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-rw-r--r--fs/io_uring.c7264
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diff --git a/fs/io_uring.c b/fs/io_uring.c
deleted file mode 100644
index 3affd96a98ba..000000000000
--- a/fs/io_uring.c
+++ /dev/null
@@ -1,7264 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Shared application/kernel submission and completion ring pairs, for
- * supporting fast/efficient IO.
- *
- * A note on the read/write ordering memory barriers that are matched between
- * the application and kernel side.
- *
- * After the application reads the CQ ring tail, it must use an
- * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
- * before writing the tail (using smp_load_acquire to read the tail will
- * do). It also needs a smp_mb() before updating CQ head (ordering the
- * entry load(s) with the head store), pairing with an implicit barrier
- * through a control-dependency in io_get_cqring (smp_store_release to
- * store head will do). Failure to do so could lead to reading invalid
- * CQ entries.
- *
- * Likewise, the application must use an appropriate smp_wmb() before
- * writing the SQ tail (ordering SQ entry stores with the tail store),
- * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
- * to store the tail will do). And it needs a barrier ordering the SQ
- * head load before writing new SQ entries (smp_load_acquire to read
- * head will do).
- *
- * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
- * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
- * updating the SQ tail; a full memory barrier smp_mb() is needed
- * between.
- *
- * Also see the examples in the liburing library:
- *
- * git://git.kernel.dk/liburing
- *
- * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
- * from data shared between the kernel and application. This is done both
- * for ordering purposes, but also to ensure that once a value is loaded from
- * data that the application could potentially modify, it remains stable.
- *
- * Copyright (C) 2018-2019 Jens Axboe
- * Copyright (c) 2018-2019 Christoph Hellwig
- */
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/syscalls.h>
-#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>
-#include <linux/file.h>
-#include <linux/fdtable.h>
-#include <linux/mm.h>
-#include <linux/mman.h>
-#include <linux/mmu_context.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/kthread.h>
-#include <linux/blkdev.h>
-#include <linux/bvec.h>
-#include <linux/net.h>
-#include <net/sock.h>
-#include <net/af_unix.h>
-#include <net/scm.h>
-#include <linux/anon_inodes.h>
-#include <linux/sched/mm.h>
-#include <linux/uaccess.h>
-#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 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;
- u32 tail ____cacheline_aligned_in_smp;
-};
-
-/*
- * This data is shared with the application through the mmap at offsets
- * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
- *
- * The offsets to the member fields are published through struct
- * io_sqring_offsets when calling io_uring_setup.
- */
-struct io_rings {
- /*
- * Head and tail offsets into the ring; the offsets need to be
- * masked to get valid indices.
- *
- * The kernel controls head of the sq ring and the tail of the cq ring,
- * and the application controls tail of the sq ring and the head of the
- * cq ring.
- */
- struct io_uring sq, cq;
- /*
- * Bitmasks to apply to head and tail offsets (constant, equals
- * ring_entries - 1)
- */
- u32 sq_ring_mask, cq_ring_mask;
- /* Ring sizes (constant, power of 2) */
- u32 sq_ring_entries, cq_ring_entries;
- /*
- * Number of invalid entries dropped by the kernel due to
- * invalid index stored in array
- *
- * Written by the kernel, shouldn't be modified by the
- * application (i.e. get number of "new events" by comparing to
- * cached value).
- *
- * After a new SQ head value was read by the application this
- * counter includes all submissions that were dropped reaching
- * the new SQ head (and possibly more).
- */
- u32 sq_dropped;
- /*
- * Runtime flags
- *
- * Written by the kernel, shouldn't be modified by the
- * application.
- *
- * The application needs a full memory barrier before checking
- * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
- */
- 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 than there is space in
- * the completion queue.
- *
- * Written by the kernel, shouldn't be modified by the
- * application (i.e. get number of "new events" by comparing to
- * cached value).
- *
- * As completion events come in out of order this counter is not
- * ordered with any other data.
- */
- u32 cq_overflow;
- /*
- * Ring buffer of completion events.
- *
- * The kernel writes completion events fresh every time they are
- * produced, so the application is allowed to modify pending
- * entries.
- */
- struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
-};
-
-struct io_mapped_ubuf {
- u64 ubuf;
- size_t len;
- struct bio_vec *bvec;
- unsigned int nr_bvecs;
-};
-
-struct fixed_file_table {
- struct file **files;
-};
-
-struct fixed_file_data {
- struct fixed_file_table *table;
- struct io_ring_ctx *ctx;
-
- struct percpu_ref refs;
- struct llist_head put_llist;
- struct work_struct ref_work;
- struct completion done;
-};
-
-struct io_ring_ctx {
- struct {
- struct percpu_ref refs;
- } ____cacheline_aligned_in_smp;
-
- struct {
- unsigned int flags;
- 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;
-
- /*
- * 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;
- 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 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;
-
- /*
- * 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 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;
- struct io_mapped_ubuf *user_bufs;
-
- struct user_struct *user;
-
- 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;
- wait_queue_head_t wait;
- } ____cacheline_aligned_in_smp;
-
- struct {
- spinlock_t completion_lock;
- 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.
- * For SQPOLL, only the single threaded io_sq_thread() will
- * manipulate the list, hence no extra locking is needed there.
- */
- struct list_head poll_list;
- struct hlist_head *cancel_hash;
- unsigned cancel_hash_bits;
- bool poll_multi_file;
-
- spinlock_t inflight_lock;
- struct list_head inflight_list;
- } ____cacheline_aligned_in_smp;
-};
-
-/*
- * First field must be the file pointer in all the
- * iocb unions! See also 'struct kiocb' in <linux/fs.h>
- */
-struct io_poll_iocb {
- struct file *file;
- 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;
- unsigned long nofile;
-};
-
-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;
- unsigned long nofile;
-};
-
-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
- * access the file pointer through any of the sub-structs,
- * or directly as just 'ki_filp' in this struct.
