ocfs2/net: Add debug interface to o2net

This patch exposes o2net information via debugfs. The information includes
the list of sockets (sock_containers) as well as the list of outstanding
messages (send_tracking). Useful for o2dlm debugging.

(This patch is derived from an earlier one written by Zach Brown that
exposed the same information via /proc.)

[Mark: checkpatch fixes]

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 441 insertions, 0 deletions

diff --git a/fs/ocfs2/cluster/netdebug.c b/fs/ocfs2/cluster/netdebug.c
new file mode 100644
index 000000000000..7bf3c0ea7bd9
--- /dev/null
+++ b/fs/ocfs2/cluster/netdebug.c
@@ -0,0 +1,441 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * netdebug.c
+ *
+ * debug functionality for o2net
+ *
+ * Copyright (C) 2005, 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ */
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+
+#include <linux/uaccess.h>
+
+#include "tcp.h"
+#include "nodemanager.h"
+#define MLOG_MASK_PREFIX ML_TCP
+#include "masklog.h"
+
+#include "tcp_internal.h"
+
+#define O2NET_DEBUG_DIR         "o2net"
+#define SC_DEBUG_NAME           "sock_containers"
+#define NST_DEBUG_NAME          "send_tracking"
+
+static struct dentry *o2net_dentry;
+static struct dentry *sc_dentry;
+static struct dentry *nst_dentry;
+
+static DEFINE_SPINLOCK(o2net_debug_lock);
+
+static LIST_HEAD(sock_containers);
+static LIST_HEAD(send_tracking);
+
+void o2net_debug_add_nst(struct o2net_send_tracking *nst)
+{
+        spin_lock(&o2net_debug_lock);
+        list_add(&nst->st_net_debug_item, &send_tracking);
+        spin_unlock(&o2net_debug_lock);
+}
+
+void o2net_debug_del_nst(struct o2net_send_tracking *nst)
+{
+        spin_lock(&o2net_debug_lock);
+        if (!list_empty(&nst->st_net_debug_item))
+                list_del_init(&nst->st_net_debug_item);
+        spin_unlock(&o2net_debug_lock);
+}
+
+static struct o2net_send_tracking
+                        *next_nst(struct o2net_send_tracking *nst_start)
+{
+        struct o2net_send_tracking *nst, *ret = NULL;
+
+        assert_spin_locked(&o2net_debug_lock);
+
+        list_for_each_entry(nst, &nst_start->st_net_debug_item,
+                            st_net_debug_item) {
+                /* discover the head of the list */
+                if (&nst->st_net_debug_item == &send_tracking)
+                        break;
+
+                /* use st_task to detect real nsts in the list */
+                if (nst->st_task != NULL) {
+                        ret = nst;
+                        break;
+                }
+        }
+
+        return ret;
+}
+
+static void *nst_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        struct o2net_send_tracking *nst, *dummy_nst = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        nst = next_nst(dummy_nst);
+        spin_unlock(&o2net_debug_lock);
+
+        return nst;
+}
+
+static void *nst_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct o2net_send_tracking *nst, *dummy_nst = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        nst = next_nst(dummy_nst);
+        list_del_init(&dummy_nst->st_net_debug_item);
+        if (nst)
+                list_add(&dummy_nst->st_net_debug_item,
+                         &nst->st_net_debug_item);
+        spin_unlock(&o2net_debug_lock);
+
+        return nst; /* unused, just needs to be null when done */
+}
+
+static int nst_seq_show(struct seq_file *seq, void *v)
+{
+        struct o2net_send_tracking *nst, *dummy_nst = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        nst = next_nst(dummy_nst);
+
+        if (nst != NULL) {
+                /* get_task_comm isn't exported.  oh well. */
+                seq_printf(seq, "%p:\n"
+                           "  pid:          %lu\n"
+                           "  tgid:         %lu\n"
+                           "  process name: %s\n"
+                           "  node:         %u\n"
+                           "  sc:           %p\n"
+                           "  message id:   %d\n"
+                           "  message type: %u\n"
+                           "  message key:  0x%08x\n"
+                           "  sock acquiry: %lu.%lu\n"
+                           "  send start:   %lu.%lu\n"
+                           "  wait start:   %lu.%lu\n",
+                           nst, (unsigned long)nst->st_task->pid,
+                           (unsigned long)nst->st_task->tgid,
+                           nst->st_task->comm, nst->st_node,
