tree 303ad17208838e8b9b1752f9427d55c84555f0f0
parent 8753333266be67ff3a984ac1f6566d31c260bee4
author Al Viro <viro@zeniv.linux.org.uk> 1326252938 -0500
committer Al Viro <viro@zeniv.linux.org.uk> 1326259212 -0500

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>