[PATCH] dell_rbu driver depends on x86[64]
[linux-2.6.git] / block / ioctl.c
1 #include <linux/sched.h>                /* for capable() */
2 #include <linux/blkdev.h>
3 #include <linux/blkpg.h>
4 #include <linux/backing-dev.h>
5 #include <linux/buffer_head.h>
6 #include <linux/smp_lock.h>
7 #include <asm/uaccess.h>
8
9 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
10 {
11         struct block_device *bdevp;
12         struct gendisk *disk;
13         struct blkpg_ioctl_arg a;
14         struct blkpg_partition p;
15         long long start, length;
16         int part;
17         int i;
18
19         if (!capable(CAP_SYS_ADMIN))
20                 return -EACCES;
21         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
22                 return -EFAULT;
23         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
24                 return -EFAULT;
25         disk = bdev->bd_disk;
26         if (bdev != bdev->bd_contains)
27                 return -EINVAL;
28         part = p.pno;
29         if (part <= 0 || part >= disk->minors)
30                 return -EINVAL;
31         switch (a.op) {
32                 case BLKPG_ADD_PARTITION:
33                         start = p.start >> 9;
34                         length = p.length >> 9;
35                         /* check for fit in a hd_struct */ 
36                         if (sizeof(sector_t) == sizeof(long) && 
37                             sizeof(long long) > sizeof(long)) {
38                                 long pstart = start, plength = length;
39                                 if (pstart != start || plength != length
40                                     || pstart < 0 || plength < 0)
41                                         return -EINVAL;
42                         }
43                         /* partition number in use? */
44                         down(&bdev->bd_sem);
45                         if (disk->part[part - 1]) {
46                                 up(&bdev->bd_sem);
47                                 return -EBUSY;
48                         }
49                         /* overlap? */
50                         for (i = 0; i < disk->minors - 1; i++) {
51                                 struct hd_struct *s = disk->part[i];
52
53                                 if (!s)
54                                         continue;
55                                 if (!(start+length <= s->start_sect ||
56                                       start >= s->start_sect + s->nr_sects)) {
57                                         up(&bdev->bd_sem);
58                                         return -EBUSY;
59                                 }
60                         }
61                         /* all seems OK */
62                         add_partition(disk, part, start, length);
63                         up(&bdev->bd_sem);
64                         return 0;
65                 case BLKPG_DEL_PARTITION:
66                         if (!disk->part[part-1])
67                                 return -ENXIO;
68                         if (disk->part[part - 1]->nr_sects == 0)
69                                 return -ENXIO;
70                         bdevp = bdget_disk(disk, part);
71                         if (!bdevp)
72                                 return -ENOMEM;
73                         down(&bdevp->bd_sem);
74                         if (bdevp->bd_openers) {
75                                 up(&bdevp->bd_sem);
76                                 bdput(bdevp);
77                                 return -EBUSY;
78                         }
79                         /* all seems OK */
80                         fsync_bdev(bdevp);
81                         invalidate_bdev(bdevp, 0);
82
83                         down(&bdev->bd_sem);
84                         delete_partition(disk, part);
85                         up(&bdev->bd_sem);
86                         up(&bdevp->bd_sem);
87                         bdput(bdevp);
88
89                         return 0;
90                 default:
91                         return -EINVAL;
92         }
93 }
94
95 static int blkdev_reread_part(struct block_device *bdev)
96 {
97         struct gendisk *disk = bdev->bd_disk;
98         int res;
99
100         if (disk->minors == 1 || bdev != bdev->bd_contains)
101                 return -EINVAL;
102         if (!capable(CAP_SYS_ADMIN))
103                 return -EACCES;
104         if (down_trylock(&bdev->bd_sem))
105                 return -EBUSY;
106         res = rescan_partitions(disk, bdev);
107         up(&bdev->bd_sem);
108         return res;
109 }
110
111 static int put_ushort(unsigned long arg, unsigned short val)
112 {
113         return put_user(val, (unsigned short __user *)arg);
114 }
115
116 static int put_int(unsigned long arg, int val)
117 {
118         return put_user(val, (int __user *)arg);
119 }
120
121 static int put_long(unsigned long arg, long val)
122 {
123         return put_user(val, (long __user *)arg);
124 }
125
126 static int put_ulong(unsigned long arg, unsigned long val)
127 {
128         return put_user(val, (unsigned long __user *)arg);
129 }
130
131 static int put_u64(unsigned long arg, u64 val)
132 {
133         return put_user(val, (u64 __user *)arg);
134 }
135
136 static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
137                                 unsigned cmd, unsigned long arg)
