Re: [libvirt PATCH 10/30] qemu_block: change qemuBlockCommit to return job pointer

On Thu, Dec 08, 2022 at 14:30:46 +0100, Pavel Hrdina wrote: > The created job will be needed by external snapshot delete code so > rework qemuBlockCommit to return that pointer. > > Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; > --- > src/qemu/qemu_block.c | 42 +++++++++++++++++++++++------------------- > src/qemu/qemu_block.h | 2 +- > src/qemu/qemu_driver.c | 5 ++++- > 3 files changed, 28 insertions(+), 21 deletions(-) > > diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c > index 24c82377b0..0a0d942e71 100644 > --- a/src/qemu/qemu_block.c > +++ b/src/qemu/qemu_block.c > @@ -3201,8 +3201,12 @@ qemuBlockExportAddNBD(virDomainObj *vm, > /* The autofinalize argument controls if the qemu block job will be automatically > * finalized. This is used when deleting external snapshots where we need to > * disable automatic finalization for some use-case. The default value passed > - * to this argument should be VIR_TRISTATE_BOOL_YES.*/ > -int > + * to this argument should be VIR_TRISTATE_BOOL_YES. > + * > + * Returns qemuBlockJobData pointer on success, NULL on error. Caller is responsible > + * to call virObjectUnref on the pointer. > + */ See, you are adding and adding to this but you didn't start off properly ;) > +qemuBlockJobData * > qemuBlockCommit(virDomainObj *vm, > virDomainDiskDef *disk, > virStorageSource *baseSource, [...] > @@ -3367,7 +3371,7 @@ qemuBlockCommit(virDomainObj *vm, > } > qemuBlockJobStarted(job, vm); > > - return 0; > + return job; [...] > > error: > if (clean_access) { [...] > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index 12fca22616..53533062e1 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -14999,6 +14999,7 @@ qemuDomainBlockCommit(virDomainPtr dom, > virStorageSource *topSource; > virStorageSource *baseSource = NULL; > virStorageSource *top_parent = NULL; > + g_autoptr(qemuBlockJobData) job = NULL; [2] > > virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW | > VIR_DOMAIN_BLOCK_COMMIT_ACTIVE | > @@ -15030,9 +15031,11 @@ qemuDomainBlockCommit(virDomainPtr dom, > base, disk->dst, NULL))) > goto endjob; > > - ret = qemuBlockCommit(vm, disk, baseSource, topSource, top_parent, > + job = qemuBlockCommit(vm, disk, baseSource, topSource, top_parent, > bandwidth, VIR_ASYNC_JOB_NONE, VIR_TRISTATE_BOOL_YES, > flags); > + if (job) > + ret = 0; > > endjob: Okay so this somehow isn't adding up for me. Prior to this patch before you returned the job [1] there wasn't anything to unref it [2]. So how come it's now needed if you don't increase reference count? Looking back at the refactoring patches moving the code out I think I see the problem there. Either way qemuBlockJobStartupFinalize() is the proper function to call rather than automatically unref it.