[RFC PATCH 08/12] fs/io_uring: Use iovec_import() not import_iovec().

[David Laight]

This is a mechanical change to this horrid code.
I think it is correct.

Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
---
 fs/io_uring.c | 165 +++++++++++++++++++++++++++++++---------------------------
 1 file changed, 87 insertions(+), 78 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d8dc2e2..27d66cf 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -77,6 +77,10 @@
 #include <linux/eventpoll.h>
 #include <linux/fs_struct.h>
 
+/* Temporary for commit bisection */
+#define sendmsg_copy_msghdr(a, b, c, d) sendmsg_copy_msghdr(a, b, c, (void *)d)
+#define recvmsg_copy_msghdr(a, b, c, d, e) recvmsg_copy_msghdr(a, b, c, d, (void *)e)
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/io_uring.h>
 
@@ -435,7 +439,7 @@ struct io_async_connect {
 };
 
 struct io_async_msghdr {
-	struct iovec			fast_iov[UIO_FASTIOV];
+	struct iovec_cache		fast_iov;
 	struct iovec			*iov;
 	struct sockaddr __user		*uaddr;
 	struct msghdr			msg;
@@ -443,7 +447,7 @@ struct io_async_msghdr {
 };
 
 struct io_async_rw {
-	struct iovec			fast_iov[UIO_FASTIOV];
+	struct iovec_cache		fast_iov;
 	struct iovec			*iov;
 	ssize_t				nr_segs;
 	ssize_t				size;
@@ -2052,47 +2056,39 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
 	return len;
 }
 
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-			       struct iovec **iovec, struct iov_iter *iter)
+static struct iovec *io_import_iovec(int rw, struct io_kiocb *req,
+			       struct iovec_cache *cache, 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);
-	}
+	if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED)
+		return ERR_PTR(io_import_fixed(req, rw, iter));
 
 	/* buffer index only valid with fixed read/write */
 	if (req->rw.kiocb.private)
-		return -EINVAL;
+		return ERR_PTR(-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 (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE)
+		return ERR_PTR(import_single_range(rw, buf, sqe_len, cache->iov, iter));
 
 	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;
+		iov_iter_init(iter, rw, iorw->iov, iorw->nr_segs, iorw->size);
+		if (iorw->iov != iorw->fast_iov.iov)
+			return iorw->iov;
+		return NULL;
 	}
 
 #ifdef CONFIG_COMPAT
 	if (req->ctx->compat)
-		return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
-						iovec, iter);
+		return compat_iovec_import(rw, buf, sqe_len, cache, iter);
 #endif
 
-	return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
+	return iovec_import(rw, buf, sqe_len, cache, iter);
 }
 
 /*
@@ -2154,13 +2150,13 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
 }
 
 static void io_req_map_rw(struct io_kiocb *req, struct iovec *iovec,
-			  struct iovec *fast_iov, struct iov_iter *iter)
+			  struct iovec_cache *fast_iov, struct iov_iter *iter)
 {
 	req->io->rw.nr_segs = iter->nr_segs;
 	req->io->rw.size = iter->count;
 	req->io->rw.iov = iovec;
 	if (!req->io->rw.iov) {
-		req->io->rw.iov = req->io->rw.fast_iov;
+		req->io->rw.iov = req->io->rw.fast_iov.iov;
 		memcpy(req->io->rw.iov, fast_iov,
 			sizeof(struct iovec) * iter->nr_segs);
 	} else {
@@ -2177,7 +2173,7 @@ static int io_alloc_async_ctx(struct io_kiocb *req)
 }
 
 static int io_setup_async_rw(struct io_kiocb *req, struct iovec *iovec,
-			     struct iovec *fast_iov, struct iov_iter *iter)
+			     struct iovec_cache *fast_iov, struct iov_iter *iter)
 {
 	if (!io_op_defs[req->opcode].async_ctx)
 		return 0;
@@ -2195,6 +2191,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 {
 	struct io_async_ctx *io;
 	struct iov_iter iter;
+	struct iovec *iov;
 	ssize_t ret;
 
 	ret = io_prep_rw(req, sqe, force_nonblock);
@@ -2209,29 +2206,30 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		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);
+	iov = io_import_iovec(READ, req, &io->rw.fast_iov, &iter);
 	req->io = io;
-	if (ret < 0)
-		return ret;
+	if (IS_ERR(iov))
+		return PTR_ERR(iov);
+	io->rw.iov = iov;
 
