From 37a3791b380584949046af6b62b54869390616dc Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Tue, 18 Feb 2020 11:34:40 +0100 Subject: [PATCH] quorum: Fix child permissions Quorum cannot share WRITE or RESIZE on its children. Presumably, it only does so because as a filter, it seemed intuitively correct to point its .bdrv_child_perm to bdrv_filter_default_perm(). However, it is not really a filter, and bdrv_filter_default_perm() does not work for it, so we have to provide a custom .bdrv_child_perm implementation. Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20200218103454.296704-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf --- block/quorum.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/block/quorum.c b/block/quorum.c index df68adcfaa..17b439056f 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -1114,6 +1114,23 @@ static char *quorum_dirname(BlockDriverState *bs, Error **errp) return NULL; } +static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, + const BdrvChildRole *role, + BlockReopenQueue *reopen_queue, + uint64_t perm, uint64_t shared, + uint64_t *nperm, uint64_t *nshared) +{ + *nperm = perm & DEFAULT_PERM_PASSTHROUGH; + + /* + * We cannot share RESIZE or WRITE, as this would make the + * children differ from each other. + */ + *nshared = (shared & (BLK_PERM_CONSISTENT_READ | + BLK_PERM_WRITE_UNCHANGED)) + | DEFAULT_PERM_UNCHANGED; +} + static const char *const quorum_strong_runtime_opts[] = { QUORUM_OPT_VOTE_THRESHOLD, QUORUM_OPT_BLKVERIFY, @@ -1143,7 +1160,7 @@ static BlockDriver bdrv_quorum = { .bdrv_add_child = quorum_add_child, .bdrv_del_child = quorum_del_child, - .bdrv_child_perm = bdrv_filter_default_perms, + .bdrv_child_perm = quorum_child_perm, .is_filter = true, .bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter,