diff options
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 5874 |
1 files changed, 4796 insertions, 1078 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 24bbe3cb7ad4..5a826017ebb8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -46,6 +46,7 @@ #include <linux/compat.h> #include <linux/refcount.h> #include <linux/uio.h> +#include <linux/bits.h> #include <linux/sched/signal.h> #include <linux/fs.h> @@ -56,7 +57,6 @@ #include <linux/mmu_context.h> #include <linux/percpu.h> #include <linux/slab.h> -#include <linux/workqueue.h> #include <linux/kthread.h> #include <linux/blkdev.h> #include <linux/bvec.h> @@ -70,13 +70,31 @@ #include <linux/nospec.h> #include <linux/sizes.h> #include <linux/hugetlb.h> +#include <linux/highmem.h> +#include <linux/namei.h> +#include <linux/fsnotify.h> +#include <linux/fadvise.h> +#include <linux/eventpoll.h> +#include <linux/fs_struct.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/io_uring.h> #include <uapi/linux/io_uring.h> #include "internal.h" +#include "io-wq.h" -#define IORING_MAX_ENTRIES 4096 -#define IORING_MAX_FIXED_FILES 1024 +#define IORING_MAX_ENTRIES 32768 +#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) + +/* + * Shift of 9 is 512 entries, or exactly one page on 64-bit archs + */ +#define IORING_FILE_TABLE_SHIFT 9 +#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT) +#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1) +#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE) struct io_uring { u32 head ____cacheline_aligned_in_smp; @@ -84,27 +102,29 @@ struct io_uring { }; /* - * This data is shared with the application through the mmap at offset - * IORING_OFF_SQ_RING. + * 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_sq_ring { +struct io_rings { /* * Head and tail offsets into the ring; the offsets need to be * masked to get valid indices. * - * The kernel controls head and the application controls tail. + * 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 r; + struct io_uring sq, cq; /* - * Bitmask to apply to head and tail offsets (constant, equals + * Bitmasks to apply to head and tail offsets (constant, equals * ring_entries - 1) */ - u32 ring_mask; - /* Ring size (constant, power of 2) */ - u32 ring_entries; + 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 @@ -117,7 +137,7 @@ struct io_sq_ring { * counter includes all submissions that were dropped reaching * the new SQ head (and possibly more). */ - u32 dropped; + u32 sq_dropped; /* * Runtime flags * @@ -127,47 +147,11 @@ struct io_sq_ring { * The application needs a full memory barrier before checking * for IORING_SQ_NEED_WAKEUP after updating the sq tail. */ - u32 flags; - /* - * 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 array[]; -}; - -/* - * This data is shared with the application through the mmap at offset - * IORING_OFF_CQ_RING. - * - * The offsets to the member fields are published through struct - * io_cqring_offsets when calling io_uring_setup. - */ -struct io_cq_ring { - /* - * Head and tail offsets into the ring; the offsets need to be - * masked to get valid indices. - * - * The application controls head and the kernel tail. - */ - struct io_uring r; - /* - * Bitmask to apply to head and tail offsets (constant, equals - * ring_entries - 1) - */ - u32 ring_mask; - /* Ring size (constant, power of 2) */ - u32 ring_entries; + u32 sq_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 thatn there is space in + * there are not more requests pending than there is space in * the completion queue. * * Written by the kernel, shouldn't be modified by the @@ -177,7 +161,7 @@ struct io_cq_ring { * As completion events come in out of order this counter is not * ordered with any other data. */ - u32 overflow; + u32 cq_overflow; /* * Ring buffer of completion events. * @@ -185,7 +169,7 @@ struct io_cq_ring { * produced, so the application is allowed to modify pending * entries. */ - struct io_uring_cqe cqes[]; + struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; }; struct io_mapped_ubuf { @@ -195,14 +179,23 @@ struct io_mapped_ubuf { unsigned int nr_bvecs; }; -struct async_list { - spinlock_t lock; - atomic_t cnt; - struct list_head list; +struct fixed_file_table { + struct file **files; +}; - struct file *file; - off_t io_end; - size_t io_len; +enum { + FFD_F_ATOMIC, +}; + +struct fixed_file_data { + struct fixed_file_table *table; + struct io_ring_ctx *ctx; + + struct percpu_ref refs; + struct llist_head put_llist; + unsigned long state; + struct work_struct ref_work; + struct completion done; }; struct io_ring_ctx { @@ -212,45 +205,57 @@ struct io_ring_ctx { struct { unsigned int flags; - bool compat; - bool account_mem; + unsigned int compat: 1; + unsigned int account_mem: 1; + unsigned int cq_overflow_flushed: 1; + unsigned int drain_next: 1; + unsigned int eventfd_async: 1; - /* SQ ring */ - struct io_sq_ring *sq_ring; + /* + * 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; unsigned cached_sq_head; unsigned sq_entries; unsigned sq_mask; unsigned sq_thread_idle; - struct io_uring_sqe *sq_sqes; + unsigned cached_sq_dropped; + atomic_t cached_cq_overflow; + unsigned long sq_check_overflow; struct list_head defer_list; + struct list_head timeout_list; + struct list_head cq_overflow_list; + + wait_queue_head_t inflight_wait; + struct io_uring_sqe *sq_sqes; } ____cacheline_aligned_in_smp; + struct io_rings *rings; + /* IO offload */ - struct workqueue_struct *sqo_wq; + struct io_wq *io_wq; struct task_struct *sqo_thread; /* if using sq thread polling */ struct mm_struct *sqo_mm; wait_queue_head_t sqo_wait; - struct completion sqo_thread_started; - - struct { - /* CQ ring */ - struct io_cq_ring *cq_ring; - unsigned cached_cq_tail; - unsigned cq_entries; - unsigned cq_mask; - struct wait_queue_head cq_wait; - struct fasync_struct *cq_fasync; - struct eventfd_ctx *cq_ev_fd; - } ____cacheline_aligned_in_smp; /* * If used, fixed file set. Writers must ensure that ->refs is dead, * readers must ensure that ->refs is alive as long as the file* is * used. Only updated through io_uring_register(2). */ - struct file **user_files; + struct fixed_file_data *file_data; unsigned nr_user_files; + int ring_fd; + struct file *ring_file; /* if used, fixed mapped user buffers */ unsigned nr_user_bufs; @@ -258,7 +263,30 @@ struct io_ring_ctx { struct user_struct *user; - struct completion ctx_done; + const struct cred *creds; + + /* 0 is for ctx quiesce/reinit/free, 1 is for sqo_thread started */ + struct completion *completions; + + /* if all else fails... */ + struct io_kiocb *fallback_req; + +#if defined(CONFIG_UNIX) + struct socket *ring_sock; +#endif + + struct idr personality_idr; + + struct { + unsigned cached_cq_tail; + unsigned cq_entries; + unsigned cq_mask; + atomic_t cq_timeouts; + unsigned long cq_check_overflow; + struct wait_queue_head cq_wait; + struct fasync_struct *cq_fasync; + struct eventfd_ctx *cq_ev_fd; + } ____cacheline_aligned_in_smp; struct { struct mutex uring_lock; @@ -267,7 +295,8 @@ struct io_ring_ctx { struct { spinlock_t completion_lock; - bool poll_multi_file; + struct llist_head poll_llist; + /* * ->poll_list is protected by the ctx->uring_lock for * io_uring instances that don't use IORING_SETUP_SQPOLL. @@ -275,22 +304,13 @@ struct io_ring_ctx { * manipulate the list, hence no extra locking is needed there. */ struct list_head poll_list; - struct list_head cancel_list; - } ____cacheline_aligned_in_smp; - - struct async_list pending_async[2]; - -#if defined(CONFIG_UNIX) - struct socket *ring_sock; -#endif -}; + struct hlist_head *cancel_hash; + unsigned cancel_hash_bits; + bool poll_multi_file; -struct sqe_submit { - const struct io_uring_sqe *sqe; - unsigned short index; - bool has_user; - bool needs_lock; - bool needs_fixed_file; + spinlock_t inflight_lock; + struct list_head inflight_list; + } ____cacheline_aligned_in_smp; }; /* @@ -299,13 +319,213 @@ struct sqe_submit { */ struct io_poll_iocb { struct file *file; - struct wait_queue_head *head; + union { + struct wait_queue_head *head; + u64 addr; + }; __poll_t events; bool done; bool canceled; struct wait_queue_entry wait; }; +struct io_close { + struct file *file; + struct file *put_file; + int fd; +}; + +struct io_timeout_data { + struct io_kiocb *req; + struct hrtimer timer; + struct timespec64 ts; + enum hrtimer_mode mode; + u32 seq_offset; +}; + +struct io_accept { + struct file *file; + struct sockaddr __user *addr; + int __user *addr_len; + int flags; +}; + +struct io_sync { + struct file *file; + loff_t len; + loff_t off; + int flags; + int mode; +}; + +struct io_cancel { + struct file *file; + u64 addr; +}; + +struct io_timeout { + struct file *file; + u64 addr; + int flags; + unsigned count; +}; + +struct io_rw { + /* NOTE: kiocb has the file as the first member, so don't do it here */ + struct kiocb kiocb; + u64 addr; + u64 len; +}; + +struct io_connect { + struct file *file; + struct sockaddr __user *addr; + int addr_len; +}; + +struct io_sr_msg { + struct file *file; + union { + struct user_msghdr __user *msg; + void __user *buf; + }; + int msg_flags; + size_t len; +}; + +struct io_open { + struct file *file; + int dfd; + union { + unsigned mask; + }; + struct filename *filename; + struct statx __user *buffer; + struct open_how how; +}; + +struct io_files_update { + struct file *file; + u64 arg; + u32 nr_args; + u32 offset; +}; + +struct io_fadvise { + struct file *file; + u64 offset; + u32 len; + u32 advice; +}; + +struct io_madvise { + struct file *file; + u64 addr; + u32 len; + u32 advice; +}; + +struct io_epoll { + struct file *file; + int epfd; + int op; + int fd; + struct epoll_event event; +}; + +struct io_async_connect { + struct sockaddr_storage address; +}; + +struct io_async_msghdr { + struct iovec fast_iov[UIO_FASTIOV]; + struct iovec *iov; + struct sockaddr __user *uaddr; + struct msghdr msg; + struct sockaddr_storage addr; +}; + +struct io_async_rw { + struct iovec fast_iov[UIO_FASTIOV]; + struct iovec *iov; + ssize_t nr_segs; + ssize_t size; +}; + +struct io_async_ctx { + union { + struct io_async_rw rw; + struct io_async_msghdr msg; + struct io_async_connect connect; + struct io_timeout_data timeout; + }; +}; + +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_LINK_NEXT_BIT, + REQ_F_FAIL_LINK_BIT, + REQ_F_INFLIGHT_BIT, + REQ_F_CUR_POS_BIT, + REQ_F_NOWAIT_BIT, + REQ_F_IOPOLL_COMPLETED_BIT, + REQ_F_LINK_TIMEOUT_BIT, + REQ_F_TIMEOUT_BIT, + REQ_F_ISREG_BIT, + REQ_F_MUST_PUNT_BIT, + REQ_F_TIMEOUT_NOSEQ_BIT, + REQ_F_COMP_LOCKED_BIT, + REQ_F_NEED_CLEANUP_BIT, + REQ_F_OVERFLOW_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), + + /* already grabbed next link */ + REQ_F_LINK_NEXT = BIT(REQ_F_LINK_NEXT_BIT), + /* fail rest of links */ + REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT), + /* on inflight list */ + 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), + /* polled IO has completed */ + REQ_F_IOPOLL_COMPLETED = BIT(REQ_F_IOPOLL_COMPLETED_BIT), + /* has linked timeout */ + REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT), + /* timeout request */ + REQ_F_TIMEOUT = BIT(REQ_F_TIMEOUT_BIT), + /* regular file */ + REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), + /* must be punted even for NONBLOCK */ + REQ_F_MUST_PUNT = BIT(REQ_F_MUST_PUNT_BIT), + /* no timeout sequence */ + REQ_F_TIMEOUT_NOSEQ = BIT(REQ_F_TIMEOUT_NOSEQ_BIT), + /* completion under lock */ + REQ_F_COMP_LOCKED = BIT(REQ_F_COMP_LOCKED_BIT), + /* needs cleanup */ + REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT), + /* in overflow list */ + REQ_F_OVERFLOW = BIT(REQ_F_OVERFLOW_BIT), +}; + /* * NOTE! Each of the iocb union members has the file pointer * as the first entry in their struct definition. So you can @@ -315,31 +535,46 @@ struct io_poll_iocb { struct io_kiocb { union { struct file *file; - struct kiocb rw; + struct io_rw rw; struct io_poll_iocb poll; + struct io_accept accept; + struct io_sync sync; + struct io_cancel cancel; + struct io_timeout timeout; + struct io_connect connect; + struct io_sr_msg sr_msg; + struct io_open open; + struct io_close close; + struct io_files_update files_update; + struct io_fadvise fadvise; + struct io_madvise madvise; + struct io_epoll epoll; }; - struct sqe_submit submit; + struct io_async_ctx *io; + /* + * llist_node is only used for poll deferred completions + */ + struct llist_node llist_node; + bool in_async; + bool needs_fixed_file; + u8 opcode; struct io_ring_ctx *ctx; - struct list_head list; + union { + struct list_head list; + struct hlist_node hash_node; + }; struct list_head link_list; unsigned int flags; refcount_t refs; -#define REQ_F_NOWAIT 1 /* must not punt to workers */ -#define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ -#define REQ_F_FIXED_FILE 4 /* ctx owns file */ -#define REQ_F_SEQ_PREV 8 /* sequential with previous */ -#define REQ_F_IO_DRAIN 16 /* drain existing IO first */ -#define REQ_F_IO_DRAINED 32 /* drain done */ -#define REQ_F_LINK 64 /* linked sqes */ -#define REQ_F_LINK_DONE 128 /* linked sqes done */ -#define REQ_F_FAIL_LINK 256 /* fail rest of links */ u64 user_data; u32 result; u32 sequence; - struct work_struct work; + struct list_head inflight_entry; + + struct io_wq_work work; }; #define IO_PLUG_THRESHOLD 2 @@ -352,8 +587,7 @@ struct io_submit_state { * io_kiocb alloc cache */ void *reqs[IO_IOPOLL_BATCH]; - unsigned int free_reqs; - unsigned int cur_req; + unsigned int free_reqs; /* * File reference cache @@ -365,7 +599,171 @@ struct io_submit_state { unsigned int ios_left; }; -static void io_sq_wq_submit_work(struct work_struct *work); +struct io_op_def { + /* needs req->io allocated for deferral/async */ + unsigned async_ctx : 1; + /* needs current->mm setup, does mm access */ + unsigned needs_mm : 1; + /* needs req->file assigned */ + unsigned needs_file : 1; + /* needs req->file assigned IFF fd is >= 0 */ + unsigned fd_non_neg : 1; + /* hash wq insertion if file is a regular file */ + unsigned hash_reg_file : 1; + /* unbound wq insertion if file is a non-regular file */ + unsigned unbound_nonreg_file : 1; + /* opcode is not supported by this kernel */ + unsigned not_supported : 1; + /* needs file table */ + unsigned file_table : 1; + /* needs ->fs */ + unsigned needs_fs : 1; +}; + +static const struct io_op_def io_op_defs[] = { + [IORING_OP_NOP] = {}, + [IORING_OP_READV] = { + .async_ctx = 1, + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_WRITEV] = { + .async_ctx = 1, + .needs_mm = 1, + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_FSYNC] = { + .needs_file = 1, + }, + [IORING_OP_READ_FIXED] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_WRITE_FIXED] = { + .needs_file = 1, + .hash_reg_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_POLL_ADD] = { + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_POLL_REMOVE] = {}, + [IORING_OP_SYNC_FILE_RANGE] = { + .needs_file = 1, + }, + [IORING_OP_SENDMSG] = { + .async_ctx = 1, + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + .needs_fs = 1, + }, + [IORING_OP_RECVMSG] = { + .async_ctx = 1, + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + .needs_fs = 1, + }, + [IORING_OP_TIMEOUT] = { + .async_ctx = 1, + .needs_mm = 1, + }, + [IORING_OP_TIMEOUT_REMOVE] = {}, + [IORING_OP_ACCEPT] = { + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + .file_table = 1, + }, + [IORING_OP_ASYNC_CANCEL] = {}, + [IORING_OP_LINK_TIMEOUT] = { + .async_ctx = 1, + .needs_mm = 1, + }, + [IORING_OP_CONNECT] = { + .async_ctx = 1, + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_FALLOCATE] = { + .needs_file = 1, + }, + [IORING_OP_OPENAT] = { + .needs_file = 1, + .fd_non_neg = 1, + .file_table = 1, + .needs_fs = 1, + }, + [IORING_OP_CLOSE] = { + .needs_file = 1, + .file_table = 1, + }, + [IORING_OP_FILES_UPDATE] = { + .needs_mm = 1, + .file_table = 1, + }, + [IORING_OP_STATX] = { + .needs_mm = 1, + .needs_file = 1, + .fd_non_neg = 1, + .needs_fs = 1, + }, + [IORING_OP_READ] = { + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_WRITE] = { + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_FADVISE] = { + .needs_file = 1, + }, + [IORING_OP_MADVISE] = { + .needs_mm = 1, + }, + [IORING_OP_SEND] = { + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_RECV] = { + .needs_mm = 1, + .needs_file = 1, + .unbound_nonreg_file = 1, + }, + [IORING_OP_OPENAT2] = { + .needs_file = 1, + .fd_non_neg = 1, + .file_table = 1, + .needs_fs = 1, + }, + [IORING_OP_EPOLL_CTL] = { + .unbound_nonreg_file = 1, + .file_table = 1, + }, +}; + +static void io_wq_submit_work(struct io_wq_work **workptr); +static void io_cqring_fill_event(struct io_kiocb *req, long res); +static void io_put_req(struct io_kiocb *req); +static void __io_double_put_req(struct io_kiocb *req); +static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req); +static void io_queue_linked_timeout(struct io_kiocb *req); +static int __io_sqe_files_update(struct io_ring_ctx *ctx, + struct io_uring_files_update *ip, + unsigned nr_args); +static int io_grab_files(struct io_kiocb *req); +static void io_ring_file_ref_flush(struct fixed_file_data *data); +static void io_cleanup_req(struct io_kiocb *req); static struct kmem_cache *req_cachep; @@ -388,60 +786,93 @@ static void io_ring_ctx_ref_free(struct percpu_ref *ref) { struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); - complete(&ctx->ctx_done); + complete(&ctx->completions[0]); } static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) { struct io_ring_ctx *ctx; - int i; + int hash_bits; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return NULL; + ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL); + if (!ctx->fallback_req) + goto err; + + ctx->completions = kmalloc(2 * sizeof(struct completion), GFP_KERNEL); + if (!ctx->completions) + goto err; + + /* + * Use 5 bits less than the max cq entries, that should give us around + * 32 entries per hash list if totally full and uniformly spread. + */ + hash_bits = ilog2(p->cq_entries); + hash_bits -= 5; + if (hash_bits <= 0) + hash_bits = 1; + ctx->cancel_hash_bits = hash_bits; + ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head), + GFP_KERNEL); + if (!ctx->cancel_hash) + goto err; + __hash_init(ctx->cancel_hash, 1U << hash_bits); + if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, - PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { - kfree(ctx); - return NULL; - } + PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) + goto err; ctx->flags = p->flags; init_waitqueue_head(&ctx->cq_wait); - init_completion(&ctx->ctx_done); - init_completion(&ctx->sqo_thread_started); + INIT_LIST_HEAD(&ctx->cq_overflow_list); + init_completion(&ctx->completions[0]); + init_completion(&ctx->completions[1]); + idr_init(&ctx->personality_idr); mutex_init(&ctx->uring_lock); init_waitqueue_head(&ctx->wait); - for (i = 0; i < ARRAY_SIZE(ctx->pending_async); i++) { - spin_lock_init(&ctx->pending_async[i].lock); - INIT_LIST_HEAD(&ctx->pending_async[i].list); - atomic_set(&ctx->pending_async[i].cnt, 0); - } spin_lock_init(&ctx->completion_lock); + init_llist_head(&ctx->poll_llist); INIT_LIST_HEAD(&ctx->poll_list); - INIT_LIST_HEAD(&ctx->cancel_list); INIT_LIST_HEAD(&ctx->defer_list); + INIT_LIST_HEAD(&ctx->timeout_list); + init_waitqueue_head(&ctx->inflight_wait); + spin_lock_init(&ctx->inflight_lock); + INIT_LIST_HEAD(&ctx->inflight_list); return ctx; +err: + if (ctx->fallback_req) + kmem_cache_free(req_cachep, ctx->fallback_req); + kfree(ctx->completions); + kfree(ctx->cancel_hash); + kfree(ctx); + return NULL; } -static inline bool io_sequence_defer(struct io_ring_ctx *ctx, - struct io_kiocb *req) +static inline bool __req_need_defer(struct io_kiocb *req) { - if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN) - return false; + struct io_ring_ctx *ctx = req->ctx; - return req->sequence != ctx->cached_cq_tail + ctx->sq_ring->dropped; + return req->sequence != ctx->cached_cq_tail + ctx->cached_sq_dropped + + atomic_read(&ctx->cached_cq_overflow); +} + +static inline bool req_need_defer(struct io_kiocb *req) +{ + if (unlikely(req->flags & REQ_F_IO_DRAIN)) + return __req_need_defer(req); + + return false; } static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) { struct io_kiocb *req; - if (list_empty(&ctx->defer_list)) - return NULL; - - req = list_first_entry(&ctx->defer_list, struct io_kiocb, list); - if (!io_sequence_defer(ctx, req)) { + req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list); + if (req && !req_need_defer(req)) { list_del_init(&req->list); return req; } @@ -449,36 +880,161 @@ static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) return NULL; } +static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + + req = list_first_entry_or_null(&ctx->timeout_list, struct io_kiocb, list); + if (req) { + if (req->flags & REQ_F_TIMEOUT_NOSEQ) + return NULL; + if (!