From 29d782710f87f01991bfc85cd9bef7d15280a5e2 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Sat, 25 May 2013 11:09:42 +0800 Subject: block: drop bs_snapshots global variable The bs_snapshots global variable points to the BlockDriverState which will be used to save vmstate. This is really a savevm.c concept but was moved into block.c:bdrv_snapshots() when it became clear that hotplug could result in a dangling pointer. While auditing the block layer's global state I came upon bs_snapshots and realized that a variable is not necessary here. Simply find the first BlockDriverState capable of internal snapshots each time this is needed. The behavior of bdrv_snapshots() is preserved across hotplug because new drives are always appended to the bdrv_states list. This means that calling the new find_vmstate_bs() function is idempotent - it returns the same BlockDriverState unless it was hot-unplugged. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Wenchao Xia Signed-off-by: Wenchao Xia Signed-off-by: Kevin Wolf --- block.c | 28 ---------------------------- 1 file changed, 28 deletions(-) (limited to 'block.c') diff --git a/block.c b/block.c index 65c0b60..e046a31 100644 --- a/block.c +++ b/block.c @@ -99,9 +99,6 @@ static QTAILQ_HEAD(, BlockDriverState) bdrv_states = static QLIST_HEAD(, BlockDriver) bdrv_drivers = QLIST_HEAD_INITIALIZER(bdrv_drivers); -/* The device to use for VM snapshots */ -static BlockDriverState *bs_snapshots; - /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; @@ -1368,9 +1365,6 @@ void bdrv_close(BlockDriverState *bs) notifier_list_notify(&bs->close_notifiers, bs); if (bs->drv) { - if (bs == bs_snapshots) { - bs_snapshots = NULL; - } if (bs->backing_hd) { bdrv_delete(bs->backing_hd); bs->backing_hd = NULL; @@ -1602,7 +1596,6 @@ void bdrv_delete(BlockDriverState *bs) bdrv_close(bs); - assert(bs != bs_snapshots); g_free(bs); } @@ -1646,9 +1639,6 @@ void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, { bs->dev_ops = ops; bs->dev_opaque = opaque; - if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) { - bs_snapshots = NULL; - } } void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, @@ -3392,24 +3382,6 @@ int bdrv_is_snapshot(BlockDriverState *bs) return !!(bs->open_flags & BDRV_O_SNAPSHOT); } -BlockDriverState *bdrv_snapshots(void) -{ - BlockDriverState *bs; - - if (bs_snapshots) { - return bs_snapshots; - } - - bs = NULL; - while ((bs = bdrv_next(bs))) { - if (bdrv_can_snapshot(bs)) { - bs_snapshots = bs; - return bs; - } - } - return NULL; -} - int bdrv_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) { -- cgit v1.1