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[PULL 28/51] block: Pull out bdrv_default_perms_for_cow()
From: |
Kevin Wolf |
Subject: |
[PULL 28/51] block: Pull out bdrv_default_perms_for_cow() |
Date: |
Fri, 15 May 2020 14:44:58 +0200 |
From: Max Reitz <address@hidden>
Right now, bdrv_format_default_perms() is used by format parents
(generally). We want to switch to a model where most parents use a
single BdrvChildClass, which then decides the permissions based on the
child role. To do so, we have to split bdrv_format_default_perms() into
separate functions for each such role.
Signed-off-by: Max Reitz <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 62 +++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 40 insertions(+), 22 deletions(-)
diff --git a/block.c b/block.c
index b3e7ae70c7..b12222a471 100644
--- a/block.c
+++ b/block.c
@@ -2468,6 +2468,44 @@ void bdrv_filter_default_perms(BlockDriverState *bs,
BdrvChild *c,
*nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
}
+static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c,
+ const BdrvChildClass *child_class,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t perm, uint64_t shared,
+ uint64_t *nperm, uint64_t *nshared)
+{
+ assert(child_class == &child_backing ||
+ (child_class == &child_of_bds && (role & BDRV_CHILD_COW)));
+
+ /*
+ * We want consistent read from backing files if the parent needs it.
+ * No other operations are performed on backing files.
+ */
+ perm &= BLK_PERM_CONSISTENT_READ;
+
+ /*
+ * If the parent can deal with changing data, we're okay with a
+ * writable and resizable backing file.
+ * TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too?
+ */
+ if (shared & BLK_PERM_WRITE) {
+ shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
+ } else {
+ shared = 0;
+ }
+
+ shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
+ BLK_PERM_WRITE_UNCHANGED;
+
+ if (bs->open_flags & BDRV_O_INACTIVE) {
+ shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
+ }
+
+ *nperm = perm;
+ *nshared = shared;
+}
+
void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
const BdrvChildClass *child_class,
BdrvChildRole role,
@@ -2505,28 +2543,8 @@ void bdrv_format_default_perms(BlockDriverState *bs,
BdrvChild *c,
*nperm = perm;
*nshared = shared;
} else {
- /* We want consistent read from backing files if the parent needs it.
- * No other operations are performed on backing files. */
- perm &= BLK_PERM_CONSISTENT_READ;
-
- /* If the parent can deal with changing data, we're okay with a
- * writable and resizable backing file. */
- /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
- if (shared & BLK_PERM_WRITE) {
- shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
- } else {
- shared = 0;
- }
-
- shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
- BLK_PERM_WRITE_UNCHANGED;
-
- if (bs->open_flags & BDRV_O_INACTIVE) {
- shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
- }
-
- *nperm = perm;
- *nshared = shared;
+ bdrv_default_perms_for_cow(bs, c, child_class, role, reopen_queue,
+ perm, shared, nperm, nshared);
}
}
--
2.25.4
- [PULL 21/51] block: Rename bdrv_inherited_options(), (continued)
- [PULL 21/51] block: Rename bdrv_inherited_options(), Kevin Wolf, 2020/05/15
- [PULL 23/51] block: Use bdrv_inherited_options(), Kevin Wolf, 2020/05/15
- [PULL 14/51] block: Add BlockDriver.is_format, Kevin Wolf, 2020/05/15
- [PULL 15/51] block: Rename BdrvChildRole to BdrvChildClass, Kevin Wolf, 2020/05/15
- [PULL 17/51] block: Add BdrvChildRole to BdrvChild, Kevin Wolf, 2020/05/15
- [PULL 18/51] block: Pass BdrvChildRole to bdrv_child_perm(), Kevin Wolf, 2020/05/15
- [PULL 22/51] block: Add generic bdrv_inherited_options(), Kevin Wolf, 2020/05/15
- [PULL 19/51] block: Pass BdrvChildRole to .inherit_options(), Kevin Wolf, 2020/05/15
- [PULL 26/51] block: Add child_of_bds, Kevin Wolf, 2020/05/15
- [PULL 24/51] block: Unify bdrv_child_cb_attach(), Kevin Wolf, 2020/05/15
- [PULL 28/51] block: Pull out bdrv_default_perms_for_cow(),
Kevin Wolf <=
- [PULL 27/51] block: Distinguish paths in *_format_default_perms, Kevin Wolf, 2020/05/15
- [PULL 29/51] block: Pull out bdrv_default_perms_for_storage(), Kevin Wolf, 2020/05/15
- [PULL 32/51] raw-format: Split raw_read_options(), Kevin Wolf, 2020/05/15
- [PULL 25/51] block: Unify bdrv_child_cb_detach(), Kevin Wolf, 2020/05/15
- [PULL 30/51] block: Relax *perms_for_storage for data children, Kevin Wolf, 2020/05/15
- [PULL 31/51] block: Add bdrv_default_perms(), Kevin Wolf, 2020/05/15
- [PULL 34/51] block: Drop child_format, Kevin Wolf, 2020/05/15
- [PULL 33/51] block: Switch child_format users to child_of_bds, Kevin Wolf, 2020/05/15
- [PULL 35/51] block: Make backing files child_of_bds children, Kevin Wolf, 2020/05/15
- [PULL 36/51] block: Drop child_backing, Kevin Wolf, 2020/05/15