e18f7c | 512 | ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) |
06ae43f3 | 513 | { |
4d03e3cc CH |
514 | struct kvec iov = { |
515 | .iov_base = (void *)buf, | |
516 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
517 | }; | |
518 | struct kiocb kiocb; | |
519 | struct iov_iter iter; | |
06ae43f3 AV |
520 | ssize_t ret; |
521 | ||
a01ac27b CH |
522 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) |
523 | return -EBADF; | |
7f7f25e8 | 524 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e | 525 | return -EINVAL; |
4d03e3cc CH |
526 | /* |
527 | * Also fail if ->write_iter and ->write are both wired up as that | |
528 | * implies very convoluted semantics. | |
529 | */ | |
530 | if (unlikely(!file->f_op->write_iter || file->f_op->write)) | |
531 | return warn_unsupported(file, "write"); | |
3e84f48e | 532 | |
4d03e3cc | 533 | init_sync_kiocb(&kiocb, file); |
4c207ef4 | 534 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
535 | iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len); |
536 | ret = file->f_op->write_iter(&kiocb, &iter); | |
06ae43f3 | 537 | if (ret > 0) { |
4c207ef4 MWO |
538 | if (pos) |
539 | *pos = kiocb.ki_pos; | |
06ae43f3 AV |
540 | fsnotify_modify(file); |
541 | add_wchar(current, ret); | |
542 | } | |
543 | inc_syscw(current); | |
544 | return ret; | |
545 | } | |
90fb7027 LT |
546 | /* |
547 | * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()", | |
548 | * but autofs is one of the few internal kernel users that actually | |
549 | * wants this _and_ can be built as a module. So we need to export | |
550 | * this symbol for autofs, even though it really isn't appropriate | |
551 | * for any other kernel modules. | |
552 | */ | |
553 | EXPORT_SYMBOL_GPL(__kernel_write); | |
2ec3a12a | 554 | |
e13ec939 CH |
555 | ssize_t kernel_write(struct file *file, const void *buf, size_t count, |
556 | loff_t *pos) | |
ac452aca | 557 | { |
81238b2c | 558 | ssize_t ret; |
ac452aca | 559 | |
81238b2c CH |
560 | ret = rw_verify_area(WRITE, file, pos, count); |
561 | if (ret) | |
562 | return ret; | |
ac452aca | 563 | |
81238b2c CH |
564 | file_start_write(file); |
565 | ret = __kernel_write(file, buf, count, pos); | |
566 | file_end_write(file); | |
567 | return ret; | |
ac452aca CH |
568 | } |
569 | EXPORT_SYMBOL(kernel_write); | |
570 | ||
1da177e4 LT |
571 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
572 | { | |
573 | ssize_t ret; | |
574 | ||
575 | if (!(file->f_mode & FMODE_WRITE)) | |
576 | return -EBADF; | |
7f7f25e8 | 577 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 | 578 | return -EINVAL; |
96d4f267 | 579 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
580 | return -EFAULT; |
581 | ||
582 | ret = rw_verify_area(WRITE, file, pos, count); | |
53ad8626 CH |
583 | if (ret) |
584 | return ret; | |
585 | if (count > MAX_RW_COUNT) | |
586 | count = MAX_RW_COUNT; | |
587 | file_start_write(file); | |
588 | if (file->f_op->write) | |
589 | ret = file->f_op->write(file, buf, count, pos); | |
590 | else if (file->f_op->write_iter) | |
591 | ret = new_sync_write(file, buf, count, pos); | |
592 | else | |
593 | ret = -EINVAL; | |
594 | if (ret > 0) { | |
595 | fsnotify_modify(file); | |
596 | add_wchar(current, ret); | |
1da177e4 | 597 | } |
53ad8626 CH |
598 | inc_syscw(current); |
599 | file_end_write(file); | |
1da177e4 LT |
600 | return ret; |
601 | } | |
602 | ||
438ab720 KS |
603 | /* file_ppos returns &file->f_pos or NULL if file is stream */ |
604 | static inline loff_t *file_ppos(struct file *file) | |
1da177e4 | 605 | { |
438ab720 | 606 | return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; |
1da177e4 LT |
607 | } |
608 | ||
3ce4a7bf | 609 | ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) |
1da177e4 | 610 | { |
9c225f26 | 611 | struct fd f = fdget_pos(fd); |
1da177e4 | 612 | ssize_t ret = -EBADF; |
1da177e4 | 613 | |
2903ff01 | 614 | if (f.file) { |
438ab720 KS |
615 | loff_t pos, *ppos = file_ppos(f.file); |
616 | if (ppos) { | |
617 | pos = *ppos; | |
618 | ppos = &pos; | |
619 | } | |
620 | ret = vfs_read(f.file, buf, count, ppos); | |
621 | if (ret >= 0 && ppos) | |
622 | f.file->f_pos = pos; | |
9c225f26 | 623 | fdput_pos(f); |
1da177e4 | 624 | } |
1da177e4 LT |
625 | return ret; |
626 | } | |
1da177e4 | 627 | |
3ce4a7bf DB |
628 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
629 | { | |
630 | return ksys_read(fd, buf, count); | |
631 | } | |
632 | ||
e7a3e8b2 | 633 | ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) |
1da177e4 | 634 | { |
9c225f26 | 635 | struct fd f = fdget_pos(fd); |
1da177e4 | 636 | ssize_t ret = -EBADF; |
1da177e4 | 637 | |
2903ff01 | 638 | if (f.file) { |
438ab720 KS |
639 | loff_t pos, *ppos = file_ppos(f.file); |
640 | if (ppos) { | |
641 | pos = *ppos; | |
642 | ppos = &pos; | |
643 | } | |
644 | ret = vfs_write(f.file, buf, count, ppos); | |
645 | if (ret >= 0 && ppos) | |
646 | f.file->f_pos = pos; | |
9c225f26 | 647 | fdput_pos(f); |
1da177e4 LT |
648 | } |
649 | ||
650 | return ret; | |
651 | } | |
652 | ||
e7a3e8b2 DB |
653 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
654 | size_t, count) | |
655 | { | |
656 | return ksys_write(fd, buf, count); | |
657 | } | |
658 | ||
