| Message ID | 1362636445-7188-9-git-send-email-xiawenc@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 03/06/2013 11:07 PM, Wenchao Xia wrote: > This patch adds a parameter to tell whether return valid snapshots > for whole VM only. > > Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> > --- > block/qapi.c | 39 +++++++++++++++++++++++++++++++++++++-- > include/block/qapi.h | 1 + > qemu-img.c | 3 ++- > 3 files changed, 40 insertions(+), 3 deletions(-) > > + * @sn: snapshot info need to be checked. s/need // > + * return 0 if valid, it means load_vmstate() for it could succeed. Reads awkwardly; how about: it means load_vmstate() could load that snapshot. > + */ > +static int snapshot_filter_vm(const QEMUSnapshotInfo *sn, BlockDriverState *bs) > +{ > + BlockDriverState *bs1 = NULL; > + QEMUSnapshotInfo s, *sn_info = &s; > + int ret = 0; > + > + /* Check logic is connected with load_vmstate(): > + Only check the devices that can snapshot, other devices that can't > + take snapshot, for example, readonly ones, will be ignored in > + load_vmstate(). */ > + while ((bs1 = bdrv_next(bs1))) { > + if (bdrv_can_snapshot(bs1) && bs1 != bs) { > + ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str, NULL); > + if (ret < 0) { > + ret = -1; This function only returns 0 or -1... > +/* return 0 on success, and @p_list will be set only on success. If > + @vm_snapshot is true, only the snapshot valid for whole vm will be got. */ grammar If @vm_snapshot is true, limit the results to snapshots valid for the whole vm. > - > + if (vm_snapshot && snapshot_filter_vm(&sn_tab[i], bs)) { ...yet you are only ever calling it in a boolean context. Would it be smarter to have the function return bool (true for valid vm snapshot, false if the image snapshot is not usable as a vm snapshot)? Also, it might be nicer to name it snapshot_valid_for_vm, as in: if (vm_snapshot && !snapshot_valid_for_vm(...)) { continue; }
δΊ 2013-3-9 6:55, Eric Blake ει: > On 03/06/2013 11:07 PM, Wenchao Xia wrote: >> This patch adds a parameter to tell whether return valid snapshots >> for whole VM only. >> >> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> >> --- >> block/qapi.c | 39 +++++++++++++++++++++++++++++++++++++-- >> include/block/qapi.h | 1 + >> qemu-img.c | 3 ++- >> 3 files changed, 40 insertions(+), 3 deletions(-) >> > >> + * @sn: snapshot info need to be checked. > > s/need // > OK. >> + * return 0 if valid, it means load_vmstate() for it could succeed. > > Reads awkwardly; how about: > > it means load_vmstate() could load that snapshot. > I forgot it may not have vmstate() but only only block snapshot, It should be: return 0 if valid, it means the snapshot is consistent for the VM. >> + */ >> +static int snapshot_filter_vm(const QEMUSnapshotInfo *sn, BlockDriverState *bs) >> +{ >> + BlockDriverState *bs1 = NULL; >> + QEMUSnapshotInfo s, *sn_info = &s; >> + int ret = 0; >> + >> + /* Check logic is connected with load_vmstate(): >> + Only check the devices that can snapshot, other devices that can't >> + take snapshot, for example, readonly ones, will be ignored in >> + load_vmstate(). */ >> + while ((bs1 = bdrv_next(bs1))) { >> + if (bdrv_can_snapshot(bs1) && bs1 != bs) { >> + ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str, NULL); >> + if (ret < 0) { >> + ret = -1; > > This function only returns 0 or -1... > OK, it should be bool. >> +/* return 0 on success, and @p_list will be set only on success. If >> + @vm_snapshot is true, only the snapshot valid for whole vm will be got. */ > > grammar > > If @vm_snapshot is true, limit the results to snapshots valid for the > whole vm. > Looks better, thanks. >> - >> + if (vm_snapshot && snapshot_filter_vm(&sn_tab[i], bs)) { > > ...yet you are only ever calling it in a boolean context. Would it be > smarter to have the function return bool (true for valid vm snapshot, > false if the image snapshot is not usable as a vm snapshot)? > > Also, it might be nicer to name it snapshot_valid_for_vm, as in: > > if (vm_snapshot && !snapshot_valid_for_vm(...)) { > continue; > } OK. >
diff --git a/block/qapi.c b/block/qapi.c index b503cfa..a90b4c7 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -12,11 +12,44 @@ */ #include "block/qapi.h" +#include "block/snapshot.h" #include "block/block_int.h" -/* return 0 on success, and @p_list will be set only on success. */ +/* + * check whether the snapshot is valid for whole vm. + * + * @sn: snapshot info need to be checked. + * @bs: where @sn was found. + * + * return 0 if valid, it means load_vmstate() for it could succeed. + */ +static int snapshot_filter_vm(const QEMUSnapshotInfo *sn, BlockDriverState *bs) +{ + BlockDriverState *bs1 = NULL; + QEMUSnapshotInfo s, *sn_info = &s; + int ret = 0; + + /* Check logic is connected with load_vmstate(): + Only check the devices that can snapshot, other devices that can't + take snapshot, for example, readonly ones, will be ignored in + load_vmstate(). */ + while ((bs1 = bdrv_next(bs1))) { + if (bdrv_can_snapshot(bs1) && bs1 != bs) { + ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str, NULL); + if (ret < 0) { + ret = -1; + break; + } + } + } + return ret; +} + +/* return 0 on success, and @p_list will be set only on success. If + @vm_snapshot is true, only the snapshot valid for whole vm will be got. */ int bdrv_query_snapshot_info_list(BlockDriverState *bs, SnapshotInfoList **p_list, + bool vm_snapshot, Error **errp) { int i, sn_count; @@ -45,7 +78,9 @@ int bdrv_query_snapshot_info_list(BlockDriverState *bs, } for (i = 0; i < sn_count; i++) { - + if (vm_snapshot && snapshot_filter_vm(&sn_tab[i], bs)) { + continue; + } info = g_new0(SnapshotInfo, 1); info->id = g_strdup(sn_tab[i].id_str); info->name = g_strdup(sn_tab[i].name); diff --git a/include/block/qapi.h b/include/block/qapi.h index 030964b..4842c12 100644 --- a/include/block/qapi.h +++ b/include/block/qapi.h @@ -6,6 +6,7 @@ int bdrv_query_snapshot_info_list(BlockDriverState *bs, SnapshotInfoList **p_list, + bool vm_snapshot, Error **errp); void bdrv_collect_image_info(BlockDriverState *bs, ImageInfo *info, diff --git a/qemu-img.c b/qemu-img.c index 32a72f5..7786953 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1735,7 +1735,8 @@ static ImageInfoList *collect_image_info_list(const char *filename, info = g_new0(ImageInfo, 1); bdrv_collect_image_info(bs, info, filename, fmt); - if (!bdrv_query_snapshot_info_list(bs, &info->snapshots, NULL)) { + if (!bdrv_query_snapshot_info_list(bs, &info->snapshots, + false, NULL)) { info->has_snapshots = true; }
This patch adds a parameter to tell whether return valid snapshots for whole VM only. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> --- block/qapi.c | 39 +++++++++++++++++++++++++++++++++++++-- include/block/qapi.h | 1 + qemu-img.c | 3 ++- 3 files changed, 40 insertions(+), 3 deletions(-)