- */
-struct io_kiocb {
- union {
- struct file *file;
- 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 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;
- union {
- struct list_head list;
- struct hlist_node hash_node;
- };
- struct list_head link_list;
- unsigned int flags;
- refcount_t refs;
- u64 user_data;
- u32 result;
- u32 sequence;
-
- struct list_head inflight_entry;
-
- struct io_wq_work work;
-};
-
-#define IO_PLUG_THRESHOLD 2
-#define IO_IOPOLL_BATCH 8
-
-struct io_submit_state {
- struct blk_plug plug;
-
- /*
- * io_kiocb alloc cache
- */
- void *reqs[IO_IOPOLL_BATCH];
- unsigned int free_reqs;
-
- /*
- * File reference cache
- */
- struct file *file;
- unsigned int fd;
- unsigned int has_refs;
- unsigned int used_refs;
- unsigned int ios_left;
-};
-
-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;
-
-static const struct file_operations io_uring_fops;
-
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (file->f_op == &io_uring_fops) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
-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->completions[0]);
-}
-
-static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
-{
- struct io_ring_ctx *ctx;
- 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))
- goto err;
-
- ctx->flags = p->flags;
- init_waitqueue_head(&ctx->cq_wait);
- 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);
- spin_lock_init(&ctx->completion_lock);
- init_llist_head(&ctx->poll_llist);
- INIT_LIST_HEAD(&ctx->poll_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 __req_need_defer(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- 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;
-
- 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;
- }
-
- 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_rings *rings = ctx->rings;
-
- /* 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);
- }
-}
-
-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(&current->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(&current->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);
- req->flags |= REQ_F_COMP_LOCKED;
- 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)
- io_queue_async_work(req);
-}
-
-static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
- unsigned tail;
-
- tail = ctx->cached_cq_tail;
- /*
- * writes to the cq entry need to come after reading head; the
- * control dependency is enough as we're using WRITE_ONCE to
- * fill the cq entry
- */
- if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
- return NULL;
-
- ctx->cached_cq_tail++;
- 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_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 (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 {
- 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_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(req, res);
- io_commit_cqring(ctx);
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-
- io_cqring_ev_posted(ctx);
-}
-
-static inline bool io_is_fallback_req(struct io_kiocb *req)
-{
- return req == (struct io_kiocb *)
- ((unsigned long) req->ctx->fallback_req & ~1UL);
-}
-
-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,
- struct io_submit_state *state)
-{
- gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
- struct io_kiocb *req;
-
- if (!state) {
- req = kmem_cache_alloc(req_cachep, gfp);
- if (unlikely(!req))
- goto fallback;
- } else if (!state->free_reqs) {
- size_t sz;
- int ret;
-
- sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
- ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
-
- /*
- * Bulk alloc is all-or-nothing. If we fail to get a batch,
- * retry single alloc to be on the safe side.
- */
- if (unlikely(ret <= 0)) {
- state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
- if (!state->reqs[0])
- goto fallback;
- ret = 1;
- }
- state->free_reqs = ret - 1;
- req = state->reqs[ret - 1];
- } else {
- state->free_reqs--;
- 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;
-fallback:
- req = io_get_fallback_req(ctx);
- if (req)
- goto got_it;
- percpu_ref_put(&ctx->refs);
- return NULL;
-}
-
-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)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (req->flags & REQ_F_NEED_CLEANUP)
- io_cleanup_req(req);
-
- 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)
-{
- __io_req_aux_free(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);
-}
-
-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)
-{
- 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.
- */
- 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;
- }
-
- 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);
-}
-
-/*
- * Called if REQ_F_LINK is set, and we fail the head request
- */
-static void io_fail_links(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- unsigned long flags;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
-
- while (!list_empty(&req->link_list)) {
- struct io_kiocb *link = list_first_entry(&req->link_list,
- struct io_kiocb, link_list);
-
- 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_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_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)
-{
- if (refcount_dec_and_test(&req->refs)) {
- io_req_find_next(req, nxtptr);
- __io_free_req(req);
- }
-}
-
-static void io_put_req(struct io_kiocb *req)
-{
- if (refcount_dec_and_test(&req->refs))
- io_free_req(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)
-{
- struct req_batch rb;
- struct io_kiocb *req;
-
- 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(req, req->result);
- (*nr_events)++;
-
- 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, &rb);
-}
-
-static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
- long min)
-{
- struct io_kiocb *req, *tmp;
- LIST_HEAD(done);
- bool spin;
- int ret;
-
- /*
- * Only spin for completions if we don't have multiple devices hanging
- * off our complete list, and we're under the requested amount.
- */
- spin = !ctx->poll_multi_file && *nr_events < min;
-
- ret = 0;
- list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) {
- struct kiocb *kiocb = &req->rw.kiocb;
-
- /*
- * Move completed entries to our local list. If we find a
- * request that requires polling, break out and complete
- * the done list first, if we have entries there.
- */
- if (req->flags & REQ_F_IOPOLL_COMPLETED) {
- list_move_tail(&req->list, &done);
- continue;
- }
- if (!list_empty(&done))
- break;
-
- ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
- if (ret < 0)
- break;
-
- if (ret && spin)
- spin = false;
- ret = 0;
- }
-
- if (!list_empty(&done))
- io_iopoll_complete(ctx, nr_events, &done);
-
- return ret;
-}
-
-/*
- * 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) && !need_resched()) {
- int ret;
-
- ret = io_do_iopoll(ctx, nr_events, min);
- if (ret < 0)
- return ret;
- if (!min || *nr_events >= min)
- return 0;
- }
-
- return 1;
-}
-
-/*
- * We can't just wait for polled events to come to us, we have to actively
- * find and complete them.
- */
-static void io_iopoll_reap_events(struct io_ring_ctx *ctx)
-{
- if (!(ctx->flags & IORING_SETUP_IOPOLL))
- return;
-
- mutex_lock(&ctx->uring_lock);
- while (!list_empty(&ctx->poll_list)) {
- 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)
-{
- int iters = 0, ret = 0;
-
- /*
- * 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);
- 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;
-
- ret = io_iopoll_getevents(ctx, nr_events, tmin);
- if (ret <= 0)
- break;
- ret = 0;
- } while (min && !*nr_events && !need_resched());
-
- mutex_unlock(&ctx->uring_lock);
- return ret;
-}
-
-static void kiocb_end_write(struct io_kiocb *req)
-{
- /*
- * Tell lockdep we inherited freeze protection from submission
- * thread.
- */
- if (req->flags & REQ_F_ISREG) {
- struct inode *inode = file_inode(req->file);
-
- __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
- }
- file_end_write(req->file);
-}
-
-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;
-}
-
-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.kiocb);
-
- if (kiocb->ki_flags & IOCB_WRITE)
- kiocb_end_write(req);
-
- if (res != req->result)
- req_set_fail_links(req);
- req->result = res;
- if (res != -EAGAIN)
- req->flags |= REQ_F_IOPOLL_COMPLETED;
-}
-
-/*
- * After the iocb has been issued, it's safe to be found on the poll list.
- * Adding the kiocb to the list AFTER submission ensures that we don't
- * find it from a io_iopoll_getevents() thread before the issuer is done
- * accessing the kiocb cookie.
- */
-static void io_iopoll_req_issued(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- /*
- * Track whether we have multiple files in our lists. This will impact
- * how we do polling eventually, not spinning if we're on potentially
- * different devices.
- */
- if (list_empty(&ctx->poll_list)) {
- ctx->poll_multi_file = false;
- } else if (!ctx->poll_multi_file) {
- struct io_kiocb *list_req;
-
- list_req = list_first_entry(&ctx->poll_list, struct io_kiocb,
- list);
- if (list_req->file != req->file)
- ctx->poll_multi_file = true;
- }
-
- /*
- * For fast devices, IO may have already completed. If it has, add
- * it to the front so we find it first.
- */
- if (req->flags & REQ_F_IOPOLL_COMPLETED)
- list_add(&req->list, &ctx->poll_list);
- else
- list_add_tail(&req->list, &ctx->poll_list);
-
- if ((ctx->flags & IORING_SETUP_SQPOLL) &&
- wq_has_sleeper(&ctx->sqo_wait))
- wake_up(&ctx->sqo_wait);
-}
-
-static void io_file_put(struct io_submit_state *state)
-{
- if (state->file) {
- int diff = state->has_refs - state->used_refs;
-
- if (diff)
- fput_many(state->file, diff);
- state->file = NULL;
- }
-}
-
-/*
- * Get as many references to a file as we have IOs left in this submission,
- * assuming most submissions are for one file, or at least that each file
- * has more than one submission.
- */
-static struct file *io_file_get(struct io_submit_state *state, int fd)
-{
- if (!state)
- return fget(fd);
-
- if (state->file) {
- if (state->fd == fd) {
- state->used_refs++;
- state->ios_left--;
- return state->file;
- }
- io_file_put(state);
- }
- state->file = fget_many(fd, state->ios_left);
- if (!state->file)
- return NULL;
-
- state->fd = fd;
- state->has_refs = state->ios_left;
- state->used_refs = 1;
- state->ios_left--;
- return state->file;
-}
-
-/*
- * If we tracked the file through the SCM inflight mechanism, we could support
- * any file. For now, just ensure that anything potentially problematic is done
- * inline.
- */
-static bool io_file_supports_async(struct file *file)
-{
- umode_t mode = file_inode(file)->i_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;
-
- return false;
-}
-
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- bool force_nonblock)
-{
- struct io_ring_ctx *ctx = req->ctx;
- struct kiocb *kiocb = &req->rw.kiocb;
- unsigned ioprio;
- int ret;
-
- if (S_ISREG(file_inode(req->file)->i_mode))
- req->flags |= REQ_F_ISREG;
-
- kiocb->ki_pos = READ_ONCE(sqe->off);
- 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) {
- ret = ioprio_check_cap(ioprio);
- if (ret)
- return ret;
-
- kiocb->ki_ioprio = ioprio;
- } else
- kiocb->ki_ioprio = get_current_ioprio();
-
- /* don't allow async punt if RWF_NOWAIT was requested */
- if ((kiocb->ki_flags & IOCB_NOWAIT) ||
- (req->file->f_flags & O_NONBLOCK))
- req->flags |= REQ_F_NOWAIT;
-
- if (force_nonblock)
- kiocb->ki_flags |= IOCB_NOWAIT;
-
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- if (!(kiocb->ki_flags & IOCB_DIRECT) ||
- !kiocb->ki_filp->f_op->iopoll)
- return -EOPNOTSUPP;
-
- 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;
-}
-
-static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
-{
- switch (ret) {
- case -EIOCBQUEUED:
- break;
- case -ERESTARTSYS:
- case -ERESTARTNOINTR:
- case -ERESTARTNOHAND:
- case -ERESTART_RESTARTBLOCK:
- /*
- * We can't just restart the syscall, since previously
- * submitted sqes may already be in progress. Just fail this
- * IO with EINTR.
- */
- ret = -EINTR;
- /* fall through */
- default:
- kiocb->ki_complete(kiocb, ret, 0);
- }
-}
-
-static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt,
- bool in_async)
-{
- 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;
- u64 buf_addr;
-
- /* attempt to use fixed buffers without having provided iovecs */
- if (unlikely(!ctx->user_bufs))
- return -EFAULT;
-
- 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 = req->rw.addr;
-
- /* overflow */
- if (buf_addr + len < buf_addr)
- return -EFAULT;
- /* not inside the mapped region */
- if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
- return -EFAULT;
-
- /*
- * May not be a start of buffer, set size appropriately
- * and advance us to the beginning.
- */
- offset = buf_addr - imu->ubuf;
- iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
-
- if (offset) {
- /*
- * Don't use iov_iter_advance() here, as it's really slow for
- * using the latter parts of a big fixed buffer - it iterates
- * over each segment manually. We can cheat a bit here, because
- * we know that:
- *
- * 1) it's a BVEC iter, we set it up
- * 2) all bvecs are PAGE_SIZE in size, except potentially the
- * first and last bvec
- *
- * So just find our index, and adjust the iterator afterwards.
- * If the offset is within the first bvec (or the whole first
- * bvec, just use iov_iter_advance(). This makes it easier
- * since we can just skip the first segment, which may not
- * be PAGE_SIZE aligned.
- */
- const struct bio_vec *bvec = imu->bvec;
-
- if (offset <= bvec->bv_len) {
- iov_iter_advance(iter, offset);
- } else {
- unsigned long seg_skip;
-
- /* skip first vec */
- offset -= bvec->bv_len;
- seg_skip = 1 + (offset >> PAGE_SHIFT);
-
- iter->bvec = bvec + seg_skip;
- iter->nr_segs -= seg_skip;
- iter->count -= bvec->bv_len + offset;
- iter->iov_offset = offset & ~PAGE_MASK;
- }
- }
-
- return len;
-}
-
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
- struct iovec **iovec, struct iov_iter *iter)
-{
- void __user *buf = u64_to_user_ptr(req->rw.addr);
- size_t sqe_len = req->rw.len;
- u8 opcode;
-
- 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 < 0 ? ret : sqe_len;
- }
-
- 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 (req->ctx->compat)
- return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
- iovec, iter);
-#endif
-
- return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
-}
-
-/*
- * For files that don't have ->read_iter() and ->write_iter(), handle them
- * by looping over ->read() or ->write() manually.
- */
-static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
- struct iov_iter *iter)
-{
- ssize_t ret = 0;
-
- /*
- * 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;
-
- while (iov_iter_count(iter)) {
- struct iovec iovec;
- ssize_t nr;
-
- if (!iov_iter_is_bvec(iter)) {
- iovec = iov_iter_iovec(iter);
- } else {
- /* 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;
-
- io_req_map_rw(req, io_size, iovec, fast_iov, iter);
- }
- return 0;
-}
-
-static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- bool force_nonblock)
-{
- struct io_async_ctx *io;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = io_prep_rw(req, sqe, force_nonblock);
- if (ret)
- return ret;
-
- if (unlikely(!(req->file->f_mode & FMODE_READ)))
- return -EBADF;
-
- /* 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;
-
- /* 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;
- }
-
- iov_count = iov_iter_count(&iter);
- ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count);
- if (!ret) {
- ssize_t ret2;
-
- 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) {
- kiocb_done(kiocb, ret2, nxt, req->in_async);
- } else {
-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_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- bool force_nonblock)
-{
- struct io_async_ctx *io;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = io_prep_rw(req, sqe, force_nonblock);
- if (ret)
- return ret;
-
- if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
- return -EBADF;
-
- /* 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;
-
- io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
- return 0;
-}
-
-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;
-
- /* 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;
- }
-
- /* 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;
-
- /*
- * Open-code file_start_write here to grab freeze protection,
- * which will be released by another thread in
- * io_complete_rw(). Fool lockdep by telling it the lock got
- * released so that it doesn't complain about the held lock when
- * we return to userspace.
- */
- if (req->flags & REQ_F_ISREG) {
- __sb_start_write(file_inode(req->file)->i_sb,
- SB_FREEZE_WRITE, true);
- __sb_writers_release(file_inode(req->file)->i_sb,
- SB_FREEZE_WRITE);
- }
- kiocb->ki_flags |= IOCB_WRITE;
-
- 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) {
- kiocb_done(kiocb, ret2, nxt, req->in_async);
- } else {
-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;
-}
-
-/*
- * IORING_OP_NOP just posts a completion event, nothing else.
