[linux-2.6-block.git] / include / linux / io_uring_types.h

#ifndef IO_URING_TYPES_H
#define IO_URING_TYPES_H

#include <linux/blkdev.h>
#include <linux/task_work.h>
#include <linux/bitmap.h>
#include <uapi/linux/io_uring.h>

struct io_wq_work_node {
	struct io_wq_work_node *next;
};

struct io_wq_work_list {
	struct io_wq_work_node *first;
	struct io_wq_work_node *last;
};

struct io_wq_work {
	struct io_wq_work_node list;
	unsigned flags;
	/* place it here instead of io_kiocb as it fills padding and saves 4B */
	int cancel_seq;
};

struct io_fixed_file {
	/* file * with additional FFS_* flags */
	unsigned long file_ptr;
};

struct io_file_table {
	struct io_fixed_file *files;
	unsigned long *bitmap;
	unsigned int alloc_hint;
};

struct io_hash_bucket {
	spinlock_t		lock;
	struct hlist_head	list;
} ____cacheline_aligned_in_smp;

struct io_hash_table {
	struct io_hash_bucket	*hbs;
	unsigned		hash_bits;
};

struct io_uring {
	u32 head ____cacheline_aligned_in_smp;
	u32 tail ____cacheline_aligned_in_smp;
};

/*
 * This data is shared with the application through the mmap at offsets
 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
 *
 * The offsets to the member fields are published through struct
 * io_sqring_offsets when calling io_uring_setup.
 */
struct io_rings {
	/*
	 * Head and tail offsets into the ring; the offsets need to be
	 * masked to get valid indices.
	 *
	 * The kernel controls head of the sq ring and the tail of the cq ring,
	 * and the application controls tail of the sq ring and the head of the
	 * cq ring.
	 */
	struct io_uring		sq, cq;
	/*
	 * Bitmasks to apply to head and tail offsets (constant, equals
	 * ring_entries - 1)
	 */
	u32			sq_ring_mask, cq_ring_mask;
	/* Ring sizes (constant, power of 2) */
	u32			sq_ring_entries, cq_ring_entries;
	/*
	 * Number of invalid entries dropped by the kernel due to
	 * invalid index stored in array
	 *
	 * Written by the kernel, shouldn't be modified by the
	 * application (i.e. get number of "new events" by comparing to
	 * cached value).
	 *
	 * After a new SQ head value was read by the application this
	 * counter includes all submissions that were dropped reaching
	 * the new SQ head (and possibly more).
	 */
	u32			sq_dropped;
	/*
	 * Runtime SQ flags
	 *
	 * Written by the kernel, shouldn't be modified by the
	 * application.
	 *
	 * The application needs a full memory barrier before checking
	 * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
	 */
	atomic_t		sq_flags;
	/*
	 * Runtime CQ flags
	 *
	 * Written by the application, shouldn't be modified by the
	 * kernel.
	 */
	u32			cq_flags;
	/*
	 * Number of completion events lost because the queue was full;
	 * this should be avoided by the application by making sure
	 * there are not more requests pending than there is space in
	 * the completion queue.
	 *
	 * Written by the kernel, shouldn't be modified by the
	 * application (i.e. get number of "new events" by comparing to
	 * cached value).
	 *
	 * As completion events come in out of order this counter is not
	 * ordered with any other data.
	 */
	u32			cq_overflow;
	/*
	 * Ring buffer of completion events.
	 *
	 * The kernel writes completion events fresh every time they are
	 * produced, so the application is allowed to modify pending
	 * entries.
	 */
	struct io_uring_cqe	cqes[] ____cacheline_aligned_in_smp;
};

struct io_restriction {
	DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
	DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
	u8 sqe_flags_allowed;
	u8 sqe_flags_required;
	bool registered;
};

struct io_submit_link {
	struct io_kiocb		*head;
	struct io_kiocb		*last;
};

struct io_submit_state {
	/* inline/task_work completion list, under ->uring_lock */
	struct io_wq_work_node	free_list;
	/* batch completion logic */
	struct io_wq_work_list	compl_reqs;
	struct io_submit_link	link;

	bool			plug_started;
	bool			need_plug;
	unsigned short		submit_nr;
	struct blk_plug		plug;
};

struct io_ev_fd {
	struct eventfd_ctx	*cq_ev_fd;
	unsigned int		eventfd_async: 1;
	struct rcu_head		rcu;
};

struct io_ring_ctx {
	/* const or read-mostly hot data */
	struct {
		struct percpu_ref	refs;

		struct io_rings		*rings;
		unsigned int		flags;
		enum task_work_notify_mode	notify_method;
		unsigned int		compat: 1;
		unsigned int		drain_next: 1;
		unsigned int		restricted: 1;
		unsigned int		off_timeout_used: 1;
		unsigned int		drain_active: 1;
		unsigned int		drain_disabled: 1;
		unsigned int		has_evfd: 1;
		unsigned int		syscall_iopoll: 1;
	} ____cacheline_aligned_in_smp;

