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root/fs/9p/v9fs.c

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DEFINITIONS

This source file includes following definitions.
  1. v9fs_parse_options
  2. v9fs_session_init
  3. v9fs_session_close
  4. v9fs_session_cancel
  5. init_v9fs
  6. exit_v9fs

/*
 *  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/transport.h>
#include <net/9p/client.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;

        /* 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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