- */
-static int io_nop(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
-
- io_cqring_add_event(req, 0);
- io_put_req(req);
- return 0;
-}
-
-static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- if (!req->file)
- return -EBADF;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- 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 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)
-{
- 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;
-
- if (io_req_cancelled(req))
- return;
-
- 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;
-
- 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;
- }
-
- req->open.nofile = rlimit(RLIMIT_NOFILE);
- 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;
-
- 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->open.nofile = rlimit(RLIMIT_NOFILE);
- 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 = build_open_flags(&req->open.how, &op);
- if (ret)
- goto err;
-
- ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
- 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;
-
- /* not cancellable, don't do io_req_cancelled() */
- __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;
-
- if (!req->file)
- return -EBADF;
-
- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
- return -EINVAL;
- if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
- return -EINVAL;
-
- 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 void io_sync_file_range_finish(struct io_wq_work **workptr)
-{
- struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
- struct io_kiocb *nxt = NULL;
- int 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) {
- 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;
-
- sr->msg_flags = READ_ONCE(sqe->msg_flags);
- sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
- sr->len = READ_ONCE(sqe->len);
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- sr->msg_flags |= MSG_CMSG_COMPAT;
-#endif
-
- if (!io || req->opcode == IORING_OP_SEND)
- return 0;
- /* iovec is already imported */
- if (req->flags & REQ_F_NEED_CLEANUP)
- return 0;
-
- 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->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)
- 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);
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- sr->msg_flags |= MSG_CMSG_COMPAT;
-#endif
-
- 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;
-
- 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 = 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;
-
- 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->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;
- }
-
- 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, 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);
- accept->nofile = rlimit(RLIMIT_NOFILE);
- return 0;
-#else
- return -EOPNOTSUPP;
-#endif
-}
-
-#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,
- accept->nofile);
- 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)
- 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_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)
- 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
-}
-
-static void io_poll_remove_one(struct io_kiocb *req)
-{
- struct io_poll_iocb *poll = &req->poll;
-
- spin_lock(&poll->head->lock);
- WRITE_ONCE(poll->canceled, true);
- if (!list_empty(&poll->wait.entry)) {
- list_del_init(&poll->wait.entry);
- io_queue_async_work(req);
- }
- spin_unlock(&poll->head->lock);
- 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);
- 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);
-}
-
-static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
-{
- 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);
- ret = io_poll_cancel(ctx, addr);
- spin_unlock_irq(&ctx->completion_lock);
-
- 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_kiocb *req, __poll_t mask, int error)
-{
- struct io_ring_ctx *ctx = req->ctx;
-
- req->poll.done = true;
- 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 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 (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;
-
- /*
- * Note that ->ki_cancel callers also delete iocb from active_reqs after
- * calling ->ki_cancel. We need the ctx_lock roundtrip here to
- * synchronize with them. In the cancellation case the list_del_init
- * itself is not actually needed, but harmless so we keep it in to
- * avoid further branches in the fast path.
- */
- spin_lock_irq(&ctx->completion_lock);
- if (!mask && ret != -ECANCELED) {
- add_wait_queue(poll->head, &poll->wait);
- spin_unlock_irq(&ctx->completion_lock);
- return;
- }
- 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 = 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);
-
- /* for instances that support it check for an event match first: */
- if (mask && !(mask & poll->events))
- return 0;
-
- list_del_init(&poll->wait.entry);
-
- /*
- * 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;
-
- 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;
-}
-
-struct io_poll_table {
- struct poll_table_struct pt;
- struct io_kiocb *req;
- int error;
-};
-
-static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
- struct poll_table_struct *p)
-{
- struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
-
- if (unlikely(pt->req->poll.head)) {
- pt->error = -EINVAL;
- return;
- }
-
- pt->error = 0;
- pt->req->poll.head = head;
- add_wait_queue(head, &pt->req->poll.wait);
-}
-
-static void io_poll_req_insert(struct io_kiocb *req)
-{
- struct io_ring_ctx *ctx = req->ctx;
- 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))
- return -EINVAL;
- if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
- return -EINVAL;
- if (!poll->file)
- return -EBADF;
-
- 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;
- poll->canceled = false;
-
- ipt.pt._qproc = io_poll_queue_proc;
- ipt.pt._key = poll->events;
- ipt.req = req;
- ipt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */
-
- /* 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);
-
- mask = vfs_poll(poll->file, &ipt.pt) & poll->events;
-
- spin_lock_irq(&ctx->completion_lock);
- if (likely(poll->head)) {
- spin_lock(&poll->head->lock);
- if (unlikely(list_empty(&poll->wait.entry))) {
- if (ipt.error)
- cancel = true;
- ipt.error = 0;
- mask = 0;
- }
- if (mask || ipt.error)
- list_del_init(&poll->wait.entry);
- else if (cancel)
- WRITE_ONCE(poll->canceled, true);
- else if (!poll->done) /* actually waiting for an event */
- io_poll_req_insert(req);
- spin_unlock(&poll->head->lock);
- }
- if (mask) { /* no async, we'd stolen it */
- ipt.error = 0;
- io_poll_complete(req, mask, 0);
- }
- spin_unlock_irq(&ctx->completion_lock);
-
- if (mask) {
- io_cqring_ev_posted(ctx);
- io_put_req_find_next(req, nxt);
- }
- return ipt.error;
-}
-
-static enum hrtimer_restart io_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;
- unsigned long flags;
-
- atomic_inc(&ctx->cq_timeouts);
-
- 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);
- 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;
- }
-
- req->sequence = ctx->cached_sq_head + count - 1;
- data->seq_offset = count;
-
- /*
- * 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 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_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
-{
- enum io_wq_cancel cancel_ret;
- int ret = 0;
-
- 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;
- }
-
- 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;
-
- 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 (!sqe)
- return 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:
- break;
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- ret = io_read_prep(req, sqe, true);
- break;
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- case IORING_OP_WRITE:
- ret = io_write_prep(req, sqe, true);
- break;
- case IORING_OP_POLL_ADD:
- ret = io_poll_add_prep(req, sqe);
- break;
- case IORING_OP_POLL_REMOVE:
- 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_prep_sfr(req, sqe);
- break;
