Commit | Line | Data |
---|---|---|
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, |
2cb1e089 | 32 | .splice_read = filemap_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 |
89cbd4c0 | 74 | * @maxsize: max size of this file in file system |
e8b96eb5 | 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); |
de4eda9d | 387 | iov_iter_ubuf(&iter, ITER_DEST, 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; |
de4eda9d | 427 | iov_iter_kvec(&iter, ITER_DEST, &iov, 1, iov.iov_len); |
4d03e3cc | 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); |
de4eda9d | 489 | iov_iter_ubuf(&iter, ITER_SOURCE, (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 */ |
06bbaa6d | 499 | ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos) |
06ae43f3 | 500 | { |
4d03e3cc | 501 | struct kiocb kiocb; |
06ae43f3 AV |
502 | ssize_t ret; |
503 | ||
a01ac27b CH |
504 | if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) |
505 | return -EBADF; | |
7f7f25e8 | 506 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e | 507 | return -EINVAL; |
4d03e3cc CH |
508 | /* |
509 | * Also fail if ->write_iter and ->write are both wired up as that | |
510 | * implies very convoluted semantics. | |
511 | */ | |
512 | if (unlikely(!file->f_op->write_iter || file->f_op->write)) | |
513 | return warn_unsupported(file, "write"); | |
3e84f48e | 514 | |
4d03e3cc | 515 | init_sync_kiocb(&kiocb, file); |
4c207ef4 | 516 | kiocb.ki_pos = pos ? *pos : 0; |
06bbaa6d | 517 | ret = file->f_op->write_iter(&kiocb, from); |
06ae43f3 | 518 | if (ret > 0) { |
4c207ef4 MWO |
519 | if (pos) |
520 | *pos = kiocb.ki_pos; | |
06ae43f3 AV |
521 | fsnotify_modify(file); |
522 | add_wchar(current, ret); | |
523 | } | |
524 | inc_syscw(current); | |
525 | return ret; | |
526 | } | |
06bbaa6d AV |
527 | |
528 | /* caller is responsible for file_start_write/file_end_write */ | |
529 | ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) | |
530 | { | |
531 | struct kvec iov = { | |
532 | .iov_base = (void *)buf, | |
533 | .iov_len = min_t(size_t, count, MAX_RW_COUNT), | |
534 | }; | |
535 | struct iov_iter iter; | |
de4eda9d | 536 | iov_iter_kvec(&iter, ITER_SOURCE, &iov, 1, iov.iov_len); |
06bbaa6d AV |
537 | return __kernel_write_iter(file, &iter, pos); |
538 | } | |
90fb7027 LT |
539 | /* |
540 | * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()", | |
541 | * but autofs is one of the few internal kernel users that actually | |
542 | * wants this _and_ can be built as a module. So we need to export | |
543 | * this symbol for autofs, even though it really isn't appropriate | |
544 | * for any other kernel modules. | |
545 | */ | |
546 | EXPORT_SYMBOL_GPL(__kernel_write); | |
2ec3a12a | 547 | |
e13ec939 CH |
548 | ssize_t kernel_write(struct file *file, const void *buf, size_t count, |
549 | loff_t *pos) | |
ac452aca | 550 | { |
81238b2c | 551 | ssize_t ret; |
ac452aca | 552 | |
81238b2c CH |
553 | ret = rw_verify_area(WRITE, file, pos, count); |
554 | if (ret) | |
555 | return ret; | |
ac452aca | 556 | |
81238b2c CH |
557 | file_start_write(file); |
558 | ret = __kernel_write(file, buf, count, pos); | |
559 | file_end_write(file); | |
560 | return ret; | |
ac452aca CH |
561 | } |
562 | EXPORT_SYMBOL(kernel_write); | |
563 | ||
1da177e4 LT |
564 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
565 | { | |
566 | ssize_t ret; | |
567 | ||
568 | if (!(file->f_mode & FMODE_WRITE)) | |
569 | return -EBADF; | |
7f7f25e8 | 570 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 | 571 | return -EINVAL; |
96d4f267 | 572 | if (unlikely(!access_ok(buf, count))) |
1da177e4 LT |
573 | return -EFAULT; |
574 | ||
575 | ret = rw_verify_area(WRITE, file, pos, count); | |
53ad8626 CH |
576 | if (ret) |
577 | return ret; | |
578 | if (count > MAX_RW_COUNT) | |
579 | count = MAX_RW_COUNT; | |
580 | file_start_write(file); | |
581 | if (file->f_op->write) | |
582 | ret = file->f_op->write(file, buf, count, pos); | |
583 | else if (file->f_op->write_iter) | |
584 | ret = new_sync_write(file, buf, count, pos); | |
585 | else | |
586 | ret = -EINVAL; | |
587 | if (ret > 0) { | |
588 | fsnotify_modify(file); | |
589 | add_wchar(current, ret); | |
1da177e4 | 590 | } |
53ad8626 CH |
591 | inc_syscw(current); |
592 | file_end_write(file); | |
1da177e4 LT |
593 | return ret; |
594 | } | |
595 | ||
438ab720 KS |
596 | /* file_ppos returns &file->f_pos or NULL if file is stream */ |
597 | static inline loff_t *file_ppos(struct file *file) | |
1da177e4 | 598 | { |
438ab720 | 599 | return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; |
1da177e4 LT |
600 | } |
601 | ||
3ce4a7bf | 602 | ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) |
1da177e4 | 603 | { |
9c225f26 | 604 | struct fd f = fdget_pos(fd); |
1da177e4 | 605 | ssize_t ret = -EBADF; |
1da177e4 | 606 | |
2903ff01 | 607 | if (f.file) { |
438ab720 KS |
608 | loff_t pos, *ppos = file_ppos(f.file); |
609 | if (ppos) { | |
610 | pos = *ppos; | |
611 | ppos = &pos; | |
612 | } | |
613 | ret = vfs_read(f.file, buf, count, ppos); | |
614 | if (ret >= 0 && ppos) | |
615 | f.file->f_pos = pos; | |
9c225f26 | 616 | fdput_pos(f); |
1da177e4 | 617 | } |
1da177e4 LT |
618 | return ret; |
619 | } | |
1da177e4 | 620 | |
3ce4a7bf DB |
621 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
622 | { | |
623 | return ksys_read(fd, buf, count); | |
624 | } | |
625 | ||
e7a3e8b2 | 626 | ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) |
1da177e4 | 627 | { |
9c225f26 | 628 | struct fd f = fdget_pos(fd); |
