block: Respect backing bs in bdrv_refresh_filename

Basically, bdrv_refresh_filename() should respect all children of a
BlockDriverState. However, generally those children are driver-specific,
so this function cannot handle the general case. On the other hand,
there are only few drivers which use other children than @file and
@backing (that being vmdk, quorum, and blkverify).

Most block drivers only use @file and/or @backing (if they use any
children at all). Both can be implemented directly in
bdrv_refresh_filename.

The user overriding the file's filename is already handled, however, the
user overriding the backing file is not. If this is done, opening the
BDS with the plain filename of its file will not be correct, so we may
not set bs->exact_filename in that case.

iotest 051 contains test cases for overriding the backing file, and so
its output changes with this patch applied.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-6-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2019-02-01 20:29:09 +01:00
parent 998c201923
commit 909936234c
3 changed files with 45 additions and 9 deletions

View file

@ -82,7 +82,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
Testing: -drive file=TEST_DIR/t.qcow2,driver=qcow2,backing.file.filename=TEST_DIR/t.qcow2.orig,if=none,id=drive0 -nodefaults
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) info block
drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2.orig"}}, "driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2"}} (qcow2)
Removable device: not locked, tray closed
Cache mode: writeback
Backing file: TEST_DIR/t.qcow2.orig (chain depth: 1)
@ -244,7 +244,7 @@ QEMU_PROG: -drive driver=null-co,cache=invalid_value: invalid cache option
Testing: -drive file=TEST_DIR/t.qcow2,cache=writeback,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) info block
drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2.base"}}, "driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2"}} (qcow2)
Removable device: not locked, tray closed
Cache mode: writeback
Backing file: TEST_DIR/t.qcow2.base (chain depth: 1)
@ -264,7 +264,7 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
Testing: -drive file=TEST_DIR/t.qcow2,cache=writethrough,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) info block
drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2.base"}}, "driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2"}} (qcow2)
Removable device: not locked, tray closed
Cache mode: writethrough
Backing file: TEST_DIR/t.qcow2.base (chain depth: 1)
@ -284,7 +284,7 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
Testing: -drive file=TEST_DIR/t.qcow2,cache=unsafe,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) info block
drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2.base"}}, "driver": "qcow2", "file": {"driver": "file", "filename": "TEST_DIR/t.qcow2"}} (qcow2)
Removable device: not locked, tray closed
Cache mode: writeback, ignore flushes
Backing file: TEST_DIR/t.qcow2.base (chain depth: 1)