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[PULL 01/34] block: Add bdrv_qapi_perm_to_blk_perm()
From: |
Max Reitz |
Subject: |
[PULL 01/34] block: Add bdrv_qapi_perm_to_blk_perm() |
Date: |
Mon, 6 Jan 2020 15:41:33 +0100 |
We need some way to correlate QAPI BlockPermission values with
BLK_PERM_* flags. We could:
(1) have the same order in the QAPI definition as the the BLK_PERM_*
flags are in LSb-first order. However, then there is no guarantee
that they actually match (e.g. when someone modifies the QAPI schema
without thinking of the BLK_PERM_* definitions).
We could add static assertions, but these would break what’s good
about this solution, namely its simplicity.
(2) define the BLK_PERM_* flags based on the BlockPermission values.
But this way whenever someone were to modify the QAPI order
(perfectly sensible in theory), the BLK_PERM_* values would change.
Because these values are used for file locking, this might break
file locking between different qemu versions.
Therefore, go the slightly more cumbersome way: Add a function to
translate from the QAPI constants to the BLK_PERM_* flags.
Signed-off-by: Max Reitz <address@hidden>
Message-id: address@hidden
Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Signed-off-by: Max Reitz <address@hidden>
---
block.c | 18 ++++++++++++++++++
include/block/block.h | 1 +
2 files changed, 19 insertions(+)
diff --git a/block.c b/block.c
index 1b6f7c86e8..28eb5a774c 100644
--- a/block.c
+++ b/block.c
@@ -2227,6 +2227,24 @@ void bdrv_format_default_perms(BlockDriverState *bs,
BdrvChild *c,
*nshared = shared;
}
+uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm)
+{
+ static const uint64_t permissions[] = {
+ [BLOCK_PERMISSION_CONSISTENT_READ] = BLK_PERM_CONSISTENT_READ,
+ [BLOCK_PERMISSION_WRITE] = BLK_PERM_WRITE,
+ [BLOCK_PERMISSION_WRITE_UNCHANGED] = BLK_PERM_WRITE_UNCHANGED,
+ [BLOCK_PERMISSION_RESIZE] = BLK_PERM_RESIZE,
+ [BLOCK_PERMISSION_GRAPH_MOD] = BLK_PERM_GRAPH_MOD,
+ };
+
+ QEMU_BUILD_BUG_ON(ARRAY_SIZE(permissions) != BLOCK_PERMISSION__MAX);
+ QEMU_BUILD_BUG_ON(1UL << ARRAY_SIZE(permissions) != BLK_PERM_ALL + 1);
+
+ assert(qapi_perm < BLOCK_PERMISSION__MAX);
+
+ return permissions[qapi_perm];
+}
+
static void bdrv_replace_child_noperm(BdrvChild *child,
BlockDriverState *new_bs)
{
diff --git a/include/block/block.h b/include/block/block.h
index 1df9848e74..e9dcfef7fa 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -280,6 +280,7 @@ enum {
};
char *bdrv_perm_names(uint64_t perm);
+uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);
/* disk I/O throttling */
void bdrv_init(void);
--
2.24.1
- [PULL 00/34] Block patches, Max Reitz, 2020/01/06
- [PULL 01/34] block: Add bdrv_qapi_perm_to_blk_perm(),
Max Reitz <=
- [PULL 02/34] block: Use bdrv_qapi_perm_to_blk_perm(), Max Reitz, 2020/01/06
- [PULL 03/34] blkdebug: Allow taking/unsharing permissions, Max Reitz, 2020/01/06
- [PULL 04/34] iotests: Add @error to wait_until_completed, Max Reitz, 2020/01/06
- [PULL 05/34] iotests: Add test for failing mirror complete, Max Reitz, 2020/01/06
- [PULL 06/34] throttle-groups: fix memory leak in throttle_group_set_limit:, Max Reitz, 2020/01/06
- [PULL 07/34] qcow2-bitmaps: fix qcow2_can_store_new_dirty_bitmap, Max Reitz, 2020/01/06
- [PULL 08/34] iotests: s/qocw2/qcow2/, Max Reitz, 2020/01/06
- [PULL 09/34] iotests/qcow2.py: Add dump-header-exts, Max Reitz, 2020/01/06
- [PULL 11/34] iotests: Add _filter_json_filename, Max Reitz, 2020/01/06
- [PULL 10/34] iotests/qcow2.py: Split feature fields into bits, Max Reitz, 2020/01/06