Commit 7521f22b authored by Al Viro's avatar Al Viro
Browse files

handle_dots(), follow_dotdot{,_rcu}(): preparation to switch to step_into() 



Right now the tail ends of follow_dotdot{,_rcu}() are pretty
much the open-coded analogues of step_into().  The differences:
	* the lack of proper LOOKUP_NO_XDEV handling in non-RCU case
(arguably a bug)
	* the lack of ->d_manage() handling (again, arguably a bug)

Adjust the calling conventions so that on the next step with could
just switch those functions to returning step_into().

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 957dd41d

fs/namei.c

+25 −27
Original line number Diff line number Diff line
@@ -1687,7 +1687,7 @@ static const char *step_into(struct nameidata *nd, int flags, 
	return pick_link(nd, &path, inode, seq, flags);

}



static int follow_dotdot_rcu(struct nameidata *nd)

static const char *follow_dotdot_rcu(struct nameidata *nd)

{

	struct dentry *parent = NULL;

	struct inode *inode = nd->inode;
@@ -1703,9 +1703,9 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
			inode = parent->d_inode;

			seq = read_seqcount_begin(&parent->d_seq);

			if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))

				return -ECHILD;

				return ERR_PTR(-ECHILD);

			if (unlikely(!path_connected(nd->path.mnt, parent)))

				return -ECHILD;

				return ERR_PTR(-ECHILD);

			break;

		} else {

			struct mount *mnt = real_mount(nd->path.mnt);
@@ -1714,11 +1714,11 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
			struct inode *inode2 = mountpoint->d_inode;

			unsigned seq = read_seqcount_begin(&mountpoint->d_seq);

			if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))

				return -ECHILD;

				return ERR_PTR(-ECHILD);

			if (&mparent->mnt == nd->path.mnt)

				break;

			if (unlikely(nd->flags & LOOKUP_NO_XDEV))

				return -ECHILD;

				return ERR_PTR(-ECHILD);

			/* we know that mountpoint was pinned */

			nd->path.dentry = mountpoint;

			nd->path.mnt = &mparent->mnt;
@@ -1728,7 +1728,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
	}

	if (unlikely(!parent)) {

		if (unlikely(nd->flags & LOOKUP_BENEATH))

			return -ECHILD;

			return ERR_PTR(-ECHILD);

	} else {

		nd->path.dentry = parent;

		nd->seq = seq;
@@ -1737,21 +1737,21 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
		struct mount *mounted;

		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);

		if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))

			return -ECHILD;

			return ERR_PTR(-ECHILD);

		if (!mounted)

			break;

		if (unlikely(nd->flags & LOOKUP_NO_XDEV))

			return -ECHILD;

			return ERR_PTR(-ECHILD);

		nd->path.mnt = &mounted->mnt;

		nd->path.dentry = mounted->mnt.mnt_root;

		inode = nd->path.dentry->d_inode;

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

	}

	nd->inode = inode;

	return 0;

	return NULL;

}



static int follow_dotdot(struct nameidata *nd)

static const char *follow_dotdot(struct nameidata *nd)

{

	struct dentry *parent = NULL;

	while (1) {
@@ -1762,34 +1762,34 @@ static int follow_dotdot(struct nameidata *nd) 
			parent = dget_parent(nd->path.dentry);

			if (unlikely(!path_connected(nd->path.mnt, parent))) {

				dput(parent);

				return -ENOENT;

				return ERR_PTR(-ENOENT);

			}

			break;

		}

		if (!follow_up(&nd->path))

			break;

		if (unlikely(nd->flags & LOOKUP_NO_XDEV))

			return -EXDEV;

			return ERR_PTR(-EXDEV);

	}

	if (unlikely(!parent)) {

		if (unlikely(nd->flags & LOOKUP_BENEATH))

			return -EXDEV;

			return ERR_PTR(-EXDEV);

	} else {

		dput(nd->path.dentry);

		nd->path.dentry = parent;

	}

	follow_mount(&nd->path);

	nd->inode = nd->path.dentry->d_inode;

	return 0;

	return NULL;

}



static inline int handle_dots(struct nameidata *nd, int type)

static const char *handle_dots(struct nameidata *nd, int type)

{

	if (type == LAST_DOTDOT) {

		int error = 0;

		const char *error = NULL;



		if (!nd->root.mnt) {

			error = set_root(nd);

			error = ERR_PTR(set_root(nd));

			if (error)

				return error;

		}
@@ -1809,12 +1809,12 @@ static inline int handle_dots(struct nameidata *nd, int type) 
			 */

			smp_rmb();

			if (unlikely(__read_seqcount_retry(&mount_lock.seqcount, nd->m_seq)))

				return -EAGAIN;

				return ERR_PTR(-EAGAIN);

			if (unlikely(__read_seqcount_retry(&rename_lock.seqcount, nd->r_seq)))

				return -EAGAIN;

				return ERR_PTR(-EAGAIN);

		}

	}

	return 0;

	return NULL;

}



static const char *walk_component(struct nameidata *nd, int flags)
@@ -1822,7 +1822,6 @@ static const char *walk_component(struct nameidata *nd, int flags) 
	struct dentry *dentry;

	struct inode *inode;

	unsigned seq;

	int err;

	/*

	 * "." and ".." are special - ".." especially so because it has

	 * to be able to know about the current root directory and
@@ -1831,8 +1830,7 @@ static const char *walk_component(struct nameidata *nd, int flags) 
	if (unlikely(nd->last_type != LAST_NORM)) {

		if (!(flags & WALK_MORE) && nd->depth)

			put_link(nd);

		err = handle_dots(nd, nd->last_type);

		return ERR_PTR(err);

		return handle_dots(nd, nd->last_type);

	}

	dentry = lookup_fast(nd, &inode, &seq);

	if (IS_ERR(dentry))
@@ -3128,10 +3126,10 @@ static const char *open_last_lookups(struct nameidata *nd, 
	if (nd->last_type != LAST_NORM) {

		if (nd->depth)

			put_link(nd);

		error = handle_dots(nd, nd->last_type);

		if (likely(!error))

			error = complete_walk(nd);

		return ERR_PTR(error);

		res = handle_dots(nd, nd->last_type);

		if (likely(!res))

			res = ERR_PTR(complete_walk(nd));

		return res;

	}



	if (!(open_flag & O_CREAT)) {

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