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-rw-r--r--block/quorum.c177
1 files changed, 129 insertions, 48 deletions
diff --git a/block/quorum.c b/block/quorum.c
index 0de07bb036..0160fe3ae9 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -29,6 +29,7 @@
#define QUORUM_OPT_VOTE_THRESHOLD "vote-threshold"
#define QUORUM_OPT_BLKVERIFY "blkverify"
#define QUORUM_OPT_REWRITE "rewrite-corrupted"
+#define QUORUM_OPT_READ_PATTERN "read-pattern"
/* This union holds a vote hash value */
typedef union QuorumVoteValue {
@@ -79,6 +80,8 @@ typedef struct BDRVQuorumState {
bool rewrite_corrupted;/* true if the driver must rewrite-on-read corrupted
* block if Quorum is reached.
*/
+
+ QuorumReadPattern read_pattern;
} BDRVQuorumState;
typedef struct QuorumAIOCB QuorumAIOCB;
@@ -122,6 +125,7 @@ struct QuorumAIOCB {
bool is_read;
int vote_ret;
+ int child_iter; /* which child to read in fifo pattern */
};
static bool quorum_vote(QuorumAIOCB *acb);
@@ -148,7 +152,6 @@ static AIOCBInfo quorum_aiocb_info = {
static void quorum_aio_finalize(QuorumAIOCB *acb)
{
- BDRVQuorumState *s = acb->common.bs->opaque;
int i, ret = 0;
if (acb->vote_ret) {
@@ -158,7 +161,8 @@ static void quorum_aio_finalize(QuorumAIOCB *acb)
acb->common.cb(acb->common.opaque, ret);
if (acb->is_read) {
- for (i = 0; i < s->num_children; i++) {
+ /* on the quorum case acb->child_iter == s->num_children - 1 */
+ for (i = 0; i <= acb->child_iter; i++) {
qemu_vfree(acb->qcrs[i].buf);
qemu_iovec_destroy(&acb->qcrs[i].qiov);
}
@@ -261,6 +265,21 @@ static void quorum_rewrite_aio_cb(void *opaque, int ret)
quorum_aio_finalize(acb);
}
+static BlockDriverAIOCB *read_fifo_child(QuorumAIOCB *acb);
+
+static void quorum_copy_qiov(QEMUIOVector *dest, QEMUIOVector *source)
+{
+ int i;
+ assert(dest->niov == source->niov);
+ assert(dest->size == source->size);
+ for (i = 0; i < source->niov; i++) {
+ assert(dest->iov[i].iov_len == source->iov[i].iov_len);
+ memcpy(dest->iov[i].iov_base,
+ source->iov[i].iov_base,
+ source->iov[i].iov_len);
+ }
+}
+
static void quorum_aio_cb(void *opaque, int ret)
{
QuorumChildRequest *sacb = opaque;
@@ -268,6 +287,21 @@ static void quorum_aio_cb(void *opaque, int ret)
BDRVQuorumState *s = acb->common.bs->opaque;
bool rewrite = false;
+ if (acb->is_read && s->read_pattern == QUORUM_READ_PATTERN_FIFO) {
+ /* We try to read next child in FIFO order if we fail to read */
+ if (ret < 0 && ++acb->child_iter < s->num_children) {
+ read_fifo_child(acb);
+ return;
+ }
+
+ if (ret == 0) {
+ quorum_copy_qiov(acb->qiov, &acb->qcrs[acb->child_iter].qiov);
+ }
+ acb->vote_ret = ret;
+ quorum_aio_finalize(acb);
+ return;
+ }
+
sacb->ret = ret;
acb->count++;
if (ret == 0) {
@@ -348,19 +382,6 @@ static bool quorum_rewrite_bad_versions(BDRVQuorumState *s, QuorumAIOCB *acb,
return count;
}
-static void quorum_copy_qiov(QEMUIOVector *dest, QEMUIOVector *source)
-{
- int i;
- assert(dest->niov == source->niov);
- assert(dest->size == source->size);
- for (i = 0; i < source->niov; i++) {
- assert(dest->iov[i].iov_len == source->iov[i].iov_len);
- memcpy(dest->iov[i].iov_base,
- source->iov[i].iov_base,
- source->iov[i].iov_len);
- }
-}
-
static void quorum_count_vote(QuorumVotes *votes,
QuorumVoteValue *value,
int index)
@@ -620,34 +641,62 @@ free_exit:
return rewrite;
}
-static BlockDriverAIOCB *quorum_aio_readv(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov,
- int nb_sectors,
- BlockDriverCompletionFunc *cb,
- void *opaque)
+static BlockDriverAIOCB *read_quorum_children(QuorumAIOCB *acb)
{
- BDRVQuorumState *s = bs->opaque;
- QuorumAIOCB *acb = quorum_aio_get(s, bs, qiov, sector_num,
- nb_sectors, cb, opaque);
+ BDRVQuorumState *s = acb->common.bs->opaque;
int i;
- acb->is_read = true;
-
for (i = 0; i < s->num_children; i++) {
- acb->qcrs[i].buf = qemu_blockalign(s->bs[i], qiov->size);
- qemu_iovec_init(&acb->qcrs[i].qiov, qiov->niov);
- qemu_iovec_clone(&acb->qcrs[i].qiov, qiov, acb->qcrs[i].buf);
+ acb->qcrs[i].buf = qemu_blockalign(s->bs[i], acb->qiov->size);
+ qemu_iovec_init(&acb->qcrs[i].qiov, acb->qiov->niov);
+ qemu_iovec_clone(&acb->qcrs[i].qiov, acb->qiov, acb->qcrs[i].buf);
