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quorum: Inline quorum_aio_cb() 

This is a conversion to a more natural coroutine style and improves the
readability of the driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Kevin Wolf 2016-11-10 16:13:15 +01:00
parent 0f31977d9d
commit 7cd9b3964e
1 changed files with 59 additions and 69 deletions
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128
block/quorum.c
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@ -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 */
};
@ -140,8 +139,6 @@ typedef struct QuorumCo {
int idx;
} QuorumCo;
static bool quorum_vote(QuorumAIOCB *acb);
static void quorum_aio_finalize(QuorumAIOCB *acb)
{
g_free(acb->qcrs);
@ -178,7 +175,6 @@ 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 +227,6 @@ 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 +277,6 @@ 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)
@ -557,17 +507,16 @@ static int quorum_vote_error(QuorumAIOCB *acb)
return ret;
}
static bool quorum_vote(QuorumAIOCB *acb)
static void quorum_vote(QuorumAIOCB *acb)
{
bool quorum = true;
bool rewrite = false;
int i, j, ret;
QuorumVoteValue hash;
BDRVQuorumState *s = acb->bs->opaque;
QuorumVoteVersion *winner;
if (quorum_has_too_much_io_failed(acb)) {
return false;
return;
}
/* get the index of the first successful read */
@ -595,7 +544,7 @@ static bool quorum_vote(QuorumAIOCB *acb)
/* Every successful read agrees */
if (quorum) {
quorum_copy_qiov(acb->qiov, &acb->qcrs[i].qiov);
return false;
return;
}
/* compute hashes for each successful read, also store indexes */
@ -630,13 +579,12 @@ static bool quorum_vote(QuorumAIOCB *acb)
/* corruption correction is enabled */
if (s->rewrite_corrupted) {
rewrite = quorum_rewrite_bad_versions(s, acb, &winner->value);
quorum_rewrite_bad_versions(s, acb, &winner->value);
}
free_exit:
/* free lists */
quorum_free_vote_list(&acb->votes);
return rewrite;
}
static void read_quorum_children_entry(void *opaque)
@ -645,13 +593,28 @@ 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];
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);
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->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)
@ -677,7 +640,18 @@ 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 */
quorum_vote(acb);
for (i = 0; i < s->num_children; i++) {
qemu_vfree(acb->qcrs[i].buf);
qemu_iovec_destroy(&acb->qcrs[i].qiov);
}
while (acb->rewrite_count) {
qemu_coroutine_yield();
}
@ -727,12 +701,26 @@ 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];
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);
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);
/* 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 +742,12 @@ 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);