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/*
* tools/blktap_user/blkif.c
*
* The blkif interface for blktap. A blkif describes an in-use virtual disk.
* (c) 2005 Andrew Warfield and Julian Chesterfield
*
* 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; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <err.h>
#include <unistd.h>
#include "blktaplib.h"
#if 0
#define DPRINTF(_f, _a...) printf ( _f , ## _a )
#else
#define DPRINTF(_f, _a...) ((void)0)
#endif
#define BLKIF_HASHSZ 1024
#define BLKIF_HASH(_d,_h) (((int)(_d)^(int)(_h))&(BLKIF_HASHSZ-1))
static blkif_t *blkif_hash[BLKIF_HASHSZ];
blkif_t *blkif_find_by_handle(domid_t domid, unsigned int handle)
{
blkif_t *blkif = blkif_hash[BLKIF_HASH(domid, handle)];
while ( (blkif != NULL) &&
((blkif->domid != domid) || (blkif->handle != handle)) )
blkif = blkif->hash_next;
return blkif;
}
blkif_t *alloc_blkif(domid_t domid)
{
blkif_t *blkif;
DPRINTF("Alloc_blkif called [%d]\n",domid);
blkif = (blkif_t *)malloc(sizeof(blkif_t));
if (!blkif)
return NULL;
memset(blkif, 0, sizeof(*blkif));
blkif->domid = domid;
blkif->devnum = -1;
return blkif;
}
/*Controller callbacks*/
static int (*new_devmap_hook)(blkif_t *blkif) = NULL;
void register_new_devmap_hook(int (*fn)(blkif_t *blkif))
{
new_devmap_hook = fn;
}
static int (*new_unmap_hook)(blkif_t *blkif) = NULL;
void register_new_unmap_hook(int (*fn)(blkif_t *blkif))
{
new_unmap_hook = fn;
}
static int (*new_blkif_hook)(blkif_t *blkif) = NULL;
void register_new_blkif_hook(int (*fn)(blkif_t *blkif))
{
new_blkif_hook = fn;
}
int blkif_init(blkif_t *blkif, long int handle, long int pdev,
long int readonly)
{
domid_t domid;
blkif_t **pblkif;
int devnum;
if (blkif == NULL)
return -EINVAL;
domid = blkif->domid;
blkif->handle = handle;
blkif->pdev = pdev;
blkif->readonly = readonly;
/*
* Call out to the new_blkif_hook.
* The tap application should define this,
* and it should return having set blkif->ops
*
*/
if (new_blkif_hook == NULL)
{
DPRINTF("Probe detected a new blkif, but no new_blkif_hook!");
return -1;
}
if (new_blkif_hook(blkif)!=0) {
DPRINTF("BLKIF: Image open failed\n");
return -1;
}
/* Now wire it in. */
pblkif = &blkif_hash[BLKIF_HASH(domid, handle)];
DPRINTF("Created hash entry: %d [%d,%ld]\n",
BLKIF_HASH(domid, handle), domid, handle);
while ( *pblkif != NULL )
{
if ( ((*pblkif)->domid == domid) &&
((*pblkif)->handle == handle) )
{
DPRINTF("Could not create blkif: already exists\n");
return -1;
}
pblkif = &(*pblkif)->hash_next;
}
blkif->hash_next = NULL;
*pblkif = blkif;
if (new_devmap_hook == NULL)
{
DPRINTF("Probe setting up new blkif but no devmap hook!");
return -1;
}
devnum = new_devmap_hook(blkif);
if (devnum == -1)
return -1;
blkif->devnum = devnum;
return 0;
}
void free_blkif(blkif_t *blkif)
{
blkif_t **pblkif, *curs;
image_t *image;
pblkif = &blkif_hash[BLKIF_HASH(blkif->domid, blkif->handle)];
while ( (curs = *pblkif) != NULL )
{
if ( blkif == curs )
{
*pblkif = curs->hash_next;
}
pblkif = &curs->hash_next;
}
if (blkif != NULL) {
if ((image=(image_t *)blkif->prv)!=NULL) {
free(blkif->prv);
}
if (blkif->info!=NULL) {
free(blkif->info);
}
if (new_unmap_hook != NULL) new_unmap_hook(blkif);
free(blkif);
}
}
void __init_blkif(void)
{
memset(blkif_hash, 0, sizeof(blkif_hash));
}
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