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author | Alberto Garcia <berto@igalia.com> | 2019-05-13 16:46:17 +0300 |
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committer | Max Reitz <mreitz@redhat.com> | 2019-05-28 20:30:55 +0200 |
commit | dd4118c792a8c2a104fe90274e8a41e0db1ebc56 (patch) | |
tree | ee01a1736fdb4874e6c1c82a58061b4b8ee373fe /block.c | |
parent | ae6b12fa4cf7d54add35531c790aaf2bd6d833f3 (diff) | |
download | qemu-dd4118c792a8c2a104fe90274e8a41e0db1ebc56.zip qemu-dd4118c792a8c2a104fe90274e8a41e0db1ebc56.tar.gz qemu-dd4118c792a8c2a104fe90274e8a41e0db1ebc56.tar.bz2 |
block: Use bdrv_unref_child() for all children in bdrv_close()
bdrv_unref_child() does the following things:
- Updates the child->bs->inherits_from pointer.
- Calls bdrv_detach_child() to remove the BdrvChild from bs->children.
- Calls bdrv_unref() to unref the child BlockDriverState.
When bdrv_unref_child() was introduced in commit 33a604075c it was not
used in bdrv_close() because the drivers that had additional children
(like quorum or blkverify) had already called bdrv_unref() on their
children during their own close functions.
This was changed later (in 0bd6e91a7e for quorum, in 3e586be0b2 for
blkverify) so there's no reason not to use bdrv_unref_child() in
bdrv_close() anymore.
After this there's also no need to remove bs->backing and bs->file
separately from the rest of the children, so bdrv_close() can be
simplified.
Now bdrv_close() unrefs all children (before this patch it was only
bs->file and bs->backing). As a result, none of the callers of
brvd_attach_child() should remove their reference to child_bs (because
this function effectively steals that reference). This patch updates a
couple of tests that were doing their own bdrv_unref().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 6d1d5feaa53aa1ab127adb73d605dc4503e3abd5.1557754872.git.berto@igalia.com
[mreitz: s/where/were/]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 16 |
1 files changed, 3 insertions, 13 deletions
@@ -3877,22 +3877,12 @@ static void bdrv_close(BlockDriverState *bs) bs->drv = NULL; } - bdrv_set_backing_hd(bs, NULL, &error_abort); - - if (bs->file != NULL) { - bdrv_unref_child(bs, bs->file); - bs->file = NULL; - } - QLIST_FOREACH_SAFE(child, &bs->children, next, next) { - /* TODO Remove bdrv_unref() from drivers' close function and use - * bdrv_unref_child() here */ - if (child->bs->inherits_from == bs) { - child->bs->inherits_from = NULL; - } - bdrv_detach_child(child); + bdrv_unref_child(bs, child); } + bs->backing = NULL; + bs->file = NULL; g_free(bs->opaque); bs->opaque = NULL; atomic_set(&bs->copy_on_read, 0); |