From: Cedric Le Goater <[EMAIL PROTECTED]>
This patch adds a struct mq_namespace holding the common attributes
of the mqueue namespace.
The current code is modified to use the default mqueue namespace
object 'init_mq_ns' and to prepare the ground for futur dynamic
objects.
Todo:
- use CONFIG_NAMESPACE when next -mm is released
Signed-off-by: Cedric Le Goater <[EMAIL PROTECTED]>
---
include/linux/mq_namespace.h | 60 +++++++++++++++++++++++
ipc/mqueue.c | 111 +++++++++++++++++++++++++++----------------
2 files changed, 130 insertions(+), 41 deletions(-)
Index: 2.6.23-rc8-mm2/include/linux/mq_namespace.h
===================================================================
--- /dev/null
+++ 2.6.23-rc8-mm2/include/linux/mq_namespace.h
@@ -0,0 +1,60 @@
+#ifndef _LINUX_MQ_NAMESPACE_H
+#define _LINUX_MQ_NAMESPACE_H
+
+#include <linux/kref.h>
+
+struct vfsmount;
+
+struct mq_namespace {
+ struct kref kref;
+ struct vfsmount *mnt;
+
+ unsigned int queues_count;
+ unsigned int queues_max;
+ unsigned int msg_max;
+ unsigned int msgsize_max;
+};
+
+extern struct mq_namespace init_mq_ns;
+
+#ifdef CONFIG_POSIX_MQUEUE
+
+#define INIT_MQ_NS(ns) .ns = &init_mq_ns,
+
+static inline struct mq_namespace *get_mq_ns(struct mq_namespace *ns)
+{
+ if (ns)
+ kref_get(&ns->kref);
+ return ns;
+}
+
+extern struct mq_namespace *copy_mq_ns(unsigned long flags,
+ struct mq_namespace *old_ns);
+extern void free_mq_ns(struct kref *kref);
+
+static inline void put_mq_ns(struct mq_namespace *ns)
+{
+ if (ns)
+ kref_put(&ns->kref, free_mq_ns);
+}
+
+#else
+
+#define INIT_MQ_NS(ns)
+
+static inline struct mq_namespace *get_mq_ns(struct mq_namespace *ns)
+{
+ return ns;
+}
+
+static inline struct mq_namespace *copy_mq_ns(unsigned long flags,
+ struct mq_namespace *old_ns)
+{
+ return old_ns;
+}
+
+static inline void put_mq_ns(struct mq_namespace *ns) { }
+
+#endif /* CONFIG_POSIX_MQUEUE */
+
+#endif /* _LINUX_MQ_H */
Index: 2.6.23-rc8-mm2/ipc/mqueue.c
===================================================================
--- 2.6.23-rc8-mm2.orig/ipc/mqueue.c
+++ 2.6.23-rc8-mm2/ipc/mqueue.c
@@ -31,6 +31,7 @@
#include <linux/mutex.h>
#include <linux/nsproxy.h>
#include <linux/pid.h>
+#include <linux/mq_namespace.h>
#include <net/sock.h>
#include "util.h"
@@ -87,12 +88,18 @@ static void remove_notification(struct m
static spinlock_t mq_lock;
static struct kmem_cache *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;
+struct mq_namespace init_mq_ns = {
+ .kref = {
+ .refcount = ATOMIC_INIT(2),
+ },
+ .mnt = NULL,
+ .queues_count = 0,
+ .queues_max = DFLT_QUEUESMAX,
+ .msg_max = DFLT_MSGMAX,
+ .msgsize_max = DFLT_MSGSIZEMAX,
+};
+
static struct ctl_table_header * mq_sysctl_table;
@@ -101,6 +108,21 @@ static inline struct mqueue_inode_info *
return container_of(inode, struct mqueue_inode_info, vfs_inode);
}
+struct mq_namespace *copy_mq_ns(unsigned long flags,
+ struct mq_namespace *old_ns)
+{
+ BUG_ON(!old_ns);
+ return get_mq_ns(old_ns);
+}
+
+void free_mq_ns(struct kref *kref)
+{
+ struct mq_namespace *mq_ns;
+
+ mq_ns = container_of(kref, struct mq_namespace, kref);
+ kfree(mq_ns);
+}
+
static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
struct mq_attr *attr)
{
@@ -235,6 +257,7 @@ static void mqueue_delete_inode(struct i
struct user_struct *user;
unsigned long mq_bytes;
int i;
+ struct mq_namespace *mq_ns = &init_mq_ns;
