diff mbox series

[RFC,v4,12/20] mm: add bdi_set_min_bytes() function

Message ID 20221119005215.3052436-13-shr@devkernel.io (mailing list archive)
State New
Headers show
Series mm/block: add bdi sysfs knobs | expand

Commit Message

Stefan Roesch Nov. 19, 2022, 12:52 a.m. UTC 
This introduces the bdi_set_min_bytes() function. The min_bytes function
does not store the min_bytes value. Instead it converts the min_bytes
value into the corresponding ratio value.

Signed-off-by: Stefan Roesch <shr@devkernel.io>
---
 include/linux/backing-dev.h |  1 +
 mm/page-writeback.c         | 14 ++++++++++++++
 2 files changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 8e04567727e6..572669758c7f 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -109,6 +109,7 @@  u64 bdi_get_min_bytes(struct backing_dev_info *bdi);
 u64 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);
+int bdi_set_min_bytes(struct backing_dev_info *bdi, u64 min_bytes);
 int bdi_set_max_bytes(struct backing_dev_info *bdi, u64 max_bytes);
 int bdi_set_strict_limit(struct backing_dev_info *bdi, unsigned int strict_limit);
 
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index cefee7210d83..3d151e7a9b6c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -750,6 +750,20 @@  u64 bdi_get_min_bytes(struct backing_dev_info *bdi)
 	return bdi_get_bytes(bdi->min_ratio);
 }
 
+int bdi_set_min_bytes(struct backing_dev_info *bdi, u64 min_bytes)
+{
+	int ret;
+	unsigned long pages = min_bytes >> PAGE_SHIFT;
+	unsigned long min_ratio;
+
+	ret = bdi_check_pages_limit(pages);
+	if (ret)
+		return ret;
+
+	min_ratio = bdi_ratio_from_pages(pages);
+	return __bdi_set_min_ratio(bdi, min_ratio);
+}
+
 u64 bdi_get_max_bytes(struct backing_dev_info *bdi)
 {
 	return bdi_get_bytes(bdi->max_ratio);