commit d668dc56631da067540b2494d2a1f29ff7b5f15a
author Al Viro <viro@zeniv.linux.org.uk> Tue Jan 10 22:35:38 2012 -0500
committer Al Viro <viro@zeniv.linux.org.uk> Wed Jan 11 00:20:12 2012 -0500
tree 303ad17208838e8b9b1752f9427d55c84555f0f0
parent 8753333266be67ff3a984ac1f6566d31c260bee4

autofs4: deal with autofs4_write/autofs4_write races

Just serialize the actual writing of packets into pipe on
a new mutex, independent from everything else in the locking
hierarchy.  As soon as something has started feeding a piece
of packet into the pipe to daemon, we *want* everything else
about to try the same to wait until we are done.

Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>