ipc: always handle a new value of auto_msgmni
authorAndrey Vagin <avagin@openvz.org>
Mon, 13 Oct 2014 22:54:10 +0000 (15:54 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 14 Oct 2014 00:18:22 +0000 (02:18 +0200)
commit1195d94e006b23c6292e78857e154872e33b6d7e
tree5ed72b5df3c9e85a844c743fcff2e364aa8186b7
parentc34d85aca91729596f876604e147892b81ecbbe9
ipc: always handle a new value of auto_msgmni

proc_dointvec_minmax() returns zero if a new value has been set.  So we
don't need to check all charecters have been handled.

Below you can find two examples.  In the new value has not been handled
properly.

$ strace ./a.out
open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3
write(3, "0\n\0", 3)                    = 2
close(3)                                = 0
exit_group(0)
$ cat /sys/kernel/debug/tracing/trace

$strace ./a.out
open("/proc/sys/kernel/auto_msgmni", O_WRONLY) = 3
write(3, "0\n", 2)                      = 2
close(3)                                = 0

$ cat /sys/kernel/debug/tracing/trace
a.out-697   [000] ....  3280.998235: unregister_ipcns_notifier <-proc_ipcauto_dointvec_minmax

Fixes: 9eefe520c814 ("ipc: do not use a negative value to re-enable msgmni automatic recomputin")
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Joe Perches <joe@perches.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ipc/ipc_sysctl.c