[PATCH v3 4/9] Introduce IOCB_SWAP kiocb flag to trigger REQ_SWAP

David Howells
2021-09-24T17:18:41Z

Introduce an IOCB_SWAP flag for the kiocb struct such that the REQ_SWAP
will get set on lower level operation structures in generic code.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Darrick J. Wong <djwong@kernel.org>
cc: linux-xfs@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---

fs/direct-io.c | 2 ++
include/linux/bio.h | 2 ++
include/linux/fs.h | 1 +
3 files changed, 5 insertions(+)

diff --git a/fs/direct-io.c b/fs/direct-io.c
index b2e86e739d7a..76eec0a68fa4 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1216,6 +1216,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
}
if (iocb->ki_flags & IOCB_HIPRI)
dio->op_flags |= REQ_HIPRI;
+ if (iocb->ki_flags & IOCB_SWAP)
+ dio->op_flags |= REQ_SWAP;

/*
* For AIO O_(D)SYNC writes we need to defer completions to a workqueue
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 00952e92eae1..b01133727494 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -787,6 +787,8 @@ static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
bio->bi_opf |= REQ_HIPRI;
if (!is_sync_kiocb(kiocb))
bio->bi_opf |= REQ_NOWAIT;
+ if (kiocb->ki_flags & IOCB_SWAP)
+ bio->bi_opf |= REQ_SWAP;
}

struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c909ca6c0eb6..c20f4423e2f1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -321,6 +321,7 @@ enum rw_hint {
#define IOCB_NOIO (1 << 20)
/* can use bio alloc cache */
#define IOCB_ALLOC_CACHE (1 << 21)
+#define IOCB_SWAP (1 << 22) /* Operation on a swapfile */

struct kiocb {
struct file *ki_filp;