Commit 962830df authored by Andi Kleen's avatar Andi Kleen Committed by Al Viro
Browse files

brlocks/lglocks: API cleanups 



lglocks and brlocks are currently generated with some complicated macros
in lglock.h.  But there's no reason to not just use common utility
functions and put all the data into a common data structure.

In preparation, this patch changes the API to look more like normal
function calls with pointers, not magic macros.

The patch is rather large because I move over all users in one go to keep
it bisectable.  This impacts the VFS somewhat in terms of lines changed.
But no actual behaviour change.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent eea62f83

fs/dcache.c

+2 −2
Original line number Diff line number Diff line
@@ -2575,7 +2575,7 @@ static int prepend_path(const struct path *path, 
	bool slash = false;

	int error = 0;



	br_read_lock(vfsmount_lock);

	br_read_lock(&vfsmount_lock);

	while (dentry != root->dentry || vfsmnt != root->mnt) {

		struct dentry * parent;
@@ -2606,7 +2606,7 @@ static int prepend_path(const struct path *path, 
		error = prepend(buffer, buflen, "/", 1);



out:

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);

	return error;



global_root:

fs/file_table.c

+8 −8
Original line number Diff line number Diff line
@@ -420,9 +420,9 @@ static inline void __file_sb_list_add(struct file *file, struct super_block *sb) 
 */

void file_sb_list_add(struct file *file, struct super_block *sb)

{

	lg_local_lock(files_lglock);

	lg_local_lock(&files_lglock);

	__file_sb_list_add(file, sb);

	lg_local_unlock(files_lglock);

	lg_local_unlock(&files_lglock);

}



/**
@@ -435,9 +435,9 @@ void file_sb_list_add(struct file *file, struct super_block *sb) 
void file_sb_list_del(struct file *file)

{

	if (!list_empty(&file->f_u.fu_list)) {

		lg_local_lock_cpu(files_lglock, file_list_cpu(file));

		lg_local_lock_cpu(&files_lglock, file_list_cpu(file));

		list_del_init(&file->f_u.fu_list);

		lg_local_unlock_cpu(files_lglock, file_list_cpu(file));

		lg_local_unlock_cpu(&files_lglock, file_list_cpu(file));

	}

}
@@ -484,7 +484,7 @@ void mark_files_ro(struct super_block *sb) 
	struct file *f;



retry:

	lg_global_lock(files_lglock);

	lg_global_lock(&files_lglock);

	do_file_list_for_each_entry(sb, f) {

		struct vfsmount *mnt;

		if (!S_ISREG(f->f_path.dentry->d_inode->i_mode))
@@ -501,12 +501,12 @@ retry: 
		file_release_write(f);

		mnt = mntget(f->f_path.mnt);

		/* This can sleep, so we can't hold the spinlock. */

		lg_global_unlock(files_lglock);

		lg_global_unlock(&files_lglock);

		mnt_drop_write(mnt);

		mntput(mnt);

		goto retry;

	} while_file_list_for_each_entry;

	lg_global_unlock(files_lglock);

	lg_global_unlock(&files_lglock);

}



void __init files_init(unsigned long mempages)
@@ -524,6 +524,6 @@ void __init files_init(unsigned long mempages) 
	n = (mempages * (PAGE_SIZE / 1024)) / 10;

	files_stat.max_files = max_t(unsigned long, n, NR_FILE);

	files_defer_init();

	lg_lock_init(files_lglock);

	lg_lock_init(&files_lglock, "files_lglock");

	percpu_counter_init(&nr_files, 0);

}

fs/namei.c

+12 −12
Original line number Diff line number Diff line
@@ -449,7 +449,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) 
	mntget(nd->path.mnt);



	rcu_read_unlock();

