Merge tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable patches:
   - Fix atomicity of pNFS commit list updates
   - Fix NFSv4 handling of open(O_CREAT|O_EXCL|O_RDONLY)
   - nfs_set_pgio_error sometimes misses errors
   - Fix a thinko in xs_connect()
   - Fix borkage in _same_data_server_addrs_locked()
   - Fix a NULL pointer dereference of migration recovery ops for v4.2
     client
   - Don't let the ctime override attribute barriers.
   - Revert "NFSv4: Remove incorrect check in can_open_delegated()"
   - Ensure flexfiles pNFS driver updates the inode after write finishes
   - flexfiles must not pollute the attribute cache with attrbutes from
     the DS
   - Fix a protocol error in layoutreturn
   - Fix a protocol issue with NFSv4.1 CLOSE stateids

  Bugfixes + cleanups
   - pNFS blocks bugfixes from Christoph
   - Various cleanups from Anna
   - More fixes for delegation corner cases
   - Don't fsync twice for O_SYNC/IS_SYNC files
   - Fix pNFS and flexfiles layoutstats bugs
   - pnfs/flexfiles: avoid duplicate tracking of mirror data
   - pnfs: Fix layoutget/layoutreturn/return-on-close serialisation
     issues
   - pnfs/flexfiles: error handling retries a layoutget before fallback
     to MDS

  Features:
   - Full support for the OPEN NFS4_CREATE_EXCLUSIVE4_1 mode from
     Kinglong
   - More RDMA client transport improvements from Chuck
   - Removal of the deprecated ib_reg_phys_mr() and ib_rereg_phys_mr()
     verbs from the SUNRPC, Lustre and core infiniband tree.
   - Optimise away the close-to-open getattr if there is no cached data"

* tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (108 commits)
  NFSv4: Respect the server imposed limit on how many changes we may cache
  NFSv4: Express delegation limit in units of pages
  Revert "NFS: Make close(2) asynchronous when closing NFS O_DIRECT files"
  NFS: Optimise away the close-to-open getattr if there is no cached data
  NFSv4.1/flexfiles: Clean up ff_layout_write_done_cb/ff_layout_commit_done_cb
  NFSv4.1/flexfiles: Mark the layout for return in ff_layout_io_track_ds_error()
  nfs: Remove unneeded checking of the return value from scnprintf
  nfs: Fix truncated client owner id without proto type
  NFSv4.1/flexfiles: Mark layout for return if the mirrors are invalid
  NFSv4.1/flexfiles: RW layouts are valid only if all mirrors are valid
  NFSv4.1/flexfiles: Fix incorrect usage of pnfs_generic_mark_devid_invalid()
  NFSv4.1/flexfiles: Fix freeing of mirrors
  NFSv4.1/pNFS: Don't request a minimal read layout beyond the end of file
  NFSv4.1/pnfs: Handle LAYOUTGET return values correctly
  NFSv4.1/pnfs: Don't ask for a read layout for an empty file.
  NFSv4.1: Fix a protocol issue with CLOSE stateids
  NFSv4.1/flexfiles: Don't mark the entire deviceid as bad for file errors
  SUNRPC: Prevent SYN+SYNACK+RST storms
  SUNRPC: xs_reset_transport must mark the connection as disconnected
  NFSv4.1/pnfs: Ensure layoutreturn reserves space for the opaque payload
  ...

34 files changed, 967 insertions, 645 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index 92dca9e90d8d..c556640dcf3b 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -46,13 +46,6 @@
 
 struct pnfs_block_dev;
 
-enum pnfs_block_volume_type {
-	PNFS_BLOCK_VOLUME_SIMPLE	= 0,
-	PNFS_BLOCK_VOLUME_SLICE		= 1,
-	PNFS_BLOCK_VOLUME_CONCAT	= 2,
-	PNFS_BLOCK_VOLUME_STRIPE	= 3,
-};
-
 #define PNFS_BLOCK_MAX_UUIDS	4
 #define PNFS_BLOCK_MAX_DEVICES	64
 
@@ -117,13 +110,6 @@ struct pnfs_block_dev {
 			struct pnfs_block_dev_map *map);
 };
 
