qemu/hw/block/block.c
Kevin Wolf dabd18f64c hw/block: Introduce share-rw qdev property
By default, don't allow another writer for block devices that are
attached to a guest device. For the cases where this setup is intended
(e.g. using a cluster filesystem on the disk), the new option can be
used to allow it.

This change affects only devices using DEFINE_BLOCK_PROPERTIES().
Devices directly using DEFINE_PROP_DRIVE() still accept writers
unconditionally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00

144 lines
4.0 KiB
C

/*
* Common code for block device models
*
* Copyright (C) 2012 Red Hat, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "hw/block/block.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
void blkconf_serial(BlockConf *conf, char **serial)
{
DriveInfo *dinfo;
if (!*serial) {
/* try to fall back to value set with legacy -drive serial=... */
dinfo = blk_legacy_dinfo(conf->blk);
if (dinfo) {
*serial = g_strdup(dinfo->serial);
}
}
}
void blkconf_blocksizes(BlockConf *conf)
{
BlockBackend *blk = conf->blk;
BlockSizes blocksizes;
int backend_ret;
backend_ret = blk_probe_blocksizes(blk, &blocksizes);
/* fill in detected values if they are not defined via qemu command line */
if (!conf->physical_block_size) {
if (!backend_ret) {
conf->physical_block_size = blocksizes.phys;
} else {
conf->physical_block_size = BDRV_SECTOR_SIZE;
}
}
if (!conf->logical_block_size) {
if (!backend_ret) {
conf->logical_block_size = blocksizes.log;
} else {
conf->logical_block_size = BDRV_SECTOR_SIZE;
}
}
}
void blkconf_apply_backend_options(BlockConf *conf, bool readonly,
bool resizable, Error **errp)
{
BlockBackend *blk = conf->blk;
BlockdevOnError rerror, werror;
uint64_t perm, shared_perm;
bool wce;
int ret;
perm = BLK_PERM_CONSISTENT_READ;
if (!readonly) {
perm |= BLK_PERM_WRITE;
}
shared_perm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
BLK_PERM_GRAPH_MOD;
if (resizable) {
shared_perm |= BLK_PERM_RESIZE;
}
if (conf->share_rw) {
shared_perm |= BLK_PERM_WRITE;
}
ret = blk_set_perm(blk, perm, shared_perm, errp);
if (ret < 0) {
return;
}
switch (conf->wce) {
case ON_OFF_AUTO_ON: wce = true; break;
case ON_OFF_AUTO_OFF: wce = false; break;
case ON_OFF_AUTO_AUTO: wce = blk_enable_write_cache(blk); break;
default:
abort();
}
rerror = conf->rerror;
if (rerror == BLOCKDEV_ON_ERROR_AUTO) {
rerror = blk_get_on_error(blk, true);
}
werror = conf->werror;
if (werror == BLOCKDEV_ON_ERROR_AUTO) {
werror = blk_get_on_error(blk, false);
}
blk_set_enable_write_cache(blk, wce);
blk_set_on_error(blk, rerror, werror);
}
void blkconf_geometry(BlockConf *conf, int *ptrans,
unsigned cyls_max, unsigned heads_max, unsigned secs_max,
Error **errp)
{
DriveInfo *dinfo;
if (!conf->cyls && !conf->heads && !conf->secs) {
/* try to fall back to value set with legacy -drive cyls=... */
dinfo = blk_legacy_dinfo(conf->blk);
if (dinfo) {
conf->cyls = dinfo->cyls;
conf->heads = dinfo->heads;
conf->secs = dinfo->secs;
if (ptrans) {
*ptrans = dinfo->trans;
}
}
}
if (!conf->cyls && !conf->heads && !conf->secs) {
hd_geometry_guess(conf->blk,
&conf->cyls, &conf->heads, &conf->secs,
ptrans);
} else if (ptrans && *ptrans == BIOS_ATA_TRANSLATION_AUTO) {
*ptrans = hd_bios_chs_auto_trans(conf->cyls, conf->heads, conf->secs);
}
if (conf->cyls || conf->heads || conf->secs) {
if (conf->cyls < 1 || conf->cyls > cyls_max) {
error_setg(errp, "cyls must be between 1 and %u", cyls_max);
return;
}
if (conf->heads < 1 || conf->heads > heads_max) {
error_setg(errp, "heads must be between 1 and %u", heads_max);
return;
}
if (conf->secs < 1 || conf->secs > secs_max) {
error_setg(errp, "secs must be between 1 and %u", secs_max);
return;
}
}
}