X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fnamespace.c;h=55442a6cf22133d2c9687636b3e3ca788eacac53;hb=1ee48af22ed6dcddea8cdf93c7f2a268cbcf0d56;hp=bf478addb852b70c1ec036e33100f93031c5dc6b;hpb=3e8e7c93d7eb091463839b5212789c4aae09459e;p=linux-2.6-omap-h63xx.git

diff --git a/fs/namespace.c b/fs/namespace.c
index bf478addb85..55442a6cf22 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -8,36 +8,27 @@
  * Heavily rewritten.
  */
 
-#include <linux/config.h>
 #include <linux/syscalls.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
 #include <linux/init.h>
+#include <linux/kernel.h>
 #include <linux/quotaops.h>
 #include <linux/acct.h>
 #include <linux/capability.h>
 #include <linux/module.h>
+#include <linux/sysfs.h>
 #include <linux/seq_file.h>
 #include <linux/namespace.h>
 #include <linux/namei.h>
 #include <linux/security.h>
 #include <linux/mount.h>
+#include <linux/ramfs.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include "pnode.h"
 
-extern int __init init_rootfs(void);
-
-#ifdef CONFIG_SYSFS
-extern int __init sysfs_init(void);
-#else
-static inline int sysfs_init(void)
-{
-	return 0;
-}
-#endif
-
 /* spinlock for vfsmount related operations, inplace of dcache_lock */
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
 
@@ -86,6 +77,15 @@ struct vfsmount *alloc_vfsmnt(const char *name)
 	return mnt;
 }
 
+int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb)
+{
+	mnt->mnt_sb = sb;
+	mnt->mnt_root = dget(sb->s_root);
+	return 0;
+}
+
+EXPORT_SYMBOL(simple_set_mnt);
+
 void free_vfsmnt(struct vfsmount *mnt)
 {
 	kfree(mnt->mnt_devname);
@@ -133,7 +133,7 @@ struct vfsmount *lookup_mnt(struct vfsmount *mnt, struct dentry *dentry)
 
 static inline int check_mnt(struct vfsmount *mnt)
 {
-	return mnt->mnt_namespace == current->namespace;
+	return mnt->mnt_namespace == current->nsproxy->namespace;
 }
 
 static void touch_namespace(struct namespace *ns)
@@ -517,10 +517,8 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
 {
 	struct vfsmount *p;
 
-	for (p = mnt; p; p = next_mnt(p, mnt)) {
-		list_del(&p->mnt_hash);
-		list_add(&p->mnt_hash, kill);
-	}
+	for (p = mnt; p; p = next_mnt(p, mnt))
+		list_move(&p->mnt_hash, kill);
 
 	if (propagate)
 		propagate_umount(kill);
@@ -576,8 +574,8 @@ static int do_umount(struct vfsmount *mnt, int flags)
 	 */
 
 	lock_kernel();
-	if ((flags & MNT_FORCE) && sb->s_op->umount_begin)
-		sb->s_op->umount_begin(sb);
+	if (sb->s_op->umount_begin)
+		sb->s_op->umount_begin(mnt, flags);
 	unlock_kernel();
 
 	/*
@@ -832,7 +830,7 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
 	if (parent_nd) {
 		detach_mnt(source_mnt, parent_nd);
 		attach_mnt(source_mnt, nd);
-		touch_namespace(current->namespace);
+		touch_namespace(current->nsproxy->namespace);
 	} else {
 		mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt);
 		commit_tree(source_mnt);
@@ -1162,6 +1160,40 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts,
 	}
 }
 
