1 files changed, 288 insertions, 133 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 28bd64ddeda..f8e54f5b908 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -24,6 +24,7 @@
 #include <linux/mqueue.h>
 #include <linux/msg.h>
 #include <linux/skbuff.h>
+#include <linux/vmalloc.h>
 #include <linux/netlink.h>
 #include <linux/syscalls.h>
 #include <linux/audit.h>
@@ -49,6 +50,12 @@
 #define STATE_PENDING	1
 #define STATE_READY	2
 
+struct posix_msg_tree_node {
+	struct rb_node		rb_node;
+	struct list_head	msg_list;
+	int			priority;
+};
+
 struct ext_wait_queue {		/* queue of sleeping tasks */
 	struct task_struct *task;
 	struct list_head list;
@@ -61,11 +68,13 @@ struct mqueue_inode_info {
 	struct inode vfs_inode;
 	wait_queue_head_t wait_q;
 
-	struct msg_msg **messages;
+	struct rb_root msg_tree;
+	struct posix_msg_tree_node *node_cache;
 	struct mq_attr attr;
 
 	struct sigevent notify;
 	struct pid* notify_owner;
+	struct user_namespace *notify_user_ns;
 	struct user_struct *user;	/* user who created, for accounting */
 	struct sock *notify_sock;
 	struct sk_buff *notify_cookie;
@@ -108,6 +117,103 @@ static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
 	return ns;
 }
 
+/* Auxiliary functions to manipulate messages' list */
+static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
+{
+	struct rb_node **p, *parent = NULL;
+	struct posix_msg_tree_node *leaf;
+
+	p = &info->msg_tree.rb_node;
+	while (*p) {
+		parent = *p;
+		leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+
+		if (likely(leaf->priority == msg->m_type))
+			goto insert_msg;
+		else if (msg->m_type < leaf->priority)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+	if (info->node_cache) {
+		leaf = info->node_cache;
+		info->node_cache = NULL;
+	} else {
+		leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
+		if (!leaf)
+			return -ENOMEM;
+		rb_init_node(&leaf->rb_node);
+		INIT_LIST_HEAD(&leaf->msg_list);
+		info->qsize += sizeof(*leaf);
+	}
+	leaf->priority = msg->m_type;
+	rb_link_node(&leaf->rb_node, parent, p);
+	rb_insert_color(&leaf->rb_node, &info->msg_tree);
+insert_msg:
+	info->attr.mq_curmsgs++;
+	info->qsize += msg->m_ts;
+	list_add_tail(&msg->m_list, &leaf->msg_list);
+	return 0;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+	struct rb_node **p, *parent = NULL;
+	struct posix_msg_tree_node *leaf;
+	struct msg_msg *msg;
+
+try_again:
+	p = &info->msg_tree.rb_node;
+	while (*p) {
+		parent = *p;
+		/*
+		 * During insert, low priorities go to the left and high to the
+		 * right.  On receive, we want the highest priorities first, so
+		 * walk all the way to the right.
+		 */
+		p = &(*p)->rb_right;
+	}
+	if (!parent) {
+		if (info->attr.mq_curmsgs) {
+			pr_warn_once("Inconsistency in POSIX message queue, "
+				     "no tree element, but supposedly messages "
+				     "should exist!\n");
+			info->attr.mq_curmsgs = 0;
+		}
+		return NULL;
+	}
+	leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
+	if (unlikely(list_empty(&leaf->msg_list))) {
+		pr_warn_once("Inconsistency in POSIX message queue, "
+			     "empty leaf node but we haven't implemented "
+			     "lazy leaf delete!\n");
+		rb_erase(&leaf->rb_node, &info->msg_tree);
+		if (info->node_cache) {
+			info->qsize -= sizeof(*leaf);
+			kfree(leaf);
+		} else {
+			info->node_cache = leaf;
+		}
+		goto try_again;
+	} else {
+		msg = list_first_entry(&leaf->msg_list,
+				       struct msg_msg, m_list);
+		list_del(&msg->m_list);
+		if (list_empty(&leaf->msg_list)) {
+			rb_erase(&leaf->rb_node, &info->msg_tree);
+			if (info->node_cache) {
+				info->qsize -= sizeof(*leaf);
+				kfree(leaf);
+			} else {
+				info->node_cache = leaf;
+			}
+		}
+	}
+	info->attr.mq_curmsgs--;
+	info->qsize -= msg->m_ts;
+	return msg;
+}
+
 static struct inode *mqueue_get_inode(struct super_block *sb,
 		struct ipc_namespace *ipc_ns, umode_t mode,
 		struct mq_attr *attr)
@@ -128,7 +234,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
 
