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* [PATCHSET v4] Support for automatic buffer selection
@ 2020-03-10 15:04 Jens Axboe
  2020-03-10 15:04 ` [PATCH 1/9] io_uring: buffer registration infrastructure Jens Axboe
                   ` (8 more replies)
  0 siblings, 9 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres

With the poll retry based async IO patchset I posted last week, the one
big missing thing for me was the ability to have automatic buffer
selection. Generally applications that handle tons of sockets like to
poll for activity on them, then issue IO when they become ready. This is
of course at least two system calls, but it also means that it provides
an application a chance to manage how many IO buffers it needs. With the
io_uring based polled IO, the application need only issue an
IORING_OP_RECV (for example, to receive socket data), it doesn't need to
poll at all. However, this means that the application no longer has an
opportune moment to select how many IO buffers to keep in flight, it has
to be equal to what it currently has pending.

I had originally intended to use BPF to provide some means of buffer
selection, but I had a hard time imagining how life times of the buffer
could be managed through that. I had a false start today, but Andres
suggested a nifty approach that also solves the life time issue.

Basically the application registers buffers with the kernel. Each buffer
is registered with a given group ID, and buffer ID. The buffers are
organized by group ID, and the application selects a buffer pool based
on this group ID. One use case might be to group by size. There's an
opcode for this, IORING_OP_PROVIDE_BUFFERS.

IORING_OP_PROVIDE_BUFFERS takes a start address, length of a buffer, and
number of buffers. It also provides a group ID with which these buffers
should be associated, and a starting buffer ID. The buffers are then
added, and the buffer ID is incremented by 1 for each buffer.

With that, when doing the same IORING_OP_RECV, no buffer is passed in
with the request. Instead, it's flagged with IOSQE_BUFFER_SELECT, and
sqe->buf_group is filled in with a valid group ID. When the kernel can
satisfy the receive, a buffer is selected from the specified group ID
pool. If none are available, the IO is terminated with -ENOBUFS. On
success, the buffer ID is passed back through the (CQE) completion
event. This tells the application what specific buffer was used.

A buffer can be used only once. On completion, the application may
choose to free it, or register it again with IORING_OP_PROVIDE_BUFFERS.

Patches can also be found in the below repo:

https://git.kernel.dk/cgit/linux-block/log/?h=io_uring-buf-select

which is sitting on top of for-5.7/io_uring.

v4:
- Address various review comments
- Fixes
- Fold in 32-bit warning fixes

v3:
- Add support for IORING_OP_READV and IORING_OP_RECVMSG
- Drop write side
- More cleanups on address space, retained state
- Add a few helpers
- Rebase on new for-5.7/io_uring

v2:
- Cleanup address space
- Fix locking for async offload issue
- Add lockdep annotation for uring_lock
- Verify sqe fields on PROVIDE_BUFFERS prep
- Fix send/recv kbuf leak on import failure
- Fix send/recv error handling on -ENOBUFS
- Change IORING_OP_PROVIDE_BUFFER to PROVIDE_BUFFERS, and allow multiple
  contig buffers in one call



^ permalink raw reply	[flat|nested] 11+ messages in thread
* [PATCH 1/9] io_uring: buffer registration infrastructure
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS Jens Axboe
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

This just prepares the ring for having lists of buffers associated with
it, that the application can provide for SQEs to consume instead of
providing their own.

The buffers are organized by group ID.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0d6f4b3b8f13..1f3ae208f6a6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -195,6 +195,13 @@ struct fixed_file_data {
 	struct completion		done;
 };
 
+struct io_buffer {
+	struct list_head list;
+	__u64 addr;
+	__s32 len;
+	__u16 bid;
+};
+
 struct io_ring_ctx {
 	struct {
 		struct percpu_ref	refs;
@@ -272,6 +279,8 @@ struct io_ring_ctx {
 	struct socket		*ring_sock;
 #endif
 
+	struct idr		io_buffer_idr;
+
 	struct idr		personality_idr;
 
 	struct {
@@ -875,6 +884,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	INIT_LIST_HEAD(&ctx->cq_overflow_list);
 	init_completion(&ctx->completions[0]);
 	init_completion(&ctx->completions[1]);
+	idr_init(&ctx->io_buffer_idr);
 	idr_init(&ctx->personality_idr);
 	mutex_init(&ctx->uring_lock);
 	init_waitqueue_head(&ctx->wait);
@@ -6524,6 +6534,30 @@ static int io_eventfd_unregister(struct io_ring_ctx *ctx)
 	return -ENXIO;
 }
 
+static int __io_destroy_buffers(int id, void *p, void *data)
+{
+	struct io_ring_ctx *ctx = data;
+	struct io_buffer *buf = p;
+
+	/* the head kbuf is the list itself */
+	while (!list_empty(&buf->list)) {
+		struct io_buffer *nxt;
+
+		nxt = list_first_entry(&buf->list, struct io_buffer, list);
+		list_del(&nxt->list);
+		kfree(nxt);
+	}
+	kfree(buf);
+	idr_remove(&ctx->io_buffer_idr, id);
+	return 0;
+}
+
+static void io_destroy_buffers(struct io_ring_ctx *ctx)
+{
+	idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx);
+	idr_destroy(&ctx->io_buffer_idr);
+}
+
 static void io_ring_ctx_free(struct io_ring_ctx *ctx)
 {
 	io_finish_async(ctx);
@@ -6534,6 +6568,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	io_sqe_buffer_unregister(ctx);
 	io_sqe_files_unregister(ctx);
 	io_eventfd_unregister(ctx);
+	io_destroy_buffers(ctx);
 	idr_destroy(&ctx->personality_idr);
 
 #if defined(CONFIG_UNIX)
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
  2020-03-10 15:04 ` [PATCH 1/9] io_uring: buffer registration infrastructure Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:19   ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 3/9] io_uring: support buffer selection for OP_READ and OP_RECV Jens Axboe
                   ` (6 subsequent siblings)
  8 siblings, 1 reply; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

IORING_OP_PROVIDE_BUFFERS uses the buffer registration infrastructure to
support passing in an addr/len that is associated with a buffer ID and
buffer group ID. The group ID is used to index and lookup the buffers,
while the buffer ID can be used to notify the application which buffer
in the group was used. The addr passed in is the starting buffer address,
and length is each buffer length. A number of buffers to add with can be
specified, in which case addr is incremented by length for each addition,
and each buffer increments the buffer ID specified.

No validation is done of the buffer ID. If the application provides
buffers within the same group with identical buffer IDs, then it'll have
a hard time telling which buffer ID was used. The only restriction is
that the buffer ID can be a max of 16-bits in size, so USHRT_MAX is the
maximum ID that can be used.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c                 | 128 +++++++++++++++++++++++++++++++++-
 include/uapi/linux/io_uring.h |  10 ++-
 2 files changed, 135 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1f3ae208f6a6..675b33cf855a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -447,6 +447,15 @@ struct io_splice {
 	unsigned int			flags;
 };
 
+struct io_provide_buf {
+	struct file			*file;
+	__u64				addr;
+	__s32				len;
+	__u32				bgid;
+	__u16				nbufs;
+	__u16				bid;
+};
+
 struct io_async_connect {
 	struct sockaddr_storage		address;
 };
@@ -572,6 +581,7 @@ struct io_kiocb {
 		struct io_madvise	madvise;
 		struct io_epoll		epoll;
 		struct io_splice	splice;
+		struct io_provide_buf	pbuf;
 	};
 
 	struct io_async_ctx		*io;
@@ -799,7 +809,8 @@ static const struct io_op_def io_op_defs[] = {
 		.needs_file		= 1,
 		.hash_reg_file		= 1,
 		.unbound_nonreg_file	= 1,
-	}
+	},
+	[IORING_OP_PROVIDE_BUFFERS] = {},
 };
 
 static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -2785,6 +2796,110 @@ static int io_openat(struct io_kiocb *req, bool force_nonblock)
 	return io_openat2(req, force_nonblock);
 }
 
