Allow elevators to sort/merge discard requests
[linux-2.6-block.git] / block / ioctl.c
CommitLineData
c59ede7b 1#include <linux/capability.h>
1da177e4
LT
2#include <linux/blkdev.h>
3#include <linux/blkpg.h>
a885c8c4 4#include <linux/hdreg.h>
1da177e4
LT
5#include <linux/backing-dev.h>
6#include <linux/buffer_head.h>
7#include <linux/smp_lock.h>
2056a782 8#include <linux/blktrace_api.h>
1da177e4
LT
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;
04ebd4ae 20 int err;
1da177e4
LT
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? */
c039e313 47 mutex_lock(&bdev->bd_mutex);
1da177e4 48 if (disk->part[part - 1]) {
c039e313 49 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
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)) {
c039e313 60 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
61 return -EBUSY;
62 }
63 }
64 /* all seems OK */
04ebd4ae 65 err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
c039e313 66 mutex_unlock(&bdev->bd_mutex);
04ebd4ae 67 return err;
1da177e4
LT
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;
2e7b651d 76 mutex_lock(&bdevp->bd_mutex);
1da177e4 77 if (bdevp->bd_openers) {
c039e313 78 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
79 bdput(bdevp);
80 return -EBUSY;
81 }
82 /* all seems OK */
83 fsync_bdev(bdevp);
f98393a6 84 invalidate_bdev(bdevp);
1da177e4 85
6d740cd5 86 mutex_lock_nested(&bdev->bd_mutex, 1);
1da177e4 87 delete_partition(disk, part);
c039e313
AV
88 mutex_unlock(&bdev->bd_mutex);
89 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
90 bdput(bdevp);
91
92 return 0;
93 default:
94 return -EINVAL;
95 }
96}
97
98static 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;
c039e313 107 if (!mutex_trylock(&bdev->bd_mutex))
1da177e4
LT
108 return -EBUSY;
109 res = rescan_partitions(disk, bdev);
c039e313 110 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
111 return res;
112}
113
d30a2605
DW
114static void blk_ioc_discard_endio(struct bio *bio, int err)
115{
116 if (err) {
117 if (err == -EOPNOTSUPP)
118 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
119 clear_bit(BIO_UPTODATE, &bio->bi_flags);
120 }
121 complete(bio->bi_private);
122}
123
124static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
125 uint64_t len)
126{
127 struct request_queue *q = bdev_get_queue(bdev);
128 int ret = 0;
129
130 if (start & 511)
131 return -EINVAL;
132 if (len & 511)
133 return -EINVAL;
134 start >>= 9;
135 len >>= 9;
136
137 if (start + len > (bdev->bd_inode->i_size >> 9))
138 return -EINVAL;
139
140 if (!q->prepare_discard_fn)
141 return -EOPNOTSUPP;
142
143 while (len && !ret) {
144 DECLARE_COMPLETION_ONSTACK(wait);
145 struct bio *bio;
146
147 bio = bio_alloc(GFP_KERNEL, 0);
148 if (!bio)
149 return -ENOMEM;
150
151 bio->bi_end_io = blk_ioc_discard_endio;
152 bio->bi_bdev = bdev;
153 bio->bi_private = &wait;
154 bio->bi_sector = start;
155
156 if (len > q->max_hw_sectors) {
157 bio->bi_size = q->max_hw_sectors << 9;
158 len -= q->max_hw_sectors;
159 start += q->max_hw_sectors;
160 } else {
161 bio->bi_size = len << 9;
162 len = 0;
163 }
e17fc0a1 164 submit_bio(DISCARD_NOBARRIER, bio);
d30a2605
DW
165
166 wait_for_completion(&wait);
167
168 if (bio_flagged(bio, BIO_EOPNOTSUPP))
169 ret = -EOPNOTSUPP;
170 else if (!bio_flagged(bio, BIO_UPTODATE))
171 ret = -EIO;
172 bio_put(bio);
173 }
174 return ret;
175}
176
1da177e4
LT
177static int put_ushort(unsigned long arg, unsigned short val)
178{
179 return put_user(val, (unsigned short __user *)arg);
180}
181
182static int put_int(unsigned long arg, int val)
183{
184 return put_user(val, (int __user *)arg);
185}
186
187static int put_long(unsigned long arg, long val)
188{
189 return put_user(val, (long __user *)arg);
190}
191
192static int put_ulong(unsigned long arg, unsigned long val)
193{
194 return put_user(val, (unsigned long __user *)arg);
195}
196
197static int put_u64(unsigned long arg, u64 val)
198{
199 return put_user(val, (u64 __user *)arg);
200}
201
bb93e3a5
AB
202static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
203 unsigned cmd, unsigned long arg)
1da177e4 204{
1da177e4
LT
205 struct backing_dev_info *bdi;
206 int ret, n;
207
208 switch (cmd) {
209 case BLKRAGET:
210 case BLKFRAGET:
211 if (!arg)
212 return -EINVAL;
213 bdi = blk_get_backing_dev_info(bdev);
214 if (bdi == NULL)
215 return -ENOTTY;
