From 7762468560c9a2283836a4abdde58301ad7fb1cf Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Tue, 6 Aug 2013 15:44:54 +0800 Subject: [PATCH 08/13] vmdk: use heap allocation for whole_grain Message-id: <1377573001-27070-9-git-send-email-famz@redhat.com> Patchwork-id: 53788 O-Subject: [RHEL-7 qemu-kvm PATCH 08/13] vmdk: use heap allocation for whole_grain Bugzilla: 995866 RH-Acked-by: Paolo Bonzini RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Kevin Wolf We should never grow the stack beyond 1 MB, otherwise we'll fall off the end. Thread stacks and coroutine stacks (1 MB) do not grow. get_cluster_offset() allocates a big stack offset, it will fail for big cluster images, change to heap allocated buffer. Signed-off-by: Fam Zheng Signed-off-by: Kevin Wolf (cherry picked from commit bf81507de38fdfa4cb6e9b46fb38691a25cb1499) Signed-off-by: Fam Zheng --- block/vmdk.c | 21 +++++++++++++-------- 1 files changed, 13 insertions(+), 8 deletions(-) diff --git a/block/vmdk.c b/block/vmdk.c index 58163ef..1af6122 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -842,16 +842,17 @@ static int get_whole_cluster(BlockDriverState *bs, uint64_t offset, bool allocate) { - /* 128 sectors * 512 bytes each = grain size 64KB */ - uint8_t whole_grain[extent->cluster_sectors * 512]; + int ret = VMDK_OK; + uint8_t *whole_grain = NULL; /* we will be here if it's first write on non-exist grain(cluster). * try to read from parent image, if exist */ if (bs->backing_hd) { - int ret; - + whole_grain = + qemu_blockalign(bs, extent->cluster_sectors << BDRV_SECTOR_BITS); if (!vmdk_is_cid_valid(bs)) { - return VMDK_ERROR; + ret = VMDK_ERROR; + goto exit; } /* floor offset to cluster */ @@ -859,17 +860,21 @@ static int get_whole_cluster(BlockDriverState *bs, ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain, extent->cluster_sectors); if (ret < 0) { - return VMDK_ERROR; + ret = VMDK_ERROR; + goto exit; } /* Write grain only into the active image */ ret = bdrv_write(extent->file, cluster_offset, whole_grain, extent->cluster_sectors); if (ret < 0) { - return VMDK_ERROR; + ret = VMDK_ERROR; + goto exit; } } - return VMDK_OK; +exit: + qemu_vfree(whole_grain); + return ret; } static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data) -- 1.7.1