if (S_ISDIR(inode->i_mode)) {
clear_inode(inode);
@@ -255,7 +278,7 @@ static void mqueue_delete_inode(struct i
if (user) {
spin_lock(&mq_lock);
user->mq_bytes -= mq_bytes;
- queues_count--;
+ mq_ns->queues_count--;
spin_unlock(&mq_lock);
free_uid(user);
}
@@ -267,20 +290,22 @@ static int mqueue_create(struct inode *d
struct inode *inode;
struct mq_attr *attr = dentry->d_fsdata;
int error;
+ struct mq_namespace *mq_ns = &init_mq_ns;
spin_lock(&mq_lock);
- if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) {
+ if (mq_ns->queues_count >= mq_ns->queues_max &&
+ !capable(CAP_SYS_RESOURCE)) {
error = -ENOSPC;
goto out_lock;
}
- queues_count++;
+ mq_ns->queues_count++;
spin_unlock(&mq_lock);
inode = mqueue_get_inode(dir->i_sb, mode, attr);
if (!inode) {
error = -ENOMEM;
spin_lock(&mq_lock);
- queues_count--;
+ mq_ns->queues_count--;
goto out_lock;
}
@@ -571,7 +596,7 @@ static void remove_notification(struct m
info->notify_owner = NULL;
}
-static int mq_attr_ok(struct mq_attr *attr)
+static int mq_attr_ok(struct mq_namespace *mq_ns, struct mq_attr *attr)
{
if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
return 0;
@@ -579,8 +604,8 @@ static int mq_attr_ok(struct mq_attr *at
if (attr->mq_maxmsg > HARD_MSGMAX)
return 0;
} else {
- if (attr->mq_maxmsg > msg_max ||
- attr->mq_msgsize > msgsize_max)
+ if (attr->mq_maxmsg > mq_ns->msg_max ||
+ attr->mq_msgsize > mq_ns->msgsize_max)
return 0;
}
/* check for overflow */
@@ -596,8 +621,9 @@ static int mq_attr_ok(struct mq_attr *at
/*
* 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)
+static struct file *do_create(struct mq_namespace *mq_ns, struct dentry *dir,
+ struct dentry *dentry, int oflag, mode_t mode,
+ struct mq_attr __user *u_attr)
{
struct mq_attr attr;
int ret;
@@ -607,7 +633,7 @@ static struct file *do_create(struct den
if (copy_from_user(&attr, u_attr, sizeof(attr)))
goto out;
ret = -EINVAL;
- if (!mq_attr_ok(&attr))
+ if (!mq_attr_ok(mq_ns, &attr))
goto out;
/* store for use during create */
dentry->d_fsdata = &attr;
@@ -619,33 +645,34 @@ static struct file *do_create(struct den
if (ret)
goto out;
- return dentry_open(dentry, mqueue_mnt, oflag);
+ return dentry_open(dentry, mq_ns->mnt, oflag);
out:
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(mq_ns->mnt);
return ERR_PTR(ret);
}
/* Opens existing queue */
-static struct file *do_open(struct dentry *dentry, int oflag)
+static struct file *do_open(struct mq_namespace *mq_ns, struct dentry *dentry,
+ int oflag)
{
static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
MAY_READ | MAY_WRITE };
if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(mq_ns->mnt);
return ERR_PTR(-EINVAL);
}
if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) {
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(mq_ns->mnt);
return ERR_PTR(-EACCES);
}
- return dentry_open(dentry, mqueue_mnt, oflag);
+ return dentry_open(dentry, mq_ns->mnt, oflag);
}
asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
@@ -655,6 +682,7 @@ asmlinkage long sys_mq_open(const char _
struct file *filp;
char *name;
int fd, error;
+ struct mq_namespace *mq_ns = &init_mq_ns;
error = audit_mq_open(oflag, mode, u_attr);
if (error != 0)
@@ -667,13 +695,13 @@ asmlinkage long sys_mq_open(const char _
if (fd < 0)
goto out_putname;
- mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ mutex_lock(&mq_ns->mnt->mnt_root->d_inode->i_mutex);
