Add support for splice(2). Out file is handled in generic path,
input file owned cared by splice* bits only.
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io_uring.c | 106 ++++++++++++++++++++++++++++++++++
include/uapi/linux/io_uring.h | 14 ++++-
2 files changed, 119 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 389db6f5568b..1c71d848c974 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -76,6 +76,7 @@
#include <linux/fadvise.h>
#include <linux/eventpoll.h>
#include <linux/fs_struct.h>
+#include <linux/splice.h>
#define CREATE_TRACE_POINTS
#include <trace/events/io_uring.h>
@@ -433,6 +434,15 @@ struct io_epoll {
struct epoll_event event;
};
+struct io_splice {
+ struct file *file_out;
+ struct file *file_in;
+ loff_t off_out;
+ loff_t off_in;
+ u64 len;
+ unsigned int flags;
+};
+
struct io_async_connect {
struct sockaddr_storage address;
};
@@ -546,6 +556,7 @@ struct io_kiocb {
struct io_fadvise fadvise;
struct io_madvise madvise;
struct io_epoll epoll;
+ struct io_splice splice;
};
struct io_async_ctx *io;
@@ -746,6 +757,11 @@ static const struct io_op_def io_op_defs[] = {
.unbound_nonreg_file = 1,
.file_table = 1,
},
+ [IORING_OP_SPLICE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ }
};
static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -760,6 +776,10 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
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 int io_get_file(struct io_submit_state *state,
+ struct io_ring_ctx *ctx,
+ int fd, struct file **out_file,
+ bool fixed);
static struct kmem_cache *req_cachep;
@@ -2412,6 +2432,77 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
return ret;
}
+static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_splice* sp = &req->splice;
+ unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
+ int ret;
+
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ return 0;
+
+ sp->file_in = NULL;
+ sp->off_in = READ_ONCE(sqe->off_in);
+ sp->off_out = READ_ONCE(sqe->off);
+ sp->len = READ_ONCE(sqe->len);
+ sp->flags = READ_ONCE(sqe->splice_flags);
+
+ if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
+ return -EINVAL;
+
+ ret = io_get_file(NULL, req->ctx, READ_ONCE(sqe->splice_fd_in),
+ &sp->file_in, (sp->flags & SPLICE_F_FD_IN_FIXED));
+ if (ret)
+ return ret;
+ req->flags |= REQ_F_NEED_CLEANUP;
+
+ if (!S_ISREG(file_inode(sp->file_in)->i_mode))
+ req->work.flags |= IO_WQ_WORK_UNBOUND;
+
+ return 0;
+}
+
+static bool io_splice_punt(struct file *file)
+{
+ if (get_pipe_info(file))
+ return false;
+ if (!io_file_supports_async(file))
+ return true;
+ return !(file->f_mode & O_NONBLOCK);
+}
+
+static int io_splice(struct io_kiocb *req, struct io_kiocb **nxt,
+ bool force_nonblock)
+{
+ struct io_splice* sp = &req->splice;
+ struct file *in = sp->file_in;
+ struct file *out = sp->file_out;
+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+ loff_t *poff_in, *poff_out;
+ long ret;
+
+ if (force_nonblock) {
+ if (io_splice_punt(in) || io_splice_punt(out))
+ return -EAGAIN;
+ flags |= SPLICE_F_NONBLOCK;
+ }
+
+ poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
+ poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
+ ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
+ if (force_nonblock && ret == -EAGAIN)
+ return -EAGAIN;
+
+ io_put_file(req->ctx, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+
+ io_cqring_add_event(req, ret);
+ if (ret != sp->len)
+ req_set_fail_links(req);
+ io_put_req_find_next(req, nxt);
+ return 0;
+}
+
/*
* IORING_OP_NOP just posts a completion event, nothing else.
