Merge tag 'nfs-for-3.19-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

  Features:
   - NFSv4.2 client support for hole punching and preallocation.
   - Further RPC/RDMA client improvements.
   - Add more RPC transport debugging tracepoints.
   - Add RPC debugging tools in debugfs.

  Bugfixes:
   - Stable fix for layoutget error handling
   - Fix a change in COMMIT behaviour resulting from the recent io code
     updates"

* tag 'nfs-for-3.19-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (28 commits)
  sunrpc: add a debugfs rpc_xprt directory with an info file in it
  sunrpc: add debugfs file for displaying client rpc_task queue
  nfs: Add DEALLOCATE support
  nfs: Add ALLOCATE support
  NFS: Clean up nfs4_init_callback()
  NFS: SETCLIENTID XDR buffer sizes are incorrect
  SUNRPC: serialize iostats updates
  xprtrdma: Display async errors
  xprtrdma: Enable pad optimization
  xprtrdma: Re-write rpcrdma_flush_cqs()
  xprtrdma: Refactor tasklet scheduling
  xprtrdma: unmap all FMRs during transport disconnect
  xprtrdma: Cap req_cqinit
  xprtrdma: Return an errno from rpcrdma_register_external()
  nfs: define nfs_inc_fscache_stats and using it as possible
  nfs: replace nfs_add_stats with nfs_inc_stats when add one
  NFS: Deletion of unnecessary checks before the function call "nfs_put_client"
  sunrpc: eliminate RPC_TRACEPOINTS
  sunrpc: eliminate RPC_DEBUG
  lockd: eliminate LOCKD_DEBUG
  ...

18 files changed, 330 insertions, 69 deletions

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 13db95f54176..56598742dde4 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -53,7 +53,7 @@ static const struct rpc_call_ops nlmsvc_grant_ops;
 static LIST_HEAD(nlm_blocked);
 static DEFINE_SPINLOCK(nlm_blocked_lock);
 
-#ifdef LOCKD_DEBUG
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 static const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
 {
 	/*
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 4f46f7a05289..77fec6a55f57 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -812,7 +812,7 @@ static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
 
 	/* Optimize common case that writes from 0 to end of file */
 	end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
-	if (end != NFS_I(inode)->npages) {
+	if (end != inode->i_mapping->nrpages) {
 		rcu_read_lock();
 		end = page_cache_next_hole(mapping, idx + 1, ULONG_MAX);
 		rcu_read_unlock();
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 73466b934090..e36a9d78ea49 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -49,7 +49,7 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
 		goto out_iput;
 	res->size = i_size_read(inode);
 	res->change_attr = delegation->change_attr;
-	if (nfsi->npages != 0)
+	if (nfsi->nrequests != 0)
 		res->change_attr++;
 	res->ctime = inode->i_ctime;
 	res->mtime = inode->i_mtime;
diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
index 9bb806a76d99..bfecac781f19 100644
--- a/fs/nfs/filelayout/filelayoutdev.c
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -204,8 +204,7 @@ destroy_ds(struct nfs4_pnfs_ds *ds)
 	ifdebug(FACILITY)
 		print_ds(ds);
 
-	if (ds->ds_clp)
-		nfs_put_client(ds->ds_clp);
+	nfs_put_client(ds->ds_clp);
 
 	while (!list_empty(&ds->ds_addrs)) {
 		da = list_first_entry(&ds->ds_addrs,
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index 3ef01f0ba0bc..d63bea8bbfbb 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -269,8 +269,8 @@ int nfs_fscache_release_page(struct page *page, gfp_t gfp)
 		if (!fscache_maybe_release_page(cookie, page, gfp))
 			return 0;
 
-		nfs_add_fscache_stats(page->mapping->host,
-				      NFSIOS_FSCACHE_PAGES_UNCACHED, 1);
+		nfs_inc_fscache_stats(page->mapping->host,
+				      NFSIOS_FSCACHE_PAGES_UNCACHED);
 	}
 
 	return 1;
@@ -293,8 +293,8 @@ void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
 
 	BUG_ON(!PageLocked(page));
 	fscache_uncache_page(cookie, page);
-	nfs_add_fscache_stats(page->mapping->host,
-			      NFSIOS_FSCACHE_PAGES_UNCACHED, 1);
+	nfs_inc_fscache_stats(page->mapping->host,
+			      NFSIOS_FSCACHE_PAGES_UNCACHED);
 }
 
