/*
* linux/fs/9p/vfs_file.c
*
* This file contians vfs file ops for 9P2000.
*
* 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/sched.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/list.h>
#include <asm/uaccess.h>
#include <linux/idr.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
static const struct file_operations v9fs_cached_file_operations;
/**
* v9fs_file_open - open a file (or directory)
* @inode: inode to be opened
* @file: file being opened
*
*/
int v9fs_file_open(struct inode *inode, struct file *file)
{
int err;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
int omode;
P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
v9ses = v9fs_inode2v9ses(inode);
omode = v9fs_uflags2omode(file->f_flags, v9fs_extended(v9ses));
fid = file->private_data;
if (!fid) {
fid = v9fs_fid_clone(file->f_path.dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
err = p9_client_open(fid, omode);
if (err < 0) {
p9_client_clunk(fid);
return err;
}
if (omode & P9_OTRUNC) {
inode->i_size = 0;
inode->i_blocks = 0;
}
if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses)))
generic_file_llseek(file, 0, SEEK_END);
}
file->private_data = fid;
if ((fid->qid.version) && (v9ses->cache)) {
P9_DPRINTK(P9_DEBUG_VFS, "cached");
/* enable cached file options */
if(file->f_op == &v9fs_file_operations)
file->f_op = &v9fs_cached_file_operations;
}
return 0;
}
/**
* v9fs_file_lock - lock a file (or directory)
* @filp: file to be locked
* @cmd: lock command
* @fl: file lock structure
*
* Bugs: this looks like a local only lock, we should extend into 9P
* by using open exclusive
*/
static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
{
int res = 0;
struct inode *inode = filp->f_path.dentry->d_inode;
P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
/* No mandatory locks */
if (__mandatory_lock(inode))
return -ENOLCK;
if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
filemap_write_and_wait(inode->i_mapping);
invalidate_mapping_pages(&inode->i_data, 0, -1);
}
return res;
}
/**
* v9fs_file_readn - read from a file
* @filp: file pointer to read
* @data: data buffer to read data into
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
ssize_t
v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
u64 offset)
{
int n, total;
struct p9_fid *fid = filp->private_data;
P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
(long long unsigned) offset, count);
n = 0;
total = 0;
do {
n = p9_client_read(fid, data, udata, offset, count);
if (n <= 0)
break;
if (data)
data += n;
if (udata)
udata += n;
offset += n;
count -= n;
total += n;
} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
if (n < 0)
total = n;
return total;
}
/**
* v9fs_file_read - read from a file
* @filp: file pointer to read
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
static ssize_t
v9fs_file_read(struct file *filp, char __user *udata, size_t count,
loff_t * offset)
{
int ret;
struct p9_fid *fid;
P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
fid = filp->private_data;
if (count > (fid->clnt->msize - P9_IOHDRSZ))
ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
else
ret = p9_client_read(fid, NULL, udata, *offset, count);
if (ret > 0)
*offset += ret;
return ret;
}
/**
* v9fs_file_write - write to a file
* @filp: file pointer to write
* @data: data buffer to write data from
* @count: size of buffer
* @offset: offset at which to write data
*
*/
static ssize_t
v9fs_file_write(struct file *filp, const char __user * data,
size_t count, loff_t * offset)
{
int n, rsize, total = 0;
struct p9_fid *fid;
struct p9_client *clnt;
struct inode *inode = filp->f_path.dentry->d_inode;
int origin = *offset;
P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
(int)count, (int)*offset);
fid = filp->private_data;
clnt = fid->clnt;
rsize = fid->iounit;
if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
rsize = clnt->msize - P9_IOHDRSZ;
do {
if (count < rsize)
rsize = count;
n = p9_client_write(fid, NULL, data+total, *offset+total,
rsize);
if (n <= 0)
break;
count -= n;
total += n;
} while (count > 0);
if (total > 0) {
invalidate_inode_pages2_range(inode->i_mapping, origin,
origin+total);
*offset += total;
}
if (*offset > inode->i_size) {
inode->i_size = *offset;
inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
}
if (n < 0)
return n;
return total;
}
static const struct file_operations v9fs_cached_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.write = v9fs_file_write,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = generic_file_readonly_mmap,
};
const struct file_operations v9fs_file_operations = {
.llseek = generic_file_llseek,
.read = v9fs_file_read,
.write = v9fs_file_write,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = generic_file_readonly_mmap,
};
