mm/list_lru: simplify the list_lru walk callback function

Now isolation no longer takes the list_lru global node lock, only use the
per-cgroup lock instead.  And this lock is inside the list_lru_one being
walked, no longer needed to pass the lock explicitly.

Link: https://lkml.kernel.org/r/20241104175257.60853-7-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: ryncsn

drivers/android/binder_alloc.c

@@ -1047,17 +1047,16 @@ void binder_alloc_vma_close(struct binder_alloc *alloc)
 /**
  * binder_alloc_free_page() - shrinker callback to free pages
  * @item:   item to free
- * @lock:   lock protecting the item
+ * @lru:    list_lru instance of the item
  * @cb_arg: callback argument
  *
  * Called from list_lru_walk() in binder_shrink_scan() to free
  * up pages when the system is under memory pressure.
  */
 enum lru_status binder_alloc_free_page(struct list_head *item,
 				       struct list_lru_one *lru,
-				       spinlock_t *lock,
 				       void *cb_arg)
-	__must_hold(lock)
+	__must_hold(&lru->lock)
 {
 	struct binder_lru_page *page = container_of(item, typeof(*page), lru);
 	struct binder_alloc *alloc = page->alloc;
@@ -1092,7 +1091,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
 
 	list_lru_isolate(lru, item);
 	spin_unlock(&alloc->lock);
-	spin_unlock(lock);
+	spin_unlock(&lru->lock);
 
 	if (vma) {
 		trace_binder_unmap_user_start(alloc, index);

drivers/android/binder_alloc.h

@@ -118,7 +118,7 @@ static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
 #endif
 enum lru_status binder_alloc_free_page(struct list_head *item,
 				       struct list_lru_one *lru,
-				       spinlock_t *lock, void *cb_arg);
+				       void *cb_arg);
 struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 					   size_t data_size,
 					   size_t offsets_size,

fs/dcache.c

@@ -1089,7 +1089,7 @@ void shrink_dentry_list(struct list_head *list)
 }
 
 static enum lru_status dentry_lru_isolate(struct list_head *item,
-		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+		struct list_lru_one *lru, void *arg)
 {
 	struct list_head *freeable = arg;
 	struct dentry	*dentry = container_of(item, struct dentry, d_lru);
@@ -1170,7 +1170,7 @@ long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc)
 }
 
 static enum lru_status dentry_lru_isolate_shrink(struct list_head *item,
-		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+		struct list_lru_one *lru, void *arg)
 {
 	struct list_head *freeable = arg;
 	struct dentry	*dentry = container_of(item, struct dentry, d_lru);

fs/gfs2/quota.c

@@ -149,7 +149,7 @@ static void gfs2_qd_list_dispose(struct list_head *list)
 
 
 static enum lru_status gfs2_qd_isolate(struct list_head *item,
-		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+		struct list_lru_one *lru, void *arg)
 {
 	struct list_head *dispose = arg;
 	struct gfs2_quota_data *qd =

fs/inode.c

@@ -881,7 +881,7 @@ void invalidate_inodes(struct super_block *sb)
  * with this flag set because they are the inodes that are out of order.
  */
 static enum lru_status inode_lru_isolate(struct list_head *item,
-		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+		struct list_lru_one *lru, void *arg)
 {
 	struct list_head *freeable = arg;
 	struct inode	*inode = container_of(item, struct inode, i_lru);
@@ -923,7 +923,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 	if (inode_has_buffers(inode) || !mapping_empty(&inode->i_data)) {
 		inode_pin_lru_isolating(inode);
 		spin_unlock(&inode->i_lock);
-		spin_unlock(lru_lock);
+		spin_unlock(&lru->lock);
 		if (remove_inode_buffers(inode)) {
 			unsigned long reap;
 			reap = invalidate_mapping_pages(&inode->i_data, 0, -1);

fs/nfs/nfs42xattr.c

@@ -802,7 +802,7 @@ static struct shrinker *nfs4_xattr_large_entry_shrinker;
 
 static enum lru_status
 cache_lru_isolate(struct list_head *item,
-	struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+	struct list_lru_one *lru, void *arg)
 {
 	struct list_head *dispose = arg;
 	struct inode *inode;
@@ -867,7 +867,7 @@ nfs4_xattr_cache_count(struct shrinker *shrink, struct shrink_control *sc)
 
 static enum lru_status
 entry_lru_isolate(struct list_head *item,
-	struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+	struct list_lru_one *lru, void *arg)
 {
 	struct list_head *dispose = arg;
 	struct nfs4_xattr_bucket *bucket;

fs/nfsd/filecache.c

@@ -487,7 +487,6 @@ void nfsd_file_net_dispose(struct nfsd_net *nn)
  * nfsd_file_lru_cb - Examine an entry on the LRU list
  * @item: LRU entry to examine
  * @lru: controlling LRU
- * @lock: LRU list lock (unused)
  * @arg: dispose list
  *
  * Return values:
@@ -497,9 +496,7 @@ void nfsd_file_net_dispose(struct nfsd_net *nn)
  */
 static enum lru_status
 nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
-		 spinlock_t *lock, void *arg)
-	__releases(lock)
-	__acquires(lock)
+		 void *arg)
 {
 	struct list_head *head = arg;
 	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);

fs/xfs/xfs_buf.c

@@ -1857,7 +1857,6 @@ static enum lru_status
 xfs_buftarg_drain_rele(
 	struct list_head	*item,
 	struct list_lru_one	*lru,
-	spinlock_t		*lru_lock,
 	void			*arg)
 
 {
@@ -1956,7 +1955,6 @@ static enum lru_status
 xfs_buftarg_isolate(
 	struct list_head	*item,
 	struct list_lru_one	*lru,
-	spinlock_t		*lru_lock,
 	void			*arg)
 {
 	struct xfs_buf		*bp = container_of(item, struct xfs_buf, b_lru);

fs/xfs/xfs_qm.c

@@ -412,9 +412,8 @@ static enum lru_status
 xfs_qm_dquot_isolate(
 	struct list_head	*item,
 	struct list_lru_one	*lru,
-	spinlock_t		*lru_lock,
 	void			*arg)
-		__releases(lru_lock) __acquires(lru_lock)
+		__releases(&lru->lock) __acquires(&lru->lock)
 {
 	struct xfs_dquot	*dqp = container_of(item,
 						struct xfs_dquot, q_lru);
@@ -460,7 +459,7 @@ xfs_qm_dquot_isolate(
 		trace_xfs_dqreclaim_dirty(dqp);
 
 		/* we have to drop the LRU lock to flush the dquot */
-		spin_unlock(lru_lock);
+		spin_unlock(&lru->lock);
 
 		error = xfs_qm_dqflush(dqp, &bp);
 		if (error)

include/linux/list_lru.h

@@ -184,7 +184,7 @@ void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
 			   struct list_head *head);
 
 typedef enum lru_status (*list_lru_walk_cb)(struct list_head *item,
-		struct list_lru_one *list, spinlock_t *lock, void *cb_arg);
+		struct list_lru_one *list, void *cb_arg);
 
 /**
  * list_lru_walk_one: walk a @lru, isolating and disposing freeable items.