/* -*- 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,
};
