[PATCH v3 4/4] io_uring: add support for zone-append

[Kanchan Joshi]

From: Selvakumar S <selvakuma.s1@xxxxxxxxxxx>

For zone-append, block-layer will return zone-relative offset via ret2
of ki_complete interface. Make changes to collect it, and send to
user-space using cqe->flags.

Signed-off-by: Selvakumar S <selvakuma.s1@xxxxxxxxxxx>
Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx>
Signed-off-by: Javier Gonzalez <javier.gonz@xxxxxxxxxxx>
---
 fs/io_uring.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 155f3d8..cbde4df 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -402,6 +402,8 @@ struct io_rw {
 	struct kiocb			kiocb;
 	u64				addr;
 	u64				len;
+	/* zone-relative offset for append, in sectors */
+	u32			append_offset;
 };
 
 struct io_connect {
@@ -541,6 +543,7 @@ enum {
 	REQ_F_NO_FILE_TABLE_BIT,
 	REQ_F_QUEUE_TIMEOUT_BIT,
 	REQ_F_WORK_INITIALIZED_BIT,
+	REQ_F_ZONE_APPEND_BIT,
 
 	/* not a real bit, just to check we're not overflowing the space */
 	__REQ_F_LAST_BIT,
@@ -598,6 +601,8 @@ enum {
 	REQ_F_QUEUE_TIMEOUT	= BIT(REQ_F_QUEUE_TIMEOUT_BIT),
 	/* io_wq_work is initialized */
 	REQ_F_WORK_INITIALIZED	= BIT(REQ_F_WORK_INITIALIZED_BIT),
+	/* to return zone relative offset for zone append*/
+	REQ_F_ZONE_APPEND	= BIT(REQ_F_ZONE_APPEND_BIT),
 };
 
 struct async_poll {
@@ -1745,6 +1750,8 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
 
 		if (req->flags & REQ_F_BUFFER_SELECTED)
 			cflags = io_put_kbuf(req);
+		if (req->flags & REQ_F_ZONE_APPEND)
+			cflags = req->rw.append_offset;
 
 		__io_cqring_fill_event(req, req->result, cflags);
 		(*nr_events)++;
@@ -1943,7 +1950,7 @@ static inline void req_set_fail_links(struct io_kiocb *req)
 		req->flags |= REQ_F_FAIL_LINK;
 }
 
-static void io_complete_rw_common(struct kiocb *kiocb, long res)
+static void io_complete_rw_common(struct kiocb *kiocb, long res, long res2)
 {
 	struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
 	int cflags = 0;
@@ -1955,6 +1962,10 @@ static void io_complete_rw_common(struct kiocb *kiocb, long res)
 		req_set_fail_links(req);
 	if (req->flags & REQ_F_BUFFER_SELECTED)
 		cflags = io_put_kbuf(req);
+	/* use cflags to return zone append completion result */
+	if (req->flags & REQ_F_ZONE_APPEND)
+		cflags = res2;
+
 	__io_cqring_add_event(req, res, cflags);
 }
 
@@ -1962,7 +1973,7 @@ static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
 {
 	struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
 
-	io_complete_rw_common(kiocb, res);
+	io_complete_rw_common(kiocb, res, res2);
 	io_put_req(req);
 }
 
@@ -1975,6 +1986,9 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
 
 	if (res != req->result)
 		req_set_fail_links(req);
+	if (req->flags & REQ_F_ZONE_APPEND)
+		req->rw.append_offset = res2;
+
 	req->result = res;
 	if (res != -EAGAIN)
 		WRITE_ONCE(req->iopoll_completed, 1);
@@ -2739,6 +2753,9 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
 						SB_FREEZE_WRITE);
 		}
 		kiocb->ki_flags |= IOCB_WRITE;
+		/* zone-append requires few extra steps during completion */
+		if (kiocb->ki_flags & IOCB_ZONE_APPEND)
+			req->flags |= REQ_F_ZONE_APPEND;
 
 		if (!force_nonblock)
 			current->signal->rlim[RLIMIT_FSIZE].rlim_cur = req->fsize;
-- 
2.7.4