Commit 474279dc authored by Al Viro's avatar Al Viro
Browse files

split __lookup_mnt() in two functions 



Instead of passing the direction as argument (and checking it on every
step through the hash chain), just have separate __lookup_mnt() and
__lookup_mnt_last().  And use the standard iterators...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7eb5e882

fs/mount.h

+2 −1
Original line number Diff line number Diff line
@@ -77,7 +77,8 @@ static inline int is_mounted(struct vfsmount *mnt) 
	return !IS_ERR_OR_NULL(real_mount(mnt));

}



extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);

extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);

extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);



static inline void get_mnt_ns(struct mnt_namespace *ns)

{

fs/namei.c

+2 −2
Original line number Diff line number Diff line
@@ -1111,7 +1111,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, 
		if (!d_mountpoint(path->dentry))

			break;



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

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

		if (!mounted)

			break;

		path->mnt = &mounted->mnt;
@@ -1132,7 +1132,7 @@ static void follow_mount_rcu(struct nameidata *nd) 
{

	while (d_mountpoint(nd->path.dentry)) {

		struct mount *mounted;

		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1);

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

		if (!mounted)

			break;

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

fs/namespace.c

+23 −19
Original line number Diff line number Diff line
@@ -548,29 +548,33 @@ static void free_vfsmnt(struct mount *mnt) 
}



/*

 * find the first or last mount at @dentry on vfsmount @mnt depending on

 * @dir. If @dir is set return the first mount else return the last mount.

 * find the first mount at @dentry on vfsmount @mnt.

 * vfsmount_lock must be held for read or write.

 */

struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry,

			      int dir)

struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry)

{

	struct list_head *head = mount_hashtable + hash(mnt, dentry);

	struct list_head *tmp = head;

	struct mount *p, *found = NULL;

	struct mount *p;



	for (;;) {

		tmp = dir ? tmp->next : tmp->prev;

		p = NULL;

		if (tmp == head)

			break;

		p = list_entry(tmp, struct mount, mnt_hash);

		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) {

			found = p;

			break;

		}

	list_for_each_entry(p, head, mnt_hash)

		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry)

			return p;

	return NULL;

}

	return found;



/*

 * find the last mount at @dentry on vfsmount @mnt.

 * vfsmount_lock must be held for read or write.

 */

struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry)

{

	struct list_head *head = mount_hashtable + hash(mnt, dentry);

	struct mount *p;



	list_for_each_entry_reverse(p, head, mnt_hash)

		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry)

			return p;

	return NULL;

}



/*
@@ -594,7 +598,7 @@ struct vfsmount *lookup_mnt(struct path *path) 
	struct mount *child_mnt;



	br_read_lock(&vfsmount_lock);

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

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

	if (child_mnt) {

		mnt_add_count(child_mnt, 1);

		br_read_unlock(&vfsmount_lock);

fs/pnode.c

+3 −3
Original line number Diff line number Diff line
@@ -310,7 +310,7 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 


	for (m = propagation_next(parent, parent); m;

	     		m = propagation_next(m, parent)) {

		child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint, 0);

		child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint);

		if (child && list_empty(&child->mnt_mounts) &&

		    (ret = do_refcount_check(child, 1)))

			break;
@@ -332,8 +332,8 @@ static void __propagate_umount(struct mount *mnt) 
	for (m = propagation_next(parent, parent); m;

			m = propagation_next(m, parent)) {



		struct mount *child = __lookup_mnt(&m->mnt,

					mnt->mnt_mountpoint, 0);

		struct mount *child = __lookup_mnt_last(&m->mnt,

						mnt->mnt_mountpoint);

		/*

		 * umount the child only if the child has no

		 * other children