[Qemu-devel] [PATCH] qemu-img create: Fix displayed default cluster size

[Qemu-devel] [PATCH] qemu-img create: Fix displayed default cluster size

[Kevin Wolf]

When not specifying a cluster size on the command line, qemu-img printed
a cluster size of 0:

    Formatting '/tmp/test.qcow2', fmt=qcow2 size=67108864
    encryption=off cluster_size=0

This patch adds the default cluster size to the QEMUOptionParameter list, so
that it displays the default value that is used.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c |    5 +++--
 block/qcow2.h |    2 ++
 block/qed.c   |    3 ++-
 block/vdi.c   |    6 ++++--
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 6ad829b..30b6692 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1069,7 +1069,7 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options)
     const char *backing_fmt = NULL;
     uint64_t sectors = 0;
     int flags = 0;
-    size_t cluster_size = 65536;
+    size_t cluster_size = DEFAULT_CLUSTER_SIZE;
     int prealloc = 0;
 
     /* Read out options */
@@ -1378,7 +1378,8 @@ static QEMUOptionParameter qcow2_create_options[] = {
     {
         .name = BLOCK_OPT_CLUSTER_SIZE,
         .type = OPT_SIZE,
-        .help = "qcow2 cluster size"
+        .help = "qcow2 cluster size",
+        .value = { .n = DEFAULT_CLUSTER_SIZE },
     },
     {
         .name = BLOCK_OPT_PREALLOC,
diff --git a/block/qcow2.h b/block/qcow2.h
index a019831..e1ae3e8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -54,6 +54,8 @@
 /* Must be at least 4 to cover all cases of refcount table growth */
 #define REFCOUNT_CACHE_SIZE 4
 
+#define DEFAULT_CLUSTER_SIZE 65536
+
 typedef struct QCowHeader {
     uint32_t magic;
     uint32_t version;
diff --git a/block/qed.c b/block/qed.c
index da0bf31..3970379 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1464,7 +1464,8 @@ static QEMUOptionParameter qed_create_options[] = {
     }, {
         .name = BLOCK_OPT_CLUSTER_SIZE,
         .type = OPT_SIZE,
-        .help = "Cluster size (in bytes)"
+        .help = "Cluster size (in bytes)",
+        .value = { .n = QED_DEFAULT_CLUSTER_SIZE },
     }, {
         .name = BLOCK_OPT_TABLE_SIZE,
         .type = OPT_SIZE,
diff --git a/block/vdi.c b/block/vdi.c
index 701745b..4c9e201 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -87,6 +87,7 @@ void uuid_unparse(const uuid_t uu, char *out);
 #define MiB     (KiB * KiB)
 
 #define SECTOR_SIZE 512
+#define DEFAULT_CLUSTER_SIZE (1 * MiB)
 
 #if defined(CONFIG_VDI_DEBUG)
 #define logout(fmt, ...) \
@@ -803,7 +804,7 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options)
     int result = 0;
     uint64_t bytes = 0;
     uint32_t blocks;
-    size_t block_size = 1 * MiB;
+    size_t block_size = DEFAULT_CLUSTER_SIZE;
     uint32_t image_type = VDI_TYPE_DYNAMIC;
     VdiHeader header;
     size_t i;
@@ -921,7 +922,8 @@ static QEMUOptionParameter vdi_create_options[] = {
     {
         .name = BLOCK_OPT_CLUSTER_SIZE,
         .type = OPT_SIZE,
-        .help = "VDI cluster (block) size"
+        .help = "VDI cluster (block) size",
+        .value = { .n = DEFAULT_CLUSTER_SIZE },
     },
 #endif
 #if defined(CONFIG_VDI_STATIC_IMAGE)
-- 
1.7.5.2