1da177e4 | 629 | ssize_t ret = -EBADF; |
1da177e4 | 630 | |
2903ff01 | 631 | if (f.file) { |
438ab720 KS |
632 | loff_t pos, *ppos = file_ppos(f.file); |
633 | if (ppos) { | |
634 | pos = *ppos; | |
635 | ppos = &pos; | |
636 | } | |
637 | ret = vfs_write(f.file, buf, count, ppos); | |
638 | if (ret >= 0 && ppos) | |
639 | f.file->f_pos = pos; | |
9c225f26 | 640 | fdput_pos(f); |
1da177e4 LT |
641 | } |
642 | ||
643 | return ret; | |
644 | } | |
645 | ||
e7a3e8b2 DB |
646 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
647 | size_t, count) | |
648 | { | |
649 | return ksys_write(fd, buf, count); | |
650 | } | |
651 | ||
36028d5d DB |
652 | ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, |
653 | loff_t pos) | |
1da177e4 | 654 | { |
2903ff01 | 655 | struct fd f; |
1da177e4 | 656 | ssize_t ret = -EBADF; |
1da177e4 LT |
657 | |
658 | if (pos < 0) | |
659 | return -EINVAL; | |
660 | ||
2903ff01 AV |
661 | f = fdget(fd); |
662 | if (f.file) { | |
1da177e4 | 663 | ret = -ESPIPE; |
2903ff01 AV |
664 | if (f.file->f_mode & FMODE_PREAD) |
665 | ret = vfs_read(f.file, buf, count, &pos); | |
666 | fdput(f); | |
1da177e4 LT |
667 | } |
668 | ||
669 | return ret; | |
670 | } | |
671 | ||
36028d5d DB |
672 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
673 | size_t, count, loff_t, pos) | |
674 | { | |
675 | return ksys_pread64(fd, buf, count, pos); | |
676 | } | |
677 | ||
59c10c52 GR |
678 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64) |
679 | COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf, | |
680 | size_t, count, compat_arg_u64_dual(pos)) | |
681 | { | |
682 | return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos)); | |
683 | } | |
684 | #endif | |
685 | ||
36028d5d DB |
686 | ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, |
687 | size_t count, loff_t pos) | |
1da177e4 | 688 | { |
2903ff01 | 689 | struct fd f; |
1da177e4 | 690 | ssize_t ret = -EBADF; |
1da177e4 LT |
691 | |
692 | if (pos < 0) | |
693 | return -EINVAL; | |
694 | ||
2903ff01 AV |
695 | f = fdget(fd); |
696 | if (f.file) { | |
1da177e4 | 697 | ret = -ESPIPE; |
2903ff01 AV |
698 | if (f.file->f_mode & FMODE_PWRITE) |
699 | ret = vfs_write(f.file, buf, count, &pos); | |
700 | fdput(f); | |
1da177e4 LT |
701 | } |
702 | ||
703 | return ret; | |
704 | } | |
705 | ||
36028d5d DB |
706 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
707 | size_t, count, loff_t, pos) | |
708 | { | |
709 | return ksys_pwrite64(fd, buf, count, pos); | |
710 | } | |
711 | ||
59c10c52 GR |
712 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64) |
713 | COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf, | |
714 | size_t, count, compat_arg_u64_dual(pos)) | |
715 | { | |
716 | return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos)); | |
717 | } | |
718 | #endif | |
719 | ||
ac15ac06 | 720 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 721 | loff_t *ppos, int type, rwf_t flags) |
293bc982 AV |
722 | { |
723 | struct kiocb kiocb; | |
293bc982 AV |
724 | ssize_t ret; |
725 | ||
726 | init_sync_kiocb(&kiocb, filp); | |
fdd2f5b7 GR |
727 | ret = kiocb_set_rw_flags(&kiocb, flags); |
728 | if (ret) | |
729 | return ret; | |
438ab720 | 730 | kiocb.ki_pos = (ppos ? *ppos : 0); |
293bc982 | 731 | |
0f78d06a | 732 | if (type == READ) |
bb7462b6 | 733 | ret = call_read_iter(filp, &kiocb, iter); |
0f78d06a | 734 | else |
bb7462b6 | 735 | ret = call_write_iter(filp, &kiocb, iter); |
599bd19b | 736 | BUG_ON(ret == -EIOCBQUEUED); |
438ab720 KS |
737 | if (ppos) |
738 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
739 | return ret; |
740 | } | |
741 | ||
ee0b3e67 | 742 | /* Do it by hand, with file-ops */ |
ac15ac06 | 743 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 744 | loff_t *ppos, int type, rwf_t flags) |
ee0b3e67 | 745 | { |
ee0b3e67 BP |
746 | ssize_t ret = 0; |
747 | ||
97be7ebe | 748 | if (flags & ~RWF_HIPRI) |
793b80ef CH |
749 | return -EOPNOTSUPP; |
750 | ||
ac15ac06 | 751 | while (iov_iter_count(iter)) { |
ee0b3e67 BP |
752 | ssize_t nr; |
753 | ||
0f78d06a | 754 | if (type == READ) { |
95e49cf8 JA |
755 | nr = filp->f_op->read(filp, iter_iov_addr(iter), |
756 | iter_iov_len(iter), ppos); | |
0f78d06a | 757 | } else { |
95e49cf8 JA |
758 | nr = filp->f_op->write(filp, iter_iov_addr(iter), |
759 | iter_iov_len(iter), ppos); | |
0f78d06a | 760 | } |
ee0b3e67 BP |
761 | |
762 | if (nr < 0) { | |
763 | if (!ret) | |
764 | ret = nr; | |
765 | break; | |
766 | } | |
767 | ret += nr; | |
95e49cf8 | 768 | if (nr != iter_iov_len(iter)) |
ee0b3e67 | 769 | break; |
ac15ac06 | 770 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
771 | } |
772 | ||
773 | return ret; | |
774 | } | |
775 | ||
19c73586 | 776 | static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 777 | loff_t *pos, rwf_t flags) |
1da177e4 | 778 | { |
1da177e4 | 779 | size_t tot_len; |
7687a7a4 | 780 | ssize_t ret = 0; |
1da177e4 | 781 | |
edab5fe3 CH |
782 | if (!(file->f_mode & FMODE_READ)) |
783 | return -EBADF; | |
784 | if (!(file->f_mode & FMODE_CAN_READ)) | |
785 | return -EINVAL; | |
786 | ||
7687a7a4 | 787 | tot_len = iov_iter_count(iter); |
0504c074 AV |
788 | if (!tot_len) |
789 | goto out; | |
19c73586 | 790 | ret = rw_verify_area(READ, file, pos, tot_len); |
e28cc715 | 791 | if (ret < 0) |
19c73586 | 792 | return ret; |
1da177e4 | 793 | |
19c73586 CH |
794 | if (file->f_op->read_iter) |
795 | ret = do_iter_readv_writev(file, iter, pos, READ, flags); | |
ee0b3e67 | 796 | else |
19c73586 | 797 | ret = do_loop_readv_writev(file, iter, pos, READ, flags); |
