namei: add mapping aware lookup helper
Various filesystems rely on the lookup_one_len() helper to lookup a single path component relative to a well-known starting point. Allow such filesystems to support idmapped mounts by adding a version of this helper to take the idmap into account when calling inode_permission(). This change is a required to let btrfs (and other filesystems) support idmapped mounts. Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David Sterba <dsterba@suse.com>
Showing
Please register or sign in to comment