Merge tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

   - massive cleanup of the NFS read/write code by Anna and Dros
   - support multiple NFS read/write requests per page in order to deal
     with non-page aligned pNFS striping.  Also cleans up the r/wsize <
     page size code nicely.
   - stable fix for ensuring inode is declared uptodate only after all
     the attributes have been checked.
   - stable fix for a kernel Oops when remounting
   - NFS over RDMA client fixes
   - move the pNFS files layout driver into its own subdirectory"

* tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
  NFS: populate ->net in mount data when remounting
  pnfs: fix lockup caused by pnfs_generic_pg_test
  NFSv4.1: Fix typo in dprintk
  NFSv4.1: Comment is now wrong and redundant to code
  NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state
  xprtrdma: Disconnect on registration failure
  xprtrdma: Remove BUG_ON() call sites
  xprtrdma: Avoid deadlock when credit window is reset
  SUNRPC: Move congestion window constants to header file
  xprtrdma: Reset connection timeout after successful reconnect
  xprtrdma: Use macros for reconnection timeout constants
  xprtrdma: Allocate missing pagelist
  xprtrdma: Remove Tavor MTU setting
  xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting
  xprtrdma: Reduce the number of hardway buffer allocations
  xprtrdma: Limit work done by completion handler
  xprtrmda: Reduce calls to ib_poll_cq() in completion handlers
  xprtrmda: Reduce lock contention in completion handlers
  xprtrdma: Split the completion queue
  xprtrdma: Make rpcrdma_ep_destroy() return void
  ...

29 files changed, 1316 insertions, 1203 deletions

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index 03192a66c143..4782e0840dcc 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -29,8 +29,6 @@ nfsv4-$(CONFIG_NFS_USE_LEGACY_DNS) += cache_lib.o
 nfsv4-$(CONFIG_SYSCTL)  += nfs4sysctl.o
 nfsv4-$(CONFIG_NFS_V4_1)        += pnfs.o pnfs_dev.o
 
-obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
-nfs_layout_nfsv41_files-y := nfs4filelayout.o nfs4filelayoutdev.o
-
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += filelayout/
 obj-$(CONFIG_PNFS_OBJLAYOUT) += objlayout/
 obj-$(CONFIG_PNFS_BLOCK) += blocklayout/
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 65d849bdf77a..9b431f44fad9 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -210,7 +210,7 @@ static void bl_end_io_read(struct bio *bio, int err)
                         SetPageUptodate(bvec->bv_page);
 
         if (err) {
-                struct nfs_read_data *rdata = par->data;
+                struct nfs_pgio_data *rdata = par->data;
                 struct nfs_pgio_header *header = rdata->header;
 
                 if (!header->pnfs_error)
@@ -224,17 +224,17 @@ static void bl_end_io_read(struct bio *bio, int err)
 static void bl_read_cleanup(struct work_struct *work)
 {
         struct rpc_task *task;
-        struct nfs_read_data *rdata;
+        struct nfs_pgio_data *rdata;
         dprintk("%s enter\n", __func__);
         task = container_of(work, struct rpc_task, u.tk_work);
-        rdata = container_of(task, struct nfs_read_data, task);
+        rdata = container_of(task, struct nfs_pgio_data, task);
         pnfs_ld_read_done(rdata);
 }
 
 static void
 bl_end_par_io_read(void *data, int unused)
 {
-        struct nfs_read_data *rdata = data;
+        struct nfs_pgio_data *rdata = data;
 
         rdata->task.tk_status = rdata->header->pnfs_error;
         INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup);
@@ -242,7 +242,7 @@ bl_end_par_io_read(void *data, int unused)
 }
 
 static enum pnfs_try_status
-bl_read_pagelist(struct nfs_read_data *rdata)
+bl_read_pagelist(struct nfs_pgio_data *rdata)
 {
         struct nfs_pgio_header *header = rdata->header;
         int i, hole;
@@ -390,7 +390,7 @@ static void bl_end_io_write_zero(struct bio *bio, int err)
         }
 
         if (unlikely(err)) {
-                struct nfs_write_data *data = par->data;
+                struct nfs_pgio_data *data = par->data;
                 struct nfs_pgio_header *header = data->header;
 
                 if (!header->pnfs_error)
@@ -405,7 +405,7 @@ static void bl_end_io_write(struct bio *bio, int err)
 {
         struct parallel_io *par = bio->bi_private;
         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-        struct nfs_write_data *data = par->data;
+        struct nfs_pgio_data *data = par->data;
         struct nfs_pgio_header *header = data->header;
 
         if (!uptodate) {
@@ -423,10 +423,10 @@ static void bl_end_io_write(struct bio *bio, int err)
 static void bl_write_cleanup(struct work_struct *work)
 {
         struct rpc_task *task;
-        struct nfs_write_data *wdata;
+        struct nfs_pgio_data *wdata;
         dprintk("%s enter\n", __func__);
         task = container_of(work, struct rpc_task, u.tk_work);
-        wdata = container_of(task, struct nfs_write_data, task);
+        wdata = container_of(task, struct nfs_pgio_data, task);
         if (likely(!wdata->header->pnfs_error)) {
                 /* Marks for LAYOUTCOMMIT */
                 mark_extents_written(BLK_LSEG2EXT(wdata->header->lseg),
@@ -438,7 +438,7 @@ static void bl_write_cleanup(struct work_struct *work)
 /* Called when last of bios associated with a bl_write_pagelist call finishes */
 static void bl_end_par_io_write(void *data, int num_se)
 {
-        struct nfs_write_data *wdata = data;
+        struct nfs_pgio_data *wdata = data;
 
         if (unlikely(wdata->header->pnfs_error)) {
                 bl_free_short_extents(&BLK_LSEG2EXT(wdata->header->lseg)->bl_inval,
@@ -673,7 +673,7 @@ check_page:
 }
 
 static enum pnfs_try_status
-bl_write_pagelist(struct nfs_write_data *wdata, int sync)
+bl_write_pagelist(struct nfs_pgio_data *wdata, int sync)
 {
         struct nfs_pgio_header *header = wdata->header;
         int i, ret, npg_zero, pg_index, last = 0;
@@ -1189,13 +1189,17 @@ bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
                 pnfs_generic_pg_init_read(pgio, req);
 }
 
-static bool
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t
 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                 struct nfs_page *req)
 {
         if (pgio->pg_dreq != NULL &&
             !is_aligned_req(req, SECTOR_SIZE))
-                return false;
+                return 0;
 
         return pnfs_generic_pg_test(pgio, prev, req);
 }
@@ -1241,13 +1245,17 @@ bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
         }
 }
 
-static bool
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t
 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                  struct nfs_page *req)
 {
         if (pgio->pg_dreq != NULL &&
             !is_aligned_req(req, PAGE_CACHE_SIZE))
-                return false;
+                return 0;
 
         return pnfs_generic_pg_test(pgio, prev, req);
 }
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index b8797ae6831f..4ad7bc388679 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -108,6 +108,97 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
         return atomic_dec_and_test(&dreq->io_count);
 }
 
