xref: /openbmc/linux/block/ioctl.c (revision d5532ee7)
1 #include <linux/capability.h>
2 #include <linux/blkdev.h>
3 #include <linux/gfp.h>
4 #include <linux/blkpg.h>
5 #include <linux/hdreg.h>
6 #include <linux/backing-dev.h>
7 #include <linux/buffer_head.h>
8 #include <linux/smp_lock.h>
9 #include <linux/blktrace_api.h>
10 #include <asm/uaccess.h>
11 
12 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
13 {
14 	struct block_device *bdevp;
15 	struct gendisk *disk;
16 	struct hd_struct *part;
17 	struct blkpg_ioctl_arg a;
18 	struct blkpg_partition p;
19 	struct disk_part_iter piter;
20 	long long start, length;
21 	int partno;
22 
23 	if (!capable(CAP_SYS_ADMIN))
24 		return -EACCES;
25 	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
26 		return -EFAULT;
27 	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
28 		return -EFAULT;
29 	disk = bdev->bd_disk;
30 	if (bdev != bdev->bd_contains)
31 		return -EINVAL;
32 	partno = p.pno;
33 	if (partno <= 0)
34 		return -EINVAL;
35 	switch (a.op) {
36 		case BLKPG_ADD_PARTITION:
37 			start = p.start >> 9;
38 			length = p.length >> 9;
39 			/* check for fit in a hd_struct */
40 			if (sizeof(sector_t) == sizeof(long) &&
41 			    sizeof(long long) > sizeof(long)) {
42 				long pstart = start, plength = length;
43 				if (pstart != start || plength != length
44 				    || pstart < 0 || plength < 0)
45 					return -EINVAL;
46 			}
47 
48 			mutex_lock(&bdev->bd_mutex);
49 
50 			/* overlap? */
51 			disk_part_iter_init(&piter, disk,
52 					    DISK_PITER_INCL_EMPTY);
53 			while ((part = disk_part_iter_next(&piter))) {
54 				if (!(start + length <= part->start_sect ||
55 				      start >= part->start_sect + part->nr_sects)) {
56 					disk_part_iter_exit(&piter);
57 					mutex_unlock(&bdev->bd_mutex);
58 					return -EBUSY;
59 				}
60 			}
61 			disk_part_iter_exit(&piter);
62 
63 			/* all seems OK */
64 			part = add_partition(disk, partno, start, length,
65 					     ADDPART_FLAG_NONE);
66 			mutex_unlock(&bdev->bd_mutex);
67 			return IS_ERR(part) ? PTR_ERR(part) : 0;
68 		case BLKPG_DEL_PARTITION:
69 			part = disk_get_part(disk, partno);
70 			if (!part)
71 				return -ENXIO;
72 
73 			bdevp = bdget(part_devt(part));
74 			disk_put_part(part);
75 			if (!bdevp)
76 				return -ENOMEM;
77 
78 			mutex_lock(&bdevp->bd_mutex);
79 			if (bdevp->bd_openers) {
80 				mutex_unlock(&bdevp->bd_mutex);
81 				bdput(bdevp);
82 				return -EBUSY;
83 			}
84 			/* all seems OK */
85 			fsync_bdev(bdevp);
86 			invalidate_bdev(bdevp);
87 
88 			mutex_lock_nested(&bdev->bd_mutex, 1);
89 			delete_partition(disk, partno);
90 			mutex_unlock(&bdev->bd_mutex);
91 			mutex_unlock(&bdevp->bd_mutex);
92 			bdput(bdevp);
93 
94 			return 0;
95 		default:
96 			return -EINVAL;
97 	}
98 }
99 
100 static int blkdev_reread_part(struct block_device *bdev)
101 {
102 	struct gendisk *disk = bdev->bd_disk;
103 	int res;
104 
105 	if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
106 		return -EINVAL;
107 	if (!capable(CAP_SYS_ADMIN))
108 		return -EACCES;
109 	if (!mutex_trylock(&bdev->bd_mutex))
110 		return -EBUSY;
111 	res = rescan_partitions(disk, bdev);
112 	mutex_unlock(&bdev->bd_mutex);
113 	return res;
114 }
115 
116 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
117 			     uint64_t len, int secure)
118 {
119 	unsigned long flags = BLKDEV_IFL_WAIT;
120 
121 	if (start & 511)
122 		return -EINVAL;
123 	if (len & 511)
124 		return -EINVAL;
125 	start >>= 9;
126 	len >>= 9;
127 
128 	if (start + len > (bdev->bd_inode->i_size >> 9))
129 		return -EINVAL;
130 	if (secure)
131 		flags |= BLKDEV_IFL_SECURE;
132 	return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
133 }
134 
135 static int put_ushort(unsigned long arg, unsigned short val)
136 {
137 	return put_user(val, (unsigned short __user *)arg);
138 }
139 
140 static int put_int(unsigned long arg, int val)
141 {
142 	return put_user(val, (int __user *)arg);
143 }
144 
145 static int put_uint(unsigned long arg, unsigned int val)
146 {
147 	return put_user(val, (unsigned int __user *)arg);
148 }
149 
150 static int put_long(unsigned long arg, long val)
151 {
152 	return put_user(val, (long __user *)arg);
153 }
154 
155 static int put_ulong(unsigned long arg, unsigned long val)
156 {
157 	return put_user(val, (unsigned long __user *)arg);
158 }
159 
160 static int put_u64(unsigned long arg, u64 val)
161 {
162 	return put_user(val, (u64 __user *)arg);
163 }
164 
165 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
166 			unsigned cmd, unsigned long arg)
167 {
168 	struct gendisk *disk = bdev->bd_disk;
169 
170 	if (disk->fops->ioctl)
171 		return disk->fops->ioctl(bdev, mode, cmd, arg);
172 
173 	return -ENOTTY;
174 }
175 /*
176  * For the record: _GPL here is only because somebody decided to slap it
177  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
178  * at all and could be open-coded without any exports by anybody who cares.
