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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
This commit is contained in:
aliguori 2009-04-07 18:43:24 +00:00
parent c87c067293
commit f141eafe28
7 changed files with 318 additions and 285 deletions
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84
block-qcow.c
View File

@ -525,7 +525,9 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num,
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;
@ -543,12 +545,8 @@ static void qcow_aio_read_cb(void *opaque, int ret)
int index_in_cluster;
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;
redo:
/* post process the read buffer */
@ -570,9 +568,8 @@ static void qcow_aio_read_cb(void *opaque, int ret)
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 */
@ -592,7 +589,7 @@ static void qcow_aio_read_cb(void *opaque, int ret)
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
if (acb->hd_aiocb == NULL)
goto fail;
goto done;
} else {
/* Note: in this case, no need to wait */
memset(acb->buf, 0, 512 * acb->n);
@ -601,14 +598,14 @@ static void qcow_aio_read_cb(void *opaque, int ret)
} 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);
goto redo;
} else {
if ((acb->cluster_offset & 511) != 0) {
ret = -EIO;
goto fail;
goto done;
}
acb->hd_iov.iov_base = acb->buf;
acb->hd_iov.iov_len = acb->n * 512;
@ -617,12 +614,22 @@ static void qcow_aio_read_cb(void *opaque, int ret)
(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 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;
@ -632,7 +639,11 @@ static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
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);
else
acb->buf = qiov->iov->iov_base;
acb->nb_sectors = nb_sectors;
acb->n = 0;
acb->cluster_offset = 0;
@ -652,12 +663,8 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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;
acb->nb_sectors -= acb->n;
acb->sector_num += acb->n;
@ -665,9 +672,8 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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);
@ -679,14 +685,14 @@ static void qcow_aio_write_cb(void *opaque, int ret)
index_in_cluster + acb->n);
if (!cluster_offset || (cluster_offset & 511) != 0) {
ret = -EIO;
goto fail;
goto done;
}
if (s->crypt_method) {
if (!acb->cluster_data) {
acb->cluster_data = qemu_mallocz(s->cluster_size);
if (!acb->cluster_data) {
ret = -ENOMEM;
goto fail;
goto done;
}
}
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
@ -704,11 +710,18 @@ static void qcow_aio_write_cb(void *opaque, int ret)
&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;
@ -721,7 +734,12 @@ static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
return NULL;
acb->hd_aiocb = NULL;
acb->sector_num = sector_num;
acb->buf = (uint8_t *)buf;
acb->qiov = qiov;
if (qiov->niov > 1) {
acb->buf = acb->orig_buf = qemu_memalign(512, qiov->size);
qemu_iovec_to_buffer(qiov, acb->buf);
} else
acb->buf = qiov->iov->iov_base;
acb->nb_sectors = nb_sectors;
acb->n = 0;
@ -909,8 +927,8 @@ BlockDriver bdrv_qcow = {
.bdrv_is_allocated = qcow_is_allocated,
.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,

93
block-qcow2.c
View File

@ -1264,7 +1264,9 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num,
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 @@ static void qcow_aio_read_cb(void *opaque, int ret)
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 @@ fail:
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 @@ fail:
&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 @@ fail:
(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 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
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 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
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 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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 @@ static void qcow_aio_write_cb(void *opaque, int ret)
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 @@ static void qcow_aio_write_cb(void *opaque, int ret)
&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 @@ static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
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 @@ BlockDriver bdrv_qcow2 = {
.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,

