Re: [PATCH 0/3] fs/9p: fix setattr/getattr issues with open files

From: Dominique Martinet
Date: Mon Jul 04 2016 - 11:19:00 EST



I *think* this introduces a race somewhere, I'm getting errors like:
cat: f.05: No such file or directory
cat: f.14: No such file or directory
cat: f.13: No such file or directory
cat: f.39: No such file or directory
cat: f.05: No such file or directory


when doing:
for file in {01..50}; do touch f.${file}; done
seq 1 1000 | xargs -n 1 -P 25 -I{} cat f.* > /dev/null



I don't get it everytime but close enough to. Server is bi-socket and
has some numa effects which help producing data-synchronization races,
it's probably harder to hit on a laptop.

I'm simply trying over a patched qemu for now, applied patches right on
top of 4.6.1, can't seem to reproduce with a vanilla 4.6.1 without any
change to qemu (still patched), so it looks kernel-side.


Can't say I've taken much time to look at the patches yet though,
sorry - I don't think it's too hard to debug though so I'll take a look
tomorrow as soon as I find time if you haven't gotten it by then.

--
Dominique