diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 79743d146be6..0c1d91756528 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1438,12 +1438,15 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 	struct dentry *temp;
 	char *path;
 	int len, pos;
+	unsigned seq;
 
 	if (dentry == NULL)
 		return ERR_PTR(-EINVAL);
 
 retry:
 	len = 0;
+	seq = read_seqbegin(&rename_lock);
+	rcu_read_lock();
 	for (temp = dentry; !IS_ROOT(temp);) {
 		struct inode *inode = temp->d_inode;
 		if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
@@ -1455,10 +1458,12 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 			len += 1 + temp->d_name.len;
 		temp = temp->d_parent;
 		if (temp == NULL) {
+			rcu_read_unlock();
 			pr_err("build_path corrupt dentry %p\n", dentry);
 			return ERR_PTR(-EINVAL);
 		}
 	}
+	rcu_read_unlock();
 	if (len)
 		len--;  /* no leading '/' */
 
@@ -1467,9 +1472,12 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 		return ERR_PTR(-ENOMEM);
 	pos = len;
 	path[pos] = 0;	/* trailing null */
+	rcu_read_lock();
 	for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
-		struct inode *inode = temp->d_inode;
+		struct inode *inode;
 
+		spin_lock(&temp->d_lock);
+		inode = temp->d_inode;
 		if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
 			dout("build_path path+%d: %p SNAPDIR\n",
 			     pos, temp);
@@ -1478,21 +1486,26 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 			break;
 		} else {
 			pos -= temp->d_name.len;
-			if (pos < 0)
+			if (pos < 0) {
+				spin_unlock(&temp->d_lock);
 				break;
+			}
 			strncpy(path + pos, temp->d_name.name,
 				temp->d_name.len);
 		}
+		spin_unlock(&temp->d_lock);
 		if (pos)
 			path[--pos] = '/';
 		temp = temp->d_parent;
 		if (temp == NULL) {
+			rcu_read_unlock();
 			pr_err("build_path corrupt dentry\n");
 			kfree(path);
 			return ERR_PTR(-EINVAL);
 		}
 	}
-	if (pos != 0) {
+	rcu_read_unlock();
+	if (pos != 0 || read_seqretry(&rename_lock, seq)) {
 		pr_err("build_path did not end path lookup where "
 		       "expected, namelen is %d, pos is %d\n", len, pos);
 		/* presumably this is only possible if racing with a
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 81914df47ef1..fa8c21d913bc 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -55,6 +55,7 @@ build_path_from_dentry(struct dentry *direntry)
 	char dirsep;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+	unsigned seq;
 
 	if (direntry == NULL)
 		return NULL;  /* not much we can do if dentry is freed and
@@ -68,22 +69,29 @@ build_path_from_dentry(struct dentry *direntry)
 		dfsplen = 0;
 cifs_bp_rename_retry:
 	namelen = dfsplen;
+	seq = read_seqbegin(&rename_lock);
+	rcu_read_lock();
 	for (temp = direntry; !IS_ROOT(temp);) {
 		namelen += (1 + temp->d_name.len);
 		temp = temp->d_parent;
 		if (temp == NULL) {
 			cERROR(1, "corrupt dentry");
+			rcu_read_unlock();
 			return NULL;
 		}
 	}
+	rcu_read_unlock();
 
 	full_path = kmalloc(namelen+1, GFP_KERNEL);
 	if (full_path == NULL)
 		return full_path;
 	full_path[namelen] = 0;	/* trailing null */
+	rcu_read_lock();
 	for (temp = direntry; !IS_ROOT(temp);) {
+		spin_lock(&temp->d_lock);
 		namelen -= 1 + temp->d_name.len;
 		if (namelen < 0) {
+			spin_unlock(&temp->d_lock);
 			break;
 		} else {
 			full_path[namelen] = dirsep;
@@ -91,14 +99,17 @@ build_path_from_dentry(struct dentry *direntry)
 				temp->d_name.len);
 			cFYI(0, "name: %s", full_path + namelen);
 		}
+		spin_unlock(&temp->d_lock);
 		temp = temp->d_parent;
 		if (temp == NULL) {
 			cERROR(1, "corrupt dentry");
+			rcu_read_unlock();
 			kfree(full_path);
 			return NULL;
 		}
 	}
-	if (namelen != dfsplen) {
+	rcu_read_unlock();
+	if (namelen != dfsplen || read_seqretry(&rename_lock, seq)) {
 		cERROR(1, "did not end path lookup where expected namelen is %d",
 			namelen);
 		/* presumably this is only possible if racing with a rename
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index e141939080f0..739fb59bcdc2 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -37,7 +37,7 @@ static DEFINE_MUTEX(read_mutex);
 /* These macros may change in future, to provide better st_ino semantics. */
 #define OFFSET(x)	((x)->i_ino)
 