 /*
@@ -343,19 +343,19 @@ int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
 	case 0: /* read BIO submitted (page in fscache) */
 		dfprintk(FSCACHE,
 			 "NFS:    readpage_from_fscache: BIO submitted\n");
-		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK, 1);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
 		return ret;
 
 	case -ENOBUFS: /* inode not in cache */
 	case -ENODATA: /* page not in cache */
-		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL, 1);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
 		dfprintk(FSCACHE,
 			 "NFS:    readpage_from_fscache %d\n", ret);
 		return 1;
 
 	default:
 		dfprintk(FSCACHE, "NFS:    readpage_from_fscache %d\n", ret);
-		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL, 1);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
 	}
 	return ret;
 }
@@ -429,11 +429,11 @@ void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
 
 	if (ret != 0) {
 		fscache_uncache_page(nfs_i_fscache(inode), page);
-		nfs_add_fscache_stats(inode,
-				      NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL, 1);
-		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED, 1);
+		nfs_inc_fscache_stats(inode,
+				      NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
 	} else {
-		nfs_add_fscache_stats(inode,
-				      NFSIOS_FSCACHE_PAGES_WRITTEN_OK, 1);
+		nfs_inc_fscache_stats(inode,
+				      NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
 	}
 }
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 00689a8a85e4..4bffe637ea32 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -192,6 +192,7 @@ void nfs_zap_caches(struct inode *inode)
 	nfs_zap_caches_locked(inode);
 	spin_unlock(&inode->i_lock);
 }
+EXPORT_SYMBOL_GPL(nfs_zap_caches);
 
 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
 {
@@ -1149,7 +1150,7 @@ static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr
 	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
 			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
 			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
-			&& nfsi->npages == 0) {
+			&& nfsi->nrequests == 0) {
 		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
 		ret |= NFS_INO_INVALID_ATTR;
 	}
@@ -1192,7 +1193,7 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
 	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
 		cur_size = i_size_read(inode);
 		new_isize = nfs_size_to_loff_t(fattr->size);
-		if (cur_size != new_isize && nfsi->npages == 0)
+		if (cur_size != new_isize && nfsi->nrequests == 0)
 			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
 	}
 
@@ -1619,7 +1620,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 		if (new_isize != cur_isize) {
 			/* Do we perhaps have any outstanding writes, or has
 			 * the file grown beyond our last write? */
-			if ((nfsi->npages == 0) || new_isize > cur_isize) {
+			if ((nfsi->nrequests == 0) || new_isize > cur_isize) {
 				i_size_write(inode, new_isize);
 				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
 				invalid &= ~NFS_INO_REVAL_PAGECACHE;
@@ -1784,7 +1785,7 @@ static void init_once(void *foo)
 	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
 	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
 	INIT_LIST_HEAD(&nfsi->commit_info.list);
-	nfsi->npages = 0;
+	nfsi->nrequests = 0;
 	nfsi->commit_info.ncommit = 0;
 	atomic_set(&nfsi->commit_info.rpcs_out, 0);
 	atomic_set(&nfsi->silly_count, 1);
diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index c5832487c456..0cb806fbd4c4 100644
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -55,6 +55,11 @@ static inline void nfs_add_fscache_stats(struct inode *inode,
 {
 	this_cpu_add(NFS_SERVER(inode)->io_stats->fscache[stat], addend);
 }
+static inline void nfs_inc_fscache_stats(struct inode *inode,
+					 enum nfs_stat_fscachecounters stat)
+{
+	this_cpu_inc(NFS_SERVER(inode)->io_stats->fscache[stat]);
+}
 #endif
 
 static inline struct nfs_iostats __percpu *nfs_alloc_iostats(void)
diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h
index d10333a197bf..7afb8947dfdf 100644
--- a/fs/nfs/nfs42.h
+++ b/fs/nfs/nfs42.h
@@ -6,6 +6,8 @@
 #define __LINUX_FS_NFS_NFS4_2_H
 
 /* nfs4.2proc.c */
+int nfs42_proc_allocate(struct file *, loff_t, loff_t);
+int nfs42_proc_deallocate(struct file *, loff_t, loff_t);
 loff_t nfs42_proc_llseek(struct file *, loff_t, int);
 
 /* nfs4.2xdr.h */
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 0886f1db5917..cb170722769c 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -32,6 +32,81 @@ static int nfs42_set_rw_stateid(nfs4_stateid *dst, struct file *file,
 	return ret;
 }
 
