1 files changed, 342 insertions, 150 deletions

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index ee9c923192e0..93798575b807 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -39,6 +39,7 @@
 #include <linux/fsnotify.h>
 #include <linux/seq_file.h>
 #include <linux/rhashtable.h>
+#include <linux/nfslocalio.h>
 
 #include "vfs.h"
 #include "nfsd.h"
@@ -52,22 +53,20 @@
 #define NFSD_FILE_CACHE_UP		     (0)
 
 /* We only care about NFSD_MAY_READ/WRITE for this cache */
-#define NFSD_FILE_MAY_MASK	(NFSD_MAY_READ|NFSD_MAY_WRITE)
+#define NFSD_FILE_MAY_MASK	(NFSD_MAY_READ|NFSD_MAY_WRITE|NFSD_MAY_LOCALIO)
 
 static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_allocations);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_releases);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_total_age);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_evictions);
 
 struct nfsd_fcache_disposal {
-	struct work_struct work;
 	spinlock_t lock;
 	struct list_head freeme;
 };
 
-static struct workqueue_struct *nfsd_filecache_wq __read_mostly;
-
 static struct kmem_cache		*nfsd_file_slab;
 static struct kmem_cache		*nfsd_file_mark_slab;
 static struct list_lru			nfsd_file_lru;
@@ -114,7 +113,7 @@ static void
 nfsd_file_schedule_laundrette(void)
 {
 	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags))
-		queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
+		queue_delayed_work(system_dfl_wq, &nfsd_filecache_laundrette,
 				   NFSD_LAUNDRETTE_DELAY);
 }
 
@@ -154,7 +153,7 @@ nfsd_file_mark_put(struct nfsd_file_mark *nfm)
 }
 
 static struct nfsd_file_mark *
-nfsd_file_mark_find_or_create(struct nfsd_file *nf, struct inode *inode)
+nfsd_file_mark_find_or_create(struct inode *inode)
 {
 	int			err;
 	struct fsnotify_mark	*mark;
@@ -162,8 +161,8 @@ nfsd_file_mark_find_or_create(struct nfsd_file *nf, struct inode *inode)
 
 	do {
 		fsnotify_group_lock(nfsd_file_fsnotify_group);
-		mark = fsnotify_find_mark(&inode->i_fsnotify_marks,
-					  nfsd_file_fsnotify_group);
+		mark = fsnotify_find_inode_mark(inode,
+						nfsd_file_fsnotify_group);
 		if (mark) {
 			nfm = nfsd_file_mark_get(container_of(mark,
 						 struct nfsd_file_mark,
@@ -218,7 +217,9 @@ nfsd_file_alloc(struct net *net, struct inode *inode, unsigned char need,
 	if (unlikely(!nf))
 		return NULL;
 
+	this_cpu_inc(nfsd_file_allocations);
 	INIT_LIST_HEAD(&nf->nf_lru);
+	INIT_LIST_HEAD(&nf->nf_gc);
 	nf->nf_birthtime = ktime_get();
 	nf->nf_file = NULL;
 	nf->nf_cred = get_current_cred();
@@ -230,6 +231,9 @@ nfsd_file_alloc(struct net *net, struct inode *inode, unsigned char need,
 	refcount_set(&nf->nf_ref, 1);
 	nf->nf_may = need;
 	nf->nf_mark = NULL;
+	nf->nf_dio_mem_align = 0;
+	nf->nf_dio_offset_align = 0;
+	nf->nf_dio_read_offset_align = 0;
 	return nf;
 }
 
@@ -283,7 +287,7 @@ nfsd_file_free(struct nfsd_file *nf)
 		nfsd_file_mark_put(nf->nf_mark);
 	if (nf->nf_file) {
 		nfsd_file_check_write_error(nf);
-		filp_close(nf->nf_file, NULL);
+		nfsd_filp_close(nf->nf_file);
 	}
 
 	/*
@@ -318,20 +322,19 @@ nfsd_file_check_writeback(struct nfsd_file *nf)
 		mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK);
 }
 
