Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:

 - Preparations of parallel lookups (the remaining main obstacle is the
   need to move security_d_instantiate(); once that becomes safe, the
   rest will be a matter of rather short series local to fs/*.c

 - preadv2/pwritev2 series from Christoph

 - assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  splice: handle zero nr_pages in splice_to_pipe()
  vfs: show_vfsstat: do not ignore errors from show_devname method
  dcache.c: new helper: __d_add()
  don't bother with __d_instantiate(dentry, NULL)
  untangle fsnotify_d_instantiate() a bit
  uninline d_add()
  replace d_add_unique() with saner primitive
  quota: use lookup_one_len_unlocked()
  cifs_get_root(): use lookup_one_len_unlocked()
  nfs_lookup: don't bother with d_instantiate(dentry, NULL)
  kill dentry_unhash()
  ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
  autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
  configfs: move d_rehash() into configfs_create() for regular files
  ceph: don't bother with d_rehash() in splice_dentry()
  namei: teach lookup_slow() to skip revalidate
  namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
  lookup_one_len_unlocked(): use lookup_dcache()
  namei: simplify invalidation logics in lookup_dcache()
  namei: change calling conventions for lookup_{fast,slow} and follow_managed()
  ...

22 files changed, 459 insertions, 410 deletions

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 9328b5861c7a..7ab923940d18 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -542,8 +542,6 @@ static struct dentry *autofs4_lookup(struct inode *dir,
 		ino->dentry = dentry;
 
 		autofs4_add_active(dentry);
-
-		d_instantiate(dentry, NULL);
 	}
 	return NULL;
 }
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 452e98dd7560..1ee54ffd3a24 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -162,6 +162,8 @@ static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer,
 				      size_t buflen, loff_t *pos)
 {
 	struct cachefiles_cache *cache = file->private_data;
+	unsigned long long b_released;
+	unsigned f_released;
 	char buffer[256];
 	int n;
 
@@ -174,6 +176,8 @@ static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer,
 	cachefiles_has_space(cache, 0, 0);
 
 	/* summarise */
+	f_released = atomic_xchg(&cache->f_released, 0);
+	b_released = atomic_long_xchg(&cache->b_released, 0);
 	clear_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
 
 	n = snprintf(buffer, sizeof(buffer),
@@ -183,15 +187,18 @@ static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer,
 		     " fstop=%llx"
 		     " brun=%llx"
 		     " bcull=%llx"
-		     " bstop=%llx",
+		     " bstop=%llx"
+		     " freleased=%x"
+		     " breleased=%llx",
 		     test_bit(CACHEFILES_CULLING, &cache->flags) ? '1' : '0',
 		     (unsigned long long) cache->frun,
 		     (unsigned long long) cache->fcull,
 		     (unsigned long long) cache->fstop,
 		     (unsigned long long) cache->brun,
 		     (unsigned long long) cache->bcull,
-		     (unsigned long long) cache->bstop
-		     );
+		     (unsigned long long) cache->bstop,
+		     f_released,
+		     b_released);
 
 	if (n > buflen)
 		return -EMSGSIZE;
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 675a3332d72f..861d611b8c05 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -291,15 +291,8 @@ static void cachefiles_drop_object(struct fscache_object *_object)
 	}
 
 	/* note that the object is now inactive */
-	if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) {
-		write_lock(&cache->active_lock);
-		if (!test_and_clear_bit(CACHEFILES_OBJECT_ACTIVE,
-					&object->flags))
-			BUG();
-		rb_erase(&object->active_node, &cache->active_nodes);
-		wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
-		write_unlock(&cache->active_lock);
-	}
+	if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags))
+		cachefiles_mark_object_inactive(cache, object);
 
 	dput(object->dentry);
 	object->dentry = NULL;
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 9c4b737a54df..2fcde1a34b7c 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -66,6 +66,8 @@ struct cachefiles_cache {
 	struct rb_root			active_nodes;	/* active nodes (can't be culled) */
 	rwlock_t			active_lock;	/* lock for active_nodes */
 	atomic_t			gravecounter;	/* graveyard uniquifier */
+	atomic_t			f_released;	/* number of objects released lately */
+	atomic_long_t			b_released;	/* number of blocks released lately */
 	unsigned			frun_percent;	/* when to stop culling (% files) */
 	unsigned			fcull_percent;	/* when to start culling (% files) */
 	unsigned			fstop_percent;	/* when to stop allocating (% files) */
@@ -157,6 +159,8 @@ extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
 /*
  * namei.c
  */
+extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
+					    struct cachefiles_object *object);
 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
 				    struct cachefiles_object *object);
 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 1c2334c163dd..4ae75006e73b 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -258,6 +258,28 @@ requeue:
 }
 
 /*
+ * Mark an object as being inactive.
+ */
+void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
+				     struct cachefiles_object *object)
+{
+	write_lock(&cache->active_lock);
+	rb_erase(&object->active_node, &cache->active_nodes);
+	clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
+	write_unlock(&cache->active_lock);
+
+	wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
+
+	/* This object can now be culled, so we need to let the daemon know
+	 * that there is something it can remove if it needs to.
+	 */
+	atomic_long_add(d_backing_inode(object->dentry)->i_blocks,
+			&cache->b_released);
+	if (atomic_inc_return(&cache->f_released))
+		cachefiles_state_changed(cache);
+}
+
+/*
  * delete an object representation from the cache
  * - file backed objects are unlinked
  * - directory backed objects are stuffed into the graveyard for userspace to
@@ -684,11 +706,7 @@ mark_active_timed_out:
 
 check_error:
 	_debug("check error %d", ret);
-	write_lock(&cache->active_lock);
-	rb_erase(&object->active_node, &cache->active_nodes);
-	clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
-	wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
-	write_unlock(&cache->active_lock);
+	cachefiles_mark_object_inactive(cache, object);
 release_dentry:
 	dput(object->dentry);
 	object->dentry = NULL;
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 5849b88bbed3..e48fd8b23257 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -977,13 +977,8 @@ out_unlock:
 /*
  * splice a dentry to an inode.
  * caller must hold directory i_mutex for this to be safe.
- *
- * we will only rehash the resulting dentry if @prehash is
- * true; @prehash will be set to false (for the benefit of
- * the caller) if we fail.
  */
-static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
-				    bool *prehash)
+static struct dentry *splice_dentry(struct dentry *dn, struct inode *in)
 {
 	struct dentry *realdn;
 