+static int io_provide_buffers_prep(struct io_kiocb *req,
+				   const struct io_uring_sqe *sqe)
+{
+	struct io_provide_buf *p = &req->pbuf;
+	u64 tmp;
+
+	if (sqe->ioprio || sqe->rw_flags)
+		return -EINVAL;
+
+	tmp = READ_ONCE(sqe->fd);
+	if (!tmp || tmp > USHRT_MAX)
+		return -E2BIG;
+	p->nbufs = tmp;
+	p->addr = READ_ONCE(sqe->addr);
+	p->len = READ_ONCE(sqe->len);
+
+	if (!access_ok(u64_to_user_ptr(p->addr), p->len))
+		return -EFAULT;
+
+	p->bgid = READ_ONCE(sqe->buf_group);
+	tmp = READ_ONCE(sqe->off);
+	if (tmp > USHRT_MAX)
+		return -E2BIG;
+	p->bid = tmp;
+	return 0;
+}
+
+static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
+{
+	struct io_buffer *buf;
+	u64 addr = pbuf->addr;
+	int i, bid = pbuf->bid;
+
+	for (i = 0; i < pbuf->nbufs; i++) {
+		buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+		if (!buf)
+			break;
+
+		buf->addr = addr;
+		buf->len = pbuf->len;
+		buf->bid = bid;
+		addr += pbuf->len;
+		bid++;
+		if (!*head) {
+			INIT_LIST_HEAD(&buf->list);
+			*head = buf;
+		} else {
+			list_add_tail(&buf->list, &(*head)->list);
+		}
+	}
+
+	return i ? i : -ENOMEM;
+}
+
+static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock)
+{
+	struct io_provide_buf *p = &req->pbuf;
+	struct io_ring_ctx *ctx = req->ctx;
+	struct io_buffer *head, *list;
+	int ret = 0;
+
+	/*
+	 * "Normal" inline submissions always hold the uring_lock, since we
+	 * grab it from the system call. Same is true for the SQPOLL offload.
+	 * The only exception is when we've detached the request and issue it
+	 * from an async worker thread, grab the lock for that case.
+	 */
+	if (!force_nonblock)
+		mutex_lock(&ctx->uring_lock);
+
+	lockdep_assert_held(&ctx->uring_lock);
+
+	list = head = idr_find(&ctx->io_buffer_idr, p->bgid);
+
+	ret = io_add_buffers(p, &head);
+	if (ret < 0)
+		goto out;
+
+	if (!list) {
+		ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
+					GFP_KERNEL);
+		if (ret < 0) {
+			while (!list_empty(&head->list)) {
+				struct io_buffer *buf;
+
+				buf = list_first_entry(&head->list,
+							struct io_buffer, list);
+				list_del(&buf->list);
+				kfree(buf);
+			}
+			kfree(head);
+			goto out;
+		}
+	}
+out:
+	if (!force_nonblock)
+		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_epoll_ctl_prep(struct io_kiocb *req,
 			     const struct io_uring_sqe *sqe)
 {
@@ -4392,6 +4507,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
 	case IORING_OP_SPLICE:
 		ret = io_splice_prep(req, sqe);
 		break;
+	case IORING_OP_PROVIDE_BUFFERS:
+		ret = io_provide_buffers_prep(req, sqe);
+		break;
 	default:
 		printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
 				req->opcode);
@@ -4669,6 +4787,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		}
 		ret = io_splice(req, force_nonblock);
 		break;
+	case IORING_OP_PROVIDE_BUFFERS:
+		if (sqe) {
+			ret = io_provide_buffers_prep(req, sqe);
+			if (ret)
+				break;
+		}
+		ret = io_provide_buffers(req, force_nonblock);
+		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 53b36311cdac..bc34a57a660b 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -45,8 +45,13 @@ struct io_uring_sqe {
 	__u64	user_data;	/* data to be passed back at completion time */
 	union {
 		struct {
-			/* index into fixed buffers, if used */
-			__u16	buf_index;
+			/* pack this to avoid bogus arm OABI complaints */
+			union {
+				/* index into fixed buffers, if used */
+				__u16	buf_index;
+				/* for grouped buffer selection */
+				__u16	buf_group;
+			} __attribute__((packed));
 			/* personality to use, if used */
 			__u16	personality;
 			__s32	splice_fd_in;
@@ -119,6 +124,7 @@ enum {
 	IORING_OP_OPENAT2,
 	IORING_OP_EPOLL_CTL,
 	IORING_OP_SPLICE,
+	IORING_OP_PROVIDE_BUFFERS,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 3/9] io_uring: support buffer selection for OP_READ and OP_RECV
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
  2020-03-10 15:04 ` [PATCH 1/9] io_uring: buffer registration infrastructure Jens Axboe
  2020-03-10 15:04 ` [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 4/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_READV Jens Axboe
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

If a server process has tons of pending socket connections, generally
it uses epoll to wait for activity. When the socket is ready for reading
(or writing), the task can select a buffer and issue a recv/send on the
given fd.

Now that we have fast (non-async thread) support, a task can have tons
of pending reads or writes pending. But that means they need buffers to
back that data, and if the number of connections is high enough, having
them preallocated for all possible connections is unfeasible.

With IORING_OP_PROVIDE_BUFFERS, an application can register buffers to
use for any request. The request then sets IOSQE_BUFFER_SELECT in the
sqe, and a given group ID in sqe->buf_group. When the fd becomes ready,
a free buffer from the specified group is selected. If none are
available, the request is terminated with -ENOBUFS. If successful, the
CQE on completion will contain the buffer ID chosen in the cqe->flags
member, encoded as:

	(buffer_id << IORING_CQE_BUFFER_SHIFT) | IORING_CQE_F_BUFFER;

Once a buffer has been consumed by a request, it is no longer available
and must be registered again with IORING_OP_PROVIDE_BUFFERS.

Requests need to support this feature. For now, IORING_OP_READ and
IORING_OP_RECV support it. This is checked on SQE submission, a CQE with
res == -EOPNOTSUPP will be posted if attempted on unsupported requests.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c                 | 206 ++++++++++++++++++++++++++++++----
 include/uapi/linux/io_uring.h |  14 +++
 2 files changed, 199 insertions(+), 21 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 675b33cf855a..65e22240a2d9 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -395,7 +395,9 @@ struct io_sr_msg {
 		void __user		*buf;
 	};
 	int				msg_flags;
+	int				bgid;
 	size_t				len;
+	struct io_buffer		*kbuf;
 };
 
 struct io_open {
@@ -490,6 +492,7 @@ enum {
 	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_BUFFER_SELECT_BIT	= IOSQE_BUFFER_SELECT_BIT,
 
 	REQ_F_LINK_NEXT_BIT,
 	REQ_F_FAIL_LINK_BIT,
@@ -506,6 +509,7 @@ enum {
 	REQ_F_NEED_CLEANUP_BIT,
 	REQ_F_OVERFLOW_BIT,
 	REQ_F_POLLED_BIT,
+	REQ_F_BUFFER_SELECTED_BIT,
 };
 
 enum {
@@ -519,6 +523,8 @@ enum {
 	REQ_F_HARDLINK		= BIT(REQ_F_HARDLINK_BIT),
 	/* IOSQE_ASYNC */
 	REQ_F_FORCE_ASYNC	= BIT(REQ_F_FORCE_ASYNC_BIT),
+	/* IOSQE_BUFFER_SELECT */
+	REQ_F_BUFFER_SELECT	= BIT(REQ_F_BUFFER_SELECT_BIT),
 