-	io_req_map_rw(req, io->rw.iov, io->rw.fast_iov, &iter);
+	io_req_map_rw(req, 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 iovec_cache cache;
+	struct iovec *iovec;
 	struct kiocb *kiocb = &req->rw.kiocb;
 	struct iov_iter iter;
 	size_t iov_count;
 	ssize_t ret;
 
-	ret = io_import_iovec(READ, req, &iovec, &iter);
-	if (ret < 0)
-		return ret;
+	iovec = io_import_iovec(READ, req, &cache, &iter);
+	if (IS_ERR(iovec))
+		return PTR_ERR(iovec);
 
 	/* Ensure we clear previously set non-block flag */
 	if (!force_nonblock)
@@ -2265,7 +2263,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
 			kiocb_done(kiocb, ret2, nxt, req->in_async);
 		} else {
 copy_iov:
-			ret = io_setup_async_rw(req, iovec, inline_vecs, &iter);
+			ret = io_setup_async_rw(req, iovec, &cache, &iter);
 			if (ret)
 				goto out_free;
 			return -EAGAIN;
@@ -2282,6 +2280,7 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 {
 	struct io_async_ctx *io;
 	struct iov_iter iter;
+	struct iovec *iov;
 	ssize_t ret;
 
 	ret = io_prep_rw(req, sqe, force_nonblock);
@@ -2296,29 +2295,30 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		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);
+	iov = io_import_iovec(WRITE, req, &io->rw.fast_iov, &iter);
 	req->io = io;
-	if (ret < 0)
-		return ret;
+	if (IS_ERR(iov))
+		return PTR_ERR(iov);
+	io->rw.iov = iov;
 
-	io_req_map_rw(req, io->rw.iov, io->rw.fast_iov, &iter);
+	io_req_map_rw(req, 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 iovec_cache cache;
+	struct iovec *iovec;
 	struct kiocb *kiocb = &req->rw.kiocb;
 	struct iov_iter iter;
 	size_t iov_count;
 	ssize_t ret;
 
-	ret = io_import_iovec(WRITE, req, &iovec, &iter);
-	if (ret < 0)
-		return ret;
+	iovec = io_import_iovec(WRITE, req, &cache, &iter);
+	if (IS_ERR(iovec))
+		return PTR_ERR(iovec);
 
 	/* Ensure we clear previously set non-block flag */
 	if (!force_nonblock)
@@ -2376,7 +2376,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
 			kiocb_done(kiocb, ret2, nxt, req->in_async);
 		} else {
 copy_iov:
-			ret = io_setup_async_rw(req, iovec, inline_vecs, &iter);
+			ret = io_setup_async_rw(req, iovec, &cache, &iter);
 			if (ret)
 				goto out_free;
 			return -EAGAIN;
@@ -2994,7 +2994,7 @@ 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;
+	struct iovec *iov;
 
 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
 	sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -3011,12 +3011,14 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	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;
+	iov = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+					&io->msg.fast_iov);
+	if (IS_ERR(iov))
+		return PTR_ERR(iov);
+
+	io->msg.iov = iov;
+	req->flags |= REQ_F_NEED_CLEANUP;
+	return 0;
 #else
 	return -EOPNOTSUPP;
 #endif
@@ -3043,19 +3045,21 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			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->iov = kmsg->fast_iov.iov;
 			kmsg->msg.msg_iter.iov = kmsg->iov;
 		} else {
 			struct io_sr_msg *sr = &req->sr_msg;
+			struct iovec *iov;
 
