diff options
| -rw-r--r-- | block/block-backend.c | 64 | ||||
| -rw-r--r-- | block/io.c | 5 | ||||
| -rw-r--r-- | include/block/block_int.h | 4 |
3 files changed, 65 insertions, 8 deletions
diff --git a/block/block-backend.c b/block/block-backend.c index 5de785026b..c05878526a 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -22,6 +22,8 @@ /* Number of coroutines to reserve per attached device model */ #define COROUTINE_POOL_RESERVATION 64 +#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ + static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); struct BlockBackend { @@ -693,15 +695,69 @@ static int blk_check_request(BlockBackend *blk, int64_t sector_num, nb_sectors * BDRV_SECTOR_SIZE); } -int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf, - int nb_sectors) +static int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, + unsigned int bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags) { - int ret = blk_check_request(blk, sector_num, nb_sectors); + int ret = blk_check_byte_request(blk, offset, bytes); if (ret < 0) { return ret; } - return bdrv_read(blk_bs(blk), sector_num, buf, nb_sectors); + return bdrv_co_do_preadv(blk_bs(blk), offset, bytes, qiov, flags); +} + +typedef struct BlkRwCo { + BlockBackend *blk; + int64_t offset; + QEMUIOVector *qiov; + int ret; + BdrvRequestFlags flags; +} BlkRwCo; + +static void blk_read_entry(void *opaque) +{ + BlkRwCo *rwco = opaque; + + rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, rwco->qiov->size, + rwco->qiov, rwco->flags); +} + +int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf, + int nb_sectors) +{ + AioContext *aio_context; + QEMUIOVector qiov; + struct iovec iov; + Coroutine *co; + BlkRwCo rwco; + + if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) { + return -EINVAL; + } + + iov = (struct iovec) { + .iov_base = buf, + .iov_len = nb_sectors * BDRV_SECTOR_SIZE, + }; + qemu_iovec_init_external(&qiov, &iov, 1); + + rwco = (BlkRwCo) { + .blk = blk, + .offset = sector_num << BDRV_SECTOR_BITS, + .qiov = &qiov, + .ret = NOT_DONE, + }; + + co = qemu_coroutine_create(blk_read_entry); + qemu_coroutine_enter(co, &rwco); + + aio_context = blk_get_aio_context(blk); + while (rwco.ret == NOT_DONE) { + aio_poll(aio_context, true); + } + + return rwco.ret; } int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf, diff --git a/block/io.c b/block/io.c index 5f9b6d623d..c7084e4932 100644 --- a/block/io.c +++ b/block/io.c @@ -44,9 +44,6 @@ static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *iov); -static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags); static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags); @@ -939,7 +936,7 @@ out: /* * Handle a read request in coroutine context */ -static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, +int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) { diff --git a/include/block/block_int.h b/include/block/block_int.h index c031db40d9..b78be8daf8 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -508,6 +508,10 @@ extern BlockDriver bdrv_qcow2; */ void bdrv_setup_io_funcs(BlockDriver *bdrv); +int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, + int64_t offset, unsigned int bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags); + int get_tmp_filename(char *filename, int size); BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, const char *filename); |