__req_need_defer(req)) { + list_del_init(&req->list); + return req; + } + } + + return NULL; +} + static void __io_commit_cqring(struct io_ring_ctx *ctx) { - struct io_cq_ring *ring = ctx->cq_ring; + struct io_rings *rings = ctx->rings; - if (ctx->cached_cq_tail != READ_ONCE(ring->r.tail)) { - /* order cqe stores with ring update */ - smp_store_release(&ring->r.tail, ctx->cached_cq_tail); + /* order cqe stores with ring update */ + smp_store_release(&rings->cq.tail, ctx->cached_cq_tail); - if (wq_has_sleeper(&ctx->cq_wait)) { - wake_up_interruptible(&ctx->cq_wait); - kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); + if (wq_has_sleeper(&ctx->cq_wait)) { + wake_up_interruptible(&ctx->cq_wait); + kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); + } +} + +static inline void io_req_work_grab_env(struct io_kiocb *req, + const struct io_op_def *def) +{ + if (!req->work.mm && def->needs_mm) { + mmgrab(current->mm); + req->work.mm = current->mm; + } + if (!req->work.creds) + req->work.creds = get_current_cred(); + if (!req->work.fs && def->needs_fs) { + spin_lock(¤t->fs->lock); + if (!current->fs->in_exec) { + req->work.fs = current->fs; + req->work.fs->users++; + } else { + req->work.flags |= IO_WQ_WORK_CANCEL; } + spin_unlock(¤t->fs->lock); + } + if (!req->work.task_pid) + req->work.task_pid = task_pid_vnr(current); +} + +static inline void io_req_work_drop_env(struct io_kiocb *req) +{ + if (req->work.mm) { + mmdrop(req->work.mm); + req->work.mm = NULL; + } + if (req->work.creds) { + put_cred(req->work.creds); + req->work.creds = NULL; + } + if (req->work.fs) { + struct fs_struct *fs = req->work.fs; + + spin_lock(&req->work.fs->lock); + if (--fs->users) + fs = NULL; + spin_unlock(&req->work.fs->lock); + if (fs) + free_fs_struct(fs); } } +static inline bool io_prep_async_work(struct io_kiocb *req, + struct io_kiocb **link) +{ + const struct io_op_def *def = &io_op_defs[req->opcode]; + bool do_hashed = false; + + if (req->flags & REQ_F_ISREG) { + if (def->hash_reg_file) + do_hashed = true; + } else { + if (def->unbound_nonreg_file) + req->work.flags |= IO_WQ_WORK_UNBOUND; + } + + io_req_work_grab_env(req, def); + + *link = io_prep_linked_timeout(req); + return do_hashed; +} + +static inline void io_queue_async_work(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *link; + bool do_hashed; + + do_hashed = io_prep_async_work(req, &link); + + trace_io_uring_queue_async_work(ctx, do_hashed, req, &req->work, + req->flags); + if (!do_hashed) { + io_wq_enqueue(ctx->io_wq, &req->work); + } else { + io_wq_enqueue_hashed(ctx->io_wq, &req->work, + file_inode(req->file)); + } + + if (link) + io_queue_linked_timeout(link); +} + +static void io_kill_timeout(struct io_kiocb *req) +{ + int ret; + + ret = hrtimer_try_to_cancel(&req->io->timeout.timer); + if (ret != -1) { + atomic_inc(&req->ctx->cq_timeouts); + list_del_init(&req->list); + io_cqring_fill_event(req, 0); + io_put_req(req); + } +} + +static void io_kill_timeouts(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req, *tmp; + + spin_lock_irq(&ctx->completion_lock); + list_for_each_entry_safe(req, tmp, &ctx->timeout_list, list) + io_kill_timeout(req); + spin_unlock_irq(&ctx->completion_lock); +} + static void io_commit_cqring(struct io_ring_ctx *ctx) { struct io_kiocb *req; + while ((req = io_get_timeout_req(ctx)) != NULL) + io_kill_timeout(req); + __io_commit_cqring(ctx); - while ((req = io_get_deferred_req(ctx)) != NULL) { - req->flags |= REQ_F_IO_DRAINED; - queue_work(ctx->sqo_wq, &req->work); - } + while ((req = io_get_deferred_req(ctx)) != NULL) + io_queue_async_work(req); } static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) { - struct io_cq_ring *ring = ctx->cq_ring; + struct io_rings *rings = ctx->rings; unsigned tail; tail = ctx->cached_cq_tail; @@ -487,64 +1043,157 @@ static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) * control dependency is enough as we're using WRITE_ONCE to * fill the cq entry */ - if (tail - READ_ONCE(ring->r.head) == ring->ring_entries) + if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries) return NULL; ctx->cached_cq_tail++; - return &ring->cqes[tail & ctx->cq_mask]; + return &rings->cqes[tail & ctx->cq_mask]; +} + +static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) +{ + if (!ctx->cq_ev_fd) + return false; + if (!ctx->eventfd_async) + return true; + return io_wq_current_is_worker() || in_interrupt(); +} + +static void __io_cqring_ev_posted(struct io_ring_ctx *ctx, bool trigger_ev) +{ + if (waitqueue_active(&ctx->wait)) + wake_up(&ctx->wait); + if (waitqueue_active(&ctx->sqo_wait)) + wake_up(&ctx->sqo_wait); + if (trigger_ev) + eventfd_signal(ctx->cq_ev_fd, 1); +} + +static void io_cqring_ev_posted(struct io_ring_ctx *ctx) +{ + __io_cqring_ev_posted(ctx, io_should_trigger_evfd(ctx)); +} + +/* Returns true if there are no backlogged entries after the flush */ +static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) +{ + struct io_rings *rings = ctx->rings; + struct io_uring_cqe *cqe; + struct io_kiocb *req; + unsigned long flags; + LIST_HEAD(list); + + if (!force) { + if (list_empty_careful(&ctx->cq_overflow_list)) + return true; + if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) == + rings->cq_ring_entries)) + return false; + } + + spin_lock_irqsave(&ctx->completion_lock, flags); + + /* if force is set, the ring is going away. always drop after that */ + if (force) + ctx->cq_overflow_flushed = 1; + + cqe = NULL; + while (!list_empty(&ctx->cq_overflow_list)) { + cqe = io_get_cqring(ctx); + if (!cqe && !force) + break; + + req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb, + list); + list_move(&req->list, &list); + req->flags &= ~REQ_F_OVERFLOW; + if (cqe) { + WRITE_ONCE(cqe->user_data, req->user_data); + WRITE_ONCE(cqe->res, req->result); + WRITE_ONCE(cqe->flags, 0); + } else { + WRITE_ONCE(ctx->rings->cq_overflow, + atomic_inc_return(&ctx->cached_cq_overflow)); + } + } + + io_commit_cqring(ctx); + if (cqe) { + clear_bit(0, &ctx->sq_check_overflow); + clear_bit(0, &ctx->cq_check_overflow); + } + spin_unlock_irqrestore(&ctx->completion_lock, flags); + io_cqring_ev_posted(ctx); + + while (!list_empty(&list)) { + req = list_first_entry(&list, struct io_kiocb, list); + list_del(&req->list); + io_put_req(req); + } + + return cqe != NULL; } -static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data, - long res) +static void io_cqring_fill_event(struct io_kiocb *req, long res) { + struct io_ring_ctx *ctx = req->ctx; struct io_uring_cqe *cqe; + trace_io_uring_complete(ctx, req->user_data, res); + /* * If we can't get a cq entry, userspace overflowed the * submission (by quite a lot). Increment the overflow count in * the ring. */ cqe = io_get_cqring(ctx); - if (cqe) { - WRITE_ONCE(cqe->user_data, ki_user_data); + if (likely(cqe)) { + WRITE_ONCE(cqe->user_data, req->user_data); WRITE_ONCE(cqe->res, res); WRITE_ONCE(cqe->flags, 0); + } else if (ctx->cq_overflow_flushed) { + WRITE_ONCE(ctx->rings->cq_overflow, + atomic_inc_return(&ctx->cached_cq_overflow)); } else { - unsigned overflow = READ_ONCE(ctx->cq_ring->overflow); - - WRITE_ONCE(ctx->cq_ring->overflow, overflow + 1); + if (list_empty(&ctx->cq_overflow_list)) { + set_bit(0, &ctx->sq_check_overflow); + set_bit(0, &ctx->cq_check_overflow); + } + req->flags |= REQ_F_OVERFLOW; + refcount_inc(&req->refs); + req->result = res; + list_add_tail(&req->list, &ctx->cq_overflow_list); } } -static void io_cqring_ev_posted(struct io_ring_ctx *ctx) -{ - if (waitqueue_active(&ctx->wait)) - wake_up(&ctx->wait); - if (waitqueue_active(&ctx->sqo_wait)) - wake_up(&ctx->sqo_wait); - if (ctx->cq_ev_fd) - eventfd_signal(ctx->cq_ev_fd, 1); -} - -static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 user_data, - long res) +static void io_cqring_add_event(struct io_kiocb *req, long res) { + struct io_ring_ctx *ctx = req->ctx; unsigned long flags; spin_lock_irqsave(&ctx->completion_lock, flags); - io_cqring_fill_event(ctx, user_data, res); + io_cqring_fill_event(req, res); io_commit_cqring(ctx); spin_unlock_irqrestore(&ctx->completion_lock, flags); io_cqring_ev_posted(ctx); } -static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) +static inline bool io_is_fallback_req(struct io_kiocb *req) { - percpu_ref_put_many(&ctx->refs, refs); + return req == (struct io_kiocb *) + ((unsigned long) req->ctx->fallback_req & ~1UL); +} - if (waitqueue_active(&ctx->wait)) - wake_up(&ctx->wait); +static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req; + + req = ctx->fallback_req; + if (!test_and_set_bit_lock(0, (unsigned long *) ctx->fallback_req)) + return req; + + return NULL; } static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, @@ -553,13 +1202,10 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; struct io_kiocb *req; - if (!percpu_ref_tryget(&ctx->refs)) - return NULL; - if (!state) { req = kmem_cache_alloc(req_cachep, gfp); if (unlikely(!req)) - goto out; + goto fallback; } else if (!state->free_reqs) { size_t sz; int ret; @@ -574,69 +1220,186 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, if (unlikely(ret <= 0)) { state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); if (!state->reqs[0]) - goto out; + goto fallback; ret = 1; } state->free_reqs = ret - 1; - state->cur_req = 1; - req = state->reqs[0]; + req = state->reqs[ret - 1]; } else { - req = state->reqs[state->cur_req]; state->free_reqs--; - state->cur_req++; + req = state->reqs[state->free_reqs]; } +got_it: + req->io = NULL; req->file = NULL; req->ctx = ctx; req->flags = 0; /* one is dropped after submission, the other at completion */ refcount_set(&req->refs, 2); req->result = 0; + INIT_IO_WORK(&req->work, io_wq_submit_work); return req; -out: - io_ring_drop_ctx_refs(ctx, 1); +fallback: + req = io_get_fallback_req(ctx); + if (req) + goto got_it; + percpu_ref_put(&ctx->refs); return NULL; } -static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) +static void __io_req_do_free(struct io_kiocb *req) +{ + if (likely(!io_is_fallback_req(req))) + kmem_cache_free(req_cachep, req); + else + clear_bit_unlock(0, (unsigned long *) req->ctx->fallback_req); +} + +static void __io_req_aux_free(struct io_kiocb *req) { - if (*nr) { - kmem_cache_free_bulk(req_cachep, *nr, reqs); - io_ring_drop_ctx_refs(ctx, *nr); - *nr = 0; + struct io_ring_ctx *ctx = req->ctx; + + kfree(req->io); + if (req->file) { + if (req->flags & REQ_F_FIXED_FILE) + percpu_ref_put(&ctx->file_data->refs); + else + fput(req->file); } + + io_req_work_drop_env(req); } static void __io_free_req(struct io_kiocb *req) { - if (req->file && !(req->flags & REQ_F_FIXED_FILE)) - fput(req->file); - io_ring_drop_ctx_refs(req->ctx, 1); - kmem_cache_free(req_cachep, req); + __io_req_aux_free(req); + + if (req->flags & REQ_F_NEED_CLEANUP) + io_cleanup_req(req); + + if (req->flags & REQ_F_INFLIGHT) { + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; + + spin_lock_irqsave(&ctx->inflight_lock, flags); + list_del(&req->inflight_entry); + if (waitqueue_active(&ctx->inflight_wait)) + wake_up(&ctx->inflight_wait); + spin_unlock_irqrestore(&ctx->inflight_lock, flags); + } + + percpu_ref_put(&req->ctx->refs); + __io_req_do_free(req); } -static void io_req_link_next(struct io_kiocb *req) +struct req_batch { + void *reqs[IO_IOPOLL_BATCH]; + int to_free; + int need_iter; +}; + +static void io_free_req_many(struct io_ring_ctx *ctx, struct req_batch *rb) { - struct io_kiocb *nxt; + int fixed_refs = rb->to_free; + + if (!rb->to_free) + return; + if (rb->need_iter) { + int i, inflight = 0; + unsigned long flags; + + fixed_refs = 0; + for (i = 0; i < rb->to_free; i++) { + struct io_kiocb *req = rb->reqs[i]; + + if (req->flags & REQ_F_FIXED_FILE) { + req->file = NULL; + fixed_refs++; + } + if (req->flags & REQ_F_INFLIGHT) + inflight++; + __io_req_aux_free(req); + } + if (!inflight) + goto do_free; + + spin_lock_irqsave(&ctx->inflight_lock, flags); + for (i = 0; i < rb->to_free; i++) { + struct io_kiocb *req = rb->reqs[i]; + + if (req->flags & REQ_F_INFLIGHT) { + list_del(&req->inflight_entry); + if (!--inflight) + break; + } + } + spin_unlock_irqrestore(&ctx->inflight_lock, flags); + + if (waitqueue_active(&ctx->inflight_wait)) + wake_up(&ctx->inflight_wait); + } +do_free: + kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs); + if (fixed_refs) + percpu_ref_put_many(&ctx->file_data->refs, fixed_refs); + percpu_ref_put_many(&ctx->refs, rb->to_free); + rb->to_free = rb->need_iter = 0; +} + +static bool io_link_cancel_timeout(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + int ret; + + ret = hrtimer_try_to_cancel(&req->io->timeout.timer); + if (ret != -1) { + io_cqring_fill_event(req, -ECANCELED); + io_commit_cqring(ctx); + req->flags &= ~REQ_F_LINK; + io_put_req(req); + return true; + } + + return false; +} + +static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr) +{ + struct io_ring_ctx *ctx = req->ctx; + bool wake_ev = false; + + /* Already got next link */ + if (req->flags & REQ_F_LINK_NEXT) + return; /* * The list should never be empty when we are called here. But could * potentially happen if the chain is messed up, check to be on the * safe side. */ - nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list); - if (nxt) { - list_del(&nxt->list); - if (!list_empty(&req->link_list)) { - INIT_LIST_HEAD(&nxt->link_list); - list_splice(&req->link_list, &nxt->link_list); - nxt->flags |= REQ_F_LINK; + while (!list_empty(&req->link_list)) { + struct io_kiocb *nxt = list_first_entry(&req->link_list, + struct io_kiocb, link_list); + + if (unlikely((req->flags & REQ_F_LINK_TIMEOUT) && + (nxt->flags & REQ_F_TIMEOUT))) { + list_del_init(&nxt->link_list); + wake_ev |= io_link_cancel_timeout(nxt); + req->flags &= ~REQ_F_LINK_TIMEOUT; + continue; } - nxt->flags |= REQ_F_LINK_DONE; - INIT_WORK(&nxt->work, io_sq_wq_submit_work); - queue_work(req->ctx->sqo_wq, &nxt->work); + list_del_init(&req->link_list); + if (!list_empty(&nxt->link_list)) + nxt->flags |= REQ_F_LINK; + *nxtptr = nxt; + break; } + + req->flags |= REQ_F_LINK_NEXT; + if (wake_ev) + io_cqring_ev_posted(ctx); } /* @@ -644,33 +1407,86 @@ static void io_req_link_next(struct io_kiocb *req) */ static void io_fail_links(struct io_kiocb *req) { - struct io_kiocb *link; + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; + + spin_lock_irqsave(&ctx->completion_lock, flags); while (!list_empty(&req->link_list)) { - link = list_first_entry(&req->link_list, struct io_kiocb, list); - list_del(&link->list); + struct io_kiocb *link = list_first_entry(&req->link_list, + struct io_kiocb, link_list); - io_cqring_add_event(req->ctx, link->user_data, -ECANCELED); - __io_free_req(link); + list_del_init(&link->link_list); + trace_io_uring_fail_link(req, link); + + if ((req->flags & REQ_F_LINK_TIMEOUT) && + link->opcode == IORING_OP_LINK_TIMEOUT) { + io_link_cancel_timeout(link); + } else { + io_cqring_fill_event(link, -ECANCELED); + __io_double_put_req(link); + } + req->flags &= ~REQ_F_LINK_TIMEOUT; } + + io_commit_cqring(ctx); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + io_cqring_ev_posted(ctx); } -static void io_free_req(struct io_kiocb *req) +static void io_req_find_next(struct io_kiocb *req, struct io_kiocb **nxt) { + if (likely(!(req->flags & REQ_F_LINK))) + return; + /* * If LINK is set, we have dependent requests in this chain. If we * didn't fail this request, queue the first one up, moving any other * dependencies to the next request. In case of failure, fail the rest * of the chain. */ - if (req->flags & REQ_F_LINK) { - if (req->flags & REQ_F_FAIL_LINK) - io_fail_links(req); - else - io_req_link_next(req); + if (req->flags & REQ_F_FAIL_LINK) { + io_fail_links(req); + } else if ((req->flags & (REQ_F_LINK_TIMEOUT | REQ_F_COMP_LOCKED)) == + REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; + + /* + * If this is a timeout link, we could be racing with the + * timeout timer. Grab the completion lock for this case to + * protect against that. + */ + spin_lock_irqsave(&ctx->completion_lock, flags); + io_req_link_next(req, nxt); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + } else { + io_req_link_next(req, nxt); } +} +static void io_free_req(struct io_kiocb *req) +{ + struct io_kiocb *nxt = NULL; + + io_req_find_next(req, &nxt); __io_free_req(req); + + if (nxt) + io_queue_async_work(nxt); +} + +/* + * Drop reference to request, return next in chain (if there is one) if this + * was the last reference to this request. + */ +__attribute__((nonnull)) +static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr) +{ + io_req_find_next(req, nxtptr); + + if (refcount_dec_and_test(&req->refs)) + __io_free_req(req); } static void io_put_req(struct io_kiocb *req) @@ -680,42 +1496,90 @@ static void io_put_req(struct io_kiocb *req) } /* + * Must only be used if we don't need to care about links, usually from + * within the completion handling itself. + */ +static void __io_double_put_req(struct io_kiocb *req) +{ + /* drop both submit and complete references */ + if (refcount_sub_and_test(2, &req->refs)) + __io_free_req(req); +} + +static void io_double_put_req(struct io_kiocb *req) +{ + /* drop both submit and complete references */ + if (refcount_sub_and_test(2, &req->refs)) + io_free_req(req); +} + +static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush) +{ + struct io_rings *rings = ctx->rings; + + if (test_bit(0, &ctx->cq_check_overflow)) { + /* + * noflush == true is from the waitqueue handler, just ensure + * we wake up the task, and the next invocation will flush the + * entries. We cannot safely to it from here. + */ + if (noflush && !list_empty(&ctx->cq_overflow_list)) + return -1U; + + io_cqring_overflow_flush(ctx, false); + } + + /* See comment at the top of this file */ + smp_rmb(); + return ctx->cached_cq_tail - READ_ONCE(rings->cq.head); +} + +static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) +{ + struct io_rings *rings = ctx->rings; + + /* make sure SQ entry isn't read before tail */ + return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; +} + +static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req) +{ + if ((req->flags & REQ_F_LINK) || io_is_fallback_req(req)) + return false; + + if (!(req->flags & REQ_F_FIXED_FILE) || req->io) + rb->need_iter++; + + rb->reqs[rb->to_free++] = req; + if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs))) + io_free_req_many(req->ctx, rb); + return true; +} + +/* * Find and free completed poll iocbs */ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, struct list_head *done) { - void *reqs[IO_IOPOLL_BATCH]; + struct req_batch rb; struct io_kiocb *req; - int to_free; - to_free = 0; + rb.to_free = rb.need_iter = 0; while (!list_empty(done)) { req = list_first_entry(done, struct io_kiocb, list); list_del(&req->list); - io_cqring_fill_event(ctx, req->user_data, req->result); + io_cqring_fill_event(req, req->result); (*nr_events)++; - if (refcount_dec_and_test(&req->refs)) { - /* If we're not using fixed files, we have to pair the - * completion part with the file put. Use regular - * completions for those, only batch free for fixed - * file and non-linked commands. - */ - if ((req->flags & (REQ_F_FIXED_FILE|REQ_F_LINK)) == - REQ_F_FIXED_FILE) { - reqs[to_free++] = req; - if (to_free == ARRAY_SIZE(reqs)) - io_free_req_many(ctx, reqs, &to_free); - } else { - io_free_req(req); - } - } + if (refcount_dec_and_test(&req->refs) && + !io_req_multi_free(&rb, req)) + io_free_req(req); } io_commit_cqring(ctx); - io_free_req_many(ctx, reqs, &to_free); + io_free_req_many(ctx, &rb); } static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, @@ -734,7 +1598,7 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, ret = 0; list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) { - struct kiocb *kiocb = &req->rw; + struct kiocb *kiocb = &req->rw.kiocb; /* * Move completed entries to our local list. If we find a @@ -764,14 +1628,14 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, } /* - * Poll for a mininum of 'min' events. Note that if min == 0 we consider that a + * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a * non-spinning poll check - we'll still enter the driver poll loop, but only * as a non-spinning completion check. */ static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, long min) { - while (!list_empty(&ctx->poll_list)) { + while (!list_empty(&ctx->poll_list) && !need_resched()) { int ret; ret = io_do_iopoll(ctx, nr_events, min); @@ -798,18 +1662,47 @@ static void io_iopoll_reap_events(struct io_ring_ctx *ctx) unsigned int nr_events = 0; io_iopoll_getevents(ctx, &nr_events, 1); + + /* + * Ensure we allow local-to-the-cpu processing to take place, + * in this case we need to ensure that we reap all events. + */ + cond_resched(); } mutex_unlock(&ctx->uring_lock); } -static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, - long min) +static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, + long min) { - int ret = 0; + int iters = 0, ret = 0; do { int tmin = 0; + /* + * Don't enter poll loop if we already have events pending. + * If we do, we can potentially be spinning for commands that + * already triggered a CQE (eg in error). + */ + if (io_cqring_events(ctx, false)) + break; + + /* + * If a submit got punted to a workqueue, we can have the + * application entering polling for a command before it gets + * issued. That app will hold the uring_lock for the duration + * of the poll right here, so we need to take a breather every + * now and then to ensure that the issue has a chance to add + * the poll to the issued list. Otherwise we can spin here + * forever, while the workqueue is stuck trying to acquire the + * very same mutex. + */ + if (!