Re: [PATCH 1/8] Use RWF_* flags for AIO operations

From: Goldwyn Rodrigues <redacted>

RWF_* flags is used for preadv2/pwritev2 calls. Port to use
it for aio operations as well. For this, aio_rw_flags is
introduced in struct iocb (using aio_reserved1) which will
carry these flags.

This is a precursor to the nowait AIO calls.

Note, the only place RWF_HIPRI comes in effect is dio_await_one().
All the rest of the locations, aio code return -EIOCBQUEUED before the
checks for RWF_HIPRI.

Signed-off-by: Goldwyn Rodrigues <redacted>
---
 fs/aio.c                     | 10 +++++++++-
 fs/read_write.c              |  7 +------
 include/linux/fs.h           | 12 ++++++++++++
 include/uapi/linux/aio_abi.h |  2 +-
 4 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index f52d925ee259..b8a33f5beef5 100644
--- a/fs/aio.c
+++ b/fs/aio.c

@@ -1541,11 +1541,17 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 	ssize_t ret;
 
 	/* enforce forwards compatibility on users */
-	if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
+	if (unlikely(iocb->aio_reserved2)) {
 		pr_debug("EINVAL: reserve field set\n");
 		return -EINVAL;
 	}
 
+	if (unlikely(iocb->aio_rw_flags & ~(RWF_HIPRI | RWF_DSYNC | RWF_SYNC))) {
+		pr_debug("EINVAL: aio_rw_flags set with incompatible flags\n");
+		return -EINVAL;
+	}
+