- case IORING_OP_SENDMSG:
- case IORING_OP_SEND:
- ret = io_sendmsg_prep(req, sqe);
- break;
- case IORING_OP_RECVMSG:
- 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;
- }
-
- return ret;
-}
-
-static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_ring_ctx *ctx = req->ctx;
- int ret;
-
- /* 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;
- }
-
- 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 void io_cleanup_req(struct io_kiocb *req)
-{
- struct io_async_ctx *io = req->io;
-
- switch (req->opcode) {
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_READ:
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- 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;
- }
-
- req->flags &= ~REQ_F_NEED_CLEANUP;
-}
-
-static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
- struct io_kiocb **nxt, bool force_nonblock)
-{
- struct io_ring_ctx *ctx = req->ctx;
- int ret;
-
- 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;
- }
- 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;
- }
- 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;
- }
-
- if (ret)
- return ret;
-
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- const bool in_async = io_wq_current_is_worker();
-
- if (req->result == -EAGAIN)
- return -EAGAIN;
-
- /* workqueue context doesn't hold uring_lock, grab it now */
- if (in_async)
- mutex_lock(&ctx->uring_lock);
-
- io_iopoll_req_issued(req);
-
- if (in_async)
- mutex_unlock(&ctx->uring_lock);
- }
-
- return 0;
-}
-
-static void io_wq_submit_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_kiocb *nxt = NULL;
- int ret = 0;
-
- /* 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;
- }
-
- 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);
- }
-
- /* 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 int io_req_needs_file(struct io_kiocb *req, int fd)
-{
- 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;
-}
-
-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_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(sqe->flags);
- fd = READ_ONCE(sqe->fd);
-
- if (!io_req_needs_file(req, fd))
- return 0;
-
- if (flags & IOSQE_FIXED_FILE) {
- if (unlikely(!ctx->file_data ||
- (unsigned) fd >= ctx->nr_user_files))
- return -EBADF;
- 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 (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;
- }
-
- return 0;
-}
-
-static int io_grab_files(struct io_kiocb *req)
-{
- int ret = -EBADF;
- struct io_ring_ctx *ctx = req->ctx;
-
- 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();
-
- return ret;
-}
-
-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;
-
- spin_lock_irqsave(&ctx->completion_lock, flags);
-
- /*
- * 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;
- }
-
- 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;
- const struct cred *old_creds = NULL;
- int ret;
-
-again:
- linked_timeout = io_prep_linked_timeout(req);
-
- if (req->work.creds && req->work.creds != current_cred()) {
- if (old_creds)
- revert_creds(old_creds);
- if (old_creds == req->work.creds)
- old_creds = NULL; /* restored original creds */
- else
- old_creds = override_creds(req->work.creds);
- }
-
- 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_find_next(req, &nxt);
-
- 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(req, ret);
- req_set_fail_links(req);
- io_put_req(req);
- }
-done_req:
- if (nxt) {
- req = nxt;
- nxt = NULL;
-
- if (req->flags & REQ_F_FORCE_ASYNC)
- goto punt;
- goto again;
- }
- if (old_creds)
- revert_creds(old_creds);
-}
-
-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| \
- IOSQE_IO_HARDLINK | IOSQE_ASYNC)
-
-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_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(sqe_flags & ~SQE_VALID_FLAGS)) {
- ret = -EINVAL;
- goto err_req;
- }
-
- id = READ_ONCE(sqe->personality);
- if (id) {
- req->work.creds = idr_find(&ctx->personality_idr, id);
- if (unlikely(!req->work.creds)) {
- ret = -EINVAL;
- goto err_req;
- }
- get_cred(req->work.creds);
- }
-
- /* 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_cqring_add_event(req, ret);
- io_double_put_req(req);
- return false;
- }
-
- /*
- * If we already have a head request, queue this one for async
- * submittal once the head completes. If we don't have a head but
- * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
- * submitted sync once the chain is complete. If none of those
- * conditions are true (normal request), then just queue it.
- */
- if (*link) {
- struct io_kiocb *head = *link;
-
- /*
- * 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;
- }
-
- 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);
-
- /* 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 {
- 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);
-
- if (io_alloc_async_ctx(req)) {
- ret = -EAGAIN;
- goto err_req;
- }
- ret = io_req_defer_prep(req, sqe);
- if (ret)
- req->flags |= REQ_F_FAIL_LINK;
- *link = req;
- } else {
- io_queue_sqe(req, sqe);
- }
- }
-
- return true;
-}
-
-/*
- * Batched submission is done, ensure local IO is flushed out.
- */
-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);
-}
-
-/*
- * Start submission side cache.
- */
-static void io_submit_state_start(struct io_submit_state *state,
- unsigned int max_ios)
-{
- blk_start_plug(&state->plug);
- state->free_reqs = 0;
- state->file = NULL;
- state->ios_left = max_ios;
-}
-
-static void io_commit_sqring(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
-
- /*
- * 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 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 io_kiocb *req,
- const struct io_uring_sqe **sqe_ptr)
-{
- u32 *sq_array = ctx->sq_array;
- unsigned head;
-
- /*
- * The cached sq head (or cq tail) serves two purposes:
- *
- * 1) allows us to batch the cost of updating the user visible
- * head updates.
- * 2) allows the kernel side to track the head on its own, even
- * though the application is the one updating it.
- */
- 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++;
- 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, 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;
- 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, nr);
- statep = &state;
- }
-
- ctx->ring_fd = ring_fd;
- ctx->ring_file = ring_file;
-
- for (i = 0; i < nr; i++) {
- 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;
- }
-
- /* 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_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 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 long timeout;
- int ret = 0;
-
- complete(&ctx->completions[1]);
-
- old_fs = get_fs();
- set_fs(USER_DS);
- old_cred = override_creds(ctx->creds);
-
- timeout = jiffies + ctx->sq_thread_idle;
- while (!kthread_should_park()) {
- unsigned int to_submit;
-
- if (!list_empty(&ctx->poll_list)) {
- unsigned nr_events = 0;
-
- mutex_lock(&ctx->uring_lock);
- if (!list_empty(&ctx->poll_list))
- io_iopoll_getevents(ctx, &nr_events, 0);
- else
- timeout = jiffies + ctx->sq_thread_idle;
- mutex_unlock(&ctx->uring_lock);
- }
-
- 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) {
- /*
- * Drop cur_mm before scheduling, we can't hold it for
- * long periods (or over schedule()). Do this before
- * adding ourselves to the waitqueue, as the unuse/drop
- * may sleep.
- */
- if (cur_mm) {
- unuse_mm(cur_mm);
- mmput(cur_mm);
- cur_mm = NULL;
- }
-
- /*
- * We're polling. If we're within the defined idle
- * period, then let us spin without work before going
- * 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 (!list_empty(&ctx->poll_list) ||
- (!time_after(jiffies, timeout) && ret != -EBUSY &&
- !percpu_ref_is_dying(&ctx->refs))) {
- cond_resched();
- continue;
- }
-
- prepare_to_wait(&ctx->sqo_wait, &wait,
- TASK_INTERRUPTIBLE);
-
- /*
- * While doing polled IO, before going to sleep, we need
- * to check if there are new reqs added to poll_list, it
- * is because reqs may have been punted to io worker and
- * will be added to poll_list later, hence check the
- * poll_list again.
