io_uring: add splice(2) support

Add support for splice(2). - output file is specified as sqe->fd, so it's handled by generic code - hash_reg_file handled by generic code as well - len is 32bit, but should be fine - the fd_in is registered file, when SPLICE_F_FD_IN_FIXED is set, which is a splice flag (i.e. sqe->splice_flags).

Pavel Begunkov committed 6 years ago

Commit 7d67af21 parent 8da11c12 files · +122 −1Browse files

Showing the changes to include/uapi/linux (1 of 2 files). Show all

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include/uapi/linux/io_uring.h+13−1

@@ -23,7 +23,10 @@ struct io_uring_sqe { · 22 unmodified lines
23	23	__u64 off; /* offset into file */
24	24	__u64 addr2;
25	25	};
26		− __u64 addr; /* pointer to buffer or iovecs */
	26	+ union {
	27	+ __u64 addr; /* pointer to buffer or iovecs */
	28	+ __u64 splice_off_in;
	29	+ };
27	30	__u32 len; /* buffer size or number of iovecs */
28	31	union {
29	32	__kernel_rwf_t rw_flags;
@@ -37,6 +40,7 @@ struct io_uring_sqe { · 7 unmodified lines
37	40	__u32 open_flags;
38	41	__u32 statx_flags;
39	42	__u32 fadvise_advice;
	43	+ __u32 splice_flags;
40	44	};
41	45	__u64 user_data; /* data to be passed back at completion time */
42	46	union {
@@ -45,6 +49,7 @@ struct io_uring_sqe { · 2 unmodified lines
45	49	__u16 buf_index;
46	50	/* personality to use, if used */
47	51	__u16 personality;
	52	+ __s32 splice_fd_in;
48	53	};
49	54	__u64 __pad2[3];
50	55	};
@@ -113,6 +118,7 @@ enum { · 62 unmodified lines
113	118	IORING_OP_RECV,
114	119	IORING_OP_OPENAT2,
115	120	IORING_OP_EPOLL_CTL,
	121	+ IORING_OP_SPLICE,
116	122
117	123	/* this goes last, obviously */
118	124	IORING_OP_LAST,
@@ -128,6 +134,12 @@ enum { · 9 unmodified lines
128	134	*/
129	135	#define IORING_TIMEOUT_ABS (1U << 0)
130	136
	137	+/*
	138	+ * sqe->splice_flags
	139	+ * extends splice(2) flags
	140	+ */
	141	+#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
	142	+
131	143	/*
132	144	* IO completion data structure (Completion Queue Entry)
133	145	*/