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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 | /* |
372 | * ranged mandatory locking does not apply to streams - it makes sense | |
373 | * only for files where position has a meaning. | |
374 | */ | |
375 | if (ppos) { | |
376 | loff_t pos = *ppos; | |
377 | ||
378 | if (unlikely(pos < 0)) { | |
379 | if (!unsigned_offsets(file)) | |
2949e842 | 380 | return -EINVAL; |
438ab720 KS |
381 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
382 | return -EOVERFLOW; | |
383 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
384 | if (!unsigned_offsets(file)) | |
2949e842 | 385 | return -EINVAL; |
438ab720 | 386 | } |
e28cc715 | 387 | } |
438ab720 | 388 | |
bc61384d | 389 | return security_file_permission(file, |
c43e259c | 390 | read_write == READ ? MAY_READ : MAY_WRITE); |
1da177e4 LT |
391 | } |
392 | ||
5d5d5689 | 393 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
394 | { |
395 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
396 | struct kiocb kiocb; | |
397 | struct iov_iter iter; | |
398 | ssize_t ret; | |
399 | ||
400 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 401 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 AV |
402 | iov_iter_init(&iter, READ, &iov, 1, len); |
403 | ||
bb7462b6 | 404 | ret = call_read_iter(filp, &kiocb, &iter); |
599bd19b | 405 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
406 | if (ppos) |
407 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
408 | return ret; |
409 | } | |
410 | ||
4d03e3cc CH |
411 | static int warn_unsupported(struct file *file, const char *op) |
412 | { | |
413 | pr_warn_ratelimited( | |
414 | "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n", | |
415 | op, file, current->pid, current->comm); | |
416 | return -EINVAL; | |
417 | } | |
418 | ||
61a707c5 CH |
419 | ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
420 | { | |
4d03e3cc CH |
421 | struct kvec iov = { |
422 | .iov_base = buf, | |
423 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
424 | }; | |
425 | struct kiocb kiocb; | |
426 | struct iov_iter iter; | |
61a707c5 CH |
427 | ssize_t ret; |
428 | ||
429 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ))) | |
430 | return -EINVAL; | |
431 | if (!(file->f_mode & FMODE_CAN_READ)) | |
432 | return -EINVAL; | |
4d03e3cc CH |
433 | /* |
434 | * Also fail if ->read_iter and ->read are both wired up as that | |
435 | * implies very convoluted semantics. | |
436 | */ | |
437 | if (unlikely(!file->f_op->read_iter || file->f_op->read)) | |
438 | return warn_unsupported(file, "read"); | |
61a707c5 | 439 | |
4d03e3cc | 440 | init_sync_kiocb(&kiocb, file); |
7b84b665 | 441 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
442 | iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len); |
443 | ret = file->f_op->read_iter(&kiocb, &iter); | |
61a707c5 | 444 | if (ret > 0) { |
7b84b665 MWO |
445 | if (pos) |
446 | *pos = kiocb.ki_pos; | |
61a707c5 CH |
447 | fsnotify_access(file); |
448 | add_rchar(current, ret); | |
449 | } | |
450 | inc_syscr(current); | |
451 | return ret; | |
452 | } | |
453 | ||
bdd1d2d3 | 454 | ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
c41fbad0 | 455 | { |
6209dd91 | 456 | ssize_t ret; |
c41fbad0 | 457 | |
6209dd91 CH |
458 | ret = rw_verify_area(READ, file, pos, count); |
459 | if (ret) | |
460 | return ret; | |
461 | return __kernel_read(file, buf, count, pos); | |
c41fbad0 CH |
462 | } |
463 | EXPORT_SYMBOL(kernel_read); | |
6fb5032e | 464 | |
1da177e4 LT |
465 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
466 | { | |
467 | ssize_t ret; | |
468 | ||
469 | if (!(file->f_mode & FMODE_READ)) | |
470 | return -EBADF; | |
7f7f25e8 | 471 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 | 472 | return -EINVAL; |
96d4f267 | 473 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
474 | return -EFAULT; |
475 | ||
476 | ret = rw_verify_area(READ, file, pos, count); | |
775802c0 CH |
477 | if (ret) |
478 | return ret; | |
479 | if (count > MAX_RW_COUNT) | |
480 | count = MAX_RW_COUNT; | |
1da177e4 | 481 | |
775802c0 CH |
482 | if (file->f_op->read) |
483 | ret = file->f_op->read(file, buf, count, pos); | |
484 | else if (file->f_op->read_iter) | |
485 | ret = new_sync_read(file, buf, count, pos); | |
486 | else | |
487 | ret = -EINVAL; | |
488 | if (ret > 0) { | |
489 | fsnotify_access(file); | |
490 | add_rchar(current, ret); | |
491 | } | |
492 | inc_syscr(current); | |
1da177e4 LT |
493 | return ret; |
494 | } | |
7fea21ae | 495 | EXPORT_SYMBOL_GPL(vfs_read); |
1da177e4 | 496 | |
5d5d5689 | 497 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
498 | { |
499 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
500 | struct kiocb kiocb; | |
501 | struct iov_iter iter; | |
502 | ssize_t ret; | |
503 | ||
504 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 505 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 AV |
506 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
507 | ||
bb7462b6 | 508 | ret = call_write_iter(filp, &kiocb, &iter); |
599bd19b | 509 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 | 510 | if (ret > 0 && ppos) |
f765b134 | 511 | *ppos = kiocb.ki_pos; |
293bc982 AV |
512 | return ret; |
513 | } | |
514 | ||
81238b2c | 515 | /* caller is responsible for file_start_write/file_end_write */ |
73e18f7c | 516 | ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) |
06ae43f3 | 517 | { |
4d03e3cc CH |
518 | struct kvec iov = { |
519 | .iov_base = (void *)buf, | |
520 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
521 | }; | |
522 | struct kiocb kiocb; | |
523 | struct iov_iter iter; | |
06ae43f3 AV |
524 | ssize_t ret; |
525 | ||
a01ac27b CH |
526 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) |
527 | return -EBADF; | |
