Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6.git] / block / ioctl.c
1 #include <linux/capability.h>
2 #include <linux/blkdev.h>
3 #include <linux/gfp.h>
4 #include <linux/blkpg.h>
5 #include <linux/hdreg.h>
6 #include <linux/backing-dev.h>
7 #include <linux/buffer_head.h>
8 #include <linux/smp_lock.h>
9 #include <linux/blktrace_api.h>
10 #include <asm/uaccess.h>
11
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;
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)
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);
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                 default:
96                         return -EINVAL;
97         }
98 }
99
100 static int blkdev_reread_part(struct block_device *bdev)
101 {
102         struct gendisk *disk = bdev->bd_disk;
103         int res;
104
105         if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
106                 return -EINVAL;
107         if (!capable(CAP_SYS_ADMIN))
108                 return -EACCES;
109         if (!mutex_trylock(&bdev->bd_mutex))
110                 return -EBUSY;
111         res = rescan_partitions(disk, bdev);
112         mutex_unlock(&bdev->bd_mutex);
113         return res;
114 }
115
116 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
117                              uint64_t len)
118 {
119         if (start & 511)
120                 return -EINVAL;
121         if (len & 511)
122                 return -EINVAL;
123         start >>= 9;
124         len >>= 9;
125
126         if (start + len > (bdev->bd_inode->i_size >> 9))
127                 return -EINVAL;
128         return blkdev_issue_discard(bdev, start, len, GFP_KERNEL,
129                                     BLKDEV_IFL_WAIT);
130 }
131
132 static int put_ushort(unsigned long arg, unsigned short val)
133 {
134         return put_user(val, (unsigned short __user *)arg);
135 }
136
137 static int put_int(unsigned long arg, int val)
138 {
139         return put_user(val, (int __user *)arg);
140 }
141
142 static int put_uint(unsigned long arg, unsigned int val)
143 {
144         return put_user(val, (unsigned int __user *)arg);
145 }
146
147 static int put_long(unsigned long arg, long val)
148 {
149         return put_user(val, (long __user *)arg);
150 }
151
152 static int put_ulong(unsigned long arg, unsigned long val)
153 {
154         return put_user(val, (unsigned long __user *)arg);
155 }
156
157 static int put_u64(unsigned long arg, u64 val)
158 {
159         return put_user(val, (u64 __user *)arg);
160 }
161
162 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
163                         unsigned cmd, unsigned long arg)
164 {
165         struct gendisk *disk = bdev->bd_disk;
166         int ret;
167
168         if (disk->fops->ioctl)
169                 return disk->fops->ioctl(bdev, mode, cmd, arg);
170
171         if (disk->fops->locked_ioctl) {
172                 lock_kernel();
173                 ret = disk->fops->locked_ioctl(bdev, mode, cmd, arg);
174                 unlock_kernel();
175                 return ret;
176         }
177
178         return -ENOTTY;
179 }
180 /*
181  * For the record: _GPL here is only because somebody decided to slap it
182  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
183  * at all and could be open-coded without any exports by anybody who cares.
184  */
185 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
186
187 /*
188  * always keep this in sync with compat_blkdev_ioctl() and
189  * compat_blkdev_locked_ioctl()
190  */
191 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
192                         unsigned long arg)
193 {
194         struct gendisk *disk = bdev->bd_disk;
195         struct backing_dev_info *bdi;
196         loff_t size;
197         int ret, n;
198
199         switch(cmd) {
200         case BLKFLSBUF:
201                 if (!capable(CAP_SYS_ADMIN))
202                         return -EACCES;
203
204                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
205                 /* -EINVAL to handle old uncorrected drivers */
206                 if (ret != -EINVAL && ret != -ENOTTY)
207                         return ret;
208
209                 lock_kernel();
210                 fsync_bdev(bdev);
211                 invalidate_bdev(bdev);
212                 unlock_kernel();
213                 return 0;
214
215         case BLKROSET:
216                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
217                 /* -EINVAL to handle old uncorrected drivers */
218                 if (ret != -EINVAL && ret != -ENOTTY)
219                         return ret;
220                 if (!capable(CAP_SYS_ADMIN))
221                         return -EACCES;
222                 if (get_user(n, (int __user *)(arg)))
223                         return -EFAULT;
224                 lock_kernel();
225                 set_device_ro(bdev, n);
226                 unlock_kernel();
227                 return 0;
228
229         case BLKDISCARD: {
230                 uint64_t range[2];
231
232                 if (!(mode & FMODE_WRITE))
233                         return -EBADF;
234
235                 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
236                         return -EFAULT;
237
238                 return blk_ioctl_discard(bdev, range[0], range[1]);
239         }
240
241         case HDIO_GETGEO: {
242                 struct hd_geometry geo;
243
244                 if (!arg)
245                         return -EINVAL;
246                 if (!disk->fops->getgeo)
247                         return -ENOTTY;
248
249                 /*
250                  * We need to set the startsect first, the driver may
251                  * want to override it.