 	if (S_ISREG(mode)) {
 		struct mqueue_inode_info *info;
-		unsigned long mq_bytes, mq_msg_tblsz;
+		unsigned long mq_bytes, mq_treesize;
 
 		inode->i_fop = &mqueue_file_operations;
 		inode->i_size = FILENT_SIZE;
@@ -139,22 +245,39 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
 		INIT_LIST_HEAD(&info->e_wait_q[0].list);
 		INIT_LIST_HEAD(&info->e_wait_q[1].list);
 		info->notify_owner = NULL;
+		info->notify_user_ns = NULL;
 		info->qsize = 0;
 		info->user = NULL;	/* set when all is ok */
+		info->msg_tree = RB_ROOT;
+		info->node_cache = NULL;
 		memset(&info->attr, 0, sizeof(info->attr));
-		info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
-		info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
+		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;
 		}
-		mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
-		info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
-		if (!info->messages)
-			goto out_inode;
+		/*
+		 * We used to allocate a static array of pointers and account
+		 * the size of that array as well as one msg_msg struct per
+		 * possible message into the queue size. That's no longer
+		 * accurate as the queue is now an rbtree and will grow and
+		 * shrink depending on usage patterns.  We can, however, still
+		 * account one msg_msg struct per message, but the nodes are
+		 * allocated depending on priority usage, and most programs
+		 * only use one, or a handful, of priorities.  However, since
+		 * this is pinned memory, we need to assume worst case, so
+		 * that means the min(mq_maxmsg, max_priorities) * struct
+		 * posix_msg_tree_node.
+		 */
+		mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+			min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+			sizeof(struct posix_msg_tree_node);
 
-		mq_bytes = (mq_msg_tblsz +
-			(info->attr.mq_maxmsg * info->attr.mq_msgsize));
+		mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+					  info->attr.mq_msgsize);
 
 		spin_lock(&mq_lock);
 		if (u->mq_bytes + mq_bytes < u->mq_bytes ||
@@ -245,11 +368,11 @@ static void mqueue_evict_inode(struct inode *inode)
 {
 	struct mqueue_inode_info *info;
 	struct user_struct *user;
-	unsigned long mq_bytes;
-	int i;
+	unsigned long mq_bytes, mq_treesize;
 	struct ipc_namespace *ipc_ns;
+	struct msg_msg *msg;
 
-	end_writeback(inode);
+	clear_inode(inode);
 
 	if (S_ISDIR(inode->i_mode))
 		return;
@@ -257,14 +380,19 @@ static void mqueue_evict_inode(struct inode *inode)
 	ipc_ns = get_ns_from_inode(inode);
 	info = MQUEUE_I(inode);
 	spin_lock(&info->lock);
-	for (i = 0; i < info->attr.mq_curmsgs; i++)
-		free_msg(info->messages[i]);
-	kfree(info->messages);
+	while ((msg = msg_get(info)) != NULL)
+		free_msg(msg);
+	kfree(info->node_cache);
 	spin_unlock(&info->lock);
 
 	/* Total amount of bytes accounted for the mqueue */
-	mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
-	    + info->attr.mq_msgsize);
+	mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+		min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+		sizeof(struct posix_msg_tree_node);
+
+	mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+				  info->attr.mq_msgsize);
+
 	user = info->user;
 	if (user) {
 		spin_lock(&mq_lock);
@@ -285,7 +413,7 @@ static void mqueue_evict_inode(struct inode *inode)
 }
 
 static int mqueue_create(struct inode *dir, struct dentry *dentry,
-				umode_t mode, struct nameidata *nd)
+				umode_t mode, bool excl)
 {
 	struct inode *inode;
 	struct mq_attr *attr = dentry->d_fsdata;
@@ -298,8 +426,9 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
 		error = -EACCES;
 		goto out_unlock;
 	}
-	if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
-			!capable(CAP_SYS_RESOURCE)) {
+	if (ipc_ns->mq_queues_count >= HARD_QUEUESMAX ||
+	    (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
+	     !capable(CAP_SYS_RESOURCE))) {
 		error = -ENOSPC;
 		goto out_unlock;
 	}
@@ -483,26 +612,6 @@ static struct ext_wait_queue *wq_get_first_waiter(
 	return list_entry(ptr, struct ext_wait_queue, list);
 }
 
