sched: Change wait_for_completion_*_timeout() to return a signed long
authorNeilBrown <neilb@suse.de>
Wed, 5 Jan 2011 01:50:16 +0000 (12:50 +1100)
committerIngo Molnar <mingo@elte.hu>
Wed, 5 Jan 2011 13:15:50 +0000 (14:15 +0100)
commit6bf4123760a5aece6e4829ce90b70b6ffd751d65
treef7c34fba897b0a1270817c415b8c095958f59add
parent27066fd484a32c80630136aa2b91c980f3198f9d
sched: Change wait_for_completion_*_timeout() to return a signed long

wait_for_completion_*_timeout() can return:

   0: if the wait timed out
 -ve: if the wait was interrupted
 +ve: if the completion was completed.

As they currently return an 'unsigned long', the last two cases
are not easily distinguished which can easily result in buggy
code, as is the case for the recently added
wait_for_completion_interruptible_timeout() call in
net/sunrpc/cache.c

So change them both to return 'long'.  As MAX_SCHEDULE_TIMEOUT
is LONG_MAX, a large +ve return value should never overflow.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110105125016.64ccab0e@notabene.brown>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
include/linux/completion.h
kernel/sched.c