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);

	nd->flags &= ~LOOKUP_RCU;

	return 0;
@@ -507,14 +507,14 @@ static int complete_walk(struct nameidata *nd) 
		if (unlikely(!__d_rcu_to_refcount(dentry, nd->seq))) {

			spin_unlock(&dentry->d_lock);

			rcu_read_unlock();

			br_read_unlock(vfsmount_lock);

			br_read_unlock(&vfsmount_lock);

			return -ECHILD;

		}

		BUG_ON(nd->inode != dentry->d_inode);

		spin_unlock(&dentry->d_lock);

		mntget(nd->path.mnt);

		rcu_read_unlock();

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

	}



	if (likely(!(nd->flags & LOOKUP_JUMPED)))
@@ -681,15 +681,15 @@ int follow_up(struct path *path) 
	struct mount *parent;

	struct dentry *mountpoint;



	br_read_lock(vfsmount_lock);

	br_read_lock(&vfsmount_lock);

	parent = mnt->mnt_parent;

	if (&parent->mnt == path->mnt) {

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

		return 0;

	}

	mntget(&parent->mnt);

	mountpoint = dget(mnt->mnt_mountpoint);

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);

	dput(path->dentry);

	path->dentry = mountpoint;

	mntput(path->mnt);
@@ -947,7 +947,7 @@ failed: 
	if (!(nd->flags & LOOKUP_ROOT))

		nd->root.mnt = NULL;

	rcu_read_unlock();

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);

	return -ECHILD;

}
@@ -1265,7 +1265,7 @@ static void terminate_walk(struct nameidata *nd) 
		if (!(nd->flags & LOOKUP_ROOT))

			nd->root.mnt = NULL;

		rcu_read_unlock();

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

	}

}
@@ -1620,7 +1620,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, 
		nd->path = nd->root;

		nd->inode = inode;

		if (flags & LOOKUP_RCU) {

			br_read_lock(vfsmount_lock);

			br_read_lock(&vfsmount_lock);

			rcu_read_lock();

			nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);

		} else {
@@ -1633,7 +1633,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, 


	if (*name=='/') {

		if (flags & LOOKUP_RCU) {

			br_read_lock(vfsmount_lock);

			br_read_lock(&vfsmount_lock);

			rcu_read_lock();

			set_root_rcu(nd);

		} else {
@@ -1646,7 +1646,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, 
			struct fs_struct *fs = current->fs;

			unsigned seq;



			br_read_lock(vfsmount_lock);

			br_read_lock(&vfsmount_lock);

			rcu_read_lock();



			do {
@@ -1682,7 +1682,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, 
			if (fput_needed)

				*fp = file;

			nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);

			br_read_lock(vfsmount_lock);

			br_read_lock(&vfsmount_lock);

			rcu_read_lock();

		} else {

			path_get(&file->f_path);

fs/namespace.c

+70 −69
Original line number Diff line number Diff line
@@ -397,7 +397,7 @@ static int mnt_make_readonly(struct mount *mnt) 
{

	int ret = 0;



	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;

	/*

	 * After storing MNT_WRITE_HOLD, we'll read the counters. This store
@@ -431,15 +431,15 @@ static int mnt_make_readonly(struct mount *mnt) 
	 */

	smp_wmb();

	mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	return ret;

}



static void __mnt_unmake_readonly(struct mount *mnt)

{

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	mnt->mnt.mnt_flags &= ~MNT_READONLY;

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

}



int sb_prepare_remount_readonly(struct super_block *sb)
@@ -451,7 +451,7 @@ int sb_prepare_remount_readonly(struct super_block *sb) 
	if (atomic_long_read(&sb->s_remove_count))

		return -EBUSY;



	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {

		if (!(mnt->mnt.mnt_flags & MNT_READONLY)) {

			mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
@@ -473,7 +473,7 @@ int sb_prepare_remount_readonly(struct super_block *sb) 
		if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)

			mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);



	return err;

