Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
[pandora-kernel.git] / block / ioctl.c
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
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
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
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
188 static int put_ushort(unsigned long arg, unsigned short val)
189 {
190         return put_user(val, (unsigned short __user *)arg);
191 }
192
193 static int put_int(unsigned long arg, int val)
194 {
195         return put_user(val, (int __user *)arg);
196 }
197
198 static int put_uint(unsigned long arg, unsigned int val)
199 {
200         return put_user(val, (unsigned int __user *)arg);
201 }
202
203 static int put_long(unsigned long arg, long val)
204 {
205         return put_user(val, (long __user *)arg);
206 }
207
208 static int put_ulong(unsigned long arg, unsigned long val)
209 {
210         return put_user(val, (unsigned long __user *)arg);
211 }
212
213 static int put_u64(unsigned long arg, u64 val)
214 {
215         return put_user(val, (u64 __user *)arg);
216 }
217
218 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
219                         unsigned cmd, unsigned long arg)
220 {
221         struct gendisk *disk = bdev->bd_disk;
222
223         if (disk->fops->ioctl)
224                 return disk->fops->ioctl(bdev, mode, cmd, arg);
225
226         return -ENOTTY;
227 }
228 /*
229  * For the record: _GPL here is only because somebody decided to slap it
230  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
231  * at all and could be open-coded without any exports by anybody who cares.
232  */
233 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
234
235 /*
236  * Is it an unrecognized ioctl? The correct returns are either
237  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
238  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
239  * code before returning.
240  *
241  * Confused drivers sometimes return EINVAL, which is wrong. It
242  * means "I understood the ioctl command, but the parameters to
243  * it were wrong".
244  *
245  * We should aim to just fix the broken drivers, the EINVAL case
246  * should go away.
247  */
248 static inline int is_unrecognized_ioctl(int ret)
249 {
250         return  ret == -EINVAL ||
251                 ret == -ENOTTY ||
252                 ret == -ENOIOCTLCMD;
253 }
254
255 /*
256  * always keep this in sync with compat_blkdev_ioctl()
257  */
258 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
259                         unsigned long arg)
260 {
261         struct gendisk *disk = bdev->bd_disk;
262         struct backing_dev_info *bdi;
263         loff_t size;
264         int ret, n;
265
266         switch(cmd) {
267         case BLKFLSBUF:
268                 if (!capable(CAP_SYS_ADMIN))
269                         return -EACCES;
270
271                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
272                 if (!is_unrecognized_ioctl(ret))
273                         return ret;
274
275                 fsync_bdev(bdev);
276                 invalidate_bdev(bdev);
277                 return 0;
278
279         case BLKROSET:
280                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
281                 if (!is_unrecognized_ioctl(ret))
282                         return ret;
283                 if (!capable(CAP_SYS_ADMIN))
284                         return -EACCES;
285                 if (get_user(n, (int __user *)(arg)))
286                         return -EFAULT;
287                 set_device_ro(bdev, n);
288                 return 0;
289
290         case BLKDISCARD:
291         case BLKSECDISCARD: {
292                 uint64_t range[2];
293
294                 if (!(mode & FMODE_WRITE))
295                         return -EBADF;
296
297                 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
298                         return -EFAULT;
299
300                 return blk_ioctl_discard(bdev, range[0], range[1],
301                                          cmd == BLKSECDISCARD);
302         }
303
304         case HDIO_GETGEO: {
305                 struct hd_geometry geo;
306
307                 if (!arg)
308                         return -EINVAL;
309                 if (!disk->fops->getgeo)
310                         return -ENOTTY;
311
312                 /*
313                  * We need to set the startsect first, the driver may
314                  * want to override it.
315                  */
316                 memset(&geo, 0, sizeof(geo));
317                 geo.start = get_start_sect(bdev);
318                 ret = disk->fops->getgeo(bdev, &geo);
319                 if (ret)
320                         return ret;
321                 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
322                                         sizeof(geo)))
323                         return -EFAULT;
324                 return 0;
325         }
326         case BLKRAGET:
327         case BLKFRAGET:
328                 if (!arg)
329                         return -EINVAL;
330                 bdi = blk_get_backing_dev_info(bdev);
331                 if (bdi == NULL)
332                         return -ENOTTY;
333                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
334         case BLKROGET:
335                 return put_int(arg, bdev_read_only(bdev) != 0);
336         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
337                 return put_int(arg, block_size(bdev));
338         case BLKSSZGET: /* get block device logical block size */
339                 return put_int(arg, bdev_logical_block_size(bdev));
340         case BLKPBSZGET: /* get block device physical block size */
341                 return put_uint(arg, bdev_physical_block_size(bdev));
342         case BLKIOMIN:
343                 return put_uint(arg, bdev_io_min(bdev));
344         case BLKIOOPT:
345                 return put_uint(arg, bdev_io_opt(bdev));
346         case BLKALIGNOFF:
347                 return put_int(arg, bdev_alignment_offset(bdev));
348         case BLKDISCARDZEROES:
349                 return put_uint(arg, bdev_discard_zeroes_data(bdev));
350         case BLKSECTGET:
351                 return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
352         case BLKROTATIONAL:
353                 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
354         case BLKRASET:
355         case BLKFRASET:
356                 if(!capable(CAP_SYS_ADMIN))
357                         return -EACCES;
358                 bdi = blk_get_backing_dev_info(bdev);
359                 if (bdi == NULL)
360                         return -ENOTTY;
361                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
362                 return 0;
363         case BLKBSZSET:
364                 /* set the logical block size */
365                 if (!capable(CAP_SYS_ADMIN))
366                         return -EACCES;
367                 if (!arg)
368                         return -EINVAL;
369                 if (get_user(n, (int __user *) arg))
370                         return -EFAULT;
371                 if (!(mode & FMODE_EXCL)) {
372                         bdgrab(bdev);
373                         if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
374                                 return -EBUSY;
375                 }
376                 ret = set_blocksize(bdev, n);
377                 if (!(mode & FMODE_EXCL))
378                         blkdev_put(bdev, mode | FMODE_EXCL);
379                 return ret;
380         case BLKPG:
381                 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
382                 break;
383         case BLKRRPART:
384                 ret = blkdev_reread_part(bdev);
385                 break;
386         case BLKGETSIZE:
387                 size = i_size_read(bdev->bd_inode);
388                 if ((size >> 9) > ~0UL)
389                         return -EFBIG;
390                 return put_ulong(arg, size >> 9);
391         case BLKGETSIZE64:
392                 return put_u64(arg, i_size_read(bdev->bd_inode));
393         case BLKTRACESTART:
394         case BLKTRACESTOP:
395         case BLKTRACESETUP:
396         case BLKTRACETEARDOWN:
397                 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
398                 break;
399         default:
400                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
401         }
402         return ret;
403 }
404 EXPORT_SYMBOL_GPL(blkdev_ioctl);