36028d5d DB |
659 | ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, |
660 | loff_t pos) | |
1da177e4 | 661 | { |
2903ff01 | 662 | struct fd f; |
1da177e4 | 663 | ssize_t ret = -EBADF; |
1da177e4 LT |
664 | |
665 | if (pos < 0) | |
666 | return -EINVAL; | |
667 | ||
2903ff01 AV |
668 | f = fdget(fd); |
669 | if (f.file) { | |
1da177e4 | 670 | ret = -ESPIPE; |
2903ff01 AV |
671 | if (f.file->f_mode & FMODE_PREAD) |
672 | ret = vfs_read(f.file, buf, count, &pos); | |
673 | fdput(f); | |
1da177e4 LT |
674 | } |
675 | ||
676 | return ret; | |
677 | } | |
678 | ||
36028d5d DB |
679 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
680 | size_t, count, loff_t, pos) | |
681 | { | |
682 | return ksys_pread64(fd, buf, count, pos); | |
683 | } | |
684 | ||
59c10c52 GR |
685 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64) |
686 | COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf, | |
687 | size_t, count, compat_arg_u64_dual(pos)) | |
688 | { | |
689 | return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos)); | |
690 | } | |
691 | #endif | |
692 | ||
36028d5d DB |
693 | ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, |
694 | size_t count, loff_t pos) | |
1da177e4 | 695 | { |
2903ff01 | 696 | struct fd f; |
1da177e4 | 697 | ssize_t ret = -EBADF; |
1da177e4 LT |
698 | |
699 | if (pos < 0) | |
700 | return -EINVAL; | |
701 | ||
2903ff01 AV |
702 | f = fdget(fd); |
703 | if (f.file) { | |
1da177e4 | 704 | ret = -ESPIPE; |
2903ff01 AV |
705 | if (f.file->f_mode & FMODE_PWRITE) |
706 | ret = vfs_write(f.file, buf, count, &pos); | |
707 | fdput(f); | |
1da177e4 LT |
708 | } |
709 | ||
710 | return ret; | |
711 | } | |
712 | ||
36028d5d DB |
713 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
714 | size_t, count, loff_t, pos) | |
715 | { | |
716 | return ksys_pwrite64(fd, buf, count, pos); | |
717 | } | |
718 | ||
59c10c52 GR |
719 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64) |
720 | COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf, | |
721 | size_t, count, compat_arg_u64_dual(pos)) | |
722 | { | |
723 | return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos)); | |
724 | } | |
725 | #endif | |
726 | ||
ac15ac06 | 727 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 728 | loff_t *ppos, int type, rwf_t flags) |
293bc982 AV |
729 | { |
730 | struct kiocb kiocb; | |
293bc982 AV |
731 | ssize_t ret; |
732 | ||
733 | init_sync_kiocb(&kiocb, filp); | |
fdd2f5b7 GR |
734 | ret = kiocb_set_rw_flags(&kiocb, flags); |
735 | if (ret) | |
736 | return ret; | |
438ab720 | 737 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 | 738 | |
0f78d06a | 739 | if (type == READ) |
bb7462b6 | 740 | ret = call_read_iter(filp, &kiocb, iter); |
0f78d06a | 741 | else |
bb7462b6 | 742 | ret = call_write_iter(filp, &kiocb, iter); |
599bd19b | 743 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
744 | if (ppos) |
745 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
746 | return ret; |
747 | } | |
748 | ||
ee0b3e67 | 749 | /* Do it by hand, with file-ops */ |
ac15ac06 | 750 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 751 | loff_t *ppos, int type, rwf_t flags) |
ee0b3e67 | 752 | { |
ee0b3e67 BP |
753 | ssize_t ret = 0; |
754 | ||
97be7ebe | 755 | if (flags & ~RWF_HIPRI) |
793b80ef CH |
756 | return -EOPNOTSUPP; |
757 | ||
ac15ac06 AV |
758 | while (iov_iter_count(iter)) { |
759 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
760 | ssize_t nr; |
761 | ||
0f78d06a MS |
762 | if (type == READ) { |
763 | nr = filp->f_op->read(filp, iovec.iov_base, | |
764 | iovec.iov_len, ppos); | |
765 | } else { | |
766 | nr = filp->f_op->write(filp, iovec.iov_base, | |
767 | iovec.iov_len, ppos); | |
768 | } | |
ee0b3e67 BP |
769 | |
770 | if (nr < 0) { | |
771 | if (!ret) | |
772 | ret = nr; | |
773 | break; | |
774 | } | |
775 | ret += nr; | |
ac15ac06 | 776 | if (nr != iovec.iov_len) |
ee0b3e67 | 777 | break; |
ac15ac06 | 778 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
779 | } |
780 | ||
781 | return ret; | |
782 | } | |
783 | ||
19c73586 | 784 | static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 785 | loff_t *pos, rwf_t flags) |
1da177e4 | 786 | { |
1da177e4 | 787 | size_t tot_len; |
7687a7a4 | 788 | ssize_t ret = 0; |
1da177e4 | 789 | |
edab5fe3 CH |
790 | if (!(file->f_mode & FMODE_READ)) |
791 | return -EBADF; | |
792 | if (!(file->f_mode & FMODE_CAN_READ)) | |
793 | return -EINVAL; | |
794 | ||
7687a7a4 | 795 | tot_len = iov_iter_count(iter); |
0504c074 AV |
796 | if (!tot_len) |
797 | goto out; | |
19c73586 | 798 | ret = rw_verify_area(READ, file, pos, tot_len); |
e28cc715 | 799 | if (ret < 0) |
19c73586 | 800 | return ret; |
1da177e4 | 801 | |
19c73586 CH |
802 | if (file->f_op->read_iter) |
803 | ret = do_iter_readv_writev(file, iter, pos, READ, flags); | |
ee0b3e67 | 804 | else |
19c73586 | 805 | ret = do_loop_readv_writev(file, iter, pos, READ, flags); |
1da177e4 | 806 | out: |
19c73586 CH |
807 | if (ret >= 0) |
808 | fsnotify_access(file); | |
1da177e4 | 809 | return ret; |
1da177e4 LT |
810 | } |
811 | ||
5dcdc43e JX |
812 | ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, |
813 | struct iov_iter *iter) | |
814 | { | |
815 | size_t tot_len; | |
