From: Anthony Liguori <anthony@codemonkey.ws>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [5008] qcow2: Try to aggregate free clusters and freed clusters ( Laurent Vivier)
Date: Thu, 14 Aug 2008 18:11:53 +0000 [thread overview]
Message-ID: <E1KThIf-0002CM-G7@cvs.savannah.gnu.org> (raw)
Revision: 5008
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5008
Author: aliguori
Date: 2008-08-14 18:11:52 +0000 (Thu, 14 Aug 2008)
Log Message:
-----------
qcow2: Try to aggregate free clusters and freed clusters (Laurent Vivier)
In alloc_cluster_offset(), try to aggregate free clusters and freed clusters.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Modified Paths:
--------------
trunk/block-qcow2.c
Modified: trunk/block-qcow2.c
===================================================================
--- trunk/block-qcow2.c 2008-08-14 18:11:00 UTC (rev 5007)
+++ trunk/block-qcow2.c 2008-08-14 18:11:52 UTC (rev 5008)
@@ -870,7 +870,7 @@
BDRVQcowState *s = bs->opaque;
int l2_index, ret;
uint64_t l2_offset, *l2_table, cluster_offset;
- int nb_available, nb_clusters, i;
+ int nb_available, nb_clusters, i, j;
uint64_t start_sect, current;
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
@@ -909,32 +909,50 @@
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
nb_clusters = 1;
- /* how many empty or how many to free ? */
+ /* how many available clusters ? */
- if (!cluster_offset) {
+ i = 0;
+ while (i < nb_clusters) {
- /* how many free clusters ? */
+ i++;
- i = 1;
- while (i < nb_clusters &&
- l2_table[l2_index + i] == 0) {
- i++;
- }
- nb_clusters = i;
+ if (!cluster_offset) {
- } else {
+ /* how many free clusters ? */
- /* how many contiguous clusters ? */
+ while (i < nb_clusters) {
+ cluster_offset = l2_table[l2_index + i];
+ if (cluster_offset != 0)
+ break;
+ i++;
+ }
- for (i = 1; i < nb_clusters; i++) {
- current = be64_to_cpu(l2_table[l2_index + i]);
- if (cluster_offset + (i << s->cluster_bits) != current)
+ if ((cluster_offset & QCOW_OFLAG_COPIED) ||
+ (cluster_offset & QCOW_OFLAG_COMPRESSED))
break;
+
+ } else {
+
+ /* how many contiguous clusters ? */
+
+ j = 1;
+ current = 0;
+ while (i < nb_clusters) {
+ current = be64_to_cpu(l2_table[l2_index + i]);
+ if (cluster_offset + (j << s->cluster_bits) != current)
+ break;
+
+ i++;
+ j++;
+ }
+
+ free_any_clusters(bs, cluster_offset, j);
+ if (current)
+ break;
+ cluster_offset = current;
}
- nb_clusters = i;
-
- free_any_clusters(bs, cluster_offset, i);
}
+ nb_clusters = i;
/* allocate a new cluster */
reply other threads:[~2008-08-14 18:11 UTC|newest]
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