#ifndef IO_URING_TYPES_H #define IO_URING_TYPES_H #include #include #include #include #include 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; }; /* * Arbitrary limit, can be raised if need be */ #define IO_RINGFD_REG_MAX 16 struct io_uring_task { /* submission side */ int cached_refs; const struct io_ring_ctx *last; struct io_wq *io_wq; struct file *registered_rings[IO_RINGFD_REG_MAX]; struct xarray xa; struct wait_queue_head wait; atomic_t in_cancel; atomic_t inflight_tracked; struct percpu_counter inflight; struct { /* task_work */ struct llist_head task_list; struct callback_head task_work; } ____cacheline_aligned_in_smp; }; struct io_uring { u32 head; u32 tail; }; /* * 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; unsigned int cqes_count; struct blk_plug plug; }; struct io_ev_fd { struct eventfd_ctx *cq_ev_fd; unsigned int eventfd_async: 1; struct rcu_head rcu; atomic_t refs; atomic_t ops; }; struct io_alloc_cache { struct io_wq_work_node list; unsigned int nr_cached; unsigned int max_cached; size_t elem_size; }; struct io_ring_ctx { /* const or read-mostly hot data */ struct { unsigned int flags; unsigned int drain_next: 1; unsigned int restricted: 1; unsigned int off_timeout_used: 1; unsigned int drain_active: 1; unsigned int has_evfd: 1; /* all CQEs should be posted only by the submitter task */ unsigned int task_complete: 1; unsigned int lockless_cq: 1; unsigned int syscall_iopoll: 1; unsigned int poll_activated: 1; unsigned int drain_disabled: 1; unsigned int compat: 1; struct task_struct *submitter_task; struct io_rings *rings; struct percpu_ref refs; enum task_work_notify_mode notify_method; } ____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; 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 io_hash_table cancel_table_locked; struct io_alloc_cache apoll_cache; struct io_alloc_cache netmsg_cache; /* * ->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; bool poll_multi_queue; } ____cacheline_aligned_in_smp; 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; unsigned cq_extra; } ____cacheline_aligned_in_smp; /* * task_work and async notification delivery cacheline. Expected to * regularly bounce b/w CPUs. */ struct { struct llist_head work_llist; unsigned long check_cq; atomic_t cq_wait_nr; atomic_t cq_timeouts; struct wait_queue_head cq_wait; } ____cacheline_aligned_in_smp; /* timeouts */ struct { spinlock_t timeout_lock; struct list_head timeout_list; struct list_head ltimeout_list; unsigned cq_last_tm_flush; } ____cacheline_aligned_in_smp; struct io_uring_cqe completion_cqes[16]; spinlock_t completion_lock; /* IRQ completion list, under ->completion_lock */ struct io_wq_work_list locked_free_list; unsigned int locked_free_nr; struct list_head io_buffers_comp; struct list_head cq_overflow_list; struct io_hash_table cancel_table; 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 int file_alloc_start; unsigned int file_alloc_end; struct xarray personalities; u32 pers_next; struct list_head io_buffers_cache; /* deferred free list, protected by ->uring_lock */ struct hlist_head io_buf_list; /* Keep this last, we don't need it for the fast path */ struct wait_queue_head poll_wq; struct io_restriction restrictions; /* slow path rsrc auxilary data, used by update/register */ struct io_mapped_ubuf *dummy_ubuf; struct io_rsrc_data *file_data; struct io_rsrc_data *buf_data; /* protected by ->uring_lock */ struct list_head rsrc_ref_list; struct io_alloc_cache rsrc_node_cache; struct wait_queue_head rsrc_quiesce_wq; unsigned rsrc_quiesce; 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 callback_head poll_wq_task_work; struct list_head defer_list; unsigned sq_thread_idle; /* protected by ->completion_lock */ unsigned evfd_last_cq_tail; /* * If IORING_SETUP_NO_MMAP is used, then the below holds * the gup'ed pages for the two rings, and the sqes. */ unsigned short n_ring_pages; unsigned short n_sqe_pages; struct page **ring_pages; struct page **sqe_pages; }; struct io_tw_state { /* ->uring_lock is taken, callbacks can use io_tw_lock to lock it */ bool locked; }; 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_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), /* 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, struct io_tw_state *ts); struct io_task_work { struct llist_node 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]; }; static inline void io_kiocb_cmd_sz_check(size_t cmd_sz) { BUILD_BUG_ON(cmd_sz > sizeof(struct io_cmd_data)); } #define io_kiocb_to_cmd(req, cmd_type) ( \ io_kiocb_cmd_sz_check(sizeof(cmd_type)) , \ ((cmd_type *)&(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; unsigned nr_tw; /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ struct hlist_node hash_node; /* 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 { u64 extra1; u64 extra2; } big_cqe; }; struct io_overflow_cqe { struct list_head list; struct io_uring_cqe cqe; }; #endif