[SCSI] scsi_debug: Convert to use root_device_register() and root_device_unregister()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ioctl.c
blobf855ea4fc88895a13b53b075b9a3fb0dbcb53d8b
1 /*
2 * linux/fs/ioctl.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
7 #include <linux/syscalls.h>
8 #include <linux/mm.h>
9 #include <linux/smp_lock.h>
10 #include <linux/capability.h>
11 #include <linux/file.h>
12 #include <linux/fs.h>
13 #include <linux/security.h>
14 #include <linux/module.h>
15 #include <linux/uaccess.h>
16 #include <linux/writeback.h>
17 #include <linux/buffer_head.h>
18 #include <linux/falloc.h>
20 #include <asm/ioctls.h>
22 /* So that the fiemap access checks can't overflow on 32 bit machines. */
23 #define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
25 /**
26 * vfs_ioctl - call filesystem specific ioctl methods
27 * @filp: open file to invoke ioctl method on
28 * @cmd: ioctl command to execute
29 * @arg: command-specific argument for ioctl
31 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
32 * returns -ENOTTY.
34 * Returns 0 on success, -errno on error.
36 static long vfs_ioctl(struct file *filp, unsigned int cmd,
37 unsigned long arg)
39 int error = -ENOTTY;
41 if (!filp->f_op || !filp->f_op->unlocked_ioctl)
42 goto out;
44 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
45 if (error == -ENOIOCTLCMD)
46 error = -EINVAL;
47 out:
48 return error;
51 static int ioctl_fibmap(struct file *filp, int __user *p)
53 struct address_space *mapping = filp->f_mapping;
54 int res, block;
56 /* do we support this mess? */
57 if (!mapping->a_ops->bmap)
58 return -EINVAL;
59 if (!capable(CAP_SYS_RAWIO))
60 return -EPERM;
61 res = get_user(block, p);
62 if (res)
63 return res;
64 res = mapping->a_ops->bmap(mapping, block);
65 return put_user(res, p);
68 /**
69 * fiemap_fill_next_extent - Fiemap helper function
70 * @fieinfo: Fiemap context passed into ->fiemap
71 * @logical: Extent logical start offset, in bytes
72 * @phys: Extent physical start offset, in bytes
73 * @len: Extent length, in bytes
74 * @flags: FIEMAP_EXTENT flags that describe this extent
76 * Called from file system ->fiemap callback. Will populate extent
77 * info as passed in via arguments and copy to user memory. On
78 * success, extent count on fieinfo is incremented.
80 * Returns 0 on success, -errno on error, 1 if this was the last
81 * extent that will fit in user array.
83 #define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
84 #define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED)
85 #define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
86 int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
87 u64 phys, u64 len, u32 flags)
89 struct fiemap_extent extent;
90 struct fiemap_extent *dest = fieinfo->fi_extents_start;
92 /* only count the extents */
93 if (fieinfo->fi_extents_max == 0) {
94 fieinfo->fi_extents_mapped++;
95 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
98 if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
99 return 1;
101 if (flags & SET_UNKNOWN_FLAGS)
102 flags |= FIEMAP_EXTENT_UNKNOWN;
103 if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
104 flags |= FIEMAP_EXTENT_ENCODED;
105 if (flags & SET_NOT_ALIGNED_FLAGS)
106 flags |= FIEMAP_EXTENT_NOT_ALIGNED;
108 memset(&extent, 0, sizeof(extent));
109 extent.fe_logical = logical;
110 extent.fe_physical = phys;
111 extent.fe_length = len;
112 extent.fe_flags = flags;
114 dest += fieinfo->fi_extents_mapped;
115 if (copy_to_user(dest, &extent, sizeof(extent)))
116 return -EFAULT;
118 fieinfo->fi_extents_mapped++;
119 if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
120 return 1;
121 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
123 EXPORT_SYMBOL(fiemap_fill_next_extent);
126 * fiemap_check_flags - check validity of requested flags for fiemap
127 * @fieinfo: Fiemap context passed into ->fiemap
128 * @fs_flags: Set of fiemap flags that the file system understands
130 * Called from file system ->fiemap callback. This will compute the
131 * intersection of valid fiemap flags and those that the fs supports. That
132 * value is then compared against the user supplied flags. In case of bad user
133 * flags, the invalid values will be written into the fieinfo structure, and
134 * -EBADR is returned, which tells ioctl_fiemap() to return those values to
135 * userspace. For this reason, a return code of -EBADR should be preserved.
