[pve-devel] [RFC PATCH kvm] add the zeroinit block driver filter
Wolfgang Bumiller
w.bumiller at proxmox.com
Fri Mar 18 12:17:39 CET 2016
---
This is a block driver filter (or hack...) to force the assumption of
a zero-initialized storage (has_zero_init) and skip appending
write_zero() requests.
We can use this for clone_disk() when converting between lvm-thin and
other storage types.
To use this the destination of a qemu-img or 'qmp drive-mirror'
command is prefixed with 'zeroinit:'
debian/patches/pve/0044-block-add-zeroinit.patch | 248 +++++++++++++++++++++++
debian/patches/series | 1 +
2 files changed, 249 insertions(+)
create mode 100644 debian/patches/pve/0044-block-add-zeroinit.patch
diff --git a/debian/patches/pve/0044-block-add-zeroinit.patch b/debian/patches/pve/0044-block-add-zeroinit.patch
new file mode 100644
index 0000000..03fc92a
--- /dev/null
+++ b/debian/patches/pve/0044-block-add-zeroinit.patch
@@ -0,0 +1,248 @@
+From 8b996ca2740d40027652ea63f52bed8f9271331b Mon Sep 17 00:00:00 2001
+From: Wolfgang Bumiller <w.bumiller at proxmox.com>
+Date: Thu, 17 Mar 2016 11:33:37 +0100
+Subject: [PATCH] block: add the zeroinit block driver filter
+
+---
+ block/Makefile.objs | 1 +
+ block/zeroinit.c | 216 ++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 2 files changed, 217 insertions(+)
+ create mode 100644 block/zeroinit.c
+
+diff --git a/block/Makefile.objs b/block/Makefile.objs
+index 58ef2ef..5bb55b0 100644
+--- a/block/Makefile.objs
++++ b/block/Makefile.objs
+@@ -4,6 +4,7 @@ block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
+ block-obj-y += qed-check.o
+ block-obj-$(CONFIG_VHDX) += vhdx.o vhdx-endian.o vhdx-log.o
+ block-obj-y += quorum.o
++block-obj-y += zeroinit.o
+ block-obj-y += parallels.o blkdebug.o blkverify.o
+ block-obj-y += block-backend.o snapshot.o qapi.o
+ block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
+diff --git a/block/zeroinit.c b/block/zeroinit.c
+new file mode 100644
+index 0000000..04a9bd0
+--- /dev/null
++++ b/block/zeroinit.c
+@@ -0,0 +1,216 @@
++/*
++ * Filter to fake a zero-initialized block device.
++ *
++ * Copyright (c) 2016 Wolfgang Bumiller <w.bumiller at proxmox.com>
++ * 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 "block/block_int.h"
++#include "qapi/qmp/qdict.h"
++#include "qapi/qmp/qstring.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_file, 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 BlockAIOCB *zeroinit_aio_readv(BlockDriverState *bs,
++ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
++ BlockCompletionFunc *cb, void *opaque)
++{
++ return bdrv_aio_readv(bs->file->bs, sector_num, qiov, nb_sectors,
++ cb, opaque);
++}
++
++static int coroutine_fn zeroinit_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
++ int nb_sectors, BdrvRequestFlags flags)
++{
++ BDRVZeroinitState *s = bs->opaque;
++ if (sector_num >= s->extents)
++ return 0;
++ return bdrv_write_zeroes(bs->file->bs, sector_num, nb_sectors, flags);
++}
++
++static BlockAIOCB *zeroinit_aio_writev(BlockDriverState *bs,
++ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
++ BlockCompletionFunc *cb, void *opaque)
++{
++ BDRVZeroinitState *s = bs->opaque;
++ int64_t extents = sector_num + nb_sectors + 1;
++ if (extents > s->extents)
++ s->extents = extents;
++ return bdrv_aio_writev(bs->file->bs, sector_num, qiov, nb_sectors,
++ cb, opaque);
++}
++
++static BlockAIOCB *zeroinit_aio_flush(BlockDriverState *bs,
++ BlockCompletionFunc *cb,
++ void *opaque)
++{
++ return bdrv_aio_flush(bs->file->bs, cb, opaque);
++}
++
++static bool zeroinit_recurse_is_first_non_filter(BlockDriverState *bs,
++ BlockDriverState *candidate)
++{
++ return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
++}
++
++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 int64_t coroutine_fn zeroinit_co_get_block_status(BlockDriverState *bs,
++ int64_t sector_num,
++ int nb_sectors, int *pnum)
++{
++ return bdrv_get_block_status(bs->file->bs, sector_num, nb_sectors, pnum);
++}
++
++static coroutine_fn BlockAIOCB *zeroinit_aio_discard(BlockDriverState *bs,
++ int64_t sector_num, int nb_sectors,
++ BlockCompletionFunc *cb, void *opaque)
++{
++ return bdrv_aio_discard(bs->file->bs, sector_num, nb_sectors, cb, opaque);
++}
++
++static int zeroinit_truncate(BlockDriverState *bs, int64_t offset)
++{
++ return bdrv_truncate(bs->file->bs, offset);
++}
++
++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_co_flush_to_disk = zeroinit_co_flush,
++
++ .bdrv_co_write_zeroes = zeroinit_co_write_zeroes,
++ .bdrv_aio_writev = zeroinit_aio_writev,
++ .bdrv_aio_readv = zeroinit_aio_readv,
++ .bdrv_aio_flush = zeroinit_aio_flush,
++
++ .is_filter = true,
++ .bdrv_recurse_is_first_non_filter = zeroinit_recurse_is_first_non_filter,
++
++ .bdrv_has_zero_init = zeroinit_has_zero_init,
++
++ .bdrv_co_get_block_status = zeroinit_co_get_block_status,
++
++ .bdrv_aio_discard = zeroinit_aio_discard,
++
++ .bdrv_truncate = zeroinit_truncate,
++ .bdrv_get_info = zeroinit_get_info,
++};
++
++static void bdrv_zeroinit_init(void)
++{
++ bdrv_register(&bdrv_zeroinit);
++}
++
++block_init(bdrv_zeroinit_init);
+--
+2.1.4
+
diff --git a/debian/patches/series b/debian/patches/series
index f07e028..e8f1710 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -41,6 +41,7 @@ pve/0040-vnc-make-x509-imply-tls-again.patch
pve/0041-PVE-VNC-authentication.patch
pve/0042-vma-writer-don-t-bail-out-on-zero-length-files.patch
pve/0043-vma-better-driver-guessing-for-bdrv_open.patch
+pve/0044-block-add-zeroinit.patch
extra/CVE-2015-8558-ehci_make_idt_processing_more_robust.patch
extra/CVE-2015-8613-scsi-initialize-info-object.patch
extra/CVE-2015-8701-net-rocker-off-by-one.patch
--
2.1.4
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