-
-static bool nfsd_file_lru_add(struct nfsd_file *nf)
+static void nfsd_file_lru_add(struct nfsd_file *nf)
 {
-	set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
-	if (list_lru_add(&nfsd_file_lru, &nf->nf_lru)) {
+	refcount_inc(&nf->nf_ref);
+	if (list_lru_add_obj(&nfsd_file_lru, &nf->nf_lru))
 		trace_nfsd_file_lru_add(nf);
-		return true;
-	}
-	return false;
+	else
+		WARN_ON(1);
+	nfsd_file_schedule_laundrette();
 }
 
 static bool nfsd_file_lru_remove(struct nfsd_file *nf)
 {
-	if (list_lru_del(&nfsd_file_lru, &nf->nf_lru)) {
+	if (list_lru_del_obj(&nfsd_file_lru, &nf->nf_lru)) {
 		trace_nfsd_file_lru_del(nf);
 		return true;
 	}
@@ -362,42 +365,55 @@ nfsd_file_put(struct nfsd_file *nf)
 
 	if (test_bit(NFSD_FILE_GC, &nf->nf_flags) &&
 	    test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
-		/*
-		 * If this is the last reference (nf_ref == 1), then try to
-		 * transfer it to the LRU.
-		 */
-		if (refcount_dec_not_one(&nf->nf_ref))
-			return;
-
-		/* Try to add it to the LRU.  If that fails, decrement. */
-		if (nfsd_file_lru_add(nf)) {
-			/* If it's still hashed, we're done */
-			if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
-				nfsd_file_schedule_laundrette();
-				return;
-			}
-
-			/*
-			 * We're racing with unhashing, so try to remove it from
-			 * the LRU. If removal fails, then someone else already
-			 * has our reference.
-			 */
-			if (!nfsd_file_lru_remove(nf))
-				return;
-		}
+		set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
+		set_bit(NFSD_FILE_RECENT, &nf->nf_flags);
 	}
+
 	if (refcount_dec_and_test(&nf->nf_ref))
 		nfsd_file_free(nf);
 }
 
+/**
+ * nfsd_file_put_local - put nfsd_file reference and arm nfsd_net_put in caller
+ * @pnf: nfsd_file of which to put the reference
+ *
+ * First save the associated net to return to caller, then put
+ * the reference of the nfsd_file.
+ */
+struct net *
+nfsd_file_put_local(struct nfsd_file __rcu **pnf)
+{
+	struct nfsd_file *nf;
+	struct net *net = NULL;
+
+	nf = unrcu_pointer(xchg(pnf, NULL));
+	if (nf) {
+		net = nf->nf_net;
+		nfsd_file_put(nf);
+	}
+	return net;
+}
+
+/**
+ * nfsd_file_file - get the backing file of an nfsd_file
+ * @nf: nfsd_file of which to access the backing file.
+ *
+ * Return backing file for @nf.
+ */
+struct file *
+nfsd_file_file(struct nfsd_file *nf)
+{
+	return nf->nf_file;
+}
+
 static void
 nfsd_file_dispose_list(struct list_head *dispose)
 {
 	struct nfsd_file *nf;
 
 	while (!list_empty(dispose)) {
-		nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
-		list_del_init(&nf->nf_lru);
+		nf = list_first_entry(dispose, struct nfsd_file, nf_gc);
+		list_del_init(&nf->nf_gc);
 		nfsd_file_free(nf);
 	}
 }
@@ -414,14 +430,53 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose)
 {
 	while(!list_empty(dispose)) {
 		struct nfsd_file *nf = list_first_entry(dispose,
-						struct nfsd_file, nf_lru);
+						struct nfsd_file, nf_gc);
 		struct nfsd_net *nn = net_generic(nf->nf_net, nfsd_net_id);
 		struct nfsd_fcache_disposal *l = nn->fcache_disposal;
+		struct svc_serv *serv;
 
