From: Cheng Yang <[email protected]> The proc_parse_options() call from proc_mount() runs only once at boot time. So on any later mount attempt, any mount options are ignored because ->s_root is already initialized. As a consequence, "mount -o <options>" will ignore the options. The only way to change mount options is "mount -o remount,<options>". To fix this, parse the mount options unconditionally.
Signed-off-by: Cheng Yang <[email protected]> --- fs/proc/inode.c | 4 ---- fs/proc/root.c | 3 +++ 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 5792f9e..ec509d1 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -493,13 +493,9 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) int proc_fill_super(struct super_block *s, void *data, int silent) { - struct pid_namespace *ns = get_pid_ns(s->s_fs_info); struct inode *root_inode; int ret; - if (!proc_parse_options(data, ns)) - return -EINVAL; - /* User space would break if executables or devices appear on proc */ s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV; s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC; diff --git a/fs/proc/root.c b/fs/proc/root.c index f4b1a9d..f5f3bf3 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -98,6 +98,9 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, ns = task_active_pid_ns(current); } + if (!proc_parse_options(data, ns)) + return ERR_PTR(-EINVAL); + return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super); } -- 1.9.1
