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, |
534f2aaa | 32 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
33 | }; |
34 | ||
35 | EXPORT_SYMBOL(generic_ro_fops); | |
36 | ||
ddef7ed2 | 37 | static inline bool unsigned_offsets(struct file *file) |
4a3956c7 | 38 | { |
cccb5a1e | 39 | return file->f_mode & FMODE_UNSIGNED_OFFSET; |
4a3956c7 KH |
40 | } |
41 | ||
46a1c2c7 JL |
42 | /** |
43 | * vfs_setpos - update the file offset for lseek | |
44 | * @file: file structure in question | |
45 | * @offset: file offset to seek to | |
46 | * @maxsize: maximum file size | |
47 | * | |
48 | * This is a low-level filesystem helper for updating the file offset to | |
49 | * the value specified by @offset if the given offset is valid and it is | |
50 | * not equal to the current file offset. | |
51 | * | |
52 | * Return the specified offset on success and -EINVAL on invalid offset. | |
53 | */ | |
54 | loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) | |
ef3d0fd2 AK |
55 | { |
56 | if (offset < 0 && !unsigned_offsets(file)) | |
57 | return -EINVAL; | |
58 | if (offset > maxsize) | |
59 | return -EINVAL; | |
60 | ||
61 | if (offset != file->f_pos) { | |
62 | file->f_pos = offset; | |
63 | file->f_version = 0; | |
64 | } | |
65 | return offset; | |
66 | } | |
46a1c2c7 | 67 | EXPORT_SYMBOL(vfs_setpos); |
ef3d0fd2 | 68 | |
3a8cff4f | 69 | /** |
5760495a | 70 | * generic_file_llseek_size - generic llseek implementation for regular files |
3a8cff4f CH |
71 | * @file: file structure to seek on |
72 | * @offset: file offset to seek to | |
965c8e59 | 73 | * @whence: type of seek |
e8b96eb5 ES |
74 | * @size: max size of this file in file system |
75 | * @eof: offset used for SEEK_END position | |
3a8cff4f | 76 | * |
5760495a | 77 | * This is a variant of generic_file_llseek that allows passing in a custom |
e8b96eb5 | 78 | * maximum file size and a custom EOF position, for e.g. hashed directories |
ef3d0fd2 AK |
79 | * |
80 | * Synchronization: | |
5760495a | 81 | * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) |
ef3d0fd2 AK |
82 | * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. |
83 | * read/writes behave like SEEK_SET against seeks. | |
3a8cff4f | 84 | */ |
9465efc9 | 85 | loff_t |
965c8e59 | 86 | generic_file_llseek_size(struct file *file, loff_t offset, int whence, |
e8b96eb5 | 87 | loff_t maxsize, loff_t eof) |
1da177e4 | 88 | { |
965c8e59 | 89 | switch (whence) { |
3a8cff4f | 90 | case SEEK_END: |
e8b96eb5 | 91 | offset += eof; |
3a8cff4f CH |
92 | break; |
93 | case SEEK_CUR: | |
5b6f1eb9 AK |
94 | /* |
95 | * Here we special-case the lseek(fd, 0, SEEK_CUR) | |
96 | * position-querying operation. Avoid rewriting the "same" | |
97 | * f_pos value back to the file because a concurrent read(), | |
98 | * write() or lseek() might have altered it | |
99 | */ | |
100 | if (offset == 0) | |
101 | return file->f_pos; | |
ef3d0fd2 AK |
102 | /* |
103 | * f_lock protects against read/modify/write race with other | |
104 | * SEEK_CURs. Note that parallel writes and reads behave | |
105 | * like SEEK_SET. | |
106 | */ | |
107 | spin_lock(&file->f_lock); | |
46a1c2c7 | 108 | offset = vfs_setpos(file, file->f_pos + offset, maxsize); |
ef3d0fd2 AK |
109 | spin_unlock(&file->f_lock); |
110 | return offset; | |
982d8165 JB |
111 | case SEEK_DATA: |
112 | /* | |
113 | * In the generic case the entire file is data, so as long as | |
114 | * offset isn't at the end of the file then the offset is data. | |
115 | */ | |
fc46820b | 116 | if ((unsigned long long)offset >= eof) |
982d8165 JB |
117 | return -ENXIO; |
118 | break; | |
119 | case SEEK_HOLE: | |
120 | /* | |
121 | * There is a virtual hole at the end of the file, so as long as | |
122 | * offset isn't i_size or larger, return i_size. | |
123 | */ | |
fc46820b | 124 | if ((unsigned long long)offset >= eof) |
982d8165 | 125 | return -ENXIO; |
e8b96eb5 | 126 | offset = eof; |
982d8165 | 127 | break; |
1da177e4 | 128 | } |
3a8cff4f | 129 | |
46a1c2c7 | 130 | return vfs_setpos(file, offset, maxsize); |
5760495a AK |
131 | } |
132 | EXPORT_SYMBOL(generic_file_llseek_size); | |
133 | ||
134 | /** | |
135 | * generic_file_llseek - generic llseek implementation for regular files | |
136 | * @file: file structure to seek on | |
137 | * @offset: file offset to seek to | |
965c8e59 | 138 | * @whence: type of seek |
5760495a AK |
139 | * |
140 | * This is a generic implemenation of ->llseek useable for all normal local | |
141 | * filesystems. It just updates the file offset to the value specified by | |
546ae2d2 | 142 | * @offset and @whence. |
5760495a | 143 | */ |
965c8e59 | 144 | loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) |
5760495a AK |
145 | { |
146 | struct inode *inode = file->f_mapping->host; | |
147 | ||
965c8e59 | 148 | return generic_file_llseek_size(file, offset, whence, |
e8b96eb5 ES |
149 | inode->i_sb->s_maxbytes, |
150 | i_size_read(inode)); | |
1da177e4 | 151 | } |
9465efc9 | 152 | EXPORT_SYMBOL(generic_file_llseek); |
1da177e4 | 153 | |
1bf9d14d AV |
154 | /** |
155 | * fixed_size_llseek - llseek implementation for fixed-sized devices | |
156 | * @file: file structure to seek on | |
157 | * @offset: file offset to seek to | |
158 | * @whence: type of seek | |
159 | * @size: size of the file | |
160 | * | |
161 | */ | |
162 | loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) | |
163 | { | |
164 | switch (whence) { | |
165 | case SEEK_SET: case SEEK_CUR: case SEEK_END: | |
166 | return generic_file_llseek_size(file, offset, whence, | |
167 | size, size); | |
168 | default: | |
169 | return -EINVAL; | |
170 | } | |
171 | } | |
172 | EXPORT_SYMBOL(fixed_size_llseek); | |
173 | ||
b25472f9 AV |
174 | /** |
175 | * no_seek_end_llseek - llseek implementation for fixed-sized devices | |
176 | * @file: file structure to seek on | |
177 | * @offset: file offset to seek to | |
178 | * @whence: type of seek | |
179 | * | |
180 | */ | |
181 | loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) | |
182 | { | |
183 | switch (whence) { | |
184 | case SEEK_SET: case SEEK_CUR: | |
185 | return generic_file_llseek_size(file, offset, whence, | |
2feb55f8 | 186 | OFFSET_MAX, 0); |
b25472f9 AV |
187 | default: |
188 | return -EINVAL; | |
189 | } | |
190 | } | |
191 | EXPORT_SYMBOL(no_seek_end_llseek); | |
192 | ||
193 | /** | |
194 | * no_seek_end_llseek_size - llseek implementation for fixed-sized devices | |
195 | * @file: file structure to seek on | |
196 | * @offset: file offset to seek to | |
197 | * @whence: type of seek | |
198 | * @size: maximal offset allowed | |
199 | * | |
200 | */ | |
201 | loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size) | |
202 | { | |
203 | switch (whence) { | |
204 | case SEEK_SET: case SEEK_CUR: | |
205 | return generic_file_llseek_size(file, offset, whence, | |
206 | size, 0); | |
207 | default: | |
208 | return -EINVAL; | |
209 | } | |
210 | } | |
211 | EXPORT_SYMBOL(no_seek_end_llseek_size); | |
212 | ||
ae6afc3f B |
213 | /** |
214 | * noop_llseek - No Operation Performed llseek implementation | |
215 | * @file: file structure to seek on | |
216 | * @offset: file offset to seek to | |
965c8e59 | 217 | * @whence: type of seek |
ae6afc3f B |
218 | * |
219 | * This is an implementation of ->llseek useable for the rare special case when | |
220 | * userspace expects the seek to succeed but the (device) file is actually not | |
221 | * able to perform the seek. In this case you use noop_llseek() instead of | |
222 | * falling back to the default implementation of ->llseek. | |
223 | */ | |
965c8e59 | 224 | loff_t noop_llseek(struct file *file, loff_t offset, int whence) |
ae6afc3f B |
225 | { |
226 | return file->f_pos; | |
227 | } | |
228 | EXPORT_SYMBOL(noop_llseek); | |
229 | ||
965c8e59 | 230 | loff_t no_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
231 | { |
232 | return -ESPIPE; | |
233 | } | |
234 | EXPORT_SYMBOL(no_llseek); | |
235 | ||
965c8e59 | 236 | loff_t default_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 237 | { |
496ad9aa | 238 | struct inode *inode = file_inode(file); |
16abef0e | 239 | loff_t retval; |
1da177e4 | 240 | |
5955102c | 241 | inode_lock(inode); |
965c8e59 | 242 | switch (whence) { |
7b8e8924 | 243 | case SEEK_END: |
982d8165 | 244 | offset += i_size_read(inode); |
1da177e4 | 245 | break; |
7b8e8924 | 246 | case SEEK_CUR: |
5b6f1eb9 AK |
247 | if (offset == 0) { |
248 | retval = file->f_pos; | |
249 | goto out; | |
250 | } | |
1da177e4 | 251 | offset += file->f_pos; |
982d8165 JB |
252 | break; |
253 | case SEEK_DATA: | |
254 | /* | |
255 | * In the generic case the entire file is data, so as | |
256 | * long as offset isn't at the end of the file then the | |
257 | * offset is data. | |
258 | */ | |
bacb2d81 DC |
259 | if (offset >= inode->i_size) { |
260 | retval = -ENXIO; | |
261 | goto out; | |
262 | } | |
