[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-block] [PULL 06/21] block/vmdk: Fix the endian problem of buf_len

From: Max Reitz
Subject: [Qemu-block] [PULL 06/21] block/vmdk: Fix the endian problem of buf_len and lba
Date: Sun, 12 Feb 2017 02:36:49 +0100

From: QingFeng Hao <address@hidden>

The problem was triggered by qemu-iotests case 055. It failed when it
was comparing the compressed vmdk image with original test.img.

The cause is that buf_len in vmdk_write_extent wasn't converted to
little-endian before it was stored to disk. But later vmdk_read_extent
read it and converted it from little-endian to cpu endian.
If the cpu is big-endian like s390, the problem will happen and
the data length read by vmdk_read_extent will become invalid!
The fix is to add the conversion in vmdk_write_extent, meanwhile,
repair the endianness problem of lba field which shall also be converted
to little-endian before storing to disk.

Cc: address@hidden
Signed-off-by: QingFeng Hao <address@hidden>
Signed-off-by: Jing Liu <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
Message-id: address@hidden
Signed-off-by: Max Reitz <address@hidden>
 block/vmdk.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index 7750212969..393c84d8b1 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1361,8 +1361,8 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t 
             goto out;
-        data->lba = offset >> BDRV_SECTOR_BITS;
-        data->size = buf_len;
+        data->lba = cpu_to_le64(offset >> BDRV_SECTOR_BITS);
+        data->size = cpu_to_le32(buf_len);
         n_bytes = buf_len + sizeof(VmdkGrainMarker);
         iov = (struct iovec) {

reply via email to

[Prev in Thread] Current Thread [Next in Thread]