2003-11-25 11:43:52

by Michal Wronski

Subject: [PATCH] 2/2 POSIX message queues

diff -urN 2.6.0-test10-orig_2/arch/i386/kernel/entry.S 2.6.0-test10-patched_2/arch/i386/kernel/entry.S
--- 2.6.0-test10-orig_2/arch/i386/kernel/entry.S 2003-11-24 16:28:52.000000000 +0100
+++ 2.6.0-test10-patched_2/arch/i386/kernel/entry.S 2003-11-24 16:46:44.000000000 +0100
@@ -882,5 +882,12 @@
.long sys_utimes
.long sys_fadvise64_64
.long sys_ni_syscall /* sys_vserver */
+ .long sys_mq_open
+ .long sys_mq_unlink /* 275 */
+ .long sys_mq_timedsend
+ .long sys_mq_timedreceive
+ .long sys_mq_notify
+ .long sys_mq_getattr
+ .long sys_mq_setattr

syscall_table_size=(.-sys_call_table)
diff -urN 2.6.0-test10-orig_2/CREDITS 2.6.0-test10-patched_2/CREDITS
--- 2.6.0-test10-orig_2/CREDITS 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/CREDITS 2003-11-21 16:48:21.000000000 +0100
@@ -289,6 +289,15 @@
S: Terni 05100
S: Italy

+N: Krzysztof Benedyczak
+E: [email protected]
+W: http://www.mat.uni.torun.pl/~golbi
+D: POSIX message queues fs (with M. Wronski)
+S: ul. Podmiejska 52
+S: Radunica
+S: 83-000 Pruszcz Gdanski
+S: Poland
+
N: Randolph Bentson
E: [email protected]
W: http://www.aa.net/~bentson/
@@ -3475,6 +3484,14 @@
S: Beaverton, OR 97005
S: USA

+N: Michal Wronski
+E: [email protected]
+W: http://www.mat.uni.torun.pl/~wrona
+D: POSIX message queues fs (with K. Benedyczak)
+S: ul. Teczowa 23/12
+S: 80-680 Gdansk-Sobieszewo
+S: Poland
+
N: Frank Xia
E: [email protected]
D: Xiafs filesystem [defunct]
diff -urN 2.6.0-test10-orig_2/Documentation/filesystems/proc.txt 2.6.0-test10-patched_2/Documentation/filesystems/proc.txt
--- 2.6.0-test10-orig_2/Documentation/filesystems/proc.txt 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/Documentation/filesystems/proc.txt 2003-11-24 17:37:30.000000000 +0100
@@ -38,6 +38,7 @@
2.8 /proc/sys/net/ipv4 - IPV4 settings
2.9 Appletalk
2.10 IPX
+ 2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem

------------------------------------------------------------------------------
Preface
@@ -1805,6 +1806,30 @@
gives the destination network, the router node (or Directly) and the network
address of the router (or Connected) for internal networks.

+2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem
+----------------------------------------------------------
+
+The "mqueue" filesystem provides the necessary kernel features to enable the
+creation of a user space library that implements the POSIX message queues
+API (as noted by the MSG tag in the POSIX 1003.1-2001 version of the System
+Interfaces specification.)
+
+The "mqueue" filesystem contains values for determining/setting the amount of
+resources used by the file system.
+
+/proc/sys/fs/mqueue/queues_max is a read/write file for setting/getting the
+maximum number of message queues allowed on the system.
+
+/proc/sys/fs/mqueue/msg_max is a read/write file for setting/getting the
+maximum number of messages in a queue value. In fact it is the limiting value
+for another (user) limit which is set in mq_open invocation. This attribute of
+a queue must be less or equal then msg_max.
+
+/proc/sys/fs/mqueue/msgsize_max is a read/write file for setting/getting the
+maximum message size value (it is every message queue's attribute set during
+its creation).
+
+
------------------------------------------------------------------------------
Summary
------------------------------------------------------------------------------
diff -urN 2.6.0-test10-orig_2/fs/Kconfig 2.6.0-test10-patched_2/fs/Kconfig
--- 2.6.0-test10-orig_2/fs/Kconfig 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/fs/Kconfig 2003-11-21 16:59:14.000000000 +0100
@@ -893,6 +893,23 @@
To compile this as a module, choose M here: the module will be called
ramfs.

+config POSIX_MQUEUE_FS
+ bool "POSIX Message Queues"
+ ---help---
+ POSIX variant of message queues is a part of IPC. In POSIX message
+ queues every message has a priority which decides about succession
+ of receiving it by a process. If you want to compile and run
+ programs written e.g. for Solaris with use of its POSIX message
+ queues (functions mq_*) say Y here. To use this feature you will
+ also need mqueue library, available from
+ <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
+
+ POSIX message queues are visible as a filesystem called 'mqueue'
+ and can be mounted somewhere if you want to do filesystem
+ operations on message queues.
+
+ If unsure, say N.
+
endmenu

menu "Miscellaneous filesystems"
diff -urN 2.6.0-test10-orig_2/include/asm-generic/siginfo.h 2.6.0-test10-patched_2/include/asm-generic/siginfo.h
--- 2.6.0-test10-orig_2/include/asm-generic/siginfo.h 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/include/asm-generic/siginfo.h 2003-11-21 16:48:21.000000000 +0100
@@ -118,6 +118,7 @@
#define __SI_FAULT (3 << 16)
#define __SI_CHLD (4 << 16)
#define __SI_RT (5 << 16)
+#define __SI_MESGQ (6 << 16)
#define __SI_CODE(T,N) ((T) | ((N) & 0xffff))
#else
#define __SI_KILL 0
@@ -126,6 +127,7 @@
#define __SI_FAULT 0
#define __SI_CHLD 0
#define __SI_RT 0
+#define __SI_MESGQ 0
#define __SI_CODE(T,N) (N)
#endif

