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root/block/ioctl.c

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DEFINITIONS

This source file includes following definitions.
  1. blkpg_ioctl
  2. blkdev_reread_part
  3. blk_ioc_discard_endio
  4. blk_ioctl_discard
  5. put_ushort
  6. put_int
  7. put_long
  8. put_ulong
  9. put_u64
  10. blkdev_locked_ioctl
  11. blkdev_driver_ioctl
  12. blkdev_ioctl

#include <linux/capability.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include <linux/smp_lock.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;
        struct blkpg_ioctl_arg a;
        struct blkpg_partition p;
        struct disk_part_iter piter;
        long long start, length;
        int partno;
        int err;

        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)
                                        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 */
                        err = add_partition(disk, partno, start, length,
                                            ADDPART_FLAG_NONE);
                        mutex_unlock(&bdev->bd_mutex);
                        return err;
                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;
                default:
                        return -EINVAL;
        }
}

static int blkdev_reread_part(struct block_device *bdev)
{
        struct gendisk *disk = bdev->bd_disk;
        int res;

        if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
                return -EINVAL;
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!mutex_trylock(&bdev->bd_mutex))
                return -EBUSY;
        res = rescan_partitions(disk, bdev);
        mutex_unlock(&bdev->bd_mutex);
        return res;
}

static void blk_ioc_discard_endio(struct bio *bio, int err)
{
        if (err) {
                if (err == -EOPNOTSUPP)
                        set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
        }
        complete(bio->bi_private);
}

static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
                             uint64_t len)
{
        struct request_queue *q = bdev_get_queue(bdev);
        int ret = 0;

        if (start & 511)
                return -EINVAL;
        if (len & 511)
                return -EINVAL;
        start >>= 9;
        len >>= 9;

        if (start + len > (bdev->bd_inode->i_size >> 9))
                return -EINVAL;

        if (!q->prepare_discard_fn)
                return -EOPNOTSUPP;

        while (len && !ret) {
                DECLARE_COMPLETION_ONSTACK(wait);
                struct bio *bio;

                bio = bio_alloc(GFP_KERNEL, 0);
                if (!bio)
                        return -ENOMEM;

                bio->bi_end_io = blk_ioc_discard_endio;
                bio->bi_bdev = bdev;
                bio->bi_private = &wait;
                bio->bi_sector = start;

                if (len > q->max_hw_sectors) {
                        bio->bi_size = q->max_hw_sectors << 9;
                        len -= q->max_hw_sectors;
                        start += q->max_hw_sectors;
                } else {
                        bio->bi_size = len << 9;
                        len = 0;
                }
                submit_bio(DISCARD_NOBARRIER, bio);

                wait_for_completion(&wait);

                if (bio_flagged(bio, BIO_EOPNOTSUPP))
                        ret = -EOPNOTSUPP;
                else if (!bio_flagged(bio, BIO_UPTODATE))
                        ret = -EIO;
                bio_put(bio);
        }
        return ret;
}

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_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);
}

static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
                                unsigned cmd, unsigned long arg)
{
        struct backing_dev_info *bdi;
        int ret, n;

        switch (cmd) {
        case BLKRAGET:
        case BLKFRAGET:
                if (!arg)
                        return -EINVAL;
                bdi = blk_get_backing_dev_info(bdev);
                if (bdi == NULL)
                        return -ENOTTY;
                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 the logical block size (cf. BLKSSZGET) */
                return put_int(arg, block_size(bdev));
        case BLKSSZGET: /* get block device hardware sector size */
                return put_int(arg, bdev_hardsect_size(bdev));
        case BLKSECTGET:
                return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
        case BLKRASET:
        case BLKFRASET:
                if(!capable(CAP_SYS_ADMIN))
                        return -EACCES;
                bdi = blk_get_backing_dev_info(bdev);
                if (bdi == NULL)
                        return -ENOTTY;
                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 (bd_claim(bdev, file) < 0)
                        return -EBUSY;
                ret = set_blocksize(bdev, n);
                bd_release(bdev);
                return ret;
        case BLKPG:
                return blkpg_ioctl(bdev, (struct blkpg_ioctl_arg __user *) arg);
        case BLKRRPART:
                return blkdev_reread_part(bdev);
        case BLKGETSIZE:
                if ((bdev->bd_inode->i_size >> 9) > ~0UL)
                        return -EFBIG;
                return put_ulong(arg, bdev->bd_inode->i_size >> 9);
        case BLKGETSIZE64:
                return put_u64(arg, bdev->bd_inode->i_size);
        case BLKTRACESTART:
        case BLKTRACESTOP:
        case BLKTRACESETUP:
        case BLKTRACETEARDOWN:
                return blk_trace_ioctl(bdev, cmd, (char __user *) arg);
        }
        return -ENOIOCTLCMD;
}

int blkdev_driver_ioctl(struct inode *inode, struct file *file,
                        struct gendisk *disk, unsigned cmd, unsigned long arg)
{
        int ret;
        if (disk->fops->unlocked_ioctl)
                return disk->fops->unlocked_ioctl(file, cmd, arg);

        if (disk->fops->ioctl) {
                lock_kernel();
                ret = disk->fops->ioctl(inode, file, cmd, arg);
                unlock_kernel();
                return ret;
        }

        return -ENOTTY;
}
EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);

/*
 * always keep this in sync with compat_blkdev_ioctl() and
 * compat_blkdev_locked_ioctl()
 */
int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
                        unsigned long arg)
{
        struct block_device *bdev = inode->i_bdev;
        struct gendisk *disk = bdev->bd_disk;
        int ret, n;

        switch(cmd) {
        case BLKFLSBUF:
                if (!capable(CAP_SYS_ADMIN))
                        return -EACCES;

                ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
                /* -EINVAL to handle old uncorrected drivers */
                if (ret != -EINVAL && ret != -ENOTTY)
                        return ret;

                lock_kernel();
                fsync_bdev(bdev);
                invalidate_bdev(bdev);
                unlock_kernel();
                return 0;

        case BLKROSET:
                ret = blkdev_driver_ioctl(inode, file, disk, cmd, arg);
                /* -EINVAL to handle old uncorrected drivers */
                if (ret != -EINVAL && ret != -ENOTTY)
                        return ret;
                if (!capable(CAP_SYS_ADMIN))
                        return -EACCES;
                if (get_user(n, (int __user *)(arg)))
                        return -EFAULT;
                lock_kernel();
                set_device_ro(bdev, n);
                unlock_kernel();
                return 0;

        case BLKDISCARD: {
                uint64_t range[2];

                if (!(file->f_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]);
        }

        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.
                 */
                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;
        }
        }

        lock_kernel();
        ret = blkdev_locked_ioctl(file, bdev, cmd, arg);
        unlock_kernel();
        if (ret != -ENOIOCTLCMD)
                return ret;

        return blkdev_driver_ioctl(inode, file, disk, cmd, arg);
}
EXPORT_SYMBOL_GPL(blkdev_ioctl);

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