Hi all, Ritesh and Eric separately reported crashes in XFS's hook function for CPU hot remove if the remove event races with a filesystem being mounted. I also noticed via generic/650 that once in a while the log will shut down over an apparent overrun of a transaction reservation; this turned out to be due to CIL percpu list aggregation failing to pick up the percpu list items from a dying CPU. Either way, the solution here is to eliminate the need for a CPU dying hook by using a private cpumask to track which CPUs have added to their percpu lists directly, and iterating with that mask. This fixes the log problems and (I think) solves a theoretical UAF bug in the inodegc code too. If you're going to start using this code, I strongly recommend pulling from my git trees, which are linked below. This has been lightly tested with fstests. Enjoy! Comments and questions are, as always, welcome. --D kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=fix-percpu-lists-6.6 --- fs/xfs/xfs_icache.c | 60 ++++++++++---------------------------------- fs/xfs/xfs_icache.h | 1 - fs/xfs/xfs_log_cil.c | 50 +++++++++++-------------------------- fs/xfs/xfs_log_priv.h | 14 ++++------ fs/xfs/xfs_mount.h | 6 +++- fs/xfs/xfs_super.c | 55 +--------------------------------------- include/linux/cpuhotplug.h | 1 - 7 files changed, 40 insertions(+), 147 deletions(-)
