On Mon, Aug 17, 2020 at 05:04:18PM -0500, Eric W. Biederman wrote: > When discussing[1] exec and posix file locks it was realized that none > of the callers of get_files_struct fundamentally needed to call > get_files_struct, and that by switching them to helper functions > instead it will both simplify their code and remove unnecessary > increments of files_struct.count. Those unnecessary increments can > result in exec unnecessarily unsharing files_struct which breaking > posix locks, and it can result in fget_light having to fallback to > fget reducing system performance. > > Using fnext_task simplifies proc_readfd_common, by moving the checking > for the maximum file descritor into the generic code, and by > remvoing the need for capturing and releasing a reference on > files_struct. Yecchhh... So you keep locking/unlocking the damn thing for each descriptor?
