[PATCH v3 1/5] io_uring/rsrc: rename io_buffer_register_bvec()/io_buffer_unregister_bvec()

[Joanne Koong <joannelkoong@gmail.com>]

Currently, io_buffer_register_bvec() takes in a request. In preparation
for supporting kernel-populated buffers in fuse io-uring (which will
need to register bvecs directly, not through a struct request), rename
this to io_buffer_register_request().

A subsequent patch will commandeer the "io_buffer_register_bvec()"
function name to support registering bvecs directly.

Rename io_buffer_unregister_bvec() to a more generic name,
io_buffer_unregister(), as both io_buffer_register_request() and
io_buffer_register_bvec() callers will use it for unregistration.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
---
 Documentation/block/ublk.rst | 14 +++++++-------
 drivers/block/ublk_drv.c     | 22 +++++++++++-----------
 include/linux/io_uring/cmd.h | 26 ++++++++++++++++++++------
 io_uring/rsrc.c              | 14 +++++++-------
 4 files changed, 45 insertions(+), 31 deletions(-)

diff --git a/Documentation/block/ublk.rst b/Documentation/block/ublk.rst
index 6ad28039663d..f014d1d69019 100644
--- a/Documentation/block/ublk.rst
+++ b/Documentation/block/ublk.rst
@@ -382,17 +382,17 @@ Zero copy
 ---------
 
 ublk zero copy relies on io_uring's fixed kernel buffer, which provides
-two APIs: `io_buffer_register_bvec()` and `io_buffer_unregister_bvec`.
+two APIs: `io_buffer_register_request()` and `io_buffer_unregister`.
 
 ublk adds IO command of `UBLK_IO_REGISTER_IO_BUF` to call
-`io_buffer_register_bvec()` for ublk server to register client request
+`io_buffer_register_request()` for ublk server to register client request
 buffer into io_uring buffer table, then ublk server can submit io_uring
 IOs with the registered buffer index. IO command of `UBLK_IO_UNREGISTER_IO_BUF`
-calls `io_buffer_unregister_bvec()` to unregister the buffer, which is
-guaranteed to be live between calling `io_buffer_register_bvec()` and
-`io_buffer_unregister_bvec()`. Any io_uring operation which supports this
-kind of kernel buffer will grab one reference of the buffer until the
-operation is completed.
+calls `io_buffer_unregister()` to unregister the buffer, which is guaranteed
+to be live between calling `io_buffer_register_request()` and
+`io_buffer_unregister()`. Any io_uring operation which supports this kind of
+kernel buffer will grab one reference of the buffer until the operation is
+completed.
 
 ublk server implementing zero copy or user copy has to be CAP_SYS_ADMIN and
 be trusted, because it is ublk server's responsibility to make sure IO buffer
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 004f367243b6..b9f293261240 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1627,8 +1627,8 @@ ublk_auto_buf_register(const struct ublk_queue *ubq, struct request *req,
 {
 	int ret;
 
-	ret = io_buffer_register_bvec(cmd, req, ublk_io_release,
-				      io->buf.auto_reg.index, issue_flags);
+	ret = io_buffer_register_request(cmd, req, ublk_io_release,
+					 io->buf.auto_reg.index, issue_flags);
 	if (ret) {
 		if (io->buf.auto_reg.flags & UBLK_AUTO_BUF_REG_FALLBACK) {
 			ublk_auto_buf_reg_fallback(ubq, req->tag);
@@ -1868,7 +1868,7 @@ static int __ublk_batch_dispatch(struct ublk_queue *ubq,
 			ublk_io_unlock(io);
 
 			if (index != -1)
-				io_buffer_unregister_bvec(data->cmd, index,
+				io_buffer_unregister(data->cmd, index,
 						data->issue_flags);
 		}
 
@@ -3091,8 +3091,8 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 	if (!req)
 		return -EINVAL;
 
-	ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index,
-				      issue_flags);
+	ret = io_buffer_register_request(cmd, req, ublk_io_release, index,
+					 issue_flags);
 	if (ret) {
 		ublk_put_req_ref(io, req);
 		return ret;
@@ -3123,8 +3123,8 @@ ublk_daemon_register_io_buf(struct io_uring_cmd *cmd,
 	if (!ublk_dev_support_zero_copy(ub) || !ublk_rq_has_data(req))
 		return -EINVAL;
 
-	ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index,
-				      issue_flags);
+	ret = io_buffer_register_request(cmd, req, ublk_io_release, index,
+					 issue_flags);
 	if (ret)
 		return ret;
 
@@ -3139,7 +3139,7 @@ static int ublk_unregister_io_buf(struct io_uring_cmd *cmd,
 	if (!(ub->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY))
 		return -EINVAL;
 