816 | ssize_t ret = 0; | |
817 | ||
818 | if (!file->f_op->read_iter) | |
819 | return -EINVAL; | |
820 | if (!(file->f_mode & FMODE_READ)) | |
821 | return -EBADF; | |
822 | if (!(file->f_mode & FMODE_CAN_READ)) | |
823 | return -EINVAL; | |
824 | ||
825 | tot_len = iov_iter_count(iter); | |
826 | if (!tot_len) | |
827 | goto out; | |
828 | ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); | |
829 | if (ret < 0) | |
830 | return ret; | |
831 | ||
832 | ret = call_read_iter(file, iocb, iter); | |
833 | out: | |
834 | if (ret >= 0) | |
835 | fsnotify_access(file); | |
836 | return ret; | |
837 | } | |
838 | EXPORT_SYMBOL(vfs_iocb_iter_read); | |
839 | ||
18e9710e | 840 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 841 | rwf_t flags) |
7687a7a4 | 842 | { |
18e9710e CH |
843 | if (!file->f_op->read_iter) |
844 | return -EINVAL; | |
845 | return do_iter_read(file, iter, ppos, flags); | |
846 | } | |
847 | EXPORT_SYMBOL(vfs_iter_read); | |
7687a7a4 | 848 | |
19c73586 | 849 | static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 850 | loff_t *pos, rwf_t flags) |
19c73586 CH |
851 | { |
852 | size_t tot_len; | |
853 | ssize_t ret = 0; | |
03d95eb2 | 854 | |
edab5fe3 CH |
855 | if (!(file->f_mode & FMODE_WRITE)) |
856 | return -EBADF; | |
857 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
858 | return -EINVAL; | |
859 | ||
19c73586 CH |
860 | tot_len = iov_iter_count(iter); |
861 | if (!tot_len) | |
862 | return 0; | |
863 | ret = rw_verify_area(WRITE, file, pos, tot_len); | |
7687a7a4 MS |
864 | if (ret < 0) |
865 | return ret; | |
866 | ||
19c73586 CH |
867 | if (file->f_op->write_iter) |
868 | ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); | |
869 | else | |
870 | ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); | |
19c73586 CH |
871 | if (ret > 0) |
872 | fsnotify_modify(file); | |
7687a7a4 MS |
873 | return ret; |
874 | } | |
875 | ||
5dcdc43e JX |
876 | ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, |
877 | struct iov_iter *iter) | |
878 | { | |
879 | size_t tot_len; | |
880 | ssize_t ret = 0; | |
881 | ||
882 | if (!file->f_op->write_iter) | |
883 | return -EINVAL; | |
884 | if (!(file->f_mode & FMODE_WRITE)) | |
885 | return -EBADF; | |
886 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
887 | return -EINVAL; | |
888 | ||
889 | tot_len = iov_iter_count(iter); | |
890 | if (!tot_len) | |
891 | return 0; | |
892 | ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); | |
893 | if (ret < 0) | |
894 | return ret; | |
895 | ||
896 | ret = call_write_iter(file, iocb, iter); | |
897 | if (ret > 0) | |
898 | fsnotify_modify(file); | |
899 | ||
900 | return ret; | |
901 | } | |
902 | EXPORT_SYMBOL(vfs_iocb_iter_write); | |
903 | ||
abbb6589 | 904 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 905 | rwf_t flags) |
abbb6589 CH |
906 | { |
907 | if (!file->f_op->write_iter) | |
908 | return -EINVAL; | |
909 | return do_iter_write(file, iter, ppos, flags); | |
910 | } | |
911 | EXPORT_SYMBOL(vfs_iter_write); | |
912 | ||
36e2c742 | 913 | static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 914 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 915 | { |
7687a7a4 MS |
916 | struct iovec iovstack[UIO_FASTIOV]; |
917 | struct iovec *iov = iovstack; | |
918 | struct iov_iter iter; | |
919 | ssize_t ret; | |
1da177e4 | 920 | |
251b42a1 | 921 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 CH |
922 | if (ret >= 0) { |
923 | ret = do_iter_read(file, &iter, pos, flags); | |
924 | kfree(iov); | |
925 | } | |
1da177e4 | 926 | |
251b42a1 CH |
927 | return ret; |
928 | } | |
1da177e4 | 929 | |
9725d4ce | 930 | static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 931 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 932 | { |
251b42a1 CH |
933 | struct iovec iovstack[UIO_FASTIOV]; |
934 | struct iovec *iov = iovstack; | |
935 | struct iov_iter iter; | |
936 | ssize_t ret; | |
1da177e4 | 937 | |
251b42a1 | 938 | ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 | 939 | if (ret >= 0) { |
62473a2d | 940 | file_start_write(file); |
edab5fe3 | 941 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 942 | file_end_write(file); |
edab5fe3 CH |
943 | kfree(iov); |
944 | } | |
251b42a1 | 945 | return ret; |
1da177e4 | 946 | } |
1da177e4 | 947 | |
f17d8b35 | 948 | static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 949 | unsigned long vlen, rwf_t flags) |
1da177e4 | 950 | { |
9c225f26 | 951 | struct fd f = fdget_pos(fd); |
1da177e4 | 952 | ssize_t ret = -EBADF; |
1da177e4 | 953 | |
2903ff01 | 954 | if (f.file) { |
438ab720 KS |
955 | loff_t pos, *ppos = file_ppos(f.file); |
956 | if (ppos) { | |
957 | pos = *ppos; | |
958 | ppos = &pos; | |
959 | } | |
960 | ret = vfs_readv(f.file, vec, vlen, ppos, flags); | |
961 | if (ret >= 0 && ppos) | |
962 | f.file->f_pos = pos; | |
9c225f26 | 963 | fdput_pos(f); |
1da177e4 LT |
964 | } |
965 | ||
966 | if (ret > 0) | |
4b98d11b AD |
967 | add_rchar(current, ret); |
968 | inc_syscr(current); | |
1da177e4 LT |
969 | return ret; |
970 | } | |
971 | ||
f17d8b35 | 972 | static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 973 | unsigned long vlen, rwf_t flags) |
1da177e4 | 974 | { |
9c225f26 | 975 | struct fd f = fdget_pos(fd); |