@@ -137,7 +139,7 @@
#define SI_KERNEL 0x80 /* sent by the kernel from somewhere */
#define SI_QUEUE -1 /* sent by sigqueue */
#define SI_TIMER __SI_CODE(__SI_TIMER,-2) /* sent by timer expiration */
-#define SI_MESGQ -3 /* sent by real time mesq state change */
+#define SI_MESGQ __SI_CODE(__SI_MESGQ,-3) /* sent by real time mesq state change */
#define SI_ASYNCIO -4 /* sent by AIO completion */
#define SI_SIGIO -5 /* sent by queued SIGIO */
#define SI_TKILL -6 /* sent by tkill system call */
diff -urN 2.6.0-test10-orig_2/include/asm-i386/unistd.h 2.6.0-test10-patched_2/include/asm-i386/unistd.h
--- 2.6.0-test10-orig_2/include/asm-i386/unistd.h 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/include/asm-i386/unistd.h 2003-11-21 16:48:21.000000000 +0100
@@ -279,8 +279,15 @@
#define __NR_utimes 271
#define __NR_fadvise64_64 272
#define __NR_vserver 273
-
-#define NR_syscalls 274
+#define __NR_mq_open 274
+#define __NR_mq_unlink (__NR_mq_open+1)
+#define __NR_mq_timedsend (__NR_mq_open+2)
+#define __NR_mq_timedreceive (__NR_mq_open+3)
+#define __NR_mq_notify (__NR_mq_open+4)
+#define __NR_mq_getattr (__NR_mq_open+5)
+#define __NR_mq_setattr (__NR_mq_open+6)
+
+#define NR_syscalls 281

/* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */

diff -urN 2.6.0-test10-orig_2/include/linux/mqueue.h 2.6.0-test10-patched_2/include/linux/mqueue.h
--- 2.6.0-test10-orig_2/include/linux/mqueue.h 1970-01-01 01:00:00.000000000 +0100
+++ 2.6.0-test10-patched_2/include/linux/mqueue.h 2003-11-24 16:37:46.000000000 +0100
@@ -0,0 +1,64 @@
+/* Copyright (C) 2003 Krzysztof Benedyczak & Michal Wronski
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ It is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this software; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _LINUX_MQUEUE_H
+#define _LINUX_MQUEUE_H
+
+#define MQ_PRIO_MAX 32768
+
+typedef int mqd_t;
+
+struct mq_attr {
+ long mq_flags; /* message queue flags */
+ long mq_maxmsg; /* maximum number of messages */
+ long mq_msgsize; /* maximum message size */
+ long mq_curmsgs; /* number of messages currently queued */
+};
+
+#ifdef __KERNEL__
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/signal.h>
+#include <linux/linkage.h>
+
+asmlinkage long sys_mq_open(const char __user *name, int oflag, mode_t mode, struct mq_attr __user *attr);
+asmlinkage long sys_mq_unlink(const char __user *name);
+asmlinkage long mq_timedsend(mqd_t mqdes, const char __user *msg_ptr, size_t msg_len, unsigned int msg_prio, const struct timespec __user *abs_timeout);
+asmlinkage ssize_t mq_timedreceive(mqd_t mqdes, char __user *msg_ptr, size_t msg_len, unsigned int __user *msg_prio, const struct timespec __user *abs_timeout);
+asmlinkage long mq_notify(mqd_t mqdes, const struct sigevent __user *notification);
+asmlinkage long mq_getattr(mqd_t mqdes, struct mq_attr __user *mqstat);
+asmlinkage long mq_setattr(mqd_t mqdes, const struct mq_attr __user *mqstat, struct mq_attr __user *omqstat);
+
+#else
+
+#include <signal.h>
+#include <fcntl.h>
+#include <time.h>
+
+mqd_t mq_open(const char *name, int oflag, /* mode_t mode, struct mq_attr *attr */ ...);
+int mq_close(mqd_t mqdes);
+int mq_unlink(const char *name);
+int mq_send(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned int msg_prio);
+int mq_timedsend(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout);
+ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned int *msg_prio);
+ssize_t mq_timedreceive(mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len, unsigned int *__restrict msg_prio, const struct timespec *__restrict abs_timeout);
+int mq_notify(mqd_t mqdes, const struct sigevent *notification);
+int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
+int mq_setattr(mqd_t mqdes, const struct mq_attr *__restrict mqstat, struct mq_attr *__restrict omqstat);
+#endif
+
+#endif
diff -urN 2.6.0-test10-orig_2/ipc/Makefile 2.6.0-test10-patched_2/ipc/Makefile
--- 2.6.0-test10-orig_2/ipc/Makefile 2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/Makefile 2003-11-21 16:48:21.000000000 +0100
@@ -5,3 +5,4 @@
obj-y := util.o

