nfsd_setattr() can kick off a CB_RECALL (via
notify_change() -> break_lease()) if a delegation is present. Before
returning NFS4ERR_DELAY, give the client holding that delegation a
chance to return it and then retry the nfsd_setattr() again, once.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs4proc.c | 18 +++++++++++++++---
fs/nfsd/nfs4state.c | 17 +++++++++++++++++
fs/nfsd/nfsd.h | 1 +
fs/nfsd/trace.h | 19 +++++++++++++++++++
fs/nfsd/xdr4.h | 2 ++
5 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 42bfe0d769ec..62a267bb2ce5 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1142,7 +1142,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
{
struct nfsd4_setattr *setattr = &u->setattr;
__be32 status = nfs_ok;
- int err;
+ int err, retries;
if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
status = nfs4_preprocess_stateid_op(rqstp, cstate,
@@ -1173,8 +1173,20 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
&setattr->sa_label);
if (status)
goto out;
- status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr,
- 0, (time64_t)0);
+
+ retries = 1;
+ do {
+ status = nfsd_setattr(rqstp, &cstate->current_fh,
+ &setattr->sa_iattr, 0, (time64_t)0);
+ if (status != nfserr_jukebox)
+ break;
+ if (!retries--)
+ break;
+
+ fh_clear_pre_post_attrs(&cstate->current_fh);
+ nfsd4_wait_for_delegreturn(rqstp, &cstate->current_fh);
+ } while (1);
+
out:
fh_drop_write(&cstate->current_fh);
return status;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0cf5a4bb36df..e3ac89d4a859 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4689,6 +4689,23 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
return ret;
}
+/**
+ * nfsd4_wait_for_delegreturn - wait for delegations to be returned
+ * @rqstp: the RPC transaction being executed
+ * @fhp: filehandle of file being waited for
+ *
+ * A better approach would wait for the DELEGRETURN operation, and
+ * retry just as soon as it was done.
+ *
+ * The timeout prevents deadlock if all nfsd threads happen to be
+ * tied up waiting for returning delegations.
+ */
+void nfsd4_wait_for_delegreturn(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+ trace_nfsd_delegreturn_wait(rqstp, fhp);
+ msleep(NFSD_DELEGRETURN_TIMEOUT);
+}
+
static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)
{
struct nfs4_delegation *dp = cb_to_delegation(cb);
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 9a8b09afc173..0b800a154828 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -341,6 +341,7 @@ void nfsd_lockd_shutdown(void);
#define NFSD_LAUNDROMAT_MINTIMEOUT 1 /* seconds */
#define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */
+#define NFSD_DELEGRETURN_TIMEOUT (30) /* milliseconds */
/*
* The following attributes are currently not supported by the NFSv4 server:
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 8c3d5f88072f..dd2654cac132 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -443,6 +443,25 @@ DEFINE_NFSD_COPY_ERR_EVENT(clone_file_range_err);
#include "filecache.h"
#include "vfs.h"
+TRACE_EVENT(nfsd_delegreturn_wait,
+ TP_PROTO(
+ const struct svc_rqst *rqstp,
+ const struct svc_fh *fhp
+ ),
+ TP_ARGS(rqstp, fhp),
+ TP_STRUCT__entry(
+ __field(u32, xid)
+ __field(u32, fh_hash)
+ ),
+ TP_fast_assign(
+ __entry->xid = be32_to_cpu(rqstp->rq_xid);
+ __entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+ ),
+ TP_printk("xid=0x%08x fh_hash=0x%08x",
+ __entry->xid, __entry->fh_hash
+ )
+);
+
DECLARE_EVENT_CLASS(nfsd_stateid_class,
TP_PROTO(stateid_t *stp),
TP_ARGS(stp),
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 7b744011f2d3..5b9213076e95 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -788,6 +788,8 @@ extern __be32 nfsd4_destroy_clientid(struct svc_rqst *, struct nfsd4_compound_st
union nfsd4_op_u *u);
__be32 nfsd4_reclaim_complete(struct svc_rqst *, struct nfsd4_compound_state *,
union nfsd4_op_u *u);
+extern void nfsd4_wait_for_delegreturn(struct svc_rqst *rqstp,
+ struct svc_fh *fhp);
extern __be32 nfsd4_process_open1(struct nfsd4_compound_state *,
struct nfsd4_open *open, struct nfsd_net *nn);
extern __be32 nfsd4_process_open2(struct svc_rqst *rqstp,
