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-rw-r--r--block/ioctl.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
new file mode 100644
index 000000000000..6e278474f9a8
--- /dev/null
+++ b/block/ioctl.c
@@ -0,0 +1,275 @@
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
9static 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
95static 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
111static int put_ushort(unsigned long arg, unsigned short val)
112{
113 return put_user(val, (unsigned short __user *)arg);
114}
115
116static int put_int(unsigned long arg, int val)
117{
118 return put_user(val, (int __user *)arg);
119}
120
121static int put_long(unsigned long arg, long val)
122{
123 return put_user(val, (long __user *)arg);
124}
125
126static int put_ulong(unsigned long arg, unsigned long val)
127{
128 return put_user(val, (unsigned long __user *)arg);
129}
130
131static int put_u64(unsigned long arg, u64 val)
132{
133 return put_user(val, (u64 __user *)arg);
134}
135
136static 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
195static 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
212int 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. */
262long 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
275EXPORT_SYMBOL_GPL(blkdev_ioctl);
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-01 03:26:08 -0400