 		spin_lock(&l->lock);
-		list_move_tail(&nf->nf_lru, &l->freeme);
+		list_move_tail(&nf->nf_gc, &l->freeme);
 		spin_unlock(&l->lock);
-		queue_work(nfsd_filecache_wq, &l->work);
+
+		/*
+		 * The filecache laundrette is shut down after the
+		 * nn->nfsd_serv pointer is cleared, but before the
+		 * svc_serv is freed.
+		 */
+		serv = nn->nfsd_serv;
+		if (serv)
+			svc_wake_up(serv);
+	}
+}
+
+/**
+ * nfsd_file_net_dispose - deal with nfsd_files waiting to be disposed.
+ * @nn: nfsd_net in which to find files to be disposed.
+ *
+ * When files held open for nfsv3 are removed from the filecache, whether
+ * due to memory pressure or garbage collection, they are queued to
+ * a per-net-ns queue.  This function completes the disposal, either
+ * directly or by waking another nfsd thread to help with the work.
+ */
+void nfsd_file_net_dispose(struct nfsd_net *nn)
+{
+	struct nfsd_fcache_disposal *l = nn->fcache_disposal;
+
+	if (!list_empty(&l->freeme)) {
+		LIST_HEAD(dispose);
+		int i;
+
+		spin_lock(&l->lock);
+		for (i = 0; i < 8 && !list_empty(&l->freeme); i++)
+			list_move(l->freeme.next, &dispose);
+		spin_unlock(&l->lock);
+		if (!list_empty(&l->freeme))
+			/* Wake up another thread to share the work
+			 * *before* doing any actual disposing.
+			 */
+			svc_wake_up(nn->nfsd_serv);
+		nfsd_file_dispose_list(&dispose);
 	}
 }
 
@@ -429,7 +484,6 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose)
  * nfsd_file_lru_cb - Examine an entry on the LRU list
  * @item: LRU entry to examine
  * @lru: controlling LRU
- * @lock: LRU list lock (unused)
  * @arg: dispose list
  *
  * Return values:
@@ -439,9 +493,7 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose)
  */
 static enum lru_status
 nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
-		 spinlock_t *lock, void *arg)
-	__releases(lock)
-	__acquires(lock)
+		 void *arg)
 {
 	struct list_head *head = arg;
 	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);
@@ -465,31 +517,71 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
 	}
 
 	/*
-	 * Put the reference held on behalf of the LRU. If it wasn't the last
-	 * one, then just remove it from the LRU and ignore it.
+	 * Put the reference held on behalf of the LRU if it is the last
+	 * reference, else rotate.
 	 */
-	if (!refcount_dec_and_test(&nf->nf_ref)) {
+	if (!refcount_dec_if_one(&nf->nf_ref)) {
 		trace_nfsd_file_gc_in_use(nf);
-		list_lru_isolate(lru, &nf->nf_lru);
-		return LRU_REMOVED;
+		return LRU_ROTATE;
 	}
 
 	/* Refcount went to zero. Unhash it and queue it to the dispose list */
 	nfsd_file_unhash(nf);
-	list_lru_isolate_move(lru, &nf->nf_lru, head);
+	list_lru_isolate(lru, &nf->nf_lru);
+	list_add(&nf->nf_gc, head);
 	this_cpu_inc(nfsd_file_evictions);
 	trace_nfsd_file_gc_disposed(nf);
 	return LRU_REMOVED;
 }
 
+static enum lru_status
+nfsd_file_gc_cb(struct list_head *item, struct list_lru_one *lru,
+		 void *arg)
+{
+	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);
+
+	if (test_and_clear_bit(NFSD_FILE_RECENT, &nf->nf_flags)) {
+		/*
+		 * "REFERENCED" really means "should be at the end of the
+		 * LRU. As we are putting it there we can clear the flag.
+		 */
+		clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
+		trace_nfsd_file_gc_aged(nf);
+		return LRU_ROTATE;
+	}
+	return nfsd_file_lru_cb(item, lru, arg);
+}
+
+/* If the shrinker runs between calls to list_lru_walk_node() in
+ * nfsd_file_gc(), the "remaining" count will be wrong.  This could
+ * result in premature freeing of some files.  This may not matter much
+ * but is easy to fix with this spinlock which temporarily disables
+ * the shrinker.
+ */
+static DEFINE_SPINLOCK(nfsd_gc_lock);
 static void
 nfsd_file_gc(void)
 {
+	unsigned long ret = 0;
 	LIST_HEAD(dispose);
-	unsigned long ret;
+	int nid;
+
+	spin_lock(&nfsd_gc_lock);
+	for_each_node_state(nid, N_NORMAL_MEMORY) {
+		unsigned long remaining = list_lru_count_node(&nfsd_file_lru, nid);
 