	/* submission data */
	struct {
		struct mutex		uring_lock;

		/*
		 * Ring buffer of indices into array of io_uring_sqe, which is
		 * mmapped by the application using the IORING_OFF_SQES offset.
		 *
		 * This indirection could e.g. be used to assign fixed
		 * io_uring_sqe entries to operations and only submit them to
		 * the queue when needed.
		 *
		 * The kernel modifies neither the indices array nor the entries
		 * array.
		 */
		u32			*sq_array;
		struct io_uring_sqe	*sq_sqes;
		unsigned		cached_sq_head;
		unsigned		sq_entries;

		/*
		 * Fixed resources fast path, should be accessed only under
		 * uring_lock, and updated through io_uring_register(2)
		 */
		struct io_rsrc_node	*rsrc_node;
		int			rsrc_cached_refs;
		atomic_t		cancel_seq;
		struct io_file_table	file_table;
		unsigned		nr_user_files;
		unsigned		nr_user_bufs;
		struct io_mapped_ubuf	**user_bufs;

		struct io_submit_state	submit_state;

		struct io_buffer_list	*io_bl;
		struct xarray		io_bl_xa;
		struct list_head	io_buffers_cache;

		struct io_hash_table	cancel_table_locked;
		struct list_head	cq_overflow_list;
		struct list_head	apoll_cache;
		struct xarray		personalities;
		u32			pers_next;
	} ____cacheline_aligned_in_smp;

	/* IRQ completion list, under ->completion_lock */
	struct io_wq_work_list	locked_free_list;
	unsigned int		locked_free_nr;

	const struct cred	*sq_creds;	/* cred used for __io_sq_thread() */
	struct io_sq_data	*sq_data;	/* if using sq thread polling */

	struct wait_queue_head	sqo_sq_wait;
	struct list_head	sqd_list;

	unsigned long		check_cq;

	struct {
		/*
		 * We cache a range of free CQEs we can use, once exhausted it
		 * should go through a slower range setup, see __io_get_cqe()
		 */
		struct io_uring_cqe	*cqe_cached;
		struct io_uring_cqe	*cqe_sentinel;

		unsigned		cached_cq_tail;
		unsigned		cq_entries;
		struct io_ev_fd	__rcu	*io_ev_fd;
		struct wait_queue_head	cq_wait;
		unsigned		cq_extra;
	} ____cacheline_aligned_in_smp;

	struct {
		spinlock_t		completion_lock;

		/*
		 * ->iopoll_list is protected by the ctx->uring_lock for
		 * io_uring instances that don't use IORING_SETUP_SQPOLL.
		 * For SQPOLL, only the single threaded io_sq_thread() will
		 * manipulate the list, hence no extra locking is needed there.
		 */
		struct io_wq_work_list	iopoll_list;
		struct io_hash_table	cancel_table;
		bool			poll_multi_queue;

		struct list_head	io_buffers_comp;
	} ____cacheline_aligned_in_smp;

	/* timeouts */
	struct {
		spinlock_t		timeout_lock;
		atomic_t		cq_timeouts;
		struct list_head	timeout_list;
		struct list_head	ltimeout_list;
		unsigned		cq_last_tm_flush;
	} ____cacheline_aligned_in_smp;

	/* Keep this last, we don't need it for the fast path */

	struct io_restriction		restrictions;
	struct task_struct		*submitter_task;

	/* slow path rsrc auxilary data, used by update/register */
	struct io_rsrc_node		*rsrc_backup_node;
	struct io_mapped_ubuf		*dummy_ubuf;
	struct io_rsrc_data		*file_data;
	struct io_rsrc_data		*buf_data;

	struct delayed_work		rsrc_put_work;
	struct llist_head		rsrc_put_llist;
	struct list_head		rsrc_ref_list;
	spinlock_t			rsrc_ref_lock;

	struct list_head		io_buffers_pages;

	#if defined(CONFIG_UNIX)
		struct socket		*ring_sock;
	#endif
	/* hashed buffered write serialization */
	struct io_wq_hash		*hash_map;

	/* Only used for accounting purposes */
	struct user_struct		*user;
	struct mm_struct		*mm_account;

	/* ctx exit and cancelation */
	struct llist_head		fallback_llist;
	struct delayed_work		fallback_work;
	struct work_struct		exit_work;
	struct list_head		tctx_list;
	struct completion		ref_comp;

