[RFC PATCH v4 3/5] io-uring/cmd: introduce io_uring_cmd_import_fixed_vec

[Sidong Yang]

io_uring_cmd_import_fixed_vec() could be used for using multiple
fixed buffer in uring_cmd callback.

Signed-off-by: Sidong Yang <sidong.yang@xxxxxxxxxx>
---
 include/linux/io_uring/cmd.h | 14 ++++++++++++++
 io_uring/uring_cmd.c         | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 598cacda4aa3..ab7ecef60787 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -44,6 +44,12 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct io_uring_cmd *ioucmd,
 			      unsigned int issue_flags);
 
+int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
+				  const struct iovec __user *uvec,
+				  unsigned long uvec_segs, int ddir,
+				  unsigned int issue_flags,
+				  struct iov_iter *iter);
+
 /*
  * Completes the request, i.e. posts an io_uring CQE and deallocates @ioucmd
  * and the corresponding io_uring request.
@@ -76,6 +82,14 @@ io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 {
 	return -EOPNOTSUPP;
 }
+int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
+				  const struct iovec __user *uvec,
+				  unsigned long uvec_segs, int ddir,
+				  unsigned int issue_flags,
+				  struct iov_iter *iter)
+{
+	return -EOPNOTSUPP;
+}
 static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
 		u64 ret2, unsigned issue_flags)
 {
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index bf4002e93ec5..effcd01b8a35 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -274,6 +274,25 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 }
 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
 
+int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
+				  const struct iovec __user *uvec,
+				  unsigned long uvec_segs, int ddir,
+				  unsigned int issue_flags,
+				  struct iov_iter *iter)
+{
+	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
+	struct io_async_cmd *ac = req->async_data;
+	int ret;
+
+	ret = io_prep_reg_iovec(req, &ac->iou_vec, uvec, uvec_segs);
+	if (ret)
+		return ret;
+
+	return io_import_reg_vec(ddir, iter, req, &ac->iou_vec, ac->iou_vec.nr,
+				 issue_flags);
+}
+EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed_vec);
+
 void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd)
 {
 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
-- 
2.43.0