-	ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb,
-			    &dispose, list_lru_count(&nfsd_file_lru));
+		while (remaining > 0) {
+			unsigned long nr = min(remaining, NFSD_FILE_GC_BATCH);
+
+			remaining -= nr;
+			ret += list_lru_walk_node(&nfsd_file_lru, nid, nfsd_file_gc_cb,
+						  &dispose, &nr);
+			if (nr)
+				/* walk aborted early */
+				remaining = 0;
+		}
+	}
+	spin_unlock(&nfsd_gc_lock);
 	trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru));
 	nfsd_file_dispose_list_delayed(&dispose);
 }
@@ -497,9 +589,9 @@ nfsd_file_gc(void)
 static void
 nfsd_file_gc_worker(struct work_struct *work)
 {
-	nfsd_file_gc();
 	if (list_lru_count(&nfsd_file_lru))
-		nfsd_file_schedule_laundrette();
+		nfsd_file_gc();
+	nfsd_file_schedule_laundrette();
 }
 
 static unsigned long
@@ -514,18 +606,18 @@ nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
 	LIST_HEAD(dispose);
 	unsigned long ret;
 
+	if (!spin_trylock(&nfsd_gc_lock))
+		return SHRINK_STOP;
+
 	ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
 				   nfsd_file_lru_cb, &dispose);
+	spin_unlock(&nfsd_gc_lock);
 	trace_nfsd_file_shrinker_removed(ret, list_lru_count(&nfsd_file_lru));
 	nfsd_file_dispose_list_delayed(&dispose);
 	return ret;
 }
 
-static struct shrinker	nfsd_file_shrinker = {
-	.scan_objects = nfsd_file_lru_scan,
-	.count_objects = nfsd_file_lru_count,
-	.seeks = 1,
-};
+static struct shrinker *nfsd_file_shrinker;
 
 /**
  * nfsd_file_cond_queue - conditionally unhash and queue a nfsd_file
@@ -555,7 +647,7 @@ nfsd_file_cond_queue(struct nfsd_file *nf, struct list_head *dispose)
 
 	/* If refcount goes to 0, then put on the dispose list */
 	if (refcount_sub_and_test(decrement, &nf->nf_ref)) {
-		list_add(&nf->nf_lru, dispose);
+		list_add(&nf->nf_gc, dispose);
 		trace_nfsd_file_closing(nf);
 	}
 }
@@ -624,50 +716,23 @@ nfsd_file_close_inode(struct inode *inode)
 void
 nfsd_file_close_inode_sync(struct inode *inode)
 {
-	struct nfsd_file *nf;
 	LIST_HEAD(dispose);
 
 	trace_nfsd_file_close(inode);
 
 	nfsd_file_queue_for_close(inode, &dispose);
-	while (!list_empty(&dispose)) {
-		nf = list_first_entry(&dispose, struct nfsd_file, nf_lru);
-		list_del_init(&nf->nf_lru);
-		nfsd_file_free(nf);
-	}
-	flush_delayed_fput();
-}
-
-/**
- * nfsd_file_delayed_close - close unused nfsd_files
- * @work: dummy
- *
- * Scrape the freeme list for this nfsd_net, and then dispose of them
- * all.
- */
-static void
-nfsd_file_delayed_close(struct work_struct *work)
-{
-	LIST_HEAD(head);
-	struct nfsd_fcache_disposal *l = container_of(work,
-			struct nfsd_fcache_disposal, work);
-
-	spin_lock(&l->lock);
-	list_splice_init(&l->freeme, &head);
-	spin_unlock(&l->lock);
-
-	nfsd_file_dispose_list(&head);
+	nfsd_file_dispose_list(&dispose);
 }
 
 static int
 nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg,
 			    void *data)
 {
-	struct file_lock *fl = data;
+	struct file_lease *fl = data;
 
 	/* Only close files for F_SETLEASE leases */
-	if (fl->fl_flags & FL_LEASE)
-		nfsd_file_close_inode(file_inode(fl->fl_file));
+	if (fl->c.flc_flags & FL_LEASE)
+		nfsd_file_close_inode(file_inode(fl->c.flc_file));
 	return 0;
 }
 
@@ -718,40 +783,40 @@ nfsd_file_cache_init(void)
 
 	ret = rhltable_init(&nfsd_file_rhltable, &nfsd_file_rhash_params);
 	if (ret)
-		return ret;
-
-	ret = -ENOMEM;
-	nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0);
-	if (!nfsd_filecache_wq)
 		goto out;
 
-	nfsd_file_slab = kmem_cache_create("nfsd_file",
-				sizeof(struct nfsd_file), 0, 0, NULL);
+	ret = -ENOMEM;
+	nfsd_file_slab = KMEM_CACHE(nfsd_file, 0);
 	if (!nfsd_file_slab) {
 		pr_err("nfsd: unable to create nfsd_file_slab\n");
 		goto out_err;
 	}
 
-	nfsd_file_mark_slab = kmem_cache_create("nfsd_file_mark",
-					sizeof(struct nfsd_file_mark), 0, 0, NULL);
+	nfsd_file_mark_slab = KMEM_CACHE(nfsd_file_mark, 0);
 	if (!nfsd_file_mark_slab) {
 		pr_err("nfsd: unable to create nfsd_file_mark_slab\n");
 		goto out_err;
 	}
 
-
 	ret = list_lru_init(&nfsd_file_lru);
 	if (ret) {
 		pr_err("nfsd: failed to init nfsd_file_lru: %d\n", ret);
 		goto out_err;
 	}
 
-	ret = register_shrinker(&nfsd_file_shrinker, "nfsd-filecache");
-	if (ret) {
-		pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret);
+	nfsd_file_shrinker = shrinker_alloc(0, "nfsd-filecache");
+	if (!nfsd_file_shrinker) {
+		ret = -ENOMEM;
+		pr_err("nfsd: failed to allocate nfsd_file_shrinker\n");
 		goto out_lru;
 	}
 
+	nfsd_file_shrinker->count_objects = nfsd_file_lru_count;
+	nfsd_file_shrinker->scan_objects = nfsd_file_lru_scan;
+	nfsd_file_shrinker->seeks = 1;
+
+	shrinker_register(nfsd_file_shrinker);
+
 	ret = lease_register_notifier(&nfsd_file_lease_notifier);
 	if (ret) {
 		pr_err("nfsd: unable to register lease notifier: %d\n", ret);
@@ -759,7 +824,7 @@ nfsd_file_cache_init(void)
 	}
 
 	nfsd_file_fsnotify_group = fsnotify_alloc_group(&nfsd_file_fsnotify_ops,
-							FSNOTIFY_GROUP_NOFS);
+							0);
 	if (IS_ERR(nfsd_file_fsnotify_group)) {
 		pr_err("nfsd: unable to create fsnotify group: %ld\n",
 			PTR_ERR(nfsd_file_fsnotify_group));
@@ -770,11 +835,13 @@ nfsd_file_cache_init(void)
 
 	INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker);
 out:
+	if (ret)
+		clear_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags);
 	return ret;
 out_notifier:
 	lease_unregister_notifier(&nfsd_file_lease_notifier);
 out_shrinker:
-	unregister_shrinker(&nfsd_file_shrinker);
+	shrinker_free(nfsd_file_shrinker);
 out_lru:
 	list_lru_destroy(&nfsd_file_lru);
 out_err:
@@ -782,8 +849,6 @@ out_err:
 	nfsd_file_slab = NULL;
 	kmem_cache_destroy(nfsd_file_mark_slab);
 	nfsd_file_mark_slab = NULL;
-	destroy_workqueue(nfsd_filecache_wq);
-	nfsd_filecache_wq = NULL;
 	rhltable_destroy(&nfsd_file_rhltable);
 	goto out;
 }
@@ -803,6 +868,14 @@ __nfsd_file_cache_purge(struct net *net)
 	struct nfsd_file *nf;
 	LIST_HEAD(dispose);
 