7f7f25e8 | 528 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e | 529 | return -EINVAL; |
4d03e3cc CH |
530 | /* |
531 | * Also fail if ->write_iter and ->write are both wired up as that | |
532 | * implies very convoluted semantics. | |
533 | */ | |
534 | if (unlikely(!file->f_op->write_iter || file->f_op->write)) | |
535 | return warn_unsupported(file, "write"); | |
3e84f48e | 536 | |
4d03e3cc | 537 | init_sync_kiocb(&kiocb, file); |
4c207ef4 | 538 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
539 | iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len); |
540 | ret = file->f_op->write_iter(&kiocb, &iter); | |
06ae43f3 | 541 | if (ret > 0) { |
4c207ef4 MWO |
542 | if (pos) |
543 | *pos = kiocb.ki_pos; | |
06ae43f3 AV |
544 | fsnotify_modify(file); |
545 | add_wchar(current, ret); | |
546 | } | |
547 | inc_syscw(current); | |
548 | return ret; | |
549 | } | |
90fb7027 LT |
550 | /* |
551 | * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()", | |
552 | * but autofs is one of the few internal kernel users that actually | |
553 | * wants this _and_ can be built as a module. So we need to export | |
554 | * this symbol for autofs, even though it really isn't appropriate | |
555 | * for any other kernel modules. | |
556 | */ | |
557 | EXPORT_SYMBOL_GPL(__kernel_write); | |
2ec3a12a | 558 | |
e13ec939 CH |
559 | ssize_t kernel_write(struct file *file, const void *buf, size_t count, |
560 | loff_t *pos) | |
ac452aca | 561 | { |
81238b2c | 562 | ssize_t ret; |
ac452aca | 563 | |
81238b2c CH |
564 | ret = rw_verify_area(WRITE, file, pos, count); |
565 | if (ret) | |
566 | return ret; | |
ac452aca | 567 | |
81238b2c CH |
568 | file_start_write(file); |
569 | ret = __kernel_write(file, buf, count, pos); | |
570 | file_end_write(file); | |
571 | return ret; | |
ac452aca CH |
572 | } |
573 | EXPORT_SYMBOL(kernel_write); | |
574 | ||
1da177e4 LT |
575 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
576 | { | |
577 | ssize_t ret; | |
578 | ||
579 | if (!(file->f_mode & FMODE_WRITE)) | |
580 | return -EBADF; | |
7f7f25e8 | 581 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 | 582 | return -EINVAL; |
96d4f267 | 583 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
584 | return -EFAULT; |
585 | ||
586 | ret = rw_verify_area(WRITE, file, pos, count); | |
53ad8626 CH |
587 | if (ret) |
588 | return ret; | |
589 | if (count > MAX_RW_COUNT) | |
590 | count = MAX_RW_COUNT; | |
591 | file_start_write(file); | |
592 | if (file->f_op->write) | |
593 | ret = file->f_op->write(file, buf, count, pos); | |
594 | else if (file->f_op->write_iter) | |
595 | ret = new_sync_write(file, buf, count, pos); | |
596 | else | |
597 | ret = -EINVAL; | |
598 | if (ret > 0) { | |
599 | fsnotify_modify(file); | |
600 | add_wchar(current, ret); | |
1da177e4 | 601 | } |
53ad8626 CH |
602 | inc_syscw(current); |
603 | file_end_write(file); | |
1da177e4 LT |
604 | return ret; |
605 | } | |
7fea21ae | 606 | EXPORT_SYMBOL_GPL(vfs_write); |
1da177e4 | 607 | |
438ab720 KS |
608 | /* file_ppos returns &file->f_pos or NULL if file is stream */ |
609 | static inline loff_t *file_ppos(struct file *file) | |
1da177e4 | 610 | { |
438ab720 | 611 | return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; |
1da177e4 LT |
612 | } |
613 | ||
3ce4a7bf | 614 | ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) |
1da177e4 | 615 | { |
9c225f26 | 616 | struct fd f = fdget_pos(fd); |
1da177e4 | 617 | ssize_t ret = -EBADF; |
1da177e4 | 618 | |
2903ff01 | 619 | if (f.file) { |
438ab720 KS |
620 | loff_t pos, *ppos = file_ppos(f.file); |
621 | if (ppos) { | |
622 | pos = *ppos; | |
623 | ppos = &pos; | |
624 | } | |
625 | ret = vfs_read(f.file, buf, count, ppos); | |
626 | if (ret >= 0 && ppos) | |
627 | f.file->f_pos = pos; | |
9c225f26 | 628 | fdput_pos(f); |
1da177e4 | 629 | } |
1da177e4 LT |
630 | return ret; |
631 | } | |
1da177e4 | 632 | |
3ce4a7bf DB |
633 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
634 | { | |
635 | return ksys_read(fd, buf, count); | |
636 | } | |
637 | ||
e7a3e8b2 | 638 | ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) |
1da177e4 | 639 | { |
9c225f26 | 640 | struct fd f = fdget_pos(fd); |
1da177e4 | 641 | ssize_t ret = -EBADF; |
1da177e4 | 642 | |
2903ff01 | 643 | if (f.file) { |
438ab720 KS |
644 | loff_t pos, *ppos = file_ppos(f.file); |
645 | if (ppos) { | |
646 | pos = *ppos; | |
647 | ppos = &pos; | |
648 | } | |
649 | ret = vfs_write(f.file, buf, count, ppos); | |
650 | if (ret >= 0 && ppos) | |
651 | f.file->f_pos = pos; | |
9c225f26 | 652 | fdput_pos(f); |
1da177e4 LT |
653 | } |
654 | ||
655 | return ret; | |
656 | } | |
657 | ||
e7a3e8b2 DB |
658 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
659 | size_t, count) | |
660 | { | |
661 | return ksys_write(fd, buf, count); | |
662 | } | |
663 | ||
36028d5d DB |
664 | ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, |
665 | loff_t pos) | |
1da177e4 | 666 | { |
2903ff01 | 667 | struct fd f; |
1da177e4 | 668 | ssize_t ret = -EBADF; |
1da177e4 LT |
669 | |
670 | if (pos < 0) | |
671 | return -EINVAL; | |
672 | ||
2903ff01 AV |
673 | f = fdget(fd); |
674 | if (f.file) { | |
1da177e4 | 675 | ret = -ESPIPE; |
2903ff01 AV |
676 | if (f.file->f_mode & FMODE_PREAD) |
677 | ret = vfs_read(f.file, buf, count, &pos); | |
678 | fdput(f); | |
1da177e4 LT |
679 | } |
680 | ||
681 | return ret; | |
682 | } | |
683 | ||
36028d5d DB |
684 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
685 | size_t, count, loff_t, pos) | |
686 | { | |
687 | return ksys_pread64(fd, buf, count, pos); | |
688 | } | |
689 | ||
690 | ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, | |
691 | size_t count, loff_t pos) | |
1da177e4 | 692 | { |
2903ff01 | 693 | struct fd f; |
1da177e4 | 694 | ssize_t ret = -EBADF; |
