[PATCH v4 15/25] fuse: refactor io-uring header copying from ring

[Joanne Koong <joannelkoong@gmail.com>]

Move header copying from ring logic into a new copy_header_from_ring()
function. This consolidates error handling.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 fs/fuse/dev_uring.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
index 7962a9876031..e8ee51bfa5fc 100644
--- a/fs/fuse/dev_uring.c
+++ b/fs/fuse/dev_uring.c
@@ -587,6 +587,18 @@ static __always_inline int copy_header_to_ring(void __user *ring,
 	return 0;
 }
 
+static __always_inline int copy_header_from_ring(void *header,
+						 const void __user *ring,
+						 size_t header_size)
+{
+	if (copy_from_user(header, ring, header_size)) {
+		pr_info_ratelimited("Copying header from ring failed.\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
 static int fuse_uring_copy_from_ring(struct fuse_ring *ring,
 				     struct fuse_req *req,
 				     struct fuse_ring_ent *ent)
@@ -597,10 +609,10 @@ static int fuse_uring_copy_from_ring(struct fuse_ring *ring,
 	int err;
 	struct fuse_uring_ent_in_out ring_in_out;
 
-	err = copy_from_user(&ring_in_out, &ent->headers->ring_ent_in_out,
-			     sizeof(ring_in_out));
+	err = copy_header_from_ring(&ring_in_out, &ent->headers->ring_ent_in_out,
+				    sizeof(ring_in_out));
 	if (err)
-		return -EFAULT;
+		return err;
 
 	err = import_ubuf(ITER_SOURCE, ent->payload, ring->max_payload_sz,
 			  &iter);
@@ -794,10 +806,10 @@ static void fuse_uring_commit(struct fuse_ring_ent *ent, struct fuse_req *req,
 	struct fuse_conn *fc = ring->fc;
 	ssize_t err = 0;
 
-	err = copy_from_user(&req->out.h, &ent->headers->in_out,
-			     sizeof(req->out.h));
+	err = copy_header_from_ring(&req->out.h, &ent->headers->in_out,
+				    sizeof(req->out.h));
 	if (err) {
-		req->out.h.error = -EFAULT;
+		req->out.h.error = err;
 		goto out;
 	}
 
-- 
2.47.3