[RFC PATCH 1/9] IOMAP_DIO_NOSYNC

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Al's patch.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/iomap/direct-io.c  | 3 ++-
 include/linux/iomap.h | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 370c3241618a..6a361131080f 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -548,7 +548,8 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		}
 
 		/* for data sync or sync, we need sync completion processing */
-		if (iocb->ki_flags & IOCB_DSYNC)
+		if (iocb->ki_flags & IOCB_DSYNC &&
+		    !(dio_flags & IOMAP_DIO_NOSYNC))
 			dio->flags |= IOMAP_DIO_NEED_SYNC;
 
 		/*
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index e552097c67e0..c8622d8f064e 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -353,6 +353,12 @@ struct iomap_dio_ops {
  */
 #define IOMAP_DIO_PARTIAL		(1 << 2)
 
+/*
+ * The caller will sync the write if needed; do not sync it within
+ * iomap_dio_rw.  Overrides IOMAP_DIO_FORCE_WAIT.
+ */
+#define IOMAP_DIO_NOSYNC		(1 << 3)
+
 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
 		unsigned int dio_flags, void *private, size_t done_before);
-- 
2.34.1