[PATCH RFC POC 41/50] KVM: guest_memfd: stop putting the descriptor back on failure

[Christian Brauner]

Rely on the fd exit path machinery.

Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
---
 virt/kvm/guest_memfd.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 625e62e1a031..e0d1cb869342 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -526,17 +526,16 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags)
 	struct gmem_file *f;
 	struct inode *inode;
 	struct file *file;
-	int fd, err;
+	const struct fd_slot *fd;
+	int err;
 
-	fd = get_unused_fd_flags(0);
-	if (fd < 0)
-		return fd;
+	fd = fd_prepare(0);
+	if (IS_ERR(fd))
+		return PTR_ERR(fd);
 
 	f = kzalloc_obj(*f);
-	if (!f) {
-		err = -ENOMEM;
-		goto err_fd;
-	}
+	if (!f)
+		return -ENOMEM;
 
 	/* __fput() will take care of fops_put(). */
 	if (!fops_get(&kvm_gmem_fops)) {
@@ -575,8 +574,7 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags)
 	xa_init(&f->bindings);
 	list_add(&f->entry, &GMEM_I(inode)->gmem_file_list);
 
-	fd_install(fd, file);
-	return fd;
+	return fd_stage(fd, file);
 
 err_inode:
 	iput(inode);
@@ -584,8 +582,6 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags)
 	fops_put(&kvm_gmem_fops);
 err_gmem:
 	kfree(f);
-err_fd:
-	put_unused_fd(fd);
 	return err;
 }
 

-- 
2.53.0