obj-$(CONFIG_SYSVIPC) += msg.o sem.o shm.o
+obj-$(CONFIG_POSIX_MQUEUE_FS) += mqueue.o
diff -urN 2.6.0-test10-orig_2/ipc/mqueue.c 2.6.0-test10-patched_2/ipc/mqueue.c
--- 2.6.0-test10-orig_2/ipc/mqueue.c 1970-01-01 01:00:00.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/mqueue.c 2003-11-24 16:37:46.000000000 +0100
@@ -0,0 +1,1260 @@
+/*
+ * POSIX message queues filesystem for Linux.
+ *
+ * Copyright (C) 2003 Krzysztof Benedyczak ([email protected])
+ * Michal Wronski ([email protected])
+ *
+ * Spinlocks: Mohamed Abbas ([email protected])
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/mqueue.h>
+#include <linux/msg.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/sysctl.h>
+#include "util.h"
+
+#define MQUEUE_MAGIC 0x19800202
+#define DIRENT_SIZE 20
+#define FILENT_SIZE 60
+#define SEND 0
+#define RECV 1
+
+#define ERRNO_OK_SIGNAL 0
+#define ERRNO_OK_THREAD 1
+#define ERRNO_REMOVE_THREAD 2
+
+/* used by sysctl */
+#define FS_MQUEUE 1
+#define CTL_QUEUESMAX 2
+#define CTL_MSGMAX 3
+#define CTL_MSGSIZEMAX 4
+
+/* default values */
+#define DFLT_QUEUESMAX 64 /* max number of message queues */
+#define DFLT_MSGMAX 40 /* max number of messages in each queue */
+#define DFLT_MSGSIZEMAX 16384 /* max message size */
+
+struct ext_wait_queue { /* queue of sleeping tasks */
+ struct task_struct *task;
+ struct list_head list;
+};
+
+struct mqueue_inode_info {
+ struct mq_attr attr;
+ struct msg_msg **messages;
+
+ struct sigevent notify;
+ pid_t notify_task;
+ pid_t notify_owner; /* == tgid of notify_task */
+
+ /* for tasks waiting for free space or message (respectively) */
+ /* this is left mainly because of poll */
+ wait_queue_head_t wait_q[2];
+ /* avoids extra invocations of wake_up */
+ wait_queue_head_t wait_q2[2];
+ struct ext_wait_queue e_wait_q[2]; /* 0=free space 1=message */
+
+ __u32 qsize; /* size of queue in memory (msgs & struct) */
+ spinlock_t lock;
+ struct inode vfs_inode;
+};
+
+static struct inode_operations mqueue_dir_inode_operations;
+static struct file_operations mqueue_file_operations;
+static struct super_operations mqueue_super_ops;
+static inline void remove_notification(struct mqueue_inode_info *info);
+
+static spinlock_t mq_lock;
+static kmem_cache_t *mqueue_inode_cachep;
+static struct vfsmount *mqueue_mnt;
+
+static unsigned int queues_count;
+static unsigned int queues_max = DFLT_QUEUESMAX;
+static unsigned int msg_max = DFLT_MSGMAX;
+static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
+
+static struct ctl_table_header * mq_sysctl_table;
+
+
+static inline struct mqueue_inode_info *MQUEUE_I(struct inode *ino)
+{
+ return list_entry(ino, struct mqueue_inode_info, vfs_inode);
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb, int mode)
+{
+ struct inode *inode;
+ struct mqueue_inode_info *ino_extra;
+ struct msg_msg **msgs = NULL;
+ int size = msg_max;
+
+ if ((mode & S_IFMT) == S_IFREG) {
+ msgs = (struct msg_msg **)kmalloc(size * sizeof(struct msg_msg *), GFP_KERNEL);
+ if (!msgs)
+ return NULL;
+ }
+
+ inode = new_inode(sb);
+ if (inode) {
+ inode->i_mode = mode;
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME;
+
+ if ((mode & S_IFMT) == S_IFREG) {
+ inode->i_fop = &mqueue_file_operations;
+ inode->i_size = FILENT_SIZE;
+ /* mqueue specific info */
+ ino_extra = MQUEUE_I(inode);
+ spin_lock_init(&(ino_extra->lock));
+ init_waitqueue_head((&(ino_extra->wait_q[0])));
+ init_waitqueue_head((&(ino_extra->wait_q[1])));
+ init_waitqueue_head((&(ino_extra->wait_q2[0])));
+ init_waitqueue_head((&(ino_extra->wait_q2[1])));
+ INIT_LIST_HEAD(&(ino_extra->e_wait_q[0].list));
+ INIT_LIST_HEAD(&(ino_extra->e_wait_q[1].list));
+ ino_extra->notify_task = 0;
+ ino_extra->notify_owner = 0;
+ ino_extra->notify.sigev_signo = 0;
+ ino_extra->notify.sigev_notify = SIGEV_NONE;
+ ino_extra->qsize = sizeof(struct mqueue_inode_info);
+ ino_extra->attr.mq_curmsgs = 0;
+ /* fill up with defaults */
+ ino_extra->attr.mq_maxmsg = size;
+ ino_extra->attr.mq_msgsize = msgsize_max;
+ ino_extra->messages = msgs;
+ } else if ((mode & S_IFMT) == S_IFDIR) {
+ inode->i_nlink++;
+ /* Some things misbehave if size == 0 on a directory */
+ inode->i_size = 2 * DIRENT_SIZE;
+ inode->i_op = &mqueue_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ }
+ } else if (msgs)
+ kfree(msgs);
+ return inode;
+}
+
+
+static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = MQUEUE_MAGIC;
+ sb->s_op = &mqueue_super_ops;
+
+ inode = mqueue_get_inode(sb, S_IFDIR | S_IRWXUGO);
+ if (!inode)
+ return -ENOMEM;
+
+ sb->s_root = d_alloc_root(inode);
+ if (!sb->s_root) {
+ iput(inode);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static struct super_block *mqueue_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ return get_sb_single(fs_type, flags, data, mqueue_fill_super);
+}
+
+static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags)
+{
+ struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
+
+ if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
+ inode_init_once(&p->vfs_inode);
+}
+
+static struct inode *mqueue_alloc_inode(struct super_block *sb)
+{
+ struct mqueue_inode_info *ei;
+
+ ei = (struct mqueue_inode_info *)kmem_cache_alloc(mqueue_inode_cachep, SLAB_KERNEL);
+ if (!ei)
+ return NULL;
+ return &ei->vfs_inode;
+}
+
+static void mqueue_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
+}
+
+static void mqueue_delete_inode(struct inode *ino)
+{
+ struct mqueue_inode_info *info;
+ int i;
+
+ if ((ino->i_mode & S_IFMT) == S_IFDIR) {
+ clear_inode(ino);
+ return;
+ }
+ info = MQUEUE_I(ino);
+ spin_lock(&info->lock);
+ for (i = 0; i < info->attr.mq_curmsgs; i++)
+ free_msg(info->messages[i]);
+ kfree(info->messages);
+ spin_unlock(&info->lock);
+
+ clear_inode(ino);
+
+ spin_lock(&mq_lock);
+ queues_count--;
+ spin_unlock(&mq_lock);
+}
+
+static int mqueue_unlink(struct inode *dir, struct dentry *dent)
+{
+ struct inode *inode = dent->d_inode;
+ dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+ dir->i_size -= DIRENT_SIZE;
+ inode->i_nlink--;
+ dput(dent);
+ return 0;
+}
+
+static struct dentry *mqueue_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ d_add(dentry, NULL);
