1 files changed, 248 insertions, 0 deletions

diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
new file mode 100644
index 000000000000..5810160d92a8
--- /dev/null
+++ b/fs/ocfs2/export.c
@@ -0,0 +1,248 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * export.c
+ *
+ * Functions to facilitate NFS exporting
+ *
+ * Copyright (C) 2002, 2005 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>
+
+#define MLOG_MASK_PREFIX ML_EXPORT
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "dir.h"
+#include "dlmglue.h"
+#include "export.h"
+#include "inode.h"
+
+#include "buffer_head_io.h"
+
+struct ocfs2_inode_handle
+{
+        u64 ih_blkno;
+        u32 ih_generation;
+};
+
+static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp)
+{
+        struct ocfs2_inode_handle *handle = vobjp;
+        struct inode *inode;
+        struct dentry *result;
+
+        mlog_entry("(0x%p, 0x%p)\n", sb, handle);
+
+        if (handle->ih_blkno == 0) {
+                mlog_errno(-ESTALE);
+                return ERR_PTR(-ESTALE);
+        }
+
+        inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno);
+
+        if (IS_ERR(inode)) {
+                mlog_errno(PTR_ERR(inode));
+                return (void *)inode;
+        }
+
+        if (handle->ih_generation != inode->i_generation) {
+                iput(inode);
+                mlog_errno(-ESTALE);
+                return ERR_PTR(-ESTALE);
+        }
+
+        result = d_alloc_anon(inode);
+
+        if (!result) {
+                iput(inode);
+                mlog_errno(-ENOMEM);
+                return ERR_PTR(-ENOMEM);
+        }
+
+        mlog_exit_ptr(result);
+        return result;
+}
+
+static struct dentry *ocfs2_get_parent(struct dentry *child)
+{
+        int status;
+        u64 blkno;
+        struct dentry *parent;
+        struct inode *inode;
+        struct inode *dir = child->d_inode;
+        struct buffer_head *dirent_bh = NULL;
+        struct ocfs2_dir_entry *dirent;
+
+        mlog_entry("(0x%p, '%.*s')\n", child,
+                   child->d_name.len, child->d_name.name);
+
+        mlog(0, "find parent of directory %"MLFu64"\n",
+             OCFS2_I(dir)->ip_blkno);
+
+        status = ocfs2_meta_lock(dir, NULL, NULL, 0);
+        if (status < 0) {
+                if (status != -ENOENT)
+                        mlog_errno(status);
+                parent = ERR_PTR(status);
+                goto bail;
+        }
+
+        status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh,
+                                          &dirent);
+        if (status < 0) {
+                parent = ERR_PTR(-ENOENT);
+                goto bail_unlock;
+        }
+
+        inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno);
+        if (IS_ERR(inode)) {
+                mlog(ML_ERROR, "Unable to create inode %"MLFu64"\n", blkno);
+                parent = ERR_PTR(-EACCES);
+                goto bail_unlock;
+        }
+
+        parent = d_alloc_anon(inode);
+        if (!parent) {
+                iput(inode);
+                parent = ERR_PTR(-ENOMEM);
+        }
+
+bail_unlock:
+        ocfs2_meta_unlock(dir, 0);
+
+        if (dirent_bh)
+                brelse(dirent_bh);
+
+bail:
+        mlog_exit_ptr(parent);
+
+        return parent;
+}
+
+static int ocfs2_encode_fh(struct dentry *dentry, __be32 *fh, int *max_len,
+                           int connectable)
+{
+        struct inode *inode = dentry->d_inode;
+        int len = *max_len;
+        int type = 1;
+        u64 blkno;
+        u32 generation;
+
+        mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry,
+                   dentry->d_name.len, dentry->d_name.name,
+                   fh, len, connectable);
+
+        if (len < 3 || (connectable && len < 6)) {
+                mlog(ML_ERROR, "fh buffer is too small for encoding\n");
+                type = 255;
+                goto bail;
+        }
+
+        blkno = OCFS2_I(inode)->ip_blkno;
+        generation = inode->i_generation;
+
+        mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n",
+             blkno, generation);
+
+        len = 3;
+        fh[0] = cpu_to_le32((u32)(blkno >> 32));
+        fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
+        fh[2] = cpu_to_le32(generation);
+
+        if (connectable && !S_ISDIR(inode->i_mode)) {
+                struct inode *parent;
+
+                spin_lock(&dentry->d_lock);
+
+                parent = dentry->d_parent->d_inode;
+                blkno = OCFS2_I(parent)->ip_blkno;
+                generation = parent->i_generation;
+
+                fh[3] = cpu_to_le32((u32)(blkno >> 32));
+                fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
+                fh[5] = cpu_to_le32(generation);
+
+                spin_unlock(&dentry->d_lock);
+
+                len = 6;
+                type = 2;
+
+                mlog(0, "Encoding parent: blkno: %"MLFu64", generation: %u\n",
+                     blkno, generation);
+        }
+        
+        *max_len = len;
+
+bail:
+        mlog_exit(type);
+        return type;
+}
+
+static struct dentry *ocfs2_decode_fh(struct super_block *sb, __be32 *fh,
+                                      int fh_len, int fileid_type,
+                                      int (*acceptable)(void *context,
+                                                        struct dentry *de),
+                                      void *context)
+{
+        struct ocfs2_inode_handle handle, parent;
+        struct dentry *ret = NULL;
+
+        mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n",
+                   sb, fh, fh_len, fileid_type, acceptable, context);
+
+        if (fh_len < 3 || fileid_type > 2)
+                goto bail;
+
+        if (fileid_type == 2) {
+                if (fh_len < 6)
+                        goto bail;
+
+                parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32;
+                parent.ih_blkno |= (u64)le32_to_cpu(fh[4]);
+                parent.ih_generation = le32_to_cpu(fh[5]);
+
+                mlog(0, "Decoding parent: blkno: %"MLFu64", generation: %u\n",
+                     parent.ih_blkno, parent.ih_generation);
+        }
+
+        handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32;
+        handle.ih_blkno |= (u64)le32_to_cpu(fh[1]);
+        handle.ih_generation = le32_to_cpu(fh[2]);
+
+        mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n",
+             handle.ih_blkno, handle.ih_generation);
+
+        ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent,
+                                                    acceptable, context);
+
+bail:
+        mlog_exit_ptr(ret);
+        return ret;
+}
+
+struct export_operations ocfs2_export_ops = {
+        .decode_fh      = ocfs2_decode_fh,
+        .encode_fh      = ocfs2_encode_fh,
+
+        .get_parent     = ocfs2_get_parent,
+        .get_dentry     = ocfs2_get_dentry,
+};