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-rw-r--r--ipc/mqueue.c173
1 files changed, 130 insertions, 43 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 609d53f7a915..3c72a05dc326 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -50,6 +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;
@@ -62,7 +68,7 @@ struct mqueue_inode_info {
struct inode vfs_inode;
wait_queue_head_t wait_q;
- struct msg_msg **messages;
+ struct rb_root msg_tree;
struct mq_attr attr;
struct sigevent notify;
@@ -110,6 +116,90 @@ 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;
+ }
+ leaf = kzalloc(sizeof(*leaf), GFP_ATOMIC);
+ if (!leaf)
+ return -ENOMEM;
+ rb_init_node(&leaf->rb_node);
+ INIT_LIST_HEAD(&leaf->msg_list);
+ leaf->priority = msg->m_type;
+ rb_link_node(&leaf->rb_node, parent, p);
+ rb_insert_color(&leaf->rb_node, &info->msg_tree);
+ info->qsize += sizeof(struct posix_msg_tree_node);
+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 (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);
+ info->qsize -= sizeof(struct posix_msg_tree_node);
+ kfree(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);
+ info->qsize -= sizeof(struct posix_msg_tree_node);
+ kfree(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)
@@ -130,7 +220,7 @@ 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;
@@ -144,6 +234,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->notify_user_ns = NULL;
info->qsize = 0;
info->user = NULL; /* set when all is ok */
+ info->msg_tree = RB_ROOT;
memset(&info->attr, 0, sizeof(info->attr));
info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
ipc_ns->mq_msg_default);
@@ -153,16 +244,25 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
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 *);
- if (mq_msg_tblsz > PAGE_SIZE)
- info->messages = vmalloc(mq_msg_tblsz);
- else
- 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 ||
@@ -253,9 +353,9 @@ 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;
clear_inode(inode);
@@ -265,17 +365,18 @@ 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]);
- if (is_vmalloc_addr(info->messages))
- vfree(info->messages);
- else
- kfree(info->messages);
+ while ((msg = msg_get(info)) != NULL)
+ free_msg(msg);
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);
@@ -495,26 +596,6 @@ 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)
{
@@ -848,7 +929,8 @@ 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);
@@ -936,7 +1018,12 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
pipelined_send(info, msg_ptr, receiver);
} else {
/* adds message to the queue */
- msg_insert(msg_ptr, info);
+ if (msg_insert(msg_ptr, info)) {
+ free_msg(msg_ptr);
+ ret = -ENOMEM;
+ spin_unlock(&info->lock);
+ goto out_fput;
+ }
__do_notify(info);
}
inode->i_atime = inode->i_mtime = inode->i_ctime =