On Fri, Oct 04, 2013 at 03:43:18PM -0700, Eric W. Biederman wrote:
>
> Signed-off-by: Eric W. Biederman <ebieder...@twitter.com>
> ---
> fs/mount.h | 1 +
> fs/namespace.c | 24 ++++++++++++++++++++++++
> 2 files changed, 25 insertions(+), 0 deletions(-)
>
> diff --git a/fs/mount.h b/fs/mount.h
> index e4342b8dfab1..7a6a2bb3f290 100644
> --- a/fs/mount.h
> +++ b/fs/mount.h
> @@ -79,6 +79,7 @@ static inline int is_mounted(struct vfsmount *mnt)
> }
>
> extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
> +extern void detach_mounts(struct dentry *dentry);
>
> static inline void get_mnt_ns(struct mnt_namespace *ns)
> {
> diff --git a/fs/namespace.c b/fs/namespace.c
> index d092964fe7f9..8eaee0c14fdb 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -1294,6 +1294,30 @@ static int do_umount(struct mount *mnt, int flags)
> return retval;
> }
>
> +void detach_mounts(struct dentry *dentry)
> +{
> + struct mount *mnt, *next;
> + struct mountpoint *mp;
> +
> + namespace_lock();
> + if (!d_mountpoint(dentry)) {
> + namespace_unlock();
> + return;
> + }
> + mp = new_mountpoint(dentry);
> + if (IS_ERR(mp)) {
> + return;
> + }
> + br_write_lock(&vfsmount_lock);
> + list_for_each_entry_safe(mnt, next, &mp->m_list, mnt_mp_list) {
I don't think list_for_each_entry_safe is actually safe enough here. Because
propageted umounts will likely remove other mounts from the same mountpoint as
well. Doing it with "while (!list_empty(&mp->m_list))" should be better, and
AFAICS it will always make progress.
> + if (!list_empty(&mnt->mnt_list))
> + umount_tree(mnt, 1);
> + }
> + br_write_unlock(&vfsmount_lock);
> + put_mountpoint(mp);
> + namespace_unlock();
> +}
> +
> /*
> * Is the caller allowed to modify his namespace?
> */
> --
> 1.7.5.4
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
