In preparation to further changes extract a helper function out of
blk_ioctl_discard() that validates if it's allowed to do a write-like
operation for the given range.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
block/ioctl.c | 47 +++++++++++++++++++++++++++++------------------
1 file changed, 29 insertions(+), 18 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index e8e4a4190f18..8df0bc8002f5 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -92,38 +92,49 @@ static int compat_blkpg_ioctl(struct block_device *bdev,
}
#endif
+static int blk_validate_write(struct block_device *bdev, blk_mode_t mode,
+ uint64_t start, uint64_t len)
+{
+ unsigned int bs_mask;
+ uint64_t end;
+
+ if (!(mode & BLK_OPEN_WRITE))
+ return -EBADF;
+ if (bdev_read_only(bdev))
+ return -EPERM;
+
+ bs_mask = bdev_logical_block_size(bdev) - 1;
+ 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;
+ err = blk_validate_write(bdev, mode, start, len);
+ if (err)
+ return err;
filemap_invalidate_lock(bdev->bd_mapping);
err = truncate_bdev_range(bdev, mode, start, start + len - 1);
--
2.45.2