95
block-raw-posix.c
View File

@ -599,8 +599,8 @@ static int posix_aio_init(void)
return 0;
}
static RawAIOCB *raw_aio_setup(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
static RawAIOCB *raw_aio_setup(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
@ -614,24 +614,25 @@ static RawAIOCB *raw_aio_setup(BlockDriverState *bs,
return NULL;
acb->aiocb.aio_fildes = s->fd;
acb->aiocb.ev_signo = SIGUSR2;
acb->aiocb.aio_buf = buf;
if (nb_sectors < 0)
acb->aiocb.aio_nbytes = -nb_sectors;
else
acb->aiocb.aio_nbytes = nb_sectors * 512;
acb->aiocb.aio_iov = qiov->iov;
acb->aiocb.aio_niov = qiov->niov;
acb->aiocb.aio_nbytes = nb_sectors * 512;
acb->aiocb.aio_offset = sector_num * 512;
acb->aiocb.aio_flags = 0;
/*
* If O_DIRECT is used the buffer needs to be aligned on a sector
* boundary. Tell the low level code to ensure that in case it's
* not done yet.
*/
if (s->aligned_buf)
acb->aiocb.aio_flags |= QEMU_AIO_SECTOR_ALIGNED;
acb->next = posix_aio_state->first_aio;
posix_aio_state->first_aio = acb;
return acb;
}
static void raw_aio_em_cb(void* opaque)
{
RawAIOCB *acb = opaque;
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_release(acb);
}
static void raw_aio_remove(RawAIOCB *acb)
{
RawAIOCB **pacb;
@ -651,28 +652,13 @@ static void raw_aio_remove(RawAIOCB *acb)
}
}
static BlockDriverAIOCB *raw_aio_read(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
RawAIOCB *acb;
/*
* If O_DIRECT is used and the buffer is not aligned fall back
* to synchronous IO.
*/
BDRVRawState *s = bs->opaque;
if (unlikely(s->aligned_buf != NULL && ((uintptr_t) buf % 512))) {
QEMUBH *bh;
acb = qemu_aio_get(bs, cb, opaque);
acb->ret = raw_pread(bs, 512 * sector_num, buf, 512 * nb_sectors);
bh = qemu_bh_new(raw_aio_em_cb, acb);
qemu_bh_schedule(bh);
return &acb->common;
}
acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
acb = raw_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque);
if (!acb)
return NULL;
if (qemu_paio_read(&acb->aiocb) < 0) {
@ -682,28 +668,13 @@ static BlockDriverAIOCB *raw_aio_read(BlockDriverState *bs,
return &acb->common;
}
static BlockDriverAIOCB *raw_aio_write(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
RawAIOCB *acb;
/*
* If O_DIRECT is used and the buffer is not aligned fall back
* to synchronous IO.
*/
BDRVRawState *s = bs->opaque;
if (unlikely(s->aligned_buf != NULL && ((uintptr_t) buf % 512))) {
QEMUBH *bh;
acb = qemu_aio_get(bs, cb, opaque);
acb->ret = raw_pwrite(bs, 512 * sector_num, buf, 512 * nb_sectors);
bh = qemu_bh_new(raw_aio_em_cb, acb);
qemu_bh_schedule(bh);
return &acb->common;
}
acb = raw_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque);
acb = raw_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque);
if (!acb)
return NULL;
if (qemu_paio_write(&acb->aiocb) < 0) {
@ -887,8 +858,8 @@ BlockDriver bdrv_raw = {
.bdrv_flush = raw_flush,
#ifdef CONFIG_AIO
.bdrv_aio_read = raw_aio_read,
.bdrv_aio_write = raw_aio_write,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
.bdrv_aio_cancel = raw_aio_cancel,
.aiocb_size = sizeof(RawAIOCB),
#endif
@ -1215,12 +1186,24 @@ static BlockDriverAIOCB *raw_aio_ioctl(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
RawAIOCB *acb;
acb = raw_aio_setup(bs, 0, buf, 0, cb, opaque);
if (!acb)
if (fd_open(bs) < 0)
return NULL;
acb = qemu_aio_get(bs, cb, opaque);
if (!acb)
return NULL;
acb->aiocb.aio_fildes = s->fd;
acb->aiocb.ev_signo = SIGUSR2;
acb->aiocb.aio_offset = 0;
acb->aiocb.aio_flags = 0;
acb->next = posix_aio_state->first_aio;
posix_aio_state->first_aio = acb;
acb->aiocb.aio_ioctl_buf = buf;
acb->aiocb.aio_ioctl_cmd = req;
if (qemu_paio_ioctl(&acb->aiocb) < 0) {
raw_aio_remove(acb);
@ -1424,8 +1407,8 @@ BlockDriver bdrv_host_device = {
.bdrv_flush = raw_flush,
#ifdef CONFIG_AIO
.bdrv_aio_read = raw_aio_read,
.bdrv_aio_write = raw_aio_write,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
.bdrv_aio_cancel = raw_aio_cancel,
.aiocb_size = sizeof(RawAIOCB),
#endif

