linux-imx

/*  Xenbus code for blkif backend

    Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>

    Copyright (C) 2005 XenSource Ltd

​

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

​

    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.

​

*/

​

#define pr_fmt(fmt) "xen-blkback: " fmt

​

#include <stdarg.h>

#include <linux/module.h>

#include <linux/kthread.h>

#include <xen/events.h>

#include <xen/grant_table.h>

#include "common.h"

​

/* On the XenBus the max length of 'ring-ref%u'. */

#define RINGREF_NAME_LEN (20)

​

struct backend_info {

    struct xenbus_device    *dev;

    struct xen_blkif    *blkif;

    struct xenbus_watch backend_watch;

    unsigned        major;

    unsigned        minor;

    char            *mode;

};

​

static struct kmem_cache *xen_blkif_cachep;

static void connect(struct backend_info *);

static int connect_ring(struct backend_info *);

static void backend_changed(struct xenbus_watch *, const char *,

                const char *);

static void xen_blkif_free(struct xen_blkif *blkif);

static void xen_vbd_free(struct xen_vbd *vbd);

​

struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be)

{

    return be->dev;

}

​

/*

 * The last request could free the device from softirq context and

 * xen_blkif_free() can sleep.

 */

static void xen_blkif_deferred_free(struct work_struct *work)

{

    struct xen_blkif *blkif;

​

    blkif = container_of(work, struct xen_blkif, free_work);

    xen_blkif_free(blkif);

}

​

static int blkback_name(struct xen_blkif *blkif, char *buf)