[Drbd-dev] [PATCH 10/16] drbd: the /proc/drbd interface

[Philipp Reisner <philipp.reisner@linbit.com>]

The convenient point of information about the state of all configured drbd devices.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

---
diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
new file mode 100644
index 0000000..432a7dd
--- /dev/null
+++ b/drivers/block/drbd/drbd_proc.c
@@ -0,0 +1,266 @@
+/*
+   drbd_proc.c
+
+   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
+
+   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
+   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
+   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
+
+   drbd 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, or (at your option)
+   any later version.
+
+   drbd 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 drbd; see the file COPYING.  If not, write to
+   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ */
+
+#include <linux/autoconf.h>
+#include <linux/module.h>
+
+#include <asm/uaccess.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/drbd.h>
+#include "drbd_int.h"
+
+static int drbd_proc_open(struct inode *inode, struct file *file);
+
+
+struct proc_dir_entry *drbd_proc;
+struct file_operations drbd_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= drbd_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+
+/*lge
+ * progress bars shamelessly adapted from driver/md/md.c
+ * output looks like
+ *	[=====>..............] 33.5% (23456/123456)
+ *	finish: 2:20:20 speed: 6,345 (6,456) K/sec
+ */
+static void drbd_syncer_progress(struct drbd_conf *mdev, struct seq_file *seq)
+{
+	unsigned long db, dt, dbdt, rt, rs_left;
+	unsigned int res;
+	int i, x, y;
+
+	drbd_get_syncer_progress(mdev, &rs_left, &res);
+
+	x = res/50;
+	y = 20-x;
+	seq_printf(seq, "\t[");
+	for (i = 1; i < x; i++)
+		seq_printf(seq, "=");
+	seq_printf(seq, ">");
+	for (i = 0; i < y; i++)
+		seq_printf(seq, ".");
+	seq_printf(seq, "] ");
+
+	seq_printf(seq, "sync'ed:%3u.%u%% ", res / 10, res % 10);
+	/* if more than 1 GB display in MB */
+	if (mdev->rs_total > 0x100000L)
+		seq_printf(seq, "(%lu/%lu)M\n\t",
+			    (unsigned long) Bit2KB(rs_left >> 10),
+			    (unsigned long) Bit2KB(mdev->rs_total >> 10));
+	else
+		seq_printf(seq, "(%lu/%lu)K\n\t",
+			    (unsigned long) Bit2KB(rs_left),
+			    (unsigned long) Bit2KB(mdev->rs_total));
+
+	/* see drivers/md/md.c
+	 * We do not want to overflow, so the order of operands and
+	 * the * 100 / 100 trick are important. We do a +1 to be
+	 * safe against division by zero. We only estimate anyway.
+	 *
+	 * dt: time from mark until now
+	 * db: blocks written from mark until now
+	 * rt: remaining time
+	 */
+	dt = (jiffies - mdev->rs_mark_time) / HZ;
+
+	if (dt > 20) {
+		/* if we made no update to rs_mark_time for too long,
+		 * we are stalled. show that. */
+		seq_printf(seq, "stalled\n");
+		return;
+	}
+
+	if (!dt)
+		dt++;
+	db = mdev->rs_mark_left - rs_left;
+	rt = (dt * (rs_left / (db/100+1)))/100; /* seconds */
+
+	seq_printf(seq, "finish: %lu:%02lu:%02lu",
+		rt / 3600, (rt % 3600) / 60, rt % 60);
+
+	/* current speed average over (SYNC_MARKS * SYNC_MARK_STEP) jiffies */
+	dbdt = Bit2KB(db/dt);
+	if (dbdt > 1000)
+		seq_printf(seq, " speed: %ld,%03ld",
+			dbdt/1000, dbdt % 1000);
+	else
+		seq_printf(seq, " speed: %ld", dbdt);
+
+	/* mean speed since syncer started
+	 * we do account for PausedSync periods */
+	dt = (jiffies - mdev->rs_start - mdev->rs_paused) / HZ;
+	if (dt <= 0)
+		dt = 1;
+	db = mdev->rs_total - rs_left;
+	dbdt = Bit2KB(db/dt);
+	if (dbdt > 1000)
+		seq_printf(seq, " (%ld,%03ld)",
+			dbdt/1000, dbdt % 1000);
+	else
+		seq_printf(seq, " (%ld)", dbdt);
+
+	seq_printf(seq, " K/sec\n");
+}
+
