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Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
[mirror_ubuntu-artful-kernel.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;
e71bf0d0 15 struct hd_struct *part;
1da177e4
LT
16 struct blkpg_ioctl_arg a;
17 struct blkpg_partition p;
e71bf0d0 18 struct disk_part_iter piter;
1da177e4 19 long long start, length;
cf771cb5 20 int partno;
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;
cf771cb5 31 partno = p.pno;
540eed56 32 if (partno <= 0)
1da177e4
LT
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 }
88e34126 46
c039e313 47 mutex_lock(&bdev->bd_mutex);
88e34126 48
1da177e4 49 /* overlap? */
e71bf0d0
TH
50 disk_part_iter_init(&piter, disk,
51 DISK_PITER_INCL_EMPTY);
52 while ((part = disk_part_iter_next(&piter))) {
53 if (!(start + length <= part->start_sect ||
54 start >= part->start_sect + part->nr_sects)) {
55 disk_part_iter_exit(&piter);
c039e313 56 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
57 return -EBUSY;
58 }
59 }
e71bf0d0
TH
60 disk_part_iter_exit(&piter);
61
1da177e4 62 /* all seems OK */
ba32929a
TH
63 part = add_partition(disk, partno, start, length,
64 ADDPART_FLAG_NONE);
c039e313 65 mutex_unlock(&bdev->bd_mutex);
ba32929a 66 return IS_ERR(part) ? PTR_ERR(part) : 0;
1da177e4 67 case BLKPG_DEL_PARTITION:
e71bf0d0
TH
68 part = disk_get_part(disk, partno);
69 if (!part)
1da177e4 70 return -ENXIO;
e71bf0d0
TH
71
72 bdevp = bdget(part_devt(part));
73 disk_put_part(part);
1da177e4
LT
74 if (!bdevp)
75 return -ENOMEM;
e71bf0d0 76
2e7b651d 77 mutex_lock(&bdevp->bd_mutex);
1da177e4 78 if (bdevp->bd_openers) {
c039e313 79 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
80 bdput(bdevp);
81 return -EBUSY;
82 }
83 /* all seems OK */
84 fsync_bdev(bdevp);
f98393a6 85 invalidate_bdev(bdevp);
1da177e4 86
6d740cd5 87 mutex_lock_nested(&bdev->bd_mutex, 1);
cf771cb5 88 delete_partition(disk, partno);
c039e313
AV
89 mutex_unlock(&bdev->bd_mutex);
90 mutex_unlock(&bdevp->bd_mutex);
1da177e4
LT
91 bdput(bdevp);
92
93 return 0;
94 default:
95 return -EINVAL;
96 }
97}
98
99static int blkdev_reread_part(struct block_device *bdev)
100{
101 struct gendisk *disk = bdev->bd_disk;
102 int res;
103
b5d0b9df 104 if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
1da177e4
LT
105 return -EINVAL;
106 if (!capable(CAP_SYS_ADMIN))
107 return -EACCES;
c039e313 108 if (!mutex_trylock(&bdev->bd_mutex))
1da177e4
LT
109 return -EBUSY;
110 res = rescan_partitions(disk, bdev);
c039e313 111 mutex_unlock(&bdev->bd_mutex);
1da177e4
LT
112 return res;
113}
114
d30a2605
DW
115static void blk_ioc_discard_endio(struct bio *bio, int err)
116{
117 if (err) {
118 if (err == -EOPNOTSUPP)
119 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
120 clear_bit(BIO_UPTODATE, &bio->bi_flags);
121 }
122 complete(bio->bi_private);
123}
124
125static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
126 uint64_t len)
127{
128 struct request_queue *q = bdev_get_queue(bdev);
129 int ret = 0;
130
131 if (start & 511)
132 return -EINVAL;
133 if (len & 511)
134 return -EINVAL;
135 start >>= 9;
136 len >>= 9;
137
138 if (start + len > (bdev->bd_inode->i_size >> 9))
139 return -EINVAL;
140
141 if (!q->prepare_discard_fn)
142 return -EOPNOTSUPP;
143
144 while (len && !ret) {
145 DECLARE_COMPLETION_ONSTACK(wait);
146 struct bio *bio;
147
148 bio = bio_alloc(GFP_KERNEL, 0);
d30a2605
DW
149
150 bio->bi_end_io = blk_ioc_discard_endio;
151 bio->bi_bdev = bdev;
152 bio->bi_private = &wait;
153 bio->bi_sector = start;
154
ae03bf63
MP
155 if (len > queue_max_hw_sectors(q)) {
156 bio->bi_size = queue_max_hw_sectors(q) << 9;
157 len -= queue_max_hw_sectors(q);
