1 files changed, 131 insertions, 0 deletions

diff --git a/fs/ocfs2/sysfile.c b/fs/ocfs2/sysfile.c
new file mode 100644
index 000000000000..600a8bc5b541
--- /dev/null
+++ b/fs/ocfs2/sysfile.c
@@ -0,0 +1,131 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * sysfile.c
+ *
+ * Initialize, read, write, etc. system files.
+ *
+ * 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/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+
+#include "ocfs2.h"
+
+#define MLOG_MASK_PREFIX ML_INODE
+#include <cluster/masklog.h>
+
+#include "alloc.h"
+#include "dir.h"
+#include "inode.h"
+#include "journal.h"
+#include "sysfile.h"
+
+#include "buffer_head_io.h"
+
+static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
+                                                   int type,
+                                                   u32 slot);
+
+static inline int is_global_system_inode(int type);
+static inline int is_in_system_inode_array(struct ocfs2_super *osb,
+                                           int type,
+                                           u32 slot);
+
+static inline int is_global_system_inode(int type)
+{
+        return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
+                type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
+}
+
+static inline int is_in_system_inode_array(struct ocfs2_super *osb,
+                                           int type,
+                                           u32 slot)
+{
+        return slot == osb->slot_num || is_global_system_inode(type);
+}
+
+struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
+                                          int type,
+                                          u32 slot)
+{
+        struct inode *inode = NULL;
+        struct inode **arr = NULL;
+
+        /* avoid the lookup if cached in local system file array */
+        if (is_in_system_inode_array(osb, type, slot))
+                arr = &(osb->system_inodes[type]);
+
+        if (arr && ((inode = *arr) != NULL)) {
+                /* get a ref in addition to the array ref */
+                inode = igrab(inode);
+                if (!inode)
+                        BUG();
+
+                return inode;
+        }
+
+        /* this gets one ref thru iget */
+        inode = _ocfs2_get_system_file_inode(osb, type, slot);
+
+        /* add one more if putting into array for first time */
+        if (arr && inode) {
+                *arr = igrab(inode);
+                if (!*arr)
+                        BUG();
+        }
+        return inode;
+}
+
+static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
+                                                   int type,
+                                                   u32 slot)
+{
+        char namebuf[40];
+        struct inode *inode = NULL;
+        u64 blkno;
+        struct buffer_head *dirent_bh = NULL;
+        struct ocfs2_dir_entry *de = NULL;
+        int status = 0;
+
+        ocfs2_sprintf_system_inode_name(namebuf,
+                                        sizeof(namebuf),
+                                        type, slot);
+
+        status = ocfs2_find_files_on_disk(namebuf, strlen(namebuf),
+                                          &blkno, osb->sys_root_inode,
+                                          &dirent_bh, &de);
+        if (status < 0) {
+                goto bail;
+        }
+
+        inode = ocfs2_iget(osb, blkno);
+        if (IS_ERR(inode)) {
+                mlog_errno(PTR_ERR(inode));
+                inode = NULL;
+                goto bail;
+        }
+bail:
+        if (dirent_bh)
+                brelse(dirent_bh);
+        return inode;
+}
+