On Mon, Jun 12, 2023 at 11:07 AM Christian Brauner <brauner@xxxxxxxxxx> wrote: > > On Sun, Jun 11, 2023 at 09:45:45PM -0700, Christoph Hellwig wrote: > > On Sun, Jun 11, 2023 at 10:47:05PM +0300, Amir Goldstein wrote: > > > Overlayfs and cachefiles use open_with_fake_path() to allocate internal > > > files, where overlayfs also puts a "fake" path in f_path - a path which > > > is not on the same fs as f_inode. > > > > But cachefs doesn't, so this needs a better explanation / documentation. > > > > > Allocate a container struct file_fake for those internal files, that > > > is used to hold the fake path along with an optional real path. > > > > The idea looks sensible, but fake a is a really weird term here. > > I know open_with_fake_path also uses it, but we really need to > > come up with a better name, and also good documentation of the > > concept here. > > It's basically a stack so I'd either use struct file_stack or > struct file_proxy; with a preference for the latter. Let the bikeshedding begin :) file_proxy too generic to my taste How about: /* File is embedded in backing_file object */ #define FMODE_BACKING ((__force fmode_t)0x2000000) This backing_file container may be usable for cachefiles or FUSE passthrough in the future to store the path of the (netfs/fuse) file that is backed by the (local) backing file. We had a short attempt to do the same for ovl - store the ovl path in the container and not the real_path, to get rid of file_dentry() calls, but it got complicated so deferreing that for later. Thanks, Amir.
