1 #include <linux/capability.h>
2 #include <linux/blkdev.h>
3 #include <linux/export.h>
4 #include <linux/gfp.h>
5 #include <linux/blkpg.h>
6 #include <linux/hdreg.h>
7 #include <linux/backing-dev.h>
8 #include <linux/fs.h>
9 #include <linux/blktrace_api.h>
10 #include <asm/uaccess.h>
11
blkpg_ioctl(struct block_device * bdev,struct blkpg_ioctl_arg __user * arg)12 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
13 {
14 struct block_device *bdevp;
15 struct gendisk *disk;
16 struct hd_struct *part, *lpart;
17 struct blkpg_ioctl_arg a;
18 struct blkpg_partition p;
19 struct disk_part_iter piter;
20 long long start, length;
21 int partno;
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;
32 partno = p.pno;
33 if (partno <= 0)
34 return -EINVAL;
35 switch (a.op) {
36 case BLKPG_ADD_PARTITION:
37 start = p.start >> 9;
38 length = p.length >> 9;
39 /* check for fit in a hd_struct */
40 if (sizeof(sector_t) == sizeof(long) &&
41 sizeof(long long) > sizeof(long)) {
42 long pstart = start, plength = length;
43 if (pstart != start || plength != length
44 || pstart < 0 || plength < 0 || partno > 65535)
45 return -EINVAL;
46 }
47
48 mutex_lock(&bdev->bd_mutex);
49
50 /* overlap? */
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);
57 mutex_unlock(&bdev->bd_mutex);
58 return -EBUSY;
59 }
60 }
61 disk_part_iter_exit(&piter);
62
63 /* all seems OK */
64 part = add_partition(disk, partno, start, length,
65 ADDPART_FLAG_NONE, NULL);
66 mutex_unlock(&bdev->bd_mutex);
67 return IS_ERR(part) ? PTR_ERR(part) : 0;
68 case BLKPG_DEL_PARTITION:
69 part = disk_get_part(disk, partno);
70 if (!part)
71 return -ENXIO;
72
73 bdevp = bdget(part_devt(part));
74 disk_put_part(part);
75 if (!bdevp)
76 return -ENOMEM;
77
78 mutex_lock(&bdevp->bd_mutex);
79 if (bdevp->bd_openers) {
80 mutex_unlock(&bdevp->bd_mutex);
81 bdput(bdevp);
82 return -EBUSY;
83 }
84 /* all seems OK */
85 fsync_bdev(bdevp);
86 invalidate_bdev(bdevp);
87
88 mutex_lock_nested(&bdev->bd_mutex, 1);
89 delete_partition(disk, partno);
90 mutex_unlock(&bdev->bd_mutex);
91 mutex_unlock(&bdevp->bd_mutex);
92 bdput(bdevp);
93
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);
147 return 0;
148 default:
149 return -EINVAL;
150 }
151 }
152
blkdev_reread_part(struct block_device * bdev)153 static int blkdev_reread_part(struct block_device *bdev)
154 {
155 struct gendisk *disk = bdev->bd_disk;
156 int res;
157
158 if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
159 return -EINVAL;
160 if (!capable(CAP_SYS_ADMIN))
161 return -EACCES;
162 if (!mutex_trylock(&bdev->bd_mutex))
163 return -EBUSY;
164 res = rescan_partitions(disk, bdev);
165 mutex_unlock(&bdev->bd_mutex);
166 return res;
167 }
168
blk_ioctl_discard(struct block_device * bdev,uint64_t start,uint64_t len,int secure)169 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
170 uint64_t len, int secure)
171 {
172 unsigned long flags = 0;
173
174 if (start & 511)
175 return -EINVAL;
176 if (len & 511)
177 return -EINVAL;
178 start >>= 9;
179 len >>= 9;
180
181 if (start + len > (i_size_read(bdev->bd_inode) >> 9))
182 return -EINVAL;
183 if (secure)
184 flags |= BLKDEV_DISCARD_SECURE;
185 return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
186 }
187
blk_ioctl_zeroout(struct block_device * bdev,uint64_t start,uint64_t len)188 static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start,
189 uint64_t len)
190 {
191 if (start & 511)
192 return -EINVAL;
193 if (len & 511)
194 return -EINVAL;
195 start >>= 9;
196 len >>= 9;
197
198 if (start + len > (i_size_read(bdev->bd_inode) >> 9))
199 return -EINVAL;
200
201 return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL);
202 }
203
put_ushort(unsigned long arg,unsigned short val)204 static int put_ushort(unsigned long arg, unsigned short val)
205 {