+ return NULL;
+}
+
+static int mqueue_create(struct inode *dir, struct dentry *dent, int mode, struct nameidata *nd)
+{
+ struct inode *ino;
+ int error;
+
+ spin_lock(&mq_lock);
+ if (queues_count >= queues_max) {
+ error = -ENOSPC;
+ goto out_lock;
+ }
+ queues_count++;
+ spin_unlock(&mq_lock);
+
+ ino = mqueue_get_inode(dir->i_sb, mode);
+ if (!ino) {
+ error = -ENOMEM;
+ spin_lock(&mq_lock);
+ queues_count--;
+ goto out_lock;
+ }
+
+ dir->i_size += DIRENT_SIZE;
+ dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+
+ d_instantiate(dent, ino);
+ dget(dent);
+ return 0;
+out_lock:
+ spin_unlock(&mq_lock);
+ return error;
+}
+
+/*
+* This is routine for system read from queue file.
+* To avoid mess with doing here some sort of mq_receive we allow
+* to read only queue size & notification info (the only values
+* that are interesting from user point of view and aren't accessible
+* through std routines)
+*/
+static ssize_t mqueue_read_file(struct file *filp, char __user *data,
+ size_t count, loff_t * off)
+{
+ size_t pos;
+ ssize_t retval;
+ char buffer[FILENT_SIZE + 1];
+ struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+
+ pos = *off;
+ if ((ssize_t) count < 0)
+ return -EINVAL;
+ if (!count)
+ return 0;
+ if (pos >= FILENT_SIZE)
+ return 0;
+ if (pos + count >= FILENT_SIZE)
+ count = FILENT_SIZE - pos - 1;
+
+ if (!access_ok(VERIFY_WRITE, data, count))
+ return -EFAULT;
+
+ snprintf(buffer, FILENT_SIZE + 1,
+ "QSIZE:%-10u NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
+ info->qsize, info->notify.sigev_notify,
+ info->notify.sigev_signo, info->notify_owner);
+
+ retval = FILENT_SIZE - *off;
+ if (copy_to_user(data, buffer + pos, retval)) {
+ retval = (ssize_t)-EFAULT;
+ goto out;
+ }
+ *off += retval;
+ filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME;
+out:
+ return retval;
+}
+
+
+static int mqueue_release_file(struct inode *ino, struct file *filp)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(ino);
+
+ spin_lock(&info->lock);
+ if (current->tgid == info->notify_owner)
+ remove_notification(info);
+
+ spin_unlock(&info->lock);
+ return 0;
+}
+
+
+static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
+{
+ struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+ int retval = 0;
+
+ poll_wait(filp, &info->wait_q[0], poll_tab);
+ poll_wait(filp, &info->wait_q[1], poll_tab);
+
+ spin_lock(&info->lock);
+ if (info->attr.mq_curmsgs)
+ retval = POLLIN | POLLRDNORM;
+
+ if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
+ retval |= POLLOUT | POLLWRNORM;
+ spin_unlock(&info->lock);
+
+ return retval;
+}
+
+/*
+* This cut&paste version of wait_event() without event checking & with
+* exclusive adding to queue.
+*/
+void inline wait_exclusive(wait_queue_head_t * wq,
+ struct mqueue_inode_info *i)
+{
+ wait_queue_t wait;
+ init_waitqueue_entry(&wait, current);
+
+ add_wait_queue_exclusive(wq, &wait);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ spin_unlock(&i->lock);
+ schedule();
+ spin_lock(&i->lock);
+
+ current->state = TASK_RUNNING;
+ remove_wait_queue(wq, &wait);
+}
+
+/* Removes from info->e_wait_q[sr] current task */
+static void wq_remove(struct mqueue_inode_info *info, int sr)
+{
+ struct ext_wait_queue *ptr;
+
+ if (!list_empty(&(info->e_wait_q[sr].list)))
+ list_for_each_entry(ptr, &(info->e_wait_q[sr].list), list) {
+ if (ptr->task == current) {
+ list_del(&(ptr->list));
+ kfree(ptr);
+ break;
+ }
+ }
+}
+
+/* adds current to info->e_wait_q[sr] before element with smaller prio */
+static inline void wq_add(struct mqueue_inode_info *info, int sr,
+ struct ext_wait_queue *tmp)
+{
+ struct ext_wait_queue *ptr;
+
+ tmp->task = current;
+
+ if (list_empty(&info->e_wait_q[sr].list))
+ list_add(&tmp->list, &info->e_wait_q[sr].list);
+ else {
+ list_for_each_entry(ptr, &info->e_wait_q[sr].list, list)
+ if (ptr->task->static_prio <= current->static_prio) {
+ /* we add before ptr element */
+ __list_add(&tmp->list, ptr->list.prev, &ptr->list);
+ return;
+ }
+ /* we add on tail */
+ list_add_tail(&tmp->list, &info->e_wait_q[sr].list);
+ }
+ return;
+}
+
+/* removes from info->e_wait_q[sr] current task.
+ * Only for wq_sleep(): as we are here current must be one
+ * before-first (last) (meaning first in order as our 'queue' is inversed) */
+static inline void wq_remove_last(struct mqueue_inode_info *info, int sr)
+{
+ struct ext_wait_queue *tmp = list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list);
+ list_del(&(tmp->list));
+ kfree(tmp);
+}
+
+/*
+ * puts current task to sleep
+ * sr: SEND or RECV
+ */
+static int wq_sleep(struct mqueue_inode_info *info, int sr,
+ signed long timeout, struct ext_wait_queue *wq_ptr)
+{
+ wait_queue_t __wait;
+ long error;
+
+ wq_add(info, sr, wq_ptr);
+
+ init_waitqueue_entry(&__wait, current);
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if ((current == (list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list))->task)
+ && ((info->attr.mq_curmsgs > 0 && sr == RECV)
+ || (info->attr.mq_curmsgs < info->attr.mq_maxmsg && sr == SEND)))
+ break;
+
+ if (signal_pending(current)) {
+ current->state = TASK_RUNNING;
+ wq_remove(info, sr);
+ return -EINTR;
+ }
+
+ spin_unlock(&info->lock);
+ error = schedule_timeout(timeout);
+ spin_lock(&info->lock);
+
+ if ((!error) && (!signal_pending(current))) {
+ wq_remove(info, sr);
+ return -ETIMEDOUT;
+ }
+ }
+ current->state = TASK_RUNNING;
+ wq_remove_last(info, sr);
+
+ return 0;
+}
+
+/* wakes up sleeping task */
+static void wq_wakeup(struct mqueue_inode_info *info, int sr)
+{
+ if (sr == SEND) {
+ /* We can't invoke wake_up for tasks waiting for free space
+ * if there is less then MAXMSG-1 messages - then wake_up was
+ * invoked previously (and finished) but mq_sleep() of proper
+ * (only one) task didn't start to continue running yet,
+ * thus we must wait until this task receives IT'S message
+ */
+ if ((info->attr.mq_curmsgs < info->attr.mq_maxmsg - 1)
+ && (!list_empty(&info->e_wait_q[sr].list)))
+ wait_exclusive(&(info->wait_q2[sr]), info);
+ } else {
+ /* As above but for tasks waiting for new message */
