| Message ID | 50f5a8389be39630e9babeb9caba8377773c1cf2.1688131022.git.bcodding@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] NFSv4: Fix dropped lock for racing OPEN and delegation return | expand |
On Fri, 2023-06-30 at 09:18 -0400, Benjamin Coddington wrote: > Commmit f5ea16137a3f ("NFSv4: Retry LOCK on OLD_STATEID during > delegation > return") attempted to solve this problem by using nfs4's generic > async error > handling, but introduced a regression where v4.0 lock recovery would > hang. > The additional complexity introduced by overloading that error > handling is > not necessary for this case. This patch expects that commit to be > reverted. > > The problem as originally explained in the above commit is: > > There's a small window where a LOCK sent during a delegation > return can > race with another OPEN on client, but the open stateid has not > yet been > updated. In this case, the client doesn't handle the OLD_STATEID > error > from the server and will lose this lock, emitting: > "NFS: nfs4_handle_delegation_recall_error: unhandled error - > 10024". > > Fix this by using the old_stateid refresh helpers if the server > replies > with OLD_STATEID. > > Suggested-by: Trond Myklebust <trondmy@hammerspace.com> > Signed-off-by: Benjamin Coddington <bcodding@redhat.com> > --- > fs/nfs/nfs4proc.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index 6bb14f6cfbc0..bdfb4ac144d2 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -7180,8 +7180,15 @@ static void nfs4_lock_done(struct rpc_task > *task, void *calldata) > } else if (!nfs4_update_lock_stateid(lsp, &data- > >res.stateid)) > goto out_restart; > break; > - case -NFS4ERR_BAD_STATEID: > case -NFS4ERR_OLD_STATEID: > + if (data->arg.new_lock_owner != 0 && > + nfs4_refresh_open_old_stateid(&data- > >arg.open_stateid, > + lsp->ls_state)) > + goto out_restart; > + if (nfs4_refresh_lock_old_stateid(&data- > >arg.lock_stateid, lsp)) > + goto out_restart; Err... You only want to call nfs4_refresh_lock_old_stateid() if data- >arg.new_lock_owner is 0. That's not guaranteed to be the case here. > + fallthrough; > + case -NFS4ERR_BAD_STATEID: > case -NFS4ERR_STALE_STATEID: > case -NFS4ERR_EXPIRED: > if (data->arg.new_lock_owner != 0) {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 6bb14f6cfbc0..bdfb4ac144d2 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7180,8 +7180,15 @@ static void nfs4_lock_done(struct rpc_task *task, void *calldata) } else if (!nfs4_update_lock_stateid(lsp, &data->res.stateid)) goto out_restart; break; - case -NFS4ERR_BAD_STATEID: case -NFS4ERR_OLD_STATEID: + if (data->arg.new_lock_owner != 0 && + nfs4_refresh_open_old_stateid(&data->arg.open_stateid, + lsp->ls_state)) + goto out_restart; + if (nfs4_refresh_lock_old_stateid(&data->arg.lock_stateid, lsp)) + goto out_restart; + fallthrough; + case -NFS4ERR_BAD_STATEID: case -NFS4ERR_STALE_STATEID: case -NFS4ERR_EXPIRED: if (data->arg.new_lock_owner != 0) {
Commmit f5ea16137a3f ("NFSv4: Retry LOCK on OLD_STATEID during delegation return") attempted to solve this problem by using nfs4's generic async error handling, but introduced a regression where v4.0 lock recovery would hang. The additional complexity introduced by overloading that error handling is not necessary for this case. This patch expects that commit to be reverted. The problem as originally explained in the above commit is: There's a small window where a LOCK sent during a delegation return can race with another OPEN on client, but the open stateid has not yet been updated. In this case, the client doesn't handle the OLD_STATEID error from the server and will lose this lock, emitting: "NFS: nfs4_handle_delegation_recall_error: unhandled error -10024". Fix this by using the old_stateid refresh helpers if the server replies with OLD_STATEID. Suggested-by: Trond Myklebust <trondmy@hammerspace.com> Signed-off-by: Benjamin Coddington <bcodding@redhat.com> --- fs/nfs/nfs4proc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)