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, *lpart; 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 || partno > 65535) 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 PTR_ERR_OR_ZERO(part); 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 case BLKPG_RESIZE_PARTITION: 96 start = p.start >> 9; 97 /* new length of partition in bytes */ 98 length = p.length >> 9; 99 /* check for fit in a hd_struct */ 100 if (sizeof(sector_t) == sizeof(long) && 101 sizeof(long long) > sizeof(long)) { 102 long pstart = start, plength = length; 103 if (pstart != start || plength != length 104 || pstart < 0 || plength < 0) 105 return -EINVAL; 106 } 107 part = disk_get_part(disk, partno); 108 if (!part) 109 return -ENXIO; 110 bdevp = bdget(part_devt(part)); 111 if (!bdevp) { 112 disk_put_part(part); 113 return -ENOMEM; 114 } 115 mutex_lock(&bdevp->bd_mutex); 116 mutex_lock_nested(&bdev->bd_mutex, 1); 117 if (start != part->start_sect) { 118 mutex_unlock(&bdevp->bd_mutex); 119 mutex_unlock(&bdev->bd_mutex); 120 bdput(bdevp); 121 disk_put_part(part); 122 return -EINVAL; 123 } 124 /* overlap? */ 125 disk_part_iter_init(&piter, disk, 126 DISK_PITER_INCL_EMPTY); 127 while ((lpart = disk_part_iter_next(&piter))) { 128 if (lpart->partno != partno && 129 !(start + length <= lpart->start_sect || 130 start >= lpart->start_sect + lpart->nr_sects) 131 ) { 132 disk_part_iter_exit(&piter); 133 mutex_unlock(&bdevp->bd_mutex); 134 mutex_unlock(&bdev->bd_mutex); 135 bdput(bdevp); 136 disk_put_part(part); 137 return -EBUSY; 138 } 139 } 140 disk_part_iter_exit(&piter); 141 part_nr_sects_write(part, (sector_t)length); 142 i_size_write(bdevp->bd_inode, p.length); 143 mutex_unlock(&bdevp->bd_mutex); 144 mutex_unlock(&bdev->bd_mutex); 145 bdput(bdevp); 146 disk_put_part(part); 147 return 0; 148 default: 149 return -EINVAL; 150 } 151 } 152 153 /* 154 * This is an exported API for the block driver, and will not 155 * acquire bd_mutex. This API should be used in case that 156 * caller has held bd_mutex already. 157 */ 158 int __blkdev_reread_part(struct block_device *bdev) 159 { 160 struct gendisk *disk = bdev->bd_disk; 161 162 if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains) 163 return -EINVAL; 164 if (!capable(CAP_SYS_ADMIN)) 165 return -EACCES; 166 167 lockdep_assert_held(&bdev->bd_mutex); 168 169 return rescan_partitions(disk, bdev); 170 } 171 EXPORT_SYMBOL(__blkdev_reread_part); 172 173 /* 174 * This is an exported API for the block driver, and will 175 * try to acquire bd_mutex. If bd_mutex has been held already 176 * in current context, please call __blkdev_reread_part(). 177 * 178 * Make sure the held locks in current context aren't required 179 * in open()/close() handler and I/O path for avoiding ABBA deadlock: 180 * - bd_mutex is held before calling block driver's open/close 181 * handler 182 * - reading partition table may submit I/O to the block device 183 */ 184 int blkdev_reread_part(struct block_device *bdev) 185 { 186 int res; 187 188 mutex_lock(&bdev->bd_mutex); 189 res = __blkdev_reread_part(bdev); 190 mutex_unlock(&bdev->bd_mutex); 191 192 return res; 193 } 194 EXPORT_SYMBOL(blkdev_reread_part); 195 196 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start, 197 uint64_t len, int secure) 198 { 199 unsigned long flags = 0; 200 201 if (start & 511) 202 return -EINVAL; 203 if (len & 511) 204 return -EINVAL; 205 start >>= 9; 206 len >>= 9; 207 208 if (start + len > (i_size_read(bdev->bd_inode) >> 