| Message ID | 1375753243-19530-10-git-send-email-famz@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Aug 06, 2013 at 09:40:42AM +0800, Fam Zheng wrote: > 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 <famz@redhat.com> > --- > block/vmdk.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/block/vmdk.c b/block/vmdk.c > index 3bcab26..21610e3 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -842,16 +842,19 @@ 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; ^^^^^^ This above line should be removed; as it is this function will always return VMDK_OK with this here, due to the scoping of this 'ret' inside the if() block. > > + 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 +862,21 @@ 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) > -- > 1.8.3.4 >
diff --git a/block/vmdk.c b/block/vmdk.c index 3bcab26..21610e3 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -842,16 +842,19 @@ 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 +862,21 @@ 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)
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 <famz@redhat.com> --- block/vmdk.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)