> On Dec 15, 2023, at 9:26 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > On Fri, 2023-12-15 at 14:19 +0000, Chuck Lever III wrote: >>> On Dec 15, 2023, at 5:59 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: >>> >>> On Fri, 2023-12-15 at 11:56 +1100, NeilBrown wrote: >>>> I sent an earlier version of this series, got some feed back, revised >>>> it, but never sent it again. Sorry. >>>> >>>> The main feedback was around the interaction between sunrpc and nfsd for >>>> handling poolstats. I have changed that so that nfsd tells sunrpc where >>>> the svc_serv pointer lives, and where to find a mutex to protect it. >>>> sunrpc then taks the mutex and accesses the pointer - if not NULL. I >>>> think this is nicer than the version that pass around funciton pointers. >>>> >>>> This series is against nfsd-next >>>> >>>> Thanks, >>>> NeilBrown >>>> >>>> >>>> [PATCH 1/5] nfsd: call nfsd_last_thread() before final nfsd_put() >>>> [PATCH 2/5] svc: don't hold reference for poolstats, only mutex. >>>> [PATCH 3/5] nfsd: hold nfsd_mutex across entire netlink operation >>>> [PATCH 4/5] SUNRPC: discard sv_refcnt, and svc_get/svc_put >>>> [PATCH 5/5] nfsd: rename nfsd_last_thread() to nfsd_destroy_serv() >>> >>> I'm not sure patch #2 is better than the version with function pointers, >>> but it seems reasonable. >>> >>> Note that patch #1 probably needs to go to v6.6 stable, and I think we >>> want #3 in v6.7 before it ships. >> >> Remind me why #3 should go into v6.7-rc ? There's no Fixes tag on >> that one. >> >> > > It's the problem I noted to Lorenzo the other day: > > > https://lore.kernel.org/linux-nfs/5d9bbb599569ce29f16e4e0eef6b291eda0f375b.camel@xxxxxxxxxx/T/#u > > Once you've dropped the nfsd_mutex, there is no guarantee that > nn->nfsd_serv will still be a valid pointer. Holding the mutex across > the operation (like Neil's patch does), should close the race. OK. I'll add: Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support") I will apply 1/3 and 3/3 to v6.7-rc, and the others will go to v6.8 (nfsd-next) once it is rebased on v6.7-rc7. -- Chuck Lever