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	if (net) {
+		struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+		nfs_localio_invalidate_clients(&nn->local_clients,
+					       &nn->local_clients_lock);
+	}
+#endif
+
 	rhltable_walk_enter(&nfsd_file_rhltable, &iter);
 	do {
 		rhashtable_walk_start(&iter);
@@ -829,7 +902,6 @@ nfsd_alloc_fcache_disposal(void)
 	l = kmalloc(sizeof(*l), GFP_KERNEL);
 	if (!l)
 		return NULL;
-	INIT_WORK(&l->work, nfsd_file_delayed_close);
 	spin_lock_init(&l->lock);
 	INIT_LIST_HEAD(&l->freeme);
 	return l;
@@ -838,7 +910,6 @@ nfsd_alloc_fcache_disposal(void)
 static void
 nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l)
 {
-	cancel_work_sync(&l->work);
 	nfsd_file_dispose_list(&l->freeme);
 	kfree(l);
 }
@@ -891,7 +962,7 @@ nfsd_file_cache_shutdown(void)
 		return;
 
 	lease_unregister_notifier(&nfsd_file_lease_notifier);
-	unregister_shrinker(&nfsd_file_shrinker);
+	shrinker_free(nfsd_file_shrinker);
 	/*
 	 * make sure all callers of nfsd_file_lru_cb are done before
 	 * calling nfsd_file_cache_purge
@@ -907,13 +978,12 @@ nfsd_file_cache_shutdown(void)
 	fsnotify_wait_marks_destroyed();
 	kmem_cache_destroy(nfsd_file_mark_slab);
 	nfsd_file_mark_slab = NULL;
-	destroy_workqueue(nfsd_filecache_wq);
-	nfsd_filecache_wq = NULL;
 	rhltable_destroy(&nfsd_file_rhltable);
 
 	for_each_possible_cpu(i) {
 		per_cpu(nfsd_file_cache_hits, i) = 0;
 		per_cpu(nfsd_file_acquisitions, i) = 0;
+		per_cpu(nfsd_file_allocations, i) = 0;
 		per_cpu(nfsd_file_releases, i) = 0;
 		per_cpu(nfsd_file_total_age, i) = 0;
 		per_cpu(nfsd_file_evictions, i) = 0;
@@ -982,41 +1052,68 @@ nfsd_file_is_cached(struct inode *inode)
 }
 
 static __be32
-nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+nfsd_file_get_dio_attrs(const struct svc_fh *fhp, struct nfsd_file *nf)
+{
+	struct inode *inode = file_inode(nf->nf_file);
+	struct kstat stat;
+	__be32 status;
+
+	/* Currently only need to get DIO alignment info for regular files */
+	if (!S_ISREG(inode->i_mode))
+		return nfs_ok;
+
+	status = fh_getattr(fhp, &stat);
+	if (status != nfs_ok)
+		return status;
+
+	trace_nfsd_file_get_dio_attrs(inode, &stat);
+
+	if (stat.result_mask & STATX_DIOALIGN) {
+		nf->nf_dio_mem_align = stat.dio_mem_align;
+		nf->nf_dio_offset_align = stat.dio_offset_align;
+	}
+	if (stat.result_mask & STATX_DIO_READ_ALIGN)
+		nf->nf_dio_read_offset_align = stat.dio_read_offset_align;
+	else
+		nf->nf_dio_read_offset_align = nf->nf_dio_offset_align;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,
+		     struct svc_cred *cred,
+		     struct auth_domain *client,
+		     struct svc_fh *fhp,
 		     unsigned int may_flags, struct file *file,
-		     struct nfsd_file **pnf, bool want_gc)
+		     umode_t type, bool want_gc, struct nfsd_file **pnf)
 {
 	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
-	struct net *net = SVC_NET(rqstp);
 	struct nfsd_file *new, *nf;
-	const struct cred *cred;
+	bool stale_retry = true;
 	bool open_retry = true;
 	struct inode *inode;
 	__be32 status;
 	int ret;
 