}
@@ -522,14 +522,14 @@ struct vfsmount *lookup_mnt(struct path *path) 
{

	struct mount *child_mnt;



	br_read_lock(vfsmount_lock);

	br_read_lock(&vfsmount_lock);

	child_mnt = __lookup_mnt(path->mnt, path->dentry, 1);

	if (child_mnt) {

		mnt_add_count(child_mnt, 1);

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

		return &child_mnt->mnt;

	} else {

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

		return NULL;

	}

}
@@ -714,9 +714,9 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void 
	mnt->mnt.mnt_sb = root->d_sb;

	mnt->mnt_mountpoint = mnt->mnt.mnt_root;

	mnt->mnt_parent = mnt;

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	return &mnt->mnt;

}

EXPORT_SYMBOL_GPL(vfs_kern_mount);
@@ -745,9 +745,9 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, 
		mnt->mnt.mnt_root = dget(root);

		mnt->mnt_mountpoint = mnt->mnt.mnt_root;

		mnt->mnt_parent = mnt;

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		list_add_tail(&mnt->mnt_instance, &sb->s_mounts);

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);



		if (flag & CL_SLAVE) {

			list_add(&mnt->mnt_slave, &old->mnt_slave_list);
@@ -803,35 +803,36 @@ static void mntput_no_expire(struct mount *mnt) 
{

put_again:

#ifdef CONFIG_SMP

	br_read_lock(vfsmount_lock);

	br_read_lock(&vfsmount_lock);

	if (likely(atomic_read(&mnt->mnt_longterm))) {

		mnt_add_count(mnt, -1);

		br_read_unlock(vfsmount_lock);

		br_read_unlock(&vfsmount_lock);

		return;

	}

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);



	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	mnt_add_count(mnt, -1);

	if (mnt_get_count(mnt)) {

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

		return;

	}

#else

	mnt_add_count(mnt, -1);

	if (likely(mnt_get_count(mnt)))

		return;

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

#endif

	if (unlikely(mnt->mnt_pinned)) {

		mnt_add_count(mnt, mnt->mnt_pinned + 1);

		mnt->mnt_pinned = 0;

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

		acct_auto_close_mnt(&mnt->mnt);

		goto put_again;

	}



	list_del(&mnt->mnt_instance);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	mntfree(mnt);

}
@@ -857,21 +858,21 @@ EXPORT_SYMBOL(mntget); 


void mnt_pin(struct vfsmount *mnt)

{

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	real_mount(mnt)->mnt_pinned++;

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

}

EXPORT_SYMBOL(mnt_pin);



void mnt_unpin(struct vfsmount *m)

{

	struct mount *mnt = real_mount(m);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	if (mnt->mnt_pinned) {

		mnt_add_count(mnt, 1);

		mnt->mnt_pinned--;

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

}

EXPORT_SYMBOL(mnt_unpin);
@@ -988,12 +989,12 @@ int may_umount_tree(struct vfsmount *m) 
	BUG_ON(!m);



	/* write lock needed for mnt_get_count */

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	for (p = mnt; p; p = next_mnt(p, mnt)) {

		actual_refs += mnt_get_count(p);

		minimum_refs += 2;

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);



	if (actual_refs > minimum_refs)

		return 0;
@@ -1020,10 +1021,10 @@ int may_umount(struct vfsmount *mnt) 
{

	int ret = 1;

	down_read(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	if (propagate_mount_busy(real_mount(mnt), 2))

		ret = 0;

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_read(&namespace_sem);

	return ret;

}
@@ -1040,13 +1041,13 @@ void release_mounts(struct list_head *head) 
			struct dentry *dentry;

			struct mount *m;



			br_write_lock(vfsmount_lock);

			br_write_lock(&vfsmount_lock);

			dentry = mnt->mnt_mountpoint;

			m = mnt->mnt_parent;

			mnt->mnt_mountpoint = mnt->mnt.mnt_root;

			mnt->mnt_parent = mnt;

			m->mnt_ghosts--;

			br_write_unlock(vfsmount_lock);

			br_write_unlock(&vfsmount_lock);

			dput(dentry);

			mntput(&m->mnt);

		}
@@ -1112,12 +1113,12 @@ static int do_umount(struct mount *mnt, int flags) 
		 * probably don't strictly need the lock here if we examined

		 * all race cases, but it's a slowpath.

