> On Dec 15, 2023, at 9:38 AM, Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote: > >> 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. Please check the two patches at the tip of the nfsd-fixes branch here: https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git I plan to apply the other three in this series to nfsd-next. -- Chuck Lever