1da177e4 | 798 | out: |
19c73586 CH |
799 | if (ret >= 0) |
800 | fsnotify_access(file); | |
1da177e4 | 801 | return ret; |
1da177e4 LT |
802 | } |
803 | ||
5dcdc43e JX |
804 | ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, |
805 | struct iov_iter *iter) | |
806 | { | |
807 | size_t tot_len; | |
808 | ssize_t ret = 0; | |
809 | ||
810 | if (!file->f_op->read_iter) | |
811 | return -EINVAL; | |
812 | if (!(file->f_mode & FMODE_READ)) | |
813 | return -EBADF; | |
814 | if (!(file->f_mode & FMODE_CAN_READ)) | |
815 | return -EINVAL; | |
816 | ||
817 | tot_len = iov_iter_count(iter); | |
818 | if (!tot_len) | |
819 | goto out; | |
820 | ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); | |
821 | if (ret < 0) | |
822 | return ret; | |
823 | ||
824 | ret = call_read_iter(file, iocb, iter); | |
825 | out: | |
826 | if (ret >= 0) | |
827 | fsnotify_access(file); | |
828 | return ret; | |
829 | } | |
830 | EXPORT_SYMBOL(vfs_iocb_iter_read); | |
831 | ||
18e9710e | 832 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 833 | rwf_t flags) |
7687a7a4 | 834 | { |
18e9710e CH |
835 | if (!file->f_op->read_iter) |
836 | return -EINVAL; | |
837 | return do_iter_read(file, iter, ppos, flags); | |
838 | } | |
839 | EXPORT_SYMBOL(vfs_iter_read); | |
7687a7a4 | 840 | |
19c73586 | 841 | static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 842 | loff_t *pos, rwf_t flags) |
19c73586 CH |
843 | { |
844 | size_t tot_len; | |
845 | ssize_t ret = 0; | |
03d95eb2 | 846 | |
edab5fe3 CH |
847 | if (!(file->f_mode & FMODE_WRITE)) |
848 | return -EBADF; | |
849 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
850 | return -EINVAL; | |
851 | ||
19c73586 CH |
852 | tot_len = iov_iter_count(iter); |
853 | if (!tot_len) | |
854 | return 0; | |
855 | ret = rw_verify_area(WRITE, file, pos, tot_len); | |
7687a7a4 MS |
856 | if (ret < 0) |
857 | return ret; | |
858 | ||
19c73586 CH |
859 | if (file->f_op->write_iter) |
860 | ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); | |
861 | else | |
862 | ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); | |
19c73586 CH |
863 | if (ret > 0) |
864 | fsnotify_modify(file); | |
7687a7a4 MS |
865 | return ret; |
866 | } | |
867 | ||
5dcdc43e JX |
868 | ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, |
869 | struct iov_iter *iter) | |
870 | { | |
871 | size_t tot_len; | |
872 | ssize_t ret = 0; | |
873 | ||
874 | if (!file->f_op->write_iter) | |
875 | return -EINVAL; | |
876 | if (!(file->f_mode & FMODE_WRITE)) | |
877 | return -EBADF; | |
878 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
879 | return -EINVAL; | |
880 | ||
881 | tot_len = iov_iter_count(iter); | |
882 | if (!tot_len) | |
883 | return 0; | |
884 | ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); | |
885 | if (ret < 0) | |
886 | return ret; | |
887 | ||
888 | ret = call_write_iter(file, iocb, iter); | |
889 | if (ret > 0) | |
890 | fsnotify_modify(file); | |
891 | ||
892 | return ret; | |
893 | } | |
894 | EXPORT_SYMBOL(vfs_iocb_iter_write); | |
895 | ||
abbb6589 | 896 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 897 | rwf_t flags) |
abbb6589 CH |
898 | { |
899 | if (!file->f_op->write_iter) | |
900 | return -EINVAL; | |
901 | return do_iter_write(file, iter, ppos, flags); | |
902 | } | |
903 | EXPORT_SYMBOL(vfs_iter_write); | |
904 | ||
36e2c742 | 905 | static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 906 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 907 | { |
7687a7a4 MS |
908 | struct iovec iovstack[UIO_FASTIOV]; |
909 | struct iovec *iov = iovstack; | |
910 | struct iov_iter iter; | |
911 | ssize_t ret; | |
1da177e4 | 912 | |
de4eda9d | 913 | ret = import_iovec(ITER_DEST, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 CH |
914 | if (ret >= 0) { |
915 | ret = do_iter_read(file, &iter, pos, flags); | |
916 | kfree(iov); | |
917 | } | |
1da177e4 | 918 | |
251b42a1 CH |
919 | return ret; |
920 | } | |
1da177e4 | 921 | |
9725d4ce | 922 | static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 923 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 924 | { |
251b42a1 CH |
925 | struct iovec iovstack[UIO_FASTIOV]; |
926 | struct iovec *iov = iovstack; | |
927 | struct iov_iter iter; | |
928 | ssize_t ret; | |
1da177e4 | 929 | |
de4eda9d | 930 | ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 | 931 | if (ret >= 0) { |
62473a2d | 932 | file_start_write(file); |
edab5fe3 | 933 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 934 | file_end_write(file); |
edab5fe3 CH |
935 | kfree(iov); |
936 | } | |
251b42a1 | 937 | return ret; |
1da177e4 | 938 | } |
1da177e4 | 939 | |
f17d8b35 | 940 | static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 941 | unsigned long vlen, rwf_t flags) |
1da177e4 | 942 | { |
9c225f26 | 943 | struct fd f = fdget_pos(fd); |
1da177e4 | 944 | ssize_t ret = -EBADF; |
1da177e4 | 945 | |
2903ff01 | 946 | if (f.file) { |
438ab720 KS |
947 | loff_t pos, *ppos = file_ppos(f.file); |
948 | if (ppos) { | |
949 | pos = *ppos; | |
950 | ppos = &pos; | |
951 | } | |
952 | ret = vfs_readv(f.file, vec, vlen, ppos, flags); | |
953 | if (ret >= 0 && ppos) | |
954 | f.file->f_pos = pos; | |
9c225f26 | 955 | fdput_pos(f); |
1da177e4 LT |
956 | } |
957 | ||
958 | if (ret > 0) | |
4b98d11b AD |
959 | add_rchar(current, ret); |
960 | inc_syscr(current); | |
1da177e4 LT |
961 | return ret; |
962 | } | |
963 | ||
f17d8b35 | 964 | static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 965 | unsigned long vlen, rwf_t flags) |
