Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/ioctl.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/syscalls.h> |
8 | #include <linux/mm.h> | |
9 | #include <linux/smp_lock.h> | |
16f7e0fe | 10 | #include <linux/capability.h> |
1da177e4 LT |
11 | #include <linux/file.h> |
12 | #include <linux/fs.h> | |
13 | #include <linux/security.h> | |
14 | #include <linux/module.h> | |
c9845ff1 | 15 | #include <linux/uaccess.h> |
68c9d702 JB |
16 | #include <linux/writeback.h> |
17 | #include <linux/buffer_head.h> | |
1da177e4 | 18 | |
1da177e4 LT |
19 | #include <asm/ioctls.h> |
20 | ||
c4b929b8 MF |
21 | /* So that the fiemap access checks can't overflow on 32 bit machines. */ |
22 | #define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent)) | |
23 | ||
deb21db7 EZ |
24 | /** |
25 | * vfs_ioctl - call filesystem specific ioctl methods | |
f6a4c8bd CH |
26 | * @filp: open file to invoke ioctl method on |
27 | * @cmd: ioctl command to execute | |
28 | * @arg: command-specific argument for ioctl | |
deb21db7 EZ |
29 | * |
30 | * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise | |
f6a4c8bd | 31 | * invokes filesystem specific ->ioctl method. If neither method exists, |
deb21db7 EZ |
32 | * returns -ENOTTY. |
33 | * | |
34 | * Returns 0 on success, -errno on error. | |
35 | */ | |
67cde595 AB |
36 | static long vfs_ioctl(struct file *filp, unsigned int cmd, |
37 | unsigned long arg) | |
1da177e4 LT |
38 | { |
39 | int error = -ENOTTY; | |
40 | ||
41 | if (!filp->f_op) | |
42 | goto out; | |
43 | ||
44 | if (filp->f_op->unlocked_ioctl) { | |
45 | error = filp->f_op->unlocked_ioctl(filp, cmd, arg); | |
46 | if (error == -ENOIOCTLCMD) | |
47 | error = -EINVAL; | |
48 | goto out; | |
64d67d21 | 49 | } else if (filp->f_op->ioctl) { |
1da177e4 | 50 | lock_kernel(); |
64d67d21 AM |
51 | error = filp->f_op->ioctl(filp->f_path.dentry->d_inode, |
52 | filp, cmd, arg); | |
1da177e4 LT |
53 | unlock_kernel(); |
54 | } | |
55 | ||
56 | out: | |
57 | return error; | |
58 | } | |
59 | ||
aa81a7c7 EZ |
60 | static int ioctl_fibmap(struct file *filp, int __user *p) |
61 | { | |
62 | struct address_space *mapping = filp->f_mapping; | |
63 | int res, block; | |
64 | ||
65 | /* do we support this mess? */ | |
66 | if (!mapping->a_ops->bmap) | |
67 | return -EINVAL; | |
68 | if (!capable(CAP_SYS_RAWIO)) | |
69 | return -EPERM; | |
70 | res = get_user(block, p); | |
71 | if (res) | |
72 | return res; | |
73 | lock_kernel(); | |
74 | res = mapping->a_ops->bmap(mapping, block); | |
75 | unlock_kernel(); | |
76 | return put_user(res, p); | |
77 | } | |
78 | ||
c4b929b8 MF |
79 | /** |
80 | * fiemap_fill_next_extent - Fiemap helper function | |
81 | * @fieinfo: Fiemap context passed into ->fiemap | |
82 | * @logical: Extent logical start offset, in bytes | |
83 | * @phys: Extent physical start offset, in bytes | |
84 | * @len: Extent length, in bytes | |
85 | * @flags: FIEMAP_EXTENT flags that describe this extent | |
86 | * | |
87 | * Called from file system ->fiemap callback. Will populate extent | |
88 | * info as passed in via arguments and copy to user memory. On | |
89 | * success, extent count on fieinfo is incremented. | |
90 | * | |
91 | * Returns 0 on success, -errno on error, 1 if this was the last | |
92 | * extent that will fit in user array. | |
93 | */ | |
94 | #define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC) | |
95 | #define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED) | |
96 | #define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE) | |
97 | int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, | |
98 | u64 phys, u64 len, u32 flags) | |
99 | { | |
