This is a conversion to a more natural coroutine style and improves the
readability of the driver.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Alberto Garcia <be...@igalia.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
block/quorum.c | 118 ++++++++++++++++++++++++++++-----------------------------
1 file changed, 57 insertions(+), 61 deletions(-)
diff --git a/block/quorum.c b/block/quorum.c
index e044010..8513414 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -130,7 +130,6 @@ struct QuorumAIOCB {
QuorumVotes votes;
bool is_read;
- bool has_completed;
int vote_ret;
int children_read; /* how many children have been read from */
};
@@ -178,7 +177,6 @@ static QuorumAIOCB *quorum_aio_get(BlockDriverState *bs,
acb->rewrite_count = 0;
acb->votes.compare = quorum_sha256_compare;
QLIST_INIT(&acb->votes.vote_list);
- acb->has_completed = false;
acb->is_read = false;
acb->vote_ret = 0;
@@ -231,13 +229,6 @@ static void quorum_rewrite_aio_cb(void *opaque, int ret)
/* one less rewrite to do */
acb->rewrite_count--;
-
- /* wait until all rewrite callbacks have completed */
- if (acb->rewrite_count) {
- return;
- }
-
- acb->has_completed = true;
qemu_coroutine_enter_if_inactive(acb->co);
}
@@ -288,45 +279,6 @@ static int quorum_fifo_aio_cb(void *opaque, int ret)
return ret;
}
-static void quorum_aio_cb(void *opaque, int ret)
-{
- QuorumChildRequest *sacb = opaque;
- QuorumAIOCB *acb = sacb->parent;
- BDRVQuorumState *s = acb->bs->opaque;
- bool rewrite = false;
- int i;
-
- sacb->ret = ret;
- if (ret == 0) {
- acb->success_count++;
- } else {
- quorum_report_bad_acb(sacb, ret);
- }
- acb->count++;
- assert(acb->count <= s->num_children);
- assert(acb->success_count <= s->num_children);
- if (acb->count < s->num_children) {
- return;
- }
-
- /* Do the vote on read */
- if (acb->is_read) {
- rewrite = quorum_vote(acb);
- for (i = 0; i < s->num_children; i++) {
- qemu_vfree(acb->qcrs[i].buf);
- qemu_iovec_destroy(&acb->qcrs[i].qiov);
- }
- } else {
- quorum_has_too_much_io_failed(acb);
- }
-
- /* if no rewrite is done the code will finish right away */
- if (!rewrite) {
- acb->has_completed = true;
- qemu_coroutine_enter_if_inactive(acb->co);
- }
-}
-
static void quorum_report_bad_versions(BDRVQuorumState *s,
QuorumAIOCB *acb,
QuorumVoteValue *value)
@@ -645,18 +597,34 @@ static void read_quorum_children_entry(void *opaque)
QuorumAIOCB *acb = co->acb;
BDRVQuorumState *s = acb->bs->opaque;
int i = co->idx;
- int ret;
+ QuorumChildRequest *sacb = &acb->qcrs[i];
+
+ sacb->bs = s->children[i]->bs;
+ sacb->ret = bdrv_co_preadv(s->children[i],
+ acb->sector_num * BDRV_SECTOR_SIZE,
+ acb->nb_sectors * BDRV_SECTOR_SIZE,
+ &acb->qcrs[i].qiov, 0);
+
+ if (sacb->ret == 0) {
+ acb->success_count++;
+ } else {
+ quorum_report_bad_acb(sacb, sacb->ret);
+ }
- acb->qcrs[i].bs = s->children[i]->bs;
- ret = bdrv_co_preadv(s->children[i], acb->sector_num * BDRV_SECTOR_SIZE,
- acb->nb_sectors * BDRV_SECTOR_SIZE,
- &acb->qcrs[i].qiov, 0);
- quorum_aio_cb(&acb->qcrs[i], ret);
+ acb->count++;
+ assert(acb->count <= s->num_children);
+ assert(acb->success_count <= s->num_children);
+
+ /* Wake up the caller after the last read */
+ if (acb->count == s->num_children) {
+ qemu_coroutine_enter_if_inactive(acb->co);
+ }
}
static int read_quorum_children(QuorumAIOCB *acb)
{
BDRVQuorumState *s = acb->bs->opaque;
+ bool rewrite = false;
int i, ret;
acb->children_read = s->num_children;
@@ -677,7 +645,19 @@ static int read_quorum_children(QuorumAIOCB *acb)
qemu_coroutine_enter(co);
}
- if (!acb->has_completed) {
+ while (acb->count < s->num_children) {
+ qemu_coroutine_yield();
+ }
+
+ /* Do the vote on read */
+ rewrite = quorum_vote(acb);
+ for (i = 0; i < s->num_children; i++) {
+ qemu_vfree(acb->qcrs[i].buf);
+ qemu_iovec_destroy(&acb->qcrs[i].qiov);
+ }
+
+ assert(rewrite == !!acb->rewrite_count);
+ while (acb->rewrite_count) {
qemu_coroutine_yield();
}
@@ -727,12 +707,26 @@ static void write_quorum_entry(void *opaque)
QuorumAIOCB *acb = co->acb;
BDRVQuorumState *s = acb->bs->opaque;
int i = co->idx;
- int ret;
+ QuorumChildRequest *sacb = &acb->qcrs[i];
+
+ sacb->bs = s->children[i]->bs;
+ sacb->ret = bdrv_co_pwritev(s->children[i],
+ acb->sector_num * BDRV_SECTOR_SIZE,
+ acb->nb_sectors * BDRV_SECTOR_SIZE,
+ acb->qiov, 0);
+ if (sacb->ret == 0) {
+ acb->success_count++;
+ } else {
+ quorum_report_bad_acb(sacb, sacb->ret);
+ }
+ acb->count++;
+ assert(acb->count <= s->num_children);
+ assert(acb->success_count <= s->num_children);
- acb->qcrs[i].bs = s->children[i]->bs;
- ret = bdrv_co_pwritev(s->children[i], acb->sector_num * BDRV_SECTOR_SIZE,
- acb->nb_sectors * BDRV_SECTOR_SIZE, acb->qiov, 0);
- quorum_aio_cb(&acb->qcrs[i], ret);
+ /* Wake up the caller after the last write */
+ if (acb->count == s->num_children) {
+ qemu_coroutine_enter_if_inactive(acb->co);
+ }
}
static int quorum_co_writev(BlockDriverState *bs,
@@ -754,10 +748,12 @@ static int quorum_co_writev(BlockDriverState *bs,
qemu_coroutine_enter(co);
}
- if (!acb->has_completed) {
+ while (acb->count < s->num_children) {
qemu_coroutine_yield();
}
+ quorum_has_too_much_io_failed(acb);
+
ret = acb->vote_ret;
quorum_aio_finalize(acb);
--
1.8.3.1
