Message ID | 20191111160216.197086-10-mreitz@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | block: Fix check_to_replace_node() | expand |
11.11.2019 19:02, Max Reitz wrote: > We will need this to verify that Quorum can let one of its children be > replaced without breaking anything else. > > Signed-off-by: Max Reitz <mreitz@redhat.com> > --- > block/quorum.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/block/quorum.c b/block/quorum.c > index 59cd524502..3a824e77e3 100644 > --- a/block/quorum.c > +++ b/block/quorum.c > @@ -67,6 +67,13 @@ typedef struct QuorumVotes { > > typedef struct QuorumChild { > BdrvChild *child; > + > + /* > + * If set, check whether this node can be replaced without any > + * other parent noticing: Unshare CONSISTENT_READ, and take the > + * WRITE permission. > + */ > + bool to_be_replaced; > } QuorumChild; > > /* the following structure holds the state of one quorum instance */ > @@ -1128,6 +1135,16 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, > uint64_t perm, uint64_t shared, > uint64_t *nperm, uint64_t *nshared) > { > + BDRVQuorumState *s = bs->opaque; > + int i; > + loop is still useless if c == NULL... if (c) { > + for (i = 0; i < s->num_children; i++) { > + if (s->children[i].child == c) { > + break; > + } > + } assert(i < s->num_children); } > + > *nperm = perm & DEFAULT_PERM_PASSTHROUGH; > > /* > @@ -1137,6 +1154,12 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, > *nshared = (shared & (BLK_PERM_CONSISTENT_READ | > BLK_PERM_WRITE_UNCHANGED)) > | DEFAULT_PERM_UNCHANGED; > + > + if (c && s->children[i].to_be_replaced) { > + /* Prepare for sudden data changes */ > + *nperm |= BLK_PERM_WRITE; > + *nshared &= ~BLK_PERM_CONSISTENT_READ; > + } > } > > static const char *const quorum_strong_runtime_opts[] = { > with or without "if (c)": Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
diff --git a/block/quorum.c b/block/quorum.c index 59cd524502..3a824e77e3 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -67,6 +67,13 @@ typedef struct QuorumVotes { typedef struct QuorumChild { BdrvChild *child; + + /* + * If set, check whether this node can be replaced without any + * other parent noticing: Unshare CONSISTENT_READ, and take the + * WRITE permission. + */ + bool to_be_replaced; } QuorumChild; /* the following structure holds the state of one quorum instance */ @@ -1128,6 +1135,16 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { + BDRVQuorumState *s = bs->opaque; + int i; + + for (i = 0; i < s->num_children; i++) { + if (s->children[i].child == c) { + break; + } + } + assert(!c || i < s->num_children); + *nperm = perm & DEFAULT_PERM_PASSTHROUGH; /* @@ -1137,6 +1154,12 @@ static void quorum_child_perm(BlockDriverState *bs, BdrvChild *c, *nshared = (shared & (BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED)) | DEFAULT_PERM_UNCHANGED; + + if (c && s->children[i].to_be_replaced) { + /* Prepare for sudden data changes */ + *nperm |= BLK_PERM_WRITE; + *nshared &= ~BLK_PERM_CONSISTENT_READ; + } } static const char *const quorum_strong_runtime_opts[] = {
We will need this to verify that Quorum can let one of its children be replaced without breaking anything else. Signed-off-by: Max Reitz <mreitz@redhat.com> --- block/quorum.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)