From 49b4262336e2875280d7d539851b5b318a86bc39 Mon Sep 17 00:00:00 2001 From: Asias He <asias@redhat.com> Date: Thu, 12 Sep 2013 07:39:33 +0200 Subject: [PATCH 13/29] block: Introduce bs->zero_beyond_eof RH-Author: Asias He <asias@redhat.com> Message-id: <1378971575-22416-3-git-send-email-asias@redhat.com> Patchwork-id: 54326 O-Subject: [RHEL7.0 qemu-kvm PATCH 2/4] block: Introduce bs->zero_beyond_eof Bugzilla: 1007226 RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com> RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com> RH-Acked-by: Fam Zheng <famz@redhat.com> BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1007226 Brew: https://brewweb.devel.redhat.com/taskinfo?taskID=6275752 In 4146b46c42e0989cb5842e04d88ab6ccb1713a48 (block: Produce zeros when protocols reading beyond end of file), we break qemu-iotests ./check -qcow2 022. This happens because qcow2 temporarily sets ->growable = 1 for vmstate accesses (which are stored beyond the end of regular image data). We introduce the bs->zero_beyond_eof to allow qcow2_load_vmstate() to disable ->zero_beyond_eof temporarily in addition to enable ->growable. [Since the broken patch "block: Produce zeros when protocols reading beyond end of file" has not been merged yet, I have applied this fix *first* and will then apply the next patch to keep the tree bisectable. -- Stefan] Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> (cherry picked from commit 0d51b4debee6fb322751a57097a1d675c7a7c38d) --- block.c | 2 ++ block/qcow2.c | 3 +++ include/block/block_int.h | 3 +++ 3 files changed, 8 insertions(+) Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> --- block.c | 2 ++ block/qcow2.c | 3 +++ include/block/block_int.h | 3 +++ 3 files changed, 8 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index f4a89b9..dbcad0e 100644 --- a/block.c +++ b/block.c @@ -708,6 +708,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, bs->open_flags = flags; bs->buffer_alignment = 512; + bs->zero_beyond_eof = true; open_flags = bdrv_open_flags(bs, flags); bs->read_only = !(open_flags & BDRV_O_RDWR); @@ -1407,6 +1408,7 @@ void bdrv_close(BlockDriverState *bs) bs->valid_key = 0; bs->sg = 0; bs->growable = 0; + bs->zero_beyond_eof = false; QDECREF(bs->options); bs->options = NULL; diff --git a/block/qcow2.c b/block/qcow2.c index abdc202..70da5bd 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1722,12 +1722,15 @@ static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, { BDRVQcowState *s = bs->opaque; int growable = bs->growable; + bool zero_beyond_eof = bs->zero_beyond_eof; int ret; BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); bs->growable = 1; + bs->zero_beyond_eof = false; ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); bs->growable = growable; + bs->zero_beyond_eof = zero_beyond_eof; return ret; } diff --git a/include/block/block_int.h b/include/block/block_int.h index 6078dd3..267be48 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -268,6 +268,9 @@ struct BlockDriverState { /* Whether the disk can expand beyond total_sectors */ int growable; + /* Whether produces zeros when read beyond eof */ + bool zero_beyond_eof; + /* the memory alignment required for the buffers handled by this driver */ int buffer_alignment; -- 1.7.1