diff options
author | Sascha Hauer <s.hauer@pengutronix.de> | 2019-12-13 12:16:51 +0100 |
---|---|---|
committer | Sascha Hauer <s.hauer@pengutronix.de> | 2020-02-14 12:16:20 +0100 |
commit | e488952b9d04fb0fc7dddd31ec639549d71c76b3 (patch) | |
tree | e8ba5665c2a15d081d684067ba1ab5f0722fa07d /common/block.c | |
parent | a18f5ad97df6b3d0768c8b741e85da077f990cc7 (diff) | |
download | barebox-e488952b9d04fb0fc7dddd31ec639549d71c76b3.tar.gz barebox-e488952b9d04fb0fc7dddd31ec639549d71c76b3.tar.xz |
block: Implement discard_range
This implements the discard_range hook. When a range of data is
discarded then we do not have to read it from the device and can
pass a zeroed buffer instead.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'common/block.c')
-rw-r--r-- | common/block.c | 21 |
1 files changed, 21 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) |