d993831fa7
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
652 lines
15 KiB
C
652 lines
15 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* dlmfs.c
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*
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* Code which implements the kernel side of a minimal userspace
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* interface to our DLM. This file handles the virtual file system
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* used for communication with userspace. Credit should go to ramfs,
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* which was a template for the fs side of this module.
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*
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* Copyright (C) 2003, 2004 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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/* Simple VFS hooks based on: */
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/*
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* Resizable simple ram filesystem for Linux.
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*
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* Copyright (C) 2000 Linus Torvalds.
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* 2000 Transmeta Corp.
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/highmem.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/backing-dev.h>
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#include <asm/uaccess.h>
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#include "cluster/nodemanager.h"
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#include "cluster/heartbeat.h"
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#include "cluster/tcp.h"
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#include "dlmapi.h"
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#include "userdlm.h"
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#include "dlmfsver.h"
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#define MLOG_MASK_PREFIX ML_DLMFS
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#include "cluster/masklog.h"
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#include "ocfs2_lockingver.h"
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static const struct super_operations dlmfs_ops;
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static const struct file_operations dlmfs_file_operations;
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static const struct inode_operations dlmfs_dir_inode_operations;
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static const struct inode_operations dlmfs_root_inode_operations;
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static const struct inode_operations dlmfs_file_inode_operations;
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static struct kmem_cache *dlmfs_inode_cache;
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struct workqueue_struct *user_dlm_worker;
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/*
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* This is the userdlmfs locking protocol version.
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*
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* See fs/ocfs2/dlmglue.c for more details on locking versions.
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*/
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static const struct dlm_protocol_version user_locking_protocol = {
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.pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
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.pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
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};
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/*
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* decodes a set of open flags into a valid lock level and a set of flags.
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* returns < 0 if we have invalid flags
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* flags which mean something to us:
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* O_RDONLY -> PRMODE level
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* O_WRONLY -> EXMODE level
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*
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* O_NONBLOCK -> LKM_NOQUEUE
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*/
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static int dlmfs_decode_open_flags(int open_flags,
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int *level,
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int *flags)
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{
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if (open_flags & (O_WRONLY|O_RDWR))
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*level = LKM_EXMODE;
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else
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*level = LKM_PRMODE;
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*flags = 0;
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if (open_flags & O_NONBLOCK)
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*flags |= LKM_NOQUEUE;
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return 0;
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}
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static int dlmfs_file_open(struct inode *inode,
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struct file *file)
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{
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int status, level, flags;
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struct dlmfs_filp_private *fp = NULL;
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struct dlmfs_inode_private *ip;
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if (S_ISDIR(inode->i_mode))
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BUG();
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mlog(0, "open called on inode %lu, flags 0x%x\n", inode->i_ino,
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file->f_flags);
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status = dlmfs_decode_open_flags(file->f_flags, &level, &flags);
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if (status < 0)
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goto bail;
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/* We don't want to honor O_APPEND at read/write time as it
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* doesn't make sense for LVB writes. */
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file->f_flags &= ~O_APPEND;
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fp = kmalloc(sizeof(*fp), GFP_NOFS);
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if (!fp) {
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status = -ENOMEM;
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goto bail;
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}
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fp->fp_lock_level = level;
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ip = DLMFS_I(inode);
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status = user_dlm_cluster_lock(&ip->ip_lockres, level, flags);
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if (status < 0) {
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/* this is a strange error to return here but I want
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* to be able userspace to be able to distinguish a
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* valid lock request from one that simply couldn't be
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* granted. */
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if (flags & LKM_NOQUEUE && status == -EAGAIN)
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status = -ETXTBSY;
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kfree(fp);
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goto bail;
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}
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file->private_data = fp;
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bail:
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return status;
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}
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static int dlmfs_file_release(struct inode *inode,
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struct file *file)
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{
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int level, status;