+/*
+ * nfs_direct_select_verf - select the right verifier
+ * @dreq - direct request possibly spanning multiple servers
+ * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs
+ * @ds_idx - index of data server in data server list, only valid if ds_clp set
+ *
+ * returns the correct verifier to use given the role of the server
+ */
+static struct nfs_writeverf *
+nfs_direct_select_verf(struct nfs_direct_req *dreq,
+                       struct nfs_client *ds_clp,
+                       int ds_idx)
+{
+        struct nfs_writeverf *verfp = &dreq->verf;
+
+#ifdef CONFIG_NFS_V4_1
+        if (ds_clp) {
+                /* pNFS is in use, use the DS verf */
+                if (ds_idx >= 0 && ds_idx < dreq->ds_cinfo.nbuckets)
+                        verfp = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
+                else
+                        WARN_ON_ONCE(1);
+        }
+#endif
+        return verfp;
+}
+
+
+/*
+ * nfs_direct_set_hdr_verf - set the write/commit verifier
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verfs
+ *
+ * Set the server's (MDS or DS) "seen" verifier
+ */
+static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq,
+                                    struct nfs_pgio_header *hdr)
+{
+        struct nfs_writeverf *verfp;
+
+        verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
+                                      hdr->data->ds_idx);
+        WARN_ON_ONCE(verfp->committed >= 0);
+        memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
+        WARN_ON_ONCE(verfp->committed < 0);
+}
+
+/*
+ * nfs_direct_cmp_hdr_verf - compare verifier for pgio header
+ * @dreq - direct request possibly spanning multiple servers
+ * @hdr - pageio header to validate against previously seen verf
+ *
+ * set the server's "seen" verf if not initialized.
+ * returns result of comparison between @hdr->verf and the "seen"
+ * verf of the server used by @hdr (DS or MDS)
+ */
+static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
+                                          struct nfs_pgio_header *hdr)
+{
+        struct nfs_writeverf *verfp;
+
+        verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
+                                         hdr->data->ds_idx);
+        if (verfp->committed < 0) {
+                nfs_direct_set_hdr_verf(dreq, hdr);
+                return 0;
+        }
+        return memcmp(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
+}
+
+#if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
+/*
+ * nfs_direct_cmp_commit_data_verf - compare verifier for commit data
+ * @dreq - direct request possibly spanning multiple servers
+ * @data - commit data to validate against previously seen verf
+ *
+ * returns result of comparison between @data->verf and the verf of
+ * the server used by @data (DS or MDS)
+ */
+static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
+                                           struct nfs_commit_data *data)
+{
+        struct nfs_writeverf *verfp;
+
+        verfp = nfs_direct_select_verf(dreq, data->ds_clp,
+                                         data->ds_commit_index);
+        WARN_ON_ONCE(verfp->committed < 0);
+        return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf));
+}
+#endif
+
 /**
  * nfs_direct_IO - NFS address space operation for direct I/O
  * @rw: direction (read or write)
@@ -168,6 +259,7 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
         kref_get(&dreq->kref);
         init_completion(&dreq->completion);
         INIT_LIST_HEAD(&dreq->mds_cinfo.list);
+        dreq->verf.committed = NFS_INVALID_STABLE_HOW;  /* not set yet */
         INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
         spin_lock_init(&dreq->lock);
 
@@ -380,8 +472,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
                         struct nfs_page *req;
                         unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
                         /* XXX do we need to do the eof zeroing found in async_filler? */
-                        req = nfs_create_request(dreq->ctx, dreq->inode,
-                                                 pagevec[i],
+                        req = nfs_create_request(dreq->ctx, pagevec[i], NULL,
                                                  pgbase, req_len);
                         if (IS_ERR(req)) {
                                 result = PTR_ERR(req);
@@ -424,7 +515,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
         size_t requested_bytes = 0;
         unsigned long seg;
 
-        NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
+        nfs_pageio_init_read(&desc, dreq->inode, false,
                              &nfs_direct_read_completion_ops);
         get_dreq(dreq);
         desc.pg_dreq = dreq;
@@ -564,7 +655,7 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
         dreq->count = 0;
         get_dreq(dreq);
 
-        NFS_PROTO(dreq->inode)->write_pageio_init(&desc, dreq->inode, FLUSH_STABLE,
+        nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false,
                               &nfs_direct_write_completion_ops);
         desc.pg_dreq = dreq;
 
@@ -603,7 +694,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
                 dprintk("NFS: %5u commit failed with error %d.\n",
                         data->task.tk_pid, status);
                 dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
-        } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) {
+        } else if (nfs_direct_cmp_commit_data_verf(dreq, data)) {
                 dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid);
                 dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
         }
@@ -750,8 +841,7 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
                         struct nfs_page *req;
                         unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
 
-                        req = nfs_create_request(dreq->ctx, dreq->inode,
-                                                 pagevec[i],
+                        req = nfs_create_request(dreq->ctx, pagevec[i], NULL,
                                                  pgbase, req_len);
                         if (IS_ERR(req)) {
                                 result = PTR_ERR(req);
@@ -813,13 +903,13 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
                         if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
                                 bit = NFS_IOHDR_NEED_RESCHED;
                         else if (dreq->flags == 0) {
-                                memcpy(&dreq->verf, hdr->verf,
-                                       sizeof(dreq->verf));
+                                nfs_direct_set_hdr_verf(dreq, hdr);
                                 bit = NFS_IOHDR_NEED_COMMIT;
                                 dreq->flags = NFS_ODIRECT_DO_COMMIT;
                         } else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) {
-                                if (memcmp(&dreq->verf, hdr->verf, sizeof(dreq->verf))) {
-                                        dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+                                if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr)) {
+                                        dreq->flags =
+                                                NFS_ODIRECT_RESCHED_WRITES;
                                         bit = NFS_IOHDR_NEED_RESCHED;
                                 } else
                                         bit = NFS_IOHDR_NEED_COMMIT;
@@ -829,6 +919,8 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
         spin_unlock(&dreq->lock);
 
         while (!list_empty(&hdr->pages)) {
+                bool do_destroy = true;
+
                 req = nfs_list_entry(hdr->pages.next);
                 nfs_list_remove_request(req);
                 switch (bit) {
@@ -836,6 +928,7 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
                 case NFS_IOHDR_NEED_COMMIT:
                         kref_get(&req->wb_kref);
                         nfs_mark_request_commit(req, hdr->lseg, &cinfo);
+                        do_destroy = false;
                 }
                 nfs_unlock_and_release_request(req);
         }
@@ -874,7 +967,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
         size_t requested_bytes = 0;
         unsigned long seg;
 
-        NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
+        nfs_pageio_init_write(&desc, inode, FLUSH_COND_STABLE, false,
                               &nfs_direct_write_completion_ops);
         desc.pg_dreq = dreq;
         get_dreq(dreq);
diff --git a/fs/nfs/filelayout/Makefile b/fs/nfs/filelayout/Makefile
new file mode 100644
index 000000000000..8516cdffb9e9
--- /dev/null
+++ b/fs/nfs/filelayout/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the pNFS Files Layout Driver kernel module
+#
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
+nfs_layout_nfsv41_files-y := filelayout.o filelayoutdev.o
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/filelayout/filelayout.c
index b9a35c05b60f..d2eba1c13b7e 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -35,11 +35,11 @@
 
 #include <linux/sunrpc/metrics.h>
 
-#include "nfs4session.h"
-#include "internal.h"
-#include "delegation.h"
-#include "nfs4filelayout.h"
-#include "nfs4trace.h"
+#include "../nfs4session.h"
+#include "../internal.h"
+#include "../delegation.h"
+#include "filelayout.h"
+#include "../nfs4trace.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
 
@@ -84,7 +84,7 @@ filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
         BUG();
 }
 
-static void filelayout_reset_write(struct nfs_write_data *data)
+static void filelayout_reset_write(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
         struct rpc_task *task = &data->task;
@@ -105,7 +105,7 @@ static void filelayout_reset_write(struct nfs_write_data *data)
         }
 }
 
-static void filelayout_reset_read(struct nfs_read_data *data)
+static void filelayout_reset_read(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
         struct rpc_task *task = &data->task;
@@ -243,7 +243,7 @@ wait_on_recovery:
 /* NFS_PROTO call done callback routines */
 
 static int filelayout_read_done_cb(struct rpc_task *task,
-                                struct nfs_read_data *data)
+                                struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
         int err;
@@ -270,7 +270,7 @@ static int filelayout_read_done_cb(struct rpc_task *task,
  * rfc5661 is not clear about which credential should be used.
  */
 static void
-filelayout_set_layoutcommit(struct nfs_write_data *wdata)
+filelayout_set_layoutcommit(struct nfs_pgio_data *wdata)
 {
         struct nfs_pgio_header *hdr = wdata->header;
 
@@ -279,7 +279,7 @@ filelayout_set_layoutcommit(struct nfs_write_data *wdata)
                 return;
 
         pnfs_set_layoutcommit(wdata);
-        dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
+        dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 }
 
