So that users can control if kernel aio is used to submit I/O.
Signed-off-by: Ming Lei <[email protected]>
---
drivers/block/loop.c | 33 +++++++++++++++++++++++++++++++++
drivers/block/loop.h | 1 +
2 files changed, 34 insertions(+)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d1f168b..47af456 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -659,6 +659,38 @@ static ssize_t loop_attr_partscan_show(struct loop_device
*lo, char *buf)
return sprintf(buf, "%s\n", partscan ? "1" : "0");
}
+static ssize_t loop_attr_do_show_use_aio(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ struct loop_device *lo = disk->private_data;
+
+ return sprintf(buf, "%s\n", lo->use_aio ? "1" : "0");
+}
+
+ssize_t loop_attr_do_store_use_aio(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ struct loop_device *lo = disk->private_data;
+ int err;
+ unsigned long v;
+
+ err = kstrtoul(buf, 10, &v);
+ if (err < 0)
+ return err;
+ if (v)
+ lo->use_aio = true;
+ else
+ lo->use_aio = false;
+ return count;
+}
+
+static struct device_attribute loop_attr_use_aio =
+ __ATTR(use_aio, S_IRUGO | S_IWUSR, loop_attr_do_show_use_aio,
+ loop_attr_do_store_use_aio);
+
LOOP_ATTR_RO(backing_file);
LOOP_ATTR_RO(offset);
LOOP_ATTR_RO(sizelimit);
@@ -671,6 +703,7 @@ static struct attribute *loop_attrs[] = {
&loop_attr_sizelimit.attr,
&loop_attr_autoclear.attr,
&loop_attr_partscan.attr,
+ &loop_attr_use_aio.attr,
NULL,
};
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index 301c27f..15049e9 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -57,6 +57,7 @@ struct loop_device {
struct list_head write_cmd_head;
struct work_struct write_work;
bool write_started;
+ bool use_aio;
int lo_state;
struct mutex lo_ctl_mutex;
--
1.7.9.5
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