[PATCH 2/5] io_uring: bpf: add io_uring_ctx setup for BPF into one list

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

Add io_uring_ctx setup for BPF into one list, and prepare for syncing
bpf struct_ops register and un-register.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 include/linux/io_uring_types.h |  5 +++++
 include/uapi/linux/io_uring.h  |  5 +++++
 io_uring/bpf.c                 | 15 +++++++++++++++
 io_uring/io_uring.c            |  7 +++++++
 io_uring/io_uring.h            |  3 ++-
 io_uring/uring_bpf.h           | 11 +++++++++++
 6 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 92780764d5fa..d2e098c3fd2c 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -465,6 +465,11 @@ struct io_ring_ctx {
 	struct io_mapped_region		ring_region;
 	/* used for optimised request parameter and wait argument passing  */
 	struct io_mapped_region		param_region;
+
+#ifdef CONFIG_IO_URING_BPF
+	/* added to uring_bpf_ctx_list */
+	struct list_head		bpf_node;
+#endif
 };
 
 /*
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index b167c1d4ce6e..b8c49813b4e5 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -237,6 +237,11 @@ enum io_uring_sqe_flags_bit {
  */
 #define IORING_SETUP_SQE_MIXED		(1U << 19)
 
+/*
+ * Allow to submit bpf IO
+ */
+#define IORING_SETUP_BPF		(1U << 20)
+
 enum io_uring_op {
 	IORING_OP_NOP,
 	IORING_OP_READV,
diff --git a/io_uring/bpf.c b/io_uring/bpf.c
index 8c47df13c7b5..bb1e37d1e804 100644
--- a/io_uring/bpf.c
+++ b/io_uring/bpf.c
@@ -7,6 +7,9 @@
 #include "io_uring.h"
 #include "uring_bpf.h"
 
+static DEFINE_MUTEX(uring_bpf_ctx_lock);
+static LIST_HEAD(uring_bpf_ctx_list);
+
 int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags)
 {
 	return -ECANCELED;
@@ -24,3 +27,15 @@ void io_uring_bpf_fail(struct io_kiocb *req)
 void io_uring_bpf_cleanup(struct io_kiocb *req)
 {
 }
+
+void uring_bpf_add_ctx(struct io_ring_ctx *ctx)
+{
+	guard(mutex)(&uring_bpf_ctx_lock);
+	list_add(&ctx->bpf_node, &uring_bpf_ctx_list);
+}
+
+void uring_bpf_del_ctx(struct io_ring_ctx *ctx)
+{
+	guard(mutex)(&uring_bpf_ctx_lock);
+	list_del(&ctx->bpf_node);
+}
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 3f0489261d11..38f03f6c28cb 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -105,6 +105,7 @@
 #include "rw.h"
 #include "alloc_cache.h"
 #include "eventfd.h"
+#include "uring_bpf.h"
 
 #define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
 			  IOSQE_IO_HARDLINK | IOSQE_ASYNC)
@@ -352,6 +353,9 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	io_napi_init(ctx);
 	mutex_init(&ctx->mmap_lock);
 
+	if (ctx->flags & IORING_SETUP_BPF)
+		uring_bpf_add_ctx(ctx);
+
 	return ctx;
 
 free_ref:
@@ -2855,6 +2859,9 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	if (!(ctx->flags & IORING_SETUP_NO_SQARRAY))
 		static_branch_dec(&io_key_has_sqarray);
 
+	if (ctx->flags & IORING_SETUP_BPF)
+		uring_bpf_del_ctx(ctx);
+
 	percpu_ref_exit(&ctx->refs);
 	free_uid(ctx->user);
 	io_req_caches_free(ctx);
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 23c268ab1c8f..4baf21a9e1ee 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -55,7 +55,8 @@
 			IORING_SETUP_NO_SQARRAY |\
 			IORING_SETUP_HYBRID_IOPOLL |\
 			IORING_SETUP_CQE_MIXED |\
-			IORING_SETUP_SQE_MIXED)
+			IORING_SETUP_SQE_MIXED |\
+			IORING_SETUP_BPF)
 
 #define IORING_ENTER_FLAGS (IORING_ENTER_GETEVENTS |\
 			IORING_ENTER_SQ_WAKEUP |\
diff --git a/io_uring/uring_bpf.h b/io_uring/uring_bpf.h
index bde774ce6ac0..b6cda6df99b1 100644
--- a/io_uring/uring_bpf.h
+++ b/io_uring/uring_bpf.h
@@ -7,6 +7,10 @@ int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags);
 int io_uring_bpf_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 void io_uring_bpf_fail(struct io_kiocb *req);
 void io_uring_bpf_cleanup(struct io_kiocb *req);
+
+void uring_bpf_add_ctx(struct io_ring_ctx *ctx);
+void uring_bpf_del_ctx(struct io_ring_ctx *ctx);
+
 #else
 static inline int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags)
 {
@@ -22,5 +26,12 @@ static inline void io_uring_bpf_fail(struct io_kiocb *req)
 static inline void io_uring_bpf_cleanup(struct io_kiocb *req)
 {
 }
+
+static inline void uring_bpf_add_ctx(struct io_ring_ctx *ctx)
+{
+}
+static inline void uring_bpf_del_ctx(struct io_ring_ctx *ctx)
+{
+}
 #endif
 #endif
-- 
2.47.0