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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 default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 231 | { |
496ad9aa | 232 | struct inode *inode = file_inode(file); |
16abef0e | 233 | loff_t retval; |
1da177e4 | 234 | |
5955102c | 235 | inode_lock(inode); |
965c8e59 | 236 | switch (whence) { |
7b8e8924 | 237 | case SEEK_END: |
982d8165 | 238 | offset += i_size_read(inode); |
1da177e4 | 239 | break; |
7b8e8924 | 240 | case SEEK_CUR: |
5b6f1eb9 AK |
241 | if (offset == 0) { |
242 | retval = file->f_pos; | |
243 | goto out; | |
244 | } | |
1da177e4 | 245 | offset += file->f_pos; |
982d8165 JB |
246 | break; |
247 | case SEEK_DATA: | |
248 | /* | |
249 | * In the generic case the entire file is data, so as | |
250 | * long as offset isn't at the end of the file then the | |
251 | * offset is data. | |
252 | */ | |
bacb2d81 DC |
253 | if (offset >= inode->i_size) { |
254 | retval = -ENXIO; | |
255 | goto out; | |
256 | } | |
982d8165 JB |
257 | break; |
258 | case SEEK_HOLE: | |
259 | /* | |
260 | * There is a virtual hole at the end of the file, so | |
261 | * as long as offset isn't i_size or larger, return | |
262 | * i_size. | |
263 | */ | |
bacb2d81 DC |
264 | if (offset >= inode->i_size) { |
265 | retval = -ENXIO; | |
266 | goto out; | |
267 | } | |
982d8165 JB |
268 | offset = inode->i_size; |
269 | break; | |
1da177e4 LT |
270 | } |
271 | retval = -EINVAL; | |
cccb5a1e | 272 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
273 | if (offset != file->f_pos) { |
274 | file->f_pos = offset; | |
275 | file->f_version = 0; | |
276 | } | |
277 | retval = offset; | |
278 | } | |
5b6f1eb9 | 279 | out: |
5955102c | 280 | inode_unlock(inode); |
1da177e4 LT |
281 | return retval; |
282 | } | |
283 | EXPORT_SYMBOL(default_llseek); | |
284 | ||
965c8e59 | 285 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 286 | { |
4e3299ea JD |
287 | if (!(file->f_mode & FMODE_LSEEK)) |
288 | return -ESPIPE; | |
289 | return file->f_op->llseek(file, offset, whence); | |
1da177e4 LT |
290 | } |
291 | EXPORT_SYMBOL(vfs_llseek); | |
292 | ||
bef17329 | 293 | static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) |
1da177e4 LT |
294 | { |
295 | off_t retval; | |
9c225f26 | 296 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
297 | if (!f.file) |
298 | return -EBADF; | |
1da177e4 LT |
299 | |
300 | retval = -EINVAL; | |
965c8e59 AM |
301 | if (whence <= SEEK_MAX) { |
302 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
303 | retval = res; |
304 | if (res != (loff_t)retval) | |
305 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
306 | } | |
9c225f26 | 307 | fdput_pos(f); |
1da177e4 LT |
308 | return retval; |
309 | } | |
310 | ||
76847e43 DB |
311 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
312 | { | |
313 | return ksys_lseek(fd, offset, whence); | |
314 | } | |
315 | ||
561c6731 AV |
316 | #ifdef CONFIG_COMPAT |
317 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
318 | { | |
76847e43 | 319 | return ksys_lseek(fd, offset, whence); |
561c6731 AV |
320 | } |
321 | #endif | |
322 | ||
9e62ccec MS |
323 | #if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \ |
324 | defined(__ARCH_WANT_SYS_LLSEEK) | |
003d7ab4 HC |
325 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
326 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 327 | unsigned int, whence) |
1da177e4 LT |
328 | { |
329 | int retval; | |
d7a15f8d | 330 | struct fd f = fdget_pos(fd); |
1da177e4 | 331 | loff_t offset; |
1da177e4 | 332 | |
2903ff01 AV |
333 | if (!f.file) |
334 | return -EBADF; | |
1da177e4 LT |
335 | |
336 | retval = -EINVAL; | |
965c8e59 | 337 | if (whence > SEEK_MAX) |
1da177e4 LT |
338 | goto out_putf; |
339 | ||
2903ff01 | 340 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 341 | whence); |
1da177e4 LT |
342 | |
343 | retval = (int)offset; | |
344 | if (offset >= 0) { | |
345 | retval = -EFAULT; | |
346 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
347 | retval = 0; | |
348 | } | |
349 | out_putf: | |
d7a15f8d | 350 | fdput_pos(f); |
1da177e4 LT |
351 | return retval; |
352 | } | |
353 | #endif | |
354 | ||
68d70d03 | 355 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 | 356 | { |
e28cc715 | 357 | if (unlikely((ssize_t) count < 0)) |
2949e842 | 358 | return -EINVAL; |
1da177e4 | 359 | |
438ab720 KS |
360 | if (ppos) { |
361 | loff_t pos = *ppos; | |
362 | ||
363 | if (unlikely(pos < 0)) { | |
364 | if (!unsigned_offsets(file)) | |
2949e842 | 365 | return -EINVAL; |
438ab720 KS |
366 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ |
367 | return -EOVERFLOW; | |
368 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
369 | if (!unsigned_offsets(file)) | |
2949e842 | 370 | return -EINVAL; |
438ab720 | 371 | } |
e28cc715 | 372 | } |
438ab720 | 373 | |
bc61384d | 374 | return security_file_permission(file, |
c43e259c | 375 | read_write == READ ? MAY_READ : MAY_WRITE); |
1da177e4 | 376 | } |
87112933 | 377 | EXPORT_SYMBOL(rw_verify_area); |
1da177e4 | 378 | |
5d5d5689 | 379 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 | 380 | { |
293bc982 AV |
381 | struct kiocb kiocb; |
382 | struct iov_iter iter; | |
383 | ssize_t ret; | |
384 | ||
385 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 386 | kiocb.ki_pos = (ppos ? *ppos : 0); |
3e20a751 | 387 | iov_iter_ubuf(&iter, READ, buf, len); |
293bc982 | 388 | |
bb7462b6 | 389 | ret = call_read_iter(filp, &kiocb, &iter); |
599bd19b | 390 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
391 | if (ppos) |
392 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
393 | return ret; |
394 | } | |
395 | ||
4d03e3cc CH |
396 | static int warn_unsupported(struct file *file, const char *op) |
397 | { | |
398 | pr_warn_ratelimited( | |
399 | "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n", | |
400 | op, file, current->pid, current->comm); | |
401 | return -EINVAL; | |
402 | } | |
403 | ||
61a707c5 CH |
404 | ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
405 | { | |
4d03e3cc CH |
406 | struct kvec iov = { |
407 | .iov_base = buf, | |
408 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
409 | }; | |
410 | struct kiocb kiocb; | |
411 | struct iov_iter iter; | |
61a707c5 CH |
412 | ssize_t ret; |
413 | ||
414 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ))) | |
415 | return -EINVAL; | |
416 | if (!(file->f_mode & FMODE_CAN_READ)) | |
417 | return -EINVAL; | |
4d03e3cc CH |
418 | /* |
