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From: Jens Axboe <axboe@kernel.dk>
To: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org
Cc: viro@zeniv.linux.org.uk, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 1/3] uio: make import_iovec()/compat_import_iovec() return bytes on success
Date: Fri, 17 May 2019 15:41:29 -0600
Message-ID: <20190517214131.5925-2-axboe@kernel.dk> (raw)
In-Reply-To: <20190517214131.5925-1-axboe@kernel.dk>

Currently these functions return < 0 on error, and 0 for success.
Change that so that we return < 0 on error, but number of bytes
for success.

Some callers already treat the return value that way, others need a
slight tweak.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/aio.c            |  9 +++++----
 fs/io_uring.c       | 16 ++++++++--------
 fs/splice.c         |  8 ++++----
 include/linux/uio.h |  4 ++--
 lib/iov_iter.c      | 15 ++++++++-------
 net/compat.c        |  3 ++-
 net/socket.c        |  3 ++-
 7 files changed, 31 insertions(+), 27 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 3490d1fa0e16..41824c710b36 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1479,8 +1479,9 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
 	return 0;
 }
 
-static int aio_setup_rw(int rw, const struct iocb *iocb, struct iovec **iovec,
-		bool vectored, bool compat, struct iov_iter *iter)
+static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
+		struct iovec **iovec, bool vectored, bool compat,
+		struct iov_iter *iter)
 {
 	void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
 	size_t len = iocb->aio_nbytes;
@@ -1537,7 +1538,7 @@ static int aio_read(struct kiocb *req, const struct iocb *iocb,
 		return -EINVAL;
 
 	ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
-	if (ret)
+	if (ret < 0)
 		return ret;
 	ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
 	if (!ret)
@@ -1565,7 +1566,7 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
 		return -EINVAL;
 
 	ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
-	if (ret)
+	if (ret < 0)
 		return ret;
 	ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
 	if (!ret) {
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 65dd05505a16..84cb31e69727 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1003,9 +1003,9 @@ static int io_import_fixed(struct io_ring_ctx *ctx, int rw,
 	return 0;
 }
 
-static int io_import_iovec(struct io_ring_ctx *ctx, int rw,
-			   const struct sqe_submit *s, struct iovec **iovec,
-			   struct iov_iter *iter)
+static ssize_t io_import_iovec(struct io_ring_ctx *ctx, int rw,
+			       const struct sqe_submit *s, struct iovec **iovec,
+			       struct iov_iter *iter)
 {
 	const struct io_uring_sqe *sqe = s->sqe;
 	void __user *buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -1023,7 +1023,7 @@ static int io_import_iovec(struct io_ring_ctx *ctx, int rw,
 	opcode = READ_ONCE(sqe->opcode);
 	if (opcode == IORING_OP_READ_FIXED ||
 	    opcode == IORING_OP_WRITE_FIXED) {
-		int ret = io_import_fixed(ctx, rw, sqe, iter);
+		ssize_t ret = io_import_fixed(ctx, rw, sqe, iter);
 		*iovec = NULL;
 		return ret;
 	}
@@ -1089,7 +1089,7 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
 	struct iov_iter iter;
 	struct file *file;
 	size_t iov_count;
-	int ret;
+	ssize_t ret;
 
 	ret = io_prep_rw(req, s, force_nonblock);
 	if (ret)
@@ -1102,7 +1102,7 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
 		return -EINVAL;
 
 	ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	iov_count = iov_iter_count(&iter);
@@ -1136,7 +1136,7 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s,
 	struct iov_iter iter;
 	struct file *file;
 	size_t iov_count;
-	int ret;
+	ssize_t ret;
 
 	ret = io_prep_rw(req, s, force_nonblock);
 	if (ret)
@@ -1149,7 +1149,7 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s,
 		return -EINVAL;
 
 	ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	iov_count = iov_iter_count(&iter);
diff --git a/fs/splice.c b/fs/splice.c
index 25212dcca2df..c5b951b0b639 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1355,7 +1355,7 @@ SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
 	struct iovec iovstack[UIO_FASTIOV];
 	struct iovec *iov = iovstack;
 	struct iov_iter iter;
-	long error;
+	ssize_t error;
 	struct fd f;
 	int type;
 
@@ -1366,7 +1366,7 @@ SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
 
 	error = import_iovec(type, uiov, nr_segs,
 			     ARRAY_SIZE(iovstack), &iov, &iter);
-	if (!error) {
+	if (error >= 0) {
 		error = do_vmsplice(f.file, &iter, flags);
 		kfree(iov);
 	}
@@ -1381,7 +1381,7 @@ COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, io
 	struct iovec iovstack[UIO_FASTIOV];
 	struct iovec *iov = iovstack;
 	struct iov_iter iter;
-	long error;
+	ssize_t error;
 	struct fd f;
 	int type;
 