	/* io-wq management, e.g. thread count */
	u32				iowq_limits[2];
	bool				iowq_limits_set;

	struct list_head		defer_list;
	unsigned			sq_thread_idle;
	/* protected by ->completion_lock */
	unsigned			evfd_last_cq_tail;
};

enum {
	REQ_F_FIXED_FILE_BIT	= IOSQE_FIXED_FILE_BIT,
	REQ_F_IO_DRAIN_BIT	= IOSQE_IO_DRAIN_BIT,
	REQ_F_LINK_BIT		= IOSQE_IO_LINK_BIT,
	REQ_F_HARDLINK_BIT	= IOSQE_IO_HARDLINK_BIT,
	REQ_F_FORCE_ASYNC_BIT	= IOSQE_ASYNC_BIT,
	REQ_F_BUFFER_SELECT_BIT	= IOSQE_BUFFER_SELECT_BIT,
	REQ_F_CQE_SKIP_BIT	= IOSQE_CQE_SKIP_SUCCESS_BIT,

	/* first byte is taken by user flags, shift it to not overlap */
	REQ_F_FAIL_BIT		= 8,
	REQ_F_INFLIGHT_BIT,
	REQ_F_CUR_POS_BIT,
	REQ_F_NOWAIT_BIT,
	REQ_F_LINK_TIMEOUT_BIT,
	REQ_F_NEED_CLEANUP_BIT,
	REQ_F_POLLED_BIT,
	REQ_F_BUFFER_SELECTED_BIT,
	REQ_F_BUFFER_RING_BIT,
	REQ_F_REISSUE_BIT,
	REQ_F_CREDS_BIT,
	REQ_F_REFCOUNT_BIT,
	REQ_F_ARM_LTIMEOUT_BIT,
	REQ_F_ASYNC_DATA_BIT,
	REQ_F_SKIP_LINK_CQES_BIT,
	REQ_F_SINGLE_POLL_BIT,
	REQ_F_DOUBLE_POLL_BIT,
	REQ_F_PARTIAL_IO_BIT,
	REQ_F_CQE32_INIT_BIT,
	REQ_F_APOLL_MULTISHOT_BIT,
	REQ_F_CLEAR_POLLIN_BIT,
	REQ_F_HASH_LOCKED_BIT,
	/* keep async read/write and isreg together and in order */
	REQ_F_SUPPORT_NOWAIT_BIT,
	REQ_F_ISREG_BIT,

	/* not a real bit, just to check we're not overflowing the space */
	__REQ_F_LAST_BIT,
};

enum {
	/* ctx owns file */
	REQ_F_FIXED_FILE	= BIT(REQ_F_FIXED_FILE_BIT),
	/* drain existing IO first */
	REQ_F_IO_DRAIN		= BIT(REQ_F_IO_DRAIN_BIT),
	/* linked sqes */
	REQ_F_LINK		= BIT(REQ_F_LINK_BIT),
	/* doesn't sever on completion < 0 */
	REQ_F_HARDLINK		= BIT(REQ_F_HARDLINK_BIT),
	/* IOSQE_ASYNC */
	REQ_F_FORCE_ASYNC	= BIT(REQ_F_FORCE_ASYNC_BIT),
	/* IOSQE_BUFFER_SELECT */
	REQ_F_BUFFER_SELECT	= BIT(REQ_F_BUFFER_SELECT_BIT),
	/* IOSQE_CQE_SKIP_SUCCESS */
	REQ_F_CQE_SKIP		= BIT(REQ_F_CQE_SKIP_BIT),

	/* fail rest of links */
	REQ_F_FAIL		= BIT(REQ_F_FAIL_BIT),
	/* on inflight list, should be cancelled and waited on exit reliably */
	REQ_F_INFLIGHT		= BIT(REQ_F_INFLIGHT_BIT),
	/* read/write uses file position */
	REQ_F_CUR_POS		= BIT(REQ_F_CUR_POS_BIT),
	/* must not punt to workers */
	REQ_F_NOWAIT		= BIT(REQ_F_NOWAIT_BIT),
	/* has or had linked timeout */
	REQ_F_LINK_TIMEOUT	= BIT(REQ_F_LINK_TIMEOUT_BIT),
	/* needs cleanup */
	REQ_F_NEED_CLEANUP	= BIT(REQ_F_NEED_CLEANUP_BIT),
	/* already went through poll handler */
	REQ_F_POLLED		= BIT(REQ_F_POLLED_BIT),
	/* buffer already selected */
	REQ_F_BUFFER_SELECTED	= BIT(REQ_F_BUFFER_SELECTED_BIT),
	/* buffer selected from ring, needs commit */
	REQ_F_BUFFER_RING	= BIT(REQ_F_BUFFER_RING_BIT),
	/* caller should reissue async */
	REQ_F_REISSUE		= BIT(REQ_F_REISSUE_BIT),
	/* supports async reads/writes */
	REQ_F_SUPPORT_NOWAIT	= BIT(REQ_F_SUPPORT_NOWAIT_BIT),
	/* regular file */
	REQ_F_ISREG		= BIT(REQ_F_ISREG_BIT),
	/* has creds assigned */
	REQ_F_CREDS		= BIT(REQ_F_CREDS_BIT),
	/* skip refcounting if not set */
	REQ_F_REFCOUNT		= BIT(REQ_F_REFCOUNT_BIT),
	/* there is a linked timeout that has to be armed */
	REQ_F_ARM_LTIMEOUT	= BIT(REQ_F_ARM_LTIMEOUT_BIT),
	/* ->async_data allocated */
	REQ_F_ASYNC_DATA	= BIT(REQ_F_ASYNC_DATA_BIT),
	/* don't post CQEs while failing linked requests */
	REQ_F_SKIP_LINK_CQES	= BIT(REQ_F_SKIP_LINK_CQES_BIT),
	/* single poll may be active */
	REQ_F_SINGLE_POLL	= BIT(REQ_F_SINGLE_POLL_BIT),
	/* double poll may active */
	REQ_F_DOUBLE_POLL	= BIT(REQ_F_DOUBLE_POLL_BIT),
	/* request has already done partial IO */
	REQ_F_PARTIAL_IO	= BIT(REQ_F_PARTIAL_IO_BIT),
	/* fast poll multishot mode */
	REQ_F_APOLL_MULTISHOT	= BIT(REQ_F_APOLL_MULTISHOT_BIT),
	/* ->extra1 and ->extra2 are initialised */
	REQ_F_CQE32_INIT	= BIT(REQ_F_CQE32_INIT_BIT),
	/* recvmsg special flag, clear EPOLLIN */
	REQ_F_CLEAR_POLLIN	= BIT(REQ_F_CLEAR_POLLIN_BIT),
	/* hashed into ->cancel_hash_locked, protected by ->uring_lock */
	REQ_F_HASH_LOCKED	= BIT(REQ_F_HASH_LOCKED_BIT),
};

typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);

struct io_task_work {
	union {
		struct llist_node	node;
		struct llist_node	fallback_node;
	};
	io_req_tw_func_t		func;
};

struct io_cqe {
	__u64	user_data;
	__s32	res;
	/* fd initially, then cflags for completion */
	union {
		__u32	flags;
		int	fd;
	};
};

/*
 * Each request type overlays its private data structure on top of this one.
 * They must not exceed this one in size.
 */
struct io_cmd_data {
	struct file		*file;
	/* each command gets 56 bytes of data */
	__u8			data[56];
};

#define io_kiocb_to_cmd(req)	((void *) &(req)->cmd)
#define cmd_to_io_kiocb(ptr)	((struct io_kiocb *) ptr)

struct io_kiocb {
	union {
		/*
		 * NOTE! Each of the io_kiocb union members has the file pointer
		 * as the first entry in their struct definition. So you can
		 * access the file pointer through any of the sub-structs,
		 * or directly as just 'file' in this struct.
		 */
		struct file		*file;
		struct io_cmd_data	cmd;
	};

	u8				opcode;
	/* polled IO has completed */
	u8				iopoll_completed;
	/*
	 * Can be either a fixed buffer index, or used with provided buffers.
	 * For the latter, before issue it points to the buffer group ID,
	 * and after selection it points to the buffer ID itself.
	 */
	u16				buf_index;
	unsigned int			flags;

	struct io_cqe			cqe;

	struct io_ring_ctx		*ctx;
	struct task_struct		*task;

	struct io_rsrc_node		*rsrc_node;

	union {
		/* store used ubuf, so we can prevent reloading */
		struct io_mapped_ubuf	*imu;

		/* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
		struct io_buffer	*kbuf;

		/*
		 * stores buffer ID for ring provided buffers, valid IFF
		 * REQ_F_BUFFER_RING is set.
		 */
		struct io_buffer_list	*buf_list;
	};

	union {
		/* used by request caches, completion batching and iopoll */
		struct io_wq_work_node	comp_list;
		/* cache ->apoll->events */
		__poll_t apoll_events;
	};
	atomic_t			refs;
	atomic_t			poll_refs;
	struct io_task_work		io_task_work;
	/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
	union {
		struct hlist_node	hash_node;
		struct {
			u64		extra1;
			u64		extra2;
		};
	};
	/* internal polling, see IORING_FEAT_FAST_POLL */
	struct async_poll		*apoll;
	/* opcode allocated if it needs to store data for async defer */
	void				*async_data;
	/* linked requests, IFF REQ_F_HARDLINK or REQ_F_LINK are set */
	struct io_kiocb			*link;
	/* custom credentials, valid IFF REQ_F_CREDS is set */
	const struct cred		*creds;
	struct io_wq_work		work;
};

struct io_overflow_cqe {
	struct list_head list;
	struct io_uring_cqe cqe;
};

