[1/9] Use RWF_* flags for AIO operations

Commit Message

Goldwyn Rodrigues April 11, 2017, 2:26 p.m. UTC

From: Goldwyn Rodrigues <[e-mail]>

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 <[e-mail]>
---
 fs/aio.c                     | 15 ++++++++++++++-
 include/uapi/linux/aio_abi.h |  2 +-
 2 files changed, 15 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig April 12, 2017, 8:33 a.m. UTC | #1

>  
> +	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;
> +	}

> +	if (iocb->aio_rw_flags & RWF_HIPRI)
> +		req->common.ki_flags |= IOCB_HIPRI;
> +	if (iocb->aio_rw_flags & RWF_DSYNC)
> +		req->common.ki_flags |= IOCB_DSYNC;
> +	if (iocb->aio_rw_flags & RWF_SYNC)
> +		req->common.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);

Pleae introduce a common helper to share this code between the
synchronous and the aio path

Patch

diff --git a/fs/aio.c b/fs/aio.c
index f52d925ee259..7cd1443ad1c8 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;
+	}
+
+
 	/* prevent overflows */
 	if (unlikely(
 	    (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
@@ -1586,6 +1592,13 @@  static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		req->common.ki_flags |= IOCB_EVENTFD;
 	}
 
+	if (iocb->aio_rw_flags & RWF_HIPRI)
+		req->common.ki_flags |= IOCB_HIPRI;
+	if (iocb->aio_rw_flags & RWF_DSYNC)
+		req->common.ki_flags |= IOCB_DSYNC;
+	if (iocb->aio_rw_flags & RWF_SYNC)
+		req->common.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
+
 	ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
 	if (unlikely(ret)) {
 		pr_debug("EFAULT: aio_key\n");
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index bb2554f7fbd1..a2d4a8ac94ca 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -79,7 +79,7 @@  struct io_event {
 struct iocb {
 	/* these are internal to the kernel/libc. */
 	__u64	aio_data;	/* data to be returned in event's data */
-	__u32	PADDED(aio_key, aio_reserved1);
+	__u32	PADDED(aio_key, aio_rw_flags);
 				/* the kernel sets aio_key to the req # */
 
 	/* common fields */