Merge tag 'v4.16-rc6' into next-general

Merge to Linux 4.16-rc6 at the request of Jarkko, for his TPM updates.

40 files changed, 661 insertions, 258 deletions

diff --git a/fs/aio.c b/fs/aio.c
index a062d75109cb..6bcd3fb5265a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -68,9 +68,9 @@ struct aio_ring {
 #define AIO_RING_PAGES	8
 
 struct kioctx_table {
-	struct rcu_head	rcu;
-	unsigned	nr;
-	struct kioctx	*table[];
+	struct rcu_head		rcu;
+	unsigned		nr;
+	struct kioctx __rcu	*table[];
 };
 
 struct kioctx_cpu {
@@ -115,7 +115,8 @@ struct kioctx {
 	struct page		**ring_pages;
 	long			nr_pages;
 
-	struct work_struct	free_work;
+	struct rcu_head		free_rcu;
+	struct work_struct	free_work;	/* see free_ioctx() */
 
 	/*
 	 * signals when all in-flight requests are done
@@ -329,7 +330,7 @@ static int aio_ring_mremap(struct vm_area_struct *vma)
 	for (i = 0; i < table->nr; i++) {
 		struct kioctx *ctx;
 
-		ctx = table->table[i];
+		ctx = rcu_dereference(table->table[i]);
 		if (ctx && ctx->aio_ring_file == file) {
 			if (!atomic_read(&ctx->dead)) {
 				ctx->user_id = ctx->mmap_base = vma->vm_start;
@@ -588,6 +589,12 @@ static int kiocb_cancel(struct aio_kiocb *kiocb)
 	return cancel(&kiocb->common);
 }
 
+/*
+ * free_ioctx() should be RCU delayed to synchronize against the RCU
+ * protected lookup_ioctx() and also needs process context to call
+ * aio_free_ring(), so the double bouncing through kioctx->free_rcu and
+ * ->free_work.
+ */
 static void free_ioctx(struct work_struct *work)
 {
 	struct kioctx *ctx = container_of(work, struct kioctx, free_work);
@@ -601,6 +608,14 @@ static void free_ioctx(struct work_struct *work)
 	kmem_cache_free(kioctx_cachep, ctx);
 }
 
+static void free_ioctx_rcufn(struct rcu_head *head)
+{
+	struct kioctx *ctx = container_of(head, struct kioctx, free_rcu);
+
+	INIT_WORK(&ctx->free_work, free_ioctx);
+	schedule_work(&ctx->free_work);
+}
+
 static void free_ioctx_reqs(struct percpu_ref *ref)
 {
 	struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
@@ -609,8 +624,8 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
 	if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
 		complete(&ctx->rq_wait->comp);
 
-	INIT_WORK(&ctx->free_work, free_ioctx);
-	schedule_work(&ctx->free_work);
+	/* Synchronize against RCU protected table->table[] dereferences */
+	call_rcu(&ctx->free_rcu, free_ioctx_rcufn);
 }
 
 /*
@@ -651,9 +666,9 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
 	while (1) {
 		if (table)
 			for (i = 0; i < table->nr; i++)
-				if (!table->table[i]) {
+				if (!rcu_access_pointer(table->table[i])) {
 					ctx->id = i;
-					table->table[i] = ctx;
+					rcu_assign_pointer(table->table[i], ctx);
 					spin_unlock(&mm->ioctx_lock);
 
 					/* While kioctx setup is in progress,
@@ -834,11 +849,11 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
 	}
 
 	table = rcu_dereference_raw(mm->ioctx_table);
-	WARN_ON(ctx != table->table[ctx->id]);
-	table->table[ctx->id] = NULL;
+	WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id]));
+	RCU_INIT_POINTER(table->table[ctx->id], NULL);
 	spin_unlock(&mm->ioctx_lock);
 
-	/* percpu_ref_kill() will do the necessary call_rcu() */
+	/* free_ioctx_reqs() will do the necessary RCU synchronization */
 	wake_up_all(&ctx->wait);
 
 	/*
@@ -880,7 +895,8 @@ void exit_aio(struct mm_struct *mm)
 
 	skipped = 0;
 	for (i = 0; i < table->nr; ++i) {
-		struct kioctx *ctx = table->table[i];
+		struct kioctx *ctx =
+			rcu_dereference_protected(table->table[i], true);
 
 		if (!ctx) {
 			skipped++;
@@ -1069,7 +1085,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
 	if (!table || id >= table->nr)
 		goto out;
 
-	ctx = table->table[id];
+	ctx = rcu_dereference(table->table[id]);
 	if (ctx && ctx->user_id == ctx_id) {
 		percpu_ref_get(&ctx->users);
 		ret = ctx;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 4a181fcb5175..fe09ef9c21f3 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1058,6 +1058,27 @@ retry:
 	return 0;
 }
 
+static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)
+{
+	struct gendisk *disk = get_gendisk(bdev->bd_dev, partno);
+
+	if (!disk)
+		return NULL;
+	/*
+	 * Now that we hold gendisk reference we make sure bdev we looked up is
+	 * not stale. If it is, it means device got removed and created before
+	 * we looked up gendisk and we fail open in such case. Associating
+	 * unhashed bdev with newly created gendisk could lead to two bdevs
+	 * (and thus two independent caches) being associated with one device
+	 * which is bad.
+	 */
+	if (inode_unhashed(bdev->bd_inode)) {
+		put_disk_and_module(disk);
+		return NULL;
+	}
+	return disk;
+}
+
 /**
  * bd_start_claiming - start claiming a block device
  * @bdev: block device of interest
@@ -1094,7 +1115,7 @@ static struct block_device *bd_start_claiming(struct block_device *bdev,
 	 * @bdev might not have been initialized properly yet, look up
 	 * and grab the outer block device the hard way.
 	 */
-	disk = get_gendisk(bdev->bd_dev, &partno);
+	disk = bdev_get_gendisk(bdev, &partno);
 	if (!disk)
 		return ERR_PTR(-ENXIO);
 
@@ -1111,8 +1132,7 @@ static struct block_device *bd_start_claiming(struct block_device *bdev,
 	else
 		whole = bdgrab(bdev);
 
-	module_put(disk->fops->owner);
-	put_disk(disk);
+	put_disk_and_module(disk);
 	if (!whole)
 		return ERR_PTR(-ENOMEM);
 
@@ -1407,10 +1427,10 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
 static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 {
 	struct gendisk *disk;
-	struct module *owner;
 	int ret;
 	int partno;
 	int perm = 0;
+	bool first_open = false;
 
 	if (mode & FMODE_READ)
 		perm |= MAY_READ;
@@ -1430,14 +1450,14 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
  restart:
 
 	ret = -ENXIO;
-	disk = get_gendisk(bdev->bd_dev, &partno);
+	disk = bdev_get_gendisk(bdev, &partno);
 	if (!disk)
 		goto out;
-	owner = disk->fops->owner;
 
 	disk_block_events(disk);
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
 	if (!bdev->bd_openers) {
+		first_open = true;
 		bdev->bd_disk = disk;
 		bdev->bd_queue = disk->queue;
 		bdev->bd_contains = bdev;
@@ -1463,8 +1483,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 					bdev->bd_queue = NULL;
 					mutex_unlock(&bdev->bd_mutex);
 					disk_unblock_events(disk);
-					put_disk(disk);
-					module_put(owner);
+					put_disk_and_module(disk);
 					goto restart;
 				}
 			}
@@ -1524,15 +1543,15 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			if (ret)
 				goto out_unlock_bdev;
 		}
-		/* only one opener holds refs to the module and disk */
-		put_disk(disk);
-		module_put(owner);
 	}
 	bdev->bd_openers++;
 	if (for_part)
 		bdev->bd_part_count++;
 	mutex_unlock(&bdev->bd_mutex);
 	disk_unblock_events(disk);
+	/* only one opener holds refs to the module and disk */
+	if (!first_open)
+		put_disk_and_module(disk);
 	return 0;
 
  out_clear:
@@ -1546,8 +1565,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
  out_unlock_bdev:
 	mutex_unlock(&bdev->bd_mutex);
 	disk_unblock_events(disk);
-	put_disk(disk);
-	module_put(owner);
+	put_disk_and_module(disk);
  out:
 	bdput(bdev);
 
