X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fnamespace.c;h=bf478addb852b70c1ec036e33100f93031c5dc6b;hb=e3474a8eb38e48dea6690d1fabd75f3c7fd2f93f;hp=2ca6145f43d6b047a4b98eabab9e1ccfd447ba81;hpb=a62e68488dd5ddb07776555fd7e0435c6d021ac1;p=linux-2.6-omap-h63xx.git

diff --git a/fs/namespace.c b/fs/namespace.c
index 2ca6145f43d..bf478addb85 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/quotaops.h>
 #include <linux/acct.h>
+#include <linux/capability.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <linux/namespace.h>
@@ -42,11 +43,15 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
 
 static int event;
 
-static struct list_head *mount_hashtable;
+static struct list_head *mount_hashtable __read_mostly;
 static int hash_mask __read_mostly, hash_bits __read_mostly;
-static kmem_cache_t *mnt_cache;
+static kmem_cache_t *mnt_cache __read_mostly;
 static struct rw_semaphore namespace_sem;
 
+/* /sys/fs */
+decl_subsys(fs, NULL, NULL);
+EXPORT_SYMBOL_GPL(fs_subsys);
+
 static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry)
 {
 	unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES);
@@ -394,6 +399,44 @@ struct seq_operations mounts_op = {
 	.show	= show_vfsmnt
 };
 
+static int show_vfsstat(struct seq_file *m, void *v)
+{
+	struct vfsmount *mnt = v;
+	int err = 0;
+
+	/* device */
+	if (mnt->mnt_devname) {
+		seq_puts(m, "device ");
+		mangle(m, mnt->mnt_devname);
+	} else
+		seq_puts(m, "no device");
+
+	/* mount point */
+	seq_puts(m, " mounted on ");
+	seq_path(m, mnt, mnt->mnt_root, " \t\n\\");
+	seq_putc(m, ' ');
+
+	/* file system type */
+	seq_puts(m, "with fstype ");
+	mangle(m, mnt->mnt_sb->s_type->name);
+
+	/* optional statistics */
+	if (mnt->mnt_sb->s_op->show_stats) {
+		seq_putc(m, ' ');
+		err = mnt->mnt_sb->s_op->show_stats(m, mnt);
+	}
+
+	seq_putc(m, '\n');
+	return err;
+}
+
+struct seq_operations mountstats_op = {
+	.start	= m_start,
+	.next	= m_next,
+	.stop	= m_stop,
+	.show	= show_vfsstat,
+};
+
 /**
  * may_umount_tree - check if a mount tree is busy
  * @mnt: root of mount tree
@@ -416,9 +459,9 @@ int may_umount_tree(struct vfsmount *mnt)
 	spin_unlock(&vfsmount_lock);
 
 	if (actual_refs > minimum_refs)
-		return -EBUSY;
+		return 0;
 
-	return 0;
+	return 1;
 }
 
 EXPORT_SYMBOL(may_umount_tree);
@@ -438,10 +481,10 @@ EXPORT_SYMBOL(may_umount_tree);
  */
 int may_umount(struct vfsmount *mnt)
 {
-	int ret = 0;
+	int ret = 1;
 	spin_lock(&vfsmount_lock);
 	if (propagate_mount_busy(mnt, 2))
-		ret = -EBUSY;
+		ret = 0;
 	spin_unlock(&vfsmount_lock);
 	return ret;
 }
@@ -489,7 +532,7 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
 		p->mnt_namespace = NULL;
 		list_del_init(&p->mnt_child);
 		if (p->mnt_parent != p)
-			mnt->mnt_mountpoint->d_mounted--;
+			p->mnt_mountpoint->d_mounted--;
 		change_mnt_propagation(p, MS_PRIVATE);
 	}
 }
@@ -1320,30 +1363,20 @@ dput_out:
 	return retval;
 }
 
-int copy_namespace(int flags, struct task_struct *tsk)
+/*
+ * Allocate a new namespace structure and populate it with contents
+ * copied from the namespace of the passed in task structure.
+ */
+struct namespace *dup_namespace(struct task_struct *tsk, struct fs_struct *fs)
 {
 	struct namespace *namespace = tsk->namespace;
 	struct namespace *new_ns;
 	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL;
-	struct fs_struct *fs = tsk->fs;
 	struct vfsmount *p, *q;
 
-	if (!namespace)
-		return 0;
-
-	get_namespace(namespace);
-
-	if (!(flags & CLONE_NEWNS))
-		return 0;
-
-	if (!capable(CAP_SYS_ADMIN)) {
-		put_namespace(namespace);
-		return -EPERM;
-	}
-
 	new_ns = kmalloc(sizeof(struct namespace), GFP_KERNEL);
 	if (!new_ns)
-		goto out;
+		return NULL;
 
 	atomic_set(&new_ns->count, 1);
 	INIT_LIST_HEAD(&new_ns->list);
@@ -1357,7 +1390,7 @@ int copy_namespace(int flags, struct task_struct *tsk)
 	if (!new_ns->root) {
 		up_write(&namespace_sem);
 		kfree(new_ns);
-		goto out;
+		return NULL;
 	}
 	spin_lock(&vfsmount_lock);
 	list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
@@ -1391,8 +1424,6 @@ int copy_namespace(int flags, struct task_struct *tsk)
 	}
 	up_write(&namespace_sem);
 
-	tsk->namespace = new_ns;
-
 	if (rootmnt)
 		mntput(rootmnt);
 	if (pwdmnt)
@@ -1400,12 +1431,39 @@ int copy_namespace(int flags, struct task_struct *tsk)
 	if (altrootmnt)
 		mntput(altrootmnt);
 
-	put_namespace(namespace);
-	return 0;
+	return new_ns;
+}
+
+int copy_namespace(int flags, struct task_struct *tsk)
+{
+	struct namespace *namespace = tsk->namespace;
+	struct namespace *new_ns;
+	int err = 0;
+
+	if (!namespace)
+		return 0;
+
+	get_namespace(namespace);
+
+	if (!(flags & CLONE_NEWNS))
+		return 0;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		err = -EPERM;
+		goto out;
+	}
+
+	new_ns = dup_namespace(tsk, tsk->fs);
+	if (!new_ns) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	tsk->namespace = new_ns;
 
 out:
 	put_namespace(namespace);
-	return -ENOMEM;
+	return err;
 }
 
 asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name,
@@ -1724,6 +1782,7 @@ void __init mnt_init(unsigned long mempages)
 		i--;
 	} while (i);
 	sysfs_init();
+	subsystem_register(&fs_subsys);
 	init_rootfs();
 	init_mount_tree();
 }