@@ -996,8 +991,6 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
 	if (IS_ERR(realdn)) {
 		pr_err("splice_dentry error %ld %p inode %p ino %llx.%llx\n",
 		       PTR_ERR(realdn), dn, in, ceph_vinop(in));
-		if (prehash)
-			*prehash = false; /* don't rehash on error */
 		dn = realdn; /* note realdn contains the error */
 		goto out;
 	} else if (realdn) {
@@ -1013,8 +1006,6 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
 		dout("dn %p attached to %p ino %llx.%llx\n",
 		     dn, d_inode(dn), ceph_vinop(d_inode(dn)));
 	}
-	if ((!prehash || *prehash) && d_unhashed(dn))
-		d_rehash(dn);
 out:
 	return dn;
 }
@@ -1247,10 +1238,8 @@ retry_lookup:
 				dout("d_delete %p\n", dn);
 				d_delete(dn);
 			} else {
-				dout("d_instantiate %p NULL\n", dn);
-				d_instantiate(dn, NULL);
 				if (have_lease && d_unhashed(dn))
-					d_rehash(dn);
+					d_add(dn, NULL);
 				update_dentry_lease(dn, rinfo->dlease,
 						    session,
 						    req->r_request_started);
@@ -1262,7 +1251,7 @@ retry_lookup:
 		if (d_really_is_negative(dn)) {
 			ceph_dir_clear_ordered(dir);
 			ihold(in);
-			dn = splice_dentry(dn, in, &have_lease);
+			dn = splice_dentry(dn, in);
 			if (IS_ERR(dn)) {
 				err = PTR_ERR(dn);
 				goto done;
@@ -1292,7 +1281,7 @@ retry_lookup:
 		dout(" linking snapped dir %p to dn %p\n", in, dn);
 		ceph_dir_clear_ordered(dir);
 		ihold(in);
-		dn = splice_dentry(dn, in, NULL);
+		dn = splice_dentry(dn, in);
 		if (IS_ERR(dn)) {
 			err = PTR_ERR(dn);
 			goto done;
@@ -1503,7 +1492,7 @@ retry_lookup:
 		}
 
 		if (d_really_is_negative(dn)) {
-			struct dentry *realdn = splice_dentry(dn, in, NULL);
+			struct dentry *realdn = splice_dentry(dn, in);
 			if (IS_ERR(realdn)) {
 				err = PTR_ERR(realdn);
 				d_drop(dn);
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index fd8805de6a50..1d86fc620e5c 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -642,9 +642,7 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb)
 		while (*s && *s != sep)
 			s++;
 
-		inode_lock(dir);
-		child = lookup_one_len(p, dentry, s - p);
-		inode_unlock(dir);
+		child = lookup_one_len_unlocked(p, dentry, s - p);
 		dput(dentry);
 		dentry = child;
 	} while (!IS_ERR(dentry));
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index b51ce6778145..ea59c891fc53 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -432,14 +432,9 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
 				(sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ?
 					configfs_init_bin_file :
 					configfs_init_file);
-	if (error) {
+	if (error)
 		configfs_put(sd);
-		return error;
-	}
-
-	d_rehash(dentry);
-
-	return 0;
+	return error;
 }
 
 static struct dentry * configfs_lookup(struct inode *dir,
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 5f24ad3ecba4..03d124ae27d7 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -201,9 +201,17 @@ int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct in
 	configfs_set_inode_lock_class(sd, inode);
 
 	init(inode);
-	d_instantiate(dentry, inode);
-	if (S_ISDIR(mode) || S_ISLNK(mode))
+	if (S_ISDIR(mode) || S_ISLNK(mode)) {
+		/*
+		 * ->symlink(), ->mkdir(), configfs_register_subsystem() or
+		 * create_default_group() - already hashed.
+		 */
+		d_instantiate(dentry, inode);
 		dget(dentry);  /* pin link and directory dentries in core */
+	} else {
+		/* ->lookup() */
+		d_add(dentry, inode);
+	}
 	return error;
 }
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 2398f9f94337..32ceae3e6112 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1745,13 +1745,12 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 	unsigned add_flags = d_flags_for_inode(inode);
 
 	spin_lock(&dentry->d_lock);
-	if (inode)
-		hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
+	hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
 	raw_write_seqcount_begin(&dentry->d_seq);
 	__d_set_inode_and_type(dentry, inode, add_flags);
 	raw_write_seqcount_end(&dentry->d_seq);
+	__fsnotify_d_instantiate(dentry);
 	spin_unlock(&dentry->d_lock);
-	fsnotify_d_instantiate(dentry, inode);
 }
 
 /**
@@ -1772,91 +1771,16 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 void d_instantiate(struct dentry *entry, struct inode * inode)
 {
 	BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
-	if (inode)
+	if (inode) {
 		spin_lock(&inode->i_lock);
-	__d_instantiate(entry, inode);
-	if (inode)
+		__d_instantiate(entry, inode);
 		spin_unlock(&inode->i_lock);
+	}
 	security_d_instantiate(entry, inode);
 }
 EXPORT_SYMBOL(d_instantiate);
 
 /**
- * d_instantiate_unique - instantiate a non-aliased dentry
- * @entry: dentry to instantiate
- * @inode: inode to attach to this dentry
- *
- * Fill in inode information in the entry. On success, it returns NULL.
- * If an unhashed alias of "entry" already exists, then we return the
- * aliased dentry instead and drop one reference to inode.
- *
- * Note that in order to avoid conflicts with rename() etc, the caller
- * had better be holding the parent directory semaphore.
- *
- * This also assumes that the inode count has been incremented
- * (or otherwise set) by the caller to indicate that it is now
- * in use by the dcache.
- */
-static struct dentry *__d_instantiate_unique(struct dentry *entry,
-					     struct inode *inode)
-{
-	struct dentry *alias;
-	int len = entry->d_name.len;
-	const char *name = entry->d_name.name;
-	unsigned int hash = entry->d_name.hash;
-
-	if (!inode) {
-		__d_instantiate(entry, NULL);
-		return NULL;
-	}
-
-	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
-		/*
-		 * Don't need alias->d_lock here, because aliases with
-		 * d_parent == entry->d_parent are not subject to name or
-		 * parent changes, because the parent inode i_mutex is held.
-		 */
-		if (alias->d_name.hash != hash)
-			continue;
-		if (alias->d_parent != entry->d_parent)
-			continue;
-		if (alias->d_name.len != len)
-			continue;
-		if (dentry_cmp(alias, name, len))
-			continue;
-		__dget(alias);
-		return alias;
-	}
-
-	__d_instantiate(entry, inode);
-	return NULL;
-}
-
-struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
-{
-	struct dentry *result;
-
-	BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
-
-	if (inode)
-		spin_lock(&inode->i_lock);
-	result = __d_instantiate_unique(entry, inode);
-	if (inode)
-		spin_unlock(&inode->i_lock);
-
-	if (!result) {
-		security_d_instantiate(entry, inode);
-		return NULL;
-	}
-
-	BUG_ON(!d_unhashed(result));
-	iput(inode);
-	return result;
-}
-
-EXPORT_SYMBOL(d_instantiate_unique);
-
-/**
  * d_instantiate_no_diralias - instantiate a non-aliased dentry
  * @entry: dentry to complete
  * @inode: inode to attach to this dentry
@@ -2436,6 +2360,86 @@ void d_rehash(struct dentry * entry)
 }
 EXPORT_SYMBOL(d_rehash);
 
