block: Fix snapshot=on for protocol parsed from filename

Since commit 9fd3171a, BDRV_O_SNAPSHOT uses an option QDict to specify
the originally requested image as the backing file of the newly created
temporary snapshot. This means that the filename is stored in
"file.filename", which is an option that is not parsed for protocol
names. Therefore things like -drive file=nbd:localhost:10809 were
broken because it looked for a local file with the literal name
'nbd:localhost:10809'.

This patch changes the way BDRV_O_SNAPSHOT works once again. We now open
the originally requested image as normal, and then do a similar
operation as for live snapshots to put the temporary snapshot on top.
This way, both driver specific options and parsed filenames work.

As a nice side effect, this results in code movement to factor
bdrv_append_temp_snapshot() out. This is a good preparation for moving
its call to drive_init() and friends eventually.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2014-04-03 12:09:34 +02:00
parent cd40890816
commit b998875dcf
4 changed files with 115 additions and 70 deletions

View file

@ -218,6 +218,14 @@ echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="$TEST_IMG"
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="$TEST_IMG",snapshot=on | _filter_qemu_io
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file.filename="$TEST_IMG",driver=qcow2,snapshot=on | _filter_qemu_io
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file.filename="$TEST_IMG",driver=qcow2 -snapshot | _filter_qemu_io
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="file:$TEST_IMG" -snapshot | _filter_qemu_io
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="file:$TEST_IMG",snapshot=on | _filter_qemu_io
# Opening a read-only file r/w with snapshot=on
chmod u-w "$TEST_IMG"
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="$TEST_IMG" -snapshot | _filter_qemu_io
echo 'qemu-io ide0-hd0 "write -P 0x22 0 4k"' | run_qemu -drive file="$TEST_IMG",snapshot=on | _filter_qemu_io
chmod u+w "$TEST_IMG"
$QEMU_IO -c "read -P 0x11 0 4k" "$TEST_IMG" | _filter_qemu_io

View file

@ -319,6 +319,34 @@ wrote 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
(qemu) qququiquit
Testing: -drive file=file:TEST_DIR/t.qcow2 -snapshot
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) qqeqemqemuqemu-qemu-iqemu-ioqemu-io qemu-io iqemu-io idqemu-io ideqemu-io ide0qemu-io ide0-qemu-io ide0-hqemu-io ide0-hdqemu-io ide0-hd0qemu-io ide0-hd0 qemu-io ide0-hd0 "qemu-io ide0-hd0 "wqemu-io ide0-hd0 "wrqemu-io ide0-hd0 "wriqemu-io ide0-hd0 "writqemu-io ide0-hd0 "writeqemu-io ide0-hd0 "write qemu-io ide0-hd0 "write -qemu-io ide0-hd0 "write -Pqemu-io ide0-hd0 "write -P qemu-io ide0-hd0 "write -P 0qemu-io ide0-hd0 "write -P 0xqemu-io ide0-hd0 "write -P 0x2qemu-io ide0-hd0 "write -P 0x22qemu-io ide0-hd0 "write -P 0x22 qemu-io ide0-hd0 "write -P 0x22 0qemu-io ide0-hd0 "write -P 0x22 0 qemu-io ide0-hd0 "write -P 0x22 0 4qemu-io ide0-hd0 "write -P 0x22 0 4kqemu-io ide0-hd0 "write -P 0x22 0 4k"
wrote 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
(qemu) qququiquit
Testing: -drive file=file:TEST_DIR/t.qcow2,snapshot=on
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) qqeqemqemuqemu-qemu-iqemu-ioqemu-io qemu-io iqemu-io idqemu-io ideqemu-io ide0qemu-io ide0-qemu-io ide0-hqemu-io ide0-hdqemu-io ide0-hd0qemu-io ide0-hd0 qemu-io ide0-hd0 "qemu-io ide0-hd0 "wqemu-io ide0-hd0 "wrqemu-io ide0-hd0 "wriqemu-io ide0-hd0 "writqemu-io ide0-hd0 "writeqemu-io ide0-hd0 "write qemu-io ide0-hd0 "write -qemu-io ide0-hd0 "write -Pqemu-io ide0-hd0 "write -P qemu-io ide0-hd0 "write -P 0qemu-io ide0-hd0 "write -P 0xqemu-io ide0-hd0 "write -P 0x2qemu-io ide0-hd0 "write -P 0x22qemu-io ide0-hd0 "write -P 0x22 qemu-io ide0-hd0 "write -P 0x22 0qemu-io ide0-hd0 "write -P 0x22 0 qemu-io ide0-hd0 "write -P 0x22 0 4qemu-io ide0-hd0 "write -P 0x22 0 4kqemu-io ide0-hd0 "write -P 0x22 0 4k"
wrote 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
(qemu) qququiquit
Testing: -drive file=TEST_DIR/t.qcow2 -snapshot
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) qqeqemqemuqemu-qemu-iqemu-ioqemu-io qemu-io iqemu-io idqemu-io ideqemu-io ide0qemu-io ide0-qemu-io ide0-hqemu-io ide0-hdqemu-io ide0-hd0qemu-io ide0-hd0 qemu-io ide0-hd0 "qemu-io ide0-hd0 "wqemu-io ide0-hd0 "wrqemu-io ide0-hd0 "wriqemu-io ide0-hd0 "writqemu-io ide0-hd0 "writeqemu-io ide0-hd0 "write qemu-io ide0-hd0 "write -qemu-io ide0-hd0 "write -Pqemu-io ide0-hd0 "write -P qemu-io ide0-hd0 "write -P 0qemu-io ide0-hd0 "write -P 0xqemu-io ide0-hd0 "write -P 0x2qemu-io ide0-hd0 "write -P 0x22qemu-io ide0-hd0 "write -P 0x22 qemu-io ide0-hd0 "write -P 0x22 0qemu-io ide0-hd0 "write -P 0x22 0 qemu-io ide0-hd0 "write -P 0x22 0 4qemu-io ide0-hd0 "write -P 0x22 0 4kqemu-io ide0-hd0 "write -P 0x22 0 4k"
wrote 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
(qemu) qququiquit
Testing: -drive file=TEST_DIR/t.qcow2,snapshot=on
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) qqeqemqemuqemu-qemu-iqemu-ioqemu-io qemu-io iqemu-io idqemu-io ideqemu-io ide0qemu-io ide0-qemu-io ide0-hqemu-io ide0-hdqemu-io ide0-hd0qemu-io ide0-hd0 qemu-io ide0-hd0 "qemu-io ide0-hd0 "wqemu-io ide0-hd0 "wrqemu-io ide0-hd0 "wriqemu-io ide0-hd0 "writqemu-io ide0-hd0 "writeqemu-io ide0-hd0 "write qemu-io ide0-hd0 "write -qemu-io ide0-hd0 "write -Pqemu-io ide0-hd0 "write -P qemu-io ide0-hd0 "write -P 0qemu-io ide0-hd0 "write -P 0xqemu-io ide0-hd0 "write -P 0x2qemu-io ide0-hd0 "write -P 0x22qemu-io ide0-hd0 "write -P 0x22 qemu-io ide0-hd0 "write -P 0x22 0qemu-io ide0-hd0 "write -P 0x22 0 qemu-io ide0-hd0 "write -P 0x22 0 4qemu-io ide0-hd0 "write -P 0x22 0 4kqemu-io ide0-hd0 "write -P 0x22 0 4k"
wrote 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
(qemu) qququiquit
read 4096/4096 bytes at offset 0
4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
Testing: -drive file=TEST_DIR/t.qcow2,snapshot=off