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struct dlmfs_inode_private *ip = DLMFS_I(inode);
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struct dlmfs_filp_private *fp =
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(struct dlmfs_filp_private *) file->private_data;
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if (S_ISDIR(inode->i_mode))
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BUG();
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mlog(0, "close called on inode %lu\n", inode->i_ino);
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status = 0;
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if (fp) {
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level = fp->fp_lock_level;
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if (level != LKM_IVMODE)
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user_dlm_cluster_unlock(&ip->ip_lockres, level);
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kfree(fp);
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file->private_data = NULL;
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}
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return 0;
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}
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static ssize_t dlmfs_file_read(struct file *filp,
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char __user *buf,
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size_t count,
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loff_t *ppos)
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{
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int bytes_left;
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ssize_t readlen;
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char *lvb_buf;
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struct inode *inode = filp->f_path.dentry->d_inode;
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mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
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inode->i_ino, count, *ppos);
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if (*ppos >= i_size_read(inode))
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return 0;
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if (!count)
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return 0;
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if (!access_ok(VERIFY_WRITE, buf, count))
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return -EFAULT;
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/* don't read past the lvb */
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if ((count + *ppos) > i_size_read(inode))
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readlen = i_size_read(inode) - *ppos;
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else
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readlen = count - *ppos;
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lvb_buf = kmalloc(readlen, GFP_NOFS);
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if (!lvb_buf)
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return -ENOMEM;
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user_dlm_read_lvb(inode, lvb_buf, readlen);
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bytes_left = __copy_to_user(buf, lvb_buf, readlen);
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readlen -= bytes_left;
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kfree(lvb_buf);
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*ppos = *ppos + readlen;
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mlog(0, "read %zd bytes\n", readlen);
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return readlen;
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}
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static ssize_t dlmfs_file_write(struct file *filp,
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const char __user *buf,
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size_t count,
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loff_t *ppos)
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{
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int bytes_left;
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ssize_t writelen;
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char *lvb_buf;
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struct inode *inode = filp->f_path.dentry->d_inode;
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mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
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inode->i_ino, count, *ppos);
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if (*ppos >= i_size_read(inode))
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return -ENOSPC;
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if (!count)
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return 0;
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if (!access_ok(VERIFY_READ, buf, count))
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return -EFAULT;
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/* don't write past the lvb */
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if ((count + *ppos) > i_size_read(inode))
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writelen = i_size_read(inode) - *ppos;
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else
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writelen = count - *ppos;
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lvb_buf = kmalloc(writelen, GFP_NOFS);
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if (!lvb_buf)
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return -ENOMEM;
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bytes_left = copy_from_user(lvb_buf, buf, writelen);
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writelen -= bytes_left;
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if (writelen)
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user_dlm_write_lvb(inode, lvb_buf, writelen);
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kfree(lvb_buf);
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*ppos = *ppos + writelen;
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mlog(0, "wrote %zd bytes\n", writelen);
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return writelen;
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}
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static void dlmfs_init_once(void *foo)
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{
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struct dlmfs_inode_private *ip =
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(struct dlmfs_inode_private *) foo;
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ip->ip_dlm = NULL;
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ip->ip_parent = NULL;
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inode_init_once(&ip->ip_vfs_inode);
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}
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static struct inode *dlmfs_alloc_inode(struct super_block *sb)
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{
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struct dlmfs_inode_private *ip;
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ip = kmem_cache_alloc(dlmfs_inode_cache, GFP_NOFS);
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if (!ip)
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return NULL;
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return &ip->ip_vfs_inode;
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}
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static void dlmfs_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
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}
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static void dlmfs_clear_inode(struct inode *inode)
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{
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int status;
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struct dlmfs_inode_private *ip;
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if (!inode)
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return;
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mlog(0, "inode %lu\n", inode->i_ino);
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ip = DLMFS_I(inode);
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if (S_ISREG(inode->i_mode)) {
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status = user_dlm_destroy_lock(&ip->ip_lockres);
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if (status < 0)