+static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
+				 loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	struct nfs42_falloc_args args = {
+		.falloc_fh	= NFS_FH(inode),
+		.falloc_offset	= offset,
+		.falloc_length	= len,
+	};
+	struct nfs42_falloc_res res;
+	struct nfs_server *server = NFS_SERVER(inode);
+	int status;
+
+	msg->rpc_argp = &args;
+	msg->rpc_resp = &res;
+
+	status = nfs42_set_rw_stateid(&args.falloc_stateid, filep, FMODE_WRITE);
+	if (status)
+		return status;
+
+	return nfs4_call_sync(server->client, server, msg,
+			      &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
+				loff_t offset, loff_t len)
+{
+	struct nfs_server *server = NFS_SERVER(file_inode(filep));
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = _nfs42_proc_fallocate(msg, filep, offset, len);
+		if (err == -ENOTSUPP)
+			return -EOPNOTSUPP;
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+
+	return err;
+}
+
+int nfs42_proc_allocate(struct file *filep, loff_t offset, loff_t len)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ALLOCATE],
+	};
+	struct inode *inode = file_inode(filep);
+	int err;
+
+	if (!nfs_server_capable(inode, NFS_CAP_ALLOCATE))
+		return -EOPNOTSUPP;
+
+	err = nfs42_proc_fallocate(&msg, filep, offset, len);
+	if (err == -EOPNOTSUPP)
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_ALLOCATE;
+	return err;
+}
+
+int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DEALLOCATE],
+	};
+	struct inode *inode = file_inode(filep);
+	int err;
+
+	if (!nfs_server_capable(inode, NFS_CAP_DEALLOCATE))
+		return -EOPNOTSUPP;
+
+	err = nfs42_proc_fallocate(&msg, filep, offset, len);
+	if (err == -EOPNOTSUPP)
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
+	return err;
+}
+
 loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
 {
 	struct inode *inode = file_inode(filep);
@@ -50,7 +125,7 @@ loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
 	struct nfs_server *server = NFS_SERVER(inode);
 	int status;
 
-	if (!(server->caps & NFS_CAP_SEEK))
+	if (!nfs_server_capable(inode, NFS_CAP_SEEK))
 		return -ENOTSUPP;
 
 	status = nfs42_set_rw_stateid(&args.sa_stateid, filep, FMODE_READ);
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index c90469b604b8..038a7e1521fa 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -4,6 +4,15 @@
 #ifndef __LINUX_FS_NFS_NFS4_2XDR_H
 #define __LINUX_FS_NFS_NFS4_2XDR_H
 
+#define encode_fallocate_maxsz		(encode_stateid_maxsz + \
+					 2 /* offset */ + \
+					 2 /* length */)
+#define encode_allocate_maxsz		(op_encode_hdr_maxsz + \
+					 encode_fallocate_maxsz)
+#define decode_allocate_maxsz		(op_decode_hdr_maxsz)
+#define encode_deallocate_maxsz		(op_encode_hdr_maxsz + \
+					 encode_fallocate_maxsz)
+#define decode_deallocate_maxsz		(op_decode_hdr_maxsz)
 #define encode_seek_maxsz		(op_encode_hdr_maxsz + \
 					 encode_stateid_maxsz + \
 					 2 /* offset */ + \
@@ -14,6 +23,18 @@
 					 2 /* offset */ + \
 					 2 /* length */)
 
+#define NFS4_enc_allocate_sz		(compound_encode_hdr_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_allocate_maxsz)
+#define NFS4_dec_allocate_sz		(compound_decode_hdr_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_allocate_maxsz)
+#define NFS4_enc_deallocate_sz		(compound_encode_hdr_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_deallocate_maxsz)
+#define NFS4_dec_deallocate_sz		(compound_decode_hdr_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_deallocate_maxsz)
 #define NFS4_enc_seek_sz		(compound_encode_hdr_maxsz + \
 					 encode_putfh_maxsz + \
 					 encode_seek_maxsz)
@@ -22,6 +43,30 @@
 					 decode_seek_maxsz)
 