137 * Returns 0 on success, -EBADR on bad flags.
139 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
141 u32 incompat_flags;
143 incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
144 if (incompat_flags) {
145 fieinfo->fi_flags = incompat_flags;
146 return -EBADR;
148 return 0;
150 EXPORT_SYMBOL(fiemap_check_flags);
152 static int fiemap_check_ranges(struct super_block *sb,
153 u64 start, u64 len, u64 *new_len)
155 u64 maxbytes = (u64) sb->s_maxbytes;
157 *new_len = len;
159 if (len == 0)
160 return -EINVAL;
162 if (start > maxbytes)
163 return -EFBIG;
166 * Shrink request scope to what the fs can actually handle.
168 if (len > maxbytes || (maxbytes - len) < start)
169 *new_len = maxbytes - start;
171 return 0;
174 static int ioctl_fiemap(struct file *filp, unsigned long arg)
176 struct fiemap fiemap;
177 struct fiemap_extent_info fieinfo = { 0, };
178 struct inode *inode = filp->f_path.dentry->d_inode;
179 struct super_block *sb = inode->i_sb;
180 u64 len;
181 int error;
183 if (!inode->i_op->fiemap)
184 return -EOPNOTSUPP;
186 if (copy_from_user(&fiemap, (struct fiemap __user *)arg,
187 sizeof(struct fiemap)))
188 return -EFAULT;
190 if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
191 return -EINVAL;
193 error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
194 &len);
195 if (error)
196 return error;
198 fieinfo.fi_flags = fiemap.fm_flags;
199 fieinfo.fi_extents_max = fiemap.fm_extent_count;
200 fieinfo.fi_extents_start = (struct fiemap_extent *)(arg + sizeof(fiemap));
202 if (fiemap.fm_extent_count != 0 &&
203 !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
204 fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
205 return -EFAULT;
207 if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
208 filemap_write_and_wait(inode->i_mapping);
210 error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
211 fiemap.fm_flags = fieinfo.fi_flags;
212 fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
213 if (copy_to_user((char *)arg, &fiemap, sizeof(fiemap)))
214 error = -EFAULT;
216 return error;
219 #ifdef CONFIG_BLOCK
221 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
223 return (offset >> inode->i_blkbits);
226 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
228 return (blk << inode->i_blkbits);
232 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
233 * @inode: the inode to map
234 * @fieinfo: the fiemap info struct that will be passed back to userspace
235 * @start: where to start mapping in the inode
236 * @len: how much space to map
237 * @get_block: the fs's get_block function
239 * This does FIEMAP for block based inodes. Basically it will just loop
240 * through get_block until we hit the number of extents we want to map, or we
241 * go past the end of the file and hit a hole.
243 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
244 * please do not use this function, it will stop at the first unmapped block
245 * beyond i_size.
247 * If you use this function directly, you need to do your own locking. Use
248 * generic_block_fiemap if you want the locking done for you.
251 int __generic_block_fiemap(struct inode *inode,
252 struct fiemap_extent_info *fieinfo, loff_t start,
253 loff_t len, get_block_t *get_block)
255 struct buffer_head map_bh;
256 sector_t start_blk, last_blk;
257 loff_t isize = i_size_read(inode);
258 u64 logical = 0, phys = 0, size = 0;
259 u32 flags = FIEMAP_EXTENT_MERGED;
260 bool past_eof = false, whole_file = false;
261 int ret = 0;
263 ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
264 if (ret)
265 return ret;
268 * Either the i_mutex or other appropriate locking needs to be held
269 * since we expect isize to not change at all through the duration of
270 * this call.
