On Tue 16-05-23 21:58:36, Darrick J. Wong wrote: > On Thu, Jan 26, 2023 at 12:22:21PM +0100, Jan Kara wrote: > > When we are renaming a directory to a different directory, we need to > > update '..' entry in the moved directory. However nothing prevents moved > > directory from being modified and even converted from the inline format > > to the normal format. When such race happens the rename code gets > > confused and we crash. Fix the problem by locking the moved directory. > > Four months later, I have a question -- > > Is it necessary for ext4_cross_rename to inode_lock_nested on both > old.inode and new.inode? We're resetting the dotdot entries on both > children in that case, which means that we also need to lock out inline > data conversions, right? Ouch, you're right. In that path we need to lock both source & target directories since lock_two_nondirectories() call in vfs_rename() will not lock them... I'll send a patch. Thanks for spotting this! Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