-	status = fh_verify(rqstp, fhp, S_IFREG,
-				may_flags|NFSD_MAY_OWNER_OVERRIDE);
+retry:
+	if (rqstp)
+		status = fh_verify(rqstp, fhp, type,
+				   may_flags|NFSD_MAY_OWNER_OVERRIDE);
+	else
+		status = fh_verify_local(net, cred, client, fhp, type,
+					 may_flags|NFSD_MAY_OWNER_OVERRIDE);
+
 	if (status != nfs_ok)
 		return status;
 	inode = d_inode(fhp->fh_dentry);
-	cred = get_current_cred();
 
-retry:
 	rcu_read_lock();
-	nf = nfsd_file_lookup_locked(net, cred, inode, need, want_gc);
+	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
 	rcu_read_unlock();
 
-	if (nf) {
-		/*
-		 * If the nf is on the LRU then it holds an extra reference
-		 * that must be put if it's removed. It had better not be
-		 * the last one however, since we should hold another.
-		 */
-		if (nfsd_file_lru_remove(nf))
-			WARN_ON_ONCE(refcount_dec_and_test(&nf->nf_ref));
+	if (nf)
 		goto wait_for_construction;
-	}
 
 	new = nfsd_file_alloc(net, inode, need, want_gc);
 	if (!new) {
@@ -1026,11 +1123,11 @@ retry:
 
 	rcu_read_lock();
 	spin_lock(&inode->i_lock);
-	nf = nfsd_file_lookup_locked(net, cred, inode, need, want_gc);
+	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
 	if (unlikely(nf)) {
 		spin_unlock(&inode->i_lock);
 		rcu_read_unlock();
-		nfsd_file_slab_free(&new->nf_rcu);
+		nfsd_file_free(new);
 		goto wait_for_construction;
 	}
 	nf = new;
@@ -1041,8 +1138,6 @@ retry:
 	if (likely(ret == 0))
 		goto open_file;
 
-	if (ret == -EEXIST)
-		goto retry;
 	trace_nfsd_file_insert_err(rqstp, inode, may_flags, ret);
 	status = nfserr_jukebox;
 	goto construction_err;
@@ -1057,7 +1152,9 @@ wait_for_construction:
 			status = nfserr_jukebox;
 			goto construction_err;
 		}
+		nfsd_file_put(nf);
 		open_retry = false;
+		fh_put(fhp);
 		goto retry;
 	}
 	this_cpu_inc(nfsd_file_cache_hits);
@@ -1074,23 +1171,38 @@ out:
 		nfsd_file_check_write_error(nf);
 		*pnf = nf;
 	}
-	put_cred(cred);
 	trace_nfsd_file_acquire(rqstp, inode, may_flags, nf, status);
 	return status;
 
 open_file:
 	trace_nfsd_file_alloc(nf);
-	nf->nf_mark = nfsd_file_mark_find_or_create(nf, inode);
-	if (nf->nf_mark) {
+
+	if (type == S_IFREG)
+		nf->nf_mark = nfsd_file_mark_find_or_create(inode);
+
+	if (type != S_IFREG || nf->nf_mark) {
 		if (file) {
 			get_file(file);
 			nf->nf_file = file;
 			status = nfs_ok;
 			trace_nfsd_file_opened(nf, status);
 		} else {
-			status = nfsd_open_verified(rqstp, fhp, may_flags,
-						    &nf->nf_file);
+			ret = nfsd_open_verified(fhp, type, may_flags, &nf->nf_file);
+			if (ret == -EOPENSTALE && stale_retry) {
+				stale_retry = false;
+				nfsd_file_unhash(nf);
+				clear_and_wake_up_bit(NFSD_FILE_PENDING,
+						      &nf->nf_flags);
+				if (refcount_dec_and_test(&nf->nf_ref))
+					nfsd_file_free(nf);
+				nf = NULL;
+				fh_put(fhp);
+				goto retry;
+			}
+			status = nfserrno(ret);
 			trace_nfsd_file_open(nf, status);
+			if (status == nfs_ok)
+				status = nfsd_file_get_dio_attrs(fhp, nf);
 		}
 	} else
 		status = nfserr_jukebox;
@@ -1100,6 +1212,9 @@ open_file:
 	 */
 	if (status != nfs_ok || inode->i_nlink == 0)
 		nfsd_file_unhash(nf);
+	else if (want_gc)
+		nfsd_file_lru_add(nf);
+
 	clear_and_wake_up_bit(NFSD_FILE_PENDING, &nf->nf_flags);
 	if (status == nfs_ok)
 		goto out;
@@ -1133,7 +1248,8 @@ __be32
 nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		     unsigned int may_flags, struct nfsd_file **pnf)
 {
-	return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, true);
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, NULL, S_IFREG, true, pnf);
 }
 
