Hi Trond Trond Myklebust 写道: > On Mon, 2009-11-09 at 17:19 +0800, Mi Jinlong wrote: >> Hi Trond et all >> >> There is a bug, when i test NFSv3 file's lock as followed: >> >> Step1: ClientA and ClientB open a same nfs file; >> Step2: ClientA locks file with write lock, it's ok; >> Step3: Cut off the network between ClientA and Server; >> Step4: ClientB can not acquire for write lock successful forever, even though >> the network partition larger than NLM_HOST_EXPIRE. >> >> As i know, If use NFSv4, step4 can success after LEASE_TIME. >> >> Is it necessary to fix NFSv3 ? >> >> The attached patch can make this case OK, but i am not sure it's good. > > Unfortunately, NLM (the NFSv2 and v3 locking protocol) is not lease > based, so the above scenario is truly an unfixable one. > > The problem with applying your patch is, in essence, that we risk > breaking another scenario where a client grabs a lock, and then holds it > for a while. > The reason this breaks is that there is no equivalent in the NLM > protocol of the NFSv4 RENEW operation to tell the server that "This > client is still alive and wants you to keep its state". Thanks for your answer! This bug seems serious, shouldn't we fix it? thanks, Mi Jinlong -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
