block: export blkdev_reread_part() and __blkdev_reread_part()
[linux-2.6-block.git] / block / ioctl.c
CommitLineData
c59ede7b 1#include <linux/capability.h>
1da177e4 2#include <linux/blkdev.h>
d5decd3b 3#include <linux/export.h>
5a0e3ad6 4#include <linux/gfp.h>
1da177e4 5#include <linux/blkpg.h>
a885c8c4 6#include <linux/hdreg.h>
1da177e4 7#include <linux/backing-dev.h>
ff01bb48 8#include <linux/fs.h>
2056a782 9#include <linux/blktrace_api.h>
1da177e4
LT
10#include <asm/uaccess.h>
11
12static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
13{
14 struct block_device *bdevp;
15 struct gendisk *disk;
c83f6bf9 16 struct hd_struct *part, *lpart;
1da177e4
LT
17 struct blkpg_ioctl_arg a;
18 struct blkpg_partition p;
e71bf0d0 19 struct disk_part_iter piter;
1da177e4 20 long long start, length;
cf771cb5 21 int partno;
1da177e4
LT
22
23 if (!capable(CAP_SYS_ADMIN))
24 return -EACCES;
25 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
26 return -EFAULT;
27 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
28 return -EFAULT;
29 disk = bdev->bd_disk;
30 if (bdev != bdev->bd_contains)
31 return -EINVAL;
cf771cb5 32 partno = p.pno;
540eed56 33 if (partno <= 0)
1da177e4
LT
34 return -EINVAL;
35 switch (a.op) {
36 case BLKPG_ADD_PARTITION:
37 start = p.start >> 9;
38 length = p.length >> 9;
c83f6bf9
VG
39 /* check for fit in a hd_struct */
40 if (sizeof(sector_t) == sizeof(long) &&
1da177e4
LT
41 sizeof(long long) > sizeof(long)) {
42 long pstart = start, plength = length;
43 if (pstart != start || plength != length
2bd6efad 44 || pstart < 0 || plength < 0 || partno > 65535)
1da177e4
LT
45 return -EINVAL;
46 }
88e34126 47
c039e313 48 mutex_lock(&bdev->bd_mutex);
88e34126 49
1da177e4 50 /* overlap? */
e71bf0d0
TH
51 disk_part_iter_init(&piter, disk,
52 DISK_PITER_INCL_EMPTY);
53 while ((part = disk_part_iter_next(&piter))) {
54 if (!(start + length <= part->start_sect ||
55 start >= part->start_sect + part->nr_sects)) {
56 disk_part_iter_exit(&piter);
c039e313 57 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
58 return -EBUSY;
59 }
60 }
e71bf0d0
TH
61 disk_part_iter_exit(&piter);
62
1da177e4 63 /* all seems OK */
ba32929a 64 part = add_partition(disk, partno, start, length,
6d1d8050 65 ADDPART_FLAG_NONE, NULL);
c039e313 66 mutex_unlock(&bdev->bd_mutex);
c7d1ba41 67 return PTR_ERR_OR_ZERO(part);
1da177e4 68 case BLKPG_DEL_PARTITION:
e71bf0d0
TH
69 part = disk_get_part(disk, partno);
70 if (!part)
1da177e4 71 return -ENXIO;
e71bf0d0
TH
72
73 bdevp = bdget(part_devt(part));
74 disk_put_part(part);
1da177e4
LT
75 if (!bdevp)
76 return -ENOMEM;
e71bf0d0 77
2e7b651d 78 mutex_lock(&bdevp->bd_mutex);
1da177e4 79 if (bdevp->bd_openers) {
c039e313 80 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
81 bdput(bdevp);
82 return -EBUSY;
83 }
84 /* all seems OK */
85 fsync_bdev(bdevp);
f98393a6 86 invalidate_bdev(bdevp);
1da177e4 87
6d740cd5 88 mutex_lock_nested(&bdev->bd_mutex, 1);
cf771cb5 89 delete_partition(disk, partno);
c039e313
AV
90 mutex_unlock(&bdev->bd_mutex);
91 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
92 bdput(bdevp);
93
c83f6bf9
VG
94 return 0;
95 case BLKPG_RESIZE_PARTITION:
96 start = p.start >> 9;
97 /* new length of partition in bytes */
98 length = p.length >> 9;
99 /* check for fit in a hd_struct */
100 if (sizeof(sector_t) == sizeof(long) &&
101 sizeof(long long) > sizeof(long)) {
102 long pstart = start, plength = length;
103 if (pstart != start || plength != length
104 || pstart < 0 || plength < 0)
105 return -EINVAL;
106 }
107 part = disk_get_part(disk, partno);
108 if (!part)
109 return -ENXIO;
110 bdevp = bdget(part_devt(part));