1da177e4 | 976 | ssize_t ret = -EBADF; |
1da177e4 | 977 | |
2903ff01 | 978 | if (f.file) { |
438ab720 KS |
979 | loff_t pos, *ppos = file_ppos(f.file); |
980 | if (ppos) { | |
981 | pos = *ppos; | |
982 | ppos = &pos; | |
983 | } | |
984 | ret = vfs_writev(f.file, vec, vlen, ppos, flags); | |
985 | if (ret >= 0 && ppos) | |
986 | f.file->f_pos = pos; | |
9c225f26 | 987 | fdput_pos(f); |
1da177e4 LT |
988 | } |
989 | ||
990 | if (ret > 0) | |
4b98d11b AD |
991 | add_wchar(current, ret); |
992 | inc_syscw(current); | |
1da177e4 LT |
993 | return ret; |
994 | } | |
995 | ||
601cc11d LT |
996 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
997 | { | |
998 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
999 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
1000 | } | |
1001 | ||
f17d8b35 | 1002 | static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1003 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1004 | { |
2903ff01 | 1005 | struct fd f; |
f3554f4b | 1006 | ssize_t ret = -EBADF; |
f3554f4b GH |
1007 | |
1008 | if (pos < 0) | |
1009 | return -EINVAL; | |
1010 | ||
2903ff01 AV |
1011 | f = fdget(fd); |
1012 | if (f.file) { | |
f3554f4b | 1013 | ret = -ESPIPE; |
2903ff01 | 1014 | if (f.file->f_mode & FMODE_PREAD) |
f17d8b35 | 1015 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1016 | fdput(f); |
f3554f4b GH |
1017 | } |
1018 | ||
1019 | if (ret > 0) | |
1020 | add_rchar(current, ret); | |
1021 | inc_syscr(current); | |
1022 | return ret; | |
1023 | } | |
1024 | ||
f17d8b35 | 1025 | static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1026 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1027 | { |
2903ff01 | 1028 | struct fd f; |
f3554f4b | 1029 | ssize_t ret = -EBADF; |
f3554f4b GH |
1030 | |
1031 | if (pos < 0) | |
1032 | return -EINVAL; | |
1033 | ||
2903ff01 AV |
1034 | f = fdget(fd); |
1035 | if (f.file) { | |
f3554f4b | 1036 | ret = -ESPIPE; |
2903ff01 | 1037 | if (f.file->f_mode & FMODE_PWRITE) |
f17d8b35 | 1038 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1039 | fdput(f); |
f3554f4b GH |
1040 | } |
1041 | ||
1042 | if (ret > 0) | |
1043 | add_wchar(current, ret); | |
1044 | inc_syscw(current); | |
1045 | return ret; | |
1046 | } | |
1047 | ||
f17d8b35 MT |
1048 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
1049 | unsigned long, vlen) | |
1050 | { | |
1051 | return do_readv(fd, vec, vlen, 0); | |
1052 | } | |
1053 | ||
1054 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, | |
1055 | unsigned long, vlen) | |
1056 | { | |
1057 | return do_writev(fd, vec, vlen, 0); | |
1058 | } | |
1059 | ||
1060 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, | |
1061 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1062 | { | |
1063 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1064 | ||
1065 | return do_preadv(fd, vec, vlen, pos, 0); | |
1066 | } | |
1067 | ||
1068 | SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, | |
1069 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1070 | rwf_t, flags) |
f17d8b35 MT |
1071 | { |
1072 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1073 | ||
1074 | if (pos == -1) | |
1075 | return do_readv(fd, vec, vlen, flags); | |
1076 | ||
1077 | return do_preadv(fd, vec, vlen, pos, flags); | |
1078 | } | |
1079 | ||
1080 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
1081 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1082 | { | |
1083 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1084 | ||
1085 | return do_pwritev(fd, vec, vlen, pos, 0); | |
1086 | } | |
1087 | ||
1088 | SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, | |
1089 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1090 | rwf_t, flags) |
f17d8b35 MT |
1091 | { |
1092 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1093 | ||
1094 | if (pos == -1) | |
1095 | return do_writev(fd, vec, vlen, flags); | |
1096 | ||
1097 | return do_pwritev(fd, vec, vlen, pos, flags); | |
1098 | } | |
1099 | ||
3523a9d4 CH |
1100 | /* |
1101 | * Various compat syscalls. Note that they all pretend to take a native | |
1102 | * iovec - import_iovec will properly treat those as compat_iovecs based on | |
1103 | * in_compat_syscall(). | |
1104 | */ | |
72ec3516 | 1105 | #ifdef CONFIG_COMPAT |
378a10f3 HC |
1106 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1107 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
3523a9d4 | 1108 | const struct iovec __user *, vec, |
378a10f3 HC |
1109 | unsigned long, vlen, loff_t, pos) |
1110 | { | |
3523a9d4 | 1111 | return do_preadv(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1112 | } |
1113 | #endif | |
1114 | ||
dfd948e3 | 1115 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
3523a9d4 | 1116 | const struct iovec __user *, vec, |
dfd948e3 | 1117 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1118 | { |
1119 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1120 | |
3523a9d4 | 1121 | return do_preadv(fd, vec, vlen, pos, 0); |
f17d8b35 MT |
1122 | } |
1123 | ||
3ebfd81f L |
1124 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 |
1125 | COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, | |
3523a9d4 | 1126 | const struct iovec __user *, vec, |
