mqueue: apply mathematics distributivity on mq_bytes calculation

[safe/jmp/linux-2.6] / ipc / mqueue.c

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index c82d7b5..15eabf9 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -47,15 +47,6 @@
 #define STATE_PENDING  1
 #define STATE_READY    2
 
-/*
- * Define the ranges various user-specified maximum values can
- * be set to.
- */
-#define MIN_MSGMAX     1               /* min value for msg_max */
-#define MAX_MSGMAX     HARD_MSGMAX     /* max value for msg_max */
-#define MIN_MSGSIZEMAX 128             /* min value for msgsize_max */
-#define MAX_MSGSIZEMAX (8192*128)      /* max value for msgsize_max */
-
 struct ext_wait_queue {                /* queue of sleeping tasks */
        struct task_struct *task;
        struct list_head list;
@@ -85,7 +76,7 @@ struct mqueue_inode_info {
 
 static const struct inode_operations mqueue_dir_inode_operations;
 static const struct file_operations mqueue_file_operations;
-static struct super_operations mqueue_super_ops;
+static const struct super_operations mqueue_super_ops;
 static void remove_notification(struct mqueue_inode_info *info);
 
 static struct kmem_cache *mqueue_inode_cachep;
@@ -143,7 +134,6 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
                        init_waitqueue_head(&info->wait_q);
                        INIT_LIST_HEAD(&info->e_wait_q[0].list);
                        INIT_LIST_HEAD(&info->e_wait_q[1].list);
-                       info->messages = NULL;
                        info->notify_owner = NULL;
                        info->qsize = 0;
                        info->user = NULL;      /* set when all is ok */
@@ -155,6 +145,10 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
                                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;
+
                        mq_bytes = (mq_msg_tblsz +
                                (info->attr.mq_maxmsg * info->attr.mq_msgsize));
 
@@ -163,18 +157,12 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
                            u->mq_bytes + mq_bytes >
                            p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
                                spin_unlock(&mq_lock);
+                               kfree(info->messages);
                                goto out_inode;
                        }
                        u->mq_bytes += mq_bytes;
                        spin_unlock(&mq_lock);
 
-                       info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
-                       if (!info->messages) {
-                               spin_lock(&mq_lock);
-                               u->mq_bytes -= mq_bytes;
-                               spin_unlock(&mq_lock);
-                               goto out_inode;
-                       }
                        /* all is ok */
                        info->user = get_uid(u);
                } else if (S_ISDIR(mode)) {
@@ -273,8 +261,9 @@ static void mqueue_delete_inode(struct inode *inode)
 
        clear_inode(inode);
 
-       mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) +
-                  (info->attr.mq_maxmsg * info->attr.mq_msgsize));
+       /* Total amount of bytes accounted for the mqueue */
+       mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
+           + info->attr.mq_msgsize);
        user = info->user;
        if (user) {
                spin_lock(&mq_lock);
@@ -613,8 +602,8 @@ static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
        /* check for overflow */
        if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
                return 0;
-       if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) +
-           (attr->mq_maxmsg * sizeof (struct msg_msg *)) <
+       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;
@@ -714,7 +703,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
        dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
        if (IS_ERR(dentry)) {
                error = PTR_ERR(dentry);
-               goto out_err;
+               goto out_putfd;
        }
        mntget(ipc_ns->mq_mnt);
 
@@ -751,7 +740,6 @@ out:
        mntput(ipc_ns->mq_mnt);
 out_putfd:
        put_unused_fd(fd);
-out_err:
        fd = error;
 out_upsem:
        mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
@@ -1231,7 +1219,7 @@ static const struct file_operations mqueue_file_operations = {
        .read = mqueue_read_file,
 };
 
-static struct super_operations mqueue_super_ops = {
+static const struct super_operations mqueue_super_ops = {
        .alloc_inode = mqueue_alloc_inode,
        .destroy_inode = mqueue_destroy_inode,
        .statfs = simple_statfs,
@@ -1271,60 +1259,6 @@ void mq_put_mnt(struct ipc_namespace *ns)
        mntput(ns->mq_mnt);
 }
 
-static int msg_max_limit_min = MIN_MSGMAX;
-static int msg_max_limit_max = MAX_MSGMAX;
-
-static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
-static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
-
-static ctl_table mq_sysctls[] = {
-       {
-               .procname       = "queues_max",
-               .data           = &init_ipc_ns.mq_queues_max,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = &proc_dointvec,
-       },
-       {
-               .procname       = "msg_max",
-               .data           = &init_ipc_ns.mq_msg_max,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = &proc_dointvec_minmax,
-               .extra1         = &msg_max_limit_min,
-               .extra2         = &msg_max_limit_max,
-       },
-       {
-               .procname       = "msgsize_max",
-               .data           = &init_ipc_ns.mq_msgsize_max,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = &proc_dointvec_minmax,
-               .extra1         = &msg_maxsize_limit_min,
-               .extra2         = &msg_maxsize_limit_max,
-       },
-       { .ctl_name = 0 }
-};
-
-static ctl_table mq_sysctl_dir[] = {
-       {
-               .procname       = "mqueue",
-               .mode           = 0555,
-               .child          = mq_sysctls,
-       },
-       { .ctl_name = 0 }
-};
-
-static ctl_table mq_sysctl_root[] = {
-       {
-               .ctl_name       = CTL_FS,
-               .procname       = "fs",
-               .mode           = 0555,
-               .child          = mq_sysctl_dir,
-       },
-       { .ctl_name = 0 }
-};
-
 static int __init init_mqueue_fs(void)
 {
        int error;
@@ -1336,7 +1270,7 @@ static int __init init_mqueue_fs(void)
                return -ENOMEM;
 
        /* ignore failues - they are not fatal */
-       mq_sysctl_table = register_sysctl_table(mq_sysctl_root);
+       mq_sysctl_table = mq_register_sysctl_table();
 
        error = register_filesystem(&mqueue_fs_type);
        if (error)