From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59830) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3Rkd-0005DZ-RS for qemu-devel@nongnu.org; Fri, 12 Jun 2015 12:24:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z3Rkc-00054y-Na for qemu-devel@nongnu.org; Fri, 12 Jun 2015 12:24:15 -0400 From: Kevin Wolf Date: Fri, 12 Jun 2015 18:23:32 +0200 Message-Id: <1434126214-11681-24-git-send-email-kwolf@redhat.com> In-Reply-To: <1434126214-11681-1-git-send-email-kwolf@redhat.com> References: <1434126214-11681-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 23/25] block: Add list of children to BlockDriverState List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org 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 +++++++++++++++++++++++++++++++++++++ include/block/block_int.h | 8 ++++++++ 2 files changed, 45 insertions(+) diff --git a/block.c b/block.c index 9a860f1..209ba39 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) diff --git a/include/block/block_int.h b/include/block/block_int.h index 662dd56..4ae5860 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -337,6 +337,12 @@ struct BdrvChildRole { extern const BdrvChildRole child_file; extern const BdrvChildRole child_format; +typedef struct BdrvChild { + BlockDriverState *bs; + const BdrvChildRole *role; + QLIST_ENTRY(BdrvChild) next; +} BdrvChild; + /* * Note: the function bdrv_append() copies and swaps contents of * BlockDriverStates, so if you add new fields to this struct, please @@ -431,6 +437,8 @@ struct BlockDriverState { /* long-running background operation */ BlockJob *job; + QLIST_HEAD(, BdrvChild) children; + QDict *options; BlockdevDetectZeroesOptions detect_zeroes; -- 1.8.3.1