3 files changed, 28 insertions, 6 deletions

diff --git a/common/block.c b/common/block.c
index 97cf5dc4de..02be80d7cc 100644
--- a/common/block.c
+++ b/common/block.c
@@ -36,7 +36,7 @@ struct chunk {
 	struct list_head list;
 };
 
-#define BUFSIZE (PAGE_SIZE * 4)
+#define BUFSIZE (PAGE_SIZE * 16)
 
 static int writebuffer_io_len(struct block_device *blk, struct chunk *chunk)
 {
@@ -161,6 +161,14 @@ static int block_cache(struct block_device *blk, int block)
 	dev_dbg(blk->dev, "%s: %d to %d\n", __func__, chunk->block_start,
 		chunk->num);
 
+	if (chunk->block_start * BLOCKSIZE(blk) >= blk->discard_start &&
+	    chunk->block_start * BLOCKSIZE(blk) + writebuffer_io_len(blk, chunk)
+	    <= blk->discard_start + blk->discard_size) {
+		memset(chunk->data, 0, writebuffer_io_len(blk, chunk));
+		list_add(&chunk->list, &blk->buffered_blocks);
+		return 0;
+	}
+
 	ret = blk->ops->read(blk, chunk->data, chunk->block_start,
 			     writebuffer_io_len(blk, chunk));
 	if (ret) {
@@ -337,11 +345,23 @@ static int block_op_flush(struct cdev *cdev)
 {
 	struct block_device *blk = cdev->priv;
 
+	blk->discard_start = blk->discard_size = 0;
+
 	return writebuffer_flush(blk);
 }
 
 static int block_op_close(struct cdev *cdev) __alias(block_op_flush);
 
+static int block_op_discard_range(struct cdev *cdev, loff_t count, loff_t offset)
+{
+	struct block_device *blk = cdev->priv;
+
+	blk->discard_start = offset;
+	blk->discard_size = count;
+
+	return 0;
+}
+
 static struct cdev_operations block_ops = {
 	.read	= block_op_read,
 #ifdef CONFIG_BLOCK_WRITE
@@ -349,6 +369,7 @@ static struct cdev_operations block_ops = {
 #endif
 	.close	= block_op_close,
 	.flush	= block_op_flush,
+	.discard_range = block_op_discard_range,
 };
 
 int blockdevice_register(struct block_device *blk)
@@ -370,7 +391,7 @@ int blockdevice_register(struct block_device *blk)
 	dev_dbg(blk->dev, "rdbufsize: %d blockbits: %d blkmask: 0x%08x\n",
 		blk->rdbufsize, blk->blockbits, blk->blkmask);
 
-	for (i = 0; i < 32; i++) {
+	for (i = 0; i < 8; i++) {
 		struct chunk *chunk = xzalloc(sizeof(*chunk));
 		chunk->data = dma_alloc(BUFSIZE);
 		chunk->num = i;
diff --git a/common/state/backend_storage.c b/common/state/backend_storage.c
index fca887e93f..fe7e89e8fb 100644
--- a/common/state/backend_storage.c
+++ b/common/state/backend_storage.c
@@ -192,6 +192,7 @@ int state_storage_read(struct state_backend_storage *storage,
 		/* Free buffer from the unused buckets */
 		free(bucket->buf);
 		bucket->buf = NULL;
+		bucket->len = 0;
 	}
 
 	/*
@@ -204,6 +205,7 @@ int state_storage_read(struct state_backend_storage *storage,
 
 	/* buffer from the used bucket is passed to the caller, do not free */
 	bucket_used->buf = NULL;
+	bucket_used->len = 0;
 
 	return 0;
 }
diff --git a/common/state/state.c b/common/state/state.c
index b168387eef..1822f37f3e 100644
--- a/common/state/state.c
+++ b/common/state/state.c
@@ -94,7 +94,7 @@ out:
  */
 static int state_do_load(struct state *state, enum state_flags flags)
 {
-	void *buf;
+	void *buf = NULL;
 	ssize_t len;
 	int ret;
 
@@ -103,7 +103,7 @@ static int state_do_load(struct state *state, enum state_flags flags)
 	if (ret) {
 		dev_err(&state->dev, "Failed to read state with format %s, %d\n",
 			state->format->name, ret);
-		return ret;
+		goto out;
 	}
 
 	ret = state->format->unpack(state->format, state, buf, len);
@@ -114,9 +114,8 @@ static int state_do_load(struct state *state, enum state_flags flags)
 	}
 
 	state->init_from_defaults = 0;
-	state->dirty = 0;
-
 out:
+	state->dirty = !!ret; /* mark dirty on error */
 	free(buf);
 	return ret;
 }