1 #include <linux/capability.h>
2 #include <linux/blkdev.h>
3 #include <linux/blkpg.h>
4 #include <linux/hdreg.h>
5 #include <linux/backing-dev.h>
6 #include <linux/buffer_head.h>
7 #include <linux/smp_lock.h>
8 #include <linux/blktrace_api.h>
9 #include <asm/uaccess.h>
10
blkpg_ioctl(struct block_device * bdev,struct blkpg_ioctl_arg __user * arg)11 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
12 {
13 struct block_device *bdevp;
14 struct gendisk *disk;
15 struct hd_struct *part;
16 struct blkpg_ioctl_arg a;
17 struct blkpg_partition p;
18 struct disk_part_iter piter;
19 long long start, length;
20 int partno;
21
22 if (!capable(CAP_SYS_ADMIN))
23 return -EACCES;
24 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
25 return -EFAULT;
26 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
27 return -EFAULT;
28 disk = bdev->bd_disk;
29 if (bdev != bdev->bd_contains)
30 return -EINVAL;
31 partno = p.pno;
32 if (partno <= 0)
33 return -EINVAL;
34 switch (a.op) {
35 case BLKPG_ADD_PARTITION:
36 start = p.start >> 9;
37 length = p.length >> 9;
38 /* check for fit in a hd_struct */
39 if (sizeof(sector_t) == sizeof(long) &&
40 sizeof(long long) > sizeof(long)) {
41 long pstart = start, plength = length;
42 if (pstart != start || plength != length
43 || pstart < 0 || plength < 0)
44 return -EINVAL;
45 }
46
47 mutex_lock(&bdev->bd_mutex);
48
49 /* overlap? */
50 disk_part_iter_init(&piter, disk,
51 DISK_PITER_INCL_EMPTY);
52 while ((part = disk_part_iter_next(&piter))) {
53 if (!(start + length <= part->start_sect ||
54 start >= part->start_sect + part->nr_sects)) {
55 disk_part_iter_exit(&piter);
56 mutex_unlock(&bdev->bd_mutex);
57 return -EBUSY;
58 }
59 }
60 disk_part_iter_exit(&piter);
61
62 /* all seems OK */
63 part = add_partition(disk, partno, start, length,
64 ADDPART_FLAG_NONE);
65 mutex_unlock(&bdev->bd_mutex);
66 return IS_ERR(part) ? PTR_ERR(part) : 0;
67 case BLKPG_DEL_PARTITION:
68 part = disk_get_part(disk, partno);
69 if (!part)
70 return -ENXIO;
71
72 bdevp = bdget(part_devt(part));
73 disk_put_part(part);
74 if (!bdevp)
75 return -ENOMEM;
76
77 mutex_lock(&bdevp->bd_mutex);
78 if (bdevp->bd_openers) {
79 mutex_unlock(&bdevp->bd_mutex);
80 bdput(bdevp);
81 return -EBUSY;
82 }
83 /* all seems OK */
84 fsync_bdev(bdevp);
85 invalidate_bdev(bdevp);
86
87 mutex_lock_nested(&bdev->bd_mutex, 1);
88 delete_partition(disk, partno);
89 mutex_unlock(&bdev->bd_mutex);
90 mutex_unlock(&bdevp->bd_mutex);
91 bdput(bdevp);
92
93 return 0;
94 default:
95 return -EINVAL;
96 }
97 }
98
blkdev_reread_part(struct block_device * bdev)99 static int blkdev_reread_part(struct block_device *bdev)
100 {
101 struct gendisk *disk = bdev->bd_disk;
102 int res;
103
104 if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
105 return -EINVAL;
106 if (!capable(CAP_SYS_ADMIN))
107 return -EACCES;
108 if (!mutex_trylock(&bdev->bd_mutex))
109 return -EBUSY;
110 res = rescan_partitions(disk, bdev);
111 mutex_unlock(&bdev->bd_mutex);
112 return res;
113 }
114
