On Tue, Mar 14, 2023 at 7:50 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> On Tue, Mar 14, 2023 at 12:21 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
> >
> > Commit 6930bcbfb6ce dropped the setting of the file_lock range when
> > decoding a nlm_lock off the wire. This causes the client side grant
> > callback to miss matching blocks and reject the lock, only to rerequest
> > it 30s later.
> >
> > Add a helper function to set the file_lock range from the start and end
> > values that the protocol uses, and have the nlm_lock decoder call that to
> > set up the file_lock args properly.
> >
> > Fixes: 6930bcbfb6ce ("lockd: detect and reject lock arguments that overflow")
> > Reported-by: Amir Goldstein <amir73il@xxxxxxxxx>
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > fs/lockd/clnt4xdr.c | 9 +--------
> > fs/lockd/xdr4.c | 13 ++++++++++++-
> > include/linux/lockd/xdr4.h | 1 +
> > 3 files changed, 14 insertions(+), 9 deletions(-)
> >
> > Hi Amir,
> >
> > Thanks for the bug report. This patch seems to fix up the 30s stalls for
> > me. Can you give it a spin and see if it also helps you? I am still
>
> Works like a charm :)
>
> I tested a backport to 5.15.y (trivial conflict in h file).
> against 5.10.109 and 5.15.88 servers.
>
> Tested-by: Amir Goldstein <amir73il@xxxxxxxxx>
>
> > seeing one test failure with nfstest_lock, but I'm not sure it's related
> > to this. I'll plan to follow up with Jorge.
>
> I don't see this failure in my tests.
>
> Please fast track this fix which also fixes an LTS 5.15.y kernel regression.
> Please cc stable and let me know if you want me to post the 5.15.y backport.
Thanks Jeff and Amir! I have the patch queued up, and I'll do a
bugfixes pull request later this week.
Anna
>
> Thanks for the prompt fix,
> Amir.
>
> >
> > Thanks,
> > Jeff
> >
> > diff --git a/fs/lockd/clnt4xdr.c b/fs/lockd/clnt4xdr.c
> > index 7df6324ccb8a..8161667c976f 100644
> > --- a/fs/lockd/clnt4xdr.c
> > +++ b/fs/lockd/clnt4xdr.c
> > @@ -261,7 +261,6 @@ static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
> > u32 exclusive;
> > int error;
> > __be32 *p;
> > - s32 end;
> >
> > memset(lock, 0, sizeof(*lock));
> > locks_init_lock(fl);
> > @@ -285,13 +284,7 @@ static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
> > fl->fl_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
> > p = xdr_decode_hyper(p, &l_offset);
> > xdr_decode_hyper(p, &l_len);
> > - end = l_offset + l_len - 1;
> > -
> > - fl->fl_start = (loff_t)l_offset;
> > - if (l_len == 0 || end < 0)
> > - fl->fl_end = OFFSET_MAX;
> > - else
> > - fl->fl_end = (loff_t)end;
> > + nlm4svc_set_file_lock_range(fl, l_offset, l_len);
> > error = 0;
> > out:
> > return error;
> > diff --git a/fs/lockd/xdr4.c b/fs/lockd/xdr4.c
> > index 712fdfeb8ef0..5fcbf30cd275 100644
> > --- a/fs/lockd/xdr4.c
> > +++ b/fs/lockd/xdr4.c
> > @@ -33,6 +33,17 @@ loff_t_to_s64(loff_t offset)
> > return res;
> > }
> >
> > +void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len)
> > +{
> > + s64 end = off + len - 1;
> > +
> > + fl->fl_start = off;
> > + if (len == 0 || end < 0)
> > + fl->fl_end = OFFSET_MAX;
> > + else
> > + fl->fl_end = end;
> > +}
> > +
> > /*
> > * NLM file handles are defined by specification to be a variable-length
> > * XDR opaque no longer than 1024 bytes. However, this implementation
> > @@ -80,7 +91,7 @@ svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
> > locks_init_lock(fl);
> > fl->fl_flags = FL_POSIX;
> > fl->fl_type = F_RDLCK;
> > -
> > + nlm4svc_set_file_lock_range(fl, lock->lock_start, lock->lock_len);
> > return true;
> > }
> >
> > diff --git a/include/linux/lockd/xdr4.h b/include/linux/lockd/xdr4.h
> > index 9a6b55da8fd6..72831e35dca3 100644
> > --- a/include/linux/lockd/xdr4.h
> > +++ b/include/linux/lockd/xdr4.h
> > @@ -22,6 +22,7 @@
> > #define nlm4_fbig cpu_to_be32(NLM_FBIG)
> > #define nlm4_failed cpu_to_be32(NLM_FAILED)
> >
> > +void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len);
> > bool nlm4svc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr);
> > bool nlm4svc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
> > bool nlm4svc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
> > --
> > 2.39.2
> >
