ceph: track pending caps flushing globally

So we know TID of the oldest pending caps flushing. Later patch will
send this information to MDS, so that MDS can trim its completed caps
flush list.

Tracking pending caps flushing globally also simplifies syncfs code.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 41 insertions, 9 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 9a25f8d66fbc..0295048724d2 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1415,6 +1415,29 @@ static void __add_cap_flushing_to_inode(struct ceph_inode_info *ci,
 	rb_insert_color(&cf->i_node, &ci->i_cap_flush_tree);
 }
 
+static void __add_cap_flushing_to_mdsc(struct ceph_mds_client *mdsc,
+				       struct ceph_cap_flush *cf)
+{
+	struct rb_node **p = &mdsc->cap_flush_tree.rb_node;
+	struct rb_node *parent = NULL;
+	struct ceph_cap_flush *other = NULL;
+
+	while (*p) {
+		parent = *p;
+		other = rb_entry(parent, struct ceph_cap_flush, g_node);
+
+		if (cf->tid < other->tid)
+			p = &(*p)->rb_left;
+		else if (cf->tid > other->tid)
+			p = &(*p)->rb_right;
+		else
+			BUG();
+	}
+
+	rb_link_node(&cf->g_node, parent, p);
+	rb_insert_color(&cf->g_node, &mdsc->cap_flush_tree);
+}
+
 /*
  * Add dirty inode to the flushing list.  Assigned a seq number so we
  * can wait for caps to flush without starving.
@@ -1449,17 +1472,16 @@ static int __mark_caps_flushing(struct inode *inode,
 	list_del_init(&ci->i_dirty_item);
 
 	cf->tid = ++mdsc->last_cap_flush_tid;
+	__add_cap_flushing_to_mdsc(mdsc, cf);
 
 	if (list_empty(&ci->i_flushing_item)) {
-		ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
 		list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
 		mdsc->num_cap_flushing++;
-		dout(" inode %p now flushing seq %lld\n", inode,
-		     ci->i_cap_flush_seq);
+		dout(" inode %p now flushing tid %llu\n", inode, cf->tid);
 	} else {
 		list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
-		dout(" inode %p now flushing (more) seq %lld\n", inode,
-		     ci->i_cap_flush_seq);
+		dout(" inode %p now flushing (more) tid %llu\n",
+		     inode, cf->tid);
 	}
 	spin_unlock(&mdsc->cap_dirty_lock);
 
@@ -2123,8 +2145,8 @@ static void kick_flushing_inode_caps(struct ceph_mds_client *mdsc,
 
 	spin_lock(&ci->i_ceph_lock);
 	cap = ci->i_auth_cap;
-	dout("kick_flushing_inode_caps %p flushing %s flush_seq %lld\n", inode,
-	     ceph_cap_string(ci->i_flushing_caps), ci->i_cap_flush_seq);
+	dout("kick_flushing_inode_caps %p flushing %s\n", inode,
+	     ceph_cap_string(ci->i_flushing_caps));
 
 	__ceph_flush_snaps(ci, &session, 1);
 
@@ -2921,12 +2943,23 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
 	     ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
 	     ceph_cap_string(ci->i_flushing_caps & ~cleaned));
 
-	if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
+	if (list_empty(&to_remove) && !cleaned)
 		goto out;
 
 	ci->i_flushing_caps &= ~cleaned;
 
 	spin_lock(&mdsc->cap_dirty_lock);
+
+	if (!list_empty(&to_remove)) {
+		list_for_each_entry(cf, &to_remove, list)
+			rb_erase(&cf->g_node, &mdsc->cap_flush_tree);
+
+		n = rb_first(&mdsc->cap_flush_tree);
+		cf = n ? rb_entry(n, struct ceph_cap_flush, g_node) : NULL;
+		if (!cf || cf->tid > flush_tid)
+			wake_up_all(&mdsc->cap_flushing_wq);
+	}
+
 	if (ci->i_flushing_caps == 0) {
 		list_del_init(&ci->i_flushing_item);
 		if (!list_empty(&session->s_cap_flushing))
@@ -2936,7 +2969,6 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
 					 struct ceph_inode_info,
 					 i_flushing_item)->vfs_inode);
 		mdsc->num_cap_flushing--;
-		wake_up_all(&mdsc->cap_flushing_wq);
 		dout(" inode %p now !flushing\n", inode);
 
 		if (ci->i_dirty_caps == 0) {