419 | * Also fail if ->read_iter and ->read are both wired up as that | |
420 | * implies very convoluted semantics. | |
421 | */ | |
422 | if (unlikely(!file->f_op->read_iter || file->f_op->read)) | |
423 | return warn_unsupported(file, "read"); | |
61a707c5 | 424 | |
4d03e3cc | 425 | init_sync_kiocb(&kiocb, file); |
7b84b665 | 426 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
427 | iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len); |
428 | ret = file->f_op->read_iter(&kiocb, &iter); | |
61a707c5 | 429 | if (ret > 0) { |
7b84b665 MWO |
430 | if (pos) |
431 | *pos = kiocb.ki_pos; | |
61a707c5 CH |
432 | fsnotify_access(file); |
433 | add_rchar(current, ret); | |
434 | } | |
435 | inc_syscr(current); | |
436 | return ret; | |
437 | } | |
438 | ||
bdd1d2d3 | 439 | ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
c41fbad0 | 440 | { |
6209dd91 | 441 | ssize_t ret; |
c41fbad0 | 442 | |
6209dd91 CH |
443 | ret = rw_verify_area(READ, file, pos, count); |
444 | if (ret) | |
445 | return ret; | |
446 | return __kernel_read(file, buf, count, pos); | |
c41fbad0 CH |
447 | } |
448 | EXPORT_SYMBOL(kernel_read); | |
6fb5032e | 449 | |
1da177e4 LT |
450 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
451 | { | |
452 | ssize_t ret; | |
453 | ||
454 | if (!(file->f_mode & FMODE_READ)) | |
455 | return -EBADF; | |
7f7f25e8 | 456 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 | 457 | return -EINVAL; |
96d4f267 | 458 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
459 | return -EFAULT; |
460 | ||
461 | ret = rw_verify_area(READ, file, pos, count); | |
775802c0 CH |
462 | if (ret) |
463 | return ret; | |
464 | if (count > MAX_RW_COUNT) | |
465 | count = MAX_RW_COUNT; | |
1da177e4 | 466 | |
775802c0 CH |
467 | if (file->f_op->read) |
468 | ret = file->f_op->read(file, buf, count, pos); | |
469 | else if (file->f_op->read_iter) | |
470 | ret = new_sync_read(file, buf, count, pos); | |
471 | else | |
472 | ret = -EINVAL; | |
473 | if (ret > 0) { | |
474 | fsnotify_access(file); | |
475 | add_rchar(current, ret); | |
476 | } | |
477 | inc_syscr(current); | |
1da177e4 LT |
478 | return ret; |
479 | } | |
480 | ||
5d5d5689 | 481 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 | 482 | { |
293bc982 AV |
483 | struct kiocb kiocb; |
484 | struct iov_iter iter; | |
485 | ssize_t ret; | |
486 | ||
487 | init_sync_kiocb(&kiocb, filp); | |
438ab720 | 488 | kiocb.ki_pos = (ppos ? *ppos : 0); |
3e20a751 | 489 | iov_iter_ubuf(&iter, WRITE, (void __user *)buf, len); |
293bc982 | 490 | |
bb7462b6 | 491 | ret = call_write_iter(filp, &kiocb, &iter); |
599bd19b | 492 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 | 493 | if (ret > 0 && ppos) |
f765b134 | 494 | *ppos = kiocb.ki_pos; |
293bc982 AV |
495 | return ret; |
496 | } | |
497 | ||
81238b2c | 498 | /* caller is responsible for file_start_write/file_end_write */ |
73e18f7c | 499 | ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) |
06ae43f3 | 500 | { |
4d03e3cc CH |
501 | struct kvec iov = { |
502 | .iov_base = (void *)buf, | |
503 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
504 | }; | |
505 | struct kiocb kiocb; | |
506 | struct iov_iter iter; | |
06ae43f3 AV |
507 | ssize_t ret; |
508 | ||
a01ac27b CH |
509 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) |
510 | return -EBADF; | |
7f7f25e8 | 511 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e | 512 | return -EINVAL; |
4d03e3cc CH |
513 | /* |
514 | * Also fail if ->write_iter and ->write are both wired up as that | |
515 | * implies very convoluted semantics. | |
516 | */ | |
517 | if (unlikely(!file->f_op->write_iter || file->f_op->write)) | |
518 | return warn_unsupported(file, "write"); | |
3e84f48e | 519 | |
4d03e3cc | 520 | init_sync_kiocb(&kiocb, file); |
4c207ef4 | 521 | kiocb.ki_pos = pos ? *pos : 0; |
4d03e3cc CH |
522 | iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len); |
523 | ret = file->f_op->write_iter(&kiocb, &iter); | |
06ae43f3 | 524 | if (ret > 0) { |
4c207ef4 MWO |
525 | if (pos) |
526 | *pos = kiocb.ki_pos; | |
06ae43f3 AV |
527 | fsnotify_modify(file); |
528 | add_wchar(current, ret); | |
529 | } | |
530 | inc_syscw(current); | |
531 | return ret; | |
532 | } | |
90fb7027 LT |
533 | /* |
534 | * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()", | |
535 | * but autofs is one of the few internal kernel users that actually | |
536 | * wants this _and_ can be built as a module. So we need to export | |
537 | * this symbol for autofs, even though it really isn't appropriate | |
538 | * for any other kernel modules. | |
539 | */ | |
540 | EXPORT_SYMBOL_GPL(__kernel_write); | |
2ec3a12a | 541 | |
e13ec939 CH |
542 | ssize_t kernel_write(struct file *file, const void *buf, size_t count, |
543 | loff_t *pos) | |
ac452aca | 544 | { |
81238b2c | 545 | ssize_t ret; |
ac452aca | 546 | |
81238b2c CH |
547 | ret = rw_verify_area(WRITE, file, pos, count); |
548 | if (ret) | |
549 | return ret; | |
ac452aca | 550 | |
81238b2c CH |
551 | file_start_write(file); |
552 | ret = __kernel_write(file, buf, count, pos); | |
553 | file_end_write(file); | |
554 | return ret; | |
ac452aca CH |
555 | } |
556 | EXPORT_SYMBOL(kernel_write); | |
557 | ||
1da177e4 LT |
558 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
559 | { | |
560 | ssize_t ret; | |
561 | ||
562 | if (!(file->f_mode & FMODE_WRITE)) | |
563 | return -EBADF; | |
7f7f25e8 | 564 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 | 565 | return -EINVAL; |
96d4f267 | 566 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
567 | return -EFAULT; |
568 | ||
569 | ret = rw_verify_area(WRITE, file, pos, count); | |
53ad8626 CH |
570 | if (ret) |
571 | return ret; | |
572 | if (count > MAX_RW_COUNT) | |
573 | count = MAX_RW_COUNT; | |
574 | file_start_write(file); | |
575 | if (file->f_op->write) | |
576 | ret = file->f_op->write(file, buf, count, pos); | |
577 | else if (file->f_op->write_iter) | |
578 | ret = new_sync_write(file, buf, count, pos); | |
579 | else | |
580 | ret = -EINVAL; | |
581 | if (ret > 0) { | |
582 | fsnotify_modify(file); | |
583 | add_wchar(current, ret); | |
1da177e4 | 584 | } |
53ad8626 CH |
585 | inc_syscw(current); |
586 | file_end_write(file); | |
1da177e4 LT |
587 | return ret; |
588 | } | |
589 | ||
438ab720 KS |
590 | /* file_ppos returns &file->f_pos or NULL if file is stream */ |
591 | static inline loff_t *file_ppos(struct file *file) | |
1da177e4 | 592 | { |
438ab720 | 593 | return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; |