(++iters & 7)) { + mutex_unlock(&ctx->uring_lock); + mutex_lock(&ctx->uring_lock); + } + if (*nr_events < min) tmin = min - *nr_events; @@ -822,41 +1715,82 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, return ret; } -static void kiocb_end_write(struct kiocb *kiocb) +static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, + long min) { - if (kiocb->ki_flags & IOCB_WRITE) { - struct inode *inode = file_inode(kiocb->ki_filp); + int ret; - /* - * Tell lockdep we inherited freeze protection from submission - * thread. - */ - if (S_ISREG(inode->i_mode)) - __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); - file_end_write(kiocb->ki_filp); - } + /* + * We disallow the app entering submit/complete with polling, but we + * still need to lock the ring to prevent racing with polled issue + * that got punted to a workqueue. + */ + mutex_lock(&ctx->uring_lock); + ret = __io_iopoll_check(ctx, nr_events, min); + mutex_unlock(&ctx->uring_lock); + return ret; } -static void io_complete_rw(struct kiocb *kiocb, long res, long res2) +static void kiocb_end_write(struct io_kiocb *req) { - struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + /* + * Tell lockdep we inherited freeze protection from submission + * thread. + */ + if (req->flags & REQ_F_ISREG) { + struct inode *inode = file_inode(req->file); - kiocb_end_write(kiocb); + __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + } + file_end_write(req->file); +} - if ((req->flags & REQ_F_LINK) && res != req->result) +static inline void req_set_fail_links(struct io_kiocb *req) +{ + if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) req->flags |= REQ_F_FAIL_LINK; - io_cqring_add_event(req->ctx, req->user_data, res); +} + +static void io_complete_rw_common(struct kiocb *kiocb, long res) +{ + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); + + if (kiocb->ki_flags & IOCB_WRITE) + kiocb_end_write(req); + + if (res != req->result) + req_set_fail_links(req); + io_cqring_add_event(req, res); +} + +static void io_complete_rw(struct kiocb *kiocb, long res, long res2) +{ + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); + + io_complete_rw_common(kiocb, res); io_put_req(req); } +static struct io_kiocb *__io_complete_rw(struct kiocb *kiocb, long res) +{ + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); + struct io_kiocb *nxt = NULL; + + io_complete_rw_common(kiocb, res); + io_put_req_find_next(req, &nxt); + + return nxt; +} + static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) { - struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); - kiocb_end_write(kiocb); + if (kiocb->ki_flags & IOCB_WRITE) + kiocb_end_write(req); - if ((req->flags & REQ_F_LINK) && res != req->result) - req->flags |= REQ_F_FAIL_LINK; + if (res != req->result) + req_set_fail_links(req); req->result = res; if (res != -EAGAIN) req->flags |= REQ_F_IOPOLL_COMPLETED; @@ -884,7 +1818,7 @@ static void io_iopoll_req_issued(struct io_kiocb *req) list_req = list_first_entry(&ctx->poll_list, struct io_kiocb, list); - if (list_req->rw.ki_filp != req->rw.ki_filp) + if (list_req->file != req->file) ctx->poll_multi_file = true; } @@ -947,7 +1881,7 @@ static bool io_file_supports_async(struct file *file) { umode_t mode = file_inode(file)->i_mode; - if (S_ISBLK(mode) || S_ISCHR(mode)) + if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISSOCK(mode)) return true; if (S_ISREG(mode) && file->f_op != &io_uring_fops) return true; @@ -955,24 +1889,27 @@ static bool io_file_supports_async(struct file *file) return false; } -static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, +static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, bool force_nonblock) { - const struct io_uring_sqe *sqe = s->sqe; struct io_ring_ctx *ctx = req->ctx; - struct kiocb *kiocb = &req->rw; + struct kiocb *kiocb = &req->rw.kiocb; unsigned ioprio; int ret; - if (!req->file) - return -EBADF; - - if (force_nonblock && !io_file_supports_async(req->file)) - force_nonblock = false; + if (S_ISREG(file_inode(req->file)->i_mode)) + req->flags |= REQ_F_ISREG; kiocb->ki_pos = READ_ONCE(sqe->off); - kiocb->ki_flags = iocb_flags(kiocb->ki_filp); + if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) { + req->flags |= REQ_F_CUR_POS; + kiocb->ki_pos = req->file->f_pos; + } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); + kiocb->ki_flags = iocb_flags(kiocb->ki_filp); + ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); + if (unlikely(ret)) + return ret; ioprio = READ_ONCE(sqe->ioprio); if (ioprio) { @@ -984,12 +1921,9 @@ static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, } else kiocb->ki_ioprio = get_current_ioprio(); - ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); - if (unlikely(ret)) - return ret; - /* don't allow async punt if RWF_NOWAIT was requested */ - if (kiocb->ki_flags & IOCB_NOWAIT) + if ((kiocb->ki_flags & IOCB_NOWAIT) || + (req->file->f_flags & O_NONBLOCK)) req->flags |= REQ_F_NOWAIT; if (force_nonblock) @@ -1002,11 +1936,18 @@ static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, kiocb->ki_flags |= IOCB_HIPRI; kiocb->ki_complete = io_complete_rw_iopoll; + req->result = 0; } else { if (kiocb->ki_flags & IOCB_HIPRI) return -EINVAL; kiocb->ki_complete = io_complete_rw; } + + req->rw.addr = READ_ONCE(sqe->addr); + req->rw.len = READ_ONCE(sqe->len); + /* we own ->private, reuse it for the buffer index */ + req->rw.kiocb.private = (void *) (unsigned long) + READ_ONCE(sqe->buf_index); return 0; } @@ -1031,11 +1972,24 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) } } -static int io_import_fixed(struct io_ring_ctx *ctx, int rw, - const struct io_uring_sqe *sqe, - struct iov_iter *iter) +static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt, + bool in_async) { - size_t len = READ_ONCE(sqe->len); + struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); + + if (req->flags & REQ_F_CUR_POS) + req->file->f_pos = kiocb->ki_pos; + if (in_async && ret >= 0 && kiocb->ki_complete == io_complete_rw) + *nxt = __io_complete_rw(kiocb, ret); + else + io_rw_done(kiocb, ret); +} + +static ssize_t io_import_fixed(struct io_kiocb *req, int rw, + struct iov_iter *iter) +{ + struct io_ring_ctx *ctx = req->ctx; + size_t len = req->rw.len; struct io_mapped_ubuf *imu; unsigned index, buf_index; size_t offset; @@ -1045,13 +1999,13 @@ static int io_import_fixed(struct io_ring_ctx *ctx, int rw, if (unlikely(!ctx->user_bufs)) return -EFAULT; - buf_index = READ_ONCE(sqe->buf_index); + buf_index = (unsigned long) req->rw.kiocb.private; if (unlikely(buf_index >= ctx->nr_user_bufs)) return -EFAULT; index = array_index_nospec(buf_index, ctx->nr_user_bufs); imu = &ctx->user_bufs[index]; - buf_addr = READ_ONCE(sqe->addr); + buf_addr = req->rw.addr; /* overflow */ if (buf_addr + len < buf_addr) @@ -1102,39 +2056,45 @@ static int io_import_fixed(struct io_ring_ctx *ctx, int rw, } } - return 0; + return len; } -static ssize_t io_import_iovec(struct io_ring_ctx *ctx, int rw, - const struct sqe_submit *s, struct iovec **iovec, - struct iov_iter *iter) +static ssize_t io_import_iovec(int rw, struct io_kiocb *req, + struct iovec **iovec, struct iov_iter *iter) { - const struct io_uring_sqe *sqe = s->sqe; - void __user *buf = u64_to_user_ptr(READ_ONCE(sqe->addr)); - size_t sqe_len = READ_ONCE(sqe->len); + void __user *buf = u64_to_user_ptr(req->rw.addr); + size_t sqe_len = req->rw.len; u8 opcode; - /* - * We're reading ->opcode for the second time, but the first read - * doesn't care whether it's _FIXED or not, so it doesn't matter - * whether ->opcode changes concurrently. The first read does care - * about whether it is a READ or a WRITE, so we don't trust this read - * for that purpose and instead let the caller pass in the read/write - * flag. - */ - opcode = READ_ONCE(sqe->opcode); - if (opcode == IORING_OP_READ_FIXED || - opcode == IORING_OP_WRITE_FIXED) { - ssize_t ret = io_import_fixed(ctx, rw, sqe, iter); + opcode = req->opcode; + if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { + *iovec = NULL; + return io_import_fixed(req, rw, iter); + } + + /* buffer index only valid with fixed read/write */ + if (req->rw.kiocb.private) + return -EINVAL; + + if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) { + ssize_t ret; + ret = import_single_range(rw, buf, sqe_len, *iovec, iter); *iovec = NULL; return ret; } - if (!s->has_user) - return -EFAULT; + if (req->io) { + struct io_async_rw *iorw = &req->io->rw; + + *iovec = iorw->iov; + iov_iter_init(iter, rw, *iovec, iorw->nr_segs, iorw->size); + if (iorw->iov == iorw->fast_iov) + *iovec = NULL; + return iorw->size; + } #ifdef CONFIG_COMPAT - if (ctx->compat) + if (req->ctx->compat) return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); #endif @@ -1143,143 +2103,259 @@ static ssize_t io_import_iovec(struct io_ring_ctx *ctx, int rw, } /* - * Make a note of the last file/offset/direction we punted to async - * context. We'll use this information to see if we can piggy back a - * sequential request onto the previous one, if it's still hasn't been - * completed by the async worker. + * For files that don't have ->read_iter() and ->write_iter(), handle them + * by looping over ->read() or ->write() manually. */ -static void io_async_list_note(int rw, struct io_kiocb *req, size_t len) +static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, + struct iov_iter *iter) { - struct async_list *async_list = &req->ctx->pending_async[rw]; - struct kiocb *kiocb = &req->rw; - struct file *filp = kiocb->ki_filp; - off_t io_end = kiocb->ki_pos + len; + ssize_t ret = 0; - if (filp == async_list->file && kiocb->ki_pos == async_list->io_end) { - unsigned long max_bytes; + /* + * Don't support polled IO through this interface, and we can't + * support non-blocking either. For the latter, this just causes + * the kiocb to be handled from an async context. + */ + if (kiocb->ki_flags & IOCB_HIPRI) + return -EOPNOTSUPP; + if (kiocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; - /* Use 8x RA size as a decent limiter for both reads/writes */ - max_bytes = filp->f_ra.ra_pages << (PAGE_SHIFT + 3); - if (!max_bytes) - max_bytes = VM_READAHEAD_PAGES << (PAGE_SHIFT + 3); + while (iov_iter_count(iter)) { + struct iovec iovec; + ssize_t nr; - /* If max len are exceeded, reset the state */ - if (async_list->io_len + len <= max_bytes) { - req->flags |= REQ_F_SEQ_PREV; - async_list->io_len += len; + if (!iov_iter_is_bvec(iter)) { + iovec = iov_iter_iovec(iter); } else { - io_end = 0; - async_list->io_len = 0; + /* fixed buffers import bvec */ + iovec.iov_base = kmap(iter->bvec->bv_page) + + iter->iov_offset; + iovec.iov_len = min(iter->count, + iter->bvec->bv_len - iter->iov_offset); } + + if (rw == READ) { + nr = file->f_op->read(file, iovec.iov_base, + iovec.iov_len, &kiocb->ki_pos); + } else { + nr = file->f_op->write(file, iovec.iov_base, + iovec.iov_len, &kiocb->ki_pos); + } + + if (iov_iter_is_bvec(iter)) + kunmap(iter->bvec->bv_page); + + if (nr < 0) { + if (!ret) + ret = nr; + break; + } + ret += nr; + if (nr != iovec.iov_len) + break; + iov_iter_advance(iter, nr); + } + + return ret; +} + +static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size, + struct iovec *iovec, struct iovec *fast_iov, + struct iov_iter *iter) +{ + req->io->rw.nr_segs = iter->nr_segs; + req->io->rw.size = io_size; + req->io->rw.iov = iovec; + if (!req->io->rw.iov) { + req->io->rw.iov = req->io->rw.fast_iov; + memcpy(req->io->rw.iov, fast_iov, + sizeof(struct iovec) * iter->nr_segs); + } else { + req->flags |= REQ_F_NEED_CLEANUP; } +} + +static int io_alloc_async_ctx(struct io_kiocb *req) +{ + if (!io_op_defs[req->opcode].async_ctx) + return 0; + req->io = kmalloc(sizeof(*req->io), GFP_KERNEL); + return req->io == NULL; +} + +static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size, + struct iovec *iovec, struct iovec *fast_iov, + struct iov_iter *iter) +{ + if (!io_op_defs[req->opcode].async_ctx) + return 0; + if (!req->io) { + if (io_alloc_async_ctx(req)) + return -ENOMEM; - /* New file? Reset state. */ - if (async_list->file != filp) { - async_list->io_len = 0; - async_list->file = filp; + io_req_map_rw(req, io_size, iovec, fast_iov, iter); } - async_list->io_end = io_end; + return 0; } -static int io_read(struct io_kiocb *req, const struct sqe_submit *s, - bool force_nonblock) +static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool force_nonblock) { - struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; - struct kiocb *kiocb = &req->rw; + struct io_async_ctx *io; struct iov_iter iter; - struct file *file; - size_t iov_count; - ssize_t read_size, ret; + ssize_t ret; - ret = io_prep_rw(req, s, force_nonblock); + ret = io_prep_rw(req, sqe, force_nonblock); if (ret) return ret; - file = kiocb->ki_filp; - if (unlikely(!(file->f_mode & FMODE_READ))) + if (unlikely(!(req->file->f_mode & FMODE_READ))) return -EBADF; - if (unlikely(!file->f_op->read_iter)) - return -EINVAL; - ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter); + /* either don't need iovec imported or already have it */ + if (!req->io || req->flags & REQ_F_NEED_CLEANUP) + return 0; + + io = req->io; + io->rw.iov = io->rw.fast_iov; + req->io = NULL; + ret = io_import_iovec(READ, req, &io->rw.iov, &iter); + req->io = io; + if (ret < 0) + return ret; + + io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter); + return 0; +} + +static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; + struct kiocb *kiocb = &req->rw.kiocb; + struct iov_iter iter; + size_t iov_count; + ssize_t io_size, ret; + + ret = io_import_iovec(READ, req, &iovec, &iter); if (ret < 0) return ret; - read_size = ret; + /* Ensure we clear previously set non-block flag */ + if (!force_nonblock) + req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; + + req->result = 0; + io_size = ret; if (req->flags & REQ_F_LINK) - req->result = read_size; + req->result = io_size; + + /* + * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so + * we know to async punt it even if it was opened O_NONBLOCK + */ + if (force_nonblock && !io_file_supports_async(req->file)) { + req->flags |= REQ_F_MUST_PUNT; + goto copy_iov; + } iov_count = iov_iter_count(&iter); - ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_count); + ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count); if (!ret) { ssize_t ret2; - ret2 = call_read_iter(file, kiocb, &iter); - /* - * In case of a short read, punt to async. This can happen - * if we have data partially cached. Alternatively we can - * return the short read, in which case the application will - * need to issue another SQE and wait for it. That SQE will - * need async punt anyway, so it's more efficient to do it - * here. - */ - if (force_nonblock && ret2 > 0 && ret2 < read_size) - ret2 = -EAGAIN; + if (req->file->f_op->read_iter) + ret2 = call_read_iter(req->file, kiocb, &iter); + else + ret2 = loop_rw_iter(READ, req->file, kiocb, &iter); + /* Catch -EAGAIN return for forced non-blocking submission */ if (!force_nonblock || ret2 != -EAGAIN) { - io_rw_done(kiocb, ret2); + kiocb_done(kiocb, ret2, nxt, req->in_async); } else { - /* - * If ->needs_lock is true, we're already in async - * context. - */ - if (!s->needs_lock) - io_async_list_note(READ, req, iov_count); - ret = -EAGAIN; +copy_iov: + ret = io_setup_async_rw(req, io_size, iovec, + inline_vecs, &iter); + if (ret) + goto out_free; + return -EAGAIN; } } +out_free: kfree(iovec); + req->flags &= ~REQ_F_NEED_CLEANUP; return ret; } -static int io_write(struct io_kiocb *req, const struct sqe_submit *s, - bool force_nonblock) +static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool force_nonblock) { - struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; - struct kiocb *kiocb = &req->rw; + struct io_async_ctx *io; struct iov_iter iter; - struct file *file; - size_t iov_count; ssize_t ret; - ret = io_prep_rw(req, s, force_nonblock); + ret = io_prep_rw(req, sqe, force_nonblock); if (ret) return ret; - file = kiocb->ki_filp; - if (unlikely(!(file->f_mode & FMODE_WRITE))) + if (unlikely(!(req->file->f_mode & FMODE_WRITE))) return -EBADF; - if (unlikely(!file->f_op->write_iter)) - return -EINVAL; - ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter); + /* either don't need iovec imported or already have it */ + if (!req->io || req->flags & REQ_F_NEED_CLEANUP) + return 0; + + io = req->io; + io->rw.iov = io->rw.fast_iov; + req->io = NULL; + ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter); + req->io = io; if (ret < 0) return ret; - if (req->flags & REQ_F_LINK) - req->result = ret; + io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter); + return 0; +} - iov_count = iov_iter_count(&iter); +static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; + struct kiocb *kiocb = &req->rw.kiocb; + struct iov_iter iter; + size_t iov_count; + ssize_t ret, io_size; + + ret = io_import_iovec(WRITE, req, &iovec, &iter); + if (ret < 0) + return ret; - ret = -EAGAIN; - if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) { - /* If ->needs_lock is true, we're already in async context. */ - if (!s->needs_lock) - io_async_list_note(WRITE, req, iov_count); - goto out_free; + /* Ensure we clear previously set non-block flag */ + if (!force_nonblock) + req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; + + req->result = 0; + io_size = ret; + if (req->flags & REQ_F_LINK) + req->result = io_size; + + /* + * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so + * we know to async punt it even if it was opened O_NONBLOCK + */ + if (force_nonblock && !io_file_supports_async(req->file)) { + req->flags |= REQ_F_MUST_PUNT; + goto copy_iov; } - ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count); + /* file path doesn't support NOWAIT for non-direct_IO */ + if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && + (req->flags & REQ_F_ISREG)) + goto copy_iov; + + iov_count = iov_iter_count(&iter); + ret = rw_verify_area(WRITE, req->file, &kiocb->ki_pos, iov_count); if (!ret) { ssize_t ret2; @@ -1290,28 +2366,37 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s, * released so that it doesn't complain about the held lock when * we return to userspace. */ - if (S_ISREG(file_inode(file)->i_mode)) { - __sb_start_write(file_inode(file)->i_sb, + if (req->flags & REQ_F_ISREG) { + __sb_start_write(file_inode(req->file)->i_sb, SB_FREEZE_WRITE, true); - __sb_writers_release(file_inode(file)->i_sb, + __sb_writers_release(file_inode(req->file)->i_sb, SB_FREEZE_WRITE); } kiocb->ki_flags |= IOCB_WRITE; - ret2 = call_write_iter(file, kiocb, &iter); + if (req->file->f_op->write_iter) + ret2 = call_write_iter(req->file, kiocb, &iter); + else + ret2 = loop_rw_iter(WRITE, req->file, kiocb, &iter); + /* + * Raw bdev writes will -EOPNOTSUPP for IOCB_NOWAIT. Just + * retry them without IOCB_NOWAIT. + */ + if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) + ret2 = -EAGAIN; if (!force_nonblock || ret2 != -EAGAIN) { - io_rw_done(kiocb, ret2); + kiocb_done(kiocb, ret2, nxt, req->in_async); } else { - /* - * If ->needs_lock is true, we're already in async - * context. - */ - if (!s->needs_lock) - io_async_list_note(WRITE, req, iov_count); - ret = -EAGAIN; +copy_iov: + ret = io_setup_async_rw(req, io_size, iovec, + inline_vecs, &iter); + if (ret) + goto out_free; + return -EAGAIN; } } out_free: + req->flags &= ~REQ_F_NEED_CLEANUP; kfree(iovec); return ret; } @@ -1319,15 +2404,14 @@ out_free: /* * IORING_OP_NOP just posts a completion event, nothing else. */ -static int io_nop(struct io_kiocb *req, u64 user_data) +static int io_nop(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; - long err = 0; if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - io_cqring_add_event(ctx, user_data, err); + io_cqring_add_event(req, 0); io_put_req(req); return 0; } @@ -1344,45 +2428,521 @@ static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) return -EINVAL; + req->sync.flags = READ_ONCE(sqe->fsync_flags); + if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC)) + return -EINVAL; + + req->sync.off = READ_ONCE(sqe->off); + req->sync.len = READ_ONCE(sqe->len); return 0; } -static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, +static bool io_req_cancelled(struct io_kiocb *req) +{ + if (req->work.flags & IO_WQ_WORK_CANCEL) { + req_set_fail_links(req); + io_cqring_add_event(req, -ECANCELED); + io_put_req(req); + return true; + } + + return false; +} + +static void io_link_work_cb(struct io_wq_work **workptr) +{ + struct io_wq_work *work = *workptr; + struct io_kiocb *link = work->data; + + io_queue_linked_timeout(link); + work->func = io_wq_submit_work; +} + +static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt) +{ + struct io_kiocb *link; + + io_prep_async_work(nxt, &link); + *workptr = &nxt->work; + if (link) { + nxt->work.flags |= IO_WQ_WORK_CB; + nxt->work.func = io_link_work_cb; + nxt->work.data = link; + } +} + +static void io_fsync_finish(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + loff_t end = req->sync.off + req->sync.len; + struct io_kiocb *nxt = NULL; + int ret; + + if (io_req_cancelled(req)) + return; + + ret = vfs_fsync_range(req->file, req->sync.off, + end > 0 ? end : LLONG_MAX, + req->sync.flags & IORING_FSYNC_DATASYNC); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, &nxt); + if (nxt) + io_wq_assign_next(workptr, nxt); +} + +static int io_fsync(struct io_kiocb *req, struct io_kiocb **nxt, bool force_nonblock) { - loff_t sqe_off = READ_ONCE(sqe->off); - loff_t sqe_len = READ_ONCE(sqe->len); - loff_t end = sqe_off + sqe_len; - unsigned fsync_flags; + struct io_wq_work *work, *old_work; + + /* fsync always requires a blocking context */ + if (force_nonblock) { + io_put_req(req); + req->work.func = io_fsync_finish; + return -EAGAIN; + } + + work = old_work = &req->work; + io_fsync_finish(&work); + if (work && work != old_work) + *nxt = container_of(work, struct io_kiocb, work); + return 0; +} + +static void io_fallocate_finish(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; + int ret; + + ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off, + req->sync.len); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, &nxt); + if (nxt) + io_wq_assign_next(workptr, nxt); +} + +static int io_fallocate_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + if (sqe->ioprio || sqe->buf_index || sqe->rw_flags) + return -EINVAL; + + req->sync.off = READ_ONCE(sqe->off); + req->sync.len = READ_ONCE(sqe->addr); + req->sync.mode = READ_ONCE(sqe->len); + return 0; +} + +static int io_fallocate(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct io_wq_work *work, *old_work; + + /* fallocate always requiring blocking context */ + if (force_nonblock) { + io_put_req(req); + req->work.func = io_fallocate_finish; + return -EAGAIN; + } + + work = old_work = &req->work; + io_fallocate_finish(&work); + if (work && work != old_work) + *nxt = container_of(work, struct io_kiocb, work); + + return 0; +} + +static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + const char __user *fname; int ret; - fsync_flags = READ_ONCE(sqe->fsync_flags); - if (unlikely(fsync_flags & ~IORING_FSYNC_DATASYNC)) + if (sqe->ioprio || sqe->buf_index) return -EINVAL; + if (sqe->flags & IOSQE_FIXED_FILE) + return -EBADF; + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; + + req->open.dfd = READ_ONCE(sqe->fd); + req->open.how.mode = READ_ONCE(sqe->len); + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + req->open.how.flags = READ_ONCE(sqe->open_flags); + + req->open.filename = getname(fname); + if (IS_ERR(req->open.filename)) { + ret = PTR_ERR(req->open.filename); + req->open.filename = NULL; + return ret; + } - ret = io_prep_fsync(req, sqe); + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +} + +static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct open_how __user *how; + const char __user *fname; + size_t len; + int ret; + + if (sqe->ioprio || sqe->buf_index) + return -EINVAL; + if (sqe->flags & IOSQE_FIXED_FILE) + return -EBADF; + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; + + req->open.dfd = READ_ONCE(sqe->fd); + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + len = READ_ONCE(sqe->len); + + if (len < OPEN_HOW_SIZE_VER0) + return -EINVAL; + + ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how, + len); if (ret) return ret; - /* fsync always requires a blocking context */ + if (!