From: Wen Congyang <wency@cn.fujitsu.com>
To: qemu devel <qemu-devel@nongnu.org>,
Eric Blake <eblake@redhat.com>,
Markus Armbruster <armbru@redhat.com>,
Alberto Garcia <berto@igalia.com>,
Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu block <qemu-block@nongnu.org>,
Jiang Yunhong <yunhong.jiang@intel.com>,
Dong Eddie <eddie.dong@intel.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Gonglei <arei.gonglei@huawei.com>,
Yang Hongyang <yanghy@cn.fujitsu.com>,
zhanghailiang <zhang.zhanghailiang@huawei.com>
Subject: [Qemu-devel] [PATCH v3 3/5] quorum: implement bdrv_add_child() and bdrv_del_child()
Date: Thu, 10 Sep 2015 17:55:03 +0800 [thread overview]
Message-ID: <1441878905-5272-4-git-send-email-wency@cn.fujitsu.com> (raw)
In-Reply-To: <1441878905-5272-1-git-send-email-wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
block.c | 6 ++---
block/quorum.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++--
include/block/block.h | 3 +++
3 files changed, 76 insertions(+), 5 deletions(-)
diff --git a/block.c b/block.c
index 682d2ec..6ffd27b 100644
--- a/block.c
+++ b/block.c
@@ -1100,9 +1100,9 @@ static int bdrv_fill_options(QDict **options, const char **pfilename,
return 0;
}
-static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
- BlockDriverState *child_bs,
- const BdrvChildRole *child_role)
+BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
+ BlockDriverState *child_bs,
+ const BdrvChildRole *child_role)
{
BdrvChild *child = g_new(BdrvChild, 1);
*child = (BdrvChild) {
diff --git a/block/quorum.c b/block/quorum.c
index 72183d6..13e33ad 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -66,6 +66,9 @@ typedef struct QuorumVotes {
typedef struct BDRVQuorumState {
BlockDriverState **bs; /* children BlockDriverStates */
int num_children; /* children count */
+ int max_children; /* The maximum children count, we need to reallocate
+ * bs if num_children grows larger than maximum.
+ */
int threshold; /* if less than threshold children reads gave the
* same result a quorum error occurs.
*/
@@ -874,9 +877,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
ret = -EINVAL;
goto exit;
}
- if (s->num_children < 2) {
+ if (s->num_children < 1) {
error_setg(&local_err,
- "Number of provided children must be greater than 1");
+ "Number of provided children must be 1 or more");
ret = -EINVAL;
goto exit;
}
@@ -925,6 +928,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
/* allocate the children BlockDriverState array */
s->bs = g_new0(BlockDriverState *, s->num_children);
opened = g_new0(bool, s->num_children);
+ s->max_children = s->num_children;
for (i = 0; i < s->num_children; i++) {
char indexstr[32];
@@ -995,6 +999,67 @@ static void quorum_attach_aio_context(BlockDriverState *bs,
}
}
+static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs,
+ Error **errp)
+{
+ BDRVQuorumState *s = bs->opaque;
+
+ bdrv_drain(bs);
+
+ if (s->num_children == s->max_children) {
+ if (s->max_children >= INT_MAX) {
+ error_setg(errp, "Too many children");
+ return;
+ }
+
+ s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1);
+ s->bs[s->num_children] = NULL;
+ s->max_children++;
+ }
+
+ bdrv_ref(child_bs);
+ bdrv_attach_child(bs, child_bs, &child_format);
+ s->bs[s->num_children++] = child_bs;
+}
+
+static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs,
+ Error **errp)
+{
+ BDRVQuorumState *s = bs->opaque;
+ BdrvChild *child;
+ int i;
+
+ for (i = 0; i < s->num_children; i++) {
+ if (s->bs[i] == child_bs) {
+ break;
+ }
+ }
+
