ioctl.c 8.58 KB
Newer Older
1
#include <linux/capability.h>
Linus Torvalds's avatar
Linus Torvalds committed
2
#include <linux/blkdev.h>
3
#include <linux/export.h>
4
#include <linux/gfp.h>
Linus Torvalds's avatar
Linus Torvalds committed
5
#include <linux/blkpg.h>
6
#include <linux/hdreg.h>
Linus Torvalds's avatar
Linus Torvalds committed
7 8
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
9
#include <linux/blktrace_api.h>
Linus Torvalds's avatar
Linus Torvalds committed
10 11 12 13 14 15
#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;
16
	struct hd_struct *part;
Linus Torvalds's avatar
Linus Torvalds committed
17 18
	struct blkpg_ioctl_arg a;
	struct blkpg_partition p;
19
	struct disk_part_iter piter;
Linus Torvalds's avatar
Linus Torvalds committed
20
	long long start, length;
21
	int partno;
Linus Torvalds's avatar
Linus Torvalds committed
22 23 24 25 26 27 28 29 30 31

	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;
32
	partno = p.pno;
33
	if (partno <= 0)
Linus Torvalds's avatar
Linus Torvalds committed
34 35 36 37 38 39 40 41 42 43 44 45 46
		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;
			}
47

48
			mutex_lock(&bdev->bd_mutex);
49

Linus Torvalds's avatar
Linus Torvalds committed
50
			/* overlap? */
51 52 53 54 55 56
			disk_part_iter_init(&piter, disk,
					    DISK_PITER_INCL_EMPTY);
			while ((part = disk_part_iter_next(&piter))) {
				if (!(start + length <= part->start_sect ||
				      start >= part->start_sect + part->nr_sects)) {
					disk_part_iter_exit(&piter);
57
					mutex_unlock(&bdev->bd_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
58 59 60
					return -EBUSY;
				}
			}
61 62
			disk_part_iter_exit(&piter);

Linus Torvalds's avatar
Linus Torvalds committed
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;
Linus Torvalds's avatar
Linus Torvalds committed
68
		case BLKPG_DEL_PARTITION:
69 70
			part = disk_get_part(disk, partno);
			if (!part)
Linus Torvalds's avatar
Linus Torvalds committed
71
				return -ENXIO;
72 73 74

			bdevp = bdget(part_devt(part));
			disk_put_part(part);
Linus Torvalds's avatar
Linus Torvalds committed
75 76
			if (!bdevp)
				return -ENOMEM;
77

78
			mutex_lock(&bdevp->bd_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
79
			if (bdevp->bd_openers) {
80
				mutex_unlock(&bdevp->bd_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
81 82 83 84 85
				bdput(bdevp);
				return -EBUSY;
			}
			/* all seems OK */
			fsync_bdev(bdevp);
86
			invalidate_bdev(bdevp);
Linus Torvalds's avatar
Linus Torvalds committed
87

88
			mutex_lock_nested(&bdev->bd_mutex, 1);
89
			delete_partition(disk, partno);
90 91
			mutex_unlock(&bdev->bd_mutex);
			mutex_unlock(&bdevp->bd_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
92 93 94 95 96 97 98 99 100 101 102 103 104
			bdput(bdevp);

			return 0;
		default:
			return -EINVAL;
	}
}

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

Tejun Heo's avatar
Tejun Heo committed
105
	if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
Linus Torvalds's avatar
Linus Torvalds committed
106 107 108
		return -EINVAL;
	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
109
	if (!mutex_trylock(&bdev->bd_mutex))
Linus Torvalds's avatar
Linus Torvalds committed
110 111
		return -EBUSY;
	res = rescan_partitions(disk, bdev);
112
	mutex_unlock(&bdev->bd_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
113 114 115
	return res;
}

116
static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
Adrian Hunter's avatar
Adrian Hunter committed
117
			     uint64_t len, int secure)
118
{
119
	unsigned long flags = 0;
Adrian Hunter's avatar
Adrian Hunter committed
120

121 122 123 124 125 126 127
	if (start & 511)
		return -EINVAL;
	if (len & 511)
		return -EINVAL;
	start >>= 9;
	len >>= 9;

128
	if (start + len > (i_size_read(bdev->bd_inode) >> 9))
129
		return -EINVAL;
Adrian Hunter's avatar
Adrian Hunter committed
130
	if (secure)
131
		flags |= BLKDEV_DISCARD_SECURE;
Adrian Hunter's avatar
Adrian Hunter committed
132
	return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
133 134
}

Linus Torvalds's avatar
Linus Torvalds committed
135 136 137 138 139 140 141 142 143 144
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);
}

Martin K. Petersen's avatar
Martin K. Petersen committed
145 146 147 148 149
static int put_uint(unsigned long arg, unsigned int val)
{
	return put_user(val, (unsigned int __user *)arg);
}

Linus Torvalds's avatar
Linus Torvalds committed
150 151 152 153 154 155 156 157 158 159 160 161 162 163 164
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);
}