(req->open.how.flags & O_PATH) && force_o_largefile()) + req->open.how.flags |= O_LARGEFILE; + + req->open.filename = getname(fname); + if (IS_ERR(req->open.filename)) { + ret = PTR_ERR(req->open.filename); + req->open.filename = NULL; + return ret; + } + + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +} + +static int io_openat2(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct open_flags op; + struct file *file; + int ret; + if (force_nonblock) return -EAGAIN; - ret = vfs_fsync_range(req->rw.ki_filp, sqe_off, - end > 0 ? end : LLONG_MAX, - fsync_flags & IORING_FSYNC_DATASYNC); + ret = build_open_flags(&req->open.how, &op); + if (ret) + goto err; - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; - io_cqring_add_event(req->ctx, sqe->user_data, ret); - io_put_req(req); + ret = get_unused_fd_flags(req->open.how.flags); + if (ret < 0) + goto err; + + file = do_filp_open(req->open.dfd, req->open.filename, &op); + if (IS_ERR(file)) { + put_unused_fd(ret); + ret = PTR_ERR(file); + } else { + fsnotify_open(file); + fd_install(ret, file); + } +err: + putname(req->open.filename); + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +} + +static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + req->open.how = build_open_how(req->open.how.flags, req->open.how.mode); + return io_openat2(req, nxt, force_nonblock); +} + +static int io_epoll_ctl_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_EPOLL) + if (sqe->ioprio || sqe->buf_index) + return -EINVAL; + + req->epoll.epfd = READ_ONCE(sqe->fd); + req->epoll.op = READ_ONCE(sqe->len); + req->epoll.fd = READ_ONCE(sqe->off); + + if (ep_op_has_event(req->epoll.op)) { + struct epoll_event __user *ev; + + ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); + if (copy_from_user(&req->epoll.event, ev, sizeof(*ev))) + return -EFAULT; + } + + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_epoll_ctl(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_EPOLL) + struct io_epoll *ie = &req->epoll; + int ret; + + ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); + if (force_nonblock && ret == -EAGAIN) + return -EAGAIN; + + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + if (sqe->ioprio || sqe->buf_index || sqe->off) + return -EINVAL; + + req->madvise.addr = READ_ONCE(sqe->addr); + req->madvise.len = READ_ONCE(sqe->len); + req->madvise.advice = READ_ONCE(sqe->fadvise_advice); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_madvise(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + struct io_madvise *ma = &req->madvise; + int ret; + + if (force_nonblock) + return -EAGAIN; + + ret = do_madvise(ma->addr, ma->len, ma->advice); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + if (sqe->ioprio || sqe->buf_index || sqe->addr) + return -EINVAL; + + req->fadvise.offset = READ_ONCE(sqe->off); + req->fadvise.len = READ_ONCE(sqe->len); + req->fadvise.advice = READ_ONCE(sqe->fadvise_advice); + return 0; +} + +static int io_fadvise(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct io_fadvise *fa = &req->fadvise; + int ret; + + if (force_nonblock) { + switch (fa->advice) { + case POSIX_FADV_NORMAL: + case POSIX_FADV_RANDOM: + case POSIX_FADV_SEQUENTIAL: + break; + default: + return -EAGAIN; + } + } + + ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +} + +static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + const char __user *fname; + unsigned lookup_flags; + int ret; + + if (sqe->ioprio || sqe->buf_index) + return -EINVAL; + if (sqe->flags & IOSQE_FIXED_FILE) + return -EBADF; + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; + + req->open.dfd = READ_ONCE(sqe->fd); + req->open.mask = READ_ONCE(sqe->len); + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + req->open.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + req->open.how.flags = READ_ONCE(sqe->statx_flags); + + if (vfs_stat_set_lookup_flags(&lookup_flags, req->open.how.flags)) + return -EINVAL; + + req->open.filename = getname_flags(fname, lookup_flags, NULL); + if (IS_ERR(req->open.filename)) { + ret = PTR_ERR(req->open.filename); + req->open.filename = NULL; + return ret; + } + + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +} + +static int io_statx(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct io_open *ctx = &req->open; + unsigned lookup_flags; + struct path path; + struct kstat stat; + int ret; + + if (force_nonblock) + return -EAGAIN; + + if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags)) + return -EINVAL; + +retry: + /* filename_lookup() drops it, keep a reference */ + ctx->filename->refcnt++; + + ret = filename_lookup(ctx->dfd, ctx->filename, lookup_flags, &path, + NULL); + if (ret) + goto err; + + ret = vfs_getattr(&path, &stat, ctx->mask, ctx->how.flags); + path_put(&path); + if (retry_estale(ret, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } + if (!ret) + ret = cp_statx(&stat, ctx->buffer); +err: + putname(ctx->filename); + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +} + +static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + /* + * If we queue this for async, it must not be cancellable. That would + * leave the 'file' in an undeterminate state. + */ + req->work.flags |= IO_WQ_WORK_NO_CANCEL; + + if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || + sqe->rw_flags || sqe->buf_index) + return -EINVAL; + if (sqe->flags & IOSQE_FIXED_FILE) + return -EBADF; + + req->close.fd = READ_ONCE(sqe->fd); + if (req->file->f_op == &io_uring_fops || + req->close.fd == req->ctx->ring_fd) + return -EBADF; + + return 0; +} + +/* only called when __close_fd_get_file() is done */ +static void __io_close_finish(struct io_kiocb *req, struct io_kiocb **nxt) +{ + int ret; + + ret = filp_close(req->close.put_file, req->work.files); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + fput(req->close.put_file); + io_put_req_find_next(req, nxt); +} + +static void io_close_finish(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; + + __io_close_finish(req, &nxt); + if (nxt) + io_wq_assign_next(workptr, nxt); +} + +static int io_close(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + int ret; + + req->close.put_file = NULL; + ret = __close_fd_get_file(req->close.fd, &req->close.put_file); + if (ret < 0) + return ret; + + /* if the file has a flush method, be safe and punt to async */ + if (req->close.put_file->f_op->flush && !io_wq_current_is_worker()) + goto eagain; + + /* + * No ->flush(), safely close from here and just punt the + * fput() to async context. + */ + __io_close_finish(req, nxt); + return 0; +eagain: + req->work.func = io_close_finish; + /* + * Do manual async queue here to avoid grabbing files - we don't + * need the files, and it'll cause io_close_finish() to close + * the file again and cause a double CQE entry for this request + */ + io_queue_async_work(req); return 0; } static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_ring_ctx *ctx = req->ctx; - int ret = 0; if (!req->file) return -EBADF; @@ -1392,45 +2952,235 @@ static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) return -EINVAL; - return ret; + req->sync.off = READ_ONCE(sqe->off); + req->sync.len = READ_ONCE(sqe->len); + req->sync.flags = READ_ONCE(sqe->sync_range_flags); + return 0; } -static int io_sync_file_range(struct io_kiocb *req, - const struct io_uring_sqe *sqe, - bool force_nonblock) +static void io_sync_file_range_finish(struct io_wq_work **workptr) { - loff_t sqe_off; - loff_t sqe_len; - unsigned flags; + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; int ret; - ret = io_prep_sfr(req, sqe); - if (ret) - return ret; + if (io_req_cancelled(req)) + return; + + ret = sync_file_range(req->file, req->sync.off, req->sync.len, + req->sync.flags); + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, &nxt); + if (nxt) + io_wq_assign_next(workptr, nxt); +} + +static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct io_wq_work *work, *old_work; /* sync_file_range always requires a blocking context */ - if (force_nonblock) + if (force_nonblock) { + io_put_req(req); + req->work.func = io_sync_file_range_finish; return -EAGAIN; + } + + work = old_work = &req->work; + io_sync_file_range_finish(&work); + if (work && work != old_work) + *nxt = container_of(work, struct io_kiocb, work); + return 0; +} + +static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_NET) + struct io_sr_msg *sr = &req->sr_msg; + struct io_async_ctx *io = req->io; + int ret; - sqe_off = READ_ONCE(sqe->off); - sqe_len = READ_ONCE(sqe->len); - flags = READ_ONCE(sqe->sync_range_flags); + sr->msg_flags = READ_ONCE(sqe->msg_flags); + sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + sr->len = READ_ONCE(sqe->len); - ret = sync_file_range(req->rw.ki_filp, sqe_off, sqe_len, flags); + if (!io || req->opcode == IORING_OP_SEND) + return 0; + /* iovec is already imported */ + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; - if (ret < 0 && (req->flags & REQ_F_LINK)) - req->flags |= REQ_F_FAIL_LINK; - io_cqring_add_event(req->ctx, sqe->user_data, ret); - io_put_req(req); + io->msg.iov = io->msg.fast_iov; + ret = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, + &io->msg.iov); + if (!ret) + req->flags |= REQ_F_NEED_CLEANUP; + return ret; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_NET) + struct io_async_msghdr *kmsg = NULL; + struct socket *sock; + int ret; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + + sock = sock_from_file(req->file, &ret); + if (sock) { + struct io_async_ctx io; + unsigned flags; + + if (req->io) { + kmsg = &req->io->msg; + kmsg->msg.msg_name = &req->io->msg.addr; + /* if iov is set, it's allocated already */ + if (!kmsg->iov) + kmsg->iov = kmsg->fast_iov; + kmsg->msg.msg_iter.iov = kmsg->iov; + } else { + struct io_sr_msg *sr = &req->sr_msg; + + kmsg = &io.msg; + kmsg->msg.msg_name = &io.msg.addr; + + io.msg.iov = io.msg.fast_iov; + ret = sendmsg_copy_msghdr(&io.msg.msg, sr->msg, + sr->msg_flags, &io.msg.iov); + if (ret) + return ret; + } + + flags = req->sr_msg.msg_flags; + if (flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + else if (force_nonblock) + flags |= MSG_DONTWAIT; + + ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); + if (force_nonblock && ret == -EAGAIN) { + if (req->io) + return -EAGAIN; + if (io_alloc_async_ctx(req)) { + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); + return -ENOMEM; + } + req->flags |= REQ_F_NEED_CLEANUP; + memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + } + + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); + req->flags &= ~REQ_F_NEED_CLEANUP; + io_cqring_add_event(req, ret); + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, nxt); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_send(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_NET) + struct socket *sock; + int ret; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + + sock = sock_from_file(req->file, &ret); + if (sock) { + struct io_sr_msg *sr = &req->sr_msg; + struct msghdr msg; + struct iovec iov; + unsigned flags; + + ret = import_single_range(WRITE, sr->buf, sr->len, &iov, + &msg.msg_iter); + if (ret) + return ret; + + msg.msg_name = NULL; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_namelen = 0; + + flags = req->sr_msg.msg_flags; + if (flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + else if (force_nonblock) + flags |= MSG_DONTWAIT; + + msg.msg_flags = flags; + ret = sock_sendmsg(sock, &msg); + if (force_nonblock && ret == -EAGAIN) + return -EAGAIN; + if (ret == -ERESTARTSYS) + ret = -EINTR; + } + + io_cqring_add_event(req, ret); + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, nxt); return 0; +#else + return -EOPNOTSUPP; +#endif } +static int io_recvmsg_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ #if defined(CONFIG_NET) -static int io_send_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, - bool force_nonblock, - long (*fn)(struct socket *, struct user_msghdr __user *, - unsigned int)) + struct io_sr_msg *sr = &req->sr_msg; + struct io_async_ctx *io = req->io; + int ret; + + sr->msg_flags = READ_ONCE(sqe->msg_flags); + sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr)); + sr->len = READ_ONCE(sqe->len); + + if (!io || req->opcode == IORING_OP_RECV) + return 0; + /* iovec is already imported */ + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; + + io->msg.iov = io->msg.fast_iov; + ret = recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, + &io->msg.uaddr, &io->msg.iov); + if (!ret) + req->flags |= REQ_F_NEED_CLEANUP; + return ret; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) { +#if defined(CONFIG_NET) + struct io_async_msghdr *kmsg = NULL; struct socket *sock; int ret; @@ -1439,44 +3189,257 @@ static int io_send_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, sock = sock_from_file(req->file, &ret); if (sock) { - struct user_msghdr __user *msg; + struct io_async_ctx io; unsigned flags; - flags = READ_ONCE(sqe->msg_flags); + if (req->io) { + kmsg = &req->io->msg; + kmsg->msg.msg_name = &req->io->msg.addr; + /* if iov is set, it's allocated already */ + if (!kmsg->iov) + kmsg->iov = kmsg->fast_iov; + kmsg->msg.msg_iter.iov = kmsg->iov; + } else { + struct io_sr_msg *sr = &req->sr_msg; + + kmsg = &io.msg; + kmsg->msg.msg_name = &io.msg.addr; + + io.msg.iov = io.msg.fast_iov; + ret = recvmsg_copy_msghdr(&io.msg.msg, sr->msg, + sr->msg_flags, &io.msg.uaddr, + &io.msg.iov); + if (ret) + return ret; + } + + flags = req->sr_msg.msg_flags; if (flags & MSG_DONTWAIT) req->flags |= REQ_F_NOWAIT; else if (force_nonblock) flags |= MSG_DONTWAIT; - msg = (struct user_msghdr __user *) (unsigned long) - READ_ONCE(sqe->addr); + ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.msg, + kmsg->uaddr, flags); + if (force_nonblock && ret == -EAGAIN) { + if (req->io) + return -EAGAIN; + if (io_alloc_async_ctx(req)) { + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); + return -ENOMEM; + } + memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); + req->flags |= REQ_F_NEED_CLEANUP; + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; + } - ret = fn(sock, msg, flags); - if (force_nonblock && ret == -EAGAIN) + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); + req->flags &= ~REQ_F_NEED_CLEANUP; + io_cqring_add_event(req, ret); + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, nxt); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_recv(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ +#if defined(CONFIG_NET) + struct socket *sock; + int ret; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + + sock = sock_from_file(req->file, &ret); + if (sock) { + struct io_sr_msg *sr = &req->sr_msg; + struct msghdr msg; + struct iovec iov; + unsigned flags; + + ret = import_single_range(READ, sr->buf, sr->len, &iov, + &msg.msg_iter); + if (ret) return ret; + + msg.msg_name = NULL; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_namelen = 0; + msg.msg_iocb = NULL; + msg.msg_flags = 0; + + flags = req->sr_msg.msg_flags; + if (flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT; + else if (force_nonblock) + flags |= MSG_DONTWAIT; + + ret = sock_recvmsg(sock, &msg, flags); + if (force_nonblock && ret == -EAGAIN) + return -EAGAIN; + if (ret == -ERESTARTSYS) + ret = -EINTR; } - io_cqring_add_event(req->ctx, sqe->user_data, ret); - io_put_req(req); + io_cqring_add_event(req, ret); + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, nxt); return 0; +#else + return -EOPNOTSUPP; +#endif } + + +static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_NET) + struct io_accept *accept = &req->accept; + + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + return -EINVAL; + if (sqe->ioprio || sqe->len || sqe->buf_index) + return -EINVAL; + + accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + accept->flags = READ_ONCE(sqe->accept_flags); + return 0; +#else + return -EOPNOTSUPP; #endif +} -static int io_sendmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, - bool force_nonblock) +#if defined(CONFIG_NET) +static int __io_accept(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) +{ + struct io_accept *accept = &req->accept; + unsigned file_flags; + int ret; + + file_flags = force_nonblock ? O_NONBLOCK : 0; + ret = __sys_accept4_file(req->file, file_flags, accept->addr, + accept->addr_len, accept->flags); + if (ret == -EAGAIN && force_nonblock) + return -EAGAIN; + if (ret == -ERESTARTSYS) + ret = -EINTR; + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; +} + +static void io_accept_finish(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; + + if (io_req_cancelled(req)) + return; + __io_accept(req, &nxt, false); + if (nxt) + io_wq_assign_next(workptr, nxt); +} +#endif + +static int io_accept(struct io_kiocb *req, struct io_kiocb **nxt, + bool force_nonblock) { #if defined(CONFIG_NET) - return io_send_recvmsg(req, sqe, force_nonblock, __sys_sendmsg_sock); + int ret; + + ret = __io_accept(req, nxt, force_nonblock); + if (ret == -EAGAIN && force_nonblock) { + req->work.func = io_accept_finish; + io_put_req(req); + return -EAGAIN; + } + return 0; #else return -EOPNOTSUPP; #endif } -static int io_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, +static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_NET) + struct io_connect *conn = &req->connect; + struct io_async_ctx *io = req->io; + + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + return -EINVAL; + if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags) + return -EINVAL; + + conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + conn->addr_len = READ_ONCE(sqe->addr2); + + if (!io) + return 0; + + return move_addr_to_kernel(conn->addr, conn->addr_len, + &io->connect.address); +#else + return -EOPNOTSUPP; +#endif +} + +static int io_connect(struct io_kiocb *req, struct io_kiocb **nxt, bool force_nonblock) { #if defined(CONFIG_NET) - return io_send_recvmsg(req, sqe, force_nonblock, __sys_recvmsg_sock); + struct io_async_ctx __io, *io; + unsigned file_flags; + int ret; + + if (req->io) { + io = req->io; + } else { + ret = move_addr_to_kernel(req->connect.addr, + req->connect.addr_len, + &__io.connect.address); + if (ret) + goto out; + io = &__io; + } + + file_flags = force_nonblock ? O_NONBLOCK : 0; + + ret = __sys_connect_file(req->file, &io->connect.address, + req->connect.addr_len, file_flags); + if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) { + if (req->io) + return -EAGAIN; + if (io_alloc_async_ctx(req)) { + ret = -ENOMEM; + goto out; + } + memcpy(&req->io->connect, &__io.connect, sizeof(__io.connect)); + return -EAGAIN; + } + if (ret == -ERESTARTSYS) + ret = -EINTR; +out: + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req_find_next(req, nxt); + return 0; #else return -EOPNOTSUPP; #endif @@ -1490,73 +3453,111 @@ static void io_poll_remove_one(struct io_kiocb *req) WRITE_ONCE(poll->canceled, true); if (!list_empty(&poll->wait.entry)) { list_del_init(&poll->wait.entry); - queue_work(req->ctx->sqo_wq, &req->work); + io_queue_async_work(req); } spin_unlock(&poll->head->lock); - - list_del_init(&req->list); + hash_del(&req->hash_node); } static void io_poll_remove_all(struct io_ring_ctx *ctx) { + struct hlist_node *tmp; struct io_kiocb *req; + int i; spin_lock_irq(&ctx->completion_lock); - while (!list_empty(&ctx->cancel_list)) { - req = list_first_entry(&ctx->cancel_list, struct io_kiocb,list); - io_poll_remove_one(req); + for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { + struct hlist_head *list; + + list = &ctx->cancel_hash[i]; + hlist_for_each_entry_safe(req, tmp, list, hash_node) + io_poll_remove_one(req); } spin_unlock_irq(&ctx->completion_lock); } -/* - * Find a running poll command that matches one specified in sqe->addr, - * and remove it if found. - */ -static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) { - struct io_ring_ctx *ctx = req->ctx; - struct io_kiocb *poll_req, *next; - int ret = -ENOENT; + struct hlist_head *list; + struct io_kiocb *req; + list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)]; + hlist_for_each_entry(req, list, hash_node) { + if (sqe_addr == req->user_data) { + io_poll_remove_one(req); + return 0; + } + } + + return -ENOENT; +} + +static int io_poll_remove_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || sqe->poll_events) return -EINVAL; + req->poll.addr = READ_ONCE(sqe->addr); + return 0; +} + +/* + * Find a running poll command that matches one specified in sqe->addr, + * and remove it if found. + */ +static int io_poll_remove(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + u64 addr; + int ret; + + addr = req->poll.addr; spin_lock_irq(&ctx->completion_lock); - list_for_each_entry_safe(poll_req, next, &ctx->cancel_list, list) { - if (READ_ONCE(sqe->addr) == poll_req->user_data) { - io_poll_remove_one(poll_req); - ret = 0; - break; - } - } + ret = io_poll_cancel(ctx, addr); spin_unlock_irq(&ctx->completion_lock); - io_cqring_add_event(req->ctx, sqe->user_data, ret); + io_cqring_add_event(req, ret); + if (ret < 0) + req_set_fail_links(req); io_put_req(req); return 0; } -static void io_poll_complete(struct io_ring_ctx *ctx, struct io_kiocb *req, - __poll_t mask) +static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) { + struct io_ring_ctx *ctx = req->ctx; + req->poll.done = true; - io_cqring_fill_event(ctx, req->user_data, mangle_poll(mask)); + if (error) + io_cqring_fill_event(req, error); + else + io_cqring_fill_event(req, mangle_poll(mask)); io_commit_cqring(ctx); } -static void io_poll_complete_work(struct work_struct *work) +static void io_poll_complete_work(struct io_wq_work **workptr) { + struct io_wq_work *work = *workptr; struct io_kiocb *req = container_of(work, struct io_kiocb, work); struct io_poll_iocb *poll = &req->poll; struct poll_table_struct pt = { ._key = poll->events }; struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *nxt = NULL; __poll_t mask = 0; + int ret = 0; - if (!READ_ONCE(poll->canceled)) + if (work->flags & IO_WQ_WORK_CANCEL) { + WRITE_ONCE(poll->canceled, true); + ret = -ECANCELED; + } else if (READ_ONCE(poll->canceled)) { + ret = -ECANCELED; + } + + if (ret != -ECANCELED) mask = vfs_poll(poll->file, &pt) & poll->events; /* @@ -1567,28 +3568,72 @@ static void io_poll_complete_work(struct work_struct *work) * avoid further branches in the fast path. */ spin_lock_irq(&ctx->completion_lock); - if (!mask && !READ_ONCE(poll->canceled)) { + if (!mask && ret != -ECANCELED) { add_wait_queue(poll->head, &poll->wait); spin_unlock_irq(&ctx->completion_lock); return; } - list_del_init(&req->list); - io_poll_complete(ctx, req, mask); + hash_del(&req->hash_node); + io_poll_complete(req, mask, ret); + spin_unlock_irq(&ctx->completion_lock); + + io_cqring_ev_posted(ctx); + + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, &nxt); + if (nxt) + io_wq_assign_next(workptr, nxt); +} + +static void __io_poll_flush(struct io_ring_ctx *ctx, struct llist_node *nodes) +{ + struct io_kiocb *req, *tmp; + struct req_batch rb; + + rb.to_free = rb.need_iter = 0; + spin_lock_irq(&ctx->completion_lock); + llist_for_each_entry_safe(req, tmp, nodes, llist_node) { + hash_del(&req->hash_node); + io_poll_complete(req, req->result, 0); + + if (refcount_dec_and_test(&req->refs) && + !io_req_multi_free(&rb, req)) { + req->flags |= REQ_F_COMP_LOCKED; + io_free_req(req); + } + } spin_unlock_irq(&ctx->completion_lock); io_cqring_ev_posted(ctx); + io_free_req_many(ctx, &rb); +} + +static void io_poll_flush(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + struct llist_node *nodes; + + nodes = llist_del_all(&req->ctx->poll_llist); + if (nodes) + __io_poll_flush(req->ctx, nodes); +} + +static void io_poll_trigger_evfd(struct io_wq_work **workptr) +{ + struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); + + eventfd_signal(req->ctx->cq_ev_fd, 1); io_put_req(req); } static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, void *key) { - struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb, - wait); + struct io_poll_iocb *poll = wait->private; struct io_kiocb *req = container_of(poll, struct io_kiocb, poll); struct io_ring_ctx *ctx = req->ctx; __poll_t mask = key_to_poll(key); - unsigned long flags; /* for instances that support it check for an event match first: */ if (mask && !