[PATCH v2 14/54] fs: add an I_LRU flag to the inode

@@ -545,6 +545,7 @@ static void __inode_add_lru(struct inode *inode, bool rotate)
 
 	if (list_lru_add_obj(&inode->i_sb->s_inode_lru, &inode->i_lru)) {
 		iobj_get(inode);
+		inode->i_state |= I_LRU;
 		this_cpu_inc(nr_unused);
 	} else if (rotate) {
 		inode->i_state |= I_REFERENCED;

@@ -574,7 +575,11 @@ void inode_add_lru(struct inode *inode)
 
 static void inode_lru_list_del(struct inode *inode)
 {
+	if (!(inode->i_state & I_LRU))
+		return;
+
 	if (list_lru_del_obj(&inode->i_sb->s_inode_lru, &inode->i_lru)) {
+		inode->i_state &= ~I_LRU;
 		iobj_put(inode);
 		this_cpu_dec(nr_unused);
 	}

@@ -955,6 +960,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 	    (inode->i_state & ~I_REFERENCED) ||
 	    !mapping_shrinkable(&inode->i_data)) {
 		list_lru_isolate(lru, &inode->i_lru);
+		inode->i_state &= ~I_LRU;
 		spin_unlock(&inode->i_lock);
 		this_cpu_dec(nr_unused);
 		return LRU_REMOVED;

@@ -991,6 +997,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 
 	WARN_ON(inode->i_state & I_NEW);
 	inode->i_state |= I_FREEING;
+	inode->i_state &= ~I_LRU;
 	list_lru_isolate_move(lru, &inode->i_lru, freeable);
 	spin_unlock(&inode->i_lock);
 

@@ -744,6 +744,11 @@ is_uncached_acl(struct posix_acl *acl)
  * I_LRU_ISOLATING	Inode is pinned being isolated from LRU without holding
  *			i_count.
  *
+ * I_LRU		Inode is on the LRU list and has an associated LRU
+ *			reference count. Used to distinguish inodes where
+ *			->i_lru is on the LRU and those that are using ->i_lru
+ *			for some other means.
+ *
  * Q: What is the difference between I_WILL_FREE and I_FREEING?
  *
  * __I_{SYNC,NEW,LRU_ISOLATING} are used to derive unique addresses to wait

@@ -774,7 +779,8 @@ enum inode_state_flags_t {
 	I_CREATING		= (1U << 14),
 	I_DONTCACHE		= (1U << 15),
 	I_SYNC_QUEUED		= (1U << 16),
-	I_PINNING_NETFS_WB	= (1U << 17)
+	I_PINNING_NETFS_WB	= (1U << 17),
+	I_LRU			= (1U << 18)
 };
 
 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)

@@ -28,7 +28,8 @@
 		{I_DONTCACHE,		"I_DONTCACHE"},		\
 		{I_SYNC_QUEUED,		"I_SYNC_QUEUED"},	\
 		{I_PINNING_NETFS_WB,	"I_PINNING_NETFS_WB"},	\
-		{I_LRU_ISOLATING,	"I_LRU_ISOLATING"}	\
+		{I_LRU_ISOLATING,	"I_LRU_ISOLATING"},	\
+		{I_LRU,			"I_LRU"}		\
 	)
 
 /* enums need to be exported to user space */