+
+/* inode->i_lock held if inode is non-NULL */
+
+static inline void __d_add(struct dentry *dentry, struct inode *inode)
+{
+	if (inode) {
+		__d_instantiate(dentry, inode);
+		spin_unlock(&inode->i_lock);
+	}
+	security_d_instantiate(dentry, inode);
+	d_rehash(dentry);
+}
+
+/**
+ * d_add - add dentry to hash queues
+ * @entry: dentry to add
+ * @inode: The inode to attach to this dentry
+ *
+ * This adds the entry to the hash queues and initializes @inode.
+ * The entry was actually filled in earlier during d_alloc().
+ */
+
+void d_add(struct dentry *entry, struct inode *inode)
+{
+	if (inode)
+		spin_lock(&inode->i_lock);
+	__d_add(entry, inode);
+}
+EXPORT_SYMBOL(d_add);
+
+/**
+ * d_exact_alias - find and hash an exact unhashed alias
+ * @entry: dentry to add
+ * @inode: The inode to go with this dentry
+ *
+ * If an unhashed dentry with the same name/parent and desired
+ * inode already exists, hash and return it.  Otherwise, return
+ * NULL.
+ *
+ * Parent directory should be locked.
+ */
+struct dentry *d_exact_alias(struct dentry *entry, struct inode *inode)
+{
+	struct dentry *alias;
+	int len = entry->d_name.len;
+	const char *name = entry->d_name.name;
+	unsigned int hash = entry->d_name.hash;
+
+	spin_lock(&inode->i_lock);
+	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
+		/*
+		 * Don't need alias->d_lock here, because aliases with
+		 * d_parent == entry->d_parent are not subject to name or
+		 * parent changes, because the parent inode i_mutex is held.
+		 */
+		if (alias->d_name.hash != hash)
+			continue;
+		if (alias->d_parent != entry->d_parent)
+			continue;
+		if (alias->d_name.len != len)
+			continue;
+		if (dentry_cmp(alias, name, len))
+			continue;
+		spin_lock(&alias->d_lock);
+		if (!d_unhashed(alias)) {
+			spin_unlock(&alias->d_lock);
+			alias = NULL;
+		} else {
+			__dget_dlock(alias);
+			_d_rehash(alias);
+			spin_unlock(&alias->d_lock);
+		}
+		spin_unlock(&inode->i_lock);
+		return alias;
+	}
+	spin_unlock(&inode->i_lock);
+	return NULL;
+}
+EXPORT_SYMBOL(d_exact_alias);
+
 /**
  * dentry_update_name_case - update case insensitive dentry with a new name
  * @dentry: dentry to be updated
@@ -2772,10 +2776,9 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 
 	BUG_ON(!d_unhashed(dentry));
 
-	if (!inode) {
-		__d_instantiate(dentry, NULL);
+	if (!inode)
 		goto out;
-	}
+
 	spin_lock(&inode->i_lock);
 	if (S_ISDIR(inode->i_mode)) {
 		struct dentry *new = __d_find_any_alias(inode);
@@ -2809,12 +2812,8 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 			return new;
 		}
 	}
-	/* already taking inode->i_lock, so d_add() by hand */
-	__d_instantiate(dentry, inode);
-	spin_unlock(&inode->i_lock);
 out:
-	security_d_instantiate(dentry, inode);
-	d_rehash(dentry);
+	__d_add(dentry, inode);
 	return NULL;
 }
 EXPORT_SYMBOL(d_splice_alias);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index d6a9012d42ad..0a8d937c6775 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -445,7 +445,8 @@ static struct bio *dio_await_one(struct dio *dio)
 		__set_current_state(TASK_UNINTERRUPTIBLE);
 		dio->waiter = current;
 		spin_unlock_irqrestore(&dio->bio_lock, flags);
-		if (!blk_poll(bdev_get_queue(dio->bio_bdev), dio->bio_cookie))
+		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
+		    !blk_poll(bdev_get_queue(dio->bio_bdev), dio->bio_cookie))
 			io_schedule();
 		/* wake up sets us TASK_RUNNING */
 		spin_lock_irqsave(&dio->bio_lock, flags);
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 11255cbcb2db..64026e53722a 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1492,16 +1492,14 @@ out:
  */
 static int
 ecryptfs_encrypt_filename(struct ecryptfs_filename *filename,
-			  struct ecryptfs_crypt_stat *crypt_stat,
 			  struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 {
 	int rc = 0;
 
 	filename->encrypted_filename = NULL;
 	filename->encrypted_filename_size = 0;
-	if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCFN_USE_MOUNT_FNEK))
-	    || (mount_crypt_stat && (mount_crypt_stat->flags
-				     & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) {
+	if (mount_crypt_stat && (mount_crypt_stat->flags
+				     & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK)) {
 		size_t packet_size;
 		size_t remaining_bytes;
 
@@ -1933,7 +1931,6 @@ out:
 int ecryptfs_encrypt_and_encode_filename(
 	char **encoded_name,
 	size_t *encoded_name_size,
-	struct ecryptfs_crypt_stat *crypt_stat,
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
 	const char *name, size_t name_size)
 {
@@ -1942,9 +1939,8 @@ int ecryptfs_encrypt_and_encode_filename(
 
 	(*encoded_name) = NULL;
 	(*encoded_name_size) = 0;
-	if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES))
-	    || (mount_crypt_stat && (mount_crypt_stat->flags
-				     & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) {
+	if (mount_crypt_stat && (mount_crypt_stat->flags
+				     & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) {
 		struct ecryptfs_filename *filename;
 
 		filename = kzalloc(sizeof(*filename), GFP_KERNEL);
@@ -1957,8 +1953,7 @@ int ecryptfs_encrypt_and_encode_filename(
 		}
 		filename->filename = (char *)name;
 		filename->filename_size = name_size;
-		rc = ecryptfs_encrypt_filename(filename, crypt_stat,
-					       mount_crypt_stat);
+		rc = ecryptfs_encrypt_filename(filename, mount_crypt_stat);
 		if (rc) {
 			printk(KERN_ERR "%s: Error attempting to encrypt "
 			       "filename; rc = [%d]\n", __func__, rc);
@@ -1969,11 +1964,9 @@ int ecryptfs_encrypt_and_encode_filename(
 			NULL, &encoded_name_no_prefix_size,
 			filename->encrypted_filename,
 			filename->encrypted_filename_size);
-		if ((crypt_stat && (crypt_stat->flags
-				    & ECRYPTFS_ENCFN_USE_MOUNT_FNEK))
-		    || (mount_crypt_stat
+		if (mount_crypt_stat
 			&& (mount_crypt_stat->flags
-			    & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK)))
+			    & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))
 			(*encoded_name_size) =
 				(ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE
 				 + encoded_name_no_prefix_size);
@@ -1991,11 +1984,9 @@ int ecryptfs_encrypt_and_encode_filename(
 			kfree(filename);
 			goto out;
 		}
-		if ((crypt_stat && (crypt_stat->flags
-				    & ECRYPTFS_ENCFN_USE_MOUNT_FNEK))
-		    || (mount_crypt_stat
+		if (mount_crypt_stat
 			&& (mount_crypt_stat->flags
-			    & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) {
+			    & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK)) {
 			memcpy((*encoded_name),
 			       ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX,
 			       ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index b7f81287c688..d123fbaa28e0 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -569,7 +569,6 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
 int ecryptfs_encrypt_and_encode_filename(
 	char **encoded_name,
 	size_t *encoded_name_size,
-	struct ecryptfs_crypt_stat *crypt_stat,
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
 	const char *name, size_t name_size);
 struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 0a8f1b469a63..121114e9a464 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -396,11 +396,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	int rc = 0;
 
