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Commit 32a7991b authored by Al Viro's avatar Al Viro
Browse files

tidy up namei.c a bit 



locking/unlocking for rcu walk taken to a couple of inline helpers

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3c0a6163

fs/namei.c

+21 −18
Original line number Diff line number Diff line
@@ -427,6 +427,18 @@ EXPORT_SYMBOL(path_put); 
 * to restart the path walk from the beginning in ref-walk mode.

 */



static inline void lock_rcu_walk(void)

{

	br_read_lock(&vfsmount_lock);

	rcu_read_lock();

}



static inline void unlock_rcu_walk(void)

{

	rcu_read_unlock();

	br_read_unlock(&vfsmount_lock);

}



/**

 * unlazy_walk - try to switch to ref-walk mode.

 * @nd: nameidata pathwalk data
@@ -480,8 +492,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) 
	}

	mntget(nd->path.mnt);



	rcu_read_unlock();

	br_read_unlock(&vfsmount_lock);

	unlock_rcu_walk();

	nd->flags &= ~LOOKUP_RCU;

	return 0;
@@ -522,15 +533,13 @@ static int complete_walk(struct nameidata *nd) 
		spin_lock(&dentry->d_lock);

		if (unlikely(!__d_rcu_to_refcount(dentry, nd->seq))) {

			spin_unlock(&dentry->d_lock);

			rcu_read_unlock();

			br_read_unlock(&vfsmount_lock);

			unlock_rcu_walk();

			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);

		unlock_rcu_walk();

	}



	if (likely(!(nd->flags & LOOKUP_JUMPED)))
@@ -985,8 +994,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
	nd->flags &= ~LOOKUP_RCU;

	if (!(nd->flags & LOOKUP_ROOT))

		nd->root.mnt = NULL;

	rcu_read_unlock();

	br_read_unlock(&vfsmount_lock);

	unlock_rcu_walk();

	return -ECHILD;

}
@@ -1323,8 +1331,7 @@ static void terminate_walk(struct nameidata *nd) 
		nd->flags &= ~LOOKUP_RCU;

		if (!(nd->flags & LOOKUP_ROOT))

			nd->root.mnt = NULL;

		rcu_read_unlock();

		br_read_unlock(&vfsmount_lock);

		unlock_rcu_walk();

	}

}
@@ -1691,8 +1698,7 @@ 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);

			rcu_read_lock();

			lock_rcu_walk();

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

		} else {

			path_get(&nd->path);
@@ -1704,8 +1710,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, 


	if (*name=='/') {

		if (flags & LOOKUP_RCU) {

			br_read_lock(&vfsmount_lock);

			rcu_read_lock();

			lock_rcu_walk();

			set_root_rcu(nd);

		} else {

			set_root(nd);
@@ -1717,8 +1722,7 @@ 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);

			rcu_read_lock();

			lock_rcu_walk();



			do {

				seq = read_seqcount_begin(&fs->seq);
@@ -1753,8 +1757,7 @@ 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);

			rcu_read_lock();

			lock_rcu_walk();

		} else {

			path_get(&file->f_path);

			fput_light(file, fput_needed);