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mlog_errno(status);
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iput(ip->ip_parent);
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goto clear_fields;
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}
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mlog(0, "we're a directory, ip->ip_dlm = 0x%p\n", ip->ip_dlm);
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/* we must be a directory. If required, lets unregister the
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* dlm context now. */
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if (ip->ip_dlm)
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user_dlm_unregister_context(ip->ip_dlm);
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clear_fields:
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ip->ip_parent = NULL;
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ip->ip_dlm = NULL;
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}
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static struct backing_dev_info dlmfs_backing_dev_info = {
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.name = "ocfs2-dlmfs",
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.ra_pages = 0, /* No readahead */
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.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
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};
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static struct inode *dlmfs_get_root_inode(struct super_block *sb)
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{
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struct inode *inode = new_inode(sb);
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int mode = S_IFDIR | 0755;
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struct dlmfs_inode_private *ip;
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if (inode) {
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ip = DLMFS_I(inode);
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inode->i_mode = mode;
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inode->i_uid = current_fsuid();
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inode->i_gid = current_fsgid();
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inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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inc_nlink(inode);
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inode->i_fop = &simple_dir_operations;
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inode->i_op = &dlmfs_root_inode_operations;
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}
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return inode;
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}
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static struct inode *dlmfs_get_inode(struct inode *parent,
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struct dentry *dentry,
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int mode)
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{
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struct super_block *sb = parent->i_sb;
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struct inode * inode = new_inode(sb);
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struct dlmfs_inode_private *ip;
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if (!inode)
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return NULL;
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inode->i_mode = mode;
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inode->i_uid = current_fsuid();
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inode->i_gid = current_fsgid();
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inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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ip = DLMFS_I(inode);
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ip->ip_dlm = DLMFS_I(parent)->ip_dlm;
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switch (mode & S_IFMT) {
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default:
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/* for now we don't support anything other than
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* directories and regular files. */
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BUG();
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break;
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case S_IFREG:
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inode->i_op = &dlmfs_file_inode_operations;
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inode->i_fop = &dlmfs_file_operations;
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i_size_write(inode, DLM_LVB_LEN);
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user_dlm_lock_res_init(&ip->ip_lockres, dentry);
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/* released at clear_inode time, this insures that we
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* get to drop the dlm reference on each lock *before*
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* we call the unregister code for releasing parent
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* directories. */
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ip->ip_parent = igrab(parent);
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BUG_ON(!ip->ip_parent);
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break;
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case S_IFDIR:
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inode->i_op = &dlmfs_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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/* directory inodes start off with i_nlink ==
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* 2 (for "." entry) */
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inc_nlink(inode);
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break;
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}
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if (parent->i_mode & S_ISGID) {
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inode->i_gid = parent->i_gid;
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if (S_ISDIR(mode))
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inode->i_mode |= S_ISGID;
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}
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return inode;
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}
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/*
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* File creation. Allocate an inode, and we're done..
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*/
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/* SMP-safe */
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static int dlmfs_mkdir(struct inode * dir,
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struct dentry * dentry,
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int mode)
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{
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int status;
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struct inode *inode = NULL;
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struct qstr *domain = &dentry->d_name;
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struct dlmfs_inode_private *ip;
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struct dlm_ctxt *dlm;
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struct dlm_protocol_version proto = user_locking_protocol;
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mlog(0, "mkdir %.*s\n", domain->len, domain->name);
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/* verify that we have a proper domain */
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if (domain->len >= O2NM_MAX_NAME_LEN) {
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status = -EINVAL;
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mlog(ML_ERROR, "invalid domain name for directory.\n");
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goto bail;
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}
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inode = dlmfs_get_inode(dir, dentry, mode | S_IFDIR);
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if (!inode) {
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status = -ENOMEM;
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mlog_errno(status);
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goto bail;
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}
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ip = DLMFS_I(inode);
