From 5c6d3f261827a67df84a7c55a0d204b882dcb6a8 Mon Sep 17 00:00:00 2001
From: Daniel Rosenberg <drosen@google.com>
Date: Thu, 4 May 2023 15:43:42 -0700
Subject: [PATCH] UPSTREAM: ANDROID: fuse-bpf: Add partial ioctl support

This adds passthrough only support for ioctls with fuse-bpf.
compat_ioctls will return -ENOTTY.

Bug: 279519292
Test: F2fsMiscTest#testAtomicWrite
Change-Id: Ia3052e465d87dc1d15ae13955fba8a7f93bc387b
Signed-off-by: Daniel Rosenberg <drosen@google.com>
---
 fs/fuse/backing.c | 13 +++++++++++++
 fs/fuse/file.c    |  9 +++++++++
 fs/fuse/fuse_i.h  |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c
index 8db2a0c87f75..eac91793e7a5 100644
--- a/fs/fuse/backing.c
+++ b/fs/fuse/backing.c
@@ -1016,6 +1016,19 @@ void *fuse_file_write_iter_finalize(struct fuse_bpf_args *fa,
 	return ERR_PTR(fwio->ret);
 }
 
+long fuse_backing_ioctl(struct file *file, unsigned int command, unsigned long arg, int flags)
+{
+	struct fuse_file *ff = file->private_data;
+	long ret;
+
+	if (flags & FUSE_IOCTL_COMPAT)
+		ret = -ENOTTY;
+	else
+		ret = vfs_ioctl(ff->backing_file, command, arg);
+
+	return ret;
+}
+
 int fuse_file_flock_backing(struct file *file, int cmd, struct file_lock *fl)
 {
 	struct fuse_file *ff = file->private_data;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 781f5fe3ab0e..ac3b4e9f5668 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3176,6 +3176,15 @@ long fuse_ioctl_common(struct file *file, unsigned int cmd,
 	if (fuse_is_bad(inode))
 		return -EIO;
 
+#ifdef CONFIG_FUSE_BPF
+	{
+		struct fuse_file *ff = file->private_data;
+
+		/* TODO - this is simply passthrough, not a proper BPF filter */
+		if (ff->backing_file)
+			return fuse_backing_ioctl(file, cmd, arg, flags);
+	}
+#endif
 	return fuse_do_ioctl(file, cmd, arg, flags);
 }
 
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 05e43ad2215e..f758c09f77fe 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1580,6 +1580,8 @@ int fuse_file_write_iter_backing(struct fuse_bpf_args *fa,
 void *fuse_file_write_iter_finalize(struct fuse_bpf_args *fa,
 		struct kiocb *iocb, struct iov_iter *from);
 
+long fuse_backing_ioctl(struct file *file, unsigned int command, unsigned long arg, int flags);
+
 int fuse_file_flock_backing(struct file *file, int cmd, struct file_lock *fl);
 ssize_t fuse_backing_mmap(struct file *file, struct vm_area_struct *vma);