blk_ioc_discard_endio(struct bio * bio,int err)115 static void blk_ioc_discard_endio(struct bio *bio, int err)
116 {
117 if (err) {
118 if (err == -EOPNOTSUPP)
119 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
120 clear_bit(BIO_UPTODATE, &bio->bi_flags);
121 }
122 complete(bio->bi_private);
123 }
124
blk_ioctl_discard(struct block_device * bdev,uint64_t start,uint64_t len)125 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
126 uint64_t len)
127 {
128 struct request_queue *q = bdev_get_queue(bdev);
129 int ret = 0;
130
131 if (start & 511)
132 return -EINVAL;
133 if (len & 511)
134 return -EINVAL;
135 start >>= 9;
136 len >>= 9;
137
138 if (start + len > (bdev->bd_inode->i_size >> 9))
139 return -EINVAL;
140
141 if (!q->prepare_discard_fn)
142 return -EOPNOTSUPP;
143
144 while (len && !ret) {
145 DECLARE_COMPLETION_ONSTACK(wait);
146 struct bio *bio;
147
148 bio = bio_alloc(GFP_KERNEL, 0);
149 if (!bio)
150 return -ENOMEM;
151
152 bio->bi_end_io = blk_ioc_discard_endio;
153 bio->bi_bdev = bdev;
154 bio->bi_private = &wait;
155 bio->bi_sector = start;
156
157 if (len > q->max_hw_sectors) {
158 bio->bi_size = q->max_hw_sectors << 9;
159 len -= q->max_hw_sectors;
160 start += q->max_hw_sectors;
161 } else {
162 bio->bi_size = len << 9;
163 len = 0;
164 }
165 submit_bio(DISCARD_NOBARRIER, bio);
166
167 wait_for_completion(&wait);
168
169 if (bio_flagged(bio, BIO_EOPNOTSUPP))
170 ret = -EOPNOTSUPP;
171 else if (!bio_flagged(bio, BIO_UPTODATE))
172 ret = -EIO;
173 bio_put(bio);
174 }
175 return ret;
176 }
177
put_ushort(unsigned long arg,unsigned short val)178 static int put_ushort(unsigned long arg, unsigned short val)
179 {
180 return put_user(val, (unsigned short __user *)arg);
181 }
182
put_int(unsigned long arg,int val)183 static int put_int(unsigned long arg, int val)
184 {
185 return put_user(val, (int __user *)arg);
186 }
187
put_long(unsigned long arg,long val)188 static int put_long(unsigned long arg, long val)
189 {
190 return put_user(val, (long __user *)arg);
191 }
192
put_ulong(unsigned long arg,unsigned long val)193 static int put_ulong(unsigned long arg, unsigned long val)
194 {
195 return put_user(val, (unsigned long __user *)arg);
196 }
197
put_u64(unsigned long arg,u64 val)198 static int put_u64(unsigned long arg, u64 val)
199 {
200 return put_user(val, (u64 __user *)arg);
201 }
202
__blkdev_driver_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)203 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
204 unsigned cmd, unsigned long arg)
205 {
206 struct gendisk *disk = bdev->bd_disk;
207 int ret;
208
209 if (disk->fops->ioctl)
210 return disk->fops->ioctl(bdev, mode, cmd, arg);
211
212 if (disk->fops->locked_ioctl) {
213 lock_kernel();
214 ret = disk->fops->locked_ioctl(bdev, mode, cmd, arg);
215 unlock_kernel();
216 return ret;
217 }
218
219 return -ENOTTY;
220 }
221 /*
222 * For the record: _GPL here is only because somebody decided to slap it
223 * on the previous export. Sheer idiocy, since it wasn't copyrightable
224 * at all and could be open-coded without any exports by anybody who cares.
