| Message ID | 20230918180100.524843-21-den@openvz.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement discard operation for Parallels images | expand |
On 9/18/23 20:00, Denis V. Lunev wrote: > * Discarding with backing stores is not supported by the format. > * There is no buffering/queueing of the discard operation. > * Only operations aligned to the cluster are supported. > > Signed-off-by: Denis V. Lunev <den@openvz.org> > --- > block/parallels.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 46 insertions(+) > > diff --git a/block/parallels.c b/block/parallels.c > index d9d36c514b..1ef23f6669 100644 > --- a/block/parallels.c > +++ b/block/parallels.c > @@ -537,6 +537,51 @@ parallels_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, > return ret; > } > > + > +static int coroutine_fn > +parallels_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) > +{ > + int ret = 0; > + uint32_t cluster, count; > + BDRVParallelsState *s = bs->opaque; > + > + /* > + * The image does not support ZERO mark inside the BAT, which means that > + * stale data could be exposed from the backing file. > + */ > + if (bs->backing) { > + return -ENOTSUP; > + } > + > + if (!QEMU_IS_ALIGNED(offset, s->cluster_size)) { > + return -ENOTSUP; > + } else if (!QEMU_IS_ALIGNED(bytes, s->cluster_size)) { > + return -ENOTSUP; > + } > + > + cluster = offset / s->cluster_size; > + count = bytes / s->cluster_size; > + > + qemu_co_mutex_lock(&s->lock); > + for (; count > 0; cluster++, count--) { > + int64_t host_off = bat2sect(s, cluster) << BDRV_SECTOR_BITS; > + if (host_off == 0) { > + continue; > + } > + > + ret = bdrv_co_pdiscard(bs->file, host_off, s->cluster_size); > + if (ret < 0) { > + goto done; > + } > + > + parallels_set_bat_entry(s, cluster, 0); > + bitmap_clear(s->used_bmap, host_cluster_index(s, host_off), 1); > + } > +done: > + qemu_co_mutex_unlock(&s->lock); > + return ret; > +} > + > static void parallels_check_unclean(BlockDriverState *bs, > BdrvCheckResult *res, > BdrvCheckMode fix) > @@ -1417,6 +1462,7 @@ static BlockDriver bdrv_parallels = { > .bdrv_co_create = parallels_co_create, > .bdrv_co_create_opts = parallels_co_create_opts, > .bdrv_co_check = parallels_co_check, > + .bdrv_co_pdiscard = parallels_co_pdiscard, > }; > > static void bdrv_parallels_init(void) Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
diff --git a/block/parallels.c b/block/parallels.c index d9d36c514b..1ef23f6669 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -537,6 +537,51 @@ parallels_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, return ret; } + +static int coroutine_fn +parallels_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) +{ + int ret = 0; + uint32_t cluster, count; + BDRVParallelsState *s = bs->opaque; + + /* + * The image does not support ZERO mark inside the BAT, which means that + * stale data could be exposed from the backing file. + */ + if (bs->backing) { + return -ENOTSUP; + } + + if (!QEMU_IS_ALIGNED(offset, s->cluster_size)) { + return -ENOTSUP; + } else if (!QEMU_IS_ALIGNED(bytes, s->cluster_size)) { + return -ENOTSUP; + } + + cluster = offset / s->cluster_size; + count = bytes / s->cluster_size; + + qemu_co_mutex_lock(&s->lock); + for (; count > 0; cluster++, count--) { + int64_t host_off = bat2sect(s, cluster) << BDRV_SECTOR_BITS; + if (host_off == 0) { + continue; + } + + ret = bdrv_co_pdiscard(bs->file, host_off, s->cluster_size); + if (ret < 0) { + goto done; + } + + parallels_set_bat_entry(s, cluster, 0); + bitmap_clear(s->used_bmap, host_cluster_index(s, host_off), 1); + } +done: + qemu_co_mutex_unlock(&s->lock); + return ret; +} + static void parallels_check_unclean(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) @@ -1417,6 +1462,7 @@ static BlockDriver bdrv_parallels = { .bdrv_co_create = parallels_co_create, .bdrv_co_create_opts = parallels_co_create_opts, .bdrv_co_check = parallels_co_check, + .bdrv_co_pdiscard = parallels_co_pdiscard, }; static void bdrv_parallels_init(void)
* Discarding with backing stores is not supported by the format. * There is no buffering/queueing of the discard operation. * Only operations aligned to the cluster are supported. Signed-off-by: Denis V. Lunev <den@openvz.org> --- block/parallels.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)