[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 14/14] block/snapshot: drop indirection around bdrv_snapshot_fall
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH 14/14] block/snapshot: drop indirection around bdrv_snapshot_fallback_ptr |
Date: |
Fri, 3 Dec 2021 21:25:53 +0100 |
Now the indirection is not actually used, we can safely reduce it to
simple pointer.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block/snapshot.c | 39 +++++++++++++++++----------------------
1 file changed, 17 insertions(+), 22 deletions(-)
diff --git a/block/snapshot.c b/block/snapshot.c
index cb184d70b4..e32f9cb2ad 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -148,34 +148,29 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState
*bs,
}
/**
- * Return a pointer to the child BDS pointer to which we can fall
+ * Return a pointer to child of given BDS to which we can fall
* back if the given BDS does not support snapshots.
* Return NULL if there is no BDS to (safely) fall back to.
- *
- * We need to return an indirect pointer because bdrv_snapshot_goto()
- * has to modify the BdrvChild pointer.
*/
-static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs)
+static BdrvChild *bdrv_snapshot_fallback_ptr(BlockDriverState *bs)
{
- BdrvChild **fallback;
- BdrvChild *child = bdrv_primary_child(bs);
+ BdrvChild *fallback = bdrv_primary_child(bs);
+ BdrvChild *child;
/* We allow fallback only to primary child */
- if (!child) {
+ if (!fallback) {
return NULL;
}
- fallback = (child == bs->file ? &bs->file : &bs->backing);
- assert(*fallback == child);
/*
* Check that there are no other children that would need to be
* snapshotted. If there are, it is not safe to fall back to
- * *fallback.
+ * fallback.
*/
QLIST_FOREACH(child, &bs->children, next) {
if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
BDRV_CHILD_FILTERED) &&
- child != *fallback)
+ child != fallback)
{
return NULL;
}
@@ -186,8 +181,8 @@ static BdrvChild
**bdrv_snapshot_fallback_ptr(BlockDriverState *bs)
static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs)
{
- BdrvChild **child_ptr = bdrv_snapshot_fallback_ptr(bs);
- return child_ptr ? (*child_ptr)->bs : NULL;
+ BdrvChild *child_ptr = bdrv_snapshot_fallback_ptr(bs);
+ return child_ptr ? child_ptr->bs : NULL;
}
int bdrv_can_snapshot(BlockDriverState *bs)
@@ -230,7 +225,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
Error **errp)
{
BlockDriver *drv = bs->drv;
- BdrvChild **fallback_ptr;
+ BdrvChild *fallback;
int ret, open_ret;
if (!drv) {
@@ -251,13 +246,13 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
return ret;
}
- fallback_ptr = bdrv_snapshot_fallback_ptr(bs);
- if (fallback_ptr) {
+ fallback = bdrv_snapshot_fallback_ptr(bs);
+ if (fallback) {
QDict *options;
QDict *file_options;
Error *local_err = NULL;
- BlockDriverState *fallback_bs = (*fallback_ptr)->bs;
- char *subqdict_prefix = g_strdup_printf("%s.", (*fallback_ptr)->name);
+ BlockDriverState *fallback_bs = fallback->bs;
+ char *subqdict_prefix = g_strdup_printf("%s.", fallback->name);
options = qdict_clone_shallow(bs->options);
@@ -268,8 +263,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
qobject_unref(file_options);
g_free(subqdict_prefix);
- /* Force .bdrv_open() below to re-attach fallback_bs on *fallback_ptr
*/
- qdict_put_str(options, (*fallback_ptr)->name,
+ /* Force .bdrv_open() below to re-attach fallback_bs on fallback */
+ qdict_put_str(options, fallback->name,
bdrv_get_node_name(fallback_bs));
/* Now close bs, apply the snapshot on fallback_bs, and re-open bs */
@@ -278,7 +273,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
}
/* .bdrv_open() will re-attach it */
- bdrv_unref_child(bs, *fallback_ptr);
+ bdrv_unref_child(bs, fallback);
ret = bdrv_snapshot_goto(fallback_bs, snapshot_id, errp);
open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err);
--
2.31.1
- [PATCH 10/14] Revert "block: Let replace_child_tran keep indirect pointer", (continued)
- [PATCH 10/14] Revert "block: Let replace_child_tran keep indirect pointer", Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 11/14] Revert "block: Restructure remove_file_or_backing_child()", Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 03/14] block/blklogwrites: don't care to remove bs->file child on failure, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 04/14] test-bdrv-graph-mod: update test_parallel_perm_update test case, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 05/14] tests-bdrv-drain: bdrv_replace_test driver: declare supports_backing, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 02/14] block: introduce bdrv_open_file_child() helper, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 12/14] Revert "block: Pass BdrvChild ** to replace_child_noperm", Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 13/14] block: Manipulate bs->file / bs->backing pointers in .attach/.detach, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 06/14] test-bdrv-graph-mod: fix filters to be filters, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 07/14] block: document connection between child roles and bs->backing/bs->file, Vladimir Sementsov-Ogievskiy, 2021/12/03
- [PATCH 14/14] block/snapshot: drop indirection around bdrv_snapshot_fallback_ptr,
Vladimir Sementsov-Ogievskiy <=
- [PATCH 08/14] block/snapshot: stress that we fallback to primary child, Vladimir Sementsov-Ogievskiy, 2021/12/03