272 if (len >= isize) {
273 whole_file = true;
274 len = isize;
277 start_blk = logical_to_blk(inode, start);
278 last_blk = logical_to_blk(inode, start + len - 1);
280 do {
282 * we set b_size to the total size we want so it will map as
283 * many contiguous blocks as possible at once
285 memset(&map_bh, 0, sizeof(struct buffer_head));
286 map_bh.b_size = len;
288 ret = get_block(inode, start_blk, &map_bh, 0);
289 if (ret)
290 break;
292 /* HOLE */
293 if (!buffer_mapped(&map_bh)) {
294 start_blk++;
297 * We want to handle the case where there is an
298 * allocated block at the front of the file, and then
299 * nothing but holes up to the end of the file properly,
300 * to make sure that extent at the front gets properly
301 * marked with FIEMAP_EXTENT_LAST
303 if (!past_eof &&
304 blk_to_logical(inode, start_blk) >= isize)
305 past_eof = 1;
308 * First hole after going past the EOF, this is our
309 * last extent
311 if (past_eof && size) {
312 flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
313 ret = fiemap_fill_next_extent(fieinfo, logical,
314 phys, size,
315 flags);
316 } else if (size) {
317 ret = fiemap_fill_next_extent(fieinfo, logical,
318 phys, size, flags);
319 size = 0;
322 /* if we have holes up to/past EOF then we're done */
323 if (start_blk > last_blk || past_eof || ret)
324 break;
325 } else {
327 * We have gone over the length of what we wanted to
328 * map, and it wasn't the entire file, so add the extent
329 * we got last time and exit.
331 * This is for the case where say we want to map all the
332 * way up to the second to the last block in a file, but
333 * the last block is a hole, making the second to last
334 * block FIEMAP_EXTENT_LAST. In this case we want to
335 * see if there is a hole after the second to last block
336 * so we can mark it properly. If we found data after
337 * we exceeded the length we were requesting, then we
338 * are good to go, just add the extent to the fieinfo
339 * and break
341 if (start_blk > last_blk && !whole_file) {
342 ret = fiemap_fill_next_extent(fieinfo, logical,
343 phys, size,
344 flags);
345 break;
349 * if size != 0 then we know we already have an extent
350 * to add, so add it.
352 if (size) {
353 ret = fiemap_fill_next_extent(fieinfo, logical,
354 phys, size,
355 flags);
356 if (ret)
357 break;
360 logical = blk_to_logical(inode, start_blk);
361 phys = blk_to_logical(inode, map_bh.b_blocknr);
362 size = map_bh.b_size;
363 flags = FIEMAP_EXTENT_MERGED;
365 start_blk += logical_to_blk(inode, size);
368 * If we are past the EOF, then we need to make sure as
369 * soon as we find a hole that the last extent we found
370 * is marked with FIEMAP_EXTENT_LAST
372 if (!past_eof && logical + size >= isize)
373 past_eof = true;
375 cond_resched();
376 } while (1);
378 /* If ret is 1 then we just hit the end of the extent array */
379 if (ret == 1)
380 ret = 0;
382 return ret;
384 EXPORT_SYMBOL(__generic_block_fiemap);
387 * generic_block_fiemap - FIEMAP for block based inodes
388 * @inode: The inode to map
389 * @fieinfo: The mapping information
390 * @start: The initial block to map
391 * @len: The length of the extect to attempt to map
392 * @get_block: The block mapping function for the fs
394 * Calls __generic_block_fiemap to map the inode, after taking
395 * the inode's mutex lock.
398 int generic_block_fiemap(struct inode *inode,
399 struct fiemap_extent_info *fieinfo, u64 start,
400 u64 len, get_block_t *get_block)
402 int ret;
403 mutex_lock(&inode->i_mutex);
404 ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
405 mutex_unlock(&inode->i_mutex);
406 return ret;
408 EXPORT_SYMBOL(generic_block_fiemap);
410 #endif /* CONFIG_BLOCK */
413 * This provides compatibility with legacy XFS pre-allocation ioctls
414 * which predate the fallocate syscall.
416 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
417 * are used here, rest are ignored.