1da177e4 LT |
695 | |
696 | if (pos < 0) | |
697 | return -EINVAL; | |
698 | ||
2903ff01 AV |
699 | f = fdget(fd); |
700 | if (f.file) { | |
1da177e4 | 701 | ret = -ESPIPE; |
2903ff01 AV |
702 | if (f.file->f_mode & FMODE_PWRITE) |
703 | ret = vfs_write(f.file, buf, count, &pos); | |
704 | fdput(f); | |
1da177e4 LT |
705 | } |
706 | ||
707 | return ret; | |
708 | } | |
709 | ||
36028d5d DB |
710 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
711 | size_t, count, loff_t, pos) | |
712 | { | |
713 | return ksys_pwrite64(fd, buf, count, pos); | |
714 | } | |
715 | ||
ac15ac06 | 716 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 717 | loff_t *ppos, int type, rwf_t flags) |
293bc982 AV |
718 | { |
719 | struct kiocb kiocb; | |
293bc982 AV |
720 | ssize_t ret; |
721 | ||
722 | init_sync_kiocb(&kiocb, filp); | |
fdd2f5b7 GR |
723 | ret = kiocb_set_rw_flags(&kiocb, flags); |
724 | if (ret) | |
725 | return ret; | |
438ab720 | 726 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 | 727 | |
0f78d06a | 728 | if (type == READ) |
bb7462b6 | 729 | ret = call_read_iter(filp, &kiocb, iter); |
0f78d06a | 730 | else |
bb7462b6 | 731 | ret = call_write_iter(filp, &kiocb, iter); |
599bd19b | 732 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
733 | if (ppos) |
734 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
735 | return ret; |
736 | } | |
737 | ||
ee0b3e67 | 738 | /* Do it by hand, with file-ops */ |
ac15ac06 | 739 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 740 | loff_t *ppos, int type, rwf_t flags) |
ee0b3e67 | 741 | { |
ee0b3e67 BP |
742 | ssize_t ret = 0; |
743 | ||
97be7ebe | 744 | if (flags & ~RWF_HIPRI) |
793b80ef CH |
745 | return -EOPNOTSUPP; |
746 | ||
ac15ac06 AV |
747 | while (iov_iter_count(iter)) { |
748 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
749 | ssize_t nr; |
750 | ||
0f78d06a MS |
751 | if (type == READ) { |
752 | nr = filp->f_op->read(filp, iovec.iov_base, | |
753 | iovec.iov_len, ppos); | |
754 | } else { | |
755 | nr = filp->f_op->write(filp, iovec.iov_base, | |
756 | iovec.iov_len, ppos); | |
757 | } | |
ee0b3e67 BP |
758 | |
759 | if (nr < 0) { | |
760 | if (!ret) | |
761 | ret = nr; | |
762 | break; | |
763 | } | |
764 | ret += nr; | |
ac15ac06 | 765 | if (nr != iovec.iov_len) |
ee0b3e67 | 766 | break; |
ac15ac06 | 767 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
768 | } |
769 | ||
770 | return ret; | |
771 | } | |
772 | ||
19c73586 | 773 | static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 774 | loff_t *pos, rwf_t flags) |
1da177e4 | 775 | { |
1da177e4 | 776 | size_t tot_len; |
7687a7a4 | 777 | ssize_t ret = 0; |
1da177e4 | 778 | |
edab5fe3 CH |
779 | if (!(file->f_mode & FMODE_READ)) |
780 | return -EBADF; | |
781 | if (!(file->f_mode & FMODE_CAN_READ)) | |
782 | return -EINVAL; | |
783 | ||
7687a7a4 | 784 | tot_len = iov_iter_count(iter); |
0504c074 AV |
785 | if (!tot_len) |
786 | goto out; | |
19c73586 | 787 | ret = rw_verify_area(READ, file, pos, tot_len); |
e28cc715 | 788 | if (ret < 0) |
19c73586 | 789 | return ret; |
1da177e4 | 790 | |
19c73586 CH |
791 | if (file->f_op->read_iter) |
792 | ret = do_iter_readv_writev(file, iter, pos, READ, flags); | |
ee0b3e67 | 793 | else |
19c73586 | 794 | ret = do_loop_readv_writev(file, iter, pos, READ, flags); |
1da177e4 | 795 | out: |
19c73586 CH |
796 | if (ret >= 0) |
797 | fsnotify_access(file); | |
1da177e4 | 798 | return ret; |
1da177e4 LT |
799 | } |
800 | ||
5dcdc43e JX |
801 | ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, |
802 | struct iov_iter *iter) | |
803 | { | |
804 | size_t tot_len; | |
805 | ssize_t ret = 0; | |
806 | ||
807 | if (!file->f_op->read_iter) | |
808 | return -EINVAL; | |
809 | if (!(file->f_mode & FMODE_READ)) | |
810 | return -EBADF; | |
811 | if (!(file->f_mode & FMODE_CAN_READ)) | |
812 | return -EINVAL; | |
813 | ||
814 | tot_len = iov_iter_count(iter); | |
815 | if (!tot_len) | |
816 | goto out; | |
817 | ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); | |
818 | if (ret < 0) | |
819 | return ret; | |
820 | ||
821 | ret = call_read_iter(file, iocb, iter); | |
822 | out: | |
823 | if (ret >= 0) | |
824 | fsnotify_access(file); | |
825 | return ret; | |
826 | } | |
827 | EXPORT_SYMBOL(vfs_iocb_iter_read); | |
828 | ||
18e9710e | 829 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 830 | rwf_t flags) |
7687a7a4 | 831 | { |
18e9710e CH |
832 | if (!file->f_op->read_iter) |
833 | return -EINVAL; | |
834 | return do_iter_read(file, iter, ppos, flags); | |
835 | } | |
836 | EXPORT_SYMBOL(vfs_iter_read); | |
7687a7a4 | 837 | |
19c73586 | 838 | static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 839 | loff_t *pos, rwf_t flags) |
19c73586 CH |
840 | { |
841 | size_t tot_len; | |
842 | ssize_t ret = 0; | |
03d95eb2 | 843 | |
edab5fe3 CH |
844 | if (!(file->f_mode & FMODE_WRITE)) |
845 | return -EBADF; | |
846 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
847 | return -EINVAL; | |
848 | ||
19c73586 CH |
849 | tot_len = iov_iter_count(iter); |
850 | if (!tot_len) | |
851 | return 0; | |
852 | ret = rw_verify_area(WRITE, file, pos, tot_len); | |
7687a7a4 MS |
853 | if (ret < 0) |
854 | return ret; | |
855 | ||
19c73586 CH |
856 | if (file->f_op->write_iter) |
857 | ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); | |
858 | else | |
859 | ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); | |
19c73586 CH |
860 | if (ret > 0) |
861 | fsnotify_modify(file); | |
7687a7a4 MS |
862 | return ret; |
863 | } | |
864 | ||
5dcdc43e JX |
865 | ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, |
866 | struct iov_iter *iter) | |
867 | { | |
868 | size_t tot_len; | |
869 | ssize_t ret = 0; | |
870 | ||
871 | if (!file->f_op->write_iter) | |
872 | return -EINVAL; | |
873 | if (!(file->f_mode & FMODE_WRITE)) | |