982d8165 JB |
263 | break; |
264 | case SEEK_HOLE: | |
265 | /* | |
266 | * There is a virtual hole at the end of the file, so | |
267 | * as long as offset isn't i_size or larger, return | |
268 | * i_size. | |
269 | */ | |
bacb2d81 DC |
270 | if (offset >= inode->i_size) { |
271 | retval = -ENXIO; | |
272 | goto out; | |
273 | } | |
982d8165 JB |
274 | offset = inode->i_size; |
275 | break; | |
1da177e4 LT |
276 | } |
277 | retval = -EINVAL; | |
cccb5a1e | 278 | if (offset >= 0 || unsigned_offsets(file)) { |
1da177e4 LT |
279 | if (offset != file->f_pos) { |
280 | file->f_pos = offset; | |
281 | file->f_version = 0; | |
282 | } | |
283 | retval = offset; | |
284 | } | |
5b6f1eb9 | 285 | out: |
5955102c | 286 | inode_unlock(inode); |
1da177e4 LT |
287 | return retval; |
288 | } | |
289 | EXPORT_SYMBOL(default_llseek); | |
290 | ||
965c8e59 | 291 | loff_t vfs_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
292 | { |
293 | loff_t (*fn)(struct file *, loff_t, int); | |
294 | ||
295 | fn = no_llseek; | |
296 | if (file->f_mode & FMODE_LSEEK) { | |
72c2d531 | 297 | if (file->f_op->llseek) |
1da177e4 LT |
298 | fn = file->f_op->llseek; |
299 | } | |
965c8e59 | 300 | return fn(file, offset, whence); |
1da177e4 LT |
301 | } |
302 | EXPORT_SYMBOL(vfs_llseek); | |
303 | ||
76847e43 | 304 | off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) |
1da177e4 LT |
305 | { |
306 | off_t retval; | |
9c225f26 | 307 | struct fd f = fdget_pos(fd); |
2903ff01 AV |
308 | if (!f.file) |
309 | return -EBADF; | |
1da177e4 LT |
310 | |
311 | retval = -EINVAL; | |
965c8e59 AM |
312 | if (whence <= SEEK_MAX) { |
313 | loff_t res = vfs_llseek(f.file, offset, whence); | |
1da177e4 LT |
314 | retval = res; |
315 | if (res != (loff_t)retval) | |
316 | retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ | |
317 | } | |
9c225f26 | 318 | fdput_pos(f); |
1da177e4 LT |
319 | return retval; |
320 | } | |
321 | ||
76847e43 DB |
322 | SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) |
323 | { | |
324 | return ksys_lseek(fd, offset, whence); | |
325 | } | |
326 | ||
561c6731 AV |
327 | #ifdef CONFIG_COMPAT |
328 | COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) | |
329 | { | |
76847e43 | 330 | return ksys_lseek(fd, offset, whence); |
561c6731 AV |
331 | } |
332 | #endif | |
333 | ||
1da177e4 | 334 | #ifdef __ARCH_WANT_SYS_LLSEEK |
003d7ab4 HC |
335 | SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, |
336 | unsigned long, offset_low, loff_t __user *, result, | |
965c8e59 | 337 | unsigned int, whence) |
1da177e4 LT |
338 | { |
339 | int retval; | |
d7a15f8d | 340 | struct fd f = fdget_pos(fd); |
1da177e4 | 341 | loff_t offset; |
1da177e4 | 342 | |
2903ff01 AV |
343 | if (!f.file) |
344 | return -EBADF; | |
1da177e4 LT |
345 | |
346 | retval = -EINVAL; | |
965c8e59 | 347 | if (whence > SEEK_MAX) |
1da177e4 LT |
348 | goto out_putf; |
349 | ||
2903ff01 | 350 | offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low, |
965c8e59 | 351 | whence); |
1da177e4 LT |
352 | |
353 | retval = (int)offset; | |
354 | if (offset >= 0) { | |
355 | retval = -EFAULT; | |
356 | if (!copy_to_user(result, &offset, sizeof(offset))) | |
357 | retval = 0; | |
358 | } | |
359 | out_putf: | |
d7a15f8d | 360 | fdput_pos(f); |
1da177e4 LT |
361 | return retval; |
362 | } | |
363 | #endif | |
364 | ||
68d70d03 | 365 | int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) |
1da177e4 LT |
366 | { |
367 | struct inode *inode; | |
368 | loff_t pos; | |
c43e259c | 369 | int retval = -EINVAL; |
1da177e4 | 370 | |
496ad9aa | 371 | inode = file_inode(file); |
e28cc715 | 372 | if (unlikely((ssize_t) count < 0)) |
c43e259c | 373 | return retval; |
1da177e4 | 374 | pos = *ppos; |
cccb5a1e AV |
375 | if (unlikely(pos < 0)) { |
376 | if (!unsigned_offsets(file)) | |
377 | return retval; | |
378 | if (count >= -pos) /* both values are in 0..LLONG_MAX */ | |
379 | return -EOVERFLOW; | |
380 | } else if (unlikely((loff_t) (pos + count) < 0)) { | |
381 | if (!unsigned_offsets(file)) | |
4a3956c7 KH |
382 | return retval; |
383 | } | |
1da177e4 | 384 | |
bd61e0a9 | 385 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { |
acc15575 CH |
386 | retval = locks_mandatory_area(inode, file, pos, pos + count - 1, |
387 | read_write == READ ? F_RDLCK : F_WRLCK); | |
e28cc715 LT |
388 | if (retval < 0) |
389 | return retval; | |
390 | } | |
bc61384d | 391 | return security_file_permission(file, |
c43e259c | 392 | read_write == READ ? MAY_READ : MAY_WRITE); |
1da177e4 LT |
393 | } |
394 | ||
5d5d5689 | 395 | static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
396 | { |
397 | struct iovec iov = { .iov_base = buf, .iov_len = len }; | |
398 | struct kiocb kiocb; | |
399 | struct iov_iter iter; | |
400 | ssize_t ret; | |
401 | ||
402 | init_sync_kiocb(&kiocb, filp); | |
403 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
404 | iov_iter_init(&iter, READ, &iov, 1, len); |
405 | ||
bb7462b6 | 406 | ret = call_read_iter(filp, &kiocb, &iter); |
599bd19b | 407 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
408 | *ppos = kiocb.ki_pos; |
409 | return ret; | |
410 | } | |
411 | ||
6fb5032e DK |
412 | ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
413 | loff_t *pos) | |
414 | { | |
6fb5032e | 415 | if (file->f_op->read) |
3d04c8a1 | 416 | return file->f_op->read(file, buf, count, pos); |
6fb5032e | 417 | else if (file->f_op->read_iter) |
3d04c8a1 | 418 | return new_sync_read(file, buf, count, pos); |
6fb5032e | 419 | else |
3d04c8a1 | 420 | return -EINVAL; |
6fb5032e DK |
421 | } |
422 | ||
bdd1d2d3 | 423 | ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
c41fbad0 CH |
424 | { |
425 | mm_segment_t old_fs; | |
bdd1d2d3 | 426 | ssize_t result; |
c41fbad0 CH |
427 | |
428 | old_fs = get_fs(); | |
429 | set_fs(get_ds()); | |
430 | /* The cast to a user pointer is valid due to the set_fs() */ | |
bdd1d2d3 | 431 | result = vfs_read(file, (void __user *)buf, count, pos); |
c41fbad0 CH |
432 | set_fs(old_fs); |
433 | return result; | |
434 | } | |
435 | EXPORT_SYMBOL(kernel_read); | |
6fb5032e | 436 | |
1da177e4 LT |
437 | ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
438 | { | |
439 | ssize_t ret; | |
440 | ||
441 | if (!(file->f_mode & FMODE_READ)) | |
442 | return -EBADF; | |
7f7f25e8 | 443 | if (!(file->f_mode & FMODE_CAN_READ)) |
1da177e4 LT |
444 | return -EINVAL; |
445 | if (unlikely(!access_ok(VERIFY_WRITE, buf, count))) | |
446 | return -EFAULT; | |
447 | ||
448 | ret = rw_verify_area(READ, file, pos, count); | |
bc61384d AV |
449 | if (!ret) { |
450 | if (count > MAX_RW_COUNT) | |
451 | count = MAX_RW_COUNT; | |
6fb5032e | 452 | ret = __vfs_read(file, buf, count, pos); |
c43e259c | 453 | if (ret > 0) { |
2a12a9d7 | 454 | fsnotify_access(file); |
c43e259c | 455 | add_rchar(current, ret); |
1da177e4 | 456 | } |
c43e259c | 457 | inc_syscr(current); |
1da177e4 LT |
458 | } |
459 | ||
460 | return ret; | |
461 | } | |
462 | ||
5d5d5689 | 463 | static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) |
293bc982 AV |
464 | { |
465 | struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len }; | |
466 | struct kiocb kiocb; | |
467 | struct iov_iter iter; | |
468 | ssize_t ret; | |
469 | ||
470 | init_sync_kiocb(&kiocb, filp); | |
471 | kiocb.ki_pos = *ppos; | |
293bc982 AV |
472 | iov_iter_init(&iter, WRITE, &iov, 1, len); |
473 | ||
bb7462b6 | 474 | ret = call_write_iter(filp, &kiocb, &iter); |
599bd19b | 475 | BUG_ON(ret == -EIOCBQUEUED); |
f765b134 AV |
476 | if (ret > 0) |
477 | *ppos = kiocb.ki_pos; | |
293bc982 AV |
478 | return ret; |
479 | } | |
480 | ||
493c84c0 AV |
481 | ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, |
482 | loff_t *pos) | |
483 | { | |
484 | if (file->f_op->write) | |
485 | return file->f_op->write(file, p, count, pos); | |
493c84c0 AV |
486 | else if (file->f_op->write_iter) |
487 | return new_sync_write(file, p, count, pos); | |
488 | else | |
489 | return -EINVAL; | |
490 | } | |
493c84c0 | 491 | |
73e18f7c | 492 | ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) |
06ae43f3 AV |
493 | { |
494 | mm_segment_t old_fs; | |
495 | const char __user *p; | |
496 | ssize_t ret; | |
497 | ||
7f7f25e8 | 498 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
3e84f48e AV |
499 | return -EINVAL; |
500 | ||
06ae43f3 AV |
501 | old_fs = get_fs(); |
502 | set_fs(get_ds()); | |
503 | p = (__force const char __user *)buf; | |
504 | if (count > MAX_RW_COUNT) | |
505 | count = MAX_RW_COUNT; | |
493c84c0 | 506 | ret = __vfs_write(file, p, count, pos); |
06ae43f3 AV |
507 | set_fs(old_fs); |
508 | if (ret > 0) { | |
509 | fsnotify_modify(file); | |
510 | add_wchar(current, ret); | |
511 | } | |
512 | inc_syscw(current); | |
513 | return ret; | |
514 | } | |
2ec3a12a AV |
515 | EXPORT_SYMBOL(__kernel_write); |
516 | ||
e13ec939 CH |
