[PATCHv6 05/11] block: add a helper function for dio alignment

Keith Busch
2022-06-10T20:22:15Z

From: Keith Busch <kbusch@kernel.org>

This will make it easier to add more complex acceptable alignment
criteria in the future.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
block/fops.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index d6b3276a6c68..9d32df6fc315 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -42,6 +42,13 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb)
return op;
}

+static bool blkdev_dio_unaligned(struct block_device *bdev, loff_t pos,
+ struct iov_iter *iter)
+{
+ return ((pos | iov_iter_alignment(iter)) &
+ (bdev_logical_block_size(bdev) - 1));
+}
+
#define DIO_INLINE_BIO_VECS 4

static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
@@ -54,8 +61,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
struct bio bio;
ssize_t ret;

- if ((pos | iov_iter_alignment(iter)) &
- (bdev_logical_block_size(bdev) - 1))
+ if (blkdev_dio_unaligned(bdev, pos, iter))
return -EINVAL;

if (nr_pages <= DIO_INLINE_BIO_VECS)
@@ -173,8 +179,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
loff_t pos = iocb->ki_pos;
int ret = 0;

- if ((pos | iov_iter_alignment(iter)) &
- (bdev_logical_block_size(bdev) - 1))
+ if (blkdev_dio_unaligned(bdev, pos, iter))
return -EINVAL;

if (iocb->ki_flags & IOCB_ALLOC_CACHE)
@@ -298,8 +303,7 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
loff_t pos = iocb->ki_pos;
int ret = 0;

- if ((pos | iov_iter_alignment(iter)) &
- (bdev_logical_block_size(bdev) - 1))
+ if (blkdev_dio_unaligned(bdev, pos, iter))
return -EINVAL;

if (iocb->ki_flags & IOCB_ALLOC_CACHE)
--
2.30.2