 	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
-	inode_lock(d_inode(lower_dir_dentry));
-	lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
+	lower_dentry = lookup_one_len_unlocked(ecryptfs_dentry->d_name.name,
 				      lower_dir_dentry,
 				      ecryptfs_dentry->d_name.len);
-	inode_unlock(d_inode(lower_dir_dentry));
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
@@ -418,18 +416,16 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	dput(lower_dentry);
 	rc = ecryptfs_encrypt_and_encode_filename(
 		&encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
-		NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
+		mount_crypt_stat, ecryptfs_dentry->d_name.name,
 		ecryptfs_dentry->d_name.len);
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to encrypt and encode "
 		       "filename; rc = [%d]\n", __func__, rc);
 		goto out;
 	}
-	inode_lock(d_inode(lower_dir_dentry));
-	lower_dentry = lookup_one_len(encrypted_and_encoded_name,
+	lower_dentry = lookup_one_len_unlocked(encrypted_and_encoded_name,
 				      lower_dir_dentry,
 				      encrypted_and_encoded_name_size);
-	inode_unlock(d_inode(lower_dir_dentry));
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
@@ -501,7 +497,6 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
 		dir->i_sb)->mount_crypt_stat;
 	rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
 						  &encoded_symlen,
-						  NULL,
 						  mount_crypt_stat, symname,
 						  strlen(symname));
 	if (rc)
diff --git a/fs/namei.c b/fs/namei.c
index 9c590e0f66e9..794f81dce766 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1220,8 +1220,8 @@ static int follow_managed(struct path *path, struct nameidata *nd)
 
 	if (need_mntput && path->mnt == mnt)
 		mntput(path->mnt);
-	if (ret == -EISDIR)
-		ret = 0;
+	if (ret == -EISDIR || !ret)
+		ret = 1;
 	if (need_mntput)
 		nd->flags |= LOOKUP_JUMPED;
 	if (unlikely(ret < 0))
@@ -1444,40 +1444,26 @@ static int follow_dotdot(struct nameidata *nd)
  * This looks up the name in dcache, possibly revalidates the old dentry and
  * allocates a new one if not found or not valid.  In the need_lookup argument
  * returns whether i_op->lookup is necessary.
- *
- * dir->d_inode->i_mutex must be held
  */
-static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir,
-				    unsigned int flags, bool *need_lookup)
+static struct dentry *lookup_dcache(const struct qstr *name,
+				    struct dentry *dir,
+				    unsigned int flags)
 {
 	struct dentry *dentry;
 	int error;
 
-	*need_lookup = false;
 	dentry = d_lookup(dir, name);
 	if (dentry) {
 		if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
 			error = d_revalidate(dentry, flags);
 			if (unlikely(error <= 0)) {
-				if (error < 0) {
-					dput(dentry);
-					return ERR_PTR(error);
-				} else {
+				if (!error)
 					d_invalidate(dentry);
-					dput(dentry);
-					dentry = NULL;
-				}
+				dput(dentry);
+				return ERR_PTR(error);
 			}
 		}
 	}
-
-	if (!dentry) {
-		dentry = d_alloc(dir, name);
-		if (unlikely(!dentry))
-			return ERR_PTR(-ENOMEM);
-
-		*need_lookup = true;
-	}
 	return dentry;
 }
 
@@ -1506,45 +1492,44 @@ static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry,
 	return dentry;
 }
 
-static struct dentry *__lookup_hash(struct qstr *name,
+static struct dentry *__lookup_hash(const struct qstr *name,
 		struct dentry *base, unsigned int flags)
 {
-	bool need_lookup;
-	struct dentry *dentry;
+	struct dentry *dentry = lookup_dcache(name, base, flags);
 
-	dentry = lookup_dcache(name, base, flags, &need_lookup);
-	if (!need_lookup)
+	if (dentry)
 		return dentry;
 
+	dentry = d_alloc(base, name);
+	if (unlikely(!dentry))
+		return ERR_PTR(-ENOMEM);
+
 	return lookup_real(base->d_inode, dentry, flags);
 }
 
-/*
- *  It's more convoluted than I'd like it to be, but... it's still fairly
- *  small and for now I'd prefer to have fast path as straight as possible.
- *  It _is_ time-critical.
- */
 static int lookup_fast(struct nameidata *nd,
 		       struct path *path, struct inode **inode,
 		       unsigned *seqp)
 {
 	struct vfsmount *mnt = nd->path.mnt;
 	struct dentry *dentry, *parent = nd->path.dentry;
-	int need_reval = 1;
 	int status = 1;
 	int err;
 
 	/*
 	 * Rename seqlock is not required here because in the off chance
-	 * of a false negative due to a concurrent rename, we're going to
-	 * do the non-racy lookup, below.
+	 * of a false negative due to a concurrent rename, the caller is
+	 * going to fall back to non-racy lookup.
 	 */
 	if (nd->flags & LOOKUP_RCU) {
 		unsigned seq;
 		bool negative;
 		dentry = __d_lookup_rcu(parent, &nd->last, &seq);
-		if (!dentry)
-			goto unlazy;
+		if (unlikely(!dentry)) {
+			if (unlazy_walk(nd, NULL, 0))
+				return -ECHILD;
+			return 0;
+		}
 
 		/*
 		 * This sequence count validates that the inode matches
@@ -1552,7 +1537,7 @@ static int lookup_fast(struct nameidata *nd,
 		 */
 		*inode = d_backing_inode(dentry);
 		negative = d_is_negative(dentry);
-		if (read_seqcount_retry(&dentry->d_seq, seq))
+		if (unlikely(read_seqcount_retry(&dentry->d_seq, seq)))
 			return -ECHILD;
 
 		/*
@@ -1562,81 +1547,89 @@ static int lookup_fast(struct nameidata *nd,
 		 * The memory barrier in read_seqcount_begin of child is
 		 *  enough, we can use __read_seqcount_retry here.
 		 */
-		if (__read_seqcount_retry(&parent->d_seq, nd->seq))
+		if (unlikely(__read_seqcount_retry(&parent->d_seq, nd->seq)))
 			return -ECHILD;
 
