Doesn't immediately fix anything as the callers don't use the return
value, but they will be fixed next.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2-snapshot.c | 48 ++++++++++++++++++++++++++++++++++++++----------
1 files changed, 38 insertions(+), 10 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index db49bb3..4d387a7 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -144,6 +144,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
uint64_t data64;
uint32_t data32;
int64_t offset, snapshots_offset;
+ int ret;
/* compute the size of the snapshots */
offset = 0;
@@ -156,6 +157,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
}
snapshots_size = offset;
+ /* Allocate space for the new snapshot list */
snapshots_offset = qcow2_alloc_clusters(bs, snapshots_size);
bdrv_flush(bs->file);
offset = snapshots_offset;
@@ -163,6 +165,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
return offset;
}
+ /* Write all snapshots to the new list */
for(i = 0; i < s->nb_snapshots; i++) {
sn = s->snapshots + i;
memset(&h, 0, sizeof(h));
@@ -178,34 +181,59 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
h.id_str_size = cpu_to_be16(id_str_size);
h.name_size = cpu_to_be16(name_size);
offset = align_offset(offset, 8);
- if (bdrv_pwrite_sync(bs->file, offset, &h, sizeof(h)) < 0)
+
+ ret = bdrv_pwrite(bs->file, offset, &h, sizeof(h));
+ if (ret < 0) {
goto fail;
+ }
offset += sizeof(h);
- if (bdrv_pwrite_sync(bs->file, offset, sn->id_str, id_str_size) < 0)
+
+ ret = bdrv_pwrite(bs->file, offset, sn->id_str, id_str_size);
+ if (ret < 0) {
goto fail;
+ }
offset += id_str_size;
- if (bdrv_pwrite_sync(bs->file, offset, sn->name, name_size) < 0)
+
+ ret = bdrv_pwrite(bs->file, offset, sn->name, name_size);
+ if (ret < 0) {
goto fail;
+ }
offset += name_size;
}
- /* update the various header fields */
+ /*
+ * Update the header to point to the new snapshot table. This requires the
+ * new table and its refcounts to be stable on disk.
+ *
+ * FIXME This should be done with a single write
+ */
+ ret = bdrv_flush(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
data64 = cpu_to_be64(snapshots_offset);
- if (bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, snapshots_offset),
- &data64, sizeof(data64)) < 0)
+ ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, snapshots_offset),
+ &data64, sizeof(data64));
+ if (ret < 0) {
goto fail;
+ }
+
data32 = cpu_to_be32(s->nb_snapshots);
- if (bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, nb_snapshots),
- &data32, sizeof(data32)) < 0)
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, nb_snapshots),
+ &data32, sizeof(data32));
+ if (ret < 0) {
goto fail;
+ }
/* free the old snapshot table */
qcow2_free_clusters(bs, s->snapshots_offset, s->snapshots_size);
s->snapshots_offset = snapshots_offset;
s->snapshots_size = snapshots_size;
return 0;
- fail:
- return -1;
+
+fail:
+ return ret;
}
static void find_new_snapshot_id(BlockDriverState *bs,
--
1.7.6.4
