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
11static 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 blkpg_ioctl_arg a;
16	struct blkpg_partition p;
17	long long start, length;
18	int part;
19	int i;
20
21	if (!capable(CAP_SYS_ADMIN))
22		return -EACCES;
23	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
24		return -EFAULT;
25	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
26		return -EFAULT;
27	disk = bdev->bd_disk;
28	if (bdev != bdev->bd_contains)
29		return -EINVAL;
30	part = p.pno;
31	if (part <= 0 || part >= disk->minors)
32		return -EINVAL;
33	switch (a.op) {
34		case BLKPG_ADD_PARTITION:
35			start = p.start >> 9;
36			length = p.length >> 9;
37			/* check for fit in a hd_struct */
38			if (sizeof(sector_t) == sizeof(long) &&
39			    sizeof(long long) > sizeof(long)) {
40				long pstart = start, plength = length;
41				if (pstart != start || plength != length
42				    || pstart < 0 || plength < 0)
43					return -EINVAL;
44			}
45			/* partition number in use? */
46			mutex_lock(&bdev->bd_mutex);
47			if (disk->part[part - 1]) {
48				mutex_unlock(&bdev->bd_mutex);
49				return -EBUSY;
50			}
51			/* overlap? */
52			for (i = 0; i < disk->minors - 1; i++) {
53				struct hd_struct *s = disk->part[i];
54
55				if (!s)
56					continue;
57				if (!(start+length <= s->start_sect ||
58				      start >= s->start_sect + s->nr_sects)) {
59					mutex_unlock(&bdev->bd_mutex);
60					return -EBUSY;
61				}
62			}
63			/* all seems OK */
64			add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
65			mutex_unlock(&bdev->bd_mutex);
66			return 0;
67		case BLKPG_DEL_PARTITION:
68			if (!disk->part[part-1])
69				return -ENXIO;
70			if (disk->part[part - 1]->nr_sects == 0)
71				return -ENXIO;
72			bdevp = bdget_disk(disk, part);
73			if (!bdevp)
74				return -ENOMEM;
75			mutex_lock(&bdevp->bd_mutex);
76			if (bdevp->bd_openers) {
77				mutex_unlock(&bdevp->bd_mutex);
78				bdput(bdevp);
79				return -EBUSY;
80			}
81			/* all seems OK */
82			fsync_bdev(bdevp);
83			invalidate_bdev(bdevp);
84
85			mutex_lock_nested(&bdev->bd_mutex, 1);
86			delete_partition(disk, part);
87			mutex_unlock(&bdev->bd_mutex);
88			mutex_unlock(&bdevp->bd_mutex);
89			bdput(bdevp);
90
91			return 0;
92		default:
93			return -EINVAL;
94	}
95}
96
97static int blkdev_reread_part(struct block_device *bdev)
98{
99	struct gendisk *disk = bdev->bd_disk;
100	int res;
101
102	if (disk->minors == 1 || bdev != bdev->bd_contains)
103		return -EINVAL;
104	if (!capable(CAP_SYS_ADMIN))
105		return -EACCES;
106	if (!mutex_trylock(&bdev->bd_mutex))
107		return -EBUSY;
108	res = rescan_partitions(disk, bdev);
109	mutex_unlock(&bdev->bd_mutex);
110	return res;
111}
112
113static int put_ushort(unsigned long arg, unsigned short val)
114{
115	return put_user(val, (unsigned short __user *)arg);
116}
117
118static int put_int(unsigned long arg, int val)
119{
120	return put_user(val, (int __user *)arg);
121}
122
123static int put_long(unsigned long arg, long val)
124{
125	return put_user(val, (long __user *)arg);
126}
127
128static int put_ulong(unsigned long arg, unsigned long val)
129{
130	return put_user(val, (unsigned long __user *)arg);
131}
132
133static int put_u64(unsigned long arg, u64 val)
134{
135	return put_user(val, (u64 __user *)arg);
136}
137
138static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
139				unsigned cmd, unsigned long arg)
140{
141	struct backing_dev_info *bdi;
142	int ret, n;
143
144	switch (cmd) {
145	case BLKRAGET:
146	case BLKFRAGET:
147		if (!arg)
148			return -EINVAL;
149		bdi = blk_get_backing_dev_info(bdev);
150		if (bdi == NULL)
151			return -ENOTTY;
152		return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
153	case BLKROGET:
154		return put_int(arg, bdev_read_only(bdev) != 0);
155	case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
156		return put_int(arg, block_size(bdev));
157	case BLKSSZGET: /* get block device hardware sector size */
158		return put_int(arg, bdev_hardsect_size(bdev));
159	case BLKSECTGET:
