1 files changed, 303 insertions, 0 deletions
diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
new file mode 100644
index 00000000000..871627961d6
--- /dev/null
+++ b/fs/ocfs2/slot_map.c
@@ -0,0 +1,303 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * slot_map.c
+ *
+ *
+ *
+ * Copyright (C) 2002, 2004 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.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/smp_lock.h>
+
+#define MLOG_MASK_PREFIX ML_SUPER
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "heartbeat.h"
+#include "inode.h"
+#include "slot_map.h"
+#include "super.h"
+#include "sysfile.h"
+
+#include "buffer_head_io.h"
+
+static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
+				    s16 global);
+static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
+			      s16 slot_num,
+			      s16 node_num);
+
+/* Use the slot information we've collected to create a map of mounted
+ * nodes. Should be holding an EX on super block. assumes slot info is
+ * up to date. Note that we call this *after* we find a slot, so our
+ * own node should be set in the map too... */
+void ocfs2_populate_mounted_map(struct ocfs2_super *osb)
+{
+	int i;
+	struct ocfs2_slot_info *si = osb->slot_info;
+
+	spin_lock(&si->si_lock);
+
+	for (i = 0; i < si->si_size; i++)
+		if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT)
+			ocfs2_node_map_set_bit(osb, &osb->mounted_map,
+					      si->si_global_node_nums[i]);
+
+	spin_unlock(&si->si_lock);
+}
+
+/* post the slot information on disk into our slot_info struct. */
+void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
+{
+	int i;
+	__le16 *disk_info;
+
+	/* we don't read the slot block here as ocfs2_super_lock
+	 * should've made sure we have the most recent copy. */
+	spin_lock(&si->si_lock);
+	disk_info = (__le16 *) si->si_bh->b_data;
+
+	for (i = 0; i < si->si_size; i++)
+		si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]);
+
+	spin_unlock(&si->si_lock);
+}
+
+/* post the our slot info stuff into it's destination bh and write it
+ * out. */
+int ocfs2_update_disk_slots(struct ocfs2_super *osb,
+			    struct ocfs2_slot_info *si)
+{
+	int status, i;
+	__le16 *disk_info = (__le16 *) si->si_bh->b_data;
+
+	spin_lock(&si->si_lock);
+	for (i = 0; i < si->si_size; i++)
+		disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]);
+	spin_unlock(&si->si_lock);
+
+	status = ocfs2_write_block(osb, si->si_bh, si->si_inode);
+	if (status < 0)
+		mlog_errno(status);
+
+	return status;
+}
+
+/* try to find global node in the slot info. Returns
+ * OCFS2_INVALID_SLOT if nothing is found. */
+static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
+				    s16 global)
+{
+	int i;
+	s16 ret = OCFS2_INVALID_SLOT;
+
+	for(i = 0; i < si->si_num_slots; i++) {
+		if (global == si->si_global_node_nums[i]) {
+			ret = (s16) i;
+			break;
+		}
+	}
+	return ret;
+}
+
+static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si)
+{
+	int i;
+	s16 ret = OCFS2_INVALID_SLOT;
+
+	for(i = 0; i < si->si_num_slots; i++) {
+		if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
+			ret = (s16) i;
+			break;
+		}
+	}
+	return ret;
+}
+
+s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
+			   s16 global)
+{
+	s16 ret;
+
+	spin_lock(&si->si_lock);
+	ret = __ocfs2_node_num_to_slot(si, global);
+	spin_unlock(&si->si_lock);
+	return ret;
+}
+
+static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
+			      s16 slot_num,
+			      s16 node_num)
+{
+	BUG_ON(slot_num == OCFS2_INVALID_SLOT);
+	BUG_ON(slot_num >= si->si_num_slots);
+	BUG_ON((node_num != O2NM_INVALID_NODE_NUM) &&
+	       (node_num >= O2NM_MAX_NODES));
+
+	si->si_global_node_nums[slot_num] = node_num;
+}
+
+void ocfs2_clear_slot(struct ocfs2_slot_info *si,
+		      s16 slot_num)
+{
+	spin_lock(&si->si_lock);
+	__ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT);
+	spin_unlock(&si->si_lock);
+}
+
+int ocfs2_init_slot_info(struct ocfs2_super *osb)
+{
+	int status, i;
+	u64 blkno;
+	struct inode *inode = NULL;
+	struct buffer_head *bh = NULL;
+	struct ocfs2_slot_info *si;
+
+	si = kcalloc(1, sizeof(struct ocfs2_slot_info), GFP_KERNEL);
+	if (!si) {
+		status = -ENOMEM;
+		mlog_errno(status);
+		goto bail;
+	}
+
+	spin_lock_init(&si->si_lock);
+	si->si_num_slots = osb->max_slots;
+	si->si_size = OCFS2_MAX_SLOTS;
+
+	for(i = 0; i < si->si_num_slots; i++)
+		si->si_global_node_nums[i] = OCFS2_INVALID_SLOT;
+
+	inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
+					    OCFS2_INVALID_SLOT);
+	if (!inode) {
+		status = -EINVAL;
+		mlog_errno(status);
+		goto bail;
+	}
+
+	status = ocfs2_extent_map_get_blocks(inode, 0ULL, 1, &blkno, NULL);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+	status = ocfs2_read_block(osb, blkno, &bh, 0, inode);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+	si->si_inode = inode;
+	si->si_bh = bh;
+	osb->slot_info = si;
+bail:
+	if (status < 0 && si)
+		ocfs2_free_slot_info(si);
+
+	return status;
+}
+
+void ocfs2_free_slot_info(struct ocfs2_slot_info *si)
+{
+	if (si->si_inode)
+		iput(si->si_inode);
+	if (si->si_bh)
+		brelse(si->si_bh);
+	kfree(si);
+}
+
+int ocfs2_find_slot(struct ocfs2_super *osb)
+{
+	int status;
+	s16 slot;
+	struct ocfs2_slot_info *si;
+
+	mlog_entry_void();
+
+	si = osb->slot_info;
+
+	ocfs2_update_slot_info(si);
+
+	spin_lock(&si->si_lock);
+	/* search for ourselves first and take the slot if it already
+	 * exists. Perhaps we need to mark this in a variable for our
+	 * own journal recovery? Possibly not, though we certainly
+	 * need to warn to the user */
+	slot = __ocfs2_node_num_to_slot(si, osb->node_num);
+	if (slot == OCFS2_INVALID_SLOT) {
+		/* if no slot yet, then just take 1st available
+		 * one. */
+		slot = __ocfs2_find_empty_slot(si);
+		if (slot == OCFS2_INVALID_SLOT) {
+			spin_unlock(&si->si_lock);
+			mlog(ML_ERROR, "no free slots available!\n");
+			status = -EINVAL;
+			goto bail;
+		}
+	} else
+		mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
+		     slot);
+
+	__ocfs2_fill_slot(si, slot, osb->node_num);
+	osb->slot_num = slot;
+	spin_unlock(&si->si_lock);
+
+	mlog(ML_NOTICE, "taking node slot %d\n", osb->slot_num);
+
+	status = ocfs2_update_disk_slots(osb, si);
+	if (status < 0)
+		mlog_errno(status);
+
+bail:
+	mlog_exit(status);
+	return status;
+}
+
+void ocfs2_put_slot(struct ocfs2_super *osb)
+{
+	int status;
+	struct ocfs2_slot_info *si = osb->slot_info;
+
+	if (!si)
+		return;
+
+	ocfs2_update_slot_info(si);
+
+	spin_lock(&si->si_lock);
+	__ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT);
+	osb->slot_num = OCFS2_INVALID_SLOT;
+	spin_unlock(&si->si_lock);
+
+	status = ocfs2_update_disk_slots(osb, si);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+bail:
+	osb->slot_info = NULL;
+	ocfs2_free_slot_info(si);
+}
+