On Thu, Dec 20, 2018 at 10:52:19AM -0500, Bruce Fields wrote:
> On Thu, Dec 20, 2018 at 10:47:25AM -0500, Chuck Lever wrote:
> >
> >
> > > On Dec 20, 2018, at 10:42 AM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> > >
> > > From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
> > >
> > > It's OK to sleep here, we just don't want to recurse into the filesystem
> > > as this writeout could be waiting on this.
> >
> > "as a writeout"
>
> Oops, thanks.
(Trond or Anna, I'm assuming you can fix that up, but let me know if
you'd rather I resent.)
--b.
>
> > > Future work: the documentation for GFP_NOFS says "Please try to avoid
> > > using this flag directly and instead use memalloc_nofs_{save,restore} to
> > > mark the whole scope which cannot/shouldn't recurse into the FS layer
> > > with a short explanation why. All allocation requests will inherit
> > > GFP_NOFS implicitly."
> > >
> > > But I'm not sure where to do this. Should the workqueue be arranging
> > > that for us in the case of workqueues created with WQ_MEM_RECLAIM?
> >
> > There seem to be plenty of uses of GFP_NOFS in NFS and sunrpc.
> > That sounds like a big project.
>
> Yeah, just noting it for future reference.
>
> --b.
>
> > > Reported-by: Trond Myklebust <trondmy@hammer.space>
> > > Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
> > > ---
> > > net/sunrpc/rpcb_clnt.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > Also, I've still got this one. (And still haven't looked into whether
> > > it should be using a memalloc_nofs_{save,restore} elsewhere instead.)
> > >
> > > diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
> > > index 08b5fa4a2852..41a971ac1c63 100644
> > > --- a/net/sunrpc/rpcb_clnt.c
> > > +++ b/net/sunrpc/rpcb_clnt.c
> > > @@ -752,7 +752,7 @@ void rpcb_getport_async(struct rpc_task *task)
> > > goto bailout_nofree;
> > > }
> > >
> > > - map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
> > > + map = kzalloc(sizeof(struct rpcbind_args), GFP_NOFS);
> > > if (!map) {
> > > status = -ENOMEM;
> > > dprintk("RPC: %5u %s: no memory available\n",
> > > @@ -770,7 +770,7 @@ void rpcb_getport_async(struct rpc_task *task)
> > > case RPCBVERS_4:
> > > case RPCBVERS_3:
> > > map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
> > > - map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
> > > + map->r_addr = rpc_sockaddr2uaddr(sap, GFP_NOFS);
> > > if (!map->r_addr) {
> > > status = -ENOMEM;
> > > dprintk("RPC: %5u %s: no memory available\n",
> > > --
> > > 2.19.2
> > >
> >
> > --
> > Chuck Lever
> >
> >
