On Tue, 30 Jan 2024 at 16:23, Al Viro <v...@zeniv.linux.org.uk> wrote: > > On Tue, Jan 30, 2024 at 11:03:52AM -0800, Linus Torvalds wrote: > > { > > struct eventfs_inode *ei; > > > > - mutex_lock(&eventfs_mutex); > > do { > > // The parent is stable because we do not do renames > > dentry = dentry->d_parent; > > @@ -247,7 +246,6 @@ static struct eventfs_inode *eventfs_find_events(struct > > dentry *dentry) > > } > > // Walk upwards until you find the events inode > > } while (!ei->is_events); > > - mutex_unlock(&eventfs_mutex); > > Unless I'm missing something, you've just lost exclusion with > removals (not that the original hadn't been suspicious in that > respect - what's to protect ei past that mutex_unlock?
No, the mutex is actually taken up the call chain, and removing it here is fixing a deadlock. Ie we have the mutex taken in eventfs_root_lookup(), and then that goes either through lookup_dir_entry() or lookup_file_dentry(), before it gets to update_inode_attr(). That series is not very clean, I'm afraid. Linus