The old qcow format is another user of the AsyncContext infrastructure. Converting it to coroutines (and therefore CoMutexes) allows to remove AsyncContexts.
Signed-off-by: Kevin Wolf <kw...@redhat.com> --- block/qcow.c | 180 ++++++++++++++++++++-------------------------------------- 1 files changed, 62 insertions(+), 118 deletions(-) diff --git a/block/qcow.c b/block/qcow.c index 227b104..6447c2a 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -73,6 +73,7 @@ typedef struct BDRVQcowState { uint32_t crypt_method_header; AES_KEY aes_encrypt_key; AES_KEY aes_decrypt_key; + CoMutex lock; } BDRVQcowState; static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); @@ -517,11 +518,11 @@ static AIOPool qcow_aio_pool = { static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque, int is_write) + int is_write) { QCowAIOCB *acb; - acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); + acb = qemu_aio_get(&qcow_aio_pool, bs, NULL, NULL); if (!acb) return NULL; acb->hd_aiocb = NULL; @@ -542,48 +543,15 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, return acb; } -static void qcow_aio_read_cb(void *opaque, int ret); -static void qcow_aio_write_cb(void *opaque, int ret); - -static void qcow_aio_rw_bh(void *opaque) -{ - QCowAIOCB *acb = opaque; - qemu_bh_delete(acb->bh); - acb->bh = NULL; - - if (acb->is_write) { - qcow_aio_write_cb(opaque, 0); - } else { - qcow_aio_read_cb(opaque, 0); - } -} - -static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) -{ - if (acb->bh) { - return -EIO; - } - - acb->bh = qemu_bh_new(cb, acb); - if (!acb->bh) { - return -EIO; - } - - qemu_bh_schedule(acb->bh); - - return 0; -} - -static void qcow_aio_read_cb(void *opaque, int ret) +static int qcow_aio_read_cb(void *opaque) { QCowAIOCB *acb = opaque; BlockDriverState *bs = acb->common.bs; BDRVQcowState *s = bs->opaque; int index_in_cluster; + int ret; acb->hd_aiocb = NULL; - if (ret < 0) - goto done; redo: /* post process the read buffer */ @@ -605,8 +573,7 @@ static void qcow_aio_read_cb(void *opaque, int ret) if (acb->nb_sectors == 0) { /* request completed */ - ret = 0; - goto done; + return 0; } /* prepare next AIO request */ @@ -623,11 +590,12 @@ static void qcow_aio_read_cb(void *opaque, int ret) acb->hd_iov.iov_base = (void *)acb->buf; acb->hd_iov.iov_len = acb->n * 512; qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); - 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) { - ret = -EIO; - goto done; + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(bs->backing_hd, acb->sector_num, + acb->n, &acb->hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + return -EIO; } } else { /* Note: in this case, no need to wait */ @@ -637,64 +605,56 @@ 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(bs, acb->cluster_offset) < 0) { - ret = -EIO; - goto done; + return -EIO; } 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 done; + return -EIO; } acb->hd_iov.iov_base = (void *)acb->buf; acb->hd_iov.iov_len = acb->n * 512; qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); - acb->hd_aiocb = bdrv_aio_readv(bs->file, + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(bs->file, (acb->cluster_offset >> 9) + index_in_cluster, - &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); - if (acb->hd_aiocb == NULL) { - ret = -EIO; - goto done; + acb->n, &acb->hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + return ret; } } - 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); + return 1; } -static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs, - int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) +static int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) { + BDRVQcowState *s = bs->opaque; QCowAIOCB *acb; int ret; - acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); - if (!acb) - return