/* * 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-io.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) { int ret = bdrv_open_file_child(NULL, options, "file", bs, errp); if (ret < 0) { return ret; } GRAPH_RDLOCK_GUARD_MAINLOOP(); 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 coroutine_fn GRAPH_RDLOCK compress_co_getlength(BlockDriverState *bs) { return bdrv_co_getlength(bs->file->bs); } static int coroutine_fn GRAPH_RDLOCK 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 GRAPH_RDLOCK 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 GRAPH_RDLOCK 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 GRAPH_RDLOCK compress_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) { return bdrv_co_pdiscard(bs->file, offset, bytes); } static void GRAPH_RDLOCK 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 coroutine_fn GRAPH_RDLOCK compress_co_eject(BlockDriverState *bs, bool eject_flag) { bdrv_co_eject(bs->file->bs, eject_flag); } static void coroutine_fn GRAPH_RDLOCK compress_co_lock_medium(BlockDriverState *bs, bool locked) { bdrv_co_lock_medium(bs->file->bs, locked); } static BlockDriver bdrv_compress = { .format_name = "compress", .bdrv_open = compress_open, .bdrv_child_perm = bdrv_default_perms, .bdrv_co_getlength = compress_co_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_co_eject = compress_co_eject, .bdrv_co_lock_medium = compress_co_lock_medium, .is_filter = true, }; static void bdrv_compress_init(void) { bdrv_register(&bdrv_compress); } block_init(bdrv_compress_init);