Re: [PATCH 09/10] add RWF_DSYNC aand RWF_SYNC

This is the per-I/O equivalent of O_DSYNC and O_SYNC, and very useful for
all kinds of file servers and storage targets.

Signed-off-by: Christoph Hellwig <redacted>
---
fs/read_write.c         | 6 +++++-
include/uapi/linux/fs.h | 2 ++
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index cf377cf..3729d8d 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c

@@ -698,12 +698,16 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,

	struct kiocb kiocb;
	ssize_t ret;

-	if (flags & ~RWF_HIPRI)
+	if (flags & ~(RWF_HIPRI | RWF_DSYNC | RWF_SYNC))
		return -EOPNOTSUPP;

	init_sync_kiocb(&kiocb, filp);
	if (flags & RWF_HIPRI)
		kiocb.ki_flags |= IOCB_HIPRI;
+	if (flags & RWF_DSYNC)
+		kiocb.ki_flags |= IOCB_DSYNC;
+	if (flags & RWF_SYNC)
+		kiocb.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
	kiocb.ki_pos = *ppos;

	ret = fn(&kiocb, iter);

diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index a079d50..7f067fe 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h

@@ -324,5 +324,7 @@ struct fscrypt_policy {

/* flags for preadv2/pwritev2: */
#define RWF_HIPRI			0x00000001 /* high priority request, poll if possible */
+#define RWF_DSYNC			0x00000002 /* per-IO O_DSYNC */
+#define RWF_SYNC			0x00000002 /* per-IO O_SYNC */