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Date:   Mon, 17 Apr 2023 18:40:05 -0700
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Message-ID: <20230418014037.2412394-6-drosen@google.com>
Subject: [RFC PATCH v3 05/37] fuse-bpf: Update fuse side uapi
From:   Daniel Rosenberg <drosen@google.com>
To:     Miklos Szeredi <miklos@szeredi.hu>, bpf@vger.kernel.org,
        Alexei Starovoitov <ast@kernel.org>
Cc:     Amir Goldstein <amir73il@gmail.com>, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org,
        Daniel Borkmann <daniel@iogearbox.net>,
        John Fastabend <john.fastabend@gmail.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Shuah Khan <shuah@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Joanne Koong <joannelkoong@gmail.com>,
        Mykola Lysenko <mykolal@fb.com>, kernel-team@android.com,
        Daniel Rosenberg <drosen@google.com>,
        Paul Lawrence <paullawrence@google.com>
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Precedence: bulk

Adds structures which will be used to inform fuse about what it is being
stacked on top of. Once filters are in place, error_in will inform the
post filter if the backing call returned an error.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
 include/uapi/linux/fuse.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 1b9d0dfae72d..04d96f34e9a1 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -607,6 +607,29 @@ struct fuse_entry_out {
 	struct fuse_attr attr;
 };
 
+#define FUSE_BPF_MAX_ENTRIES	2
+
+enum fuse_bpf_type {
+	FUSE_ENTRY_BACKING		= 1,
+	FUSE_ENTRY_BPF			= 2,
+	FUSE_ENTRY_REMOVE_BACKING	= 3,
+	FUSE_ENTRY_REMOVE_BPF		= 4,
+};
+
+#define BPF_FUSE_NAME_MAX 15
+
+struct fuse_bpf_entry_out {
+	uint32_t	entry_type;
+	uint32_t	unused;
+	union {
+		struct {
+			uint64_t unused2;
+			uint64_t fd;
+		};
+		char name[BPF_FUSE_NAME_MAX + 1];
+	};
+};
+
 struct fuse_forget_in {
 	uint64_t	nlookup;
 };
-- 
2.40.0.634.g4ca3ef3211-goog