1da177e4 LT |
594 | } |
595 | ||
3ce4a7bf | 596 | ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) |
1da177e4 | 597 | { |
9c225f26 | 598 | struct fd f = fdget_pos(fd); |
1da177e4 | 599 | ssize_t ret = -EBADF; |
1da177e4 | 600 | |
2903ff01 | 601 | if (f.file) { |
438ab720 KS |
602 | loff_t pos, *ppos = file_ppos(f.file); |
603 | if (ppos) { | |
604 | pos = *ppos; | |
605 | ppos = &pos; | |
606 | } | |
607 | ret = vfs_read(f.file, buf, count, ppos); | |
608 | if (ret >= 0 && ppos) | |
609 | f.file->f_pos = pos; | |
9c225f26 | 610 | fdput_pos(f); |
1da177e4 | 611 | } |
1da177e4 LT |
612 | return ret; |
613 | } | |
1da177e4 | 614 | |
3ce4a7bf DB |
615 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
616 | { | |
617 | return ksys_read(fd, buf, count); | |
618 | } | |
619 | ||
e7a3e8b2 | 620 | ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) |
1da177e4 | 621 | { |
9c225f26 | 622 | struct fd f = fdget_pos(fd); |
1da177e4 | 623 | ssize_t ret = -EBADF; |
1da177e4 | 624 | |
2903ff01 | 625 | if (f.file) { |
438ab720 KS |
626 | loff_t pos, *ppos = file_ppos(f.file); |
627 | if (ppos) { | |
628 | pos = *ppos; | |
629 | ppos = &pos; | |
630 | } | |
631 | ret = vfs_write(f.file, buf, count, ppos); | |
632 | if (ret >= 0 && ppos) | |
633 | f.file->f_pos = pos; | |
9c225f26 | 634 | fdput_pos(f); |
1da177e4 LT |
635 | } |
636 | ||
637 | return ret; | |
638 | } | |
639 | ||
e7a3e8b2 DB |
640 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
641 | size_t, count) | |
642 | { | |
643 | return ksys_write(fd, buf, count); | |
644 | } | |
645 | ||
36028d5d DB |
646 | ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, |
647 | loff_t pos) | |
1da177e4 | 648 | { |
2903ff01 | 649 | struct fd f; |
1da177e4 | 650 | ssize_t ret = -EBADF; |
1da177e4 LT |
651 | |
652 | if (pos < 0) | |
653 | return -EINVAL; | |
654 | ||
2903ff01 AV |
655 | f = fdget(fd); |
656 | if (f.file) { | |
1da177e4 | 657 | ret = -ESPIPE; |
2903ff01 AV |
658 | if (f.file->f_mode & FMODE_PREAD) |
659 | ret = vfs_read(f.file, buf, count, &pos); | |
660 | fdput(f); | |
1da177e4 LT |
661 | } |
662 | ||
663 | return ret; | |
664 | } | |
665 | ||
36028d5d DB |
666 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
667 | size_t, count, loff_t, pos) | |
668 | { | |
669 | return ksys_pread64(fd, buf, count, pos); | |
670 | } | |
671 | ||
59c10c52 GR |
672 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64) |
673 | COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf, | |
674 | size_t, count, compat_arg_u64_dual(pos)) | |
675 | { | |
676 | return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos)); | |
677 | } | |
678 | #endif | |
679 | ||
36028d5d DB |
680 | ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, |
681 | size_t count, loff_t pos) | |
1da177e4 | 682 | { |
2903ff01 | 683 | struct fd f; |
1da177e4 | 684 | ssize_t ret = -EBADF; |
1da177e4 LT |
685 | |
686 | if (pos < 0) | |
687 | return -EINVAL; | |
688 | ||
2903ff01 AV |
689 | f = fdget(fd); |
690 | if (f.file) { | |
1da177e4 | 691 | ret = -ESPIPE; |
2903ff01 AV |
692 | if (f.file->f_mode & FMODE_PWRITE) |
693 | ret = vfs_write(f.file, buf, count, &pos); | |
694 | fdput(f); | |
1da177e4 LT |
695 | } |
696 | ||
697 | return ret; | |
698 | } | |
699 | ||
36028d5d DB |
700 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
701 | size_t, count, loff_t, pos) | |
702 | { | |
703 | return ksys_pwrite64(fd, buf, count, pos); | |
704 | } | |
705 | ||
59c10c52 GR |
706 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64) |
707 | COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf, | |
708 | size_t, count, compat_arg_u64_dual(pos)) | |
709 | { | |
710 | return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos)); | |
711 | } | |
712 | #endif | |
713 | ||
ac15ac06 | 714 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 715 | loff_t *ppos, int type, rwf_t flags) |
293bc982 AV |
716 | { |
717 | struct kiocb kiocb; | |
293bc982 AV |
718 | ssize_t ret; |
719 | ||
720 | init_sync_kiocb(&kiocb, filp); | |
fdd2f5b7 GR |
721 | ret = kiocb_set_rw_flags(&kiocb, flags); |
722 | if (ret) | |
723 | return ret; | |
438ab720 | 724 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 | 725 | |
0f78d06a | 726 | if (type == READ) |
bb7462b6 | 727 | ret = call_read_iter(filp, &kiocb, iter); |
0f78d06a | 728 | else |
bb7462b6 | 729 | ret = call_write_iter(filp, &kiocb, iter); |
599bd19b | 730 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
731 | if (ppos) |
732 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
733 | return ret; |
734 | } | |
735 | ||
ee0b3e67 | 736 | /* Do it by hand, with file-ops */ |
ac15ac06 | 737 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 738 | loff_t *ppos, int type, rwf_t flags) |
ee0b3e67 | 739 | { |
ee0b3e67 BP |
740 | ssize_t ret = 0; |
741 | ||
97be7ebe | 742 | if (flags & ~RWF_HIPRI) |
793b80ef CH |
743 | return -EOPNOTSUPP; |
744 | ||
ac15ac06 AV |
745 | while (iov_iter_count(iter)) { |
746 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
747 | ssize_t nr; |
748 | ||
0f78d06a MS |
749 | if (type == READ) { |
750 | nr = filp->f_op->read(filp, iovec.iov_base, | |
751 | iovec.iov_len, ppos); | |
752 | } else { | |
753 | nr = filp->f_op->write(filp, iovec.iov_base, | |
754 | iovec.iov_len, ppos); | |
755 | } | |
ee0b3e67 BP |
756 | |
757 | if (nr < 0) { | |
758 | if (!ret) | |
759 | ret = nr; | |
760 | break; | |
761 | } | |
762 | ret += nr; | |
ac15ac06 | 763 | if (nr != iovec.iov_len) |
ee0b3e67 | 764 | break; |
ac15ac06 | 765 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
766 | } |
767 | ||
768 | return ret; | |
769 | } | |
770 | ||
19c73586 | 771 | static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 772 | loff_t *pos, rwf_t flags) |
1da177e4 | 773 | { |
1da177e4 | 774 | size_t tot_len; |
7687a7a4 | 775 | ssize_t ret = 0; |
1da177e4 | 776 | |
edab5fe3 CH |
777 | if (!(file->f_mode & FMODE_READ)) |
778 | return -EBADF; | |
779 | if (!(file->f_mode & FMODE_CAN_READ)) | |
780 | return -EINVAL; | |
781 | ||
7687a7a4 | 782 | tot_len = iov_iter_count(iter); |
0504c074 AV |
783 | if (!tot_len) |
784 | goto out; | |
19c73586 | 785 | ret = rw_verify_area(READ, file, pos, tot_len); |
e28cc715 | 786 | if (ret < 0) |
19c73586 | 787 | return ret; |
1da177e4 | 788 | |
19c73586 CH |
789 | if (file->f_op->read_iter) |
790 | ret = do_iter_readv_writev(file, iter, pos, READ, flags); | |
ee0b3e67 | 791 | else |
19c73586 | 792 | ret = do_loop_readv_writev(file, iter, pos, READ, flags); |
