blockdev: add refcount to DriveInfo

The host part of a block device can be deleted with in progress
block migration.

To fix this, add a reference count to DriveInfo, freeing resources
on last reference.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Marcelo Tosatti 2011-01-26 12:12:32 -02:00 committed by Kevin Wolf
parent 8f794c557c
commit 84fb392526
3 changed files with 20 additions and 4 deletions

View File

@ -71,7 +71,7 @@ void blockdev_auto_del(BlockDriverState *bs)
DriveInfo *dinfo = drive_get_by_blockdev(bs);
if (dinfo && dinfo->auto_del) {
drive_uninit(dinfo);
drive_put_ref(dinfo);
}
}
@ -178,7 +178,7 @@ static void bdrv_format_print(void *opaque, const char *name)
error_printf(" %s", name);
}
void drive_uninit(DriveInfo *dinfo)
static void drive_uninit(DriveInfo *dinfo)
{
qemu_opts_del(dinfo->opts);
bdrv_delete(dinfo->bdrv);
@ -186,6 +186,19 @@ void drive_uninit(DriveInfo *dinfo)
qemu_free(dinfo);
}
void drive_put_ref(DriveInfo *dinfo)
{
assert(dinfo->refcount);
if (--dinfo->refcount == 0) {
drive_uninit(dinfo);
}
}
void drive_get_ref(DriveInfo *dinfo)
{
dinfo->refcount++;
}
static int parse_block_error_action(const char *buf, int is_read)
{
if (!strcmp(buf, "ignore")) {
@ -453,6 +466,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
dinfo->bus = bus_id;
dinfo->unit = unit_id;
dinfo->opts = opts;
dinfo->refcount = 1;
if (serial)
strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
QTAILQ_INSERT_TAIL(&drives, dinfo, next);

View File

@ -36,13 +36,15 @@ struct DriveInfo {
QemuOpts *opts;
char serial[BLOCK_SERIAL_STRLEN + 1];
QTAILQ_ENTRY(DriveInfo) next;
int refcount;
};
DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit);
DriveInfo *drive_get_by_index(BlockInterfaceType type, int index);
int drive_get_max_bus(BlockInterfaceType type);
DriveInfo *drive_get_next(BlockInterfaceType type);
void drive_uninit(DriveInfo *dinfo);
void drive_get_ref(DriveInfo *dinfo);
void drive_put_ref(DriveInfo *dinfo);
DriveInfo *drive_get_by_blockdev(BlockDriverState *bs);
QemuOpts *drive_def(const char *optstr);

View File

@ -147,7 +147,7 @@ void drive_hot_add(Monitor *mon, const QDict *qdict)
err:
if (dinfo)
drive_uninit(dinfo);
drive_put_ref(dinfo);
return;
}