Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...

[linux-2.6-microblaze.git] / ipc / mqueue.c

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 360e564..a808f29 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -325,9 +325,8 @@ err:
 static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct inode *inode;
-       struct ipc_namespace *ns = data;
+       struct ipc_namespace *ns = sb->s_fs_info;
 
-       sb->s_fs_info = ns;
        sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
        sb->s_blocksize = PAGE_SIZE;
        sb->s_blocksize_bits = PAGE_SHIFT;
@@ -344,44 +343,18 @@ static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
        return 0;
 }
 
-static struct file_system_type mqueue_fs_type;
-/*
- * Return value is pinned only by reference in ->mq_mnt; it will
- * live until ipcns dies.  Caller does not need to drop it.
- */
-static struct vfsmount *mq_internal_mount(void)
-{
-       struct ipc_namespace *ns = current->nsproxy->ipc_ns;
-       struct vfsmount *m = ns->mq_mnt;
-       if (m)
-               return m;
-       m = kern_mount_data(&mqueue_fs_type, ns);
-       spin_lock(&mq_lock);
-       if (unlikely(ns->mq_mnt)) {
-               spin_unlock(&mq_lock);
-               if (!IS_ERR(m))
-                       kern_unmount(m);
-               return ns->mq_mnt;
-       }
-       if (!IS_ERR(m))
-               ns->mq_mnt = m;
-       spin_unlock(&mq_lock);
-       return m;
-}
-
 static struct dentry *mqueue_mount(struct file_system_type *fs_type,
                         int flags, const char *dev_name,
                         void *data)
 {
-       struct vfsmount *m;
-       if (flags & SB_KERNMOUNT)
-               return mount_nodev(fs_type, flags, data, mqueue_fill_super);
-       m = mq_internal_mount();
-       if (IS_ERR(m))
-               return ERR_CAST(m);
-       atomic_inc(&m->mnt_sb->s_active);
-       down_write(&m->mnt_sb->s_umount);
-       return dget(m->mnt_root);
+       struct ipc_namespace *ns;
+       if (flags & SB_KERNMOUNT) {
+               ns = data;
+               data = NULL;
+       } else {
+               ns = current->nsproxy->ipc_ns;
+       }
+       return mount_ns(fs_type, flags, data, ns, ns->user_ns, mqueue_fill_super);
 }
 
 static void init_once(void *foo)
@@ -578,10 +551,10 @@ static __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *po
 
        spin_lock(&info->lock);
        if (info->attr.mq_curmsgs)
-               retval = POLLIN | POLLRDNORM;
+               retval = EPOLLIN | EPOLLRDNORM;
 
        if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
-               retval |= POLLOUT | POLLWRNORM;
+               retval |= EPOLLOUT | EPOLLWRNORM;
        spin_unlock(&info->lock);
 
        return retval;
@@ -771,16 +744,13 @@ static int prepare_open(struct dentry *dentry, int oflag, int ro,
 static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
                      struct mq_attr *attr)
 {
-       struct vfsmount *mnt = mq_internal_mount();
-       struct dentry *root;
+       struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
+       struct dentry *root = mnt->mnt_root;
        struct filename *name;
        struct path path;
        int fd, error;
        int ro;
 
-       if (IS_ERR(mnt))
-               return PTR_ERR(mnt);
-
        audit_mq_open(oflag, mode, attr);
 
        if (IS_ERR(name = getname(u_name)))
@@ -791,7 +761,6 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
                goto out_putname;
 
        ro = mnt_want_write(mnt);       /* we'll drop it in any case */
-       root = mnt->mnt_root;
        inode_lock(d_inode(root));
        path.dentry = lookup_one_len(name->name, root, strlen(name->name));
        if (IS_ERR(path.dentry)) {
@@ -840,9 +809,6 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
        struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
        struct vfsmount *mnt = ipc_ns->mq_mnt;
 
-       if (!mnt)
-               return -ENOENT;
-
        name = getname(u_name);
        if (IS_ERR(name))
                return PTR_ERR(name);
@@ -1569,26 +1535,28 @@ int mq_init_ns(struct ipc_namespace *ns)
        ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
        ns->mq_msg_default   = DFLT_MSG;
        ns->mq_msgsize_default  = DFLT_MSGSIZE;
-       ns->mq_mnt = NULL;
 
+       ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
+       if (IS_ERR(ns->mq_mnt)) {
+               int err = PTR_ERR(ns->mq_mnt);
+               ns->mq_mnt = NULL;
+               return err;
+       }
        return 0;
 }
 
 void mq_clear_sbinfo(struct ipc_namespace *ns)
 {
-       if (ns->mq_mnt)
-               ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+       ns->mq_mnt->mnt_sb->s_fs_info = NULL;
 }
 
 void mq_put_mnt(struct ipc_namespace *ns)
 {
-       if (ns->mq_mnt)
-               kern_unmount(ns->mq_mnt);
+       kern_unmount(ns->mq_mnt);
 }
 
 static int __init init_mqueue_fs(void)
 {
-       struct vfsmount *m;
        int error;
 
        mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
@@ -1610,10 +1578,6 @@ static int __init init_mqueue_fs(void)
        if (error)
                goto out_filesystem;
 
-       m = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
-       if (IS_ERR(m))
-               goto out_filesystem;
-       init_ipc_ns.mq_mnt = m;
        return 0;
 
 out_filesystem: