On 10/27/2020 2:20 PM, Jason Gunthorpe wrote:
There are two flows for handling RDMA_CM_EVENT_ROUTE_RESOLVED, either the handler triggers a completion and another thread does rdma_connect() or the handler directly calls rdma_connect(). In all cases rdma_connect() needs to hold the handler_mutex, but when handler's are invoked this is already held by the core code. This causes ULPs using the 2nd method to deadlock. Provide a rdma_connect_locked() and have all ULPs call it from their handlers. Link: https://lore.kernel.org/r/0-v1-75e124dbad74+b05-rdma_connect_locking_jgg@xxxxxxxxxx Reported-and-tested-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx> Fixes: 2a7cec538169 ("RDMA/cma: Fix locking for the RDMA_CM_CONNECT state") Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx> Acked-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> --- drivers/infiniband/core/cma.c | 40 +++++++++++++++++++++--- drivers/infiniband/ulp/iser/iser_verbs.c | 2 +- drivers/infiniband/ulp/rtrs/rtrs-clt.c | 4 +-- drivers/nvme/host/rdma.c | 4 +-- include/rdma/rdma_cm.h | 14 ++------- net/rds/ib_cm.c | 5 +-- 6 files changed, 46 insertions(+), 23 deletions(-) v2: - Remove extra code from nvme (Chao) - Fix long lines (CH) I've applied this version to rdma-rc - expecting to get these ULPs unbroken for rc2 release Thanks, Jason
iser and nvme/rdma looks good to me, Reviewed-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