@@ -1770,8 +1788,6 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 			disk->fops->release(disk, mode);
 	}
 	if (!bdev->bd_openers) {
-		struct module *owner = disk->fops->owner;
-
 		disk_put_part(bdev->bd_part);
 		bdev->bd_part = NULL;
 		bdev->bd_disk = NULL;
@@ -1779,8 +1795,7 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 			victim = bdev->bd_contains;
 		bdev->bd_contains = NULL;
 
-		put_disk(disk);
-		module_put(owner);
+		put_disk_and_module(disk);
 	}
 	mutex_unlock(&bdev->bd_mutex);
 	bdput(bdev);
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index f94b2d8c744a..26484648d090 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1519,6 +1519,7 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
 		if (!node)
 			break;
 		bytenr = node->val;
+		shared.share_count = 0;
 		cond_resched();
 	}
 
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1a462ab85c49..da308774b8a4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2974,7 +2974,7 @@ static inline void free_fs_info(struct btrfs_fs_info *fs_info)
 	kfree(fs_info->super_copy);
 	kfree(fs_info->super_for_commit);
 	security_free_mnt_opts(&fs_info->security_opts);
-	kfree(fs_info);
+	kvfree(fs_info);
 }
 
 /* tree mod log functions from ctree.c */
@@ -3095,7 +3095,10 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 			  int cow);
 
-int btrfs_find_name_in_ext_backref(struct btrfs_path *path,
+int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
+			       const char *name,
+			       int name_len, struct btrfs_inode_ref **ref_ret);
+int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
 				   u64 ref_objectid, const char *name,
 				   int name_len,
 				   struct btrfs_inode_extref **extref_ret);
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 39c968f80157..65e1a76bf755 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -22,10 +22,10 @@
 #include "transaction.h"
 #include "print-tree.h"
 
-static int find_name_in_backref(struct btrfs_path *path, const char *name,
-			 int name_len, struct btrfs_inode_ref **ref_ret)
+int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
+			       const char *name,
+			       int name_len, struct btrfs_inode_ref **ref_ret)
 {
-	struct extent_buffer *leaf;
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
 	unsigned long name_ptr;
@@ -33,9 +33,8 @@ static int find_name_in_backref(struct btrfs_path *path, const char *name,
 	u32 cur_offset = 0;
 	int len;
 
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+	item_size = btrfs_item_size_nr(leaf, slot);
+	ptr = btrfs_item_ptr_offset(leaf, slot);
 	while (cur_offset < item_size) {
 		ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
 		len = btrfs_inode_ref_name_len(leaf, ref);
@@ -44,18 +43,19 @@ static int find_name_in_backref(struct btrfs_path *path, const char *name,
 		if (len != name_len)
 			continue;
 		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
-			*ref_ret = ref;
+			if (ref_ret)
+				*ref_ret = ref;
 			return 1;
 		}
 	}
 	return 0;
 }
 
-int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
+int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
+				   u64 ref_objectid,
 				   const char *name, int name_len,
 				   struct btrfs_inode_extref **extref_ret)
 {
-	struct extent_buffer *leaf;
 	struct btrfs_inode_extref *extref;
 	unsigned long ptr;
 	unsigned long name_ptr;
@@ -63,9 +63,8 @@ int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
 	u32 cur_offset = 0;
 	int ref_name_len;
 
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+	item_size = btrfs_item_size_nr(leaf, slot);
+	ptr = btrfs_item_ptr_offset(leaf, slot);
 
 	/*
 	 * Search all extended backrefs in this item. We're only
@@ -113,7 +112,9 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 		return ERR_PTR(ret);
 	if (ret > 0)
 		return NULL;
-	if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
+	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+					    ref_objectid, name, name_len,
+					    &extref))
 		return NULL;
 	return extref;
 }
@@ -155,7 +156,8 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	 * This should always succeed so error here will make the FS
 	 * readonly.
 	 */
-	if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
+	if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+					    ref_objectid,
 					    name, name_len, &extref)) {
 		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
 		ret = -EROFS;
@@ -225,7 +227,8 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 	} else if (ret < 0) {
 		goto out;
 	}
-	if (!find_name_in_backref(path, name, name_len, &ref)) {
+	if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+					name, name_len, &ref)) {
 		ret = -ENOENT;
 		search_ext_refs = 1;
 		goto out;
@@ -293,7 +296,9 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
 				      ins_len);
 	if (ret == -EEXIST) {
-		if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+		if (btrfs_find_name_in_ext_backref(path->nodes[0],
+						   path->slots[0],
+						   ref_objectid,
 						   name, name_len, NULL))
 			goto out;
 
@@ -351,7 +356,8 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	if (ret == -EEXIST) {
 		u32 old_size;
 
-		if (find_name_in_backref(path, name, name_len, &ref))
+		if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+					       name, name_len, &ref))
 			goto out;
 
 		old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
@@ -365,7 +371,9 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 		ret = 0;
 	} else if (ret < 0) {
 		if (ret == -EOVERFLOW) {
-			if (find_name_in_backref(path, name, name_len, &ref))
+			if (btrfs_find_name_in_backref(path->nodes[0],
+						       path->slots[0],
+						       name, name_len, &ref))
 				ret = -EEXIST;
 			else
 				ret = -EMLINK;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a79299a89b7d..f53470112670 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2043,12 +2043,15 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
 			     struct inode *inode, struct list_head *list)
 {
 	struct btrfs_ordered_sum *sum;
+	int ret;
 
 	list_for_each_entry(sum, list, list) {
 		trans->adding_csums = true;
-		btrfs_csum_file_blocks(trans,
+		ret = btrfs_csum_file_blocks(trans,
 		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
 		trans->adding_csums = false;
+		if (ret)
+			return ret;
 	}
 	return 0;
 }
@@ -3062,7 +3065,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 		goto out;
 	}
 
-	add_pending_csums(trans, inode, &ordered_extent->list);
+	ret = add_pending_csums(trans, inode, &ordered_extent->list);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
 
 	btrfs_ordered_update_i_size(inode, 0, ordered_extent);
 	ret = btrfs_update_inode_fallback(trans, root, inode);
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index dec0907dfb8a..fcfc20de2df3 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1370,6 +1370,7 @@ static int find_bio_stripe(struct btrfs_raid_bio *rbio,
 		stripe_start = stripe->physical;
 		if (physical >= stripe_start &&
 		    physical < stripe_start + rbio->stripe_len &&
+		    stripe->dev->bdev &&
 		    bio->bi_disk == stripe->dev->bdev->bd_disk &&
 		    bio->bi_partno == stripe->dev->bdev->bd_partno) {
 			return i;
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index f0c3f00e97cb..cd2298d185dd 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3268,8 +3268,22 @@ static int relocate_file_extent_cluster(struct inode *inode,
 			nr++;
 		}
 
-		btrfs_set_extent_delalloc(inode, page_start, page_end, 0, NULL,
-					  0);
+		ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
+						NULL, 0);
+		if (ret) {
+			unlock_page(page);
+			put_page(page);
+			btrfs_delalloc_release_metadata(BTRFS_I(inode),
+							 PAGE_SIZE);
+			btrfs_delalloc_release_extents(BTRFS_I(inode),
+			                               PAGE_SIZE);
+
+			clear_extent_bits(&BTRFS_I(inode)->io_tree,
+					  page_start, page_end,
+					  EXTENT_LOCKED | EXTENT_BOUNDARY);
+			goto out;
+
+		}
 		set_page_dirty(page);
 
 		unlock_extent(&BTRFS_I(inode)->io_tree,
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index f306c608dc28..484e2af793de 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -5005,6 +5005,9 @@ static int send_hole(struct send_ctx *sctx, u64 end)
 	u64 len;
 	int ret = 0;
 
