From: Wen Congyang <we...@cn.fujitsu.com>
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
Signed-off-by: Gonglei <arei.gong...@huawei.com>
Signed-off-by: Changlong Xie <xiecl.f...@cn.fujitsu.com>
---
block.c | 8 ++--
block/quorum.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++-
include/block/block.h | 4 ++
3 files changed, 128 insertions(+), 6 deletions(-)
diff --git a/block.c b/block.c
index a347008..b9e99da 100644
--- a/block.c
+++ b/block.c
@@ -1196,10 +1196,10 @@ static int bdrv_fill_options(QDict **options, const
char *filename,
return 0;
}
-static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
- BlockDriverState *child_bs,
- const char *child_name,
- const BdrvChildRole *child_role)
+BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
+ BlockDriverState *child_bs,
+ const char *child_name,
+ const BdrvChildRole *child_role)
{
BdrvChild *child = g_new(BdrvChild, 1);
*child = (BdrvChild) {
diff --git a/block/quorum.c b/block/quorum.c
index 6793f12..e73418c 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -23,6 +23,7 @@
#include "qapi/qmp/qstring.h"
#include "qapi-event.h"
#include "crypto/hash.h"
+#include "qemu/bitmap.h"
#define HASH_LENGTH 32
@@ -80,6 +81,8 @@ typedef struct BDRVQuorumState {
bool rewrite_corrupted;/* true if the driver must rewrite-on-read corrupted
* block if Quorum is reached.
*/
+ unsigned long *index_bitmap;
+ int bsize;
QuorumReadPattern read_pattern;
} BDRVQuorumState;
@@ -875,9 +878,9 @@ 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;
}
@@ -926,6 +929,7 @@ static int quorum_open(BlockDriverState *bs, QDict
*options, int flags,
/* allocate the children array */
s->children = g_new0(BdrvChild *, s->num_children);
opened = g_new0(bool, s->num_children);
+ s->index_bitmap = bitmap_new(s->num_children);
for (i = 0; i < s->num_children; i++) {
char indexstr[32];
@@ -941,6 +945,8 @@ static int quorum_open(BlockDriverState *bs, QDict
*options, int flags,
opened[i] = true;
}
+ bitmap_set(s->index_bitmap, 0, s->num_children);
+ s->bsize = s->num_children;
g_free(opened);
goto exit;
@@ -997,6 +1003,115 @@ static void quorum_attach_aio_context(BlockDriverState
*bs,
}
}
+static int get_new_child_index(BDRVQuorumState *s)
+{
+ int index;
+
+ index = find_next_zero_bit(s->index_bitmap, s->bsize, 0);
+ if (index < s->bsize) {
+ return index;
+ }
+
+ if ((s->bsize % BITS_PER_LONG) == 0) {
+ s->index_bitmap = bitmap_zero_extend(s->index_bitmap, s->bsize,
+ s->bsize + 1);
+ }
+
+ return s->bsize++;
+}
+
+static void remove_child_index(BDRVQuorumState *s, int index)
+{
+ int last_index;
+ long new_len;
+
+ assert(index < s->bsize);
+
+ clear_bit(index, s->index_bitmap);
+ if (index < s->bsize - 1) {
+ /*
+ * The last bit is always set, and we don't clear
+ * the last bit.
+ */
+ return;
+ }
+
+ last_index = find_last_bit(s->index_bitmap, s->bsize);
+ s->bsize = last_index + 1;
+ if (BITS_TO_LONGS(last_index + 1) == BITS_TO_LONGS(s->bsize)) {
+ return;
+ }
+
+ new_len = BITS_TO_LONGS(last_index + 1) * sizeof(unsigned long);
+ s->index_bitmap = g_realloc(s->index_bitmap, new_len);
+}
+
+static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs,
+ Error **errp)
+{
+ BDRVQuorumState *s = bs->opaque;
+ BdrvChild *child;
+ char indexstr[32];
+ int index, ret;
+
+ index = get_new_child_index(s);
+ ret = snprintf(indexstr, 32, "children.%d", index);
+ if (ret < 0 || ret >= 32) {
+ error_setg(errp, "cannot generate child name");
+ return;
+ }
+
+ bdrv_drain(bs);
+
+ assert(s->num_children <= INT_MAX / sizeof(BdrvChild *));
+ if (s->num_children == INT_MAX / sizeof(BdrvChild *)) {
+ error_setg(errp, "Too many children");
+ return;
+ }
+ s->children = g_renew(BdrvChild *, s->children, s->num_children + 1);
+
+ bdrv_ref(child_bs);
+ child = bdrv_attach_child(bs, child_bs, indexstr, &child_format);
+ s->children[s->num_children++] = child;
+ set_bit(index, s->index_bitmap);
+}
+
+static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs,
+ Error **errp)
+{
+ BDRVQuorumState *s = bs->opaque;
+ BdrvChild *child;
+ int i, index;
+
+ for (i = 0; i < s->num_children; i++) {
+ if (s->children[i]->bs == child_bs) {
+ break;
+ }
+ }
+
+ /* we have checked it in bdrv_del_child() */
+ assert(i < s->num_children);
+ child = s->children[i];
+
+ if (s->num_children <= s->threshold) {
+ error_setg(errp,
+ "The number of children cannot be lower than the vote threshold
%d",
+ s->threshold);
+ return;
+ }
+
+ /* child->name is "children.%d" */
+ index = atoi(child->name + 9);
+
+ bdrv_drain(bs);
+ /* We can safely remove this child now */
+ memmove(&s->children[i], &s->children[i + 1],
+ (s->num_children - i - 1) * sizeof(void *));
+ s->children = g_renew(BdrvChild *, s->children, --s->num_children);
+ remove_child_index(s, index);
+ bdrv_unref_child(bs, child);
+}
+
static void quorum_refresh_filename(BlockDriverState *bs, QDict *options)
{
BDRVQuorumState *s = bs->opaque;
@@ -1052,6 +1167,9 @@ 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 863a7c8..6c7e54b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -513,6 +513,10 @@ 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 char *child_name,
+ 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);
--
1.9.3
