Now that we process a request in the same coroutine from beginning to
end and don't drop out of it any more, we can look like a proper
coroutine-based driver and simply call qed_aio_next_io() and get a
return value from it instead of spawning an additional coroutine that
reenters the parent when it's done.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
---
block/qed.c | 101 +++++++++++++-----------------------------------------------
block/qed.h | 3 +-
2 files changed, 22 insertions(+), 82 deletions(-)
diff --git a/block/qed.c b/block/qed.c
index cd3ef55..e53f6b5 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -21,10 +21,6 @@
#include "qapi/qmp/qerror.h"
#include "sysemu/block-backend.h"
-static const AIOCBInfo qed_aiocb_info = {
- .aiocb_size = sizeof(QEDAIOCB),
-};
-
static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
const char *filename)
{
@@ -253,13 +249,6 @@ static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
return l2_table;
}
-static void qed_aio_next_io(QEDAIOCB *acb);
-
-static void qed_aio_start_io(QEDAIOCB *acb)
-{
- qed_aio_next_io(acb);
-}
-
static void qed_plug_allocating_write_reqs(BDRVQEDState *s)
{
assert(!s->allocating_write_reqs_plugged);
@@ -751,7 +740,7 @@ static int64_t coroutine_fn
bdrv_qed_co_get_block_status(BlockDriverState *bs,
static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
{
- return acb->common.bs->opaque;
+ return acb->bs->opaque;
}
/**
@@ -888,28 +877,10 @@ static void qed_update_l2_table(BDRVQEDState *s, QEDTable
*table, int index,
}
}
-static void qed_aio_complete_bh(void *opaque)
-{
- QEDAIOCB *acb = opaque;
- BDRVQEDState *s = acb_to_s(acb);
- BlockCompletionFunc *cb = acb->common.cb;
- void *user_opaque = acb->common.opaque;
- int ret = acb->bh_ret;
-
- qemu_aio_unref(acb);
-
- /* Invoke callback */
- qed_acquire(s);
- cb(user_opaque, ret);
- qed_release(s);
-}
-
-static void qed_aio_complete(QEDAIOCB *acb, int ret)
+static void qed_aio_complete(QEDAIOCB *acb)
{
BDRVQEDState *s = acb_to_s(acb);
- trace_qed_aio_complete(s, acb, ret);
-
/* Free resources */
qemu_iovec_destroy(&acb->cur_qiov);
qed_unref_l2_cache_entry(acb->request.l2_table);
@@ -920,11 +891,6 @@ static void qed_aio_complete(QEDAIOCB *acb, int ret)
acb->qiov->iov[0].iov_base = NULL;
}
- /* Arrange for a bh to invoke the completion function */
- acb->bh_ret = ret;
- aio_bh_schedule_oneshot(bdrv_get_aio_context(acb->common.bs),
- qed_aio_complete_bh, acb);
-
/* Start next allocating write request waiting behind this one. Note that
* requests enqueue themselves when they first hit an unallocated cluster
* but they wait until the entire request is finished before waking up the
@@ -1172,7 +1138,7 @@ static int qed_aio_write_inplace(QEDAIOCB *acb, uint64_t
offset, size_t len)
struct iovec *iov = acb->qiov->iov;
if (!iov->iov_base) {
- iov->iov_base = qemu_try_blockalign(acb->common.bs, iov->iov_len);
+ iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len);
if (iov->iov_base == NULL) {
return -ENOMEM;
}
@@ -1231,7 +1197,7 @@ static int qed_aio_read_data(void *opaque, int ret,
uint64_t offset, size_t len)
{
QEDAIOCB *acb = opaque;
BDRVQEDState *s = acb_to_s(acb);
- BlockDriverState *bs = acb->common.bs;
+ BlockDriverState *bs = acb->bs;
/* Adjust offset into cluster */
offset += qed_offset_into_cluster(s, acb->cur_pos);
@@ -1260,7 +1226,7 @@ static int qed_aio_read_data(void *opaque, int ret,
uint64_t offset, size_t len)
/**
* Begin next I/O or complete the request
*/
-static void qed_aio_next_io(QEDAIOCB *acb)
+static int qed_aio_next_io(QEDAIOCB *acb)
{
BDRVQEDState *s = acb_to_s(acb);
uint64_t offset;
@@ -1282,16 +1248,15 @@ static void qed_aio_next_io(QEDAIOCB *acb)
/* Complete request */
if (acb->cur_pos >= acb->end_pos) {
- qed_aio_complete(acb, 0);
- return;
+ ret = 0;
+ break;
}
/* Find next cluster and start I/O */
len = acb->end_pos - acb->cur_pos;
ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset);
if (ret < 0) {
- qed_aio_complete(acb, ret);
- return;
+ break;
}
if (acb->flags & QED_AIOCB_WRITE) {
@@ -1301,56 +1266,32 @@ static void qed_aio_next_io(QEDAIOCB *acb)
}
if (ret < 0 && ret != -EAGAIN) {
- qed_aio_complete(acb, ret);
- return;
+ break;
}
}
-}
-typedef struct QEDRequestCo {
- Coroutine *co;
- bool done;
- int ret;
-} QEDRequestCo;
-
-static void qed_co_request_cb(void *opaque, int ret)
-{
- QEDRequestCo *co = opaque;
-
- co->done = true;
- co->ret = ret;
- qemu_coroutine_enter_if_inactive(co->co);
+ trace_qed_aio_complete(s, acb, ret);
+ qed_aio_complete(acb);
+ return ret;
}
static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t
sector_num,
QEMUIOVector *qiov, int nb_sectors,
int flags)
{
- QEDRequestCo co = {
- .co = qemu_coroutine_self(),
- .done = false,
+ QEDAIOCB acb = {
+ .bs = bs,
+ .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE,
+ .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE,
+ .qiov = qiov,
+ .flags = flags,
};
- QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, qed_co_request_cb, &co);
-
- trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, &co, flags);
+ qemu_iovec_init(&acb.cur_qiov, qiov->niov);
- acb->flags = flags;
- acb->qiov = qiov;
- acb->qiov_offset = 0;
- acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE;
- acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE;
- acb->backing_qiov = NULL;
- acb->request.l2_table = NULL;
- qemu_iovec_init(&acb->cur_qiov, qiov->niov);
+ trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags);
/* Start request */
- qed_aio_start_io(acb);
-
- if (!co.done) {
- qemu_coroutine_yield();
- }
-
- return co.ret;
+ return qed_aio_next_io(&acb);
}
static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs,
diff --git a/block/qed.h b/block/qed.h
index 37558e4..fb80943 100644
--- a/block/qed.h
+++ b/block/qed.h
@@ -129,8 +129,7 @@ enum {
};
typedef struct QEDAIOCB {
- BlockAIOCB common;
- int bh_ret; /* final return status for completion bh */
+ BlockDriverState *bs;
QSIMPLEQ_ENTRY(QEDAIOCB) next; /* next request */
int flags; /* QED_AIOCB_* bits ORed together */
uint64_t end_pos; /* request end on block device, in bytes */
--
1.8.3.1