874 | return -EBADF; | |
875 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
876 | return -EINVAL; | |
877 | ||
878 | tot_len = iov_iter_count(iter); | |
879 | if (!tot_len) | |
880 | return 0; | |
881 | ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); | |
882 | if (ret < 0) | |
883 | return ret; | |
884 | ||
885 | ret = call_write_iter(file, iocb, iter); | |
886 | if (ret > 0) | |
887 | fsnotify_modify(file); | |
888 | ||
889 | return ret; | |
890 | } | |
891 | EXPORT_SYMBOL(vfs_iocb_iter_write); | |
892 | ||
abbb6589 | 893 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 894 | rwf_t flags) |
abbb6589 CH |
895 | { |
896 | if (!file->f_op->write_iter) | |
897 | return -EINVAL; | |
898 | return do_iter_write(file, iter, ppos, flags); | |
899 | } | |
900 | EXPORT_SYMBOL(vfs_iter_write); | |
901 | ||
36e2c742 | 902 | static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 903 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 904 | { |
7687a7a4 MS |
905 | struct iovec iovstack[UIO_FASTIOV]; |
906 | struct iovec *iov = iovstack; | |
907 | struct iov_iter iter; | |
908 | ssize_t ret; | |
1da177e4 | 909 | |
251b42a1 | 910 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 CH |
911 | if (ret >= 0) { |
912 | ret = do_iter_read(file, &iter, pos, flags); | |
913 | kfree(iov); | |
914 | } | |
1da177e4 | 915 | |
251b42a1 CH |
916 | return ret; |
917 | } | |
1da177e4 | 918 | |
9725d4ce | 919 | static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 920 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 921 | { |
251b42a1 CH |
922 | struct iovec iovstack[UIO_FASTIOV]; |
923 | struct iovec *iov = iovstack; | |
924 | struct iov_iter iter; | |
925 | ssize_t ret; | |
1da177e4 | 926 | |
251b42a1 | 927 | ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 | 928 | if (ret >= 0) { |
62473a2d | 929 | file_start_write(file); |
edab5fe3 | 930 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 931 | file_end_write(file); |
edab5fe3 CH |
932 | kfree(iov); |
933 | } | |
251b42a1 | 934 | return ret; |
1da177e4 | 935 | } |
1da177e4 | 936 | |
f17d8b35 | 937 | static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 938 | unsigned long vlen, rwf_t flags) |
1da177e4 | 939 | { |
9c225f26 | 940 | struct fd f = fdget_pos(fd); |
1da177e4 | 941 | ssize_t ret = -EBADF; |
1da177e4 | 942 | |
2903ff01 | 943 | if (f.file) { |
438ab720 KS |
944 | loff_t pos, *ppos = file_ppos(f.file); |
945 | if (ppos) { | |
946 | pos = *ppos; | |
947 | ppos = &pos; | |
948 | } | |
949 | ret = vfs_readv(f.file, vec, vlen, ppos, flags); | |
950 | if (ret >= 0 && ppos) | |
951 | f.file->f_pos = pos; | |
9c225f26 | 952 | fdput_pos(f); |
1da177e4 LT |
953 | } |
954 | ||
955 | if (ret > 0) | |
4b98d11b AD |
956 | add_rchar(current, ret); |
957 | inc_syscr(current); | |
1da177e4 LT |
958 | return ret; |
959 | } | |
960 | ||
f17d8b35 | 961 | static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 962 | unsigned long vlen, rwf_t flags) |
1da177e4 | 963 | { |
9c225f26 | 964 | struct fd f = fdget_pos(fd); |
1da177e4 | 965 | ssize_t ret = -EBADF; |
1da177e4 | 966 | |
2903ff01 | 967 | if (f.file) { |
438ab720 KS |
968 | loff_t pos, *ppos = file_ppos(f.file); |
969 | if (ppos) { | |
970 | pos = *ppos; | |
971 | ppos = &pos; | |
972 | } | |
973 | ret = vfs_writev(f.file, vec, vlen, ppos, flags); | |
974 | if (ret >= 0 && ppos) | |
975 | f.file->f_pos = pos; | |
9c225f26 | 976 | fdput_pos(f); |
1da177e4 LT |
977 | } |
978 | ||
979 | if (ret > 0) | |
4b98d11b AD |
980 | add_wchar(current, ret); |
981 | inc_syscw(current); | |
1da177e4 LT |
982 | return ret; |
983 | } | |
984 | ||
601cc11d LT |
985 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
986 | { | |
987 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
988 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
989 | } | |
990 | ||
f17d8b35 | 991 | static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 992 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 993 | { |
2903ff01 | 994 | struct fd f; |
f3554f4b | 995 | ssize_t ret = -EBADF; |
f3554f4b GH |
996 | |
997 | if (pos < 0) | |
998 | return -EINVAL; | |
999 | ||
2903ff01 AV |
1000 | f = fdget(fd); |
1001 | if (f.file) { | |
f3554f4b | 1002 | ret = -ESPIPE; |
2903ff01 | 1003 | if (f.file->f_mode & FMODE_PREAD) |
f17d8b35 | 1004 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1005 | fdput(f); |
f3554f4b GH |
1006 | } |
1007 | ||
1008 | if (ret > 0) | |
1009 | add_rchar(current, ret); | |
1010 | inc_syscr(current); | |
1011 | return ret; | |
1012 | } | |
1013 | ||
f17d8b35 | 1014 | static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1015 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1016 | { |
2903ff01 | 1017 | struct fd f; |
f3554f4b | 1018 | ssize_t ret = -EBADF; |
f3554f4b GH |
1019 | |
1020 | if (pos < 0) | |
1021 | return -EINVAL; | |
1022 | ||
2903ff01 AV |
1023 | f = fdget(fd); |
1024 | if (f.file) { | |
f3554f4b | 1025 | ret = -ESPIPE; |
2903ff01 | 1026 | if (f.file->f_mode & FMODE_PWRITE) |
f17d8b35 | 1027 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1028 | fdput(f); |
f3554f4b GH |
1029 | } |
1030 | ||
1031 | if (ret > 0) | |
1032 | add_wchar(current, ret); | |
1033 | inc_syscw(current); | |
1034 | return ret; | |
1035 | } | |
1036 | ||
f17d8b35 MT |
1037 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
1038 | unsigned long, vlen) | |
1039 | { | |
1040 | return do_readv(fd, vec, vlen, 0); | |
1041 | } | |
1042 | ||
1043 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, | |
1044 | unsigned long, vlen) | |
1045 | { | |
1046 | return do_writev(fd, vec, vlen, 0); | |
1047 | } | |
1048 | ||
1049 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, | |
1050 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1051 | { | |