+                           nst->st_sc, nst->st_id, nst->st_msg_type,
+                           nst->st_msg_key,
+                           nst->st_sock_time.tv_sec, nst->st_sock_time.tv_usec,
+                           nst->st_send_time.tv_sec, nst->st_send_time.tv_usec,
+                           nst->st_status_time.tv_sec,
+                           nst->st_status_time.tv_usec);
+        }
+
+        spin_unlock(&o2net_debug_lock);
+
+        return 0;
+}
+
+static void nst_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations nst_seq_ops = {
+        .start = nst_seq_start,
+        .next = nst_seq_next,
+        .stop = nst_seq_stop,
+        .show = nst_seq_show,
+};
+
+static int nst_fop_open(struct inode *inode, struct file *file)
+{
+        struct o2net_send_tracking *dummy_nst;
+        struct seq_file *seq;
+        int ret;
+
+        dummy_nst = kmalloc(sizeof(struct o2net_send_tracking), GFP_KERNEL);
+        if (dummy_nst == NULL) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        dummy_nst->st_task = NULL;
+
+        ret = seq_open(file, &nst_seq_ops);
+        if (ret)
+                goto out;
+
+        seq = file->private_data;
+        seq->private = dummy_nst;
+        o2net_debug_add_nst(dummy_nst);
+
+        dummy_nst = NULL;
+
+out:
+        kfree(dummy_nst);
+        return ret;
+}
+
+static int nst_fop_release(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq = file->private_data;
+        struct o2net_send_tracking *dummy_nst = seq->private;
+
+        o2net_debug_del_nst(dummy_nst);
+        return seq_release_private(inode, file);
+}
+
+static struct file_operations nst_seq_fops = {
+        .open = nst_fop_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = nst_fop_release,
+};
+
+void o2net_debug_add_sc(struct o2net_sock_container *sc)
+{
+        spin_lock(&o2net_debug_lock);
+        list_add(&sc->sc_net_debug_item, &sock_containers);
+        spin_unlock(&o2net_debug_lock);
+}
+
+void o2net_debug_del_sc(struct o2net_sock_container *sc)
+{
+        spin_lock(&o2net_debug_lock);
+        list_del_init(&sc->sc_net_debug_item);
+        spin_unlock(&o2net_debug_lock);
+}
+
+static struct o2net_sock_container
+                        *next_sc(struct o2net_sock_container *sc_start)
+{
+        struct o2net_sock_container *sc, *ret = NULL;
+
+        assert_spin_locked(&o2net_debug_lock);
+
+        list_for_each_entry(sc, &sc_start->sc_net_debug_item,
+                            sc_net_debug_item) {
+                /* discover the head of the list miscast as a sc */
+                if (&sc->sc_net_debug_item == &sock_containers)
+                        break;
+
+                /* use sc_page to detect real scs in the list */
+                if (sc->sc_page != NULL) {
+                        ret = sc;
+                        break;
+                }
+        }
+
+        return ret;
+}
+
+static void *sc_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        struct o2net_sock_container *sc, *dummy_sc = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        sc = next_sc(dummy_sc);
+        spin_unlock(&o2net_debug_lock);
+
+        return sc;
+}
+
+static void *sc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct o2net_sock_container *sc, *dummy_sc = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        sc = next_sc(dummy_sc);
+        list_del_init(&dummy_sc->sc_net_debug_item);
+        if (sc)
+                list_add(&dummy_sc->sc_net_debug_item, &sc->sc_net_debug_item);
+        spin_unlock(&o2net_debug_lock);
+
+        return sc; /* unused, just needs to be null when done */
+}
+
+#define TV_SEC_USEC(TV) TV.tv_sec, TV.tv_usec
+
+static int sc_seq_show(struct seq_file *seq, void *v)
+{
+        struct o2net_sock_container *sc, *dummy_sc = seq->private;
+
+        spin_lock(&o2net_debug_lock);
+        sc = next_sc(dummy_sc);
+
+        if (sc != NULL) {
+                struct inet_sock *inet = NULL;
+
+                __be32 saddr = 0, daddr = 0;
+                __be16 sport = 0, dport = 0;
+
+                if (sc->sc_sock) {
+                        inet = inet_sk(sc->sc_sock->sk);
+                        /* the stack's structs aren't sparse endian clean */
+                        saddr = (__force __be32)inet->saddr;
+                        daddr = (__force __be32)inet->daddr;
+                        sport = (__force __be16)inet->sport;
+                        dport = (__force __be16)inet->dport;
+                }
+
+                /* XXX sigh, inet-> doesn't have sparse annotation so any
