7 files changed, 169 insertions, 3 deletions

diff --git a/include/linux/file.h b/include/linux/file.h
index 6b2fb032416c..3fcddff56bc4 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -13,6 +13,7 @@
 struct file;
 
 extern void fput(struct file *);
+extern void fput_many(struct file *, unsigned int);
 
 struct file_operations;
 struct vfsmount;
@@ -44,6 +45,7 @@ static inline void fdput(struct fd fd)
 }
 
 extern struct file *fget(unsigned int fd);
+extern struct file *fget_many(unsigned int fd, unsigned int refs);
 extern struct file *fget_raw(unsigned int fd);
 extern unsigned long __fdget(unsigned int fd);
 extern unsigned long __fdget_raw(unsigned int fd);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7442329a0011..0a257d89208e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -961,7 +961,9 @@ static inline struct file *get_file(struct file *f)
         atomic_long_inc(&f->f_count);
         return f;
 }
-#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
+#define get_file_rcu_many(x, cnt)       \
+        atomic_long_add_unless(&(x)->f_count, (cnt), 0)
+#define get_file_rcu(x) get_file_rcu_many((x), 1)
 #define fput_atomic(x)  atomic_long_add_unless(&(x)->f_count, -1, 1)
 #define file_count(x)   atomic_long_read(&(x)->f_count)
 
@@ -3511,4 +3513,13 @@ extern void inode_nohighmem(struct inode *inode);
 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
                        int advice);
 
+#if defined(CONFIG_IO_URING)
+extern struct sock *io_uring_get_socket(struct file *file);
+#else
+static inline struct sock *io_uring_get_socket(struct file *file)
+{
+        return NULL;
+}
+#endif
+
 #endif /* _LINUX_FS_H */
diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h
index 39ad98c09c58..c7b5f86b91a1 100644
--- a/include/linux/sched/user.h
+++ b/include/linux/sched/user.h
@@ -40,7 +40,7 @@ struct user_struct {
         kuid_t uid;
 
 #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \
-    defined(CONFIG_NET)
+    defined(CONFIG_NET) || defined(CONFIG_IO_URING)
         atomic_long_t locked_vm;
 #endif
 
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 94369f5bd8e5..c2962953bf11 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -69,6 +69,7 @@ struct file_handle;
 struct sigaltstack;
 struct rseq;
 union bpf_attr;
+struct io_uring_params;
 
 #include <linux/types.h>
 #include <linux/aio_abi.h>
@@ -314,6 +315,13 @@ asmlinkage long sys_io_pgetevents_time32(aio_context_t ctx_id,
                                 struct io_event __user *events,
                                 struct old_timespec32 __user *timeout,
                                 const struct __aio_sigset *sig);
+asmlinkage long sys_io_uring_setup(u32 entries,
+                                struct io_uring_params __user *p);
+asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit,
+                                u32 min_complete, u32 flags,
+                                const sigset_t __user *sig, size_t sigsz);
+asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op,
+                                void __user *arg, unsigned int nr_args);
 
 /* fs/xattr.c */
 asmlinkage long sys_setxattr(const char __user *path, const char __user *name,
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index ddbba838d048..3426d6dacc45 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -10,6 +10,7 @@
 
 void unix_inflight(struct user_struct *user, struct file *fp);
 void unix_notinflight(struct user_struct *user, struct file *fp);
+void unix_destruct_scm(struct sk_buff *skb);
 void unix_gc(void);
 void wait_for_unix_gc(void);
 struct sock *unix_get_socket(struct file *filp);
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 12cdf611d217..bf4624efe5e6 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -824,8 +824,15 @@ __SYSCALL(__NR_futex_time64, sys_futex)
 __SYSCALL(__NR_sched_rr_get_interval_time64, sys_sched_rr_get_interval)
 #endif
 
+#define __NR_io_uring_setup 425
+__SYSCALL(__NR_io_uring_setup, sys_io_uring_setup)
+#define __NR_io_uring_enter 426
+__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter)
+#define __NR_io_uring_register 427
+__SYSCALL(__NR_io_uring_register, sys_io_uring_register)
+
 #undef __NR_syscalls
-#define __NR_syscalls 424
+#define __NR_syscalls 428
 