+/*
+ * go through the vfsmounts we've just consigned to the graveyard to
+ * - check that they're still dead
+ * - delete the vfsmount from the appropriate namespace under lock
+ * - dispose of the corpse
+ */
+static void expire_mount_list(struct list_head *graveyard, struct list_head *mounts)
+{
+	struct namespace *namespace;
+	struct vfsmount *mnt;
+
+	while (!list_empty(graveyard)) {
+		LIST_HEAD(umounts);
+		mnt = list_entry(graveyard->next, struct vfsmount, mnt_expire);
+		list_del_init(&mnt->mnt_expire);
+
+		/* don't do anything if the namespace is dead - all the
+		 * vfsmounts from it are going away anyway */
+		namespace = mnt->mnt_namespace;
+		if (!namespace || !namespace->root)
+			continue;
+		get_namespace(namespace);
+
+		spin_unlock(&vfsmount_lock);
+		down_write(&namespace_sem);
+		expire_mount(mnt, mounts, &umounts);
+		up_write(&namespace_sem);
+		release_mounts(&umounts);
+		mntput(mnt);
+		put_namespace(namespace);
+		spin_lock(&vfsmount_lock);
+	}
+}
+
 /*
  * process a list of expirable mountpoints with the intent of discarding any
  * mountpoints that aren't in use and haven't been touched since last we came
@@ -1169,7 +1201,6 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts,
  */
 void mark_mounts_for_expiry(struct list_head *mounts)
 {
-	struct namespace *namespace;
 	struct vfsmount *mnt, *next;
 	LIST_HEAD(graveyard);
 
@@ -1193,38 +1224,79 @@ void mark_mounts_for_expiry(struct list_head *mounts)
 		list_move(&mnt->mnt_expire, &graveyard);
 	}
 
-	/*
-	 * go through the vfsmounts we've just consigned to the graveyard to
-	 * - check that they're still dead
-	 * - delete the vfsmount from the appropriate namespace under lock
-	 * - dispose of the corpse
-	 */
-	while (!list_empty(&graveyard)) {
-		LIST_HEAD(umounts);
-		mnt = list_entry(graveyard.next, struct vfsmount, mnt_expire);
-		list_del_init(&mnt->mnt_expire);
+	expire_mount_list(&graveyard, mounts);
 
-		/* don't do anything if the namespace is dead - all the
-		 * vfsmounts from it are going away anyway */
-		namespace = mnt->mnt_namespace;
-		if (!namespace || !namespace->root)
+	spin_unlock(&vfsmount_lock);
+}
+
+EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
+
+/*
+ * Ripoff of 'select_parent()'
+ *
+ * search the list of submounts for a given mountpoint, and move any
+ * shrinkable submounts to the 'graveyard' list.
+ */
+static int select_submounts(struct vfsmount *parent, struct list_head *graveyard)
+{
+	struct vfsmount *this_parent = parent;
+	struct list_head *next;
+	int found = 0;
+
+repeat:
+	next = this_parent->mnt_mounts.next;
+resume:
+	while (next != &this_parent->mnt_mounts) {
+		struct list_head *tmp = next;
+		struct vfsmount *mnt = list_entry(tmp, struct vfsmount, mnt_child);
+
+		next = tmp->next;
+		if (!(mnt->mnt_flags & MNT_SHRINKABLE))
 			continue;
-		get_namespace(namespace);
+		/*
+		 * Descend a level if the d_mounts list is non-empty.
+		 */
+		if (!list_empty(&mnt->mnt_mounts)) {
+			this_parent = mnt;
+			goto repeat;
+		}
 
-		spin_unlock(&vfsmount_lock);
-		down_write(&namespace_sem);
-		expire_mount(mnt, mounts, &umounts);
-		up_write(&namespace_sem);
-		release_mounts(&umounts);
-		mntput(mnt);
-		put_namespace(namespace);
-		spin_lock(&vfsmount_lock);
+		if (!propagate_mount_busy(mnt, 1)) {
+			mntget(mnt);
+			list_move_tail(&mnt->mnt_expire, graveyard);
+			found++;
+		}
 	}
+	/*
+	 * All done at this level ... ascend and resume the search
+	 */
+	if (this_parent != parent) {
+		next = this_parent->mnt_child.next;
+		this_parent = this_parent->mnt_parent;
+		goto resume;
+	}
+	return found;
+}
+
+/*
+ * process a list of expirable mountpoints with the intent of discarding any
+ * submounts of a specific parent mountpoint
+ */
+void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts)
+{
+	LIST_HEAD(graveyard);
+	int found;
+
+	spin_lock(&vfsmount_lock);
+
+	/* extract submounts of 'mountpoint' from the expiration list */
+	while ((found = select_submounts(mountpoint, &graveyard)) != 0)
+		expire_mount_list(&graveyard, mounts);
 
 	spin_unlock(&vfsmount_lock);
 }
 
-EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
+EXPORT_SYMBOL_GPL(shrink_submounts);
 
