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cef0184c11
Commit b231cca438 ("message queues: increase range limits") changed
mqueue default value when attr parameter is specified NULL from hard
coded value to fs.mqueue.{msg,msgsize}_max sysctl value.
This made large side effect. When user need to use two mqueue
applications 1) using !NULL attr parameter and it require big message
size and 2) using NULL attr parameter and only need small size message,
app (1) require to raise fs.mqueue.msgsize_max and app (2) consume large
memory size even though it doesn't need.
Doug Ledford propsed to switch back it to static hard coded value.
However it also has a compatibility problem. Some applications might
started depend on the default value is tunable.
The solution is to separate default value from maximum value.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Joe Korty <joe.korty@ccur.com>
Cc: Amerigo Wang <amwang@redhat.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
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* Copyright (C) 2007 IBM Corporation
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*
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* Author: Cedric Le Goater <clg@fr.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#include <linux/nsproxy.h>
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#include <linux/ipc_namespace.h>
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#include <linux/sysctl.h>
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#ifdef CONFIG_PROC_SYSCTL
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static void *get_mq(ctl_table *table)
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{
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char *which = table->data;
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struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
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which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
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return which;
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}
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static int proc_mq_dointvec_minmax(ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table mq_table;
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memcpy(&mq_table, table, sizeof(mq_table));
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mq_table.data = get_mq(table);
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return proc_dointvec_minmax(&mq_table, write, buffer,
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lenp, ppos);
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}
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#else
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#define proc_mq_dointvec_minmax NULL
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#endif
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static int msg_queues_limit_min = MIN_QUEUESMAX;
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static int msg_queues_limit_max = HARD_QUEUESMAX;
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static int msg_max_limit_min = MIN_MSGMAX;
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static int msg_max_limit_max = HARD_MSGMAX;
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static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
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static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
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static ctl_table mq_sysctls[] = {
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{
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.procname = "queues_max",
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.data = &init_ipc_ns.mq_queues_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_queues_limit_min,
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.extra2 = &msg_queues_limit_max,
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},
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{
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.procname = "msg_max",
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.data = &init_ipc_ns.mq_msg_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_max_limit_min,
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.extra2 = &msg_max_limit_max,
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},
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{
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.procname = "msgsize_max",
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.data = &init_ipc_ns.mq_msgsize_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_maxsize_limit_min,
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.extra2 = &msg_maxsize_limit_max,
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},
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{
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.procname = "msg_default",
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.data = &init_ipc_ns.mq_msg_default,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_max_limit_min,
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.extra2 = &msg_max_limit_max,
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},
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{
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.procname = "msgsize_default",
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.data = &init_ipc_ns.mq_msgsize_default,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_maxsize_limit_min,
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.extra2 = &msg_maxsize_limit_max,
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},
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{}
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};
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static ctl_table mq_sysctl_dir[] = {
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{
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.procname = "mqueue",
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.mode = 0555,
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.child = mq_sysctls,
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},
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{}
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};
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static ctl_table mq_sysctl_root[] = {
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{
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.procname = "fs",
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.mode = 0555,
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.child = mq_sysctl_dir,
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},
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{}
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};
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struct ctl_table_header *mq_register_sysctl_table(void)
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{
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return register_sysctl_table(mq_sysctl_root);
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}
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