 		*seqp = seq;
-		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
+		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
 			status = d_revalidate(dentry, nd->flags);
-			if (unlikely(status <= 0)) {
-				if (status != -ECHILD)
-					need_reval = 0;
-				goto unlazy;
-			}
+		if (unlikely(status <= 0)) {
+			if (unlazy_walk(nd, dentry, seq))
+				return -ECHILD;
+			if (status == -ECHILD)
+				status = d_revalidate(dentry, nd->flags);
+		} else {
+			/*
+			 * Note: do negative dentry check after revalidation in
+			 * case that drops it.
+			 */
+			if (unlikely(negative))
+				return -ENOENT;
+			path->mnt = mnt;
+			path->dentry = dentry;
+			if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
+				return 1;
+			if (unlazy_walk(nd, dentry, seq))
+				return -ECHILD;
 		}
-		/*
-		 * Note: do negative dentry check after revalidation in
-		 * case that drops it.
-		 */
-		if (negative)
-			return -ENOENT;
-		path->mnt = mnt;
-		path->dentry = dentry;
-		if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
-			return 0;
-unlazy:
-		if (unlazy_walk(nd, dentry, seq))
-			return -ECHILD;
 	} else {
 		dentry = __d_lookup(parent, &nd->last);
+		if (unlikely(!dentry))
+			return 0;
+		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
+			status = d_revalidate(dentry, nd->flags);
 	}
-
-	if (unlikely(!dentry))
-		goto need_lookup;
-
-	if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
-		status = d_revalidate(dentry, nd->flags);
 	if (unlikely(status <= 0)) {
-		if (status < 0) {
-			dput(dentry);
-			return status;
-		}
-		d_invalidate(dentry);
+		if (!status)
+			d_invalidate(dentry);
 		dput(dentry);
-		goto need_lookup;
+		return status;
 	}
-
 	if (unlikely(d_is_negative(dentry))) {
 		dput(dentry);
 		return -ENOENT;
 	}
+
 	path->mnt = mnt;
 	path->dentry = dentry;
 	err = follow_managed(path, nd);
-	if (likely(!err))
+	if (likely(err > 0))
 		*inode = d_backing_inode(path->dentry);
 	return err;
-
-need_lookup:
-	return 1;
 }
 
 /* Fast lookup failed, do it the slow way */
-static int lookup_slow(struct nameidata *nd, struct path *path)
+static struct dentry *lookup_slow(const struct qstr *name,
+				  struct dentry *dir,
+				  unsigned int flags)
 {
-	struct dentry *dentry, *parent;
-
-	parent = nd->path.dentry;
-	BUG_ON(nd->inode != parent->d_inode);
-
-	inode_lock(parent->d_inode);
-	dentry = __lookup_hash(&nd->last, parent, nd->flags);
-	inode_unlock(parent->d_inode);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-	path->mnt = nd->path.mnt;
-	path->dentry = dentry;
-	return follow_managed(path, nd);
+	struct dentry *dentry;
+	inode_lock(dir->d_inode);
+	dentry = d_lookup(dir, name);
+	if (unlikely(dentry)) {
+		if ((dentry->d_flags & DCACHE_OP_REVALIDATE) &&
+		    !(flags & LOOKUP_NO_REVAL)) {
+			int error = d_revalidate(dentry, flags);
+			if (unlikely(error <= 0)) {
+				if (!error)
+					d_invalidate(dentry);
+				dput(dentry);
+				dentry = ERR_PTR(error);
+			}
+		}
+		if (dentry) {
+			inode_unlock(dir->d_inode);
+			return dentry;
+		}
+	}
+	dentry = d_alloc(dir, name);
+	if (unlikely(!dentry)) {
+		inode_unlock(dir->d_inode);
+		return ERR_PTR(-ENOMEM);
+	}
+	dentry = lookup_real(dir->d_inode, dentry, flags);
+	inode_unlock(dir->d_inode);
+	return dentry;
 }
 
 static inline int may_lookup(struct nameidata *nd)
@@ -1740,18 +1733,23 @@ static int walk_component(struct nameidata *nd, int flags)
 		return err;
 	}
 	err = lookup_fast(nd, &path, &inode, &seq);
-	if (unlikely(err)) {
+	if (unlikely(err <= 0)) {
 		if (err < 0)
 			return err;
-
-		err = lookup_slow(nd, &path);
-		if (err < 0)
+		path.dentry = lookup_slow(&nd->last, nd->path.dentry,
+					  nd->flags);
+		if (IS_ERR(path.dentry))
+			return PTR_ERR(path.dentry);
+		if (unlikely(d_is_negative(path.dentry))) {
+			dput(path.dentry);
+			return -ENOENT;
+		}
+		path.mnt = nd->path.mnt;
+		err = follow_managed(&path, nd);
+		if (unlikely(err < 0))
 			return err;
 
 		seq = 0;	/* we are already out of RCU mode */
-		err = -ENOENT;
-		if (d_is_negative(path.dentry))
-			goto out_path_put;
 		inode = d_backing_inode(path.dentry);
 	}
 
@@ -1764,10 +1762,6 @@ static int walk_component(struct nameidata *nd, int flags)
 	nd->inode = inode;
 	nd->seq = seq;
 	return 0;
-
-out_path_put:
-	path_to_nameidata(&path, nd);
-	return err;
 }
 
 /*
@@ -2373,21 +2367,9 @@ struct dentry *lookup_one_len_unlocked(const char *name,
 	if (err)
 		return ERR_PTR(err);
 
-	/*
-	 * __d_lookup() is used to try to get a quick answer and avoid the
-	 * mutex.  A false-negative does no harm.
-	 */
-	ret = __d_lookup(base, &this);
-	if (ret && unlikely(ret->d_flags & DCACHE_OP_REVALIDATE)) {
-		dput(ret);
-		ret = NULL;
-	}
-	if (ret)
-		return ret;
-
-	inode_lock(base->d_inode);
-	ret =  __lookup_hash(&this, base, 0);
-	inode_unlock(base->d_inode);
+	ret = lookup_dcache(&this, base, 0);
+	if (!ret)
+		ret = lookup_slow(&this, base, 0);
 	return ret;
 }
 EXPORT_SYMBOL(lookup_one_len_unlocked);
@@ -2465,31 +2447,21 @@ mountpoint_last(struct nameidata *nd, struct path *path)
 		if (error)
 			return error;
 		dentry = dget(nd->path.dentry);
-		goto done;
-	}
-
-	inode_lock(dir->d_inode);
-	dentry = d_lookup(dir, &nd->last);
-	if (!dentry) {
-		/*
-		 * No cached dentry. Mounted dentries are pinned in the cache,
-		 * so that means that this dentry is probably a symlink or the
-		 * path doesn't actually point to a mounted dentry.
-		 */
-		dentry = d_alloc(dir, &nd->last);
+	} else {
+		dentry = d_lookup(dir, &nd->last);
 		if (!dentry) {
-			inode_unlock(dir->d_inode);
-			return -ENOMEM;
-		}
-		dentry = lookup_real(dir->d_inode, dentry, nd->flags);
-		if (IS_ERR(dentry)) {
-			inode_unlock(dir->d_inode);
-			return PTR_ERR(dentry);
+			/*
+			 * No cached dentry. Mounted dentries are pinned in the
+			 * cache, so that means that this dentry is probably
+			 * a symlink or the path doesn't actually point
+			 * to a mounted dentry.
+			 */
+			dentry = lookup_slow(&nd->last, dir,
+					     nd->flags | LOOKUP_NO_REVAL);
+			if (IS_ERR(dentry))
+				return PTR_ERR(dentry);
 		}
 	}
-	inode_unlock(dir->d_inode);
-
-done:
 	if (d_is_negative(dentry)) {
 		dput(dentry);
 		return -ENOENT;
@@ -3018,16 +2990,22 @@ static int lookup_open(struct nameidata *nd, struct path *path,
 	struct inode *dir_inode = dir->d_inode;
 	struct dentry *dentry;
 	int error;
-	bool need_lookup;
+	bool need_lookup = false;
 