+ if ((info->attr.mq_curmsgs > 1) && (!list_empty(&info->e_wait_q[sr].list)))
+ wait_exclusive(&(info->wait_q2[sr]), info);
+ }
+ /* We can wake up now - either all are sleeping or queue is empty. */
+ if (!list_empty(&info->e_wait_q[sr].list))
+ wake_up_process((list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list))->task);
+ /* for poll */
+ wake_up_interruptible(&(info->wait_q[sr]));
+}
+
+
+/* Auxiliary functions to manipulate messages' list */
+static inline 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->messages[k + 1] = ptr;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+ return info->messages[--(info->attr.mq_curmsgs)];
+}
+
+/*
+ * The next function is only to split too long sys_mq_timedsend
+ */
+static inline void __do_notify(struct mqueue_inode_info *info)
+{
+ struct siginfo sig_i;
+ struct task_struct *p;
+
+ /* notification
+ * invoked when there is registered process and there isn't process
+ * waiting synchronously for message AND state of queue changed from
+ * empty to not empty */
+ if ((info->notify.sigev_notify != SIGEV_NONE) && list_empty(&info->e_wait_q[RECV].list)
+ && info->attr.mq_curmsgs == 1) {
+
+ sig_i.si_signo = info->notify.sigev_signo;
+ sig_i.si_errno = ERRNO_OK_SIGNAL;
+ sig_i.si_code = SI_MESGQ;
+ sig_i.si_value = info->notify.sigev_value;
+ sig_i.si_pid = current->tgid;
+ sig_i.si_uid = current->uid;
+
+ /* sends signal */
+ if (info->notify.sigev_notify == SIGEV_SIGNAL) {
+ kill_proc_info(info->notify.sigev_signo,
+ &sig_i, info->notify_task);
+ } else if (info->notify.sigev_notify == SIGEV_THREAD ||
+ info->notify.sigev_notify == SIGEV_THREAD_ID) {
+ sig_i.si_errno = ERRNO_OK_THREAD;
+ read_lock(&tasklist_lock);
+ p = find_task_by_pid(info->notify_task);
+ if (p && (p->tgid == info->notify_owner))
+ send_sig_info(info->notify.sigev_signo, &sig_i, p);
+ read_unlock(&tasklist_lock);
+ }
+ /* after notification unregisters process */
+ info->notify_task = 0;
+ info->notify_owner = 0;
+ info->notify.sigev_signo = 0;
+ info->notify.sigev_notify = SIGEV_NONE;
+ }
+}
+
+static inline long prepare_timeout(const struct timespec __user *arg)
+{
+ struct timespec ts, nowts;
+ long timeout;
+
+ if (arg) {
+ if (copy_from_user(&ts, arg, sizeof(struct timespec)))
+ return -EFAULT;
+
+ if (ts.tv_nsec < 0 || ts.tv_sec < 0
+ || ts.tv_nsec >= NSEC_PER_SEC)
+ return -EINVAL;
+ nowts = CURRENT_TIME;
+ /* first subtract as jiffies can't be too big */
+ ts.tv_sec -= nowts.tv_sec;
+ if (ts.tv_nsec < nowts.tv_nsec) {
+ ts.tv_nsec += NSEC_PER_SEC;
+ ts.tv_sec--;
+ }
+ ts.tv_nsec -= nowts.tv_nsec;
+ if (ts.tv_sec < 0)
+ return 0;
+
+ timeout = timespec_to_jiffies(&ts) + 1;
+ } else
+ return MAX_SCHEDULE_TIMEOUT;
+
+ return timeout;
+}
+
+
+static inline void remove_notification(struct mqueue_inode_info *info)
+{
+ struct siginfo sig_i;
+ struct task_struct *p;
+
+ if (info->notify.sigev_notify == SIGEV_THREAD) {
+ /* cancel waiting thread */
+ sig_i.si_signo = info->notify.sigev_signo;
+ sig_i.si_errno = ERRNO_REMOVE_THREAD;
+ sig_i.si_code = SI_MESGQ;
+ sig_i.si_value = info->notify.sigev_value;
+ sig_i.si_pid = current->tgid;
+ sig_i.si_uid = current->uid;
+
+ read_lock(&tasklist_lock);
+ p = find_task_by_pid(info->notify_task);
+
+ if (p && (p->tgid == info->notify_owner))
+ send_sig_info(info->notify.sigev_signo, &sig_i, p);
+ read_unlock(&tasklist_lock);
+ }
+ info->notify_task = 0;
+ info->notify_owner = 0;
+ info->notify.sigev_signo = 0;
+ info->notify.sigev_notify = SIGEV_NONE;
+}
+
+/*
+ * Invoked when creating a new queue via sys_mq_open
+ */
+static struct file *do_create(struct dentry *dir, struct dentry *dentry,
+ int oflag, mode_t mode, struct mq_attr __user *u_attr)
+{
+ struct file *filp;
+ struct inode *ino;
+ struct mqueue_inode_info *info;
+ struct msg_msg **msgs = NULL;
+ struct mq_attr attr;
+ int ret;
+
+ if (u_attr != NULL) {
+ if (copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
+ return ERR_PTR(-EFAULT);
+
+ if (attr.mq_maxmsg <= 0 || attr.mq_msgsize <= 0
+ || attr.mq_maxmsg > msg_max || attr.mq_msgsize > msgsize_max)
+ return ERR_PTR(-EINVAL);
+ msgs = (struct msg_msg **)kmalloc(attr.mq_maxmsg * sizeof(struct msg_msg *), GFP_KERNEL);
+ if (!msgs)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ret = vfs_create(dir->d_inode, dentry, mode, NULL);
+ if (ret) {
+ if (msgs)
+ kfree(msgs);
+ return ERR_PTR(ret);
+ }
+
+ ino = dentry->d_inode;
+ info = MQUEUE_I(ino);
+ if (u_attr != NULL) {
+ info->attr.mq_maxmsg = attr.mq_maxmsg;
+ info->attr.mq_msgsize = attr.mq_msgsize;
+ kfree(info->messages);
+ info->messages = msgs;
+ }
+
+ filp = dentry_open(dentry, mqueue_mnt, oflag);
+ if (!IS_ERR(filp))
+ dget(dentry);
+
+ return filp;
+}
+
+/* opens existing queue */
+static struct file *do_open(struct dentry *dentry, int oflag)
+{
+ struct file *filp;
+ static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, MAY_READ | MAY_WRITE };
+
+ if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+ return ERR_PTR(-EINVAL);
+
+ if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL))
+ return ERR_PTR(-EACCES);
+
+ filp = dentry_open(dentry, mqueue_mnt, oflag);
+
+ if (!IS_ERR(filp))
+ dget(dentry);
+
+ return filp;
+}
+
+asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
+ struct mq_attr __user *attr)
+{
+ struct dentry *dentry;
+ struct file *filp;
+ char *name;
+ int fd, error;
+
+ if (IS_ERR(name = getname(u_name)))
+ return PTR_ERR(name);
+
+ fd = get_unused_fd();
+ if (fd < 0)
+ goto out_putname;
+
+ down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+ dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ if (IS_ERR(dentry)) {
+ error = PTR_ERR(dentry);
+ goto out_err;
+ }
+ mntget(mqueue_mnt);
+
+ if (oflag & O_CREAT) {
+ if (dentry->d_inode) { /* entry already exists */
+ filp = (oflag & O_EXCL) ? ERR_PTR(-EEXIST) : do_open(dentry, oflag);
+ } else {
+ filp = do_create(mqueue_mnt->mnt_root, dentry, oflag, mode, attr);
+ }
+ } else
+ filp = (dentry->d_inode) ? do_open(dentry, oflag) : ERR_PTR(-ENOENT);
+
+ dput(dentry);
+
+ if (IS_ERR(filp)) {
+ error = PTR_ERR(filp);
+ goto out_putfd;
+ }
+
