From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Wolfgang Bumiller Date: Mon, 6 Apr 2020 12:16:47 +0200 Subject: [PATCH] PVE: block: add the zeroinit block driver filter Signed-off-by: Thomas Lamprecht --- block/meson.build | 1 + block/zeroinit.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 197 insertions(+) create mode 100644 block/zeroinit.c diff --git a/block/meson.build b/block/meson.build index 0450914c7a..7a0bc3df09 100644 --- a/block/meson.build +++ b/block/meson.build @@ -41,6 +41,7 @@ block_ss.add(files( 'vmdk.c', 'vpc.c', 'write-threshold.c', + 'zeroinit.c', ), zstd, zlib, gnutls) softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('blkreplay.c')) diff --git a/block/zeroinit.c b/block/zeroinit.c new file mode 100644 index 0000000000..5529627f7e --- /dev/null +++ b/block/zeroinit.c @@ -0,0 +1,196 @@ +/* + * Filter to fake a zero-initialized block device. + * + * Copyright (c) 2016 Wolfgang Bumiller + * Copyright (c) 2016 Proxmox Server Solutions GmbH + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "block/block_int.h" +#include "qapi/qmp/qdict.h" +#include "qapi/qmp/qstring.h" +#include "qemu/cutils.h" +#include "qemu/option.h" +#include "qemu/module.h" + +typedef struct { + bool has_zero_init; + int64_t extents; +} BDRVZeroinitState; + +/* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */ +static void zeroinit_parse_filename(const char *filename, QDict *options, + Error **errp) +{ + QString *raw_path; + + /* Parse the blkverify: prefix */ + if (!strstart(filename, "zeroinit:", &filename)) { + /* There was no prefix; therefore, all options have to be already + present in the QDict (except for the filename) */ + return; + } + + raw_path = qstring_from_str(filename); + qdict_put(options, "x-next", raw_path); +} + +static QemuOptsList runtime_opts = { + .name = "zeroinit", + .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), + .desc = { + { + .name = "x-next", + .type = QEMU_OPT_STRING, + .help = "[internal use only, will be removed]", + }, + { + .name = "x-zeroinit", + .type = QEMU_OPT_BOOL, + .help = "set has_initialized_zero flag", + }, + { /* end of list */ } + }, +}; + +static int zeroinit_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + BDRVZeroinitState *s = bs->opaque; + QemuOpts *opts; + Error *local_err = NULL; + int ret; + + s->extents = 0; + + opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; + } + + /* Open the raw file */ + bs->file = bdrv_open_child(qemu_opt_get(opts, "x-next"), options, "next", + bs, &child_of_bds, BDRV_CHILD_FILTERED, false, &local_err); + if (local_err) { + ret = -EINVAL; + error_propagate(errp, local_err); + goto fail; + } + + /* set the options */ + s->has_zero_init = qemu_opt_get_bool(opts, "x-zeroinit", true); + + ret = 0; +fail: + if (ret < 0) { + bdrv_unref_child(bs, bs->file); + } + qemu_opts_del(opts); + return ret; +} + +static void zeroinit_close(BlockDriverState *bs) +{ + BDRVZeroinitState *s = bs->opaque; + (void)s; +} + +static int64_t zeroinit_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + +static int coroutine_fn zeroinit_co_preadv(BlockDriverState *bs, + uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) +{ + return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); +} + +static int coroutine_fn zeroinit_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, + int count, BdrvRequestFlags flags) +{ + BDRVZeroinitState *s = bs->opaque; + if (offset >= s->extents) + return 0; + return bdrv_pwrite_zeroes(bs->file, offset, count, flags); +} + +static int coroutine_fn zeroinit_co_pwritev(BlockDriverState *bs, + uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) +{ + BDRVZeroinitState *s = bs->opaque; + int64_t extents = offset + bytes; + if (extents > s->extents) + s->extents = extents; + return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); +} + +static coroutine_fn int zeroinit_co_flush(BlockDriverState *bs) +{ + return bdrv_co_flush(bs->file->bs); +} + +static int zeroinit_has_zero_init(BlockDriverState *bs) +{ + BDRVZeroinitState *s = bs->opaque; + return s->has_zero_init; +} + +static int coroutine_fn zeroinit_co_pdiscard(BlockDriverState *bs, + int64_t offset, int count) +{ + return bdrv_co_pdiscard(bs->file, offset, count); +} + +static int zeroinit_co_truncate(BlockDriverState *bs, int64_t offset, + _Bool exact, PreallocMode prealloc, + BdrvRequestFlags req_flags, Error **errp) +{ + return bdrv_co_truncate(bs->file, offset, exact, prealloc, req_flags, errp); +} + +static int zeroinit_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) +{ + return bdrv_get_info(bs->file->bs, bdi); +} + +static BlockDriver bdrv_zeroinit = { + .format_name = "zeroinit", + .protocol_name = "zeroinit", + .instance_size = sizeof(BDRVZeroinitState), + + .bdrv_parse_filename = zeroinit_parse_filename, + .bdrv_file_open = zeroinit_open, + .bdrv_close = zeroinit_close, + .bdrv_getlength = zeroinit_getlength, + .bdrv_child_perm = bdrv_default_perms, + .bdrv_co_flush_to_disk = zeroinit_co_flush, + + .bdrv_co_pwrite_zeroes = zeroinit_co_pwrite_zeroes, + .bdrv_co_pwritev = zeroinit_co_pwritev, + .bdrv_co_preadv = zeroinit_co_preadv, + .bdrv_co_flush = zeroinit_co_flush, + + .is_filter = true, + + .bdrv_has_zero_init = zeroinit_has_zero_init, + + .bdrv_co_pdiscard = zeroinit_co_pdiscard, + + .bdrv_co_truncate = zeroinit_co_truncate, + .bdrv_get_info = zeroinit_get_info, +}; + +static void bdrv_zeroinit_init(void) +{ + bdrv_register(&bdrv_zeroinit); +} + +block_init(bdrv_zeroinit_init);