| Message ID | 20200611171143.21589-2-den@openvz.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: seriously improve savevm performance | expand |
11.06.2020 20:11, Denis V. Lunev wrote: > qemu_fclose() could return error, f.e. if bdrv_co_flush() will return > the error. > > This validation will become more important once we will start waiting of > asynchronous IO operations, started from bdrv_write_vmstate(), which are > coming soon. > > Signed-off-by: Denis V. Lunev<den@openvz.org> > CC: Kevin Wolf<kwolf@redhat.com> > CC: Max Reitz<mreitz@redhat.com> > CC: Stefan Hajnoczi<stefanha@redhat.com> > CC: Fam Zheng<fam@euphon.net> > CC: Juan Quintela<quintela@redhat.com> > CC: "Dr. David Alan Gilbert"<dgilbert@redhat.com> > CC: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> > CC: Denis Plotnikov<dplotnikov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
* Denis V. Lunev (den@openvz.org) wrote: > qemu_fclose() could return error, f.e. if bdrv_co_flush() will return > the error. > > This validation will become more important once we will start waiting of > asynchronous IO operations, started from bdrv_write_vmstate(), which are > coming soon. > > Signed-off-by: Denis V. Lunev <den@openvz.org> > CC: Kevin Wolf <kwolf@redhat.com> > CC: Max Reitz <mreitz@redhat.com> > CC: Stefan Hajnoczi <stefanha@redhat.com> > CC: Fam Zheng <fam@euphon.net> > CC: Juan Quintela <quintela@redhat.com> > CC: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > CC: Denis Plotnikov <dplotnikov@virtuozzo.com> We check the return value in very few other places; I think in the migration case we do flushes and assume that if the flushes work we were OK; then most of the closes happen on error paths or after points we think we're done. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > migration/savevm.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/migration/savevm.c b/migration/savevm.c > index c00a6807d9..0ff5bb40ed 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -2628,7 +2628,7 @@ int save_snapshot(const char *name, Error **errp) > { > BlockDriverState *bs, *bs1; > QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1; > - int ret = -1; > + int ret = -1, ret2; > QEMUFile *f; > int saved_vm_running; > uint64_t vm_state_size; > @@ -2712,10 +2712,14 @@ int save_snapshot(const char *name, Error **errp) > } > ret = qemu_savevm_state(f, errp); > vm_state_size = qemu_ftell(f); > - qemu_fclose(f); > + ret2 = qemu_fclose(f); > if (ret < 0) { > goto the_end; > } > + if (ret2 < 0) { > + ret = ret2; > + goto the_end; > + } > > /* The bdrv_all_create_snapshot() call that follows acquires the AioContext > * for itself. BDRV_POLL_WHILE() does not support nested locking because > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/migration/savevm.c b/migration/savevm.c index c00a6807d9..0ff5bb40ed 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2628,7 +2628,7 @@ int save_snapshot(const char *name, Error **errp) { BlockDriverState *bs, *bs1; QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1; - int ret = -1; + int ret = -1, ret2; QEMUFile *f; int saved_vm_running; uint64_t vm_state_size; @@ -2712,10 +2712,14 @@ int save_snapshot(const char *name, Error **errp) } ret = qemu_savevm_state(f, errp); vm_state_size = qemu_ftell(f); - qemu_fclose(f); + ret2 = qemu_fclose(f); if (ret < 0) { goto the_end; } + if (ret2 < 0) { + ret = ret2; + goto the_end; + } /* The bdrv_all_create_snapshot() call that follows acquires the AioContext * for itself. BDRV_POLL_WHILE() does not support nested locking because
qemu_fclose() could return error, f.e. if bdrv_co_flush() will return the error. This validation will become more important once we will start waiting of asynchronous IO operations, started from bdrv_write_vmstate(), which are coming soon. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <fam@euphon.net> CC: Juan Quintela <quintela@redhat.com> CC: "Dr. David Alan Gilbert" <dgilbert@redhat.com> CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> CC: Denis Plotnikov <dplotnikov@virtuozzo.com> --- migration/savevm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)