[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-block] [PATCH V3] block/vhdx: add check for truncated image fi
From: |
Kevin Wolf |
Subject: |
Re: [Qemu-block] [PATCH V3] block/vhdx: add check for truncated image files |
Date: |
Wed, 4 Sep 2019 16:09:49 +0200 |
User-agent: |
Mutt/1.12.0 (2019-05-25) |
Am 03.09.2019 um 15:35 hat Peter Lieven geschrieben:
> qemu is currently not able to detect truncated vhdx image files.
> Add a basic check if all allocated blocks are reachable at open and
> report all errors during bdrv_co_check.
>
> Signed-off-by: Peter Lieven <address@hidden>
> ---
> V3: - check for bdrv_getlength failure [Kevin]
> - use uint32_t for i [Kevin]
> - check for BAT entry overflow [Kevin]
> - break on !errcnt in second check
>
> V2: - add error reporting [Kevin]
> - use bdrv_getlength instead of bdrv_get_allocated_file_size [Kevin]
> - factor out BAT entry check and add error reporting for region
> overlaps
> - already check on vhdx_open
Something still seems to be wrong with this patch:
213 fail [15:50:13] [15:50:14] (last: 2s) output
mismatch (see 213.out.bad)
--- /home/kwolf/source/qemu/tests/qemu-iotests/213.out 2019-06-28
14:19:50.065797707 +0200
+++ /home/kwolf/source/qemu/tests/qemu-iotests/213.out.bad 2019-09-04
15:50:14.582053976 +0200
@@ -46,10 +46,8 @@
{"execute": "job-dismiss", "arguments": {"id": "job0"}}
{"return": {}}
-image: TEST_IMG
-file format: IMGFMT
-virtual size: 32 MiB (33554432 bytes)
-cluster_size: 268435456
+qemu-img: VHDX BAT entry 0 offset points after end of file. Image has
probably been truncated.
+qemu-img: Could not open 'TEST_IMG': Could not open 'TEST_IMG': Invalid
argument
=== Invalid BlockdevRef ===
I can reproduce this manually with the following qemu-img invocations.
It seems all three options must be given to reproduce the error:
$ ./qemu-img create -f vhdx -o
block_size=268435456,subformat=fixed,block_state_zero=off /tmp/test.vhdx 32M
Formatting '/tmp/test.vhdx', fmt=vhdx size=33554432 log_size=1048576
block_size=268435456 subformat=fixed block_state_zero=off
$ ./qemu-img info /tmp/test.vhdx
qemu-img: VHDX BAT entry 0 offset points after end of file. Image has
probably been truncated.
qemu-img: Could not open '/tmp/test.vhdx': Could not open '/tmp/test.vhdx':
Invalid argument
If I add the offsets to the error message (would probably nice to have),
I get:
qemu-img: VHDX BAT entry 0 offset 8388608 points after end of file
(41943040). Image has probably been truncated.
So it seems that the file is large enough to hold 32M + metadata, but we
don't increase the file size to hold a full block (256M). Is this a
problem in the way we create images or are partial blocks at the end
expected?
Kevin