165 166 167 168
int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
			unsigned cmd, unsigned long arg)
{
	struct gendisk *disk = bdev->bd_disk;
169 170 171

	if (disk->fops->ioctl)
		return disk->fops->ioctl(bdev, mode, cmd, arg);
172 173 174 175 176 177 178 179 180 181

	return -ENOTTY;
}
/*
 * For the record: _GPL here is only because somebody decided to slap it
 * on the previous export.  Sheer idiocy, since it wasn't copyrightable
 * at all and could be open-coded without any exports by anybody who cares.
 */
EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);

182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201
/*
 * Is it an unrecognized ioctl? The correct returns are either
 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
 * code before returning.
 *
 * Confused drivers sometimes return EINVAL, which is wrong. It
 * means "I understood the ioctl command, but the parameters to
 * it were wrong".
 *
 * We should aim to just fix the broken drivers, the EINVAL case
 * should go away.
 */
static inline int is_unrecognized_ioctl(int ret)
{
	return	ret == -EINVAL ||
		ret == -ENOTTY ||
		ret == -ENOIOCTLCMD;
}

202
/*
203
 * always keep this in sync with compat_blkdev_ioctl()
204
 */
205
int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
206 207 208
			unsigned long arg)
{
	struct gendisk *disk = bdev->bd_disk;
209 210
	struct backing_dev_info *bdi;
	loff_t size;
211 212 213
	int ret, n;

	switch(cmd) {
Linus Torvalds's avatar
Linus Torvalds committed
214 215 216
	case BLKFLSBUF:
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;
217

218
		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
219
		if (!is_unrecognized_ioctl(ret))
220 221
			return ret;

Linus Torvalds's avatar
Linus Torvalds committed
222
		fsync_bdev(bdev);
223
		invalidate_bdev(bdev);
Linus Torvalds's avatar
Linus Torvalds committed
224
		return 0;
225

Linus Torvalds's avatar
Linus Torvalds committed
226
	case BLKROSET:
227
		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
228
		if (!is_unrecognized_ioctl(ret))
229
			return ret;
Linus Torvalds's avatar
Linus Torvalds committed
230 231 232 233 234 235
		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;
		if (get_user(n, (int __user *)(arg)))
			return -EFAULT;
		set_device_ro(bdev, n);
		return 0;
236

Adrian Hunter's avatar
Adrian Hunter committed
237 238
	case BLKDISCARD:
	case BLKSECDISCARD: {
239 240
		uint64_t range[2];

241
		if (!(mode & FMODE_WRITE))
242 243 244 245 246
			return -EBADF;

		if (copy_from_user(range, (void __user *)arg, sizeof(range)))
			return -EFAULT;

Adrian Hunter's avatar
Adrian Hunter committed
247 248
		return blk_ioctl_discard(bdev, range[0], range[1],
					 cmd == BLKSECDISCARD);
249 250
	}

251 252 253 254 255 256 257 258 259 260 261 262
	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.
		 */
263
		memset(&geo, 0, sizeof(geo));
264 265 266 267 268 269 270 271 272
		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;
	}
273 274 275 276 277 278 279 280 281 282
	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);
Martin K. Petersen's avatar
Martin K. Petersen committed
283
	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
284
		return put_int(arg, block_size(bdev));
Martin K. Petersen's avatar
Martin K. Petersen committed
285
	case BLKSSZGET: /* get block device logical block size */
286
		return put_int(arg, bdev_logical_block_size(bdev));
Martin K. Petersen's avatar
Martin K. Petersen committed
287 288 289 290 291 292 293 294
	case BLKPBSZGET: /* get block device physical block size */
		return put_uint(arg, bdev_physical_block_size(bdev));
	case BLKIOMIN:
		return put_uint(arg, bdev_io_min(bdev));
	case BLKIOOPT:
		return put_uint(arg, bdev_io_opt(bdev));
	case BLKALIGNOFF:
		return put_int(arg, bdev_alignment_offset(bdev));
295 296
	case BLKDISCARDZEROES:
		return put_uint(arg, bdev_discard_zeroes_data(bdev));
297
	case BLKSECTGET:
298
		return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315
	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;
316 317 318 319 320
		if (!(mode & FMODE_EXCL)) {
			bdgrab(bdev);
			if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
				return -EBUSY;
		}
321
		ret = set_blocksize(bdev, n);
322
		if (!(mode & FMODE_EXCL))
323
			blkdev_put(bdev, mode | FMODE_EXCL);
324
		return ret;
325 326 327 328 329 330 331
	case BLKPG:
		ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
		break;
	case BLKRRPART:
		ret = blkdev_reread_part(bdev);
		break;
	case BLKGETSIZE:
332
		size = i_size_read(bdev->bd_inode);
333 334 335 336
		if ((size >> 9) > ~0UL)
			return -EFBIG;
		return put_ulong(arg, size >> 9);
	case BLKGETSIZE64:
337
		return put_u64(arg, i_size_read(bdev->bd_inode));
338 339 340 341 342 343 344 345 346 347
	case BLKTRACESTART:
	case BLKTRACESTOP:
	case BLKTRACESETUP:
	case BLKTRACETEARDOWN:
		ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
		break;
	default:
		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
	}
	return ret;
Linus Torvalds's avatar
Linus Torvalds committed
348
}
349
EXPORT_SYMBOL_GPL(blkdev_ioctl);