29.09.2020 15:38, Andrey Shinkevich wrote:
Provide API for the COR-filter insertion/removal.
Also, drop the filter child permissions for an inactive state when the
filter node is being removed.
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
block/copy-on-read.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++
block/copy-on-read.h | 35 ++++++++++++++++++++++
2 files changed, 119 insertions(+)
create mode 100644 block/copy-on-read.h
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index cb03e0f..3c8231f 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -23,11 +23,21 @@
#include "qemu/osdep.h"
#include "block/block_int.h"
#include "qemu/module.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qdict.h"
+#include "block/copy-on-read.h"
+
+
+typedef struct BDRVStateCOR {
+ bool active;
+} BDRVStateCOR;
static int cor_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
+ BDRVStateCOR *state = bs->opaque;
+
bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
false, errp);
@@ -42,6 +52,13 @@ static int cor_open(BlockDriverState *bs, QDict *options,
int flags,
((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
bs->file->bs->supported_zero_flags);
+ state->active = true;
+
+ /*
+ * We don't need to call bdrv_child_refresh_perms() now as the permissions
+ * will be updated later when the filter node gets its parent.
+ */
+
return 0;
}
@@ -57,6 +74,17 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChild *c,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
+ BDRVStateCOR *s = bs->opaque;
+
+ if (!s->active) {
+ /*
+ * While the filter is being removed
+ */
+ *nperm = 0;
+ *nshared = BLK_PERM_ALL;
+ return;
+ }
+
*nperm = perm & PERM_PASSTHROUGH;
*nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
@@ -135,6 +163,7 @@ static void cor_lock_medium(BlockDriverState *bs, bool locked)
static BlockDriver bdrv_copy_on_read = {
.format_name = "copy-on-read",
+ .instance_size = sizeof(BDRVStateCOR),
.bdrv_open = cor_open,
.bdrv_child_perm = cor_child_perm,
@@ -159,4 +188,59 @@ static void bdrv_copy_on_read_init(void)
bdrv_register(&bdrv_copy_on_read);
}
+
+BlockDriverState *bdrv_cor_filter_append(BlockDriverState *bs,
+ QDict *node_options,
+ int flags, Error **errp)
Ok, now function can add ~any filter, not only COR.. But it's a pair for
bdrv_cor_filter_drop(), and with "active" hack we don't want make the functions
generic I think. So it's OK for now to keep function here and named _cor_.
+{
+ BlockDriverState *cor_filter_bs;
+ Error *local_err = NULL;
+
+ cor_filter_bs = bdrv_open(NULL, NULL, node_options, flags, errp);
+ if (cor_filter_bs == NULL) {
+ error_prepend(errp, "Could not create COR-filter node: ");
+ return NULL;
+ }
You've dropped setting ->implicit field if filter_node_name not specified.
Probably caller now can do it.. I don't really care about implicit case, so it's
OK for me if it works with iotests.
So,
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
--
Best regards,
Vladimir