This adds the bdi_set_strict_limit function to be able to set/unset the
BDI_CAP_STRICTLIMIT flag.
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
---
include/linux/backing-dev.h | 1 +
mm/page-writeback.c | 15 +++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 439815cc1ab9..9c984ffc8a0a 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -104,6 +104,7 @@ static inline unsigned long wb_stat_error(void)
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);
+int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit);
/*
* Flags in backing_dev_info::capability
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7e9d8d857ecc..3745b886722f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -698,6 +698,21 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
}
EXPORT_SYMBOL(bdi_set_max_ratio);
+int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit)
+{
+ if (strict_limit > 1)
+ return -EINVAL;
+
+ spin_lock_bh(&bdi_lock);
+ if (strict_limit)
+ bdi->capabilities |= BDI_CAP_STRICTLIMIT;
+ else
+ bdi->capabilities &= ~BDI_CAP_STRICTLIMIT;
+ spin_unlock_bh(&bdi_lock);
+
+ return 0;
+}
+
static unsigned long dirty_freerun_ceiling(unsigned long thresh,
unsigned long bg_thresh)
{
--
2.30.2