+ QLIST_FOREACH(child, &bs->children, next) {
+ if (child->bs == child_bs) {
+ break;
+ }
+ }
+
+ /* we have checked it in bdrv_del_child() */
+ assert(i < s->num_children && child);
+
+ if (s->num_children <= s->threshold) {
+ error_setg(errp,
+ "The number of children cannot be lower than the vote threshold %d",
+ s->threshold);
+ return;
+ }
+
+ bdrv_drain(bs);
+ /* We can safely remove this child now */
+ memmove(&s->bs[i], &s->bs[i + 1],
+ (s->num_children - i - 1) * sizeof(void *));
+ s->num_children--;
+ s->bs[s->num_children] = NULL;
+ bdrv_unref_child(bs, child);
+}
+
static void quorum_refresh_filename(BlockDriverState *bs)
{
BDRVQuorumState *s = bs->opaque;
@@ -1063,6 +1128,9 @@ static BlockDriver bdrv_quorum = {
.bdrv_detach_aio_context = quorum_detach_aio_context,
.bdrv_attach_aio_context = quorum_attach_aio_context,
+ .bdrv_add_child = quorum_add_child,
+ .bdrv_del_child = quorum_del_child,
+
.is_filter = true,
.bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter,
diff --git a/include/block/block.h b/include/block/block.h
index 8480af7..97188b1 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -503,6 +503,9 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs);
void bdrv_ref(BlockDriverState *bs);
void bdrv_unref(BlockDriverState *bs);
void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
+BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
+ BlockDriverState *child_bs,
+ const BdrvChildRole *child_role);
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
--
2.4.3
next prev parent reply other threads:[~2015-09-10 9:56 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-10 9:55 [Qemu-devel] [PATCH v3 0/5] qapi: child add/delete support Wen Congyang
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 1/5] support nbd driver in blockdev-add Wen Congyang
2015-09-14 14:27 ` Markus Armbruster
2015-09-14 15:47 ` Eric Blake
2015-09-15 1:39 ` Wen Congyang
2015-09-15 7:37 ` Markus Armbruster
2015-09-15 8:01 ` Wen Congyang
2015-09-15 11:12 ` Markus Armbruster
2015-09-16 5:59 ` Wen Congyang
2015-09-16 8:21 ` Markus Armbruster
2015-09-16 8:24 ` Wen Congyang
2015-09-16 11:18 ` Markus Armbruster
2015-09-16 14:53 ` [Qemu-devel] [Qemu-block] " Eric Blake
2015-09-17 1:06 ` Wen Congyang
2015-09-17 1:04 ` [Qemu-devel] " Wen Congyang
2015-09-17 5:01 ` Markus Armbruster
2015-09-15 13:03 ` Eric Blake
2015-09-15 13:26 ` Kevin Wolf
2015-09-15 2:20 ` Wen Congyang
2015-09-15 2:27 ` Wen Congyang
2015-09-15 3:46 ` Eric Blake
2015-09-15 3:58 ` Wen Congyang
2015-09-15 13:11 ` Eric Blake
2015-09-16 7:11 ` Wen Congyang
2015-09-16 14:55 ` Eric Blake
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 2/5] Add new block driver interface to add/delete a BDS's child Wen Congyang
2015-09-10 9:55 ` Wen Congyang [this message]
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 4/5] qmp: add monitor command to add/remove a child Wen Congyang
2015-09-10 10:04 ` Daniel P. Berrange
2015-09-10 10:34 ` Wen Congyang
2015-09-14 14:36 ` Markus Armbruster
2015-09-14 15:34 ` Kevin Wolf
2015-09-14 16:09 ` Markus Armbruster
2015-09-15 2:40 ` Wen Congyang
2015-09-15 7:49 ` Markus Armbruster
2015-09-15 7:57 ` Wen Congyang
2015-09-16 6:31 ` Wen Congyang
2015-09-16 8:29 ` Markus Armbruster
2015-09-14 15:37 ` Kevin Wolf
2015-09-15 2:33 ` Wen Congyang
2015-09-15 8:56 ` Alberto Garcia
2015-09-15 9:20 ` Kevin Wolf
2015-09-15 9:26 ` [Qemu-devel] [Qemu-block] " Kevin Wolf
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 5/5] hmp: " Wen Congyang
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