Message ID | 20240512061136.726299-1-andrea.righi@canonical.com |
---|---|
Headers | show |
Series | fix autopkgtest-virt-qemu regression with 6.8 | expand |
On 5/12/24 08:09, Andrea Righi wrote: > BugLink: https://bugs.launchpad.net/bugs/2056461 > > [Impact] > > It seems that kernel 6.8 introduced a regression in the 9pfs related to > caching and netfslib, that can cause some user-space apps to read > content from files that is not up-to-date (when they are used in a > producer/consumer fashion). > > It seems that the offending commit is this one: > > 80105ed2fd27 ("9p: Use netfslib read/write_iter") > > Reverting the commit seems to fix the problem. However the actual bug > might be in netfslib or how netfslib is used in the 9p context. > > The regression has been reported upstream and we are still investigating > (https://lore.kernel.org/lkml/Zj0ErxVBE3DYT2Ea@gpd/). > > In the meantime it probably makes sense to temporarily revert the commit > as a SAUCE patch. Then we will drop the SAUCE patch once we'll have a > proper fix upstream. > > [Test case] > > The following test should complete correctly without any timeout: > > pull-lp-source -d hello > autopkgtest-buildvm-ubuntu-cloud -r noble > autopkgtest -U hello*.dsc -- qemu ./autopkgtest-noble-amd64.img > > [Fix] > > Revert the following commit (until we have a proper fix upstream): > > 80105ed2fd27 ("9p: Use netfslib read/write_iter") > > [Regression potential] > > We may experience other regressions related to 9pfs with this change, > however it's quite unlikely to happen since we are reverting a commit, > restoring the previous behavior. > Acked-by: Tim Gardner <tim.gardner@canonical.com>
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On Sun, May 12 2024, Andrea Righi wrote: > BugLink: https://bugs.launchpad.net/bugs/2056461 > > [Impact] > > It seems that kernel 6.8 introduced a regression in the 9pfs related to > caching and netfslib, that can cause some user-space apps to read > content from files that is not up-to-date (when they are used in a > producer/consumer fashion). > > It seems that the offending commit is this one: > > 80105ed2fd27 ("9p: Use netfslib read/write_iter") > > Reverting the commit seems to fix the problem. However the actual bug > might be in netfslib or how netfslib is used in the 9p context. > > The regression has been reported upstream and we are still investigating > (https://lore.kernel.org/lkml/Zj0ErxVBE3DYT2Ea@gpd/). > > In the meantime it probably makes sense to temporarily revert the commit > as a SAUCE patch. Then we will drop the SAUCE patch once we'll have a > proper fix upstream. > > [Test case] > > The following test should complete correctly without any timeout: > > pull-lp-source -d hello > autopkgtest-buildvm-ubuntu-cloud -r noble > autopkgtest -U hello*.dsc -- qemu ./autopkgtest-noble-amd64.img > > [Fix] > > Revert the following commit (until we have a proper fix upstream): > > 80105ed2fd27 ("9p: Use netfslib read/write_iter") > > [Regression potential] > > We may experience other regressions related to 9pfs with this change, > however it's quite unlikely to happen since we are reverting a commit, > restoring the previous behavior. Acked-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> - -- Regards, Marcelo -----BEGIN PGP SIGNATURE----- iQHQBAEBCgA6FiEExJjLjAfVL0XbfEr56e82LoessAkFAmZPJ8AcHG1hcmNlbG8u Y2VycmlAY2Fub25pY2FsLmNvbQAKCRDp7zYuh6ywCS5xC/4sPqGVimwzKH7o7qRs dTlHbhDNPYbLNvdmKZe1Q4DQpNera1/v7+I0u2NZqTs5D41wpn1/4tHxEy2YNI1P kNiE4OsX9L4ZdDoFquFTf4Ii1EbPZaDFK1JPWTehqv7eDKZ9OMYST+mIJvFwk6d9 hyMnMzb+/ZGrl8r8wo4STSjuucsnBw4uy8orCEDdp+AcFWhRhQWoE1/T5OLRQVrg Wv7pU1OeIJ2DFDt+I4p2e4irPGDefSmjQvVe7bd/FxxXX6bXuW0kGNrGc7gn3eIl FktfwioxYwHNRiDqJfJZ44byKkpoLQML6l2LniRPGmdizrj2F/I/GzqAu4hFBec/ gk7JsU8wrcf10UQhpIs7joZdpY5GIj4eJQcQV9iGmm/4Cyk4DBCaNefxr9KOQkoR JTGqKX0Zv4tnh1gtzBER9WLqOInSUHMisAvF+VthA/0B3M8tLbwrX2l2Vkn5QV8G b9l2qhP/5h4Gdly8VaITLpk7mOy6zH9UlhlNMJOwfyqGpkY= =+qfu -----END PGP SIGNATURE-----