*/
@@ -4227,6 +4318,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
case IORING_OP_EPOLL_CTL:
ret = io_epoll_ctl_prep(req, sqe);
break;
+ case IORING_OP_SPLICE:
+ ret = io_splice_prep(req, sqe);
+ break;
default:
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
req->opcode);
@@ -4289,6 +4383,10 @@ static void io_cleanup_req(struct io_kiocb *req)
case IORING_OP_STATX:
putname(req->open.filename);
break;
+ case IORING_OP_SPLICE:
+ io_put_file(req->ctx, req->splice.file_in,
+ (req->splice.flags & SPLICE_F_FD_IN_FIXED));
+ break;
}
req->flags &= ~REQ_F_NEED_CLEANUP;
@@ -4492,6 +4590,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
}
ret = io_epoll_ctl(req, nxt, force_nonblock);
break;
+ case IORING_OP_SPLICE:
+ if (sqe) {
+ ret = io_splice_prep(req, sqe);
+ if (ret < 0)
+ break;
+ }
+ ret = io_splice(req, nxt, force_nonblock);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 3f7961c1c243..bc2fe0281de7 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -23,7 +23,10 @@ struct io_uring_sqe {
__u64 off; /* offset into file */
__u64 addr2;
};
- __u64 addr; /* pointer to buffer or iovecs */
+ union {
+ __u64 addr; /* pointer to buffer or iovecs */
+ __u64 off_in;
+ };
__u32 len; /* buffer size or number of iovecs */
union {
__kernel_rwf_t rw_flags;
@@ -37,6 +40,7 @@ struct io_uring_sqe {
__u32 open_flags;
__u32 statx_flags;
__u32 fadvise_advice;
+ __u32 splice_flags;
};
__u64 user_data; /* data to be passed back at completion time */
union {
@@ -45,6 +49,7 @@ struct io_uring_sqe {
__u16 buf_index;
/* personality to use, if used */
__u16 personality;
+ __u32 splice_fd_in;
};
__u64 __pad2[3];
};
@@ -113,6 +118,7 @@ enum {
IORING_OP_RECV,
IORING_OP_OPENAT2,
IORING_OP_EPOLL_CTL,
+ IORING_OP_SPLICE,
/* this goes last, obviously */
IORING_OP_LAST,
@@ -128,6 +134,12 @@ enum {
*/
#define IORING_TIMEOUT_ABS (1U << 0)
+/*
+ * sqe->splice_flags
+ * extends splice(2) flags
+ */
+#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
+
/*
* IO completion data structure (Completion Queue Entry)
*/
--
2.24.0
Hi Pavel,
> +static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> +{
> + struct io_splice* sp = &req->splice;
> + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
> + int ret;
> +
> + if (req->flags & REQ_F_NEED_CLEANUP)
> + return 0;
> +
> + sp->file_in = NULL;
> + sp->off_in = READ_ONCE(sqe->off_in);
> + sp->off_out = READ_ONCE(sqe->off);
> + sp->len = READ_ONCE(sqe->len);
> + sp->flags = READ_ONCE(sqe->splice_flags);
> +
> + if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
> + return -EINVAL;
Why is ioprio not supported?
metze
On 2/17/2020 6:18 PM, Stefan Metzmacher wrote:
> Hi Pavel,
>
>> +static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>> +{
>> + struct io_splice* sp = &req->splice;
>> + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
>> + int ret;
>> +
>> + if (req->flags & REQ_F_NEED_CLEANUP)
>> + return 0;
>> +
>> + sp->file_in = NULL;
>> + sp->off_in = READ_ONCE(sqe->off_in);
>> + sp->off_out = READ_ONCE(sqe->off);
>> + sp->len = READ_ONCE(sqe->len);
>> + sp->flags = READ_ONCE(sqe->splice_flags);
>> +
>> + if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
>> + return -EINVAL;
>
> Why is ioprio not supported?
Because there is no way to set it without changing much of splice code.
It may be added later
BTW, it seems, only opcodes cares about ioprio are read*/write*.
recv*() and send*() don't reject it, but never use.
--
Pavel Begunkov
Am 17.02.20 um 16:40 schrieb Pavel Begunkov:
> On 2/17/2020 6:18 PM, Stefan Metzmacher wrote:
>> Hi Pavel,
>>
>>> +static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>>> +{
>>> + struct io_splice* sp = &req->splice;
>>> + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
>>> + int ret;
>>> +
>>> + if (req->flags & REQ_F_NEED_CLEANUP)
>>> + return 0;
>>> +
>>> + sp->file_in = NULL;
>>> + sp->off_in = READ_ONCE(sqe->off_in);
>>> + sp->off_out = READ_ONCE(sqe->off);
>>> + sp->len = READ_ONCE(sqe->len);
>>> + sp->flags = READ_ONCE(sqe->splice_flags);
>>> +
>>> + if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
>>> + return -EINVAL;
>>
>> Why is ioprio not supported?
>
> Because there is no way to set it without changing much of splice code.
> It may be added later
>
> BTW, it seems, only opcodes cares about ioprio are read*/write*.
> recv*() and send*() don't reject it, but never use.
I guess it's more like a hint, so should we just ignore it until
it's passed down? Otherwise applications need to do some logic to
find out if they can pass a value or not.
I'm not sure what's better, but I think it needs to be discussed...
metze
On 2/17/2020 6:54 PM, Stefan Metzmacher wrote:
> Am 17.02.20 um 16:40 schrieb Pavel Begunkov:
>> On 2/17/2020 6:18 PM, Stefan Metzmacher wrote:
>>> Hi Pavel,
>>>
>>>> +static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>>>> +{
>>>> + struct io_splice* sp = &req->splice;
>>>> + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
>>>> + int ret;
>>>> +
>>>> + if (req->flags & REQ_F_NEED_CLEANUP)
>>>> + return 0;
>>>> +
>>>> + sp->file_in = NULL;
>>>> + sp->off_in = READ_ONCE(sqe->off_in);
>>>> + sp->off_out = READ_ONCE(sqe->off);
>>>> + sp->len = READ_ONCE(sqe->len);
>>>> + sp->flags = READ_ONCE(sqe->splice_flags);
>>>> +
>>>> + if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
>>>> + return -EINVAL;
>>>
>>> Why is ioprio not supported?
>>
>> Because there is no way to set it without changing much of splice code.
>> It may be added later
>>
>> BTW, it seems, only opcodes cares about ioprio are read*/write*.
>> recv*() and send*() don't reject it, but never use.
>
> I guess it's more like a hint, so should we just ignore it until
> it's passed down? Otherwise applications need to do some logic to
> find out if they can pass a value or not.
Then it probably needs to validate the value, but not just ignore it
> I'm not sure what's better, but I think it needs to be discussed...
meh, let's see what Jens think
--
Pavel Begunkov