225 */
226 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
227
228 /*
229 * always keep this in sync with compat_blkdev_ioctl() and
230 * compat_blkdev_locked_ioctl()
231 */
blkdev_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)232 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
233 unsigned long arg)
234 {
235 struct gendisk *disk = bdev->bd_disk;
236 struct backing_dev_info *bdi;
237 loff_t size;
238 int ret, n;
239
240 switch(cmd) {
241 case BLKFLSBUF:
242 if (!capable(CAP_SYS_ADMIN))
243 return -EACCES;
244
245 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
246 /* -EINVAL to handle old uncorrected drivers */
247 if (ret != -EINVAL && ret != -ENOTTY)
248 return ret;
249
250 lock_kernel();
251 fsync_bdev(bdev);
252 invalidate_bdev(bdev);
253 unlock_kernel();
254 return 0;
255
256 case BLKROSET:
257 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
258 /* -EINVAL to handle old uncorrected drivers */
259 if (ret != -EINVAL && ret != -ENOTTY)
260 return ret;
261 if (!capable(CAP_SYS_ADMIN))
262 return -EACCES;
263 if (get_user(n, (int __user *)(arg)))
264 return -EFAULT;
265 lock_kernel();
266 set_device_ro(bdev, n);
267 unlock_kernel();
268 return 0;
269
270 case BLKDISCARD: {
271 uint64_t range[2];
272
273 if (!(mode & FMODE_WRITE))
274 return -EBADF;
275
276 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
277 return -EFAULT;
278
279 return blk_ioctl_discard(bdev, range[0], range[1]);
280 }
281
282 case HDIO_GETGEO: {
283 struct hd_geometry geo;
284
285 if (!arg)
286 return -EINVAL;
287 if (!disk->fops->getgeo)
288 return -ENOTTY;
289
290 /*
291 * We need to set the startsect first, the driver may
292 * want to override it.
293 */
294 geo.start = get_start_sect(bdev);
295 ret = disk->fops->getgeo(bdev, &geo);
296 if (ret)
297 return ret;
298 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
299 sizeof(geo)))
300 return -EFAULT;
301 return 0;
302 }
303 case BLKRAGET:
304 case BLKFRAGET:
305 if (!arg)
306 return -EINVAL;
307 bdi = blk_get_backing_dev_info(bdev);
308 if (bdi == NULL)
309 return -ENOTTY;
310 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
311 case BLKROGET:
312 return put_int(arg, bdev_read_only(bdev) != 0);
313 case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
314 return put_int(arg, block_size(bdev));
315 case BLKSSZGET: /* get block device hardware sector size */
316 return put_int(arg, bdev_hardsect_size(bdev));
317 case BLKSECTGET:
318 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
319 case BLKRASET:
320 case BLKFRASET:
321 if(!capable(CAP_SYS_ADMIN))
322 return -EACCES;
323 bdi = blk_get_backing_dev_info(bdev);
324 if (bdi == NULL)
325 return -ENOTTY;
326 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
327 return 0;
328 case BLKBSZSET:
329 /* set the logical block size */
330 if (!capable(CAP_SYS_ADMIN))
331 return -EACCES;
332 if (!arg)
333 return -EINVAL;
334 if (get_user(n, (int __user *) arg))
335 return -EFAULT;
336 if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
337 return -EBUSY;
338 ret = set_blocksize(bdev, n);
339 if (!(mode & FMODE_EXCL))
340 bd_release(bdev);
341 return ret;
342 case BLKPG:
343 lock_kernel();
344 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
345 unlock_kernel();
346 break;
347 case BLKRRPART:
348 lock_kernel();
349 ret = blkdev_reread_part(bdev);
350 unlock_kernel();
351 break;
352 case BLKGETSIZE:
353 size = bdev->bd_inode->i_size;
354 if ((size >> 9) > ~0UL)
355 return -EFBIG;
356 return put_ulong(arg, size >> 9);
357 case BLKGETSIZE64:
358 return put_u64(arg, bdev->bd_inode->i_size);
359 case BLKTRACESTART:
360 case BLKTRACESTOP:
361 case BLKTRACESETUP:
362 case BLKTRACETEARDOWN:
363 lock_kernel();
364 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
365 unlock_kernel();
366 break;
367 default:
368 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
369 }
370 return ret;
371 }
372 EXPORT_SYMBOL_GPL(blkdev_ioctl);
373