517 | ssize_t kernel_write(struct file *file, const void *buf, size_t count, |
518 | loff_t *pos) | |
ac452aca CH |
519 | { |
520 | mm_segment_t old_fs; | |
521 | ssize_t res; | |
522 | ||
523 | old_fs = get_fs(); | |
524 | set_fs(get_ds()); | |
525 | /* The cast to a user pointer is valid due to the set_fs() */ | |
e13ec939 | 526 | res = vfs_write(file, (__force const char __user *)buf, count, pos); |
ac452aca CH |
527 | set_fs(old_fs); |
528 | ||
529 | return res; | |
530 | } | |
531 | EXPORT_SYMBOL(kernel_write); | |
532 | ||
1da177e4 LT |
533 | ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
534 | { | |
535 | ssize_t ret; | |
536 | ||
537 | if (!(file->f_mode & FMODE_WRITE)) | |
538 | return -EBADF; | |
7f7f25e8 | 539 | if (!(file->f_mode & FMODE_CAN_WRITE)) |
1da177e4 LT |
540 | return -EINVAL; |
541 | if (unlikely(!access_ok(VERIFY_READ, buf, count))) | |
542 | return -EFAULT; | |
543 | ||
544 | ret = rw_verify_area(WRITE, file, pos, count); | |
bc61384d AV |
545 | if (!ret) { |
546 | if (count > MAX_RW_COUNT) | |
547 | count = MAX_RW_COUNT; | |
03d95eb2 | 548 | file_start_write(file); |
493c84c0 | 549 | ret = __vfs_write(file, buf, count, pos); |
c43e259c | 550 | if (ret > 0) { |
2a12a9d7 | 551 | fsnotify_modify(file); |
c43e259c | 552 | add_wchar(current, ret); |
1da177e4 | 553 | } |
c43e259c | 554 | inc_syscw(current); |
03d95eb2 | 555 | file_end_write(file); |
1da177e4 LT |
556 | } |
557 | ||
558 | return ret; | |
559 | } | |
560 | ||
1da177e4 LT |
561 | static inline loff_t file_pos_read(struct file *file) |
562 | { | |
563 | return file->f_pos; | |
564 | } | |
565 | ||
566 | static inline void file_pos_write(struct file *file, loff_t pos) | |
567 | { | |
568 | file->f_pos = pos; | |
569 | } | |
570 | ||
3cdad428 | 571 | SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) |
1da177e4 | 572 | { |
9c225f26 | 573 | struct fd f = fdget_pos(fd); |
1da177e4 | 574 | ssize_t ret = -EBADF; |
1da177e4 | 575 | |
2903ff01 AV |
576 | if (f.file) { |
577 | loff_t pos = file_pos_read(f.file); | |
578 | ret = vfs_read(f.file, buf, count, &pos); | |
5faf153e AV |
579 | if (ret >= 0) |
580 | file_pos_write(f.file, pos); | |
9c225f26 | 581 | fdput_pos(f); |
1da177e4 | 582 | } |
1da177e4 LT |
583 | return ret; |
584 | } | |
1da177e4 | 585 | |
e7a3e8b2 | 586 | ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) |
1da177e4 | 587 | { |
9c225f26 | 588 | struct fd f = fdget_pos(fd); |
1da177e4 | 589 | ssize_t ret = -EBADF; |
1da177e4 | 590 | |
2903ff01 AV |
591 | if (f.file) { |
592 | loff_t pos = file_pos_read(f.file); | |
593 | ret = vfs_write(f.file, buf, count, &pos); | |
5faf153e AV |
594 | if (ret >= 0) |
595 | file_pos_write(f.file, pos); | |
9c225f26 | 596 | fdput_pos(f); |
1da177e4 LT |
597 | } |
598 | ||
599 | return ret; | |
600 | } | |
601 | ||
e7a3e8b2 DB |
602 | SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, |
603 | size_t, count) | |
604 | { | |
605 | return ksys_write(fd, buf, count); | |
606 | } | |
607 | ||
4a0fd5bf AV |
608 | SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, |
609 | size_t, count, loff_t, pos) | |
1da177e4 | 610 | { |
2903ff01 | 611 | struct fd f; |
1da177e4 | 612 | ssize_t ret = -EBADF; |
1da177e4 LT |
613 | |
614 | if (pos < 0) | |
615 | return -EINVAL; | |
616 | ||
2903ff01 AV |
617 | f = fdget(fd); |
618 | if (f.file) { | |
1da177e4 | 619 | ret = -ESPIPE; |
2903ff01 AV |
620 | if (f.file->f_mode & FMODE_PREAD) |
621 | ret = vfs_read(f.file, buf, count, &pos); | |
622 | fdput(f); | |
1da177e4 LT |
623 | } |
624 | ||
625 | return ret; | |
626 | } | |
627 | ||
4a0fd5bf AV |
628 | SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, |
629 | size_t, count, loff_t, pos) | |
1da177e4 | 630 | { |
2903ff01 | 631 | struct fd f; |
1da177e4 | 632 | ssize_t ret = -EBADF; |
1da177e4 LT |
633 | |
634 | if (pos < 0) | |
635 | return -EINVAL; | |
636 | ||
2903ff01 AV |
637 | f = fdget(fd); |
638 | if (f.file) { | |
1da177e4 | 639 | ret = -ESPIPE; |
2903ff01 AV |
640 | if (f.file->f_mode & FMODE_PWRITE) |
641 | ret = vfs_write(f.file, buf, count, &pos); | |
642 | fdput(f); | |
1da177e4 LT |
643 | } |
644 | ||
645 | return ret; | |
646 | } | |
647 | ||
ac15ac06 | 648 | static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 649 | loff_t *ppos, int type, rwf_t flags) |
293bc982 AV |
650 | { |
651 | struct kiocb kiocb; | |
293bc982 AV |
652 | ssize_t ret; |
653 | ||
654 | init_sync_kiocb(&kiocb, filp); | |
fdd2f5b7 GR |
655 | ret = kiocb_set_rw_flags(&kiocb, flags); |
656 | if (ret) | |
657 | return ret; | |
293bc982 | 658 | kiocb.ki_pos = *ppos; |
293bc982 | 659 | |
0f78d06a | 660 | if (type == READ) |
bb7462b6 | 661 | ret = call_read_iter(filp, &kiocb, iter); |
0f78d06a | 662 | else |
bb7462b6 | 663 | ret = call_write_iter(filp, &kiocb, iter); |
599bd19b | 664 | BUG_ON(ret == -EIOCBQUEUED); |
293bc982 AV |
665 | *ppos = kiocb.ki_pos; |
666 | return ret; | |
667 | } | |
668 | ||
ee0b3e67 | 669 | /* Do it by hand, with file-ops */ |
ac15ac06 | 670 | static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, |
ddef7ed2 | 671 | loff_t *ppos, int type, rwf_t flags) |
ee0b3e67 | 672 | { |
ee0b3e67 BP |
673 | ssize_t ret = 0; |
674 | ||
97be7ebe | 675 | if (flags & ~RWF_HIPRI) |
793b80ef CH |
676 | return -EOPNOTSUPP; |
677 | ||
ac15ac06 AV |
678 | while (iov_iter_count(iter)) { |
679 | struct iovec iovec = iov_iter_iovec(iter); | |
ee0b3e67 BP |
680 | ssize_t nr; |
681 | ||
0f78d06a MS |
682 | if (type == READ) { |
683 | nr = filp->f_op->read(filp, iovec.iov_base, | |
684 | iovec.iov_len, ppos); | |
685 | } else { | |
686 | nr = filp->f_op->write(filp, iovec.iov_base, | |
687 | iovec.iov_len, ppos); | |
688 | } | |
ee0b3e67 BP |
689 | |
690 | if (nr < 0) { | |
691 | if (!ret) | |
692 | ret = nr; | |
693 | break; | |
694 | } | |
695 | ret += nr; | |
ac15ac06 | 696 | if (nr != iovec.iov_len) |
ee0b3e67 | 697 | break; |
ac15ac06 | 698 | iov_iter_advance(iter, nr); |
ee0b3e67 BP |
699 | } |
700 | ||
701 | return ret; | |
702 | } | |
703 | ||
1da177e4 LT |
704 | /* A write operation does a read from user space and vice versa */ |
705 | #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) | |
706 | ||
ffecee4f VN |
707 | /** |
708 | * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace | |
709 | * into the kernel and check that it is valid. | |
710 | * | |
711 | * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE. | |
712 | * @uvector: Pointer to the userspace array. | |
713 | * @nr_segs: Number of elements in userspace array. | |
714 | * @fast_segs: Number of elements in @fast_pointer. | |
715 | * @fast_pointer: Pointer to (usually small on-stack) kernel array. | |
716 | * @ret_pointer: (output parameter) Pointer to a variable that will point to | |
717 | * either @fast_pointer, a newly allocated kernel array, or NULL, | |
718 | * depending on which array was used. | |
719 | * | |
720 | * This function copies an array of &struct iovec of @nr_segs from | |
721 | * userspace into the kernel and checks that each element is valid (e.g. | |
722 | * it does not point to a kernel address or cause overflow by being too | |
723 | * large, etc.). | |
724 | * | |
725 | * As an optimization, the caller may provide a pointer to a small | |
726 | * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long | |
727 | * (the size of this array, or 0 if unused, should be given in @fast_segs). | |
728 | * | |
729 | * @ret_pointer will always point to the array that was used, so the | |
730 | * caller must take care not to call kfree() on it e.g. in case the | |
731 | * @fast_pointer array was used and it was allocated on the stack. | |
732 | * | |
733 | * Return: The total number of bytes covered by the iovec array on success | |
734 | * or a negative error code on error. | |
735 | */ | |
eed4e51f BP |
736 | ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, |
737 | unsigned long nr_segs, unsigned long fast_segs, | |
738 | struct iovec *fast_pointer, | |
ac34ebb3 | 739 | struct iovec **ret_pointer) |
435f49a5 | 740 | { |
eed4e51f | 741 | unsigned long seg; |
435f49a5 | 742 | ssize_t ret; |
eed4e51f BP |
743 | struct iovec *iov = fast_pointer; |
744 | ||
435f49a5 LT |
745 | /* |
746 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
747 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
748 | * traditionally returned zero for zero segments, so... | |
749 | */ | |
eed4e51f BP |
750 | if (nr_segs == 0) { |
751 | ret = 0; | |
435f49a5 | 752 | goto out; |
eed4e51f BP |
753 | } |
754 | ||
435f49a5 LT |
755 | /* |
756 | * First get the "struct iovec" from user memory and | |
757 | * verify all the pointers | |
758 | */ | |
eed4e51f BP |
759 | if (nr_segs > UIO_MAXIOV) { |
760 | ret = -EINVAL; | |
435f49a5 | 761 | goto out; |
eed4e51f BP |
762 | } |
763 | if (nr_segs > fast_segs) { | |
435f49a5 | 764 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
eed4e51f BP |