1da177e4 | 966 | { |
9c225f26 | 967 | struct fd f = fdget_pos(fd); |
1da177e4 | 968 | ssize_t ret = -EBADF; |
1da177e4 | 969 | |
2903ff01 | 970 | if (f.file) { |
438ab720 KS |
971 | loff_t pos, *ppos = file_ppos(f.file); |
972 | if (ppos) { | |
973 | pos = *ppos; | |
974 | ppos = &pos; | |
975 | } | |
976 | ret = vfs_writev(f.file, vec, vlen, ppos, flags); | |
977 | if (ret >= 0 && ppos) | |
978 | f.file->f_pos = pos; | |
9c225f26 | 979 | fdput_pos(f); |
1da177e4 LT |
980 | } |
981 | ||
982 | if (ret > 0) | |
4b98d11b AD |
983 | add_wchar(current, ret); |
984 | inc_syscw(current); | |
1da177e4 LT |
985 | return ret; |
986 | } | |
987 | ||
601cc11d LT |
988 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
989 | { | |
990 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
991 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
992 | } | |
993 | ||
f17d8b35 | 994 | static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 995 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 996 | { |
2903ff01 | 997 | struct fd f; |
f3554f4b | 998 | ssize_t ret = -EBADF; |
f3554f4b GH |
999 | |
1000 | if (pos < 0) | |
1001 | return -EINVAL; | |
1002 | ||
2903ff01 AV |
1003 | f = fdget(fd); |
1004 | if (f.file) { | |
f3554f4b | 1005 | ret = -ESPIPE; |
2903ff01 | 1006 | if (f.file->f_mode & FMODE_PREAD) |
f17d8b35 | 1007 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1008 | fdput(f); |
f3554f4b GH |
1009 | } |
1010 | ||
1011 | if (ret > 0) | |
1012 | add_rchar(current, ret); | |
1013 | inc_syscr(current); | |
1014 | return ret; | |
1015 | } | |
1016 | ||
f17d8b35 | 1017 | static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1018 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1019 | { |
2903ff01 | 1020 | struct fd f; |
f3554f4b | 1021 | ssize_t ret = -EBADF; |
f3554f4b GH |
1022 | |
1023 | if (pos < 0) | |
1024 | return -EINVAL; | |
1025 | ||
2903ff01 AV |
1026 | f = fdget(fd); |
1027 | if (f.file) { | |
f3554f4b | 1028 | ret = -ESPIPE; |
2903ff01 | 1029 | if (f.file->f_mode & FMODE_PWRITE) |
f17d8b35 | 1030 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1031 | fdput(f); |
f3554f4b GH |
1032 | } |
1033 | ||
1034 | if (ret > 0) | |
1035 | add_wchar(current, ret); | |
1036 | inc_syscw(current); | |
1037 | return ret; | |
1038 | } | |
1039 | ||
f17d8b35 MT |
1040 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
1041 | unsigned long, vlen) | |
1042 | { | |
1043 | return do_readv(fd, vec, vlen, 0); | |
1044 | } | |
1045 | ||
1046 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, | |
1047 | unsigned long, vlen) | |
1048 | { | |
1049 | return do_writev(fd, vec, vlen, 0); | |
1050 | } | |
1051 | ||
1052 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, | |
1053 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1054 | { | |
1055 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1056 | ||
1057 | return do_preadv(fd, vec, vlen, pos, 0); | |
1058 | } | |
1059 | ||
1060 | SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, | |
1061 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1062 | rwf_t, flags) |
f17d8b35 MT |
1063 | { |
1064 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1065 | ||
1066 | if (pos == -1) | |
1067 | return do_readv(fd, vec, vlen, flags); | |
1068 | ||
1069 | return do_preadv(fd, vec, vlen, pos, flags); | |
1070 | } | |
1071 | ||
1072 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
1073 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1074 | { | |
1075 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1076 | ||
1077 | return do_pwritev(fd, vec, vlen, pos, 0); | |
1078 | } | |
1079 | ||
1080 | SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, | |
1081 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1082 | rwf_t, flags) |
f17d8b35 MT |
1083 | { |
1084 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1085 | ||
1086 | if (pos == -1) | |
1087 | return do_writev(fd, vec, vlen, flags); | |
1088 | ||
1089 | return do_pwritev(fd, vec, vlen, pos, flags); | |
1090 | } | |
1091 | ||
3523a9d4 CH |
1092 | /* |
1093 | * Various compat syscalls. Note that they all pretend to take a native | |
1094 | * iovec - import_iovec will properly treat those as compat_iovecs based on | |
1095 | * in_compat_syscall(). | |
1096 | */ | |
72ec3516 | 1097 | #ifdef CONFIG_COMPAT |
378a10f3 HC |
1098 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1099 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
3523a9d4 | 1100 | const struct iovec __user *, vec, |
378a10f3 HC |
1101 | unsigned long, vlen, loff_t, pos) |
1102 | { | |
3523a9d4 | 1103 | return do_preadv(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1104 | } |
1105 | #endif | |
1106 | ||
dfd948e3 | 1107 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
3523a9d4 | 1108 | const struct iovec __user *, vec, |
dfd948e3 | 1109 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1110 | { |
1111 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1112 | |
3523a9d4 | 1113 | return do_preadv(fd, vec, vlen, pos, 0); |
f17d8b35 MT |
1114 | } |
1115 | ||
3ebfd81f L |
1116 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 |
1117 | COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, | |
3523a9d4 | 1118 | const struct iovec __user *, vec, |
ddef7ed2 | 1119 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1120 | { |
cc4b1242 | 1121 | if (pos == -1) |
3523a9d4 CH |
1122 | return do_readv(fd, vec, vlen, flags); |
1123 | return do_preadv(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1124 | } |