1da177e4 | 793 | out: |
19c73586 CH |
794 | if (ret >= 0) |
795 | fsnotify_access(file); | |
1da177e4 | 796 | return ret; |
1da177e4 LT |
797 | } |
798 | ||
5dcdc43e JX |
799 | ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, |
800 | struct iov_iter *iter) | |
801 | { | |
802 | size_t tot_len; | |
803 | ssize_t ret = 0; | |
804 | ||
805 | if (!file->f_op->read_iter) | |
806 | return -EINVAL; | |
807 | if (!(file->f_mode & FMODE_READ)) | |
808 | return -EBADF; | |
809 | if (!(file->f_mode & FMODE_CAN_READ)) | |
810 | return -EINVAL; | |
811 | ||
812 | tot_len = iov_iter_count(iter); | |
813 | if (!tot_len) | |
814 | goto out; | |
815 | ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); | |
816 | if (ret < 0) | |
817 | return ret; | |
818 | ||
819 | ret = call_read_iter(file, iocb, iter); | |
820 | out: | |
821 | if (ret >= 0) | |
822 | fsnotify_access(file); | |
823 | return ret; | |
824 | } | |
825 | EXPORT_SYMBOL(vfs_iocb_iter_read); | |
826 | ||
18e9710e | 827 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 828 | rwf_t flags) |
7687a7a4 | 829 | { |
18e9710e CH |
830 | if (!file->f_op->read_iter) |
831 | return -EINVAL; | |
832 | return do_iter_read(file, iter, ppos, flags); | |
833 | } | |
834 | EXPORT_SYMBOL(vfs_iter_read); | |
7687a7a4 | 835 | |
19c73586 | 836 | static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 837 | loff_t *pos, rwf_t flags) |
19c73586 CH |
838 | { |
839 | size_t tot_len; | |
840 | ssize_t ret = 0; | |
03d95eb2 | 841 | |
edab5fe3 CH |
842 | if (!(file->f_mode & FMODE_WRITE)) |
843 | return -EBADF; | |
844 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
845 | return -EINVAL; | |
846 | ||
19c73586 CH |
847 | tot_len = iov_iter_count(iter); |
848 | if (!tot_len) | |
849 | return 0; | |
850 | ret = rw_verify_area(WRITE, file, pos, tot_len); | |
7687a7a4 MS |
851 | if (ret < 0) |
852 | return ret; | |
853 | ||
19c73586 CH |
854 | if (file->f_op->write_iter) |
855 | ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); | |
856 | else | |
857 | ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); | |
19c73586 CH |
858 | if (ret > 0) |
859 | fsnotify_modify(file); | |
7687a7a4 MS |
860 | return ret; |
861 | } | |
862 | ||
5dcdc43e JX |
863 | ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, |
864 | struct iov_iter *iter) | |
865 | { | |
866 | size_t tot_len; | |
867 | ssize_t ret = 0; | |
868 | ||
869 | if (!file->f_op->write_iter) | |
870 | return -EINVAL; | |
871 | if (!(file->f_mode & FMODE_WRITE)) | |
872 | return -EBADF; | |
873 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
874 | return -EINVAL; | |
875 | ||
876 | tot_len = iov_iter_count(iter); | |
877 | if (!tot_len) | |
878 | return 0; | |
879 | ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); | |
880 | if (ret < 0) | |
881 | return ret; | |
882 | ||
883 | ret = call_write_iter(file, iocb, iter); | |
884 | if (ret > 0) | |
885 | fsnotify_modify(file); | |
886 | ||
887 | return ret; | |
888 | } | |
889 | EXPORT_SYMBOL(vfs_iocb_iter_write); | |
890 | ||
abbb6589 | 891 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 892 | rwf_t flags) |
abbb6589 CH |
893 | { |
894 | if (!file->f_op->write_iter) | |
895 | return -EINVAL; | |
896 | return do_iter_write(file, iter, ppos, flags); | |
897 | } | |
898 | EXPORT_SYMBOL(vfs_iter_write); | |
899 | ||
36e2c742 | 900 | static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 901 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 902 | { |
7687a7a4 MS |
903 | struct iovec iovstack[UIO_FASTIOV]; |
904 | struct iovec *iov = iovstack; | |
905 | struct iov_iter iter; | |
906 | ssize_t ret; | |
1da177e4 | 907 | |
251b42a1 | 908 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 CH |
909 | if (ret >= 0) { |
910 | ret = do_iter_read(file, &iter, pos, flags); | |
911 | kfree(iov); | |
912 | } | |
1da177e4 | 913 | |
251b42a1 CH |
914 | return ret; |
915 | } | |
1da177e4 | 916 | |
9725d4ce | 917 | static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 918 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 919 | { |
251b42a1 CH |
920 | struct iovec iovstack[UIO_FASTIOV]; |
921 | struct iovec *iov = iovstack; | |
922 | struct iov_iter iter; | |
923 | ssize_t ret; | |
1da177e4 | 924 | |
251b42a1 | 925 | ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 | 926 | if (ret >= 0) { |
62473a2d | 927 | file_start_write(file); |
edab5fe3 | 928 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 929 | file_end_write(file); |
edab5fe3 CH |
930 | kfree(iov); |
931 | } | |
251b42a1 | 932 | return ret; |
1da177e4 | 933 | } |
1da177e4 | 934 | |
f17d8b35 | 935 | static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 936 | unsigned long vlen, rwf_t flags) |
1da177e4 | 937 | { |
9c225f26 | 938 | struct fd f = fdget_pos(fd); |
1da177e4 | 939 | ssize_t ret = -EBADF; |
1da177e4 | 940 | |
2903ff01 | 941 | if (f.file) { |
438ab720 KS |
942 | loff_t pos, *ppos = file_ppos(f.file); |
943 | if (ppos) { | |
944 | pos = *ppos; | |
945 | ppos = &pos; | |
946 | } | |
947 | ret = vfs_readv(f.file, vec, vlen, ppos, flags); | |
948 | if (ret >= 0 && ppos) | |
949 | f.file->f_pos = pos; | |
9c225f26 | 950 | fdput_pos(f); |
1da177e4 LT |
951 | } |
952 | ||
953 | if (ret > 0) | |
4b98d11b AD |
954 | add_rchar(current, ret); |
955 | inc_syscr(current); | |
1da177e4 LT |
956 | return ret; |
957 | } | |
958 | ||
f17d8b35 | 959 | static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 960 | unsigned long vlen, rwf_t flags) |
1da177e4 | 961 | { |
9c225f26 | 962 | struct fd f = fdget_pos(fd); |
1da177e4 | 963 | ssize_t ret = -EBADF; |
1da177e4 | 964 | |
2903ff01 | 965 | if (f.file) { |
438ab720 KS |
966 | loff_t pos, *ppos = file_ppos(f.file); |
967 | if (ppos) { | |
968 | pos = *ppos; | |
969 | ppos = &pos; | |
970 | } | |
971 | ret = vfs_writev(f.file, vec, vlen, ppos, flags); | |
972 | if (ret >= 0 && ppos) | |
973 | f.file->f_pos = pos; | |
9c225f26 | 974 | fdput_pos(f); |
1da177e4 LT |
975 | } |
976 | ||
977 | if (ret > 0) | |
4b98d11b AD |
978 | add_wchar(current, ret); |
979 | inc_syscw(current); | |
1da177e4 LT |
980 | return ret; |
981 | } | |
982 | ||
601cc11d LT |
983 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
984 | { | |
985 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
986 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
987 | } | |
988 | ||
f17d8b35 | 989 | static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 990 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 991 | { |