 
+static void encode_fallocate(struct xdr_stream *xdr,
+			     struct nfs42_falloc_args *args)
+{
+	encode_nfs4_stateid(xdr, &args->falloc_stateid);
+	encode_uint64(xdr, args->falloc_offset);
+	encode_uint64(xdr, args->falloc_length);
+}
+
+static void encode_allocate(struct xdr_stream *xdr,
+			    struct nfs42_falloc_args *args,
+			    struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_ALLOCATE, decode_allocate_maxsz, hdr);
+	encode_fallocate(xdr, args);
+}
+
+static void encode_deallocate(struct xdr_stream *xdr,
+			      struct nfs42_falloc_args *args,
+			      struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_DEALLOCATE, decode_deallocate_maxsz, hdr);
+	encode_fallocate(xdr, args);
+}
+
 static void encode_seek(struct xdr_stream *xdr,
 			struct nfs42_seek_args *args,
 			struct compound_hdr *hdr)
@@ -33,6 +78,42 @@ static void encode_seek(struct xdr_stream *xdr,
 }
 
 /*
+ * Encode ALLOCATE request
+ */
+static void nfs4_xdr_enc_allocate(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  struct nfs42_falloc_args *args)
+{
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->falloc_fh, &hdr);
+	encode_allocate(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode DEALLOCATE request
+ */
+static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    struct nfs42_falloc_args *args)
+{
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->falloc_fh, &hdr);
+	encode_deallocate(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
  * Encode SEEK request
  */
 static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
@@ -50,6 +131,16 @@ static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
 	encode_nops(&hdr);
 }
 
+static int decode_allocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
+{
+	return decode_op_hdr(xdr, OP_ALLOCATE);
+}
+
+static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
+{
+	return decode_op_hdr(xdr, OP_DEALLOCATE);
+}
+
 static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
 {
 	int status;
@@ -73,6 +164,54 @@ out_overflow:
 }
 
 /*
+ * Decode ALLOCATE request
+ */
+static int nfs4_xdr_dec_allocate(struct rpc_rqst *rqstp,
+				 struct xdr_stream *xdr,
+				 struct nfs42_falloc_res *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_allocate(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode DEALLOCATE request
+ */
+static int nfs4_xdr_dec_deallocate(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr,
+				   struct nfs42_falloc_res *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_deallocate(xdr, res);
+out:
+	return status;
+}
+
+/*
  * Decode SEEK request
  */
 static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index be6cac37ea10..a08178764cf9 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -226,6 +226,7 @@ int nfs4_replace_transport(struct nfs_server *server,
 				const struct nfs4_fs_locations *locations);
 
 /* nfs4proc.c */
+extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
 			  struct rpc_message *, struct nfs4_sequence_args *,
 			  struct nfs4_sequence_res *, int);
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index ffdb28d86cf8..03311259b0c4 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -241,28 +241,25 @@ void nfs4_free_client(struct nfs_client *clp)
  */
 static int nfs4_init_callback(struct nfs_client *clp)
 {
+	struct rpc_xprt *xprt;
 	int error;
 
-	if (clp->rpc_ops->version == 4) {
-		struct rpc_xprt *xprt;
+	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
 
-		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
-
-		if (nfs4_has_session(clp)) {
-			error = xprt_setup_backchannel(xprt,
-						NFS41_BC_MIN_CALLBACKS);
-			if (error < 0)
-				return error;
-		}
-
-		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
-		if (error < 0) {
-			dprintk("%s: failed to start callback. Error = %d\n",
-				__func__, error);
+	if (nfs4_has_session(clp)) {
+		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
+		if (error < 0)
 			return error;
-		}
-		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
 	}
+
+	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
+	if (error < 0) {
+		dprintk("%s: failed to start callback. Error = %d\n",
+			__func__, error);
+		return error;
+	}
+	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
+
 	return 0;
 }
 
@@ -498,8 +495,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
 			atomic_inc(&pos->cl_count);
 			spin_unlock(&nn->nfs_client_lock);
 
-			if (prev)
-				nfs_put_client(prev);
+			nfs_put_client(prev);
 			prev = pos;
 
 			status = nfs_wait_client_init_complete(pos);
@@ -517,8 +513,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
 		atomic_inc(&pos->cl_count);
 		spin_unlock(&nn->nfs_client_lock);
 
-		if (prev)
-			nfs_put_client(prev);
+		nfs_put_client(prev);
 		prev = pos;
 
 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
@@ -549,8 +544,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
 
 	/* No match found. The server lost our clientid */
 out:
-	if (prev)
-		nfs_put_client(prev);
+	nfs_put_client(prev);
 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
 	return status;
 }
@@ -641,8 +635,7 @@ int nfs41_walk_client_list(struct nfs_client *new,
 			atomic_inc(&pos->cl_count);
 			spin_unlock(&nn->nfs_client_lock);
 