765 | if (iov == NULL) { |
766 | ret = -ENOMEM; | |
435f49a5 | 767 | goto out; |
eed4e51f | 768 | } |
435f49a5 | 769 | } |
eed4e51f BP |
770 | if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { |
771 | ret = -EFAULT; | |
435f49a5 | 772 | goto out; |
eed4e51f BP |
773 | } |
774 | ||
435f49a5 | 775 | /* |
eed4e51f BP |
776 | * According to the Single Unix Specification we should return EINVAL |
777 | * if an element length is < 0 when cast to ssize_t or if the | |
778 | * total length would overflow the ssize_t return value of the | |
779 | * system call. | |
435f49a5 LT |
780 | * |
781 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
782 | * overflow case. | |
783 | */ | |
eed4e51f | 784 | ret = 0; |
435f49a5 LT |
785 | for (seg = 0; seg < nr_segs; seg++) { |
786 | void __user *buf = iov[seg].iov_base; | |
787 | ssize_t len = (ssize_t)iov[seg].iov_len; | |
eed4e51f BP |
788 | |
789 | /* see if we we're about to use an invalid len or if | |
790 | * it's about to overflow ssize_t */ | |
435f49a5 | 791 | if (len < 0) { |
eed4e51f | 792 | ret = -EINVAL; |
435f49a5 | 793 | goto out; |
eed4e51f | 794 | } |
ac34ebb3 | 795 | if (type >= 0 |
fcf63409 | 796 | && unlikely(!access_ok(vrfy_dir(type), buf, len))) { |
eed4e51f | 797 | ret = -EFAULT; |
435f49a5 LT |
798 | goto out; |
799 | } | |
800 | if (len > MAX_RW_COUNT - ret) { | |
801 | len = MAX_RW_COUNT - ret; | |
802 | iov[seg].iov_len = len; | |
eed4e51f | 803 | } |
eed4e51f | 804 | ret += len; |
435f49a5 | 805 | } |
eed4e51f BP |
806 | out: |
807 | *ret_pointer = iov; | |
808 | return ret; | |
809 | } | |
810 | ||
f5029855 AV |
811 | #ifdef CONFIG_COMPAT |
812 | ssize_t compat_rw_copy_check_uvector(int type, | |
813 | const struct compat_iovec __user *uvector, unsigned long nr_segs, | |
814 | unsigned long fast_segs, struct iovec *fast_pointer, | |
815 | struct iovec **ret_pointer) | |
816 | { | |
817 | compat_ssize_t tot_len; | |
818 | struct iovec *iov = *ret_pointer = fast_pointer; | |
819 | ssize_t ret = 0; | |
820 | int seg; | |
821 | ||
822 | /* | |
823 | * SuS says "The readv() function *may* fail if the iovcnt argument | |
824 | * was less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
825 | * traditionally returned zero for zero segments, so... | |
826 | */ | |
827 | if (nr_segs == 0) | |
828 | goto out; | |
829 | ||
830 | ret = -EINVAL; | |
831 | if (nr_segs > UIO_MAXIOV) | |
832 | goto out; | |
833 | if (nr_segs > fast_segs) { | |
834 | ret = -ENOMEM; | |
835 | iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); | |
836 | if (iov == NULL) | |
837 | goto out; | |
838 | } | |
839 | *ret_pointer = iov; | |
840 | ||
841 | ret = -EFAULT; | |
842 | if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) | |
843 | goto out; | |
844 | ||
845 | /* | |
846 | * Single unix specification: | |
847 | * We should -EINVAL if an element length is not >= 0 and fitting an | |
848 | * ssize_t. | |
849 | * | |
850 | * In Linux, the total length is limited to MAX_RW_COUNT, there is | |
851 | * no overflow possibility. | |
852 | */ | |
853 | tot_len = 0; | |
854 | ret = -EINVAL; | |
855 | for (seg = 0; seg < nr_segs; seg++) { | |
856 | compat_uptr_t buf; | |
857 | compat_ssize_t len; | |
858 | ||
859 | if (__get_user(len, &uvector->iov_len) || | |
860 | __get_user(buf, &uvector->iov_base)) { | |
861 | ret = -EFAULT; | |
862 | goto out; | |
863 | } | |
864 | if (len < 0) /* size_t not fitting in compat_ssize_t .. */ | |
865 | goto out; | |
866 | if (type >= 0 && | |
867 | !access_ok(vrfy_dir(type), compat_ptr(buf), len)) { | |
868 | ret = -EFAULT; | |
869 | goto out; | |
870 | } | |
871 | if (len > MAX_RW_COUNT - tot_len) | |
872 | len = MAX_RW_COUNT - tot_len; | |
873 | tot_len += len; | |
874 | iov->iov_base = compat_ptr(buf); | |
875 | iov->iov_len = (compat_size_t) len; | |
876 | uvector++; | |
877 | iov++; | |
878 | } | |
879 | ret = tot_len; | |
880 | ||
881 | out: | |
882 | return ret; | |
883 | } | |
884 | #endif | |
885 | ||
19c73586 | 886 | static ssize_t do_iter_read(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 887 | loff_t *pos, rwf_t flags) |
1da177e4 | 888 | { |
1da177e4 | 889 | size_t tot_len; |
7687a7a4 | 890 | ssize_t ret = 0; |
1da177e4 | 891 | |
edab5fe3 CH |
892 | if (!(file->f_mode & FMODE_READ)) |
893 | return -EBADF; | |
894 | if (!(file->f_mode & FMODE_CAN_READ)) | |
895 | return -EINVAL; | |
896 | ||
7687a7a4 | 897 | tot_len = iov_iter_count(iter); |
0504c074 AV |
898 | if (!tot_len) |
899 | goto out; | |
19c73586 | 900 | ret = rw_verify_area(READ, file, pos, tot_len); |
e28cc715 | 901 | if (ret < 0) |
19c73586 | 902 | return ret; |
1da177e4 | 903 | |
19c73586 CH |
904 | if (file->f_op->read_iter) |
905 | ret = do_iter_readv_writev(file, iter, pos, READ, flags); | |
ee0b3e67 | 906 | else |
19c73586 | 907 | ret = do_loop_readv_writev(file, iter, pos, READ, flags); |
1da177e4 | 908 | out: |
19c73586 CH |
909 | if (ret >= 0) |
910 | fsnotify_access(file); | |
1da177e4 | 911 | return ret; |
1da177e4 LT |
912 | } |
913 | ||
18e9710e | 914 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 915 | rwf_t flags) |
7687a7a4 | 916 | { |
18e9710e CH |
917 | if (!file->f_op->read_iter) |
918 | return -EINVAL; | |
919 | return do_iter_read(file, iter, ppos, flags); | |
920 | } | |
921 | EXPORT_SYMBOL(vfs_iter_read); | |
7687a7a4 | 922 | |
19c73586 | 923 | static ssize_t do_iter_write(struct file *file, struct iov_iter *iter, |
ddef7ed2 | 924 | loff_t *pos, rwf_t flags) |
19c73586 CH |
925 | { |
926 | size_t tot_len; | |
927 | ssize_t ret = 0; | |
03d95eb2 | 928 | |
edab5fe3 CH |
929 | if (!(file->f_mode & FMODE_WRITE)) |
930 | return -EBADF; | |
931 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
932 | return -EINVAL; | |
933 | ||
19c73586 CH |
934 | tot_len = iov_iter_count(iter); |
935 | if (!tot_len) | |
936 | return 0; | |
937 | ret = rw_verify_area(WRITE, file, pos, tot_len); | |
7687a7a4 MS |
938 | if (ret < 0) |
939 | return ret; | |
940 | ||
19c73586 CH |
941 | if (file->f_op->write_iter) |
942 | ret = do_iter_readv_writev(file, iter, pos, WRITE, flags); | |
943 | else | |
944 | ret = do_loop_readv_writev(file, iter, pos, WRITE, flags); | |
19c73586 CH |
945 | if (ret > 0) |
946 | fsnotify_modify(file); | |
7687a7a4 MS |
947 | return ret; |
948 | } | |
949 | ||
abbb6589 | 950 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
ddef7ed2 | 951 | rwf_t flags) |
abbb6589 CH |
952 | { |
953 | if (!file->f_op->write_iter) | |
954 | return -EINVAL; | |
955 | return do_iter_write(file, iter, ppos, flags); | |
956 | } | |
957 | EXPORT_SYMBOL(vfs_iter_write); | |
958 | ||
1da177e4 | 959 | ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 960 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 961 | { |
7687a7a4 MS |
962 | struct iovec iovstack[UIO_FASTIOV]; |
963 | struct iovec *iov = iovstack; | |
964 | struct iov_iter iter; | |
965 | ssize_t ret; | |
1da177e4 | 966 | |
251b42a1 | 967 | ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 CH |
968 | if (ret >= 0) { |
969 | ret = do_iter_read(file, &iter, pos, flags); | |
970 | kfree(iov); | |
971 | } | |
1da177e4 | 972 | |
251b42a1 CH |
973 | return ret; |
974 | } | |
1da177e4 | 975 | |
9725d4ce | 976 | static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, |
ddef7ed2 | 977 | unsigned long vlen, loff_t *pos, rwf_t flags) |
1da177e4 | 978 | { |
251b42a1 CH |
979 | struct iovec iovstack[UIO_FASTIOV]; |
980 | struct iovec *iov = iovstack; | |
981 | struct iov_iter iter; | |
982 | ssize_t ret; | |
1da177e4 | 983 | |
251b42a1 | 984 | ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter); |
edab5fe3 | 985 | if (ret >= 0) { |
62473a2d | 986 | file_start_write(file); |
edab5fe3 | 987 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 988 | file_end_write(file); |
edab5fe3 CH |
989 | kfree(iov); |
990 | } | |
251b42a1 | 991 | return ret; |
1da177e4 | 992 | } |
1da177e4 | 993 | |
f17d8b35 | 994 | static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 995 | unsigned long vlen, rwf_t flags) |
1da177e4 | 996 | { |
9c225f26 | 997 | struct fd f = fdget_pos(fd); |
1da177e4 | 998 | ssize_t ret = -EBADF; |
1da177e4 | 999 | |
2903ff01 AV |
1000 | if (f.file) { |
1001 | loff_t pos = file_pos_read(f.file); | |
f17d8b35 | 1002 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
5faf153e AV |
1003 | if (ret >= 0) |
1004 | file_pos_write(f.file, pos); | |
9c225f26 | 1005 | fdput_pos(f); |
1da177e4 LT |
1006 | } |
1007 | ||
1008 | if (ret > 0) | |
4b98d11b AD |
1009 | add_rchar(current, ret); |
1010 | inc_syscr(current); | |
1da177e4 LT |
1011 | return ret; |
1012 | } | |
1013 | ||
f17d8b35 | 1014 | static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1015 | unsigned long vlen, rwf_t flags) |
1da177e4 | 1016 | { |
9c225f26 | 1017 | struct fd f = fdget_pos(fd); |
1da177e4 | 1018 | ssize_t ret = -EBADF; |
1da177e4 | 1019 | |
2903ff01 AV |