(mask & poll->events)) @@ -1596,16 +3641,45 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, list_del_init(&poll->wait.entry); - if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) { - list_del(&req->list); - io_poll_complete(ctx, req, mask); - spin_unlock_irqrestore(&ctx->completion_lock, flags); + /* + * Run completion inline if we can. We're using trylock here because + * we are violating the completion_lock -> poll wq lock ordering. + * If we have a link timeout we're going to need the completion_lock + * for finalizing the request, mark us as having grabbed that already. + */ + if (mask) { + unsigned long flags; - io_cqring_ev_posted(ctx); - io_put_req(req); - } else { - queue_work(ctx->sqo_wq, &req->work); + if (llist_empty(&ctx->poll_llist) && + spin_trylock_irqsave(&ctx->completion_lock, flags)) { + bool trigger_ev; + + hash_del(&req->hash_node); + io_poll_complete(req, mask, 0); + + trigger_ev = io_should_trigger_evfd(ctx); + if (trigger_ev && eventfd_signal_count()) { + trigger_ev = false; + req->work.func = io_poll_trigger_evfd; + } else { + req->flags |= REQ_F_COMP_LOCKED; + io_put_req(req); + req = NULL; + } + spin_unlock_irqrestore(&ctx->completion_lock, flags); + __io_cqring_ev_posted(ctx, trigger_ev); + } else { + req->result = mask; + req->llist_node.next = NULL; + /* if the list wasn't empty, we're done */ + if (!llist_add(&req->llist_node, &ctx->poll_llist)) + req = NULL; + else + req->work.func = io_poll_flush; + } } + if (req) + io_queue_async_work(req); return 1; } @@ -1631,13 +3705,18 @@ static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, add_wait_queue(head, &pt->req->poll.wait); } -static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static void io_poll_req_insert(struct io_kiocb *req) { - struct io_poll_iocb *poll = &req->poll; struct io_ring_ctx *ctx = req->ctx; - struct io_poll_table ipt; - bool cancel = false; - __poll_t mask; + struct hlist_head *list; + + list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; + hlist_add_head(&req->hash_node, list); +} + +static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_poll_iocb *poll = &req->poll; u16 events; if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) @@ -1647,9 +3726,21 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (!poll->file) return -EBADF; - INIT_WORK(&req->work, io_poll_complete_work); events = READ_ONCE(sqe->poll_events); poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; + return 0; +} + +static int io_poll_add(struct io_kiocb *req, struct io_kiocb **nxt) +{ + struct io_poll_iocb *poll = &req->poll; + struct io_ring_ctx *ctx = req->ctx; + struct io_poll_table ipt; + bool cancel = false; + __poll_t mask; + + INIT_IO_WORK(&req->work, io_poll_complete_work); + INIT_HLIST_NODE(&req->hash_node); poll->head = NULL; poll->done = false; @@ -1663,6 +3754,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) /* initialized the list so that we can do list_empty checks */ INIT_LIST_HEAD(&poll->wait.entry); init_waitqueue_func_entry(&poll->wait, io_poll_wake); + poll->wait.private = poll; INIT_LIST_HEAD(&req->list); @@ -1682,334 +3774,823 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) else if (cancel) WRITE_ONCE(poll->canceled, true); else if (!poll->done) /* actually waiting for an event */ - list_add_tail(&req->list, &ctx->cancel_list); + io_poll_req_insert(req); spin_unlock(&poll->head->lock); } if (mask) { /* no async, we'd stolen it */ ipt.error = 0; - io_poll_complete(ctx, req, mask); + io_poll_complete(req, mask, 0); } spin_unlock_irq(&ctx->completion_lock); if (mask) { io_cqring_ev_posted(ctx); - io_put_req(req); + io_put_req_find_next(req, nxt); } return ipt.error; } -static int io_req_defer(struct io_ring_ctx *ctx, struct io_kiocb *req, - const struct io_uring_sqe *sqe) +static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) { - struct io_uring_sqe *sqe_copy; + struct io_timeout_data *data = container_of(timer, + struct io_timeout_data, timer); + struct io_kiocb *req = data->req; + struct io_ring_ctx *ctx = req->ctx; + unsigned long flags; - if (!io_sequence_defer(ctx, req) && list_empty(&ctx->defer_list)) - return 0; + atomic_inc(&ctx->cq_timeouts); - sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); - if (!sqe_copy) - return -EAGAIN; + spin_lock_irqsave(&ctx->completion_lock, flags); + /* + * We could be racing with timeout deletion. If the list is empty, + * then timeout lookup already found it and will be handling it. + */ + if (!list_empty(&req->list)) { + struct io_kiocb *prev; + + /* + * Adjust the reqs sequence before the current one because it + * will consume a slot in the cq_ring and the cq_tail + * pointer will be increased, otherwise other timeout reqs may + * return in advance without waiting for enough wait_nr. + */ + prev = req; + list_for_each_entry_continue_reverse(prev, &ctx->timeout_list, list) + prev->sequence++; + list_del_init(&req->list); + } + + io_cqring_fill_event(req, -ETIME); + io_commit_cqring(ctx); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + + io_cqring_ev_posted(ctx); + req_set_fail_links(req); + io_put_req(req); + return HRTIMER_NORESTART; +} + +static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) +{ + struct io_kiocb *req; + int ret = -ENOENT; + + list_for_each_entry(req, &ctx->timeout_list, list) { + if (user_data == req->user_data) { + list_del_init(&req->list); + ret = 0; + break; + } + } + + if (ret == -ENOENT) + return ret; + + ret = hrtimer_try_to_cancel(&req->io->timeout.timer); + if (ret == -1) + return -EALREADY; + + req_set_fail_links(req); + io_cqring_fill_event(req, -ECANCELED); + io_put_req(req); + return 0; +} + +static int io_timeout_remove_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len) + return -EINVAL; + + req->timeout.addr = READ_ONCE(sqe->addr); + req->timeout.flags = READ_ONCE(sqe->timeout_flags); + if (req->timeout.flags) + return -EINVAL; + + return 0; +} + +/* + * Remove or update an existing timeout command + */ +static int io_timeout_remove(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + int ret; spin_lock_irq(&ctx->completion_lock); - if (!io_sequence_defer(ctx, req) && list_empty(&ctx->defer_list)) { - spin_unlock_irq(&ctx->completion_lock); - kfree(sqe_copy); - return 0; + ret = io_timeout_cancel(ctx, req->timeout.addr); + + io_cqring_fill_event(req, ret); + io_commit_cqring(ctx); + spin_unlock_irq(&ctx->completion_lock); + io_cqring_ev_posted(ctx); + if (ret < 0) + req_set_fail_links(req); + io_put_req(req); + return 0; +} + +static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool is_timeout_link) +{ + struct io_timeout_data *data; + unsigned flags; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->ioprio || sqe->buf_index || sqe->len != 1) + return -EINVAL; + if (sqe->off && is_timeout_link) + return -EINVAL; + flags = READ_ONCE(sqe->timeout_flags); + if (flags & ~IORING_TIMEOUT_ABS) + return -EINVAL; + + req->timeout.count = READ_ONCE(sqe->off); + + if (!req->io && io_alloc_async_ctx(req)) + return -ENOMEM; + + data = &req->io->timeout; + data->req = req; + req->flags |= REQ_F_TIMEOUT; + + if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) + return -EFAULT; + + if (flags & IORING_TIMEOUT_ABS) + data->mode = HRTIMER_MODE_ABS; + else + data->mode = HRTIMER_MODE_REL; + + hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); + return 0; +} + +static int io_timeout(struct io_kiocb *req) +{ + unsigned count; + struct io_ring_ctx *ctx = req->ctx; + struct io_timeout_data *data; + struct list_head *entry; + unsigned span = 0; + + data = &req->io->timeout; + + /* + * sqe->off holds how many events that need to occur for this + * timeout event to be satisfied. If it isn't set, then this is + * a pure timeout request, sequence isn't used. + */ + count = req->timeout.count; + if (!count) { + req->flags |= REQ_F_TIMEOUT_NOSEQ; + spin_lock_irq(&ctx->completion_lock); + entry = ctx->timeout_list.prev; + goto add; } - memcpy(sqe_copy, sqe, sizeof(*sqe_copy)); - req->submit.sqe = sqe_copy; + req->sequence = ctx->cached_sq_head + count - 1; + data->seq_offset = count; - INIT_WORK(&req->work, io_sq_wq_submit_work); - list_add_tail(&req->list, &ctx->defer_list); + /* + * Insertion sort, ensuring the first entry in the list is always + * the one we need first. + */ + spin_lock_irq(&ctx->completion_lock); + list_for_each_prev(entry, &ctx->timeout_list) { + struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, list); + unsigned nxt_sq_head; + long long tmp, tmp_nxt; + u32 nxt_offset = nxt->io->timeout.seq_offset; + + if (nxt->flags & REQ_F_TIMEOUT_NOSEQ) + continue; + + /* + * Since cached_sq_head + count - 1 can overflow, use type long + * long to store it. + */ + tmp = (long long)ctx->cached_sq_head + count - 1; + nxt_sq_head = nxt->sequence - nxt_offset + 1; + tmp_nxt = (long long)nxt_sq_head + nxt_offset - 1; + + /* + * cached_sq_head may overflow, and it will never overflow twice + * once there is some timeout req still be valid. + */ + if (ctx->cached_sq_head < nxt_sq_head) + tmp += UINT_MAX; + + if (tmp > tmp_nxt) + break; + + /* + * Sequence of reqs after the insert one and itself should + * be adjusted because each timeout req consumes a slot. + */ + span++; + nxt->sequence++; + } + req->sequence -= span; +add: + list_add(&req->list, entry); + data->timer.function = io_timeout_fn; + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); spin_unlock_irq(&ctx->completion_lock); - return -EIOCBQUEUED; + return 0; +} + +static bool io_cancel_cb(struct io_wq_work *work, void *data) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + return req->user_data == (unsigned long) data; } -static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, - const struct sqe_submit *s, bool force_nonblock) +static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) { - int ret, opcode; + enum io_wq_cancel cancel_ret; + int ret = 0; - req->user_data = READ_ONCE(s->sqe->user_data); + cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr); + switch (cancel_ret) { + case IO_WQ_CANCEL_OK: + ret = 0; + break; + case IO_WQ_CANCEL_RUNNING: + ret = -EALREADY; + break; + case IO_WQ_CANCEL_NOTFOUND: + ret = -ENOENT; + break; + } - if (unlikely(s->index >= ctx->sq_entries)) + return ret; +} + +static void io_async_find_and_cancel(struct io_ring_ctx *ctx, + struct io_kiocb *req, __u64 sqe_addr, + struct io_kiocb **nxt, int success_ret) +{ + unsigned long flags; + int ret; + + ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr); + if (ret != -ENOENT) { + spin_lock_irqsave(&ctx->completion_lock, flags); + goto done; + } + + spin_lock_irqsave(&ctx->completion_lock, flags); + ret = io_timeout_cancel(ctx, sqe_addr); + if (ret != -ENOENT) + goto done; + ret = io_poll_cancel(ctx, sqe_addr); +done: + if (!ret) + ret = success_ret; + io_cqring_fill_event(req, ret); + io_commit_cqring(ctx); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + io_cqring_ev_posted(ctx); + + if (ret < 0) + req_set_fail_links(req); + io_put_req_find_next(req, nxt); +} + +static int io_async_cancel_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->flags || sqe->ioprio || sqe->off || sqe->len || + sqe->cancel_flags) return -EINVAL; - opcode = READ_ONCE(s->sqe->opcode); - switch (opcode) { + req->cancel.addr = READ_ONCE(sqe->addr); + return 0; +} + +static int io_async_cancel(struct io_kiocb *req, struct io_kiocb **nxt) +{ + struct io_ring_ctx *ctx = req->ctx; + + io_async_find_and_cancel(ctx, req, req->cancel.addr, nxt, 0); + return 0; +} + +static int io_files_update_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + if (sqe->flags || sqe->ioprio || sqe->rw_flags) + return -EINVAL; + + req->files_update.offset = READ_ONCE(sqe->off); + req->files_update.nr_args = READ_ONCE(sqe->len); + if (!req->files_update.nr_args) + return -EINVAL; + req->files_update.arg = READ_ONCE(sqe->addr); + return 0; +} + +static int io_files_update(struct io_kiocb *req, bool force_nonblock) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_uring_files_update up; + int ret; + + if (force_nonblock) + return -EAGAIN; + + up.offset = req->files_update.offset; + up.fds = req->files_update.arg; + + mutex_lock(&ctx->uring_lock); + ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args); + mutex_unlock(&ctx->uring_lock); + + if (ret < 0) + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req(req); + return 0; +} + +static int io_req_defer_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + ssize_t ret = 0; + + if (io_op_defs[req->opcode].file_table) { + ret = io_grab_files(req); + if (unlikely(ret)) + return ret; + } + + io_req_work_grab_env(req, &io_op_defs[req->opcode]); + + switch (req->opcode) { case IORING_OP_NOP: - ret = io_nop(req, req->user_data); break; case IORING_OP_READV: - if (unlikely(s->sqe->buf_index)) - return -EINVAL; - ret = io_read(req, s, force_nonblock); - break; - case IORING_OP_WRITEV: - if (unlikely(s->sqe->buf_index)) - return -EINVAL; - ret = io_write(req, s, force_nonblock); - break; case IORING_OP_READ_FIXED: - ret = io_read(req, s, force_nonblock); + case IORING_OP_READ: + ret = io_read_prep(req, sqe, true); break; + case IORING_OP_WRITEV: case IORING_OP_WRITE_FIXED: - ret = io_write(req, s, force_nonblock); - break; - case IORING_OP_FSYNC: - ret = io_fsync(req, s->sqe, force_nonblock); + case IORING_OP_WRITE: + ret = io_write_prep(req, sqe, true); break; case IORING_OP_POLL_ADD: - ret = io_poll_add(req, s->sqe); + ret = io_poll_add_prep(req, sqe); break; case IORING_OP_POLL_REMOVE: - ret = io_poll_remove(req, s->sqe); + ret = io_poll_remove_prep(req, sqe); + break; + case IORING_OP_FSYNC: + ret = io_prep_fsync(req, sqe); break; case IORING_OP_SYNC_FILE_RANGE: - ret = io_sync_file_range(req, s->sqe, force_nonblock); + ret = io_prep_sfr(req, sqe); break; case IORING_OP_SENDMSG: - ret = io_sendmsg(req, s->sqe, force_nonblock); + case IORING_OP_SEND: + ret = io_sendmsg_prep(req, sqe); break; case IORING_OP_RECVMSG: - ret = io_recvmsg(req, s->sqe, force_nonblock); + case IORING_OP_RECV: + ret = io_recvmsg_prep(req, sqe); + break; + case IORING_OP_CONNECT: + ret = io_connect_prep(req, sqe); + break; + case IORING_OP_TIMEOUT: + ret = io_timeout_prep(req, sqe, false); + break; + case IORING_OP_TIMEOUT_REMOVE: + ret = io_timeout_remove_prep(req, sqe); + break; + case IORING_OP_ASYNC_CANCEL: + ret = io_async_cancel_prep(req, sqe); + break; + case IORING_OP_LINK_TIMEOUT: + ret = io_timeout_prep(req, sqe, true); + break; + case IORING_OP_ACCEPT: + ret = io_accept_prep(req, sqe); + break; + case IORING_OP_FALLOCATE: + ret = io_fallocate_prep(req, sqe); + break; + case IORING_OP_OPENAT: + ret = io_openat_prep(req, sqe); + break; + case IORING_OP_CLOSE: + ret = io_close_prep(req, sqe); + break; + case IORING_OP_FILES_UPDATE: + ret = io_files_update_prep(req, sqe); + break; + case IORING_OP_STATX: + ret = io_statx_prep(req, sqe); + break; + case IORING_OP_FADVISE: + ret = io_fadvise_prep(req, sqe); + break; + case IORING_OP_MADVISE: + ret = io_madvise_prep(req, sqe); + break; + case IORING_OP_OPENAT2: + ret = io_openat2_prep(req, sqe); + break; + case IORING_OP_EPOLL_CTL: + ret = io_epoll_ctl_prep(req, sqe); break; default: + printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", + req->opcode); ret = -EINVAL; break; } - if (ret) - return ret; + return ret; +} - if (ctx->flags & IORING_SETUP_IOPOLL) { - if (req->result == -EAGAIN) - return -EAGAIN; +static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_ring_ctx *ctx = req->ctx; + int ret; - /* workqueue context doesn't hold uring_lock, grab it now */ - if (s->needs_lock) - mutex_lock(&ctx->uring_lock); - io_iopoll_req_issued(req); - if (s->needs_lock) - mutex_unlock(&ctx->uring_lock); + /* Still need defer if there is pending req in defer list. */ + if (!req_need_defer(req) && list_empty(&ctx->defer_list)) + return 0; + + if (!req->io && io_alloc_async_ctx(req)) + return -EAGAIN; + + ret = io_req_defer_prep(req, sqe); + if (ret < 0) + return ret; + + spin_lock_irq(&ctx->completion_lock); + if (!req_need_defer(req) && list_empty(&ctx->defer_list)) { + spin_unlock_irq(&ctx->completion_lock); + return 0; } - return 0; + trace_io_uring_defer(ctx, req, req->user_data); + list_add_tail(&req->list, &ctx->defer_list); + spin_unlock_irq(&ctx->completion_lock); + return -EIOCBQUEUED; } -static struct async_list *io_async_list_from_sqe(struct io_ring_ctx *ctx, - const struct io_uring_sqe *sqe) +static void io_cleanup_req(struct io_kiocb *req) { - switch (sqe->opcode) { + struct io_async_ctx *io = req->io; + + switch (req->opcode) { case IORING_OP_READV: case IORING_OP_READ_FIXED: - return &ctx->pending_async[READ]; + case IORING_OP_READ: case IORING_OP_WRITEV: case IORING_OP_WRITE_FIXED: - return &ctx->pending_async[WRITE]; - default: - return NULL; + case IORING_OP_WRITE: + if (io->rw.iov != io->rw.fast_iov) + kfree(io->rw.iov); + break; + case IORING_OP_SENDMSG: + case IORING_OP_RECVMSG: + if (io->msg.iov != io->msg.fast_iov) + kfree(io->msg.iov); + break; + case IORING_OP_OPENAT: + case IORING_OP_OPENAT2: + case IORING_OP_STATX: + putname(req->open.filename); + break; } -} - -static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) -{ - u8 opcode = READ_ONCE(sqe->opcode); - return !(opcode == IORING_OP_READ_FIXED || - opcode == IORING_OP_WRITE_FIXED); + req->flags &= ~REQ_F_NEED_CLEANUP; } -static void io_sq_wq_submit_work(struct work_struct *work) +static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, + struct io_kiocb **nxt, bool force_nonblock) { - struct io_kiocb *req = container_of(work, struct io_kiocb, work); struct io_ring_ctx *ctx = req->ctx; - struct mm_struct *cur_mm = NULL; - struct async_list *async_list; - LIST_HEAD(req_list); - mm_segment_t old_fs; int ret; - async_list = io_async_list_from_sqe(ctx, req->submit.sqe); -restart: - do { - struct sqe_submit *s = &req->submit; - const struct io_uring_sqe *sqe = s->sqe; - unsigned int flags = req->flags; - - /* Ensure we clear previously set non-block flag */ - req->rw.ki_flags &= ~IOCB_NOWAIT; - - ret = 0; - if (io_sqe_needs_user(sqe) && !cur_mm) { - if (!mmget_not_zero(ctx->sqo_mm)) { - ret = -EFAULT; - } else { - cur_mm = ctx->sqo_mm; - use_mm(cur_mm); - old_fs = get_fs(); - set_fs(USER_DS); - } + switch (req->opcode) { + case IORING_OP_NOP: + ret = io_nop(req); + break; + case IORING_OP_READV: + case IORING_OP_READ_FIXED: + case IORING_OP_READ: + if (sqe) { + ret = io_read_prep(req, sqe, force_nonblock); + if (ret < 0) + break; } - - if (!ret) { - s->has_user = cur_mm != NULL; - s->needs_lock = true; - do { - ret = __io_submit_sqe(ctx, req, s, false); - /* - * We can get EAGAIN for polled IO even though - * we're forcing a sync submission from here, - * since we can't wait for request slots on the - * block side. - */ - if (ret != -EAGAIN) - break; - cond_resched(); - } while (1); + ret = io_read(req, nxt, force_nonblock); + break; + case IORING_OP_WRITEV: + case IORING_OP_WRITE_FIXED: + case IORING_OP_WRITE: + if (sqe) { + ret = io_write_prep(req, sqe, force_nonblock); + if (ret < 0) + break; } - - /* drop submission reference */ - io_put_req(req); - - if (ret) { - io_cqring_add_event(ctx, sqe->user_data, ret); - io_put_req(req); + ret = io_write(req, nxt, force_nonblock); + break; + case IORING_OP_FSYNC: + if (sqe) { + ret = io_prep_fsync(req, sqe); + if (ret < 0) + break; + } + ret = io_fsync(req, nxt, force_nonblock); + break; + case IORING_OP_POLL_ADD: + if (sqe) { + ret = io_poll_add_prep(req, sqe); + if (ret) + break; + } + ret = io_poll_add(req, nxt); + break; + case IORING_OP_POLL_REMOVE: + if (sqe) { + ret = io_poll_remove_prep(req, sqe); + if (ret < 0) + break; + } + ret = io_poll_remove(req); + break; + case IORING_OP_SYNC_FILE_RANGE: + if (sqe) { + ret = io_prep_sfr(req, sqe); + if (ret < 0) + break; + } + ret = io_sync_file_range(req, nxt, force_nonblock); + break; + case IORING_OP_SENDMSG: + case IORING_OP_SEND: + if (sqe) { + ret = io_sendmsg_prep(req, sqe); + if (ret < 0) + break; + } + if (req->opcode == IORING_OP_SENDMSG) + ret = io_sendmsg(req, nxt, force_nonblock); + else + ret = io_send(req, nxt, force_nonblock); + break; + case IORING_OP_RECVMSG: + case IORING_OP_RECV: + if (sqe) { + ret = io_recvmsg_prep(req, sqe); + if (ret) + break; + } + if (req->opcode == IORING_OP_RECVMSG) + ret = io_recvmsg(req, nxt, force_nonblock); + else + ret = io_recv(req, nxt, force_nonblock); + break; + case IORING_OP_TIMEOUT: + if (sqe) { + ret = io_timeout_prep(req, sqe, false); + if (ret) + break; + } + ret = io_timeout(req); + break; + case IORING_OP_TIMEOUT_REMOVE: + if (sqe) { + ret = io_timeout_remove_prep(req, sqe); + if (ret) + break; + } + ret = io_timeout_remove(req); + break; + case IORING_OP_ACCEPT: + if (sqe) { + ret = io_accept_prep(req, sqe); + if (ret) + break; + } + ret = io_accept(req, nxt, force_nonblock); + break; + case IORING_OP_CONNECT: + if (sqe) { + ret = io_connect_prep(req, sqe); + if (ret) + break; + } + ret = io_connect(req, nxt, force_nonblock); + break; + case IORING_OP_ASYNC_CANCEL: + if (sqe) { + ret = io_async_cancel_prep(req, sqe); + if (ret) + break; + } + ret = io_async_cancel(req, nxt); + break; + case IORING_OP_FALLOCATE: + if (sqe) { + ret = io_fallocate_prep(req, sqe); + if (ret) + break; + } + ret = io_fallocate(req, nxt, force_nonblock); + break; + case IORING_OP_OPENAT: + if (sqe) { + ret = io_openat_prep(req, sqe); + if (ret) + break; + } + ret = io_openat(req, nxt, force_nonblock); + break; + case IORING_OP_CLOSE: + if (sqe) { + ret = io_close_prep(req, sqe); + if (ret) + break; + } + ret = io_close(req, nxt, force_nonblock); + break; + case IORING_OP_FILES_UPDATE: + if (sqe) { + ret = io_files_update_prep(req, sqe); + if (ret) + break; + } + ret = io_files_update(req, force_nonblock); + break; + case IORING_OP_STATX: + if (sqe) { + ret = io_statx_prep(req, sqe); + if (ret) + break; + } + ret = io_statx(req, nxt, force_nonblock); + break; + case IORING_OP_FADVISE: + if (sqe) { + ret = io_fadvise_prep(req, sqe); + if (ret) + break; + } + ret = io_fadvise(req, nxt, force_nonblock); + break; + case IORING_OP_MADVISE: + if (sqe) { + ret = io_madvise_prep(req, sqe); + if (ret) + break; + } + ret = io_madvise(req, nxt, force_nonblock); + break; + case IORING_OP_OPENAT2: + if (sqe) { + ret = io_openat2_prep(req, sqe); + if (ret) + break; } + ret = io_openat2(req, nxt, force_nonblock); + break; + case IORING_OP_EPOLL_CTL: + if (sqe) { + ret = io_epoll_ctl_prep(req, sqe); + if (ret) + break; + } + ret = io_epoll_ctl(req, nxt, force_nonblock); + break; + default: + ret = -EINVAL; + break; + } - /* async context always use a copy of the sqe */ - kfree(sqe); + if (ret) + return ret; - /* req from defer and link list needn't decrease async cnt */ - if (flags & (REQ_F_IO_DRAINED | REQ_F_LINK_DONE)) - goto out; + if (ctx->flags & IORING_SETUP_IOPOLL) { + const bool in_async = io_wq_current_is_worker(); - if (!async_list) - break; - if (!list_empty(&req_list)) { - req = list_first_entry(&req_list, struct io_kiocb, - list); - list_del(&req->list); - continue; - } - if (list_empty(&async_list->list)) - break; + if (req->result == -EAGAIN) + return -EAGAIN; - req = NULL; - spin_lock(&async_list->lock); - if (list_empty(&async_list->list)) { - spin_unlock(&async_list->lock); - break; - } - list_splice_init(&async_list->list, &req_list); - spin_unlock(&async_list->lock); + /* workqueue context doesn't hold uring_lock, grab it now */ + if (in_async) + mutex_lock(&ctx->uring_lock); - req = list_first_entry(&req_list, struct io_kiocb, list); - list_del(&req->list); - } while (req); + io_iopoll_req_issued(req); - /* - * Rare case of racing with a submitter. If we find the count has - * dropped to zero AND we have pending work items, then restart - * the processing. This is a tiny race window. - */ - if (async_list) { - ret = atomic_dec_return(&async_list->cnt); - while (!ret && !list_empty(&async_list->list)) { - spin_lock(&async_list->lock); - atomic_inc(&async_list->cnt); - list_splice_init(&async_list->list, &req_list); - spin_unlock(&async_list->lock); - - if (!list_empty(&req_list)) { - req = list_first_entry(&req_list, - struct io_kiocb, list); - list_del(&req->list); - goto restart; - } - ret = atomic_dec_return(&async_list->cnt); - } + if (in_async) + mutex_unlock(&ctx->uring_lock); } -out: - if (cur_mm) { - set_fs(old_fs); - unuse_mm(cur_mm); - mmput(cur_mm); - } + return 0; } -/* - * See if we can piggy back onto previously submitted work, that is still - * running. We currently only allow this if the new request is sequential - * to the previous one we punted. - */ -static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req) +static void io_wq_submit_work(struct io_wq_work **workptr) { - bool ret = false; + struct io_wq_work *work = *workptr; + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_kiocb *nxt = NULL; + int ret = 0; - if (!list) - return false; - if (!