block: don't init rq fields unnecessarily
[linux-2.6.git] / block / ioctl.c
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 hd_struct *part;
16         struct blkpg_ioctl_arg a;
17         struct blkpg_partition p;
18         struct disk_part_iter piter;
19         long long start, length;
20         int partno;
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         partno = p.pno;
32         if (partno <= 0)
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
47                         mutex_lock(&bdev->bd_mutex);
48
49                         /* overlap? */
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);
56                                         mutex_unlock(&bdev->bd_mutex);
57                                         return -EBUSY;
58                                 }
59                         }
60                         disk_part_iter_exit(&piter);
61
62                         /* all seems OK */
63                         part = add_partition(disk, partno, start, length,
64                                              ADDPART_FLAG_NONE);
65                         mutex_unlock(&bdev->bd_mutex);
66                         return IS_ERR(part) ? PTR_ERR(part) : 0;
67                 case BLKPG_DEL_PARTITION:
68                         part = disk_get_part(disk, partno);
69                         if (!part)
70                                 return -ENXIO;
71
72                         bdevp = bdget(part_devt(part));
73                         disk_put_part(part);
74                         if (!bdevp)
75                                 return -ENOMEM;
76
77                         mutex_lock(&bdevp->bd_mutex);
78                         if (bdevp->bd_openers) {
79                                 mutex_unlock(&bdevp->bd_mutex);
80                                 bdput(bdevp);
81                                 return -EBUSY;
82                         }
83                         /* all seems OK */
84                         fsync_bdev(bdevp);
85                         invalidate_bdev(bdevp);
86
87                         mutex_lock_nested(&bdev->bd_mutex, 1);
88                         delete_partition(disk, partno);
89                         mutex_unlock(&bdev->bd_mutex);
90                         mutex_unlock(&bdevp->bd_mutex);
91                         bdput(bdevp);
92
93                         return 0;
94                 default:
95                         return -EINVAL;
96         }
97 }
98
99 static int blkdev_reread_part(struct block_device *bdev)
100 {
101         struct gendisk *disk = bdev->bd_disk;
102         int res;
103
104         if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
105                 return -EINVAL;
106         if (!capable(CAP_SYS_ADMIN))
107                 return -EACCES;
108         if (!mutex_trylock(&bdev->bd_mutex))
109                 return -EBUSY;
110         res = rescan_partitions(disk, bdev);
111         mutex_unlock(&bdev->bd_mutex);
112         return res;
113 }
114
115 static 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
125 static 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);
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
155                 if (len > q->max_hw_sectors) {
156                         bio->bi_size = q->max_hw_sectors << 9;
157                         len -= q->max_hw_sectors;
158                         start += q->max_hw_sectors;
159                 } else {
160                         bio->bi_size = len << 9;
161                         len = 0;
162                 }
163                 submit_bio(DISCARD_NOBARRIER, bio);
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
176 static int put_ushort(unsigned long arg, unsigned short val)
177 {
178         return put_user(val, (unsigned short __user *)arg);
179 }
180
181 static int put_int(unsigned long arg, int val)
182 {
183         return put_user(val, (int __user *)arg);
184 }
185
186 static int put_long(unsigned long arg, long val)
187 {
188         return put_user(val, (long __user *)arg);
189 }
190
191 static int put_ulong(unsigned long arg, unsigned long val)
192 {
193         return put_user(val, (unsigned long __user *)arg);
194 }
195
196 static int put_u64(unsigned long arg, u64 val)
197 {
198         return put_user(val, (u64 __user *)arg);
199 }
200
201 int __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;
206
207         if (disk->fops->ioctl)
208                 return disk->fops->ioctl(bdev, mode, cmd, arg);
209
210         if (disk->fops->locked_ioctl) {
211                 lock_kernel();
212                 ret = disk->fops->locked_ioctl(bdev, mode, cmd, arg);
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  */
224 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
225
226 /*
227  * always keep this in sync with compat_blkdev_ioctl() and
228  * compat_blkdev_locked_ioctl()
229  */
230 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
231                         unsigned long arg)
232 {
233         struct gendisk *disk = bdev->bd_disk;
234         struct backing_dev_info *bdi;
235         loff_t size;
236         int ret, n;
237
238         switch(cmd) {
239         case BLKFLSBUF:
240                 if (!capable(CAP_SYS_ADMIN))
241                         return -EACCES;
242
243                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
244                 /* -EINVAL to handle old uncorrected drivers */
245                 if (ret != -EINVAL && ret != -ENOTTY)
246                         return ret;
247
248                 lock_kernel();
249                 fsync_bdev(bdev);
250                 invalidate_bdev(bdev);
251                 unlock_kernel();
252                 return 0;
253
254         case BLKROSET:
255                 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
256                 /* -EINVAL to handle old uncorrected drivers */
257                 if (ret != -EINVAL && ret != -ENOTTY)
258                         return ret;
259                 if (!capable(CAP_SYS_ADMIN))
260                         return -EACCES;
261                 if (get_user(n, (int __user *)(arg)))
262                         return -EFAULT;
263                 lock_kernel();
264                 set_device_ro(bdev, n);
265                 unlock_kernel();
266                 return 0;
267
268         case BLKDISCARD: {
269                 uint64_t range[2];
270
271                 if (!(mode & FMODE_WRITE))
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
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         }
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 */
314                 return put_int(arg, bdev_hardsect_size(bdev));
315         case BLKSECTGET:
316                 return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
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;
324                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
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;
334                 if (!(mode & FMODE_EXCL) && bd_claim(bdev, &bdev) < 0)
335                         return -EBUSY;
336                 ret = set_blocksize(bdev, n);
337                 if (!(mode & FMODE_EXCL))
338                         bd_release(bdev);
339                 return ret;
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;
369 }
370 EXPORT_SYMBOL_GPL(blkdev_ioctl);