-enum exstate4 {
-	PNFS_BLOCK_READWRITE_DATA	= 0,
-	PNFS_BLOCK_READ_DATA		= 1,
-	PNFS_BLOCK_INVALID_DATA		= 2, /* mapped, but data is invalid */
-	PNFS_BLOCK_NONE_DATA		= 3  /* unmapped, it's a hole */
-};
-
 /* sector_t fields are all in 512-byte sectors */
 struct pnfs_block_extent {
 	union {
@@ -134,15 +120,12 @@ struct pnfs_block_extent {
 	sector_t	be_f_offset;	/* the starting offset in the file */
 	sector_t	be_length;	/* the size of the extent */
 	sector_t	be_v_offset;	/* the starting offset in the volume */
-	enum exstate4	be_state;	/* the state of this extent */
+	enum pnfs_block_extent_state be_state;	/* the state of this extent */
 #define EXTENT_WRITTEN		1
 #define EXTENT_COMMITTING	2
 	unsigned int	be_tag;
 };
 
-/* on the wire size of the extent */
-#define BL_EXTENT_SIZE	(7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE)
-
 struct pnfs_block_layout {
 	struct pnfs_layout_hdr	bl_layout;
 	struct rb_root		bl_ext_rw;
diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index e535599a0719..a861bbdfe577 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -22,7 +22,7 @@ bl_free_device(struct pnfs_block_dev *dev)
 		kfree(dev->children);
 	} else {
 		if (dev->bdev)
-			blkdev_put(dev->bdev, FMODE_READ);
+			blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE);
 	}
 }
 
@@ -65,6 +65,11 @@ nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
 				return -EIO;
 			p = xdr_decode_hyper(p, &b->simple.sigs[i].offset);
 			b->simple.sigs[i].sig_len = be32_to_cpup(p++);
+			if (b->simple.sigs[i].sig_len > PNFS_BLOCK_UUID_LEN) {
+				pr_info("signature too long: %d\n",
+					b->simple.sigs[i].sig_len);
+				return -EIO;
+			}
 
 			p = xdr_inline_decode(xdr, b->simple.sigs[i].sig_len);
 			if (!p)
@@ -195,7 +200,7 @@ bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d,
 	if (!dev)
 		return -EIO;
 
-	d->bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
+	d->bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
 	if (IS_ERR(d->bdev)) {
 		printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n",
 			MAJOR(dev), MINOR(dev), PTR_ERR(d->bdev));
diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c
index 31d0b5e53dfd..c59a59c37f3d 100644
--- a/fs/nfs/blocklayout/extent_tree.c
+++ b/fs/nfs/blocklayout/extent_tree.c
@@ -462,6 +462,12 @@ out:
 	return err;
 }
 
+static size_t ext_tree_layoutupdate_size(size_t count)
+{
+	return sizeof(__be32) /* number of entries */ +
+		PNFS_BLOCK_EXTENT_SIZE * count;
+}
+
 static void ext_tree_free_commitdata(struct nfs4_layoutcommit_args *arg,
 		size_t buffer_size)
 {
@@ -489,7 +495,7 @@ static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
 			continue;
 
 		(*count)++;
-		if (*count * BL_EXTENT_SIZE > buffer_size) {
+		if (ext_tree_layoutupdate_size(*count) > buffer_size) {
 			/* keep counting.. */
 			ret = -ENOSPC;
 			continue;
@@ -530,7 +536,7 @@ retry:
 	if (unlikely(ret)) {
 		ext_tree_free_commitdata(arg, buffer_size);
 
-		buffer_size = sizeof(__be32) + BL_EXTENT_SIZE * count;
+		buffer_size = ext_tree_layoutupdate_size(count);
 		count = 0;
 
 		arg->layoutupdate_pages =
@@ -549,17 +555,14 @@ retry:
 	}
 
 	*start_p = cpu_to_be32(count);
-	arg->layoutupdate_len = sizeof(__be32) + BL_EXTENT_SIZE * count;
+	arg->layoutupdate_len = ext_tree_layoutupdate_size(count);
 
 	if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
-		__be32 *p = start_p;
+		void *p = start_p, *end = p + arg->layoutupdate_len;
 		int i = 0;
 
