| Message ID | 20170627224616.18538-2-el13635@mail.ntua.gr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 28, 2017 at 01:46:15AM +0300, Manos Pitsidianakis wrote: > @@ -3406,13 +3410,18 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp) > > assert(child->perm & BLK_PERM_RESIZE); > > - if (!drv) { > - error_setg(errp, "No medium inserted"); > - return -ENOMEDIUM; > - } > - if (!drv->bdrv_truncate) { > - error_setg(errp, "Image format driver does not support resize"); > - return -ENOTSUP; > + if (!drv || !drv->bdrv_truncate) { bs->drv == NULL means the BDS is closed. We should not forward to bs->file. In practice bs->file will be NULL but please leave the original if statement unchanged so it's clear that !drv results in -ENOMEDIUM. The same applies to the other changes below. > @@ -3832,10 +3844,15 @@ void bdrv_get_backing_filename(BlockDriverState *bs, > int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) > { > BlockDriver *drv = bs->drv; > - if (!drv) > - return -ENOMEDIUM; > - if (!drv->bdrv_get_info) > - return -ENOTSUP; > + if (!drv || !drv->bdrv_get_info) { > + if (bs->file && bs->file->bs) { > + return bdrv_get_info(bs->file->bs, bdi); > + } > + if (!drv) > + return -ENOMEDIUM; QEMU coding style always uses curly braces, even when the if statement body is just 1 line. > diff --git a/block/io.c b/block/io.c > index c72d7015..c1b73226 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -2403,6 +2403,10 @@ int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf) > > bdrv_inc_in_flight(bs); > if (!drv || (!drv->bdrv_aio_ioctl && !drv->bdrv_co_ioctl)) { > + if (bs->file && bs->file->bs) { > + bdrv_dec_in_flight(bs); > + return bdrv_co_ioctl(bs->file->bs, req, buf); bdrv_dec_in_flight() must happen after the request finishes, otherwise bdrv_drain() will break.
On Wed, Jun 28, 2017 at 01:46:15AM +0300, Manos Pitsidianakis wrote: > The following functions fail if bs->drv does not implement them: > > bdrv_probe_blocksizes > bdrv_probe_geometry > bdrv_truncate > bdrv_has_zero_init > bdrv_get_info > bdrv_media_changed > bdrv_eject > bdrv_lock_medium > bdrv_co_ioctl > > Instead, the call should be passed to bs->file if it exists, to allow > filter drivers to support those methods without implementing them. > > Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> > --- > block.c | 45 ++++++++++++++++++++++++++++++++++----------- > block/io.c | 4 ++++ > 2 files changed, 38 insertions(+), 11 deletions(-) Will you send a block/raw-format.c patch that removes the forwarding functions that are no longer needed?
On 06/29/2017 09:05 AM, Stefan Hajnoczi wrote: > On Wed, Jun 28, 2017 at 01:46:15AM +0300, Manos Pitsidianakis wrote: >> The following functions fail if bs->drv does not implement them: >> >> bdrv_probe_blocksizes >> bdrv_probe_geometry >> bdrv_truncate >> bdrv_has_zero_init >> bdrv_get_info >> bdrv_media_changed >> bdrv_eject >> bdrv_lock_medium >> bdrv_co_ioctl >> >> Instead, the call should be passed to bs->file if it exists, to allow >> filter drivers to support those methods without implementing them. >> >> Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> >> --- >> block.c | 45 ++++++++++++++++++++++++++++++++++----------- >> block/io.c | 4 ++++ >> 2 files changed, 38 insertions(+), 11 deletions(-) > > Will you send a block/raw-format.c patch that removes the forwarding > functions that are no longer needed? block/raw-format.c does some additional things thanks to its 'offset' parameter, so I think it will have to still implement things directly rather than relying on defaults.
