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yaml
---
r: 309764
b: refs/heads/master
c: d662985
h: refs/heads/master
v: v3
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Doug Ledford authored and Linus Torvalds committed Jun 1, 2012
1 parent 0b585f0 commit 98cf88f
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Showing 2 changed files with 131 additions and 44 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 50069a5851323ba5def0e414a21e234345016870
refs/heads/master: d6629859b36d953a4b1369b749f178736911bf10
173 changes: 130 additions & 43 deletions trunk/ipc/mqueue.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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)
Expand All @@ -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;
Expand All @@ -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);
Expand All @@ -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 ||
Expand Down Expand Up @@ -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);

Expand All @@ -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);
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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 =
Expand Down

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