206 return put_user(val, (unsigned short __user *)arg);
207 }
208
put_int(unsigned long arg,int val)209 static int put_int(unsigned long arg, int val)
210 {
211 return put_user(val, (int __user *)arg);
212 }
213
put_uint(unsigned long arg,unsigned int val)214 static int put_uint(unsigned long arg, unsigned int val)
215 {
216 return put_user(val, (unsigned int __user *)arg);
217 }
218
put_long(unsigned long arg,long val)219 static int put_long(unsigned long arg, long val)
220 {
221 return put_user(val, (long __user *)arg);
222 }
223
put_ulong(unsigned long arg,unsigned long val)224 static int put_ulong(unsigned long arg, unsigned long val)
225 {
226 return put_user(val, (unsigned long __user *)arg);
227 }
228
put_u64(unsigned long arg,u64 val)229 static int put_u64(unsigned long arg, u64 val)
230 {
231 return put_user(val, (u64 __user *)arg);
232 }
233
__blkdev_driver_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)234 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
235 unsigned cmd, unsigned long arg)
236 {
237 struct gendisk *disk = bdev->bd_disk;
238
239 if (disk->fops->ioctl)
240 return disk->fops->ioctl(bdev, mode, cmd, arg);
241
242 return -ENOTTY;
243 }
244 /*
245 * For the record: _GPL here is only because somebody decided to slap it
246 * on the previous export. Sheer idiocy, since it wasn't copyrightable
247 * at all and could be open-coded without any exports by anybody who cares.
248 */
249 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
250
251 /*
252 * Is it an unrecognized ioctl? The correct returns are either
253 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
254 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
255 * code before returning.
256 *
257 * Confused drivers sometimes return EINVAL, which is wrong. It
258 * means "I understood the ioctl command, but the parameters to
259 * it were wrong".
260 *
261 * We should aim to just fix the broken drivers, the EINVAL case
262 * should go away.
263 */
is_unrecognized_ioctl(int ret)264 static inline int is_unrecognized_ioctl(int ret)
265 {
266 return ret == -EINVAL ||
267 ret == -ENOTTY ||
268 ret == -ENOIOCTLCMD;
269 }
270
271 /*
272 * always keep this in sync with compat_blkdev_ioctl()
273 */
blkdev_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)274 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
275 unsigned long arg)
276 {
277 struct gendisk *disk = bdev->bd_disk;
278 struct backing_dev_info *bdi;
279 loff_t size;
280 int ret, n;
281
282 switch(cmd) {
283 case BLKFLSBUF:
284 if (!capable(CAP_SYS_ADMIN))
285 return -EACCES;
286
287 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
288 if (!is_unrecognized_ioctl(ret))
289 return ret;
290
291 fsync_bdev(bdev);
292 invalidate_bdev(bdev);
293 return 0;
294
295 case BLKROSET:
296 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
297 if (!is_unrecognized_ioctl(ret))
298 return ret;
299 if (!capable(CAP_SYS_ADMIN))
300 return -EACCES;
301 if (get_user(n, (int __user *)(arg)))
302 return -EFAULT;
303 set_device_ro(bdev, n);
304 return 0;
305
306 case BLKDISCARD:
307 case BLKSECDISCARD: {
308 uint64_t range[2];
309
310 if (!(mode & FMODE_WRITE))
311 return -EBADF;
312
313 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
314 return -EFAULT;
315
316 return blk_ioctl_discard(bdev, range[0], range[1],
317 cmd == BLKSECDISCARD);
318 }
319 case BLKZEROOUT: {
320 uint64_t range[2];
321
322 if (!(mode & FMODE_WRITE))
323 return -EBADF;
324
325 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
326 return -EFAULT;
327
328 return blk_ioctl_zeroout(bdev, range[0], range[1]);
329 }
330
331 case HDIO_GETGEO: {
332 struct hd_geometry geo;
333
334 if (!arg)
335 return -EINVAL;
336 if (!disk->fops->getgeo)
337 return -ENOTTY;
338
339 /*
340 * We need to set the startsect first, the driver may
341 * want to override it.