+ fd_install(fd, filp);
+ goto out_upsem;
+
+out_putfd:
+ mntput(mqueue_mnt);
+ put_unused_fd(fd);
+out_err:
+ fd = error;
+out_upsem:
+ up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+out_putname:
+ putname(name);
+ return fd;
+}
+
+
+asmlinkage long sys_mq_unlink(const char __user *u_name)
+{
+ int err;
+ char *name;
+ struct dentry *dentry;
+ struct inode *ino = NULL;
+
+ name = getname(u_name);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+ dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ if (IS_ERR(dentry)) {
+ err = PTR_ERR(dentry);
+ goto out_unlock;
+ }
+
+ if (!dentry->d_inode) {
+ err = -ENOENT;
+ goto out_unlock;
+ }
+
+ if (permission(dentry->d_inode, MAY_WRITE, NULL)) {
+ err = -EACCES;
+ goto out_err;
+ }
+ ino = dentry->d_inode;
+ if (ino)
+ atomic_inc(&ino->i_count);
+
+ err = vfs_unlink(dentry->d_parent->d_inode, dentry);
+out_err:
+ dput(dentry);
+
+out_unlock:
+ up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+ putname(name);
+ if (ino)
+ iput(ino);
+
+ return err;
+}
+
+
+static long do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+ size_t msg_len, unsigned int msg_prio, const long timeout)
+{
+ struct file *filp;
+ struct inode *ino;
+ struct ext_wait_queue *wq_ptr;
+ struct msg_msg *msg_ptr;
+ int ret;
+ struct mqueue_inode_info *info = MQUEUE_I(ino);
+
+ ret = -EBADF;
+ filp = fget(mqdes);
+ if (!filp)
+ goto out;
+
+ ino = filp->f_dentry->d_inode;
+ if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+ goto out_fput;
+ info = MQUEUE_I(ino);
+
+ if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
+ goto out_fput;
+
+ /* first try to allocate memory, before doing anything with
+ * existing queues */
+ msg_ptr = load_msg((void *)u_msg_ptr, msg_len);
+ if (IS_ERR(msg_ptr)) {
+ ret = PTR_ERR(msg_ptr);
+ goto out_fput;
+ }
+
+ /* This memory may be unnecessary but we must alloc it here
+ * because of spinlock. kfree is called in wq_remove(_last) */
+ wq_ptr = kmalloc(sizeof(struct ext_wait_queue), GFP_KERNEL);
+ if (wq_ptr == NULL) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+
+ spin_lock(&info->lock);
+
+ if ((filp->f_flags & O_NONBLOCK) && (info->attr.mq_curmsgs == info->attr.mq_maxmsg)) {
+ ret = -EAGAIN;
+ goto out_1unlock;
+ }
+
+ if (msg_len > info->attr.mq_msgsize) {
+ ret = -EMSGSIZE;
+ goto out_1unlock;
+ }
+
+ /* checks if queue is full -> I'm waiting as O_NONBLOCK isn't
+ * set then. mq_receive wakes up only 1 task */
+ if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
+ ret = wq_sleep(info, SEND, timeout, wq_ptr);
+ if (ret)
+ goto out_1unlock_nofree;
+ } else
+ kfree(wq_ptr);
+
+ /* adds message to the queue */
+ msg_ptr->m_ts = msg_len;
+ msg_ptr->m_type = msg_prio;
+
+ msg_insert(msg_ptr, info);
+
+ info->qsize += msg_len;
+ ino->i_atime = ino->i_mtime = ino->i_ctime = CURRENT_TIME;
+ __do_notify(info);
+
+ /* after sending message we must wake up (ONLY 1 no matter which) */
+ /* task sleeping in wq_wakeup() */
+ wake_up(&(info->wait_q2[SEND]));
+
+ /* wakes up task waiting for message */
+ wq_wakeup(info, RECV);
+
+ spin_unlock(&info->lock);
+ ret = 0;
+ goto out_fput;
+
+ /* I hate this goto convention... */
+out_1unlock:
+ kfree(wq_ptr);
+out_1unlock_nofree:
+ spin_unlock(&info->lock);
+out_free:
+ free_msg(msg_ptr);
+out_fput:
+ fput(filp);
+out:
+ return ret;
+}
+
+asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+ size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout)
+{
+ long timeout;
+
+ if (msg_prio >= (unsigned long) MQ_PRIO_MAX)
+ return -EINVAL;
+
+ if ((timeout = prepare_timeout(u_abs_timeout)) < 0)
+ return timeout;
+ return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, timeout);
+}
+
+
+static ssize_t do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+ size_t msg_len, unsigned int __user *u_msg_prio, const long timeout)
+{
+ ssize_t ret;
+ struct msg_msg *msg_ptr;
+ struct file *filp;
+ struct inode *ino;
+ struct mqueue_inode_info *info;
+ struct ext_wait_queue *wq_ptr;
+
+ ret = -EBADF;
+ filp = fget(mqdes);
+ if (!filp)
+ goto out;
+
+ ino = filp->f_dentry->d_inode;
+ if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+ goto out_fput;
+ info = MQUEUE_I(ino);
+
+ if ((filp->f_flags & O_ACCMODE) == O_WRONLY)
+ goto out_fput;
+
+ /* The same as in send */
+ wq_ptr = kmalloc(sizeof(struct ext_wait_queue), GFP_KERNEL);
+ if (wq_ptr == NULL) {
+ ret = -ENOMEM;
+ goto out_fput;
+ }
+
+ spin_lock(&info->lock);
+
+ /* checks if O_NONBLOCK is set and queue is empty */
+ if ((filp->f_flags & O_NONBLOCK) && (info->attr.mq_curmsgs == 0)) {
+ ret = -EAGAIN;
+ goto out_1unlock;
+ }
+
+ /* checks if buffer is big enough */
+ if (msg_len < info->attr.mq_msgsize) {
+ ret = -EMSGSIZE;
+ goto out_1unlock;
+ }
+
+ /* checks if queue is empty -> as O_NONBLOCK isn't set then
+ * we must wait */
+ if (info->attr.mq_curmsgs == 0) {
+ ret = wq_sleep(info, RECV, timeout, wq_ptr);
+ if (ret < 0)
+ goto out_unlock_only;
+ } else
+ kfree(wq_ptr);
+
+ msg_ptr = msg_get(info);
+ ret = msg_ptr->m_ts;
+
+ info->qsize -= ret;
+ ino->i_atime = ino->i_mtime = ino->i_ctime = CURRENT_TIME;
+
+ /* after receive we can wakeup 1 task waiting in wq_wakeup */
+ wake_up(&(info->wait_q2[RECV]));
+ /* wakes up task waiting for sending message */
+ wq_wakeup(info, SEND);
+
+ spin_unlock(&info->lock);
+
+ if (u_msg_prio) {
+ if (put_user(msg_ptr->m_type, u_msg_prio)) {
+ ret = -EFAULT;
+ goto out_2free;
+ }
+ }
+ if (store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts))
+ ret = -EFAULT;
+
+out_2free:
+ free_msg(msg_ptr);
+ goto out_fput;
+out_1unlock:
+ kfree(wq_ptr);
+out_unlock_only:
+ spin_unlock(&info->lock);
+out_fput:
+ fput(filp);
+out:
+ return ret;
+}
+
+asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+ size_t msg_len, unsigned int __user *u_msg_prio,
+ const struct timespec __user *u_abs_timeout)
+{
+ long timeout;
+
+ if ((timeout = prepare_timeout(u_abs_timeout)) < 0)
+ return timeout;
+ return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, timeout);
+}
+
+
+/* Notes: the case when user wants us to deregister (with NULL as pointer or SIGEV_NONE)