 	/* already grabbed next link */
 	REQ_F_LINK_NEXT		= BIT(REQ_F_LINK_NEXT_BIT),
@@ -550,6 +556,8 @@ enum {
 	REQ_F_OVERFLOW		= BIT(REQ_F_OVERFLOW_BIT),
 	/* already went through poll handler */
 	REQ_F_POLLED		= BIT(REQ_F_POLLED_BIT),
+	/* buffer already selected */
+	REQ_F_BUFFER_SELECTED	= BIT(REQ_F_BUFFER_SELECTED_BIT),
 };
 
 struct async_poll {
@@ -612,6 +620,7 @@ struct io_kiocb {
 			struct callback_head	task_work;
 			struct hlist_node	hash_node;
 			struct async_poll	*apoll;
+			int			cflags;
 		};
 		struct io_wq_work	work;
 	};
@@ -661,6 +670,8 @@ struct io_op_def {
 	/* set if opcode supports polled "wait" */
 	unsigned		pollin : 1;
 	unsigned		pollout : 1;
+	/* op supports buffer selection */
+	unsigned		buffer_select : 1;
 };
 
 static const struct io_op_def io_op_defs[] = {
@@ -770,6 +781,7 @@ static const struct io_op_def io_op_defs[] = {
 		.needs_file		= 1,
 		.unbound_nonreg_file	= 1,
 		.pollin			= 1,
+		.buffer_select		= 1,
 	},
 	[IORING_OP_WRITE] = {
 		.needs_mm		= 1,
@@ -794,6 +806,7 @@ static const struct io_op_def io_op_defs[] = {
 		.needs_file		= 1,
 		.unbound_nonreg_file	= 1,
 		.pollin			= 1,
+		.buffer_select		= 1,
 	},
 	[IORING_OP_OPENAT2] = {
 		.needs_file		= 1,
@@ -1170,7 +1183,7 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
 		if (cqe) {
 			WRITE_ONCE(cqe->user_data, req->user_data);
 			WRITE_ONCE(cqe->res, req->result);
-			WRITE_ONCE(cqe->flags, 0);
+			WRITE_ONCE(cqe->flags, req->cflags);
 		} else {
 			WRITE_ONCE(ctx->rings->cq_overflow,
 				atomic_inc_return(&ctx->cached_cq_overflow));
@@ -1194,7 +1207,7 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
 	return cqe != NULL;
 }
 
-static void io_cqring_fill_event(struct io_kiocb *req, long res)
+static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	struct io_uring_cqe *cqe;
@@ -1210,7 +1223,7 @@ static void io_cqring_fill_event(struct io_kiocb *req, long res)
 	if (likely(cqe)) {
 		WRITE_ONCE(cqe->user_data, req->user_data);
 		WRITE_ONCE(cqe->res, res);
-		WRITE_ONCE(cqe->flags, 0);
+		WRITE_ONCE(cqe->flags, cflags);
 	} else if (ctx->cq_overflow_flushed) {
 		WRITE_ONCE(ctx->rings->cq_overflow,
 				atomic_inc_return(&ctx->cached_cq_overflow));
@@ -1222,23 +1235,34 @@ static void io_cqring_fill_event(struct io_kiocb *req, long res)
 		req->flags |= REQ_F_OVERFLOW;
 		refcount_inc(&req->refs);
 		req->result = res;
+		req->cflags = cflags;
 		list_add_tail(&req->list, &ctx->cq_overflow_list);
 	}
 }
 
-static void io_cqring_add_event(struct io_kiocb *req, long res)
+static void io_cqring_fill_event(struct io_kiocb *req, long res)
+{
+	__io_cqring_fill_event(req, res, 0);
+}
+
+static void __io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	unsigned long flags;
 
 	spin_lock_irqsave(&ctx->completion_lock, flags);
-	io_cqring_fill_event(req, res);
+	__io_cqring_fill_event(req, res, cflags);
 	io_commit_cqring(ctx);
 	spin_unlock_irqrestore(&ctx->completion_lock, flags);
 
 	io_cqring_ev_posted(ctx);
 }
 
+static void io_cqring_add_event(struct io_kiocb *req, long res)
+{
+	__io_cqring_add_event(req, res, 0);
+}
+
 static inline bool io_is_fallback_req(struct io_kiocb *req)
 {
 	return req == (struct io_kiocb *)
@@ -1660,6 +1684,18 @@ static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req)
 	return true;
 }
 
+static int io_put_kbuf(struct io_kiocb *req)
+{
+	struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr;
+	int cflags;
+
+	cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
+	cflags |= IORING_CQE_F_BUFFER;
+	req->rw.addr = 0;
+	kfree(kbuf);
+	return cflags;
+}
+
 /*
  * Find and free completed poll iocbs
  */
@@ -1671,10 +1707,15 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
 
 	rb.to_free = rb.need_iter = 0;
 	while (!list_empty(done)) {
+		int cflags = 0;
+
 		req = list_first_entry(done, struct io_kiocb, list);
 		list_del(&req->list);
 
-		io_cqring_fill_event(req, req->result);
+		if (req->flags & REQ_F_BUFFER_SELECTED)
+			cflags = io_put_kbuf(req);
+
+		__io_cqring_fill_event(req, req->result, cflags);
 		(*nr_events)++;
 
 		if (refcount_dec_and_test(&req->refs) &&
@@ -1849,13 +1890,16 @@ static inline void req_set_fail_links(struct io_kiocb *req)
 static void io_complete_rw_common(struct kiocb *kiocb, long res)
 {
 	struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+	int cflags = 0;
 
 	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);
+	if (req->flags & REQ_F_BUFFER_SELECTED)
+		cflags = io_put_kbuf(req);
+	__io_cqring_add_event(req, res, cflags);
 }
 
 static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
@@ -2033,7 +2077,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 
 	req->rw.addr = READ_ONCE(sqe->addr);
 	req->rw.len = READ_ONCE(sqe->len);
-	/* we own ->private, reuse it for the buffer index */
+	/* we own ->private, reuse it for the buffer index  / buffer ID */
 	req->rw.kiocb.private = (void *) (unsigned long)
 					READ_ONCE(sqe->buf_index);
 	return 0;
@@ -2146,8 +2190,61 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
 	return len;
 }
 
+static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+	if (needs_lock)
+		mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+	/*
+	 * "Normal" inline submissions always hold the uring_lock, since we
+	 * grab it from the system call. Same is true for the SQPOLL offload.
+	 * The only exception is when we've detached the request and issue it
+	 * from an async worker thread, grab the lock for that case.
+	 */
+	if (needs_lock)
+		mutex_lock(&ctx->uring_lock);
+}
+
+static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
+					  int bgid, struct io_buffer *kbuf,
+					  bool needs_lock)
+{
+	struct io_buffer *head;
+
+	if (req->flags & REQ_F_BUFFER_SELECTED)
+		return kbuf;
+
+	io_ring_submit_lock(req->ctx, needs_lock);
+
+	lockdep_assert_held(&req->ctx->uring_lock);
+
+	head = idr_find(&req->ctx->io_buffer_idr, bgid);
+	if (head) {
+		if (!list_empty(&head->list)) {
+			kbuf = list_last_entry(&head->list, struct io_buffer,
+							list);
+			list_del(&kbuf->list);
+		} else {
+			kbuf = head;
+			idr_remove(&req->ctx->io_buffer_idr, bgid);
+		}
+		if (*len > kbuf->len)
+			*len = kbuf->len;
+	} else {
+		kbuf = ERR_PTR(-ENOBUFS);
+	}
+
+	io_ring_submit_unlock(req->ctx, needs_lock);
+
+	return kbuf;
+}
+
 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-			       struct iovec **iovec, struct iov_iter *iter)
+			       struct iovec **iovec, struct iov_iter *iter,
+			       bool needs_lock)
 {
 	void __user *buf = u64_to_user_ptr(req->rw.addr);
 	size_t sqe_len = req->rw.len;
@@ -2159,12 +2256,29 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 		return io_import_fixed(req, rw, iter);
 	}
 
