Revision 212a5a8f block.c
| b/block.c | ||
|---|---|---|
| 5094 | 5094 |
return bs->drv->bdrv_amend_options(bs, options); |
| 5095 | 5095 |
} |
| 5096 | 5096 |
|
| 5097 |
ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs) |
|
| 5097 |
/* Used to recurse on single child block filters. |
|
| 5098 |
* Single child block filter will store their child in bs->file. |
|
| 5099 |
*/ |
|
| 5100 |
bool bdrv_generic_is_first_non_filter(BlockDriverState *bs, |
|
| 5101 |
BlockDriverState *candidate) |
|
| 5098 | 5102 |
{
|
| 5099 |
if (bs->drv->bdrv_check_ext_snapshot) {
|
|
| 5100 |
return bs->drv->bdrv_check_ext_snapshot(bs); |
|
| 5103 |
if (!bs->drv) {
|
|
| 5104 |
return false; |
|
| 5105 |
} |
|
| 5106 |
|
|
| 5107 |
if (!bs->drv->authorizations[BS_IS_A_FILTER]) {
|
|
| 5108 |
if (bs == candidate) {
|
|
| 5109 |
return true; |
|
| 5110 |
} else {
|
|
| 5111 |
return false; |
|
| 5112 |
} |
|
| 5113 |
} |
|
| 5114 |
|
|
| 5115 |
if (!bs->drv->authorizations[BS_FILTER_PASS_DOWN]) {
|
|
| 5116 |
return false; |
|
| 5101 | 5117 |
} |
| 5102 | 5118 |
|
| 5103 |
if (bs->file && bs->file->drv && bs->file->drv->bdrv_check_ext_snapshot) {
|
|
| 5104 |
return bs->file->drv->bdrv_check_ext_snapshot(bs); |
|
| 5119 |
if (!bs->file) {
|
|
| 5120 |
return false; |
|
| 5121 |
} |
|
| 5122 |
|
|
| 5123 |
return bdrv_recurse_is_first_non_filter(bs->file, candidate); |
|
| 5124 |
} |
|
| 5125 |
|
|
| 5126 |
bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, |
|
| 5127 |
BlockDriverState *candidate) |
|
| 5128 |
{
|
|
| 5129 |
if (bs->drv && bs->drv->bdrv_recurse_is_first_non_filter) {
|
|
| 5130 |
return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); |
|
| 5105 | 5131 |
} |
| 5106 | 5132 |
|
| 5107 |
/* external snapshots are allowed by default */ |
|
| 5108 |
return EXT_SNAPSHOT_ALLOWED; |
|
| 5133 |
return bdrv_generic_is_first_non_filter(bs, candidate); |
|
| 5109 | 5134 |
} |
| 5110 | 5135 |
|
| 5111 |
ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs) |
|
| 5136 |
/* This function checks if the candidate is the first non filter bs down it's |
|
| 5137 |
* bs chain. Since we don't have pointers to parents it explore all bs chains |
|
| 5138 |
* from the top. Some filters can choose not to pass down the recursion. |
|
| 5139 |
*/ |
|
| 5140 |
bool bdrv_is_first_non_filter(BlockDriverState *candidate) |
|
| 5112 | 5141 |
{
|
| 5113 |
return EXT_SNAPSHOT_FORBIDDEN; |
|
| 5142 |
BlockDriverState *bs; |
|
| 5143 |
|
|
| 5144 |
/* walk down the bs forest recursively */ |
|
| 5145 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
| 5146 |
bool perm; |
|
| 5147 |
|
|
| 5148 |
if (!bs->file) {
|
|
| 5149 |
continue; |
|
| 5150 |
} |
|
| 5151 |
|
|
| 5152 |
perm = bdrv_recurse_is_first_non_filter(bs->file, candidate); |
|
| 5153 |
|
|
| 5154 |
/* candidate is the first non filter */ |
|
| 5155 |
if (perm) {
|
|
| 5156 |
return true; |
|
| 5157 |
} |
|
| 5158 |
} |
|
| 5159 |
|
|
| 5160 |
return false; |
|
| 5114 | 5161 |
} |
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