@@ -1392,7 +1392,7 @@ COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, io
 
 	error = compat_import_iovec(type, iov32, nr_segs,
 			     ARRAY_SIZE(iovstack), &iov, &iter);
-	if (!error) {
+	if (error >= 0) {
 		error = do_vmsplice(f.file, &iter, flags);
 		kfree(iov);
 	}
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 2d0131ad4604..a61ceb6575ab 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -279,13 +279,13 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct
 size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
 		struct iov_iter *i);
 
-int import_iovec(int type, const struct iovec __user * uvector,
+ssize_t import_iovec(int type, const struct iovec __user * uvector,
 		 unsigned nr_segs, unsigned fast_segs,
 		 struct iovec **iov, struct iov_iter *i);
 
 #ifdef CONFIG_COMPAT
 struct compat_iovec;
-int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
+ssize_t compat_import_iovec(int type, const struct compat_iovec __user * uvector,
 		 unsigned nr_segs, unsigned fast_segs,
 		 struct iovec **iov, struct iov_iter *i);
 #endif
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f74fa832f3aa..ad23f930f703 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1633,9 +1633,9 @@ EXPORT_SYMBOL(dup_iter);
  * on-stack array was used or not (and regardless of whether this function
  * returns an error or not).
  *
- * Return: 0 on success or negative error code on error.
+ * Return: Negative error code on error, bytes imported on success
  */
-int import_iovec(int type, const struct iovec __user * uvector,
+ssize_t import_iovec(int type, const struct iovec __user * uvector,
 		 unsigned nr_segs, unsigned fast_segs,
 		 struct iovec **iov, struct iov_iter *i)
 {
@@ -1651,16 +1651,17 @@ int import_iovec(int type, const struct iovec __user * uvector,
 	}
 	iov_iter_init(i, type, p, nr_segs, n);
 	*iov = p == *iov ? NULL : p;
-	return 0;
+	return n;
 }
 EXPORT_SYMBOL(import_iovec);
 
 #ifdef CONFIG_COMPAT
 #include <linux/compat.h>
 
-int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
-		 unsigned nr_segs, unsigned fast_segs,
-		 struct iovec **iov, struct iov_iter *i)
+ssize_t compat_import_iovec(int type,
+		const struct compat_iovec __user * uvector,
+		unsigned nr_segs, unsigned fast_segs,
+		struct iovec **iov, struct iov_iter *i)
 {
 	ssize_t n;
 	struct iovec *p;
@@ -1674,7 +1675,7 @@ int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
 	}
 	iov_iter_init(i, type, p, nr_segs, n);
 	*iov = p == *iov ? NULL : p;
-	return 0;
+	return n;
 }
 #endif
 
diff --git a/net/compat.c b/net/compat.c
index a031bd333092..eb498fbf35de 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -79,9 +79,10 @@ int get_compat_msghdr(struct msghdr *kmsg,
 
 	kmsg->msg_iocb = NULL;
 
-	return compat_import_iovec(save_addr ? READ : WRITE,
+	err = compat_import_iovec(save_addr ? READ : WRITE,
 				   compat_ptr(msg.msg_iov), msg.msg_iovlen,
 				   UIO_FASTIOV, iov, &kmsg->msg_iter);
+	return err < 0 ? err : 0;
 }
 
 /* Bleech... */
diff --git a/net/socket.c b/net/socket.c
index bdd6942f6152..418ae316e6f8 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2208,9 +2208,10 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
 
 	kmsg->msg_iocb = NULL;
 
-	return import_iovec(save_addr ? READ : WRITE,
+	err = import_iovec(save_addr ? READ : WRITE,
 			    msg.msg_iov, msg.msg_iovlen,
 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
+	return err < 0 ? err : 0;
 }
 
 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
-- 
2.17.1


  reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-17 21:41 [PATCHSET 0/3] io_uring: support for linked SQEs Jens Axboe
2019-05-17 21:41 ` Jens Axboe [this message]
2019-05-17 21:41 ` [PATCH 2/3] io_uring: punt short reads to async context Jens Axboe
2019-05-17 21:41 ` [PATCH 3/3] io_uring: add support for sqe links Jens Axboe
2019-05-22 16:34 ` [PATCHSET 0/3] io_uring: support for linked SQEs Christoph Hellwig
2019-05-22 16:49   ` Jens Axboe
2019-05-29 20:29 [PATCHSET v2 " Jens Axboe
2019-05-29 20:29 ` [PATCH 1/3] uio: make import_iovec()/compat_import_iovec() return bytes on success Jens Axboe

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