 	*opened &= ~FILE_CREATED;
-	dentry = lookup_dcache(&nd->last, dir, nd->flags, &need_lookup);
+	dentry = lookup_dcache(&nd->last, dir, nd->flags);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
-	/* Cached positive dentry: will open in f_op->open */
-	if (!need_lookup && dentry->d_inode)
+	if (!dentry) {
+		dentry = d_alloc(dir, &nd->last);
+		if (unlikely(!dentry))
+			return -ENOMEM;
+		need_lookup = true;
+	} else if (dentry->d_inode) {
+		/* Cached positive dentry: will open in f_op->open */
 		goto out_no_open;
+	}
 
 	if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
 		return atomic_open(nd, dentry, path, file, op, got_write,
@@ -3111,13 +3089,14 @@ static int do_last(struct nameidata *nd,
 			nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
 		/* we _can_ be in RCU mode here */
 		error = lookup_fast(nd, &path, &inode, &seq);
-		if (likely(!error))
+		if (likely(error > 0))
 			goto finish_lookup;
 
 		if (error < 0)
 			return error;
 
 		BUG_ON(nd->inode != dir->d_inode);
+		BUG_ON(nd->flags & LOOKUP_RCU);
 	} else {
 		/* create side of things */
 		/*
@@ -3172,12 +3151,6 @@ retry_lookup:
 	}
 
 	/*
-	 * create/update audit record if it already exists.
-	 */
-	if (d_is_positive(path.dentry))
-		audit_inode(nd->name, path.dentry, 0);
-
-	/*
 	 * If atomic_open() acquired write access it is dropped now due to
 	 * possible mount and symlink following (this might be optimized away if
 	 * necessary...)
@@ -3187,6 +3160,16 @@ retry_lookup:
 		got_write = false;
 	}
 
+	if (unlikely(d_is_negative(path.dentry))) {
+		path_to_nameidata(&path, nd);
+		return -ENOENT;
+	}
+
+	/*
+	 * create/update audit record if it already exists.
+	 */
+	audit_inode(nd->name, path.dentry, 0);
+
 	if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) {
 		path_to_nameidata(&path, nd);
 		return -EEXIST;
@@ -3196,12 +3179,7 @@ retry_lookup:
 	if (unlikely(error < 0))
 		return error;
 
-	BUG_ON(nd->flags & LOOKUP_RCU);
 	seq = 0;	/* out of RCU mode, so the value doesn't matter */
-	if (unlikely(d_is_negative(path.dentry))) {
-		path_to_nameidata(&path, nd);
-		return -ENOENT;
-	}
 	inode = d_backing_inode(path.dentry);
 finish_lookup:
 	if (nd->depth)
@@ -3707,31 +3685,6 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 	return sys_mkdirat(AT_FDCWD, pathname, mode);
 }
 
-/*
- * The dentry_unhash() helper will try to drop the dentry early: we
- * should have a usage count of 1 if we're the only user of this
- * dentry, and if that is true (possibly after pruning the dcache),
- * then we drop the dentry now.
- *
- * A low-level filesystem can, if it choses, legally
- * do a
- *
- *	if (!d_unhashed(dentry))
- *		return -EBUSY;
- *
- * if it cannot handle the case of removing a directory
- * that is still in use by something else..
- */
-void dentry_unhash(struct dentry *dentry)
-{
-	shrink_dcache_parent(dentry);
-	spin_lock(&dentry->d_lock);
-	if (dentry->d_lockref.count == 1)
-		__d_drop(dentry);
-	spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL(dentry_unhash);
-
 int vfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	int error = may_delete(dir, dentry, 1);
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 9cce67043f92..4bfa7d8bcade 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1360,19 +1360,15 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
 	dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
 	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
 
-	res = ERR_PTR(-ENAMETOOLONG);
-	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
-		goto out;
+	if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen))
+		return ERR_PTR(-ENAMETOOLONG);
 
 	/*
 	 * If we're doing an exclusive create, optimize away the lookup
 	 * but don't hash the dentry.
 	 */
-	if (nfs_is_exclusive_create(dir, flags)) {
-		d_instantiate(dentry, NULL);
-		res = NULL;
-		goto out;
-	}
+	if (nfs_is_exclusive_create(dir, flags))
+		return NULL;
 
 	res = ERR_PTR(-ENOMEM);
 	fhandle = nfs_alloc_fhandle();
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 14881594dd07..400a70b3be7b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2461,14 +2461,15 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
 
 	dentry = opendata->dentry;
 	if (d_really_is_negative(dentry)) {
-		/* FIXME: Is this d_drop() ever needed? */
+		struct dentry *alias;
 		d_drop(dentry);
-		dentry = d_add_unique(dentry, igrab(state->inode));
-		if (dentry == NULL) {
-			dentry = opendata->dentry;
-		} else {
+		alias = d_exact_alias(dentry, state->inode);
+		if (!alias)
+			alias = d_splice_alias(igrab(state->inode), dentry);
+		/* d_splice_alias() can't fail here - it's a non-directory */
+		if (alias) {
 			dput(ctx->dentry);
-			ctx->dentry = dentry;
+			ctx->dentry = dentry = alias;
 		}
 		nfs_set_verifier(dentry,
 				nfs_save_change_attribute(d_inode(opendata->dir)));
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 5d2a57e4c03a..d40010e4f1a9 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -870,7 +870,7 @@ __be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
 
 	oldfs = get_fs();
 	set_fs(KERNEL_DS);
-	host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
+	host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset, 0);
 	set_fs(oldfs);
 	return nfsd_finish_read(file, count, host_err);
 }
@@ -957,7 +957,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
 
