otocol own proc entry when the entry is accessed. What I, lsof user, need is just inode number of bluetooth socket. However, people may want more information. The bt_procfs_init takes a function pointer for customizing the show handler of seq_operations. In v4 patch, __acquires and __releases attributes are added to suppress sparse warning. Suggested by Andrei Emeltchenko. In v5 patch, linux/proc_fs.h is included to use PDE. Build error is reported by Fengguang Wu. Signed-off-by: Masatake YAMATO Signed-off-by: Gustavo Padovan Æ