diff options
authorPeter Zijlstra <>2011-07-25 17:11:57 -0700
committerLinus Torvalds <>2011-07-25 20:57:07 -0700
commitccb6108f5b0b541d3eb332c3a73e645c0f84278e (patch)
parent2b934c6236983392d01bef22e43af3051cac16f5 (diff)
mm/backing-dev.c: reset bdi min_ratio in bdi_unregister()
Vito said: : The system has many usb disks coming and going day to day, with their : respective bdi's having min_ratio set to 1 when inserted. It works for : some time until eventually min_ratio can no longer be set, even when the : active set of bdi's seen in /sys/class/bdi/*/min_ratio doesn't add up to : anywhere near 100. : : This then leads to an unrelated starvation problem caused by write-heavy : fuse mounts being used atop the usb disks, a problem the min_ratio setting : at the underlying devices bdi effectively prevents. Fix this leakage by resetting the bdi min_ratio when unregistering the BDI. Signed-off-by: Peter Zijlstra <> Reported-by: Vito Caputo <> Cc: Wu Fengguang <> Cc: Miklos Szeredi <> Cc: <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f032e6e1e09a..e56fe35cef05 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -606,6 +606,7 @@ static void bdi_prune_sb(struct backing_dev_info *bdi)
void bdi_unregister(struct backing_dev_info *bdi)
if (bdi->dev) {
+ bdi_set_min_ratio(bdi, 0);