+ * and he isn't currently owner of notification will be silently discarded.
+ * It isn't explicitly defined in the POSIX.
+ */
+asmlinkage long sys_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
+{
+ int ret;
+ struct file *filp;
+ struct inode *ino;
+ struct sigevent notification;
+ struct mqueue_inode_info *info;
+
+ if (u_notification != NULL) {
+ if (copy_from_user(&notification, u_notification, sizeof(struct sigevent)))
+ return -EFAULT;
+
+ if (unlikely(notification.sigev_notify != SIGEV_NONE &&
+ notification.sigev_notify != SIGEV_SIGNAL &&
+ notification.sigev_notify != SIGEV_THREAD))
+ return -EINVAL;
+ }
+
+ ret = -EBADF;
+ filp = fget(mqdes);
+ if (!filp)
+ goto out;
+
+ ino = filp->f_dentry->d_inode;
+ if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+ goto out_fput;
+ info = MQUEUE_I(ino);
+
+ ret = 0;
+ spin_lock(&info->lock);
+
+ if (u_notification == NULL || notification.sigev_notify == SIGEV_NONE) {
+ if (info->notify_owner == current->tgid)
+ remove_notification(info);
+ goto out_unlock;
+ }
+
+ if (info->notify_task) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ /* add notification */
+ if (notification.sigev_signo < 0 || notification.sigev_signo > _NSIG)
+ ret = -EINVAL;
+ else {
+ info->notify_task = current->pid;
+ info->notify_owner = current->tgid;
+ info->notify.sigev_signo = notification.sigev_signo;
+ info->notify.sigev_notify = notification.sigev_notify;
+ info->notify.sigev_value = notification.sigev_value;
+ }
+out_unlock:
+ ino->i_atime = ino->i_ctime = CURRENT_TIME;
+ spin_unlock(&info->lock);
+out_fput:
+ fput(filp);
+out:
+ return ret;
+}
+
+asmlinkage long sys_mq_getattr(mqd_t mqdes, struct mq_attr __user *u_mqstat)
+{
+ int ret;
+ struct mq_attr attr;
+ struct file *filp;
+ struct inode *ino;
+ struct mqueue_inode_info *info;
+
+ if (u_mqstat == NULL)
+ return -EINVAL;
+
+ ret = -EBADF;
+ filp = fget(mqdes);
+ if (!filp)
+ goto out;
+
+ ino = filp->f_dentry->d_inode;
+ if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+ goto out_fput;
+ info = MQUEUE_I(ino);
+
+ spin_lock(&info->lock);
+ attr = info->attr;
+ attr.mq_flags = filp->f_flags;
+ ino->i_atime = ino->i_ctime = CURRENT_TIME;
+
+ spin_unlock(&info->lock);
+
+ ret = 0;
+ if (copy_to_user(u_mqstat, &attr, sizeof(struct mq_attr)))
+ ret = -EFAULT;
+
+out_fput:
+ fput(filp);
+out:
+ return ret;
+}
+
+asmlinkage long sys_mq_setattr(mqd_t mqdes, const struct mq_attr __user *u_mqstat,
+ struct mq_attr __user *u_omqstat)
+{
+ int ret;
+ struct mq_attr mqstat, omqstat;
+ struct file *filp;
+ struct inode *ino;
+ struct mqueue_inode_info *info;
+
+ if (u_mqstat == NULL)
+ return -EINVAL;
+
+ if (copy_from_user(&mqstat, u_mqstat, sizeof (struct mq_attr)))
+ return -EFAULT;
+
+ ret = -EBADF;
+ filp = fget(mqdes);
+ if (!filp)
+ goto out;
+
+ ino = filp->f_dentry->d_inode;
+ if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+ goto out_fput;
+ info = MQUEUE_I(ino);
+
+ spin_lock(&info->lock);
+
+ omqstat = info->attr;
+ omqstat.mq_flags = filp->f_flags;
+
+ if (mqstat.mq_flags & O_NONBLOCK)
+ filp->f_flags |= O_NONBLOCK;
+ else
+ filp->f_flags &= ~O_NONBLOCK;
+
+ ino->i_atime = ino->i_ctime = CURRENT_TIME;
+
+ spin_unlock(&info->lock);
+
+ ret = 0;
+ if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, sizeof(struct mq_attr)))
+ ret = -EFAULT;
+
+out_fput:
+ fput(filp);
+out:
+ return ret;
+}
+
+
+static struct inode_operations mqueue_dir_inode_operations = {
+ .lookup = mqueue_lookup,
+ .create = mqueue_create,
+ .unlink = mqueue_unlink,
+};
+
+static struct file_operations mqueue_file_operations = {
+ .release = mqueue_release_file,
+ .poll = mqueue_poll_file,
+ .read = mqueue_read_file,
+};
+
+static struct super_operations mqueue_super_ops = {
+ .alloc_inode = mqueue_alloc_inode,
+ .destroy_inode = mqueue_destroy_inode,
+ .statfs = simple_statfs,
+ .delete_inode = mqueue_delete_inode,
+ .drop_inode = generic_delete_inode,
+};
+
+static struct file_system_type mqueue_fs_type = {
+ .name = "mqueue",
+ .get_sb = mqueue_get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static ctl_table mq_sysctls[] = {
+ {
+ .ctl_name = CTL_QUEUESMAX,
+ .procname = "queues_max",
+ .data = &queues_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_MSGMAX,
+ .procname = "msg_max",
+ .data = &msg_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_MSGSIZEMAX,
+ .procname = "msgsize_max",
+ .data = &msgsize_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ { .ctl_name = 0 }
+};
+
+static ctl_table mq_sysctl_dir[] = {
+ {
+ .ctl_name = FS_MQUEUE,
+ .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;
+
+ mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
+ sizeof(struct mqueue_inode_info), 0, SLAB_HWCACHE_ALIGN, init_once, NULL);
+
+ if (mqueue_inode_cachep == NULL)
+ return -ENOMEM;
+
+ mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0);
+ if (!mq_sysctl_table) {
+ error = -ENOMEM;
+ goto out_inodecache;
+ }
+
+ error = register_filesystem(&mqueue_fs_type);
+ if (error)
+ goto out_inodecache;
+
+ if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
+ unregister_filesystem(&mqueue_fs_type);
+ unregister_sysctl_table(mq_sysctl_table);
+ error = PTR_ERR(mqueue_mnt);
+ goto out_inodecache;
+ }
+
+ /* internal initialization - not common for vfs */
+ queues_count = 0;
+ spin_lock_init(&mq_lock);
+
+ return 0;
+
+out_inodecache:
+ if (kmem_cache_destroy(mqueue_inode_cachep))
+ printk(KERN_INFO "mqueue_inode_cache: not all structures were freed\n");
+ return error;
+}
+
+static void __exit exit_mqueue_fs(void)
+{
+ unregister_filesystem(&mqueue_fs_type);
+ unregister_sysctl_table(mq_sysctl_table);
+
+ if (kmem_cache_destroy(mqueue_inode_cachep))
+ printk(KERN_INFO "mqueue_inode_cache: not all structures were freed\n");
+}
+
+__initcall(init_mqueue_fs);
diff -urN 2.6.0-test10-orig_2/ipc/util.c 2.6.0-test10-patched_2/ipc/util.c
--- 2.6.0-test10-orig_2/ipc/util.c 2003-11-21 17:11:17.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/util.c 2003-11-24 17:47:23.000000000 +0100
@@ -24,10 +24,13 @@
#include <linux/security.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>
+#include <linux/mqueue.h>