ddef7ed2 | 1127 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1128 | { |
cc4b1242 | 1129 | if (pos == -1) |
3523a9d4 CH |
1130 | return do_readv(fd, vec, vlen, flags); |
1131 | return do_preadv(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1132 | } |
1133 | #endif | |
1134 | ||
f17d8b35 | 1135 | COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, |
3523a9d4 | 1136 | const struct iovec __user *, vec, |
f17d8b35 | 1137 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, |
ddef7ed2 | 1138 | rwf_t, flags) |
f17d8b35 MT |
1139 | { |
1140 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1141 | ||
1142 | if (pos == -1) | |
3523a9d4 CH |
1143 | return do_readv(fd, vec, vlen, flags); |
1144 | return do_preadv(fd, vec, vlen, pos, flags); | |
72ec3516 AV |
1145 | } |
1146 | ||
378a10f3 HC |
1147 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1148 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
3523a9d4 | 1149 | const struct iovec __user *, vec, |
378a10f3 HC |
1150 | unsigned long, vlen, loff_t, pos) |
1151 | { | |
3523a9d4 | 1152 | return do_pwritev(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1153 | } |
1154 | #endif | |
1155 | ||
dfd948e3 | 1156 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
3523a9d4 | 1157 | const struct iovec __user *,vec, |
dfd948e3 | 1158 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1159 | { |
1160 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1161 | |
3523a9d4 | 1162 | return do_pwritev(fd, vec, vlen, pos, 0); |
72ec3516 | 1163 | } |
f17d8b35 | 1164 | |
3ebfd81f L |
1165 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 |
1166 | COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, | |
3523a9d4 | 1167 | const struct iovec __user *, vec, |
ddef7ed2 | 1168 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1169 | { |
cc4b1242 | 1170 | if (pos == -1) |
3523a9d4 CH |
1171 | return do_writev(fd, vec, vlen, flags); |
1172 | return do_pwritev(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1173 | } |
1174 | #endif | |
1175 | ||
f17d8b35 | 1176 | COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, |
3523a9d4 | 1177 | const struct iovec __user *,vec, |
ddef7ed2 | 1178 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) |
f17d8b35 MT |
1179 | { |
1180 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1181 | ||
1182 | if (pos == -1) | |
3523a9d4 CH |
1183 | return do_writev(fd, vec, vlen, flags); |
1184 | return do_pwritev(fd, vec, vlen, pos, flags); | |
72ec3516 | 1185 | } |
3523a9d4 | 1186 | #endif /* CONFIG_COMPAT */ |
72ec3516 | 1187 | |
19f4fc3a AV |
1188 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1189 | size_t count, loff_t max) | |
1da177e4 | 1190 | { |
2903ff01 AV |
1191 | struct fd in, out; |
1192 | struct inode *in_inode, *out_inode; | |
b964bf53 | 1193 | struct pipe_inode_info *opipe; |
1da177e4 | 1194 | loff_t pos; |
7995bd28 | 1195 | loff_t out_pos; |
1da177e4 | 1196 | ssize_t retval; |
2903ff01 | 1197 | int fl; |
1da177e4 LT |
1198 | |
1199 | /* | |
1200 | * Get input file, and verify that it is ok.. | |
1201 | */ | |
1202 | retval = -EBADF; | |
2903ff01 AV |
1203 | in = fdget(in_fd); |
1204 | if (!in.file) | |
1da177e4 | 1205 | goto out; |
2903ff01 | 1206 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1207 | goto fput_in; |
1da177e4 | 1208 | retval = -ESPIPE; |
7995bd28 AV |
1209 | if (!ppos) { |
1210 | pos = in.file->f_pos; | |
1211 | } else { | |
1212 | pos = *ppos; | |
2903ff01 | 1213 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1214 | goto fput_in; |
7995bd28 AV |
1215 | } |
1216 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1217 | if (retval < 0) |
1da177e4 | 1218 | goto fput_in; |
bc61384d AV |
1219 | if (count > MAX_RW_COUNT) |
1220 | count = MAX_RW_COUNT; | |
1da177e4 | 1221 | |
1da177e4 LT |
1222 | /* |
1223 | * Get output file, and verify that it is ok.. | |
1224 | */ | |
1225 | retval = -EBADF; | |
2903ff01 AV |
1226 | out = fdget(out_fd); |
1227 | if (!out.file) | |
1da177e4 | 1228 | goto fput_in; |
2903ff01 | 1229 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 | 1230 | goto fput_out; |
496ad9aa AV |
1231 | in_inode = file_inode(in.file); |
1232 | out_inode = file_inode(out.file); | |
7995bd28 | 1233 | out_pos = out.file->f_pos; |
1da177e4 | 1234 | |
1da177e4 LT |
1235 | if (!max) |
1236 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1237 | ||
1da177e4 LT |
1238 | if (unlikely(pos + count > max)) { |
1239 | retval = -EOVERFLOW; | |
1240 | if (pos >= max) | |
1241 | goto fput_out; | |
1242 | count = max - pos; | |
1243 | } | |
1244 | ||
d96e6e71 | 1245 | fl = 0; |
534f2aaa | 1246 | #if 0 |
d96e6e71 JA |
1247 | /* |
1248 | * We need to debate whether we can enable this or not. The | |
1249 | * man page documents EAGAIN return for the output at least, | |
1250 | * and the application is arguably buggy if it doesn't expect | |
1251 | * EAGAIN on a non-blocking file descriptor. | |
1252 | */ | |
2903ff01 | 1253 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1254 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1255 | #endif |
b964bf53 AV |
1256 | opipe = get_pipe_info(out.file, true); |
1257 | if (!opipe) { | |
1258 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
