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[Qemu-block] [PATCH v2 01/21] qcow2: Add .bdrv_join_options callback
From: |
Kevin Wolf |
Subject: |
[Qemu-block] [PATCH v2 01/21] qcow2: Add .bdrv_join_options callback |
Date: |
Mon, 23 Nov 2015 16:59:40 +0100 |
qcow2 accepts a few driver-specific options that overlap semantically
(e.g. "overlap-check" is an alias of "overlap-check.template", and any
missing cache size option is derived from the given ones).
When bdrv_reopen() merges the set of updated options with left out
options that should be kept at their old value, we need to consider this
and filter out any duplicates (which would generally cause errors
because new and old value would contradict each other).
This patch adds a .bdrv_join_options callback to BlockDriver and
implements it for qcow2.
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
include/block/block_int.h | 1 +
2 files changed, 48 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index 88f56c8..9baaf4d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1282,6 +1282,52 @@ static void qcow2_reopen_abort(BDRVReopenState *state)
g_free(state->opaque);
}
+static void qcow2_join_options(QDict *options, QDict *old_options)
+{
+ bool has_new_overlap_template =
+ qdict_haskey(options, QCOW2_OPT_OVERLAP) ||
+ qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE);
+ bool has_new_total_cache_size =
+ qdict_haskey(options, QCOW2_OPT_CACHE_SIZE);
+ bool has_all_cache_options;
+
+ /* New overlap template overrides all old overlap options */
+ if (has_new_overlap_template) {
+ qdict_del(old_options, QCOW2_OPT_OVERLAP);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2);
+ }
+
+ /* New total cache size overrides all old options */
+ if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) {
+ qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE);
+ qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+ }
+
+ qdict_join(options, old_options, false);
+
+ /*
+ * If after merging all cache size options are set, an old total size is
+ * overwritten. Do keep all options, however, if all three are new. The
+ * resulting error message is what we want to happen.
+ */
+ has_all_cache_options =
+ qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) ||
+ qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) ||
+ qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+
+ if (has_all_cache_options && !has_new_total_cache_size) {
+ qdict_del(options, QCOW2_OPT_CACHE_SIZE);
+ }
+}
+
static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum)
{
@@ -3145,6 +3191,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_reopen_prepare = qcow2_reopen_prepare,
.bdrv_reopen_commit = qcow2_reopen_commit,
.bdrv_reopen_abort = qcow2_reopen_abort,
+ .bdrv_join_options = qcow2_join_options,
.bdrv_create = qcow2_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_get_block_status = qcow2_co_get_block_status,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 4012e36..77dc165 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -121,6 +121,7 @@ struct BlockDriver {
BlockReopenQueue *queue, Error **errp);
void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
+ void (*bdrv_join_options)(QDict *options, QDict *old_options);
int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
Error **errp);
--
1.8.3.1
- Re: [Qemu-block] [PATCH v2 02/21] block: Fix reopen with semantically overlapping options, (continued)
- [Qemu-block] [PATCH v2 06/21] block: Exclude nested options only for children in append_open_options(), Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 03/21] mirror: Error out when a BDS would get two BBs, Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 01/21] qcow2: Add .bdrv_join_options callback,
Kevin Wolf <=
- [Qemu-block] [PATCH v2 07/21] block: Pass driver-specific options to .bdrv_refresh_filename(), Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 09/21] block: Allow specifying child options in reopen, Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 10/21] block: reopen: Document option precedence and refactor accordingly, Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 12/21] block: Split out parse_json_protocol(), Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 08/21] block: Keep "driver" in bs->options, Kevin Wolf, 2015/11/23
- [Qemu-block] [PATCH v2 14/21] blockdev: Set 'format' indicates non-empty drive, Kevin Wolf, 2015/11/23