-/* Auxiliary functions to manipulate messages' list */
-static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
-{
-	int k;
-
-	k = info->attr.mq_curmsgs - 1;
-	while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
-		info->messages[k + 1] = info->messages[k];
-		k--;
-	}
-	info->attr.mq_curmsgs++;
-	info->qsize += ptr->m_ts;
-	info->messages[k + 1] = ptr;
-}
-
-static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
-{
-	info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
-	return info->messages[info->attr.mq_curmsgs];
-}
 
 static inline void set_cookie(struct sk_buff *skb, char code)
 {
@@ -536,8 +645,7 @@ static void __do_notify(struct mqueue_inode_info *info)
 			rcu_read_lock();
 			sig_i.si_pid = task_tgid_nr_ns(current,
 						ns_of_pid(info->notify_owner));
-			sig_i.si_uid = user_ns_map_uid(info->user->user_ns,
-						current_cred(), current_uid());
+			sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid());
 			rcu_read_unlock();
 
 			kill_pid_info(info->notify.sigev_signo,
@@ -550,7 +658,9 @@ static void __do_notify(struct mqueue_inode_info *info)
 		}
 		/* after notification unregisters process */
 		put_pid(info->notify_owner);
+		put_user_ns(info->notify_user_ns);
 		info->notify_owner = NULL;
+		info->notify_user_ns = NULL;
 	}
 	wake_up(&info->wait_q);
 }
@@ -575,36 +685,44 @@ static void remove_notification(struct mqueue_inode_info *info)
 		netlink_sendskb(info->notify_sock, info->notify_cookie);
 	}
 	put_pid(info->notify_owner);
+	put_user_ns(info->notify_user_ns);
 	info->notify_owner = NULL;
+	info->notify_user_ns = NULL;
 }
 
 static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
 {
+	int mq_treesize;
+	unsigned long total_size;
+
 	if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
-		return 0;
+		return -EINVAL;
 	if (capable(CAP_SYS_RESOURCE)) {
-		if (attr->mq_maxmsg > HARD_MSGMAX)
-			return 0;
+		if (attr->mq_maxmsg > HARD_MSGMAX ||
+		    attr->mq_msgsize > HARD_MSGSIZEMAX)
+			return -EINVAL;
 	} else {
 		if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
 				attr->mq_msgsize > ipc_ns->mq_msgsize_max)
-			return 0;
+			return -EINVAL;
 	}
 	/* check for overflow */
 	if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
-		return 0;
-	if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
-	    + sizeof (struct msg_msg *))) <
-	    (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
-		return 0;
-	return 1;
+		return -EOVERFLOW;
+	mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) +
+		min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) *
+		sizeof(struct posix_msg_tree_node);
+	total_size = attr->mq_maxmsg * attr->mq_msgsize;
+	if (total_size + mq_treesize < total_size)
+		return -EOVERFLOW;
+	return 0;
 }
 
 /*
  * Invoked when creating a new queue via sys_mq_open
  */
-static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
-			struct dentry *dentry, int oflag, umode_t mode,
+static struct file *do_create(struct ipc_namespace *ipc_ns, struct inode *dir,
+			struct path *path, int oflag, umode_t mode,
 			struct mq_attr *attr)
 {
 	const struct cred *cred = current_cred();
@@ -612,76 +730,65 @@ static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
 	int ret;
 
 	if (attr) {
-		if (!mq_attr_ok(ipc_ns, attr)) {
-			ret = -EINVAL;
-			goto out;
-		}
+		ret = mq_attr_ok(ipc_ns, attr);
+		if (ret)
+			return ERR_PTR(ret);
 		/* store for use during create */
-		dentry->d_fsdata = attr;
+		path->dentry->d_fsdata = attr;
+	} else {
+		struct mq_attr def_attr;
+
+		def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+					 ipc_ns->mq_msg_default);
+		def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+					  ipc_ns->mq_msgsize_default);
+		ret = mq_attr_ok(ipc_ns, &def_attr);
+		if (ret)
+			return ERR_PTR(ret);
 	}
 
