From: Max Reitz <mreitz@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>
Subject: [PATCH v4 16/34] block: Pull out bdrv_default_perms_for_cow()
Date: Wed, 13 May 2020 13:05:26 +0200 [thread overview]
Message-ID: <20200513110544.176672-17-mreitz@redhat.com> (raw)
In-Reply-To: <20200513110544.176672-1-mreitz@redhat.com>
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 <mreitz@redhat.com>
---
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);
}
}
--
2.26.2
next prev parent reply other threads:[~2020-05-13 11:22 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 11:05 [PATCH v4 00/34] block: Introduce real BdrvChildRole Max Reitz
2020-05-13 11:05 ` [PATCH v4 01/34] block: Mark commit, mirror, blkreplay as filters Max Reitz
2020-05-13 11:05 ` [PATCH v4 02/34] block: Add BlockDriver.is_format Max Reitz
2020-05-13 11:05 ` [PATCH v4 03/34] block: Rename BdrvChildRole to BdrvChildClass Max Reitz
2020-05-13 11:05 ` [PATCH v4 04/34] block: Add BdrvChildRole and BdrvChildRoleBits Max Reitz
2020-05-13 17:36 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 05/34] block: Add BdrvChildRole to BdrvChild Max Reitz
2020-05-13 11:05 ` [PATCH v4 06/34] block: Pass BdrvChildRole to bdrv_child_perm() Max Reitz
2020-05-13 11:05 ` [PATCH v4 07/34] block: Pass BdrvChildRole to .inherit_options() Max Reitz
2020-05-13 11:05 ` [PATCH v4 08/34] block: Pass parent_is_format " Max Reitz
2020-05-13 11:05 ` [PATCH v4 09/34] block: Rename bdrv_inherited_options() Max Reitz
2020-05-13 11:05 ` [PATCH v4 10/34] block: Add generic bdrv_inherited_options() Max Reitz
2020-05-13 20:13 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 11/34] block: Use bdrv_inherited_options() Max Reitz
2020-05-13 20:18 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 12/34] block: Unify bdrv_child_cb_attach() Max Reitz
2020-05-13 20:26 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 13/34] block: Unify bdrv_child_cb_detach() Max Reitz
2020-05-13 20:27 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 14/34] block: Add child_of_bds Max Reitz
2020-05-13 20:29 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 15/34] block: Distinguish paths in *_format_default_perms Max Reitz
2020-05-13 20:30 ` Eric Blake
2020-05-13 11:05 ` Max Reitz [this message]
2020-05-13 20:33 ` [PATCH v4 16/34] block: Pull out bdrv_default_perms_for_cow() Eric Blake
2020-05-13 11:05 ` [PATCH v4 17/34] block: Pull out bdrv_default_perms_for_storage() Max Reitz
2020-05-13 11:05 ` [PATCH v4 18/34] block: Relax *perms_for_storage for data children Max Reitz
2020-05-13 20:38 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 19/34] block: Add bdrv_default_perms() Max Reitz
2020-05-13 20:43 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 20/34] raw-format: Split raw_read_options() Max Reitz
2020-05-13 11:05 ` [PATCH v4 21/34] block: Switch child_format users to child_of_bds Max Reitz
2020-05-13 11:05 ` [PATCH v4 22/34] block: Drop child_format Max Reitz
2020-05-13 11:05 ` [PATCH v4 23/34] block: Make backing files child_of_bds children Max Reitz
2020-05-13 20:46 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 24/34] block: Drop child_backing Max Reitz
2020-05-13 20:47 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 25/34] block: Make format drivers use child_of_bds Max Reitz
2020-05-13 11:05 ` [PATCH v4 26/34] block: Make filter " Max Reitz
2020-05-13 21:02 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 27/34] block: Use child_of_bds in remaining places Max Reitz
2020-05-13 21:08 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 28/34] tests: Use child_of_bds instead of child_file Max Reitz
2020-05-13 11:05 ` [PATCH v4 29/34] block: Use bdrv_default_perms() Max Reitz
2020-05-13 11:05 ` [PATCH v4 30/34] block: Make bdrv_filter_default_perms() static Max Reitz
2020-05-13 11:05 ` [PATCH v4 31/34] block: Drop bdrv_format_default_perms() Max Reitz
2020-05-13 11:05 ` [PATCH v4 32/34] block: Drop child_file Max Reitz
2020-05-13 21:11 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 33/34] block: Pass BdrvChildRole in remaining cases Max Reitz
2020-05-13 21:12 ` Eric Blake
2020-05-13 11:05 ` [PATCH v4 34/34] block: Drop @child_class from bdrv_child_perm() Max Reitz
2020-05-13 21:15 ` Eric Blake
2020-05-13 16:36 ` [PATCH v4 00/34] block: Introduce real BdrvChildRole Kevin Wolf
2020-05-14 13:44 ` Kevin Wolf
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