1259 | if (retval < 0) | |
1260 | goto fput_out; | |
1261 | file_start_write(out.file); | |
1262 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, | |
1263 | count, fl); | |
1264 | file_end_write(out.file); | |
1265 | } else { | |
1266 | retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); | |
1267 | } | |
1da177e4 LT |
1268 | |
1269 | if (retval > 0) { | |
4b98d11b AD |
1270 | add_rchar(current, retval); |
1271 | add_wchar(current, retval); | |
a68c2f12 SW |
1272 | fsnotify_access(in.file); |
1273 | fsnotify_modify(out.file); | |
7995bd28 AV |
1274 | out.file->f_pos = out_pos; |
1275 | if (ppos) | |
1276 | *ppos = pos; | |
1277 | else | |
1278 | in.file->f_pos = pos; | |
1da177e4 | 1279 | } |
1da177e4 | 1280 | |
4b98d11b AD |
1281 | inc_syscr(current); |
1282 | inc_syscw(current); | |
7995bd28 | 1283 | if (pos > max) |
1da177e4 LT |
1284 | retval = -EOVERFLOW; |
1285 | ||
1286 | fput_out: | |
2903ff01 | 1287 | fdput(out); |
1da177e4 | 1288 | fput_in: |
2903ff01 | 1289 | fdput(in); |
1da177e4 LT |
1290 | out: |
1291 | return retval; | |
1292 | } | |
1293 | ||
002c8976 | 1294 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1295 | { |
1296 | loff_t pos; | |
1297 | off_t off; | |
1298 | ssize_t ret; | |
1299 | ||
1300 | if (offset) { | |
1301 | if (unlikely(get_user(off, offset))) | |
1302 | return -EFAULT; | |
1303 | pos = off; | |
1304 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1305 | if (unlikely(put_user(pos, offset))) | |
1306 | return -EFAULT; | |
1307 | return ret; | |
1308 | } | |
1309 | ||
1310 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1311 | } | |
1312 | ||
002c8976 | 1313 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1314 | { |
1315 | loff_t pos; | |
1316 | ssize_t ret; | |
1317 | ||
1318 | if (offset) { | |
1319 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1320 | return -EFAULT; | |
1321 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1322 | if (unlikely(put_user(pos, offset))) | |
1323 | return -EFAULT; | |
1324 | return ret; | |
1325 | } | |
1326 | ||
1327 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1328 | } | |
19f4fc3a AV |
1329 | |
1330 | #ifdef CONFIG_COMPAT | |
1331 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1332 | compat_off_t __user *, offset, compat_size_t, count) | |
1333 | { | |
1334 | loff_t pos; | |
1335 | off_t off; | |
1336 | ssize_t ret; | |
1337 | ||
1338 | if (offset) { | |
1339 | if (unlikely(get_user(off, offset))) | |
1340 | return -EFAULT; | |
1341 | pos = off; | |
1342 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1343 | if (unlikely(put_user(pos, offset))) | |
1344 | return -EFAULT; | |
1345 | return ret; | |
1346 | } | |
1347 | ||
1348 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1349 | } | |
1350 | ||
1351 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1352 | compat_loff_t __user *, offset, compat_size_t, count) | |
1353 | { | |
1354 | loff_t pos; | |
1355 | ssize_t ret; | |
1356 | ||
1357 | if (offset) { | |
1358 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1359 | return -EFAULT; | |
1360 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1361 | if (unlikely(put_user(pos, offset))) | |
1362 | return -EFAULT; | |
1363 | return ret; | |
1364 | } | |
1365 | ||
1366 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1367 | } | |
1368 | #endif | |
29732938 | 1369 | |
f16acc9d DC |
1370 | /** |
1371 | * generic_copy_file_range - copy data between two files | |
1372 | * @file_in: file structure to read from | |
1373 | * @pos_in: file offset to read from | |
1374 | * @file_out: file structure to write data to | |
1375 | * @pos_out: file offset to write data to | |
1376 | * @len: amount of data to copy | |
1377 | * @flags: copy flags | |
1378 | * | |
1379 | * This is a generic filesystem helper to copy data from one file to another. | |
1380 | * It has no constraints on the source or destination file owners - the files | |
1381 | * can belong to different superblocks and different filesystem types. Short | |
1382 | * copies are allowed. | |
1383 | * | |
1384 | * This should be called from the @file_out filesystem, as per the | |
1385 | * ->copy_file_range() method. | |
1386 | * | |
1387 | * Returns the number of bytes copied or a negative error indicating the | |
1388 | * failure. | |
1389 | */ | |
1390 | ||
1391 | ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, | |
1392 | struct file *file_out, loff_t pos_out, | |
1393 | size_t len, unsigned int flags) | |
1394 | { | |
1395 | return do_splice_direct(file_in, &pos_in, file_out, &pos_out, | |
1396 | len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); | |
1397 | } | |
1398 | EXPORT_SYMBOL(generic_copy_file_range); | |
1399 | ||
64bf5ff5 DC |
1400 | static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, |
1401 | struct file *file_out, loff_t pos_out, | |
1402 | size_t len, unsigned int flags) | |
1403 | { | |
5dae222a AG |
1404 | /* |
1405 | * Although we now allow filesystems to handle cross sb copy, passing | |
1406 | * a file of the wrong filesystem type to filesystem driver can result | |
1407 | * in an attempt to dereference the wrong type of ->private_data, so | |
