On Fri, Jan 08, 2010 at 06:22:01PM -0800, Linus Torvalds wrote: > > > On Sat, 9 Jan 2010, Al Viro wrote: > > > > Well, sure - it steps on i_mutex-before-mmmap_sem first from ls somewhere and > > records the ordering for posterity. Then NFS steps into mmap() (on a > > different inode) and gets conflicting ordering. > > Look closer: the inodes for directories and for non-directories have > i_mutex in different lockdep classes. > > So that "on a different inode" thing should have made it a non-issue, > since there is no actual chain back. There is "mmap_sem -> > i_mutex_regular_file" (for mmap) and there is "i_mutex_directory -> > mmap_sem" (for filldir), but that isn't an ABBA. > > The problem _seems_ to be (if I read Andi's chain correctly) that a > directory hasn't gone through the i_mutex_dir_key change, so filldir ends > up being counted against the default i_mutex_key. Interesting... There's nfs_update_inode(), but it ought to scream bloody murder on the type change (and its return value is ignore by nfs_fhget(), BTW). -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