100 | struct fiemap_extent extent; | |
101 | struct fiemap_extent *dest = fieinfo->fi_extents_start; | |
102 | ||
103 | /* only count the extents */ | |
104 | if (fieinfo->fi_extents_max == 0) { | |
105 | fieinfo->fi_extents_mapped++; | |
106 | return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0; | |
107 | } | |
108 | ||
109 | if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max) | |
110 | return 1; | |
111 | ||
112 | if (flags & SET_UNKNOWN_FLAGS) | |
113 | flags |= FIEMAP_EXTENT_UNKNOWN; | |
114 | if (flags & SET_NO_UNMOUNTED_IO_FLAGS) | |
115 | flags |= FIEMAP_EXTENT_ENCODED; | |
116 | if (flags & SET_NOT_ALIGNED_FLAGS) | |
117 | flags |= FIEMAP_EXTENT_NOT_ALIGNED; | |
118 | ||
119 | memset(&extent, 0, sizeof(extent)); | |
120 | extent.fe_logical = logical; | |
121 | extent.fe_physical = phys; | |
122 | extent.fe_length = len; | |
123 | extent.fe_flags = flags; | |
124 | ||
125 | dest += fieinfo->fi_extents_mapped; | |
126 | if (copy_to_user(dest, &extent, sizeof(extent))) | |
127 | return -EFAULT; | |
128 | ||
129 | fieinfo->fi_extents_mapped++; | |
130 | if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max) | |
131 | return 1; | |
132 | return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0; | |
133 | } | |
134 | EXPORT_SYMBOL(fiemap_fill_next_extent); | |
135 | ||
136 | /** | |
137 | * fiemap_check_flags - check validity of requested flags for fiemap | |
138 | * @fieinfo: Fiemap context passed into ->fiemap | |
139 | * @fs_flags: Set of fiemap flags that the file system understands | |
140 | * | |
141 | * Called from file system ->fiemap callback. This will compute the | |
142 | * intersection of valid fiemap flags and those that the fs supports. That | |
143 | * value is then compared against the user supplied flags. In case of bad user | |
144 | * flags, the invalid values will be written into the fieinfo structure, and | |
145 | * -EBADR is returned, which tells ioctl_fiemap() to return those values to | |
146 | * userspace. For this reason, a return code of -EBADR should be preserved. | |
147 | * | |
148 | * Returns 0 on success, -EBADR on bad flags. | |
149 | */ | |
150 | int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags) | |
151 | { | |
152 | u32 incompat_flags; | |
153 | ||
154 | incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags); | |
155 | if (incompat_flags) { | |
156 | fieinfo->fi_flags = incompat_flags; | |
157 | return -EBADR; | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | EXPORT_SYMBOL(fiemap_check_flags); | |
162 | ||
163 | static int fiemap_check_ranges(struct super_block *sb, | |
164 | u64 start, u64 len, u64 *new_len) | |
165 | { | |
166 | *new_len = len; | |
167 | ||
168 | if (len == 0) | |
169 | return -EINVAL; | |
170 | ||
171 | if (start > sb->s_maxbytes) | |
172 | return -EFBIG; | |
173 | ||
174 | /* | |
175 | * Shrink request scope to what the fs can actually handle. | |
176 | */ | |
177 | if ((len > sb->s_maxbytes) || | |
178 | (sb->s_maxbytes - len) < start) | |
179 | *new_len = sb->s_maxbytes - start; | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
184 | static int ioctl_fiemap(struct file *filp, unsigned long arg) | |
185 | { | |
186 | struct fiemap fiemap; | |
187 | struct fiemap_extent_info fieinfo = { 0, }; | |
188 | struct inode *inode = filp->f_path.dentry->d_inode; | |
189 | struct super_block *sb = inode->i_sb; | |
190 | u64 len; | |
191 | int error; | |
192 | ||
193 | if (!inode->i_op->fiemap) | |
194 | return -EOPNOTSUPP; | |
195 | ||
196 | if (copy_from_user(&fiemap, (struct fiemap __user *)arg, | |
197 | sizeof(struct fiemap))) | |
198 | return -EFAULT; | |
199 | ||