+	if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
+		return send_update_extent(sctx, offset, end - offset);
+
 	p = fs_path_alloc();
 	if (!p)
 		return -ENOMEM;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 6e71a2a78363..4b817947e00f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1545,7 +1545,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 	 * it for searching for existing supers, so this lets us do that and
 	 * then open_ctree will properly initialize everything later.
 	 */
-	fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
+	fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
 	if (!fs_info) {
 		error = -ENOMEM;
 		goto error_sec_opts;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 4fd19b4d6675..434457794c27 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -967,7 +967,9 @@ static noinline int backref_in_log(struct btrfs_root *log,
 	ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 
 	if (key->type == BTRFS_INODE_EXTREF_KEY) {
-		if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+		if (btrfs_find_name_in_ext_backref(path->nodes[0],
+						   path->slots[0],
+						   ref_objectid,
 						   name, namelen, NULL))
 			match = 1;
 
@@ -1191,7 +1193,8 @@ static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
 	read_extent_buffer(eb, *name, (unsigned long)&extref->name,
 			   *namelen);
 
-	*index = btrfs_inode_extref_index(eb, extref);
+	if (index)
+		*index = btrfs_inode_extref_index(eb, extref);
 	if (parent_objectid)
 		*parent_objectid = btrfs_inode_extref_parent(eb, extref);
 
@@ -1212,12 +1215,102 @@ static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
 
 	read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
 
-	*index = btrfs_inode_ref_index(eb, ref);
+	if (index)
+		*index = btrfs_inode_ref_index(eb, ref);
 
 	return 0;
 }
 
 /*
+ * Take an inode reference item from the log tree and iterate all names from the
+ * inode reference item in the subvolume tree with the same key (if it exists).
+ * For any name that is not in the inode reference item from the log tree, do a
+ * proper unlink of that name (that is, remove its entry from the inode
+ * reference item and both dir index keys).
+ */
+static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *root,
+				 struct btrfs_path *path,
+				 struct btrfs_inode *inode,
+				 struct extent_buffer *log_eb,
+				 int log_slot,
+				 struct btrfs_key *key)
+{
+	int ret;
+	unsigned long ref_ptr;
+	unsigned long ref_end;
+	struct extent_buffer *eb;
+
+again:
+	btrfs_release_path(path);
+	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+	if (ret > 0) {
+		ret = 0;
+		goto out;
+	}
+	if (ret < 0)
+		goto out;
+
+	eb = path->nodes[0];
+	ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
+	ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]);
+	while (ref_ptr < ref_end) {
+		char *name = NULL;
+		int namelen;
+		u64 parent_id;
+
+		if (key->type == BTRFS_INODE_EXTREF_KEY) {
+			ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
+						NULL, &parent_id);
+		} else {
+			parent_id = key->offset;
+			ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
+					     NULL);
+		}
+		if (ret)
+			goto out;
+
+		if (key->type == BTRFS_INODE_EXTREF_KEY)
+			ret = btrfs_find_name_in_ext_backref(log_eb, log_slot,
+							     parent_id, name,
+							     namelen, NULL);
+		else
+			ret = btrfs_find_name_in_backref(log_eb, log_slot, name,
+							 namelen, NULL);
+
+		if (!ret) {
+			struct inode *dir;
+
+			btrfs_release_path(path);
+			dir = read_one_inode(root, parent_id);
+			if (!dir) {
+				ret = -ENOENT;
+				kfree(name);
+				goto out;
+			}
+			ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
+						 inode, name, namelen);
+			kfree(name);
+			iput(dir);
+			if (ret)
+				goto out;
+			goto again;
+		}
+
+		kfree(name);
+		ref_ptr += namelen;
+		if (key->type == BTRFS_INODE_EXTREF_KEY)
+			ref_ptr += sizeof(struct btrfs_inode_extref);
+		else
+			ref_ptr += sizeof(struct btrfs_inode_ref);
+	}
+	ret = 0;
+ out:
+	btrfs_release_path(path);
+	return ret;
+}
+
+/*
  * replay one inode back reference item found in the log tree.
  * eb, slot and key refer to the buffer and key found in the log tree.
  * root is the destination we are replaying into, and path is for temp
@@ -1345,6 +1438,19 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
 		}
 	}
 
+	/*
+	 * Before we overwrite the inode reference item in the subvolume tree
+	 * with the item from the log tree, we must unlink all names from the
+	 * parent directory that are in the subvolume's tree inode reference
+	 * item, otherwise we end up with an inconsistent subvolume tree where
+	 * dir index entries exist for a name but there is no inode reference
+	 * item with the same name.
+	 */
+	ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
+				    key);
+	if (ret)
+		goto out;
+
 	/* finally write the back reference in the inode */
 	ret = overwrite_item(trans, root, path, eb, slot, key);
 out:
@@ -5853,7 +5959,7 @@ int btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	 * this will force the logging code to walk the dentry chain
 	 * up for the file
 	 */
-	if (S_ISREG(inode->vfs_inode.i_mode))
+	if (!S_ISDIR(inode->vfs_inode.i_mode))
 		inode->last_unlink_trans = trans->transid;
 
 	/*
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2ceb924ca0d6..b2d05c6b1c56 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4829,10 +4829,13 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	ndevs = min(ndevs, devs_max);
 
 	/*
-	 * the primary goal is to maximize the number of stripes, so use as many
-	 * devices as possible, even if the stripes are not maximum sized.
+	 * The primary goal is to maximize the number of stripes, so use as
+	 * many devices as possible, even if the stripes are not maximum sized.
+	 *
+	 * The DUP profile stores more than one stripe per device, the
+	 * max_avail is the total size so we have to adjust.
 	 */
-	stripe_size = devices_info[ndevs-1].max_avail;
+	stripe_size = div_u64(devices_info[ndevs - 1].max_avail, dev_stripes);
 	num_stripes = ndevs * dev_stripes;
 
 	/*
@@ -4867,8 +4870,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 			stripe_size = devices_info[ndevs-1].max_avail;
 	}
 
-	stripe_size = div_u64(stripe_size, dev_stripes);
-
 	/* align to BTRFS_STRIPE_LEN */
 	stripe_size = round_down(stripe_size, BTRFS_STRIPE_LEN);
 
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6582c4507e6c..0e5bd3e3344e 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3965,6 +3965,32 @@ void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
 }
 
 /*
+ * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps. If it
+ * looks like the link count will hit 0, drop any other caps (other
+ * than PIN) we don't specifically want (due to the file still being
+ * open).
+ */
+int ceph_drop_caps_for_unlink(struct inode *inode)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+
+	spin_lock(&ci->i_ceph_lock);
+	if (inode->i_nlink == 1) {
+		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
+
+		ci->i_ceph_flags |= CEPH_I_NODELAY;
+		if (__ceph_caps_dirty(ci)) {
+			struct ceph_mds_client *mdsc =
+				ceph_inode_to_client(inode)->mdsc;
+			__cap_delay_requeue_front(mdsc, ci);
+		}
+	}
+	spin_unlock(&ci->i_ceph_lock);
+	return drop;
+}
+
+/*
  * Helpers for embedding cap and dentry lease releases into mds
  * requests.
  *
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 0c4346806e17..f1d9c6cc0491 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1003,26 +1003,6 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 }
 