(req->flags & REQ_F_SEQ_PREV)) - return false; - if (!atomic_read(&list->cnt)) - return false; + /* if NO_CANCEL is set, we must still run the work */ + if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) == + IO_WQ_WORK_CANCEL) { + ret = -ECANCELED; + } - ret = true; - spin_lock(&list->lock); - list_add_tail(&req->list, &list->list); - /* - * Ensure we see a simultaneous modification from io_sq_wq_submit_work() - */ - smp_mb(); - if (!atomic_read(&list->cnt)) { - list_del_init(&req->list); - ret = false; + if (!ret) { + req->in_async = true; + do { + ret = io_issue_sqe(req, NULL, &nxt, false); + /* + * We can get EAGAIN for polled IO even though we're + * forcing a sync submission from here, since we can't + * wait for request slots on the block side. + */ + if (ret != -EAGAIN) + break; + cond_resched(); + } while (1); } - spin_unlock(&list->lock); - return ret; + + /* drop submission reference */ + io_put_req(req); + + if (ret) { + req_set_fail_links(req); + io_cqring_add_event(req, ret); + io_put_req(req); + } + + /* if a dependent link is ready, pass it back */ + if (!ret && nxt) + io_wq_assign_next(workptr, nxt); } -static bool io_op_needs_file(const struct io_uring_sqe *sqe) +static int io_req_needs_file(struct io_kiocb *req, int fd) { - int op = READ_ONCE(sqe->opcode); + if (!io_op_defs[req->opcode].needs_file) + return 0; + if ((fd == -1 || fd == AT_FDCWD) && io_op_defs[req->opcode].fd_non_neg) + return 0; + return 1; +} - switch (op) { - case IORING_OP_NOP: - case IORING_OP_POLL_REMOVE: - return false; - default: - return true; - } +static inline struct file *io_file_from_index(struct io_ring_ctx *ctx, + int index) +{ + struct fixed_file_table *table; + + table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT]; + return table->files[index & IORING_FILE_TABLE_MASK];; } -static int io_req_set_file(struct io_ring_ctx *ctx, const struct sqe_submit *s, - struct io_submit_state *state, struct io_kiocb *req) +static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, + const struct io_uring_sqe *sqe) { + struct io_ring_ctx *ctx = req->ctx; unsigned flags; int fd; - flags = READ_ONCE(s->sqe->flags); - fd = READ_ONCE(s->sqe->fd); - - if (flags & IOSQE_IO_DRAIN) { - req->flags |= REQ_F_IO_DRAIN; - req->sequence = ctx->cached_sq_head - 1; - } + flags = READ_ONCE(sqe->flags); + fd = READ_ONCE(sqe->fd); - if (!io_op_needs_file(s->sqe)) + if (!io_req_needs_file(req, fd)) return 0; if (flags & IOSQE_FIXED_FILE) { - if (unlikely(!ctx->user_files || + if (unlikely(!ctx->file_data || (unsigned) fd >= ctx->nr_user_files)) return -EBADF; - req->file = ctx->user_files[fd]; + fd = array_index_nospec(fd, ctx->nr_user_files); + req->file = io_file_from_index(ctx, fd); + if (!req->file) + return -EBADF; req->flags |= REQ_F_FIXED_FILE; + percpu_ref_get(&ctx->file_data->refs); } else { - if (s->needs_fixed_file) + if (req->needs_fixed_file) return -EBADF; + trace_io_uring_file_get(ctx, fd); req->file = io_file_get(state, fd); if (unlikely(!req->file)) return -EBADF; @@ -2018,90 +4599,252 @@ static int io_req_set_file(struct io_ring_ctx *ctx, const struct sqe_submit *s, return 0; } -static int io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, - struct sqe_submit *s) +static int io_grab_files(struct io_kiocb *req) { - int ret; + int ret = -EBADF; + struct io_ring_ctx *ctx = req->ctx; - ret = io_req_defer(ctx, req, s->sqe); - if (ret) { - if (ret != -EIOCBQUEUED) { - io_free_req(req); - io_cqring_add_event(ctx, s->sqe->user_data, ret); - } + if (req->work.files) return 0; + if (!ctx->ring_file) + return -EBADF; + + rcu_read_lock(); + spin_lock_irq(&ctx->inflight_lock); + /* + * We use the f_ops->flush() handler to ensure that we can flush + * out work accessing these files if the fd is closed. Check if + * the fd has changed since we started down this path, and disallow + * this operation if it has. + */ + if (fcheck(ctx->ring_fd) == ctx->ring_file) { + list_add(&req->inflight_entry, &ctx->inflight_list); + req->flags |= REQ_F_INFLIGHT; + req->work.files = current->files; + ret = 0; } + spin_unlock_irq(&ctx->inflight_lock); + rcu_read_unlock(); - ret = __io_submit_sqe(ctx, req, s, true); - if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { - struct io_uring_sqe *sqe_copy; + return ret; +} - sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); - if (sqe_copy) { - struct async_list *list; +static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) +{ + struct io_timeout_data *data = container_of(timer, + struct io_timeout_data, timer); + struct io_kiocb *req = data->req; + struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *prev = NULL; + unsigned long flags; - memcpy(sqe_copy, s->sqe, sizeof(*sqe_copy)); - s->sqe = sqe_copy; + spin_lock_irqsave(&ctx->completion_lock, flags); - memcpy(&req->submit, s, sizeof(*s)); - list = io_async_list_from_sqe(ctx, s->sqe); - if (!io_add_to_prev_work(list, req)) { - if (list) - atomic_inc(&list->cnt); - INIT_WORK(&req->work, io_sq_wq_submit_work); - queue_work(ctx->sqo_wq, &req->work); - } + /* + * We don't expect the list to be empty, that will only happen if we + * race with the completion of the linked work. + */ + if (!list_empty(&req->link_list)) { + prev = list_entry(req->link_list.prev, struct io_kiocb, + link_list); + if (refcount_inc_not_zero(&prev->refs)) { + list_del_init(&req->link_list); + prev->flags &= ~REQ_F_LINK_TIMEOUT; + } else + prev = NULL; + } - /* - * Queued up for async execution, worker will release - * submit reference when the iocb is actually submitted. - */ - return 0; + spin_unlock_irqrestore(&ctx->completion_lock, flags); + + if (prev) { + req_set_fail_links(prev); + io_async_find_and_cancel(ctx, req, prev->user_data, NULL, + -ETIME); + io_put_req(prev); + } else { + io_cqring_add_event(req, -ETIME); + io_put_req(req); + } + return HRTIMER_NORESTART; +} + +static void io_queue_linked_timeout(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + + /* + * If the list is now empty, then our linked request finished before + * we got a chance to setup the timer + */ + spin_lock_irq(&ctx->completion_lock); + if (!list_empty(&req->link_list)) { + struct io_timeout_data *data = &req->io->timeout; + + data->timer.function = io_link_timeout_fn; + hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), + data->mode); + } + spin_unlock_irq(&ctx->completion_lock); + + /* drop submission reference */ + io_put_req(req); +} + +static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) +{ + struct io_kiocb *nxt; + + if (!(req->flags & REQ_F_LINK)) + return NULL; + + nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, + link_list); + if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT) + return NULL; + + req->flags |= REQ_F_LINK_TIMEOUT; + return nxt; +} + +static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_kiocb *linked_timeout; + struct io_kiocb *nxt = NULL; + int ret; + +again: + linked_timeout = io_prep_linked_timeout(req); + + ret = io_issue_sqe(req, sqe, &nxt, true); + + /* + * We async punt it if the file wasn't marked NOWAIT, or if the file + * doesn't support non-blocking read/write attempts + */ + if (ret == -EAGAIN && (!(req->flags & REQ_F_NOWAIT) || + (req->flags & REQ_F_MUST_PUNT))) { +punt: + if (io_op_defs[req->opcode].file_table) { + ret = io_grab_files(req); + if (ret) + goto err; } + + /* + * Queued up for async execution, worker will release + * submit reference when the iocb is actually submitted. + */ + io_queue_async_work(req); + goto done_req; } +err: /* drop submission reference */ io_put_req(req); + if (linked_timeout) { + if (!ret) + io_queue_linked_timeout(linked_timeout); + else + io_put_req(linked_timeout); + } + /* and drop final reference, if we failed */ if (ret) { - io_cqring_add_event(ctx, req->user_data, ret); - if (req->flags & REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + io_cqring_add_event(req, ret); + req_set_fail_links(req); io_put_req(req); } +done_req: + if (nxt) { + req = nxt; + nxt = NULL; - return ret; + if (req->flags & REQ_F_FORCE_ASYNC) + goto punt; + goto again; + } +} + +static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + int ret; + + ret = io_req_defer(req, sqe); + if (ret) { + if (ret != -EIOCBQUEUED) { +fail_req: + io_cqring_add_event(req, ret); + req_set_fail_links(req); + io_double_put_req(req); + } + } else if (req->flags & REQ_F_FORCE_ASYNC) { + ret = io_req_defer_prep(req, sqe); + if (unlikely(ret < 0)) + goto fail_req; + /* + * Never try inline submit of IOSQE_ASYNC is set, go straight + * to async execution. + */ + req->work.flags |= IO_WQ_WORK_CONCURRENT; + io_queue_async_work(req); + } else { + __io_queue_sqe(req, sqe); + } +} + +static inline void io_queue_link_head(struct io_kiocb *req) +{ + if (unlikely(req->flags & REQ_F_FAIL_LINK)) { + io_cqring_add_event(req, -ECANCELED); + io_double_put_req(req); + } else + io_queue_sqe(req, NULL); } -#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK) +#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ + IOSQE_IO_HARDLINK | IOSQE_ASYNC) -static void io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, +static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, struct io_submit_state *state, struct io_kiocb **link) { - struct io_uring_sqe *sqe_copy; - struct io_kiocb *req; - int ret; + const struct cred *old_creds = NULL; + struct io_ring_ctx *ctx = req->ctx; + unsigned int sqe_flags; + int ret, id; + + sqe_flags = READ_ONCE(sqe->flags); /* enforce forwards compatibility on users */ - if (unlikely(s->sqe->flags & ~SQE_VALID_FLAGS)) { + if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) { ret = -EINVAL; - goto err; + goto err_req; } - req = io_get_req(ctx, state); - if (unlikely(!req)) { - ret = -EAGAIN; - goto err; + id = READ_ONCE(sqe->personality); + if (id) { + const struct cred *personality_creds; + + personality_creds = idr_find(&ctx->personality_idr, id); + if (unlikely(!personality_creds)) { + ret = -EINVAL; + goto err_req; + } + old_creds = override_creds(personality_creds); } - ret = io_req_set_file(ctx, s, state, req); + /* same numerical values with corresponding REQ_F_*, safe to copy */ + req->flags |= sqe_flags & (IOSQE_IO_DRAIN|IOSQE_IO_HARDLINK| + IOSQE_ASYNC); + + ret = io_req_set_file(state, req, sqe); if (unlikely(ret)) { err_req: - io_free_req(req); -err: - io_cqring_add_event(ctx, s->sqe->user_data, ret); - return; + io_cqring_add_event(req, ret); + io_double_put_req(req); + if (old_creds) + revert_creds(old_creds); + return false; } /* @@ -2112,26 +4855,58 @@ err: * conditions are true (normal request), then just queue it. */ if (*link) { - struct io_kiocb *prev = *link; + struct io_kiocb *head = *link; - sqe_copy = kmemdup(s->sqe, sizeof(*sqe_copy), GFP_KERNEL); - if (!sqe_copy) { + /* + * Taking sequential execution of a link, draining both sides + * of the link also fullfils IOSQE_IO_DRAIN semantics for all + * requests in the link. So, it drains the head and the + * next after the link request. The last one is done via + * drain_next flag to persist the effect across calls. + */ + if (sqe_flags & IOSQE_IO_DRAIN) { + head->flags |= REQ_F_IO_DRAIN; + ctx->drain_next = 1; + } + if (io_alloc_async_ctx(req)) { ret = -EAGAIN; goto err_req; } - s->sqe = sqe_copy; - memcpy(&req->submit, s, sizeof(*s)); - list_add_tail(&req->list, &prev->link_list); - } else if (s->sqe->flags & IOSQE_IO_LINK) { - req->flags |= REQ_F_LINK; + ret = io_req_defer_prep(req, sqe); + if (ret) { + /* fail even hard links since we don't submit */ + head->flags |= REQ_F_FAIL_LINK; + goto err_req; + } + trace_io_uring_link(ctx, req, head); + list_add_tail(&req->link_list, &head->link_list); - memcpy(&req->submit, s, sizeof(*s)); - INIT_LIST_HEAD(&req->link_list); - *link = req; + /* last request of a link, enqueue the link */ + if (!(sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK))) { + io_queue_link_head(head); + *link = NULL; + } } else { - io_queue_sqe(ctx, req, s); + if (unlikely(ctx->drain_next)) { + req->flags |= REQ_F_IO_DRAIN; + req->ctx->drain_next = 0; + } + if (sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) { + req->flags |= REQ_F_LINK; + INIT_LIST_HEAD(&req->link_list); + ret = io_req_defer_prep(req, sqe); + if (ret) + req->flags |= REQ_F_FAIL_LINK; + *link = req; + } else { + io_queue_sqe(req, sqe); + } } + + if (old_creds) + revert_creds(old_creds); + return true; } /* @@ -2142,15 +4917,14 @@ static void io_submit_state_end(struct io_submit_state *state) blk_finish_plug(&state->plug); io_file_put(state); if (state->free_reqs) - kmem_cache_free_bulk(req_cachep, state->free_reqs, - &state->reqs[state->cur_req]); + kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs); } /* * Start submission side cache. */ static void io_submit_state_start(struct io_submit_state *state, - struct io_ring_ctx *ctx, unsigned max_ios) + unsigned int max_ios) { blk_start_plug(&state->plug); state->free_reqs = 0; @@ -2160,29 +4934,28 @@ static void io_submit_state_start(struct io_submit_state *state, static void io_commit_sqring(struct io_ring_ctx *ctx) { - struct io_sq_ring *ring = ctx->sq_ring; + struct io_rings *rings = ctx->rings; - if (ctx->cached_sq_head != READ_ONCE(ring->r.head)) { - /* - * Ensure any loads from the SQEs are done at this point, - * since once we write the new head, the application could - * write new data to them. - */ - smp_store_release(&ring->r.head, ctx->cached_sq_head); - } + /* + * Ensure any loads from the SQEs are done at this point, + * since once we write the new head, the application could + * write new data to them. + */ + smp_store_release(&rings->sq.head, ctx->cached_sq_head); } /* - * Fetch an sqe, if one is available. Note that s->sqe will point to memory + * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory * that is mapped by userspace. This means that care needs to be taken to * ensure that reads are stable, as we cannot rely on userspace always * being a good citizen. If members of the sqe are validated and then later * used, it's important that those reads are done through READ_ONCE() to * prevent a re-load down the line. */ -static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) +static bool io_get_sqring(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct io_uring_sqe **sqe_ptr) { - struct io_sq_ring *ring = ctx->sq_ring; + u32 *sq_array = ctx->sq_array; unsigned head; /* @@ -2193,101 +4966,157 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) * 2) allows the kernel side to track the head on its own, even * though the application is the one updating it. */ - head = ctx->cached_sq_head; - /* make sure SQ entry isn't read before tail */ - if (head == smp_load_acquire(&ring->r.tail)) - return false; - - head = READ_ONCE(ring->array[head & ctx->sq_mask]); - if (head < ctx->sq_entries) { - s->index = head; - s->sqe = &ctx->sq_sqes[head]; + head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]); + if (likely(head < ctx->sq_entries)) { + /* + * All io need record the previous position, if LINK vs DARIN, + * it can be used to mark the position of the first IO in the + * link list. + */ + req->sequence = ctx->cached_sq_head; + *sqe_ptr = &ctx->sq_sqes[head]; + req->opcode = READ_ONCE((*sqe_ptr)->opcode); + req->user_data = READ_ONCE((*sqe_ptr)->user_data); ctx->cached_sq_head++; return true; } /* drop invalid entries */ ctx->cached_sq_head++; - ring->dropped++; + ctx->cached_sq_dropped++; + WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped); return false; } -static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes, - unsigned int nr, bool has_user, bool mm_fault) +static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, + struct file *ring_file, int ring_fd, + struct mm_struct **mm, bool async) { struct io_submit_state state, *statep = NULL; struct io_kiocb *link = NULL; - bool prev_was_link = false; int i, submitted = 0; + bool mm_fault = false; + + /* if we have a backlog and couldn't flush it all, return BUSY */ + if (test_bit(0, &ctx->sq_check_overflow)) { + if (!list_empty(&ctx->cq_overflow_list) && + !io_cqring_overflow_flush(ctx, false)) + return -EBUSY; + } + + /* make sure SQ entry isn't read before tail */ + nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx)); + + if (!percpu_ref_tryget_many(&ctx->refs, nr)) + return -EAGAIN; if (nr > IO_PLUG_THRESHOLD) { - io_submit_state_start(&state, ctx, nr); + io_submit_state_start(&state, nr); statep = &state; } + ctx->ring_fd = ring_fd; + ctx->ring_file = ring_file; + for (i = 0; i < nr; i++) { - /* - * If previous wasn't linked and we have a linked command, - * that's the end of the chain. Submit the previous link. - */ - if (!prev_was_link && link) { - io_queue_sqe(ctx, link, &link->submit); - link = NULL; + const struct io_uring_sqe *sqe; + struct io_kiocb *req; + int err; + + req = io_get_req(ctx, statep); + if (unlikely(!req)) { + if (!submitted) + submitted = -EAGAIN; + break; + } + if (!io_get_sqring(ctx, req, &sqe)) { + __io_req_do_free(req); + break; } - prev_was_link = (sqes[i].sqe->flags & IOSQE_IO_LINK) != 0; - if (unlikely(mm_fault)) { - io_cqring_add_event(ctx, sqes[i].sqe->user_data, - -EFAULT); - } else { - sqes[i].has_user = has_user; - sqes[i].needs_lock = true; - sqes[i].needs_fixed_file = true; - io_submit_sqe(ctx, &sqes[i], statep, &link); - submitted++; + /* will complete beyond this point, count as submitted */ + submitted++; + + if (unlikely(req->opcode >= IORING_OP_LAST)) { + err = -EINVAL; +fail_req: + io_cqring_add_event(req, err); + io_double_put_req(req); + break; } + + if (io_op_defs[req->opcode].needs_mm && !*mm) { + mm_fault = mm_fault || !mmget_not_zero(ctx->sqo_mm); + if (unlikely(mm_fault)) { + err = -EFAULT; + goto fail_req; + } + use_mm(ctx->sqo_mm); + *mm = ctx->sqo_mm; + } + + req->in_async = async; + req->needs_fixed_file = async; + trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data, + true, async); + if (!io_submit_sqe(req, sqe, statep, &link)) + break; } + if (unlikely(submitted != nr)) { + int ref_used = (submitted == -EAGAIN) ? 