Messages in this thread | | | Date | Sun, 26 Oct 2014 23:42:30 +0000 | From | Al Viro <> | Subject | Re: fs: lockup on rename_mutex in fs/dcache.c:1035 |
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On Sun, Oct 26, 2014 at 04:33:11PM -0700, Linus Torvalds wrote: > On Sun, Oct 26, 2014 at 2:57 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > > .. snip .. > > in d_walk(), __list_del() instead of list_del() in __dentry_kill(), d_u.d_child > > turning into d_child everywhere, while d_alias turns into d_u.d_alias... > > > > It looks like that way we would get no retries on the second pass. Comments? > > Since I missed the whole issue with d_child.next, I'm not sure any > comments from me would be helpful. > > It does sound like trying to be more careful with d_child and using > d_alias instead is a good idea. d_alias is only used under the dentry > lock, and not in any horribly subtle situations, right? So that sounds > like a good change regardless of this particular fix - making the > union happen in a less nasty place..
OK... See vfs.git#experimental-d_walk - the first commit there moves d_rcu from d_child to d_alias, the second is basically "skip the killed siblings rather than restarting the tree walk".
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