@@ -305,7 +305,7 @@ filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
  */
 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 {
-        struct nfs_read_data *rdata = data;
+        struct nfs_pgio_data *rdata = data;
 
         if (unlikely(test_bit(NFS_CONTEXT_BAD, &rdata->args.context->flags))) {
                 rpc_exit(task, -EIO);
@@ -317,7 +317,7 @@ static void filelayout_read_prepare(struct rpc_task *task, void *data)
                 rpc_exit(task, 0);
                 return;
         }
-        rdata->read_done_cb = filelayout_read_done_cb;
+        rdata->pgio_done_cb = filelayout_read_done_cb;
 
         if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
                         &rdata->args.seq_args,
@@ -331,7 +331,7 @@ static void filelayout_read_prepare(struct rpc_task *task, void *data)
 
 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 {
-        struct nfs_read_data *rdata = data;
+        struct nfs_pgio_data *rdata = data;
 
         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 
@@ -347,14 +347,14 @@ static void filelayout_read_call_done(struct rpc_task *task, void *data)
 
 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 {
-        struct nfs_read_data *rdata = data;
+        struct nfs_pgio_data *rdata = data;
 
         rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
 }
 
 static void filelayout_read_release(void *data)
 {
-        struct nfs_read_data *rdata = data;
+        struct nfs_pgio_data *rdata = data;
         struct pnfs_layout_hdr *lo = rdata->header->lseg->pls_layout;
 
         filelayout_fenceme(lo->plh_inode, lo);
@@ -363,7 +363,7 @@ static void filelayout_read_release(void *data)
 }
 
 static int filelayout_write_done_cb(struct rpc_task *task,
-                                struct nfs_write_data *data)
+                                struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
         int err;
@@ -419,7 +419,7 @@ static int filelayout_commit_done_cb(struct rpc_task *task,
 
 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 {
-        struct nfs_write_data *wdata = data;
+        struct nfs_pgio_data *wdata = data;
 
         if (unlikely(test_bit(NFS_CONTEXT_BAD, &wdata->args.context->flags))) {
                 rpc_exit(task, -EIO);
@@ -443,7 +443,7 @@ static void filelayout_write_prepare(struct rpc_task *task, void *data)
 
 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 {
-        struct nfs_write_data *wdata = data;
+        struct nfs_pgio_data *wdata = data;
 
         if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
             task->tk_status == 0) {
@@ -457,14 +457,14 @@ static void filelayout_write_call_done(struct rpc_task *task, void *data)
 
 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 {
-        struct nfs_write_data *wdata = data;
+        struct nfs_pgio_data *wdata = data;
 
         rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
 }
 
 static void filelayout_write_release(void *data)
 {
-        struct nfs_write_data *wdata = data;
+        struct nfs_pgio_data *wdata = data;
         struct pnfs_layout_hdr *lo = wdata->header->lseg->pls_layout;
 
         filelayout_fenceme(lo->plh_inode, lo);
@@ -529,7 +529,7 @@ static const struct rpc_call_ops filelayout_commit_call_ops = {
 };
 
 static enum pnfs_try_status
-filelayout_read_pagelist(struct nfs_read_data *data)
+filelayout_read_pagelist(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
         struct pnfs_layout_segment *lseg = hdr->lseg;
@@ -560,6 +560,7 @@ filelayout_read_pagelist(struct nfs_read_data *data)
         /* No multipath support. Use first DS */
         atomic_inc(&ds->ds_clp->cl_count);
         data->ds_clp = ds->ds_clp;
+        data->ds_idx = idx;
         fh = nfs4_fl_select_ds_fh(lseg, j);
         if (fh)
                 data->args.fh = fh;
@@ -568,14 +569,14 @@ filelayout_read_pagelist(struct nfs_read_data *data)
         data->mds_offset = offset;
 
         /* Perform an asynchronous read to ds */
-        nfs_initiate_read(ds_clnt, data,
-                                  &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
+        nfs_initiate_pgio(ds_clnt, data,
+                            &filelayout_read_call_ops, 0, RPC_TASK_SOFTCONN);
         return PNFS_ATTEMPTED;
 }
 
 /* Perform async writes. */
 static enum pnfs_try_status
-filelayout_write_pagelist(struct nfs_write_data *data, int sync)
+filelayout_write_pagelist(struct nfs_pgio_data *data, int sync)
 {
         struct nfs_pgio_header *hdr = data->header;
         struct pnfs_layout_segment *lseg = hdr->lseg;
@@ -600,20 +601,18 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
                 __func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 
-        data->write_done_cb = filelayout_write_done_cb;
+        data->pgio_done_cb = filelayout_write_done_cb;
         atomic_inc(&ds->ds_clp->cl_count);
         data->ds_clp = ds->ds_clp;
+        data->ds_idx = idx;
         fh = nfs4_fl_select_ds_fh(lseg, j);
         if (fh)
                 data->args.fh = fh;
-        /*
-         * Get the file offset on the dserver. Set the write offset to
-         * this offset and save the original offset.
-         */
+
         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 
         /* Perform an asynchronous write */
-        nfs_initiate_write(ds_clnt, data,
+        nfs_initiate_pgio(ds_clnt, data,
                                     &filelayout_write_call_ops, sync,
                                     RPC_TASK_SOFTCONN);
         return PNFS_ATTEMPTED;
@@ -637,7 +636,6 @@ filelayout_check_layout(struct pnfs_layout_hdr *lo,
         struct nfs4_deviceid_node *d;
         struct nfs4_file_layout_dsaddr *dsaddr;
         int status = -EINVAL;
-        struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
 
         dprintk("--> %s\n", __func__);
 
@@ -655,7 +653,7 @@ filelayout_check_layout(struct pnfs_layout_hdr *lo,
                 goto out;
         }
 
-        if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
+        if (!fl->stripe_unit) {
                 dprintk("%s Invalid stripe unit (%u)\n",
                         __func__, fl->stripe_unit);
                 goto out;
@@ -692,12 +690,6 @@ filelayout_check_layout(struct pnfs_layout_hdr *lo,
                 goto out_put;
         }
 
-        if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
-                dprintk("%s Stripe unit (%u) not aligned with rsize %u "
-                        "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
-                        nfss->wsize);
-        }
-
         status = 0;
 out:
         dprintk("--> %s returns %d\n", __func__, status);
@@ -850,11 +842,15 @@ filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 {
         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
         struct pnfs_commit_bucket *buckets;
-        int size;
+        int size, i;
 
         if (fl->commit_through_mds)
                 return 0;
-        if (cinfo->ds->nbuckets != 0) {
+
+        size = (fl->stripe_type == STRIPE_SPARSE) ?
+                fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
+
+        if (cinfo->ds->nbuckets >= size) {
                 /* This assumes there is only one IOMODE_RW lseg.  What
                  * we really want to do is have a layout_hdr level
                  * dictionary of <multipath_list4, fh> keys, each
@@ -864,30 +860,36 @@ filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
                 return 0;
         }
 
-        size = (fl->stripe_type == STRIPE_SPARSE) ?
-                fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
-
         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
                           gfp_flags);
         if (!buckets)
                 return -ENOMEM;
-        else {
-                int i;
+        for (i = 0; i < size; i++) {
+                INIT_LIST_HEAD(&buckets[i].written);
+                INIT_LIST_HEAD(&buckets[i].committing);
+                /* mark direct verifier as unset */
+                buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
+        }
 
