ksmbd: synthesize empty AFP_AfpInfo xattr on first probe

Once a server advertises the AAPL COPYFILE capability, macOS requires
an AFP_AfpInfo stream on every file it looks at for Finder type/
creator/icon resolution. smb2_set_stream_name_xattr() currently
returns -EBADF (STATUS_OBJECT_NAME_NOT_FOUND) when a client opens
AFP_AfpInfo with FILE_OPEN disposition and the xattr doesn't exist
yet, which macOS treats as fatal for that file: Finder falls back to
showing a generic icon, and file operations that depend on succeeding
against this stream (e.g. Cmd+D duplication) fail.

Synthesize a 60-byte zeroed AFP_AfpInfo xattr (magic 0x00051607,
version 0x00020000, both big-endian per the AFP_AfpInfo wire format)
on first FILE_OPEN probe instead. type=0/creator=0 tells macOS to fall
back to extension-based type detection, which is correct for files with
no explicit Finder metadata. The synthesized xattr persists on disk, so
this only pays the extra write once per file; a later genuine write from
macOS (e.g. after the user assigns a custom icon) overwrites it normally.

Assisted-by: Claude:claude-sonnet-5
Signed-off-by: Gael Blivet <gael.blivet@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions