#include <linux/capability.h> #include <linux/blkdev.h> #include <linux/export.h> #include <linux/gfp.h> #include <linux/blkpg.h> #include <linux/hdreg.h> #include <linux/backing-dev.h> #include <linux/fs.h> #include <linux/blktrace_api.h> #include <asm/uaccess.h> static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg) { struct block_device *bdevp; struct gendisk *disk; struct hd_struct *part, *lpart; struct blkpg_ioctl_arg a; struct blkpg_partition p; struct disk_part_iter piter; long long start, length; int partno; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg))) return -EFAULT; if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition))) return -EFAULT; disk = bdev->bd_disk; if (bdev != bdev->bd_contains) return -EINVAL; partno = p.pno; if (partno <= 0) return -EINVAL; switch (a.op) { case BLKPG_ADD_PARTITION: start = p.start >> 9; length = p.length >> 9; /* check for fit in a hd_struct */ if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length || pstart < 0 || plength < 0 || partno > 65535) return -EINVAL; } mutex_lock(&bdev->bd_mutex); /* overlap? */ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); while ((part = disk_part_iter_next(&piter))) { if (!(start + length <= part->start_sect || start >= part->start_sect + part->nr_sects)) { disk_part_iter_exit(&piter); mutex_unlock(&bdev->bd_mutex); return -EBUSY; } } disk_part_iter_exit(&piter); /* all seems OK */ part = add_partition(disk, partno, start, length, ADDPART_FLAG_NONE, NULL); mutex_unlock(&bdev->bd_mutex); return PTR_ERR_OR_ZERO(part); case BLKPG_DEL_PARTITION: part = disk_get_part(disk, partno); if (!part) return -ENXIO; bdevp = bdget(part_devt(part)); disk_put_part(part); if (!bdevp) return -ENOMEM; mutex_lock(&bdevp->bd_mutex); if (bdevp->bd_openers) { mutex_unlock(&bdevp->bd_mutex); bdput(bdevp); return -EBUSY; } /* all seems OK */ fsync_bdev(bdevp); invalidate_bdev(bdevp); mutex_lock_nested(&bdev->bd_mutex, 1); delete_partition(disk, partno); mutex_unlock(&bdev->bd_mutex); mutex_unlock(&bdevp->bd_mutex); bdput(bdevp); return 0; case BLKPG_RESIZE_PARTITION: start = p.start >> 9; /* new length of partition in bytes */ length = p.length >> 9; /* check for fit in a hd_struct */ if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length || pstart < 0 || plength < 0) return -EINVAL; } part = disk_get_part(disk, partno); if (!part) return -ENXIO; bdevp = bdget(part_devt(part)); if (!bdevp) { disk_put_part(part); return -ENOMEM; } mutex_lock(&bdevp->bd_mutex); mutex_lock_nested(&bdev->bd_mutex, 1); if (start != part->start_sect) { mutex_unlock(&bdevp->bd_mutex); mutex_unlock(&bdev->bd_mutex); bdput(bdevp); disk_put_part(part); return -EINVAL; } /* overlap? */ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); while ((lpart = disk_part_iter_next(&piter))) { if (lpart->partno != partno && !(start + length <= lpart->start_sect || start >= lpart->start_sect + lpart->nr_sects) ) { disk_part_iter_exit(&piter); mutex_unlock(&bdevp->bd_mutex); mutex_unlock(&bdev->bd_mutex); bdput(bdevp); disk_put_part(part); return -EBUSY; } } disk_part_iter_exit(&piter); part_nr_sects_write(part, (sector_t)length); i_size_write(bdevp->bd_inode, p.length); mutex_unlock(&bdevp->bd_mutex); mutex_unlock(&bdev->bd_mutex); bdput(bdevp); disk_put_part(part); return 0; default: return -EINVAL; } } /* * This is an exported API for the block driver, and will not * acquire bd_mutex. This API should be used in case that * caller has held bd_mutex already. */ int __blkdev_reread_part(struct block_device *bdev) { struct gendisk *disk = bdev->bd_disk; if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; lockdep_assert_held(&bdev->bd_mutex); return rescan_partitions(disk, bdev); } EXPORT_SYMBOL(__blkdev_reread_part); /* * This is an exported API for the block driver, and will * try to acquire bd_mutex. If bd_mutex has been held already * in current context, please call __blkdev_reread_part(). * * Make sure the held locks in current context aren't required * in open()/close() handler and I/O path for avoiding ABBA deadlock: * - bd_mutex is held before calling block driver's open/close * handler * - reading partition table may submit I/O to the block device */ int blkdev_reread_part(struct block_device *bdev) { int res; mutex_lock(&bdev->bd_mutex); res = __blkdev_reread_part(bdev); mutex_unlock(&bdev->bd_mutex); return res; } EXPORT_SYMBOL(blkdev_reread_part); static int blk_ioctl_discard(struct block_device *bdev, uint64_t start, uint64_t len, int secure) { unsigned long flags = 0; if (start & 511) return -EINVAL; if (len & 511) return -EINVAL; start >>= 9; len >>= 9; if (start + len > (i_size_read(bdev->bd_inode) >> 9)) return -EINVAL; if (secure) flags |= BLKDEV_DISCARD_SECURE; return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags); } static int blk_ioctl_zeroout(struct block_device *bdev, uint64_t start, uint64_t len) { if (start & 511) return -EINVAL; if (len & 511) return -EINVAL; start >>= 9; len >>= 9; if (start + len > (i_size_read(bdev->bd_inode) >> 9)) return -EINVAL; return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false); } static int put_ushort(unsigned long arg, unsigned short val) { return put_user(val, (unsigned short __user *)arg); } static int put_int(unsigned long arg, int