 	/* Write the data. */
 	oldfs = get_fs(); set_fs(KERNEL_DS);
-	host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos);
+	host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos, 0);
 	set_fs(oldfs);
 	if (host_err < 0)
 		goto out_nfserr;
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 2256e7e23e67..3f1190d18991 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -199,6 +199,8 @@ static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
 	if (sb->s_op->show_devname) {
 		seq_puts(m, "device ");
 		err = sb->s_op->show_devname(m, mnt_path.dentry);
+		if (err)
+			goto out;
 	} else {
 		if (r->mnt_devname) {
 			seq_puts(m, "device ");
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 3c3b81bb6dfe..04ca0cc6d065 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2430,9 +2430,7 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
 	struct dentry *dentry;
 	int error;
 
-	inode_lock(d_inode(sb->s_root));
-	dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
-	inode_unlock(d_inode(sb->s_root));
+	dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
diff --git a/fs/read_write.c b/fs/read_write.c
index dadf24e5c95b..cf377cf9dfe3 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -693,12 +693,17 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
 EXPORT_SYMBOL(iov_shorten);
 
 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
-		loff_t *ppos, iter_fn_t fn)
+		loff_t *ppos, iter_fn_t fn, int flags)
 {
 	struct kiocb kiocb;
 	ssize_t ret;
 
+	if (flags & ~RWF_HIPRI)
+		return -EOPNOTSUPP;
+
 	init_sync_kiocb(&kiocb, filp);
+	if (flags & RWF_HIPRI)
+		kiocb.ki_flags |= IOCB_HIPRI;
 	kiocb.ki_pos = *ppos;
 
 	ret = fn(&kiocb, iter);
@@ -709,10 +714,13 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
 
 /* Do it by hand, with file-ops */
 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
-		loff_t *ppos, io_fn_t fn)
+		loff_t *ppos, io_fn_t fn, int flags)
 {
 	ssize_t ret = 0;
 
+	if (flags & ~RWF_HIPRI)
+		return -EOPNOTSUPP;
+
 	while (iov_iter_count(iter)) {
 		struct iovec iovec = iov_iter_iovec(iter);
 		ssize_t nr;
@@ -813,7 +821,8 @@ out:
 
 static ssize_t do_readv_writev(int type, struct file *file,
 			       const struct iovec __user * uvector,
-			       unsigned long nr_segs, loff_t *pos)
+			       unsigned long nr_segs, loff_t *pos,
+			       int flags)
 {
 	size_t tot_len;
 	struct iovec iovstack[UIO_FASTIOV];
@@ -845,9 +854,9 @@ static ssize_t do_readv_writev(int type, struct file *file,
 	}
 
 	if (iter_fn)
-		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
+		ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
 	else
-		ret = do_loop_readv_writev(file, &iter, pos, fn);
+		ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
 
 	if (type != READ)
 		file_end_write(file);
@@ -864,40 +873,40 @@ out:
 }
 
 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
-		  unsigned long vlen, loff_t *pos)
+		  unsigned long vlen, loff_t *pos, int flags)
 {
 	if (!(file->f_mode & FMODE_READ))
 		return -EBADF;
 	if (!(file->f_mode & FMODE_CAN_READ))
 		return -EINVAL;
 
-	return do_readv_writev(READ, file, vec, vlen, pos);
+	return do_readv_writev(READ, file, vec, vlen, pos, flags);
 }
 
 EXPORT_SYMBOL(vfs_readv);
 
 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
-		   unsigned long vlen, loff_t *pos)
+		   unsigned long vlen, loff_t *pos, int flags)
 {
 	if (!(file->f_mode & FMODE_WRITE))
 		return -EBADF;
 	if (!(file->f_mode & FMODE_CAN_WRITE))
 		return -EINVAL;
 
-	return do_readv_writev(WRITE, file, vec, vlen, pos);
+	return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
 }
 
 EXPORT_SYMBOL(vfs_writev);
 
-SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
-		unsigned long, vlen)
+static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
+			unsigned long vlen, int flags)
 {
 	struct fd f = fdget_pos(fd);
 	ssize_t ret = -EBADF;
 
 	if (f.file) {
 		loff_t pos = file_pos_read(f.file);
-		ret = vfs_readv(f.file, vec, vlen, &pos);
+		ret = vfs_readv(f.file, vec, vlen, &pos, flags);
 		if (ret >= 0)
 			file_pos_write(f.file, pos);
 		fdput_pos(f);
@@ -909,15 +918,15 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
 	return ret;
 }
 
-SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
-		unsigned long, vlen)
+static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
+			 unsigned long vlen, int flags)
 {
 	struct fd f = fdget_pos(fd);
 	ssize_t ret = -EBADF;
 
 	if (f.file) {
 		loff_t pos = file_pos_read(f.file);
-		ret = vfs_writev(f.file, vec, vlen, &pos);
+		ret = vfs_writev(f.file, vec, vlen, &pos, flags);
 		if (ret >= 0)
 			file_pos_write(f.file, pos);
 		fdput_pos(f);
@@ -935,10 +944,9 @@ static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
 	return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
 }
 
-SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
-		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
+			 unsigned long vlen, loff_t pos, int flags)
 {
-	loff_t pos = pos_from_hilo(pos_h, pos_l);
 	struct fd f;
 	ssize_t ret = -EBADF;
 
@@ -949,7 +957,7 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
 	if (f.file) {
 		ret = -ESPIPE;
 		if (f.file->f_mode & FMODE_PREAD)
-			ret = vfs_readv(f.file, vec, vlen, &pos);
+			ret = vfs_readv(f.file, vec, vlen, &pos, flags);
 		fdput(f);
 	}
 
@@ -959,10 +967,9 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
 	return ret;
 }
 
-SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
-		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
+			  unsigned long vlen, loff_t pos, int flags)
 {
-	loff_t pos = pos_from_hilo(pos_h, pos_l);
 	struct fd f;
 	ssize_t ret = -EBADF;
 
@@ -973,7 +980,7 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
 	if (f.file) {
 		ret = -ESPIPE;
 		if (f.file->f_mode & FMODE_PWRITE)
-			ret = vfs_writev(f.file, vec, vlen, &pos);
+			ret = vfs_writev(f.file, vec, vlen, &pos, flags);
 		fdput(f);
 	}
 
@@ -983,11 +990,64 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
 	return ret;
 }
 
+SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
+{
+	return do_readv(fd, vec, vlen, 0);
+}
+
+SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
+{
+	return do_writev(fd, vec, vlen, 0);
+}
+
+SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+	return do_preadv(fd, vec, vlen, pos, 0);
+}
+
+SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
+		int, flags)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+	if (pos == -1)
+		return do_readv(fd, vec, vlen, flags);
+
+	return do_preadv(fd, vec, vlen, pos, flags);
+}
+
+SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+	return do_pwritev(fd, vec, vlen, pos, 0);
+}
+
+SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
+		int, flags)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+
+	if (pos == -1)
+		return do_writev(fd, vec, vlen, flags);
+
+	return do_pwritev(fd, vec, vlen, pos, flags);
+}
+
 #ifdef CONFIG_COMPAT
 
 static ssize_t compat_do_readv_writev(int type, struct file *file,
 			       const struct compat_iovec __user *uvector,
-			       unsigned long nr_segs, loff_t *pos)
+			       unsigned long nr_segs, loff_t *pos,
+			       int flags)
 {
 	compat_ssize_t tot_len;
 	struct iovec iovstack[UIO_FASTIOV];
@@ -1019,9 +1079,9 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
 	}
 
 	if (iter_fn)
-		ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
+		ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
 	else
-		ret = do_loop_readv_writev(file, &iter, pos, fn);
+		ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
 
 	if (type != READ)
 		file_end_write(file);
@@ -1039,7 +1099,7 @@ out:
 
 static size_t compat_readv(struct file *file,
 			   const struct compat_iovec __user *vec,
-			   unsigned long vlen, loff_t *pos)
+			   unsigned long vlen, loff_t *pos, int flags)
 {
 	ssize_t ret = -EBADF;
 