2903ff01 | 992 | struct fd f; |
f3554f4b | 993 | ssize_t ret = -EBADF; |
f3554f4b GH |
994 | |
995 | if (pos < 0) | |
996 | return -EINVAL; | |
997 | ||
2903ff01 AV |
998 | f = fdget(fd); |
999 | if (f.file) { | |
f3554f4b | 1000 | ret = -ESPIPE; |
2903ff01 | 1001 | if (f.file->f_mode & FMODE_PREAD) |
f17d8b35 | 1002 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1003 | fdput(f); |
f3554f4b GH |
1004 | } |
1005 | ||
1006 | if (ret > 0) | |
1007 | add_rchar(current, ret); | |
1008 | inc_syscr(current); | |
1009 | return ret; | |
1010 | } | |
1011 | ||
f17d8b35 | 1012 | static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1013 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1014 | { |
2903ff01 | 1015 | struct fd f; |
f3554f4b | 1016 | ssize_t ret = -EBADF; |
f3554f4b GH |
1017 | |
1018 | if (pos < 0) | |
1019 | return -EINVAL; | |
1020 | ||
2903ff01 AV |
1021 | f = fdget(fd); |
1022 | if (f.file) { | |
f3554f4b | 1023 | ret = -ESPIPE; |
2903ff01 | 1024 | if (f.file->f_mode & FMODE_PWRITE) |
f17d8b35 | 1025 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1026 | fdput(f); |
f3554f4b GH |
1027 | } |
1028 | ||
1029 | if (ret > 0) | |
1030 | add_wchar(current, ret); | |
1031 | inc_syscw(current); | |
1032 | return ret; | |
1033 | } | |
1034 | ||
f17d8b35 MT |
1035 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
1036 | unsigned long, vlen) | |
1037 | { | |
1038 | return do_readv(fd, vec, vlen, 0); | |
1039 | } | |
1040 | ||
1041 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, | |
1042 | unsigned long, vlen) | |
1043 | { | |
1044 | return do_writev(fd, vec, vlen, 0); | |
1045 | } | |
1046 | ||
1047 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, | |
1048 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1049 | { | |
1050 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1051 | ||
1052 | return do_preadv(fd, vec, vlen, pos, 0); | |
1053 | } | |
1054 | ||
1055 | SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, | |
1056 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1057 | rwf_t, flags) |
f17d8b35 MT |
1058 | { |
1059 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1060 | ||
1061 | if (pos == -1) | |
1062 | return do_readv(fd, vec, vlen, flags); | |
1063 | ||
1064 | return do_preadv(fd, vec, vlen, pos, flags); | |
1065 | } | |
1066 | ||
1067 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
1068 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1069 | { | |
1070 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1071 | ||
1072 | return do_pwritev(fd, vec, vlen, pos, 0); | |
1073 | } | |
1074 | ||
1075 | SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, | |
1076 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1077 | rwf_t, flags) |
f17d8b35 MT |
1078 | { |
1079 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1080 | ||
1081 | if (pos == -1) | |
1082 | return do_writev(fd, vec, vlen, flags); | |
1083 | ||
1084 | return do_pwritev(fd, vec, vlen, pos, flags); | |
1085 | } | |
1086 | ||
3523a9d4 CH |
1087 | /* |
1088 | * Various compat syscalls. Note that they all pretend to take a native | |
1089 | * iovec - import_iovec will properly treat those as compat_iovecs based on | |
1090 | * in_compat_syscall(). | |
1091 | */ | |
72ec3516 | 1092 | #ifdef CONFIG_COMPAT |
378a10f3 HC |
1093 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1094 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
3523a9d4 | 1095 | const struct iovec __user *, vec, |
378a10f3 HC |
1096 | unsigned long, vlen, loff_t, pos) |
1097 | { | |
3523a9d4 | 1098 | return do_preadv(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1099 | } |
1100 | #endif | |
1101 | ||
dfd948e3 | 1102 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
3523a9d4 | 1103 | const struct iovec __user *, vec, |
dfd948e3 | 1104 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1105 | { |
1106 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1107 | |
3523a9d4 | 1108 | return do_preadv(fd, vec, vlen, pos, 0); |
f17d8b35 MT |
1109 | } |
1110 | ||
3ebfd81f L |
1111 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 |
1112 | COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, | |
3523a9d4 | 1113 | const struct iovec __user *, vec, |
ddef7ed2 | 1114 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1115 | { |
cc4b1242 | 1116 | if (pos == -1) |
3523a9d4 CH |
1117 | return do_readv(fd, vec, vlen, flags); |
1118 | return do_preadv(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1119 | } |
1120 | #endif | |
1121 | ||
f17d8b35 | 1122 | COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, |
3523a9d4 | 1123 | const struct iovec __user *, vec, |
f17d8b35 | 1124 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, |
ddef7ed2 | 1125 | rwf_t, flags) |
f17d8b35 MT |
1126 | { |
1127 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1128 | ||
1129 | if (pos == -1) | |
3523a9d4 CH |
1130 | return do_readv(fd, vec, vlen, flags); |
1131 | return do_preadv(fd, vec, vlen, pos, flags); | |
72ec3516 AV |
1132 | } |
1133 | ||
378a10f3 HC |
1134 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1135 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
3523a9d4 | 1136 | const struct iovec __user *, vec, |
378a10f3 HC |
1137 | unsigned long, vlen, loff_t, pos) |
1138 | { | |
3523a9d4 | 1139 | return do_pwritev(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1140 | } |
1141 | #endif | |
1142 | ||
dfd948e3 | 1143 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
3523a9d4 | 1144 | const struct iovec __user *,vec, |
dfd948e3 | 1145 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1146 | { |
1147 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1148 | |
3523a9d4 | 1149 | return do_pwritev(fd, vec, vlen, pos, 0); |
72ec3516 | 1150 | } |
f17d8b35 | 1151 | |
3ebfd81f L |
1152 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 |
1153 | COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, | |
3523a9d4 | 1154 | const struct iovec __user *, vec, |
ddef7ed2 | 1155 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1156 | { |
cc4b1242 | 1157 | if (pos == -1) |
3523a9d4 CH |
1158 | return do_writev(fd, vec, vlen, flags); |
1159 | return do_pwritev(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1160 | } |
1161 | #endif | |
1162 | ||
f17d8b35 | 1163 | COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, |
3523a9d4 | 1164 | const struct iovec __user *,vec, |
ddef7ed2 | 1165 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) |