 /*
- * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
- * looks like the link count will hit 0, drop any other caps (other
- * than PIN) we don't specifically want (due to the file still being
- * open).
- */
-static int drop_caps_for_unlink(struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
-
-	spin_lock(&ci->i_ceph_lock);
-	if (inode->i_nlink == 1) {
-		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
-		ci->i_ceph_flags |= CEPH_I_NODELAY;
-	}
-	spin_unlock(&ci->i_ceph_lock);
-	return drop;
-}
-
-/*
  * rmdir and unlink are differ only by the metadata op code
  */
 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
@@ -1056,7 +1036,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
-	req->r_inode_drop = drop_caps_for_unlink(inode);
+	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
 	err = ceph_mdsc_do_request(mdsc, dir, req);
 	if (!err && !req->r_reply_info.head->is_dentry)
 		d_delete(dentry);
@@ -1104,8 +1084,10 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	/* release LINK_RDCACHE on source inode (mds will lock it) */
 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
-	if (d_really_is_positive(new_dentry))
-		req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
+	if (d_really_is_positive(new_dentry)) {
+		req->r_inode_drop =
+			ceph_drop_caps_for_unlink(d_inode(new_dentry));
+	}
 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
 	if (!err && !req->r_reply_info.head->is_dentry) {
 		/*
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index a62d2a9841dc..fb2bc9c15a23 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -225,6 +225,7 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		break;
 	case Opt_mds_namespace:
+		kfree(fsopt->mds_namespace);
 		fsopt->mds_namespace = kstrndup(argstr[0].from,
 						argstr[0].to-argstr[0].from,
 						GFP_KERNEL);
@@ -232,6 +233,7 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		break;
 	case Opt_fscache_uniq:
+		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = kstrndup(argstr[0].from,
 					       argstr[0].to-argstr[0].from,
 					       GFP_KERNEL);
@@ -711,14 +713,17 @@ static int __init init_caches(void)
 		goto bad_dentry;
 
 	ceph_file_cachep = KMEM_CACHE(ceph_file_info, SLAB_MEM_SPREAD);
-
 	if (!ceph_file_cachep)
 		goto bad_file;
 
-	if ((error = ceph_fscache_register()))
-		goto bad_file;
+	error = ceph_fscache_register();
+	if (error)
+		goto bad_fscache;
 
 	return 0;
+
+bad_fscache:
+	kmem_cache_destroy(ceph_file_cachep);
 bad_file:
 	kmem_cache_destroy(ceph_dentry_cachep);
 bad_dentry:
@@ -836,7 +841,6 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 	int err;
 	unsigned long started = jiffies;  /* note the start time */
 	struct dentry *root;
-	int first = 0;   /* first vfsmount for this super_block */
 
 	dout("mount start %p\n", fsc);
 	mutex_lock(&fsc->client->mount_mutex);
@@ -861,17 +865,17 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 			path = fsc->mount_options->server_path + 1;
 			dout("mount opening path %s\n", path);
 		}
+
+		err = ceph_fs_debugfs_init(fsc);
+		if (err < 0)
+			goto out;
+
 		root = open_root_dentry(fsc, path, started);
 		if (IS_ERR(root)) {
 			err = PTR_ERR(root);
 			goto out;
 		}
 		fsc->sb->s_root = dget(root);
-		first = 1;
-
-		err = ceph_fs_debugfs_init(fsc);
-		if (err < 0)
-			goto fail;
 	} else {
 		root = dget(fsc->sb->s_root);
 	}
@@ -881,11 +885,6 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 	mutex_unlock(&fsc->client->mount_mutex);
 	return root;
 
-fail:
-	if (first) {
-		dput(fsc->sb->s_root);
-		fsc->sb->s_root = NULL;
-	}
 out:
 	mutex_unlock(&fsc->client->mount_mutex);
 	return ERR_PTR(err);
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 21b2e5b004eb..1c2086e0fec2 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -987,7 +987,7 @@ extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
 			    struct ceph_mds_session *session);
 extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
 extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
-
+extern int  ceph_drop_caps_for_unlink(struct inode *inode);
 extern int ceph_encode_inode_release(void **p, struct inode *inode,
 				     int mds, int drop, int unless, int force);
 extern int ceph_encode_dentry_release(void **p, struct dentry *dn,
diff --git a/fs/dcache.c b/fs/dcache.c
index 7c38f39958bc..8945e6cabd93 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -647,11 +647,16 @@ again:
 		spin_unlock(&parent->d_lock);
 		goto again;
 	}
-	rcu_read_unlock();
-	if (parent != dentry)
+	if (parent != dentry) {
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-	else
+		if (unlikely(dentry->d_lockref.count < 0)) {
+			spin_unlock(&parent->d_lock);
+			parent = NULL;
+		}
+	} else {
 		parent = NULL;
+	}
+	rcu_read_unlock();
 	return parent;
 }
 
@@ -2474,7 +2479,7 @@ struct dentry *d_alloc_parallel(struct dentry *parent,
 
 retry:
 	rcu_read_lock();
-	seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
+	seq = smp_load_acquire(&parent->d_inode->i_dir_seq);
 	r_seq = read_seqbegin(&rename_lock);
 	dentry = __d_lookup_rcu(parent, name, &d_seq);
 	if (unlikely(dentry)) {
@@ -2495,8 +2500,14 @@ retry:
 		rcu_read_unlock();
 		goto retry;
 	}
+
+	if (unlikely(seq & 1)) {
+		rcu_read_unlock();
+		goto retry;
+	}
+
 	hlist_bl_lock(b);
-	if (unlikely(parent->d_inode->i_dir_seq != seq)) {
+	if (unlikely(READ_ONCE(parent->d_inode->i_dir_seq) != seq)) {
 		hlist_bl_unlock(b);
 		rcu_read_unlock();
 		goto retry;
diff --git a/fs/direct-io.c b/fs/direct-io.c
index a0ca9e48e993..1357ef563893 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1274,8 +1274,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 	 */
 	if (dio->is_async && iov_iter_rw(iter) == WRITE) {
 		retval = 0;
-		if ((iocb->ki_filp->f_flags & O_DSYNC) ||
-		    IS_SYNC(iocb->ki_filp->f_mapping->host))
+		if (iocb->ki_flags & IOCB_DSYNC)
 			retval = dio_set_defer_completion(dio);
 		else if (!dio->inode->i_sb->s_dio_done_wq) {
 			/*
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 5f22e74bbade..8e568428c88b 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/efi.h>
+#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/mount.h>
@@ -74,6 +75,11 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
 	ssize_t size = 0;
 	int err;
 
+	while (!__ratelimit(&file->f_cred->user->ratelimit)) {
+		if (!msleep_interruptible(50))
+			return -EINTR;
+	}
+
 	err = efivar_entry_size(var, &datasize);
 
 	/*
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 86d6a4435c87..51f940e76c5e 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -807,9 +807,6 @@ do_alloc:
 			iomap->length = hole_size(inode, lblock, &mp);
 		else
 			iomap->length = size - pos;
-	} else {
-		if (height <= ip->i_height)
-			iomap->length = hole_size(inode, lblock, &mp);
 	}
 	goto out_release;
 }
diff --git a/fs/namei.c b/fs/namei.c
index 921ae32dbc80..cafa365eeb70 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -559,9 +559,10 @@ static int __nd_alloc_stack(struct nameidata *nd)
 static bool path_connected(const struct path *path)
 {
 	struct vfsmount *mnt = path->mnt;
+	struct super_block *sb = mnt->mnt_sb;
 
