/* * 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));}