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[Qemu-devel] [PATCH v2 25/31] qed: Implement .bdrv_co_readv/writev
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH v2 25/31] qed: Implement .bdrv_co_readv/writev |
Date: |
Fri, 16 Jun 2017 19:37:10 +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 | 97 ++++++++++++++++++++++++++-----------------------------------
1 file changed, 42 insertions(+), 55 deletions(-)
diff --git a/block/qed.c b/block/qed.c
index e762169..a5111fd 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1322,16 +1322,32 @@ 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 qed_co_request_cb(void *opaque, int ret)
{
- QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque);
+ QEDRequestCo *co = opaque;
- trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors,
- opaque, flags);
+ co->done = true;
+ co->ret = ret;
+ qemu_coroutine_enter_if_inactive(co->co);
+}
+
+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 = 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);
acb->flags = flags;
acb->qiov = qiov;
@@ -1344,43 +1360,26 @@ 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 coroutine_fn 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 coroutine_fn 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,
@@ -1388,9 +1387,7 @@ 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;
@@ -1407,19 +1404,9 @@ 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)
@@ -1615,8 +1602,8 @@ 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 v2 17/31] qed: Add return value to qed_aio_write_l1_update(), (continued)
- [Qemu-devel] [PATCH v2 17/31] qed: Add return value to qed_aio_write_l1_update(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 14/31] qed: Make qed_aio_read_data() synchronous, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 16/31] qed: Inline qed_commit_l2_update(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 18/31] qed: Add return value to qed_aio_write_l2_update(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 19/31] qed: Add return value to qed_aio_write_main(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 20/31] qed: Add return value to qed_aio_write_cow(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 21/31] qed: Add return value to qed_aio_write_inplace/alloc(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 24/31] qed: Remove recursion in qed_aio_next_io(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 22/31] qed: Add return value to qed_aio_read/write_data(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 23/31] qed: Remove ret argument from qed_aio_next_io(), Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 25/31] qed: Implement .bdrv_co_readv/writev,
Kevin Wolf <=
- [Qemu-devel] [PATCH v2 26/31] qed: Use CoQueue for serialising allocations, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 27/31] qed: Simplify request handling, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 28/31] qed: Use a coroutine for need_check_timer, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 30/31] qed: Use bdrv_co_* for coroutine_fns, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 29/31] qed: Add coroutine_fn to I/O path functions, Kevin Wolf, 2017/06/16
- [Qemu-devel] [PATCH v2 31/31] block: Remove bdrv_aio_readv/writev/flush(), Kevin Wolf, 2017/06/16
- Re: [Qemu-devel] [PATCH v2 00/31] qed: Convert to coroutines, Stefan Hajnoczi, 2017/06/19
- Re: [Qemu-devel] [PATCH v2 00/31] qed: Convert to coroutines, Kevin Wolf, 2017/06/22