- */
- if ((ctx->flags & IORING_SETUP_IOPOLL) &&
- !list_empty_careful(&ctx->poll_list)) {
- finish_wait(&ctx->sqo_wait, &wait);
- continue;
- }
-
- /* Tell userspace we may need a wakeup call */
- ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
- /* make sure to read SQ tail after writing flags */
- smp_mb();
-
- to_submit = io_sqring_entries(ctx);
- if (!to_submit || ret == -EBUSY) {
- if (kthread_should_park()) {
- finish_wait(&ctx->sqo_wait, &wait);
- break;
- }
- if (signal_pending(current))
- flush_signals(current);
- schedule();
- finish_wait(&ctx->sqo_wait, &wait);
-
- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
- continue;
- }
- finish_wait(&ctx->sqo_wait, &wait);
-
- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
- }
-
- mutex_lock(&ctx->uring_lock);
- ret = io_submit_sqes(ctx, to_submit, NULL, -1, &cur_mm, true);
- mutex_unlock(&ctx->uring_lock);
- timeout = jiffies + ctx->sq_thread_idle;
- }
-
- set_fs(old_fs);
- if (cur_mm) {
- unuse_mm(cur_mm);
- mmput(cur_mm);
- }
- revert_creds(old_cred);
-
- kthread_parkme();
-
- return 0;
-}
-
-struct io_wait_queue {
- struct wait_queue_entry wq;
- struct io_ring_ctx *ctx;
- unsigned to_wait;
- unsigned nr_timeouts;
-};
-
-static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush)
-{
- struct io_ring_ctx *ctx = iowq->ctx;
-
- /*
- * 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 int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
- int wake_flags, void *key)
-{
- 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);
-}
-
-/*
- * Wait until events become available, if we don't already have some. The
- * application must reap them itself, as they reside on the shared cq ring.
- */
-static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
- const sigset_t __user *sig, size_t sigsz)
-{
- 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(ctx, false) >= min_events)
- return 0;
-
- if (sig) {
-#ifdef CONFIG_COMPAT
- if (in_compat_syscall())
- ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
- sigsz);
- else
-#endif
- ret = set_user_sigmask(sig, sigsz);
-
- if (ret)
- return ret;
- }
-
- 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(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
-}
-
-static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
-{
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#else
- int 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 void io_file_ref_exit_and_free(struct work_struct *work)
-{
- struct fixed_file_data *data;
-
- data = container_of(work, struct fixed_file_data, ref_work);
-
- /*
- * Ensure any percpu-ref atomic switch callback has run, it could have
- * been in progress when the files were being unregistered. Once
- * that's done, we can safely exit and free the ref and containing
- * data structure.
- */
- rcu_barrier();
- percpu_ref_exit(&data->refs);
- kfree(data);
-}
-
-static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
-{
- 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);
-
- __io_sqe_files_unregister(ctx);
- 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);
- INIT_WORK(&data->ref_work, io_file_ref_exit_and_free);
- queue_work(system_wq, &data->ref_work);
- ctx->file_data = NULL;
- ctx->nr_user_files = 0;
- return 0;
-}
-
-static void io_sq_thread_stop(struct io_ring_ctx *ctx)
-{
- if (ctx->sqo_thread) {
- 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
- * set to a single CPU.
- */
- kthread_park(ctx->sqo_thread);
- kthread_stop(ctx->sqo_thread);
- ctx->sqo_thread = NULL;
- }
-}
-
-static void io_finish_async(struct io_ring_ctx *ctx)
-{
- io_sq_thread_stop(ctx);
-
- if (ctx->io_wq) {
- io_wq_destroy(ctx->io_wq);
- ctx->io_wq = NULL;
- }
-}
-
-#if defined(CONFIG_UNIX)
-/*
- * 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
- * loops in the file referencing.
- */
-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, nr_files;
-
- if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {
- unsigned long inflight = ctx->user->unix_inflight + nr;
-
- if (inflight > task_rlimit(current, RLIMIT_NOFILE))
- return -EMFILE;
- }
-
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- skb->sk = sk;
-
- nr_files = 0;
- fpl->user = get_uid(ctx->user);
- for (i = 0; i < nr; 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++;
- }
-
- 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_files; i++)
- fput(fpl->fp[i]);
- } else {
- kfree_skb(skb);
- kfree(fpl);
- }
-
- return 0;
-}
-
-/*
- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
- * causes regular reference counting to break down. We rely on the UNIX
- * garbage collection to take care of this problem for us.
- */
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- unsigned left, total;
- int ret = 0;
-
- total = 0;
- left = ctx->nr_user_files;
- while (left) {
- unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-
- ret = __io_sqe_files_scm(ctx, this_files, total);
- if (ret)
- break;
- left -= this_files;
- total += this_files;
- }
-
- if (!ret)
- return 0;
-
- while (total < ctx->nr_user_files) {
- struct file *file = io_file_from_index(ctx, total);
-
- if (file)
- fput(file);
- total++;
- }
-
- return ret;
-}
-#else
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- return 0;
-}
-#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_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->file_data)
- return -EBUSY;
- if (!nr_args)
- return -EINVAL;
- if (nr_args > IORING_MAX_FIXED_FILES)
- return -EMFILE;
-
- 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;
-
- ret = -EFAULT;
- if (copy_from_user(&fd, &fds[i], sizeof(fd)))
- break;
- /* allow sparse sets */
- if (fd == -1) {
- ret = 0;
- continue;
- }
-
- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
- index = i & IORING_FILE_TABLE_MASK;
- file = fget(fd);
-
- ret = -EBADF;
- 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
- * 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);
- break;
- }
- ret = 0;
- table->files[index] = file;
- }
-
- if (ret) {
- 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->file_data->table);
- kfree(ctx->file_data);
- ctx->file_data = NULL;
- ctx->nr_user_files = 0;
- return ret;
- }
-
- ret = io_sqe_files_scm(ctx);
- if (ret)
- io_sqe_files_unregister(ctx);
-
- 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;
-
- /*
- * Juggle reference to ensure we hit zero, if needed, so we can
- * switch back to percpu mode
- */
- data = container_of(ref, struct fixed_file_data, refs);
- percpu_ref_put(&data->refs);
- percpu_ref_get(&data->refs);
-}
-
-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) {
- 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)
- 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)
-{
- int ret;
-
- init_waitqueue_head(&ctx->sqo_wait);
- mmgrab(current->mm);
- ctx->sqo_mm = current->mm;
-
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- ret = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
- goto err;
-
- ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
- if (!ctx->sq_thread_idle)
- ctx->sq_thread_idle = HZ;
-
- if (p->flags & IORING_SETUP_SQ_AFF) {
- int cpu = p->sq_thread_cpu;
-
- ret = -EINVAL;