0 : submitted; + + percpu_ref_put_many(&ctx->refs, nr - ref_used); + } if (link) - io_queue_sqe(ctx, link, &link->submit); + io_queue_link_head(link); if (statep) io_submit_state_end(&state); + /* Commit SQ ring head once we've consumed and submitted all SQEs */ + io_commit_sqring(ctx); + return submitted; } static int io_sq_thread(void *data) { - struct sqe_submit sqes[IO_IOPOLL_BATCH]; struct io_ring_ctx *ctx = data; struct mm_struct *cur_mm = NULL; + const struct cred *old_cred; mm_segment_t old_fs; DEFINE_WAIT(wait); unsigned inflight; unsigned long timeout; + int ret; - complete(&ctx->sqo_thread_started); + complete(&ctx->completions[1]); old_fs = get_fs(); set_fs(USER_DS); + old_cred = override_creds(ctx->creds); - timeout = inflight = 0; + ret = timeout = inflight = 0; while (!kthread_should_park()) { - bool all_fixed, mm_fault = false; - int i; + unsigned int to_submit; if (inflight) { unsigned nr_events = 0; if (ctx->flags & IORING_SETUP_IOPOLL) { /* - * We disallow the app entering submit/complete - * with polling, but we still need to lock the - * ring to prevent racing with polled issue - * that got punted to a workqueue. + * inflight is the count of the maximum possible + * entries we submitted, but it can be smaller + * if we dropped some of them. If we don't have + * poll entries available, then we know that we + * have nothing left to poll for. Reset the + * inflight count to zero in that case. */ mutex_lock(&ctx->uring_lock); - io_iopoll_check(ctx, &nr_events, 0); + if (!list_empty(&ctx->poll_list)) + __io_iopoll_check(ctx, &nr_events, 0); + else + inflight = 0; mutex_unlock(&ctx->uring_lock); } else { /* @@ -2302,14 +5131,24 @@ static int io_sq_thread(void *data) timeout = jiffies + ctx->sq_thread_idle; } - if (!io_get_sqring(ctx, &sqes[0])) { + to_submit = io_sqring_entries(ctx); + + /* + * If submit got -EBUSY, flag us as needing the application + * to enter the kernel to reap and flush events. + */ + if (!to_submit || ret == -EBUSY) { /* * We're polling. If we're within the defined idle * period, then let us spin without work before going - * to sleep. + * to sleep. The exception is if we got EBUSY doing + * more IO, we should wait for the application to + * reap events and wake us up. */ - if (inflight || !time_after(jiffies, timeout)) { - cpu_relax(); + if (inflight || + (!time_after(jiffies, timeout) && ret != -EBUSY && + !percpu_ref_is_dying(&ctx->refs))) { + cond_resched(); continue; } @@ -2329,11 +5168,12 @@ static int io_sq_thread(void *data) TASK_INTERRUPTIBLE); /* Tell userspace we may need a wakeup call */ - ctx->sq_ring->flags |= IORING_SQ_NEED_WAKEUP; + ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; /* make sure to read SQ tail after writing flags */ smp_mb(); - if (!io_get_sqring(ctx, &sqes[0])) { + to_submit = io_sqring_entries(ctx); + if (!to_submit || ret == -EBUSY) { if (kthread_should_park()) { finish_wait(&ctx->sqo_wait, &wait); break; @@ -2343,39 +5183,19 @@ static int io_sq_thread(void *data) schedule(); finish_wait(&ctx->sqo_wait, &wait); - ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP; + ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; continue; } finish_wait(&ctx->sqo_wait, &wait); - ctx->sq_ring->flags &= ~IORING_SQ_NEED_WAKEUP; + ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; } - i = 0; - all_fixed = true; - do { - if (all_fixed && io_sqe_needs_user(sqes[i].sqe)) - all_fixed = false; - - i++; - if (i == ARRAY_SIZE(sqes)) - break; - } while (io_get_sqring(ctx, &sqes[i])); - - /* Unless all new commands are FIXED regions, grab mm */ - if (!all_fixed && !cur_mm) { - mm_fault = !mmget_not_zero(ctx->sqo_mm); - if (!mm_fault) { - use_mm(ctx->sqo_mm); - cur_mm = ctx->sqo_mm; - } - } - - inflight += io_submit_sqes(ctx, sqes, i, cur_mm != NULL, - mm_fault); - - /* Commit SQ ring head once we've consumed all SQEs */ - io_commit_sqring(ctx); + mutex_lock(&ctx->uring_lock); + ret = io_submit_sqes(ctx, to_submit, NULL, -1, &cur_mm, true); + mutex_unlock(&ctx->uring_lock); + if (ret > 0) + inflight += ret; } set_fs(old_fs); @@ -2383,61 +5203,44 @@ static int io_sq_thread(void *data) unuse_mm(cur_mm); mmput(cur_mm); } + revert_creds(old_cred); kthread_parkme(); return 0; } -static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) -{ - struct io_submit_state state, *statep = NULL; - struct io_kiocb *link = NULL; - bool prev_was_link = false; - int i, submit = 0; - - if (to_submit > IO_PLUG_THRESHOLD) { - io_submit_state_start(&state, ctx, to_submit); - statep = &state; - } - - for (i = 0; i < to_submit; i++) { - struct sqe_submit s; - - if (!io_get_sqring(ctx, &s)) - break; - - /* - * If previous wasn't linked and we have a linked command, - * that's the end of the chain. Submit the previous link. - */ - if (!prev_was_link && link) { - io_queue_sqe(ctx, link, &link->submit); - link = NULL; - } - prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0; - - s.has_user = true; - s.needs_lock = false; - s.needs_fixed_file = false; - submit++; - io_submit_sqe(ctx, &s, statep, &link); - } - io_commit_sqring(ctx); +struct io_wait_queue { + struct wait_queue_entry wq; + struct io_ring_ctx *ctx; + unsigned to_wait; + unsigned nr_timeouts; +}; - if (link) - io_queue_sqe(ctx, link, &link->submit); - if (statep) - io_submit_state_end(statep); +static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush) +{ + struct io_ring_ctx *ctx = iowq->ctx; - return submit; + /* + * Wake up if we have enough events, or if a timeout occurred since we + * started waiting. For timeouts, we always want to return to userspace, + * regardless of event count. + */ + return io_cqring_events(ctx, noflush) >= iowq->to_wait || + atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; } -static unsigned io_cqring_events(struct io_cq_ring *ring) +static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, + int wake_flags, void *key) { - /* See comment at the top of this file */ - smp_rmb(); - return READ_ONCE(ring->r.tail) - READ_ONCE(ring->r.head); + struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, + wq); + + /* use noflush == true, as we can't safely rely on locking context */ + if (!io_should_wake(iowq, true)) + return -1; + + return autoremove_wake_function(curr, mode, wake_flags, key); } /* @@ -2447,10 +5250,19 @@ static unsigned io_cqring_events(struct io_cq_ring *ring) static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, const sigset_t __user *sig, size_t sigsz) { - struct io_cq_ring *ring = ctx->cq_ring; - int ret; + struct io_wait_queue iowq = { + .wq = { + .private = current, + .func = io_wake_function, + .entry = LIST_HEAD_INIT(iowq.wq.entry), + }, + .ctx = ctx, + .to_wait = min_events, + }; + struct io_rings *rings = ctx->rings; + int ret = 0; - if (io_cqring_events(ring) >= min_events) + if (io_cqring_events(ctx, false) >= min_events) return 0; if (sig) { @@ -2466,12 +5278,24 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, return ret; } - ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events); - restore_saved_sigmask_unless(ret == -ERESTARTSYS); - if (ret == -ERESTARTSYS) - ret = -EINTR; + iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); + trace_io_uring_cqring_wait(ctx, min_events); + do { + prepare_to_wait_exclusive(&ctx->wait, &iowq.wq, + TASK_INTERRUPTIBLE); + if (io_should_wake(&iowq, false)) + break; + schedule(); + if (signal_pending(current)) { + ret = -EINTR; + break; + } + } while (1); + finish_wait(&ctx->wait, &iowq.wq); + + restore_saved_sigmask_unless(ret == -EINTR); - return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0; + return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; } static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) @@ -2487,19 +5311,45 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) #else int i; - for (i = 0; i < ctx->nr_user_files; i++) - fput(ctx->user_files[i]); + for (i = 0; i < ctx->nr_user_files; i++) { + struct file *file; + + file = io_file_from_index(ctx, i); + if (file) + fput(file); + } #endif } +static void io_file_ref_kill(struct percpu_ref *ref) +{ + struct fixed_file_data *data; + + data = container_of(ref, struct fixed_file_data, refs); + complete(&data->done); +} + static int io_sqe_files_unregister(struct io_ring_ctx *ctx) { - if (!ctx->user_files) + struct fixed_file_data *data = ctx->file_data; + unsigned nr_tables, i; + + if (!data) return -ENXIO; + percpu_ref_kill_and_confirm(&data->refs, io_file_ref_kill); + flush_work(&data->ref_work); + wait_for_completion(&data->done); + io_ring_file_ref_flush(data); + percpu_ref_exit(&data->refs); + __io_sqe_files_unregister(ctx); - kfree(ctx->user_files); - ctx->user_files = NULL; + nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE); + for (i = 0; i < nr_tables; i++) + kfree(data->table[i].files); + kfree(data->table); + kfree(data); + ctx->file_data = NULL; ctx->nr_user_files = 0; return 0; } @@ -2507,7 +5357,7 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) static void io_sq_thread_stop(struct io_ring_ctx *ctx) { if (ctx->sqo_thread) { - wait_for_completion(&ctx->sqo_thread_started); + wait_for_completion(&ctx->completions[1]); /* * The park is a bit of a work-around, without it we get * warning spews on shutdown with SQPOLL set and affinity @@ -2523,21 +5373,13 @@ static void io_finish_async(struct io_ring_ctx *ctx) { io_sq_thread_stop(ctx); - if (ctx->sqo_wq) { - destroy_workqueue(ctx->sqo_wq); - ctx->sqo_wq = NULL; + if (ctx->io_wq) { + io_wq_destroy(ctx->io_wq); + ctx->io_wq = NULL; } } #if defined(CONFIG_UNIX) -static void io_destruct_skb(struct sk_buff *skb) -{ - struct io_ring_ctx *ctx = skb->sk->sk_user_data; - - io_finish_async(ctx); - unix_destruct_scm(skb); -} - /* * Ensure the UNIX gc is aware of our file set, so we are certain that * the io_uring can be safely unregistered on process exit, even if we have @@ -2548,7 +5390,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) struct sock *sk = ctx->ring_sock->sk; struct scm_fp_list *fpl; struct sk_buff *skb; - int i; + int i, nr_files; if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { unsigned long inflight = ctx->user->unix_inflight + nr; @@ -2568,21 +5410,33 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) } skb->sk = sk; - skb->destructor = io_destruct_skb; + nr_files = 0; fpl->user = get_uid(ctx->user); for (i = 0; i < nr; i++) { - fpl->fp[i] = get_file(ctx->user_files[i + offset]); - unix_inflight(fpl->user, fpl->fp[i]); + struct file *file = io_file_from_index(ctx, i + offset); + + if (!file) + continue; + fpl->fp[nr_files] = get_file(file); + unix_inflight(fpl->user, fpl->fp[nr_files]); + nr_files++; } - fpl->max = fpl->count = nr; - UNIXCB(skb).fp = fpl; - refcount_add(skb->truesize, &sk->sk_wmem_alloc); - skb_queue_head(&sk->sk_receive_queue, skb); + if (nr_files) { + fpl->max = SCM_MAX_FD; + fpl->count = nr_files; + UNIXCB(skb).fp = fpl; + skb->destructor = unix_destruct_scm; + refcount_add(skb->truesize, &sk->sk_wmem_alloc); + skb_queue_head(&sk->sk_receive_queue, skb); - for (i = 0; i < nr; i++) - fput(fpl->fp[i]); + for (i = 0; i < nr_files; i++) + fput(fpl->fp[i]); + } else { + kfree_skb(skb); + kfree(fpl); + } return 0; } @@ -2613,7 +5467,10 @@ static int io_sqe_files_scm(struct io_ring_ctx *ctx) return 0; while (total < ctx->nr_user_files) { - fput(ctx->user_files[total]); + struct file *file = io_file_from_index(ctx, total); + + if (file) + fput(file); total++; } @@ -2626,34 +5483,214 @@ static int io_sqe_files_scm(struct io_ring_ctx *ctx) } #endif +static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables, + unsigned nr_files) +{ + int i; + + for (i = 0; i < nr_tables; i++) { + struct fixed_file_table *table = &ctx->file_data->table[i]; + unsigned this_files; + + this_files = min(nr_files, IORING_MAX_FILES_TABLE); + table->files = kcalloc(this_files, sizeof(struct file *), + GFP_KERNEL); + if (!table->files) + break; + nr_files -= this_files; + } + + if (i == nr_tables) + return 0; + + for (i = 0; i < nr_tables; i++) { + struct fixed_file_table *table = &ctx->file_data->table[i]; + kfree(table->files); + } + return 1; +} + +static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file) +{ +#if defined(CONFIG_UNIX) + struct sock *sock = ctx->ring_sock->sk; + struct sk_buff_head list, *head = &sock->sk_receive_queue; + struct sk_buff *skb; + int i; + + __skb_queue_head_init(&list); + + /* + * Find the skb that holds this file in its SCM_RIGHTS. When found, + * remove this entry and rearrange the file array. + */ + skb = skb_dequeue(head); + while (skb) { + struct scm_fp_list *fp; + + fp = UNIXCB(skb).fp; + for (i = 0; i < fp->count; i++) { + int left; + + if (fp->fp[i] != file) + continue; + + unix_notinflight(fp->user, fp->fp[i]); + left = fp->count - 1 - i; + if (left) { + memmove(&fp->fp[i], &fp->fp[i + 1], + left * sizeof(struct file *)); + } + fp->count--; + if (!fp->count) { + kfree_skb(skb); + skb = NULL; + } else { + __skb_queue_tail(&list, skb); + } + fput(file); + file = NULL; + break; + } + + if (!file) + break; + + __skb_queue_tail(&list, skb); + + skb = skb_dequeue(head); + } + + if (skb_peek(&list)) { + spin_lock_irq(&head->lock); + while ((skb = __skb_dequeue(&list)) != NULL) + __skb_queue_tail(head, skb); + spin_unlock_irq(&head->lock); + } +#else + fput(file); +#endif +} + +struct io_file_put { + struct llist_node llist; + struct file *file; + struct completion *done; +}; + +static void io_ring_file_ref_flush(struct fixed_file_data *data) +{ + struct io_file_put *pfile, *tmp; + struct llist_node *node; + + while ((node = llist_del_all(&data->put_llist)) != NULL) { + llist_for_each_entry_safe(pfile, tmp, node, llist) { + io_ring_file_put(data->ctx, pfile->file); + if (pfile->done) + complete(pfile->done); + else + kfree(pfile); + } + } +} + +static void io_ring_file_ref_switch(struct work_struct *work) +{ + struct fixed_file_data *data; + + data = container_of(work, struct fixed_file_data, ref_work); + io_ring_file_ref_flush(data); + percpu_ref_get(&data->refs); + percpu_ref_switch_to_percpu(&data->refs); +} + +static void io_file_data_ref_zero(struct percpu_ref *ref) +{ + struct fixed_file_data *data; + + data = container_of(ref, struct fixed_file_data, refs); + + /* + * We can't safely switch from inside this context, punt to wq. If + * the table ref is going away, the table is being unregistered. + * Don't queue up the async work for that case, the caller will + * handle it. + */ + if (!percpu_ref_is_dying(&data->refs)) + queue_work(system_wq, &data->ref_work); +} + static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) { __s32 __user *fds = (__s32 __user *) arg; + unsigned nr_tables; + struct file *file; int fd, ret = 0; unsigned i; - if (ctx->user_files) + if (ctx->file_data) return -EBUSY; if (!nr_args) return -EINVAL; if (nr_args > IORING_MAX_FIXED_FILES) return -EMFILE; - ctx->user_files = kcalloc(nr_args, sizeof(struct file *), GFP_KERNEL); - if (!ctx->user_files) + ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL); + if (!ctx->file_data) return -ENOMEM; + ctx->file_data->ctx = ctx; + init_completion(&ctx->file_data->done); + + nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); + ctx->file_data->table = kcalloc(nr_tables, + sizeof(struct fixed_file_table), + GFP_KERNEL); + if (!ctx->file_data->table) { + kfree(ctx->file_data); + ctx->file_data = NULL; + return -ENOMEM; + } + + if (percpu_ref_init(&ctx->file_data->refs, io_file_data_ref_zero, + PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { + kfree(ctx->file_data->table); + kfree(ctx->file_data); + ctx->file_data = NULL; + return -ENOMEM; + } + ctx->file_data->put_llist.first = NULL; + INIT_WORK(&ctx->file_data->ref_work, io_ring_file_ref_switch); + + if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) { + percpu_ref_exit(&ctx->file_data->refs); + kfree(ctx->file_data->table); + kfree(ctx->file_data); + ctx->file_data = NULL; + return -ENOMEM; + } + + for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { + struct fixed_file_table *table; + unsigned index; - for (i = 0; i < nr_args; i++) { ret = -EFAULT; if (copy_from_user(&fd, &fds[i], sizeof(fd))) break; + /* allow sparse sets */ + if (fd == -1) { + ret = 0; + continue; + } - ctx->user_files[i] = fget(fd); + table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; + index = i & IORING_FILE_TABLE_MASK; + file = fget(fd); ret = -EBADF; - if (!ctx->user_files[i]) + if (!file) break; + /* * Don't allow io_uring instances to be registered. If UNIX * isn't enabled, then this causes a reference cycle and this @@ -2661,20 +5698,26 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, * handle it just fine, but there's still no point in allowing * a ring fd as it doesn't support regular read/write anyway. */ - if (ctx->user_files[i]->f_op == &io_uring_fops) { - fput(ctx->user_files[i]); + if (file->f_op == &io_uring_fops) { + fput(file); break; } - ctx->nr_user_files++; ret = 0; + table->files[index] = file; } if (ret) { - for (i = 0; i < ctx->nr_user_files; i++) - fput(ctx->user_files[i]); + for (i = 0; i < ctx->nr_user_files; i++) { + file = io_file_from_index(ctx, i); + if (file) + fput(file); + } + for (i = 0; i < nr_tables; i++) + kfree(ctx->file_data->table[i].files); - kfree(ctx->user_files); - ctx->user_files = NULL; + kfree(ctx->file_data->table); + kfree(ctx->file_data); + ctx->file_data = NULL; ctx->nr_user_files = 0; return ret; } @@ -2686,6 +5729,240 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, return ret; } +static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, + int index) +{ +#if defined(CONFIG_UNIX) + struct sock *sock = ctx->ring_sock->sk; + struct sk_buff_head *head = &sock->sk_receive_queue; + struct sk_buff *skb; + + /* + * See if we can merge this file into an existing skb SCM_RIGHTS + * file set. If there's no room, fall back to allocating a new skb + * and filling it in. + */ + spin_lock_irq(&head->lock); + skb = skb_peek(head); + if (skb) { + struct scm_fp_list *fpl = UNIXCB(skb).fp; + + if (fpl->count < SCM_MAX_FD) { + __skb_unlink(skb, head); + spin_unlock_irq(&head->lock); + fpl->fp[fpl->count] = get_file(file); + unix_inflight(fpl->user, fpl->fp[fpl->count]); + fpl->count++; + spin_lock_irq(&head->lock); + __skb_queue_head(head, skb); + } else { + skb = NULL; + } + } + spin_unlock_irq(&head->lock); + + if (skb) { + fput(file); + return 0; + } + + return __io_sqe_files_scm(ctx, 1, index); +#else + return 0; +#endif +} + +static void io_atomic_switch(struct percpu_ref *ref) +{ + struct fixed_file_data *data; + + data = container_of(ref, struct fixed_file_data, refs); + clear_bit(FFD_F_ATOMIC, &data->state); +} + +static bool io_queue_file_removal(struct fixed_file_data *data, + struct file *file) +{ + struct io_file_put *pfile, pfile_stack; + DECLARE_COMPLETION_ONSTACK(done); + + /* + * If we fail allocating the struct we need for doing async reomval + * of this file, just punt to sync and wait for it. + */ + pfile = kzalloc(sizeof(*pfile), GFP_KERNEL); + if (!pfile) { + pfile = &pfile_stack; + pfile->done = &done; + } + + pfile->file = file; + llist_add(&pfile->llist, &data->put_llist); + + if (pfile == &pfile_stack) { + if (!test_and_set_bit(FFD_F_ATOMIC, &data->state)) { + percpu_ref_put(&data->refs); + percpu_ref_switch_to_atomic(&data->refs, + io_atomic_switch); + } + wait_for_completion(&done); + flush_work(&data->ref_work); + return false; + } + + return true; +} + +static int __io_sqe_files_update(struct io_ring_ctx *ctx, + struct io_uring_files_update *up, + unsigned nr_args) +{ + struct fixed_file_data *data = ctx->file_data; + bool ref_switch = false; + struct file *file; + __s32 __user *fds; + int fd, i, err; + __u32 done; + + if (check_add_overflow(up->offset, nr_args, &done)) + return -EOVERFLOW; + if (done > ctx->nr_user_files) + return -EINVAL; + + done = 0; + fds = u64_to_user_ptr(up->fds); + while (nr_args) { + struct fixed_file_table *table; + unsigned index; + + err = 0; + if (copy_from_user(&fd, &fds[done], sizeof(fd))) { + err = -EFAULT; + break; + } + i = array_index_nospec(up->offset, ctx->nr_user_files); + table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; + index = i & IORING_FILE_TABLE_MASK; + if (table->files[index]) { + file = io_file_from_index(ctx, index); + table->files[index] = NULL; + if (io_queue_file_removal(data, file)) + ref_switch = true; + } + if (fd != -1) { + file = fget(fd); + if (!file) { + err = -EBADF; + break; + } + /* + * Don't allow io_uring instances to be registered. If + * UNIX isn't enabled, then this causes a reference + * cycle and this instance can never get freed. If UNIX + * is enabled we'll handle it just fine, but there's + * still no point in allowing a ring fd as it doesn't + * support regular read/write anyway. + */ + if (file->f_op == &io_uring_fops) { + fput(file); + err = -EBADF; + break; + } + table->files[index] = file; + err = io_sqe_file_register(ctx, file, i); + if (err) + break; + } + nr_args--; + done++; + up->offset++; + } + + if (ref_switch && !test_and_set_bit(FFD_F_ATOMIC, &data->state)) { + percpu_ref_put(&data->refs); + percpu_ref_switch_to_atomic(&data->refs, io_atomic_switch); + } + + return done ? done : err; +} +static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct io_uring_files_update up; + + if (!ctx->file_data) + return -ENXIO; + if (!nr_args) + return -EINVAL; + if (copy_from_user(&up, arg, sizeof(up))) + return -EFAULT; + if (up.resv) + return -EINVAL; + + return __io_sqe_files_update(ctx, &up, nr_args); +} + +static void io_put_work(struct io_wq_work *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + io_put_req(req); +} + +static void io_get_work(struct io_wq_work *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + refcount_inc(&req->refs); +} + +static int io_init_wq_offload(struct io_ring_ctx *ctx, + struct io_uring_params *p) +{ + struct io_wq_data data; + struct fd f; + struct io_ring_ctx *ctx_attach; + unsigned int concurrency; + int ret = 0; + + data.user = ctx->user; + data.get_work = io_get_work; + data.put_work = io_put_work; + + if (!(p->flags & IORING_SETUP_ATTACH_WQ)) { + /* Do QD, or 4 * CPUS, whatever is smallest */ + concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); + + ctx->io_wq = io_wq_create(concurrency, &data); + if (IS_ERR(ctx->io_wq)) { + ret = PTR_ERR(ctx->io_wq); + ctx->io_wq = NULL; + } + return ret; + } + + f = fdget(p->wq_fd); + if (!f.file) + return -EBADF; + + if (f.file->f_op != &io_uring_fops) { + ret = -EINVAL; + goto out_fput; + } + + ctx_attach = f.file->private_data; + /* @io_wq is protected by holding the fd */ + if (!io_wq_get(ctx_attach->io_wq, &data)) { + ret = -EINVAL; + goto out_fput; + } + + ctx->io_wq = ctx_attach->io_wq; +out_fput: + fdput(f); + return ret; +} + static int io_sq_offload_start(struct io_ring_ctx *ctx, struct io_uring_params *p) { @@ -2732,17 +6009,13 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx, goto err; } - /* Do QD, or 2 * CPUS, whatever is smallest */ - ctx->sqo_wq = alloc_workqueue("io_ring-wq", WQ_UNBOUND | WQ_FREEZABLE, - min(ctx->sq_entries - 1, 2 * num_online_cpus())); - if (!ctx->sqo_wq) { - ret = -ENOMEM; + ret = io_init_wq_offload(ctx, p); + if (ret) goto err; - } return 0; err: - io_sq_thread_stop(ctx); + io_finish_async(ctx); mmdrop(ctx->sqo_mm); ctx->sqo_mm = NULL; return ret; @@ -2791,17 +6064,45 @@ static void *io_mem_alloc(size_t size) return (void *) __get_free_pages(gfp_flags, get_order(size)); } +static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, + size_t *sq_offset) +{ + struct io_rings *rings; + size_t off, sq_array_size; + + off = struct_size(rings, cqes, cq_entries); + if (off == SIZE_MAX) + return SIZE_MAX; + +#ifdef CONFIG_SMP + off = ALIGN(off, SMP_CACHE_BYTES); + if (off == 0) + return SIZE_MAX; +#endif + + sq_array_size = array_size(sizeof(u32), sq_entries); + if (sq_array_size == SIZE_MAX) + return SIZE_MAX; + + if (check_add_overflow(off, sq_array_size, &off)) + return SIZE_MAX; + + if (sq_offset) + *sq_offset = off; + + return off; +} + static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) { - struct io_sq_ring *sq_ring; - struct io_cq_ring *cq_ring; - size_t bytes; + size_t pages; - bytes = struct_size(sq_ring, array, sq_entries); - bytes += array_size(sizeof(struct io_uring_sqe), sq_entries); - bytes += struct_size(cq_ring, cqes, cq_entries); + pages = (size_t)1 << get_order( + rings_size(sq_entries, cq_entries, NULL)); + pages += (size_t)1 << get_order( + array_size(sizeof(struct io_uring_sqe), sq_entries)); - return (bytes + PAGE_SIZE - 1) / PAGE_SIZE; + return pages; } static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) @@ -2815,7 +6116,7 @@ static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; for (j = 0; j < imu->nr_bvecs; j++) - put_page(imu->bvec[j].bv_page); + unpin_user_page(imu->bvec[j].bv_page); if (ctx->account_mem) io_unaccount_mem(ctx->user, imu->nr_bvecs); @@ -2843,7 +6144,7 @@ static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) return -EFAULT; - dst->iov_base = (void __user *) (unsigned long) ciov.iov_base; + dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base); dst->iov_len = ciov.iov_len; return 0; } @@ -2936,7 +6237,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, ret = 0; down_read(¤t->mm->mmap_sem); - pret = get_user_pages(ubuf, nr_pages, + pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, pages, vmas); if (pret == nr_pages) { @@ -2959,10 +6260,8 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, * if we did partial map, or found file backed vmas, * release any pages we did get */ - if (pret > 0) { - for (j = 0; j < pret; j++) - put_page(pages[j]); - } + if (pret > 0) + unpin_user_pages(pages, pret); if (ctx->account_mem) io_unaccount_mem(ctx->user, nr_pages); kvfree(imu->bvec); @@ -3048,15 +6347,18 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) } #endif - io_mem_free(ctx->sq_ring); + io_mem_free(ctx->rings); io_mem_free(ctx->sq_sqes); - io_mem_free(ctx->cq_ring); percpu_ref_exit(&ctx->refs); if (ctx->account_mem) io_unaccount_mem(ctx->user, ring_pages(ctx->sq_entries, ctx->cq_entries)); free_uid(ctx->user); + put_cred(ctx->creds); + kfree(ctx->completions); + kfree(ctx->cancel_hash); + kmem_cache_free(req_cachep, ctx->fallback_req); kfree(ctx); } @@ -3071,10 +6373,10 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) * io_commit_cqring */ smp_rmb(); - if (READ_ONCE(ctx->sq_ring->r.tail) - ctx->cached_sq_head != - ctx->sq_ring->ring_entries) + if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != + ctx->rings->sq_ring_entries) mask |= EPOLLOUT | EPOLLWRNORM; - if (READ_ONCE(ctx->cq_ring->r.head) != ctx->cached_cq_tail) + if (io_cqring_events(ctx, false)) mask |= EPOLLIN | EPOLLRDNORM; return mask; @@ -3087,15 +6389,45 @@ static int io_uring_fasync(int fd, struct file *file, int on) return fasync_helper(fd, file, on, &ctx->cq_fasync); } +static int io_remove_personalities(int id, void *p, void *data) +{ + struct io_ring_ctx *ctx = data; + const struct cred *cred; + + cred = idr_remove(&ctx->personality_idr, id); + if (cred) + put_cred(cred); + return 0; +} + static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); percpu_ref_kill(&ctx->refs); mutex_unlock(&ctx->uring_lock); + /* + * Wait for sq thread to idle, if we have one. It won't spin on new + * work after we've killed the ctx ref above. This is important to do + * before we cancel existing commands, as the thread could otherwise + * be queueing new work post that. If that's work we need to cancel, + * it could cause shutdown to hang. + */ + while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait)) + cpu_relax(); + + io_kill_timeouts(ctx); io_poll_remove_all(ctx); + + if (ctx->io_wq) + io_wq_cancel_all(ctx->io_wq); + io_iopoll_reap_events(ctx); - wait_for_completion(&ctx->ctx_done); + /* if we failed setting up the ctx, we might not have any rings */ + if (ctx->rings) + io_cqring_overflow_flush(ctx, true); + idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx); + wait_for_completion(&ctx->completions[0]); io_ring_ctx_free(ctx); } @@ -3108,37 +6440,149 @@ static int io_uring_release(struct inode *inode, struct file *file) return 0; } -static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +static void io_uring_cancel_files(struct io_ring_ctx *ctx, + struct files_struct *files) +{ + struct io_kiocb *req; + DEFINE_WAIT(wait); + + while (!list_empty_careful(&ctx->inflight_list)) { + struct io_kiocb *cancel_req = NULL; + + spin_lock_irq(&ctx->inflight_lock); + list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { + if (req->work.files != files) + continue; + /* req is being completed, ignore */ + if (!refcount_inc_not_zero(&req->refs)) + continue; + cancel_req = req; + break; + } + if (cancel_req) + prepare_to_wait(&ctx->inflight_wait, &wait, + TASK_UNINTERRUPTIBLE); + spin_unlock_irq(&ctx->inflight_lock); + + /* We need to keep going until we don't find a matching req */ + if (!cancel_req) + break; + + if (cancel_req->flags & REQ_F_OVERFLOW) { + spin_lock_irq(&ctx->completion_lock); + list_del(&cancel_req->list); + cancel_req->flags &= ~REQ_F_OVERFLOW; + if (list_empty(&ctx->cq_overflow_list)) { + clear_bit(0, &ctx->sq_check_overflow); + clear_bit(0, &ctx->cq_check_overflow); + } + spin_unlock_irq(&ctx->completion_lock); + + WRITE_ONCE(ctx->rings->cq_overflow, + atomic_inc_return(&ctx->cached_cq_overflow)); + + /* + * Put inflight ref and overflow ref. If that's + * all we had, then we're done with this request. + */ + if (refcount_sub_and_test(2, &cancel_req->refs)) { + io_put_req(cancel_req); + continue; + } + } + + io_wq_cancel_work(ctx->io_wq, &cancel_req->work); + io_put_req(cancel_req); + schedule(); + } + finish_wait(&ctx->inflight_wait, &wait); +} + +static int io_uring_flush(struct file *file, void *data) { - loff_t offset = (loff_t) vma->vm_pgoff << PAGE_SHIFT; - unsigned long sz = vma->vm_end - vma->vm_start; struct io_ring_ctx *ctx = file->private_data; - unsigned long pfn; + + io_uring_cancel_files(ctx, data); + + /* + * If the task is going away, cancel work it may have pending + */ + if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) + io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current)); + + return 0; +} + +static void *io_uring_validate_mmap_request(struct file *file, + loff_t pgoff, size_t sz) +{ + struct io_ring_ctx *ctx = file->private_data; + loff_t offset = pgoff << PAGE_SHIFT; struct page *page; void *ptr; switch (offset) { case IORING_OFF_SQ_RING: - ptr = ctx->sq_ring; + case IORING_OFF_CQ_RING: + ptr = ctx->rings; break; case IORING_OFF_SQES: ptr = ctx->sq_sqes; break; - case IORING_OFF_CQ_RING: - ptr = ctx->cq_ring; - break; default: - return -EINVAL; + return ERR_PTR(-EINVAL); } page = virt_to_head_page(ptr); - if (sz > (PAGE_SIZE << compound_order(page))) - return -EINVAL; + if (sz > page_size(page)) + return ERR_PTR(-EINVAL); + + return ptr; +} + +#ifdef CONFIG_MMU + +static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +{ + size_t sz = vma->vm_end - vma->vm_start; + unsigned long pfn; + void *ptr; + + ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); pfn = virt_to_phys(ptr) >> PAGE_SHIFT; return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); } +#else /* !CONFIG_MMU */ + +static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) +{ + return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL; +} + +static unsigned int io_uring_nommu_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; +} + +static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + void *ptr; + + ptr = io_uring_validate_mmap_request(file, pgoff, len); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + + return (unsigned long) ptr; +} + +#endif /* !CONFIG_MMU */ + SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, u32, min_complete, u32, flags, const sigset_t __user *, sig, size_t, sigsz) @@ -3169,20 +6613,25 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, * Just return the requested submit count, and wake the thread if * we were asked to. */ + ret = 0; if (ctx->flags & IORING_SETUP_SQPOLL) { + if (!list_empty_careful(&ctx->cq_overflow_list)) + io_cqring_overflow_flush(ctx, false); if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sqo_wait); submitted = to_submit; - goto out_ctx; - } - - ret = 0; - if (to_submit) { - to_submit = min(to_submit, ctx->sq_entries); + } else if (to_submit) { + struct mm_struct *cur_mm; mutex_lock(&ctx->uring_lock); - submitted = io_ring_submit(ctx, to_submit); + /* already have mm, so io_submit_sqes() won't try to grab it */ + cur_mm = ctx->sqo_mm; + submitted = io_submit_sqes(ctx, to_submit, f.file, fd, + &cur_mm, false); mutex_unlock(&ctx->uring_lock); + + if (submitted != to_submit) + goto out; } if (flags & IORING_ENTER_GETEVENTS) { unsigned nr_events = 0; @@ -3190,62 +6639,145 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, min_complete = min(min_complete, ctx->cq_entries); if (ctx->flags & IORING_SETUP_IOPOLL) { - mutex_lock(&ctx->uring_lock); ret = io_iopoll_check(ctx, &nr_events, min_complete); - mutex_unlock(&ctx->uring_lock); } else { ret = io_cqring_wait(ctx, min_complete, sig, sigsz); } } -out_ctx: - io_ring_drop_ctx_refs(ctx, 1); +out: + percpu_ref_put(&ctx->refs); out_fput: fdput(f); return submitted ? submitted : ret; } +static int io_uring_show_cred(int id, void *p, void *data) +{ + const struct cred *cred = p; + struct seq_file *m = data; + struct user_namespace *uns = seq_user_ns(m); + struct group_info *gi; + kernel_cap_t cap; + unsigned __capi; + int g; + + seq_printf(m, "%5d\n", id); + seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid)); + seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid)); + seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid)); + seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid)); + seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid)); + seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid)); + seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid)); + seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid)); + seq_puts(m, "\n\tGroups:\t"); + gi = cred->group_info; + for (g = 0; g < gi->ngroups; g++) { + seq_put_decimal_ull(m, g ? " " : "", + from_kgid_munged(uns, gi->gid[g])); + } + seq_puts(m, "\n\tCapEff:\t"); + cap = cred->cap_effective; + CAP_FOR_EACH_U32(__capi) + seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8); + seq_putc(m, '\n'); + return 0; +} + +static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) +{ + int i; + + mutex_lock(&ctx->uring_lock); + seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files); + for (i = 0; i < ctx->nr_user_files; i++) { + struct fixed_file_table *table; + struct file *f; + + table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; + f = table->files[i & IORING_FILE_TABLE_MASK]; + if (f) + seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname); + else + seq_printf(m, "%5u: <none>\n", i); + } + seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); + for (i = 0; i < ctx->nr_user_bufs; i++) { + struct io_mapped_ubuf *buf = &ctx->user_bufs[i]; + + seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, + (unsigned int) buf->len); + } + if (!idr_is_empty(&ctx->personality_idr)) { + seq_printf(m, "Personalities:\n"); + idr_for_each(&ctx->personality_idr, io_uring_show_cred, m); + } + mutex_unlock(&ctx->uring_lock); +} + +static void io_uring_show_fdinfo(struct seq_file *m, struct file *f) +{ + struct io_ring_ctx *ctx = f->private_data; + + if (percpu_ref_tryget(&ctx->refs)) { + __io_uring_show_fdinfo(ctx, m); + percpu_ref_put(&ctx->refs); + } +} + static const struct file_operations io_uring_fops = { .release = io_uring_release, + .flush = io_uring_flush, .mmap = io_uring_mmap, +#ifndef CONFIG_MMU + .get_unmapped_area = io_uring_nommu_get_unmapped_area, + .mmap_capabilities = io_uring_nommu_mmap_capabilities, +#endif .poll = io_uring_poll, .fasync = io_uring_fasync, + .show_fdinfo = io_uring_show_fdinfo, }; static int io_allocate_scq_urings(struct io_ring_ctx *ctx, struct io_uring_params *p) { - struct io_sq_ring *sq_ring; - struct io_cq_ring *cq_ring; - size_t size; + struct io_rings *rings; + size_t size, sq_array_offset; - sq_ring = io_mem_alloc(struct_size(sq_ring, array, p->sq_entries)); - if (!sq_ring) + size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset); + if (size == SIZE_MAX) + return -EOVERFLOW; + + rings = io_mem_alloc(size); + if (!rings) return -ENOMEM; - ctx->sq_ring = sq_ring; - sq_ring->ring_mask = p->sq_entries - 1; - sq_ring->ring_entries = p->sq_entries; - ctx->sq_mask = sq_ring->ring_mask; - ctx->sq_entries = sq_ring->ring_entries; + ctx->rings = rings; + ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); + rings->sq_ring_mask = p->sq_entries - 1; + rings->cq_ring_mask = p->cq_entries - 1; + rings->sq_ring_entries = p->sq_entries; + rings->cq_ring_entries = p->cq_entries; + ctx->sq_mask = rings->sq_ring_mask; + ctx->cq_mask = rings->cq_ring_mask; + ctx->sq_entries = rings->sq_ring_entries; + ctx->cq_entries = rings->cq_ring_entries; size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); - if (size == SIZE_MAX) + if (size == SIZE_MAX) { + io_mem_free(ctx->rings); + ctx->rings = NULL; return -EOVERFLOW; + } ctx->sq_sqes = io_mem_alloc(size); - if (!ctx->sq_sqes) - return -ENOMEM; - - cq_ring = io_mem_alloc(struct_size(cq_ring, cqes, p->cq_entries)); - if (!cq_ring) + if (!ctx->sq_sqes) { + io_mem_free(ctx->rings); + ctx->rings = NULL; return -ENOMEM; + } - ctx->cq_ring = cq_ring; - cq_ring->ring_mask = p->cq_entries - 1; - cq_ring->ring_entries = p->cq_entries; - ctx->cq_mask = cq_ring->ring_mask; - ctx->cq_entries = cq_ring->ring_entries; return 0; } @@ -3281,7 +6813,6 @@ static int io_uring_get_fd(struct io_ring_ctx *ctx) #if defined(CONFIG_UNIX) ctx->ring_sock->file = file; - ctx->ring_sock->sk->sk_user_data = ctx; #endif fd_install(ret, file); return ret; @@ -3300,17 +6831,40 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p) bool account_mem; int ret; - if (!entries || entries > IORING_MAX_ENTRIES) + if (!entries) return -EINVAL; + if (entries > IORING_MAX_ENTRIES) { + if (!(p->flags & IORING_SETUP_CLAMP)) + return -EINVAL; + entries = IORING_MAX_ENTRIES; + } /* * Use twice as many entries for the CQ ring. It's possible for the * application to drive a higher depth than the size of the SQ ring, * since the sqes are only used at submission time. This allows for - * some flexibility in overcommitting a bit. + * some flexibility in overcommitting a bit. If the application has + * set IORING_SETUP_CQSIZE, it will have passed in the desired number + * of CQ ring entries manually. */ p->sq_entries = roundup_pow_of_two(entries); - p->cq_entries = 2 * p->sq_entries; + if (p->flags & IORING_SETUP_CQSIZE) { + /* + * If IORING_SETUP_CQSIZE is set, we do the same roundup + * to a power-of-two, if it isn't already. We do NOT impose + * any cq vs sq ring sizing. + */ + if (p->cq_entries < p->sq_entries) + return -EINVAL; + if (p->cq_entries > IORING_MAX_CQ_ENTRIES) { + if (!(p->flags & IORING_SETUP_CLAMP)) + return -EINVAL; + p->cq_entries = IORING_MAX_CQ_ENTRIES; + } + p->cq_entries = roundup_pow_of_two(p->cq_entries); + } else { + p->cq_entries = 2 * p->sq_entries; + } user = get_uid(current_user()); account_mem = !capable(CAP_IPC_LOCK); @@ -3335,6 +6889,7 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p) ctx->compat = in_compat_syscall(); ctx->account_mem = account_mem; ctx->user = user; + ctx->creds = get_current_cred(); ret = io_allocate_scq_urings(ctx, p); if (ret) @@ -3344,26 +6899,35 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p) if (ret) goto err; + memset(&p->sq_off, 0, sizeof(p->sq_off)); + p->sq_off.head = offsetof(struct io_rings, sq.head); + p->sq_off.tail = offsetof(struct io_rings, sq.tail); + p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); + p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); + p->sq_off.flags = offsetof(struct io_rings, sq_flags); + p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); + p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; + + memset(&p->cq_off, 0, sizeof(p->cq_off)); + p->cq_off.head = offsetof(struct io_rings, cq.head); + p->cq_off.tail = offsetof(struct io_rings, cq.tail); + p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); + p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); + p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); + p->cq_off.cqes = offsetof(struct io_rings, cqes); + + /* + * Install ring fd as the very last thing, so we don't risk someone + * having closed it before we finish setup + */ ret = io_uring_get_fd(ctx); if (ret < 0) goto err; - memset(&p->sq_off, 0, sizeof(p->sq_off)); - p->sq_off.head = offsetof(struct io_sq_ring, r.head); - p->sq_off.tail = offsetof(struct io_sq_ring, r.tail); - p->sq_off.ring_mask = offsetof(struct io_sq_ring, ring_mask); - p->sq_off.ring_entries = offsetof(struct io_sq_ring, ring_entries); - p->sq_off.flags = offsetof(struct io_sq_ring, flags); - p->sq_off.dropped = offsetof(struct io_sq_ring, dropped); - p->sq_off.array = offsetof(struct io_sq_ring, array); - - memset(&p->cq_off, 0, sizeof(p->cq_off)); - p->cq_off.head = offsetof(struct io_cq_ring, r.head); - p->cq_off.tail = offsetof(struct io_cq_ring, r.tail); - p->cq_off.ring_mask = offsetof(struct io_cq_ring, ring_mask); - p->cq_off.ring_entries = offsetof(struct io_cq_ring, ring_entries); - p->cq_off.overflow = offsetof(struct io_cq_ring, overflow); - p->cq_off.cqes = offsetof(struct io_cq_ring, cqes); + p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | + IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | + IORING_FEAT_CUR_PERSONALITY; + trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); return ret; err: io_ring_ctx_wait_and_kill(ctx); @@ -3389,7 +6953,8 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params) } if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | - IORING_SETUP_SQ_AFF)) + IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE | + IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ)) return -EINVAL; ret = io_uring_create(entries, &p); @@ -3408,6 +6973,84 @@ SYSCALL_DEFINE2(io_uring_setup, u32, entries, return io_uring_setup(entries, params); } +static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) +{ + struct io_uring_probe *p; + size_t size; + int i, ret; + + size = struct_size(p, ops, nr_args); + if (size == SIZE_MAX) + return -EOVERFLOW; + p = kzalloc(size, GFP_KERNEL); + if (!p) + return -ENOMEM; + + ret = -EFAULT; + if (copy_from_user(p, arg, size)) + goto out; + ret = -EINVAL; + if (memchr_inv(p, 0, size)) + goto out; + + p->last_op = IORING_OP_LAST - 1; + if (nr_args > IORING_OP_LAST) + nr_args = IORING_OP_LAST; + + for (i = 0; i < nr_args; i++) { + p->ops[i].op = i; + if (!io_op_defs[i].not_supported) + p->ops[i].flags = IO_URING_OP_SUPPORTED; + } + p->ops_len = i; + + ret = 0; + if (copy_to_user(arg, p, size)) + ret = -EFAULT; +out: + kfree(p); + return ret; +} + +static int io_register_personality(struct io_ring_ctx *ctx) +{ + const struct cred *creds = get_current_cred(); + int id; + + id = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1, + USHRT_MAX, GFP_KERNEL); + if (id < 0) + put_cred(creds); + return id; +} + +static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) +{ + const struct cred *old_creds; + + old_creds = idr_remove(&ctx->personality_idr, id); + if (old_creds) { + put_cred(old_creds); + return 0; + } + + return -EINVAL; +} + +static bool io_register_op_must_quiesce(int op) +{ + switch (op) { + case IORING_UNREGISTER_FILES: + case IORING_REGISTER_FILES_UPDATE: + case IORING_REGISTER_PROBE: + case IORING_REGISTER_PERSONALITY: + case IORING_UNREGISTER_PERSONALITY: + return false; + default: + return true; + } +} + static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, void __user *arg, unsigned nr_args) __releases(ctx->uring_lock) @@ -3423,18 +7066,26 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, if (percpu_ref_is_dying(&ctx->refs)) return -ENXIO; - percpu_ref_kill(&ctx->refs); + if (io_register_op_must_quiesce(opcode)) { + percpu_ref_kill(&ctx->refs); - /* - * Drop uring mutex before waiting for references to exit. If another - * thread is currently inside io_uring_enter() it might need to grab - * the uring_lock to make progress. If we hold it here across the drain - * wait, then we can deadlock. It's safe to drop the mutex here, since - * no new references will come in after we've killed the percpu ref. - */ - mutex_unlock(&ctx->uring_lock); - wait_for_completion(&ctx->ctx_done); - mutex_lock(&ctx->uring_lock); + /* + * Drop uring mutex before waiting for references to exit. If + * another thread is currently inside io_uring_enter() it might + * need to grab the uring_lock to make progress. If we hold it + * here across the drain wait, then we can deadlock. It's safe + * to drop the mutex here, since no new references will come in + * after we've killed the percpu ref. + */ + mutex_unlock(&ctx->uring_lock); + ret = wait_for_completion_interruptible(&ctx->completions[0]); + mutex_lock(&ctx->uring_lock); + if (ret) { + percpu_ref_resurrect(&ctx->refs); + ret = -EINTR; + goto out; + } + } switch (opcode) { case IORING_REGISTER_BUFFERS: @@ -3455,11 +7106,21 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; ret = io_sqe_files_unregister(ctx); break; + case IORING_REGISTER_FILES_UPDATE: + ret = io_sqe_files_update(ctx, arg, nr_args); + break; case IORING_REGISTER_EVENTFD: + case IORING_REGISTER_EVENTFD_ASYNC: ret = -EINVAL; if (nr_args != 1) break; ret = io_eventfd_register(ctx, arg); + if (ret) + break; + if (opcode == IORING_REGISTER_EVENTFD_ASYNC) + ctx->eventfd_async = 1; + else + ctx->eventfd_async = 0; break; case IORING_UNREGISTER_EVENTFD: ret = -EINVAL; @@ -3467,14 +7128,35 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; ret = io_eventfd_unregister(ctx); break; + case IORING_REGISTER_PROBE: + ret = -EINVAL; + if (!arg || nr_args > 256) + break; + ret = io_probe(ctx, arg, nr_args); + break; + case IORING_REGISTER_PERSONALITY: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_register_personality(ctx); + break; + case IORING_UNREGISTER_PERSONALITY: + ret = -EINVAL; + if (arg) + break; + ret = io_unregister_personality(ctx, nr_args); + break; default: ret = -EINVAL; break; } - /* bring the ctx back to life */ - reinit_completion(&ctx->ctx_done); - percpu_ref_reinit(&ctx->refs); + if (io_register_op_must_quiesce(opcode)) { + /* bring the ctx back to life */ + percpu_ref_reinit(&ctx->refs); +out: + reinit_completion(&ctx->completions[0]); + } return ret; } @@ -3498,6 +7180,8 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, mutex_lock(&ctx->uring_lock); ret = __io_uring_register(ctx, opcode, arg, nr_args); mutex_unlock(&ctx->uring_lock); + trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs, + ctx->cq_ev_fd != NULL, ret); out_fput: fdput(f); return ret; @@ -3505,6 +7189,40 @@ out_fput: static int __init io_uring_init(void) { +#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \ + BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ + BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \ +} while (0) + +#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \ + __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename) + BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64); + BUILD_BUG_SQE_ELEM(0, __u8, opcode); + BUILD_BUG_SQE_ELEM(1, __u8, flags); + BUILD_BUG_SQE_ELEM(2, __u16, ioprio); + BUILD_BUG_SQE_ELEM(4, __s32, fd); + BUILD_BUG_SQE_ELEM(8, __u64, off); + BUILD_BUG_SQE_ELEM(8, __u64, addr2); + BUILD_BUG_SQE_ELEM(16, __u64, addr); + BUILD_BUG_SQE_ELEM(24, __u32, len); + BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags); + BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags); + BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags); + BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags); + BUILD_BUG_SQE_ELEM(28, __u16, poll_events); + BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags); + BUILD_BUG_SQE_ELEM(28, __u32, msg_flags); + BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags); + BUILD_BUG_SQE_ELEM(28, __u32, accept_flags); + BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags); + BUILD_BUG_SQE_ELEM(28, __u32, open_flags); + BUILD_BUG_SQE_ELEM(28, __u32, statx_flags); + BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice); + BUILD_BUG_SQE_ELEM(32, __u64, user_data); + BUILD_BUG_SQE_ELEM(40, __u16, buf_index); + BUILD_BUG_SQE_ELEM(42, __u16, personality); + + BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST); req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); return 0; }; |
