summaryrefslogtreecommitdiffstats
path: root/block/ioctl.c
blob: 9fddb99c3efb1ee307d60989c6e42401f542fa4c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
#include <linux/capability.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include <linux/smp_lock.h>
#include <linux/blktrace_api.h>
#include <asm/uaccess.h>

static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
{
	struct block_device *bdevp;
	struct gendisk *disk;
	struct blkpg_ioctl_arg a;
	struct blkpg_partition p;
	long long start, length;
	int part;
	int i;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
		return -EFAULT;
	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
		return -EFAULT;
	disk = bdev->bd_disk;
	if (bdev != bdev->bd_contains)
		return -EINVAL;
	part = p.pno;
	if (part <= 0 || part >= disk->minors)
		return -EINVAL;
	switch (a.op) {
		case BLKPG_ADD_PARTITION:
			start = p.start >> 9;
			length = p.length >> 9;
			/* check for fit in a hd_struct */ 
			if (sizeof(sector_t) == sizeof(long) && 
			    sizeof(long long) > sizeof(long)) {
				long pstart = start, plength = length;
				if (pstart != start || plength != length
				    || pstart < 0 || plength < 0)
					return -EINVAL;
			}
			/* partition number in use? */
			mutex_lock(&bdev->bd_mutex);
			if (disk->part[part - 1]) {
				mutex_unlock(&bdev->bd_mutex);
				return -EBUSY;
			}
			/* overlap? */
			for (i = 0; i < disk->minors - 1; i++) {
				struct hd_struct *s = disk->part[i];

				if (!s)
					continue;
				if (!(start+length <= s->start_sect ||
				      start >= s->start_sect + s->nr_sects)) {
					mutex_unlock(&bdev->bd_mutex);
					return -EBUSY;
				}
			}
			/* all seems OK */
			add_partition(disk, part, start, length);
			mutex_unlock(&bdev->bd_mutex);
			return 0;
		case BLKPG_DEL_PARTITION:
			if (!disk->part[part-1])
				return -ENXIO;
			if (disk->part[part - 1]->nr_sects == 0)
				return -ENXIO;
			bdevp = bdget_disk(disk, part);
			if (!bdevp)
				return -ENOMEM;
			mutex_lock(&bdevp->bd_mutex);
			if (bdevp->bd_openers) {
				mutex_unlock(&bdevp->bd_mutex);
				bdput(bdevp);
				return -EBUSY;
			}
			/* all seems OK */
			fsync_bdev(bdevp);
			invalidate_bdev(bdevp, 0);

			mutex_lock(&bdev->bd_mutex);
			delete_partition(disk, part);
			mutex_unlock(&bdev->bd_mutex);
			mutex_unlock(&bdevp->bd_mutex);
			bdput(bdevp);

			return 0;
		default:
			return -EINVAL;
	}
}

static int blkdev_reread_part(struct block_device *bdev)
{
	struct gendisk *disk = bdev->bd_disk;
	int res;

	if (disk->minors == 1 || bdev != bdev->bd_contains)
		return -EINVAL;
	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	if (!mutex_trylock(&bdev->bd_mutex))
		return -EBUSY;
	res = rescan_partitions(disk, bdev);
	mutex_unlock(&bdev->bd_mutex);
	return res;
}

static int put_ushort(unsigned long arg, unsigned short val)
{
	return put_user(val, (unsigned short __user *)arg);
}

static int put_int(unsigned long arg, int val)
{
	return put_user(val, (int __user *)arg);
}

static int put_long(unsigned long arg, long val)
{
	return put_user(val, (long __user *)arg);
}

static int put_ulong(unsigned long arg, unsigned long val)
{
	return put_user(val, (unsigned long __user *)arg);
}

static int put_u64(unsigned long arg, u64 val)
{
	return put_user(val, (u64 __user *)arg);
}

static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
				unsigned cmd, unsigned long arg)
{
	struct backing_dev_info *bdi;
	int ret, n;

