xref: /linux/block/ioctl.c (revision 1795cf48b322b4d19230a40dbe7181acedd34a94)
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 
11 static 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 	int err;
21 
22 	if (!capable(CAP_SYS_ADMIN))
23 		return -EACCES;
24 	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
25 		return -EFAULT;
26 	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
27 		return -EFAULT;
28 	disk = bdev->bd_disk;
29 	if (bdev != bdev->bd_contains)
30 		return -EINVAL;
31 	part = p.pno;
32 	if (part <= 0 || part >= disk->minors)
33 		return -EINVAL;
34 	switch (a.op) {
35 		case BLKPG_ADD_PARTITION:
36 			start = p.start >> 9;
37 			length = p.length >> 9;
38 			/* check for fit in a hd_struct */
39 			if (sizeof(sector_t) == sizeof(long) &&
40 			    sizeof(long long) > sizeof(long)) {
41 				long pstart = start, plength = length;
42 				if (pstart != start || plength != length
43 				    || pstart < 0 || plength < 0)
44 					return -EINVAL;
45 			}
46 			/* partition number in use? */
47 			mutex_lock(&bdev->bd_mutex);
48 			if (disk->part[part - 1]) {
49 				mutex_unlock(&bdev->bd_mutex);
50 				return -EBUSY;
51 			}
52 			/* overlap? */
53 			for (i = 0; i < disk->minors - 1; i++) {
54 				struct hd_struct *s = disk->part[i];
55 
56 				if (!s)
57 					continue;
58 				if (!(start+length <= s->start_sect ||
59 				      start >= s->start_sect + s->nr_sects)) {
60 					mutex_unlock(&bdev->bd_mutex);
61 					return -EBUSY;
62 				}
63 			}
64 			/* all seems OK */
65 			err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
66 			mutex_unlock(&bdev->bd_mutex);
67 			return err;
68 		case BLKPG_DEL_PARTITION:
69 			if (!disk->part[part-1])
70 				return -ENXIO;
71 			if (disk->part[part - 1]->nr_sects == 0)
72 				return -ENXIO;
73 			bdevp = bdget_disk(disk, part);
74 			if (!bdevp)
75 				return -ENOMEM;
76 			mutex_lock(&bdevp->bd_mutex);
77 			if (bdevp->bd_openers) {
78 				mutex_unlock(&bdevp->bd_mutex);
79 				bdput(bdevp);
80 				return -EBUSY;
81 			}
82 			/* all seems OK */
83 			fsync_bdev(bdevp);
84 			invalidate_bdev(bdevp);
85 
86 			mutex_lock_nested(&bdev->bd_mutex, 1);
87 			delete_partition(disk, part);
88 			mutex_unlock(&bdev->bd_mutex);
89 			mutex_unlock(&bdevp->bd_mutex);
90 			bdput(bdevp);
91 
92 			return 0;
93 		default:
94 			return -EINVAL;
95 	}
96 }
97 
98 static int blkdev_reread_part(struct block_device *bdev)
99 {
100 	struct gendisk *disk = bdev->bd_disk;
101 	int res;
102 
103 	if (disk->minors == 1 || bdev != bdev->bd_contains)
104 		return -EINVAL;
105 	if (!capable(CAP_SYS_ADMIN))
106 		return -EACCES;
107 	if (!mutex_trylock(&bdev->bd_mutex))
108 		return -EBUSY;
109 	res = rescan_partitions(disk, bdev);
110 	mutex_unlock(&bdev->bd_mutex);
111 	return res;
112 }
113 
114 static int put_ushort(unsigned long arg, unsigned short val)
115 {
116 	return put_user(val, (unsigned short __user *)arg);
117 }
118 
119 static int put_int(unsigned long arg, int val)
120 {
121 	return put_user(val, (int __user *)arg);
122 }
123 
124 static int put_long(unsigned long arg, long val)
125 {
126 	return put_user(val, (long __user *)arg);
127 }
128 
129 static int put_ulong(unsigned long arg, unsigned long val)
130 {
131 	return put_user(val, (unsigned long __user *)arg);
132 }
133 
134 static int put_u64(unsigned long arg, u64 val)
135 {
136 	return put_user(val, (u64 __user *)arg);
137 }
138 
139 static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
140 				unsigned cmd, unsigned long arg)
141 {
142 	struct backing_dev_info *bdi;
143 	int ret, n;
144 
145 	switch (cmd) {
146 	case BLKRAGET:
147 	case BLKFRAGET:
148 		if (!arg)
149 			return -EINVAL;
150 		bdi = blk_get_backing_dev_info(bdev);
151 		if (bdi == NULL)
152 			return -ENOTTY;
153 		return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
154 	case BLKROGET:
155 		return put_int(arg, bdev_read_only(bdev) != 0);
