diff options
| -rw-r--r-- | common/block.c | 21 | ||||
| -rw-r--r-- | include/block.h | 3 |
2 files changed, 24 insertions, 0 deletions
diff --git a/common/block.c b/common/block.c index 97cf5dc4de..8b43c3c83a 100644 --- a/common/block.c +++ b/common/block.c @@ -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) diff --git a/include/block.h b/include/block.h index 91377679b0..d35c4ecdf4 100644 --- a/include/block.h +++ b/include/block.h @@ -23,6 +23,9 @@ struct block_device { int rdbufsize; int blkmask; + loff_t discard_start; + loff_t discard_size; + struct list_head buffered_blocks; struct list_head idle_blocks; |