9)) 209 return -EINVAL; 210 if (secure) 211 flags |= BLKDEV_DISCARD_SECURE; 212 return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags); 213 } 214 215 static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start, 216 uint64_t len) 217 { 218 if (start & 511) 219 return -EINVAL; 220 if (len & 511) 221 return -EINVAL; 222 start >>= 9; 223 len >>= 9; 224 225 if (start + len > (i_size_read(bdev->bd_inode) >> 9)) 226 return -EINVAL; 227 228 return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false); 229 } 230 231 static int put_ushort(unsigned long arg, unsigned short val) 232 { 233 return put_user(val, (unsigned short __user *)arg); 234 } 235 236 static int put_int(unsigned long arg, int val) 237 { 238 return put_user(val, (int __user *)arg); 239 } 240 241 static int put_uint(unsigned long arg, unsigned int val) 242 { 243 return put_user(val, (unsigned int __user *)arg); 244 } 245 246 static int put_long(unsigned long arg, long val) 247 { 248 return put_user(val, (long __user *)arg); 249 } 250 251 static int put_ulong(unsigned long arg, unsigned long val) 252 { 253 return put_user(val, (unsigned long __user *)arg); 254 } 255 256 static int put_u64(unsigned long arg, u64 val) 257 { 258 return put_user(val, (u64 __user *)arg); 259 } 260 261 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, 262 unsigned cmd, unsigned long arg) 263 { 264 struct gendisk *disk = bdev->bd_disk; 265 266 if (disk->fops->ioctl) 267 return disk->fops->ioctl(bdev, mode, cmd, arg); 268 269 return -ENOTTY; 270 } 271 /* 272 * For the record: _GPL here is only because somebody decided to slap it 273 * on the previous export. Sheer idiocy, since it wasn't copyrightable 274 * at all and could be open-coded without any exports by anybody who cares. 275 */ 276 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl); 277 278 /* 279 * Is it an unrecognized ioctl? The correct returns are either 280 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a 281 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl 282 * code before returning. 283 * 284 * Confused drivers sometimes return EINVAL, which is wrong. It 285 * means "I understood the ioctl command, but the parameters to 286 * it were wrong". 287 * 288 * We should aim to just fix the broken drivers, the EINVAL case 289 * should go away. 290 */ 291 static inline int is_unrecognized_ioctl(int ret) 292 { 293 return ret == -EINVAL || 294 ret == -ENOTTY || 295 ret == -ENOIOCTLCMD; 296 } 297 298 /* 299 * always keep this in sync with compat_blkdev_ioctl() 300 */ 301 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, 302 unsigned long arg) 303 { 304 struct gendisk *disk = bdev->bd_disk; 305 struct backing_dev_info *bdi; 306 loff_t size; 307 int ret, n; 308 unsigned int max_sectors; 309 310 switch(cmd) { 311 case BLKFLSBUF: 312 if (!capable(CAP_SYS_ADMIN)) 313 return -EACCES; 314 315 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 316 if (!is_unrecognized_ioctl(ret)) 317 return ret; 318 319 fsync_bdev(bdev); 320 invalidate_bdev(bdev); 321 return 0; 322 323 case BLKROSET: 324 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 325 if (!is_unrecognized_ioctl(ret)) 326 return ret; 327 if (!capable(CAP_SYS_ADMIN)) 328 return -EACCES; 329 if (get_user(n, (int __user *)(arg))) 330 return -EFAULT; 331 set_device_ro(bdev, n); 332 return 0; 333 334 case BLKDISCARD: 335 case BLKSECDISCARD: { 336 uint64_t range[2]; 337 338 if (!