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fbedadc16e
linux/fs/9p/v9fs.c
Eric Van Hensbergen fbedadc16e 9p: move readn meta-function from client to fs layer 
There are a couple of methods in the client code which aren't actually
wire operations.  To keep things organized cleaner, these operations are
being moved to the fs layer.

This patch moves the readn meta-function (which executes multiple wire
reads until a buffer is full) to the fs layer.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-17 11:04:43 -05:00

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/*
* linux/fs/9p/v9fs.c
*
* This file contains functions assisting in mapping VFS to 9P2000
*
* Copyright (C) 2004-2008 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/parser.h>
#include <linux/idr.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
/*
* Option Parsing (code inspired by NFS code)
* NOTE: each transport will parse its own options
*/
enum {
/* Options that take integer arguments */
Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
/* String options */
Opt_uname, Opt_remotename, Opt_trans,
/* Options that take no arguments */
Opt_nodevmap,
/* Cache options */
Opt_cache_loose,
/* Access options */
Opt_access,
/* Error token */
Opt_err
};
static const match_table_t tokens = {
{Opt_debug, "debug=%x"},
{Opt_dfltuid, "dfltuid=%u"},
{Opt_dfltgid, "dfltgid=%u"},
{Opt_afid, "afid=%u"},
{Opt_uname, "uname=%s"},
{Opt_remotename, "aname=%s"},
{Opt_nodevmap, "nodevmap"},
{Opt_cache_loose, "cache=loose"},
{Opt_cache_loose, "loose"},
{Opt_access, "access=%s"},
{Opt_err, NULL}
};
/**
* v9fs_parse_options - parse mount options into session structure
* @v9ses: existing v9fs session information
*
* Return 0 upon success, -ERRNO upon failure.
*/
static int v9fs_parse_options(struct v9fs_session_info *v9ses)
{
char *options;
substring_t args[MAX_OPT_ARGS];
char *p;
int option = 0;
char *s, *e;
int ret = 0;
/* setup defaults */
v9ses->afid = ~0;
v9ses->debug = 0;
v9ses->cache = 0;
if (!v9ses->options)
return 0;
options = kstrdup(v9ses->options, GFP_KERNEL);
if (!options) {
P9_DPRINTK(P9_DEBUG_ERROR,
"failed to allocate copy of option string\n");
return -ENOMEM;
}
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
if (token < Opt_uname) {
int r = match_int(&args[0], &option);
if (r < 0) {
P9_DPRINTK(P9_DEBUG_ERROR,
"integer field, but no integer?\n");
ret = r;
continue;
}
}
switch (token) {
case Opt_debug:
v9ses->debug = option;
#ifdef CONFIG_NET_9P_DEBUG
p9_debug_level = option;
#endif
break;
case Opt_dfltuid:
v9ses->dfltuid = option;
break;
case Opt_dfltgid:
v9ses->dfltgid = option;
break;
case Opt_afid:
v9ses->afid = option;
break;
case Opt_uname:
match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
break;
case Opt_remotename:
match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
break;
case Opt_nodevmap:
v9ses->nodev = 1;
break;
case Opt_cache_loose:
v9ses->cache = CACHE_LOOSE;
break;
case Opt_access:
s = match_strdup(&args[0]);
if (!s) {
P9_DPRINTK(P9_DEBUG_ERROR,
"failed to allocate copy"
" of option argument\n");
ret = -ENOMEM;
break;
}
v9ses->flags &= ~V9FS_ACCESS_MASK;
if (strcmp(s, "user") == 0)
v9ses->flags |= V9FS_ACCESS_USER;
else if (strcmp(s, "any") == 0)
v9ses->flags |= V9FS_ACCESS_ANY;
else {
v9ses->flags |= V9FS_ACCESS_SINGLE;
v9ses->uid = simple_strtol(s, &e, 10);
if (*e != '\0')
v9ses->uid = ~0;
}
kfree(s);
break;
default:
continue;
}
}
kfree(options);
return ret;
}
/**
* v9fs_session_init - initialize session
* @v9ses: session information structure
* @dev_name: device being mounted
* @data: options
*
*/
struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data)
{
int retval = -EINVAL;
struct p9_fid *fid;
int rc;
v9ses->uname = __getname();
if (!v9ses->uname)
return ERR_PTR(-ENOMEM);
v9ses->aname = __getname();
if (!v9ses->aname) {
__putname(v9ses->uname);
return ERR_PTR(-ENOMEM);
}
v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
strcpy(v9ses->uname, V9FS_DEFUSER);
strcpy(v9ses->aname, V9FS_DEFANAME);
v9ses->uid = ~0;
v9ses->dfltuid = V9FS_DEFUID;
v9ses->dfltgid = V9FS_DEFGID;
if (data) {
v9ses->options = kstrdup(data, GFP_KERNEL);
if (!v9ses->options) {
P9_DPRINTK(P9_DEBUG_ERROR,
"failed to allocate copy of option string\n");
retval = -ENOMEM;
goto error;
}
}
rc = v9fs_parse_options(v9ses);
if (rc < 0) {
retval = rc;
goto error;
}
v9ses->clnt = p9_client_create(dev_name, v9ses->options);
if (IS_ERR(v9ses->clnt)) {
retval = PTR_ERR(v9ses->clnt);
v9ses->clnt = NULL;
P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
goto error;
}
if (!v9ses->clnt->dotu)
v9ses->flags &= ~V9FS_EXTENDED;
v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
/* for legacy mode, fall back to V9FS_ACCESS_ANY */
if (!v9fs_extended(v9ses) &&
((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
v9ses->flags &= ~V9FS_ACCESS_MASK;
v9ses->flags |= V9FS_ACCESS_ANY;
v9ses->uid = ~0;
}
fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
v9ses->aname);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
fid = NULL;
P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
goto error;
}
if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
fid->uid = v9ses->uid;
else
fid->uid = ~0;
return fid;
error:
return ERR_PTR(retval);
}
/**
* v9fs_session_close - shutdown a session
* @v9ses: session information structure
*
*/
void v9fs_session_close(struct v9fs_session_info *v9ses)
{
if (v9ses->clnt) {
p9_client_destroy(v9ses->clnt);
v9ses->clnt = NULL;
}
__putname(v9ses->uname);
__putname(v9ses->aname);
kfree(v9ses->options);
}
/**
* v9fs_session_cancel - terminate a session
* @v9ses: session to terminate
*
* mark transport as disconnected and cancel all pending requests.
*/
void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
p9_client_disconnect(v9ses->clnt);
}
extern int v9fs_error_init(void);
/**
* v9fs_init - Initialize module
*
*/
static int __init init_v9fs(void)
{
printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
/* TODO: Setup list of registered trasnport modules */
return register_filesystem(&v9fs_fs_type);
}
/**
* v9fs_init - shutdown module
*
*/
static void __exit exit_v9fs(void)
{
unregister_filesystem(&v9fs_fs_type);
}
module_init(init_v9fs)
module_exit(exit_v9fs)
MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_LICENSE("GPL");
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