Fix races around the access to ->s_options
Put generic_show_options read access to s_options under rcu_read_lock,
split save_mount_options() into "we are setting it the first time"
(uses in foo_fill_super()) and "we are relacing and freeing the old one",
synchronize_rcu() before kfree() in the latter.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 5ce695e..63f5183 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -507,8 +507,7 @@
kfree(new_opts);
return -EINVAL;
}
- kfree(sb->s_options);
- sb->s_options = new_opts;
+ replace_mount_options(sb, new_opts);
sbi->s_flags = mount_flags;
sbi->s_mode = mode;