198
block.c
View File

@ -47,25 +47,21 @@
#define SECTOR_BITS 9
#define SECTOR_SIZE (1 << SECTOR_BITS)
static AIOPool vectored_aio_pool;
typedef struct BlockDriverAIOCBSync {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
/* vector translation state */
QEMUIOVector *qiov;
uint8_t *bounce;
int is_write;
} BlockDriverAIOCBSync;
static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
@ -144,10 +140,10 @@ void path_combine(char *dest, int dest_size,
static void bdrv_register(BlockDriver *bdrv)
{
if (!bdrv->bdrv_aio_read) {
if (!bdrv->bdrv_aio_readv) {
/* add AIO emulation layer */
bdrv->bdrv_aio_read = bdrv_aio_read_em;
bdrv->bdrv_aio_write = bdrv_aio_write_em;
bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
} else if (!bdrv->bdrv_read) {
@ -1295,90 +1291,9 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
/**************************************************************/
/* async I/Os */
typedef struct VectorTranslationAIOCB {
BlockDriverAIOCB common;
QEMUIOVector *iov;
uint8_t *bounce;
int is_write;
BlockDriverAIOCB *aiocb;
} VectorTranslationAIOCB;
static void bdrv_aio_cancel_vector(BlockDriverAIOCB *_acb)
{
VectorTranslationAIOCB *acb
= container_of(_acb, VectorTranslationAIOCB, common);
bdrv_aio_cancel(acb->aiocb);
}
static void bdrv_aio_rw_vector_cb(void *opaque, int ret)
{
VectorTranslationAIOCB *s = (VectorTranslationAIOCB *)opaque;
if (!s->is_write) {
qemu_iovec_from_buffer(s->iov, s->bounce, s->iov->size);
}
qemu_vfree(s->bounce);
s->common.cb(s->common.opaque, ret);
qemu_aio_release(s);
}
static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *iov,
int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque,
int is_write)
{
VectorTranslationAIOCB *s = qemu_aio_get_pool(&vectored_aio_pool, bs,
cb, opaque);
s->iov = iov;
s->bounce = qemu_memalign(512, nb_sectors * 512);
s->is_write = is_write;
if (is_write) {
qemu_iovec_to_buffer(s->iov, s->bounce);
s->aiocb = bdrv_aio_write(bs, sector_num, s->bounce, nb_sectors,
bdrv_aio_rw_vector_cb, s);
} else {
s->aiocb = bdrv_aio_read(bs, sector_num, s->bounce, nb_sectors,
bdrv_aio_rw_vector_cb, s);
}
if (!s->aiocb) {
qemu_vfree(s->bounce);
qemu_aio_release(s);
return NULL;
}
return &s->common;
}
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
cb, opaque, 0);
}
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
cb, opaque, 1);
}
static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
@ -1388,7 +1303,8 @@ static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
@ -1399,9 +1315,9 @@ static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
return ret;
}
static BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriver *drv = bs->drv;
BlockDriverAIOCB *ret;
@ -1413,7 +1329,8 @@ static BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num
if (bdrv_check_request(bs, sector_num, nb_sectors))
return NULL;
ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
cb, opaque);
if (ret) {
/* Update stats even though technically transfer has not happened. */
@ -1436,42 +1353,62 @@ void bdrv_aio_cancel(BlockDriverAIOCB *acb)
static void bdrv_aio_bh_cb(void *opaque)
{
BlockDriverAIOCBSync *acb = opaque;
qemu_vfree(acb->bounce);
if (!acb->is_write)
qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_release(acb);
}
static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *qiov,
int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque,
int is_write)
{
BlockDriverAIOCBSync *acb;
int ret;
acb = qemu_aio_get(bs, cb, opaque);
acb->is_write = is_write;
acb->qiov = qiov;
acb->bounce = qemu_memalign(512, qiov->size);
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
ret = bdrv_read(bs, sector_num, buf, nb_sectors);
acb->ret = ret;
if (is_write) {
qemu_iovec_to_buffer(acb->qiov, acb->bounce);
acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
} else {
acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
}
qemu_bh_schedule(acb->bh);
return &acb->common;
}
static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BlockDriverAIOCBSync *acb;
int ret;
acb = qemu_aio_get(bs, cb, opaque);
if (!acb->bh)
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
ret = bdrv_write(bs, sector_num, buf, nb_sectors);
acb->ret = ret;
qemu_bh_schedule(acb->bh);
return &acb->common;
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
}
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
}
static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
{
BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
@ -1494,10 +1431,15 @@ static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_ret = NOT_DONE;
acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
bdrv_rw_em_cb, &async_ret);
iov.iov_base = buf;
iov.iov_len = nb_sectors * 512;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL)
return -1;
@ -1513,10 +1455,15 @@ static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_ret = NOT_DONE;
acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
bdrv_rw_em_cb, &async_ret);
iov.iov_base = (void *)buf;
iov.iov_len = nb_sectors * 512;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL)
return -1;
while (async_ret == NOT_DONE) {
@ -1527,9 +1474,6 @@ static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
void bdrv_init(void)
{
aio_pool_init(&vectored_aio_pool, sizeof(VectorTranslationAIOCB),
bdrv_aio_cancel_vector);
bdrv_register(&bdrv_raw);
bdrv_register(&bdrv_host_device);
#ifndef _WIN32

8
block_int.h
View File

@ -54,11 +54,11 @@ struct BlockDriver {
int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
int (*bdrv_make_empty)(BlockDriverState *bs);
/* aio */
BlockDriverAIOCB *(*bdrv_aio_read)(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *(*bdrv_aio_write)(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
void (*bdrv_aio_cancel)(BlockDriverAIOCB *acb);
int aiocb_size;