1052 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1053 | ||
1054 | return do_preadv(fd, vec, vlen, pos, 0); | |
1055 | } | |
1056 | ||
1057 | SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, | |
1058 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1059 | rwf_t, flags) |
f17d8b35 MT |
1060 | { |
1061 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1062 | ||
1063 | if (pos == -1) | |
1064 | return do_readv(fd, vec, vlen, flags); | |
1065 | ||
1066 | return do_preadv(fd, vec, vlen, pos, flags); | |
1067 | } | |
1068 | ||
1069 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
1070 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1071 | { | |
1072 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1073 | ||
1074 | return do_pwritev(fd, vec, vlen, pos, 0); | |
1075 | } | |
1076 | ||
1077 | SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, | |
1078 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1079 | rwf_t, flags) |
f17d8b35 MT |
1080 | { |
1081 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1082 | ||
1083 | if (pos == -1) | |
1084 | return do_writev(fd, vec, vlen, flags); | |
1085 | ||
1086 | return do_pwritev(fd, vec, vlen, pos, flags); | |
1087 | } | |
1088 | ||
3523a9d4 CH |
1089 | /* |
1090 | * Various compat syscalls. Note that they all pretend to take a native | |
1091 | * iovec - import_iovec will properly treat those as compat_iovecs based on | |
1092 | * in_compat_syscall(). | |
1093 | */ | |
72ec3516 | 1094 | #ifdef CONFIG_COMPAT |
378a10f3 HC |
1095 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1096 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
3523a9d4 | 1097 | const struct iovec __user *, vec, |
378a10f3 HC |
1098 | unsigned long, vlen, loff_t, pos) |
1099 | { | |
3523a9d4 | 1100 | return do_preadv(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1101 | } |
1102 | #endif | |
1103 | ||
dfd948e3 | 1104 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
3523a9d4 | 1105 | const struct iovec __user *, vec, |
dfd948e3 | 1106 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1107 | { |
1108 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1109 | |
3523a9d4 | 1110 | return do_preadv(fd, vec, vlen, pos, 0); |
f17d8b35 MT |
1111 | } |
1112 | ||
3ebfd81f L |
1113 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 |
1114 | COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, | |
3523a9d4 | 1115 | const struct iovec __user *, vec, |
ddef7ed2 | 1116 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1117 | { |
cc4b1242 | 1118 | if (pos == -1) |
3523a9d4 CH |
1119 | return do_readv(fd, vec, vlen, flags); |
1120 | return do_preadv(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1121 | } |
1122 | #endif | |
1123 | ||
f17d8b35 | 1124 | COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, |
3523a9d4 | 1125 | const struct iovec __user *, vec, |
f17d8b35 | 1126 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, |
ddef7ed2 | 1127 | rwf_t, flags) |
f17d8b35 MT |
1128 | { |
1129 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1130 | ||
1131 | if (pos == -1) | |
3523a9d4 CH |
1132 | return do_readv(fd, vec, vlen, flags); |
1133 | return do_preadv(fd, vec, vlen, pos, flags); | |
72ec3516 AV |
1134 | } |
1135 | ||
378a10f3 HC |
1136 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1137 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
3523a9d4 | 1138 | const struct iovec __user *, vec, |
378a10f3 HC |
1139 | unsigned long, vlen, loff_t, pos) |
1140 | { | |
3523a9d4 | 1141 | return do_pwritev(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1142 | } |
1143 | #endif | |
1144 | ||
dfd948e3 | 1145 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
3523a9d4 | 1146 | const struct iovec __user *,vec, |
dfd948e3 | 1147 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1148 | { |
1149 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1150 | |
3523a9d4 | 1151 | return do_pwritev(fd, vec, vlen, pos, 0); |
72ec3516 | 1152 | } |
f17d8b35 | 1153 | |
3ebfd81f L |
1154 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 |
1155 | COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, | |
3523a9d4 | 1156 | const struct iovec __user *, vec, |
ddef7ed2 | 1157 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1158 | { |
cc4b1242 | 1159 | if (pos == -1) |
3523a9d4 CH |
1160 | return do_writev(fd, vec, vlen, flags); |
1161 | return do_pwritev(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1162 | } |
1163 | #endif | |
1164 | ||
f17d8b35 | 1165 | COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, |
3523a9d4 | 1166 | const struct iovec __user *,vec, |
ddef7ed2 | 1167 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) |
f17d8b35 MT |
1168 | { |
1169 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1170 | ||
1171 | if (pos == -1) | |
3523a9d4 CH |
1172 | return do_writev(fd, vec, vlen, flags); |
1173 | return do_pwritev(fd, vec, vlen, pos, flags); | |
72ec3516 | 1174 | } |
3523a9d4 | 1175 | #endif /* CONFIG_COMPAT */ |
72ec3516 | 1176 | |
19f4fc3a AV |
1177 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1178 | size_t count, loff_t max) | |
1da177e4 | 1179 | { |
2903ff01 AV |
1180 | struct fd in, out; |
1181 | struct inode *in_inode, *out_inode; | |
b964bf53 | 1182 | struct pipe_inode_info *opipe; |
1da177e4 | 1183 | loff_t pos; |
7995bd28 | 1184 | loff_t out_pos; |
1da177e4 | 1185 | ssize_t retval; |
2903ff01 | 1186 | int fl; |
1da177e4 LT |
1187 | |
1188 | /* | |
1189 | * Get input file, and verify that it is ok.. | |
1190 | */ | |
1191 | retval = -EBADF; | |
2903ff01 AV |
1192 | in = fdget(in_fd); |
1193 | if (!in.file) | |
1da177e4 | 1194 | goto out; |
2903ff01 | 1195 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1196 | goto fput_in; |