-	/* Only bind mounts can have disconnected paths */
-	if (mnt->mnt_root == mnt->mnt_sb->s_root)
+	/* Bind mounts and multi-root filesystems can have disconnected paths */
+	if (!(sb->s_iflags & SB_I_MULTIROOT) && (mnt->mnt_root == sb->s_root))
 		return true;
 
 	return is_subdir(path->dentry, mnt->mnt_root);
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 2435af56b87e..a50d7813e3ea 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -572,7 +572,7 @@ out:
 }
 
 static bool
-validate_bitmap_values(unsigned long mask)
+validate_bitmap_values(unsigned int mask)
 {
 	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
 }
@@ -596,17 +596,15 @@ __be32 nfs4_callback_recallany(void *argp, void *resp,
 		goto out;
 
 	status = cpu_to_be32(NFS4_OK);
-	if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
-		     &args->craa_type_mask))
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_RDATA_DLG))
 		flags = FMODE_READ;
-	if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
-		     &args->craa_type_mask))
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_WDATA_DLG))
 		flags |= FMODE_WRITE;
-	if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
-		     &args->craa_type_mask))
-		pnfs_recall_all_layouts(cps->clp);
 	if (flags)
 		nfs_expire_unused_delegation_types(cps->clp, flags);
+
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_FILE_LAYOUT))
+		pnfs_recall_all_layouts(cps->clp);
 out:
 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 	return status;
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 8c10b0562e75..621c517b325c 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -86,10 +86,10 @@ struct nfs_direct_req {
 	struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX];
 	int			mirror_count;
 
+	loff_t			io_start;	/* Start offset for I/O */
 	ssize_t			count,		/* bytes actually processed */
 				max_count,	/* max expected count */
 				bytes_left,	/* bytes left to be sent */
-				io_start,	/* start of IO */
 				error;		/* any reported error */
 	struct completion	completion;	/* wait for i/o completion */
 
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 49f848fd1f04..7327930ad970 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -873,7 +873,7 @@ static void nfs3_nlm_release_call(void *data)
 	}
 }
 
-const struct nlmclnt_operations nlmclnt_fl_close_lock_ops = {
+static const struct nlmclnt_operations nlmclnt_fl_close_lock_ops = {
 	.nlmclnt_alloc_call = nfs3_nlm_alloc_call,
 	.nlmclnt_unlock_prepare = nfs3_nlm_unlock_prepare,
 	.nlmclnt_release_call = nfs3_nlm_release_call,
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 04612c24d394..979631411a0e 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -868,8 +868,10 @@ static int nfs4_set_client(struct nfs_server *server,
 	if (IS_ERR(clp))
 		return PTR_ERR(clp);
 
-	if (server->nfs_client == clp)
+	if (server->nfs_client == clp) {
+		nfs_put_client(clp);
 		return -ELOOP;
+	}
 
 	/*
 	 * Query for the lease time on clientid setup or renewal
@@ -1244,11 +1246,11 @@ int nfs4_update_server(struct nfs_server *server, const char *hostname,
 				clp->cl_proto, clnt->cl_timeout,
 				clp->cl_minorversion, net);
 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
-	nfs_put_client(clp);
 	if (error != 0) {
 		nfs_server_insert_lists(server);
 		return error;
 	}
+	nfs_put_client(clp);
 
 	if (server->nfs_client->cl_hostname == NULL)
 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c13e826614b5..ee723aa153a3 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -292,8 +292,11 @@ pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 void
 pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 {
-	struct inode *inode = lo->plh_inode;
+	struct inode *inode;
 
+	if (!lo)
+		return;
+	inode = lo->plh_inode;
 	pnfs_layoutreturn_before_put_layout_hdr(lo);
 
 	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
@@ -1241,10 +1244,12 @@ retry:
 	spin_lock(&ino->i_lock);
 	lo = nfsi->layout;
 	if (!lo || !pnfs_layout_is_valid(lo) ||
-	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
+	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		lo = NULL;
 		goto out_noroc;
+	}
+	pnfs_get_layout_hdr(lo);
 	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
-		pnfs_get_layout_hdr(lo);
 		spin_unlock(&ino->i_lock);
 		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
 				TASK_UNINTERRUPTIBLE);
@@ -1312,10 +1317,12 @@ out_noroc:
 		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 		if (ld->prepare_layoutreturn)
 			ld->prepare_layoutreturn(args);
+		pnfs_put_layout_hdr(lo);
 		return true;
 	}
 	if (layoutreturn)
 		pnfs_send_layoutreturn(lo, &stateid, iomode, true);
+	pnfs_put_layout_hdr(lo);
 	return false;
 }
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 29bacdc56f6a..5e470e233c83 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2631,6 +2631,8 @@ struct dentry *nfs_fs_mount_common(struct nfs_server *server,
 		/* initial superblock/root creation */
 		mount_info->fill_super(s, mount_info);
 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
+		if (!(server->flags & NFS_MOUNT_UNSHARED))
+			s->s_iflags |= SB_I_MULTIROOT;
 	}
 
 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 7428a669d7a7..e7d8ceae8f26 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1876,40 +1876,43 @@ int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 	return status;
 }
 
-int nfs_commit_inode(struct inode *inode, int how)
+static int __nfs_commit_inode(struct inode *inode, int how,
+		struct writeback_control *wbc)
 {
 	LIST_HEAD(head);
 	struct nfs_commit_info cinfo;
 	int may_wait = how & FLUSH_SYNC;
-	int error = 0;
-	int res;
+	int ret, nscan;
 
 	nfs_init_cinfo_from_inode(&cinfo, inode);
 	nfs_commit_begin(cinfo.mds);
-	res = nfs_scan_commit(inode, &head, &cinfo);
-	if (res)
-		error = nfs_generic_commit_list(inode, &head, how, &cinfo);
+	for (;;) {
+		ret = nscan = nfs_scan_commit(inode, &head, &cinfo);
+		if (ret <= 0)
+			break;
+		ret = nfs_generic_commit_list(inode, &head, how, &cinfo);
+		if (ret < 0)
+			break;
+		ret = 0;
+		if (wbc && wbc->sync_mode == WB_SYNC_NONE) {
+			if (nscan < wbc->nr_to_write)
+				wbc->nr_to_write -= nscan;
+			else
+				wbc->nr_to_write = 0;
+		}
+		if (nscan < INT_MAX)
+			break;
+		cond_resched();
+	}
 	nfs_commit_end(cinfo.mds);
-	if (res == 0)
-		return res;
-	if (error < 0)
-		goto out_error;
-	if (!may_wait)
-		goto out_mark_dirty;
-	error = wait_on_commit(cinfo.mds);
-	if (error < 0)
-		return error;
-	return res;
-out_error:
-	res = error;
-	/* Note: If we exit without ensuring that the commit is complete,
-	 * we must mark the inode as dirty. Otherwise, future calls to
-	 * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure
-	 * that the data is on the disk.
-	 */
-out_mark_dirty:
-	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
-	return res;
+	if (ret || !may_wait)
+		return ret;
+	return wait_on_commit(cinfo.mds);
+}
+
+int nfs_commit_inode(struct inode *inode, int how)
+{
+	return __nfs_commit_inode(inode, how, NULL);
 }
 EXPORT_SYMBOL_GPL(nfs_commit_inode);
 
@@ -1919,11 +1922,11 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 	int flags = FLUSH_SYNC;
 	int ret = 0;
 
-	/* no commits means nothing needs to be done */
-	if (!atomic_long_read(&nfsi->commit_info.ncommit))
-		return ret;
-
 	if (wbc->sync_mode == WB_SYNC_NONE) {
+		/* no commits means nothing needs to be done */
+		if (!atomic_long_read(&nfsi->commit_info.ncommit))
+			goto check_requests_outstanding;
+
 		/* Don't commit yet if this is a non-blocking flush and there
 		 * are a lot of outstanding writes for this mapping.
 		 */
@@ -1934,16 +1937,16 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 		flags = 0;
 	}
 
-	ret = nfs_commit_inode(inode, flags);
-	if (ret >= 0) {
-		if (wbc->sync_mode == WB_SYNC_NONE) {
-			if (ret < wbc->nr_to_write)
-				wbc->nr_to_write -= ret;
-			else
-				wbc->nr_to_write = 0;
-		}
-		return 0;
-	}
+	ret = __nfs_commit_inode(inode, flags, wbc);
+	if (!ret) {
+		if (flags & FLUSH_SYNC)
+			return 0;
+	} else if (atomic_long_read(&nfsi->commit_info.ncommit))
+		goto out_mark_dirty;
+
+check_requests_outstanding:
+	if (!atomic_read(&nfsi->commit_info.rpcs_out))
+		return ret;
 out_mark_dirty:
 	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 	return ret;
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig
index 406e72de88f6..ce6ff5a0a6e4 100644
--- a/fs/overlayfs/Kconfig
+++ b/fs/overlayfs/Kconfig
@@ -24,6 +24,8 @@ config OVERLAY_FS_REDIRECT_DIR
 	  an overlay which has redirects on a kernel that doesn't support this
 	  feature will have unexpected results.
 