1408 | * avoid doing that until we really have a good reason. NFS defines | |
1409 | * several different file_system_type structures, but they all end up | |
1410 | * using the same ->copy_file_range() function pointer. | |
1411 | */ | |
1412 | if (file_out->f_op->copy_file_range && | |
1413 | file_out->f_op->copy_file_range == file_in->f_op->copy_file_range) | |
64bf5ff5 DC |
1414 | return file_out->f_op->copy_file_range(file_in, pos_in, |
1415 | file_out, pos_out, | |
1416 | len, flags); | |
1417 | ||
1418 | return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, | |
1419 | flags); | |
1420 | } | |
1421 | ||
407e9c63 DW |
1422 | /* |
1423 | * Performs necessary checks before doing a file copy | |
1424 | * | |
1425 | * Can adjust amount of bytes to copy via @req_count argument. | |
1426 | * Returns appropriate error code that caller should return or | |
1427 | * zero in case the copy should be allowed. | |
1428 | */ | |
1429 | static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, | |
1430 | struct file *file_out, loff_t pos_out, | |
1431 | size_t *req_count, unsigned int flags) | |
1432 | { | |
1433 | struct inode *inode_in = file_inode(file_in); | |
1434 | struct inode *inode_out = file_inode(file_out); | |
1435 | uint64_t count = *req_count; | |
1436 | loff_t size_in; | |
1437 | int ret; | |
1438 | ||
1439 | ret = generic_file_rw_checks(file_in, file_out); | |
1440 | if (ret) | |
1441 | return ret; | |
1442 | ||
1443 | /* Don't touch certain kinds of inodes */ | |
1444 | if (IS_IMMUTABLE(inode_out)) | |
1445 | return -EPERM; | |
1446 | ||
1447 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1448 | return -ETXTBSY; | |
1449 | ||
1450 | /* Ensure offsets don't wrap. */ | |
1451 | if (pos_in + count < pos_in || pos_out + count < pos_out) | |
1452 | return -EOVERFLOW; | |
1453 | ||
1454 | /* Shorten the copy to EOF */ | |
1455 | size_in = i_size_read(inode_in); | |
1456 | if (pos_in >= size_in) | |
1457 | count = 0; | |
1458 | else | |
1459 | count = min(count, size_in - (uint64_t)pos_in); | |
1460 | ||
1461 | ret = generic_write_check_limits(file_out, pos_out, &count); | |
1462 | if (ret) | |
1463 | return ret; | |
1464 | ||
1465 | /* Don't allow overlapped copying within the same file. */ | |
1466 | if (inode_in == inode_out && | |
1467 | pos_out + count > pos_in && | |
1468 | pos_out < pos_in + count) | |
1469 | return -EINVAL; | |
1470 | ||
1471 | *req_count = count; | |
1472 | return 0; | |
1473 | } | |
1474 | ||
29732938 ZB |
1475 | /* |
1476 | * copy_file_range() differs from regular file read and write in that it | |
1477 | * specifically allows return partial success. When it does so is up to | |
1478 | * the copy_file_range method. | |
1479 | */ | |
1480 | ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, | |
1481 | struct file *file_out, loff_t pos_out, | |
1482 | size_t len, unsigned int flags) | |
1483 | { | |
29732938 ZB |
1484 | ssize_t ret; |
1485 | ||
1486 | if (flags != 0) | |
1487 | return -EINVAL; | |
1488 | ||
96e6e8f4 AG |
1489 | ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, |
1490 | flags); | |
a3171351 AG |
1491 | if (unlikely(ret)) |
1492 | return ret; | |
11cbfb10 | 1493 | |
29732938 | 1494 | ret = rw_verify_area(READ, file_in, &pos_in, len); |
bc61384d AV |
1495 | if (unlikely(ret)) |
1496 | return ret; | |
1497 | ||
1498 | ret = rw_verify_area(WRITE, file_out, &pos_out, len); | |
1499 | if (unlikely(ret)) | |
29732938 ZB |
1500 | return ret; |
1501 | ||
29732938 ZB |
1502 | if (len == 0) |
1503 | return 0; | |
1504 | ||
bfe219d3 | 1505 | file_start_write(file_out); |
29732938 | 1506 | |
a76b5b04 CH |
1507 | /* |
1508 | * Try cloning first, this is supported by more file systems, and | |
1509 | * more efficient if both clone and copy are supported (e.g. NFS). | |
1510 | */ | |
5dae222a AG |
1511 | if (file_in->f_op->remap_file_range && |
1512 | file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) { | |
42ec3d4c DW |
1513 | loff_t cloned; |
1514 | ||
1515 | cloned = file_in->f_op->remap_file_range(file_in, pos_in, | |
1516 | file_out, pos_out, | |
eca3654e DW |
1517 | min_t(loff_t, MAX_RW_COUNT, len), |
1518 | REMAP_FILE_CAN_SHORTEN); | |
42ec3d4c DW |
1519 | if (cloned > 0) { |
1520 | ret = cloned; | |
a76b5b04 CH |
1521 | goto done; |
1522 | } | |
1523 | } | |
1524 | ||
64bf5ff5 DC |
1525 | ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len, |
1526 | flags); | |
1527 | WARN_ON_ONCE(ret == -EOPNOTSUPP); | |
a76b5b04 | 1528 | done: |
29732938 ZB |
1529 | if (ret > 0) { |
1530 | fsnotify_access(file_in); | |
1531 | add_rchar(current, ret); | |
1532 | fsnotify_modify(file_out); | |
1533 | add_wchar(current, ret); | |
1534 | } | |
a76b5b04 | 1535 | |
29732938 ZB |
1536 | inc_syscr(current); |
1537 | inc_syscw(current); | |
1538 | ||
bfe219d3 | 1539 | file_end_write(file_out); |
29732938 ZB |
1540 | |
1541 | return ret; | |
1542 | } | |
1543 | EXPORT_SYMBOL(vfs_copy_file_range); | |
1544 | ||
1545 | SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, | |
1546 | int, fd_out, loff_t __user *, off_out, | |
1547 | size_t, len, unsigned int, flags) | |
1548 | { | |
1549 | loff_t pos_in; | |
1550 | loff_t pos_out; | |
1551 | struct fd f_in; | |
1552 | struct fd f_out; | |
