[PATCH 2/8] vfs - add path_is_mountpoint() helper

From: Ian Kent d_mountpoint() can only be used reliably to establish if a dentry is not mounted in any namespace. It isn't aware of the possibility there may be multiple mounts using a given dentry that may be in a different namespace. Add helper functions, path_is_mountpoint() and an rcu versio

[RFC PATCH 2/8] vfs - add path_is_mountpoint() helper

From: Ian Kent d_mountpoint() can only be used reliably to establish if a dentry is not mounted in any namespace. It isn't aware of the possibility there may be multiple mounts using a given dentry that may be in a different namespace. Add helper functions, path_is_mountpoint() and an rcu versio