}
for (i = 0; i < s->num_children; i++) {
- bdrv_aio_readv(s->bs[i], sector_num, &acb->qcrs[i].qiov, nb_sectors,
- quorum_aio_cb, &acb->qcrs[i]);
+ bdrv_aio_readv(s->bs[i], acb->sector_num, &acb->qcrs[i].qiov,
+ acb->nb_sectors, quorum_aio_cb, &acb->qcrs[i]);
}
return &acb->common;
}
+static BlockDriverAIOCB *read_fifo_child(QuorumAIOCB *acb)
+{
+ BDRVQuorumState *s = acb->common.bs->opaque;
+
+ acb->qcrs[acb->child_iter].buf = qemu_blockalign(s->bs[acb->child_iter],
+ acb->qiov->size);
+ qemu_iovec_init(&acb->qcrs[acb->child_iter].qiov, acb->qiov->niov);
+ qemu_iovec_clone(&acb->qcrs[acb->child_iter].qiov, acb->qiov,
+ acb->qcrs[acb->child_iter].buf);
+ bdrv_aio_readv(s->bs[acb->child_iter], acb->sector_num,
+ &acb->qcrs[acb->child_iter].qiov, acb->nb_sectors,
+ quorum_aio_cb, &acb->qcrs[acb->child_iter]);
+
+ return &acb->common;
+}
+
+static BlockDriverAIOCB *quorum_aio_readv(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BlockDriverCompletionFunc *cb,
+ void *opaque)
+{
+ BDRVQuorumState *s = bs->opaque;
+ QuorumAIOCB *acb = quorum_aio_get(s, bs, qiov, sector_num,
+ nb_sectors, cb, opaque);
+ acb->is_read = true;
+
+ if (s->read_pattern == QUORUM_READ_PATTERN_QUORUM) {
+ acb->child_iter = s->num_children - 1;
+ return read_quorum_children(acb);
+ }
+
+ acb->child_iter = 0;
+ return read_fifo_child(acb);
+}
+
static BlockDriverAIOCB *quorum_aio_writev(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *qiov,
@@ -787,10 +836,33 @@ static QemuOptsList quorum_runtime_opts = {
.type = QEMU_OPT_BOOL,
.help = "Rewrite corrupted block on read quorum",
},
+ {
+ .name = QUORUM_OPT_READ_PATTERN,
+ .type = QEMU_OPT_STRING,
+ .help = "Allowed pattern: quorum, fifo. Quorum is default",
+ },
{ /* end of list */ }
},
};
+static int parse_read_pattern(const char *opt)
+{
+ int i;
+
+ if (!opt) {
+ /* Set quorum as default */
+ return QUORUM_READ_PATTERN_QUORUM;
+ }
+
+ for (i = 0; i < QUORUM_READ_PATTERN_MAX; i++) {
+ if (!strcmp(opt, QuorumReadPattern_lookup[i])) {
+ return i;
+ }
+ }
+
+ return -EINVAL;
+}
+
static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
@@ -832,28 +904,37 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
}
s->threshold = qemu_opt_get_number(opts, QUORUM_OPT_VOTE_THRESHOLD, 0);
-
- /* and validate it against s->num_children */
- ret = quorum_valid_threshold(s->threshold, s->num_children, &local_err);
+ ret = parse_read_pattern(qemu_opt_get(opts, QUORUM_OPT_READ_PATTERN));
if (ret < 0) {
+ error_setg(&local_err, "Please set read-pattern as fifo or quorum");
goto exit;
}
+ s->read_pattern = ret;
- /* is the driver in blkverify mode */
- if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false) &&
- s->num_children == 2 && s->threshold == 2) {
- s->is_blkverify = true;
- } else if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false)) {
- fprintf(stderr, "blkverify mode is set by setting blkverify=on "
- "and using two files with vote_threshold=2\n");
- }
+ if (s->read_pattern == QUORUM_READ_PATTERN_QUORUM) {
+ /* and validate it against s->num_children */
+ ret = quorum_valid_threshold(s->threshold, s->num_children, &local_err);
+ if (ret < 0) {
+ goto exit;
+ }
- s->rewrite_corrupted = qemu_opt_get_bool(opts, QUORUM_OPT_REWRITE, false);
- if (s->rewrite_corrupted && s->is_blkverify) {
- error_setg(&local_err,
- "rewrite-corrupted=on cannot be used with blkverify=on");
- ret = -EINVAL;
- goto exit;
+ /* is the driver in blkverify mode */
+ if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false) &&
+ s->num_children == 2 && s->threshold == 2) {
+ s->is_blkverify = true;
+ } else if (qemu_opt_get_bool(opts, QUORUM_OPT_BLKVERIFY, false)) {
+ fprintf(stderr, "blkverify mode is set by setting blkverify=on "
+ "and using two files with vote_threshold=2\n");
+ }
+
+ s->rewrite_corrupted = qemu_opt_get_bool(opts, QUORUM_OPT_REWRITE,
+ false);
+ if (s->rewrite_corrupted && s->is_blkverify) {
+ error_setg(&local_err,
+ "rewrite-corrupted=on cannot be used with blkverify=on");
+ ret = -EINVAL;
+ goto exit;
+ }
}
/* allocate the children BlockDriverState array */