NULL; + acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, 0); - ret = qcow_schedule_bh(qcow_aio_rw_bh, acb); - if (ret < 0) { - if (acb->qiov->niov > 1) { - qemu_vfree(acb->orig_buf); - } - qemu_aio_release(acb); - return NULL; + qemu_co_mutex_lock(&s->lock); + do { + ret = qcow_aio_read_cb(acb); + } while (ret > 0); + qemu_co_mutex_unlock(&s->lock); + + if (acb->qiov->niov > 1) { + qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); + qemu_vfree(acb->orig_buf); } + qemu_aio_release(acb); - return &acb->common; + return ret; } -static void qcow_aio_write_cb(void *opaque, int ret) +static int qcow_aio_write_cb(void *opaque) { QCowAIOCB *acb = opaque; BlockDriverState *bs = acb->common.bs; @@ -702,20 +662,17 @@ static void qcow_aio_write_cb(void *opaque, int ret) int index_in_cluster; uint64_t cluster_offset; const uint8_t *src_buf; + int ret; acb->hd_aiocb = NULL; - if (ret < 0) - goto done; - acb->nb_sectors -= acb->n; acb->sector_num += acb->n; acb->buf += acb->n * 512; if (acb->nb_sectors == 0) { /* request completed */ - ret = 0; - goto done; + return 0; } index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); @@ -726,16 +683,11 @@ static void qcow_aio_write_cb(void *opaque, int ret) index_in_cluster, index_in_cluster + acb->n); if (!cluster_offset || (cluster_offset & 511) != 0) { - ret = -EIO; - goto done; + return -EIO; } if (s->crypt_method) { if (!acb->cluster_data) { acb->cluster_data = qemu_mallocz(s->cluster_size); - if (!acb->cluster_data) { - ret = -ENOMEM; - goto done; - } } encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, acb->n, 1, &s->aes_encrypt_key); @@ -747,26 +699,19 @@ static void qcow_aio_write_cb(void *opaque, int ret) acb->hd_iov.iov_base = (void *)src_buf; acb->hd_iov.iov_len = acb->n * 512; qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); - acb->hd_aiocb = bdrv_aio_writev(bs->file, - (cluster_offset >> 9) + index_in_cluster, - &acb->hd_qiov, acb->n, - qcow_aio_write_cb, acb); - if (acb->hd_aiocb == NULL) { - ret = -EIO; - goto done; + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_writev(bs->file, + (cluster_offset >> 9) + index_in_cluster, + acb->n, &acb->hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + return ret; } - return; - -done: - if (acb->qiov->niov > 1) - qemu_vfree(acb->orig_buf); - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); + return 1; } -static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs, - int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) +static int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) { BDRVQcowState *s = bs->opaque; QCowAIOCB *acb; @@ -774,21 +719,20 @@ static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs, s->cluster_cache_offset = -1; /* disable compressed cache */ - acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); - if (!acb) - return NULL; + acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, 1); + qemu_co_mutex_lock(&s->lock); + do { + ret = qcow_aio_write_cb(acb); + } while (ret > 0); + qemu_co_mutex_unlock(&s->lock); - ret = qcow_schedule_bh(qcow_aio_rw_bh, acb); - if (ret < 0) { - if (acb->qiov->niov > 1) { - qemu_vfree(acb->orig_buf); - } - qemu_aio_release(acb); - return NULL; + if (acb->qiov->niov > 1) { + qemu_vfree(acb->orig_buf); } + qemu_aio_release(acb); - return &acb->common; + return ret; } static void qcow_close(BlockDriverState *bs) @@ -1020,8 +964,8 @@ static BlockDriver bdrv_qcow = { .bdrv_is_allocated = qcow_is_allocated, .bdrv_set_key = qcow_set_key, .bdrv_make_empty = qcow_make_empty, - .bdrv_aio_readv = qcow_aio_readv, - .bdrv_aio_writev = qcow_aio_writev, + .bdrv_co_readv = qcow_co_readv, + .bdrv_co_writev = qcow_co_writev, .bdrv_aio_flush = qcow_aio_flush, .bdrv_write_compressed = qcow_write_compressed, .bdrv_get_info = qcow_get_info, -- 1.7.6