1 #include <linux/capability.h> 2 #include <linux/blkdev.h> 3 #include <linux/export.h> 4 #include <linux/gfp.h> 5 #include <linux/blkpg.h> 6 #include <linux/hdreg.h> 7 #include <linux/backing-dev.h> 8 #include <linux/fs.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, NULL); 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_part_scan_enabled(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 = 0; 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 > (i_size_read(bdev->bd_inode) >> 9)) 129 return -EINVAL; 130 if (secure) 131 flags |= BLKDEV_DISCARD_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 * Is it an unrecognized ioctl? The correct returns are either 184 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a 185 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl 186 * code before returning. 187 * 188 * Confused drivers sometimes return EINVAL, which is wrong. It 189 * means "I understood the ioctl command, but the parameters to 190 * it were wrong". 191 * 192 * We should aim to just fix the broken drivers, the EINVAL case 193 * should go away. 194 */ 195 static inline int is_unrecognized_ioctl(int ret) 196 { 197 return ret == -EINVAL || 198 ret == -ENOTTY || 199 ret == -ENOIOCTLCMD; 200 } 201 202 /* 203 * always keep this in sync with compat_blkdev_ioctl() 204 */ 205 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, 206 unsigned long arg) 207 { 208 struct gendisk *disk = bdev->bd_disk; 209 struct backing_dev_info *bdi; 210 loff_t size; 211 int ret, n; 212 213 switch(cmd) { 214 case BLKFLSBUF: 215 if (!capable(CAP_SYS_ADMIN)) 216 return -EACCES; 217 218 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 219 if (!is_unrecognized_ioctl(ret)) 220 return ret; 221 222 fsync_bdev(bdev); 223 invalidate_bdev(bdev); 224 return 0; 225 226 case BLKROSET: 227 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 228 if (!is_unrecognized_ioctl(ret)) 229 return ret; 230 if (!capable(CAP_SYS_ADMIN)) 231 return -EACCES; 232 if (get_user(n, (int __user *)(arg))) 233 return -EFAULT; 234 set_device_ro(bdev, n); 235 return 0; 236 237 case BLKDISCARD: 238 case BLKSECDISCARD: { 239 uint64_t range[2]; 240 241 if (!(mode & FMODE_WRITE)) 242 return -EBADF; 243 244 if (copy_from_user(range, (void __user *)arg, sizeof(range))) 245 return -EFAULT; 246 247 return blk_ioctl_discard(bdev, range[0], range[1], 248 cmd == BLKSECDISCARD); 249 } 250 251 case HDIO_GETGEO: { 252 struct hd_geometry geo; 253 254 if (!arg) 255 return -EINVAL; 256 if (!disk->fops->getgeo) 257 return -ENOTTY; 258 259 /* 260 * We need to set the startsect first, the driver may 261 * want to override it. 262 */ 263 memset(&geo, 0, sizeof(geo)); 264 geo.start = get_start_sect(bdev); 265 ret = disk->fops->getgeo(bdev, &geo); 266 if (ret) 267 return ret; 268 if (copy_to_user((struct hd_geometry __user *)arg, &geo, 269 sizeof(geo))) 270 return -EFAULT; 271 return 0; 272 } 273 case BLKRAGET: 274 case BLKFRAGET: 275 if (!arg) 276 return -EINVAL; 277 bdi = blk_get_backing_dev_info(bdev); 278 if (bdi == NULL) 279 return -ENOTTY; 280 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512); 281 case BLKROGET: 282 return put_int(arg, bdev_read_only(bdev) != 0); 283 case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */ 284 return put_int(arg, block_size(bdev)); 285 case BLKSSZGET: /* get block device logical block size */ 286 return put_int(arg, bdev_logical_block_size(bdev)); 287 case BLKPBSZGET: /* get block device physical block size */ 288 return put_uint(arg, bdev_physical_block_size(bdev)); 289 case BLKIOMIN: 290 return put_uint(arg, bdev_io_min(bdev)); 291 case BLKIOOPT: 292 return put_uint(arg, bdev_io_opt(bdev)); 293 case BLKALIGNOFF: 294 return put_int(arg, bdev_alignment_offset(bdev)); 295 case BLKDISCARDZEROES: 296 return put_uint(arg, bdev_discard_zeroes_data(bdev)); 297 case BLKSECTGET: 298 return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev))); 299 case BLKROTATIONAL: 300 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev))); 301 case BLKRASET: 302 case BLKFRASET: 303 if(!capable(CAP_SYS_ADMIN)) 304 return -EACCES; 305 bdi = blk_get_backing_dev_info(bdev); 306 if (bdi == NULL) 307 return -ENOTTY; 308 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; 309 return 0; 310 case BLKBSZSET: 311 /* set the logical block size */ 312 if (!capable(CAP_SYS_ADMIN)) 313 return -EACCES; 314 if (!arg) 315 return -EINVAL; 316 if (get_user(n, (int __user *) arg)) 317 return -EFAULT; 318 if (!(mode & FMODE_EXCL)) { 319 bdgrab(bdev); 320 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0) 321 return -EBUSY; 322 } 323 ret = set_blocksize(bdev, n); 324 if (!(mode & FMODE_EXCL)) 325 blkdev_put(bdev, mode | FMODE_EXCL); 326 return ret; 327 case BLKPG: 328 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg); 329 break; 330 case BLKRRPART: 331 ret = blkdev_reread_part(bdev); 332 break; 333 case BLKGETSIZE: 334 size = i_size_read(bdev->bd_inode); 335 if ((size >> 9) > ~0UL) 336 return -EFBIG; 337 return put_ulong(arg, size >> 9); 338 case BLKGETSIZE64: 339 return put_u64(arg, i_size_read(bdev->bd_inode)); 340 case BLKTRACESTART: 341 case BLKTRACESTOP: 342 case BLKTRACESETUP: 343 case BLKTRACETEARDOWN: 344 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg); 345 break; 346 default: 347 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 348 } 349 return ret; 350 } 351 EXPORT_SYMBOL_GPL(blkdev_ioctl); 352