116
posix-aio-compat.c
View File

@ -20,6 +20,7 @@
#include <stdlib.h>
#include <stdio.h>
#include "osdep.h"
#include "qemu-common.h"
#include "posix-aio-compat.h"
@ -76,45 +77,110 @@ static void thread_create(pthread_t *thread, pthread_attr_t *attr,
if (ret) die2(ret, "pthread_create");
}
static size_t handle_aiocb_readwrite(struct qemu_paiocb *aiocb)
static size_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb)
{
int ret;
ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf);
if (ret == -1)
return -errno;
return ret;
}
/*
* Check if we need to copy the data in the aiocb into a new
* properly aligned buffer.
*/
static int aiocb_needs_copy(struct qemu_paiocb *aiocb)
{
if (aiocb->aio_flags & QEMU_AIO_SECTOR_ALIGNED) {
int i;
for (i = 0; i < aiocb->aio_niov; i++)
if ((uintptr_t) aiocb->aio_iov[i].iov_base % 512)
return 1;
}
return 0;
}
static size_t handle_aiocb_rw_linear(struct qemu_paiocb *aiocb, char *buf)
{
size_t offset = 0;
ssize_t len;
size_t len;
while (offset < aiocb->aio_nbytes) {
if (aiocb->aio_type == QEMU_PAIO_WRITE)
len = pwrite(aiocb->aio_fildes,
(const char *)aiocb->aio_buf + offset,
if (aiocb->aio_type == QEMU_PAIO_WRITE)
len = pwrite(aiocb->aio_fildes,
(const char *)buf + offset,
aiocb->aio_nbytes - offset,
aiocb->aio_offset + offset);
else
len = pread(aiocb->aio_fildes,
buf + offset,
aiocb->aio_nbytes - offset,
aiocb->aio_offset + offset);
else
len = pread(aiocb->aio_fildes,
(char *)aiocb->aio_buf + offset,
aiocb->aio_nbytes - offset,
aiocb->aio_offset + offset);
if (len == -1 && errno == EINTR)
continue;
else if (len == -1) {
offset = -errno;
break;
} else if (len == 0)
break;
if (len == -1 && errno == EINTR)
continue;
else if (len == -1) {
offset = -errno;
break;
} else if (len == 0)
break;
offset += len;
offset += len;
}
return offset;
}
static size_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb)
static size_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
{
int ret;
size_t nbytes;
char *buf;
ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_buf);
if (ret == -1)
return -errno;
return ret;
if (!aiocb_needs_copy(aiocb) && aiocb->aio_niov == 1) {
/*
* If there is just a single buffer, and it is properly aligned
* we can just use plain pread/pwrite without any problems.
*/
return handle_aiocb_rw_linear(aiocb, aiocb->aio_iov->iov_base);
}
/*
* Ok, we have to do it the hard way, copy all segments into
* a single aligned buffer.
*/
buf = qemu_memalign(512, aiocb->aio_nbytes);
if (aiocb->aio_type == QEMU_PAIO_WRITE) {
char *p = buf;
int i;
for (i = 0; i < aiocb->aio_niov; ++i) {
memcpy(p, aiocb->aio_iov[i].iov_base, aiocb->aio_iov[i].iov_len);
p += aiocb->aio_iov[i].iov_len;
}
}
nbytes = handle_aiocb_rw_linear(aiocb, buf);
if (aiocb->aio_type != QEMU_PAIO_WRITE) {
char *p = buf;
size_t count = aiocb->aio_nbytes, copy;
int i;
for (i = 0; i < aiocb->aio_niov && count; ++i) {
copy = count;
if (copy > aiocb->aio_iov[i].iov_len)
copy = aiocb->aio_iov[i].iov_len;
memcpy(aiocb->aio_iov[i].iov_base, p, copy);
p += copy;
count -= copy;
}
}
qemu_vfree(buf);
return nbytes;
}
static void *aio_thread(void *unused)
@ -157,7 +223,7 @@ static void *aio_thread(void *unused)
switch (aiocb->aio_type) {
case QEMU_PAIO_READ:
case QEMU_PAIO_WRITE:
ret = handle_aiocb_readwrite(aiocb);
ret = handle_aiocb_rw(aiocb);
break;
case QEMU_PAIO_IOCTL:
ret = handle_aiocb_ioctl(aiocb);

9
posix-aio-compat.h
View File

@ -27,11 +27,18 @@
struct qemu_paiocb
{
int aio_fildes;
void *aio_buf;
union {
struct iovec *aio_iov;
void *aio_ioctl_buf;
};
int aio_niov;
size_t aio_nbytes;
#define aio_ioctl_cmd aio_nbytes /* for QEMU_PAIO_IOCTL */
int ev_signo;
off_t aio_offset;
unsigned aio_flags;
/* 512 byte alignment required for buffer, offset and length */
#define QEMU_AIO_SECTOR_ALIGNED 0x01
/* private */
TAILQ_ENTRY(qemu_paiocb) node;