-                spin_lock(cinfo->lock);
-                if (cinfo->ds->nbuckets != 0)
-                        kfree(buckets);
-                else {
-                        cinfo->ds->buckets = buckets;
-                        cinfo->ds->nbuckets = size;
-                        for (i = 0; i < size; i++) {
-                                INIT_LIST_HEAD(&buckets[i].written);
-                                INIT_LIST_HEAD(&buckets[i].committing);
-                        }
-                }
-                spin_unlock(cinfo->lock);
-                return 0;
+        spin_lock(cinfo->lock);
+        if (cinfo->ds->nbuckets >= size)
+                goto out;
+        for (i = 0; i < cinfo->ds->nbuckets; i++) {
+                list_splice(&cinfo->ds->buckets[i].written,
+                            &buckets[i].written);
+                list_splice(&cinfo->ds->buckets[i].committing,
+                            &buckets[i].committing);
+                buckets[i].direct_verf.committed =
+                        cinfo->ds->buckets[i].direct_verf.committed;
+                buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
+                buckets[i].clseg = cinfo->ds->buckets[i].clseg;
         }
+        swap(cinfo->ds->buckets, buckets);
+        cinfo->ds->nbuckets = size;
+out:
+        spin_unlock(cinfo->lock);
+        kfree(buckets);
+        return 0;
 }
 
 static struct pnfs_layout_segment *
@@ -915,47 +917,51 @@ filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 /*
  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
  *
- * return true  : coalesce page
- * return false : don't coalesce page
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
  */
-static bool
+static size_t
 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                    struct nfs_page *req)
 {
+        unsigned int size;
         u64 p_stripe, r_stripe;
-        u32 stripe_unit;
+        u32 stripe_offset;
+        u64 segment_offset = pgio->pg_lseg->pls_range.offset;
+        u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 
-        if (!pnfs_generic_pg_test(pgio, prev, req) ||
-            !nfs_generic_pg_test(pgio, prev, req))
-                return false;
+        /* calls nfs_generic_pg_test */
+        size = pnfs_generic_pg_test(pgio, prev, req);
+        if (!size)
+                return 0;
 
-        p_stripe = (u64)req_offset(prev);
-        r_stripe = (u64)req_offset(req);
-        stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
+        /* see if req and prev are in the same stripe */
+        if (prev) {
+                p_stripe = (u64)req_offset(prev) - segment_offset;
+                r_stripe = (u64)req_offset(req) - segment_offset;
+                do_div(p_stripe, stripe_unit);
+                do_div(r_stripe, stripe_unit);
 
-        do_div(p_stripe, stripe_unit);
-        do_div(r_stripe, stripe_unit);
+                if (p_stripe != r_stripe)
+                        return 0;
+        }
 
-        return (p_stripe == r_stripe);
+        /* calculate remaining bytes in the current stripe */
+        div_u64_rem((u64)req_offset(req) - segment_offset,
+                        stripe_unit,
+                        &stripe_offset);
+        WARN_ON_ONCE(stripe_offset > stripe_unit);
+        if (stripe_offset >= stripe_unit)
+                return 0;
+        return min(stripe_unit - (unsigned int)stripe_offset, size);
 }
 
 static void
 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
                         struct nfs_page *req)
 {
-        WARN_ON_ONCE(pgio->pg_lseg != NULL);
-
-        if (req->wb_offset != req->wb_pgbase) {
-                /*
-                 * Handling unaligned pages is difficult, because have to
-                 * somehow split a req in two in certain cases in the
-                 * pg.test code.  Avoid this by just not using pnfs
-                 * in this case.
-                 */
-                nfs_pageio_reset_read_mds(pgio);
-                return;
-        }
-        pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+        if (!pgio->pg_lseg)
+                pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                            req->wb_context,
                                            0,
                                            NFS4_MAX_UINT64,
@@ -973,11 +979,8 @@ filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
         struct nfs_commit_info cinfo;
         int status;
 
-        WARN_ON_ONCE(pgio->pg_lseg != NULL);
-
-        if (req->wb_offset != req->wb_pgbase)
-                goto out_mds;
-        pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+        if (!pgio->pg_lseg)
+                pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                            req->wb_context,
                                            0,
                                            NFS4_MAX_UINT64,
@@ -1067,6 +1070,7 @@ filelayout_choose_commit_list(struct nfs_page *req,
          */
         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
         i = select_bucket_index(fl, j);
+        spin_lock(cinfo->lock);
         buckets = cinfo->ds->buckets;
         list = &buckets[i].written;
         if (list_empty(list)) {
@@ -1080,6 +1084,7 @@ filelayout_choose_commit_list(struct nfs_page *req,
         }
         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
         cinfo->ds->nwritten++;
+        spin_unlock(cinfo->lock);
         return list;
 }
 
@@ -1176,6 +1181,7 @@ transfer_commit_list(struct list_head *src, struct list_head *dst,
         return ret;
 }
 
+/* Note called with cinfo->lock held. */
 static int
 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
                                struct nfs_commit_info *cinfo,
@@ -1220,15 +1226,18 @@ static void filelayout_recover_commit_reqs(struct list_head *dst,
                                            struct nfs_commit_info *cinfo)
 {
         struct pnfs_commit_bucket *b;
+        struct pnfs_layout_segment *freeme;
         int i;
 
+restart:
         spin_lock(cinfo->lock);
         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
                 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
-                        spin_unlock(cinfo->lock);
-                        pnfs_put_lseg(b->wlseg);
+                        freeme = b->wlseg;
                         b->wlseg = NULL;
-                        spin_lock(cinfo->lock);
+                        spin_unlock(cinfo->lock);
+                        pnfs_put_lseg(freeme);
+                        goto restart;
                 }
         }
         cinfo->ds->nwritten = 0;
@@ -1243,6 +1252,7 @@ alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
         struct nfs_commit_data *data;
         int i, j;
         unsigned int nreq = 0;
+        struct pnfs_layout_segment *freeme;
 
         fl_cinfo = cinfo->ds;
         bucket = fl_cinfo->buckets;
@@ -1253,8 +1263,10 @@ alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
                 if (!data)
                         break;
                 data->ds_commit_index = i;
+                spin_lock(cinfo->lock);
                 data->lseg = bucket->clseg;
                 bucket->clseg = NULL;
+                spin_unlock(cinfo->lock);
                 list_add(&data->pages, list);
                 nreq++;
         }
@@ -1264,8 +1276,11 @@ alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
                 if (list_empty(&bucket->committing))
                         continue;
                 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
-                pnfs_put_lseg(bucket->clseg);
+                spin_lock(cinfo->lock);
+                freeme = bucket->clseg;
                 bucket->clseg = NULL;
+                spin_unlock(cinfo->lock);
+                pnfs_put_lseg(freeme);
         }
         /* Caller will clean up entries put on list */
         return nreq;
@@ -1330,7 +1345,7 @@ filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
         struct nfs4_filelayout *flo;
 
         flo = kzalloc(sizeof(*flo), gfp_flags);
-        return &flo->generic_hdr;
+        return flo != NULL ? &flo->generic_hdr : NULL;
 }
 
 static void
diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/filelayout/filelayout.h
index cebd20e7e923..ffbddf2219ea 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/filelayout/filelayout.h
@@ -30,7 +30,7 @@
 #ifndef FS_NFS_NFS4FILELAYOUT_H
 #define FS_NFS_NFS4FILELAYOUT_H
 
-#include "pnfs.h"
+#include "../pnfs.h"
 
 /*
  * Default data server connection timeout and retrans vaules.
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
index b9c61efe9660..44bf0140a4c7 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -33,9 +33,9 @@
 #include <linux/module.h>
 #include <linux/sunrpc/addr.h>
 
-#include "internal.h"
-#include "nfs4session.h"
-#include "nfs4filelayout.h"
+#include "../internal.h"
+#include "../nfs4session.h"
+#include "filelayout.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
 
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 66984a9aafaa..b94f80420a58 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -120,7 +120,8 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
 
         security_d_instantiate(ret, inode);
         spin_lock(&ret->d_lock);
-        if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
+        if (IS_ROOT(ret) && !ret->d_fsdata &&
+            !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
                 ret->d_fsdata = name;
                 name = NULL;
         }
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e6f7398d2b3c..c496f8a74639 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1575,18 +1575,20 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                         inode->i_version = fattr->change_attr;
                 }
         } else if (server->caps & NFS_CAP_CHANGE_ATTR)
-                invalid |= save_cache_validity;
+                nfsi->cache_validity |= save_cache_validity;
 
         if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
                 memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
         } else if (server->caps & NFS_CAP_MTIME)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_REVAL_FORCED);
 
         if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
                 memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
         } else if (server->caps & NFS_CAP_CTIME)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_REVAL_FORCED);
 
         /* Check if our cached file size is stale */
@@ -1608,7 +1610,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                                         (long long)new_isize);
                 }
         } else
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_REVAL_PAGECACHE
                                 | NFS_INO_REVAL_FORCED);
 
