On 05/31/2016 03:15 AM, Denis V. Lunev wrote: > From: Pavel Butsykin > > This patch just adds the interface to the bdrv_co_pwritev_compressed, > which is currently not used but will be useful for safe implementation of the > bdrv_co_write_compressed callback in format drivers. > > Signed-off-by: Pavel Butsykin > Signed-off-by: Denis V. Lunev > CC: Jeff Cody > CC: Markus Armbruster > CC: Eric Blake > CC: John Snow > CC: Stefan Hajnoczi > CC: Kevin Wolf > --- > block/io.c | 78 +++++++++++++++++++++++++++++++++++++++++++---- > include/block/block_int.h | 5 +++ > qemu-img.c | 2 +- > 3 files changed, 78 insertions(+), 7 deletions(-) > > diff --git a/block/io.c b/block/io.c > index c5bb6ae..54cd9a4 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -1779,8 +1779,8 @@ int bdrv_is_allocated_above(BlockDriverState *top, > return 0; > } > > -int bdrv_pwrite_compressed(BlockDriverState *bs, int64_t offset, > - const void *buf, int count) > +int coroutine_fn bdrv_co_pwritev_compressed(BlockDriverState *bs, > + int64_t offset, unsigned int bytes, QEMUIOVector *qiov) Why the rename s/count/bytes/? Would it be better to get the name right in 1/11? > { > BlockDriver *drv = bs->drv; > int ret; > @@ -1788,18 +1788,84 @@ int bdrv_pwrite_compressed(BlockDriverState *bs, int64_t offset, > if (!drv) { > return -ENOMEDIUM; > } > - if (!drv->bdrv_write_compressed) { > + > + if (!drv->bdrv_co_write_compressed) { > return -ENOTSUP; This is a (temporary) regression - since none of the drivers have .bdrv_co_write_compressed yet, you will always fail. Rather, the transition period should support both interfaces at once... > } > - ret = bdrv_check_byte_request(bs, offset, count); > + > + ret = bdrv_check_byte_request(bs, offset, bytes); > if (ret < 0) { > return ret; > } > > assert(QLIST_EMPTY(&bs->dirty_bitmaps)); > + assert(qemu_in_coroutine()); > + > + return drv->bdrv_co_write_compressed(bs, offset >> BDRV_SECTOR_BITS, > + bytes >> BDRV_SECTOR_BITS, qiov); ...and call into either the old or the new interface according to what is present. > +int bdrv_pwrite_compressed(BlockDriverState *bs, int64_t offset, > + const void *buf, int count) > +{ > + BdrvWriteCompressedCo data; > + QEMUIOVector qiov; > + BlockDriver *drv = bs->drv; > + struct iovec iov = { > + .iov_base = (void *)buf, > + .iov_len = count, > + }; > + qemu_iovec_init_external(&qiov, &iov, 1); > > - return drv->bdrv_write_compressed(bs, offset >> BDRV_SECTOR_BITS, buf, > - count >> BDRV_SECTOR_BITS); > + data = (BdrvWriteCompressedCo) { > + .bs = bs, > + .offset = offset, > + .qiov = &qiov, > + .ret = -EINPROGRESS, > + }; > + > + if (!drv) { > + return -ENOMEDIUM; > + } > + > + if (drv->bdrv_write_compressed) { > + int ret = bdrv_check_byte_request(bs, offset, count); > + if (ret < 0) { > + return ret; > + } > + assert(QLIST_EMPTY(&bs->dirty_bitmaps)); > + return drv->bdrv_write_compressed(bs, offset >> BDRV_SECTOR_BITS, buf, > + count >> BDRV_SECTOR_BITS); > + } Oh, you're catering to the old code up front, without a coroutine, and only the new code gets coroutine treatment. Maybe it's okay after all. > + > + if (qemu_in_coroutine()) { > + /* Fast-path if already in coroutine context */ > + bdrv_write_compressed_co_entry(&data); > + } else { > + AioContext *aio_context = bdrv_get_aio_context(bs); > + > + Coroutine *co = qemu_coroutine_create(bdrv_write_compressed_co_entry); > + qemu_coroutine_enter(co, &data); > + while (data.ret == -EINPROGRESS) { > + aio_poll(aio_context, true); > + } > + } > + return data.ret; > } > > int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, > diff --git a/include/block/block_int.h b/include/block/block_int.h > index 30a9717..ccba9c9 100644 > --- a/include/block/block_int.h > +++ b/include/block/block_int.h > @@ -207,6 +207,9 @@ struct BlockDriver { > int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, > const uint8_t *buf, int nb_sectors); > > + int coroutine_fn (*bdrv_co_write_compressed)(BlockDriverState *bs, Might be better to name this bdrv_co_pwrite_compressed if we want to make it byte-based... > + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); ...it seems odd that you have to add a new sector-based interface given that you are trying to convert to byte-based. > + > int (*bdrv_snapshot_create)(BlockDriverState *bs, > QEMUSnapshotInfo *sn_info); > int (*bdrv_snapshot_goto)(BlockDriverState *bs, > @@ -535,6 +538,8 @@ int coroutine_fn bdrv_co_preadv(BlockDriverState *bs, > int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs, > int64_t offset, unsigned int bytes, QEMUIOVector *qiov, > BdrvRequestFlags flags); > +int coroutine_fn bdrv_co_pwritev_compressed(BlockDriverState *bs, > + int64_t offset, unsigned int bytes, QEMUIOVector *qiov); > > int get_tmp_filename(char *filename, int size); > BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, > diff --git a/qemu-img.c b/qemu-img.c > index eb744d4..ab54027 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -2024,7 +2024,7 @@ static int img_convert(int argc, char **argv) > const char *preallocation = > qemu_opt_get(opts, BLOCK_OPT_PREALLOC); > > - if (!drv->bdrv_write_compressed) { > + if (!drv->bdrv_write_compressed && !drv->bdrv_co_write_compressed) { > error_report("Compression not supported for this file format"); > ret = -1; > goto out; > -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org