From: Zheng Qixing <zhengqix...@huawei.com> Hello,
During reliability testing of the dm module, we discovered two bugs when performing create/remove and suspend/resume operations at high frequency. Analysis revealed that race conditions between suspend and table load operations cause asymmetric handling of q->quiesce_depth and null pointer dereference issues with q->tag_set. To address the q->tag_set null pointer issue, patch 2 determines whether to perform certain suspend actions for request-based devices based on the existence of the table (map). For detailed information, please refer to the patch commits. Additionally, since modern Linux kernels have indeed transitioned to multi-queue as the default (and single-queue is largely deprecated), is using queue_is_mq() to determine dm_request_based() obsolete? Zheng Qixing (2): dm: fix queue start/stop imbalance under suspend/load/resume races dm: fix NULL pointer dereference in __dm_suspend() drivers/md/dm-core.h | 1 + drivers/md/dm.c | 13 ++++++++----- 2 files changed, 9 insertions(+), 5 deletions(-) -- 2.39.2