	switch (cmd) {
	case BLKRAGET:
	case BLKFRAGET:
		if (!arg)
			return -EINVAL;
		bdi = blk_get_backing_dev_info(bdev);
		if (bdi == NULL)
			return -ENOTTY;
		return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
	case BLKROGET:
		return put_int(arg, bdev_read_only(bdev) != 0);
	case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
		return put_int(arg, block_size(bdev));
	case BLKSSZGET: /* get block device hardware sector size */
		return put_int(arg, bdev_hardsect_size(bdev));
	case BLKSECTGET:
		return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
	case BLKRASET:
	case BLKFRASET:
		if(!capable(CAP_SYS_ADMIN))
			return -EACCES;
		bdi = blk_get_backing_dev_info(bdev);
		if (bdi == NULL)
			return -ENOTTY;
		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
		return 0;
	case BLKBSZSET:
		/* set the logical block size */
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;
		if (!arg)
			return -EINVAL;
		if (get_user(n, (int __user *) arg))
			return -EFAULT;
		if (bd_claim(bdev, file) < 0)
			return -EBUSY;
		ret = set_blocksize(bdev, n);
		bd_release(bdev);
		return ret;
	case BLKPG:
		return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
	case BLKRRPART:
		return blkdev_reread_part(bdev);
	case BLKGETSIZE:
		if ((bdev->bd_inode->i_size >> 9) > ~0UL)
			return -EFBIG;
		return put_ulong(arg, bdev->bd_inode->i_size >> 9);
	case BLKGETSIZE64:
		return put_u64(arg, bdev->bd_inode->i_size);
	case BLKTRACESTART:
	case BLKTRACESTOP:
	case BLKTRACESETUP:
	case BLKTRACETEARDOWN:
		return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
	}
	return -ENOIOCTLCMD;
}

int blkdev_driver_ioctl(struct inode *inode, struct file *file,
			struct gendisk *disk, unsigned cmd, unsigned long arg)
{
	int ret;
	if (disk->fops->unlocked_ioctl)
		return disk->fops->unlocked_ioctl(file, cmd, arg);

	if (disk->fops->ioctl) {
		lock_kernel();
		ret = disk->fops->ioctl(inode, file, cmd, arg);
		unlock_kernel();
		return ret;
	}

	return -ENOTTY;
}
EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);

int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
			unsigned long arg)
{
	struct block_device *bdev = inode->i_bdev;
	struct gendisk *disk = bdev->bd_disk;
	int ret, n;

	switch(cmd) {
	case BLKFLSBUF:
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;

		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
		/* -EINVAL to handle old uncorrected drivers */
		if (ret != -EINVAL && ret != -ENOTTY)
			return ret;

		lock_kernel();
		fsync_bdev(bdev);
		invalidate_bdev(bdev, 0);
		unlock_kernel();
		return 0;

	case BLKROSET:
		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
		/* -EINVAL to handle old uncorrected drivers */
		if (ret != -EINVAL && ret != -ENOTTY)
			return ret;
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;
		if (get_user(n, (int __user *)(arg)))
			return -EFAULT;
		lock_kernel();
		set_device_ro(bdev, n);
		unlock_kernel();
		return 0;
	case HDIO_GETGEO: {
		struct hd_geometry geo;

		if (!arg)
			return -EINVAL;
		if (!disk->fops->getgeo)
			return -ENOTTY;

		/*
		 * We need to set the startsect first, the driver may
		 * want to override it.
		 */
		geo.start = get_start_sect(bdev);
		ret = disk->fops->getgeo(bdev, &geo);
		if (ret)
			return ret;
		if (copy_to_user((struct hd_geometry __user *)arg, &geo,
					sizeof(geo)))
			return -EFAULT;
		return 0;
	}
	}

	lock_kernel();
	ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
	unlock_kernel();
	if (ret != -ENOIOCTLCMD)
		return ret;

	return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
}

/* Most of the generic ioctls are handled in the normal fallback path.
   This assumes the blkdev's low level compat_ioctl always returns
   ENOIOCTLCMD for unknown ioctls. */
long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
	struct block_device *bdev = file->f_dentry->d_inode->i_bdev;
	struct gendisk *disk = bdev->bd_disk;
	int ret = -ENOIOCTLCMD;
	if (disk->fops->compat_ioctl) {
		lock_kernel();
		ret = disk->fops->compat_ioctl(file, cmd, arg);
		unlock_kernel();
	}
	return ret;
}

EXPORT_SYMBOL_GPL(blkdev_ioctl);