111 if (!bdevp) {
112 disk_put_part(part);
113 return -ENOMEM;
114 }
115 mutex_lock(&bdevp->bd_mutex);
116 mutex_lock_nested(&bdev->bd_mutex, 1);
117 if (start != part->start_sect) {
118 mutex_unlock(&bdevp->bd_mutex);
119 mutex_unlock(&bdev->bd_mutex);
120 bdput(bdevp);
121 disk_put_part(part);
122 return -EINVAL;
123 }
124 /* overlap? */
125 disk_part_iter_init(&piter, disk,
126 DISK_PITER_INCL_EMPTY);
127 while ((lpart = disk_part_iter_next(&piter))) {
128 if (lpart->partno != partno &&
129 !(start + length <= lpart->start_sect ||
130 start >= lpart->start_sect + lpart->nr_sects)
131 ) {
132 disk_part_iter_exit(&piter);
133 mutex_unlock(&bdevp->bd_mutex);
134 mutex_unlock(&bdev->bd_mutex);
135 bdput(bdevp);
136 disk_put_part(part);
137 return -EBUSY;
138 }
139 }
140 disk_part_iter_exit(&piter);
141 part_nr_sects_write(part, (sector_t)length);
142 i_size_write(bdevp->bd_inode, p.length);
143 mutex_unlock(&bdevp->bd_mutex);
144 mutex_unlock(&bdev->bd_mutex);
145 bdput(bdevp);
146 disk_put_part(part);
1da177e4
LT
147 return 0;
148 default:
149 return -EINVAL;
150 }
151}
152
be324177
JW
153/*
154 * This is an exported API for the block driver, and will not
155 * acquire bd_mutex. This API should be used in case that
156 * caller has held bd_mutex already.
157 */
158int __blkdev_reread_part(struct block_device *bdev)
1da177e4
LT
159{
160 struct gendisk *disk = bdev->bd_disk;
1da177e4 161
d27769ec 162 if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
1da177e4
LT
163 return -EINVAL;
164 if (!capable(CAP_SYS_ADMIN))
165 return -EACCES;
be324177
JW
166
167 lockdep_assert_held(&bdev->bd_mutex);
168
169 return rescan_partitions(disk, bdev);
170}
171EXPORT_SYMBOL(__blkdev_reread_part);
172
173/*
174 * This is an exported API for the block driver, and will
175 * try to acquire bd_mutex. If bd_mutex has been held already
176 * in current context, please call __blkdev_reread_part().
177 */
178int blkdev_reread_part(struct block_device *bdev)
179{
180 int res;
181
c039e313 182 if (!mutex_trylock(&bdev->bd_mutex))
1da177e4 183 return -EBUSY;
be324177 184 res = __blkdev_reread_part(bdev);
c039e313 185 mutex_unlock(&bdev->bd_mutex);
be324177 186
1da177e4
LT
187 return res;
188}
be324177 189EXPORT_SYMBOL(blkdev_reread_part);
1da177e4 190
d30a2605 191static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
8d57a98c 192 uint64_t len, int secure)
d30a2605 193{
dd3932ed 194 unsigned long flags = 0;
8d57a98c 195
d30a2605
DW
196 if (start & 511)
197 return -EINVAL;
198 if (len & 511)
199 return -EINVAL;
200 start >>= 9;
201 len >>= 9;
202
77304d2a 203 if (start + len > (i_size_read(bdev->bd_inode) >> 9))
d30a2605 204 return -EINVAL;
8d57a98c 205 if (secure)
dd3932ed 206 flags |= BLKDEV_DISCARD_SECURE;
8d57a98c 207 return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
d30a2605
DW
208}
209
66ba32dc
MP
210static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start,
211 uint64_t len)
212{
213 if (start & 511)
214 return -EINVAL;
215 if (len & 511)
216 return -EINVAL;
217 start >>= 9;
218 len >>= 9;
219
220 if (start + len > (i_size_read(bdev->bd_inode) >> 9))
221 return -EINVAL;
222
d93ba7a5 223 return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
66ba32dc
MP
224}
225
1da177e4
LT
226static int put_ushort(unsigned long arg, unsigned short val)
227{
228 return put_user(val, (unsigned short __user *)arg);
229}
230
231static int put_int(unsigned long arg, int val)
232{
233 return put_user(val, (int __user *)arg);
234}
235
ac481c20
MP
236static int put_uint(unsigned long arg, unsigned int val)
237{
238 return put_user(val, (unsigned int __user *)arg);