342 */
343 memset(&geo, 0, sizeof(geo));
344 geo.start = get_start_sect(bdev);
345 ret = disk->fops->getgeo(bdev, &geo);
346 if (ret)
347 return ret;
348 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
349 sizeof(geo)))
350 return -EFAULT;
351 return 0;
352 }
353 case BLKRAGET:
354 case BLKFRAGET:
355 if (!arg)
356 return -EINVAL;
357 bdi = blk_get_backing_dev_info(bdev);
358 if (bdi == NULL)
359 return -ENOTTY;
360 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
361 case BLKROGET:
362 return put_int(arg, bdev_read_only(bdev) != 0);
363 case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
364 return put_int(arg, block_size(bdev));
365 case BLKSSZGET: /* get block device logical block size */
366 return put_int(arg, bdev_logical_block_size(bdev));
367 case BLKPBSZGET: /* get block device physical block size */
368 return put_uint(arg, bdev_physical_block_size(bdev));
369 case BLKIOMIN:
370 return put_uint(arg, bdev_io_min(bdev));
371 case BLKIOOPT:
372 return put_uint(arg, bdev_io_opt(bdev));
373 case BLKALIGNOFF:
374 return put_int(arg, bdev_alignment_offset(bdev));
375 case BLKDISCARDZEROES:
376 return put_uint(arg, bdev_discard_zeroes_data(bdev));
377 case BLKSECTGET:
378 return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
379 case BLKROTATIONAL:
380 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
381 case BLKRASET:
382 case BLKFRASET:
383 if(!capable(CAP_SYS_ADMIN))
384 return -EACCES;
385 bdi = blk_get_backing_dev_info(bdev);
386 if (bdi == NULL)
387 return -ENOTTY;
388 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
389 return 0;
390 case BLKBSZSET:
391 /* set the logical block size */
392 if (!capable(CAP_SYS_ADMIN))
393 return -EACCES;
394 if (!arg)
395 return -EINVAL;
396 if (get_user(n, (int __user *) arg))
397 return -EFAULT;
398 if (!(mode & FMODE_EXCL)) {
399 bdgrab(bdev);
400 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
401 return -EBUSY;
402 }
403 ret = set_blocksize(bdev, n);
404 if (!(mode & FMODE_EXCL))
405 blkdev_put(bdev, mode | FMODE_EXCL);
406 return ret;
407 case BLKPG:
408 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
409 break;
410 case BLKRRPART:
411 ret = blkdev_reread_part(bdev);
412 break;
413 case BLKGETSIZE:
414 size = i_size_read(bdev->bd_inode);
415 if ((size >> 9) > ~0UL)
416 return -EFBIG;
417 return put_ulong(arg, size >> 9);
418 case BLKGETSIZE64:
419 return put_u64(arg, i_size_read(bdev->bd_inode));
420 case BLKTRACESTART:
421 case BLKTRACESTOP:
422 case BLKTRACESETUP:
423 case BLKTRACETEARDOWN:
424 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
425 break;
426 default:
427 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
428 }
429 return ret;
430 }
431 EXPORT_SYMBOL_GPL(blkdev_ioctl);
432