156 	case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
157 		return put_int(arg, block_size(bdev));
158 	case BLKSSZGET: /* get block device hardware sector size */
159 		return put_int(arg, bdev_hardsect_size(bdev));
160 	case BLKSECTGET:
161 		return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
162 	case BLKRASET:
163 	case BLKFRASET:
164 		if(!capable(CAP_SYS_ADMIN))
165 			return -EACCES;
166 		bdi = blk_get_backing_dev_info(bdev);
167 		if (bdi == NULL)
168 			return -ENOTTY;
169 		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
170 		return 0;
171 	case BLKBSZSET:
172 		/* set the logical block size */
173 		if (!capable(CAP_SYS_ADMIN))
174 			return -EACCES;
175 		if (!arg)
176 			return -EINVAL;
177 		if (get_user(n, (int __user *) arg))
178 			return -EFAULT;
179 		if (bd_claim(bdev, file) < 0)
180 			return -EBUSY;
181 		ret = set_blocksize(bdev, n);
182 		bd_release(bdev);
183 		return ret;
184 	case BLKPG:
185 		return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
186 	case BLKRRPART:
187 		return blkdev_reread_part(bdev);
188 	case BLKGETSIZE:
189 		if ((bdev->bd_inode->i_size >> 9) > ~0UL)
190 			return -EFBIG;
191 		return put_ulong(arg, bdev->bd_inode->i_size >> 9);
192 	case BLKGETSIZE64:
193 		return put_u64(arg, bdev->bd_inode->i_size);
194 	case BLKTRACESTART:
195 	case BLKTRACESTOP:
196 	case BLKTRACESETUP:
197 	case BLKTRACETEARDOWN:
198 		return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
199 	}
200 	return -ENOIOCTLCMD;
201 }
202 
203 int blkdev_driver_ioctl(struct inode *inode, struct file *file,
204 			struct gendisk *disk, unsigned cmd, unsigned long arg)
205 {
206 	int ret;
207 	if (disk->fops->unlocked_ioctl)
208 		return disk->fops->unlocked_ioctl(file, cmd, arg);
209 
210 	if (disk->fops->ioctl) {
211 		lock_kernel();
212 		ret = disk->fops->ioctl(inode, file, cmd, arg);
213 		unlock_kernel();
214 		return ret;
215 	}
216 
217 	return -ENOTTY;
218 }
219 EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
220 
221 /*
222  * always keep this in sync with compat_blkdev_ioctl() and
223  * compat_blkdev_locked_ioctl()
224  */
225 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
226 			unsigned long arg)
227 {
228 	struct block_device *bdev = inode->i_bdev;
229 	struct gendisk *disk = bdev->bd_disk;
230 	int ret, n;
231 
232 	switch(cmd) {
233 	case BLKFLSBUF:
234 		if (!capable(CAP_SYS_ADMIN))
235 			return -EACCES;
236 
237 		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
238 		/* -EINVAL to handle old uncorrected drivers */
239 		if (ret != -EINVAL && ret != -ENOTTY)
240 			return ret;
241 
242 		lock_kernel();
243 		fsync_bdev(bdev);
244 		invalidate_bdev(bdev);
245 		unlock_kernel();
246 		return 0;
247 
248 	case BLKROSET:
249 		ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
250 		/* -EINVAL to handle old uncorrected drivers */
251 		if (ret != -EINVAL && ret != -ENOTTY)
252 			return ret;
253 		if (!capable(CAP_SYS_ADMIN))
254 			return -EACCES;
255 		if (get_user(n, (int __user *)(arg)))
256 			return -EFAULT;
257 		lock_kernel();
258 		set_device_ro(bdev, n);
259 		unlock_kernel();
260 		return 0;
261 	case HDIO_GETGEO: {
262 		struct hd_geometry geo;
263 
264 		if (!arg)
265 			return -EINVAL;
266 		if (!disk->fops->getgeo)
267 			return -ENOTTY;
268 
269 		/*
270 		 * We need to set the startsect first, the driver may
271 		 * want to override it.
272 		 */
273 		geo.start = get_start_sect(bdev);
274 		ret = disk->fops->getgeo(bdev, &geo);
275 		if (ret)
276 			return ret;
277 		if (copy_to_user((struct hd_geometry __user *)arg, &geo,
278 					sizeof(geo)))
279 			return -EFAULT;
280 		return 0;
281 	}
282 	}
283 
284 	lock_kernel();
285 	ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
286 	unlock_kernel();
287 	if (ret != -ENOIOCTLCMD)
288 		return ret;
289 
290 	return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
291 }
292 EXPORT_SYMBOL_GPL(blkdev_ioctl);
293