From 8aec08094570562bc305df33b088926d983c3540 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 7 Jun 2007 12:20:32 -0400 Subject: [PATCH] new helpers - collect_mounts() and release_collected_mounts() Get a snapshot of a subtree, creating private clones of vfsmounts for all its components and release such snapshot resp. Signed-off-by: Al Viro --- fs/namespace.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'fs/namespace.c') diff --git a/fs/namespace.c b/fs/namespace.c index 860752998fb..06083885b21 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -246,7 +246,7 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, list_add(&mnt->mnt_slave, &old->mnt_slave_list); mnt->mnt_master = old; CLEAR_MNT_SHARED(mnt); - } else { + } else if (!(flag & CL_PRIVATE)) { if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old)) list_add(&mnt->mnt_share, &old->mnt_share); if (IS_MNT_SLAVE(old)) @@ -746,6 +746,26 @@ Enomem: return NULL; } +struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry) +{ + struct vfsmount *tree; + down_read(&namespace_sem); + tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE); + up_read(&namespace_sem); + return tree; +} + +void drop_collected_mounts(struct vfsmount *mnt) +{ + LIST_HEAD(umount_list); + down_read(&namespace_sem); + spin_lock(&vfsmount_lock); + umount_tree(mnt, 0, &umount_list); + spin_unlock(&vfsmount_lock); + up_read(&namespace_sem); + release_mounts(&umount_list); +} + /* * @source_mnt : mount tree to be attached * @nd : place the mount tree @source_mnt is attached -- cgit v1.2.3