Am 24.01.2013 03:57, schrieb Wenchao Xia: > This patch add function bdrv_query_snapshot_infolist(), which will > return snapshot info of an image in qmp object format. The implementation > code are mostly copied from qemu-img.c with modification to fit more > for qmp based block layer API. > To help filter out snapshot info not needed, a call back function is > added in bdrv_query_snapshot_infolist(). > bdrv_can_read_snapshot() should be called before call this function, > to avoid got *errp set unexpectedly. > > Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com> > Reviewed-by: Eric Blake <ebl...@redhat.com> > --- > block.c | 60 > +++++++++++++++++++++++++++++++++++++++++++++++++ > include/block/block.h | 7 +++++ > 2 files changed, 67 insertions(+), 0 deletions(-) > > diff --git a/block.c b/block.c > index 934bb3f..7cdb6c6 100644 > --- a/block.c > +++ b/block.c > @@ -2842,6 +2842,66 @@ int coroutine_fn > bdrv_co_is_allocated_above(BlockDriverState *top, > return 0; > } > > +SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs, > + SnapshotFilterFunc filter,
This filter things looks overengineered to me, and no patch in this series really uses it. Do we really need it? > + void *opaque, > + Error **errp) > +{ > + int i, sn_count; > + QEMUSnapshotInfo *sn_tab = NULL; > + SnapshotInfoList *info_list, *cur_item = NULL, *head = NULL; > + > + sn_count = bdrv_snapshot_list(bs, &sn_tab); > + if (sn_count < 0) { > + /* Now bdrv_snapshot_list() use negative value to tip error, so a > check > + * of it was done here. In future errp can be set by that function > + * itself, by changing the call back functions in c files in ./block. > + */ > + const char *dev = bdrv_get_device_name(bs); > + if (sn_count == -ENOMEDIUM) { > + error_setg(errp, "Device '%s' is not inserted.", dev); > + } else if (sn_count == -ENOTSUP) { > + error_setg(errp, > + "Device '%s' does not support internal snapshot.", > + dev); > + } else { > + error_setg(errp, > + "Device '%s' got %d for bdrv_snapshot_list().", > + dev, sn_count); strerror(-sn_count) would make the error message more useful. You could also consider using switch instead of an if/else if chain. > + } > + return NULL; > + } > + > + for (i = 0; i < sn_count; i++) { > + if (filter && filter(&sn_tab[i], opaque) != 0) { > + continue; > + } > + > + info_list = g_new0(SnapshotInfoList, 1); > + > + info_list->value = g_new0(SnapshotInfo, 1); > + info_list->value->id = g_strdup(sn_tab[i].id_str); > + info_list->value->name = g_strdup(sn_tab[i].name); > + info_list->value->vm_state_size = sn_tab[i].vm_state_size; > + info_list->value->date_sec = sn_tab[i].date_sec; > + info_list->value->date_nsec = sn_tab[i].date_nsec; > + info_list->value->vm_clock_sec = sn_tab[i].vm_clock_nsec / > 1000000000; > + info_list->value->vm_clock_nsec = sn_tab[i].vm_clock_nsec % > 1000000000; Did I already mention somewhere that I'm a fan of compound literals? Looks so much nicer than repeating info_list->value-> in each line. ;-) Kevin