erofs: fix handling kern_mount() failure

Al Viro · Al Viro · commit 2c88c16dc20e · 2024-02-20T02:09:02.000-05:00
if you have a variable that holds NULL or  a pointer to live struct mount,
do not shove ERR_PTR() into it - not if you later treat "not NULL" as
"holds a pointer to object".

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
@@ -381,11 +381,12 @@ static int erofs_fscache_init_domain(struct super_block *sb)
 		goto out;
 
 	if (!erofs_pseudo_mnt) {
-		erofs_pseudo_mnt = kern_mount(&erofs_fs_type);
-		if (IS_ERR(erofs_pseudo_mnt)) {
-			err = PTR_ERR(erofs_pseudo_mnt);
+		struct vfsmount *mnt = kern_mount(&erofs_fs_type);
+		if (IS_ERR(mnt)) {
+			err = PTR_ERR(mnt);
 			goto out;
 		}
+		erofs_pseudo_mnt = mnt;
 	}
 
 	domain->volume = sbi->volume;

Original file line number	Diff line number	Diff line change
`@@ -381,11 +381,12 @@ static int erofs_fscache_init_domain(struct super_block *sb)`
`381`	`381`	`goto out;`
`382`	`382`
`383`	`383`	`if (!erofs_pseudo_mnt) {`
`384`		`- erofs_pseudo_mnt = kern_mount(&erofs_fs_type);`
`385`		`- if (IS_ERR(erofs_pseudo_mnt)) {`
`386`		`- err = PTR_ERR(erofs_pseudo_mnt);`
	`384`	`+ struct vfsmount *mnt = kern_mount(&erofs_fs_type);`
	`385`	`+ if (IS_ERR(mnt)) {`
	`386`	`+ err = PTR_ERR(mnt);`
`387`	`387`	`goto out;`
`388`	`388`	`}`
	`389`	`+ erofs_pseudo_mnt = mnt;`
`389`	`390`	`}`
`390`	`391`
`391`	`392`	`domain->volume = sbi->volume;`