On 3/11/20 01:53, santosh.shilimkar@xxxxxxxxxx wrote: > On 3/6/20 4:11 AM, zerons wrote: >> >> >> On 2/28/20 02:10, santosh.shilimkar@xxxxxxxxxx wrote: >>> >>>>> On 18 Feb 2020, at 14:13, zerons <sironhide0null@xxxxxxxxx> wrote: >>>>> >>>>> Hi, all >>>>> >>>>> In net/rds/rdma.c >>>>> (https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/net/rds/rdma.c?h=v5.5.3*n419__;Iw!!GqivPVa7Brio!OwwQCLtjDsKmhaIz0sfaOVSuC4ai5t5_FgB7yqNExGOCBtACtIGLF61NNJyqSDtIAcGoPg$ ), >>>>> there may be a race condition between rds_rdma_unuse() and rds_free_mr(). >>>>> >>> Hmmm.. I didn't see email before in my inbox. Please post questions/patches on netdev in future which is the correct mailing list. >>> >>>>> It seems that this one need some specific devices to run test, >>>>> unfortunately, I don't have any of these. >>>>> I've already sent two emails to the maintainer for help, no response yet, >>>>> (the email address may not be in use). >>>>> >>>>> 0) in rds_recv_incoming_exthdrs(), it calls rds_rdma_unuse() when receive an >>>>> extension header with force=0, if the victim mr does not have RDS_RDMA_USE_ONCE >>>>> flag set, then the mr would stay in the rbtree. Without any lock, it tries to >>>>> call mr->r_trans->sync_mr(). >>>>> > MR won't stay in the rbtree with force flag. If the MR is used or > use_once is set in both cases its removed from the tree. > See "if (mr->r_use_once || force)" > Sorry, I may misunderstand. Did you mean that if the MR is *used*, it is removed from the tree with or without the force flag in rds_rdma_unuse(), even when r_use_once is not set? Regards,
