Messages in this thread | | | From | Rui Wang <> | Subject | Re: [PATCH] ovl: fix getcwd() failure after unsuccessful rmdir | Date | Mon, 1 Feb 2016 23:36:52 +0800 |
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On Sat, Jan 30, 2016 5:44 PM Konstantin Khlebnikov <koct9i@gmail.com> wrote: > On Fri, Jan 8, 2016 at 6:09 PM, Rui Wang <rui.y.wang@intel.com> wrote: > ovl_remove_upper() should do d_drop() only after it successfully > removes the dir, otherwise a subsequent getcwd() system call will > fail, breaking userspace programs. > > This is to fix: https://bugzilla.kernel.org/show_bug.cgi?id=110491 > > Signed-off-by: Rui Wang <rui.y.wang@intel.com> > > Reviewed-by: Konstantin Khlebnikov <koct9i@gmail.com> > > The same problem also in ovl_remove_and_whiteout() - when we remove > non-pure dentry. It checks that directory isn't empty before, but > I'm sure that vfs_rename which exchanges dentry and whiteout could > fail for some reason and we'll end with unhashed dentry when nothing > actually has been changed.
Yes I had the same feeling. There's a "goto out_d_drop" which causes d_drop() to be called if ovl_do_rename() fails. but I wasn't able to find a way to reproduce this problem, so I only fixed the problem described in bug110491. It's what I could reliably test.
Thanks Rui
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