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[Qemu-block] [PATCH v2 0/3] block: Fix backing paths for filenames with
[Qemu-block] [PATCH v2 0/3] block: Fix backing paths for filenames with colons
Mon, 22 May 2017 21:52:14 +0200
There are (at least) two issues with filenames that contain colons when
trying to use relative backing filenames with them, for each of which
there is a patch in this series.
The first patch fixes an issue in the general block layer
(path_combine() does not have the same opinion on what constitutes a
protocol prefix as path_has_protocl()), the second fixes an issue in
file-* (when stripping off the optional "file:" prefix we should not
create a filename that seems to have another valid protocol prefix).
The third patch adds a test.
Bonus info: The following is something I did not change, although it is
$ mkdir foo && cd foo
$ ../qemu-img create -f qcow2 file:image:base.qcow2 64M
Formatting 'file:image:base.qcow2', fmt=qcow2 size=67108864
encryption=off cluster_size=65536 lazy_refcounts=off
$ ../qemu-img create -f qcow2 -b file:image:base.qcow2 file:image:top.qcow2
Formatting 'file:image:top.qcow2', fmt=qcow2 size=67108864
cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ cd ..
$ ./qemu-img info foo/image:top.qcow2
file format: qcow2
virtual size: 64M (67108864 bytes)
disk size: 196K
backing file: file:image:base.qcow2
Format specific information:
lazy refcounts: false
refcount bits: 16
$ ./qemu-io foo/image:top.qcow2
can't open device foo/image:top.qcow2: Could not open backing file:
Could not open './image:base.qcow2': No such file or directory
Patch 3 adds a comment to the test which explains this behavior in a bit
more detail, but the gist is this: qemu generally thinks that
protocol-prefixed filenames are absolute filenames; but from a
file-posix perspective, "file:foo" is still a relative filename.
I think the above behavior is what we want and that it's the best we can
do, but it still is weird, so I just wanted to mention it.
- Kept patch 1 unchanged
- Added patch 2
- Extended patch 3 (did NOT change the patch title)
git-backport-diff against v2:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively
001/3:[----] [--] 'block: Fix backing paths for filenames with colons'
002/3:[down] 'block/file-*: *_parse_filename() and colons'
003/3: [FC] 'iotests: Add test for colon handling'
Max Reitz (3):
block: Fix backing paths for filenames with colons
block/file-*: *_parse_filename() and colons
iotests: Add test for colon handling
include/block/block_int.h | 3 ++
block.c | 50 ++++++++++++++++++---
block/file-posix.c | 17 ++------
block/file-win32.c | 12 +-----
tests/qemu-iotests/126 | 105 +++++++++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/126.out | 23 ++++++++++
tests/qemu-iotests/group | 1 +
7 files changed, 182 insertions(+), 29 deletions(-)
create mode 100755 tests/qemu-iotests/126
create mode 100644 tests/qemu-iotests/126.out
- [Qemu-block] [PATCH v2 0/3] block: Fix backing paths for filenames with colons,
Max Reitz <=