-		for (p = start_p;
-		     p < start_p + arg->layoutupdate_len;
-		     p += PAGE_SIZE) {
+		for ( ; p < end; p += PAGE_SIZE)
 			arg->layoutupdate_pages[i++] = vmalloc_to_page(p);
-		}
 	}
 
 	dprintk("%s found %zu ranges\n", __func__, count);
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 2c4a0b565d28..75f7c0a7538a 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -162,10 +162,6 @@ nfs41_callback_up(struct svc_serv *serv)
 	spin_lock_init(&serv->sv_cb_lock);
 	init_waitqueue_head(&serv->sv_cb_waitq);
 	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-	if (IS_ERR(rqstp)) {
-		svc_xprt_put(serv->sv_bc_xprt);
-		serv->sv_bc_xprt = NULL;
-	}
 	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
 	return rqstp;
 }
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 29e3c1b011b7..b85cf7a30232 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -40,8 +40,11 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 
 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
-	if (inode == NULL)
+	if (inode == NULL) {
+		trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
+				-ntohl(res->status));
 		goto out;
+	}
 	nfsi = NFS_I(inode);
 	rcu_read_lock();
 	delegation = rcu_dereference(nfsi->delegation);
@@ -60,6 +63,7 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
 	res->status = 0;
 out_iput:
 	rcu_read_unlock();
+	trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status));
 	iput(inode);
 out:
 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
@@ -194,6 +198,7 @@ unlock:
 	spin_unlock(&ino->i_lock);
 	pnfs_free_lseg_list(&free_me_list);
 	pnfs_put_layout_hdr(lo);
+	trace_nfs4_cb_layoutrecall_inode(clp, &args->cbl_fh, ino, -rv);
 	iput(ino);
 out:
 	return rv;
@@ -554,7 +559,7 @@ __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
 	status = htonl(NFS4_OK);
 
 	nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
-	nfs41_server_notify_target_slotid_update(cps->clp);
+	nfs41_notify_server(cps->clp);
 out:
 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 	return status;
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 4a90c9bb3135..57c5a02f6213 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -20,6 +20,7 @@
 #include <linux/stat.h>
 #include <linux/errno.h>
 #include <linux/unistd.h>
+#include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/metrics.h>
@@ -285,116 +286,6 @@ void nfs_put_client(struct nfs_client *clp)
 }
 EXPORT_SYMBOL_GPL(nfs_put_client);
 
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-/*
- * Test if two ip6 socket addresses refer to the same socket by
- * comparing relevant fields. The padding bytes specifically, are not
- * compared. sin6_flowinfo is not compared because it only affects QoS
- * and sin6_scope_id is only compared if the address is "link local"
- * because "link local" addresses need only be unique to a specific
- * link. Conversely, ordinary unicast addresses might have different
- * sin6_scope_id.
- *
- * The caller should ensure both socket addresses are AF_INET6.
- */
-static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
-	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
-
-	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
-		return 0;
-	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
-		return sin1->sin6_scope_id == sin2->sin6_scope_id;
-
-	return 1;
-}
-#else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
-static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	return 0;
-}
-#endif
-
-/*
- * Test if two ip4 socket addresses refer to the same socket, by
- * comparing relevant fields. The padding bytes specifically, are
- * not compared.
- *
- * The caller should ensure both socket addresses are AF_INET.
- */
-static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
-	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
-
-	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
-}
-
-static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
-				const struct sockaddr *sa2)
-{
-	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
-	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
-
-	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
-		(sin1->sin6_port == sin2->sin6_port);
-}
-
-static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
-				const struct sockaddr *sa2)
-{
-	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
-	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
-
-	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
-		(sin1->sin_port == sin2->sin_port);
-}
-
-#if defined(CONFIG_NFS_V4_1)
-/*
- * Test if two socket addresses represent the same actual socket,
- * by comparing (only) relevant fields, excluding the port number.
- */
-int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
-			      const struct sockaddr *sa2)
-{
-	if (sa1->sa_family != sa2->sa_family)
-		return 0;
-
-	switch (sa1->sa_family) {
-	case AF_INET:
-		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
-	case AF_INET6:
-		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
-	}
-	return 0;
-}
-EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
-#endif /* CONFIG_NFS_V4_1 */
-
-/*
- * Test if two socket addresses represent the same actual socket,
- * by comparing (only) relevant fields, including the port number.
- */
-static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
-			    const struct sockaddr *sa2)
-{
-	if (sa1->sa_family != sa2->sa_family)
-		return 0;
-
-	switch (sa1->sa_family) {
-	case AF_INET:
-		return nfs_sockaddr_cmp_ip4(sa1, sa2);
-	case AF_INET6:
-		return nfs_sockaddr_cmp_ip6(sa1, sa2);
-	}
-	return 0;
-}
-
 /*
  * Find an nfs_client on the list that matches the initialisation data
  * that is supplied.
@@ -421,7 +312,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
 		if (clp->cl_minorversion != data->minorversion)
 			continue;
 		/* Match the full socket address */
-		if (!nfs_sockaddr_cmp(sap, clap))
+		if (!rpc_cmp_addr_port(sap, clap))
 			continue;
 
