diff options
Diffstat (limited to 'include/linux/io_uring_types.h')
| -rw-r--r-- | include/linux/io_uring_types.h | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h new file mode 100644 index 000000000..5fd664fb7 --- /dev/null +++ b/include/linux/io_uring_types.h @@ -0,0 +1,609 @@ +#ifndef IO_URING_TYPES_H +#define IO_URING_TYPES_H + +#include <linux/blkdev.h> +#include <linux/task_work.h> +#include <linux/bitmap.h> +#include <linux/llist.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; +}; + +/* + * 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 |