From 6e93e7c41fdfdee3068770cae79380e1d986b76a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 8 Apr 2015 13:49:41 +0200 Subject: block: Add list of children to BlockDriverState This allows iterating over all children of a given BDS, not only including bs->file and bs->backing_hd, but also driver-specific ones like VMDK extents or Quorum children. For bdrv_swap(), the list of children of the swapped BDS stays at that BDS (because that's where the pointers stay as well). The list head moves and pointers to it must be fixed up therefore. The list of children in the parent of the swapped BDS is not affected by the swap. The contents of the BDS objects is swapped, so the existing pointer in the parent automatically points to the newly swapped in BDS. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Max Reitz --- block.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'block.c') diff --git a/block.c b/block.c index 9a860f12c7..209ba39d31 100644 --- a/block.c +++ b/block.c @@ -1325,6 +1325,19 @@ out: return ret; } +static void bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const BdrvChildRole *child_role) +{ + BdrvChild *child = g_new(BdrvChild, 1); + *child = (BdrvChild) { + .bs = child_bs, + .role = child_role, + }; + + QLIST_INSERT_HEAD(&parent_bs->children, child, next); +} + /* * Opens a disk image (raw, qcow2, vmdk, ...) * @@ -1377,6 +1390,9 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, return -ENODEV; } bdrv_ref(bs); + if (child_role) { + bdrv_attach_child(parent, bs, child_role); + } *pbs = bs; return 0; } @@ -1520,6 +1536,10 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, goto close_and_fail; } + if (child_role) { + bdrv_attach_child(parent, bs, child_role); + } + QDECREF(options); *pbs = bs; return 0; @@ -1814,6 +1834,13 @@ void bdrv_close(BlockDriverState *bs) notifier_list_notify(&bs->close_notifiers, bs); if (bs->drv) { + BdrvChild *child, *next; + + QLIST_FOREACH_SAFE(child, &bs->children, next, next) { + QLIST_REMOVE(child, next); + g_free(child); + } + if (bs->backing_hd) { BlockDriverState *backing_hd = bs->backing_hd; bdrv_set_backing_hd(bs, NULL); @@ -2005,9 +2032,18 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list); } + /* + * Update lh_first.le_prev for non-empty lists. + * + * The head of the op blocker list doesn't change because it is moved back + * in bdrv_move_feature_fields(). + */ assert(QLIST_EMPTY(&bs_old->tracked_requests)); assert(QLIST_EMPTY(&bs_new->tracked_requests)); + QLIST_FIX_HEAD_PTR(&bs_new->children, next); + QLIST_FIX_HEAD_PTR(&bs_old->children, next); + bdrv_rebind(bs_new); bdrv_rebind(bs_old); } @@ -2030,6 +2066,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) /* The contents of 'tmp' will become bs_top, as we are * swapping bs_new and bs_top contents. */ bdrv_set_backing_hd(bs_top, bs_new); + bdrv_attach_child(bs_top, bs_new, &child_backing); } static void bdrv_delete(BlockDriverState *bs) -- cgit v1.2.3