Re: [PATCH v4 3/3] fs: Add aio iopriority support for block_dev
From: Jens Axboe <axboe@kernel.dk>
Date: 2018-05-18 15:14:07
Also in:
linux-block, linux-fsdevel, lkml
On 5/17/18 2:38 PM, adam.manzanares@wdc.com wrote:
From: Adam Manzanares <redacted> This is the per-I/O equivalent of the ioprio_set system call. When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field. When a bio is created for an aio request by the block dev we set the priority value of the bio to the user supplied value. This patch depends on block: add ioprio_check_cap function
Actually, one comment on this one:
quoted hunk ↗ jump to hunk
diff --git a/fs/aio.c b/fs/aio.c index f3eae5d5771b..ff3107aa82d5 100644 --- a/fs/aio.c +++ b/fs/aio.c@@ -1451,6 +1451,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) if (iocb->aio_flags & IOCB_FLAG_RESFD) req->ki_flags |= IOCB_EVENTFD; req->ki_hint = file_write_hint(req->ki_filp); + if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { + /* + * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then + * aio_reqprio is interpreted as an I/O scheduling + * class and priority. + */ + ret = ioprio_check_cap(iocb->aio_reqprio); + if (ret) { + pr_debug("aio ioprio check cap error\n"); + return -EINVAL; + } + + req->ki_ioprio = iocb->aio_reqprio; + req->ki_flags |= IOCB_IOPRIO; + }
Do we really need IOCB_IOPRIO? All zeroes is no priority set anyway, so we should be able to get by with just setting ->ki_ioprio to either the priority, or 0.
quoted hunk ↗ jump to hunk
diff --git a/fs/block_dev.c b/fs/block_dev.c index 7ec920e27065..970bef79caa6 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c@@ -355,6 +355,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) bio->bi_write_hint = iocb->ki_hint; bio->bi_private = dio; bio->bi_end_io = blkdev_bio_end_io; + if (iocb->ki_flags & IOCB_IOPRIO) + bio->bi_ioprio = iocb->ki_ioprio;
And then this assignment can just happen unconditionally. -- Jens Axboe -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: <a href=mailto:"aart@kvack.org">aart@kvack.org</a>