216 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
217 case BLKROGET:
218 return put_int(arg, bdev_read_only(bdev) != 0);
219 case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
220 return put_int(arg, block_size(bdev));
221 case BLKSSZGET: /* get block device hardware sector size */
222 return put_int(arg, bdev_hardsect_size(bdev));
223 case BLKSECTGET:
224 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
225 case BLKRASET:
226 case BLKFRASET:
227 if(!capable(CAP_SYS_ADMIN))
228 return -EACCES;
229 bdi = blk_get_backing_dev_info(bdev);
230 if (bdi == NULL)
231 return -ENOTTY;
232 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
233 return 0;
234 case BLKBSZSET:
235 /* set the logical block size */
236 if (!capable(CAP_SYS_ADMIN))
237 return -EACCES;
238 if (!arg)
239 return -EINVAL;
240 if (get_user(n, (int __user *) arg))
241 return -EFAULT;
242 if (bd_claim(bdev, file) < 0)
243 return -EBUSY;
244 ret = set_blocksize(bdev, n);
245 bd_release(bdev);
246 return ret;
247 case BLKPG:
248 return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
249 case BLKRRPART:
250 return blkdev_reread_part(bdev);
251 case BLKGETSIZE:
252 if ((bdev->bd_inode->i_size >> 9) > ~0UL)
253 return -EFBIG;
254 return put_ulong(arg, bdev->bd_inode->i_size >> 9);
255 case BLKGETSIZE64:
256 return put_u64(arg, bdev->bd_inode->i_size);
2056a782
JA
257 case BLKTRACESTART:
258 case BLKTRACESTOP:
259 case BLKTRACESETUP:
260 case BLKTRACETEARDOWN:
261 return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
bb93e3a5
AB
262 }
263 return -ENOIOCTLCMD;
264}
265
7006f6ec
AK
266int blkdev_driver_ioctl(struct inode *inode, struct file *file,
267 struct gendisk *disk, unsigned cmd, unsigned long arg)
bb93e3a5
AB
268{
269 int ret;
270 if (disk->fops->unlocked_ioctl)
271 return disk->fops->unlocked_ioctl(file, cmd, arg);
272
273 if (disk->fops->ioctl) {
274 lock_kernel();
275 ret = disk->fops->ioctl(inode, file, cmd, arg);
276 unlock_kernel();
277 return ret;
278 }
279
280 return -ENOTTY;
281}
7006f6ec 282EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
bb93e3a5 283
f58c4c0a
AB
284/*
285 * always keep this in sync with compat_blkdev_ioctl() and
286 * compat_blkdev_locked_ioctl()
287 */
bb93e3a5
AB
288int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
289 unsigned long arg)
290{
291 struct block_device *bdev = inode->i_bdev;
292 struct gendisk *disk = bdev->bd_disk;
293 int ret, n;
294
295 switch(cmd) {
1da177e4
LT
296 case BLKFLSBUF:
297 if (!capable(CAP_SYS_ADMIN))
298 return -EACCES;
bb93e3a5
AB
299
300 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
301 /* -EINVAL to handle old uncorrected drivers */
302 if (ret != -EINVAL && ret != -ENOTTY)
303 return ret;
304
305 lock_kernel();
1da177e4 306 fsync_bdev(bdev);
f98393a6 307 invalidate_bdev(bdev);
bb93e3a5 308 unlock_kernel();
1da177e4 309 return 0;
bb93e3a5 310
1da177e4 311 case BLKROSET:
bb93e3a5
AB
312 ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
313 /* -EINVAL to handle old uncorrected drivers */
314 if (ret != -EINVAL && ret != -ENOTTY)
315 return ret;
1da177e4
LT
316 if (!capable(CAP_SYS_ADMIN))
317 return -EACCES;
318 if (get_user(n, (int __user *)(arg)))
319 return -EFAULT;
bb93e3a5 320 lock_kernel();
1da177e4 321 set_device_ro(bdev, n);
bb93e3a5 322 unlock_kernel();
1da177e4 323 return 0;
d30a2605
DW
324
325 case BLKDISCARD: {
326 uint64_t range[2];
327
328 if (!(file->f_mode & FMODE_WRITE))
329 return -EBADF;
330
331 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
332 return -EFAULT;
333
334 return blk_ioctl_discard(bdev, range[0], range[1]);
335 }
336
a885c8c4
CH
337 case HDIO_GETGEO: {
338 struct hd_geometry geo;
339
340 if (!arg)
341 return -EINVAL;
342 if (!disk->fops->getgeo)
343 return -ENOTTY;
344
345 /*
346 * We need to set the startsect first, the driver may
347 * want to override it.
348 */
349 geo.start = get_start_sect(bdev);
350 ret = disk->fops->getgeo(bdev, &geo);
351 if (ret)
352 return ret;
353 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
354 sizeof(geo)))
355 return -EFAULT;
356 return 0;
357 }
1da177e4 358 }
bb93e3a5
AB
359
360 lock_kernel();
361 ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
362 unlock_kernel();
363 if (ret != -ENOIOCTLCMD)
364 return ret;
365
366 return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
1da177e4 367}
68f66feb 368EXPORT_SYMBOL_GPL(blkdev_ioctl);