There is a case that locking hits a bug and users wants to disable locking like bug in Linux kernel. This commit adds option to configure locking for file source. Signed-off-by: Hiroki Narukawa <hnarukaw(a)yahoo-corp.jp&gt; --- docs/formatdomain.rst | 5 +++++ src/conf/domain_conf.c | 8 ++++++++ src/conf/schemas/domaincommon.rng | 5 +++++ src/conf/storage_source_conf.h | 3 +++ 4 files changed, 21 insertions(+) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index 0a4f9d9000..95869d573c 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -2782,6 +2782,11 @@ paravirtualized driver is specified via the ``disk`` element. via the filesystem. The filename passed via ``file`` can still be used to generate paths to write into image metadata when doing block operations but libvirt will not access these natively. + + :since:`Since 10.1.0` a new optional attribute ``locking`` can be added + which can take "on" or "off". Basically this option should be kept + default, but it can be used explicitly for workaround about bug in + locking. ``block`` The ``dev`` attribute specifies the fully-qualified path to the host device to serve as the disk. :since:`Since 0.0.3` diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 3597959e33..b7cefffc7c 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7563,6 +7563,10 @@ virDomainStorageSourceParse(xmlNodePtr node, ctxt, flags) < 0) return -1; + if (virXMLPropTristateSwitch(node, "locking", VIR_XML_PROP_NONE, + &src->locking) < 0) + return -1; + /* People sometimes pass a bogus '' source path when they mean to omit the * source element completely (e.g. CDROM without media). This is just a * little compatibility check to help those broken apps */ @@ -22544,6 +22548,10 @@ virDomainDiskSourceFormat(virBuffer *buf, if (attrIndex && src->id != 0) virBufferAsprintf(&attrBuf, " index='%u'", src->id); + if (src->locking) + virBufferEscapeString(&attrBuf, " locking='%s'", + virTristateSwitchTypeToString(src->locking)); + if (virDomainDiskSourceFormatPrivateData(&childBuf, src, flags, xmlopt) < 0) return -1; diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng index df44cd9857..8ccb1dd162 100644 --- a/src/conf/schemas/domaincommon.rng +++ b/src/conf/schemas/domaincommon.rng @@ -1789,6 +1789,11 @@ <ref name="positiveInteger"/> </attribute> </optional> + <optional> + <attribute name="locking"> + <ref name="virOnOff"/> + </attribute> + </optional> <optional> <element name="slices"> <element name="slice"> diff --git a/src/conf/storage_source_conf.h b/src/conf/storage_source_conf.h index 05b4bda16c..3984614a3d 100644 --- a/src/conf/storage_source_conf.h +++ b/src/conf/storage_source_conf.h @@ -356,6 +356,9 @@ struct _virStorageSource { /* image is shared across hosts */ bool shared; + /* intended to use for workaround */ + virTristateSwitch locking; + /* backing chain of the storage source */ virStorageSource *backingStore; -- 2.25.1

On Wed, Feb 14, 2024 at 13:17:39 +0100, Peter Krempa wrote: To elaborate on the qemu XML namespace integration: Currently we parse the namespace elements only on a global scope, so per-disk XML attributes are not supported. Thus to add per-disk or per-device XML namespace attributes a new parsing callback will be needed. A second option would be to do it similarly to how we allow override of device parameters: https://libvirt.org/drvqemu.html#overriding-properties-of-qemu-devices The image to override would be identified using the TARGET[INDEX] tuple (e.g. vda[1]) as declared in the XML.

There is a case that locking hits a bug and users wants to disable locking like bug in Linux kernel. This commit adds actual qemu option to the domain conf added in previous commit. Signed-off-by: Hiroki Narukawa <hnarukaw(a)yahoo-corp.jp&gt; --- src/qemu/qemu_block.c | 7 ++++++ tests/qemublocktest.c | 1 + ...le-raw-aio_native-locking-off-srconly.json | 10 ++++++++ .../file-raw-aio_native-locking-off.json | 23 +++++++++++++++++++ .../file-raw-aio_native-locking-off.xml | 12 ++++++++++ 5 files changed, 53 insertions(+) create mode 100644 tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off-srconly.json create mode 100644 tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.json create mode 100644 tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.xml diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c index 738b72d7ea..5905898b38 100644 --- a/src/qemu/qemu_block.c +++ b/src/qemu/qemu_block.c @@ -852,6 +852,13 @@ qemuBlockStorageSourceGetFileProps(virStorageSource *src, "S:aio", iomode, "S:pr-manager", prManagerAlias, NULL) < 0); + + if (src->locking) { + const char *lockingStr = virTristateSwitchTypeToString(src->locking); + if (virJSONValueObjectAdd(&ret, "S:locking", lockingStr, NULL) < 0) + return NULL; + } + return ret; } diff --git a/tests/qemublocktest.c b/tests/qemublocktest.c index c581bd1748..3b005cb475 100644 --- a/tests/qemublocktest.c +++ b/tests/qemublocktest.c @@ -1116,6 +1116,7 @@ mymain(void) TEST_DISK_TO_JSON("dir-fat-readonly"); TEST_DISK_TO_JSON("dir-fat-floppy"); TEST_DISK_TO_JSON("file-raw-aio_native"); + TEST_DISK_TO_JSON("file-raw-aio_native-locking-off"); TEST_DISK_TO_JSON("file-backing_basic-aio_threads"); TEST_DISK_TO_JSON("file-backing_basic-aio_io_uring"); TEST_DISK_TO_JSON("file-raw-luks"); diff --git a/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off-srconly.json b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off-srconly.json new file mode 100644 index 0000000000..88c9970ccf --- /dev/null +++ b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off-srconly.json @@ -0,0 +1,10 @@ +( + source only properties: + { + "driver": "file", + "filename": "/path/to/i.img", + "locking": "off" + } + backing store string: + /path/to/i.img +) diff --git a/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.json b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.json new file mode 100644 index 0000000000..aeb483e4b4 --- /dev/null +++ b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.json @@ -0,0 +1,23 @@ +{ + "node-name": "test1", + "read-only": false, + "cache": { + "direct": true, + "no-flush": false + }, + "driver": "raw", + "file": "test2" +} +{ + "driver": "file", + "filename": "/path/to/i.img", + "aio": "native", + "locking": "off", + "node-name": "test2", + "auto-read-only": true, + "discard": "unmap", + "cache": { + "direct": true, + "no-flush": false + } +} diff --git a/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.xml b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.xml new file mode 100644 index 0000000000..9e6a9d26bc --- /dev/null +++ b/tests/qemublocktestdata/xml2json/file-raw-aio_native-locking-off.xml @@ -0,0 +1,12 @@ +<disk device='disk'> + <driver name='qemu' type='raw' io='native' cache='none'/> + <source file='/path/to/i.img' locking='off'> + <privateData> + <nodenames> + <nodename type='storage' name='test2'/> + <nodename type='format' name='test1'/> + </nodenames> + </privateData> + </source> + <target dev='vda'/> +</disk> -- 2.25.1