1020 | if (f.file) { |
1021 | loff_t pos = file_pos_read(f.file); | |
f17d8b35 | 1022 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
5faf153e AV |
1023 | if (ret >= 0) |
1024 | file_pos_write(f.file, pos); | |
9c225f26 | 1025 | fdput_pos(f); |
1da177e4 LT |
1026 | } |
1027 | ||
1028 | if (ret > 0) | |
4b98d11b AD |
1029 | add_wchar(current, ret); |
1030 | inc_syscw(current); | |
1da177e4 LT |
1031 | return ret; |
1032 | } | |
1033 | ||
601cc11d LT |
1034 | static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) |
1035 | { | |
1036 | #define HALF_LONG_BITS (BITS_PER_LONG / 2) | |
1037 | return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; | |
1038 | } | |
1039 | ||
f17d8b35 | 1040 | static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1041 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1042 | { |
2903ff01 | 1043 | struct fd f; |
f3554f4b | 1044 | ssize_t ret = -EBADF; |
f3554f4b GH |
1045 | |
1046 | if (pos < 0) | |
1047 | return -EINVAL; | |
1048 | ||
2903ff01 AV |
1049 | f = fdget(fd); |
1050 | if (f.file) { | |
f3554f4b | 1051 | ret = -ESPIPE; |
2903ff01 | 1052 | if (f.file->f_mode & FMODE_PREAD) |
f17d8b35 | 1053 | ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1054 | fdput(f); |
f3554f4b GH |
1055 | } |
1056 | ||
1057 | if (ret > 0) | |
1058 | add_rchar(current, ret); | |
1059 | inc_syscr(current); | |
1060 | return ret; | |
1061 | } | |
1062 | ||
f17d8b35 | 1063 | static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, |
ddef7ed2 | 1064 | unsigned long vlen, loff_t pos, rwf_t flags) |
f3554f4b | 1065 | { |
2903ff01 | 1066 | struct fd f; |
f3554f4b | 1067 | ssize_t ret = -EBADF; |
f3554f4b GH |
1068 | |
1069 | if (pos < 0) | |
1070 | return -EINVAL; | |
1071 | ||
2903ff01 AV |
1072 | f = fdget(fd); |
1073 | if (f.file) { | |
f3554f4b | 1074 | ret = -ESPIPE; |
2903ff01 | 1075 | if (f.file->f_mode & FMODE_PWRITE) |
f17d8b35 | 1076 | ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
2903ff01 | 1077 | fdput(f); |
f3554f4b GH |
1078 | } |
1079 | ||
1080 | if (ret > 0) | |
1081 | add_wchar(current, ret); | |
1082 | inc_syscw(current); | |
1083 | return ret; | |
1084 | } | |
1085 | ||
f17d8b35 MT |
1086 | SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, |
1087 | unsigned long, vlen) | |
1088 | { | |
1089 | return do_readv(fd, vec, vlen, 0); | |
1090 | } | |
1091 | ||
1092 | SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, | |
1093 | unsigned long, vlen) | |
1094 | { | |
1095 | return do_writev(fd, vec, vlen, 0); | |
1096 | } | |
1097 | ||
1098 | SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, | |
1099 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1100 | { | |
1101 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1102 | ||
1103 | return do_preadv(fd, vec, vlen, pos, 0); | |
1104 | } | |
1105 | ||
1106 | SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, | |
1107 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1108 | rwf_t, flags) |
f17d8b35 MT |
1109 | { |
1110 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1111 | ||
1112 | if (pos == -1) | |
1113 | return do_readv(fd, vec, vlen, flags); | |
1114 | ||
1115 | return do_preadv(fd, vec, vlen, pos, flags); | |
1116 | } | |
1117 | ||
1118 | SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, | |
1119 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) | |
1120 | { | |
1121 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1122 | ||
1123 | return do_pwritev(fd, vec, vlen, pos, 0); | |
1124 | } | |
1125 | ||
1126 | SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, | |
1127 | unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, | |
ddef7ed2 | 1128 | rwf_t, flags) |
f17d8b35 MT |
1129 | { |
1130 | loff_t pos = pos_from_hilo(pos_h, pos_l); | |
1131 | ||
1132 | if (pos == -1) | |
1133 | return do_writev(fd, vec, vlen, flags); | |
1134 | ||
1135 | return do_pwritev(fd, vec, vlen, pos, flags); | |
1136 | } | |
1137 | ||
72ec3516 | 1138 | #ifdef CONFIG_COMPAT |
72ec3516 AV |
1139 | static size_t compat_readv(struct file *file, |
1140 | const struct compat_iovec __user *vec, | |
ddef7ed2 | 1141 | unsigned long vlen, loff_t *pos, rwf_t flags) |
72ec3516 | 1142 | { |
72ec3516 AV |
1143 | struct iovec iovstack[UIO_FASTIOV]; |
1144 | struct iovec *iov = iovstack; | |
ac15ac06 | 1145 | struct iov_iter iter; |
72ec3516 | 1146 | ssize_t ret; |
72ec3516 | 1147 | |
26c87fb7 | 1148 | ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter); |
edab5fe3 CH |
1149 | if (ret >= 0) { |
1150 | ret = do_iter_read(file, &iter, pos, flags); | |
1151 | kfree(iov); | |
1152 | } | |
72ec3516 AV |
1153 | if (ret > 0) |
1154 | add_rchar(current, ret); | |
1155 | inc_syscr(current); | |
1156 | return ret; | |
1157 | } | |
1158 | ||
f17d8b35 MT |
1159 | static size_t do_compat_readv(compat_ulong_t fd, |
1160 | const struct compat_iovec __user *vec, | |
ddef7ed2 | 1161 | compat_ulong_t vlen, rwf_t flags) |
72ec3516 | 1162 | { |
9c225f26 | 1163 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1164 | ssize_t ret; |
1165 | loff_t pos; | |
1166 | ||
1167 | if (!f.file) | |
1168 | return -EBADF; | |
1169 | pos = f.file->f_pos; | |
f17d8b35 | 1170 | ret = compat_readv(f.file, vec, vlen, &pos, flags); |
5faf153e AV |
1171 | if (ret >= 0) |
1172 | f.file->f_pos = pos; | |
9c225f26 | 1173 | fdput_pos(f); |
72ec3516 | 1174 | return ret; |
f17d8b35 | 1175 | |
72ec3516 AV |
1176 | } |
1177 | ||
f17d8b35 MT |
1178 | COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, |
1179 | const struct compat_iovec __user *,vec, | |
1180 | compat_ulong_t, vlen) | |
1181 | { | |
1182 | return do_compat_readv(fd, vec, vlen, 0); | |
1183 | } | |
1184 | ||
1185 | static long do_compat_preadv64(unsigned long fd, | |
378a10f3 | 1186 | const struct compat_iovec __user *vec, |
ddef7ed2 | 1187 | unsigned long vlen, loff_t pos, rwf_t flags) |
72ec3516 AV |
1188 | { |
1189 | struct fd f; | |
1190 | ssize_t ret; | |
1191 | ||
1192 | if (pos < 0) | |
1193 | return -EINVAL; | |
1194 | f = fdget(fd); | |
1195 | if (!f.file) | |
1196 | return -EBADF; | |
1197 | ret = -ESPIPE; | |
1198 | if (f.file->f_mode & FMODE_PREAD) | |
f17d8b35 | 1199 | ret = compat_readv(f.file, vec, vlen, &pos, flags); |
72ec3516 AV |
1200 | fdput(f); |
1201 | return ret; | |
1202 | } | |
1203 | ||
378a10f3 HC |
1204 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 |
1205 | COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, | |
1206 | const struct compat_iovec __user *,vec, | |
1207 | unsigned long, vlen, loff_t, pos) | |
1208 | { | |
f17d8b35 | 1209 | return do_compat_preadv64(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1210 | } |
1211 | #endif | |
1212 | ||
dfd948e3 | 1213 | COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, |
72ec3516 | 1214 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1215 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1216 | { |
1217 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1218 | |
f17d8b35 MT |
1219 | return do_compat_preadv64(fd, vec, vlen, pos, 0); |
1220 | } | |
1221 | ||
3ebfd81f L |
1222 | #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 |
1223 | COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, | |
1224 | const struct compat_iovec __user *,vec, | |
ddef7ed2 | 1225 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f L |
1226 | { |
1227 | return do_compat_preadv64(fd, vec, vlen, pos, flags); | |
1228 | } | |
1229 | #endif | |
1230 | ||
f17d8b35 MT |
1231 | COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, |
1232 | const struct compat_iovec __user *,vec, | |
1233 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, | |
ddef7ed2 | 1234 | rwf_t, flags) |
f17d8b35 MT |
1235 | { |
1236 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1237 | ||
1238 | if (pos == -1) | |
1239 | return do_compat_readv(fd, vec, vlen, flags); | |
1240 | ||
1241 | return do_compat_preadv64(fd, vec, vlen, pos, flags); | |
72ec3516 AV |
1242 | } |
1243 | ||
1244 | static size_t compat_writev(struct file *file, | |
1245 | const struct compat_iovec __user *vec, | |
ddef7ed2 | 1246 | unsigned long vlen, loff_t *pos, rwf_t flags) |
72ec3516 | 1247 | { |
26c87fb7 CH |
1248 | struct iovec iovstack[UIO_FASTIOV]; |
1249 | struct iovec *iov = iovstack; | |
1250 | struct iov_iter iter; | |
edab5fe3 | 1251 | ssize_t ret; |
72ec3516 | 1252 | |
26c87fb7 | 1253 | ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter); |
edab5fe3 | 1254 | if (ret >= 0) { |
62473a2d | 1255 | file_start_write(file); |
edab5fe3 | 1256 | ret = do_iter_write(file, &iter, pos, flags); |
62473a2d | 1257 | file_end_write(file); |
edab5fe3 CH |
1258 | kfree(iov); |
1259 | } | |
72ec3516 AV |
1260 | if (ret > 0) |
1261 | add_wchar(current, ret); | |
1262 | inc_syscw(current); | |
1263 | return ret; | |
1264 | } | |
1265 | ||
f17d8b35 MT |
