Messages in this thread | | | Date | Mon, 25 Jul 2011 03:44:44 +0100 | From | Al Viro <> | Subject | Re: kdevtmpfs oops since yesterdays vfs merge |
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On Sun, Jul 24, 2011 at 09:56:12PM -0400, Dave Jones wrote:
> [ 7.760774] dracut: luksOpen /dev/sda2 luks-b5a1fb36-5672-4191-a260-e3f389eb0bb6 > [ 14.787158] nodename: dm-0 > [ 15.082391] nodename: dm-0 > > > when it triggers the bug_on(), it's that second nodename that is garbage.
Interesting... The next experiment would be to stick BUG_ON(!req.dev) into devtmpfs_create_node() right after the assigment to that field.
We couldn't be hit by the lack of barriers here, could we? Store to req.dev happens before spin_unlock(&req_lock), so by the time when that request is seen by loop in devtmpfsd() and passed to handle() it should be seen - we have grabbed req_lock, found a pointer to req, dropped req_lock and called handle(). Should've been enough...
Might be interesting to print &req from devtmpfs_create_node(), both on entry and on exit, and print req right before the call of handle()...
Incidentally, that disassembly shows one really ugly thing - offset of ->devt in struct device is 0x3c0. IOW, each of those suckers eats a kilobyte... ;-/
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