diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 21 |
1 files changed, 14 insertions, 7 deletions
@@ -4218,14 +4218,15 @@ BlockDriverState *bdrv_find_base(BlockDriverState *bs) /* * Return true if at least one of the backing links between @bs and * @base is frozen. @errp is set if that's the case. + * @base must be reachable from @bs, or NULL. */ bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, Error **errp) { BlockDriverState *i; - for (i = bs; i != base && i->backing; i = backing_bs(i)) { - if (i->backing->frozen) { + for (i = bs; i != base; i = backing_bs(i)) { + if (i->backing && i->backing->frozen) { error_setg(errp, "Cannot change '%s' link from '%s' to '%s'", i->backing->name, i->node_name, backing_bs(i)->node_name); @@ -4240,6 +4241,7 @@ bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, * Freeze all backing links between @bs and @base. * If any of the links is already frozen the operation is aborted and * none of the links are modified. + * @base must be reachable from @bs, or NULL. * Returns 0 on success. On failure returns < 0 and sets @errp. */ int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, @@ -4251,8 +4253,10 @@ int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, return -EPERM; } - for (i = bs; i != base && i->backing; i = backing_bs(i)) { - i->backing->frozen = true; + for (i = bs; i != base; i = backing_bs(i)) { + if (i->backing) { + i->backing->frozen = true; + } } return 0; @@ -4261,14 +4265,17 @@ int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, /* * Unfreeze all backing links between @bs and @base. The caller must * ensure that all links are frozen before using this function. + * @base must be reachable from @bs, or NULL. */ void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base) { BlockDriverState *i; - for (i = bs; i != base && i->backing; i = backing_bs(i)) { - assert(i->backing->frozen); - i->backing->frozen = false; + for (i = bs; i != base; i = backing_bs(i)) { + if (i->backing) { + assert(i->backing->frozen); + i->backing->frozen = false; + } } } |