[PATCH v4 41/54] convert functionfs

Al Viro
2025-11-18T05:16:11Z

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@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 40868ceb765c..4bf61017b42d 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1899,17 +1899,18 @@ 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;
}

@@ -2098,7 +2099,7 @@ static void ffs_data_reset(struct ffs_data *ffs);
static void
ffs_fs_kill_sb(struct super_block *sb)
{
- kill_litter_super(sb);
+ kill_anon_super(sb);
if (sb->s_fs_info) {
struct ffs_data *ffs = sb->s_fs_info;
ffs->state = FFS_CLOSING;
--
2.47.3