Re: [PATCH 5/6] fsmount: do not use legacy MS_ flags

From: David Howells
Date: Sun Sep 23 2018 - 18:45:26 EST


Christian Brauner <christian@xxxxxxxxxx> wrote:

> Of course, I'm not sure what the reasons for all of the other arguments to
> this function are since it's not yet implemented.

Well, dfd, path and atflags are pretty standard. atflags conveys things like
AT_EMPTY_PATH or AT_SYMLINK_NOFOLLOW and dfd conveys a file descriptor
pointing to a vfs object or AT_FDCWD.

> Seems that attr_values and attr_mask could be compacted to a single
> attr_mask maybe?

If you don't have a mask, you can't really do recursion. Without the mask,
you have to supply the entire set of options absolutely - and this would get
stamped on everything in the target range.

With a mask in combination with the set of desired values, you can turn on or
off a specific subset of the attributes without affecting the rest - without
needing to know the rest.

David