[PATCH 2/3] io_uring/rw: mark readv/writev as vectored in the opcode definition

[Jens Axboe <axboe@kernel.dk>]

This is cleaner than gating on the opcode type, particularly as more
read/write type opcodes may be added.

Then we can use that for the data import, and for __io_read() on
whether or not we need to copy state.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/opdef.c |  2 ++
 io_uring/opdef.h |  2 ++
 io_uring/rw.c    | 10 ++++++----
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 1d26ef10fc16..bfb7c53389c0 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -65,6 +65,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.ioprio			= 1,
 		.iopoll			= 1,
 		.iopoll_queue		= 1,
+		.vectored		= 1,
 		.prep			= io_prep_rw,
 		.issue			= io_read,
 	},
@@ -78,6 +79,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.ioprio			= 1,
 		.iopoll			= 1,
 		.iopoll_queue		= 1,
+		.vectored		= 1,
 		.prep			= io_prep_rw,
 		.issue			= io_write,
 	},
diff --git a/io_uring/opdef.h b/io_uring/opdef.h
index c22c8696e749..9e5435ec27d0 100644
--- a/io_uring/opdef.h
+++ b/io_uring/opdef.h
@@ -29,6 +29,8 @@ struct io_issue_def {
 	unsigned		iopoll_queue : 1;
 	/* opcode specific path will handle ->async_data allocation if needed */
 	unsigned		manual_alloc : 1;
+	/* vectored opcode, set if 1) vectored, and 2) handler needs to know */
+	unsigned		vectored : 1;
 
 	int (*issue)(struct io_kiocb *, unsigned int);
 	int (*prep)(struct io_kiocb *, const struct io_uring_sqe *);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 402e8bf002d6..c3bf38419230 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -388,8 +388,7 @@ static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req,
 	buf = u64_to_user_ptr(rw->addr);
 	sqe_len = rw->len;
 
-	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE ||
-	    (req->flags & REQ_F_BUFFER_SELECT)) {
+	if (!io_issue_defs[opcode].vectored || req->flags & REQ_F_BUFFER_SELECT) {
 		if (io_do_buffer_select(req)) {
 			buf = io_buffer_select(req, &sqe_len, issue_flags);
 			if (!buf)
@@ -776,8 +775,11 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
 
 	if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
 		req->flags &= ~REQ_F_REISSUE;
-		/* if we can poll, just do that */
-		if (req->opcode == IORING_OP_READ && file_can_poll(req->file))
+		/*
+		 * If we can poll, just do that. For a vectored read, we'll
+		 * need to copy state first.
+		 */
+		if (file_can_poll(req->file) && !io_issue_defs[req->opcode].vectored)
 			return -EAGAIN;
 		/* IOPOLL retry should happen for io-wq threads */
 		if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
-- 
2.40.1