+                 * use of it here generates a warning with -Wbitwise */
+                seq_printf(seq, "%p:\n"
+                           "  krefs:           %d\n"
+                           "  sock:            %u.%u.%u.%u:%u -> "
+                                              "%u.%u.%u.%u:%u\n"
+                           "  remote node:     %s\n"
+                           "  page off:        %zu\n"
+                           "  handshake ok:    %u\n"
+                           "  timer:           %lu.%lu\n"
+                           "  data ready:      %lu.%lu\n"
+                           "  advance start:   %lu.%lu\n"
+                           "  advance stop:    %lu.%lu\n"
+                           "  func start:      %lu.%lu\n"
+                           "  func stop:       %lu.%lu\n"
+                           "  func key:        %u\n"
+                           "  func type:       %u\n",
+                           sc,
+                           atomic_read(&sc->sc_kref.refcount),
+                           NIPQUAD(saddr), inet ? ntohs(sport) : 0,
+                           NIPQUAD(daddr), inet ? ntohs(dport) : 0,
+                           sc->sc_node->nd_name,
+                           sc->sc_page_off,
+                           sc->sc_handshake_ok,
+                           TV_SEC_USEC(sc->sc_tv_timer),
+                           TV_SEC_USEC(sc->sc_tv_data_ready),
+                           TV_SEC_USEC(sc->sc_tv_advance_start),
+                           TV_SEC_USEC(sc->sc_tv_advance_stop),
+                           TV_SEC_USEC(sc->sc_tv_func_start),
+                           TV_SEC_USEC(sc->sc_tv_func_stop),
+                           sc->sc_msg_key,
+                           sc->sc_msg_type);
+        }
+
+
+        spin_unlock(&o2net_debug_lock);
+
+        return 0;
+}
+
+static void sc_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations sc_seq_ops = {
+        .start = sc_seq_start,
+        .next = sc_seq_next,
+        .stop = sc_seq_stop,
+        .show = sc_seq_show,
+};
+
+static int sc_fop_open(struct inode *inode, struct file *file)
+{
+        struct o2net_sock_container *dummy_sc;
+        struct seq_file *seq;
+        int ret;
+
+        dummy_sc = kmalloc(sizeof(struct o2net_sock_container), GFP_KERNEL);
+        if (dummy_sc == NULL) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        dummy_sc->sc_page = NULL;
+
+        ret = seq_open(file, &sc_seq_ops);
+        if (ret)
+                goto out;
+
+        seq = file->private_data;
+        seq->private = dummy_sc;
+        o2net_debug_add_sc(dummy_sc);
+
+        dummy_sc = NULL;
+
+out:
+        kfree(dummy_sc);
+        return ret;
+}
+
+static int sc_fop_release(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq = file->private_data;
+        struct o2net_sock_container *dummy_sc = seq->private;
+
+        o2net_debug_del_sc(dummy_sc);
+        return seq_release_private(inode, file);
+}
+
+static struct file_operations sc_seq_fops = {
+        .open = sc_fop_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = sc_fop_release,
+};
+
+int o2net_debugfs_init(void)
+{
+        o2net_dentry = debugfs_create_dir(O2NET_DEBUG_DIR, NULL);
+        if (!o2net_dentry) {
+                mlog_errno(-ENOMEM);
+                goto bail;
+        }
+
+        nst_dentry = debugfs_create_file(NST_DEBUG_NAME, S_IFREG|S_IRUSR,
+                                         o2net_dentry, NULL,
+                                         &nst_seq_fops);
+        if (!nst_dentry) {
+                mlog_errno(-ENOMEM);
+                goto bail;
+        }
+
+        sc_dentry = debugfs_create_file(SC_DEBUG_NAME, S_IFREG|S_IRUSR,
+                                        o2net_dentry, NULL,
+                                        &sc_seq_fops);
+        if (!sc_dentry) {
+                mlog_errno(-ENOMEM);
+                goto bail;
+        }
+
+        return 0;
+bail:
+        if (sc_dentry)
+                debugfs_remove(sc_dentry);
+        if (nst_dentry)
+                debugfs_remove(nst_dentry);
+        if (o2net_dentry)
+                debugfs_remove(o2net_dentry);
+        return -ENOMEM;
+}
+
+void o2net_debugfs_exit(void)
+{
+        if (sc_dentry)
+                debugfs_remove(sc_dentry);
+        if (nst_dentry)
+                debugfs_remove(nst_dentry);
+        if (o2net_dentry)
+                debugfs_remove(o2net_dentry);
+}
+
+#endif  /* CONFIG_DEBUG_FS */