+static void resync_dump_detail(struct seq_file *seq, struct lc_element *e)
+{
+	struct bm_extent *bme = lc_entry(e, struct bm_extent, lce);
+
+	seq_printf(seq, "%5d %s %s\n", bme->rs_left,
+		   bme->flags & BME_NO_WRITES ? "NO_WRITES" : "---------",
+		   bme->flags & BME_LOCKED ? "LOCKED" : "------"
+		   );
+}
+
+static int drbd_seq_show(struct seq_file *seq, void *v)
+{
+	int i, hole = 0;
+	const char *sn;
+	struct drbd_conf *mdev;
+
+	static char write_ordering_chars[] = {
+		[WO_none] = 'n',
+		[WO_drain_io] = 'd',
+		[WO_bdev_flush] = 'f',
+		[WO_bio_barrier] = 'b',
+	};
+
+	seq_printf(seq, "version: " REL_VERSION " (api:%d/proto:%d-%d)\n%s\n",
+		   API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX, drbd_buildtag());
+
+	/*
+	  cs .. connection state
+	  ro .. node role (local/remote)
+	  ds .. disk state (local/remote)
+	     protocol
+	     various flags
+	  ns .. network send
+	  nr .. network receive
+	  dw .. disk write
+	  dr .. disk read
+	  al .. activity log write count
+	  bm .. bitmap update write count
+	  pe .. pending (waiting for ack or data reply)
+	  ua .. unack'd (still need to send ack or data reply)
+	  ap .. application requests accepted, but not yet completed
+	  ep .. number of epochs currently "on the fly", P_BARRIER_ACK pending
+	  wo .. write ordering mode currently in use
+	 oos .. known out-of-sync kB
+	*/
+
+	for (i = 0; i < minor_count; i++) {
+		mdev = minor_to_mdev(i);
+		if (!mdev) {
+			hole = 1;
+			continue;
+		}
+		if (hole) {
+			hole = 0;
+			seq_printf(seq, "\n");
+		}
+
+		sn = conns_to_name(mdev->state.conn);
+
+		if (mdev->state.conn == C_STANDALONE &&
+		    mdev->state.disk == D_DISKLESS &&
+		    mdev->state.role == R_SECONDARY) {
+			seq_printf(seq, "%2d: cs:Unconfigured\n", i);
+		} else {
+			seq_printf(seq,
+			   "%2d: cs:%s ro:%s/%s ds:%s/%s %c %c%c%c%c%c\n"
+			   "    ns:%u nr:%u dw:%u dr:%u al:%u bm:%u "
+			   "lo:%d pe:%d ua:%d ap:%d ep:%d wo:%c",
+			   i, sn,
+			   roles_to_name(mdev->state.role),
+			   roles_to_name(mdev->state.peer),
+			   disks_to_name(mdev->state.disk),
+			   disks_to_name(mdev->state.pdsk),
+			   (mdev->net_conf == NULL ? ' ' :
+			    (mdev->net_conf->wire_protocol - DRBD_PROT_A+'A')),
+			   mdev->state.susp ? 's' : 'r',
+			   mdev->state.aftr_isp ? 'a' : '-',
+			   mdev->state.peer_isp ? 'p' : '-',
+			   mdev->state.user_isp ? 'u' : '-',
+			   mdev->congestion_reason ?: '-',
+			   mdev->send_cnt/2,
+			   mdev->recv_cnt/2,
+			   mdev->writ_cnt/2,
+			   mdev->read_cnt/2,
+			   mdev->al_writ_cnt,
+			   mdev->bm_writ_cnt,
+			   atomic_read(&mdev->local_cnt),
+			   atomic_read(&mdev->ap_pending_cnt) +
+			   atomic_read(&mdev->rs_pending_cnt),
+			   atomic_read(&mdev->unacked_cnt),
+			   atomic_read(&mdev->ap_bio_cnt),
+			   mdev->epochs,
+			   write_ordering_chars[mdev->write_ordering]
+			);
+			seq_printf(seq, " oos:%lu\n",
+				   Bit2KB(drbd_bm_total_weight(mdev)));
+		}
+		if (mdev->state.conn == C_SYNC_SOURCE ||
+		    mdev->state.conn == C_SYNC_TARGET)
+			drbd_syncer_progress(mdev, seq);
+
+		if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
+			seq_printf(seq, "\t%3d%%      %lu/%lu\n",
+				   (int)((mdev->rs_total-mdev->ov_left) /
+					 (mdev->rs_total/100+1)),
+				   mdev->rs_total - mdev->ov_left,
+				   mdev->rs_total);
+
+		if (proc_details >= 1 && get_ldev_if_state(mdev, D_FAILED)) {
+			lc_seq_printf_stats(seq, mdev->resync);
+			lc_seq_printf_stats(seq, mdev->act_log);
+			put_ldev(mdev);
+		}
+
+		if (proc_details >= 2) {
+			if (mdev->resync) {
+				lc_seq_dump_details(seq, mdev->resync, "rs_left",
+					resync_dump_detail);
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int drbd_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, drbd_seq_show, PDE(inode)->data);
+}
+
+/* PROC FS stuff end */