val) { return put_user(val, (int __user *)arg); } static int put_uint(unsigned long arg, unsigned int val) { return put_user(val, (unsigned int __user *)arg); } static int put_long(unsigned long arg, long val) { return put_user(val, (long __user *)arg); } static int put_ulong(unsigned long arg, unsigned long val) { return put_user(val, (unsigned long __user *)arg); } static int put_u64(unsigned long arg, u64 val) { return put_user(val, (u64 __user *)arg); } int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, unsigned long arg) { struct gendisk *disk = bdev->bd_disk; if (disk->fops->ioctl) return disk->fops->ioctl(bdev, mode, cmd, arg); return -ENOTTY; } /* * For the record: _GPL here is only because somebody decided to slap it * on the previous export. Sheer idiocy, since it wasn't copyrightable * at all and could be open-coded without any exports by anybody who cares. */ EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl); /* * Is it an unrecognized ioctl? The correct returns are either * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl * code before returning. * * Confused drivers sometimes return EINVAL, which is wrong. It * means "I understood the ioctl command, but the parameters to * it were wrong". * * We should aim to just fix the broken drivers, the EINVAL case * should go away. */ static inline int is_unrecognized_ioctl(int ret) { return ret == -EINVAL || ret == -ENOTTY || ret == -ENOIOCTLCMD; } /* * always keep this in sync with compat_blkdev_ioctl() */ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, unsigned long arg) { struct gendisk *disk = bdev->bd_disk; struct backing_dev_info *bdi; loff_t size; int ret, n; unsigned int max_sectors; switch(cmd) { case BLKFLSBUF: if (!capable(CAP_SYS_ADMIN)) return -EACCES; ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); if (!is_unrecognized_ioctl(ret)) return ret; fsync_bdev(bdev); invalidate_bdev(bdev); return 0; case BLKROSET: ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); if (!is_unrecognized_ioctl(ret)) return ret; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (get_user(n, (int __user *)(arg))) return -EFAULT; set_device_ro(bdev, n); return 0; case BLKDISCARD: case BLKSECDISCARD: { uint64_t range[2]; if (!(mode & FMODE_WRITE)) return -EBADF; if (copy_from_user(range, (void __user *)arg, sizeof(range))) return -EFAULT; return blk_ioctl_discard(bdev, range[0], range[1], cmd == BLKSECDISCARD); } case BLKZEROOUT: { uint64_t range[2]; if (!(mode & FMODE_WRITE)) return -EBADF; if (copy_from_user(range, (void __user *)arg, sizeof(range))) return -EFAULT; return blk_ioctl_zeroout(bdev, range[0], range[1]); } case HDIO_GETGEO: { struct hd_geometry geo; if (!arg) return -EINVAL; if (!disk->fops->getgeo) return -ENOTTY; /* * We need to set the startsect first, the driver may * want to override it. */ memset(&geo, 0, sizeof(geo)); geo.start = get_start_sect(bdev); ret = disk->fops->getgeo(bdev, &geo); if (ret) return ret; if (copy_to_user((struct hd_geometry __user *)arg, &geo, sizeof(geo))) return -EFAULT; return 0; } case BLKRAGET: case BLKFRAGET: if (!arg) return -EINVAL; bdi = blk_get_backing_dev_info(bdev); return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512); case BLKROGET: return put_int(arg, bdev_read_only(bdev) != 0); case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */ return put_int(arg, block_size(bdev)); case BLKSSZGET: /* get block device logical block size */ return put_int(arg, bdev_logical_block_size(bdev)); case BLKPBSZGET: /* get block device physical block size */ return put_uint(arg, bdev_physical_block_size(bdev)); case BLKIOMIN: return put_uint(arg, bdev_io_min(bdev)); case BLKIOOPT: return put_uint(arg, bdev_io_opt(bdev)); case BLKALIGNOFF: return put_int(arg, bdev_alignment_offset(bdev)); case BLKDISCARDZEROES: return put_uint(arg, bdev_discard_zeroes_data(bdev)); case BLKSECTGET: max_sectors = min_t(unsigned int, USHRT_MAX, queue_max_sectors(bdev_get_queue(bdev))); return put_ushort(arg, max_sectors); case BLKROTATIONAL: return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev))); case BLKRASET: case BLKFRASET: if(!capable(CAP_SYS_ADMIN)) return -EACCES; bdi = blk_get_backing_dev_info(bdev); bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; return 0; case BLKBSZSET: /* set the logical block size */ if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (!arg) return -EINVAL; if (get_user(n, (int __user *) arg)) return -EFAULT; if (!(mode & FMODE_EXCL)) { bdgrab(bdev); if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0) return -EBUSY; } ret = set_blocksize(bdev, n); if (!(mode & FMODE_EXCL)) blkdev_put(bdev, mode | FMODE_EXCL); return ret; case BLKPG: ret = blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg); break; case BLKRRPART: ret = blkdev_reread_part(bdev); break; case BLKGETSIZE: size = i_size_read(bdev->bd_inode); if ((size >> 9) > ~0UL) return -EFBIG; return put_ulong(arg, size >> 9); case BLKGETSIZE64: return put_u64(arg, i_size_read(bdev->bd_inode)); case BLKTRACESTART: case BLKTRACESTOP: case BLKTRACESETUP: case BLKTRACETEARDOWN: ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg); break; default: ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); } return ret; } EXPORT_SYMBOL_GPL(blkdev_ioctl);