239}
240
1da177e4
LT
241static int put_long(unsigned long arg, long val)
242{
243 return put_user(val, (long __user *)arg);
244}
245
246static int put_ulong(unsigned long arg, unsigned long val)
247{
248 return put_user(val, (unsigned long __user *)arg);
249}
250
251static int put_u64(unsigned long arg, u64 val)
252{
253 return put_user(val, (u64 __user *)arg);
254}
255
633a08b8
AV
256int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
257 unsigned cmd, unsigned long arg)
258{
259 struct gendisk *disk = bdev->bd_disk;
d4430d62
AV
260
261 if (disk->fops->ioctl)
262 return disk->fops->ioctl(bdev, mode, cmd, arg);
633a08b8 263
633a08b8
AV
264 return -ENOTTY;
265}
266/*
267 * For the record: _GPL here is only because somebody decided to slap it
268 * on the previous export. Sheer idiocy, since it wasn't copyrightable
269 * at all and could be open-coded without any exports by anybody who cares.
270 */
271EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
272
07d106d0
LT
273/*
274 * Is it an unrecognized ioctl? The correct returns are either
275 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
276 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
277 * code before returning.
278 *
279 * Confused drivers sometimes return EINVAL, which is wrong. It
280 * means "I understood the ioctl command, but the parameters to
281 * it were wrong".
282 *
283 * We should aim to just fix the broken drivers, the EINVAL case
284 * should go away.
285 */
286static inline int is_unrecognized_ioctl(int ret)
287{
288 return ret == -EINVAL ||
289 ret == -ENOTTY ||
290 ret == -ENOIOCTLCMD;
291}
292
f58c4c0a 293/*
8a6cfeb6 294 * always keep this in sync with compat_blkdev_ioctl()
f58c4c0a 295 */
56b26add 296int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
bb93e3a5
AB
297 unsigned long arg)
298{
bb93e3a5 299 struct gendisk *disk = bdev->bd_disk;
45048d09
AV
300 struct backing_dev_info *bdi;
301 loff_t size;
bb93e3a5 302 int ret, n;
63f26496 303 unsigned int max_sectors;
bb93e3a5
AB
304
305 switch(cmd) {
1da177e4
LT
306 case BLKFLSBUF:
307 if (!capable(CAP_SYS_ADMIN))
308 return -EACCES;
bb93e3a5 309
e436fdae 310 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
07d106d0 311 if (!is_unrecognized_ioctl(ret))
bb93e3a5
AB
312 return ret;
313
1da177e4 314 fsync_bdev(bdev);
f98393a6 315 invalidate_bdev(bdev);
1da177e4 316 return 0;
bb93e3a5 317
1da177e4 318 case BLKROSET:
e436fdae 319 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
07d106d0 320 if (!is_unrecognized_ioctl(ret))
bb93e3a5 321 return ret;
1da177e4
LT
322 if (!capable(CAP_SYS_ADMIN))
323 return -EACCES;
324 if (get_user(n, (int __user *)(arg)))
325 return -EFAULT;
326 set_device_ro(bdev, n);
327 return 0;
d30a2605 328
8d57a98c
AH
329 case BLKDISCARD:
330 case BLKSECDISCARD: {
d30a2605
DW
331 uint64_t range[2];
332
e436fdae 333 if (!(mode & FMODE_WRITE))
d30a2605
DW
334 return -EBADF;
335
336 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
337 return -EFAULT;
338
8d57a98c
AH
339 return blk_ioctl_discard(bdev, range[0], range[1],
340 cmd == BLKSECDISCARD);
d30a2605 341 }
66ba32dc
MP
342 case BLKZEROOUT: {
343 uint64_t range[2];
344
345 if (!(mode & FMODE_WRITE))
346 return -EBADF;
347
348 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
349 return -EFAULT;
350
351 return blk_ioctl_zeroout(bdev, range[0], range[1]);
352 }
d30a2605 353
a885c8c4
CH
354 case HDIO_GETGEO: {
355 struct hd_geometry geo;
356
357 if (!arg)
358 return -EINVAL;
359 if (!disk->fops->getgeo)
360 return -ENOTTY;
361
362 /*
363 * We need to set the startsect first, the driver may
364 * want to override it.