-	/* buffer index only valid with fixed read/write */
-	if (req->rw.kiocb.private)
+	/* buffer index only valid with fixed read/write, or buffer select  */
+	if (req->rw.kiocb.private && !(req->flags & REQ_F_BUFFER_SELECT))
 		return -EINVAL;
 
 	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
 		ssize_t ret;
+
+		if (req->flags & REQ_F_BUFFER_SELECT) {
+			struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr;
+			int bgid;
+
+			bgid = (int) (unsigned long) req->rw.kiocb.private;
+			kbuf = io_buffer_select(req, &sqe_len, bgid, kbuf,
+						needs_lock);
+			if (IS_ERR(kbuf)) {
+				*iovec = NULL;
+				return PTR_ERR(kbuf);
+			}
+			req->rw.addr = (u64) kbuf;
+			req->flags |= REQ_F_BUFFER_SELECTED;
+			buf = u64_to_user_ptr(kbuf->addr);
+		}
+
 		ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
 		*iovec = NULL;
 		return ret < 0 ? ret : sqe_len;
@@ -2307,7 +2421,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	io = req->io;
 	io->rw.iov = io->rw.fast_iov;
 	req->io = NULL;
-	ret = io_import_iovec(READ, req, &io->rw.iov, &iter);
+	ret = io_import_iovec(READ, req, &io->rw.iov, &iter, !force_nonblock);
 	req->io = io;
 	if (ret < 0)
 		return ret;
@@ -2324,7 +2438,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
 	size_t iov_count;
 	ssize_t io_size, ret;
 
-	ret = io_import_iovec(READ, req, &iovec, &iter);
+	ret = io_import_iovec(READ, req, &iovec, &iter, !force_nonblock);
 	if (ret < 0)
 		return ret;
 
@@ -2396,7 +2510,7 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	io = req->io;
 	io->rw.iov = io->rw.fast_iov;
 	req->io = NULL;
-	ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter);
+	ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter, !force_nonblock);
 	req->io = io;
 	if (ret < 0)
 		return ret;
@@ -2413,7 +2527,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
 	size_t iov_count;
 	ssize_t ret, io_size;
 
-	ret = io_import_iovec(WRITE, req, &iovec, &iter);
+	ret = io_import_iovec(WRITE, req, &iovec, &iter, !force_nonblock);
 	if (ret < 0)
 		return ret;
 
@@ -3380,6 +3494,27 @@ static int io_send(struct io_kiocb *req, bool force_nonblock)
 #endif
 }
 
+static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
+					       int *cflags, bool needs_lock)
+{
+	struct io_sr_msg *sr = &req->sr_msg;
+	struct io_buffer *kbuf;
+
+	if (!(req->flags & REQ_F_BUFFER_SELECT))
+		return NULL;
+
+	kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
+	if (IS_ERR(kbuf))
+		return kbuf;
+
+	sr->kbuf = kbuf;
+	req->flags |= REQ_F_BUFFER_SELECTED;
+
+	*cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
+	*cflags |= IORING_CQE_F_BUFFER;
+	return kbuf;
+}
+
 static int io_recvmsg_prep(struct io_kiocb *req,
 			   const struct io_uring_sqe *sqe)
 {
@@ -3391,6 +3526,7 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
 	sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
 	sr->len = READ_ONCE(sqe->len);
+	sr->bgid = READ_ONCE(sqe->buf_group);
 
 #ifdef CONFIG_COMPAT
 	if (req->ctx->compat)
@@ -3480,8 +3616,9 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 static int io_recv(struct io_kiocb *req, bool force_nonblock)
 {
 #if defined(CONFIG_NET)
+	struct io_buffer *kbuf = NULL;
 	struct socket *sock;
-	int ret;
+	int ret, cflags = 0;
 
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
@@ -3489,15 +3626,25 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock)
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_sr_msg *sr = &req->sr_msg;
+		void __user *buf = sr->buf;
 		struct msghdr msg;
 		struct iovec iov;
 		unsigned flags;
 
-		ret = import_single_range(READ, sr->buf, sr->len, &iov,
+		kbuf = io_recv_buffer_select(req, &cflags, !force_nonblock);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
+		else if (kbuf)
+			buf = u64_to_user_ptr(kbuf->addr);
+
+		ret = import_single_range(READ, buf, sr->len, &iov,
 						&msg.msg_iter);
-		if (ret)
+		if (ret) {
+			kfree(kbuf);
 			return ret;
+		}
 
+		req->flags |= REQ_F_NEED_CLEANUP;
 		msg.msg_name = NULL;
 		msg.msg_control = NULL;
 		msg.msg_controllen = 0;
@@ -3518,7 +3665,9 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock)
 			ret = -EINTR;
 	}
 
-	io_cqring_add_event(req, ret);
+	kfree(kbuf);
+	req->flags &= ~REQ_F_NEED_CLEANUP;
+	__io_cqring_add_event(req, ret, cflags);
 	if (ret < 0)
 		req_set_fail_links(req);
 	io_put_req(req);
@@ -4556,6 +4705,9 @@ static void io_cleanup_req(struct io_kiocb *req)
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
 	case IORING_OP_READ:
+		if (req->flags & REQ_F_BUFFER_SELECTED)
+			kfree((void *)(unsigned long)req->rw.addr);
+		/* fallthrough */
 	case IORING_OP_WRITEV:
 	case IORING_OP_WRITE_FIXED:
 	case IORING_OP_WRITE:
@@ -4567,6 +4719,10 @@ static void io_cleanup_req(struct io_kiocb *req)
 		if (io->msg.iov != io->msg.fast_iov)
 			kfree(io->msg.iov);
 		break;
+	case IORING_OP_RECV:
+		if (req->flags & REQ_F_BUFFER_SELECTED)
+			kfree(req->sr_msg.kbuf);
+		break;
 	case IORING_OP_OPENAT:
 	case IORING_OP_OPENAT2:
 	case IORING_OP_STATX:
@@ -5144,7 +5300,8 @@ static inline void io_queue_link_head(struct io_kiocb *req)
 }
 
 #define SQE_VALID_FLAGS	(IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK|	\
-				IOSQE_IO_HARDLINK | IOSQE_ASYNC)
+				IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
+				IOSQE_BUFFER_SELECT)
 
 static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 			  struct io_submit_state *state, struct io_kiocb **link)
@@ -5161,6 +5318,12 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		goto err_req;
 	}
 