1125 | #endif | |
1126 | ||
f17d8b35 | 1127 | COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, |
3523a9d4 | 1128 | const struct iovec __user *, vec, |
f17d8b35 | 1129 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, |
ddef7ed2 | 1130 | rwf_t, flags) |
f17d8b35 MT |
1131 | { |
1132 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1133 | ||
1134 | if (pos == -1) | |
3523a9d4 CH |
1135 | return do_readv(fd, vec, vlen, flags); |
1136 | return do_preadv(fd, vec, vlen, pos, flags); | |
72ec3516 AV |
1137 | } |
1138 | ||
378a10f3 HC |
1139 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1140 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
3523a9d4 | 1141 | const struct iovec __user *, vec, |
378a10f3 HC |
1142 | unsigned long, vlen, loff_t, pos) |
1143 | { | |
3523a9d4 | 1144 | return do_pwritev(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1145 | } |
1146 | #endif | |
1147 | ||
dfd948e3 | 1148 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
3523a9d4 | 1149 | const struct iovec __user *,vec, |
dfd948e3 | 1150 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1151 | { |
1152 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1153 | |
3523a9d4 | 1154 | return do_pwritev(fd, vec, vlen, pos, 0); |
72ec3516 | 1155 | } |
f17d8b35 | 1156 | |
3ebfd81f L |
1157 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 |
1158 | COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, | |
3523a9d4 | 1159 | const struct iovec __user *, vec, |
ddef7ed2 | 1160 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f | 1161 | { |
cc4b1242 | 1162 | if (pos == -1) |
3523a9d4 CH |
1163 | return do_writev(fd, vec, vlen, flags); |
1164 | return do_pwritev(fd, vec, vlen, pos, flags); | |
3ebfd81f L |
1165 | } |
1166 | #endif | |
1167 | ||
f17d8b35 | 1168 | COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, |
3523a9d4 | 1169 | const struct iovec __user *,vec, |
ddef7ed2 | 1170 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) |
f17d8b35 MT |
1171 | { |
1172 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1173 | ||
1174 | if (pos == -1) | |
3523a9d4 CH |
1175 | return do_writev(fd, vec, vlen, flags); |
1176 | return do_pwritev(fd, vec, vlen, pos, flags); | |
72ec3516 | 1177 | } |
3523a9d4 | 1178 | #endif /* CONFIG_COMPAT */ |
72ec3516 | 1179 | |
19f4fc3a AV |
1180 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1181 | size_t count, loff_t max) | |
1da177e4 | 1182 | { |
2903ff01 AV |
1183 | struct fd in, out; |
1184 | struct inode *in_inode, *out_inode; | |
b964bf53 | 1185 | struct pipe_inode_info *opipe; |
1da177e4 | 1186 | loff_t pos; |
7995bd28 | 1187 | loff_t out_pos; |
1da177e4 | 1188 | ssize_t retval; |
2903ff01 | 1189 | int fl; |
1da177e4 LT |
1190 | |
1191 | /* | |
1192 | * Get input file, and verify that it is ok.. | |
1193 | */ | |
1194 | retval = -EBADF; | |
2903ff01 AV |
1195 | in = fdget(in_fd); |
1196 | if (!in.file) | |
1da177e4 | 1197 | goto out; |
2903ff01 | 1198 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1199 | goto fput_in; |
1da177e4 | 1200 | retval = -ESPIPE; |
7995bd28 AV |
1201 | if (!ppos) { |
1202 | pos = in.file->f_pos; | |
1203 | } else { | |
1204 | pos = *ppos; | |
2903ff01 | 1205 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1206 | goto fput_in; |
7995bd28 AV |
1207 | } |
1208 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1209 | if (retval < 0) |
1da177e4 | 1210 | goto fput_in; |
bc61384d AV |
1211 | if (count > MAX_RW_COUNT) |
1212 | count = MAX_RW_COUNT; | |
1da177e4 | 1213 | |
1da177e4 LT |
1214 | /* |
1215 | * Get output file, and verify that it is ok.. | |
1216 | */ | |
1217 | retval = -EBADF; | |
2903ff01 AV |
1218 | out = fdget(out_fd); |
1219 | if (!out.file) | |
1da177e4 | 1220 | goto fput_in; |
2903ff01 | 1221 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 | 1222 | goto fput_out; |
496ad9aa AV |
1223 | in_inode = file_inode(in.file); |
1224 | out_inode = file_inode(out.file); | |
7995bd28 | 1225 | out_pos = out.file->f_pos; |
1da177e4 | 1226 | |
1da177e4 LT |
1227 | if (!max) |
1228 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1229 | ||
1da177e4 LT |
1230 | if (unlikely(pos + count > max)) { |
1231 | retval = -EOVERFLOW; | |
1232 | if (pos >= max) | |
1233 | goto fput_out; | |
1234 | count = max - pos; | |
1235 | } | |
1236 | ||
d96e6e71 | 1237 | fl = 0; |
534f2aaa | 1238 | #if 0 |
d96e6e71 JA |
1239 | /* |
1240 | * We need to debate whether we can enable this or not. The | |
1241 | * man page documents EAGAIN return for the output at least, | |
1242 | * and the application is arguably buggy if it doesn't expect | |
1243 | * EAGAIN on a non-blocking file descriptor. | |
1244 | */ | |
2903ff01 | 1245 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1246 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1247 | #endif |
b964bf53 AV |
1248 | opipe = get_pipe_info(out.file, true); |
1249 | if (!opipe) { | |
1250 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
1251 | if (retval < 0) | |
1252 | goto fput_out; | |
1253 | file_start_write(out.file); | |
1254 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, | |
1255 | count, fl); | |
1256 | file_end_write(out.file); | |
1257 | } else { | |
bdeb77bc AV |
1258 | if (out.file->f_flags & O_NONBLOCK) |
1259 | fl |= SPLICE_F_NONBLOCK; | |
1260 | ||
b964bf53 AV |
1261 | retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl); |
1262 | } | |
1da177e4 LT |
1263 | |
1264 | if (retval > 0) { | |
4b98d11b AD |
1265 | add_rchar(current, retval); |
