On Fri, Dec 20, 2024 at 01:54:20PM +1100, NeilBrown wrote: > i_rwsem *may* be held exclusively or *may* be held shared, in which case > an exclusive lock will be held on the dentry - provided by a later > patch. > > This will allow a graceful transition from exclusive to shared locking > for directory updates. > +A "mixed" lock means that either that i_rwsem on the directory is held > +exclusively, or it is held as a shared lock, and an exclusive lock is held > +on the dentry in that directory. ... it also means that ->d_parent and ->d_name are completely unstable. Yes, really - have rmdir victim moved around on server, then look it up in a new place and you'll get __d_unalias() move the existing dentry to new location right under you.
