[PATCH 33/39] convert functionfs

[Al Viro]

All files are regular; ep0 is there all along, other ep* may appear
and go away during the filesystem lifetime; all of those are guaranteed
to be gone by the time we umount it.

Object creation is in ffs_sb_create_file(), removals - at ->kill_sb()
time (for ep0) or by simple_remove_by_name() from ffs_epfiles_destroy()
(for the rest of them).

Switch ffs_sb_create_file() to simple_start_creating()/d_make_persistent()/
simple_done_creating() and that's it.

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
---
 drivers/usb/gadget/function/f_fs.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 5c9a7bd4e41e..65d9109b4051 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1870,17 +1870,18 @@ static int ffs_sb_create_file(struct super_block *sb, const char *name,
 	struct dentry	*dentry;
 	struct inode	*inode;
 
-	dentry = d_alloc_name(sb->s_root, name);
-	if (!dentry)
-		return -ENOMEM;
-
 	inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
-	if (!inode) {
-		dput(dentry);
+	if (!inode)
 		return -ENOMEM;
+	dentry = simple_start_creating(sb->s_root, name);
+	if (IS_ERR(dentry)) {
+		iput(inode);
+		return PTR_ERR(dentry);
 	}
 
-	d_add(dentry, inode);
+	d_make_persistent(dentry, inode);
+
+	simple_done_creating(dentry);
 	return 0;
 }
 
@@ -2067,7 +2068,7 @@ static int ffs_fs_init_fs_context(struct fs_context *fc)
 static void
 ffs_fs_kill_sb(struct super_block *sb)
 {
-	kill_litter_super(sb);
+	kill_anon_super(sb);
 	if (sb->s_fs_info)
 		ffs_data_closed(sb->s_fs_info);
 }
-- 
2.47.3