f17d8b35 MT |
1166 | { |
1167 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1168 | ||
1169 | if (pos == -1) | |
3523a9d4 CH |
1170 | return do_writev(fd, vec, vlen, flags); |
1171 | return do_pwritev(fd, vec, vlen, pos, flags); | |
72ec3516 | 1172 | } |
3523a9d4 | 1173 | #endif /* CONFIG_COMPAT */ |
72ec3516 | 1174 | |
19f4fc3a AV |
1175 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1176 | size_t count, loff_t max) | |
1da177e4 | 1177 | { |
2903ff01 AV |
1178 | struct fd in, out; |
1179 | struct inode *in_inode, *out_inode; | |
b964bf53 | 1180 | struct pipe_inode_info *opipe; |
1da177e4 | 1181 | loff_t pos; |
7995bd28 | 1182 | loff_t out_pos; |
1da177e4 | 1183 | ssize_t retval; |
2903ff01 | 1184 | int fl; |
1da177e4 LT |
1185 | |
1186 | /* | |
1187 | * Get input file, and verify that it is ok.. | |
1188 | */ | |
1189 | retval = -EBADF; | |
2903ff01 AV |
1190 | in = fdget(in_fd); |
1191 | if (!in.file) | |
1da177e4 | 1192 | goto out; |
2903ff01 | 1193 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1194 | goto fput_in; |
1da177e4 | 1195 | retval = -ESPIPE; |
7995bd28 AV |
1196 | if (!ppos) { |
1197 | pos = in.file->f_pos; | |
1198 | } else { | |
1199 | pos = *ppos; | |
2903ff01 | 1200 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1201 | goto fput_in; |
7995bd28 AV |
1202 | } |
1203 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1204 | if (retval < 0) |
1da177e4 | 1205 | goto fput_in; |
bc61384d AV |
1206 | if (count > MAX_RW_COUNT) |
1207 | count = MAX_RW_COUNT; | |
1da177e4 | 1208 | |
1da177e4 LT |
1209 | /* |
1210 | * Get output file, and verify that it is ok.. | |
1211 | */ | |
1212 | retval = -EBADF; | |
2903ff01 AV |
1213 | out = fdget(out_fd); |
1214 | if (!out.file) | |
1da177e4 | 1215 | goto fput_in; |
2903ff01 | 1216 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 | 1217 | goto fput_out; |
496ad9aa AV |
1218 | in_inode = file_inode(in.file); |
1219 | out_inode = file_inode(out.file); | |
7995bd28 | 1220 | out_pos = out.file->f_pos; |
1da177e4 | 1221 | |
1da177e4 LT |
1222 | if (!max) |
1223 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1224 | ||
1da177e4 LT |
1225 | if (unlikely(pos + count > max)) { |
1226 | retval = -EOVERFLOW; | |
1227 | if (pos >= max) | |
1228 | goto fput_out; | |
1229 | count = max - pos; | |
1230 | } | |
1231 | ||
d96e6e71 | 1232 | fl = 0; |
534f2aaa | 1233 | #if 0 |
d96e6e71 JA |
1234 | /* |
1235 | * We need to debate whether we can enable this or not. The | |
1236 | * man page documents EAGAIN return for the output at least, | |
1237 | * and the application is arguably buggy if it doesn't expect | |
1238 | * EAGAIN on a non-blocking file descriptor. | |
1239 | */ | |
2903ff01 | 1240 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1241 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1242 | #endif |
b964bf53 AV |
1243 | opipe = get_pipe_info(out.file, true); |
1244 | if (!opipe) { | |
1245 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
1246 | if (retval < 0) | |
1247 | goto fput_out; | |
1248 | file_start_write(out.file); | |
1249 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, | |
1250 | count, fl); | |
1251 | file_end_write(out.file); | |
1252 | } else { | |
bdeb77bc AV |
1253 | if (out.file->f_flags & O_NONBLOCK) |
1254 | fl |= SPLICE_F_NONBLOCK; | |
1255 | ||
b964bf53 AV |
1256 | retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); |
1257 | } | |
1da177e4 LT |
1258 | |
1259 | if (retval > 0) { | |
4b98d11b AD |
1260 | add_rchar(current, retval); |
1261 | add_wchar(current, retval); | |
a68c2f12 SW |
1262 | fsnotify_access(in.file); |
1263 | fsnotify_modify(out.file); | |
7995bd28 AV |
1264 | out.file->f_pos = out_pos; |
1265 | if (ppos) | |
1266 | *ppos = pos; | |
1267 | else | |
1268 | in.file->f_pos = pos; | |
1da177e4 | 1269 | } |
1da177e4 | 1270 | |
4b98d11b AD |
1271 | inc_syscr(current); |
1272 | inc_syscw(current); | |
7995bd28 | 1273 | if (pos > max) |
1da177e4 LT |
1274 | retval = -EOVERFLOW; |
1275 | ||
1276 | fput_out: | |
2903ff01 | 1277 | fdput(out); |
1da177e4 | 1278 | fput_in: |
2903ff01 | 1279 | fdput(in); |
1da177e4 LT |
1280 | out: |
1281 | return retval; | |
1282 | } | |
1283 | ||
002c8976 | 1284 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1285 | { |
1286 | loff_t pos; | |
1287 | off_t off; | |
1288 | ssize_t ret; | |
1289 | ||
1290 | if (offset) { | |
1291 | if (unlikely(get_user(off, offset))) | |
1292 | return -EFAULT; | |
1293 | pos = off; | |
1294 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1295 | if (unlikely(put_user(pos, offset))) | |
1296 | return -EFAULT; | |
1297 | return ret; | |
1298 | } | |
1299 | ||
1300 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1301 | } | |
1302 | ||
002c8976 | 1303 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1304 | { |
1305 | loff_t pos; | |
1306 | ssize_t ret; | |
1307 | ||
1308 | if (offset) { | |
1309 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1310 | return -EFAULT; | |
1311 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1312 | if (unlikely(put_user(pos, offset))) | |
1313 | return -EFAULT; | |
1314 | return ret; | |
1315 | } | |
1316 | ||
1317 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1318 | } | |
19f4fc3a AV |
1319 | |
1320 | #ifdef CONFIG_COMPAT | |
1321 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1322 | compat_off_t __user *, offset, compat_size_t, count) | |
1323 | { | |
1324 | loff_t pos; | |
1325 | off_t off; | |
1326 | ssize_t ret; | |
1327 | ||
1328 | if (offset) { | |
1329 | if (unlikely(get_user(off, offset))) | |
1330 | return -EFAULT; | |
1331 | pos = off; | |
1332 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1333 | if (unlikely(put_user(pos, offset))) | |
1334 | return -EFAULT; | |
1335 | return ret; | |
1336 | } | |
1337 | ||
1338 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1339 | } | |
1340 | ||
1341 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1342 | compat_loff_t __user *, offset, compat_size_t, count) | |
1343 | { | |
1344 | loff_t pos; | |
1345 | ssize_t ret; | |
1346 | ||
1347 | if (offset) { | |
1348 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1349 | return -EFAULT; | |
1350 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1351 | if (unlikely(put_user(pos, offset))) | |
1352 | return -EFAULT; | |
1353 | return ret; | |
1354 | } | |
1355 | ||
1356 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1357 | } | |
1358 | #endif | |
29732938 | 1359 | |
f16acc9d DC |
1360 | /** |