- if (cpu >= nr_cpu_ids)
- goto err;
- if (!cpu_online(cpu))
- goto err;
-
- ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread,
- ctx, cpu,
- "io_uring-sq");
- } else {
- ctx->sqo_thread = kthread_create(io_sq_thread, ctx,
- "io_uring-sq");
- }
- if (IS_ERR(ctx->sqo_thread)) {
- ret = PTR_ERR(ctx->sqo_thread);
- ctx->sqo_thread = NULL;
- goto err;
- }
- wake_up_process(ctx->sqo_thread);
- } else if (p->flags & IORING_SETUP_SQ_AFF) {
- /* Can't have SQ_AFF without SQPOLL */
- ret = -EINVAL;
- goto err;
- }
-
- ret = io_init_wq_offload(ctx, p);
- if (ret)
- goto err;
-
- return 0;
-err:
- io_finish_async(ctx);
- mmdrop(ctx->sqo_mm);
- ctx->sqo_mm = NULL;
- return ret;
-}
-
-static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages)
-{
- atomic_long_sub(nr_pages, &user->locked_vm);
-}
-
-static int io_account_mem(struct user_struct *user, unsigned long nr_pages)
-{
- unsigned long page_limit, cur_pages, new_pages;
-
- /* Don't allow more pages than we can safely lock */
- page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- do {
- cur_pages = atomic_long_read(&user->locked_vm);
- new_pages = cur_pages + nr_pages;
- if (new_pages > page_limit)
- return -ENOMEM;
- } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
- new_pages) != cur_pages);
-
- return 0;
-}
-
-static void io_mem_free(void *ptr)
-{
- struct page *page;
-
- if (!ptr)
- return;
-
- page = virt_to_head_page(ptr);
- if (put_page_testzero(page))
- free_compound_page(page);
-}
-
-static void *io_mem_alloc(size_t size)
-{
- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
- __GFP_NORETRY;
-
- 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)
-{
- size_t pages;
-
- 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 pages;
-}
-
-static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
-{
- int i, j;
-
- if (!ctx->user_bufs)
- return -ENXIO;
-
- for (i = 0; i < ctx->nr_user_bufs; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
-
- for (j = 0; j < imu->nr_bvecs; j++)
- unpin_user_page(imu->bvec[j].bv_page);
-
- if (ctx->account_mem)
- io_unaccount_mem(ctx->user, imu->nr_bvecs);
- kvfree(imu->bvec);
- imu->nr_bvecs = 0;
- }
-
- kfree(ctx->user_bufs);
- ctx->user_bufs = NULL;
- ctx->nr_user_bufs = 0;
- return 0;
-}
-
-static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
- void __user *arg, unsigned index)
-{
- struct iovec __user *src;
-
-#ifdef CONFIG_COMPAT
- if (ctx->compat) {
- struct compat_iovec __user *ciovs;
- struct compat_iovec ciov;
-
- ciovs = (struct compat_iovec __user *) arg;
- if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
- return -EFAULT;
-
- dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
- dst->iov_len = ciov.iov_len;
- return 0;
- }
-#endif
- src = (struct iovec __user *) arg;
- if (copy_from_user(dst, &src[index], sizeof(*dst)))
- return -EFAULT;
- return 0;
-}
-
-static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
- unsigned nr_args)
-{
- struct vm_area_struct **vmas = NULL;
- struct page **pages = NULL;
- int i, j, got_pages = 0;
- int ret = -EINVAL;
-
- if (ctx->user_bufs)
- return -EBUSY;
- if (!nr_args || nr_args > UIO_MAXIOV)
- return -EINVAL;
-
- ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
- GFP_KERNEL);
- if (!ctx->user_bufs)
- return -ENOMEM;
-
- for (i = 0; i < nr_args; i++) {
- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
- unsigned long off, start, end, ubuf;
- int pret, nr_pages;
- struct iovec iov;
- size_t size;
-
- ret = io_copy_iov(ctx, &iov, arg, i);
- if (ret)
- goto err;
-
- /*
- * Don't impose further limits on the size and buffer
- * constraints here, we'll -EINVAL later when IO is
- * submitted if they are wrong.
- */
- ret = -EFAULT;
- if (!iov.iov_base || !iov.iov_len)
- goto err;
-
- /* arbitrary limit, but we need something */
- if (iov.iov_len > SZ_1G)
- goto err;
-
- ubuf = (unsigned long) iov.iov_base;
- end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- start = ubuf >> PAGE_SHIFT;
- nr_pages = end - start;
-
- if (ctx->account_mem) {
- ret = io_account_mem(ctx->user, nr_pages);
- if (ret)
- goto err;
- }
-
- ret = 0;
- if (!pages || nr_pages > got_pages) {
- kfree(vmas);
- kfree(pages);
- pages = kvmalloc_array(nr_pages, sizeof(struct page *),
- GFP_KERNEL);
- vmas = kvmalloc_array(nr_pages,
- sizeof(struct vm_area_struct *),
- GFP_KERNEL);
- if (!pages || !vmas) {
- ret = -ENOMEM;
- if (ctx->account_mem)
- io_unaccount_mem(ctx->user, nr_pages);
- goto err;
- }
- got_pages = nr_pages;
- }
-
- imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
- GFP_KERNEL);
- ret = -ENOMEM;
- if (!imu->bvec) {
- if (ctx->account_mem)
- io_unaccount_mem(ctx->user, nr_pages);
- goto err;
- }
-
- ret = 0;
- down_read(&current->mm->mmap_sem);
- pret = pin_user_pages(ubuf, nr_pages,
- FOLL_WRITE | FOLL_LONGTERM,
- pages, vmas);
- if (pret == nr_pages) {
- /* don't support file backed memory */
- for (j = 0; j < nr_pages; j++) {
- struct vm_area_struct *vma = vmas[j];
-
- if (vma->vm_file &&
- !is_file_hugepages(vma->vm_file)) {
- ret = -EOPNOTSUPP;
- break;
- }
- }
- } else {
- ret = pret < 0 ? pret : -EFAULT;
- }
- up_read(&current->mm->mmap_sem);
- if (ret) {
- /*
- * if we did partial map, or found file backed vmas,
- * release any pages we did get
- */
- if (pret > 0)
- unpin_user_pages(pages, pret);
- if (ctx->account_mem)
- io_unaccount_mem(ctx->user, nr_pages);
- kvfree(imu->bvec);
- goto err;
- }
-
- off = ubuf & ~PAGE_MASK;
- size = iov.iov_len;
- for (j = 0; j < nr_pages; j++) {
- size_t vec_len;
-
- vec_len = min_t(size_t, size, PAGE_SIZE - off);
- imu->bvec[j].bv_page = pages[j];
- imu->bvec[j].bv_len = vec_len;
- imu->bvec[j].bv_offset = off;
- off = 0;
- size -= vec_len;
- }
- /* store original address for later verification */
- imu->ubuf = ubuf;
- imu->len = iov.iov_len;
- imu->nr_bvecs = nr_pages;
-
- ctx->nr_user_bufs++;
- }
- kvfree(pages);
- kvfree(vmas);
- return 0;
-err:
- kvfree(pages);
- kvfree(vmas);
- io_sqe_buffer_unregister(ctx);
- return ret;
-}
-
-static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
-{
- __s32 __user *fds = arg;
- int fd;
-
- if (ctx->cq_ev_fd)
- return -EBUSY;
-
- if (copy_from_user(&fd, fds, sizeof(*fds)))
- return -EFAULT;
-
- ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
- if (IS_ERR(ctx->cq_ev_fd)) {
- int ret = PTR_ERR(ctx->cq_ev_fd);
- ctx->cq_ev_fd = NULL;
- return ret;
- }
-
- return 0;
-}
-
-static int io_eventfd_unregister(struct io_ring_ctx *ctx)
-{
- if (ctx->cq_ev_fd) {
- eventfd_ctx_put(ctx->cq_ev_fd);
- ctx->cq_ev_fd = NULL;
- return 0;
- }
-
- return -ENXIO;
-}
-
-static void io_ring_ctx_free(struct io_ring_ctx *ctx)
-{
- io_finish_async(ctx);
- if (ctx->sqo_mm)
- mmdrop(ctx->sqo_mm);
-
- io_iopoll_reap_events(ctx);
- io_sqe_buffer_unregister(ctx);
- io_sqe_files_unregister(ctx);
- io_eventfd_unregister(ctx);
- idr_destroy(&ctx->personality_idr);
-
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
-
- io_mem_free(ctx->rings);
- io_mem_free(ctx->sq_sqes);
-
- 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);
-}
-
-static __poll_t io_uring_poll(struct file *file, poll_table *wait)
-{
- struct io_ring_ctx *ctx = file->private_data;