#endif
Commit	Line	Data
e27f928e JA	1	#ifndef IO_URING_TYPES_H
	2	#define IO_URING_TYPES_H
	3
	4	#include <linux/blkdev.h>
	5	#include <linux/task_work.h>
d9b57aa3 JA	6	#include <linux/bitmap.h>
d9b57aa3 JA	7	#include <uapi/linux/io_uring.h>
e27f928e	8
ab1c84d8 PB	9	struct io_wq_work_node {
	10	struct io_wq_work_node *next;
	11	};
	12
	13	struct io_wq_work_list {
	14	struct io_wq_work_node *first;
	15	struct io_wq_work_node *last;
	16	};
	17
	18	struct io_wq_work {
	19	struct io_wq_work_node list;
	20	unsigned flags;
	21	/* place it here instead of io_kiocb as it fills padding and saves 4B */
	22	int cancel_seq;
	23	};
	24
	25	struct io_fixed_file {
	26	/* file * with additional FFS_* flags */
	27	unsigned long file_ptr;
	28	};
	29
	30	struct io_file_table {
	31	struct io_fixed_file *files;
	32	unsigned long *bitmap;
	33	unsigned int alloc_hint;
	34	};
e27f928e	35
e6f89be6 PB	36	struct io_hash_bucket {
	37	spinlock_t lock;
	38	struct hlist_head list;
	39	} ____cacheline_aligned_in_smp;
	40
	41	struct io_hash_table {
	42	struct io_hash_bucket *hbs;
	43	unsigned hash_bits;
	44	};
	45
e27f928e JA	46	struct io_uring {
	47	u32 head ____cacheline_aligned_in_smp;
	48	u32 tail ____cacheline_aligned_in_smp;
	49	};
	50
	51	/*
	52	* This data is shared with the application through the mmap at offsets
	53	* IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
	54	*
	55	* The offsets to the member fields are published through struct
	56	* io_sqring_offsets when calling io_uring_setup.
	57	*/
	58	struct io_rings {
	59	/*
	60	* Head and tail offsets into the ring; the offsets need to be
	61	* masked to get valid indices.
	62	*
	63	* The kernel controls head of the sq ring and the tail of the cq ring,
	64	* and the application controls tail of the sq ring and the head of the
	65	* cq ring.
	66	*/
	67	struct io_uring sq, cq;
	68	/*
	69	* Bitmasks to apply to head and tail offsets (constant, equals
	70	* ring_entries - 1)
	71	*/
	72	u32 sq_ring_mask, cq_ring_mask;
	73	/* Ring sizes (constant, power of 2) */
	74	u32 sq_ring_entries, cq_ring_entries;
	75	/*
	76	* Number of invalid entries dropped by the kernel due to
	77	* invalid index stored in array
	78	*
	79	* Written by the kernel, shouldn't be modified by the
	80	* application (i.e. get number of "new events" by comparing to
	81	* cached value).
	82	*
	83	* After a new SQ head value was read by the application this
	84	* counter includes all submissions that were dropped reaching
	85	* the new SQ head (and possibly more).
	86	*/
	87	u32 sq_dropped;
	88	/*
	89	* Runtime SQ flags
	90	*
	91	* Written by the kernel, shouldn't be modified by the
	92	* application.
	93	*
	94	* The application needs a full memory barrier before checking
	95	* for IORING_SQ_NEED_WAKEUP after updating the sq tail.
	96	*/
	97	atomic_t sq_flags;
	98	/*
	99	* Runtime CQ flags
	100	*
	101	* Written by the application, shouldn't be modified by the
	102	* kernel.
	103	*/
	104	u32 cq_flags;
	105	/*
	106	* Number of completion events lost because the queue was full;
	107	* this should be avoided by the application by making sure
	108	* there are not more requests pending than there is space in
	109	* the completion queue.
110	*
111	* Written by the kernel, shouldn't be modified by the
112	* application (i.e. get number of "new events" by comparing to
113	* cached value).
114	*
115	* As completion events come in out of order this counter is not
116	* ordered with any other data.
117	*/
118	u32 cq_overflow;
119	/*
120	* Ring buffer of completion events.
121	*
122	* The kernel writes completion events fresh every time they are
123	* produced, so the application is allowed to modify pending
124	* entries.
125	*/
126	struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
127	};
128
129	struct io_restriction {
130	DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
131	DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
132	u8 sqe_flags_allowed;
133	u8 sqe_flags_required;
134	bool registered;
135	};
136
137	struct io_submit_link {
138	struct io_kiocb *head;
139	struct io_kiocb *last;
140	};
141
142	struct io_submit_state {
143	/* inline/task_work completion list, under ->uring_lock */
144	struct io_wq_work_node free_list;
145	/* batch completion logic */
