Not used anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 Documentation/filesystems/porting.rst |  7 +++++++
 fs/dcache.c                           | 21 ---------------------
 fs/internal.h                         |  1 -
 fs/super.c                            |  8 --------
 include/linux/dcache.h                |  1 -
 include/linux/fs.h                    |  1 -
 6 files changed, 7 insertions(+), 32 deletions(-)

diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 7233b04668fc..4921b3b0662a 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1309,3 +1309,10 @@ a different length, use
 	vfs_parse_fs_qstr(fc, key, &QSTR_LEN(value, len))
 
 instead.
+
+---
+
+**mandatory**
+
+kill_litter_super() is gone; convert to DCACHE_PERSISTENT use (as all
+in-tree filesystems have done).
diff --git a/fs/dcache.c b/fs/dcache.c
index 3cc6c3876177..5ee2e78a91b3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -3167,27 +3167,6 @@ bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 }
 EXPORT_SYMBOL(is_subdir);
 
-static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry)
-{
-	struct dentry *root = data;
-	if (dentry != root) {
-		if (d_unhashed(dentry) || !dentry->d_inode ||
-		    dentry->d_flags & DCACHE_PERSISTENT)
-			return D_WALK_SKIP;
-
-		if (!(dentry->d_flags & DCACHE_GENOCIDE)) {
-			dentry->d_flags |= DCACHE_GENOCIDE;
-			dentry->d_lockref.count--;
-		}
-	}
-	return D_WALK_CONTINUE;
-}
-
-void d_genocide(struct dentry *parent)
-{
-	d_walk(parent, parent, d_genocide_kill);
-}
-
 void d_mark_tmpfile(struct file *file, struct inode *inode)
 {
 	struct dentry *dentry = file->f_path.dentry;
diff --git a/fs/internal.h b/fs/internal.h
index 9b2b4d116880..144686af6c36 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -227,7 +227,6 @@ extern void shrink_dcache_for_umount(struct super_block *);
 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
 extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
 				const struct qstr *name, unsigned *seq);
-extern void d_genocide(struct dentry *);
 
 /*
  * pipe.c
diff --git a/fs/super.c b/fs/super.c
index 5bab94fb7e03..ee001f684d2a 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1284,14 +1284,6 @@ void kill_anon_super(struct super_block *sb)
 }
 EXPORT_SYMBOL(kill_anon_super);
 
-void kill_litter_super(struct super_block *sb)
-{
-	if (sb->s_root)
-		d_genocide(sb->s_root);
-	kill_anon_super(sb);
-}
-EXPORT_SYMBOL(kill_litter_super);
-
 int set_anon_super_fc(struct super_block *sb, struct fs_context *fc)
 {
 	return set_anon_super(sb, NULL);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 6ec4066825e3..20a85144a00e 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -198,7 +198,6 @@ enum dentry_flags {
 	DCACHE_REFERENCED		= BIT(6),	/* Recently used, don't discard. */
 	DCACHE_DONTCACHE		= BIT(7),	/* Purge from memory on final dput() */
 	DCACHE_CANT_MOUNT		= BIT(8),
-	DCACHE_GENOCIDE			= BIT(9),
 	DCACHE_SHRINK_LIST		= BIT(10),
 	DCACHE_OP_WEAK_REVALIDATE	= BIT(11),
 	/*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f5037c556f61..95933ceaae51 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2728,7 +2728,6 @@ void retire_super(struct super_block *sb);
 void generic_shutdown_super(struct super_block *sb);
 void kill_block_super(struct super_block *sb);
 void kill_anon_super(struct super_block *sb);
-void kill_litter_super(struct super_block *sb);
 void deactivate_super(struct super_block *sb);
 void deactivate_locked_super(struct super_block *sb);
 int set_anon_super(struct super_block *s, void *data);
-- 
2.47.3