io_uring: split out cmd api into a separate header

linux/io_uring.h is slowly becoming a rubbish bin where we put
anything exposed to other subsystems. For instance, the task exit
hooks and io_uring cmd infra are completely orthogonal and don't need
each other's definitions. Start cleaning it up by splitting out all
command bits into a new header file.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ec50bae6e21f371d3850796e716917fc141225a.1701391955.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

MAINTAINERS

@@ -11102,6 +11102,7 @@ L:	io-uring@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.dk/linux-block
 T:	git git://git.kernel.dk/liburing
+F:	include/linux/io_uring/
 F:	include/linux/io_uring.h
 F:	include/linux/io_uring_types.h
 F:	include/trace/events/io_uring.h

drivers/block/ublk_drv.c

@@ -36,7 +36,7 @@
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
 #include <linux/cdev.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 #include <linux/blk-mq.h>
 #include <linux/delay.h>
 #include <linux/mm.h>

drivers/nvme/host/ioctl.c

@@ -5,7 +5,7 @@
  */
 #include <linux/ptrace.h>	/* for force_successful_syscall_return */
 #include <linux/nvme_ioctl.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 #include "nvme.h"
 
 enum {

include/linux/io_uring.h

@@ -6,71 +6,13 @@
 #include <linux/xarray.h>
 #include <uapi/linux/io_uring.h>
 
-enum io_uring_cmd_flags {
-	IO_URING_F_COMPLETE_DEFER	= 1,
-	IO_URING_F_UNLOCKED		= 2,
-	/* the request is executed from poll, it should not be freed */
-	IO_URING_F_MULTISHOT		= 4,
-	/* executed by io-wq */
-	IO_URING_F_IOWQ			= 8,
-	/* int's last bit, sign checks are usually faster than a bit test */
-	IO_URING_F_NONBLOCK		= INT_MIN,
-
-	/* ctx state flags, for URING_CMD */
-	IO_URING_F_SQE128		= (1 << 8),
-	IO_URING_F_CQE32		= (1 << 9),
-	IO_URING_F_IOPOLL		= (1 << 10),
-
-	/* set when uring wants to cancel a previously issued command */
-	IO_URING_F_CANCEL		= (1 << 11),
-	IO_URING_F_COMPAT		= (1 << 12),
-};
-
-/* only top 8 bits of sqe->uring_cmd_flags for kernel internal use */
-#define IORING_URING_CMD_CANCELABLE	(1U << 30)
-#define IORING_URING_CMD_POLLED		(1U << 31)
-
-struct io_uring_cmd {
-	struct file	*file;
-	const struct io_uring_sqe *sqe;
-	union {
-		/* callback to defer completions to task context */
-		void (*task_work_cb)(struct io_uring_cmd *cmd, unsigned);
-		/* used for polled completion */
-		void *cookie;
-	};
-	u32		cmd_op;
-	u32		flags;
-	u8		pdu[32]; /* available inline for free use */
-};
-
-static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
-{
-	return sqe->cmd;
-}
-
 #if defined(CONFIG_IO_URING)
-int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
-			      struct iov_iter *iter, void *ioucmd);
-void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
-			unsigned issue_flags);
 struct sock *io_uring_get_socket(struct file *file);
 void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
 void io_uring_unreg_ringfd(void);
 const char *io_uring_get_opcode(u8 opcode);
-void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
+int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
-			    void (*task_work_cb)(struct io_uring_cmd *, unsigned),
-			    unsigned flags);
-/* users should follow semantics of IOU_F_TWQ_LAZY_WAKE */
-void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
-			void (*task_work_cb)(struct io_uring_cmd *, unsigned));
-
-static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
-			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
-{
-	__io_uring_cmd_do_in_task(ioucmd, task_work_cb, 0);
-}
 
 static inline void io_uring_files_cancel(void)
 {
@@ -89,28 +31,7 @@ static inline void io_uring_free(struct task_struct *tsk)
 	if (tsk->io_uring)
 		__io_uring_free(tsk);
 }
-int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
-void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
-		unsigned int issue_flags);
-struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd);
 #else
-static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
-			      struct iov_iter *iter, void *ioucmd)
-{
-	return -EOPNOTSUPP;
-}
-static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
-		ssize_t ret2, unsigned issue_flags)
-{
-}
-static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
-			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
-{
-}
-static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
-			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
-{
-}
 static inline struct sock *io_uring_get_socket(struct file *file)
 {
 	return NULL;
@@ -133,14 +54,6 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
 {
 	return -EOPNOTSUPP;
 }
-static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
-		unsigned int issue_flags)
-{
-}
-static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd)
-{
-	return NULL;
-}
 #endif
 