146	struct io_wq_work_list compl_reqs;
147	struct io_submit_link link;
148
149	bool plug_started;
150	bool need_plug;
e27f928e JA	151	unsigned short submit_nr;
	152	struct blk_plug plug;
	153	};
	154
	155	struct io_ev_fd {
	156	struct eventfd_ctx *cq_ev_fd;
	157	unsigned int eventfd_async: 1;
	158	struct rcu_head rcu;
	159	};
	160
e27f928e JA	161	struct io_ring_ctx {
	162	/* const or read-mostly hot data */
	163	struct {
	164	struct percpu_ref refs;
	165
	166	struct io_rings *rings;
	167	unsigned int flags;
	168	enum task_work_notify_mode notify_method;
	169	unsigned int compat: 1;
	170	unsigned int drain_next: 1;
	171	unsigned int restricted: 1;
	172	unsigned int off_timeout_used: 1;
	173	unsigned int drain_active: 1;
	174	unsigned int drain_disabled: 1;
	175	unsigned int has_evfd: 1;
	176	unsigned int syscall_iopoll: 1;
	177	} ____cacheline_aligned_in_smp;
	178
	179	/* submission data */
	180	struct {
	181	struct mutex uring_lock;
	182
	183	/*
	184	* Ring buffer of indices into array of io_uring_sqe, which is
	185	* mmapped by the application using the IORING_OFF_SQES offset.
	186	*
	187	* This indirection could e.g. be used to assign fixed
	188	* io_uring_sqe entries to operations and only submit them to
	189	* the queue when needed.
	190	*
	191	* The kernel modifies neither the indices array nor the entries
	192	* array.
	193	*/
	194	u32 *sq_array;
	195	struct io_uring_sqe *sq_sqes;
	196	unsigned cached_sq_head;
	197	unsigned sq_entries;
e27f928e JA	198
	199	/*
	200	* Fixed resources fast path, should be accessed only under
	201	* uring_lock, and updated through io_uring_register(2)
	202	*/
	203	struct io_rsrc_node *rsrc_node;
	204	int rsrc_cached_refs;
	205	atomic_t cancel_seq;
	206	struct io_file_table file_table;
	207	unsigned nr_user_files;
	208	unsigned nr_user_bufs;
	209	struct io_mapped_ubuf **user_bufs;
	210
	211	struct io_submit_state submit_state;
	212
	213	struct io_buffer_list *io_bl;
	214	struct xarray io_bl_xa;
	215	struct list_head io_buffers_cache;
	216
9ca9fb24	217	struct io_hash_table cancel_table_locked;
e27f928e JA	218	struct list_head cq_overflow_list;
	219	struct list_head apoll_cache;
	220	struct xarray personalities;
	221	u32 pers_next;
e27f928e JA	222	} ____cacheline_aligned_in_smp;
	223
	224	/* IRQ completion list, under ->completion_lock */
	225	struct io_wq_work_list locked_free_list;
	226	unsigned int locked_free_nr;
	227
	228	const struct cred sq_creds; / cred used for __io_sq_thread() */
	229	struct io_sq_data sq_data; / if using sq thread polling */
	230
	231	struct wait_queue_head sqo_sq_wait;
	232	struct list_head sqd_list;
	233
	234	unsigned long check_cq;
	235
	236	struct {
	237	/*
	238	* We cache a range of free CQEs we can use, once exhausted it
	239	* should go through a slower range setup, see __io_get_cqe()
	240	*/
	241	struct io_uring_cqe *cqe_cached;
	242	struct io_uring_cqe *cqe_sentinel;
	243
	244	unsigned cached_cq_tail;
	245	unsigned cq_entries;
	246	struct io_ev_fd __rcu *io_ev_fd;
	247	struct wait_queue_head cq_wait;
	248	unsigned cq_extra;
e27f928e JA	249	} ____cacheline_aligned_in_smp;
	250
	251	struct {
	252	spinlock_t completion_lock;
	253
e27f928e JA	254	/*
	255	* ->iopoll_list is protected by the ctx->uring_lock for
	256	* io_uring instances that don't use IORING_SETUP_SQPOLL.
	257	* For SQPOLL, only the single threaded io_sq_thread() will
	258	* manipulate the list, hence no extra locking is needed there.
	259	*/
	260	struct io_wq_work_list iopoll_list;
e6f89be6	261	struct io_hash_table cancel_table;
e27f928e JA	262	bool poll_multi_queue;
	263
	264	struct list_head io_buffers_comp;
	265	} ____cacheline_aligned_in_smp;
	266
aff5b2df PB	267	/* timeouts */
	268	struct {
	269	spinlock_t timeout_lock;
	270	atomic_t cq_timeouts;
	271	struct list_head timeout_list;
	272	struct list_head ltimeout_list;
	273	unsigned cq_last_tm_flush;
	274	} ____cacheline_aligned_in_smp;
	275
e27f928e	276	/* Keep this last, we don't need it for the fast path */
22eb2a3f PB	277
22eb2a3f PB	278	struct io_restriction restrictions;
97bbdc06	279	struct task_struct *submitter_task;
22eb2a3f PB	280
	281	/* slow path rsrc auxilary data, used by update/register */
	282	struct io_rsrc_node *rsrc_backup_node;
	283	struct io_mapped_ubuf *dummy_ubuf;