1553 | ssize_t ret = -EBADF; | |
1554 | ||
1555 | f_in = fdget(fd_in); | |
1556 | if (!f_in.file) | |
1557 | goto out2; | |
1558 | ||
1559 | f_out = fdget(fd_out); | |
1560 | if (!f_out.file) | |
1561 | goto out1; | |
1562 | ||
1563 | ret = -EFAULT; | |
1564 | if (off_in) { | |
1565 | if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) | |
1566 | goto out; | |
1567 | } else { | |
1568 | pos_in = f_in.file->f_pos; | |
1569 | } | |
1570 | ||
1571 | if (off_out) { | |
1572 | if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) | |
1573 | goto out; | |
1574 | } else { | |
1575 | pos_out = f_out.file->f_pos; | |
1576 | } | |
1577 | ||
1578 | ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, | |
1579 | flags); | |
1580 | if (ret > 0) { | |
1581 | pos_in += ret; | |
1582 | pos_out += ret; | |
1583 | ||
1584 | if (off_in) { | |
1585 | if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) | |
1586 | ret = -EFAULT; | |
1587 | } else { | |
1588 | f_in.file->f_pos = pos_in; | |
1589 | } | |
1590 | ||
1591 | if (off_out) { | |
1592 | if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) | |
1593 | ret = -EFAULT; | |
1594 | } else { | |
1595 | f_out.file->f_pos = pos_out; | |
1596 | } | |
1597 | } | |
1598 | ||
1599 | out: | |
1600 | fdput(f_out); | |
1601 | out1: | |
1602 | fdput(f_in); | |
1603 | out2: | |
1604 | return ret; | |
1605 | } | |
04b38d60 | 1606 | |
edc58dd0 | 1607 | /* |
407e9c63 DW |
1608 | * Don't operate on ranges the page cache doesn't support, and don't exceed the |
1609 | * LFS limits. If pos is under the limit it becomes a short access. If it | |
1610 | * exceeds the limit we return -EFBIG. | |
edc58dd0 | 1611 | */ |
407e9c63 | 1612 | int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) |
edc58dd0 | 1613 | { |
407e9c63 DW |
1614 | struct inode *inode = file->f_mapping->host; |
1615 | loff_t max_size = inode->i_sb->s_maxbytes; | |
1616 | loff_t limit = rlimit(RLIMIT_FSIZE); | |
edc58dd0 | 1617 | |
407e9c63 DW |
1618 | if (limit != RLIM_INFINITY) { |
1619 | if (pos >= limit) { | |
1620 | send_sig(SIGXFSZ, current, 0); | |
1621 | return -EFBIG; | |
edc58dd0 | 1622 | } |
407e9c63 DW |
1623 | *count = min(*count, limit - pos); |
1624 | } | |
edc58dd0 | 1625 | |
407e9c63 DW |
1626 | if (!(file->f_flags & O_LARGEFILE)) |
1627 | max_size = MAX_NON_LFS; | |
c32e5f39 | 1628 | |
407e9c63 DW |
1629 | if (unlikely(pos >= max_size)) |
1630 | return -EFBIG; | |
c32e5f39 | 1631 | |
407e9c63 | 1632 | *count = min(*count, max_size - pos); |
c32e5f39 | 1633 | |
c32e5f39 | 1634 | return 0; |
c32e5f39 | 1635 | } |
04b38d60 | 1636 | |
f6f7a25a OS |
1637 | /* Like generic_write_checks(), but takes size of write instead of iter. */ |
1638 | int generic_write_checks_count(struct kiocb *iocb, loff_t *count) | |
876bec6f | 1639 | { |
407e9c63 DW |
1640 | struct file *file = iocb->ki_filp; |
1641 | struct inode *inode = file->f_mapping->host; | |
876bec6f | 1642 | |
407e9c63 | 1643 | if (IS_SWAPFILE(inode)) |
876bec6f DW |
1644 | return -ETXTBSY; |
1645 | ||
f6f7a25a | 1646 | if (!*count) |
407e9c63 | 1647 | return 0; |
5de4480a | 1648 | |
407e9c63 DW |
1649 | if (iocb->ki_flags & IOCB_APPEND) |
1650 | iocb->ki_pos = i_size_read(inode); | |
1b4f42a1 | 1651 | |
407e9c63 DW |
1652 | if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) |
1653 | return -EINVAL; | |
1b4f42a1 | 1654 | |
f6f7a25a OS |
1655 | return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); |
1656 | } | |
1657 | EXPORT_SYMBOL(generic_write_checks_count); | |
1658 | ||
1659 | /* | |
1660 | * Performs necessary checks before doing a write | |
1661 | * | |
1662 | * Can adjust writing position or amount of bytes to write. | |
1663 | * Returns appropriate error code that caller should return or | |
1664 | * zero in case that write should be allowed. | |
1665 | */ | |
1666 | ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) | |
1667 | { | |
1668 | loff_t count = iov_iter_count(from); | |
1669 | int ret; | |
1670 | ||
1671 | ret = generic_write_checks_count(iocb, &count); | |
1b4f42a1 MS |
1672 | if (ret) |
1673 | return ret; | |
1674 | ||
407e9c63 DW |
1675 | iov_iter_truncate(from, count); |
1676 | return iov_iter_count(from); | |
1b4f42a1 | 1677 | } |
407e9c63 | 1678 | EXPORT_SYMBOL(generic_write_checks); |
1b4f42a1 | 1679 | |
407e9c63 DW |
1680 | /* |
1681 | * Performs common checks before doing a file copy/clone | |
1682 | * from @file_in to @file_out. | |
1683 | */ | |
1684 | int generic_file_rw_checks(struct file *file_in, struct file *file_out) | |
54dbc151 | 1685 | { |
407e9c63 DW |
1686 | struct inode *inode_in = file_inode(file_in); |
1687 | struct inode *inode_out = file_inode(file_out); | |
54dbc151 | 1688 | |
407e9c63 DW |
1689 | /* Don't copy dirs, pipes, sockets... */ |
1690 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
494633fa | 1691 | return -EISDIR; |
407e9c63 | 1692 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) |
22725ce4 DW |
1693 | return -EINVAL; |
1694 | ||
407e9c63 DW |
1695 | if (!(file_in->f_mode & FMODE_READ) || |
1696 | !(file_out->f_mode & FMODE_WRITE) || | |
1697 | (file_out->f_flags & O_APPEND)) | |
1698 | return -EBADF; | |
1b4f42a1 | 1699 | |
407e9c63 | 1700 | return 0; |
54dbc151 | 1701 | } |