Re: [PATCHv4 5/9] block: add a helper function for dio alignment
From: Damien Le Moal <hidden>
Date: 2022-05-26 01:54:11
Also in:
linux-fsdevel
On 2022/05/26 10:06, Keith Busch wrote:
quoted hunk ↗ jump to hunk
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> --- block/fops.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)diff --git a/block/fops.c b/block/fops.c index b9b83030e0df..bd6c2e13a4e3 100644 --- a/block/fops.c +++ b/block/fops.c@@ -42,6 +42,16 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb) return op; } +static int blkdev_dio_aligned(struct block_device *bdev, loff_t pos, + struct iov_iter *iter) +{ + if ((pos | iov_iter_alignment(iter)) & + (bdev_logical_block_size(bdev) - 1)) + return -EINVAL; + + return 0; +}
Nit: The name of this helper really suggest a bool return, which would be a more flexible interface I think: if (!blkdev_dio_aligned(bdev, pos, iter)) return -EINVAL; <-- or whatever error code the caller wants. And that will allow you to get rid of the ret variable in a least __blkdev_direct_IO_async.
quoted hunk ↗ jump to hunk
+ #define DIO_INLINE_BIO_VECS 4 static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,@@ -54,9 +64,9 @@ 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)) - return -EINVAL; + ret = blkdev_dio_aligned(bdev, pos, iter); + if (ret) + return ret; if (nr_pages <= DIO_INLINE_BIO_VECS) vecs = inline_vecs;@@ -171,11 +181,11 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, bool is_read = (iov_iter_rw(iter) == READ), is_sync; unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); loff_t pos = iocb->ki_pos; - int ret = 0; + int ret; - if ((pos | iov_iter_alignment(iter)) & - (bdev_logical_block_size(bdev) - 1)) - return -EINVAL; + ret = blkdev_dio_aligned(bdev, pos, iter); + if (ret) + return ret; if (iocb->ki_flags & IOCB_ALLOC_CACHE) opf |= REQ_ALLOC_CACHE;@@ -296,11 +306,11 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, struct blkdev_dio *dio; struct bio *bio; loff_t pos = iocb->ki_pos; - int ret = 0; + int ret; - if ((pos | iov_iter_alignment(iter)) & - (bdev_logical_block_size(bdev) - 1)) - return -EINVAL; + ret = blkdev_dio_aligned(bdev, pos, iter); + if (ret) + return ret; if (iocb->ki_flags & IOCB_ALLOC_CACHE) opf |= REQ_ALLOC_CACHE;
-- Damien Le Moal Western Digital Research