 /**
@@ -1157,7 +1273,54 @@ __be32
 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		  unsigned int may_flags, struct nfsd_file **pnf)
 {
-	return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, false);
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, NULL, S_IFREG, false, pnf);
+}
+
+/**
+ * nfsd_file_acquire_local - Get a struct nfsd_file with an open file for localio
+ * @net: The network namespace in which to perform a lookup
+ * @cred: the user credential with which to validate access
+ * @client: the auth_domain for LOCALIO lookup
+ * @fhp: the NFS filehandle of the file to be opened
+ * @may_flags: NFSD_MAY_ settings for the file
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * This file lookup interface provide access to a file given the
+ * filehandle and credential.  No connection-based authorisation
+ * is performed and in that way it is quite different to other
+ * file access mediated by nfsd.  It allows a kernel module such as the NFS
+ * client to reach across network and filesystem namespaces to access
+ * a file.  The security implications of this should be carefully
+ * considered before use.
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put().
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
+			struct auth_domain *client, struct svc_fh *fhp,
+			unsigned int may_flags, struct nfsd_file **pnf)
+{
+	/*
+	 * Save creds before calling nfsd_file_do_acquire() (which calls
+	 * nfsd_setuser). Important because caller (LOCALIO) is from
+	 * client context.
+	 */
+	const struct cred *save_cred = get_current_cred();
+	__be32 beres;
+
+	beres = nfsd_file_do_acquire(NULL, net, cred, client, fhp, may_flags,
+				     NULL, S_IFREG, false, pnf);
+	put_cred(revert_creds(save_cred));
+	return beres;
 }
 
 /**
@@ -1183,7 +1346,34 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			 unsigned int may_flags, struct file *file,
 			 struct nfsd_file **pnf)
 {
-	return nfsd_file_do_acquire(rqstp, fhp, may_flags, file, pnf, false);
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, file, S_IFREG, false, pnf);
+}
+
+/**
+ * nfsd_file_acquire_dir - Get a struct nfsd_file with an open directory
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file to be opened
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put(). This opens directories only, and only
+ * in O_RDONLY mode.
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_dir(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		      struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL, fhp,
+				    NFSD_MAY_READ|NFSD_MAY_64BIT_COOKIE,
+				    NULL, S_IFDIR, false, pnf);
 }
 
 /*
@@ -1193,7 +1383,7 @@ nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
  */
 int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 {
-	unsigned long releases = 0, evictions = 0;
+	unsigned long allocations = 0, releases = 0, evictions = 0;
 	unsigned long hits = 0, acquisitions = 0;
 	unsigned int i, count = 0, buckets = 0;
 	unsigned long lru = 0, total_age = 0;
@@ -1218,6 +1408,7 @@ int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 	for_each_possible_cpu(i) {
 		hits += per_cpu(nfsd_file_cache_hits, i);
 		acquisitions += per_cpu(nfsd_file_acquisitions, i);
+		allocations += per_cpu(nfsd_file_allocations, i);
 		releases += per_cpu(nfsd_file_releases, i);
 		total_age += per_cpu(nfsd_file_total_age, i);
 		evictions += per_cpu(nfsd_file_evictions, i);
@@ -1228,6 +1419,7 @@ int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 	seq_printf(m, "lru entries:   %lu\n", lru);
 	seq_printf(m, "cache hits:    %lu\n", hits);
 	seq_printf(m, "acquisitions:  %lu\n", acquisitions);
+	seq_printf(m, "allocations:   %lu\n", allocations);
 	seq_printf(m, "releases:      %lu\n", releases);
 	seq_printf(m, "evictions:     %lu\n", evictions);
 	if (releases)