From: Miklos Szeredi <mszeredi@redhat.com>
Date: Wed, 11 Nov 2020 16:22:32 +0000 (+0100)
Subject: fuse: get rid of fuse_mount refcount
X-Git-Tag: accepted/tizen/unified/20230118.172025~8236^2~12
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=514b5e3ff45e6cfc39cfa7c094727d8e6d885986;p=platform%2Fkernel%2Flinux-rpi.git

fuse: get rid of fuse_mount refcount

Fuse mount now only ever has a refcount of one (before being freed) so the
count field is unnecessary.

Remove the refcounting and fold fuse_mount_put() into callers.  The only
caller of fuse_mount_put() where fm->fc was NULL is fuse_dentry_automount()
and here the fuse_conn_put() can simply be omitted.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index ff7dbeb..e9c2445 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -328,12 +328,11 @@ static struct vfsmount *fuse_dentry_automount(struct path *path)
 	if (!fm)
 		goto out_put_fsc;
 
-	refcount_set(&fm->count, 1);
 	fsc->s_fs_info = fm;
 	sb = sget_fc(fsc, NULL, set_anon_super_fc);
 	if (IS_ERR(sb)) {
 		err = PTR_ERR(sb);
-		fuse_mount_put(fm);
+		kfree(fm);
 		goto out_put_fsc;
 	}
 	fm->fc = fuse_conn_get(fc);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index c036c4d..919aaf1 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -801,9 +801,6 @@ struct fuse_mount {
 	/* Underlying (potentially shared) connection to the FUSE server */
 	struct fuse_conn *fc;
 
-	/* Refcount */
-	refcount_t count;
-
 	/*
 	 * Super block for this connection (fc->killsb must be held when
 	 * accessing this).
@@ -1024,11 +1021,6 @@ void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
  */
 void fuse_conn_put(struct fuse_conn *fc);
 
-/**
- * Release reference to fuse_mount
- */
-void fuse_mount_put(struct fuse_mount *fm);
-
 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
 struct fuse_dev *fuse_dev_alloc(void);
 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6547085..dd45dec 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -452,7 +452,8 @@ static void fuse_put_super(struct super_block *sb)
 {
 	struct fuse_mount *fm = get_fuse_mount_super(sb);
 
-	fuse_mount_put(fm);
+	fuse_conn_put(fm->fc);
+	kfree(fm);
 }
 
 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
@@ -705,7 +706,6 @@ void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
 	INIT_LIST_HEAD(&fc->mounts);
 	list_add(&fm->fc_entry, &fc->mounts);
 	fm->fc = fc;
-	refcount_set(&fm->count, 1);
 }
 EXPORT_SYMBOL_GPL(fuse_conn_init);
 
@@ -732,16 +732,6 @@ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 }
 EXPORT_SYMBOL_GPL(fuse_conn_get);
 
-void fuse_mount_put(struct fuse_mount *fm)
-{
-	if (refcount_dec_and_test(&fm->count)) {
-		if (fm->fc)
-			fuse_conn_put(fm->fc);
-		kfree(fm);
-	}
-}
-EXPORT_SYMBOL_GPL(fuse_mount_put);
-
 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 {
 	struct fuse_attr attr;
@@ -1458,7 +1448,8 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
 	return 0;
 
  err_put_conn:
-	fuse_mount_put(fm);
+	fuse_conn_put(fc);
+	kfree(fm);
 	sb->s_fs_info = NULL;
  err_fput:
 	fput(file);
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 14d65db..62d89b9 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1445,15 +1445,18 @@ static int virtio_fs_get_tree(struct fs_context *fsc)
 
 	fsc->s_fs_info = fm;
 	sb = sget_fc(fsc, virtio_fs_test_super, set_anon_super_fc);
-	if (fsc->s_fs_info)
-		fuse_mount_put(fm);
+	if (fsc->s_fs_info) {
+		fuse_conn_put(fc);
+		kfree(fm);
+	}
 	if (IS_ERR(sb))
 		return PTR_ERR(sb);
 
 	if (!sb->s_root) {
 		err = virtio_fs_fill_super(sb, fsc);
 		if (err) {
-			fuse_mount_put(fm);
+			fuse_conn_put(fc);
+			kfree(fm);
 			sb->s_fs_info = NULL;
 			deactivate_locked_super(sb);
 			return err;