 		atomic_inc(&clp->cl_count);
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 029d688a969f..2714ef835bdd 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -175,7 +175,7 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
 		if (delegation->inode != NULL) {
 			nfs4_stateid_copy(&delegation->stateid, &res->delegation);
 			delegation->type = res->delegation_type;
-			delegation->maxsize = res->maxsize;
+			delegation->pagemod_limit = res->pagemod_limit;
 			oldcred = delegation->cred;
 			delegation->cred = get_rpccred(cred);
 			clear_bit(NFS_DELEGATION_NEED_RECLAIM,
@@ -337,7 +337,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
 		return -ENOMEM;
 	nfs4_stateid_copy(&delegation->stateid, &res->delegation);
 	delegation->type = res->delegation_type;
-	delegation->maxsize = res->maxsize;
+	delegation->pagemod_limit = res->pagemod_limit;
 	delegation->change_attr = inode->i_version;
 	delegation->cred = get_rpccred(cred);
 	delegation->inode = inode;
@@ -900,3 +900,28 @@ bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
 	rcu_read_unlock();
 	return ret;
 }
+
+/**
+ * nfs4_delegation_flush_on_close - Check if we must flush file on close
+ * @inode: inode to check
+ *
+ * This function checks the number of outstanding writes to the file
+ * against the delegation 'space_limit' field to see if
+ * the spec requires us to flush the file on close.
+ */
+bool nfs4_delegation_flush_on_close(const struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_delegation *delegation;
+	bool ret = true;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(nfsi->delegation);
+	if (delegation == NULL || !(delegation->type & FMODE_WRITE))
+		goto out;
+	if (nfsi->nrequests < delegation->pagemod_limit)
+		ret = false;
+out:
+	rcu_read_unlock();
+	return ret;
+}
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index e3c20a3ccc93..a44829173e57 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -18,7 +18,7 @@ struct nfs_delegation {
 	struct inode *inode;
 	nfs4_stateid stateid;
 	fmode_t type;
-	loff_t maxsize;
+	unsigned long pagemod_limit;
 	__u64 change_attr;
 	unsigned long flags;
 	spinlock_t lock;
@@ -61,6 +61,7 @@ bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, fmode_
 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
 int nfs4_have_delegation(struct inode *inode, fmode_t flags);
 int nfs4_check_delegation(struct inode *inode, fmode_t flags);
+bool nfs4_delegation_flush_on_close(const struct inode *inode);
 
 #endif
 
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 547308a5ec6f..3d8e4ffa0a33 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -583,26 +583,19 @@ out_nopages:
 }
 
 static
-void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
+void nfs_readdir_free_pages(struct page **pages, unsigned int npages)
 {
 	unsigned int i;
 	for (i = 0; i < npages; i++)
 		put_page(pages[i]);
 }
 
-static
-void nfs_readdir_free_large_page(void *ptr, struct page **pages,
-		unsigned int npages)
-{
-	nfs_readdir_free_pagearray(pages, npages);
-}
-
 /*
  * nfs_readdir_large_page will allocate pages that must be freed with a call
- * to nfs_readdir_free_large_page
+ * to nfs_readdir_free_pagearray
  */
 static
-int nfs_readdir_large_page(struct page **pages, unsigned int npages)
+int nfs_readdir_alloc_pages(struct page **pages, unsigned int npages)
 {
 	unsigned int i;
 
@@ -615,7 +608,7 @@ int nfs_readdir_large_page(struct page **pages, unsigned int npages)
 	return 0;
 
 out_freepages:
-	nfs_readdir_free_pagearray(pages, i);
+	nfs_readdir_free_pages(pages, i);
 	return -ENOMEM;
 }
 
@@ -623,7 +616,6 @@ static
 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
 {
 	struct page *pages[NFS_MAX_READDIR_PAGES];
-	void *pages_ptr = NULL;
 	struct nfs_entry entry;
 	struct file	*file = desc->file;
 	struct nfs_cache_array *array;
@@ -653,7 +645,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
 	memset(array, 0, sizeof(struct nfs_cache_array));
 	array->eof_index = -1;
 
-	status = nfs_readdir_large_page(pages, array_size);
+	status = nfs_readdir_alloc_pages(pages, array_size);
 	if (status < 0)
 		goto out_release_array;
 	do {
@@ -671,7 +663,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
 		}
 	} while (array->eof_index < 0);
 