-#if defined(CONFIG_SYSVIPC)
-
+#if defined(CONFIG_SYSVIPC) || defined(CONFIG_POSIX_MQUEUE_FS)
#include "util.h"
+#endif
+
+#if defined(CONFIG_SYSVIPC)

/**
* ipc_init - initialise IPC subsystem
@@ -612,7 +615,7 @@

#endif /* CONFIG_SYSVIPC */

-#ifdef CONFIG_SYSVIPC
+#if defined(CONFIG_POSIX_MQUEUE_FS) || defined(CONFIG_SYSVIPC)

void free_msg(struct msg_msg* msg)
{
@@ -714,4 +717,51 @@
return 0;
}

-#endif /* CONFIG_SYSVIPC */
+#endif /* CONFIG_POSIX_MQUEUE_FS || CONFIG_SYSVIPC */
+
+#if !defined(CONFIG_POSIX_MQUEUE_FS)
+
+/*
+ * Return ENOSYS when posix mqueue filesystem is not compiled in
+ */
+
+asmlinkage long sys_mq_open(const char *name, int oflag, mode_t mode,
+ struct mq_attr *attr)
+{
+ return (mqd_t)-ENOSYS;
+}
+
+asmlinkage long sys_mq_unlink(const char *name)
+{
+ return -ENOSYS;
+}
+
+asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char *msg_ptr,
+ size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout)
+{
+ return -ENOSYS;
+}
+
+asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char *msg_ptr,
+ size_t msg_len, unsigned int *msg_prio, const struct timespec *abs_timeout)
+{
+ return -ENOSYS;
+}
+
+asmlinkage long sys_mq_notify(mqd_t mqdes, const struct sigevent *notification)
+{
+ return -ENOSYS;
+}
+
+asmlinkage long sys_mq_getattr(mqd_t mqdes, struct mq_attr *mqstat)
+{
+ return -ENOSYS;
+}
+
+asmlinkage long sys_mq_setattr(mqd_t mqdes, const struct mq_attr *mqstat,
+ struct mq_attr *omqstat)
+{
+ return -ENOSYS;
+}
+
+#endif /* ! CONFIG_POSIX_MQUEUE_FS */
diff -urN 2.6.0-test10-orig_2/kernel/signal.c 2.6.0-test10-patched_2/kernel/signal.c
--- 2.6.0-test10-orig_2/kernel/signal.c 2003-11-24 16:28:58.000000000 +0100
+++ 2.6.0-test10-patched_2/kernel/signal.c 2003-11-24 16:51:48.000000000 +0100
@@ -2044,6 +2044,7 @@
err |= __put_user(from->si_stime, &to->si_stime);
break;
case __SI_RT: /* This is not generated by the kernel as of now. */
+ case __SI_MESGQ: /* But this is */
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_int, &to->si_int);