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authorTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
committerTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
commite02cda008591317b1625707ff8e115a4841aa889 (patch)
treeaee302e3cf8b59ec2d32ec481be3d1afddfc8968 /block/filter-compress.c
parentcc668e6b7e0ffd8c9d130513d12053cf5eda1d3b (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.c159
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);