Since later this function will be used so improve it. The only caller of it
now is qemu-img, and it is not impacted by introduce function
bdrv_snapshot_load_tmp_by_id_or_name() that call bdrv_snapshot_load_tmp()
twice to keep old search logic. bdrv_snapshot_load_tmp_by_id_or_name() return
int to let caller know the errno, and errno will be used later.
Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
---
block/qcow2-snapshot.c | 16 +++++++++++-
block/qcow2.h | 5 +++-
block/snapshot.c | 58 +++++++++++++++++++++++++++++++++++++++++++-
include/block/block_int.h | 4 ++-
include/block/snapshot.h | 7 ++++-
qemu-img.c | 8 ++++-
6 files changed, 89 insertions(+), 9 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 5e8a779..4911ebe 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -669,7 +669,10 @@ int qcow2_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_tab)
return s->nb_snapshots;
}
-int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name)
+int qcow2_snapshot_load_tmp(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp)
{
int i, snapshot_index;
BDRVQcowState *s = bs->opaque;
@@ -677,12 +680,17 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, const
char *snapshot_name)
uint64_t *new_l1_table;
int new_l1_bytes;
int ret;
+ const char *device = bdrv_get_device_name(bs);
assert(bs->read_only);
/* Search the snapshot */
- snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name);
+ snapshot_index = find_snapshot_by_id_and_name(bs, snapshot_id, name);
if (snapshot_index < 0) {
+ error_setg(errp,
+ "Can't find a snapshot with ID '%s' and name '%s' "
+ "on device '%s'",
+ STR_OR_NULL(snapshot_id), STR_OR_NULL(name), device);
return -ENOENT;
}
sn = &s->snapshots[snapshot_index];
@@ -693,6 +701,10 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, const
char *snapshot_name)
ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table,
new_l1_bytes);
if (ret < 0) {
+ error_setg(errp,
+ "Failed to read l1 table for snapshot with ID '%s' and name
"
+ "'%s' on device '%s'",
+ sn->id_str, sn->name, device);
g_free(new_l1_table);
return ret;
}
diff --git a/block/qcow2.h b/block/qcow2.h
index c90e5d6..12cfeaf 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -472,7 +472,10 @@ int qcow2_snapshot_delete(BlockDriverState *bs,
const char *name,
Error **errp);
int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
-int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name);
+int qcow2_snapshot_load_tmp(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
void qcow2_free_snapshots(BlockDriverState *bs);
int qcow2_read_snapshots(BlockDriverState *bs);
diff --git a/block/snapshot.c b/block/snapshot.c
index a05c0c0..2ae3099 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -265,18 +265,72 @@ int bdrv_snapshot_list(BlockDriverState *bs,
return -ENOTSUP;
}
+/**
+ * Temporarily load an internal snapshot by @snapshot_id and @name.
+ * @bs: block device used in the operation
+ * @snapshot_id: unique snapshot ID, or NULL
+ * @name: snapshot name, or NULL
+ * @errp: location to store error
+ *
+ * If both @snapshot_id and @name are specified, load the first one with
+ * id @snapshot_id and name @name.
+ * If only @snapshot_id is specified, load the first one with id
+ * @snapshot_id.
+ * If only @name is specified, load the first one with name @name.
+ * if none is specified, return -ENINVAL.
+ *
+ * Returns: 0 on success, -errno on fail. If @bs is not inserted, return
+ * -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support
+ * internal snapshot, return -ENOTSUP. If qemu can't find one matching @id and
+ * @name, return -ENOENT. If @bs do not support parameter @snapshot_id or
+ * @name, return -EINVAL. If @errp != NULL, it will always be filled on
+ * failure.
+ */
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
- const char *snapshot_name)
+ const char *snapshot_id,
+ const char *name,
+ Error **errp)
{
BlockDriver *drv = bs->drv;
+ const char *device = bdrv_get_device_name(bs);
if (!drv) {
+ error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
return -ENOMEDIUM;
}
+ if (!snapshot_id && !name) {
+ error_setg(errp, "snapshot_id and name are both NULL");
+ return -EINVAL;
+ }
if (!bs->read_only) {
+ error_setg(errp, "Device '%s' is not readonly", device);
return -EINVAL;
}
if (drv->bdrv_snapshot_load_tmp) {
- return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
+ return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp);
}
+ error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
+ drv->format_name, device,
+ "temporarily load internal snapshot");
return -ENOTSUP;
}
+
+int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
+ const char *id_or_name,
+ Error **errp)
+{
+ int ret;
+ Error *local_err = NULL;
+
+ ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
+ if (ret == -ENOENT || ret == -EINVAL) {
+ error_free(local_err);
+ local_err = NULL;
+ ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err);
+ }
+
+ if (error_is_set(&local_err)) {
+ error_propagate(errp, local_err);
+ }
+
+ return ret;
+}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 3eeb6fe..554cadd 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -160,7 +160,9 @@ struct BlockDriver {
int (*bdrv_snapshot_list)(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
- const char *snapshot_name);
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 012bf22..d05bea7 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -61,5 +61,10 @@ void bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
int bdrv_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
- const char *snapshot_name);
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
+int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
+ const char *id_or_name,
+ Error **errp);
#endif
diff --git a/qemu-img.c b/qemu-img.c
index 926f0a0..6df58ed 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1260,8 +1260,12 @@ static int img_convert(int argc, char **argv)
ret = -1;
goto out;
}
- if (bdrv_snapshot_load_tmp(bs[0], snapshot_name) < 0) {
- error_report("Failed to load snapshot");
+
+ bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
+ if (error_is_set(&local_err)) {
+ error_report("Failed to load snapshot: %s",
+ error_get_pretty(local_err));
+ error_free(local_err);
ret = -1;
goto out;
}
--
1.7.1