 /*
  * 32 bit systems traditionally used different
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
new file mode 100644
index 000000000000..e23408692118
--- /dev/null
+++ b/include/uapi/linux/io_uring.h
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Header file for the io_uring interface.
+ *
+ * Copyright (C) 2019 Jens Axboe
+ * Copyright (C) 2019 Christoph Hellwig
+ */
+#ifndef LINUX_IO_URING_H
+#define LINUX_IO_URING_H
+
+#include <linux/fs.h>
+#include <linux/types.h>
+
+/*
+ * IO submission data structure (Submission Queue Entry)
+ */
+struct io_uring_sqe {
+        __u8    opcode;         /* type of operation for this sqe */
+        __u8    flags;          /* IOSQE_ flags */
+        __u16   ioprio;         /* ioprio for the request */
+        __s32   fd;             /* file descriptor to do IO on */
+        __u64   off;            /* offset into file */
+        __u64   addr;           /* pointer to buffer or iovecs */
+        __u32   len;            /* buffer size or number of iovecs */
+        union {
+                __kernel_rwf_t  rw_flags;
+                __u32           fsync_flags;
+                __u16           poll_events;
+        };
+        __u64   user_data;      /* data to be passed back at completion time */
+        union {
+                __u16   buf_index;      /* index into fixed buffers, if used */
+                __u64   __pad2[3];
+        };
+};
+
+/*
+ * sqe->flags
+ */
+#define IOSQE_FIXED_FILE        (1U << 0)       /* use fixed fileset */
+
+/*
+ * io_uring_setup() flags
+ */
+#define IORING_SETUP_IOPOLL     (1U << 0)       /* io_context is polled */
+#define IORING_SETUP_SQPOLL     (1U << 1)       /* SQ poll thread */
+#define IORING_SETUP_SQ_AFF     (1U << 2)       /* sq_thread_cpu is valid */
+
+#define IORING_OP_NOP           0
+#define IORING_OP_READV         1
+#define IORING_OP_WRITEV        2
+#define IORING_OP_FSYNC         3
+#define IORING_OP_READ_FIXED    4
+#define IORING_OP_WRITE_FIXED   5
+#define IORING_OP_POLL_ADD      6
+#define IORING_OP_POLL_REMOVE   7
+
+/*
+ * sqe->fsync_flags
+ */
+#define IORING_FSYNC_DATASYNC   (1U << 0)
+
+/*
+ * IO completion data structure (Completion Queue Entry)
+ */
+struct io_uring_cqe {
+        __u64   user_data;      /* sqe->data submission passed back */
+        __s32   res;            /* result code for this event */
+        __u32   flags;
+};
+
+/*
+ * Magic offsets for the application to mmap the data it needs
+ */
+#define IORING_OFF_SQ_RING              0ULL
+#define IORING_OFF_CQ_RING              0x8000000ULL
+#define IORING_OFF_SQES                 0x10000000ULL
+
+/*
+ * Filled with the offset for mmap(2)
+ */
+struct io_sqring_offsets {
+        __u32 head;
+        __u32 tail;
+        __u32 ring_mask;
+        __u32 ring_entries;
+        __u32 flags;
+        __u32 dropped;
+        __u32 array;
+        __u32 resv1;
+        __u64 resv2;
+};
+
+/*
+ * sq_ring->flags
+ */
+#define IORING_SQ_NEED_WAKEUP   (1U << 0) /* needs io_uring_enter wakeup */
+
+struct io_cqring_offsets {
+        __u32 head;
+        __u32 tail;
+        __u32 ring_mask;
+        __u32 ring_entries;
+        __u32 overflow;
+        __u32 cqes;
+        __u64 resv[2];
+};
+
+/*
+ * io_uring_enter(2) flags
+ */
+#define IORING_ENTER_GETEVENTS  (1U << 0)
+#define IORING_ENTER_SQ_WAKEUP  (1U << 1)
+
+/*
+ * Passed in for io_uring_setup(2). Copied back with updated info on success
+ */
+struct io_uring_params {
+        __u32 sq_entries;
+        __u32 cq_entries;
+        __u32 flags;
+        __u32 sq_thread_cpu;
+        __u32 sq_thread_idle;
+        __u32 resv[5];
+        struct io_sqring_offsets sq_off;
+        struct io_cqring_offsets cq_off;
+};
+
+/*
+ * io_uring_register(2) opcodes and arguments
+ */
+#define IORING_REGISTER_BUFFERS         0
+#define IORING_UNREGISTER_BUFFERS       1
+#define IORING_REGISTER_FILES           2
+#define IORING_UNREGISTER_FILES         3
+
+#endif