+ dentry = lookup_one_len(name, mq_ns->mnt->mnt_root, strlen(name));
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
goto out_err;
}
- mntget(mqueue_mnt);
+ mntget(mq_ns->mnt);
if (oflag & O_CREAT) {
if (dentry->d_inode) { /* entry already exists */
@@ -681,12 +709,12 @@ asmlinkage long sys_mq_open(const char _
error = -EEXIST;
if (oflag & O_EXCL)
goto out;
- filp = do_open(dentry, oflag);
+ filp = do_open(mq_ns, dentry, oflag);
} else {
- error = mnt_want_write(mqueue_mnt);
+ error = mnt_want_write(mq_ns->mnt);
if (error)
goto out;
- filp = do_create(mqueue_mnt->mnt_root, dentry,
+ filp = do_create(mq_ns, mq_ns->mnt->mnt_root, dentry,
oflag, mode, u_attr);
}
} else {
@@ -694,7 +722,7 @@ asmlinkage long sys_mq_open(const char _
if (!dentry->d_inode)
goto out;
audit_inode(name, dentry);
- filp = do_open(dentry, oflag);
+ filp = do_open(mq_ns, dentry, oflag);
}
if (IS_ERR(filp)) {
@@ -708,13 +736,13 @@ asmlinkage long sys_mq_open(const char _
out:
dput(dentry);
- mntput(mqueue_mnt);
+ mntput(mq_ns->mnt);
out_putfd:
put_unused_fd(fd);
out_err:
fd = error;
out_upsem:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+ mutex_unlock(&mq_ns->mnt->mnt_root->d_inode->i_mutex);
out_putname:
putname(name);
return fd;
@@ -726,14 +754,15 @@ asmlinkage long sys_mq_unlink(const char
char *name;
struct dentry *dentry;
struct inode *inode = NULL;
+ struct mq_namespace *mq_ns = &init_mq_ns;
name = getname(u_name);
if (IS_ERR(name))
return PTR_ERR(name);
- mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex,
+ mutex_lock_nested(&mq_ns->mnt->mnt_root->d_inode->i_mutex,
I_MUTEX_PARENT);
- dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+ dentry = lookup_one_len(name, mq_ns->mnt->mnt_root, strlen(name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock;
@@ -747,16 +776,16 @@ asmlinkage long sys_mq_unlink(const char
inode = dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
- err = mnt_want_write(mqueue_mnt);
+ err = mnt_want_write(mq_ns->mnt);
if (err)
goto out_err;
err = vfs_unlink(dentry->d_parent->d_inode, dentry);
- mnt_drop_write(mqueue_mnt);
+ mnt_drop_write(mq_ns->mnt);
out_err:
dput(dentry);
out_unlock:
- mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex);
+ mutex_unlock(&mq_ns->mnt->mnt_root->d_inode->i_mutex);
putname(name);
if (inode)
iput(inode);
@@ -1201,14 +1230,14 @@ static int msg_maxsize_limit_max = INT_M
static ctl_table mq_sysctls[] = {
{
.procname = "queues_max",
- .data = &queues_max,
+ .data = &init_mq_ns.queues_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.procname = "msg_max",
- .data = &msg_max,
+ .data = &init_mq_ns.msg_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
@@ -1217,7 +1246,7 @@ static ctl_table mq_sysctls[] = {
},
{
.procname = "msgsize_max",
- .data = &msgsize_max,
+ .data = &init_mq_ns.msgsize_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
@@ -1263,13 +1292,13 @@ static int __init init_mqueue_fs(void)
if (error)
goto out_sysctl;
- if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
- error = PTR_ERR(mqueue_mnt);
+ init_mq_ns.mnt = kern_mount(&mqueue_fs_type);
+ if (IS_ERR(init_mq_ns.mnt)) {
+ error = PTR_ERR(init_mq_ns.mnt);
goto out_filesystem;
}
/* internal initialization - not common for vfs */
- queues_count = 0;
spin_lock_init(&mq_lock);
return 0;
--
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