linux/fs/9p/vfs_file.c
Eric Van Hensbergen 51a87c552d 9p: rework client code to use new protocol support functions
Now that the new protocol functions are in place, this patch switches
the client code to using the new support code.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-17 11:04:45 -05:00

272 lines
6.2 KiB
C

/*
* 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 %d 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,
};