Messages in this thread | | | Subject | Re: Race inotify_rm_watch vs umount | From | Eric Paris <> | Date | Fri, 10 Jun 2011 09:46:05 -0400 |
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On Fri, 2011-06-10 at 20:20 +0900, OGAWA Hirofumi wrote: > Hi, > > I'm looking the race inotify_rm_watch() vs umount(). This race become the > cause of Oops. You can see the oops at > > https://bugzilla.kernel.org/show_bug.cgi?id=22602 > > So, what race?
Ok, I see what you are saying, I'll see what I can do. I'm a little scared to call something like iput() under a lock though. I might be able to make the bigest lock a mutex and fix this....
I'll add this to my test suite.
-Eric > > umount inotify_rm_watch > ... fsnotify_destroy_mark() > fsnotify_destroy_inode_mark() > /* removed from i_fsnotify_marks */ > generic_shutdown_super() > fsnotify_unmount_inodes() > put_super() > iput() > iput_final() > /* this is after put_super() */ > > Like above, inotify doesn't guarantee to call final iput() before > put_super(). With this violation, FS driver can oops. > > Well, so, what are requested for inotify? We can't simply take > sb->s_umount in inotify_rm_watch()? > > Any ideas? > > Thanks.
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