1266 | static size_t do_compat_writev(compat_ulong_t fd, |
1267 | const struct compat_iovec __user* vec, | |
ddef7ed2 | 1268 | compat_ulong_t vlen, rwf_t flags) |
72ec3516 | 1269 | { |
9c225f26 | 1270 | struct fd f = fdget_pos(fd); |
72ec3516 AV |
1271 | ssize_t ret; |
1272 | loff_t pos; | |
1273 | ||
1274 | if (!f.file) | |
1275 | return -EBADF; | |
1276 | pos = f.file->f_pos; | |
f17d8b35 | 1277 | ret = compat_writev(f.file, vec, vlen, &pos, flags); |
5faf153e AV |
1278 | if (ret >= 0) |
1279 | f.file->f_pos = pos; | |
9c225f26 | 1280 | fdput_pos(f); |
72ec3516 AV |
1281 | return ret; |
1282 | } | |
1283 | ||
f17d8b35 MT |
1284 | COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, |
1285 | const struct compat_iovec __user *, vec, | |
1286 | compat_ulong_t, vlen) | |
1287 | { | |
1288 | return do_compat_writev(fd, vec, vlen, 0); | |
1289 | } | |
1290 | ||
1291 | static long do_compat_pwritev64(unsigned long fd, | |
378a10f3 | 1292 | const struct compat_iovec __user *vec, |
ddef7ed2 | 1293 | unsigned long vlen, loff_t pos, rwf_t flags) |
72ec3516 AV |
1294 | { |
1295 | struct fd f; | |
1296 | ssize_t ret; | |
1297 | ||
1298 | if (pos < 0) | |
1299 | return -EINVAL; | |
1300 | f = fdget(fd); | |
1301 | if (!f.file) | |
1302 | return -EBADF; | |
1303 | ret = -ESPIPE; | |
1304 | if (f.file->f_mode & FMODE_PWRITE) | |
f17d8b35 | 1305 | ret = compat_writev(f.file, vec, vlen, &pos, flags); |
72ec3516 AV |
1306 | fdput(f); |
1307 | return ret; | |
1308 | } | |
1309 | ||
378a10f3 HC |
1310 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 |
1311 | COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, | |
1312 | const struct compat_iovec __user *,vec, | |
1313 | unsigned long, vlen, loff_t, pos) | |
1314 | { | |
f17d8b35 | 1315 | return do_compat_pwritev64(fd, vec, vlen, pos, 0); |
378a10f3 HC |
1316 | } |
1317 | #endif | |
1318 | ||
dfd948e3 | 1319 | COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, |
72ec3516 | 1320 | const struct compat_iovec __user *,vec, |
dfd948e3 | 1321 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high) |
72ec3516 AV |
1322 | { |
1323 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
378a10f3 | 1324 | |
f17d8b35 | 1325 | return do_compat_pwritev64(fd, vec, vlen, pos, 0); |
72ec3516 | 1326 | } |
f17d8b35 | 1327 | |
3ebfd81f L |
1328 | #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 |
1329 | COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, | |
1330 | const struct compat_iovec __user *,vec, | |
ddef7ed2 | 1331 | unsigned long, vlen, loff_t, pos, rwf_t, flags) |
3ebfd81f L |
1332 | { |
1333 | return do_compat_pwritev64(fd, vec, vlen, pos, flags); | |
1334 | } | |
1335 | #endif | |
1336 | ||
f17d8b35 MT |
1337 | COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, |
1338 | const struct compat_iovec __user *,vec, | |
ddef7ed2 | 1339 | compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) |
f17d8b35 MT |
1340 | { |
1341 | loff_t pos = ((loff_t)pos_high << 32) | pos_low; | |
1342 | ||
1343 | if (pos == -1) | |
1344 | return do_compat_writev(fd, vec, vlen, flags); | |
1345 | ||
1346 | return do_compat_pwritev64(fd, vec, vlen, pos, flags); | |
72ec3516 | 1347 | } |
f17d8b35 | 1348 | |
72ec3516 AV |
1349 | #endif |
1350 | ||
19f4fc3a AV |
1351 | static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, |
1352 | size_t count, loff_t max) | |
1da177e4 | 1353 | { |
2903ff01 AV |
1354 | struct fd in, out; |
1355 | struct inode *in_inode, *out_inode; | |
1da177e4 | 1356 | loff_t pos; |
7995bd28 | 1357 | loff_t out_pos; |
1da177e4 | 1358 | ssize_t retval; |
2903ff01 | 1359 | int fl; |
1da177e4 LT |
1360 | |
1361 | /* | |
1362 | * Get input file, and verify that it is ok.. | |
1363 | */ | |
1364 | retval = -EBADF; | |
2903ff01 AV |
1365 | in = fdget(in_fd); |
1366 | if (!in.file) | |
1da177e4 | 1367 | goto out; |
2903ff01 | 1368 | if (!(in.file->f_mode & FMODE_READ)) |
1da177e4 | 1369 | goto fput_in; |
1da177e4 | 1370 | retval = -ESPIPE; |
7995bd28 AV |
1371 | if (!ppos) { |
1372 | pos = in.file->f_pos; | |
1373 | } else { | |
1374 | pos = *ppos; | |
2903ff01 | 1375 | if (!(in.file->f_mode & FMODE_PREAD)) |
1da177e4 | 1376 | goto fput_in; |
7995bd28 AV |
1377 | } |
1378 | retval = rw_verify_area(READ, in.file, &pos, count); | |
e28cc715 | 1379 | if (retval < 0) |
1da177e4 | 1380 | goto fput_in; |
bc61384d AV |
1381 | if (count > MAX_RW_COUNT) |
1382 | count = MAX_RW_COUNT; | |
1da177e4 | 1383 | |
1da177e4 LT |
1384 | /* |
1385 | * Get output file, and verify that it is ok.. | |
1386 | */ | |
1387 | retval = -EBADF; | |
2903ff01 AV |
1388 | out = fdget(out_fd); |
1389 | if (!out.file) | |
1da177e4 | 1390 | goto fput_in; |
2903ff01 | 1391 | if (!(out.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
1392 | goto fput_out; |
1393 | retval = -EINVAL; | |
496ad9aa AV |
1394 | in_inode = file_inode(in.file); |
1395 | out_inode = file_inode(out.file); | |
7995bd28 AV |
1396 | out_pos = out.file->f_pos; |
1397 | retval = rw_verify_area(WRITE, out.file, &out_pos, count); | |
e28cc715 | 1398 | if (retval < 0) |
1da177e4 LT |
1399 | goto fput_out; |
1400 | ||
1da177e4 LT |
1401 | if (!max) |
1402 | max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); | |
1403 | ||
1da177e4 LT |
1404 | if (unlikely(pos + count > max)) { |
1405 | retval = -EOVERFLOW; | |
1406 | if (pos >= max) | |
1407 | goto fput_out; | |
1408 | count = max - pos; | |
1409 | } | |
1410 | ||
d96e6e71 | 1411 | fl = 0; |
534f2aaa | 1412 | #if 0 |
d96e6e71 JA |
1413 | /* |
1414 | * We need to debate whether we can enable this or not. The | |
1415 | * man page documents EAGAIN return for the output at least, | |
1416 | * and the application is arguably buggy if it doesn't expect | |
1417 | * EAGAIN on a non-blocking file descriptor. | |
1418 | */ | |
2903ff01 | 1419 | if (in.file->f_flags & O_NONBLOCK) |
d96e6e71 | 1420 | fl = SPLICE_F_NONBLOCK; |
534f2aaa | 1421 | #endif |
50cd2c57 | 1422 | file_start_write(out.file); |
7995bd28 | 1423 | retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); |
50cd2c57 | 1424 | file_end_write(out.file); |
1da177e4 LT |
1425 | |
1426 | if (retval > 0) { | |
4b98d11b AD |
1427 | add_rchar(current, retval); |
1428 | add_wchar(current, retval); | |
a68c2f12 SW |
1429 | fsnotify_access(in.file); |
1430 | fsnotify_modify(out.file); | |
7995bd28 AV |
1431 | out.file->f_pos = out_pos; |
1432 | if (ppos) | |
1433 | *ppos = pos; | |
1434 | else | |
1435 | in.file->f_pos = pos; | |
1da177e4 | 1436 | } |
1da177e4 | 1437 | |
4b98d11b AD |
1438 | inc_syscr(current); |
1439 | inc_syscw(current); | |
7995bd28 | 1440 | if (pos > max) |
1da177e4 LT |
1441 | retval = -EOVERFLOW; |
1442 | ||
1443 | fput_out: | |
2903ff01 | 1444 | fdput(out); |
1da177e4 | 1445 | fput_in: |
2903ff01 | 1446 | fdput(in); |
1da177e4 LT |
1447 | out: |
1448 | return retval; | |
1449 | } | |
1450 | ||
002c8976 | 1451 | SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) |
1da177e4 LT |
1452 | { |
1453 | loff_t pos; | |
1454 | off_t off; | |
1455 | ssize_t ret; | |
1456 | ||
1457 | if (offset) { | |
1458 | if (unlikely(get_user(off, offset))) | |
1459 | return -EFAULT; | |
1460 | pos = off; | |
1461 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1462 | if (unlikely(put_user(pos, offset))) | |
1463 | return -EFAULT; | |
1464 | return ret; | |
1465 | } | |
1466 | ||
1467 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1468 | } | |
1469 | ||
002c8976 | 1470 | SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) |
1da177e4 LT |
1471 | { |
1472 | loff_t pos; | |
1473 | ssize_t ret; | |
1474 | ||
1475 | if (offset) { | |
1476 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1477 | return -EFAULT; | |
1478 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1479 | if (unlikely(put_user(pos, offset))) | |
1480 | return -EFAULT; | |
1481 | return ret; | |
1482 | } | |
1483 | ||
1484 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1485 | } | |
19f4fc3a AV |
1486 | |
1487 | #ifdef CONFIG_COMPAT | |
1488 | COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, | |
1489 | compat_off_t __user *, offset, compat_size_t, count) | |
1490 | { | |
1491 | loff_t pos; | |
1492 | off_t off; | |
1493 | ssize_t ret; | |
1494 | ||
1495 | if (offset) { | |
1496 | if (unlikely(get_user(off, offset))) | |
1497 | return -EFAULT; | |
1498 | pos = off; | |
1499 | ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); | |
1500 | if (unlikely(put_user(pos, offset))) | |
1501 | return -EFAULT; | |
1502 | return ret; | |
1503 | } | |
1504 | ||
1505 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1506 | } | |
1507 | ||
1508 | COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, | |
1509 | compat_loff_t __user *, offset, compat_size_t, count) | |
1510 | { | |
1511 | loff_t pos; | |
1512 | ssize_t ret; | |
1513 | ||
1514 | if (offset) { | |
1515 | if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) | |
