![Latchesar Ionkov](/assets/img/avatar_default.png)
Implement a new way of creating special files. Instead of Tcreate+Twstat, add one more field to Tcreate that contains special file description. Signed-off-by: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
279 lines
6.3 KiB
C
279 lines
6.3 KiB
C
/*
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* linux/fs/9p/vfs_file.c
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*
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* This file contians vfs file ops for 9P2000.
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (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
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* GNU 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 License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/inet.h>
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#include <linux/version.h>
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#include <linux/list.h>
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#include <asm/uaccess.h>
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#include <linux/idr.h>
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#include "debug.h"
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#include "v9fs.h"
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#include "9p.h"
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#include "v9fs_vfs.h"
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#include "fid.h"
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/**
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* v9fs_file_open - open a file (or directory)
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* @inode: inode to be opened
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* @file: file being opened
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*
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*/
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int v9fs_file_open(struct inode *inode, struct file *file)
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{
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struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
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struct v9fs_fid *vfid;
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struct v9fs_fcall *fcall = NULL;
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int omode;
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int fid = V9FS_NOFID;
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int err;
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dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file);
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vfid = v9fs_fid_lookup(file->f_dentry);
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if (!vfid) {
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dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n");
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return -EBADF;
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}
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fid = v9fs_get_idpool(&v9ses->fidpool);
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if (fid < 0) {
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eprintk(KERN_WARNING, "newfid fails!\n");
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return -ENOSPC;
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}
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err = v9fs_t_walk(v9ses, vfid->fid, fid, NULL, NULL);
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if (err < 0) {
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dprintk(DEBUG_ERROR, "rewalk didn't work\n");
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goto put_fid;
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}
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/* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */
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/* translate open mode appropriately */
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omode = v9fs_uflags2omode(file->f_flags);
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err = v9fs_t_open(v9ses, fid, omode, &fcall);
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if (err < 0) {
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PRINT_FCALL_ERROR("open failed", fcall);
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goto clunk_fid;
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}
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vfid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
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if (vfid == NULL) {
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dprintk(DEBUG_ERROR, "out of memory\n");
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err = -ENOMEM;
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goto clunk_fid;
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}
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file->private_data = vfid;
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vfid->fid = fid;
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vfid->fidopen = 1;
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vfid->fidclunked = 0;
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vfid->iounit = fcall->params.ropen.iounit;
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vfid->rdir_pos = 0;
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vfid->rdir_fcall = NULL;
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vfid->filp = file;
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kfree(fcall);
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return 0;
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clunk_fid:
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v9fs_t_clunk(v9ses, fid);
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put_fid:
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v9fs_put_idpool(fid, &v9ses->fidpool);
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kfree(fcall);
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return err;
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}
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/**
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* v9fs_file_lock - lock a file (or directory)
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* @inode: inode to be opened
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* @file: file being opened
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*
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* XXX - this looks like a local only lock, we should extend into 9P
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* by using open exclusive
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*/
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static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
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{
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int res = 0;
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struct inode *inode = filp->f_dentry->d_inode;
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dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
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/* No mandatory locks */
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if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
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return -ENOLCK;
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if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
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filemap_write_and_wait(inode->i_mapping);
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invalidate_inode_pages(&inode->i_data);
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}
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return res;
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}
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/**
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* v9fs_file_read - read from a file
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* @filep: file pointer to read
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* @data: data buffer to read data into
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* @count: size of buffer
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* @offset: offset at which to read data
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*
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*/
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static ssize_t
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v9fs_file_read(struct file *filp, char __user * data, size_t count,
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loff_t * offset)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
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struct v9fs_fid *v9f = filp->private_data;
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struct v9fs_fcall *fcall = NULL;
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int fid = v9f->fid;
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int rsize = 0;
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int result = 0;
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int total = 0;
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int n;
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dprintk(DEBUG_VFS, "\n");
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rsize = v9ses->maxdata - V9FS_IOHDRSZ;
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if (v9f->iounit != 0 && rsize > v9f->iounit)
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rsize = v9f->iounit;
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do {
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if (count < rsize)
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rsize = count;
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result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall);
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if (result < 0) {
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printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n",
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result);
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kfree(fcall);
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return total;
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} else
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*offset += result;
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n = copy_to_user(data, fcall->params.rread.data, result);
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if (n) {
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dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n);
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kfree(fcall);
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return -EFAULT;
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}
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count -= result;
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data += result;
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total += result;
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kfree(fcall);
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if (result < rsize)
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break;
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} while (count);
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return total;
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}
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/**
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* v9fs_file_write - write to a file
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* @filep: file pointer to write
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* @data: data buffer to write data from
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* @count: size of buffer
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* @offset: offset at which to write data
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*
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*/
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static ssize_t
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v9fs_file_write(struct file *filp, const char __user * data,
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size_t count, loff_t * offset)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
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struct v9fs_fid *v9fid = filp->private_data;
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struct v9fs_fcall *fcall;
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int fid = v9fid->fid;
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int result = -EIO;
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int rsize = 0;
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int total = 0;
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dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
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(int)*offset);
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rsize = v9ses->maxdata - V9FS_IOHDRSZ;
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if (v9fid->iounit != 0 && rsize > v9fid->iounit)
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rsize = v9fid->iounit;
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do {
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if (count < rsize)
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rsize = count;
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result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall);
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if (result < 0) {
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PRINT_FCALL_ERROR("error while writing", fcall);
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kfree(fcall);
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return result;
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} else
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*offset += result;
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kfree(fcall);
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fcall = NULL;
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if (result != rsize) {
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eprintk(KERN_ERR,
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"short write: v9fs_t_write returned %d\n",
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result);
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break;
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}
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count -= result;
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data += result;
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total += result;
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} while (count);
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invalidate_inode_pages2(inode->i_mapping);
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return total;
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}
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struct file_operations v9fs_file_operations = {
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.llseek = generic_file_llseek,
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.read = v9fs_file_read,
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.write = v9fs_file_write,
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.open = v9fs_file_open,
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.release = v9fs_dir_release,
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.lock = v9fs_file_lock,
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.mmap = generic_file_mmap,
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};
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