138 {
139         struct backing_dev_info *bdi;
140         int ret, n;
141
142         switch (cmd) {
143         case BLKRAGET:
144         case BLKFRAGET:
145                 if (!arg)
146                         return -EINVAL;
147                 bdi = blk_get_backing_dev_info(bdev);
148                 if (bdi == NULL)
149                         return -ENOTTY;
150                 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
151         case BLKROGET:
152                 return put_int(arg, bdev_read_only(bdev) != 0);
153         case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
154                 return put_int(arg, block_size(bdev));
155         case BLKSSZGET: /* get block device hardware sector size */
156                 return put_int(arg, bdev_hardsect_size(bdev));
157         case BLKSECTGET:
158                 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
159         case BLKRASET:
160         case BLKFRASET:
161                 if(!capable(CAP_SYS_ADMIN))
162                         return -EACCES;
163                 bdi = blk_get_backing_dev_info(bdev);
164                 if (bdi == NULL)
165                         return -ENOTTY;
166                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
167                 return 0;
168         case BLKBSZSET:
169                 /* set the logical block size */
170                 if (!capable(CAP_SYS_ADMIN))
171                         return -EACCES;
172                 if (!arg)
173                         return -EINVAL;
174                 if (get_user(n, (int __user *) arg))
175                         return -EFAULT;
176                 if (bd_claim(bdev, file) < 0)
177                         return -EBUSY;
178                 ret = set_blocksize(bdev, n);
179                 bd_release(bdev);
180                 return ret;
181         case BLKPG:
182                 return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
183         case BLKRRPART:
184                 return blkdev_reread_part(bdev);
185         case BLKGETSIZE:
186                 if ((bdev->bd_inode->i_size >> 9) > ~0UL)
187                         return -EFBIG;
188                 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
189         case BLKGETSIZE64:
190                 return put_u64(arg, bdev->bd_inode->i_size);
191         }
192         return -ENOIOCTLCMD;
193 }
194
195 static int blkdev_driver_ioctl(struct inode *inode, struct file *file,
196                 struct gendisk *disk, unsigned cmd, unsigned long arg)
197 {
198         int ret;
199         if (disk->fops->unlocked_ioctl)
200                 return disk->fops->unlocked_ioctl(file, cmd, arg);
201
202         if (disk->fops->ioctl) {
203                 lock_kernel();
204                 ret = disk->fops->ioctl(inode, file, cmd, arg);
205                 unlock_kernel();
206                 return ret;
207         }
208
209         return -ENOTTY;
210 }
211
212 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
213                         unsigned long arg)
214 {
215         struct block_device *bdev = inode->i_bdev;
216         struct gendisk *disk = bdev->bd_disk;
217         int ret, n;
218
219         switch(cmd) {
220         case BLKFLSBUF:
221                 if (!capable(CAP_SYS_ADMIN))
222                         return -EACCES;
223
224                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
225                 /* -EINVAL to handle old uncorrected drivers */
226                 if (ret != -EINVAL && ret != -ENOTTY)
227                         return ret;
228
229                 lock_kernel();
230                 fsync_bdev(bdev);
231                 invalidate_bdev(bdev, 0);
232                 unlock_kernel();
233                 return 0;
234
235         case BLKROSET:
236                 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
237                 /* -EINVAL to handle old uncorrected drivers */
238                 if (ret != -EINVAL && ret != -ENOTTY)
239                         return ret;
240                 if (!capable(CAP_SYS_ADMIN))
241                         return -EACCES;
242                 if (get_user(n, (int __user *)(arg)))
243                         return -EFAULT;
244                 lock_kernel();
245                 set_device_ro(bdev, n);
246                 unlock_kernel();
247                 return 0;
248         }
249
250         lock_kernel();
251         ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
252         unlock_kernel();
253         if (ret != -ENOIOCTLCMD)
254                 return ret;
255
256         return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
257 }
258
259 /* Most of the generic ioctls are handled in the normal fallback path.
260    This assumes the blkdev's low level compat_ioctl always returns
261    ENOIOCTLCMD for unknown ioctls. */
262 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
263 {
264         struct block_device *bdev = file->f_dentry->d_inode->i_bdev;
265         struct gendisk *disk = bdev->bd_disk;
266         int ret = -ENOIOCTLCMD;
267         if (disk->fops->compat_ioctl) {
268                 lock_kernel();
269                 ret = disk->fops->compat_ioctl(file, cmd, arg);
270                 unlock_kernel();
271         }
272         return ret;
273 }
274
275 EXPORT_SYMBOL_GPL(blkdev_ioctl);