1361 | * generic_copy_file_range - copy data between two files | |
1362 | * @file_in: file structure to read from | |
1363 | * @pos_in: file offset to read from | |
1364 | * @file_out: file structure to write data to | |
1365 | * @pos_out: file offset to write data to | |
1366 | * @len: amount of data to copy | |
1367 | * @flags: copy flags | |
1368 | * | |
1369 | * This is a generic filesystem helper to copy data from one file to another. | |
1370 | * It has no constraints on the source or destination file owners - the files | |
1371 | * can belong to different superblocks and different filesystem types. Short | |
1372 | * copies are allowed. | |
1373 | * | |
1374 | * This should be called from the @file_out filesystem, as per the | |
1375 | * ->copy_file_range() method. | |
1376 | * | |
1377 | * Returns the number of bytes copied or a negative error indicating the | |
1378 | * failure. | |
1379 | */ | |
1380 | ||
1381 | ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, | |
1382 | struct file *file_out, loff_t pos_out, | |
1383 | size_t len, unsigned int flags) | |
1384 | { | |
1385 | return do_splice_direct(file_in, &pos_in, file_out, &pos_out, | |
1386 | len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); | |
1387 | } | |
1388 | EXPORT_SYMBOL(generic_copy_file_range); | |
1389 | ||
407e9c63 DW |
1390 | /* |
1391 | * Performs necessary checks before doing a file copy | |
1392 | * | |
1393 | * Can adjust amount of bytes to copy via @req_count argument. | |
1394 | * Returns appropriate error code that caller should return or | |
1395 | * zero in case the copy should be allowed. | |
1396 | */ | |
1397 | static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, | |
1398 | struct file *file_out, loff_t pos_out, | |
1399 | size_t *req_count, unsigned int flags) | |
1400 | { | |
1401 | struct inode *inode_in = file_inode(file_in); | |
1402 | struct inode *inode_out = file_inode(file_out); | |
1403 | uint64_t count = *req_count; | |
1404 | loff_t size_in; | |
1405 | int ret; | |
1406 | ||
1407 | ret = generic_file_rw_checks(file_in, file_out); | |
1408 | if (ret) | |
1409 | return ret; | |
1410 | ||
868f9f2f AG |
1411 | /* |
1412 | * We allow some filesystems to handle cross sb copy, but passing | |
1413 | * a file of the wrong filesystem type to filesystem driver can result | |
1414 | * in an attempt to dereference the wrong type of ->private_data, so | |
1415 | * avoid doing that until we really have a good reason. | |
1416 | * | |
1417 | * nfs and cifs define several different file_system_type structures | |
1418 | * and several different sets of file_operations, but they all end up | |
1419 | * using the same ->copy_file_range() function pointer. | |
1420 | */ | |
1421 | if (file_out->f_op->copy_file_range) { | |
1422 | if (file_in->f_op->copy_file_range != | |
1423 | file_out->f_op->copy_file_range) | |
1424 | return -EXDEV; | |
1425 | } else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) { | |
1426 | return -EXDEV; | |
1427 | } | |
1428 | ||
407e9c63 DW |
1429 | /* Don't touch certain kinds of inodes */ |
1430 | if (IS_IMMUTABLE(inode_out)) | |
1431 | return -EPERM; | |
1432 | ||
1433 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1434 | return -ETXTBSY; | |
1435 | ||
1436 | /* Ensure offsets don't wrap. */ | |
1437 | if (pos_in + count < pos_in || pos_out + count < pos_out) | |
1438 | return -EOVERFLOW; | |
1439 | ||
1440 | /* Shorten the copy to EOF */ | |
1441 | size_in = i_size_read(inode_in); | |
1442 | if (pos_in >= size_in) | |
1443 | count = 0; | |
1444 | else | |
1445 | count = min(count, size_in - (uint64_t)pos_in); | |
1446 | ||
1447 | ret = generic_write_check_limits(file_out, pos_out, &count); | |
1448 | if (ret) | |
1449 | return ret; | |
1450 | ||
1451 | /* Don't allow overlapped copying within the same file. */ | |
1452 | if (inode_in == inode_out && | |
1453 | pos_out + count > pos_in && | |
1454 | pos_out < pos_in + count) | |
1455 | return -EINVAL; | |
1456 | ||
1457 | *req_count = count; | |
1458 | return 0; | |
1459 | } | |
1460 | ||
29732938 ZB |
1461 | /* |
1462 | * copy_file_range() differs from regular file read and write in that it | |
1463 | * specifically allows return partial success. When it does so is up to | |
1464 | * the copy_file_range method. | |
1465 | */ | |
1466 | ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, | |
1467 | struct file *file_out, loff_t pos_out, | |
1468 | size_t len, unsigned int flags) | |
1469 | { | |
29732938 ZB |
1470 | ssize_t ret; |
1471 | ||
1472 | if (flags != 0) | |
1473 | return -EINVAL; | |
1474 | ||
96e6e8f4 AG |
1475 | ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, |
1476 | flags); | |
a3171351 AG |
1477 | if (unlikely(ret)) |
1478 | return ret; | |
11cbfb10 | 1479 | |
29732938 | 1480 | ret = rw_verify_area(READ, file_in, &pos_in, len); |
bc61384d AV |
1481 | if (unlikely(ret)) |
1482 | return ret; | |
1483 | ||
1484 | ret = rw_verify_area(WRITE, file_out, &pos_out, len); | |
1485 | if (unlikely(ret)) | |
29732938 ZB |
1486 | return ret; |
1487 | ||
29732938 ZB |
1488 | if (len == 0) |
1489 | return 0; | |
1490 | ||
bfe219d3 | 1491 | file_start_write(file_out); |
29732938 | 1492 | |
a76b5b04 | 1493 | /* |
868f9f2f AG |
1494 | * Cloning is supported by more file systems, so we implement copy on |
1495 | * same sb using clone, but for filesystems where both clone and copy | |
1496 | * are supported (e.g. nfs,cifs), we only call the copy method. | |
a76b5b04 | 1497 | */ |
868f9f2f AG |
1498 | if (file_out->f_op->copy_file_range) { |
1499 | ret = file_out->f_op->copy_file_range(file_in, pos_in, | |
1500 | file_out, pos_out, | |
1501 | len, flags); | |
1502 | goto done; | |
1503 | } | |
1504 | ||
5dae222a AG |
1505 | if (file_in->f_op->remap_file_range && |
1506 | file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) { | |
868f9f2f | 1507 | ret = file_in->f_op->remap_file_range(file_in, pos_in, |
42ec3d4c | 1508 | file_out, pos_out, |
eca3654e DW |
1509 | min_t(loff_t, MAX_RW_COUNT, len), |
1510 | REMAP_FILE_CAN_SHORTEN); | |
868f9f2f | 1511 | if (ret > 0) |
a76b5b04 | 1512 | goto done; |
a76b5b04 CH |
1513 | } |
1514 | ||
868f9f2f AG |
1515 | /* |
1516 | * We can get here for same sb copy of filesystems that do not implement | |
1517 | * ->copy_file_range() in case filesystem does not support clone or in | |
1518 | * case filesystem supports clone but rejected the clone request (e.g. | |
1519 | * because it was not block aligned). | |
1520 | * | |