158 start += queue_max_hw_sectors(q);
d30a2605
DW
159 } else {
160 bio->bi_size = len << 9;
161 len = 0;
162 }
e17fc0a1 163 submit_bio(DISCARD_NOBARRIER, bio);
d30a2605
DW
164
165 wait_for_completion(&wait);
166
167 if (bio_flagged(bio, BIO_EOPNOTSUPP))
168 ret = -EOPNOTSUPP;
169 else if (!bio_flagged(bio, BIO_UPTODATE))
170 ret = -EIO;
171 bio_put(bio);
172 }
173 return ret;
174}
175
1da177e4
LT
176static int put_ushort(unsigned long arg, unsigned short val)
177{
178 return put_user(val, (unsigned short __user *)arg);
179}
180
181static int put_int(unsigned long arg, int val)
182{
183 return put_user(val, (int __user *)arg);
184}
185
186static int put_long(unsigned long arg, long val)
187{
188 return put_user(val, (long __user *)arg);
189}
190
191static int put_ulong(unsigned long arg, unsigned long val)
192{
193 return put_user(val, (unsigned long __user *)arg);
194}
195
196static int put_u64(unsigned long arg, u64 val)
197{
198 return put_user(val, (u64 __user *)arg);
199}
200
633a08b8
AV
201int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
202 unsigned cmd, unsigned long arg)
203{
204 struct gendisk *disk = bdev->bd_disk;
205 int ret;
d4430d62
AV
206
207 if (disk->fops->ioctl)
208 return disk->fops->ioctl(bdev, mode, cmd, arg);
633a08b8 209
d4430d62 210 if (disk->fops->locked_ioctl) {
633a08b8 211 lock_kernel();
d4430d62 212 ret = disk->fops->locked_ioctl(bdev, mode, cmd, arg);
633a08b8
AV
213 unlock_kernel();
214 return ret;
215 }
216
217 return -ENOTTY;
218}
219/*
220 * For the record: _GPL here is only because somebody decided to slap it
221 * on the previous export. Sheer idiocy, since it wasn't copyrightable
222 * at all and could be open-coded without any exports by anybody who cares.
223 */
224EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
225
f58c4c0a
AB
226/*
227 * always keep this in sync with compat_blkdev_ioctl() and
228 * compat_blkdev_locked_ioctl()
229 */
56b26add 230int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
bb93e3a5
AB
231 unsigned long arg)
232{
bb93e3a5 233 struct gendisk *disk = bdev->bd_disk;
45048d09
AV
234 struct backing_dev_info *bdi;
235 loff_t size;
bb93e3a5
AB
236 int ret, n;
237
238 switch(cmd) {
1da177e4
LT
239 case BLKFLSBUF:
240 if (!capable(CAP_SYS_ADMIN))
241 return -EACCES;
bb93e3a5 242
e436fdae 243 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
bb93e3a5
AB
244 /* -EINVAL to handle old uncorrected drivers */
245 if (ret != -EINVAL && ret != -ENOTTY)
246 return ret;
247
248 lock_kernel();
1da177e4 249 fsync_bdev(bdev);
f98393a6 250 invalidate_bdev(bdev);
bb93e3a5 251 unlock_kernel();
1da177e4 252 return 0;
bb93e3a5 253
1da177e4 254 case BLKROSET:
e436fdae 255 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
bb93e3a5
AB
256 /* -EINVAL to handle old uncorrected drivers */
257 if (ret != -EINVAL && ret != -ENOTTY)
258 return ret;
1da177e4
LT
259 if (!capable(CAP_SYS_ADMIN))
260 return -EACCES;
261 if (get_user(n, (int __user *)(arg)))
262 return -EFAULT;
bb93e3a5 263 lock_kernel();
1da177e4 264 set_device_ro(bdev, n);
bb93e3a5 265 unlock_kernel();
1da177e4 266 return 0;
d30a2605
DW
267
268 case BLKDISCARD: {
269 uint64_t range[2];
270
e436fdae 271 if (!(mode & FMODE_WRITE))
d30a2605
DW
272 return -EBADF;
273
274 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
275 return -EFAULT;
276
277 return blk_ioctl_discard(bdev, range[0], range[1]);
278 }
279
a885c8c4
CH
280 case HDIO_GETGEO: {
281 struct hd_geometry geo;
282
283 if (!arg)
284 return -EINVAL;
285 if (!disk->fops->getgeo)
286 return -ENOTTY;
287
288 /*
289 * We need to set the startsect first, the driver may
290 * want to override it.