-			if (prev)
-				nfs_put_client(prev);
+			nfs_put_client(prev);
 			prev = pos;
 
 			status = nfs_wait_client_init_complete(pos);
@@ -675,8 +668,7 @@ int nfs41_walk_client_list(struct nfs_client *new,
 	/* No matching nfs_client found. */
 	spin_unlock(&nn->nfs_client_lock);
 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
-	if (prev)
-		nfs_put_client(prev);
+	nfs_put_client(prev);
 	return status;
 }
 #endif	/* CONFIG_NFS_V4_1 */
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index c51fb4db9bfe..8b46389c4c5b 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -3,6 +3,8 @@
  *
  *  Copyright (C) 1992  Rick Sladkey
  */
+#include <linux/fs.h>
+#include <linux/falloc.h>
 #include <linux/nfs_fs.h>
 #include "internal.h"
 #include "fscache.h"
@@ -134,6 +136,32 @@ static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
 		return nfs_file_llseek(filep, offset, whence);
 	}
 }
+
+static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	long ret;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
+		return -EOPNOTSUPP;
+
+	ret = inode_newsize_ok(inode, offset + len);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&inode->i_mutex);
+	if (mode & FALLOC_FL_PUNCH_HOLE)
+		ret = nfs42_proc_deallocate(filep, offset, len);
+	else
+		ret = nfs42_proc_allocate(filep, offset, len);
+	mutex_unlock(&inode->i_mutex);
+
+	nfs_zap_caches(inode);
+	return ret;
+}
 #endif /* CONFIG_NFS_V4_2 */
 
 const struct file_operations nfs4_file_operations = {
@@ -155,6 +183,9 @@ const struct file_operations nfs4_file_operations = {
 	.flock		= nfs_flock,
 	.splice_read	= nfs_file_splice_read,
 	.splice_write	= iter_file_splice_write,
+#ifdef CONFIG_NFS_V4_2
+	.fallocate	= nfs42_fallocate,
+#endif /* CONFIG_NFS_V4_2 */
 	.check_flags	= nfs_check_flags,
 	.setlease	= simple_nosetlease,
 };
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 69dc20a743f9..e7f8d5ff2581 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -158,8 +158,6 @@ static int nfs4_map_errors(int err)
 		return -EACCES;
 	case -NFS4ERR_MINOR_VERS_MISMATCH:
 		return -EPROTONOSUPPORT;
-	case -NFS4ERR_ACCESS:
-		return -EACCES;
 	case -NFS4ERR_FILE_OPEN:
 		return -EBUSY;
 	default:
@@ -344,7 +342,7 @@ static int nfs4_delay(struct rpc_clnt *clnt, long *timeout)
 /* This is the error handling routine for processes that are allowed
  * to sleep.
  */
-static int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
+int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
 {
 	struct nfs_client *clp = server->nfs_client;
 	struct nfs4_state *state = exception->state;
@@ -7704,6 +7702,9 @@ nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags)
 
 	dprintk("--> %s\n", __func__);
 
+	/* nfs4_layoutget_release calls pnfs_put_layout_hdr */
+	pnfs_get_layout_hdr(NFS_I(inode)->layout);
+
 	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
 	if (!lgp->args.layout.pages) {
 		nfs4_layoutget_release(lgp);
@@ -7716,9 +7717,6 @@ nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags)
 	lgp->res.seq_res.sr_slot = NULL;
 	nfs4_init_sequence(&lgp->args.seq_args, &lgp->res.seq_res, 0);
 
-	/* nfs4_layoutget_release calls pnfs_put_layout_hdr */
-	pnfs_get_layout_hdr(NFS_I(inode)->layout);
-
 	task = rpc_run_task(&task_setup_data);
 	if (IS_ERR(task))
 		return ERR_CAST(task);
@@ -8426,6 +8424,8 @@ static const struct nfs4_minor_version_ops nfs_v4_2_minor_ops = {
 		| NFS_CAP_POSIX_LOCK
 		| NFS_CAP_STATEID_NFSV41
 		| NFS_CAP_ATOMIC_OPEN_V1
+		| NFS_CAP_ALLOCATE
+		| NFS_CAP_DEALLOCATE
 		| NFS_CAP_SEEK,
 	.init_client = nfs41_init_client,
 	.shutdown_client = nfs41_shutdown_client,
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 206c08a60c7f..cb4376b78ed9 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -141,13 +141,15 @@ static int nfs4_stat_to_errno(int);
 				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
 				XDR_QUADLEN(NFS4_SETCLIENTID_NAMELEN) + \
 				1 /* sc_prog */ + \
-				XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
-				XDR_QUADLEN(RPCBIND_MAXUADDRLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN) + \
 				1) /* sc_cb_ident */
 #define decode_setclientid_maxsz \
 				(op_decode_hdr_maxsz + \
-				2 + \
-				1024) /* large value for CLID_INUSE */
+				2 /* clientid */ + \
+				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 #define encode_setclientid_confirm_maxsz \
 				(op_encode_hdr_maxsz + \
 				3 + (NFS4_VERIFIER_SIZE >> 2))
@@ -7394,6 +7396,8 @@ struct rpc_procinfo	nfs4_procedures[] = {
 #endif /* CONFIG_NFS_V4_1 */
 #ifdef CONFIG_NFS_V4_2
 	PROC(SEEK,		enc_seek,		dec_seek),
+	PROC(ALLOCATE,		enc_allocate,		dec_allocate),
+	PROC(DEALLOCATE,	enc_deallocate,		dec_deallocate),
 #endif /* CONFIG_NFS_V4_2 */
 };
 
