From a639f12a8385eed5540d9aa6589673ff1b3e5039 Mon Sep 17 00:00:00 2001
From: braam <braam>
Date: Sun, 24 Mar 2002 23:36:24 +0000
Subject: [PATCH] *** empty log message ***

---
 lustre/ldlm/ldlm_extent.c |  93 +++++++++++++++++++++++++++++++
 lustre/lib/pack_generic.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 229 insertions(+)
 create mode 100644 lustre/ldlm/ldlm_extent.c
 create mode 100644 lustre/lib/pack_generic.c

diff --git a/lustre/ldlm/ldlm_extent.c b/lustre/ldlm/ldlm_extent.c
new file mode 100644
index 0000000..3e1724d
--- /dev/null
+++ b/lustre/ldlm/ldlm_extent.c
@@ -0,0 +1,93 @@
+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ * Copyright (C) 2002 Cluster File Systems, Inc.
+ *
+ * This code is issued under the GNU General Public License.
+ * See the file COPYING in this distribution
+ *
+ * by Cluster File Systems, Inc.
+ * authors, Peter Braam <braam@clusterfs.com> & 
+ * Phil Schwan <phil@clusterfs.com>
+ */
+
+#define EXPORT_SYMTAB
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/unistd.h>
+
+#define DEBUG_SUBSYSTEM S_LDLM
+
+#include <linux/obd_support.h>
+#include <linux/obd_class.h>
+#include <linux/lustre_dlm.h>
+
+/* This function will be called to judge if the granted queue of another child
+ * (read: another extent) is conflicting and needs its granted queue walked to
+ * issue callbacks.
+ *
+ * This helps to find conflicts between read and write locks on overlapping
+ * extents. */
+int ldlm_extent_compat(struct ldlm_resource *child, struct ldlm_resource *new)
+{
+        struct ldlm_extent *child_ex, *new_ex;
+
+	child_ex = ldlm_res2extent(child);
+	new_ex = ldlm_res2extent(new);
+
+	if (MAX(child_ex->start, new_ex->start) >
+	    MIN(child_ex->end, new_ex->end))
+		return 0;
+
+        return 1;
+}
+
+/* The purpose of this function is to return:
+ * - the maximum extent
+ * - containing the requested extent
+ * - and not overlapping existing extents outside the requested one
+ *
+ * An alternative policy is to not shrink the new extent when conflicts exist.
+ *
+ * To reconstruct our formulas, take a deep breath. */
+int ldlm_extent_policy(struct ldlm_resource *parent,
+		       __u64 *res_id_in, __u64 *res_id_out,
+		       ldlm_mode_t mode, void *data)
+{
+        struct ldlm_extent *new_ex, *req_ex;
+        struct list_head *tmp;
+
+        req_ex = (struct ldlm_extent *)res_id_in;
+
+        new_ex = (struct ldlm_extent *)res_id_out;
+        new_ex->start = 0;
+        new_ex->end = ~0;
+
+        list_for_each(tmp, &parent->lr_children) {
+                struct ldlm_resource *res;
+                struct ldlm_extent *res_ex;
+                res = list_entry(tmp, struct ldlm_resource, lr_childof);
+
+                res_ex = ldlm_res2extent(res);
+
+                if (res_ex->end < req_ex->start)
+                        new_ex->start = MIN(res_ex->end, new_ex->start);
+                else {
+                        if (res_ex->start < req_ex->start)
+                                /* Policy: minimize conflict overlap */
+                                new_ex->start = req_ex->start;
+                }
+                if (res_ex->start > req_ex->end)
+                        new_ex->end = MAX(res_ex->start, new_ex->end);
+                else {
+                        if (res_ex->end > req_ex->end)
+                                /* Policy: minimize conflict overlap */
+                                new_ex->end = req_ex->end;
+                }
+        }
+
+	return 0;
+}
+
diff --git a/lustre/lib/pack_generic.c b/lustre/lib/pack_generic.c
new file mode 100644
index 0000000..06a4306
--- /dev/null
+++ b/lustre/lib/pack_generic.c
@@ -0,0 +1,136 @@
+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ *  Copyright (C) 2001 Cluster File Systems, Inc. <braam@clusterfs.com>
+ *
+ *   This file is part of Lustre, http://www.lustre.org.
+ *
+ *   Lustre is free software; you can redistribute it and/or
+ *   modify it under the terms of version 2 of the GNU General Public
+ *   License as published by the Free Software Foundation.
+ *
+ *   Lustre 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 Lustre; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * (Un)packing of OST requests
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched.h>
+#include <linux/lp.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <asm/poll.h>
+#include <asm/uaccess.h>
+
+#define DEBUG_SUBSYSTEM S_CLASS
+
+#include <linux/obd_class.h>
+#include <linux/lustre_net.h>
+
+int lustre_pack_msg(int count, int *lens, char **bufs, int *len, char **buf)
+{
+        char *ptr;
+        struct lustre_msg *m;
+        int size = 0;
+        int i;
+
+        for (i=0 ; i<count; i++) { 
+                size += size_round(lens[i]);
+        }
+        *len = sizeof(*m) + size; 
+
+        OBD_ALLOC(*buf, *len);
+        if (!*buf) {
+                EXIT;
+                return -ENOMEM;
+        }
+
+        memset(*buf, 0, *len); 
+        m = (struct lustre_msg *)(*buf);
+        m->type = PTL_RPC_REQUEST;
+
+        m->bufcount = HTON__u32(count);
+        for (i=0 ; i<count; i++) { 
+                m->buflens[i] = HTON__u32(lens[i]);
+        }
+        
+        ptr = *buf + sizeof(*m) + sizeof(__u32) * count;
+        for (i=0 ; i<count ; i++) { 
+                LOGL(buf[i], lens[i], ptr); 
+        }
+
+        return 0;
+}
+
+int lustre_unpack_msg(char *buf, int len)
+{
+        struct lustre_msg *m = (struct lustre_msg *)buf;
+        int required_len, i;
+
+        required_len = sizeof(*m);
+        if (len < required_len) { 
+                RETURN(-EINVAL);
+        }
+
+        m->bufcount = NTOH__u32(m->bufcount); 
+
+        required_len += m->bufcount * sizeof(__u32); 
+        if (len < required_len) { 
+                RETURN(-EINVAL);
+        }
+
+        for (i=0; i<m->bufcount; i++) { 
+                m->buflens[i] = NTOH__u32(m->buflens[i]);
+                required_len += size_round(m->buflens[i]);
+        }
+
+        if (len < required_len) { 
+                RETURN(-EINVAL);
+        }
+
+        EXIT;
+        return 0;
+}
+
+void *lustre_msg_buf(int n, struct lustre_msg *m)
+{
+        int i;
+        int offset;
+
+        if (n >= m->bufcount || n < 0) { 
+                CERROR("referencing bad sub buffer!\n"); 
+                return NULL;
+        }
+
+        if (m->buflens[n] == 0)
+                return NULL;
+
+        offset = sizeof(*m) + m->bufcount * sizeof(__u32);
+
+        for (i=0; i < n;  i++ ) 
+                offset += size_round(m->buflens[i]); 
+
+        return (char *)m + offset;
+}
-- 
1.8.3.1