160		return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
161	case BLKRASET:
162	case BLKFRASET:
163		if(!capable(CAP_SYS_ADMIN))
164			return -EACCES;
165		bdi = blk_get_backing_dev_info(bdev);
166		if (bdi == NULL)
167			return -ENOTTY;
168		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
169		return 0;
170	case BLKBSZSET:
171		/* set the logical block size */
172		if (!capable(CAP_SYS_ADMIN))
173			return -EACCES;
174		if (!arg)
175			return -EINVAL;
176		if (get_user(n, (int __user *) arg))
177			return -EFAULT;
178		if (bd_claim(bdev, file) < 0)
179			return -EBUSY;
180		ret = set_blocksize(bdev, n);
181		bd_release(bdev);
182		return ret;
183	case BLKPG:
184		return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
185	case BLKRRPART:
186		return blkdev_reread_part(bdev);
187	case BLKGETSIZE:
188		if ((bdev->bd_inode->i_size >> 9) > ~0UL)
189			return -EFBIG;
190		return put_ulong(arg, bdev->bd_inode->i_size >> 9);
191	case BLKGETSIZE64:
192		return put_u64(arg, bdev->bd_inode->i_size);
193	case BLKTRACESTART:
194	case BLKTRACESTOP:
195	case BLKTRACESETUP:
196	case BLKTRACETEARDOWN:
197		return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
198	}
199	return -ENOIOCTLCMD;
200}
201
202int blkdev_driver_ioctl(struct inode *inode, struct file *file,
203			struct gendisk *disk, unsigned cmd, unsigned long arg)
204{
205	int ret;
206	if (disk->fops->unlocked_ioctl)
207		return disk->fops->unlocked_ioctl(file, cmd, arg);
208
209	if (disk->fops->ioctl) {
210		lock_kernel();
211		ret = disk->fops->ioctl(inode, file, cmd, arg);
212		unlock_kernel();
213		return ret;
214	}
215
216	return -ENOTTY;
217}
218EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
219
220int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
221			unsigned long arg)
222{
223	struct block_device *bdev = inode->i_bdev;
224	struct gendisk *disk = bdev->bd_disk;
225	int ret, n;
226
227	switch(cmd) {
228	case BLKFLSBUF:
229		if (!capable(CAP_SYS_ADMIN))
230			return -EACCES;
231
232		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
233		/* -EINVAL to handle old uncorrected drivers */
234		if (ret != -EINVAL && ret != -ENOTTY)
235			return ret;
236
237		lock_kernel();
238		fsync_bdev(bdev);
239		invalidate_bdev(bdev);
240		unlock_kernel();
241		return 0;
242
243	case BLKROSET:
244		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
245		/* -EINVAL to handle old uncorrected drivers */
246		if (ret != -EINVAL && ret != -ENOTTY)
247			return ret;
248		if (!capable(CAP_SYS_ADMIN))
249			return -EACCES;
250		if (get_user(n, (int __user *)(arg)))
251			return -EFAULT;
252		lock_kernel();
253		set_device_ro(bdev, n);
254		unlock_kernel();
255		return 0;
256	case HDIO_GETGEO: {
257		struct hd_geometry geo;
258
259		if (!arg)
260			return -EINVAL;
261		if (!disk->fops->getgeo)
262			return -ENOTTY;
263
264		/*
265		 * We need to set the startsect first, the driver may
266		 * want to override it.
267		 */
268		geo.start = get_start_sect(bdev);
269		ret = disk->fops->getgeo(bdev, &geo);
270		if (ret)
271			return ret;
272		if (copy_to_user((struct hd_geometry __user *)arg, &geo,
273					sizeof(geo)))
274			return -EFAULT;
275		return 0;
276	}
277	}
278
279	lock_kernel();
280	ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
281	unlock_kernel();
282	if (ret != -ENOIOCTLCMD)
283		return ret;
284
285	return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
286}
287
288/* Most of the generic ioctls are handled in the normal fallback path.
289   This assumes the blkdev's low level compat_ioctl always returns
290   ENOIOCTLCMD for unknown ioctls. */
291long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
292{
293	struct block_device *bdev = file->f_path.dentry->d_inode->i_bdev;
294	struct gendisk *disk = bdev->bd_disk;
295	int ret = -ENOIOCTLCMD;
296	if (disk->fops->compat_ioctl) {
297		lock_kernel();
298		ret = disk->fops->compat_ioctl(file, cmd, arg);
299		unlock_kernel();
300	}
301	return ret;
302}
303
304EXPORT_SYMBOL_GPL(blkdev_ioctl);
305