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authorKevin Wolf <kwolf@redhat.com>2011-11-16 12:00:59 +0100
committerKevin Wolf <kwolf@redhat.com>2011-12-05 14:51:35 +0100
commit07fd8779001c3e6ff3ac25416a31381ff8aca308 (patch)
tree6adf5398a58fa3167516c7e0d2f99769bfabe4ea /block/qcow2-snapshot.c
parent42deb29fed92577db57c54e844f852481600b756 (diff)
qcow2: Return real error code in qcow2_write_snapshots
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 <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Diffstat (limited to 'block/qcow2-snapshot.c')
-rw-r--r--block/qcow2-snapshot.c48
1 files changed, 38 insertions, 10 deletions
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 4134bbc253..e91a286333 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -140,6 +140,7 @@ 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;
@@ -152,6 +153,7 @@ 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;
@@ -159,6 +161,7 @@ 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));
@@ -174,34 +177,59 @@ 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,