252                  */
253                 geo.start = get_start_sect(bdev);
254                 ret = disk->fops->getgeo(bdev, &geo);
255                 if (ret)
256                         return ret;
257                 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
258                                         sizeof(geo)))
259                         return -EFAULT;
260                 return 0;
261         }
262         case BLKRAGET:
263         case BLKFRAGET:
264                 if (!arg)
265                         return -EINVAL;
266                 bdi = blk_get_backing_dev_info(bdev);
267                 if (bdi == NULL)
268                         return -ENOTTY;
269                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
270         case BLKROGET:
271                 return put_int(arg, bdev_read_only(bdev) != 0);
272         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
273                 return put_int(arg, block_size(bdev));
274         case BLKSSZGET: /* get block device logical block size */
275                 return put_int(arg, bdev_logical_block_size(bdev));
276         case BLKPBSZGET: /* get block device physical block size */
277                 return put_uint(arg, bdev_physical_block_size(bdev));
278         case BLKIOMIN:
279                 return put_uint(arg, bdev_io_min(bdev));
280         case BLKIOOPT:
281                 return put_uint(arg, bdev_io_opt(bdev));
282         case BLKALIGNOFF:
283                 return put_int(arg, bdev_alignment_offset(bdev));
284         case BLKDISCARDZEROES:
285                 return put_uint(arg, bdev_discard_zeroes_data(bdev));
286         case BLKSECTGET:
287                 return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
288         case BLKRASET:
289         case BLKFRASET:
290                 if(!capable(CAP_SYS_ADMIN))
291                         return -EACCES;
292                 bdi = blk_get_backing_dev_info(bdev);
293                 if (bdi == NULL)
294                         return -ENOTTY;
295                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
296                 return 0;
297         case BLKBSZSET:
298                 /* set the logical block size */
299                 if (!capable(CAP_SYS_ADMIN))
300                         return -EACCES;
301                 if (!arg)
302                         return -EINVAL;
303                 if (get_user(n, (int __user *) arg))
304                         return -EFAULT;
305                 if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
306                         return -EBUSY;
307                 ret = set_blocksize(bdev, n);
308                 if (!(mode & FMODE_EXCL))
309                         bd_release(bdev);
310                 return ret;
311         case BLKPG:
312                 lock_kernel();
313                 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
314                 unlock_kernel();
315                 break;
316         case BLKRRPART:
317                 lock_kernel();
318                 ret = blkdev_reread_part(bdev);
319                 unlock_kernel();
320                 break;
321         case BLKGETSIZE:
322                 size = bdev->bd_inode->i_size;
323                 if ((size >> 9) > ~0UL)
324                         return -EFBIG;
325                 return put_ulong(arg, size >> 9);
326         case BLKGETSIZE64:
327                 return put_u64(arg, bdev->bd_inode->i_size);
328         case BLKTRACESTART:
329         case BLKTRACESTOP:
330         case BLKTRACESETUP:
331         case BLKTRACETEARDOWN:
332                 lock_kernel();
333                 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
334                 unlock_kernel();
335                 break;
336         default:
337                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
338         }
339         return ret;
340 }
341 EXPORT_SYMBOL_GPL(blkdev_ioctl);