200 | if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS) | |
201 | return -EINVAL; | |
202 | ||
203 | error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length, | |
204 | &len); | |
205 | if (error) | |
206 | return error; | |
207 | ||
208 | fieinfo.fi_flags = fiemap.fm_flags; | |
209 | fieinfo.fi_extents_max = fiemap.fm_extent_count; | |
210 | fieinfo.fi_extents_start = (struct fiemap_extent *)(arg + sizeof(fiemap)); | |
211 | ||
212 | if (fiemap.fm_extent_count != 0 && | |
213 | !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start, | |
214 | fieinfo.fi_extents_max * sizeof(struct fiemap_extent))) | |
215 | return -EFAULT; | |
216 | ||
217 | if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC) | |
218 | filemap_write_and_wait(inode->i_mapping); | |
219 | ||
220 | error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len); | |
221 | fiemap.fm_flags = fieinfo.fi_flags; | |
222 | fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped; | |
223 | if (copy_to_user((char *)arg, &fiemap, sizeof(fiemap))) | |
224 | error = -EFAULT; | |
225 | ||
226 | return error; | |
227 | } | |
228 | ||
06270d5d AB |
229 | #ifdef CONFIG_BLOCK |
230 | ||
68c9d702 JB |
231 | #define blk_to_logical(inode, blk) (blk << (inode)->i_blkbits) |
232 | #define logical_to_blk(inode, offset) (offset >> (inode)->i_blkbits); | |
233 | ||
e9079cce SW |
234 | /** |
235 | * __generic_block_fiemap - FIEMAP for block based inodes (no locking) | |
68c9d702 JB |
236 | * @inode - the inode to map |
237 | * @arg - the pointer to userspace where we copy everything to | |
238 | * @get_block - the fs's get_block function | |
239 | * | |
240 | * This does FIEMAP for block based inodes. Basically it will just loop | |
241 | * through get_block until we hit the number of extents we want to map, or we | |
242 | * go past the end of the file and hit a hole. | |
243 | * | |
244 | * If it is possible to have data blocks beyond a hole past @inode->i_size, then | |
245 | * please do not use this function, it will stop at the first unmapped block | |
e9079cce SW |
246 | * beyond i_size. |
247 | * | |
248 | * If you use this function directly, you need to do your own locking. Use | |
249 | * generic_block_fiemap if you want the locking done for you. | |
68c9d702 | 250 | */ |
e9079cce SW |
251 | |
252 | int __generic_block_fiemap(struct inode *inode, | |
253 | struct fiemap_extent_info *fieinfo, u64 start, | |
254 | u64 len, get_block_t *get_block) | |
68c9d702 JB |
255 | { |
256 | struct buffer_head tmp; | |
257 | unsigned int start_blk; | |
258 | long long length = 0, map_len = 0; | |
259 | u64 logical = 0, phys = 0, size = 0; | |
260 | u32 flags = FIEMAP_EXTENT_MERGED; | |
261 | int ret = 0; | |
262 | ||
263 | if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))) | |
264 | return ret; | |
265 | ||
266 | start_blk = logical_to_blk(inode, start); | |
267 | ||
68c9d702 JB |
268 | length = (long long)min_t(u64, len, i_size_read(inode)); |
269 | map_len = length; | |
270 | ||
271 | do { | |
272 | /* | |
273 | * we set b_size to the total size we want so it will map as | |
274 | * many contiguous blocks as possible at once | |
275 | */ | |
276 | memset(&tmp, 0, sizeof(struct buffer_head)); | |
277 | tmp.b_size = map_len; | |
278 | ||
279 | ret = get_block(inode, start_blk, &tmp, 0); | |
280 | if (ret) | |
281 | break; | |
282 | ||
283 | /* HOLE */ | |
284 | if (!buffer_mapped(&tmp)) { | |
285 | /* | |
286 | * first hole after going past the EOF, this is our | |
287 | * last extent | |
288 | */ | |
289 | if (length <= 0) { | |
290 | flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST; | |
291 | ret = fiemap_fill_next_extent(fieinfo, logical, | |