- __poll_t mask = 0;
-
- poll_wait(file, &ctx->cq_wait, wait);
- /*
- * synchronizes with barrier from wq_has_sleeper call in
- * io_commit_cqring
- */
- smp_rmb();
- if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head !=
- ctx->rings->sq_ring_entries)
- mask |= EPOLLOUT | EPOLLWRNORM;
- if (io_cqring_events(ctx, false))
- mask |= EPOLLIN | EPOLLRDNORM;
-
- return mask;
-}
-
-static int io_uring_fasync(int fd, struct file *file, int on)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- 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);
- /* 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);
-}
-
-static int io_uring_release(struct inode *inode, struct file *file)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- file->private_data = NULL;
- io_ring_ctx_wait_and_kill(ctx);
- return 0;
-}
-
-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)
-{
- struct io_ring_ctx *ctx = file->private_data;
-
- 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:
- case IORING_OFF_CQ_RING:
- ptr = ctx->rings;
- break;
- case IORING_OFF_SQES:
- ptr = ctx->sq_sqes;
- break;
- default:
- return ERR_PTR(-EINVAL);
- }
-
- page = virt_to_head_page(ptr);
- 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)
-{
- struct io_ring_ctx *ctx;
- long ret = -EBADF;
- int submitted = 0;
- struct fd f;
-
- if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP))
- return -EINVAL;
-
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
-
- ret = -EOPNOTSUPP;
- if (f.file->f_op != &io_uring_fops)
- goto out_fput;
-
- ret = -ENXIO;
- ctx = f.file->private_data;
- if (!percpu_ref_tryget(&ctx->refs))
- goto out_fput;
-
- /*
- * For SQ polling, the thread will do all submissions and completions.
- * 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;
- } else if (to_submit) {
- struct mm_struct *cur_mm;
-
- mutex_lock(&ctx->uring_lock);
- /* 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;
-
- min_complete = min(min_complete, ctx->cq_entries);
-
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- ret = io_iopoll_check(ctx, &nr_events, min_complete);
- } else {
- ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
- }
- }
-
-out:
- percpu_ref_put(&ctx->refs);
-out_fput:
- fdput(f);
- return submitted ? submitted : ret;
-}
-
-#ifdef CONFIG_PROC_FS
-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);
- }
-}
-#endif
-
-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,
-#ifdef CONFIG_PROC_FS
- .show_fdinfo = io_uring_show_fdinfo,
-#endif
-};
-
-static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
- struct io_uring_params *p)
-{
- struct io_rings *rings;
- size_t size, sq_array_offset;
-
- 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->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) {
- io_mem_free(ctx->rings);
- ctx->rings = NULL;
- return -EOVERFLOW;
- }
-
- ctx->sq_sqes = io_mem_alloc(size);
- if (!ctx->sq_sqes) {
- io_mem_free(ctx->rings);
- ctx->rings = NULL;
- return -ENOMEM;
- }
-
- return 0;
-}
-
-/*
- * Allocate an anonymous fd, this is what constitutes the application
- * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
- */
-static int io_uring_get_fd(struct io_ring_ctx *ctx)
-{
- struct file *file;
- int ret;
-
-#if defined(CONFIG_UNIX)
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ret;
-#endif
-
- ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
- if (ret < 0)
- goto err;
-
- file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
- O_RDWR | O_CLOEXEC);
- if (IS_ERR(file)) {
- put_unused_fd(ret);
- ret = PTR_ERR(file);
- goto err;
- }
-
-#if defined(CONFIG_UNIX)
- ctx->ring_sock->file = file;
-#endif
- fd_install(ret, file);
- return ret;
-err:
-#if defined(CONFIG_UNIX)
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
-#endif
- return ret;
-}
-
-static int io_uring_create(unsigned entries, struct io_uring_params *p)
-{
- struct user_struct *user = NULL;
- struct io_ring_ctx *ctx;
- bool account_mem;
- int ret;
-
- 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. 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);
- 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);
-
- if (account_mem) {
- ret = io_account_mem(user,
- ring_pages(p->sq_entries, p->cq_entries));
- if (ret) {
- free_uid(user);
- return ret;
- }
- }
-
- ctx = io_ring_ctx_alloc(p);
- if (!ctx) {
- if (account_mem)
- io_unaccount_mem(user, ring_pages(p->sq_entries,
- p->cq_entries));
- free_uid(user);
- return -ENOMEM;
- }
- 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)
- goto err;
-
- ret = io_sq_offload_start(ctx, 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;
-
- 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);
- return ret;
-}
-
-/*
- * Sets up an aio uring context, and returns the fd. Applications asks for a
- * ring size, we return the actual sq/cq ring sizes (among other things) in the
- * params structure passed in.
- */
-static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
-{
- struct io_uring_params p;
- long ret;
- int i;
-
- if (copy_from_user(&p, params, sizeof(p)))
- return -EFAULT;
- for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
- if (p.resv[i])
- return -EINVAL;
- }
-
- if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
- IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
- IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ))
- return -EINVAL;
-
- ret = io_uring_create(entries, &p);
- if (ret < 0)
- return ret;
-
- if (copy_to_user(params, &p, sizeof(p)))
- return -EFAULT;
-
- return ret;
-}
-
-SYSCALL_DEFINE2(io_uring_setup, u32, entries,
- struct io_uring_params __user *, params)
-{
- 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)
- __acquires(ctx->uring_lock)
-{
- int ret;
-
- /*
- * We're inside the ring mutex, if the ref is already dying, then
- * someone else killed the ctx or is already going through
- * io_uring_register().
- */
- if (percpu_ref_is_dying(&ctx->refs))
- return -ENXIO;
-
- 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);
- 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:
- ret = io_sqe_buffer_register(ctx, arg, nr_args);
- break;
- case IORING_UNREGISTER_BUFFERS:
- ret = -EINVAL;
- if (arg || nr_args)
- break;
- ret = io_sqe_buffer_unregister(ctx);
- break;
- case IORING_REGISTER_FILES:
- ret = io_sqe_files_register(ctx, arg, nr_args);
- break;
- case IORING_UNREGISTER_FILES:
- ret = -EINVAL;
- if (arg || nr_args)
- 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;
- if (arg || nr_args)
- 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;
- }
-
- 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;
-}
-
-SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
- void __user *, arg, unsigned int, nr_args)
-{
- struct io_ring_ctx *ctx;
- long ret = -EBADF;
- struct fd f;
-
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
-
- ret = -EOPNOTSUPP;
- if (f.file->f_op != &io_uring_fops)
- goto out_fput;
-
- ctx = f.file->private_data;
-
- 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;
-}
-
-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;
-};
-__initcall(io_uring_init);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.