@@ -1616,7 +1619,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
         if (fattr->valid & NFS_ATTR_FATTR_ATIME)
                 memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));
         else if (server->caps & NFS_CAP_ATIME)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATIME
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATIME
                                 | NFS_INO_REVAL_FORCED);
 
         if (fattr->valid & NFS_ATTR_FATTR_MODE) {
@@ -1627,7 +1631,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                         invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL;
                 }
         } else if (server->caps & NFS_CAP_MODE)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_INVALID_ACCESS
                                 | NFS_INO_INVALID_ACL
                                 | NFS_INO_REVAL_FORCED);
@@ -1638,7 +1643,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                         inode->i_uid = fattr->uid;
                 }
         } else if (server->caps & NFS_CAP_OWNER)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_INVALID_ACCESS
                                 | NFS_INO_INVALID_ACL
                                 | NFS_INO_REVAL_FORCED);
@@ -1649,7 +1655,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                         inode->i_gid = fattr->gid;
                 }
         } else if (server->caps & NFS_CAP_OWNER_GROUP)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_INVALID_ACCESS
                                 | NFS_INO_INVALID_ACL
                                 | NFS_INO_REVAL_FORCED);
@@ -1662,7 +1669,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                         set_nlink(inode, fattr->nlink);
                 }
         } else if (server->caps & NFS_CAP_NLINK)
-                invalid |= save_cache_validity & (NFS_INO_INVALID_ATTR
+                nfsi->cache_validity |= save_cache_validity &
+                                (NFS_INO_INVALID_ATTR
                                 | NFS_INO_REVAL_FORCED);
 
         if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index dd8bfc2e2464..8b69cba1bb04 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -231,13 +231,20 @@ extern void nfs_destroy_writepagecache(void);
 
 extern int __init nfs_init_directcache(void);
 extern void nfs_destroy_directcache(void);
-extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
                               struct nfs_pgio_header *hdr,
                               void (*release)(struct nfs_pgio_header *hdr));
 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 int nfs_iocounter_wait(struct nfs_io_counter *c);
 
+extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
+struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *);
+void nfs_rw_header_free(struct nfs_pgio_header *);
+void nfs_pgio_data_release(struct nfs_pgio_data *);
+int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
+int nfs_initiate_pgio(struct rpc_clnt *, struct nfs_pgio_data *,
+                      const struct rpc_call_ops *, int, int);
+
 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 {
         c->flags = 0;
@@ -395,19 +402,11 @@ extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool
 
 struct nfs_pgio_completion_ops;
 /* read.c */
-extern struct nfs_read_header *nfs_readhdr_alloc(void);
-extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
-                        struct inode *inode,
+                        struct inode *inode, bool force_mds,
                         const struct nfs_pgio_completion_ops *compl_ops);
-extern int nfs_initiate_read(struct rpc_clnt *clnt,
-                             struct nfs_read_data *data,
-                             const struct rpc_call_ops *call_ops, int flags);
 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
-extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
-                              struct nfs_pgio_header *hdr);
 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
-extern void nfs_readdata_release(struct nfs_read_data *rdata);
 
 /* super.c */
 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
@@ -422,19 +421,10 @@ int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 
 /* write.c */
 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
-                        struct inode *inode, int ioflags,
+                        struct inode *inode, int ioflags, bool force_mds,
                         const struct nfs_pgio_completion_ops *compl_ops);
-extern struct nfs_write_header *nfs_writehdr_alloc(void);
-extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
-extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
-                             struct nfs_pgio_header *hdr);
 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
-extern void nfs_writedata_release(struct nfs_write_data *wdata);
 extern void nfs_commit_free(struct nfs_commit_data *p);
-extern int nfs_initiate_write(struct rpc_clnt *clnt,
-                              struct nfs_write_data *data,
-                              const struct rpc_call_ops *call_ops,
-                              int how, int flags);
 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
@@ -447,6 +437,7 @@ extern void nfs_init_commit(struct nfs_commit_data *data,
                             struct nfs_commit_info *cinfo);
 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
                          struct nfs_commit_info *cinfo, int max);
+unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
                     struct nfs_commit_info *cinfo);
 void nfs_mark_request_commit(struct nfs_page *req,
@@ -492,7 +483,7 @@ static inline void nfs_inode_dio_wait(struct inode *inode)
 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
 
 /* nfs4proc.c */
-extern void __nfs4_read_done_cb(struct nfs_read_data *);
+extern void __nfs4_read_done_cb(struct nfs_pgio_data *);
 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
                             const struct rpc_timeout *timeparms,
                             const char *ip_addr);
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 62db136339ea..5f61b83f4a1c 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -103,7 +103,7 @@ static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
 /*
  *      typedef opaque  nfsdata<>;
  */
-static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_readres *result)
+static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
 {
         u32 recvd, count;
         __be32 *p;
@@ -613,7 +613,7 @@ static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
  *      };
  */
 static void encode_readargs(struct xdr_stream *xdr,
-                            const struct nfs_readargs *args)
+                            const struct nfs_pgio_args *args)
 {
         u32 offset = args->offset;
         u32 count = args->count;
@@ -629,7 +629,7 @@ static void encode_readargs(struct xdr_stream *xdr,
 
 static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
                                   struct xdr_stream *xdr,
-                                  const struct nfs_readargs *args)
+                                  const struct nfs_pgio_args *args)
 {
         encode_readargs(xdr, args);
         prepare_reply_buffer(req, args->pages, args->pgbase,
@@ -649,7 +649,7 @@ static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
  *      };
  */
 static void encode_writeargs(struct xdr_stream *xdr,
-                             const struct nfs_writeargs *args)
+                             const struct nfs_pgio_args *args)
 {
         u32 offset = args->offset;
         u32 count = args->count;
@@ -669,7 +669,7 @@ static void encode_writeargs(struct xdr_stream *xdr,
 
 static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
                                    struct xdr_stream *xdr,
-                                   const struct nfs_writeargs *args)
+                                   const struct nfs_pgio_args *args)
 {
         encode_writeargs(xdr, args);
         xdr->buf->flags |= XDRBUF_WRITE;
@@ -857,7 +857,7 @@ out_default:
  *      };
  */
 static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
-                                struct nfs_readres *result)
+                                struct nfs_pgio_res *result)
 {
         enum nfs_stat status;
         int error;
@@ -878,7 +878,7 @@ out_default:
 }
 
 static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
-                                 struct nfs_writeres *result)
+                                 struct nfs_pgio_res *result)
 {
         /* All NFSv2 writes are "file sync" writes */
         result->verf->committed = NFS_FILE_SYNC;
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index db60149c4579..e7daa42bbc86 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -795,7 +795,7 @@ nfs3_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
         return status;
 }
 
-static int nfs3_read_done(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs3_read_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct inode *inode = data->header->inode;
 
@@ -807,18 +807,18 @@ static int nfs3_read_done(struct rpc_task *task, struct nfs_read_data *data)
         return 0;
 }
 
-static void nfs3_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
+static void nfs3_proc_read_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         msg->rpc_proc = &nfs3_procedures[NFS3PROC_READ];
 }
 
-static int nfs3_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs3_proc_pgio_rpc_prepare(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         rpc_call_start(task);
         return 0;
 }
 
-static int nfs3_write_done(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs3_write_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct inode *inode = data->header->inode;
 
@@ -829,17 +829,11 @@ static int nfs3_write_done(struct rpc_task *task, struct nfs_write_data *data)
         return 0;
 }
 
-static void nfs3_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
+static void nfs3_proc_write_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         msg->rpc_proc = &nfs3_procedures[NFS3PROC_WRITE];
 }
 
-static int nfs3_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
-{
-        rpc_call_start(task);
-        return 0;
-}
-
 static void nfs3_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
 {
         rpc_call_start(task);
@@ -946,13 +940,10 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
         .fsinfo         = nfs3_proc_fsinfo,
         .pathconf       = nfs3_proc_pathconf,
         .decode_dirent  = nfs3_decode_dirent,
+        .pgio_rpc_prepare = nfs3_proc_pgio_rpc_prepare,
         .read_setup     = nfs3_proc_read_setup,
-        .read_pageio_init = nfs_pageio_init_read,
-        .read_rpc_prepare = nfs3_proc_read_rpc_prepare,
         .read_done      = nfs3_read_done,
         .write_setup    = nfs3_proc_write_setup,
-        .write_pageio_init = nfs_pageio_init_write,
-        .write_rpc_prepare = nfs3_proc_write_rpc_prepare,
         .write_done     = nfs3_write_done,
         .commit_setup   = nfs3_proc_commit_setup,
         .commit_rpc_prepare = nfs3_proc_commit_rpc_prepare,
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index fa6d72131c19..8f4cbe7f4aa8 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -953,7 +953,7 @@ static void nfs3_xdr_enc_readlink3args(struct rpc_rqst *req,
  *      };
  */
 static void encode_read3args(struct xdr_stream *xdr,
-                             const struct nfs_readargs *args)
+                             const struct nfs_pgio_args *args)
 {
         __be32 *p;
 
