storage: Ensure 'qemu-img resize' size arg is a 512 multiple

qemu-img resize will fail with "The new size must be a multiple of 512"
if libvirt doesn't round it first.
This fixes rhbz#951495

Signed-off-by: Christophe Fergeau <cfergeau@redhat.com>
(cherry picked from commit 9a8f39d097448b2b43c4a05d0edc213eacfc9ea6)

diff --git a/src/internal.h b/src/internal.h
index 83f468db43ad423c4d66003008b6e6d049b2edd5..2f18418c74fa89c5c01a76f384f0a5cbc95a852f 100644 (file)
--- a/src/internal.h
+++ b/src/internal.h
@@ -246,6 +246,9 @@
 /* divide value by size, rounding up */
 # define VIR_DIV_UP(value, size) (((value) + (size) - 1) / (size))
 
+/* round up value to the closest multiple of size */
+# define VIR_ROUND_UP(value, size) (VIR_DIV_UP(value, size) * (size))
+
 
 # if WITH_DTRACE_PROBES
 #  ifndef LIBVIRT_PROBES_H

diff --git a/src/libvirt.c b/src/libvirt.c
index 08c413456f4d06d95b133da03b2fb4f568b58650..8c052571637e4cac2ad89542b4c7d2fe02e9f1cf 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -13307,7 +13307,8 @@ error:
  * Changes the capacity of the storage volume @vol to @capacity. The
  * operation will fail if the new capacity requires allocation that would
  * exceed the remaining free space in the parent pool.  The contents of
- * the new capacity will appear as all zero bytes.
+ * the new capacity will appear as all zero bytes. The capacity value will
+ * be rounded to the granularity supported by the hypervisor.
  *
  * Normally, the operation will attempt to affect capacity with a minimum
  * impact on allocation (that is, the default operation favors a sparse

diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index cf213b8c091c4f2e08f018463cb5e3d043973914..466ff3cf107cd04451093744b2b6d8f3da622d7b 100644 (file)
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -1204,6 +1204,10 @@ virStorageBackendFilesystemResizeQemuImg(const char *path,
         return -1;
     }
 
+    /* Round capacity as qemu-img resize errors out on sizes which are not
+     * a multiple of 512 */
+    capacity = VIR_ROUND_UP(capacity, 512);
+
     cmd = virCommandNew(img_tool);
     virCommandAddArgList(cmd, "resize", path, NULL);
     virCommandAddArgFormat(cmd, "%llu", capacity);