1266 | add_wchar(current, retval); | |
a68c2f12 SW |
1267 | fsnotify_access(in.file); |
1268 | fsnotify_modify(out.file); | |
7995bd28 AV |
1269 | out.file->f_pos = out_pos; |
1270 | if (ppos) | |
1271 | *ppos = pos; | |
1272 | else | |
1273 | in.file->f_pos = pos; | |
1da177e4 | 1274 | } |
1da177e4 | 1275 | |
4b98d11b AD |
1276 | inc_syscr(current); |
1277 | inc_syscw(current); | |
7995bd28 | 1278 | if (pos > max) |
1da177e4 LT |
1279 | retval = -EOVERFLOW; |
1280 | ||
1281 | fput_out: | |
2903ff01 | 1282 | fdput(out); |
1da177e4 | 1283 | fput_in: |
2903ff01 | 1284 | fdput(in); |
1da177e4 LT |
1285 | out: |
1286 | return retval; | |
1287 | } | |
1288 | ||
002c8976 | 1289 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1290 | { |
1291 | loff_t pos; | |
1292 | off_t off; | |
1293 | ssize_t ret; | |
1294 | ||
1295 | if (offset) { | |
1296 | if (unlikely(get_user(off, offset))) | |
1297 | return -EFAULT; | |
1298 | pos = off; | |
1299 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1300 | if (unlikely(put_user(pos, offset))) | |
1301 | return -EFAULT; | |
1302 | return ret; | |
1303 | } | |
1304 | ||
1305 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1306 | } | |
1307 | ||
002c8976 | 1308 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1309 | { |
1310 | loff_t pos; | |
1311 | ssize_t ret; | |
1312 | ||
1313 | if (offset) { | |
1314 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1315 | return -EFAULT; | |
1316 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1317 | if (unlikely(put_user(pos, offset))) | |
1318 | return -EFAULT; | |
1319 | return ret; | |
1320 | } | |
1321 | ||
1322 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1323 | } | |
19f4fc3a AV |
1324 | |
1325 | #ifdef CONFIG_COMPAT | |
1326 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1327 | compat_off_t __user *, offset, compat_size_t, count) | |
1328 | { | |
1329 | loff_t pos; | |
1330 | off_t off; | |
1331 | ssize_t ret; | |
1332 | ||
1333 | if (offset) { | |
1334 | if (unlikely(get_user(off, offset))) | |
1335 | return -EFAULT; | |
1336 | pos = off; | |
1337 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1338 | if (unlikely(put_user(pos, offset))) | |
1339 | return -EFAULT; | |
1340 | return ret; | |
1341 | } | |
1342 | ||
1343 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1344 | } | |
1345 | ||
1346 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1347 | compat_loff_t __user *, offset, compat_size_t, count) | |
1348 | { | |
1349 | loff_t pos; | |
1350 | ssize_t ret; | |
1351 | ||
1352 | if (offset) { | |
1353 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1354 | return -EFAULT; | |
1355 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1356 | if (unlikely(put_user(pos, offset))) | |
1357 | return -EFAULT; | |
1358 | return ret; | |
1359 | } | |
1360 | ||
1361 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1362 | } | |
1363 | #endif | |
29732938 | 1364 | |
f16acc9d DC |
1365 | /** |
1366 | * generic_copy_file_range - copy data between two files | |
1367 | * @file_in: file structure to read from | |
1368 | * @pos_in: file offset to read from | |
1369 | * @file_out: file structure to write data to | |
1370 | * @pos_out: file offset to write data to | |
1371 | * @len: amount of data to copy | |
1372 | * @flags: copy flags | |
1373 | * | |
1374 | * This is a generic filesystem helper to copy data from one file to another. | |
1375 | * It has no constraints on the source or destination file owners - the files | |
1376 | * can belong to different superblocks and different filesystem types. Short | |
1377 | * copies are allowed. | |
1378 | * | |
1379 | * This should be called from the @file_out filesystem, as per the | |
1380 | * ->copy_file_range() method. | |
1381 | * | |
1382 | * Returns the number of bytes copied or a negative error indicating the | |
1383 | * failure. | |
1384 | */ | |
1385 | ||
1386 | ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, | |
1387 | struct file *file_out, loff_t pos_out, | |
1388 | size_t len, unsigned int flags) | |
1389 | { | |
10bc8e4a AG |
1390 | lockdep_assert(sb_write_started(file_inode(file_out)->i_sb)); |
1391 | ||
f16acc9d DC |
1392 | return do_splice_direct(file_in, &pos_in, file_out, &pos_out, |
1393 | len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); | |
1394 | } | |
1395 | EXPORT_SYMBOL(generic_copy_file_range); | |
1396 | ||
407e9c63 DW |
1397 | /* |
1398 | * Performs necessary checks before doing a file copy | |
1399 | * | |
1400 | * Can adjust amount of bytes to copy via @req_count argument. | |
1401 | * Returns appropriate error code that caller should return or | |
1402 | * zero in case the copy should be allowed. | |
1403 | */ | |
1404 | static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, | |
1405 | struct file *file_out, loff_t pos_out, | |
1406 | size_t *req_count, unsigned int flags) | |
1407 | { | |
1408 | struct inode *inode_in = file_inode(file_in); | |
1409 | struct inode *inode_out = file_inode(file_out); | |
1410 | uint64_t count = *req_count; | |
1411 | loff_t size_in; | |
1412 | int ret; | |
1413 | ||
1414 | ret = generic_file_rw_checks(file_in, file_out); | |
1415 | if (ret) | |
1416 | return ret; | |
1417 | ||
868f9f2f AG |
1418 | /* |
1419 | * We allow some filesystems to handle cross sb copy, but passing | |
1420 | * a file of the wrong filesystem type to filesystem driver can result | |
1421 | * in an attempt to dereference the wrong type of ->private_data, so | |