		 */

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		if (mnt_get_count(mnt) != 2) {

			br_write_unlock(vfsmount_lock);

			br_write_unlock(&vfsmount_lock);

			return -EBUSY;

		}

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);



		if (!xchg(&mnt->mnt_expiry_mark, 1))

			return -EAGAIN;
@@ -1159,7 +1160,7 @@ static int do_umount(struct mount *mnt, int flags) 
	}



	down_write(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	event++;



	if (!(flags & MNT_DETACH))
@@ -1171,7 +1172,7 @@ static int do_umount(struct mount *mnt, int flags) 
			umount_tree(mnt, 1, &umount_list);

		retval = 0;

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_write(&namespace_sem);

	release_mounts(&umount_list);

	return retval;
@@ -1286,19 +1287,19 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, 
			q = clone_mnt(p, p->mnt.mnt_root, flag);

			if (!q)

				goto Enomem;

			br_write_lock(vfsmount_lock);

			br_write_lock(&vfsmount_lock);

			list_add_tail(&q->mnt_list, &res->mnt_list);

			attach_mnt(q, &path);

			br_write_unlock(vfsmount_lock);

			br_write_unlock(&vfsmount_lock);

		}

	}

	return res;

Enomem:

	if (res) {

		LIST_HEAD(umount_list);

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		umount_tree(res, 0, &umount_list);

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

		release_mounts(&umount_list);

	}

	return NULL;
@@ -1318,9 +1319,9 @@ void drop_collected_mounts(struct vfsmount *mnt) 
{

	LIST_HEAD(umount_list);

	down_write(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	umount_tree(real_mount(mnt), 0, &umount_list);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_write(&namespace_sem);

	release_mounts(&umount_list);

}
@@ -1448,7 +1449,7 @@ static int attach_recursive_mnt(struct mount *source_mnt, 
	if (err)

		goto out_cleanup_ids;



	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);



	if (IS_MNT_SHARED(dest_mnt)) {

		for (p = source_mnt; p; p = next_mnt(p, source_mnt))
@@ -1467,7 +1468,7 @@ static int attach_recursive_mnt(struct mount *source_mnt, 
		list_del_init(&child->mnt_hash);

		commit_tree(child);

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);



	return 0;
@@ -1565,10 +1566,10 @@ static int do_change_type(struct path *path, int flag) 
			goto out_unlock;

	}



	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))

		change_mnt_propagation(m, type);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);



 out_unlock:

	up_write(&namespace_sem);
@@ -1617,9 +1618,9 @@ static int do_loopback(struct path *path, char *old_name, 


	err = graft_tree(mnt, path);

	if (err) {

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		umount_tree(mnt, 0, &umount_list);

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

	}

out2:

	unlock_mount(path);
@@ -1677,16 +1678,16 @@ static int do_remount(struct path *path, int flags, int mnt_flags, 
	else

		err = do_remount_sb(sb, flags, data, 0);

	if (!err) {

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		mnt_flags |= mnt->mnt.mnt_flags & MNT_PROPAGATION_MASK;

		mnt->mnt.mnt_flags = mnt_flags;

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

	}

	up_write(&sb->s_umount);

	if (!err) {

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		touch_mnt_namespace(mnt->mnt_ns);

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

	}

	return err;

}
@@ -1893,9 +1894,9 @@ fail: 
	/* remove m from any expiration list it may be on */

	if (!list_empty(&mnt->mnt_expire)) {

		down_write(&namespace_sem);

		br_write_lock(vfsmount_lock);

		br_write_lock(&vfsmount_lock);

		list_del_init(&mnt->mnt_expire);

		br_write_unlock(vfsmount_lock);

		br_write_unlock(&vfsmount_lock);

		up_write(&namespace_sem);