 /*
  * Some copy_from_user() implementations do not return the exact number of
@@ -1369,7 +1441,7 @@ dput_out:
  */
 struct namespace *dup_namespace(struct task_struct *tsk, struct fs_struct *fs)
 {
-	struct namespace *namespace = tsk->namespace;
+	struct namespace *namespace = tsk->nsproxy->namespace;
 	struct namespace *new_ns;
 	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL;
 	struct vfsmount *p, *q;
@@ -1436,7 +1508,7 @@ struct namespace *dup_namespace(struct task_struct *tsk, struct fs_struct *fs)
 
 int copy_namespace(int flags, struct task_struct *tsk)
 {
-	struct namespace *namespace = tsk->namespace;
+	struct namespace *namespace = tsk->nsproxy->namespace;
 	struct namespace *new_ns;
 	int err = 0;
 
@@ -1459,7 +1531,7 @@ int copy_namespace(int flags, struct task_struct *tsk)
 		goto out;
 	}
 
-	tsk->namespace = new_ns;
+	tsk->nsproxy->namespace = new_ns;
 
 out:
 	put_namespace(namespace);
@@ -1682,7 +1754,7 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
 	detach_mnt(user_nd.mnt, &root_parent);
 	attach_mnt(user_nd.mnt, &old_nd);     /* mount old root on put_old */
 	attach_mnt(new_nd.mnt, &root_parent); /* mount new_root on / */
-	touch_namespace(current->namespace);
+	touch_namespace(current->nsproxy->namespace);
 	spin_unlock(&vfsmount_lock);
 	chroot_fs_refs(&user_nd, &new_nd);
 	security_sb_post_pivotroot(&user_nd, &new_nd);
@@ -1708,7 +1780,6 @@ static void __init init_mount_tree(void)
 {
 	struct vfsmount *mnt;
 	struct namespace *namespace;
-	struct task_struct *g, *p;
 
 	mnt = do_kern_mount("rootfs", 0, "rootfs", NULL);
 	if (IS_ERR(mnt))
@@ -1724,13 +1795,8 @@ static void __init init_mount_tree(void)
 	namespace->root = mnt;
 	mnt->mnt_namespace = namespace;
 
-	init_task.namespace = namespace;
-	read_lock(&tasklist_lock);
-	do_each_thread(g, p) {
-		get_namespace(namespace);
-		p->namespace = namespace;
-	} while_each_thread(g, p);
-	read_unlock(&tasklist_lock);
+	init_task.nsproxy->namespace = namespace;
+	get_namespace(namespace);
 
 	set_fs_pwd(current->fs, namespace->root, namespace->root->mnt_root);
 	set_fs_root(current->fs, namespace->root, namespace->root->mnt_root);
@@ -1741,6 +1807,7 @@ void __init mnt_init(unsigned long mempages)
 	struct list_head *d;
 	unsigned int nr_hash;
 	int i;
+	int err;
 
 	init_rwsem(&namespace_sem);
 
@@ -1781,8 +1848,14 @@ void __init mnt_init(unsigned long mempages)
 		d++;
 		i--;
 	} while (i);
-	sysfs_init();
-	subsystem_register(&fs_subsys);
+	err = sysfs_init();
+	if (err)
+		printk(KERN_WARNING "%s: sysfs_init error: %d\n",
+			__FUNCTION__, err);
+	err = subsystem_register(&fs_subsys);
+	if (err)
+		printk(KERN_WARNING "%s: subsystem_register error: %d\n",
+			__FUNCTION__, err);
 	init_rootfs();
 	init_mount_tree();
 }