push down vector linearization to posix-aio-compat.c (Christoph Hellwig)
Make all AIO requests vectored and defer linearization until the actual
I/O thread. This prepares for using native preadv/pwritev.
Also enables asynchronous direct I/O by handling that case in the I/O thread.
Qcow and qcow2 propably want to be adopted to directly deal with multi-segment
requests, but that can be implemented later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7020 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/block-qcow2.c b/block-qcow2.c
index dd28c28..3bd38b0 100644
--- a/block-qcow2.c
+++ b/block-qcow2.c
@@ -1264,7 +1264,9 @@
typedef struct QCowAIOCB {
BlockDriverAIOCB common;
int64_t sector_num;
+ QEMUIOVector *qiov;
uint8_t *buf;
+ void *orig_buf;
int nb_sectors;
int n;
uint64_t cluster_offset;
@@ -1307,12 +1309,8 @@
int index_in_cluster, n1;
acb->hd_aiocb = NULL;
- if (ret < 0) {
-fail:
- acb->common.cb(acb->common.opaque, ret);
- qemu_aio_release(acb);
- return;
- }
+ if (ret < 0)
+ goto done;
/* post process the read buffer */
if (!acb->cluster_offset) {
@@ -1333,9 +1331,8 @@
if (acb->nb_sectors == 0) {
/* request completed */
- acb->common.cb(acb->common.opaque, 0);
- qemu_aio_release(acb);
- return;
+ ret = 0;
+ goto done;
}
/* prepare next AIO request */
@@ -1356,32 +1353,32 @@
&acb->hd_qiov, acb->n,
qcow_aio_read_cb, acb);
if (acb->hd_aiocb == NULL)
- goto fail;
+ goto done;
} else {
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
if (ret < 0)
- goto fail;
+ goto done;
}
} else {
/* Note: in this case, no need to wait */
memset(acb->buf, 0, 512 * acb->n);
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
if (ret < 0)
- goto fail;
+ goto done;
}
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
/* add AIO support for compressed blocks ? */
if (decompress_cluster(s, acb->cluster_offset) < 0)
- goto fail;
+ goto done;
memcpy(acb->buf,
s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
if (ret < 0)
- goto fail;
+ goto done;
} else {
if ((acb->cluster_offset & 511) != 0) {
ret = -EIO;
- goto fail;
+ goto done;
}
acb->hd_iov.iov_base = acb->buf;
@@ -1391,13 +1388,22 @@
(acb->cluster_offset >> 9) + index_in_cluster,
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
if (acb->hd_aiocb == NULL)
- goto fail;
+ goto done;
}
+
+ return;
+done:
+ if (acb->qiov->niov > 1) {
+ qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
+ qemu_vfree(acb->orig_buf);
+ }
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
}
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
- int64_t sector_num, uint8_t *buf, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque)
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque, int is_write)
{
QCowAIOCB *acb;
@@ -1406,7 +1412,13 @@
return NULL;
acb->hd_aiocb = NULL;
acb->sector_num = sector_num;
- acb->buf = buf;
+ acb->qiov = qiov;
+ if (qiov->niov > 1) {
+ acb->buf = acb->orig_buf = qemu_memalign(512, qiov->size);
+ if (is_write)
+ qemu_iovec_to_buffer(qiov, acb->buf);
+ } else
+ acb->buf = qiov->iov->iov_base;
acb->nb_sectors = nb_sectors;
acb->n = 0;
acb->cluster_offset = 0;
@@ -1414,13 +1426,13 @@
return acb;
}
-static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
- int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
QCowAIOCB *acb;
- acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
if (!acb)
return NULL;
@@ -1439,16 +1451,12 @@
acb->hd_aiocb = NULL;
- if (ret < 0) {
- fail:
- acb->common.cb(acb->common.opaque, ret);
- qemu_aio_release(acb);
- return;
- }
+ if (ret < 0)
+ goto done;
if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) {
free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters);
- goto fail;
+ goto done;
}
acb->nb_sectors -= acb->n;
@@ -1457,9 +1465,8 @@
if (acb->nb_sectors == 0) {
/* request completed */
- acb->common.cb(acb->common.opaque, 0);
- qemu_aio_release(acb);
- return;
+ ret = 0;
+ goto done;
}
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
@@ -1473,7 +1480,7 @@
n_end, &acb->n, &acb->l2meta);
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) {
ret = -EIO;
- goto fail;
+ goto done;
}
if (s->crypt_method) {
if (!acb->cluster_data) {
@@ -1494,11 +1501,19 @@
&acb->hd_qiov, acb->n,
qcow_aio_write_cb, acb);
if (acb->hd_aiocb == NULL)
- goto fail;
+ goto done;
+
+ return;
+
+done:
+ if (acb->qiov->niov > 1)
+ qemu_vfree(acb->orig_buf);
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
}
-static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
- int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVQcowState *s = bs->opaque;
@@ -1506,7 +1521,7 @@
s->cluster_cache_offset = -1; /* disable compressed cache */
- acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque);
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
if (!acb)
return NULL;
@@ -2771,8 +2786,8 @@
.bdrv_set_key = qcow_set_key,
.bdrv_make_empty = qcow_make_empty,
- .bdrv_aio_read = qcow_aio_read,
- .bdrv_aio_write = qcow_aio_write,
+ .bdrv_aio_readv = qcow_aio_readv,
+ .bdrv_aio_writev = qcow_aio_writev,
.bdrv_aio_cancel = qcow_aio_cancel,
.aiocb_size = sizeof(QCowAIOCB),
.bdrv_write_compressed = qcow_write_compressed,
