Hi,
We are seeing a number of cases when blocked fuse requests prevent
the system from suspending, which is a little important on laptops.
Usually something like this:
[ 36.281038] Freezing user space processes
[ 56.284961] Freezing user space processes failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0):
[ 56.285069] task:secagentd state:D stack:0 pid:1792 ppid:1711 flags:0x00004006
[ 56.285084] Call Trace:
[ 56.285091] <TASK>
[ 56.285111] schedule+0x612/0x2230
[ 56.285136] fuse_get_req+0x108/0x2d0
[ 56.285179] fuse_simple_request+0x40/0x630
[ 56.285203] fuse_getxattr+0x15d/0x1c0
[...]
Which looks like wait_event_killable_exclusive() in fuse_get_req().
And we were wondering if we could do something about it. For example,
perhaps, something like:
---
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f182a4ca1bb32..587cea3a0407d 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -241,7 +241,7 @@ static struct fuse_req *fuse_get_req(struct fuse_conn *fc, bool for_background)
if (fuse_block_alloc(fc, for_background)) {
err = -EINTR;
- if (wait_event_killable_exclusive(fc->blocked_waitq,
+ if (wait_event_freezable_killable_exclusive(fc->blocked_waitq,
!fuse_block_alloc(fc, for_background)))
goto out;
}
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 5b65f720261a9..1c8fdf1e02785 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -628,6 +628,19 @@ do { \
__ret; \
})
+#define __wait_event_freezable_killable_exclusive(wq, condition) \
+ ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \
+ freezable_schedule())
+
+#define wait_event_freezable_killable_exclusive(wq, condition) \
+({ \
+ int __ret = 0; \
+ might_sleep(); \
+ if (!(condition)) \
+ __ret = __wait_event_freezable_killable_exclusive(wq, \
+ condition); \
+ __ret; \
+})
#define __wait_event_freezable_exclusive(wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
---
Would this be a terrible idea?