diff --git a/block.c b/block.c index 69439628..ad11230a 100644 --- a/block.c +++ b/block.c @@ -494,6 +494,8 @@ int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) if (drv && drv->bdrv_probe_blocksizes) { return drv->bdrv_probe_blocksizes(bs, bsz); + } else if (bs->file && bs->file->bs) { + return bdrv_probe_blocksizes(bs->file->bs, bsz); } return -ENOTSUP; @@ -511,6 +513,8 @@ int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) if (drv && drv->bdrv_probe_geometry) { return drv->bdrv_probe_geometry(bs, geo); + } else if (bs->file && bs->file->bs) { + return bdrv_probe_geometry(bs->file->bs, geo); } return -ENOTSUP; @@ -3406,13 +3410,18 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp) assert(child->perm & BLK_PERM_RESIZE); - if (!drv) { - error_setg(errp, "No medium inserted"); - return -ENOMEDIUM; - } - if (!drv->bdrv_truncate) { - error_setg(errp, "Image format driver does not support resize"); - return -ENOTSUP; + if (!drv || !drv->bdrv_truncate) { + if (bs->file && bs->file->bs) { + return bdrv_truncate(bs->file, offset, errp); + } + if (!drv) { + error_setg(errp, "No medium inserted"); + return -ENOMEDIUM; + } + if (!drv->bdrv_truncate) { + error_setg(errp, "Image format driver does not support resize"); + return -ENOTSUP; + } } if (bs->read_only) { error_setg(errp, "Image is read-only"); @@ -3778,6 +3787,9 @@ int bdrv_has_zero_init(BlockDriverState *bs) if (bs->drv->bdrv_has_zero_init) { return bs->drv->bdrv_has_zero_init(bs); } + if (bs->file && bs->file->bs) { + return bdrv_has_zero_init(bs->file->bs); + } /* safe default */ return 0; @@ -3832,10 +3844,15 @@ void bdrv_get_backing_filename(BlockDriverState *bs, int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { BlockDriver *drv = bs->drv; - if (!drv) - return -ENOMEDIUM; - if (!drv->bdrv_get_info) - return -ENOTSUP; + if (!drv || !drv->bdrv_get_info) { + if (bs->file && bs->file->bs) { + return bdrv_get_info(bs->file->bs, bdi); + } + if (!drv) + return -ENOMEDIUM; + if (!drv->bdrv_get_info) + return -ENOTSUP; + } memset(bdi, 0, sizeof(*bdi)); return drv->bdrv_get_info(bs, bdi); } @@ -4205,6 +4222,8 @@ int bdrv_media_changed(BlockDriverState *bs) if (drv && drv->bdrv_media_changed) { return drv->bdrv_media_changed(bs); + } else if (bs->file && bs->file->bs) { + bdrv_media_changed(bs->file->bs); } return -ENOTSUP; } @@ -4218,6 +4237,8 @@ void bdrv_eject(BlockDriverState *bs, bool eject_flag) if (drv && drv->bdrv_eject) { drv->bdrv_eject(bs, eject_flag); + } else if (bs->file && bs->file->bs) { + bdrv_eject(bs->file->bs, eject_flag); } } @@ -4233,6 +4254,8 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked) if (drv && drv->bdrv_lock_medium) { drv->bdrv_lock_medium(bs, locked); + } else if (bs->file && bs->file->bs) { + bdrv_lock_medium(bs->file->bs, locked); } } diff --git a/block/io.c b/block/io.c index c72d7015..c1b73226 100644 --- a/block/io.c +++ b/block/io.c @@ -2403,6 +2403,10 @@ int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf) bdrv_inc_in_flight(bs); if (!drv || (!drv->bdrv_aio_ioctl && !drv->bdrv_co_ioctl)) { + if (bs->file && bs->file->bs) { + bdrv_dec_in_flight(bs); + return bdrv_co_ioctl(bs->file->bs, req, buf); + } co.ret = -ENOTSUP; goto out; }
The following functions fail if bs->drv does not implement them: bdrv_probe_blocksizes bdrv_probe_geometry bdrv_truncate bdrv_has_zero_init bdrv_get_info bdrv_media_changed bdrv_eject bdrv_lock_medium bdrv_co_ioctl Instead, the call should be passed to bs->file if it exists, to allow filter drivers to support those methods without implementing them. Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> --- block.c | 45 ++++++++++++++++++++++++++++++++++----------- block/io.c | 4 ++++ 2 files changed, 38 insertions(+), 11 deletions(-)