tree 88f7f49abb5944725f3b60d8f28a41580e7f915f
parent 43574c1afea4f798592c03cf4d4ecea4fd0a8416
author Al Viro <viro@zeniv.linux.org.uk> 1315604197 -0400
committer Richard Weinberger <richard@nod.at> 1332631793 +0100

um: convert count_lock to mutex, fix a race in line_open()

If two processes are opening the same line, the second to get
into line_open() will decide that it doesn't need to do anything
(correctly) or wait for anything.  The latter, unfortunately,
is incorrect - the first opener might not be through yet.  We
need to have exclusion covering the entire line_init(), including
the blocking parts.  Moreover, the next patch will need to
widen the exclusion on mconsole side of things, also including
the blocking bits, so let's just convert that sucker to mutex...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>