1422 | * avoid doing that until we really have a good reason. | |
1423 | * | |
1424 | * nfs and cifs define several different file_system_type structures | |
1425 | * and several different sets of file_operations, but they all end up | |
1426 | * using the same ->copy_file_range() function pointer. | |
1427 | */ | |
10bc8e4a AG |
1428 | if (flags & COPY_FILE_SPLICE) { |
1429 | /* cross sb splice is allowed */ | |
1430 | } else if (file_out->f_op->copy_file_range) { | |
868f9f2f AG |
1431 | if (file_in->f_op->copy_file_range != |
1432 | file_out->f_op->copy_file_range) | |
1433 | return -EXDEV; | |
1434 | } else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) { | |
1435 | return -EXDEV; | |
1436 | } | |
1437 | ||
407e9c63 DW |
1438 | /* Don't touch certain kinds of inodes */ |
1439 | if (IS_IMMUTABLE(inode_out)) | |
1440 | return -EPERM; | |
1441 | ||
1442 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1443 | return -ETXTBSY; | |
1444 | ||
1445 | /* Ensure offsets don't wrap. */ | |
1446 | if (pos_in + count < pos_in || pos_out + count < pos_out) | |
1447 | return -EOVERFLOW; | |
1448 | ||
1449 | /* Shorten the copy to EOF */ | |
1450 | size_in = i_size_read(inode_in); | |
1451 | if (pos_in >= size_in) | |
1452 | count = 0; | |
1453 | else | |
1454 | count = min(count, size_in - (uint64_t)pos_in); | |
1455 | ||
1456 | ret = generic_write_check_limits(file_out, pos_out, &count); | |
1457 | if (ret) | |
1458 | return ret; | |
1459 | ||
1460 | /* Don't allow overlapped copying within the same file. */ | |
1461 | if (inode_in == inode_out && | |
1462 | pos_out + count > pos_in && | |
1463 | pos_out < pos_in + count) | |
1464 | return -EINVAL; | |
1465 | ||
1466 | *req_count = count; | |
1467 | return 0; | |
1468 | } | |
1469 | ||
29732938 ZB |
1470 | /* |
1471 | * copy_file_range() differs from regular file read and write in that it | |
1472 | * specifically allows return partial success. When it does so is up to | |
1473 | * the copy_file_range method. | |
1474 | */ | |
1475 | ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, | |
1476 | struct file *file_out, loff_t pos_out, | |
1477 | size_t len, unsigned int flags) | |
1478 | { | |
29732938 | 1479 | ssize_t ret; |
10bc8e4a | 1480 | bool splice = flags & COPY_FILE_SPLICE; |
29732938 | 1481 | |
10bc8e4a | 1482 | if (flags & ~COPY_FILE_SPLICE) |
29732938 ZB |
1483 | return -EINVAL; |
1484 | ||
96e6e8f4 AG |
1485 | ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, |
1486 | flags); | |
a3171351 AG |
1487 | if (unlikely(ret)) |
1488 | return ret; | |
11cbfb10 | 1489 | |
29732938 | 1490 | ret = rw_verify_area(READ, file_in, &pos_in, len); |
bc61384d AV |
1491 | if (unlikely(ret)) |
1492 | return ret; | |
1493 | ||
1494 | ret = rw_verify_area(WRITE, file_out, &pos_out, len); | |
1495 | if (unlikely(ret)) | |
29732938 ZB |
1496 | return ret; |
1497 | ||
29732938 ZB |
1498 | if (len == 0) |
1499 | return 0; | |
1500 | ||
bfe219d3 | 1501 | file_start_write(file_out); |
29732938 | 1502 | |
a76b5b04 | 1503 | /* |
868f9f2f AG |
1504 | * Cloning is supported by more file systems, so we implement copy on |
1505 | * same sb using clone, but for filesystems where both clone and copy | |
1506 | * are supported (e.g. nfs,cifs), we only call the copy method. | |
a76b5b04 | 1507 | */ |
10bc8e4a | 1508 | if (!splice && file_out->f_op->copy_file_range) { |
868f9f2f AG |
1509 | ret = file_out->f_op->copy_file_range(file_in, pos_in, |
1510 | file_out, pos_out, | |
1511 | len, flags); | |
1512 | goto done; | |
1513 | } | |
1514 | ||
10bc8e4a | 1515 | if (!splice && file_in->f_op->remap_file_range && |
5dae222a | 1516 | file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) { |
868f9f2f | 1517 | ret = file_in->f_op->remap_file_range(file_in, pos_in, |
42ec3d4c | 1518 | file_out, pos_out, |
eca3654e DW |
1519 | min_t(loff_t, MAX_RW_COUNT, len), |
1520 | REMAP_FILE_CAN_SHORTEN); | |
868f9f2f | 1521 | if (ret > 0) |
a76b5b04 | 1522 | goto done; |
a76b5b04 CH |
1523 | } |
1524 | ||
868f9f2f AG |
1525 | /* |
1526 | * We can get here for same sb copy of filesystems that do not implement | |
1527 | * ->copy_file_range() in case filesystem does not support clone or in | |
1528 | * case filesystem supports clone but rejected the clone request (e.g. | |
1529 | * because it was not block aligned). | |
1530 | * | |
1531 | * In both cases, fall back to kernel copy so we are able to maintain a | |
1532 | * consistent story about which filesystems support copy_file_range() | |
1533 | * and which filesystems do not, that will allow userspace tools to | |
1534 | * make consistent desicions w.r.t using copy_file_range(). | |
10bc8e4a AG |
1535 | * |
1536 | * We also get here if caller (e.g. nfsd) requested COPY_FILE_SPLICE. | |
868f9f2f AG |
1537 | */ |
1538 | ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, | |
1539 | flags); | |
1540 | ||
a76b5b04 | 1541 | done: |
29732938 ZB |
1542 | if (ret > 0) { |
1543 | fsnotify_access(file_in); | |
1544 | add_rchar(current, ret); | |
1545 | fsnotify_modify(file_out); | |
1546 | add_wchar(current, ret); | |
1547 | } | |
a76b5b04 | 1548 | |
29732938 ZB |
1549 | inc_syscr(current); |
1550 | inc_syscw(current); | |
1551 | ||
bfe219d3 | 1552 | file_end_write(file_out); |
29732938 ZB |
1553 | |
1554 | return ret; | |
1555 | } | |
1556 | EXPORT_SYMBOL(vfs_copy_file_range); | |
1557 | ||
1558 | SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, | |
1559 | int, fd_out, loff_t __user *, off_out, | |
1560 | size_t, len, unsigned int, flags) | |
1561 | { | |