+	  If unsure, say N.
+
 config OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW
 	bool "Overlayfs: follow redirects even if redirects are turned off"
 	default y
@@ -32,8 +34,13 @@ config OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW
 	  Disable this to get a possibly more secure configuration, but that
 	  might not be backward compatible with previous kernels.
 
+	  If backward compatibility is not an issue, then it is safe and
+	  recommended to say N here.
+
 	  For more information, see Documentation/filesystems/overlayfs.txt
 
+	  If unsure, say Y.
+
 config OVERLAY_FS_INDEX
 	bool "Overlayfs: turn on inodes index feature by default"
 	depends on OVERLAY_FS
@@ -51,6 +58,8 @@ config OVERLAY_FS_INDEX
 	  That is, mounting an overlay which has an inodes index on a kernel
 	  that doesn't support this feature will have unexpected results.
 
+	  If unsure, say N.
+
 config OVERLAY_FS_NFS_EXPORT
 	bool "Overlayfs: turn on NFS export feature by default"
 	depends on OVERLAY_FS
@@ -72,3 +81,8 @@ config OVERLAY_FS_NFS_EXPORT
 	  Note, that the NFS export feature is not backward compatible.
 	  That is, mounting an overlay which has a full index on a kernel
 	  that doesn't support this feature will have unexpected results.
+
+	  Most users should say N here and enable this feature on a case-by-
+	  case basis with the "nfs_export=on" mount option.
+
+	  Say N unless you fully understand the consequences.
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index bb94ce9da5c8..87bd4148f4fb 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -19,6 +19,142 @@
 #include <linux/ratelimit.h>
 #include "overlayfs.h"
 
+static int ovl_encode_maybe_copy_up(struct dentry *dentry)
+{
+	int err;
+
+	if (ovl_dentry_upper(dentry))
+		return 0;
+
+	err = ovl_want_write(dentry);
+	if (!err) {
+		err = ovl_copy_up(dentry);
+		ovl_drop_write(dentry);
+	}
+
+	if (err) {
+		pr_warn_ratelimited("overlayfs: failed to copy up on encode (%pd2, err=%i)\n",
+				    dentry, err);
+	}
+
+	return err;
+}
+
+/*
+ * Before encoding a non-upper directory file handle from real layer N, we need
+ * to check if it will be possible to reconnect an overlay dentry from the real
+ * lower decoded dentry. This is done by following the overlay ancestry up to a
+ * "layer N connected" ancestor and verifying that all parents along the way are
+ * "layer N connectable". If an ancestor that is NOT "layer N connectable" is
+ * found, we need to copy up an ancestor, which is "layer N connectable", thus
+ * making that ancestor "layer N connected". For example:
+ *
+ * layer 1: /a
+ * layer 2: /a/b/c
+ *
+ * The overlay dentry /a is NOT "layer 2 connectable", because if dir /a is
+ * copied up and renamed, upper dir /a will be indexed by lower dir /a from
+ * layer 1. The dir /a from layer 2 will never be indexed, so the algorithm (*)
+ * in ovl_lookup_real_ancestor() will not be able to lookup a connected overlay
+ * dentry from the connected lower dentry /a/b/c.
+ *
+ * To avoid this problem on decode time, we need to copy up an ancestor of
+ * /a/b/c, which is "layer 2 connectable", on encode time. That ancestor is
+ * /a/b. After copy up (and index) of /a/b, it will become "layer 2 connected"
+ * and when the time comes to decode the file handle from lower dentry /a/b/c,
+ * ovl_lookup_real_ancestor() will find the indexed ancestor /a/b and decoding
+ * a connected overlay dentry will be accomplished.
+ *
+ * (*) the algorithm in ovl_lookup_real_ancestor() can be improved to lookup an
+ * entry /a in the lower layers above layer N and find the indexed dir /a from
+ * layer 1. If that improvement is made, then the check for "layer N connected"
+ * will need to verify there are no redirects in lower layers above N. In the
+ * example above, /a will be "layer 2 connectable". However, if layer 2 dir /a
+ * is a target of a layer 1 redirect, then /a will NOT be "layer 2 connectable":
+ *
+ * layer 1: /A (redirect = /a)
+ * layer 2: /a/b/c
+ */
+
+/* Return the lowest layer for encoding a connectable file handle */
+static int ovl_connectable_layer(struct dentry *dentry)
+{
+	struct ovl_entry *oe = OVL_E(dentry);
+
+	/* We can get overlay root from root of any layer */
+	if (dentry == dentry->d_sb->s_root)
+		return oe->numlower;
+
+	/*
+	 * If it's an unindexed merge dir, then it's not connectable with any
+	 * lower layer
+	 */
+	if (ovl_dentry_upper(dentry) &&
+	    !ovl_test_flag(OVL_INDEX, d_inode(dentry)))
+		return 0;
+
+	/* We can get upper/overlay path from indexed/lower dentry */
+	return oe->lowerstack[0].layer->idx;
+}
+
+/*
+ * @dentry is "connected" if all ancestors up to root or a "connected" ancestor
+ * have the same uppermost lower layer as the origin's layer. We may need to
+ * copy up a "connectable" ancestor to make it "connected". A "connected" dentry
+ * cannot become non "connected", so cache positive result in dentry flags.
+ *
+ * Return the connected origin layer or < 0 on error.
+ */
+static int ovl_connect_layer(struct dentry *dentry)
+{
+	struct dentry *next, *parent = NULL;
+	int origin_layer;
+	int err = 0;
+
+	if (WARN_ON(dentry == dentry->d_sb->s_root) ||
+	    WARN_ON(!ovl_dentry_lower(dentry)))
+		return -EIO;
+
+	origin_layer = OVL_E(dentry)->lowerstack[0].layer->idx;
+	if (ovl_dentry_test_flag(OVL_E_CONNECTED, dentry))
+		return origin_layer;
+
+	/* Find the topmost origin layer connectable ancestor of @dentry */
+	next = dget(dentry);
+	for (;;) {
+		parent = dget_parent(next);
+		if (WARN_ON(parent == next)) {
+			err = -EIO;
+			break;
+		}
+
+		/*
+		 * If @parent is not origin layer connectable, then copy up
+		 * @next which is origin layer connectable and we are done.
+		 */
+		if (ovl_connectable_layer(parent) < origin_layer) {
+			err = ovl_encode_maybe_copy_up(next);
+			break;
+		}
+
+		/* If @parent is connected or indexed we are done */
+		if (ovl_dentry_test_flag(OVL_E_CONNECTED, parent) ||
+		    ovl_test_flag(OVL_INDEX, d_inode(parent)))
+			break;
+
+		dput(next);
+		next = parent;
+	}
+
+	dput(parent);
+	dput(next);
+
+	if (!err)
+		ovl_dentry_set_flag(OVL_E_CONNECTED, dentry);
+
+	return err ?: origin_layer;
+}
+
 /*
  * We only need to encode origin if there is a chance that the same object was
  * encoded pre copy up and then we need to stay consistent with the same
@@ -41,73 +177,59 @@
  * L = lower file handle
  *
  * (*) Connecting an overlay dir from real lower dentry is not always
- * possible when there are redirects in lower layers. To mitigate this case,
- * we copy up the lower dir first and then encode an upper dir file handle.
+ * possible when there are redirects in lower layers and non-indexed merge dirs.
+ * To mitigate those case, we may copy up the lower dir ancestor before encode
+ * a lower dir file handle.
+ *
+ * Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
  */
-static bool ovl_should_encode_origin(struct dentry *dentry)
+static int ovl_check_encode_origin(struct dentry *dentry)
 {
 	struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
 