@@ -966,7 +966,7 @@ static void encode_read3args(struct xdr_stream *xdr,
 
 static void nfs3_xdr_enc_read3args(struct rpc_rqst *req,
                                    struct xdr_stream *xdr,
-                                   const struct nfs_readargs *args)
+                                   const struct nfs_pgio_args *args)
 {
         encode_read3args(xdr, args);
         prepare_reply_buffer(req, args->pages, args->pgbase,
@@ -992,7 +992,7 @@ static void nfs3_xdr_enc_read3args(struct rpc_rqst *req,
  *      };
  */
 static void encode_write3args(struct xdr_stream *xdr,
-                              const struct nfs_writeargs *args)
+                              const struct nfs_pgio_args *args)
 {
         __be32 *p;
 
@@ -1008,7 +1008,7 @@ static void encode_write3args(struct xdr_stream *xdr,
 
 static void nfs3_xdr_enc_write3args(struct rpc_rqst *req,
                                     struct xdr_stream *xdr,
-                                    const struct nfs_writeargs *args)
+                                    const struct nfs_pgio_args *args)
 {
         encode_write3args(xdr, args);
         xdr->buf->flags |= XDRBUF_WRITE;
@@ -1589,7 +1589,7 @@ out_default:
  *      };
  */
 static int decode_read3resok(struct xdr_stream *xdr,
-                             struct nfs_readres *result)
+                             struct nfs_pgio_res *result)
 {
         u32 eof, count, ocount, recvd;
         __be32 *p;
@@ -1625,7 +1625,7 @@ out_overflow:
 }
 
 static int nfs3_xdr_dec_read3res(struct rpc_rqst *req, struct xdr_stream *xdr,
-                                 struct nfs_readres *result)
+                                 struct nfs_pgio_res *result)
 {
         enum nfs_stat status;
         int error;
@@ -1673,7 +1673,7 @@ out_status:
  *      };
  */
 static int decode_write3resok(struct xdr_stream *xdr,
-                              struct nfs_writeres *result)
+                              struct nfs_pgio_res *result)
 {
         __be32 *p;
 
@@ -1697,7 +1697,7 @@ out_eio:
 }
 
 static int nfs3_xdr_dec_write3res(struct rpc_rqst *req, struct xdr_stream *xdr,
-                                  struct nfs_writeres *result)
+                                  struct nfs_pgio_res *result)
 {
         enum nfs_stat status;
         int error;
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index e1d1badbe53c..f63cb87cd730 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -337,7 +337,7 @@ nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
  */
 static inline void
 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
-                         struct rpc_message *msg, struct nfs_write_data *wdata)
+                         struct rpc_message *msg, struct nfs_pgio_data *wdata)
 {
         if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
             !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
@@ -369,7 +369,7 @@ nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
 
 static inline void
 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
-                         struct rpc_message *msg, struct nfs_write_data *wdata)
+                         struct rpc_message *msg, struct nfs_pgio_data *wdata)
 {
 }
 #endif /* CONFIG_NFS_V4_1 */
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 8de3407e0360..464db9dd6318 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -100,8 +100,7 @@ nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
                         break;
                 mutex_lock(&inode->i_mutex);
                 ret = nfs_file_fsync_commit(file, start, end, datasync);
-                if (!ret && !datasync)
-                        /* application has asked for meta-data sync */
+                if (!ret)
                         ret = pnfs_layoutcommit_inode(inode, true);
                 mutex_unlock(&inode->i_mutex);
                 /*
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 7f55fed8dc64..285ad5334018 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2027,7 +2027,7 @@ static int _nfs4_proc_open(struct nfs4_opendata *data)
                         return status;
         }
         if (!(o_res->f_attr->valid & NFS_ATTR_FATTR))
-                _nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr, o_res->f_label);
+                nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr, o_res->f_label);
         return 0;
 }
 
@@ -4033,12 +4033,12 @@ static bool nfs4_error_stateid_expired(int err)
         return false;
 }
 
-void __nfs4_read_done_cb(struct nfs_read_data *data)
+void __nfs4_read_done_cb(struct nfs_pgio_data *data)
 {
         nfs_invalidate_atime(data->header->inode);
 }
 
-static int nfs4_read_done_cb(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs4_read_done_cb(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct nfs_server *server = NFS_SERVER(data->header->inode);
 
@@ -4055,7 +4055,7 @@ static int nfs4_read_done_cb(struct rpc_task *task, struct nfs_read_data *data)
 }
 
 static bool nfs4_read_stateid_changed(struct rpc_task *task,
-                struct nfs_readargs *args)
+                struct nfs_pgio_args *args)
 {
 
         if (!nfs4_error_stateid_expired(task->tk_status) ||
@@ -4068,7 +4068,7 @@ static bool nfs4_read_stateid_changed(struct rpc_task *task,
         return true;
 }
 
-static int nfs4_read_done(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
 
         dprintk("--> %s\n", __func__);
@@ -4077,19 +4077,19 @@ static int nfs4_read_done(struct rpc_task *task, struct nfs_read_data *data)
                 return -EAGAIN;
         if (nfs4_read_stateid_changed(task, &data->args))
                 return -EAGAIN;
-        return data->read_done_cb ? data->read_done_cb(task, data) :
+        return data->pgio_done_cb ? data->pgio_done_cb(task, data) :
                                     nfs4_read_done_cb(task, data);
 }
 
-static void nfs4_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
+static void nfs4_proc_read_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         data->timestamp   = jiffies;
-        data->read_done_cb = nfs4_read_done_cb;
+        data->pgio_done_cb = nfs4_read_done_cb;
         msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
         nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0);
 }
 
-static int nfs4_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs4_proc_pgio_rpc_prepare(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         if (nfs4_setup_sequence(NFS_SERVER(data->header->inode),
                         &data->args.seq_args,
@@ -4097,14 +4097,14 @@ static int nfs4_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_dat
                         task))
                 return 0;
         if (nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
-                                data->args.lock_context, FMODE_READ) == -EIO)
+                                data->args.lock_context, data->header->rw_ops->rw_mode) == -EIO)
                 return -EIO;
         if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
                 return -EIO;
         return 0;
 }
 
-static int nfs4_write_done_cb(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs4_write_done_cb(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct inode *inode = data->header->inode;
         
@@ -4121,7 +4121,7 @@ static int nfs4_write_done_cb(struct rpc_task *task, struct nfs_write_data *data
 }
 
 static bool nfs4_write_stateid_changed(struct rpc_task *task,
-                struct nfs_writeargs *args)
+                struct nfs_pgio_args *args)
 {
 
         if (!nfs4_error_stateid_expired(task->tk_status) ||
@@ -4134,18 +4134,18 @@ static bool nfs4_write_stateid_changed(struct rpc_task *task,
         return true;
 }
 
-static int nfs4_write_done(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs4_write_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         if (!nfs4_sequence_done(task, &data->res.seq_res))
                 return -EAGAIN;
         if (nfs4_write_stateid_changed(task, &data->args))
                 return -EAGAIN;
-        return data->write_done_cb ? data->write_done_cb(task, data) :
+        return data->pgio_done_cb ? data->pgio_done_cb(task, data) :
                 nfs4_write_done_cb(task, data);
 }
 
 static
-bool nfs4_write_need_cache_consistency_data(const struct nfs_write_data *data)
+bool nfs4_write_need_cache_consistency_data(const struct nfs_pgio_data *data)
 {
         const struct nfs_pgio_header *hdr = data->header;
 
