On 18.06.2020 07:39, Damien Le Moal wrote:

On 2020/06/18 2:27, Kanchan Joshi wrote:

quoted

From: Selvakumar S <redacted>

Introduce three new opcodes for zone-append -

   IORING_OP_ZONE_APPEND     : non-vectord, similiar to IORING_OP_WRITE
   IORING_OP_ZONE_APPENDV    : vectored, similar to IORING_OP_WRITEV
   IORING_OP_ZONE_APPEND_FIXED : append using fixed-buffers

Repurpose cqe->flags to return zone-relative offset.

Signed-off-by: SelvaKumar S <redacted>
Signed-off-by: Kanchan Joshi <redacted>
Signed-off-by: Nitesh Shetty <redacted>
Signed-off-by: Javier Gonzalez <redacted>
---
 fs/io_uring.c                 | 72 +++++++++++++++++++++++++++++++++++++++++--
 include/uapi/linux/io_uring.h |  8 ++++-
 2 files changed, 77 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 155f3d8..c14c873 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c

@@ -649,6 +649,10 @@ struct io_kiocb {
 	unsigned long		fsize;
 	u64			user_data;
 	u32			result;
+#ifdef CONFIG_BLK_DEV_ZONED
+	/* zone-relative offset for append, in bytes */
+	u32			append_offset;

this can overflow. u64 is needed.

We chose to do it this way to start with because struct io_uring_cqe
only has space for u32 when we reuse the flags.

We can of course create a new cqe structure, but that will come with
larger changes to io_uring for supporting append.

Do you believe this is a better approach?

Javier