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block: introduce blk_validate_byte_range()

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In preparation to further changes extract a helper function out of
blk_ioctl_discard() that validates if we can do IO against the given
range of disk byte addresses.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/19a7779323c71e742a2f511e4cf49efcfd68cfd4.1726072086.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2024-09-11 17:34:40 +01:00 committed by Jens Axboe
parent a12c883a0a
commit 7a07210bbc
1 changed files with 32 additions and 19 deletions
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51
block/ioctl.c
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@ -92,41 +92,54 @@ static int compat_blkpg_ioctl(struct block_device *bdev,
}
#endif
/*
* Check that [start, start + len) is a valid range from the block device's
* perspective, including verifying that it can be correctly translated into
* logical block addresses.
*/
static int blk_validate_byte_range(struct block_device *bdev,
uint64_t start, uint64_t len)
{
unsigned int bs_mask = bdev_logical_block_size(bdev) - 1;
uint64_t end;
if ((start | len) & bs_mask)
return -EINVAL;
if (!len)
return -EINVAL;
if (check_add_overflow(start, len, &end) || end > bdev_nr_bytes(bdev))
return -EINVAL;
return 0;
}
static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
unsigned long arg)
{
unsigned int bs_mask = bdev_logical_block_size(bdev) - 1;
uint64_t range[2], start, len, end;
uint64_t range[2], start, len;
struct bio *prev = NULL, *bio;
sector_t sector, nr_sects;
struct blk_plug plug;
int err;
if (!(mode & BLK_OPEN_WRITE))
return -EBADF;
if (!bdev_max_discard_sectors(bdev))
return -EOPNOTSUPP;
if (bdev_read_only(bdev))
return -EPERM;
if (copy_from_user(range, (void __user *)arg, sizeof(range)))
return -EFAULT;
start = range[0];
len = range[1];
if (!len)
return -EINVAL;
if ((start | len) & bs_mask)
return -EINVAL;
if (!bdev_max_discard_sectors(bdev))
return -EOPNOTSUPP;
if (check_add_overflow(start, len, &end) ||
end > bdev_nr_bytes(bdev))
return -EINVAL;
if (!(mode & BLK_OPEN_WRITE))
return -EBADF;
if (bdev_read_only(bdev))
return -EPERM;
err = blk_validate_byte_range(bdev, start, len);
if (err)
return err;
filemap_invalidate_lock(bdev->bd_mapping);
err = truncate_bdev_range(bdev, mode, start, end - 1);
err = truncate_bdev_range(bdev, mode, start, start + len - 1);
if (err)
goto fail;