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-rw-r--r--Documentation/sysctl/fs.txt7
-rw-r--r--include/linux/ipc_namespace.h2
-rw-r--r--ipc/mq_sysctl.c18
-rw-r--r--ipc/mqueue.c9
4 files changed, 33 insertions, 3 deletions
diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt
index 88fd7f5c8dc..13d6166d7a2 100644
--- a/Documentation/sysctl/fs.txt
+++ b/Documentation/sysctl/fs.txt
@@ -225,6 +225,13 @@ a queue must be less or equal then msg_max.
maximum message size value (it is every message queue's attribute set during
its creation).
+/proc/sys/fs/mqueue/msg_default is a read/write file for setting/getting the
+default number of messages in a queue value if attr parameter of mq_open(2) is
+NULL. If it exceed msg_max, the default value is initialized msg_max.
+
+/proc/sys/fs/mqueue/msgsize_default is a read/write file for setting/getting
+the default message size value if attr parameter of mq_open(2) is NULL. If it
+exceed msgsize_max, the default value is initialized msgsize_max.
4. /proc/sys/fs/epoll - Configuration options for the epoll interface
--------------------------------------------------------
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 2488535a32a..5499c92a915 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -62,6 +62,8 @@ struct ipc_namespace {
unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
+ unsigned int mq_msg_default;
+ unsigned int mq_msgsize_default;
/* user_ns which owns the ipc ns */
struct user_namespace *user_ns;
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
index e22336a09b4..383d638340b 100644
--- a/ipc/mq_sysctl.c
+++ b/ipc/mq_sysctl.c
@@ -73,6 +73,24 @@ static ctl_table mq_sysctls[] = {
.extra1 = &msg_maxsize_limit_min,
.extra2 = &msg_maxsize_limit_max,
},
+ {
+ .procname = "msg_default",
+ .data = &init_ipc_ns.mq_msg_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_default",
+ .data = &init_ipc_ns.mq_msgsize_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_mq_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
{}
};
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 6828e2c93ce..609d53f7a91 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -145,9 +145,10 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->qsize = 0;
info->user = NULL; /* set when all is ok */
memset(&info->attr, 0, sizeof(info->attr));
- info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, DFLT_MSG);
- info->attr.mq_msgsize =
- min(ipc_ns->mq_msgsize_max, DFLT_MSGSIZE);
+ info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
if (attr) {
info->attr.mq_maxmsg = attr->mq_maxmsg;
info->attr.mq_msgsize = attr->mq_msgsize;
@@ -1261,6 +1262,8 @@ int mq_init_ns(struct ipc_namespace *ns)
ns->mq_queues_max = DFLT_QUEUESMAX;
ns->mq_msg_max = DFLT_MSGMAX;
ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+ ns->mq_msg_default = DFLT_MSG;
+ ns->mq_msgsize_default = DFLT_MSGSIZE;
ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
if (IS_ERR(ns->mq_mnt)) {