On 5/13/22 14:57, Claudio Fontana wrote:

On 5/13/22 9:54 AM, Michal Privoznik wrote:

...

When no VIR_DOMAIN_SAVE_PARAM_FILE typed param is set when calling virDomainSaveParams() then in turn virQEMUFileOpenAs() tries to open a NULL path.

We have two options now: 1) require the typed param, which in turn may be promoted to a regular argument, or

2) use this opportunity to make the API behave like virDomainManagedSave() and use typed params to pass extra arguments, instead of having to invent new managed save API with typed params.

Let's go with option 2, as it is more future proof.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/libvirt-domain.c | 2 ++ src/qemu/qemu_driver.c | 33 ++++++++++++++++++++------------- 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index d1d62daa71..208c2438fe 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -1007,6 +1007,8 @@ virDomainSaveFlags(virDomainPtr domain, const char *to, * @flags: bitwise-OR of virDomainSaveRestoreFlags * * This method extends virDomainSaveFlags by adding parameters. + * If VIR_DOMAIN_SAVE_PARAM_FILE is not provided then a managed save is + * performed (see virDomainManagedSave). * * Returns 0 in case of success and -1 in case of failure. * diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 7d8c7176d9..0b31c73bb9 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2772,6 +2772,7 @@ qemuDomainManagedSavePath(virQEMUDriver *driver, virDomainObj *vm) static int qemuDomainManagedSaveHelper(virQEMUDriver *driver, virDomainObj *vm, + const char *dxml, unsigned int flags) { g_autoptr(virQEMUDriverConfig) cfg = NULL; @@ -2799,7 +2800,7 @@ qemuDomainManagedSaveHelper(virQEMUDriver *driver, VIR_INFO("Saving state of domain '%s' to '%s'", vm->def->name, path);

if (qemuDomainSaveInternal(driver, vm, path, compressed, - compressor, NULL, flags) < 0) + compressor, dxml, flags) < 0) return -1;

vm->hasManagedSave = true; @@ -2853,17 +2854,18 @@ qemuDomainSave(virDomainPtr dom, const char *path)

static int qemuDomainSaveParams(virDomainPtr dom, - virTypedParameterPtr params, int nparams, + virTypedParameterPtr params, + int nparams, unsigned int flags) { + virQEMUDriver *driver = dom->conn->privateData; + g_autoptr(virQEMUDriverConfig) cfg = NULL; + virDomainObj *vm = NULL; + g_autoptr(virCommand) compressor = NULL; const char *to = NULL; const char *dxml = NULL; - virQEMUDriver *driver = dom->conn->privateData; int compressed; - g_autoptr(virCommand) compressor = NULL; int ret = -1; - virDomainObj *vm = NULL; - g_autoptr(virQEMUDriverConfig) cfg = NULL;

virCheckFlags(VIR_DOMAIN_SAVE_BYPASS_CACHE | VIR_DOMAIN_SAVE_RUNNING | @@ -2884,18 +2886,23 @@ qemuDomainSaveParams(virDomainPtr dom, VIR_DOMAIN_SAVE_PARAM_DXML, &dxml) < 0) return -1;

- cfg = virQEMUDriverGetConfig(driver); - if ((compressed = qemuSaveImageGetCompressionProgram(cfg->saveImageFormat, - &compressor, - "save", false)) < 0) - goto cleanup; - if (!(vm = qemuDomainObjFromDomain(dom))) goto cleanup;

if (virDomainSaveParamsEnsureACL(dom->conn, vm->def) < 0) goto cleanup;

+ if (!to) { + /* If no save path was provided then this behaves as managed save. */ + return qemuDomainManagedSaveHelper(driver, vm, dxml, flags); + }

Is this sufficient? In some cases I am seeing that omitted string parameters are passed as the empty string. In my multifd series I encountered this with the optional --parallel-compression argument,

that in this case would mean:

if (!to || !to[0])

That's likely caused by virsh. I haven't checked your patches yet, but depending on how the argument is queried for in virsh you may get a NULL or an empty string. However, empty string doesn't matter as it produces sensible error message: No such file or directory: '' Michal

On 5/13/22 9:54 AM, Michal Privoznik wrote:

Calling virDomainRestoreFlags() with no typed params results in an error in open() because it tries to open a NULL path. Obviously, this is wrong and path to restore from must be provided, at least for now until other sources of restore are introduced. Then this limitation can be relaxed.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/libvirt-domain.c | 4 +++- src/qemu/qemu_driver.c | 6 ++++++ 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index 208c2438fe..a32630a6e9 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -1190,7 +1190,9 @@ virDomainRestoreFlags(virConnectPtr conn, const char *from, const char *dxml, * @nparams: number of restore parameters * @flags: bitwise-OR of virDomainSaveRestoreFlags * - * This method extends virDomainRestoreFlags by adding parameters. + * This method extends virDomainRestoreFlags by adding parameters. For + * now, VIR_DOMAIN_SAVE_PARAM_FILE is required but this requirement may + * be lifted in the future. * * Returns 0 in case of success and -1 in case of failure. * diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 0b31c73bb9..702fd0239c 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5967,6 +5967,12 @@ qemuDomainRestoreParams(virConnectPtr conn, VIR_DOMAIN_SAVE_PARAM_DXML, &dxml) < 0) return -1;

+ if (!path) {

Similarly to before, should the check be (!path || !path[0]) ? Thanks C

+ virReportError(VIR_ERR_INVALID_ARG, "%s", + _("missing path to restore from")); + return -1; + } + ret = qemuDomainRestoreInternal(conn, path, dxml, flags, virDomainRestoreParamsEnsureACL); return ret;