@@ -4158,7 +4158,7 @@ bool nfs4_write_need_cache_consistency_data(const struct nfs_write_data *data)
         return nfs4_have_delegation(hdr->inode, FMODE_READ) == 0;
 }
 
-static void nfs4_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
+static void nfs4_proc_write_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         struct nfs_server *server = NFS_SERVER(data->header->inode);
 
@@ -4168,8 +4168,8 @@ static void nfs4_proc_write_setup(struct nfs_write_data *data, struct rpc_messag
         } else
                 data->args.bitmask = server->cache_consistency_bitmask;
 
-        if (!data->write_done_cb)
-                data->write_done_cb = nfs4_write_done_cb;
+        if (!data->pgio_done_cb)
+                data->pgio_done_cb = nfs4_write_done_cb;
         data->res.server = server;
         data->timestamp   = jiffies;
 
@@ -4177,21 +4177,6 @@ static void nfs4_proc_write_setup(struct nfs_write_data *data, struct rpc_messag
         nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1);
 }
 
-static int nfs4_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
-{
-        if (nfs4_setup_sequence(NFS_SERVER(data->header->inode),
-                        &data->args.seq_args,
-                        &data->res.seq_res,
-                        task))
-                return 0;
-        if (nfs4_set_rw_stateid(&data->args.stateid, data->args.context,
-                                data->args.lock_context, FMODE_WRITE) == -EIO)
-                return -EIO;
-        if (unlikely(test_bit(NFS_CONTEXT_BAD, &data->args.context->flags)))
-                return -EIO;
-        return 0;
-}
-
 static void nfs4_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
 {
         nfs4_setup_sequence(NFS_SERVER(data->inode),
@@ -8432,13 +8417,10 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
         .pathconf       = nfs4_proc_pathconf,
         .set_capabilities = nfs4_server_capabilities,
         .decode_dirent  = nfs4_decode_dirent,
+        .pgio_rpc_prepare = nfs4_proc_pgio_rpc_prepare,
         .read_setup     = nfs4_proc_read_setup,
-        .read_pageio_init = pnfs_pageio_init_read,
-        .read_rpc_prepare = nfs4_proc_read_rpc_prepare,
         .read_done      = nfs4_read_done,
         .write_setup    = nfs4_proc_write_setup,
-        .write_pageio_init = pnfs_pageio_init_write,
-        .write_rpc_prepare = nfs4_proc_write_rpc_prepare,
         .write_done     = nfs4_write_done,
         .commit_setup   = nfs4_proc_commit_setup,
         .commit_rpc_prepare = nfs4_proc_commit_rpc_prepare,
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index c0583b9bef71..848f6853c59e 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1456,7 +1456,7 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs
          * server that doesn't support a grace period.
          */
         spin_lock(&sp->so_lock);
-        write_seqcount_begin(&sp->so_reclaim_seqcount);
+        raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
 restart:
         list_for_each_entry(state, &sp->so_states, open_states) {
                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
@@ -1519,13 +1519,13 @@ restart:
                 spin_lock(&sp->so_lock);
                 goto restart;
         }
-        write_seqcount_end(&sp->so_reclaim_seqcount);
+        raw_write_seqcount_end(&sp->so_reclaim_seqcount);
         spin_unlock(&sp->so_lock);
         return 0;
 out_err:
         nfs4_put_open_state(state);
         spin_lock(&sp->so_lock);
-        write_seqcount_end(&sp->so_reclaim_seqcount);
+        raw_write_seqcount_end(&sp->so_reclaim_seqcount);
         spin_unlock(&sp->so_lock);
         return status;
 }
diff --git a/fs/nfs/nfs4trace.h b/fs/nfs/nfs4trace.h
index 849cf146db30..0a744f3a86f6 100644
--- a/fs/nfs/nfs4trace.h
+++ b/fs/nfs/nfs4trace.h
@@ -932,7 +932,7 @@ DEFINE_NFS4_IDMAP_EVENT(nfs4_map_gid_to_group);
 
 DECLARE_EVENT_CLASS(nfs4_read_event,
                 TP_PROTO(
-                        const struct nfs_read_data *data,
+                        const struct nfs_pgio_data *data,
                         int error
                 ),
 
@@ -972,7 +972,7 @@ DECLARE_EVENT_CLASS(nfs4_read_event,
 #define DEFINE_NFS4_READ_EVENT(name) \
         DEFINE_EVENT(nfs4_read_event, name, \
                         TP_PROTO( \
-                                const struct nfs_read_data *data, \
+                                const struct nfs_pgio_data *data, \
                                 int error \
                         ), \
                         TP_ARGS(data, error))
@@ -983,7 +983,7 @@ DEFINE_NFS4_READ_EVENT(nfs4_pnfs_read);
 
 DECLARE_EVENT_CLASS(nfs4_write_event,
                 TP_PROTO(
-                        const struct nfs_write_data *data,
+                        const struct nfs_pgio_data *data,
                         int error
                 ),
 
@@ -1024,7 +1024,7 @@ DECLARE_EVENT_CLASS(nfs4_write_event,
 #define DEFINE_NFS4_WRITE_EVENT(name) \
         DEFINE_EVENT(nfs4_write_event, name, \
                         TP_PROTO( \
-                                const struct nfs_write_data *data, \
+                                const struct nfs_pgio_data *data, \
                                 int error \
                         ), \
                         TP_ARGS(data, error))
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 73ce8d4fe2c8..939ae606cfa4 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1556,7 +1556,8 @@ static void encode_putrootfh(struct xdr_stream *xdr, struct compound_hdr *hdr)
         encode_op_hdr(xdr, OP_PUTROOTFH, decode_putrootfh_maxsz, hdr);
 }
 
-static void encode_read(struct xdr_stream *xdr, const struct nfs_readargs *args, struct compound_hdr *hdr)
+static void encode_read(struct xdr_stream *xdr, const struct nfs_pgio_args *args,
+                        struct compound_hdr *hdr)
 {
         __be32 *p;
 
@@ -1701,7 +1702,8 @@ static void encode_setclientid_confirm(struct xdr_stream *xdr, const struct nfs4
         encode_nfs4_verifier(xdr, &arg->confirm);
 }
 
-static void encode_write(struct xdr_stream *xdr, const struct nfs_writeargs *args, struct compound_hdr *hdr)
+static void encode_write(struct xdr_stream *xdr, const struct nfs_pgio_args *args,
+                         struct compound_hdr *hdr)
 {
         __be32 *p;
 
@@ -2451,7 +2453,7 @@ static void nfs4_xdr_enc_readdir(struct rpc_rqst *req, struct xdr_stream *xdr,
  * Encode a READ request
  */
 static void nfs4_xdr_enc_read(struct rpc_rqst *req, struct xdr_stream *xdr,
-                              struct nfs_readargs *args)
+                              struct nfs_pgio_args *args)
 {
         struct compound_hdr hdr = {
                 .minorversion = nfs4_xdr_minorversion(&args->seq_args),
@@ -2513,7 +2515,7 @@ static void nfs4_xdr_enc_getacl(struct rpc_rqst *req, struct xdr_stream *xdr,
  * Encode a WRITE request
  */
 static void nfs4_xdr_enc_write(struct rpc_rqst *req, struct xdr_stream *xdr,
-                               struct nfs_writeargs *args)
+                               struct nfs_pgio_args *args)
 {
         struct compound_hdr hdr = {
                 .minorversion = nfs4_xdr_minorversion(&args->seq_args),
@@ -5085,7 +5087,8 @@ static int decode_putrootfh(struct xdr_stream *xdr)
         return decode_op_hdr(xdr, OP_PUTROOTFH);
 }
 
-static int decode_read(struct xdr_stream *xdr, struct rpc_rqst *req, struct nfs_readres *res)
+static int decode_read(struct xdr_stream *xdr, struct rpc_rqst *req,
+                       struct nfs_pgio_res *res)
 {
         __be32 *p;
         uint32_t count, eof, recvd;
@@ -5339,7 +5342,7 @@ static int decode_setclientid_confirm(struct xdr_stream *xdr)
         return decode_op_hdr(xdr, OP_SETCLIENTID_CONFIRM);
 }
 
