qcow2 format: keep 'num_free_bytes', and show it upon 'info blockstats' (Uri Lublin)

'num_free_bytes' is the number of non-allocated bytes below highest-allocation.
It's useful, together with the highest-allocation, to figure out how
fragmented the image is, and how likely it will run out-of-space soon.

For example when the highest allocation is high (almost end-of-disk), but 
many bytes (clusters) are free, and can be re-allocated when neeeded, than
we know it's probably not going to reach end-of-disk-space soon.

Added bookkeeping to block-qcow2.c
Export it using BlockDeviceInfo
Show it upon 'info blockstats' if BlockDeviceInfo exists

Signed-off-by: Uri Lublin <uril@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6407 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 3 insertions, 2 deletions

diff --git a/block.c b/block.c
index a3fcfa0157..50ec589587 100644
--- a/block.c
+++ b/block.c
@@ -1090,8 +1090,9 @@ void bdrv_info_stats (void)
 		     bs->rd_bytes, bs->wr_bytes,
 		     bs->rd_ops, bs->wr_ops);
         if (bdrv_get_info(bs, &bdi) == 0)
-            term_printf(" high=%" PRIu64,
-                        bdi.highest_alloc);
+            term_printf(" high=%" PRId64
+                        " bytes_free=%" PRId64,
+                        bdi.highest_alloc, bdi.num_free_bytes);
         term_printf("\n");
     }
 }