Re: "Sleeping with non-sleepable lock" in NFS on recent -current

On 2019-Sep-16 09:32:52 +0300, Konstantin Belousov <kostikbel_at_gmail.com> wrote:
>On Mon, Sep 16, 2019 at 04:12:05PM +1000, Peter Jeremy wrote:
>> I'm consistently seeing panics in the NFS code on recent -current on aarm64.
>> The panics are one of the following two:
>> Sleeping on "vmopar" with the following non-sleepable locks held:
>> exclusive sleep mutex NEWNFSnode lock (NEWNFSnode lock) r = 0 (0xfffffd0078b346f0) locked _at_ /usr/src/sys/fs/nfsclient/nfs_clport.c:432
>> 
>> Sleeping thread (tid 100077, pid 35) owns a non-sleepable lock
>> 
>> Both panics have nearly identical backtraces (see below).  I'm running
>> diskless on a Rock64 with both filesystem and swap over NFS.  The panics
>> can be fairly reliably triggered by any of:
>> * "make -j4 buildworld"
>> * linking the kernel (as part of buildkernel)
>> * "make installworld"
>> 
>> Has anyone else seen this?
...

>Weird since this should have been fixed long time ago.  Anyway, please
>try the following, it should fix the rest of cases.
>
>diff --git a/sys/fs/nfsclient/nfs_clport.c b/sys/fs/nfsclient/nfs_clport.c
...
>_at__at_ -540,7 +541,7 _at__at_ nfscl_loadattrcache(struct vnode **vpp, struct nfsvattr *nap, void *nvaper,
> 			} else {
> 				np->n_size = vap->va_size;
> 				np->n_flag |= NSIZECHANGED;
>-				vnode_pager_setsize(vp, np->n_size);
>+				setnsize = 1;

Should this else block include a "nsize = np->n_size;"?  Without it,
nsize will remain set to 0, which looks wrong.

-- 
Peter Jeremy