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/*
* linux/fs/9p/vfs_dir.c
*
* This file contains vfs directory ops for the 9P2000 protocol.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
/**
* struct p9_rdir - readdir accounting
* @mutex: mutex protecting readdir
* @head: start offset of current dirread buffer
* @tail: end offset of current dirread buffer
* @buf: dirread buffer
*
* private structure for keeping track of readdir
* allocated on demand
*/
struct p9_rdir {
struct mutex mutex;
int head;
int tail;
uint8_t *buf;
};
/**
* dt_type - return file type
* @mistat: mistat structure
*
*/
static inline int dt_type(struct p9_wstat *mistat)
{
unsigned long perm = mistat->mode;
int rettype = DT_REG;
if (perm & P9_DMDIR)
rettype = DT_DIR;
if (perm & P9_DMSYMLINK)
rettype = DT_LNK;
return rettype;
}
static void p9stat_init(struct p9_wstat *stbuf)
{
stbuf->name = NULL;
stbuf->uid = NULL;
stbuf->gid = NULL;
stbuf->muid = NULL;
stbuf->extension = NULL;
}
/**
* v9fs_dir_readdir - read a directory
* @filp: opened file structure
* @dirent: directory structure ???
* @filldir: function to populate directory structure ???
*
*/
static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
int over;
struct p9_wstat st;
int err = 0;
struct p9_fid *fid;
int buflen;
int reclen = 0;
struct p9_rdir *rdir;
P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
fid = filp->private_data;
buflen = fid->clnt->msize - P9_IOHDRSZ;
/* allocate rdir on demand */
if (!fid->rdir) {
rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
if (rdir == NULL) {
err = -ENOMEM;
goto exit;
}
spin_lock(&filp->f_dentry->d_lock);
if (!fid->rdir) {
rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
mutex_init(&rdir->mutex);
rdir->head = rdir->tail = 0;
fid->rdir = (void *) rdir;
rdir = NULL;
}
spin_unlock(&filp->f_dentry->d_lock);
kfree(rdir);
}
rdir = (struct p9_rdir *) fid->rdir;
err = mutex_lock_interruptible(&rdir->mutex);
while (err == 0) {
if (rdir->tail == rdir->head) {
err = v9fs_file_readn(filp, rdir->buf, NULL,
buflen, filp->f_pos);
if (err <= 0)
goto unlock_and_exit;
rdir->head = 0;
rdir->tail = err;
}
while (rdir->head < rdir->tail) {
p9stat_init(&st);
err = p9stat_read(rdir->buf + rdir->head,
buflen - rdir->head, &st,
fid->clnt->proto_version);
if (err) {
P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
err = -EIO;
p9stat_free(&st);
goto unlock_and_exit;
}
reclen = st.size+2;
over = filldir(dirent, st.name, strlen(st.name),
filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
p9stat_free(&st);
if (over) {
err = 0;
goto unlock_and_exit;
}
rdir->head += reclen;
filp->f_pos += reclen;
}
}
unlock_and_exit:
mutex_unlock(&rdir->mutex);
exit:
return err;
}
/**
* v9fs_dir_release - close a directory
* @inode: inode of the directory
* @filp: file pointer to a directory
*
*/
int v9fs_dir_release(struct inode *inode, struct file *filp)
{
struct p9_fid *fid;
fid = filp->private_data;
P9_DPRINTK(P9_DEBUG_VFS,
"inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
filemap_write_and_wait(inode->i_mapping);
p9_client_clunk(fid);
return 0;
}
const struct file_operations v9fs_dir_operations = {
.read = generic_read_dir,
.llseek = generic_file_llseek,
.readdir = v9fs_dir_readdir,
.open = v9fs_file_open,
.release = v9fs_dir_release,
};
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