[PATCH 07/19] hypfs: use d_genocide to kill fs entries

[Christoph Hellwig]

hypfs is entirely synthetic and doesn't care about i_nlink when dropping
entries from the cache.  Switch to d_genocide instead of a home grown
file remove loop for unmount and write (yes, really!).

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 arch/s390/hypfs/inode.c | 37 ++-----------------------------------
 1 file changed, 2 insertions(+), 35 deletions(-)

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index dbe8a7dcafa922..3261fb9cade648 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -64,33 +64,6 @@ static void hypfs_add_dentry(struct dentry *dentry)
 	hypfs_last_dentry = dentry;
 }
 
-static void hypfs_remove(struct dentry *dentry)
-{
-	struct dentry *parent;
-
-	parent = dentry->d_parent;
-	inode_lock(d_inode(parent));
-	if (simple_positive(dentry)) {
-		if (d_is_dir(dentry))
-			simple_rmdir(d_inode(parent), dentry);
-		else
-			simple_unlink(d_inode(parent), dentry);
-	}
-	d_drop(dentry);
-	dput(dentry);
-	inode_unlock(d_inode(parent));
-}
-
-static void hypfs_delete_tree(struct dentry *root)
-{
-	while (hypfs_last_dentry) {
-		struct dentry *next_dentry;
-		next_dentry = hypfs_last_dentry->d_fsdata;
-		hypfs_remove(hypfs_last_dentry);
-		hypfs_last_dentry = next_dentry;
-	}
-}
-
 static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
 {
 	struct inode *ret = new_inode(sb);
@@ -183,14 +156,14 @@ static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		rc = -EBUSY;
 		goto out;
 	}
-	hypfs_delete_tree(sb->s_root);
+	d_genocide(sb->s_root);
 	if (MACHINE_IS_VM)
 		rc = hypfs_vm_create_files(sb->s_root);
 	else
 		rc = hypfs_diag_create_files(sb->s_root);
 	if (rc) {
 		pr_err("Updating the hypfs tree failed\n");
-		hypfs_delete_tree(sb->s_root);
+		d_genocide(sb->s_root);
 		goto out;
 	}
 	hypfs_update_update(sb);
@@ -323,12 +296,6 @@ static int hypfs_init_fs_context(struct fs_context *fc)
 
 static void hypfs_kill_super(struct super_block *sb)
 {
-	struct hypfs_sb_info *sb_info = sb->s_fs_info;
-
-	if (sb->s_root)
-		hypfs_delete_tree(sb->s_root);
-	if (sb_info && sb_info->update_file)
-		hypfs_remove(sb_info->update_file);
 	kill_litter_super(sb);
 	kfree(sb->s_fs_info);
 }
-- 
2.39.2