+	if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
+	    !io_op_defs[req->opcode].buffer_select) {
+		ret = -EOPNOTSUPP;
+		goto err_req;
+	}
+
 	id = READ_ONCE(sqe->personality);
 	if (id) {
 		req->work.creds = idr_find(&ctx->personality_idr, id);
@@ -5173,7 +5336,8 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 
 	/* same numerical values with corresponding REQ_F_*, safe to copy */
 	req->flags |= sqe_flags & (IOSQE_IO_DRAIN | IOSQE_IO_HARDLINK |
-					IOSQE_ASYNC | IOSQE_FIXED_FILE);
+					IOSQE_ASYNC | IOSQE_FIXED_FILE |
+					IOSQE_BUFFER_SELECT);
 
 	ret = io_req_set_file(state, req, sqe);
 	if (unlikely(ret)) {
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index bc34a57a660b..9b263d9b24e6 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -66,6 +66,7 @@ enum {
 	IOSQE_IO_LINK_BIT,
 	IOSQE_IO_HARDLINK_BIT,
 	IOSQE_ASYNC_BIT,
+	IOSQE_BUFFER_SELECT_BIT,
 };
 
 /*
@@ -81,6 +82,8 @@ enum {
 #define IOSQE_IO_HARDLINK	(1U << IOSQE_IO_HARDLINK_BIT)
 /* always go async */
 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
+/* select buffer from sqe->buf_group */
+#define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
 
 /*
  * io_uring_setup() flags
@@ -155,6 +158,17 @@ struct io_uring_cqe {
 	__u32	flags;
 };
 
+/*
+ * cqe->flags
+ *
+ * IORING_CQE_F_BUFFER	If set, the upper 16 bits are the buffer ID
+ */
+#define IORING_CQE_F_BUFFER		(1U << 0)
+
+enum {
+	IORING_CQE_BUFFER_SHIFT		= 16,
+};
+
 /*
  * Magic offsets for the application to mmap the data it needs
  */
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 4/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_READV
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (2 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 3/9] io_uring: support buffer selection for OP_READ and OP_RECV Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 5/9] net: abstract out normal and compat msghdr import Jens Axboe
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

This adds support for the vectored read. This is limited to supporting
just 1 segment in the iov, and is provided just for convenience for
applications that use IORING_OP_READV already.

The iov helpers will be used for IORING_OP_RECVMSG as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 111 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 97 insertions(+), 14 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 65e22240a2d9..b02272d08870 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -682,6 +682,7 @@ static const struct io_op_def io_op_defs[] = {
 		.needs_file		= 1,
 		.unbound_nonreg_file	= 1,
 		.pollin			= 1,
+		.buffer_select		= 1,
 	},
 	[IORING_OP_WRITEV] = {
 		.async_ctx		= 1,
@@ -1686,9 +1687,10 @@ static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req)
 
 static int io_put_kbuf(struct io_kiocb *req)
 {
-	struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr;
+	struct io_buffer *kbuf;
 	int cflags;
 
+	kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
 	cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
 	cflags |= IORING_CQE_F_BUFFER;
 	req->rw.addr = 0;
@@ -2242,12 +2244,95 @@ static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
 	return kbuf;
 }
 
+static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
+					bool needs_lock)
+{
+	struct io_buffer *kbuf;
+	int bgid;
+
+	kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+	bgid = (int) (unsigned long) req->rw.kiocb.private;
+	kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
+	if (IS_ERR(kbuf))
+		return kbuf;
+	req->rw.addr = (u64) (unsigned long) kbuf;
+	req->flags |= REQ_F_BUFFER_SELECTED;
+	return u64_to_user_ptr(kbuf->addr);
+}
+
+#ifdef CONFIG_COMPAT
+static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
+				bool needs_lock)
+{
+	struct compat_iovec __user *uiov;
+	compat_ssize_t clen;
+	void __user *buf;
+	ssize_t len;
+
+	uiov = u64_to_user_ptr(req->rw.addr);
+	if (!access_ok(uiov, sizeof(*uiov)))
+		return -EFAULT;
+	if (__get_user(clen, &uiov->iov_len))
+		return -EFAULT;
+	if (clen < 0)
+		return -EINVAL;
+
+	len = clen;
+	buf = io_rw_buffer_select(req, &len, needs_lock);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+	iov[0].iov_base = buf;
+	iov[0].iov_len = (compat_size_t) len;
+	return 0;
+}
+#endif
+
+static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+				      bool needs_lock)
+{
+	struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
+	void __user *buf;
+	ssize_t len;
+
+	if (copy_from_user(iov, uiov, sizeof(*uiov)))
+		return -EFAULT;
+
+	len = iov[0].iov_len;
+	if (len < 0)
+		return -EINVAL;
+	buf = io_rw_buffer_select(req, &len, needs_lock);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+	iov[0].iov_base = buf;
+	iov[0].iov_len = len;
+	return 0;
+}
+
+static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+				    bool needs_lock)
+{
+	if (req->flags & REQ_F_BUFFER_SELECTED)
+		return 0;
+	if (!req->rw.len)
+		return 0;
+	else if (req->rw.len > 1)
+		return -EINVAL;
+
+#ifdef CONFIG_COMPAT
+	if (req->ctx->compat)
+		return io_compat_import(req, iov, needs_lock);
+#endif
+
+	return __io_iov_buffer_select(req, iov, needs_lock);
+}
+
 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 			       struct iovec **iovec, struct iov_iter *iter,
 			       bool needs_lock)
 {
 	void __user *buf = u64_to_user_ptr(req->rw.addr);
 	size_t sqe_len = req->rw.len;
+	ssize_t ret;
 	u8 opcode;
 
 	opcode = req->opcode;
@@ -2261,22 +2346,12 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 		return -EINVAL;
 
 	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
-		ssize_t ret;
-
 		if (req->flags & REQ_F_BUFFER_SELECT) {
-			struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr;
-			int bgid;
-
-			bgid = (int) (unsigned long) req->rw.kiocb.private;
-			kbuf = io_buffer_select(req, &sqe_len, bgid, kbuf,
-						needs_lock);
-			if (IS_ERR(kbuf)) {
+			buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
+			if (IS_ERR(buf)) {
 				*iovec = NULL;
-				return PTR_ERR(kbuf);
+				return PTR_ERR(buf);
 			}
-			req->rw.addr = (u64) kbuf;
-			req->flags |= REQ_F_BUFFER_SELECTED;
-			buf = u64_to_user_ptr(kbuf->addr);
 		}
 
 		ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
@@ -2294,6 +2369,14 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 		return iorw->size;
 	}
 
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		ret = io_iov_buffer_select(req, *iovec, needs_lock);
+		if (!ret)
+			iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len);
+		*iovec = NULL;
+		return ret;
+	}
+
 #ifdef CONFIG_COMPAT
 	if (req->ctx->compat)
 		return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 5/9] net: abstract out normal and compat msghdr import
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (3 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 4/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_READV Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 6/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_RECVMSG Jens Axboe
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe, David Miller

This splits it into two parts, one that imports the message, and one
that imports the iovec. This allows a caller to only do the first part,
and import the iovec manually afterwards.

No functional changes in this patch.

Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/socket.h |  4 ++++
 include/net/compat.h   |  3 +++
 net/compat.c           | 30 +++++++++++++++++++++++-------
 net/socket.c           | 25 +++++++++++++++++++++----
 4 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 2d2313403101..fc59ac825561 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -391,6 +391,10 @@ extern int recvmsg_copy_msghdr(struct msghdr *msg,
 			       struct user_msghdr __user *umsg, unsigned flags,
 			       struct sockaddr __user **uaddr,
 			       struct iovec **iov);
+extern int __copy_msghdr_from_user(struct msghdr *kmsg,
+				   struct user_msghdr __user *umsg,
+				   struct sockaddr __user **save_addr,
+				   struct iovec __user **uiov, size_t *nsegs);
 
 /* helpers which do the actual work for syscalls */
 extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size,
diff --git a/include/net/compat.h b/include/net/compat.h
index f277653c7e17..e341260642fe 100644
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -38,6 +38,9 @@ struct compat_cmsghdr {
 #define compat_mmsghdr	mmsghdr
 #endif /* defined(CONFIG_COMPAT) */
 
+int __get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg,
+			struct sockaddr __user **save_addr, compat_uptr_t *ptr,
+			compat_size_t *len);
 int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *,
 		      struct sockaddr __user **, struct iovec **);
 struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval);
diff --git a/net/compat.c b/net/compat.c
index 47d99c784947..4bed96e84d9a 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -33,10 +33,10 @@
 #include <linux/uaccess.h>
 #include <net/compat.h>
 
-int get_compat_msghdr(struct msghdr *kmsg,
-		      struct compat_msghdr __user *umsg,
-		      struct sockaddr __user **save_addr,
-		      struct iovec **iov)
+int __get_compat_msghdr(struct msghdr *kmsg,
+			struct compat_msghdr __user *umsg,
+			struct sockaddr __user **save_addr,
+			compat_uptr_t *ptr, compat_size_t *len)
 {
 	struct compat_msghdr msg;
 	ssize_t err;
@@ -79,10 +79,26 @@ int get_compat_msghdr(struct msghdr *kmsg,
 		return -EMSGSIZE;
 
 	kmsg->msg_iocb = NULL;
+	*ptr = msg.msg_iov;
+	*len = msg.msg_iovlen;
+	return 0;
+}
+
+int get_compat_msghdr(struct msghdr *kmsg,
+		      struct compat_msghdr __user *umsg,
+		      struct sockaddr __user **save_addr,
+		      struct iovec **iov)
+{
+	compat_uptr_t ptr;
+	compat_size_t len;
+	ssize_t err;
+
+	err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
+	if (err)
+		return err;
 
-	err = compat_import_iovec(save_addr ? READ : WRITE,
-				   compat_ptr(msg.msg_iov), msg.msg_iovlen,
-				   UIO_FASTIOV, iov, &kmsg->msg_iter);
+	err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr),
+				   len, UIO_FASTIOV, iov, &kmsg->msg_iter);
 	return err < 0 ? err : 0;
 }
 
diff --git a/net/socket.c b/net/socket.c
index b79a05de7c6e..70ede74ab24b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2226,10 +2226,10 @@ struct used_address {
 	unsigned int name_len;
 };
 
-static int copy_msghdr_from_user(struct msghdr *kmsg,
-				 struct user_msghdr __user *umsg,
-				 struct sockaddr __user **save_addr,
-				 struct iovec **iov)
+int __copy_msghdr_from_user(struct msghdr *kmsg,
+			    struct user_msghdr __user *umsg,
+			    struct sockaddr __user **save_addr,
+			    struct iovec __user **uiov, size_t *nsegs)
 {
 	struct user_msghdr msg;
 	ssize_t err;
@@ -2271,6 +2271,23 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
 		return -EMSGSIZE;
 
 	kmsg->msg_iocb = NULL;
+	*uiov = msg.msg_iov;
+	*nsegs = msg.msg_iovlen;
+	return 0;
+}
+
+static int copy_msghdr_from_user(struct msghdr *kmsg,
+				 struct user_msghdr __user *umsg,
+				 struct sockaddr __user **save_addr,
+				 struct iovec **iov)
+{
+	struct user_msghdr msg;
+	ssize_t err;
+
+	err = __copy_msghdr_from_user(kmsg, umsg, save_addr, &msg.msg_iov,
+					&msg.msg_iovlen);
+	if (err)
+		return err;
 
 	err = import_iovec(save_addr ? READ : WRITE,
 			    msg.msg_iov, msg.msg_iovlen,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 6/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_RECVMSG
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (4 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 5/9] net: abstract out normal and compat msghdr import Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 7/9] io_uring: provide means of removing buffers Jens Axboe
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

Like IORING_OP_READV, this is limited to supporting just a single
segment in the iovec passed in.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 118 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 106 insertions(+), 12 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index b02272d08870..ed898fb24612 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -44,6 +44,7 @@
 #include <linux/errno.h>
 #include <linux/syscalls.h>
 #include <linux/compat.h>
+#include <net/compat.h>
 #include <linux/refcount.h>
 #include <linux/uio.h>
 #include <linux/bits.h>
@@ -729,6 +730,7 @@ static const struct io_op_def io_op_defs[] = {
 		.unbound_nonreg_file	= 1,
 		.needs_fs		= 1,
 		.pollin			= 1,
+		.buffer_select		= 1,
 	},
 	[IORING_OP_TIMEOUT] = {
 		.async_ctx		= 1,
@@ -3577,6 +3579,92 @@ static int io_send(struct io_kiocb *req, bool force_nonblock)
 #endif
 }
 
+static int __io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_ctx *io)
+{
+	struct io_sr_msg *sr = &req->sr_msg;
+	struct iovec __user *uiov;
+	size_t iov_len;
+	int ret;
+
+	ret = __copy_msghdr_from_user(&io->msg.msg, sr->msg, &io->msg.uaddr,
+					&uiov, &iov_len);
+	if (ret)
+		return ret;
+
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		if (iov_len > 1)
+			return -EINVAL;
+		if (copy_from_user(io->msg.iov, uiov, sizeof(*uiov)))
+			return -EFAULT;
+		sr->len = io->msg.iov[0].iov_len;
+		iov_iter_init(&io->msg.msg.msg_iter, READ, io->msg.iov, 1,
+				sr->len);
+		io->msg.iov = NULL;
+	} else {
+		ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
+					&io->msg.iov, &io->msg.msg.msg_iter);
+		if (ret > 0)
+			ret = 0;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
+					struct io_async_ctx *io)
+{
+	struct compat_msghdr __user *msg_compat;
+	struct io_sr_msg *sr = &req->sr_msg;
+	struct compat_iovec __user *uiov;
+	compat_uptr_t ptr;
+	compat_size_t len;
+	int ret;
+
+	msg_compat = (struct compat_msghdr __user *) sr->msg;
+	ret = __get_compat_msghdr(&io->msg.msg, msg_compat, &io->msg.uaddr,
+					&ptr, &len);
+	if (ret)
+		return ret;
+
+	uiov = compat_ptr(ptr);
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		compat_ssize_t clen;
+
+		if (len > 1)
+			return -EINVAL;
+		if (!access_ok(uiov, sizeof(*uiov)))
+			return -EFAULT;
+		if (__get_user(clen, &uiov->iov_len))
+			return -EFAULT;
+		if (clen < 0)
+			return -EINVAL;
+		sr->len = io->msg.iov[0].iov_len;
+		io->msg.iov = NULL;
+	} else {
+		ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV,
+						&io->msg.iov,
+						&io->msg.msg.msg_iter);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static int io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_ctx *io)
+{
+	io->msg.iov = io->msg.fast_iov;
+
+#ifdef CONFIG_COMPAT
+	if (req->ctx->compat)
+		return __io_compat_recvmsg_copy_hdr(req, io);
+#endif
+
+	return __io_recvmsg_copy_hdr(req, io);
+}
+
 static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
 					       int *cflags, bool needs_lock)
 {
@@ -3622,9 +3710,7 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 	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);
+	ret = io_recvmsg_copy_hdr(req, io);
 	if (!ret)
 		req->flags |= REQ_F_NEED_CLEANUP;
 	return ret;
@@ -3638,13 +3724,14 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 #if defined(CONFIG_NET)
 	struct io_async_msghdr *kmsg = NULL;
 	struct socket *sock;
-	int ret;
+	int ret, cflags = 0;
 