-	return io_buffer_unregister_bvec(cmd, index, issue_flags);
+	return io_buffer_unregister(cmd, index, issue_flags);
 }
 
 static int ublk_check_fetch_buf(const struct ublk_device *ub, __u64 buf_addr)
@@ -3280,7 +3280,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 		goto out;
 
 	/*
-	 * io_buffer_unregister_bvec() doesn't access the ubq or io,
+	 * io_buffer_unregister() doesn't access the ubq or io,
 	 * so no need to validate the q_id, tag, or task
 	 */
 	if (_IOC_NR(cmd_op) == UBLK_IO_UNREGISTER_IO_BUF)
@@ -3347,7 +3347,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 		req = ublk_fill_io_cmd(io, cmd);
 		ret = ublk_config_io_buf(ub, io, cmd, addr, &buf_idx);
 		if (buf_idx != UBLK_INVALID_BUF_IDX)
-			io_buffer_unregister_bvec(cmd, buf_idx, issue_flags);
+			io_buffer_unregister(cmd, buf_idx, issue_flags);
 		compl = ublk_need_complete_req(ub, io);
 
 		if (req_op(req) == REQ_OP_ZONE_APPEND)
@@ -3682,7 +3682,7 @@ static int ublk_batch_commit_io(struct ublk_queue *ubq,
 	}
 
 	if (buf_idx != UBLK_INVALID_BUF_IDX)
-		io_buffer_unregister_bvec(data->cmd, buf_idx, data->issue_flags);
+		io_buffer_unregister(data->cmd, buf_idx, data->issue_flags);
 	if (req_op(req) == REQ_OP_ZONE_APPEND)
 		req->__sector = ublk_batch_zone_lba(uc, elem);
 	if (compl)
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 89e1a80d9f5f..165d436073a4 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -106,6 +106,12 @@ bool io_uring_is_kmbuf_ring(struct io_uring_cmd *cmd, unsigned int buf_group,
 struct io_br_sel io_ring_buffer_select(struct io_kiocb *req, size_t *len,
 				       struct io_buffer_list *bl,
 				       unsigned int issue_flags);
+
+int io_buffer_register_request(struct io_uring_cmd *cmd, struct request *rq,
+			       void (*release)(void *), unsigned int index,
+			       unsigned int issue_flags);
+int io_buffer_unregister(struct io_uring_cmd *cmd, unsigned int index,
+			 unsigned int issue_flags);
 #else
 static inline int
 io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
@@ -184,6 +190,20 @@ static inline struct io_br_sel io_ring_buffer_select(struct io_kiocb *req,
 	};
 	return sel;
 }
+static inline int io_buffer_register_request(struct io_uring_cmd *cmd,
+					     struct request *rq,
+					     void (*release)(void *),
+					     unsigned int index,
+					     unsigned int issue_flags)
+{
+	return -EOPNOTSUPP;
+}
+static inline int io_buffer_unregister(struct io_uring_cmd *cmd,
+				       unsigned int index,
+				       unsigned int issue_flags)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 static inline struct io_uring_cmd *io_uring_cmd_from_tw(struct io_tw_req tw_req)
@@ -233,10 +253,4 @@ static inline void io_uring_cmd_done32(struct io_uring_cmd *ioucmd, s32 ret,
 	return __io_uring_cmd_done(ioucmd, ret, res2, issue_flags, true);
 }
 
-int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
-			    void (*release)(void *), unsigned int index,
-			    unsigned int issue_flags);
-int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
-			      unsigned int issue_flags);
-
 #endif /* _LINUX_IO_URING_CMD_H */
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 52554ed89b11..7579f6992a25 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -924,9 +924,9 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
 	return ret;
 }
 
-int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
-			    void (*release)(void *), unsigned int index,
-			    unsigned int issue_flags)
+int io_buffer_register_request(struct io_uring_cmd *cmd, struct request *rq,
+			       void (*release)(void *), unsigned int index,
+			       unsigned int issue_flags)
 {
 	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
@@ -986,10 +986,10 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
 	io_ring_submit_unlock(ctx, issue_flags);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(io_buffer_register_bvec);
+EXPORT_SYMBOL_GPL(io_buffer_register_request);
 
-int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
-			      unsigned int issue_flags)
+int io_buffer_unregister(struct io_uring_cmd *cmd, unsigned int index,
+			 unsigned int issue_flags)
 {
 	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
@@ -1019,7 +1019,7 @@ int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
 	io_ring_submit_unlock(ctx, issue_flags);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(io_buffer_unregister_bvec);
+EXPORT_SYMBOL_GPL(io_buffer_unregister);
 
 static int validate_fixed_range(u64 buf_addr, size_t len,
 				const struct io_mapped_ubuf *imu)
-- 
2.52.0