1da177e4 | 1197 | retval = -ESPIPE; |
7995bd28 AV |
1198 | if (!ppos) { |
1199 | pos = in.file->f_pos; | |
1200 | } else { | |
1201 | pos = *ppos; | |
2903ff01 | 1202 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1203 | goto fput_in; |
7995bd28 AV |
1204 | } |
1205 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1206 | if (retval < 0) |
1da177e4 | 1207 | goto fput_in; |
bc61384d AV |
1208 | if (count > MAX_RW_COUNT) |
1209 | count = MAX_RW_COUNT; | |
1da177e4 | 1210 | |
1da177e4 LT |
1211 | /* |
1212 | * Get output file, and verify that it is ok.. | |
1213 | */ | |
1214 | retval = -EBADF; | |
2903ff01 AV |
1215 | out = fdget(out_fd); |
1216 | if (!out.file) | |
1da177e4 | 1217 | goto fput_in; |
2903ff01 | 1218 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 | 1219 | goto fput_out; |
496ad9aa AV |
1220 | in_inode = file_inode(in.file); |
1221 | out_inode = file_inode(out.file); | |
7995bd28 | 1222 | out_pos = out.file->f_pos; |
1da177e4 | 1223 | |
1da177e4 LT |
1224 | if (!max) |
1225 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1226 | ||
1da177e4 LT |
1227 | if (unlikely(pos + count > max)) { |
1228 | retval = -EOVERFLOW; | |
1229 | if (pos >= max) | |
1230 | goto fput_out; | |
1231 | count = max - pos; | |
1232 | } | |
1233 | ||
d96e6e71 | 1234 | fl = 0; |
534f2aaa | 1235 | #if 0 |
d96e6e71 JA |
1236 | /* |
1237 | * We need to debate whether we can enable this or not. The | |
1238 | * man page documents EAGAIN return for the output at least, | |
1239 | * and the application is arguably buggy if it doesn't expect | |
1240 | * EAGAIN on a non-blocking file descriptor. | |
1241 | */ | |
2903ff01 | 1242 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1243 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1244 | #endif |
b964bf53 AV |
1245 | opipe = get_pipe_info(out.file, true); |
1246 | if (!opipe) { | |
1247 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
1248 | if (retval < 0) | |
1249 | goto fput_out; | |
1250 | file_start_write(out.file); | |
1251 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, | |
1252 | count, fl); | |
1253 | file_end_write(out.file); | |
1254 | } else { | |
1255 | retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); | |
1256 | } | |
1da177e4 LT |
1257 | |
1258 | if (retval > 0) { | |
4b98d11b AD |
1259 | add_rchar(current, retval); |
1260 | add_wchar(current, retval); | |
a68c2f12 SW |
1261 | fsnotify_access(in.file); |
1262 | fsnotify_modify(out.file); | |
7995bd28 AV |
1263 | out.file->f_pos = out_pos; |
1264 | if (ppos) | |
1265 | *ppos = pos; | |
1266 | else | |
1267 | in.file->f_pos = pos; | |
1da177e4 | 1268 | } |
1da177e4 | 1269 | |
4b98d11b AD |
1270 | inc_syscr(current); |
1271 | inc_syscw(current); | |
7995bd28 | 1272 | if (pos > max) |
1da177e4 LT |
1273 | retval = -EOVERFLOW; |
1274 | ||
1275 | fput_out: | |
2903ff01 | 1276 | fdput(out); |
1da177e4 | 1277 | fput_in: |
2903ff01 | 1278 | fdput(in); |
1da177e4 LT |
1279 | out: |
1280 | return retval; | |
1281 | } | |
1282 | ||
002c8976 | 1283 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1284 | { |
1285 | loff_t pos; | |
1286 | off_t off; | |
1287 | ssize_t ret; | |
1288 | ||
1289 | if (offset) { | |
1290 | if (unlikely(get_user(off, offset))) | |
1291 | return -EFAULT; | |
1292 | pos = off; | |
1293 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1294 | if (unlikely(put_user(pos, offset))) | |
1295 | return -EFAULT; | |
1296 | return ret; | |
1297 | } | |
1298 | ||
1299 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1300 | } | |
1301 | ||
002c8976 | 1302 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1303 | { |
1304 | loff_t pos; | |
1305 | ssize_t ret; | |
1306 | ||
1307 | if (offset) { | |
1308 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1309 | return -EFAULT; | |
1310 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1311 | if (unlikely(put_user(pos, offset))) | |
1312 | return -EFAULT; | |
1313 | return ret; | |
1314 | } | |
1315 | ||
1316 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1317 | } | |
19f4fc3a AV |
1318 | |
1319 | #ifdef CONFIG_COMPAT | |
1320 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1321 | compat_off_t __user *, offset, compat_size_t, count) | |
1322 | { | |
1323 | loff_t pos; | |
1324 | off_t off; | |
1325 | ssize_t ret; | |
1326 | ||
1327 | if (offset) { | |
1328 | if (unlikely(get_user(off, offset))) | |
1329 | return -EFAULT; | |
1330 | pos = off; | |
1331 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1332 | if (unlikely(put_user(pos, offset))) | |
1333 | return -EFAULT; | |
1334 | return ret; | |
1335 | } | |
1336 | ||
1337 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1338 | } | |
1339 | ||
1340 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1341 | compat_loff_t __user *, offset, compat_size_t, count) | |
1342 | { | |
1343 | loff_t pos; | |
1344 | ssize_t ret; | |
1345 | ||
1346 | if (offset) { | |
1347 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1348 | return -EFAULT; | |
1349 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1350 | if (unlikely(put_user(pos, offset))) | |
1351 | return -EFAULT; | |
1352 | return ret; | |
1353 | } | |
1354 | ||
1355 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1356 | } | |
1357 | #endif | |
29732938 | 1358 | |
f16acc9d DC |
1359 | /** |
1360 | * generic_copy_file_range - copy data between two files | |
1361 | * @file_in: file structure to read from | |
1362 | * @pos_in: file offset to read from | |
1363 | * @file_out: file structure to write data to | |
1364 | * @pos_out: file offset to write data to | |
1365 | * @len: amount of data to copy | |
1366 | * @flags: copy flags | |
1367 | * | |
1368 | * This is a generic filesystem helper to copy data from one file to another. | |