+	/* Upper file handle for pure upper */
 	if (!ovl_dentry_lower(dentry))
-		return false;
+		return 0;
 
 	/*
-	 * Decoding a merge dir, whose origin's parent is under a redirected
-	 * lower dir is not always possible. As a simple aproximation, we do
-	 * not encode lower dir file handles when overlay has multiple lower
-	 * layers and origin is below the topmost lower layer.
+	 * Upper file handle for non-indexed upper.
 	 *
-	 * TODO: copy up only the parent that is under redirected lower.
+	 * Root is never indexed, so if there's an upper layer, encode upper for
+	 * root.
 	 */
-	if (d_is_dir(dentry) && ofs->upper_mnt &&
-	    OVL_E(dentry)->lowerstack[0].layer->idx > 1)
-		return false;
-
-	/* Decoding a non-indexed upper from origin is not implemented */
 	if (ovl_dentry_upper(dentry) &&
 	    !ovl_test_flag(OVL_INDEX, d_inode(dentry)))
-		return false;
-
-	return true;
-}
-
-static int ovl_encode_maybe_copy_up(struct dentry *dentry)
-{
-	int err;
-
-	if (ovl_dentry_upper(dentry))
 		return 0;
 
-	err = ovl_want_write(dentry);
-	if (err)
-		return err;
-
-	err = ovl_copy_up(dentry);
+	/*
+	 * Decoding a merge dir, whose origin's ancestor is under a redirected
+	 * lower dir or under a non-indexed upper is not always possible.
+	 * ovl_connect_layer() will try to make origin's layer "connected" by
+	 * copying up a "connectable" ancestor.
+	 */
+	if (d_is_dir(dentry) && ofs->upper_mnt)
+		return ovl_connect_layer(dentry);
 
-	ovl_drop_write(dentry);
-	return err;
+	/* Lower file handle for indexed and non-upper dir/non-dir */
+	return 1;
 }
 
 static int ovl_d_to_fh(struct dentry *dentry, char *buf, int buflen)
 {
-	struct dentry *origin = ovl_dentry_lower(dentry);
 	struct ovl_fh *fh = NULL;
-	int err;
+	int err, enc_lower;
 
 	/*
-	 * If we should not encode a lower dir file handle, copy up and encode
-	 * an upper dir file handle.
+	 * Check if we should encode a lower or upper file handle and maybe
+	 * copy up an ancestor to make lower file handle connectable.
 	 */
-	if (!ovl_should_encode_origin(dentry)) {
-		err = ovl_encode_maybe_copy_up(dentry);
-		if (err)
-			goto fail;
-
-		origin = NULL;
-	}
+	err = enc_lower = ovl_check_encode_origin(dentry);
+	if (enc_lower < 0)
+		goto fail;
 
-	/* Encode an upper or origin file handle */
-	fh = ovl_encode_fh(origin ?: ovl_dentry_upper(dentry), !origin);
+	/* Encode an upper or lower file handle */
+	fh = ovl_encode_fh(enc_lower ? ovl_dentry_lower(dentry) :
+				       ovl_dentry_upper(dentry), !enc_lower);
 	err = PTR_ERR(fh);
 	if (IS_ERR(fh))
 		goto fail;
@@ -355,8 +477,8 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
 		dput(upper);
 	}
 
-	if (!this)
-		return NULL;
+	if (IS_ERR_OR_NULL(this))
+		return this;
 
 	if (WARN_ON(ovl_dentry_real_at(this, layer->idx) != real)) {
 		dput(this);
@@ -498,7 +620,7 @@ static struct dentry *ovl_lookup_real(struct super_block *sb,
 			if (err == -ECHILD) {
 				this = ovl_lookup_real_ancestor(sb, real,
 								layer);
-				err = IS_ERR(this) ? PTR_ERR(this) : 0;
+				err = PTR_ERR_OR_ZERO(this);
 			}
 			if (!err) {
 				dput(connected);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index fcd97b783fa1..3b1bd469accd 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -669,38 +669,59 @@ struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
 	return inode;
 }
 
+/*
+ * Does overlay inode need to be hashed by lower inode?
+ */
+static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
+			     struct dentry *lower, struct dentry *index)
+{
+	struct ovl_fs *ofs = sb->s_fs_info;
+
+	/* No, if pure upper */
+	if (!lower)
+		return false;
+
+	/* Yes, if already indexed */
+	if (index)
+		return true;
+
+	/* Yes, if won't be copied up */
+	if (!ofs->upper_mnt)
+		return true;
+
+	/* No, if lower hardlink is or will be broken on copy up */
+	if ((upper || !ovl_indexdir(sb)) &&
+	    !d_is_dir(lower) && d_inode(lower)->i_nlink > 1)
+		return false;
+
+	/* No, if non-indexed upper with NFS export */
+	if (sb->s_export_op && upper)
+		return false;
+
+	/* Otherwise, hash by lower inode for fsnotify */
+	return true;
+}
+
 struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
 			    struct dentry *lowerdentry, struct dentry *index,
 			    unsigned int numlower)
 {
-	struct ovl_fs *ofs = sb->s_fs_info;
 	struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
 	struct inode *inode;
-	/* Already indexed or could be indexed on copy up? */
-	bool indexed = (index || (ovl_indexdir(sb) && !upperdentry));
-	struct dentry *origin = indexed ? lowerdentry : NULL;
+	bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry, index);
 	bool is_dir;
 
-	if (WARN_ON(upperdentry && indexed && !lowerdentry))
-		return ERR_PTR(-EIO);
-
 	if (!realinode)
 		realinode = d_inode(lowerdentry);
 
 	/*
-	 * Copy up origin (lower) may exist for non-indexed non-dir upper, but
-	 * we must not use lower as hash key in that case.
-	 * Hash non-dir that is or could be indexed by origin inode.
-	 * Hash dir that is or could be merged by origin inode.
-	 * Hash pure upper and non-indexed non-dir by upper inode.
-	 * Hash non-indexed dir by upper inode for NFS export.
+	 * Copy up origin (lower) may exist for non-indexed upper, but we must
+	 * not use lower as hash key if this is a broken hardlink.
 	 */
 	is_dir = S_ISDIR(realinode->i_mode);
-	if (is_dir && (indexed || !sb->s_export_op || !ofs->upper_mnt))
-		origin = lowerdentry;
-
-	if (upperdentry || origin) {
-		struct inode *key = d_inode(origin ?: upperdentry);
+	if (upperdentry || bylower) {
+		struct inode *key = d_inode(bylower ? lowerdentry :
+						      upperdentry);
 		unsigned int nlink = is_dir ? 1 : realinode->i_nlink;
 
 		inode = iget5_locked(sb, (unsigned long) key,
@@ -728,6 +749,7 @@ struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
 			nlink = ovl_get_nlink(lowerdentry, upperdentry, nlink);
 		set_nlink(inode, nlink);
 	} else {
+		/* Lower hardlink that will be broken on copy up */
 		inode = new_inode(sb);
 		if (!inode)
 			goto out_nomem;
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index de3e6da1d5a5..70fcfcc684cc 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -913,9 +913,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 		stack[ctr].layer = lower.layer;
 		ctr++;
 
-		if (d.stop)
-			break;
-
 		/*
 		 * Following redirects can have security consequences: it's like
 		 * a symlink into the lower layer without the permission checks.
@@ -933,6 +930,9 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 			goto out_put;
 		}
 
