From: Lukas Straub <lukasstra...@web.de> If we remove the child with the highest index from the quorum, decrement s->next_child_index. This way we get stable children names as long as we only remove the last child.
Signed-off-by: Lukas Straub <lukasstra...@web.de> Fixes: https://bugs.launchpad.net/bugs/1881231 Reviewed-by: Zhang Chen <chen.zh...@intel.com> Reviewed-by: Alberto Garcia <be...@igalia.com> Message-Id: <5d5f930424c1c770754041aa8ad6421dc4e2b58e.1596536719.git.lukasstra...@web.de> Signed-off-by: Max Reitz <mre...@redhat.com> --- block/quorum.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/block/quorum.c b/block/quorum.c index 6df9449fc2..e846a7e892 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -29,6 +29,8 @@ #define HASH_LENGTH 32 +#define INDEXSTR_LEN 32 + #define QUORUM_OPT_VOTE_THRESHOLD "vote-threshold" #define QUORUM_OPT_BLKVERIFY "blkverify" #define QUORUM_OPT_REWRITE "rewrite-corrupted" @@ -970,9 +972,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, opened = g_new0(bool, s->num_children); for (i = 0; i < s->num_children; i++) { - char indexstr[32]; - ret = snprintf(indexstr, 32, "children.%d", i); - assert(ret < 32); + char indexstr[INDEXSTR_LEN]; + ret = snprintf(indexstr, INDEXSTR_LEN, "children.%d", i); + assert(ret < INDEXSTR_LEN); s->children[i] = bdrv_open_child(NULL, options, indexstr, bs, &child_of_bds, BDRV_CHILD_DATA, false, @@ -1024,7 +1026,7 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, { BDRVQuorumState *s = bs->opaque; BdrvChild *child; - char indexstr[32]; + char indexstr[INDEXSTR_LEN]; int ret; if (s->is_blkverify) { @@ -1039,8 +1041,8 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, return; } - ret = snprintf(indexstr, 32, "children.%u", s->next_child_index); - if (ret < 0 || ret >= 32) { + ret = snprintf(indexstr, INDEXSTR_LEN, "children.%u", s->next_child_index); + if (ret < 0 || ret >= INDEXSTR_LEN) { error_setg(errp, "cannot generate child name"); return; } @@ -1068,6 +1070,7 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, Error **errp) { BDRVQuorumState *s = bs->opaque; + char indexstr[INDEXSTR_LEN]; int i; for (i = 0; i < s->num_children; i++) { @@ -1089,6 +1092,11 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, /* We know now that num_children > threshold, so blkverify must be false */ assert(!s->is_blkverify); + snprintf(indexstr, INDEXSTR_LEN, "children.%u", s->next_child_index - 1); + if (!strncmp(child->name, indexstr, INDEXSTR_LEN)) { + s->next_child_index--; + } + bdrv_drained_begin(bs); /* We can safely remove this child now */ -- 2.26.2
