[PATCH] lock exclusively in collect_mounts() and drop_collected_mounts()
Taking namespace_sem shared there isn't worth the trouble, especially with vfsmount ID allocation about to be added. That way we know that umount_tree(), copy_tree() and clone_mnt() are _always_ serialized by namespace_sem. umount_tree() still needs vfsmount_lock (it manipulates hash chains, among other things), but that's a separate story. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
parent
6d59e7f582
commit
1a60a28077
|
@ -1091,20 +1091,20 @@ Enomem:
|
|||
struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry)
|
||||
{
|
||||
struct vfsmount *tree;
|
||||
down_read(&namespace_sem);
|
||||
down_write(&namespace_sem);
|
||||
tree = copy_tree(mnt, dentry, CL_COPY_ALL | CL_PRIVATE);
|
||||
up_read(&namespace_sem);
|
||||
up_write(&namespace_sem);
|
||||
return tree;
|
||||
}
|
||||
|
||||
void drop_collected_mounts(struct vfsmount *mnt)
|
||||
{
|
||||
LIST_HEAD(umount_list);
|
||||
down_read(&namespace_sem);
|
||||
down_write(&namespace_sem);
|
||||
spin_lock(&vfsmount_lock);
|
||||
umount_tree(mnt, 0, &umount_list);
|
||||
spin_unlock(&vfsmount_lock);
|
||||
up_read(&namespace_sem);
|
||||
up_write(&namespace_sem);
|
||||
release_mounts(&umount_list);
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in New Issue