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[Qemu-devel] [PULL 28/30] qcow2: count_contiguous_clusters and compressi
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 28/30] qcow2: count_contiguous_clusters and compression |
Date: |
Fri, 27 Sep 2013 17:39:28 +0200 |
From: Max Reitz <address@hidden>
The function is not intended to be used on compressed clusters and will
not work correctly, if used anyway, since L2E_OFFSET_MASK is not the
right mask for determining the offset of compressed clusters. Therefore,
assert that the first cluster is not compressed and always include the
compression flag in the mask of significant flags, i.e., stop the search
as soon as a compressed cluster occurs.
Signed-off-by: Max Reitz <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2-cluster.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 91d07f2..8b2361a 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -284,12 +284,15 @@ static int count_contiguous_clusters(uint64_t
nb_clusters, int cluster_size,
uint64_t *l2_table, uint64_t start, uint64_t stop_flags)
{
int i;
- uint64_t mask = stop_flags | L2E_OFFSET_MASK;
- uint64_t offset = be64_to_cpu(l2_table[0]) & mask;
+ uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW2_CLUSTER_COMPRESSED;
+ uint64_t first_entry = be64_to_cpu(l2_table[0]);
+ uint64_t offset = first_entry & mask;
if (!offset)
return 0;
+ assert(qcow2_get_cluster_type(first_entry) != QCOW2_CLUSTER_COMPRESSED);
+
for (i = start; i < start + nb_clusters; i++) {
uint64_t l2_entry = be64_to_cpu(l2_table[i]) & mask;
if (offset + (uint64_t) i * cluster_size != l2_entry) {
--
1.8.1.4
- [Qemu-devel] [PULL 15/30] block: vpc - use QEMU_PACKED for on-disk structures, (continued)
- [Qemu-devel] [PULL 15/30] block: vpc - use QEMU_PACKED for on-disk structures, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 20/30] qemu-iotests: fix qmp.py search path, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 14/30] block: vdi - use QEMU_PACKED for on-disk structures, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 13/30] rbd: avoid qemu_rbd_snap_list() memory leaks, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 18/30] qcow2: Assert against currently impossible overflow, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 16/30] block: qcow2 - used QEMU_PACKED for on-disk structures, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 19/30] block: use DIV_ROUND_UP in bdrv_co_do_readv, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 21/30] qemu-iotests: Add basic ability to use binary sample images, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 22/30] qemu-iotests: Quote $TEST_IMG* and $TEST_DIR usage, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 26/30] qcow2: Always use error path in l2_allocate, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 28/30] qcow2: count_contiguous_clusters and compression,
Kevin Wolf <=
- [Qemu-devel] [PULL 27/30] qcow2: Free only newly allocated clusters on error, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 29/30] qcow2: COMPRESSED on count_contiguous_clusters, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 30/30] qcow2: Remove useless count_contiguous_clusters() parameter, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 24/30] qemu-iotests: Preallocated zero clusters in 061, Kevin Wolf, 2013/09/27
- [Qemu-devel] [PULL 25/30] qcow2: Don't put invalid L2 table into cache, Kevin Wolf, 2013/09/27