 	mode &= ~current_umask();
-	ret = mnt_want_write(ipc_ns->mq_mnt);
-	if (ret)
-		goto out;
-	ret = vfs_create(dir->d_inode, dentry, mode, NULL);
-	dentry->d_fsdata = NULL;
+	ret = mnt_want_write(path->mnt);
 	if (ret)
-		goto out_drop_write;
-
-	result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
+		return ERR_PTR(ret);
+	ret = vfs_create(dir, path->dentry, mode, true);
+	path->dentry->d_fsdata = NULL;
+	if (!ret)
+		result = dentry_open(path, oflag, cred);
+	else
+		result = ERR_PTR(ret);
 	/*
 	 * dentry_open() took a persistent mnt_want_write(),
 	 * so we can now drop this one.
 	 */
-	mnt_drop_write(ipc_ns->mq_mnt);
+	mnt_drop_write(path->mnt);
 	return result;
-
-out_drop_write:
-	mnt_drop_write(ipc_ns->mq_mnt);
-out:
-	dput(dentry);
-	mntput(ipc_ns->mq_mnt);
-	return ERR_PTR(ret);
 }
 
 /* Opens existing queue */
-static struct file *do_open(struct ipc_namespace *ipc_ns,
-				struct dentry *dentry, int oflag)
+static struct file *do_open(struct path *path, int oflag)
 {
-	int ret;
-	const struct cred *cred = current_cred();
-
 	static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
 						  MAY_READ | MAY_WRITE };
-
-	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
-		ret = -EINVAL;
-		goto err;
-	}
-
-	if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
-		ret = -EACCES;
-		goto err;
-	}
-
-	return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
-
-err:
-	dput(dentry);
-	mntput(ipc_ns->mq_mnt);
-	return ERR_PTR(ret);
+	int acc;
+	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+		return ERR_PTR(-EINVAL);
+	acc = oflag2acc[oflag & O_ACCMODE];
+	if (inode_permission(path->dentry->d_inode, acc))
+		return ERR_PTR(-EACCES);
+	return dentry_open(path, oflag, current_cred());
 }
 
 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
 		struct mq_attr __user *, u_attr)
 {
-	struct dentry *dentry;
+	struct path path;
 	struct file *filp;
 	char *name;
 	struct mq_attr attr;
 	int fd, error;
 	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
+	struct dentry *root = ipc_ns->mq_mnt->mnt_root;
 
 	if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
 		return -EFAULT;
@@ -695,52 +802,49 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
 	if (fd < 0)
 		goto out_putname;
 
-	mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
-	dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
-	if (IS_ERR(dentry)) {
-		error = PTR_ERR(dentry);
+	error = 0;
+	mutex_lock(&root->d_inode->i_mutex);
+	path.dentry = lookup_one_len(name, root, strlen(name));
+	if (IS_ERR(path.dentry)) {
+		error = PTR_ERR(path.dentry);
 		goto out_putfd;
 	}
-	mntget(ipc_ns->mq_mnt);
+	path.mnt = mntget(ipc_ns->mq_mnt);
 
 	if (oflag & O_CREAT) {
-		if (dentry->d_inode) {	/* entry already exists */
-			audit_inode(name, dentry);
+		if (path.dentry->d_inode) {	/* entry already exists */
+			audit_inode(name, path.dentry);
 			if (oflag & O_EXCL) {
 				error = -EEXIST;
 				goto out;
 			}
-			filp = do_open(ipc_ns, dentry, oflag);
+			filp = do_open(&path, oflag);
 		} else {
-			filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
-						dentry, oflag, mode,
+			filp = do_create(ipc_ns, root->d_inode,
+						&path, oflag, mode,
 						u_attr ? &attr : NULL);
 		}
 	} else {
-		if (!dentry->d_inode) {
+		if (!path.dentry->d_inode) {
 			error = -ENOENT;
 			goto out;
 		}
-		audit_inode(name, dentry);
-		filp = do_open(ipc_ns, dentry, oflag);
+		audit_inode(name, path.dentry);
+		filp = do_open(&path, oflag);
 	}
 