1369 | * It has no constraints on the source or destination file owners - the files | |
1370 | * can belong to different superblocks and different filesystem types. Short | |
1371 | * copies are allowed. | |
1372 | * | |
1373 | * This should be called from the @file_out filesystem, as per the | |
1374 | * ->copy_file_range() method. | |
1375 | * | |
1376 | * Returns the number of bytes copied or a negative error indicating the | |
1377 | * failure. | |
1378 | */ | |
1379 | ||
1380 | ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, | |
1381 | struct file *file_out, loff_t pos_out, | |
1382 | size_t len, unsigned int flags) | |
1383 | { | |
1384 | return do_splice_direct(file_in, &pos_in, file_out, &pos_out, | |
1385 | len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); | |
1386 | } | |
1387 | EXPORT_SYMBOL(generic_copy_file_range); | |
1388 | ||
64bf5ff5 DC |
1389 | static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, |
1390 | struct file *file_out, loff_t pos_out, | |
1391 | size_t len, unsigned int flags) | |
1392 | { | |
5dae222a AG |
1393 | /* |
1394 | * Although we now allow filesystems to handle cross sb copy, passing | |
1395 | * a file of the wrong filesystem type to filesystem driver can result | |
1396 | * in an attempt to dereference the wrong type of ->private_data, so | |
1397 | * avoid doing that until we really have a good reason. NFS defines | |
1398 | * several different file_system_type structures, but they all end up | |
1399 | * using the same ->copy_file_range() function pointer. | |
1400 | */ | |
1401 | if (file_out->f_op->copy_file_range && | |
1402 | file_out->f_op->copy_file_range == file_in->f_op->copy_file_range) | |
64bf5ff5 DC |
1403 | return file_out->f_op->copy_file_range(file_in, pos_in, |
1404 | file_out, pos_out, | |
1405 | len, flags); | |
1406 | ||
1407 | return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, | |
1408 | flags); | |
1409 | } | |
1410 | ||
407e9c63 DW |
1411 | /* |
1412 | * Performs necessary checks before doing a file copy | |
1413 | * | |
1414 | * Can adjust amount of bytes to copy via @req_count argument. | |
1415 | * Returns appropriate error code that caller should return or | |
1416 | * zero in case the copy should be allowed. | |
1417 | */ | |
1418 | static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, | |
1419 | struct file *file_out, loff_t pos_out, | |
1420 | size_t *req_count, unsigned int flags) | |
1421 | { | |
1422 | struct inode *inode_in = file_inode(file_in); | |
1423 | struct inode *inode_out = file_inode(file_out); | |
1424 | uint64_t count = *req_count; | |
1425 | loff_t size_in; | |
1426 | int ret; | |
1427 | ||
1428 | ret = generic_file_rw_checks(file_in, file_out); | |
1429 | if (ret) | |
1430 | return ret; | |
1431 | ||
1432 | /* Don't touch certain kinds of inodes */ | |
1433 | if (IS_IMMUTABLE(inode_out)) | |
1434 | return -EPERM; | |
1435 | ||
1436 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1437 | return -ETXTBSY; | |
1438 | ||
1439 | /* Ensure offsets don't wrap. */ | |
1440 | if (pos_in + count < pos_in || pos_out + count < pos_out) | |
1441 | return -EOVERFLOW; | |
1442 | ||
1443 | /* Shorten the copy to EOF */ | |
1444 | size_in = i_size_read(inode_in); | |
1445 | if (pos_in >= size_in) | |
1446 | count = 0; | |
1447 | else | |
1448 | count = min(count, size_in - (uint64_t)pos_in); | |
1449 | ||
1450 | ret = generic_write_check_limits(file_out, pos_out, &count); | |
1451 | if (ret) | |
1452 | return ret; | |
1453 | ||
1454 | /* Don't allow overlapped copying within the same file. */ | |
1455 | if (inode_in == inode_out && | |
1456 | pos_out + count > pos_in && | |
1457 | pos_out < pos_in + count) | |
1458 | return -EINVAL; | |
1459 | ||
1460 | *req_count = count; | |
1461 | return 0; | |
1462 | } | |
1463 | ||
29732938 ZB |
1464 | /* |
1465 | * copy_file_range() differs from regular file read and write in that it | |
1466 | * specifically allows return partial success. When it does so is up to | |
1467 | * the copy_file_range method. | |
1468 | */ | |
1469 | ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, | |
1470 | struct file *file_out, loff_t pos_out, | |
1471 | size_t len, unsigned int flags) | |
1472 | { | |
29732938 ZB |
1473 | ssize_t ret; |
1474 | ||
1475 | if (flags != 0) | |
1476 | return -EINVAL; | |
1477 | ||
96e6e8f4 AG |
1478 | ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, |
1479 | flags); | |
a3171351 AG |
1480 | if (unlikely(ret)) |
1481 | return ret; | |
11cbfb10 | 1482 | |
29732938 | 1483 | ret = rw_verify_area(READ, file_in, &pos_in, len); |
bc61384d AV |
1484 | if (unlikely(ret)) |
1485 | return ret; | |
1486 | ||
1487 | ret = rw_verify_area(WRITE, file_out, &pos_out, len); | |
1488 | if (unlikely(ret)) | |
29732938 ZB |
1489 | return ret; |
1490 | ||
29732938 ZB |
1491 | if (len == 0) |
1492 | return 0; | |
1493 | ||
bfe219d3 | 1494 | file_start_write(file_out); |
29732938 | 1495 | |
a76b5b04 CH |
1496 | /* |
1497 | * Try cloning first, this is supported by more file systems, and | |
1498 | * more efficient if both clone and copy are supported (e.g. NFS). | |
1499 | */ | |
5dae222a AG |
1500 | if (file_in->f_op->remap_file_range && |
1501 | file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) { | |
42ec3d4c DW |
1502 | loff_t cloned; |
1503 | ||
1504 | cloned = file_in->f_op->remap_file_range(file_in, pos_in, | |
1505 | file_out, pos_out, | |
eca3654e DW |
1506 | min_t(loff_t, MAX_RW_COUNT, len), |
1507 | REMAP_FILE_CAN_SHORTEN); | |
42ec3d4c DW |
1508 | if (cloned > 0) { |
1509 | ret = cloned; | |
a76b5b04 CH |
1510 | goto done; |
1511 | } | |
1512 | } | |
1513 | ||
64bf5ff5 DC |
1514 | ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len, |
1515 | flags); | |
1516 | WARN_ON_ONCE(ret == -EOPNOTSUPP); | |
a76b5b04 | 1517 | done: |