 			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;
+			iov = sendmsg_copy_msghdr(&io.msg.msg, sr->msg,
+					sr->msg_flags, &io.msg.fast_iov);
+			if (IS_ERR(iov))
+				return PTR_ERR(iov);
+
+			io.msg.iov = iov;
 		}
 
 		flags = req->sr_msg.msg_flags;
@@ -3069,7 +3073,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			if (req->io)
 				return -EAGAIN;
 			if (io_alloc_async_ctx(req)) {
-				if (kmsg->iov != kmsg->fast_iov)
+				if (kmsg->iov != kmsg->fast_iov.iov)
 					kfree(kmsg->iov);
 				return -ENOMEM;
 			}
@@ -3081,7 +3085,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			ret = -EINTR;
 	}
 
-	if (kmsg && kmsg->iov != kmsg->fast_iov)
+	if (kmsg && kmsg->iov != kmsg->fast_iov.iov)
 		kfree(kmsg->iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
 	io_cqring_add_event(req, ret);
@@ -3151,7 +3155,7 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 #if defined(CONFIG_NET)
 	struct io_sr_msg *sr = &req->sr_msg;
 	struct io_async_ctx *io = req->io;
-	int ret;
+	struct iovec *iov;
 
 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
 	sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -3168,12 +3172,14 @@ 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);
-	if (!ret)
-		req->flags |= REQ_F_NEED_CLEANUP;
-	return ret;
+	iov = recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+					&io->msg.uaddr, &io->msg.fast_iov);
+	if (IS_ERR(iov))
+		return PTR_ERR(iov);
+
+	io->msg.iov = iov;
+	req->flags |= REQ_F_NEED_CLEANUP;
+	return 0;
 #else
 	return -EOPNOTSUPP;
 #endif
@@ -3200,20 +3206,23 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			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->iov = kmsg->fast_iov.iov;
 			kmsg->msg.msg_iter.iov = kmsg->iov;
 		} else {
 			struct io_sr_msg *sr = &req->sr_msg;
+			struct iovec *iov;
 
 			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,
+			io.msg.iov = io.msg.fast_iov.iov;
+			iov = recvmsg_copy_msghdr(&io.msg.msg, sr->msg,
 					sr->msg_flags, &io.msg.uaddr,
-					&io.msg.iov);
-			if (ret)
-				return ret;
+					&io.msg.fast_iov);
+			if (IS_ERR(iov))
+				return PTR_ERR(iov);
+
+			io.msg.iov = iov;
 		}
 
 		flags = req->sr_msg.msg_flags;
@@ -3228,7 +3237,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			if (req->io)
 				return -EAGAIN;
 			if (io_alloc_async_ctx(req)) {
-				if (kmsg->iov != kmsg->fast_iov)
+				if (kmsg->iov != kmsg->fast_iov.iov)
 					kfree(kmsg->iov);
 				return -ENOMEM;
 			}
@@ -3240,7 +3249,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			ret = -EINTR;
 	}
 
-	if (kmsg && kmsg->iov != kmsg->fast_iov)
+	if (kmsg && kmsg->iov != kmsg->fast_iov.iov)
 		kfree(kmsg->iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
 	io_cqring_add_event(req, ret);
@@ -4269,12 +4278,12 @@ static void io_cleanup_req(struct io_kiocb *req)
 	case IORING_OP_WRITEV:
 	case IORING_OP_WRITE_FIXED:
 	case IORING_OP_WRITE:
-		if (io->rw.iov != io->rw.fast_iov)
+		if (io->rw.iov != io->rw.fast_iov.iov)
 			kfree(io->rw.iov);
 		break;
 	case IORING_OP_SENDMSG:
 	case IORING_OP_RECVMSG:
-		if (io->msg.iov != io->msg.fast_iov)
+		if (io->msg.iov != io->msg.fast_iov.iov)
 			kfree(io->msg.iov);
 		break;
 	case IORING_OP_OPENAT:
-- 
1.8.1.2

-
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