Am 26.11.2013 um 13:18 hat Fam Zheng geschrieben: > On 2013年11月26日 18:48, Kevin Wolf wrote: > >Strictly speaking, this is only required for has_zero_init() == false, > >but it's easy enough to just do a cluster-aligned write that is padded > >with zeros after the header. > > > >This fixes that after 'qemu-img create' header extensions are attempted > >to be parsed that are really just random leftover data. > > > >Cc: qemu-sta...@nongnu.org > >Signed-off-by: Kevin Wolf <kw...@redhat.com> > >--- > > block/qcow2.c | 37 +++++++++++++++++++++---------------- > > 1 file changed, 21 insertions(+), 16 deletions(-) > > > >diff --git a/block/qcow2.c b/block/qcow2.c > >index 6e5d98d..7c18587 100644 > >--- a/block/qcow2.c > >+++ b/block/qcow2.c > >@@ -1471,7 +1471,7 @@ static int qcow2_create2(const char *filename, int64_t > >total_size, > > * size for any qcow2 image. > > */ > > BlockDriverState* bs; > >- QCowHeader header; > >+ QCowHeader *header; > > uint8_t* refcount_table; > > Error *local_err = NULL; > > int ret; > >@@ -1489,30 +1489,35 @@ static int qcow2_create2(const char *filename, > >int64_t total_size, > > } > > > > /* Write the header */ > >- memset(&header, 0, sizeof(header)); > >- header.magic = cpu_to_be32(QCOW_MAGIC); > >- header.version = cpu_to_be32(version); > >- header.cluster_bits = cpu_to_be32(cluster_bits); > >- header.size = cpu_to_be64(0); > >- header.l1_table_offset = cpu_to_be64(0); > >- header.l1_size = cpu_to_be32(0); > >- header.refcount_table_offset = cpu_to_be64(cluster_size); > >- header.refcount_table_clusters = cpu_to_be32(1); > >- header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT); > >- header.header_length = cpu_to_be32(sizeof(header)); > >+ QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); > >+ header = g_malloc(cluster_size); > >+ memset(header, 0, cluster_size); > > Could just be: > > header = g_malloc0(cluster_size); > > But either way,
Yes, that's better. I'll change it. > Reviewed-by: Fam Zheng <f...@redhat.com> Thanks. Kevin