-	nfs_readdir_free_large_page(pages_ptr, pages, array_size);
+	nfs_readdir_free_pages(pages, array_size);
 out_release_array:
 	nfs_readdir_release_array(page);
 out_label_free:
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index cc4fa1ed61fc..c0f9b1ed12b9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -82,7 +82,8 @@ nfs_file_release(struct inode *inode, struct file *filp)
 	dprintk("NFS: release(%pD2)\n", filp);
 
 	nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
-	return nfs_release(inode, filp);
+	nfs_file_clear_open_context(filp);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(nfs_file_release);
 
@@ -141,7 +142,7 @@ EXPORT_SYMBOL_GPL(nfs_file_llseek);
 /*
  * Flush all dirty pages, and check for write errors.
  */
-int
+static int
 nfs_file_flush(struct file *file, fl_owner_t id)
 {
 	struct inode	*inode = file_inode(file);
@@ -152,17 +153,9 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 	if ((file->f_mode & FMODE_WRITE) == 0)
 		return 0;
 
-	/*
-	 * If we're holding a write delegation, then just start the i/o
-	 * but don't wait for completion (or send a commit).
-	 */
-	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
-		return filemap_fdatawrite(file->f_mapping);
-
 	/* Flush writes to the server and return any errors */
 	return vfs_fsync(file, 0);
 }
-EXPORT_SYMBOL_GPL(nfs_file_flush);
 
 ssize_t
 nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
@@ -644,12 +637,10 @@ static const struct vm_operations_struct nfs_file_vm_ops = {
 	.page_mkwrite = nfs_vm_page_mkwrite,
 };
 
-static int nfs_need_sync_write(struct file *filp, struct inode *inode)
+static int nfs_need_check_write(struct file *filp, struct inode *inode)
 {
 	struct nfs_open_context *ctx;
 
-	if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC))
-		return 1;
 	ctx = nfs_file_open_context(filp);
 	if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) ||
 	    nfs_ctx_key_to_expire(ctx))
@@ -699,8 +690,8 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 	if (result > 0)
 		written = result;
 
-	/* Return error values for O_DSYNC and IS_SYNC() */
-	if (result >= 0 && nfs_need_sync_write(file, inode)) {
+	/* Return error values */
+	if (result >= 0 && nfs_need_check_write(file, inode)) {
 		int err = vfs_fsync(file, 0);
 		if (err < 0)
 			result = err;
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index b3289d701eea..fbc5a56de875 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -34,6 +34,7 @@ ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
 	ffl = kzalloc(sizeof(*ffl), gfp_flags);
 	if (ffl) {
 		INIT_LIST_HEAD(&ffl->error_list);
+		INIT_LIST_HEAD(&ffl->mirrors);
 		return &ffl->generic_hdr;
 	} else
 		return NULL;
@@ -135,6 +136,95 @@ decode_name(struct xdr_stream *xdr, u32 *id)
 	return 0;
 }
 
+static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
+		const struct nfs4_ff_layout_mirror *m2)
+{
+	int i, j;
+
+	if (m1->fh_versions_cnt != m2->fh_versions_cnt)
+		return false;
+	for (i = 0; i < m1->fh_versions_cnt; i++) {
+		bool found_fh = false;
+		for (j = 0; j < m2->fh_versions_cnt; i++) {
+			if (nfs_compare_fh(&m1->fh_versions[i],
+					&m2->fh_versions[j]) == 0) {
+				found_fh = true;
+				break;
+			}
+		}
+		if (!found_fh)
+			return false;
+	}
+	return true;
+}
+
+static struct nfs4_ff_layout_mirror *
+ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
+		struct nfs4_ff_layout_mirror *mirror)
+{
+	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
+	struct nfs4_ff_layout_mirror *pos;
+	struct inode *inode = lo->plh_inode;
+
+	spin_lock(&inode->i_lock);
+	list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
+		if (mirror->mirror_ds != pos->mirror_ds)
+			continue;
+		if (!ff_mirror_match_fh(mirror, pos))
+			continue;
+		if (atomic_inc_not_zero(&pos->ref)) {
+			spin_unlock(&inode->i_lock);
+			return pos;
+		}
+	}
+	list_add(&mirror->mirrors, &ff_layout->mirrors);
+	mirror->layout = lo;
+	spin_unlock(&inode->i_lock);
+	return mirror;
+}
+
+static void
+ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	struct inode *inode;
+	if (mirror->layout == NULL)
+		return;
+	inode = mirror->layout->plh_inode;
+	spin_lock(&inode->i_lock);
+	list_del(&mirror->mirrors);
+	spin_unlock(&inode->i_lock);
+	mirror->layout = NULL;
+}
+
+static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+
+	mirror = kzalloc(sizeof(*mirror), gfp_flags);
+	if (mirror != NULL) {
+		spin_lock_init(&mirror->lock);
+		atomic_set(&mirror->ref, 1);
+		INIT_LIST_HEAD(&mirror->mirrors);
+	}
+	return mirror;
+}
+
+static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	ff_layout_remove_mirror(mirror);
+	kfree(mirror->fh_versions);
+	if (mirror->cred)
+		put_rpccred(mirror->cred);
+	nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
+	kfree(mirror);
+}
+
+static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	if (mirror != NULL && atomic_dec_and_test(&mirror->ref))
+		ff_layout_free_mirror(mirror);
+}
+
 static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 {
 	int i;
@@ -144,11 +234,7 @@ static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 			/* normally mirror_ds is freed in
 			 * .free_deviceid_node but we still do it here
 			 * for .alloc_lseg error path */
-			if (fls->mirror_array[i]) {
-				kfree(fls->mirror_array[i]->fh_versions);
-				nfs4_ff_layout_put_deviceid(fls->mirror_array[i]->mirror_ds);
-				kfree(fls->mirror_array[i]);
-			}
+			ff_layout_put_mirror(fls->mirror_array[i]);
 		}
 		kfree(fls->mirror_array);
 		fls->mirror_array = NULL;
@@ -181,6 +267,65 @@ static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
 	}
 }
 