179  */
180 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
181 
182 /*
183  * always keep this in sync with compat_blkdev_ioctl()
184  */
185 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
186 			unsigned long arg)
187 {
188 	struct gendisk *disk = bdev->bd_disk;
189 	struct backing_dev_info *bdi;
190 	loff_t size;
191 	int ret, n;
192 
193 	switch(cmd) {
194 	case BLKFLSBUF:
195 		if (!capable(CAP_SYS_ADMIN))
196 			return -EACCES;
197 
198 		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
199 		/* -EINVAL to handle old uncorrected drivers */
200 		if (ret != -EINVAL && ret != -ENOTTY)
201 			return ret;
202 
203 		fsync_bdev(bdev);
204 		invalidate_bdev(bdev);
205 		return 0;
206 
207 	case BLKROSET:
208 		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
209 		/* -EINVAL to handle old uncorrected drivers */
210 		if (ret != -EINVAL && ret != -ENOTTY)
211 			return ret;
212 		if (!capable(CAP_SYS_ADMIN))
213 			return -EACCES;
214 		if (get_user(n, (int __user *)(arg)))
215 			return -EFAULT;
216 		set_device_ro(bdev, n);
217 		return 0;
218 
219 	case BLKDISCARD:
220 	case BLKSECDISCARD: {
221 		uint64_t range[2];
222 
223 		if (!(mode & FMODE_WRITE))
224 			return -EBADF;
225 
226 		if (copy_from_user(range, (void __user *)arg, sizeof(range)))
227 			return -EFAULT;
228 
229 		return blk_ioctl_discard(bdev, range[0], range[1],
230 					 cmd == BLKSECDISCARD);
231 	}
232 
233 	case HDIO_GETGEO: {
234 		struct hd_geometry geo;
235 
236 		if (!arg)
237 			return -EINVAL;
238 		if (!disk->fops->getgeo)
239 			return -ENOTTY;
240 
241 		/*
242 		 * We need to set the startsect first, the driver may
243 		 * want to override it.
244 		 */
245 		geo.start = get_start_sect(bdev);
246 		ret = disk->fops->getgeo(bdev, &geo);
247 		if (ret)
248 			return ret;
249 		if (copy_to_user((struct hd_geometry __user *)arg, &geo,
250 					sizeof(geo)))
251 			return -EFAULT;
252 		return 0;
253 	}
254 	case BLKRAGET:
255 	case BLKFRAGET:
256 		if (!arg)
257 			return -EINVAL;
258 		bdi = blk_get_backing_dev_info(bdev);
259 		if (bdi == NULL)
260 			return -ENOTTY;
261 		return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
262 	case BLKROGET:
263 		return put_int(arg, bdev_read_only(bdev) != 0);
264 	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
265 		return put_int(arg, block_size(bdev));
266 	case BLKSSZGET: /* get block device logical block size */
267 		return put_int(arg, bdev_logical_block_size(bdev));
268 	case BLKPBSZGET: /* get block device physical block size */
269 		return put_uint(arg, bdev_physical_block_size(bdev));
270 	case BLKIOMIN:
271 		return put_uint(arg, bdev_io_min(bdev));
272 	case BLKIOOPT:
273 		return put_uint(arg, bdev_io_opt(bdev));
274 	case BLKALIGNOFF:
275 		return put_int(arg, bdev_alignment_offset(bdev));
276 	case BLKDISCARDZEROES:
277 		return put_uint(arg, bdev_discard_zeroes_data(bdev));
278 	case BLKSECTGET:
279 		return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
280 	case BLKRASET:
281 	case BLKFRASET:
282 		if(!capable(CAP_SYS_ADMIN))
283 			return -EACCES;
284 		bdi = blk_get_backing_dev_info(bdev);
285 		if (bdi == NULL)
286 			return -ENOTTY;
287 		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
288 		return 0;
289 	case BLKBSZSET:
290 		/* set the logical block size */
291 		if (!capable(CAP_SYS_ADMIN))
292 			return -EACCES;
293 		if (!arg)
294 			return -EINVAL;
295 		if (get_user(n, (int __user *) arg))
296 			return -EFAULT;
297 		if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
298 			return -EBUSY;
299 		ret = set_blocksize(bdev, n);
300 		if (!(mode & FMODE_EXCL))
301 			bd_release(bdev);
302 		return ret;
303 	case BLKPG:
304 		ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
305 		break;
306 	case BLKRRPART:
307 		ret = blkdev_reread_part(bdev);
308 		break;
309 	case BLKGETSIZE:
310 		size = bdev->bd_inode->i_size;
311 		if ((size >> 9) > ~0UL)
312 			return -EFBIG;
313 		return put_ulong(arg, size >> 9);
314 	case BLKGETSIZE64:
315 		return put_u64(arg, bdev->bd_inode->i_size);
316 	case BLKTRACESTART:
317 	case BLKTRACESTOP:
318 	case BLKTRACESETUP:
319 	case BLKTRACETEARDOWN:
320 		ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
321 		break;
322 	default:
323 		ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
324 	}
325 	return ret;
326 }
327 EXPORT_SYMBOL_GPL(blkdev_ioctl);
328