[PATCH v2 15/50] convert bpf

Al Viro
2025-10-28T00:46:21Z

object creation goes through the normal VFS paths or approximation
thereof (user_path_create()/done_path_create() in case of bpf_obj_do_pin(),
open-coded simple_{start,done}_creating() in bpf_iter_link_pin_kernel()
at mount time), removals go entirely through the normal VFS paths (and
->unlink() is simple_unlink() there).

Enough to have bpf_dentry_finalize() use d_make_persistent() instead
of dget() and we are done.

Convert bpf_iter_link_pin_kernel() to simple_{start,done}_creating(),
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
kernel/bpf/inode.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 81780bcf8d25..9f866a010dad 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -144,8 +144,7 @@ static int bpf_inode_type(const struct inode *inode, enum bpf_type *type)
static void bpf_dentry_finalize(struct dentry *dentry, struct inode *inode,
struct inode *dir)
{
- d_instantiate(dentry, inode);
- dget(dentry);
+ d_make_persistent(dentry, inode);

inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
}
@@ -420,16 +419,12 @@ static int bpf_iter_link_pin_kernel(struct dentry *parent,
struct dentry *dentry;
int ret;

- inode_lock(parent->d_inode);
- dentry = lookup_noperm(&QSTR(name), parent);
- if (IS_ERR(dentry)) {
- inode_unlock(parent->d_inode);
+ dentry = simple_start_creating(parent, name);
+ if (IS_ERR(dentry))
return PTR_ERR(dentry);
- }
ret = bpf_mkobj_ops(dentry, mode, link, &bpf_link_iops,
&bpf_iter_fops);
- dput(dentry);
- inode_unlock(parent->d_inode);
+ simple_done_creating(dentry);
return ret;
}

@@ -1080,7 +1075,7 @@ static void bpf_kill_super(struct super_block *sb)
{
struct bpf_mount_opts *opts = sb->s_fs_info;

- kill_litter_super(sb);
+ kill_anon_super(sb);
kfree(opts);
}

--
2.47.3