(mode & FMODE_WRITE)) 339 return -EBADF; 340 341 if (copy_from_user(range, (void __user *)arg, sizeof(range))) 342 return -EFAULT; 343 344 return blk_ioctl_discard(bdev, range[0], range[1], 345 cmd == BLKSECDISCARD); 346 } 347 case BLKZEROOUT: { 348 uint64_t range[2]; 349 350 if (!(mode & FMODE_WRITE)) 351 return -EBADF; 352 353 if (copy_from_user(range, (void __user *)arg, sizeof(range))) 354 return -EFAULT; 355 356 return blk_ioctl_zeroout(bdev, range[0], range[1]); 357 } 358 359 case HDIO_GETGEO: { 360 struct hd_geometry geo; 361 362 if (!arg) 363 return -EINVAL; 364 if (!disk->fops->getgeo) 365 return -ENOTTY; 366 367 /* 368 * We need to set the startsect first, the driver may 369 * want to override it. 370 */ 371 memset(&geo, 0, sizeof(geo)); 372 geo.start = get_start_sect(bdev); 373 ret = disk->fops->getgeo(bdev, &geo); 374 if (ret) 375 return ret; 376 if (copy_to_user((struct hd_geometry __user *)arg, &geo, 377 sizeof(geo))) 378 return -EFAULT; 379 return 0; 380 } 381 case BLKRAGET: 382 case BLKFRAGET: 383 if (!arg) 384 return -EINVAL; 385 bdi = blk_get_backing_dev_info(bdev); 386 return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512); 387 case BLKROGET: 388 return put_int(arg, bdev_read_only(bdev) != 0); 389 case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */ 390 return put_int(arg, block_size(bdev)); 391 case BLKSSZGET: /* get block device logical block size */ 392 return put_int(arg, bdev_logical_block_size(bdev)); 393 case BLKPBSZGET: /* get block device physical block size */ 394 return put_uint(arg, bdev_physical_block_size(bdev)); 395 case BLKIOMIN: 396 return put_uint(arg, bdev_io_min(bdev)); 397 case BLKIOOPT: 398 return put_uint(arg, bdev_io_opt(bdev)); 399 case BLKALIGNOFF: 400 return put_int(arg, bdev_alignment_offset(bdev)); 401 case BLKDISCARDZEROES: 402 return put_uint(arg, bdev_discard_zeroes_data(bdev)); 403 case BLKSECTGET: 404 max_sectors = min_t(unsigned int, USHRT_MAX, 405 queue_max_sectors(bdev_get_queue(bdev))); 406 return put_ushort(arg, max_sectors); 407 case BLKROTATIONAL: 408 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev))); 409 case BLKRASET: 410 case BLKFRASET: 411 if(!capable(CAP_SYS_ADMIN)) 412 return -EACCES; 413 bdi = blk_get_backing_dev_info(bdev); 414 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; 415 return 0; 416 case BLKBSZSET: 417 /* set the logical block size */ 418 if (!capable(CAP_SYS_ADMIN)) 419 return -EACCES; 420 if (!arg) 421 return -EINVAL; 422 if (get_user(n, (int __user *) arg)) 423 return -EFAULT; 424 if (!(mode & FMODE_EXCL)) { 425 bdgrab(bdev); 426 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0) 427 return -EBUSY; 428 } 429 ret = set_blocksize(bdev, n); 430 if (!(mode & FMODE_EXCL)) 431 blkdev_put(bdev, mode | FMODE_EXCL); 432 return ret; 433 case BLKPG: 434 ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg); 435 break; 436 case BLKRRPART: 437 ret = blkdev_reread_part(bdev); 438 break; 439 case BLKGETSIZE: 440 size = i_size_read(bdev->bd_inode); 441 if ((size >> 9) > ~0UL) 442 return -EFBIG; 443 return put_ulong(arg, size >> 9); 444 case BLKGETSIZE64: 445 return put_u64(arg, i_size_read(bdev->bd_inode)); 446 case BLKTRACESTART: 447 case BLKTRACESTOP: 448 case BLKTRACESETUP: 449 case BLKTRACETEARDOWN: 450 ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg); 451 break; 452 default: 453 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); 454 } 455 return ret; 456 } 457 EXPORT_SYMBOL_GPL(blkdev_ioctl); 458