1516 | return -EFAULT; | |
1517 | ret = do_sendfile(out_fd, in_fd, &pos, count, 0); | |
1518 | if (unlikely(put_user(pos, offset))) | |
1519 | return -EFAULT; | |
1520 | return ret; | |
1521 | } | |
1522 | ||
1523 | return do_sendfile(out_fd, in_fd, NULL, count, 0); | |
1524 | } | |
1525 | #endif | |
29732938 ZB |
1526 | |
1527 | /* | |
1528 | * copy_file_range() differs from regular file read and write in that it | |
1529 | * specifically allows return partial success. When it does so is up to | |
1530 | * the copy_file_range method. | |
1531 | */ | |
1532 | ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, | |
1533 | struct file *file_out, loff_t pos_out, | |
1534 | size_t len, unsigned int flags) | |
1535 | { | |
1536 | struct inode *inode_in = file_inode(file_in); | |
1537 | struct inode *inode_out = file_inode(file_out); | |
1538 | ssize_t ret; | |
1539 | ||
1540 | if (flags != 0) | |
1541 | return -EINVAL; | |
1542 | ||
11cbfb10 AG |
1543 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) |
1544 | return -EISDIR; | |
1545 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1546 | return -EINVAL; | |
1547 | ||
29732938 | 1548 | ret = rw_verify_area(READ, file_in, &pos_in, len); |
bc61384d AV |
1549 | if (unlikely(ret)) |
1550 | return ret; | |
1551 | ||
1552 | ret = rw_verify_area(WRITE, file_out, &pos_out, len); | |
1553 | if (unlikely(ret)) | |
29732938 ZB |
1554 | return ret; |
1555 | ||
1556 | if (!(file_in->f_mode & FMODE_READ) || | |
1557 | !(file_out->f_mode & FMODE_WRITE) || | |
eac70053 | 1558 | (file_out->f_flags & O_APPEND)) |
29732938 ZB |
1559 | return -EBADF; |
1560 | ||
1561 | /* this could be relaxed once a method supports cross-fs copies */ | |
1562 | if (inode_in->i_sb != inode_out->i_sb) | |
1563 | return -EXDEV; | |
1564 | ||
1565 | if (len == 0) | |
1566 | return 0; | |
1567 | ||
bfe219d3 | 1568 | file_start_write(file_out); |
29732938 | 1569 | |
a76b5b04 CH |
1570 | /* |
1571 | * Try cloning first, this is supported by more file systems, and | |
1572 | * more efficient if both clone and copy are supported (e.g. NFS). | |
1573 | */ | |
1574 | if (file_in->f_op->clone_file_range) { | |
1575 | ret = file_in->f_op->clone_file_range(file_in, pos_in, | |
1576 | file_out, pos_out, len); | |
1577 | if (ret == 0) { | |
1578 | ret = len; | |
1579 | goto done; | |
1580 | } | |
1581 | } | |
1582 | ||
1583 | if (file_out->f_op->copy_file_range) { | |
eac70053 AS |
1584 | ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, |
1585 | pos_out, len, flags); | |
a76b5b04 CH |
1586 | if (ret != -EOPNOTSUPP) |
1587 | goto done; | |
1588 | } | |
eac70053 | 1589 | |
a76b5b04 CH |
1590 | ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, |
1591 | len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); | |
eac70053 | 1592 | |
a76b5b04 | 1593 | done: |
29732938 ZB |
1594 | if (ret > 0) { |
1595 | fsnotify_access(file_in); | |
1596 | add_rchar(current, ret); | |
1597 | fsnotify_modify(file_out); | |
1598 | add_wchar(current, ret); | |
1599 | } | |
a76b5b04 | 1600 | |
29732938 ZB |
1601 | inc_syscr(current); |
1602 | inc_syscw(current); | |
1603 | ||
bfe219d3 | 1604 | file_end_write(file_out); |
29732938 ZB |
1605 | |
1606 | return ret; | |
1607 | } | |
1608 | EXPORT_SYMBOL(vfs_copy_file_range); | |
1609 | ||
1610 | SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, | |
1611 | int, fd_out, loff_t __user *, off_out, | |
1612 | size_t, len, unsigned int, flags) | |
1613 | { | |
1614 | loff_t pos_in; | |
1615 | loff_t pos_out; | |
1616 | struct fd f_in; | |
1617 | struct fd f_out; | |
1618 | ssize_t ret = -EBADF; | |
1619 | ||
1620 | f_in = fdget(fd_in); | |
1621 | if (!f_in.file) | |
1622 | goto out2; | |
1623 | ||
1624 | f_out = fdget(fd_out); | |
1625 | if (!f_out.file) | |
1626 | goto out1; | |
1627 | ||
1628 | ret = -EFAULT; | |
1629 | if (off_in) { | |
1630 | if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) | |
1631 | goto out; | |
1632 | } else { | |
1633 | pos_in = f_in.file->f_pos; | |
1634 | } | |
1635 | ||
1636 | if (off_out) { | |
1637 | if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) | |
1638 | goto out; | |
1639 | } else { | |
1640 | pos_out = f_out.file->f_pos; | |
1641 | } | |
1642 | ||
1643 | ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, | |
1644 | flags); | |
1645 | if (ret > 0) { | |
1646 | pos_in += ret; | |
1647 | pos_out += ret; | |
1648 | ||
1649 | if (off_in) { | |
1650 | if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) | |
1651 | ret = -EFAULT; | |
1652 | } else { | |
1653 | f_in.file->f_pos = pos_in; | |
1654 | } | |
1655 | ||
1656 | if (off_out) { | |
1657 | if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) | |
1658 | ret = -EFAULT; | |
1659 | } else { | |
1660 | f_out.file->f_pos = pos_out; | |
1661 | } | |
1662 | } | |
1663 | ||
1664 | out: | |
1665 | fdput(f_out); | |
1666 | out1: | |
1667 | fdput(f_in); | |
1668 | out2: | |
1669 | return ret; | |
1670 | } | |
04b38d60 CH |
1671 | |
1672 | static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write) | |
1673 | { | |
1674 | struct inode *inode = file_inode(file); | |
1675 | ||
1676 | if (unlikely(pos < 0)) | |
1677 | return -EINVAL; | |
1678 | ||
1679 | if (unlikely((loff_t) (pos + len) < 0)) | |
1680 | return -EINVAL; | |
1681 | ||
1682 | if (unlikely(inode->i_flctx && mandatory_lock(inode))) { | |
1683 | loff_t end = len ? pos + len - 1 : OFFSET_MAX; | |
1684 | int retval; | |
1685 | ||
1686 | retval = locks_mandatory_area(inode, file, pos, end, | |
1687 | write ? F_WRLCK : F_RDLCK); | |
1688 | if (retval < 0) | |
1689 | return retval; | |
1690 | } | |
1691 | ||
1692 | return security_file_permission(file, write ? MAY_WRITE : MAY_READ); | |
1693 | } | |
1694 | ||
876bec6f DW |
1695 | /* |
1696 | * Check that the two inodes are eligible for cloning, the ranges make | |
1697 | * sense, and then flush all dirty data. Caller must ensure that the | |
1698 | * inodes have been locked against any other modifications. | |
22725ce4 DW |
1699 | * |
1700 | * Returns: 0 for "nothing to clone", 1 for "something to clone", or | |
1701 | * the usual negative error code. | |
876bec6f DW |
1702 | */ |
1703 | int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, | |
1704 | struct inode *inode_out, loff_t pos_out, | |
1705 | u64 *len, bool is_dedupe) | |
1706 | { | |
1707 | loff_t bs = inode_out->i_sb->s_blocksize; | |
1708 | loff_t blen; | |
1709 | loff_t isize; | |
1710 | bool same_inode = (inode_in == inode_out); | |
1711 | int ret; | |
1712 | ||
1713 | /* Don't touch certain kinds of inodes */ | |
1714 | if (IS_IMMUTABLE(inode_out)) | |
1715 | return -EPERM; | |
1716 | ||
1717 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1718 | return -ETXTBSY; | |
1719 | ||
1720 | /* Don't reflink dirs, pipes, sockets... */ | |
1721 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
1722 | return -EISDIR; | |
1723 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1724 | return -EINVAL; | |
1725 | ||
1726 | /* Are we going all the way to the end? */ | |
1727 | isize = i_size_read(inode_in); | |
22725ce4 | 1728 | if (isize == 0) |
876bec6f | 1729 | return 0; |
876bec6f DW |
1730 | |
1731 | /* Zero length dedupe exits immediately; reflink goes to EOF. */ | |
1732 | if (*len == 0) { | |
22725ce4 | 1733 | if (is_dedupe || pos_in == isize) |
876bec6f | 1734 | return 0; |
22725ce4 DW |
1735 | if (pos_in > isize) |
1736 | return -EINVAL; | |
876bec6f DW |
1737 | *len = isize - pos_in; |
1738 | } | |
1739 | ||
1740 | /* Ensure offsets don't wrap and the input is inside i_size */ | |
1741 | if (pos_in + *len < pos_in || pos_out + *len < pos_out || | |
1742 | pos_in + *len > isize) | |
1743 | return -EINVAL; | |
1744 | ||
1745 | /* Don't allow dedupe past EOF in the dest file */ | |
1746 | if (is_dedupe) { | |
1747 | loff_t disize; | |
1748 | ||
1749 | disize = i_size_read(inode_out); | |
1750 | if (pos_out >= disize || pos_out + *len > disize) | |
1751 | return -EINVAL; | |
1752 | } | |
1753 | ||
1754 | /* If we're linking to EOF, continue to the block boundary. */ | |
1755 | if (pos_in + *len == isize) | |
1756 | blen = ALIGN(isize, bs) - pos_in; | |
1757 | else | |
1758 | blen = *len; | |
1759 | ||
1760 | /* Only reflink if we're aligned to block boundaries */ | |
1761 | if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || | |
1762 | !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) | |
1763 | return -EINVAL; | |
1764 | ||
1765 | /* Don't allow overlapped reflink within the same file */ | |
1766 | if (same_inode) { | |
1767 | if (pos_out + blen > pos_in && pos_out < pos_in + blen) | |
1768 | return -EINVAL; | |
1769 | } | |
1770 | ||
1771 | /* Wait for the completion of any pending IOs on both files */ | |
1772 | inode_dio_wait(inode_in); | |
1773 | if (!same_inode) | |
1774 | inode_dio_wait(inode_out); | |