+		if (d.stop)
+			break;
+
 		if (d.redirect && d.redirect[0] == '/' && poe != roe) {
 			poe = roe;
 			/* Find the current layer on the root dentry */
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 0df25a9c94bd..225ff1171147 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -40,6 +40,7 @@ enum ovl_inode_flag {
 enum ovl_entry_flag {
 	OVL_E_UPPER_ALIAS,
 	OVL_E_OPAQUE,
+	OVL_E_CONNECTED,
 };
 
 /*
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 9ee37c76091d..7c24619ae7fc 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1359,6 +1359,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 
 	/* Root is always merge -> can have whiteouts */
 	ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry));
+	ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry);
 	ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
 		       ovl_dentry_lower(root_dentry));
 
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 9990957264e3..76bf9cc62074 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -118,13 +118,22 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		err |= __put_user(kinfo->si_trapno, &uinfo->ssi_trapno);
 #endif
 #ifdef BUS_MCEERR_AO
-		/* 
+		/*
+		 * Other callers might not initialize the si_lsb field,
+		 * so check explicitly for the right codes here.
+		 */
+		if (kinfo->si_signo == SIGBUS &&
+		     kinfo->si_code == BUS_MCEERR_AO)
+			err |= __put_user((short) kinfo->si_addr_lsb,
+					  &uinfo->ssi_addr_lsb);
+#endif
+#ifdef BUS_MCEERR_AR
+		/*
 		 * Other callers might not initialize the si_lsb field,
 		 * so check explicitly for the right codes here.
 		 */
 		if (kinfo->si_signo == SIGBUS &&
-		    (kinfo->si_code == BUS_MCEERR_AR ||
-		     kinfo->si_code == BUS_MCEERR_AO))
+		    kinfo->si_code == BUS_MCEERR_AR)
 			err |= __put_user((short) kinfo->si_addr_lsb,
 					  &uinfo->ssi_addr_lsb);
 #endif
diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index fd975524f460..05c66e05ae20 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -767,7 +767,7 @@ int
 xfs_scrub_agfl(
 	struct xfs_scrub_context	*sc)
 {
-	struct xfs_scrub_agfl_info	sai = { 0 };
+	struct xfs_scrub_agfl_info	sai;
 	struct xfs_agf			*agf;
 	xfs_agnumber_t			agno;
 	unsigned int			agflcount;
@@ -795,6 +795,7 @@ xfs_scrub_agfl(
 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
 		goto out;
 	}
+	memset(&sai, 0, sizeof(sai));
 	sai.sz_entries = agflcount;
 	sai.entries = kmem_zalloc(sizeof(xfs_agblock_t) * agflcount, KM_NOFS);
 	if (!sai.entries) {
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 66e1edbfb2b2..046469fcc1b8 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -955,15 +955,29 @@ static inline bool imap_needs_alloc(struct inode *inode,
 		(IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN);
 }
 
+static inline bool needs_cow_for_zeroing(struct xfs_bmbt_irec *imap, int nimaps)
+{
+	return nimaps &&
+		imap->br_startblock != HOLESTARTBLOCK &&
+		imap->br_state != XFS_EXT_UNWRITTEN;
+}
+
 static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags)
 {
 	/*
-	 * COW writes will allocate delalloc space, so we need to make sure
-	 * to take the lock exclusively here.
+	 * COW writes may allocate delalloc space or convert unwritten COW
+	 * extents, so we need to make sure to take the lock exclusively here.
 	 */
 	if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO)))
 		return true;
-	if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE))
+
+	/*
+	 * Extents not yet cached requires exclusive access, don't block.
+	 * This is an opencoded xfs_ilock_data_map_shared() to cater for the
+	 * non-blocking behaviour.
+	 */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
+	    !(ip->i_df.if_flags & XFS_IFEXTENTS))
 		return true;
 	return false;
 }
@@ -993,16 +1007,18 @@ xfs_file_iomap_begin(
 		return xfs_file_iomap_begin_delay(inode, offset, length, iomap);
 	}
 
-	if (need_excl_ilock(ip, flags)) {
+	if (need_excl_ilock(ip, flags))
 		lockmode = XFS_ILOCK_EXCL;
-		xfs_ilock(ip, XFS_ILOCK_EXCL);
-	} else {
-		lockmode = xfs_ilock_data_map_shared(ip);
-	}
+	else
+		lockmode = XFS_ILOCK_SHARED;
 
-	if ((flags & IOMAP_NOWAIT) && !(ip->i_df.if_flags & XFS_IFEXTENTS)) {
-		error = -EAGAIN;
-		goto out_unlock;
+	if (flags & IOMAP_NOWAIT) {
+		if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+			return -EAGAIN;
+		if (!xfs_ilock_nowait(ip, lockmode))
+			return -EAGAIN;
+	} else {
+		xfs_ilock(ip, lockmode);
 	}
 
 	ASSERT(offset <= mp->m_super->s_maxbytes);
@@ -1024,7 +1040,9 @@ xfs_file_iomap_begin(
 			goto out_unlock;
 	}
 
-	if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
+	if (xfs_is_reflink_inode(ip) &&
+	    ((flags & IOMAP_WRITE) ||
+	     ((flags & IOMAP_ZERO) && needs_cow_for_zeroing(&imap, nimaps)))) {
 		if (flags & IOMAP_DIRECT) {
 			/*
 			 * A reflinked inode will result in CoW alloc.
diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c
index 3a55d6fc271b..7a39f40645f7 100644
--- a/fs/xfs/xfs_refcount_item.c
+++ b/fs/xfs/xfs_refcount_item.c
@@ -23,6 +23,7 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
+#include "xfs_shared.h"
 #include "xfs_mount.h"
 #include "xfs_defer.h"
 #include "xfs_trans.h"
@@ -456,10 +457,12 @@ xfs_cui_recover(
 	 * transaction.  Normally, any work that needs to be deferred
 	 * gets attached to the same defer_ops that scheduled the
 	 * refcount update.  However, we're in log recovery here, so we
-	 * we create our own defer_ops and use that to finish up any
-	 * work that doesn't fit.
+	 * we use the passed in defer_ops and to finish up any work that
+	 * doesn't fit.  We need to reserve enough blocks to handle a
+	 * full btree split on either end of the refcount range.
 	 */
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
+			mp->m_refc_maxlevels * 2, 0, XFS_TRANS_RESERVE, &tp);
 	if (error)
 		return error;
 	cudp = xfs_trans_get_cud(tp, cuip);
diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c
index f3b139c9aa16..49d3124863a8 100644
--- a/fs/xfs/xfs_rmap_item.c
+++ b/fs/xfs/xfs_rmap_item.c
@@ -23,6 +23,7 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
+#include "xfs_shared.h"
 #include "xfs_mount.h"
 #include "xfs_defer.h"
 #include "xfs_trans.h"
@@ -470,7 +471,8 @@ xfs_rui_recover(
 		}
 	}
 
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
+			mp->m_rmap_maxlevels, 0, XFS_TRANS_RESERVE, &tp);
 	if (error)
 		return error;
 	rudp = xfs_trans_get_rud(tp, ruip);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 7aba628dc527..93588ea3d3d2 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -250,6 +250,7 @@ xfs_parseargs(
 				return -EINVAL;
 			break;
 		case Opt_logdev:
+			kfree(mp->m_logname);
 			mp->m_logname = match_strdup(args);
 			if (!mp->m_logname)
 				return -ENOMEM;
@@ -258,6 +259,7 @@ xfs_parseargs(
 			xfs_warn(mp, "%s option not allowed on this system", p);
 			return -EINVAL;
 		case Opt_rtdev:
+			kfree(mp->m_rtname);
 			mp->m_rtname = match_strdup(args);
 			if (!mp->m_rtname)
 				return -ENOMEM;