	}

	mntput(m);
@@ -1911,11 +1912,11 @@ fail: 
void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)

{

	down_write(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);



	list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list);



	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_write(&namespace_sem);

}

EXPORT_SYMBOL(mnt_set_expiry);
@@ -1935,7 +1936,7 @@ void mark_mounts_for_expiry(struct list_head *mounts) 
		return;



	down_write(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);



	/* extract from the expiration list every vfsmount that matches the

	 * following criteria:
@@ -1954,7 +1955,7 @@ void mark_mounts_for_expiry(struct list_head *mounts) 
		touch_mnt_namespace(mnt->mnt_ns);

		umount_tree(mnt, 1, &umounts);

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_write(&namespace_sem);



	release_mounts(&umounts);
@@ -2218,9 +2219,9 @@ void mnt_make_shortterm(struct vfsmount *m) 
	struct mount *mnt = real_mount(m);

	if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))

		return;

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	atomic_dec(&mnt->mnt_longterm);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

#endif

}
@@ -2250,9 +2251,9 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, 
		return ERR_PTR(-ENOMEM);

	}

	new_ns->root = new;

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	list_add_tail(&new_ns->list, &new->mnt_list);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);



	/*

	 * Second pass: switch the tsk->fs->* elements and mark new vfsmounts
@@ -2416,9 +2417,9 @@ bool is_path_reachable(struct mount *mnt, struct dentry *dentry, 
int path_is_under(struct path *path1, struct path *path2)

{

	int res;

	br_read_lock(vfsmount_lock);

	br_read_lock(&vfsmount_lock);

	res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);

	br_read_unlock(vfsmount_lock);

	br_read_unlock(&vfsmount_lock);

	return res;

}

EXPORT_SYMBOL(path_is_under);
@@ -2505,7 +2506,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, 
	/* make sure we can reach put_old from new_root */

	if (!is_path_reachable(real_mount(old.mnt), old.dentry, &new))

		goto out4;

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	detach_mnt(new_mnt, &parent_path);

	detach_mnt(root_mnt, &root_parent);

	/* mount old root on put_old */
@@ -2513,7 +2514,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, 
	/* mount new_root on / */

	attach_mnt(new_mnt, &root_parent);

	touch_mnt_namespace(current->nsproxy->mnt_ns);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	chroot_fs_refs(&root, &new);

	error = 0;

out4:
@@ -2576,7 +2577,7 @@ void __init mnt_init(void) 
	for (u = 0; u < HASH_SIZE; u++)

		INIT_LIST_HEAD(&mount_hashtable[u]);



	br_lock_init(vfsmount_lock);

	br_lock_init(&vfsmount_lock);



	err = sysfs_init();

	if (err)
@@ -2596,9 +2597,9 @@ void put_mnt_ns(struct mnt_namespace *ns) 
	if (!atomic_dec_and_test(&ns->count))

		return;

	down_write(&namespace_sem);

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	umount_tree(ns->root, 0, &umount_list);

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	up_write(&namespace_sem);

	release_mounts(&umount_list);

	kfree(ns);

fs/pnode.c

+2 −2
Original line number Diff line number Diff line
@@ -257,12 +257,12 @@ int propagate_mnt(struct mount *dest_mnt, struct dentry *dest_dentry, 
		prev_src_mnt  = child;

	}

out:

	br_write_lock(vfsmount_lock);

	br_write_lock(&vfsmount_lock);

	while (!list_empty(&tmp_list)) {

		child = list_first_entry(&tmp_list, struct mount, mnt_hash);

		umount_tree(child, 0, &umount_list);

	}

	br_write_unlock(vfsmount_lock);

	br_write_unlock(&vfsmount_lock);

	release_mounts(&umount_list);

	return ret;

}

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