This adds a function to return the specified value for min_bytes. It
converts the stored min_ratio of the bdi to the corresponding bytes
value. This is an approximation as it is based on the value that is
returned by global_dirty_limits(), which can change. The returned
value can be different than the value when the min_bytes value was set.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/backing-dev.h | 1 +
mm/page-writeback.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 5eb1ae3410b2..621329f25bbe 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -105,6 +105,7 @@ static inline unsigned long wb_stat_error(void)
/* BDI ratio is expressed as part per 1000 for finer granularity. */
#define BDI_RATIO_SCALE 10
+unsigned long long bdi_get_min_bytes(struct backing_dev_info *bdi);
unsigned long long bdi_get_max_bytes(struct backing_dev_info *bdi);
int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index a6594ebdcbd8..a37a25994ad8 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -739,6 +739,12 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio)
}
EXPORT_SYMBOL(bdi_set_max_ratio);
+unsigned long long bdi_get_min_bytes(struct backing_dev_info *bdi)
+{
+ return bdi_get_bytes(bdi->min_ratio);
+}
+EXPORT_SYMBOL_GPL(bdi_get_min_bytes);
+
unsigned long long bdi_get_max_bytes(struct backing_dev_info *bdi)
{
return bdi_get_bytes(bdi->max_ratio);
--
2.30.2