365 */
a014741c 366 memset(&geo, 0, sizeof(geo));
a885c8c4
CH
367 geo.start = get_start_sect(bdev);
368 ret = disk->fops->getgeo(bdev, &geo);
369 if (ret)
370 return ret;
371 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
372 sizeof(geo)))
373 return -EFAULT;
374 return 0;
375 }
45048d09
AV
376 case BLKRAGET:
377 case BLKFRAGET:
378 if (!arg)
379 return -EINVAL;
380 bdi = blk_get_backing_dev_info(bdev);
45048d09
AV
381 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
382 case BLKROGET:
383 return put_int(arg, bdev_read_only(bdev) != 0);
ac481c20 384 case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
45048d09 385 return put_int(arg, block_size(bdev));
ac481c20 386 case BLKSSZGET: /* get block device logical block size */
e1defc4f 387 return put_int(arg, bdev_logical_block_size(bdev));
ac481c20
MP
388 case BLKPBSZGET: /* get block device physical block size */
389 return put_uint(arg, bdev_physical_block_size(bdev));
390 case BLKIOMIN:
391 return put_uint(arg, bdev_io_min(bdev));
392 case BLKIOOPT:
393 return put_uint(arg, bdev_io_opt(bdev));
394 case BLKALIGNOFF:
395 return put_int(arg, bdev_alignment_offset(bdev));
98262f27
MP
396 case BLKDISCARDZEROES:
397 return put_uint(arg, bdev_discard_zeroes_data(bdev));
45048d09 398 case BLKSECTGET:
63f26496
AM
399 max_sectors = min_t(unsigned int, USHRT_MAX,
400 queue_max_sectors(bdev_get_queue(bdev)));
401 return put_ushort(arg, max_sectors);
ef00f59c
MP
402 case BLKROTATIONAL:
403 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
45048d09
AV
404 case BLKRASET:
405 case BLKFRASET:
406 if(!capable(CAP_SYS_ADMIN))
407 return -EACCES;
408 bdi = blk_get_backing_dev_info(bdev);
45048d09 409 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
45048d09
AV
410 return 0;
411 case BLKBSZSET:
412 /* set the logical block size */
413 if (!capable(CAP_SYS_ADMIN))
414 return -EACCES;
415 if (!arg)
416 return -EINVAL;
417 if (get_user(n, (int __user *) arg))
418 return -EFAULT;
3c522ced
MS
419 if (!(mode & FMODE_EXCL)) {
420 bdgrab(bdev);
421 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
422 return -EBUSY;
423 }
45048d09 424 ret = set_blocksize(bdev, n);
6af3a56e 425 if (!(mode & FMODE_EXCL))
e525fd89 426 blkdev_put(bdev, mode | FMODE_EXCL);
bb93e3a5 427 return ret;
45048d09 428 case BLKPG:
45048d09 429 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
45048d09
AV
430 break;
431 case BLKRRPART:
45048d09 432 ret = blkdev_reread_part(bdev);
45048d09
AV
433 break;
434 case BLKGETSIZE:
77304d2a 435 size = i_size_read(bdev->bd_inode);
45048d09
AV
436 if ((size >> 9) > ~0UL)
437 return -EFBIG;
438 return put_ulong(arg, size >> 9);
439 case BLKGETSIZE64:
77304d2a 440 return put_u64(arg, i_size_read(bdev->bd_inode));
45048d09
AV
441 case BLKTRACESTART:
442 case BLKTRACESTOP:
443 case BLKTRACESETUP:
444 case BLKTRACETEARDOWN:
45048d09 445 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
45048d09
AV
446 break;
447 default:
448 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
449 }
450 return ret;
1da177e4 451}
68f66feb 452EXPORT_SYMBOL_GPL(blkdev_ioctl);