[RFC PATCH 2/7] io_uring: add helper __io_buffer_[un]register_bvec

[Ming Lei <ming.lei@redhat.com>]

Add helper __io_buffer_[un]register_bvec and prepare for supporting to
register bvec buffer into specified io_uring and buffer index.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 io_uring/rsrc.c | 88 ++++++++++++++++++++++++++-----------------------
 1 file changed, 46 insertions(+), 42 deletions(-)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 66d2c11e2f46..5f8ab130a573 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -918,11 +918,9 @@ 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 io_buf_data *buf,
-			    unsigned int issue_flags)
+static int __io_buffer_register_bvec(struct io_ring_ctx *ctx,
+				     struct io_buf_data *buf)
 {
-	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
 	unsigned int index = buf->index;
 	struct request *rq = buf->rq;
@@ -931,32 +929,23 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd,
 	struct io_rsrc_node *node;
 	struct bio_vec bv, *bvec;
 	u16 nr_bvecs;
-	int ret = 0;
 
-	io_ring_submit_lock(ctx, issue_flags);
-	if (index >= data->nr) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-	index = array_index_nospec(index, data->nr);
+	if (index >= data->nr)
+		return -EINVAL;
 
-	if (data->nodes[index]) {
-		ret = -EBUSY;
-		goto unlock;
-	}
+	index = array_index_nospec(index, data->nr);
+	if (data->nodes[index])
+		return -EBUSY;
 
 	node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER);
-	if (!node) {
-		ret = -ENOMEM;
-		goto unlock;
-	}
+	if (!node)
+		return -ENOMEM;
 
 	nr_bvecs = blk_rq_nr_phys_segments(rq);
 	imu = io_alloc_imu(ctx, nr_bvecs);
 	if (!imu) {
 		kfree(node);
-		ret = -ENOMEM;
-		goto unlock;
+		return -ENOMEM;
 	}
 
 	imu->ubuf = 0;
@@ -976,43 +965,58 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd,
 
 	node->buf = imu;
 	data->nodes[index] = node;
-unlock:
+
+	return 0;
+}
+
+int io_buffer_register_bvec(struct io_uring_cmd *cmd,
+			    struct io_buf_data *buf,
+			    unsigned int issue_flags)
+{
+	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
+	int ret;
+
+	io_ring_submit_lock(ctx, issue_flags);
+	ret = __io_buffer_register_bvec(ctx, buf);
 	io_ring_submit_unlock(ctx, issue_flags);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(io_buffer_register_bvec);
 
-int io_buffer_unregister_bvec(struct io_uring_cmd *cmd,
-			      struct io_buf_data *buf,
-			      unsigned int issue_flags)
+static int __io_buffer_unregister_bvec(struct io_ring_ctx *ctx,
+				       struct io_buf_data *buf)
 {
-	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
 	unsigned index = buf->index;
 	struct io_rsrc_node *node;
-	int ret = 0;
 
-	io_ring_submit_lock(ctx, issue_flags);
-	if (index >= data->nr) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-	index = array_index_nospec(index, data->nr);
+	if (index >= data->nr)
+		return -EINVAL;
 
+	index = array_index_nospec(index, data->nr);
 	node = data->nodes[index];
-	if (!node) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-	if (!node->buf->is_kbuf) {
-		ret = -EBUSY;
-		goto unlock;
-	}
+	if (!node)
+		return -EINVAL;
+	if (!node->buf->is_kbuf)
+		return -EBUSY;
 
 	io_put_rsrc_node(ctx, node);
 	data->nodes[index] = NULL;
-unlock:
+	return 0;
+}
+
+int io_buffer_unregister_bvec(struct io_uring_cmd *cmd,
+			      struct io_buf_data *buf,
+			      unsigned int issue_flags)
+{
+	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
+	int ret;
+
+	io_ring_submit_lock(ctx, issue_flags);
+	ret = __io_buffer_unregister_bvec(ctx, buf);
 	io_ring_submit_unlock(ctx, issue_flags);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(io_buffer_unregister_bvec);
-- 
2.47.0