https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=198570

Mateusz Guzik <[email protected]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[email protected]

--- Comment #5 from Mateusz Guzik <[email protected]> ---
Reliable resolution in terms of always providing a path if it exists would
indeed be a great qualify of life improvement, but that's readily possible
because of the way name caching was implemented in Unix systems.

The opening comment asks about interest in fixing the problem, but does not
provide any ideas how to do it.

For this to work the kernel would need to track the last path component used to
open the file *and* have a way of resolving it upwards. In practice this means
preventing parent entries from being freed all the way up.

Except as is:
1. name caching is currently optional -- whatever the filesystem it can opt to
NOT add an entry into it. But let's say this gets changed to be mandatory.

2. names are not tracked on open to begin with, you only get the vnode. as in,
the kernel has no idea what name was used to get to it.

3. and of course nothing prevents names from being freed up on memory pressure

Finally, the entire problem is strongly linked to the functionality currently
provided by nullfs: a proper machinery to handle the above would also obsolete
nullfs.

All of this *can* be done but it constitutes significant effort and I don't
believe there are any takers.

-- 
You are receiving this mail because:
You are the assignee for the bug.

Reply via email to