292 | phys, size, | |
293 | flags); | |
294 | break; | |
295 | } | |
296 | ||
297 | length -= blk_to_logical(inode, 1); | |
298 | ||
299 | /* if we have holes up to/past EOF then we're done */ | |
300 | if (length <= 0) | |
301 | break; | |
302 | ||
303 | start_blk++; | |
304 | } else { | |
305 | if (length <= 0 && size) { | |
306 | ret = fiemap_fill_next_extent(fieinfo, logical, | |
307 | phys, size, | |
308 | flags); | |
309 | if (ret) | |
310 | break; | |
311 | } | |
312 | ||
313 | logical = blk_to_logical(inode, start_blk); | |
314 | phys = blk_to_logical(inode, tmp.b_blocknr); | |
315 | size = tmp.b_size; | |
316 | flags = FIEMAP_EXTENT_MERGED; | |
317 | ||
318 | length -= tmp.b_size; | |
319 | start_blk += logical_to_blk(inode, size); | |
320 | ||
321 | /* | |
322 | * if we are past the EOF we need to loop again to see | |
323 | * if there is a hole so we can mark this extent as the | |
324 | * last one, and if not keep mapping things until we | |
325 | * find a hole, or we run out of slots in the extent | |
326 | * array | |
327 | */ | |
328 | if (length <= 0) | |
329 | continue; | |
330 | ||
331 | ret = fiemap_fill_next_extent(fieinfo, logical, phys, | |
332 | size, flags); | |
333 | if (ret) | |
334 | break; | |
335 | } | |
336 | cond_resched(); | |
337 | } while (1); | |
338 | ||
68c9d702 JB |
339 | /* if ret is 1 then we just hit the end of the extent array */ |
340 | if (ret == 1) | |
341 | ret = 0; | |
342 | ||
343 | return ret; | |
344 | } | |
e9079cce SW |
345 | EXPORT_SYMBOL(__generic_block_fiemap); |
346 | ||
347 | /** | |
348 | * generic_block_fiemap - FIEMAP for block based inodes | |
349 | * @inode: The inode to map | |
350 | * @fieinfo: The mapping information | |
351 | * @start: The initial block to map | |
352 | * @len: The length of the extect to attempt to map | |
353 | * @get_block: The block mapping function for the fs | |
354 | * | |
355 | * Calls __generic_block_fiemap to map the inode, after taking | |
356 | * the inode's mutex lock. | |
357 | */ | |
358 | ||
359 | int generic_block_fiemap(struct inode *inode, | |
360 | struct fiemap_extent_info *fieinfo, u64 start, | |
361 | u64 len, get_block_t *get_block) | |
362 | { | |
363 | int ret; | |
364 | mutex_lock(&inode->i_mutex); | |
365 | ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block); | |
366 | mutex_unlock(&inode->i_mutex); | |
367 | return ret; | |
368 | } | |
68c9d702 JB |
369 | EXPORT_SYMBOL(generic_block_fiemap); |
370 | ||
06270d5d AB |
371 | #endif /* CONFIG_BLOCK */ |
372 | ||
1da177e4 LT |
373 | static int file_ioctl(struct file *filp, unsigned int cmd, |
374 | unsigned long arg) | |
375 | { | |
c9845ff1 | 376 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
377 | int __user *p = (int __user *)arg; |
378 | ||
379 | switch (cmd) { | |
c9845ff1 | 380 | case FIBMAP: |
aa81a7c7 | 381 | return ioctl_fibmap(filp, p); |
c4b929b8 MF |
382 | case FS_IOC_FIEMAP: |
383 | return ioctl_fiemap(filp, arg); | |
c9845ff1 EZ |
384 | case FIGETBSZ: |
385 | return put_user(inode->i_sb->s_blocksize, p); | |
386 | case FIONREAD: | |
387 | return put_user(i_size_read(inode) - filp->f_pos, p); | |
1da177e4 LT |
388 | } |
389 | ||
deb21db7 | 390 | return vfs_ioctl(filp, cmd, arg); |
1da177e4 LT |
391 | } |
392 | ||
aa81a7c7 EZ |
393 | static int ioctl_fionbio(struct file *filp, int __user *argp) |
394 | { | |
395 | unsigned int flag; | |
396 | int on, error; | |
397 | ||
398 | error = get_user(on, argp); | |
399 | if (error) | |
400 | return error; | |
401 | flag = O_NONBLOCK; | |
402 | #ifdef __sparc__ | |
403 | /* SunOS compatibility item. */ | |
404 | if (O_NONBLOCK != O_NDELAY) | |
