@@ -1853,6 +1853,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
/* lock */
bs_dest->lock_level = bs_src->lock_level;
+ bs_dest->lock_notifiers = bs_src->lock_notifiers;
memcpy(bs_dest->op_blockers, bs_src->op_blockers,
sizeof(bs_dest->op_blockers));
@@ -2602,8 +2602,20 @@ void bdrv_flush_io_queue(BlockDriverState *bs)
}
}
+static void bdrv_lock_notify(BlockDriverState *bs, bool locking)
+{
+ BdrvLockEvent event = (BdrvLockEvent) {
+ .bs = bs,
+ .locking = locking,
+ };
+ notifier_list_notify(&bs->lock_notifiers, &event);
+}
+
void bdrv_lock(BlockDriverState *bs)
{
+ if (bs->lock_level == 0) {
+ bdrv_lock_notify(bs, true);
+ }
bs->lock_level++;
bdrv_drain(bs);
}
@@ -2612,4 +2624,11 @@ void bdrv_unlock(BlockDriverState *bs)
{
bs->lock_level--;
assert(bs->lock_level >= 0);
+ if (bs->lock_level == 0) {
+ bdrv_lock_notify(bs, false);
+ }
+}
+void bdrv_add_lock_unlock_notifier(BlockDriverState *bs, Notifier *notifier)
+{
+ notifier_list_add(&bs->lock_notifiers, notifier);
}
@@ -606,6 +606,18 @@ void bdrv_lock(BlockDriverState *bs);
*/
void bdrv_unlock(BlockDriverState *bs);
+typedef struct {
+ BlockDriverState *bs;
+ bool locking;
+} BdrvLockEvent;
+
+/**
+ * bdrv_add_lock_unlock_notifier:
+ *
+ * Add a notifier that will get notified when bs is locked or unlocked, with a
+ * BdrvLockEvent data.
+ */
+void bdrv_add_lock_unlock_notifier(BlockDriverState *bs, Notifier *notifier);
BlockAcctStats *bdrv_get_stats(BlockDriverState *bs);
#endif
@@ -435,6 +435,7 @@ struct BlockDriverState {
NotifierWithReturn write_threshold_notifier;
int lock_level;
+ NotifierList lock_notifiers;
};
Callers will be notified upon bdrv_lock if it was not locked, and bdrv_unlock if it becomes unlocked. It can be used to pause and resume devices. Signed-off-by: Fam Zheng <famz@redhat.com> --- block.c | 1 + block/io.c | 19 +++++++++++++++++++ include/block/block.h | 12 ++++++++++++ include/block/block_int.h | 1 + 4 files changed, 33 insertions(+)