-	if (IS_ERR(filp)) {
+	if (!IS_ERR(filp))
+		fd_install(fd, filp);
+	else
 		error = PTR_ERR(filp);
-		goto out_putfd;
-	}
-
-	fd_install(fd, filp);
-	goto out_upsem;
-
 out:
-	dput(dentry);
-	mntput(ipc_ns->mq_mnt);
+	path_put(&path);
 out_putfd:
-	put_unused_fd(fd);
-	fd = error;
-out_upsem:
-	mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
+	if (error) {
+		put_unused_fd(fd);
+		fd = error;
+	}
+	mutex_unlock(&root->d_inode->i_mutex);
 out_putname:
 	putname(name);
 	return fd;
@@ -832,7 +936,8 @@ static inline void pipelined_receive(struct mqueue_inode_info *info)
 		wake_up_interruptible(&info->wait_q);
 		return;
 	}
-	msg_insert(sender->msg, info);
+	if (msg_insert(sender->msg, info))
+		return;
 	list_del(&sender->list);
 	sender->state = STATE_PENDING;
 	wake_up_process(sender->task);
@@ -852,7 +957,8 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
 	struct mqueue_inode_info *info;
 	ktime_t expires, *timeout = NULL;
 	struct timespec ts;
-	int ret;
+	struct posix_msg_tree_node *new_leaf = NULL;
+	int ret = 0;
 
 	if (u_abs_timeout) {
 		int res = prepare_timeout(u_abs_timeout, &expires, &ts);
@@ -900,34 +1006,60 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
 	msg_ptr->m_ts = msg_len;
 	msg_ptr->m_type = msg_prio;
 
+	/*
+	 * msg_insert really wants us to have a valid, spare node struct so
+	 * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+	 * fall back to that if necessary.
+	 */
+	if (!info->node_cache)
+		new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
 	spin_lock(&info->lock);
 
+	if (!info->node_cache && new_leaf) {
+		/* Save our speculative allocation into the cache */
+		rb_init_node(&new_leaf->rb_node);
+		INIT_LIST_HEAD(&new_leaf->msg_list);
+		info->node_cache = new_leaf;
+		info->qsize += sizeof(*new_leaf);
+		new_leaf = NULL;
+	} else {
+		kfree(new_leaf);
+	}
+
 	if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
 		if (filp->f_flags & O_NONBLOCK) {
-			spin_unlock(&info->lock);
 			ret = -EAGAIN;
 		} else {
 			wait.task = current;
 			wait.msg = (void *) msg_ptr;
 			wait.state = STATE_NONE;
 			ret = wq_sleep(info, SEND, timeout, &wait);
+			/*
+			 * wq_sleep must be called with info->lock held, and
+			 * returns with the lock released
+			 */
+			goto out_free;
 		}
-		if (ret < 0)
-			free_msg(msg_ptr);
 	} else {
 		receiver = wq_get_first_waiter(info, RECV);
 		if (receiver) {
 			pipelined_send(info, msg_ptr, receiver);
 		} else {
 			/* adds message to the queue */
-			msg_insert(msg_ptr, info);
+			ret = msg_insert(msg_ptr, info);
+			if (ret)
+				goto out_unlock;
 			__do_notify(info);
 		}
 		inode->i_atime = inode->i_mtime = inode->i_ctime =
 				CURRENT_TIME;
-		spin_unlock(&info->lock);
-		ret = 0;
 	}
+out_unlock:
+	spin_unlock(&info->lock);
+out_free:
+	if (ret)
+		free_msg(msg_ptr);
 out_fput:
 	fput(filp);
 out:
@@ -946,6 +1078,7 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
 	struct ext_wait_queue wait;
 	ktime_t expires, *timeout = NULL;
 	struct timespec ts;
+	struct posix_msg_tree_node *new_leaf = NULL;
 
 	if (u_abs_timeout) {
 		int res = prepare_timeout(u_abs_timeout, &expires, &ts);
@@ -981,7 +1114,26 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
 		goto out_fput;
 	}
 
+	/*
+	 * msg_insert really wants us to have a valid, spare node struct so
+	 * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
+	 * fall back to that if necessary.
+	 */
+	if (!info->node_cache)
+		new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
+
 	spin_lock(&info->lock);
+
+	if (!info->node_cache && new_leaf) {
+		/* Save our speculative allocation into the cache */
+		rb_init_node(&new_leaf->rb_node);
+		INIT_LIST_HEAD(&new_leaf->msg_list);
+		info->node_cache = new_leaf;
+		info->qsize += sizeof(*new_leaf);
+	} else {
+		kfree(new_leaf);
+	}
+
 	if (info->attr.mq_curmsgs == 0) {
 		if (filp->f_flags & O_NONBLOCK) {
 			spin_unlock(&info->lock);
@@ -1140,6 +1292,7 @@ retry:
 		}
 
 		info->notify_owner = get_pid(task_tgid(current));
+		info->notify_user_ns = get_user_ns(current_user_ns());
 		inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	}
 	spin_unlock(&info->lock);
@@ -1245,6 +1398,8 @@ 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)) {