-static unsigned long cramino(struct cramfs_inode *cino, unsigned int offset)
+static unsigned long cramino(const struct cramfs_inode *cino, unsigned int offset)
 {
 	if (!cino->offset)
 		return offset + 1;
@@ -61,7 +61,7 @@ static unsigned long cramino(struct cramfs_inode *cino, unsigned int offset)
 }
 
 static struct inode *get_cramfs_inode(struct super_block *sb,
-	struct cramfs_inode *cramfs_inode, unsigned int offset)
+	const struct cramfs_inode *cramfs_inode, unsigned int offset)
 {
 	struct inode *inode;
 	static struct timespec zerotime;
@@ -317,7 +317,7 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
 	/* Set it all up.. */
 	sb->s_op = &cramfs_ops;
 	root = get_cramfs_inode(sb, &super.root, 0);
-	if (!root)
+	if (IS_ERR(root))
 		goto out;
 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
@@ -423,6 +423,7 @@ static int cramfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
 	unsigned int offset = 0;
+	struct inode *inode = NULL;
 	int sorted;
 
 	mutex_lock(&read_mutex);
@@ -449,8 +450,8 @@ static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, s
 
 		for (;;) {
 			if (!namelen) {
-				mutex_unlock(&read_mutex);
-				return ERR_PTR(-EIO);
+				inode = ERR_PTR(-EIO);
+				goto out;
 			}
 			if (name[namelen-1])
 				break;
@@ -462,17 +463,18 @@ static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, s
 		if (retval > 0)
 			continue;
 		if (!retval) {
-			struct cramfs_inode entry = *de;
-			mutex_unlock(&read_mutex);
-			d_add(dentry, get_cramfs_inode(dir->i_sb, &entry, dir_off));
-			return NULL;
+			inode = get_cramfs_inode(dir->i_sb, de, dir_off);
+			break;
 		}
 		/* else (retval < 0) */
 		if (sorted)
 			break;
 	}
+out:
 	mutex_unlock(&read_mutex);
-	d_add(dentry, NULL);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	d_add(dentry, inode);
 	return NULL;
 }
 
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index 06065bd37fc3..c57beddcc217 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -913,7 +913,7 @@ struct dentry *exofs_get_parent(struct dentry *child)
 	unsigned long ino = exofs_parent_ino(child);
 
 	if (!ino)
-		return NULL;
+		return ERR_PTR(-ESTALE);
 
 	return d_obtain_alias(exofs_iget(child->d_inode->i_sb, ino));
 }
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index 87ed48e0343d..85c098a499f3 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -139,7 +139,8 @@ static int file_removed(struct dentry *dentry, const char *file)
 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
 				   struct nameidata *nd)
 {
-	struct dentry *proc_dentry, *new, *parent;
+	struct dentry *proc_dentry, *parent;
+	struct qstr *name = &dentry->d_name;
 	struct inode *inode;
 	int err, deleted;
 
@@ -149,23 +150,9 @@ static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
 	else if (deleted)
 		return ERR_PTR(-ENOENT);
 
-	err = -ENOMEM;
 	parent = HPPFS_I(ino)->proc_dentry;
 	mutex_lock(&parent->d_inode->i_mutex);
-	proc_dentry = d_lookup(parent, &dentry->d_name);
-	if (proc_dentry == NULL) {
-		proc_dentry = d_alloc(parent, &dentry->d_name);
-		if (proc_dentry == NULL) {
-			mutex_unlock(&parent->d_inode->i_mutex);
-			goto out;
-		}
-		new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
-						       proc_dentry, NULL);
-		if (new) {
-			dput(proc_dentry);
-			proc_dentry = new;
-		}
-	}
+	proc_dentry = lookup_one_len(name->name, parent, name->len);
 	mutex_unlock(&parent->d_inode->i_mutex);
 
 	if (IS_ERR(proc_dentry))
@@ -174,13 +161,11 @@ static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
 	err = -ENOMEM;
 	inode = get_inode(ino->i_sb, proc_dentry);
 	if (!inode)
-		goto out_dput;
+		goto out;
 
  	d_add(dentry, inode);
 	return NULL;
 
- out_dput:
-	dput(proc_dentry);
  out:
 	return ERR_PTR(err);
 }
@@ -690,8 +675,10 @@ static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
 	struct inode *proc_ino = dentry->d_inode;
 	struct inode *inode = new_inode(sb);
 
-	if (!inode)
+	if (!inode) {
+		dput(dentry);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	if (S_ISDIR(dentry->d_inode->i_mode)) {
 		inode->i_op = &hppfs_dir_iops;
@@ -704,7 +691,7 @@ static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
 		inode->i_fop = &hppfs_file_fops;
 	}
 
-	HPPFS_I(inode)->proc_dentry = dget(dentry);
+	HPPFS_I(inode)->proc_dentry = dentry;
 
 	inode->i_uid = proc_ino->i_uid;
 	inode->i_gid = proc_ino->i_gid;
@@ -737,7 +724,7 @@ static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
 	sb->s_fs_info = proc_mnt;
 
 	err = -ENOMEM;
-	root_inode = get_inode(sb, proc_mnt->mnt_sb->s_root);
+	root_inode = get_inode(sb, dget(proc_mnt->mnt_sb->s_root));
 	if (!root_inode)
 		goto out_mntput;
 
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 29309e25417f..b57aab9a1184 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -56,16 +56,12 @@ static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, stru
 
 	lock_ufs(dir->i_sb);
 	ino = ufs_inode_by_name(dir, &dentry->d_name);
-	if (ino) {
+	if (ino)
 		inode = ufs_iget(dir->i_sb, ino);
-		if (IS_ERR(inode)) {
-			unlock_ufs(dir->i_sb);
-			return ERR_CAST(inode);
-		}
-	}
 	unlock_ufs(dir->i_sb);
-	d_add(dentry, inode);
-	return NULL;
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	return d_splice_alias(inode, dentry);
 }
 
 /*