	284	struct io_rsrc_data *file_data;
	285	struct io_rsrc_data *buf_data;
	286
	287	struct delayed_work rsrc_put_work;
	288	struct llist_head rsrc_put_llist;
	289	struct list_head rsrc_ref_list;
	290	spinlock_t rsrc_ref_lock;
	291
	292	struct list_head io_buffers_pages;
	293
	294	#if defined(CONFIG_UNIX)
	295	struct socket *ring_sock;
	296	#endif
	297	/* hashed buffered write serialization */
	298	struct io_wq_hash *hash_map;
	299
	300	/* Only used for accounting purposes */
	301	struct user_struct *user;
	302	struct mm_struct *mm_account;
	303
	304	/* ctx exit and cancelation */
	305	struct llist_head fallback_llist;
	306	struct delayed_work fallback_work;
	307	struct work_struct exit_work;
	308	struct list_head tctx_list;
	309	struct completion ref_comp;
	310
	311	/* io-wq management, e.g. thread count */
	312	u32 iowq_limits[2];
	313	bool iowq_limits_set;
	314
	315	struct list_head defer_list;
	316	unsigned sq_thread_idle;
305bef98 PB	317	/* protected by ->completion_lock */
305bef98 PB	318	unsigned evfd_last_cq_tail;
e27f928e JA	319	};
	320
	321	enum {
	322	REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
	323	REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
	324	REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
	325	REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
	326	REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
	327	REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
	328	REQ_F_CQE_SKIP_BIT = IOSQE_CQE_SKIP_SUCCESS_BIT,
	329
	330	/* first byte is taken by user flags, shift it to not overlap */
	331	REQ_F_FAIL_BIT = 8,
	332	REQ_F_INFLIGHT_BIT,
	333	REQ_F_CUR_POS_BIT,
	334	REQ_F_NOWAIT_BIT,
	335	REQ_F_LINK_TIMEOUT_BIT,
	336	REQ_F_NEED_CLEANUP_BIT,
	337	REQ_F_POLLED_BIT,
	338	REQ_F_BUFFER_SELECTED_BIT,
	339	REQ_F_BUFFER_RING_BIT,
e27f928e JA	340	REQ_F_REISSUE_BIT,
	341	REQ_F_CREDS_BIT,
	342	REQ_F_REFCOUNT_BIT,
	343	REQ_F_ARM_LTIMEOUT_BIT,
	344	REQ_F_ASYNC_DATA_BIT,
	345	REQ_F_SKIP_LINK_CQES_BIT,
	346	REQ_F_SINGLE_POLL_BIT,
	347	REQ_F_DOUBLE_POLL_BIT,
	348	REQ_F_PARTIAL_IO_BIT,
	349	REQ_F_CQE32_INIT_BIT,
	350	REQ_F_APOLL_MULTISHOT_BIT,
	351	REQ_F_CLEAR_POLLIN_BIT,
9ca9fb24	352	REQ_F_HASH_LOCKED_BIT,
e27f928e JA	353	/* keep async read/write and isreg together and in order */
	354	REQ_F_SUPPORT_NOWAIT_BIT,
	355	REQ_F_ISREG_BIT,
	356
	357	/* not a real bit, just to check we're not overflowing the space */
	358	__REQ_F_LAST_BIT,
	359	};
	360
	361	enum {
	362	/* ctx owns file */
	363	REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
	364	/* drain existing IO first */
	365	REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
	366	/* linked sqes */
	367	REQ_F_LINK = BIT(REQ_F_LINK_BIT),
	368	/* doesn't sever on completion < 0 */
	369	REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
	370	/* IOSQE_ASYNC */
	371	REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
	372	/* IOSQE_BUFFER_SELECT */
	373	REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
	374	/* IOSQE_CQE_SKIP_SUCCESS */
	375	REQ_F_CQE_SKIP = BIT(REQ_F_CQE_SKIP_BIT),
	376
	377	/* fail rest of links */
	378	REQ_F_FAIL = BIT(REQ_F_FAIL_BIT),
	379	/* on inflight list, should be cancelled and waited on exit reliably */
	380	REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
	381	/* read/write uses file position */
	382	REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
	383	/* must not punt to workers */
	384	REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
	385	/* has or had linked timeout */
	386	REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
	387	/* needs cleanup */
	388	REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
	389	/* already went through poll handler */
	390	REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
	391	/* buffer already selected */
	392	REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
	393	/* buffer selected from ring, needs commit */
	394	REQ_F_BUFFER_RING = BIT(REQ_F_BUFFER_RING_BIT),
e27f928e JA	395	/* caller should reissue async */
	396	REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
	397	/* supports async reads/writes */
	398	REQ_F_SUPPORT_NOWAIT = BIT(REQ_F_SUPPORT_NOWAIT_BIT),
	399	/* regular file */
	400	REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
