On Fri, Jul 28, 2017 at 09:43:57AM +0200, Erik Skultety wrote:
v1 here https://www.redhat.com/archives/libvir-list/2017-June/msg00826.html
This series addresses [1]. It builds on top of [2], series which introduces a few small fixes and improvements. Even though that one hasn't gotten a review yet, you can fetch and build this from my github branch [3].
Changes since v1: - moved the device handling routine into a detached worker thread, so the event loop wouldn't block - adjusted virFileAccess according to the reviewer's comments
Notes: Merging the nodedev obj's refactor storing the list of nodedev objects in a self-lockable object made it possible to drop the driver locks at certain spots either completely or at least rearrange them according to the needs. The worker thread therefore doesn't need to hold the driver lock while waiting on the device's attributes to appear (which would be wrong anyway, since it would still block the event loop) and only acquires the driver lock when doing sanity checks on the udev monitor.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1463285 [2] https://www.redhat.com/archives/libvir-list/2017-July/msg01077.html [3] https://github.com/eskultety/libvirt/commits/mdev-nodedev-next
Erik Skultety (5): nodedev: Introduce udevCheckMonitorFD helper function udev: Split udevEventHandleCallback in two functions udev: Convert udevEventHandleThread to an actual thread routine util: Introduce virFileWaitForAccess nodedev: Work around the uevent race by hooking up virFileWaitForAccess
src/libvirt_private.syms | 1 + src/node_device/node_device_udev.c | 194 +++++++++++++++++++++++++++++++------ src/util/virfile.c | 29 ++++++ src/util/virfile.h | 2 + 4 files changed, 194 insertions(+), 32 deletions(-)
SNACK, I was pointed out that the worker thread spams the log with an unexpected error("monitor received NULL"), so it looks like there's a race somewhere. I checked the event counting, that looks okay, except that there's quite a few events coming on the fd during daemon's init phase and for most of them, there's nothing coming out of the monitor actually. I need to investigate more. Erik