29732938 ZB |
1518 | if (ret > 0) { |
1519 | fsnotify_access(file_in); | |
1520 | add_rchar(current, ret); | |
1521 | fsnotify_modify(file_out); | |
1522 | add_wchar(current, ret); | |
1523 | } | |
a76b5b04 | 1524 | |
29732938 ZB |
1525 | inc_syscr(current); |
1526 | inc_syscw(current); | |
1527 | ||
bfe219d3 | 1528 | file_end_write(file_out); |
29732938 ZB |
1529 | |
1530 | return ret; | |
1531 | } | |
1532 | EXPORT_SYMBOL(vfs_copy_file_range); | |
1533 | ||
1534 | SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, | |
1535 | int, fd_out, loff_t __user *, off_out, | |
1536 | size_t, len, unsigned int, flags) | |
1537 | { | |
1538 | loff_t pos_in; | |
1539 | loff_t pos_out; | |
1540 | struct fd f_in; | |
1541 | struct fd f_out; | |
1542 | ssize_t ret = -EBADF; | |
1543 | ||
1544 | f_in = fdget(fd_in); | |
1545 | if (!f_in.file) | |
1546 | goto out2; | |
1547 | ||
1548 | f_out = fdget(fd_out); | |
1549 | if (!f_out.file) | |
1550 | goto out1; | |
1551 | ||
1552 | ret = -EFAULT; | |
1553 | if (off_in) { | |
1554 | if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) | |
1555 | goto out; | |
1556 | } else { | |
1557 | pos_in = f_in.file->f_pos; | |
1558 | } | |
1559 | ||
1560 | if (off_out) { | |
1561 | if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) | |
1562 | goto out; | |
1563 | } else { | |
1564 | pos_out = f_out.file->f_pos; | |
1565 | } | |
1566 | ||
1567 | ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, | |
1568 | flags); | |
1569 | if (ret > 0) { | |
1570 | pos_in += ret; | |
1571 | pos_out += ret; | |
1572 | ||
1573 | if (off_in) { | |
1574 | if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) | |
1575 | ret = -EFAULT; | |
1576 | } else { | |
1577 | f_in.file->f_pos = pos_in; | |
1578 | } | |
1579 | ||
1580 | if (off_out) { | |
1581 | if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) | |
1582 | ret = -EFAULT; | |
1583 | } else { | |
1584 | f_out.file->f_pos = pos_out; | |
1585 | } | |
1586 | } | |
1587 | ||
1588 | out: | |
1589 | fdput(f_out); | |
1590 | out1: | |
1591 | fdput(f_in); | |
1592 | out2: | |
1593 | return ret; | |
1594 | } | |
04b38d60 | 1595 | |
edc58dd0 | 1596 | /* |
407e9c63 DW |
1597 | * Don't operate on ranges the page cache doesn't support, and don't exceed the |
1598 | * LFS limits. If pos is under the limit it becomes a short access. If it | |
1599 | * exceeds the limit we return -EFBIG. | |
edc58dd0 | 1600 | */ |
407e9c63 | 1601 | int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) |
edc58dd0 | 1602 | { |
407e9c63 DW |
1603 | struct inode *inode = file->f_mapping->host; |
1604 | loff_t max_size = inode->i_sb->s_maxbytes; | |
1605 | loff_t limit = rlimit(RLIMIT_FSIZE); | |
edc58dd0 | 1606 | |
407e9c63 DW |
1607 | if (limit != RLIM_INFINITY) { |
1608 | if (pos >= limit) { | |
1609 | send_sig(SIGXFSZ, current, 0); | |
1610 | return -EFBIG; | |
edc58dd0 | 1611 | } |
407e9c63 DW |
1612 | *count = min(*count, limit - pos); |
1613 | } | |
edc58dd0 | 1614 | |
407e9c63 DW |
1615 | if (!(file->f_flags & O_LARGEFILE)) |
1616 | max_size = MAX_NON_LFS; | |
c32e5f39 | 1617 | |
407e9c63 DW |
1618 | if (unlikely(pos >= max_size)) |
1619 | return -EFBIG; | |
c32e5f39 | 1620 | |
407e9c63 | 1621 | *count = min(*count, max_size - pos); |
c32e5f39 | 1622 | |
c32e5f39 | 1623 | return 0; |
c32e5f39 | 1624 | } |
04b38d60 | 1625 | |
876bec6f | 1626 | /* |
407e9c63 | 1627 | * Performs necessary checks before doing a write |
22725ce4 | 1628 | * |
407e9c63 DW |
1629 | * Can adjust writing position or amount of bytes to write. |
1630 | * Returns appropriate error code that caller should return or | |
1631 | * zero in case that write should be allowed. | |
876bec6f | 1632 | */ |
407e9c63 | 1633 | ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) |
876bec6f | 1634 | { |
407e9c63 DW |
1635 | struct file *file = iocb->ki_filp; |
1636 | struct inode *inode = file->f_mapping->host; | |
1637 | loff_t count; | |
876bec6f DW |
1638 | int ret; |
1639 | ||
407e9c63 | 1640 | if (IS_SWAPFILE(inode)) |
876bec6f DW |
1641 | return -ETXTBSY; |
1642 | ||
407e9c63 DW |
1643 | if (!iov_iter_count(from)) |
1644 | return 0; | |
5de4480a | 1645 | |
407e9c63 DW |
1646 | /* FIXME: this is for backwards compatibility with 2.4 */ |
1647 | if (iocb->ki_flags & IOCB_APPEND) | |
1648 | iocb->ki_pos = i_size_read(inode); | |
1b4f42a1 | 1649 | |
407e9c63 DW |
1650 | if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) |
1651 | return -EINVAL; | |
1b4f42a1 | 1652 | |
407e9c63 DW |
1653 | count = iov_iter_count(from); |
1654 | ret = generic_write_check_limits(file, iocb->ki_pos, &count); | |
1b4f42a1 MS |
1655 | if (ret) |
1656 | return ret; | |
1657 | ||
407e9c63 DW |
1658 | iov_iter_truncate(from, count); |
1659 | return iov_iter_count(from); | |
1b4f42a1 | 1660 | } |
407e9c63 | 1661 | EXPORT_SYMBOL(generic_write_checks); |
1b4f42a1 | 1662 | |
407e9c63 DW |
1663 | /* |
1664 | * Performs common checks before doing a file copy/clone | |
1665 | * from @file_in to @file_out. | |
1666 | */ | |
1667 | int generic_file_rw_checks(struct file *file_in, struct file *file_out) | |
54dbc151 | 1668 | { |
407e9c63 DW |
1669 | struct inode *inode_in = file_inode(file_in); |
1670 | struct inode *inode_out = file_inode(file_out); | |
54dbc151 | 1671 | |
407e9c63 DW |
1672 | /* Don't copy dirs, pipes, sockets... */ |
1673 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
494633fa | 1674 | return -EISDIR; |
407e9c63 | 1675 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) |
22725ce4 DW |
1676 | return -EINVAL; |
1677 | ||
407e9c63 DW |
1678 | if (!(file_in->f_mode & FMODE_READ) || |
1679 | !(file_out->f_mode & FMODE_WRITE) || | |
1680 | (file_out->f_flags & O_APPEND)) | |
1681 | return -EBADF; | |
1b4f42a1 | 1682 | |
407e9c63 | 1683 | return 0; |
54dbc151 | 1684 | } |