1775 | ||
1776 | ret = filemap_write_and_wait_range(inode_in->i_mapping, | |
1777 | pos_in, pos_in + *len - 1); | |
1778 | if (ret) | |
1779 | return ret; | |
1780 | ||
1781 | ret = filemap_write_and_wait_range(inode_out->i_mapping, | |
1782 | pos_out, pos_out + *len - 1); | |
1783 | if (ret) | |
1784 | return ret; | |
1785 | ||
1786 | /* | |
1787 | * Check that the extents are the same. | |
1788 | */ | |
1789 | if (is_dedupe) { | |
1790 | bool is_same = false; | |
1791 | ||
1792 | ret = vfs_dedupe_file_range_compare(inode_in, pos_in, | |
1793 | inode_out, pos_out, *len, &is_same); | |
1794 | if (ret) | |
1795 | return ret; | |
1796 | if (!is_same) | |
1797 | return -EBADE; | |
1798 | } | |
1799 | ||
22725ce4 | 1800 | return 1; |
876bec6f DW |
1801 | } |
1802 | EXPORT_SYMBOL(vfs_clone_file_prep_inodes); | |
1803 | ||
04b38d60 CH |
1804 | int vfs_clone_file_range(struct file *file_in, loff_t pos_in, |
1805 | struct file *file_out, loff_t pos_out, u64 len) | |
1806 | { | |
1807 | struct inode *inode_in = file_inode(file_in); | |
1808 | struct inode *inode_out = file_inode(file_out); | |
1809 | int ret; | |
1810 | ||
b335e9d9 AG |
1811 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) |
1812 | return -EISDIR; | |
1813 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1814 | return -EINVAL; | |
1815 | ||
913b86e9 AG |
1816 | /* |
1817 | * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on | |
1818 | * the same mount. Practically, they only need to be on the same file | |
1819 | * system. | |
1820 | */ | |
1821 | if (inode_in->i_sb != inode_out->i_sb) | |
04b38d60 CH |
1822 | return -EXDEV; |
1823 | ||
04b38d60 CH |
1824 | if (!(file_in->f_mode & FMODE_READ) || |
1825 | !(file_out->f_mode & FMODE_WRITE) || | |
0fcbf996 | 1826 | (file_out->f_flags & O_APPEND)) |
04b38d60 CH |
1827 | return -EBADF; |
1828 | ||
0fcbf996 CH |
1829 | if (!file_in->f_op->clone_file_range) |
1830 | return -EOPNOTSUPP; | |
1831 | ||
04b38d60 CH |
1832 | ret = clone_verify_area(file_in, pos_in, len, false); |
1833 | if (ret) | |
1834 | return ret; | |
1835 | ||
1836 | ret = clone_verify_area(file_out, pos_out, len, true); | |
1837 | if (ret) | |
1838 | return ret; | |
1839 | ||
1840 | if (pos_in + len > i_size_read(inode_in)) | |
1841 | return -EINVAL; | |
1842 | ||
04b38d60 CH |
1843 | ret = file_in->f_op->clone_file_range(file_in, pos_in, |
1844 | file_out, pos_out, len); | |
1845 | if (!ret) { | |
1846 | fsnotify_access(file_in); | |
1847 | fsnotify_modify(file_out); | |
1848 | } | |
1849 | ||
04b38d60 CH |
1850 | return ret; |
1851 | } | |
1852 | EXPORT_SYMBOL(vfs_clone_file_range); | |
54dbc151 | 1853 | |
876bec6f DW |
1854 | /* |
1855 | * Read a page's worth of file data into the page cache. Return the page | |
1856 | * locked. | |
1857 | */ | |
1858 | static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset) | |
1859 | { | |
1860 | struct address_space *mapping; | |
1861 | struct page *page; | |
1862 | pgoff_t n; | |
1863 | ||
1864 | n = offset >> PAGE_SHIFT; | |
1865 | mapping = inode->i_mapping; | |
1866 | page = read_mapping_page(mapping, n, NULL); | |
1867 | if (IS_ERR(page)) | |
1868 | return page; | |
1869 | if (!PageUptodate(page)) { | |
1870 | put_page(page); | |
1871 | return ERR_PTR(-EIO); | |
1872 | } | |
1873 | lock_page(page); | |
1874 | return page; | |
1875 | } | |
1876 | ||
1877 | /* | |
1878 | * Compare extents of two files to see if they are the same. | |
1879 | * Caller must have locked both inodes to prevent write races. | |
1880 | */ | |
1881 | int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, | |
1882 | struct inode *dest, loff_t destoff, | |
1883 | loff_t len, bool *is_same) | |
1884 | { | |
1885 | loff_t src_poff; | |
1886 | loff_t dest_poff; | |
1887 | void *src_addr; | |
1888 | void *dest_addr; | |
1889 | struct page *src_page; | |
1890 | struct page *dest_page; | |
1891 | loff_t cmp_len; | |
1892 | bool same; | |
1893 | int error; | |
1894 | ||
1895 | error = -EINVAL; | |
1896 | same = true; | |
1897 | while (len) { | |
1898 | src_poff = srcoff & (PAGE_SIZE - 1); | |
1899 | dest_poff = destoff & (PAGE_SIZE - 1); | |
1900 | cmp_len = min(PAGE_SIZE - src_poff, | |
1901 | PAGE_SIZE - dest_poff); | |
1902 | cmp_len = min(cmp_len, len); | |
1903 | if (cmp_len <= 0) | |
1904 | goto out_error; | |
1905 | ||
1906 | src_page = vfs_dedupe_get_page(src, srcoff); | |
1907 | if (IS_ERR(src_page)) { | |
1908 | error = PTR_ERR(src_page); | |
1909 | goto out_error; | |
1910 | } | |
1911 | dest_page = vfs_dedupe_get_page(dest, destoff); | |
1912 | if (IS_ERR(dest_page)) { | |
1913 | error = PTR_ERR(dest_page); | |
1914 | unlock_page(src_page); | |
1915 | put_page(src_page); | |
1916 | goto out_error; | |
1917 | } | |
1918 | src_addr = kmap_atomic(src_page); | |
1919 | dest_addr = kmap_atomic(dest_page); | |
1920 | ||
1921 | flush_dcache_page(src_page); | |
1922 | flush_dcache_page(dest_page); | |
1923 | ||
1924 | if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) | |
1925 | same = false; | |
1926 | ||
1927 | kunmap_atomic(dest_addr); | |
1928 | kunmap_atomic(src_addr); | |
1929 | unlock_page(dest_page); | |
1930 | unlock_page(src_page); | |
1931 | put_page(dest_page); | |
1932 | put_page(src_page); | |
1933 | ||
1934 | if (!same) | |
1935 | break; | |
1936 | ||
1937 | srcoff += cmp_len; | |
1938 | destoff += cmp_len; | |
1939 | len -= cmp_len; | |
1940 | } | |
1941 | ||
1942 | *is_same = same; | |
1943 | return 0; | |
1944 | ||
1945 | out_error: | |
1946 | return error; | |
1947 | } | |
1948 | EXPORT_SYMBOL(vfs_dedupe_file_range_compare); | |
1949 | ||
54dbc151 DW |
1950 | int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) |
1951 | { | |
1952 | struct file_dedupe_range_info *info; | |
1953 | struct inode *src = file_inode(file); | |
1954 | u64 off; | |
1955 | u64 len; | |
1956 | int i; | |
1957 | int ret; | |
1958 | bool is_admin = capable(CAP_SYS_ADMIN); | |
1959 | u16 count = same->dest_count; | |
1960 | struct file *dst_file; | |
1961 | loff_t dst_off; | |
1962 | ssize_t deduped; | |
1963 | ||
1964 | if (!(file->f_mode & FMODE_READ)) | |
1965 | return -EINVAL; | |
1966 | ||
1967 | if (same->reserved1 || same->reserved2) | |
1968 | return -EINVAL; | |
1969 | ||
1970 | off = same->src_offset; | |
1971 | len = same->src_length; | |
1972 | ||
1973 | ret = -EISDIR; | |
1974 | if (S_ISDIR(src->i_mode)) | |
1975 | goto out; | |
1976 | ||
1977 | ret = -EINVAL; | |
1978 | if (!S_ISREG(src->i_mode)) | |
1979 | goto out; | |
1980 | ||
1981 | ret = clone_verify_area(file, off, len, false); | |
1982 | if (ret < 0) | |
1983 | goto out; | |
1984 | ret = 0; | |
1985 | ||
22725ce4 DW |
1986 | if (off + len > i_size_read(src)) |
1987 | return -EINVAL; | |
1988 | ||
54dbc151 DW |
1989 | /* pre-format output fields to sane values */ |
1990 | for (i = 0; i < count; i++) { | |
1991 | same->info[i].bytes_deduped = 0ULL; | |
1992 | same->info[i].status = FILE_DEDUPE_RANGE_SAME; | |
1993 | } | |
1994 | ||
1995 | for (i = 0, info = same->info; i < count; i++, info++) { | |
1996 | struct inode *dst; | |
1997 | struct fd dst_fd = fdget(info->dest_fd); | |
1998 | ||
1999 | dst_file = dst_fd.file; | |
2000 | if (!dst_file) { | |
2001 | info->status = -EBADF; | |
2002 | goto next_loop; | |
2003 | } | |
2004 | dst = file_inode(dst_file); | |
2005 | ||
2006 | ret = mnt_want_write_file(dst_file); | |
2007 | if (ret) { | |
2008 | info->status = ret; | |
2009 | goto next_loop; | |
2010 | } | |
2011 | ||
2012 | dst_off = info->dest_offset; | |
2013 | ret = clone_verify_area(dst_file, dst_off, len, true); | |
2014 | if (ret < 0) { | |
2015 | info->status = ret; | |
2016 | goto next_file; | |
2017 | } | |
2018 | ret = 0; | |
2019 | ||
2020 | if (info->reserved) { | |
2021 | info->status = -EINVAL; | |
2022 | } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { | |
2023 | info->status = -EINVAL; | |
2024 | } else if (file->f_path.mnt != dst_file->f_path.mnt) { | |
2025 | info->status = -EXDEV; | |
2026 | } else if (S_ISDIR(dst->i_mode)) { | |
2027 | info->status = -EISDIR; | |
2028 | } else if (dst_file->f_op->dedupe_file_range == NULL) { | |
2029 | info->status = -EINVAL; | |
2030 | } else { | |
2031 | deduped = dst_file->f_op->dedupe_file_range(file, off, | |
2032 | len, dst_file, | |
2033 | info->dest_offset); | |
2034 | if (deduped == -EBADE) | |
2035 | info->status = FILE_DEDUPE_RANGE_DIFFERS; | |
2036 | else if (deduped < 0) | |
2037 | info->status = deduped; | |
2038 | else | |
2039 | info->bytes_deduped += deduped; | |
2040 | } | |
2041 | ||
2042 | next_file: | |
2043 | mnt_drop_write_file(dst_file); | |
2044 | next_loop: | |
2045 | fdput(dst_fd); | |
e62e560f DW |
2046 | |
2047 | if (fatal_signal_pending(current)) | |
2048 | goto out; | |
54dbc151 DW |
2049 | } |
2050 | ||
2051 | out: | |
2052 | return ret; | |
2053 | } | |
2054 | EXPORT_SYMBOL(vfs_dedupe_file_range); |