IPVS updates a destination's overload status from connection accounting and destination configuration paths, while schedulers read it from packet processing paths.
Patch 1, authored by Julian, updates the overload state whenever a destination's connection thresholds change. It also limits the upper threshold to the range that can be compared safely with the connection counter. Patch 2 moves overload state out of dest->flags, which it previously shared with the independent availability state. It uses a separate bitset and bitops so updates to the two states cannot clobber each other. KCSAN reports the original race between __ip_vs_update_dest() and ip_vs_sh_schedule(), as well as between ip_vs_bind_dest() and the SH scheduler. The series keeps reader-side synchronization lightweight. test_bit() does not provide a fresh cross-field snapshot, so schedulers may still observe stale destination state as they could before this change. Changes in v3: - Add Julian's fix to properly refresh OVERLOAD on destination edit and reject upper thresholds above INT_MAX before comparing them with the signed connection counter as patch 1/2. - Keep AVAILABLE in dest->flags and move OVERLOAD to a separate bitset. - Link to v2: https://lore.kernel.org/netfilter-devel/[email protected]/ Julian Anastasov (1): ipvs: properly update the overload flag on dest edit Yizhou Zhao (1): ipvs: use bitops for destination overload state include/net/ip_vs.h | 10 ++++++++ include/uapi/linux/ip_vs.h | 6 ----- net/netfilter/ipvs/ip_vs_conn.c | 44 ++++++++++++++++++++++---------- net/netfilter/ipvs/ip_vs_ctl.c | 26 +++++++++++++------ net/netfilter/ipvs/ip_vs_dh.c | 4 +-- net/netfilter/ipvs/ip_vs_fo.c | 2 +- net/netfilter/ipvs/ip_vs_lblc.c | 4 +-- net/netfilter/ipvs/ip_vs_lblcr.c | 8 +++--- net/netfilter/ipvs/ip_vs_lc.c | 2 +- net/netfilter/ipvs/ip_vs_mh.c | 2 +- net/netfilter/ipvs/ip_vs_nq.c | 2 +- net/netfilter/ipvs/ip_vs_ovf.c | 2 +- net/netfilter/ipvs/ip_vs_rr.c | 2 +- net/netfilter/ipvs/ip_vs_sed.c | 4 +-- net/netfilter/ipvs/ip_vs_sh.c | 2 +- net/netfilter/ipvs/ip_vs_twos.c | 4 +-- net/netfilter/ipvs/ip_vs_wlc.c | 4 +-- net/netfilter/ipvs/ip_vs_wrr.c | 2 +- 18 files changed, 81 insertions(+), 49 deletions(-) base-commit: 2c7c88a412aa6d09cd04b414211b4ef8553b5309 -- 2.34.1