 #endif

include/linux/io_uring/cmd.h

@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _LINUX_IO_URING_CMD_H
+#define _LINUX_IO_URING_CMD_H
+
+#include <uapi/linux/io_uring.h>
+#include <linux/io_uring_types.h>
+
+/* only top 8 bits of sqe->uring_cmd_flags for kernel internal use */
+#define IORING_URING_CMD_CANCELABLE	(1U << 30)
+#define IORING_URING_CMD_POLLED		(1U << 31)
+
+struct io_uring_cmd {
+	struct file	*file;
+	const struct io_uring_sqe *sqe;
+	union {
+		/* callback to defer completions to task context */
+		void (*task_work_cb)(struct io_uring_cmd *cmd, unsigned);
+		/* used for polled completion */
+		void *cookie;
+	};
+	u32		cmd_op;
+	u32		flags;
+	u8		pdu[32]; /* available inline for free use */
+};
+
+static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
+{
+	return sqe->cmd;
+}
+
+#if defined(CONFIG_IO_URING)
+int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
+			      struct iov_iter *iter, void *ioucmd);
+void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
+			unsigned issue_flags);
+void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
+			    void (*task_work_cb)(struct io_uring_cmd *, unsigned),
+			    unsigned flags);
+/* users should follow semantics of IOU_F_TWQ_LAZY_WAKE */
+void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
+			void (*task_work_cb)(struct io_uring_cmd *, unsigned));
+
+static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
+			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
+{
+	__io_uring_cmd_do_in_task(ioucmd, task_work_cb, 0);
+}
+
+void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
+		unsigned int issue_flags);
+struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd);
+
+#else
+static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
+			      struct iov_iter *iter, void *ioucmd)
+{
+	return -EOPNOTSUPP;
+}
+static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
+		ssize_t ret2, unsigned issue_flags)
+{
+}
+static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
+			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
+{
+}
+static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
+			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
+{
+}
+static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
+		unsigned int issue_flags)
+{
+}
+static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd)
+{
+	return NULL;
+}
+#endif
+
+#endif /* _LINUX_IO_URING_CMD_H */

include/linux/io_uring_types.h

@@ -7,6 +7,26 @@
 #include <linux/llist.h>
 #include <uapi/linux/io_uring.h>
 
+enum io_uring_cmd_flags {
+	IO_URING_F_COMPLETE_DEFER	= 1,
+	IO_URING_F_UNLOCKED		= 2,
+	/* the request is executed from poll, it should not be freed */
+	IO_URING_F_MULTISHOT		= 4,
+	/* executed by io-wq */
+	IO_URING_F_IOWQ			= 8,
+	/* int's last bit, sign checks are usually faster than a bit test */
+	IO_URING_F_NONBLOCK		= INT_MIN,
+
+	/* ctx state flags, for URING_CMD */
+	IO_URING_F_SQE128		= (1 << 8),
+	IO_URING_F_CQE32		= (1 << 9),
+	IO_URING_F_IOPOLL		= (1 << 10),
+
+	/* set when uring wants to cancel a previously issued command */
+	IO_URING_F_CANCEL		= (1 << 11),
+	IO_URING_F_COMPAT		= (1 << 12),
+};
+
 struct io_wq_work_node {
 	struct io_wq_work_node *next;
 };

io_uring/io_uring.c

@@ -70,6 +70,7 @@
 #include <linux/fadvise.h>
 #include <linux/task_work.h>
 #include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 #include <linux/audit.h>
 #include <linux/security.h>
 #include <asm/shmparam.h>

io_uring/rw.c

@@ -10,7 +10,7 @@
 #include <linux/poll.h>
 #include <linux/nospec.h>
 #include <linux/compat.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 
 #include <uapi/linux/io_uring.h>
 

io_uring/uring_cmd.c

@@ -2,7 +2,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/file.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 #include <linux/security.h>
 #include <linux/nospec.h>
 

security/selinux/hooks.c

@@ -91,7 +91,7 @@
 #include <uapi/linux/mount.h>
 #include <linux/fsnotify.h>
 #include <linux/fanotify.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 
 #include "avc.h"
 #include "objsec.h"

security/smack/smack_lsm.c

@@ -42,7 +42,7 @@
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
 #include <linux/watch_queue.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/cmd.h>
 #include "smack.h"
 
 #define TRANS_TRUE	"TRUE"