δΊ 2013-2-27 23:30, Markus Armbruster ει:
> Wenchao Xia <xiaw...@linux.vnet.ibm.com> writes:
>
>> This patch add function bdrv_query_image_info(), which will return
>> image info in qmp object format. The implementation code are based
>> on the code moved from qemu-img.c, but use block layer function to get
>> snapshot info.
>> A check with bdrv_can_read_snapshot(), was done before collecting
>> snapshot info.
>>
>> Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
>> ---
>> block.c | 38 ++++++++++++++++++++++++++++++++------
>> include/block/block.h | 5 +----
>> qemu-img.c | 13 +++++--------
>> 3 files changed, 38 insertions(+), 18 deletions(-)
>>
>> diff --git a/block.c b/block.c
>> index 8d0145a..71fc9e7 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -2880,15 +2880,33 @@ SnapshotInfoList
>> *bdrv_query_snapshot_infolist(BlockDriverState *bs,
>> return head;
>> }
>>
>> -void collect_image_info(BlockDriverState *bs,
>> - ImageInfo *info,
>> - const char *filename)
>> +/* collect all internal snapshot info in a image for ImageInfo */
>> +static void collect_snapshots_info(BlockDriverState *bs,
>> + ImageInfo *info,
>> + Error **errp)
>> +{
>> + SnapshotInfoList *info_list;
>> +
>> + if (!bdrv_can_read_snapshot(bs)) {
>> + return;
>> + }
>> + info_list = bdrv_query_snapshot_infolist(bs, NULL, NULL, errp);
>
> Suggest to store straight into info_list->snapshots, like you did in the
> previous patch.
>
OK.
>> + if (info_list != NULL) {
>> + info->has_snapshots = true;
>> + info->snapshots = info_list;
>> + }
>> +}
>> +
>> +static void collect_image_info(BlockDriverState *bs,
>> + ImageInfo *info)
>> {
>> uint64_t total_sectors;
>> - char backing_filename[1024];
>> + const char *backing_filename;
>> char backing_filename2[1024];
>> BlockDriverInfo bdi;
>> + const char *filename;
>>
>> + filename = bs->filename;
>> bdrv_get_geometry(bs, &total_sectors);
>>
>> info->filename = g_strdup(filename);
>> @@ -2908,8 +2926,8 @@ void collect_image_info(BlockDriverState *bs,
>> info->dirty_flag = bdi.is_dirty;
>> info->has_dirty_flag = true;
>> }
>> - bdrv_get_backing_filename(bs, backing_filename,
>> sizeof(backing_filename));
>> - if (backing_filename[0] != '\0') {
>> + backing_filename = bs->backing_file;
>> + if (backing_filename && backing_filename[0] != '\0') {
>> info->backing_filename = g_strdup(backing_filename);
>> info->has_backing_filename = true;
>> bdrv_get_full_backing_filename(bs, backing_filename2,
>> @@ -2928,6 +2946,14 @@ void collect_image_info(BlockDriverState *bs,
>> }
>> }
>>
>> +ImageInfo *bdrv_query_image_info(BlockDriverState *bs, Error **errp)
>> +{
>> + ImageInfo *info = g_new0(ImageInfo, 1);
>> + collect_image_info(bs, info);
>> + collect_snapshots_info(bs, info, errp);
>> + return info;
>> +}
>
> Please return NULL on error.
>
OK.
>> +
>> BlockInfo *bdrv_query_info(BlockDriverState *bs)
>> {
>> BlockInfo *info = g_malloc0(sizeof(*info));
>> diff --git a/include/block/block.h b/include/block/block.h
>> index 51a14f2..f033807 100644
>> --- a/include/block/block.h
>> +++ b/include/block/block.h
>> @@ -326,6 +326,7 @@ SnapshotInfoList
>> *bdrv_query_snapshot_infolist(BlockDriverState *bs,
>> SnapshotFilterFunc filter,
>> void *opaque,
>> Error **errp);
>> +ImageInfo *bdrv_query_image_info(BlockDriverState *bs, Error **errp);
>> BlockInfo *bdrv_query_info(BlockDriverState *s);
>> BlockStats *bdrv_query_stats(const BlockDriverState *bs);
>> bool bdrv_can_read_snapshot(BlockDriverState *bs);
>> @@ -456,8 +457,4 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const
>> char *event,
>> const char *tag);
>> int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
>> bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
>> -
>> -void collect_image_info(BlockDriverState *bs,
>> - ImageInfo *info,
>> - const char *filename);
>> #endif
>> diff --git a/qemu-img.c b/qemu-img.c
>> index 1034cc5..90f4bf4 100644
>> --- a/qemu-img.c
>> +++ b/qemu-img.c
>> @@ -1257,6 +1257,7 @@ static ImageInfoList *collect_image_info_list(const
>> char *filename,
>> ImageInfoList *head = NULL;
>> ImageInfoList **last = &head;
>> GHashTable *filenames;
>> + Error *err = NULL;
>>
>> filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL,
>> NULL);
>>
>> @@ -1278,14 +1279,10 @@ static ImageInfoList *collect_image_info_list(const
>> char *filename,
>> goto err;
>> }
>>
>> - info = g_new0(ImageInfo, 1);
>> - collect_image_info(bs, info, filename);
>> - if (bdrv_can_read_snapshot(bs)) {
>> - info->snapshots = bdrv_query_snapshot_infolist(bs, NULL,
>> - NULL, NULL);
>> - if (info->snapshots) {
>> - info->has_snapshots = true;
>> - }
>> + info = bdrv_query_image_info(bs, &err);
>> + if (error_is_set(&err)) {
>> + bdrv_delete(bs);
>> + goto err;
>
> Leaks info. Easy error to make, because returning non-null on error is
> rather surprising. That's why I want you to return NULL then.
>
> And then this can be simplified to
>
> info = bdrv_query_image_info(bs, NULL);
> if (!info) {
>
OK.
>> }
>>
>> elem = g_new0(ImageInfoList, 1);
>
--
Best Regards
Wenchao Xia