1562 | loff_t pos_in; | |
1563 | loff_t pos_out; | |
1564 | struct fd f_in; | |
1565 | struct fd f_out; | |
1566 | ssize_t ret = -EBADF; | |
1567 | ||
1568 | f_in = fdget(fd_in); | |
1569 | if (!f_in.file) | |
1570 | goto out2; | |
1571 | ||
1572 | f_out = fdget(fd_out); | |
1573 | if (!f_out.file) | |
1574 | goto out1; | |
1575 | ||
1576 | ret = -EFAULT; | |
1577 | if (off_in) { | |
1578 | if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) | |
1579 | goto out; | |
1580 | } else { | |
1581 | pos_in = f_in.file->f_pos; | |
1582 | } | |
1583 | ||
1584 | if (off_out) { | |
1585 | if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) | |
1586 | goto out; | |
1587 | } else { | |
1588 | pos_out = f_out.file->f_pos; | |
1589 | } | |
1590 | ||
10bc8e4a AG |
1591 | ret = -EINVAL; |
1592 | if (flags != 0) | |
1593 | goto out; | |
1594 | ||
29732938 ZB |
1595 | ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, |
1596 | flags); | |
1597 | if (ret > 0) { | |
1598 | pos_in += ret; | |
1599 | pos_out += ret; | |
1600 | ||
1601 | if (off_in) { | |
1602 | if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) | |
1603 | ret = -EFAULT; | |
1604 | } else { | |
1605 | f_in.file->f_pos = pos_in; | |
1606 | } | |
1607 | ||
1608 | if (off_out) { | |
1609 | if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) | |
1610 | ret = -EFAULT; | |
1611 | } else { | |
1612 | f_out.file->f_pos = pos_out; | |
1613 | } | |
1614 | } | |
1615 | ||
1616 | out: | |
1617 | fdput(f_out); | |
1618 | out1: | |
1619 | fdput(f_in); | |
1620 | out2: | |
1621 | return ret; | |
1622 | } | |
04b38d60 | 1623 | |
edc58dd0 | 1624 | /* |
407e9c63 DW |
1625 | * Don't operate on ranges the page cache doesn't support, and don't exceed the |
1626 | * LFS limits. If pos is under the limit it becomes a short access. If it | |
1627 | * exceeds the limit we return -EFBIG. | |
edc58dd0 | 1628 | */ |
407e9c63 | 1629 | int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) |
edc58dd0 | 1630 | { |
407e9c63 DW |
1631 | struct inode *inode = file->f_mapping->host; |
1632 | loff_t max_size = inode->i_sb->s_maxbytes; | |
1633 | loff_t limit = rlimit(RLIMIT_FSIZE); | |
edc58dd0 | 1634 | |
407e9c63 DW |
1635 | if (limit != RLIM_INFINITY) { |
1636 | if (pos >= limit) { | |
1637 | send_sig(SIGXFSZ, current, 0); | |
1638 | return -EFBIG; | |
edc58dd0 | 1639 | } |
407e9c63 DW |
1640 | *count = min(*count, limit - pos); |
1641 | } | |
edc58dd0 | 1642 | |
407e9c63 DW |
1643 | if (!(file->f_flags & O_LARGEFILE)) |
1644 | max_size = MAX_NON_LFS; | |
c32e5f39 | 1645 | |
407e9c63 DW |
1646 | if (unlikely(pos >= max_size)) |
1647 | return -EFBIG; | |
c32e5f39 | 1648 | |
407e9c63 | 1649 | *count = min(*count, max_size - pos); |
c32e5f39 | 1650 | |
c32e5f39 | 1651 | return 0; |
c32e5f39 | 1652 | } |
04b38d60 | 1653 | |
f6f7a25a OS |
1654 | /* Like generic_write_checks(), but takes size of write instead of iter. */ |
1655 | int generic_write_checks_count(struct kiocb *iocb, loff_t *count) | |
876bec6f | 1656 | { |
407e9c63 DW |
1657 | struct file *file = iocb->ki_filp; |
1658 | struct inode *inode = file->f_mapping->host; | |
876bec6f | 1659 | |
407e9c63 | 1660 | if (IS_SWAPFILE(inode)) |
876bec6f DW |
1661 | return -ETXTBSY; |
1662 | ||
f6f7a25a | 1663 | if (!*count) |
407e9c63 | 1664 | return 0; |
5de4480a | 1665 | |
407e9c63 DW |
1666 | if (iocb->ki_flags & IOCB_APPEND) |
1667 | iocb->ki_pos = i_size_read(inode); | |
1b4f42a1 | 1668 | |
80175539 SR |
1669 | if ((iocb->ki_flags & IOCB_NOWAIT) && |
1670 | !((iocb->ki_flags & IOCB_DIRECT) || | |
1671 | (file->f_mode & FMODE_BUF_WASYNC))) | |
407e9c63 | 1672 | return -EINVAL; |
1b4f42a1 | 1673 | |
f6f7a25a OS |
1674 | return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); |
1675 | } | |
1676 | EXPORT_SYMBOL(generic_write_checks_count); | |
1677 | ||
1678 | /* | |
1679 | * Performs necessary checks before doing a write | |
1680 | * | |
1681 | * Can adjust writing position or amount of bytes to write. | |
1682 | * Returns appropriate error code that caller should return or | |
1683 | * zero in case that write should be allowed. | |
1684 | */ | |
1685 | ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) | |
1686 | { | |
1687 | loff_t count = iov_iter_count(from); | |
1688 | int ret; | |
1689 | ||
1690 | ret = generic_write_checks_count(iocb, &count); | |
1b4f42a1 MS |
1691 | if (ret) |
1692 | return ret; | |
1693 | ||
407e9c63 DW |
1694 | iov_iter_truncate(from, count); |
1695 | return iov_iter_count(from); | |
1b4f42a1 | 1696 | } |
407e9c63 | 1697 | EXPORT_SYMBOL(generic_write_checks); |
1b4f42a1 | 1698 | |
407e9c63 DW |
1699 | /* |
1700 | * Performs common checks before doing a file copy/clone | |
1701 | * from @file_in to @file_out. | |
1702 | */ | |
1703 | int generic_file_rw_checks(struct file *file_in, struct file *file_out) | |
54dbc151 | 1704 | { |
407e9c63 DW |
1705 | struct inode *inode_in = file_inode(file_in); |
1706 | struct inode *inode_out = file_inode(file_out); | |
54dbc151 | 1707 | |
407e9c63 DW |
1708 | /* Don't copy dirs, pipes, sockets... */ |
1709 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
494633fa | 1710 | return -EISDIR; |
407e9c63 | 1711 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) |
22725ce4 DW |
1712 | return -EINVAL; |
1713 | ||
407e9c63 DW |
1714 | if (!(file_in->f_mode & FMODE_READ) || |
1715 | !(file_out->f_mode & FMODE_WRITE) || | |
1716 | (file_out->f_flags & O_APPEND)) | |
1717 | return -EBADF; | |
1b4f42a1 | 1718 | |
407e9c63 | 1719 | return 0; |
54dbc151 | 1720 | } |