Merge branch 'drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[linux-2.6.git] / block / ioctl.c
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
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
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
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
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
178 static int put_ushort(unsigned long arg, unsigned short val)
179 {
180         return put_user(val, (unsigned short __user *)arg);
181 }
182
183 static int put_int(unsigned long arg, int val)
184 {
185         return put_user(val, (int __user *)arg);
186 }
187
188 static int put_long(unsigned long arg, long val)
189 {
190         return put_user(val, (long __user *)arg);
191 }
192
193 static int put_ulong(unsigned long arg, unsigned long val)
194 {
195         return put_user(val, (unsigned long __user *)arg);
196 }
197
198 static int put_u64(unsigned long arg, u64 val)
199 {
200         return put_user(val, (u64 __user *)arg);
201 }
202
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  */
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);