+static bool
+ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
+		const struct pnfs_layout_range *l2)
+{
+	u64 end1, end2;
+
+	if (l1->iomode != l2->iomode)
+		return l1->iomode != IOMODE_READ;
+	end1 = pnfs_calc_offset_end(l1->offset, l1->length);
+	end2 = pnfs_calc_offset_end(l2->offset, l2->length);
+	if (end1 < l2->offset)
+		return false;
+	if (end2 < l1->offset)
+		return true;
+	return l2->offset <= l1->offset;
+}
+
+static bool
+ff_lseg_merge(struct pnfs_layout_segment *new,
+		struct pnfs_layout_segment *old)
+{
+	u64 new_end, old_end;
+
+	if (new->pls_range.iomode != old->pls_range.iomode)
+		return false;
+	old_end = pnfs_calc_offset_end(old->pls_range.offset,
+			old->pls_range.length);
+	if (old_end < new->pls_range.offset)
+		return false;
+	new_end = pnfs_calc_offset_end(new->pls_range.offset,
+			new->pls_range.length);
+	if (new_end < old->pls_range.offset)
+		return false;
+
+	/* Mergeable: copy info from 'old' to 'new' */
+	if (new_end < old_end)
+		new_end = old_end;
+	if (new->pls_range.offset < old->pls_range.offset)
+		new->pls_range.offset = old->pls_range.offset;
+	new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
+			new_end);
+	if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
+		set_bit(NFS_LSEG_ROC, &new->pls_flags);
+	if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
+		set_bit(NFS_LSEG_LAYOUTRETURN, &new->pls_flags);
+	return true;
+}
+
+static void
+ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_segment *lseg,
+		struct list_head *free_me)
+{
+	pnfs_generic_layout_insert_lseg(lo, lseg,
+			ff_lseg_range_is_after,
+			ff_lseg_merge,
+			free_me);
+}
+
 static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
 {
 	int i, j;
@@ -246,6 +391,7 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 		goto out_err_free;
 
 	for (i = 0; i < fls->mirror_array_cnt; i++) {
+		struct nfs4_ff_layout_mirror *mirror;
 		struct nfs4_deviceid devid;
 		struct nfs4_deviceid_node *idnode;
 		u32 ds_count;
@@ -262,17 +408,13 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 		if (ds_count != 1)
 			goto out_err_free;
 
-		fls->mirror_array[i] =
-			kzalloc(sizeof(struct nfs4_ff_layout_mirror),
-				gfp_flags);
+		fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 		if (fls->mirror_array[i] == NULL) {
 			rc = -ENOMEM;
 			goto out_err_free;
 		}
 
-		spin_lock_init(&fls->mirror_array[i]->lock);
 		fls->mirror_array[i]->ds_count = ds_count;
-		fls->mirror_array[i]->lseg = &fls->generic_hdr;
 
 		/* deviceid */
 		rc = decode_deviceid(&stream, &devid);
@@ -338,6 +480,12 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 		if (rc)
 			goto out_err_free;
 
+		mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
+		if (