From 25191e5ff0804bbd3b9e9dd86fb538c06710cee2 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 13 May 2020 13:05:33 +0200 Subject: [PATCH] block: Make backing files child_of_bds children Make all parents of backing files pass the appropriate BdrvChildRole. By doing so, we can switch their BdrvChildClass over to the generic child_of_bds, which will do the right thing when given a correct BdrvChildRole. Signed-off-by: Max Reitz Message-Id: <20200513110544.176672-24-mreitz@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block.c | 26 ++++++++++++++++++++------ block/backup-top.c | 2 +- block/vvfat.c | 3 ++- tests/test-bdrv-drain.c | 13 +++++++------ 4 files changed, 30 insertions(+), 14 deletions(-) diff --git a/block.c b/block.c index 85b4f947ba..131ae20ffc 100644 --- a/block.c +++ b/block.c @@ -2941,6 +2941,20 @@ static bool bdrv_inherits_from_recursive(BlockDriverState *child, return child != NULL; } +/* + * Return the BdrvChildRole for @bs's backing child. bs->backing is + * mostly used for COW backing children (role = COW), but also for + * filtered children (role = FILTERED | PRIMARY). + */ +static BdrvChildRole bdrv_backing_role(BlockDriverState *bs) +{ + if (bs->drv && bs->drv->is_filter) { + return BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY; + } else { + return BDRV_CHILD_COW; + } +} + /* * Sets the backing file link of a BDS. A new reference is created; callers * which don't need their own reference any more must call bdrv_unref(). @@ -2968,8 +2982,8 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, goto out; } - bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing, - 0, errp); + bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds, + bdrv_backing_role(bs), errp); /* If backing_hd was already part of bs's backing chain, and * inherits_from pointed recursively to bs then let's update it to * point directly to bs (else it will become NULL). */ @@ -3066,7 +3080,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, } backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs, - &child_backing, 0, errp); + &child_of_bds, bdrv_backing_role(bs), errp); if (!backing_hd) { bs->open_flags |= BDRV_O_NO_BACKING; error_prepend(errp, "Could not open backing file: "); @@ -3895,8 +3909,8 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) if (state->replace_backing_bs && state->new_backing_bs) { uint64_t nperm, nshared; bdrv_child_perm(state->bs, state->new_backing_bs, - NULL, &child_backing, 0, bs_queue, - state->perm, state->shared_perm, + NULL, &child_of_bds, bdrv_backing_role(state->bs), + bs_queue, state->perm, state->shared_perm, &nperm, &nshared); ret = bdrv_check_update_perm(state->new_backing_bs, NULL, nperm, nshared, NULL, NULL, errp); @@ -6852,7 +6866,7 @@ void bdrv_refresh_filename(BlockDriverState *bs) drv->bdrv_gather_child_options(bs, opts, backing_overridden); } else { QLIST_FOREACH(child, &bs->children, next) { - if (child->klass == &child_backing && !backing_overridden) { + if (child == bs->backing && !backing_overridden) { /* We can skip the backing BDS if it has not been overridden */ continue; } diff --git a/block/backup-top.c b/block/backup-top.c index e2b4d2acd3..f059617095 100644 --- a/block/backup-top.c +++ b/block/backup-top.c @@ -143,7 +143,7 @@ static void backup_top_child_perm(BlockDriverState *bs, BdrvChild *c, return; } - if (child_class == &child_file) { + if (!(role & BDRV_CHILD_FILTERED)) { /* * Target child * diff --git a/block/vvfat.c b/block/vvfat.c index b4c8417dbd..e8848a0497 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -3219,7 +3219,8 @@ static void vvfat_child_perm(BlockDriverState *bs, BdrvChild *c, { BDRVVVFATState *s = bs->opaque; - assert(c == s->qcow || child_class == &child_backing); + assert(c == s->qcow || + (child_class == &child_of_bds && (role & BDRV_CHILD_COW))); if (c == s->qcow) { /* This is a private node, nobody should try to attach to it */ diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c index b3d7960bd0..15393a0140 100644 --- a/tests/test-bdrv-drain.c +++ b/tests/test-bdrv-drain.c @@ -96,7 +96,7 @@ static void bdrv_test_child_perm(BlockDriverState *bs, BdrvChild *c, * bdrv_format_default_perms() accepts only these two, so disguise * detach_by_driver_cb_parent as one of them. */ - if (child_class != &child_file && child_class != &child_backing) { + if (child_class != &child_file && child_class != &child_of_bds) { child_class = &child_file; } @@ -1399,8 +1399,8 @@ static void test_detach_indirect(bool by_parent_cb) bdrv_ref(a); child_b = bdrv_attach_child(parent_b, b, "PB-B", &child_file, 0, &error_abort); - child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_backing, 0, - &error_abort); + child_a = bdrv_attach_child(parent_b, a, "PB-A", &child_of_bds, + BDRV_CHILD_COW, &error_abort); bdrv_ref(a); bdrv_attach_child(parent_a, a, "PA-A", @@ -1793,7 +1793,7 @@ static void test_drop_intermediate_poll(void) int i; int ret; - chain_child_class = child_backing; + chain_child_class = child_of_bds; chain_child_class.update_filename = drop_intermediate_poll_update_filename; for (i = 0; i < 3; i++) { @@ -1816,7 +1816,7 @@ static void test_drop_intermediate_poll(void) /* Takes the reference to chain[i - 1] */ chain[i]->backing = bdrv_attach_child(chain[i], chain[i - 1], "chain", &chain_child_class, - 0, &error_abort); + BDRV_CHILD_COW, &error_abort); } } @@ -2034,7 +2034,8 @@ static void do_test_replace_child_mid_drain(int old_drain_count, bdrv_ref(old_child_bs); parent_bs->backing = bdrv_attach_child(parent_bs, old_child_bs, "child", - &child_backing, 0, &error_abort); + &child_of_bds, BDRV_CHILD_COW, + &error_abort); for (i = 0; i < old_drain_count; i++) { bdrv_drained_begin(old_child_bs);