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From:   Lorenzo Bianconi <lorenzo@kernel.org>
To:     linux-nfs@vger.kernel.org
Cc:     lorenzo.bianconi@redhat.com, chuck.lever@oracle.com,
        jlayton@kernel.org
Subject: [RFC] NFSD: add rpc_status entry in nfsd debug filesystem
Date:   Thu, 29 Jun 2023 12:17:33 +0200
Message-ID: <bac972c22c5acfa43969bb1bf164341b16ea045c.1688032742.git.lorenzo@kernel.org>
MIME-Version: 1.0
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Introduce rpc_status entry in nfsd debug filesystem in order to dump
pending RPC requests debugging information.

Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=366
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 fs/nfsd/nfs4proc.c |  4 +--
 fs/nfsd/nfsctl.c   | 18 ++++++++++++++
 fs/nfsd/nfsd.h     |  2 ++
 fs/nfsd/nfssvc.c   | 61 ++++++++++++++++++++++++++++++++++++++++++++++
 net/sunrpc/svc.c   |  2 +-
 5 files changed, 83 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 5ae670807449..a4dd1ef104c3 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2452,8 +2452,6 @@ static inline void nfsd4_increment_op_stats(u32 opnum)
 
 static const struct nfsd4_operation nfsd4_ops[];
 
-static const char *nfsd4_op_name(unsigned opnum);
-
 /*
  * Enforce NFSv4.1 COMPOUND ordering rules:
  *
@@ -3583,7 +3581,7 @@ void warn_on_nonidempotent_op(struct nfsd4_op *op)
 	}
 }
 
-static const char *nfsd4_op_name(unsigned opnum)
+const char *nfsd4_op_name(unsigned opnum)
 {
 	if (opnum < ARRAY_SIZE(nfsd4_ops))
 		return nfsd4_ops[opnum].op_name;
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 1489e0b703b4..9d0b0a53510b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -57,6 +57,8 @@ enum {
 	NFSD_RecoveryDir,
 	NFSD_V4EndGrace,
 #endif
+	NFSD_Rpc_Status,
+
 	NFSD_MaxReserved
 };
 
@@ -195,6 +197,21 @@ static inline struct net *netns(struct file *file)
 	return file_inode(file)->i_sb->s_fs_info;
 }
 
+static int nfsd_rpc_status_show(struct seq_file *m, void *v)
+{
+	struct nfsd_net *nn = net_generic(file_inode(m->file)->i_sb->s_fs_info,
+					  nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	if (nn->nfsd_serv)
+		nsfd_rpc_status(m, nn->nfsd_serv);
+	mutex_unlock(&nfsd_mutex);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(nfsd_rpc_status);
+
 /*
  * write_unlock_ip - Release all locks used by a client
  *
@@ -1400,6 +1417,7 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
 		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
 #endif
+		[NFSD_Rpc_Status] = {"rpc_status", &nfsd_rpc_status_fops, S_IRUGO},
 		/* last one */ {""}
 	};
 
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index d88498f8b275..a149157ec243 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -87,6 +87,7 @@ bool		nfssvc_encode_voidres(struct svc_rqst *rqstp,
  */
 int		nfsd_svc(int nrservs, struct net *net, const struct cred *cred);
 int		nfsd_dispatch(struct svc_rqst *rqstp);
+void		nsfd_rpc_status(struct seq_file *m, struct svc_serv *serv);
 
 int		nfsd_nrthreads(struct net *);
 int		nfsd_nrpools(struct net *);
@@ -506,6 +507,7 @@ extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn);
 
 extern void nfsd4_init_leases_net(struct nfsd_net *nn);
 
+const char *nfsd4_op_name(unsigned opnum);
 #else /* CONFIG_NFSD_V4 */
 static inline int nfsd4_is_junction(struct dentry *dentry)
 {
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 9c7b1ef5be40..7a881f9a3a13 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -1142,3 +1142,64 @@ int nfsd_pool_stats_release(struct inode *inode, struct file *file)
 	mutex_unlock(&nfsd_mutex);
 	return ret;
 }
+
+void nsfd_rpc_status(struct seq_file *m, struct svc_serv *serv)
+{
+	int i;
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	rcu_read_lock();
+
+	for (i = 0; i < serv->sv_nrpools; i++) {
+		struct svc_rqst *rqstp;
+
+		seq_puts(m, "XID        | FLAGS      | PROG       |");
+		seq_puts(m, " VERS       | PROC\t|");
+		seq_puts(m, " REMOTE - LOCAL IP ADDR");
+		seq_puts(m, "\t\t\t\t\t\t\t\t   | NFS4 COMPOUND OPS\n");
+		list_for_each_entry_rcu(rqstp,
+					&serv->sv_pools[i].sp_all_threads,
+					rq_all) {
+			if (!test_bit(RQ_BUSY, &rqstp->rq_flags))
+				continue;
+
+			seq_printf(m,
+				   "0x%08x | 0x%08lx | 0x%08x | NFSv%d      | %s\t|",
+				   be32_to_cpu(rqstp->rq_xid), rqstp->rq_flags,
+				   rqstp->rq_prog, rqstp->rq_vers,
+				   svc_proc_name(rqstp));
+
+			if (rqstp->rq_addr.ss_family == AF_INET) {
+				seq_printf(m, " %pI4 - %pI4\t\t\t\t\t\t\t   |",
+					   &((struct sockaddr_in *)&rqstp->rq_addr)->sin_addr,
+					   &((struct sockaddr_in *)&rqstp->rq_daddr)->sin_addr);
+			} else if (rqstp->rq_addr.ss_family == AF_INET6) {
+				seq_printf(m, " %pI6 - %pI6 |",
+					   &((struct sockaddr_in6 *)&rqstp->rq_addr)->sin6_addr,
+					   &((struct sockaddr_in6 *)&rqstp->rq_daddr)->sin6_addr);
+			} else {
+				seq_printf(m, " Unknown address family: %hu\n",
+					   rqstp->rq_addr.ss_family);
+				continue;
+			}
+#ifdef CONFIG_NFSD_V4
+			if (rqstp->rq_vers == NFS4_VERSION &&
+			    rqstp->rq_proc == NFSPROC4_COMPOUND) {
+				/* NFSv4 compund */
+				struct nfsd4_compoundargs *args = rqstp->rq_argp;
+				struct nfsd4_compoundres *resp = rqstp->rq_resp;
+
+				while (resp->opcnt < args->opcnt) {
+					struct nfsd4_op *op = &args->ops[resp->opcnt++];
+
+					seq_printf(m, " %s", nfsd4_op_name(op->opnum));
+				}
+			}
+#endif /* CONFIG_NFSD_V4 */
+			seq_puts(m, "\n");
+		}
+	}
+
+	rcu_read_unlock();
+}
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index e6d4cec61e47..f99cad92e9f4 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1625,7 +1625,7 @@ const char *svc_proc_name(const struct svc_rqst *rqstp)
 		return rqstp->rq_procinfo->pc_name;
 	return "unknown";
 }
-
+EXPORT_SYMBOL_GPL(svc_proc_name);
 
 /**
  * svc_encode_result_payload - mark a range of bytes as a result payload
-- 
2.41.0