diff options
author | Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> | 2023-10-10 11:40:56 +0000 |
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committer | Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> | 2023-10-10 11:40:56 +0000 |
commit | e02cda008591317b1625707ff8e115a4841aa889 (patch) | |
tree | aee302e3cf8b59ec2d32ec481be3d1afddfc8968 /block/filter-compress.c | |
parent | cc668e6b7e0ffd8c9d130513d12053cf5eda1d3b (diff) |
Introduce Virtio-loopback epsilon release:
Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.
Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9
Diffstat (limited to 'block/filter-compress.c')
-rw-r--r-- | block/filter-compress.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/block/filter-compress.c b/block/filter-compress.c new file mode 100644 index 000000000..d5be53861 --- /dev/null +++ b/block/filter-compress.c @@ -0,0 +1,159 @@ +/* + * Compress filter block driver + * + * Copyright (c) 2019 Virtuozzo International GmbH + * + * Author: + * Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> + * (based on block/copy-on-read.c by Max Reitz) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 or + * (at your option) any later version of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "block/block_int.h" +#include "qemu/module.h" +#include "qapi/error.h" + + +static int compress_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, + BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, + false, errp); + if (!bs->file) { + return -EINVAL; + } + + if (!bs->file->bs->drv || !block_driver_can_compress(bs->file->bs->drv)) { + error_setg(errp, + "Compression is not supported for underlying format: %s", + bdrv_get_format_name(bs->file->bs) ?: "(no format)"); + + return -ENOTSUP; + } + + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | + (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); + + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | + ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) & + bs->file->bs->supported_zero_flags); + + return 0; +} + + +static int64_t compress_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + + +static int coroutine_fn compress_co_preadv_part(BlockDriverState *bs, + int64_t offset, int64_t bytes, + QEMUIOVector *qiov, + size_t qiov_offset, + BdrvRequestFlags flags) +{ + return bdrv_co_preadv_part(bs->file, offset, bytes, qiov, qiov_offset, + flags); +} + + +static int coroutine_fn compress_co_pwritev_part(BlockDriverState *bs, + int64_t offset, + int64_t bytes, + QEMUIOVector *qiov, + size_t qiov_offset, + BdrvRequestFlags flags) +{ + return bdrv_co_pwritev_part(bs->file, offset, bytes, qiov, qiov_offset, + flags | BDRV_REQ_WRITE_COMPRESSED); +} + + +static int coroutine_fn compress_co_pwrite_zeroes(BlockDriverState *bs, + int64_t offset, int64_t bytes, + BdrvRequestFlags flags) +{ + return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); +} + + +static int coroutine_fn compress_co_pdiscard(BlockDriverState *bs, + int64_t offset, int64_t bytes) +{ + return bdrv_co_pdiscard(bs->file, offset, bytes); +} + + +static void compress_refresh_limits(BlockDriverState *bs, Error **errp) +{ + BlockDriverInfo bdi; + int ret; + + if (!bs->file) { + return; + } + + ret = bdrv_get_info(bs->file->bs, &bdi); + if (ret < 0 || bdi.cluster_size == 0) { + return; + } + + bs->bl.request_alignment = bdi.cluster_size; +} + + +static void compress_eject(BlockDriverState *bs, bool eject_flag) +{ + bdrv_eject(bs->file->bs, eject_flag); +} + + +static void compress_lock_medium(BlockDriverState *bs, bool locked) +{ + bdrv_lock_medium(bs->file->bs, locked); +} + + +static BlockDriver bdrv_compress = { + .format_name = "compress", + + .bdrv_open = compress_open, + .bdrv_child_perm = bdrv_default_perms, + + .bdrv_getlength = compress_getlength, + + .bdrv_co_preadv_part = compress_co_preadv_part, + .bdrv_co_pwritev_part = compress_co_pwritev_part, + .bdrv_co_pwrite_zeroes = compress_co_pwrite_zeroes, + .bdrv_co_pdiscard = compress_co_pdiscard, + .bdrv_refresh_limits = compress_refresh_limits, + + .bdrv_eject = compress_eject, + .bdrv_lock_medium = compress_lock_medium, + + .has_variable_length = true, + .is_filter = true, +}; + +static void bdrv_compress_init(void) +{ + bdrv_register(&bdrv_compress); +} + +block_init(bdrv_compress_init); |