- 根目录:
- fs
- ocfs2
- export.c
/* -*- 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>
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dir.h"
#include "dlmglue.h"
#include "dcache.h"
#include "export.h"
#include "inode.h"
#include "buffer_head_io.h"
#include "suballoc.h"
#include "ocfs2_trace.h"
struct ocfs2_inode_handle
{
u64 ih_blkno;
u32 ih_generation;
};
static struct dentry *ocfs2_get_dentry(struct super_block *sb,
struct ocfs2_inode_handle *handle)
{
struct inode *inode;
struct ocfs2_super *osb = OCFS2_SB(sb);
u64 blkno = handle->ih_blkno;
int status, set;
struct dentry *result;
trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno);
if (blkno == 0) {
result = ERR_PTR(-ESTALE);
goto bail;
}
inode = ocfs2_ilookup(sb, blkno);
/*
* If the inode exists in memory, we only need to check it's
* generation number
*/
if (inode)
goto check_gen;
/*
* This will synchronize us against ocfs2_delete_inode() on
* all nodes
*/
status = ocfs2_nfs_sync_lock(osb, 1);
if (status < 0) {
mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
goto check_err;
}
status = ocfs2_test_inode_bit(osb, blkno, &set);
trace_ocfs2_get_dentry_test_bit(status, set);
if (status < 0) {
if (status == -EINVAL) {
/*
* The blkno NFS gave us doesn't even show up
* as an inode, we return -ESTALE to be
* nice
*/
status = -ESTALE;
} else
mlog(ML_ERROR, "test inode bit failed %d\n", status);
goto unlock_nfs_sync;
}
/* If the inode allocator bit is clear, this inode must be stale */
if (!set) {
status = -ESTALE;
goto unlock_nfs_sync;
}
inode = ocfs2_iget(osb, blkno, 0, 0);
unlock_nfs_sync:
ocfs2_nfs_sync_unlock(osb, 1);
check_err:
if (status < 0) {
if (status == -ESTALE) {
trace_ocfs2_get_dentry_stale((unsigned long long)blkno,
handle->ih_generation);
}
result = ERR_PTR(status);
goto bail;
}
if (IS_ERR(inode)) {
mlog_errno(PTR_ERR(inode));
result = (void *)inode;
goto bail;
}
check_gen:
if (handle->ih_generation != inode->i_generation) {
iput(inode);
trace_ocfs2_get_dentry_generation((unsigned long long)blkno,
handle->ih_generation,
inode->i_generation);
result = ERR_PTR(-ESTALE);
goto bail;
}
result = d_obtain_alias(inode);
if (IS_ERR(result))
mlog_errno(PTR_ERR(result));
bail:
trace_ocfs2_get_dentry_end(result);
return result;
}
static struct dentry *ocfs2_get_parent(struct dentry *child)
{
int status;
u64 blkno;
struct dentry *parent;
struct inode *dir = child->d_inode;
trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
(unsigned long long)OCFS2_I(dir)->ip_blkno);
status = ocfs2_inode_lock(dir, NULL, 0);
if (status < 0) {
if (status != -ENOENT)
mlog_errno(status);
parent = ERR_PTR(status);
goto bail;
}
status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
if (status < 0) {
parent = ERR_PTR(-ENOENT);
goto bail_unlock;
}
parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
bail_unlock:
ocfs2_inode_unlock(dir, 0);
bail:
trace_ocfs2_get_parent_end(parent);
return parent;
}
static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len,
int connectable)
{
struct inode *inode = dentry->d_inode;
int len = *max_len;
int type = 1;
u64 blkno;
u32 generation;
__le32 *fh = (__force __le32 *) fh_in;
trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len,
dentry->d_name.name,
fh, len, connectable);
if (connectable && (len < 6)) {
*max_len = 6;
type = 255;
goto bail;
} else if (len < 3) {
*max_len = 3;
type = 255;
goto bail;
}
blkno = OCFS2_I(inode)->ip_blkno;
generation = inode->i_generation;
trace_ocfs2_encode_fh_self((unsigned long long)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;
trace_ocfs2_encode_fh_parent((unsigned long long)blkno,
generation);
}
*max_len = len;
bail:
trace_ocfs2_encode_fh_type(type);
return type;
}
static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
struct ocfs2_inode_handle handle;
if (fh_len < 3 || fh_type > 2)
return NULL;
handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32;
handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
handle.ih_generation = le32_to_cpu(fid->raw[2]);
return ocfs2_get_dentry(sb, &handle);
}
static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
struct ocfs2_inode_handle parent;
if (fh_type != 2 || fh_len < 6)
return NULL;
parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32;
parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
parent.ih_generation = le32_to_cpu(fid->raw[5]);
return ocfs2_get_dentry(sb, &parent);
}
const struct export_operations ocfs2_export_ops = {
.encode_fh = ocfs2_encode_fh,
.fh_to_dentry = ocfs2_fh_to_dentry,
.fh_to_parent = ocfs2_fh_to_parent,
.get_parent = ocfs2_get_parent,
};