291 */
292 geo.start = get_start_sect(bdev);
293 ret = disk->fops->getgeo(bdev, &geo);
294 if (ret)
295 return ret;
296 if (copy_to_user((struct hd_geometry __user *)arg, &geo,
297 sizeof(geo)))
298 return -EFAULT;
299 return 0;
300 }
45048d09
AV
301 case BLKRAGET:
302 case BLKFRAGET:
303 if (!arg)
304 return -EINVAL;
305 bdi = blk_get_backing_dev_info(bdev);
306 if (bdi == NULL)
307 return -ENOTTY;
308 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
309 case BLKROGET:
310 return put_int(arg, bdev_read_only(bdev) != 0);
311 case BLKBSZGET: /* get the logical block size (cf. BLKSSZGET) */
312 return put_int(arg, block_size(bdev));
313 case BLKSSZGET: /* get block device hardware sector size */
e1defc4f 314 return put_int(arg, bdev_logical_block_size(bdev));
45048d09 315 case BLKSECTGET:
ae03bf63 316 return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
45048d09
AV
317 case BLKRASET:
318 case BLKFRASET:
319 if(!capable(CAP_SYS_ADMIN))
320 return -EACCES;
321 bdi = blk_get_backing_dev_info(bdev);
322 if (bdi == NULL)
323 return -ENOTTY;
45048d09 324 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
45048d09
AV
325 return 0;
326 case BLKBSZSET:
327 /* set the logical block size */
328 if (!capable(CAP_SYS_ADMIN))
329 return -EACCES;
330 if (!arg)
331 return -EINVAL;
332 if (get_user(n, (int __user *) arg))
333 return -EFAULT;
6af3a56e 334 if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
45048d09
AV
335 return -EBUSY;
336 ret = set_blocksize(bdev, n);
6af3a56e
AV
337 if (!(mode & FMODE_EXCL))
338 bd_release(bdev);
bb93e3a5 339 return ret;
45048d09
AV
340 case BLKPG:
341 lock_kernel();
342 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
343 unlock_kernel();
344 break;
345 case BLKRRPART:
346 lock_kernel();
347 ret = blkdev_reread_part(bdev);
348 unlock_kernel();
349 break;
350 case BLKGETSIZE:
351 size = bdev->bd_inode->i_size;
352 if ((size >> 9) > ~0UL)
353 return -EFBIG;
354 return put_ulong(arg, size >> 9);
355 case BLKGETSIZE64:
356 return put_u64(arg, bdev->bd_inode->i_size);
357 case BLKTRACESTART:
358 case BLKTRACESTOP:
359 case BLKTRACESETUP:
360 case BLKTRACETEARDOWN:
361 lock_kernel();
362 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
363 unlock_kernel();
364 break;
365 default:
366 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
367 }
368 return ret;
1da177e4 369}
68f66feb 370EXPORT_SYMBOL_GPL(blkdev_ioctl);