405 | flag |= O_NDELAY; | |
406 | #endif | |
407 | if (on) | |
408 | filp->f_flags |= flag; | |
409 | else | |
410 | filp->f_flags &= ~flag; | |
411 | return error; | |
412 | } | |
413 | ||
414 | static int ioctl_fioasync(unsigned int fd, struct file *filp, | |
415 | int __user *argp) | |
416 | { | |
417 | unsigned int flag; | |
418 | int on, error; | |
419 | ||
420 | error = get_user(on, argp); | |
421 | if (error) | |
422 | return error; | |
423 | flag = on ? FASYNC : 0; | |
424 | ||
425 | /* Did FASYNC state change ? */ | |
426 | if ((flag ^ filp->f_flags) & FASYNC) { | |
218d11a8 | 427 | if (filp->f_op && filp->f_op->fasync) |
aa81a7c7 | 428 | error = filp->f_op->fasync(fd, filp, on); |
218d11a8 | 429 | else |
aa81a7c7 EZ |
430 | error = -ENOTTY; |
431 | } | |
432 | if (error) | |
433 | return error; | |
434 | ||
435 | if (on) | |
436 | filp->f_flags |= FASYNC; | |
437 | else | |
438 | filp->f_flags &= ~FASYNC; | |
439 | return error; | |
440 | } | |
441 | ||
1da177e4 LT |
442 | /* |
443 | * When you add any new common ioctls to the switches above and below | |
444 | * please update compat_sys_ioctl() too. | |
445 | * | |
deb21db7 | 446 | * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d. |
1da177e4 LT |
447 | * It's just a simple helper for sys_ioctl and compat_sys_ioctl. |
448 | */ | |
deb21db7 EZ |
449 | int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, |
450 | unsigned long arg) | |
1da177e4 | 451 | { |
aa81a7c7 EZ |
452 | int error = 0; |
453 | int __user *argp = (int __user *)arg; | |
1da177e4 LT |
454 | |
455 | switch (cmd) { | |
c9845ff1 EZ |
456 | case FIOCLEX: |
457 | set_close_on_exec(fd, 1); | |
458 | break; | |
1da177e4 | 459 | |
c9845ff1 EZ |
460 | case FIONCLEX: |
461 | set_close_on_exec(fd, 0); | |
462 | break; | |
1da177e4 | 463 | |
c9845ff1 | 464 | case FIONBIO: |
218d11a8 JC |
465 | /* BKL needed to avoid races tweaking f_flags */ |
466 | lock_kernel(); | |
aa81a7c7 | 467 | error = ioctl_fionbio(filp, argp); |
218d11a8 | 468 | unlock_kernel(); |
c9845ff1 EZ |
469 | break; |
470 | ||
471 | case FIOASYNC: | |
218d11a8 JC |
472 | /* BKL needed to avoid races tweaking f_flags */ |
473 | lock_kernel(); | |
aa81a7c7 | 474 | error = ioctl_fioasync(fd, filp, argp); |
218d11a8 | 475 | unlock_kernel(); |
c9845ff1 EZ |
476 | break; |
477 | ||
478 | case FIOQSIZE: | |
479 | if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) || | |
480 | S_ISREG(filp->f_path.dentry->d_inode->i_mode) || | |
481 | S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) { | |
482 | loff_t res = | |
483 | inode_get_bytes(filp->f_path.dentry->d_inode); | |
484 | error = copy_to_user((loff_t __user *)arg, &res, | |
485 | sizeof(res)) ? -EFAULT : 0; | |
486 | } else | |
487 | error = -ENOTTY; | |
488 | break; | |
489 | default: | |
490 | if (S_ISREG(filp->f_path.dentry->d_inode->i_mode)) | |
491 | error = file_ioctl(filp, cmd, arg); | |
492 | else | |
deb21db7 | 493 | error = vfs_ioctl(filp, cmd, arg); |
c9845ff1 | 494 | break; |
1da177e4 LT |
495 | } |
496 | return error; | |
497 | } | |
498 | ||
499 | asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) | |
500 | { | |
c9845ff1 | 501 | struct file *filp; |
1da177e4 LT |
502 | int error = -EBADF; |
503 | int fput_needed; | |
504 | ||
505 | filp = fget_light(fd, &fput_needed); | |
506 | if (!filp) | |
507 | goto out; | |
508 | ||
509 | error = security_file_ioctl(filp, cmd, arg); | |
510 | if (error) | |
511 | goto out_fput; | |
512 | ||
deb21db7 | 513 | error = do_vfs_ioctl(filp, fd, cmd, arg); |
1da177e4 LT |
514 | out_fput: |
515 | fput_light(filp, fput_needed); | |
516 | out: | |
517 | return error; | |
518 | } |