419 int ioctl_preallocate(struct file *filp, void __user *argp)
421 struct inode *inode = filp->f_path.dentry->d_inode;
422 struct space_resv sr;
424 if (copy_from_user(&sr, argp, sizeof(sr)))
425 return -EFAULT;
427 switch (sr.l_whence) {
428 case SEEK_SET:
429 break;
430 case SEEK_CUR:
431 sr.l_start += filp->f_pos;
432 break;
433 case SEEK_END:
434 sr.l_start += i_size_read(inode);
435 break;
436 default:
437 return -EINVAL;
440 return do_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
443 static int file_ioctl(struct file *filp, unsigned int cmd,
444 unsigned long arg)
446 struct inode *inode = filp->f_path.dentry->d_inode;
447 int __user *p = (int __user *)arg;
449 switch (cmd) {
450 case FIBMAP:
451 return ioctl_fibmap(filp, p);
452 case FIONREAD:
453 return put_user(i_size_read(inode) - filp->f_pos, p);
454 case FS_IOC_RESVSP:
455 case FS_IOC_RESVSP64:
456 return ioctl_preallocate(filp, p);
459 return vfs_ioctl(filp, cmd, arg);
462 static int ioctl_fionbio(struct file *filp, int __user *argp)
464 unsigned int flag;
465 int on, error;
467 error = get_user(on, argp);
468 if (error)
469 return error;
470 flag = O_NONBLOCK;
471 #ifdef __sparc__
472 /* SunOS compatibility item. */
473 if (O_NONBLOCK != O_NDELAY)
474 flag |= O_NDELAY;
475 #endif
476 spin_lock(&filp->f_lock);
477 if (on)
478 filp->f_flags |= flag;
479 else
480 filp->f_flags &= ~flag;
481 spin_unlock(&filp->f_lock);
482 return error;
485 static int ioctl_fioasync(unsigned int fd, struct file *filp,
486 int __user *argp)
488 unsigned int flag;
489 int on, error;
491 error = get_user(on, argp);
492 if (error)
493 return error;
494 flag = on ? FASYNC : 0;
496 /* Did FASYNC state change ? */
497 if ((flag ^ filp->f_flags) & FASYNC) {
498 if (filp->f_op && filp->f_op->fasync)
499 /* fasync() adjusts filp->f_flags */
500 error = filp->f_op->fasync(fd, filp, on);
501 else
502 error = -ENOTTY;
504 return error < 0 ? error : 0;
507 static int ioctl_fsfreeze(struct file *filp)
509 struct super_block *sb = filp->f_path.dentry->d_inode->i_sb;
511 if (!capable(CAP_SYS_ADMIN))
512 return -EPERM;
514 /* If filesystem doesn't support freeze feature, return. */
515 if (sb->s_op->freeze_fs == NULL)
516 return -EOPNOTSUPP;
518 /* Freeze */
519 return freeze_super(sb);
522 static int ioctl_fsthaw(struct file *filp)
524 struct super_block *sb = filp->f_path.dentry->d_inode->i_sb;
526 if (!capable(CAP_SYS_ADMIN))
527 return -EPERM;
529 /* Thaw */
530 return thaw_super(sb);
534 * When you add any new common ioctls to the switches above and below
535 * please update compat_sys_ioctl() too.
537 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
538 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
540 int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
541 unsigned long arg)
543 int error = 0;
544 int __user *argp = (int __user *)arg;
546 switch (cmd) {
547 case FIOCLEX:
548 set_close_on_exec(fd, 1);
549 break;
551 case FIONCLEX:
552 set_close_on_exec(fd, 0);
553 break;
555 case FIONBIO:
556 error = ioctl_fionbio(filp, argp);
557 break;
559 case FIOASYNC:
560 error = ioctl_fioasync(fd, filp, argp);
561 break;
563 case FIOQSIZE:
564 if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) ||
565 S_ISREG(filp->f_path.dentry->d_inode->i_mode) ||
566 S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) {
567 loff_t res =
568 inode_get_bytes(filp->f_path.dentry->d_inode);
569 error = copy_to_user((loff_t __user *)arg, &res,
570 sizeof(res)) ? -EFAULT : 0;
571 } else
572 error = -ENOTTY;
573 break;
575 case FIFREEZE:
576 error = ioctl_fsfreeze(filp);
577 break;
579 case FITHAW:
580 error = ioctl_fsthaw(filp);
581 break;
583 case FS_IOC_FIEMAP:
584 return ioctl_fiemap(filp, arg);
586 case FIGETBSZ:
588 struct inode *inode = filp->f_path.dentry->d_inode;
589 int __user *p = (int __user *)arg;
590 return put_user(inode->i_sb->s_blocksize, p);
593 default:
594 if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
595 error = file_ioctl(filp, cmd, arg);
596 else
597 error = vfs_ioctl(filp, cmd, arg);
598 break;
600 return error;
603 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
605 struct file *filp;
606 int error = -EBADF;
607 int fput_needed;
609 filp = fget_light(fd, &fput_needed);
610 if (!filp)
611 goto out;
613 error = security_file_ioctl(filp, cmd, arg);
614 if (error)
615 goto out_fput;
617 error = do_vfs_ioctl(filp, fd, cmd, arg);
618 out_fput:
619 fput_light(filp, fput_needed);
620 out:
621 return error;