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
 
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
+		struct io_buffer *kbuf;
 		struct io_async_ctx io;
 		unsigned flags;
 
@@ -3656,19 +3743,23 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 				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);
+			ret = io_recvmsg_copy_hdr(req, &io);
 			if (ret)
 				return ret;
 		}
 
+		kbuf = io_recv_buffer_select(req, &cflags, !force_nonblock);
+		if (IS_ERR(kbuf)) {
+			return PTR_ERR(kbuf);
+		} else if (kbuf) {
+			kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+			iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
+					1, req->sr_msg.len);
+		}
+
 		flags = req->sr_msg.msg_flags;
 		if (flags & MSG_DONTWAIT)
 			req->flags |= REQ_F_NOWAIT;
@@ -3686,7 +3777,7 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 	if (kmsg && kmsg->iov != kmsg->fast_iov)
 		kfree(kmsg->iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
-	io_cqring_add_event(req, ret);
+	__io_cqring_add_event(req, ret, cflags);
 	if (ret < 0)
 		req_set_fail_links(req);
 	io_put_req(req);
@@ -4797,8 +4888,11 @@ static void io_cleanup_req(struct io_kiocb *req)
 		if (io->rw.iov != io->rw.fast_iov)
 			kfree(io->rw.iov);
 		break;
-	case IORING_OP_SENDMSG:
 	case IORING_OP_RECVMSG:
+		if (req->flags & REQ_F_BUFFER_SELECTED)
+			kfree(req->sr_msg.kbuf);
+		/* fallthrough */
+	case IORING_OP_SENDMSG:
 		if (io->msg.iov != io->msg.fast_iov)
 			kfree(io->msg.iov);
 		break;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 7/9] io_uring: provide means of removing buffers
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (5 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 6/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_RECVMSG Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 8/9] io_uring: add end-of-bits marker and build time verify it Jens Axboe
  2020-03-10 15:04 ` [PATCH 9/9] io_uring: Fix unused function warnings Jens Axboe
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

We have IORING_OP_PROVIDE_BUFFERS, but the only way to remove buffers
is to trigger IO on them. The usual case of shrinking a buffer pool
would be to just not replenish the buffers when IO completes, and
instead just free it. But it may be nice to have a way to manually
remove a number of buffers from a given group, and
IORING_OP_REMOVE_BUFFERS provides that functionality.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c                 | 102 +++++++++++++++++++++++++++-------
 include/uapi/linux/io_uring.h |   1 +
 2 files changed, 84 insertions(+), 19 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ed898fb24612..0760a0099760 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -827,6 +827,7 @@ static const struct io_op_def io_op_defs[] = {
 		.unbound_nonreg_file	= 1,
 	},
 	[IORING_OP_PROVIDE_BUFFERS] = {},
+	[IORING_OP_REMOVE_BUFFERS] = {},
 };
 
 static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -2995,6 +2996,75 @@ static int io_openat(struct io_kiocb *req, bool force_nonblock)
 	return io_openat2(req, force_nonblock);
 }
 
+static int io_remove_buffers_prep(struct io_kiocb *req,
+				  const struct io_uring_sqe *sqe)
+{
+	struct io_provide_buf *p = &req->pbuf;
+	u64 tmp;
+
+	if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off)
+		return -EINVAL;
+
+	tmp = READ_ONCE(sqe->fd);
+	if (!tmp || tmp > USHRT_MAX)
+		return -EINVAL;
+
+	memset(p, 0, sizeof(*p));
+	p->nbufs = tmp;
+	p->bgid = READ_ONCE(sqe->buf_group);
+	return 0;
+}
+
+static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
+			       int bgid, unsigned nbufs)
+{
+	unsigned i = 0;
+
+	/* shouldn't happen */
+	if (!nbufs)
+		return 0;
+
+	/* the head kbuf is the list itself */
+	while (!list_empty(&buf->list)) {
+		struct io_buffer *nxt;
+
+		nxt = list_first_entry(&buf->list, struct io_buffer, list);
+		list_del(&nxt->list);
+		kfree(nxt);
+		if (++i == nbufs)
+			return i;
+	}
+	i++;
+	kfree(buf);
+	idr_remove(&ctx->io_buffer_idr, bgid);
+
+	return i;
+}
+
+static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock)
+{
+	struct io_provide_buf *p = &req->pbuf;
+	struct io_ring_ctx *ctx = req->ctx;
+	struct io_buffer *head;
+	int ret = 0;
+
+	io_ring_submit_lock(ctx, !force_nonblock);
+
+	lockdep_assert_held(&ctx->uring_lock);
+
+	ret = -ENOENT;
+	head = idr_find(&ctx->io_buffer_idr, p->bgid);
+	if (head)
+		ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
+
+	io_ring_submit_lock(ctx, !force_nonblock);
+	if (ret < 0)
+		req_set_fail_links(req);
+	io_cqring_add_event(req, ret);
+	io_put_req(req);
+	return 0;
+}
+
 static int io_provide_buffers_prep(struct io_kiocb *req,
 				   const struct io_uring_sqe *sqe)
 {
@@ -3077,15 +3147,7 @@ static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock)
 		ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
 					GFP_KERNEL);
 		if (ret < 0) {
-			while (!list_empty(&head->list)) {
-				struct io_buffer *buf;
-
-				buf = list_first_entry(&head->list,
-							struct io_buffer, list);
-				list_del(&buf->list);
-				kfree(buf);
-			}
-			kfree(head);
+			__io_remove_buffers(ctx, head, p->bgid, -1U);
 			goto out;
 		}
 	}
@@ -4833,6 +4895,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
 	case IORING_OP_PROVIDE_BUFFERS:
 		ret = io_provide_buffers_prep(req, sqe);
 		break;
+	case IORING_OP_REMOVE_BUFFERS:
+		ret = io_remove_buffers_prep(req, sqe);
+		break;
 	default:
 		printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
 				req->opcode);
@@ -5128,6 +5193,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		}
 		ret = io_provide_buffers(req, force_nonblock);
 		break;
+	case IORING_OP_REMOVE_BUFFERS:
+		if (sqe) {
+			ret = io_remove_buffers_prep(req, sqe);
+			if (ret)
+				break;
+		}
+		ret = io_remove_buffers(req, force_nonblock);
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -7006,16 +7079,7 @@ static int __io_destroy_buffers(int id, void *p, void *data)
 	struct io_ring_ctx *ctx = data;
 	struct io_buffer *buf = p;
 
-	/* the head kbuf is the list itself */
-	while (!list_empty(&buf->list)) {
-		struct io_buffer *nxt;
-
-		nxt = list_first_entry(&buf->list, struct io_buffer, list);
-		list_del(&nxt->list);
-		kfree(nxt);
-	}
-	kfree(buf);
-	idr_remove(&ctx->io_buffer_idr, id);
+	__io_remove_buffers(ctx, buf, id, -1U);
 	return 0;
 }
 
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 9b263d9b24e6..cef4c0c0f26b 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -128,6 +128,7 @@ enum {
 	IORING_OP_EPOLL_CTL,
 	IORING_OP_SPLICE,
 	IORING_OP_PROVIDE_BUFFERS,
+	IORING_OP_REMOVE_BUFFERS,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 8/9] io_uring: add end-of-bits marker and build time verify it
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (6 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 7/9] io_uring: provide means of removing buffers Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  2020-03-10 15:04 ` [PATCH 9/9] io_uring: Fix unused function warnings Jens Axboe
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, Jens Axboe