1521 | * In both cases, fall back to kernel copy so we are able to maintain a | |
1522 | * consistent story about which filesystems support copy_file_range() | |
1523 | * and which filesystems do not, that will allow userspace tools to | |
1524 | * make consistent desicions w.r.t using copy_file_range(). | |
1525 | */ | |
1526 | ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, | |
1527 | flags); | |
1528 | ||
a76b5b04 | 1529 | done: |
29732938 ZB |
1530 | if (ret > 0) { |
1531 | fsnotify_access(file_in); | |
1532 | add_rchar(current, ret); | |
1533 | fsnotify_modify(file_out); | |
1534 | add_wchar(current, ret); | |
1535 | } | |
a76b5b04 | 1536 | |
29732938 ZB |
1537 | inc_syscr(current); |
1538 | inc_syscw(current); | |
1539 | ||
bfe219d3 | 1540 | file_end_write(file_out); |
29732938 ZB |
1541 | |
1542 | return ret; | |
1543 | } | |
1544 | EXPORT_SYMBOL(vfs_copy_file_range); | |
1545 | ||
1546 | SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, | |
1547 | int, fd_out, loff_t __user *, off_out, | |
1548 | size_t, len, unsigned int, flags) | |
1549 | { | |
1550 | loff_t pos_in; | |
1551 | loff_t pos_out; | |
1552 | struct fd f_in; | |
1553 | struct fd f_out; | |
1554 | ssize_t ret = -EBADF; | |
1555 | ||
1556 | f_in = fdget(fd_in); | |
1557 | if (!f_in.file) | |
1558 | goto out2; | |
1559 | ||
1560 | f_out = fdget(fd_out); | |
1561 | if (!f_out.file) | |
1562 | goto out1; | |
1563 | ||
1564 | ret = -EFAULT; | |
1565 | if (off_in) { | |
1566 | if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) | |
1567 | goto out; | |
1568 | } else { | |
1569 | pos_in = f_in.file->f_pos; | |
1570 | } | |
1571 | ||
1572 | if (off_out) { | |
1573 | if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) | |
1574 | goto out; | |
1575 | } else { | |
1576 | pos_out = f_out.file->f_pos; | |
1577 | } | |
1578 | ||
1579 | ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, | |
1580 | flags); | |
1581 | if (ret > 0) { | |
1582 | pos_in += ret; | |
1583 | pos_out += ret; | |
1584 | ||
1585 | if (off_in) { | |
1586 | if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) | |
1587 | ret = -EFAULT; | |
1588 | } else { | |
1589 | f_in.file->f_pos = pos_in; | |
1590 | } | |
1591 | ||
1592 | if (off_out) { | |
1593 | if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) | |
1594 | ret = -EFAULT; | |
1595 | } else { | |
1596 | f_out.file->f_pos = pos_out; | |
1597 | } | |
1598 | } | |
1599 | ||
1600 | out: | |
1601 | fdput(f_out); | |
1602 | out1: | |
1603 | fdput(f_in); | |
1604 | out2: | |
1605 | return ret; | |
1606 | } | |
04b38d60 | 1607 | |
edc58dd0 | 1608 | /* |
407e9c63 DW |
1609 | * Don't operate on ranges the page cache doesn't support, and don't exceed the |
1610 | * LFS limits. If pos is under the limit it becomes a short access. If it | |
1611 | * exceeds the limit we return -EFBIG. | |
edc58dd0 | 1612 | */ |
407e9c63 | 1613 | int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) |
edc58dd0 | 1614 | { |
407e9c63 DW |
1615 | struct inode *inode = file->f_mapping->host; |
1616 | loff_t max_size = inode->i_sb->s_maxbytes; | |
1617 | loff_t limit = rlimit(RLIMIT_FSIZE); | |
edc58dd0 | 1618 | |
407e9c63 DW |
1619 | if (limit != RLIM_INFINITY) { |
1620 | if (pos >= limit) { | |
1621 | send_sig(SIGXFSZ, current, 0); | |
1622 | return -EFBIG; | |
edc58dd0 | 1623 | } |
407e9c63 DW |
1624 | *count = min(*count, limit - pos); |
1625 | } | |
edc58dd0 | 1626 | |
407e9c63 DW |
1627 | if (!(file->f_flags & O_LARGEFILE)) |
1628 | max_size = MAX_NON_LFS; | |
c32e5f39 | 1629 | |
407e9c63 DW |
1630 | if (unlikely(pos >= max_size)) |
1631 | return -EFBIG; | |
c32e5f39 | 1632 | |
407e9c63 | 1633 | *count = min(*count, max_size - pos); |
c32e5f39 | 1634 | |
c32e5f39 | 1635 | return 0; |
c32e5f39 | 1636 | } |
04b38d60 | 1637 | |
f6f7a25a OS |
1638 | /* Like generic_write_checks(), but takes size of write instead of iter. */ |
1639 | int generic_write_checks_count(struct kiocb *iocb, loff_t *count) | |
876bec6f | 1640 | { |
407e9c63 DW |
1641 | struct file *file = iocb->ki_filp; |
1642 | struct inode *inode = file->f_mapping->host; | |
876bec6f | 1643 | |
407e9c63 | 1644 | if (IS_SWAPFILE(inode)) |
876bec6f DW |
1645 | return -ETXTBSY; |
1646 | ||
f6f7a25a | 1647 | if (!*count) |
407e9c63 | 1648 | return 0; |
5de4480a | 1649 | |
407e9c63 DW |
1650 | if (iocb->ki_flags & IOCB_APPEND) |
1651 | iocb->ki_pos = i_size_read(inode); | |
1b4f42a1 | 1652 | |
80175539 SR |
1653 | if ((iocb->ki_flags & IOCB_NOWAIT) && |
1654 | !((iocb->ki_flags & IOCB_DIRECT) || | |
1655 | (file->f_mode & FMODE_BUF_WASYNC))) | |
407e9c63 | 1656 | return -EINVAL; |
1b4f42a1 | 1657 | |
f6f7a25a OS |
1658 | return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); |
1659 | } | |
1660 | EXPORT_SYMBOL(generic_write_checks_count); | |
1661 | ||
1662 | /* | |
1663 | * Performs necessary checks before doing a write | |
1664 | * | |
1665 | * Can adjust writing position or amount of bytes to write. | |
1666 | * Returns appropriate error code that caller should return or | |
1667 | * zero in case that write should be allowed. | |
1668 | */ | |
1669 | ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) | |
1670 | { | |
1671 | loff_t count = iov_iter_count(from); | |
1672 | int ret; | |
1673 | ||
1674 | ret = generic_write_checks_count(iocb, &count); | |
1b4f42a1 MS |
1675 | if (ret) |
1676 | return ret; | |
1677 | ||
407e9c63 DW |
1678 | iov_iter_truncate(from, count); |
1679 | return iov_iter_count(from); | |
1b4f42a1 | 1680 | } |
407e9c63 | 1681 | EXPORT_SYMBOL(generic_write_checks); |
1b4f42a1 | 1682 | |
407e9c63 DW |
1683 | /* |
1684 | * Performs common checks before doing a file copy/clone | |
1685 | * from @file_in to @file_out. | |
1686 | */ | |
1687 | int generic_file_rw_checks(struct file *file_in, struct file *file_out) | |
54dbc151 | 1688 | { |
407e9c63 DW |
1689 | struct inode *inode_in = file_inode(file_in); |
1690 | struct inode *inode_out = file_inode(file_out); | |
54dbc151 | 1691 | |
407e9c63 DW |
1692 | /* Don't copy dirs, pipes, sockets... */ |
1693 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
494633fa | 1694 | return -EISDIR; |
407e9c63 | 1695 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) |
22725ce4 DW |
1696 | return -EINVAL; |
1697 | ||
407e9c63 DW |
1698 | if (!(file_in->f_mode & FMODE_READ) || |
1699 | !(file_out->f_mode & FMODE_WRITE) || | |
1700 | (file_out->f_flags & O_APPEND)) | |
1701 | return -EBADF; | |
1b4f42a1 | 1702 | |
407e9c63 | 1703 | return 0; |
54dbc151 | 1704 | } |