@@ -1050,7 +1110,7 @@ static size_t compat_readv(struct file *file,
 	if (!(file->f_mode & FMODE_CAN_READ))
 		goto out;
 
-	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
+	ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
 
 out:
 	if (ret > 0)
@@ -1059,9 +1119,9 @@ out:
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
-		compat_ulong_t, vlen)
+static size_t do_compat_readv(compat_ulong_t fd,
+				 const struct compat_iovec __user *vec,
+				 compat_ulong_t vlen, int flags)
 {
 	struct fd f = fdget_pos(fd);
 	ssize_t ret;
@@ -1070,16 +1130,24 @@ COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
 	if (!f.file)
 		return -EBADF;
 	pos = f.file->f_pos;
-	ret = compat_readv(f.file, vec, vlen, &pos);
+	ret = compat_readv(f.file, vec, vlen, &pos, flags);
 	if (ret >= 0)
 		f.file->f_pos = pos;
 	fdput_pos(f);
 	return ret;
+
+}
+
+COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen)
+{
+	return do_compat_readv(fd, vec, vlen, 0);
 }
 
-static long __compat_sys_preadv64(unsigned long fd,
+static long do_compat_preadv64(unsigned long fd,
 				  const struct compat_iovec __user *vec,
-				  unsigned long vlen, loff_t pos)
+				  unsigned long vlen, loff_t pos, int flags)
 {
 	struct fd f;
 	ssize_t ret;
@@ -1091,7 +1159,7 @@ static long __compat_sys_preadv64(unsigned long fd,
 		return -EBADF;
 	ret = -ESPIPE;
 	if (f.file->f_mode & FMODE_PREAD)
-		ret = compat_readv(f.file, vec, vlen, &pos);
+		ret = compat_readv(f.file, vec, vlen, &pos, flags);
 	fdput(f);
 	return ret;
 }
@@ -1101,7 +1169,7 @@ COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
 		const struct compat_iovec __user *,vec,
 		unsigned long, vlen, loff_t, pos)
 {
-	return __compat_sys_preadv64(fd, vec, vlen, pos);
+	return do_compat_preadv64(fd, vec, vlen, pos, 0);
 }
 #endif
 
@@ -1111,12 +1179,25 @@ COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-	return __compat_sys_preadv64(fd, vec, vlen, pos);
+	return do_compat_preadv64(fd, vec, vlen, pos, 0);
+}
+
+COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
+		int, flags)
+{
+	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+	if (pos == -1)
+		return do_compat_readv(fd, vec, vlen, flags);
+
+	return do_compat_preadv64(fd, vec, vlen, pos, flags);
 }
 
 static size_t compat_writev(struct file *file,
 			    const struct compat_iovec __user *vec,
-			    unsigned long vlen, loff_t *pos)
+			    unsigned long vlen, loff_t *pos, int flags)
 {
 	ssize_t ret = -EBADF;
 
@@ -1127,7 +1208,7 @@ static size_t compat_writev(struct file *file,
 	if (!(file->f_mode & FMODE_CAN_WRITE))
 		goto out;
 
-	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);
+	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, 0);
 
 out:
 	if (ret > 0)
@@ -1136,9 +1217,9 @@ out:
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
-		const struct compat_iovec __user *, vec,
-		compat_ulong_t, vlen)
+static size_t do_compat_writev(compat_ulong_t fd,
+				  const struct compat_iovec __user* vec,
+				  compat_ulong_t vlen, int flags)
 {
 	struct fd f = fdget_pos(fd);
 	ssize_t ret;
@@ -1147,16 +1228,23 @@ COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
 	if (!f.file)
 		return -EBADF;
 	pos = f.file->f_pos;
-	ret = compat_writev(f.file, vec, vlen, &pos);
+	ret = compat_writev(f.file, vec, vlen, &pos, flags);
 	if (ret >= 0)
 		f.file->f_pos = pos;
 	fdput_pos(f);
 	return ret;
 }
 
-static long __compat_sys_pwritev64(unsigned long fd,
+COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
+		const struct compat_iovec __user *, vec,
+		compat_ulong_t, vlen)
+{
+	return do_compat_writev(fd, vec, vlen, 0);
+}
+
+static long do_compat_pwritev64(unsigned long fd,
 				   const struct compat_iovec __user *vec,
-				   unsigned long vlen, loff_t pos)
+				   unsigned long vlen, loff_t pos, int flags)
 {
 	struct fd f;
 	ssize_t ret;
@@ -1168,7 +1256,7 @@ static long __compat_sys_pwritev64(unsigned long fd,
 		return -EBADF;
 	ret = -ESPIPE;
 	if (f.file->f_mode & FMODE_PWRITE)
-		ret = compat_writev(f.file, vec, vlen, &pos);
+		ret = compat_writev(f.file, vec, vlen, &pos, flags);
 	fdput(f);
 	return ret;
 }
@@ -1178,7 +1266,7 @@ COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
 		const struct compat_iovec __user *,vec,
 		unsigned long, vlen, loff_t, pos)
 {
-	return __compat_sys_pwritev64(fd, vec, vlen, pos);
+	return do_compat_pwritev64(fd, vec, vlen, pos, 0);
 }
 #endif
 
@@ -1188,8 +1276,21 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-	return __compat_sys_pwritev64(fd, vec, vlen, pos);
+	return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+}
+
+COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
+		const struct compat_iovec __user *,vec,
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
+{
+	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+
+	if (pos == -1)
+		return do_compat_writev(fd, vec, vlen, flags);
+
+	return do_compat_pwritev64(fd, vec, vlen, pos, flags);
 }
+
 #endif
 
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
diff --git a/fs/splice.c b/fs/splice.c
index 82bc0d64fc38..9947b5c69664 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -185,6 +185,9 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 	unsigned int spd_pages = spd->nr_pages;
 	int ret, do_wakeup, page_nr;
 
+	if (!spd_pages)
+		return 0;
+
 	ret = 0;
 	do_wakeup = 0;
 	page_nr = 0;
@@ -577,7 +580,7 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 	old_fs = get_fs();
 	set_fs(get_ds());
 	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
+	res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0);
 	set_fs(old_fs);
 
 	return res;