Not easy to tell if we're going over the size of bits we can shove
in req->flags, so add an end-of-bits marker and a BUILD_BUG_ON()
check for it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0760a0099760..f8a3f6843698 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -511,6 +511,9 @@ enum {
 	REQ_F_OVERFLOW_BIT,
 	REQ_F_POLLED_BIT,
 	REQ_F_BUFFER_SELECTED_BIT,
+
+	/* not a real bit, just to check we're not overflowing the space */
+	__REQ_F_LAST_BIT,
 };
 
 enum {
@@ -8006,6 +8009,7 @@ static int __init io_uring_init(void)
 	BUILD_BUG_SQE_ELEM(44, __s32,  splice_fd_in);
 
 	BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
+	BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
 	req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
 	return 0;
 };
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH 9/9] io_uring: Fix unused function warnings
  2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
                   ` (7 preceding siblings ...)
  2020-03-10 15:04 ` [PATCH 8/9] io_uring: add end-of-bits marker and build time verify it Jens Axboe
@ 2020-03-10 15:04 ` Jens Axboe
  8 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:04 UTC (permalink / raw)
  To: io-uring; +Cc: andres, YueHaibing, Hulk Robot, Jens Axboe

From: YueHaibing <yuehaibing@huawei.com>

If CONFIG_NET is not set, gcc warns:

fs/io_uring.c:3110:12: warning: io_setup_async_msg defined but not used [-Wunused-function]
 static int io_setup_async_msg(struct io_kiocb *req,
            ^~~~~~~~~~~~~~~~~~

There are many funcions wraped by CONFIG_NET, move them
together to simplify code, also fix this warning.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>

Minor tweaks.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 94 ++++++++++++++++++++++++++++-----------------------
 1 file changed, 52 insertions(+), 42 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index f8a3f6843698..83439cf9f5e7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3485,6 +3485,7 @@ static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
 	return 0;
 }
 
+#if defined(CONFIG_NET)
 static int io_setup_async_msg(struct io_kiocb *req,
 			      struct io_async_msghdr *kmsg)
 {
@@ -3502,7 +3503,6 @@ static int io_setup_async_msg(struct io_kiocb *req,
 
 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;
@@ -3528,14 +3528,10 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	if (!ret)
 		req->flags |= REQ_F_NEED_CLEANUP;
 	return ret;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	struct io_async_msghdr *kmsg = NULL;
 	struct socket *sock;
 	int ret;
@@ -3589,14 +3585,10 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
 		req_set_fail_links(req);
 	io_put_req(req);
 	return 0;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int io_send(struct io_kiocb *req, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	struct socket *sock;
 	int ret;
 
@@ -3639,9 +3631,6 @@ static int io_send(struct io_kiocb *req, bool force_nonblock)
 		req_set_fail_links(req);
 	io_put_req(req);
 	return 0;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int __io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_ctx *io)
@@ -3754,7 +3743,6 @@ static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
 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;
@@ -3779,14 +3767,10 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 	if (!ret)
 		req->flags |= REQ_F_NEED_CLEANUP;
 	return ret;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	struct io_async_msghdr *kmsg = NULL;
 	struct socket *sock;
 	int ret, cflags = 0;
@@ -3847,14 +3831,10 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 		req_set_fail_links(req);
 	io_put_req(req);
 	return 0;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int io_recv(struct io_kiocb *req, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	struct io_buffer *kbuf = NULL;
 	struct socket *sock;
 	int ret, cflags = 0;
@@ -3911,15 +3891,10 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock)
 		req_set_fail_links(req);
 	io_put_req(req);
 	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)))
@@ -3931,12 +3906,8 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
 	accept->flags = READ_ONCE(sqe->accept_flags);
 	return 0;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
-#if defined(CONFIG_NET)
 static int __io_accept(struct io_kiocb *req, bool force_nonblock)
 {
 	struct io_accept *accept = &req->accept;
@@ -3966,11 +3937,9 @@ static void io_accept_finish(struct io_wq_work **workptr)
 	__io_accept(req, false);
 	io_steal_work(req, workptr);
 }
-#endif
 
 static int io_accept(struct io_kiocb *req, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	int ret;
 
 	ret = __io_accept(req, force_nonblock);
@@ -3979,14 +3948,10 @@ static int io_accept(struct io_kiocb *req, bool force_nonblock)
 		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;
 
@@ -4003,14 +3968,10 @@ static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 	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, bool force_nonblock)
 {
-#if defined(CONFIG_NET)
 	struct io_async_ctx __io, *io;
 	unsigned file_flags;
 	int ret;
@@ -4048,10 +4009,59 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock)
 	io_cqring_add_event(req, ret);
 	io_put_req(req);
 	return 0;
-#else
+}
+#else /* !CONFIG_NET */
+static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_send(struct io_kiocb *req, bool force_nonblock)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_recvmsg_prep(struct io_kiocb *req,
+			   const struct io_uring_sqe *sqe)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_recv(struct io_kiocb *req, bool force_nonblock)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_accept(struct io_kiocb *req, bool force_nonblock)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	return -EOPNOTSUPP;
+}
+
+static int io_connect(struct io_kiocb *req, bool force_nonblock)
+{
 	return -EOPNOTSUPP;
-#endif
 }
+#endif /* CONFIG_NET */
 
 struct io_poll_table {
 	struct poll_table_struct pt;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* Re: [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS
  2020-03-10 15:04 ` [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS Jens Axboe
@ 2020-03-10 15:19   ` Jens Axboe
  0 siblings, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2020-03-10 15:19 UTC (permalink / raw)
  To: io-uring; +Cc: andres

On 3/10/20 9:04 AM, Jens Axboe wrote:
> +static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock)
> +{
> +	struct io_provide_buf *p = &req->pbuf;
> +	struct io_ring_ctx *ctx = req->ctx;
> +	struct io_buffer *head, *list;
> +	int ret = 0;
> +
> +	/*
> +	 * "Normal" inline submissions always hold the uring_lock, since we
> +	 * grab it from the system call. Same is true for the SQPOLL offload.
> +	 * The only exception is when we've detached the request and issue it
> +	 * from an async worker thread, grab the lock for that case.
> +	 */
> +	if (!force_nonblock)
> +		mutex_lock(&ctx->uring_lock);

I mistakenly introduced io_ring_submit_lock() in patch 3 instead of this
one, I've corrected this mistake in the git branch.

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2020-03-10 15:19 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-10 15:04 [PATCHSET v4] Support for automatic buffer selection Jens Axboe
2020-03-10 15:04 ` [PATCH 1/9] io_uring: buffer registration infrastructure Jens Axboe
2020-03-10 15:04 ` [PATCH 2/9] io_uring: add IORING_OP_PROVIDE_BUFFERS Jens Axboe
2020-03-10 15:19   ` Jens Axboe
2020-03-10 15:04 ` [PATCH 3/9] io_uring: support buffer selection for OP_READ and OP_RECV Jens Axboe
2020-03-10 15:04 ` [PATCH 4/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_READV Jens Axboe
2020-03-10 15:04 ` [PATCH 5/9] net: abstract out normal and compat msghdr import Jens Axboe
2020-03-10 15:04 ` [PATCH 6/9] io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_RECVMSG Jens Axboe
2020-03-10 15:04 ` [PATCH 7/9] io_uring: provide means of removing buffers Jens Axboe
2020-03-10 15:04 ` [PATCH 8/9] io_uring: add end-of-bits marker and build time verify it Jens Axboe
2020-03-10 15:04 ` [PATCH 9/9] io_uring: Fix unused function warnings Jens Axboe

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