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index ed0db61f8543..2b5e769beb16 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -258,6 +258,7 @@ bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
 static inline void
 nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
 {
+	struct inode *inode;
 	WARN_ON_ONCE(prev == req);
 
 	if (!prev) {
@@ -276,12 +277,16 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
 		 * nfs_page_group_destroy is called */
 		kref_get(&req->wb_head->wb_kref);
 
-		/* grab extra ref if head request has extra ref from
-		 * the write/commit path to handle handoff between write
-		 * and commit lists */
+		/* grab extra ref and bump the request count if head request
+		 * has extra ref from the write/commit path to handle handoff
+		 * between write and commit lists. */
 		if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
+			inode = page_file_mapping(req->wb_page)->host;
 			set_bit(PG_INODE_REF, &req->wb_flags);
 			kref_get(&req->wb_kref);
+			spin_lock(&inode->i_lock);
+			NFS_I(inode)->nrequests++;
+			spin_unlock(&inode->i_lock);
 		}
 	}
 }
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index beff2769c5c5..c91a4799c562 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -269,7 +269,7 @@ int nfs_readpage(struct file *file, struct page *page)
 	dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
 		page, PAGE_CACHE_SIZE, page_file_index(page));
 	nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
-	nfs_add_stats(inode, NFSIOS_READPAGES, 1);
+	nfs_inc_stats(inode, NFSIOS_READPAGES);
 
 	/*
 	 * Try to flush any pending writes to the file..
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f83b02dc9166..af3af685a9e3 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -575,7 +575,7 @@ static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, st
 	int ret;
 
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
-	nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
+	nfs_inc_stats(inode, NFSIOS_WRITEPAGES);
 
 	nfs_pageio_cond_complete(pgio, page_file_index(page));
 	ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
@@ -670,7 +670,8 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 	nfs_lock_request(req);
 
 	spin_lock(&inode->i_lock);
-	if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
+	if (!nfsi->nrequests &&
+	    NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
 		inode->i_version++;
 	/*
 	 * Swap-space should not get truncated. Hence no need to plug the race
@@ -681,9 +682,11 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 		SetPagePrivate(req->wb_page);
 		set_page_private(req->wb_page, (unsigned long)req);
 	}
-	nfsi->npages++;
+	nfsi->nrequests++;
 	/* this a head request for a page group - mark it as having an
-	 * extra reference so sub groups can follow suit */
+	 * extra reference so sub groups can follow suit.
+	 * This flag also informs pgio layer when to bump nrequests when
+	 * adding subrequests. */
 	WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
 	kref_get(&req->wb_kref);
 	spin_unlock(&inode->i_lock);
@@ -709,7 +712,11 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 			wake_up_page(head->wb_page, PG_private);
 			clear_bit(PG_MAPPED, &head->wb_flags);
 		}
-		nfsi->npages--;
+		nfsi->nrequests--;
+		spin_unlock(&inode->i_lock);
+	} else {
+		spin_lock(&inode->i_lock);
+		nfsi->nrequests--;
 		spin_unlock(&inode->i_lock);
 	}
 
@@ -1735,7 +1742,7 @@ static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_contr
 		/* Don't commit yet if this is a non-blocking flush and there
 		 * are a lot of outstanding writes for this mapping.
 		 */
-		if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1))
+		if (nfsi->commit_info.ncommit <= (nfsi->nrequests >> 1))
 			goto out_mark_dirty;
 
 		/* don't wait for the COMMIT response */