include/uapi/linux/io_uring.h

File Facts

System

Linux kernel

Corpus path

include/uapi/linux/io_uring.h

Extension

.h

Size

28367 bytes

Lines

1066

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/fs.h
• linux/types.h
• linux/io_uring/zcrx.h
• linux/time_types.h

Detected Declarations

• struct io_uring_sqe
• struct io_uring_attr_pi
• struct io_uring_cqe
• struct io_sqring_offsets
• struct io_cqring_offsets
• struct io_uring_params
• struct io_uring_files_update
• struct io_uring_region_desc
• struct io_uring_mem_region_reg
• struct io_uring_rsrc_register
• struct io_uring_rsrc_update
• struct io_uring_rsrc_update2
• struct io_uring_probe_op
• struct io_uring_probe
• struct io_uring_restriction
• struct io_uring_task_restriction
• struct io_uring_clock_register
• struct io_uring_clone_buffers
• struct io_uring_buf
• struct io_uring_buf_ring
• struct io_uring_buf_reg
• struct io_uring_buf_status
• struct io_uring_napi
• struct io_uring_reg_wait
• struct io_uring_getevents_arg
• struct io_uring_sync_cancel_reg
• struct io_uring_file_index_range
• struct io_uring_recvmsg_out
• struct io_timespec
• enum io_uring_sqe_flags_bit
• enum io_uring_op
• enum io_uring_msg_ring_flags
• enum io_uring_register_op
• enum io_wq_type
• enum io_uring_register_pbuf_ring_flags
• enum io_uring_napi_op
• enum io_uring_napi_tracking_strategy
• enum io_uring_register_restriction_op
• enum io_uring_socket_op

Annotated Snippet

struct io_uring_sqe {
	__u8	opcode;		/* type of operation for this sqe */
	__u8	flags;		/* IOSQE_ flags */
	__u16	ioprio;		/* ioprio for the request */
	__s32	fd;		/* file descriptor to do IO on */
	union {
		__u64	off;	/* offset into file */
		__u64	addr2;
		struct {
			__u32	cmd_op;
			__u32	__pad1;
		};
	};
	union {
		__u64	addr;	/* pointer to buffer or iovecs */
		__u64	splice_off_in;
		struct {
			__u32	level;
			__u32	optname;
		};
	};
	__u32	len;		/* buffer size or number of iovecs */
	union {
		__u32		rw_flags;
		__u32		fsync_flags;
		__u16		poll_events;	/* compatibility */
		__u32		poll32_events;	/* word-reversed for BE */
		__u32		sync_range_flags;
		__u32		msg_flags;
		__u32		timeout_flags;
		__u32		accept_flags;
		__u32		cancel_flags;
		__u32		open_flags;
		__u32		statx_flags;
		__u32		fadvise_advice;
		__u32		splice_flags;
		__u32		rename_flags;
		__u32		unlink_flags;
		__u32		hardlink_flags;
		__u32		xattr_flags;
		__u32		msg_ring_flags;
		__u32		uring_cmd_flags;
		__u32		waitid_flags;
		__u32		futex_flags;
		__u32		install_fd_flags;
		__u32		nop_flags;
		__u32		pipe_flags;
	};
	__u64	user_data;	/* data to be passed back at completion time */
	/* pack this to avoid bogus arm OABI complaints */
	union {
		/* index into fixed buffers, if used */
		__u16	buf_index;
		/* for grouped buffer selection */
		__u16	buf_group;
	} __attribute__((packed));
	/* personality to use, if used */
	__u16	personality;
	union {
		__s32	splice_fd_in;
		__u32	file_index;
		__u32	zcrx_ifq_idx;
		__u32	optlen;
		struct {
			__u16	addr_len;
			__u16	__pad3[1];
		};
		struct {
			__u8	write_stream;
			__u8	__pad4[3];
		};
	};
	union {
		struct {
			__u64	addr3;
			__u64	__pad2[1];
		};
		struct {
			__u64	attr_ptr; /* pointer to attribute information */
			__u64	attr_type_mask; /* bit mask of attributes */
		};
		__u64	optval;
		/*
		 * If the ring is initialized with IORING_SETUP_SQE128, then
		 * this field is used for 80 bytes of arbitrary command data
		 */
		__u8	cmd[0];
	};
};

Annotation

• Immediate include surface: `linux/fs.h`, `linux/types.h`, `linux/io_uring/zcrx.h`, `linux/time_types.h`.
• Detected declarations: `struct io_uring_sqe`, `struct io_uring_attr_pi`, `struct io_uring_cqe`, `struct io_sqring_offsets`, `struct io_cqring_offsets`, `struct io_uring_params`, `struct io_uring_files_update`, `struct io_uring_region_desc`, `struct io_uring_mem_region_reg`, `struct io_uring_rsrc_register`.
• Atlas domain: Core OS / Core Kernel Interface.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.