From 7cd9b3964e2e8056c5863b6d9fd376bc0c1fcdf6 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 10 Nov 2016 16:13:15 +0100 Subject: 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 Reviewed-by: Alberto Garcia Reviewed-by: Eric Blake --- block/quorum.c | 128 ++++++++++++++++++++++++++------------------------------- 1 file changed, 59 insertions(+), 69 deletions(-) (limited to 'block') diff --git a/block/quorum.c b/block/quorum.c index e044010717..2c280bbef7 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 */ }; @@ -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]; + + 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) @@ -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]; + + 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 +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); -- cgit v1.2.3