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dlm = user_dlm_register_context(domain, &proto);
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if (IS_ERR(dlm)) {
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status = PTR_ERR(dlm);
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mlog(ML_ERROR, "Error %d could not register domain \"%.*s\"\n",
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status, domain->len, domain->name);
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goto bail;
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}
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ip->ip_dlm = dlm;
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inc_nlink(dir);
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d_instantiate(dentry, inode);
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dget(dentry); /* Extra count - pin the dentry in core */
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status = 0;
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bail:
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if (status < 0)
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iput(inode);
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return status;
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}
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static int dlmfs_create(struct inode *dir,
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struct dentry *dentry,
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int mode,
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struct nameidata *nd)
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{
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int status = 0;
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struct inode *inode;
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struct qstr *name = &dentry->d_name;
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mlog(0, "create %.*s\n", name->len, name->name);
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/* verify name is valid and doesn't contain any dlm reserved
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* characters */
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if (name->len >= USER_DLM_LOCK_ID_MAX_LEN ||
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name->name[0] == '$') {
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status = -EINVAL;
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mlog(ML_ERROR, "invalid lock name, %.*s\n", name->len,
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name->name);
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goto bail;
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}
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inode = dlmfs_get_inode(dir, dentry, mode | S_IFREG);
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if (!inode) {
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status = -ENOMEM;
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mlog_errno(status);
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goto bail;
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}
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d_instantiate(dentry, inode);
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dget(dentry); /* Extra count - pin the dentry in core */
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bail:
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return status;
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}
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static int dlmfs_unlink(struct inode *dir,
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struct dentry *dentry)
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{
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int status;
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struct inode *inode = dentry->d_inode;
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mlog(0, "unlink inode %lu\n", inode->i_ino);
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/* if there are no current holders, or none that are waiting
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* to acquire a lock, this basically destroys our lockres. */
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status = user_dlm_destroy_lock(&DLMFS_I(inode)->ip_lockres);
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if (status < 0) {
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mlog(ML_ERROR, "unlink %.*s, error %d from destroy\n",
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dentry->d_name.len, dentry->d_name.name, status);
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goto bail;
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}
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status = simple_unlink(dir, dentry);
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bail:
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return status;
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}
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static int dlmfs_fill_super(struct super_block * sb,
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void * data,
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int silent)
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{
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struct inode * inode;
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struct dentry * root;
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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sb->s_blocksize = PAGE_CACHE_SIZE;
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|
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
|
|
sb->s_magic = DLMFS_MAGIC;
|
|
sb->s_op = &dlmfs_ops;
|
|
inode = dlmfs_get_root_inode(sb);
|
|
if (!inode)
|
|
return -ENOMEM;
|
|
|
|
root = d_alloc_root(inode);
|
|
if (!root) {
|
|
iput(inode);
|
|
return -ENOMEM;
|
|
}
|
|
sb->s_root = root;
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations dlmfs_file_operations = {
|
|
.open = dlmfs_file_open,
|
|
.release = dlmfs_file_release,
|
|
.read = dlmfs_file_read,
|
|
.write = dlmfs_file_write,
|
|
};
|
|
|
|
static const struct inode_operations dlmfs_dir_inode_operations = {
|
|
.create = dlmfs_create,
|
|
.lookup = simple_lookup,
|
|
.unlink = dlmfs_unlink,
|
|
};
|
|
|
|
/* this way we can restrict mkdir to only the toplevel of the fs. */
|
|
static const struct inode_operations dlmfs_root_inode_operations = {
|
|
.lookup = simple_lookup,
|
|
.mkdir = dlmfs_mkdir,
|
|
.rmdir = simple_rmdir,
|
|
};
|
|
|
|
static const struct super_operations dlmfs_ops = {
|
|
.statfs = simple_statfs,
|
|
.alloc_inode = dlmfs_alloc_inode,
|
|
.destroy_inode = dlmfs_destroy_inode,
|
|
.clear_inode = dlmfs_clear_inode,
|
|
.drop_inode = generic_delete_inode,
|
|
};
|
|
|
|
static const struct inode_operations dlmfs_file_inode_operations = {
|
|
.getattr = simple_getattr,
|
|
};
|
|
|
|
static int dlmfs_get_sb(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_nodev(fs_type, flags, data, dlmfs_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type dlmfs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "ocfs2_dlmfs",
|
|
.get_sb = dlmfs_get_sb,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
static int __init init_dlmfs_fs(void)
|
|
{
|
|
int status;
|
|
int cleanup_inode = 0, cleanup_worker = 0;
|
|
|
|
dlmfs_print_version();
|
|
|
|
status = bdi_init(&dlmfs_backing_dev_info);
|
|
if (status)
|
|
return status;
|
|
|
|
dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache",
|
|
sizeof(struct dlmfs_inode_private),
|
|
0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
|
|
SLAB_MEM_SPREAD),
|
|
dlmfs_init_once);
|
|
if (!dlmfs_inode_cache) {
|
|
status = -ENOMEM;
|
|
goto bail;
|
|
}
|
|
cleanup_inode = 1;
|
|
|
|
user_dlm_worker = create_singlethread_workqueue("user_dlm");
|
|
if (!user_dlm_worker) {
|
|
status = -ENOMEM;
|
|
goto bail;
|
|
}
|
|
cleanup_worker = 1;
|
|
|
|
status = register_filesystem(&dlmfs_fs_type);
|
|
bail:
|
|
if (status) {
|
|
if (cleanup_inode)
|
|
kmem_cache_destroy(dlmfs_inode_cache);
|
|
if (cleanup_worker)
|
|
destroy_workqueue(user_dlm_worker);
|
|
bdi_destroy(&dlmfs_backing_dev_info);
|
|
} else
|
|
printk("OCFS2 User DLM kernel interface loaded\n");
|
|
return status;
|
|
}
|
|
|
|
static void __exit exit_dlmfs_fs(void)
|
|
{
|
|
unregister_filesystem(&dlmfs_fs_type);
|
|
|
|
flush_workqueue(user_dlm_worker);
|
|
destroy_workqueue(user_dlm_worker);
|
|
|
|
kmem_cache_destroy(dlmfs_inode_cache);
|
|
|
|
bdi_destroy(&dlmfs_backing_dev_info);
|
|
}
|
|
|
|
MODULE_AUTHOR("Oracle");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(init_dlmfs_fs)
|
|
module_exit(exit_dlmfs_fs)
|