bcachefs: Debug mode for c->writes references

This adds a debug mode where we split up the c->writes refcount into
distinct refcounts for every codepath that takes a reference, and adds
sysfs code to print the value of each ref.

This will make it easier to debug shutdown hangs due to refcount leaks.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
index 4e9c963dbd23..6287e926f605 100644
--- a/fs/bcachefs/btree_update_interior.c
+++ b/fs/bcachefs/btree_update_interior.c
@@ -2036,7 +2036,7 @@ void async_btree_node_rewrite_work(struct work_struct *work)
 
 	bch2_trans_do(c, NULL, NULL, 0,
 		      async_btree_node_rewrite_trans(&trans, a));
-	percpu_ref_put(&c->writes);
+	bch2_write_ref_put(c, BCH_WRITE_REF_node_rewrite);
 	kfree(a);
 }
 
@@ -2044,12 +2044,12 @@ void bch2_btree_node_rewrite_async(struct bch_fs *c, struct btree *b)
 {
 	struct async_btree_rewrite *a;
 
-	if (!percpu_ref_tryget_live(&c->writes))
+	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_node_rewrite))
 		return;
 
 	a = kmalloc(sizeof(*a), GFP_NOFS);
 	if (!a) {
-		percpu_ref_put(&c->writes);
+		bch2_write_ref_put(c, BCH_WRITE_REF_node_rewrite);
 		return;
 	}