	401	/* has creds assigned */
	402	REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
	403	/* skip refcounting if not set */
	404	REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT),
	405	/* there is a linked timeout that has to be armed */
	406	REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT),
	407	/* ->async_data allocated */
	408	REQ_F_ASYNC_DATA = BIT(REQ_F_ASYNC_DATA_BIT),
	409	/* don't post CQEs while failing linked requests */
	410	REQ_F_SKIP_LINK_CQES = BIT(REQ_F_SKIP_LINK_CQES_BIT),
	411	/* single poll may be active */
	412	REQ_F_SINGLE_POLL = BIT(REQ_F_SINGLE_POLL_BIT),
	413	/* double poll may active */
	414	REQ_F_DOUBLE_POLL = BIT(REQ_F_DOUBLE_POLL_BIT),
	415	/* request has already done partial IO */
	416	REQ_F_PARTIAL_IO = BIT(REQ_F_PARTIAL_IO_BIT),
	417	/* fast poll multishot mode */
	418	REQ_F_APOLL_MULTISHOT = BIT(REQ_F_APOLL_MULTISHOT_BIT),
	419	/* ->extra1 and ->extra2 are initialised */
	420	REQ_F_CQE32_INIT = BIT(REQ_F_CQE32_INIT_BIT),
	421	/* recvmsg special flag, clear EPOLLIN */
	422	REQ_F_CLEAR_POLLIN = BIT(REQ_F_CLEAR_POLLIN_BIT),
9ca9fb24 PB	423	/* hashed into ->cancel_hash_locked, protected by ->uring_lock */
9ca9fb24 PB	424	REQ_F_HASH_LOCKED = BIT(REQ_F_HASH_LOCKED_BIT),
e27f928e JA	425	};
	426
	427	typedef void (io_req_tw_func_t)(struct io_kiocb req, bool *locked);
	428
	429	struct io_task_work {
	430	union {
f88262e6	431	struct llist_node node;
e27f928e JA	432	struct llist_node fallback_node;
	433	};
	434	io_req_tw_func_t func;
	435	};
	436
	437	struct io_cqe {
	438	__u64 user_data;
	439	__s32 res;
	440	/* fd initially, then cflags for completion */
	441	union {
	442	__u32 flags;
	443	int fd;
	444	};
	445	};
	446
	447	/*
	448	* Each request type overlays its private data structure on top of this one.
	449	* They must not exceed this one in size.
	450	*/
	451	struct io_cmd_data {
	452	struct file *file;
	453	/* each command gets 56 bytes of data */
	454	__u8 data[56];
	455	};
	456
	457	#define io_kiocb_to_cmd(req) ((void *) &(req)->cmd)
	458	#define cmd_to_io_kiocb(ptr) ((struct io_kiocb *) ptr)
	459
	460	struct io_kiocb {
	461	union {
	462	/*
	463	* NOTE! Each of the io_kiocb union members has the file pointer
	464	* as the first entry in their struct definition. So you can
	465	* access the file pointer through any of the sub-structs,
	466	* or directly as just 'file' in this struct.
	467	*/
	468	struct file *file;
	469	struct io_cmd_data cmd;
	470	};
	471
	472	u8 opcode;
	473	/* polled IO has completed */
	474	u8 iopoll_completed;
	475	/*
	476	* Can be either a fixed buffer index, or used with provided buffers.
	477	* For the latter, before issue it points to the buffer group ID,
	478	* and after selection it points to the buffer ID itself.
	479	*/
	480	u16 buf_index;
	481	unsigned int flags;
	482
	483	struct io_cqe cqe;
	484
	485	struct io_ring_ctx *ctx;
	486	struct task_struct *task;
	487
	488	struct io_rsrc_node *rsrc_node;
	489
	490	union {
	491	/* store used ubuf, so we can prevent reloading */
	492	struct io_mapped_ubuf *imu;
	493
	494	/* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
	495	struct io_buffer *kbuf;
496
497	/*
498	* stores buffer ID for ring provided buffers, valid IFF
499	* REQ_F_BUFFER_RING is set.
500	*/
501	struct io_buffer_list *buf_list;
502	};
503
504	union {
505	/* used by request caches, completion batching and iopoll */
506	struct io_wq_work_node comp_list;
507	/* cache ->apoll->events */
508	__poll_t apoll_events;
509	};
510	atomic_t refs;
511	atomic_t poll_refs;
512	struct io_task_work io_task_work;
513	/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
514	union {
515	struct hlist_node hash_node;
516	struct {
517	u64 extra1;
518	u64 extra2;
519	};
520	};
521	/* internal polling, see IORING_FEAT_FAST_POLL */
522	struct async_poll *apoll;
523	/* opcode allocated if it needs to store data for async defer */
524	void *async_data;
525	/* linked requests, IFF REQ_F_HARDLINK or REQ_F_LINK are set */
526	struct io_kiocb *link;
527	/* custom credentials, valid IFF REQ_F_CREDS is set */
528	const struct cred *creds;
529	struct io_wq_work work;
530	};
531
a4ad4f74 JA	532	struct io_overflow_cqe {
	533	struct list_head list;
	534	struct io_uring_cqe cqe;
	535	};
	536
e27f928e	537	#endif