Add a helper function to enable the REQ_OP_WRITE_ZEROES operations
when null_blk is configured with the non-membacked operations.
Since write-zeroes is a non-trivial I/O operation we need this to
add a blktest so we can test the non-trivial I/O path from the
application to the block layer.
Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
---
drivers/block/null_blk/main.c | 13 +++++++++++++
drivers/block/null_blk/null_blk.h | 1 +
2 files changed, 14 insertions(+)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 1f154f92f4c2..fc3e883f7b84 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -209,6 +209,10 @@ static bool g_discard;
module_param_named(discard, g_discard, bool, 0444);
MODULE_PARM_DESC(discard, "Support discard operations (requires memory-backed null_blk device). Default: false");
+static bool g_write_zeroes;
+module_param_named(write_zeroes, g_write_zeroes, bool, 0444);
+MODULE_PARM_DESC(write_zeroes, "Support write-zeores operations. Default: false");
+
static unsigned long g_cache_size;
module_param_named(cache_size, g_cache_size, ulong, 0444);
MODULE_PARM_DESC(mbps, "Cache size in MiB for memory-backed device. Default: 0 (none)");
@@ -678,6 +682,7 @@ static struct nullb_device *null_alloc_dev(void)
dev->blocking = g_blocking;
dev->memory_backed = g_memory_backed;
dev->discard = g_discard;
+ dev->write_zeroes = g_write_zeroes;
dev->cache_size = g_cache_size;
dev->mbps = g_mbps;
dev->use_per_node_hctx = g_use_per_node_hctx;
@@ -1800,6 +1805,13 @@ static void null_config_discard(struct nullb *nullb)
blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9);
}
+static void null_config_write_zeroes(struct nullb *nullb)
+{
+ if (!nullb->dev->write_zeroes)
+ return;
+ blk_queue_max_write_zeroes_sectors(nullb->q, UINT_MAX >> 9);
+}
+
static const struct block_device_operations null_bio_ops = {
.owner = THIS_MODULE,
.submit_bio = null_submit_bio,
@@ -2111,6 +2123,7 @@ static int null_add_dev(struct nullb_device *dev)
blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1);
null_config_discard(nullb);
+ null_config_write_zeroes(nullb);
if (config_item_name(&dev->item)) {
/* Use configfs dir name as the device name */
diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h
index 94ff68052b1e..2c0c9c29158f 100644
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -111,6 +111,7 @@ struct nullb_device {
bool power; /* power on/off the device */
bool memory_backed; /* if data is stored in memory */
bool discard; /* if support discard */
+ bool write_zeroes; /* if support write_zeroes */
bool zoned; /* if device is zoned */
bool virt_boundary; /* virtual boundary on/off for the device */
bool no_sched; /* no IO scheduler for the device */
--
2.29.0
