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[Qemu-devel] [PATCH 25/29] qed: Implement .bdrv_co_readv/writev
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 25/29] qed: Implement .bdrv_co_readv/writev |
Date: |
Fri, 26 May 2017 22:22:06 +0200 |
Most of the qed code is now synchronous and matches the coroutine model.
One notable exception is the serialisation between requests which can
still schedule a callback. Before we can replace this with coroutine
locks, let's convert the driver's external interfaces to the coroutine
versions.
We need to be careful to handle both requests that call the completion
callback directly from the calling coroutine (i.e. fully synchronous
code) and requests that involve some callback, so that we need to yield
and wait for the completion callback coming from outside the coroutine.
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qed.c | 94 +++++++++++++++++++++++++------------------------------------
1 file changed, 39 insertions(+), 55 deletions(-)
diff --git a/block/qed.c b/block/qed.c
index 6a83df2..29c3dc5 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1326,16 +1326,31 @@ static void qed_aio_next_io(QEDAIOCB *acb)
}
}
-static BlockAIOCB *qed_aio_setup(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb,
- void *opaque, int flags)
+typedef struct QEDRequestCo {
+ Coroutine *co;
+ bool done;
+ int ret;
+} QEDRequestCo;
+
+static void coroutine_fn qed_co_request_cb(void *opaque, int ret)
+{
+ QEDRequestCo *co = opaque;
+
+ co->done = true;
+ co->ret = ret;
+ qemu_coroutine_enter_if_inactive(co->co);
+}
+
+static int qed_co_request(BlockDriverState *bs, int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors, int flags)
{
- QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque);
+ QEDRequestCo co = {
+ .co = qemu_coroutine_self(),
+ .done = false,
+ };
+ 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,
- opaque, flags);
+ trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, &co, flags);
acb->flags = flags;
acb->qiov = qiov;
@@ -1348,43 +1363,24 @@ static BlockAIOCB *qed_aio_setup(BlockDriverState *bs,
/* Start request */
qed_aio_start_io(acb);
- return &acb->common;
-}
-static BlockAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb,
- void *opaque)
-{
- return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ if (!co.done) {
+ qemu_coroutine_yield();
+ }
+
+ return co.ret;
}
-static BlockAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs,
- int64_t sector_num,
- QEMUIOVector *qiov, int nb_sectors,
- BlockCompletionFunc *cb,
- void *opaque)
+static int bdrv_qed_co_readv(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, QEMUIOVector *qiov)
{
- return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb,
- opaque, QED_AIOCB_WRITE);
+ return qed_co_request(bs, sector_num, qiov, nb_sectors, 0);
}
-typedef struct {
- Coroutine *co;
- int ret;
- bool done;
-} QEDWriteZeroesCB;
-
-static void coroutine_fn qed_co_pwrite_zeroes_cb(void *opaque, int ret)
+static int bdrv_qed_co_writev(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, QEMUIOVector *qiov)
{
- QEDWriteZeroesCB *cb = opaque;
-
- cb->done = true;
- cb->ret = ret;
- if (cb->co) {
- aio_co_wake(cb->co);
- }
+ return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE);
}
static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
@@ -1392,9 +1388,7 @@ static int coroutine_fn
bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
int count,
BdrvRequestFlags flags)
{
- BlockAIOCB *blockacb;
BDRVQEDState *s = bs->opaque;
- QEDWriteZeroesCB cb = { .done = false };
QEMUIOVector qiov;
struct iovec iov;
@@ -1411,19 +1405,9 @@ static int coroutine_fn
bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
iov.iov_len = count;
qemu_iovec_init_external(&qiov, &iov, 1);
- blockacb = qed_aio_setup(bs, offset >> BDRV_SECTOR_BITS, &qiov,
- count >> BDRV_SECTOR_BITS,
- qed_co_pwrite_zeroes_cb, &cb,
- QED_AIOCB_WRITE | QED_AIOCB_ZERO);
- if (!blockacb) {
- return -EIO;
- }
- if (!cb.done) {
- cb.co = qemu_coroutine_self();
- qemu_coroutine_yield();
- }
- assert(cb.done);
- return cb.ret;
+ return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov,
+ count >> BDRV_SECTOR_BITS,
+ QED_AIOCB_WRITE | QED_AIOCB_ZERO);
}
static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset, Error
**errp)
@@ -1619,8 +1603,8 @@ static BlockDriver bdrv_qed = {
.bdrv_create = bdrv_qed_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_get_block_status = bdrv_qed_co_get_block_status,
- .bdrv_aio_readv = bdrv_qed_aio_readv,
- .bdrv_aio_writev = bdrv_qed_aio_writev,
+ .bdrv_co_readv = bdrv_qed_co_readv,
+ .bdrv_co_writev = bdrv_qed_co_writev,
.bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
.bdrv_truncate = bdrv_qed_truncate,
.bdrv_getlength = bdrv_qed_getlength,
--
1.8.3.1
- [Qemu-devel] [PATCH 21/29] qed: Add return value to qed_aio_write_inplace/alloc(), (continued)
- [Qemu-devel] [PATCH 21/29] qed: Add return value to qed_aio_write_inplace/alloc(), Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 23/29] qed: Remove ret argument from qed_aio_next_io(), Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 22/29] qed: Add return value to qed_aio_read/write_data(), Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 24/29] qed: Remove recursion in qed_aio_next_io(), Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 26/29] qed: Use CoQueue for serialising allocations, Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 25/29] qed: Implement .bdrv_co_readv/writev,
Kevin Wolf <=
- [Qemu-devel] [PATCH 27/29] qed: Simplify request handling, Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 28/29] qed: Use a coroutine for need_check_timer, Kevin Wolf, 2017/05/26
- [Qemu-devel] [PATCH 29/29] block: Remove bdrv_aio_readv/writev_flush(), Kevin Wolf, 2017/05/26
- Re: [Qemu-devel] [Qemu-block] [PATCH 00/29] qed: Convert to coroutines, Paolo Bonzini, 2017/05/29