-static int decode_write(struct xdr_stream *xdr, struct nfs_writeres *res)
+static int decode_write(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 {
         __be32 *p;
         int status;
@@ -6636,7 +6639,7 @@ out:
  * Decode Read response
  */
 static int nfs4_xdr_dec_read(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
-                             struct nfs_readres *res)
+                             struct nfs_pgio_res *res)
 {
         struct compound_hdr hdr;
         int status;
@@ -6661,7 +6664,7 @@ out:
  * Decode WRITE response
  */
 static int nfs4_xdr_dec_write(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
-                              struct nfs_writeres *res)
+                              struct nfs_pgio_res *res)
 {
         struct compound_hdr hdr;
         int status;
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 5457745dd4f1..611320753db2 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -439,7 +439,7 @@ static void _read_done(struct ore_io_state *ios, void *private)
         objlayout_read_done(&objios->oir, status, objios->sync);
 }
 
-int objio_read_pagelist(struct nfs_read_data *rdata)
+int objio_read_pagelist(struct nfs_pgio_data *rdata)
 {
         struct nfs_pgio_header *hdr = rdata->header;
         struct objio_state *objios;
@@ -487,7 +487,7 @@ static void _write_done(struct ore_io_state *ios, void *private)
 static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
 {
         struct objio_state *objios = priv;
-        struct nfs_write_data *wdata = objios->oir.rpcdata;
+        struct nfs_pgio_data *wdata = objios->oir.rpcdata;
         struct address_space *mapping = wdata->header->inode->i_mapping;
         pgoff_t index = offset / PAGE_SIZE;
         struct page *page;
@@ -531,7 +531,7 @@ static const struct _ore_r4w_op _r4w_op = {
         .put_page = &__r4w_put_page,
 };
 
-int objio_write_pagelist(struct nfs_write_data *wdata, int how)
+int objio_write_pagelist(struct nfs_pgio_data *wdata, int how)
 {
         struct nfs_pgio_header *hdr = wdata->header;
         struct objio_state *objios;
@@ -564,14 +564,22 @@ int objio_write_pagelist(struct nfs_write_data *wdata, int how)
         return 0;
 }
 
-static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t objio_pg_test(struct nfs_pageio_descriptor *pgio,
                           struct nfs_page *prev, struct nfs_page *req)
 {
-        if (!pnfs_generic_pg_test(pgio, prev, req))
-                return false;
+        unsigned int size;
+
+        size = pnfs_generic_pg_test(pgio, prev, req);
+
+        if (!size || pgio->pg_count + req->wb_bytes >
+            (unsigned long)pgio->pg_layout_private)
+                return 0;
 
-        return pgio->pg_count + req->wb_bytes <=
-                        (unsigned long)pgio->pg_layout_private;
+        return min(size, req->wb_bytes);
 }
 
 static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index e4f9cbfec67b..765d3f54e986 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -53,10 +53,10 @@ objlayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
         struct objlayout *objlay;
 
         objlay = kzalloc(sizeof(struct objlayout), gfp_flags);
-        if (objlay) {
-                spin_lock_init(&objlay->lock);
-                INIT_LIST_HEAD(&objlay->err_list);
-        }
+        if (!objlay)
+                return NULL;
+        spin_lock_init(&objlay->lock);
+        INIT_LIST_HEAD(&objlay->err_list);
         dprintk("%s: Return %p\n", __func__, objlay);
         return &objlay->pnfs_layout;
 }
@@ -229,11 +229,11 @@ objlayout_io_set_result(struct objlayout_io_res *oir, unsigned index,
 static void _rpc_read_complete(struct work_struct *work)
 {
         struct rpc_task *task;
-        struct nfs_read_data *rdata;
+        struct nfs_pgio_data *rdata;
 
         dprintk("%s enter\n", __func__);
         task = container_of(work, struct rpc_task, u.tk_work);
-        rdata = container_of(task, struct nfs_read_data, task);
+        rdata = container_of(task, struct nfs_pgio_data, task);
 
         pnfs_ld_read_done(rdata);
 }
@@ -241,7 +241,7 @@ static void _rpc_read_complete(struct work_struct *work)
 void
 objlayout_read_done(struct objlayout_io_res *oir, ssize_t status, bool sync)
 {
-        struct nfs_read_data *rdata = oir->rpcdata;
+        struct nfs_pgio_data *rdata = oir->rpcdata;
 
         oir->status = rdata->task.tk_status = status;
         if (status >= 0)
@@ -266,7 +266,7 @@ objlayout_read_done(struct objlayout_io_res *oir, ssize_t status, bool sync)
  * Perform sync or async reads.
  */
 enum pnfs_try_status
-objlayout_read_pagelist(struct nfs_read_data *rdata)
+objlayout_read_pagelist(struct nfs_pgio_data *rdata)
 {
         struct nfs_pgio_header *hdr = rdata->header;
         struct inode *inode = hdr->inode;
@@ -312,11 +312,11 @@ objlayout_read_pagelist(struct nfs_read_data *rdata)
 static void _rpc_write_complete(struct work_struct *work)
 {
         struct rpc_task *task;
-        struct nfs_write_data *wdata;
+        struct nfs_pgio_data *wdata;
 
         dprintk("%s enter\n", __func__);
         task = container_of(work, struct rpc_task, u.tk_work);
-        wdata = container_of(task, struct nfs_write_data, task);
+        wdata = container_of(task, struct nfs_pgio_data, task);
 
         pnfs_ld_write_done(wdata);
 }
@@ -324,7 +324,7 @@ static void _rpc_write_complete(struct work_struct *work)
 void
 objlayout_write_done(struct objlayout_io_res *oir, ssize_t status, bool sync)
 {
-        struct nfs_write_data *wdata = oir->rpcdata;
+        struct nfs_pgio_data *wdata = oir->rpcdata;
 
         oir->status = wdata->task.tk_status = status;
         if (status >= 0) {
@@ -351,7 +351,7 @@ objlayout_write_done(struct objlayout_io_res *oir, ssize_t status, bool sync)
  * Perform sync or async writes.
  */
 enum pnfs_try_status
-objlayout_write_pagelist(struct nfs_write_data *wdata,
+objlayout_write_pagelist(struct nfs_pgio_data *wdata,
                          int how)
 {
         struct nfs_pgio_header *hdr = wdata->header;
diff --git a/fs/nfs/objlayout/objlayout.h b/fs/nfs/objlayout/objlayout.h
index 87aa1dec6120..01e041029a6c 100644
--- a/fs/nfs/objlayout/objlayout.h
+++ b/fs/nfs/objlayout/objlayout.h
@@ -119,8 +119,8 @@ extern void objio_free_lseg(struct pnfs_layout_segment *lseg);
  */
 extern void objio_free_result(struct objlayout_io_res *oir);
 
-extern int objio_read_pagelist(struct nfs_read_data *rdata);
-extern int objio_write_pagelist(struct nfs_write_data *wdata, int how);
+extern int objio_read_pagelist(struct nfs_pgio_data *rdata);
+extern int objio_write_pagelist(struct nfs_pgio_data *wdata, int how);
 
 /*
  * callback API
@@ -168,10 +168,10 @@ extern struct pnfs_layout_segment *objlayout_alloc_lseg(
 extern void objlayout_free_lseg(struct pnfs_layout_segment *);
 
 extern enum pnfs_try_status objlayout_read_pagelist(
-        struct nfs_read_data *);
+        struct nfs_pgio_data *);
 
 extern enum pnfs_try_status objlayout_write_pagelist(
-        struct nfs_write_data *,
+        struct nfs_pgio_data *,
         int how);
 
 extern void objlayout_encode_layoutcommit(
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 03ed984ab4d8..b6ee3a6ee96d 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -24,9 +24,14 @@
 #include "internal.h"
 #include "pnfs.h"
 
+#define NFSDBG_FACILITY         NFSDBG_PAGECACHE
+
 static struct kmem_cache *nfs_page_cachep;
+static const struct rpc_call_ops nfs_pgio_common_ops;
+
+static void nfs_free_request(struct nfs_page *);
 
-bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
+static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
 {
         p->npages = pagecount;
         if (pagecount <= ARRAY_SIZE(p->page_array))
@@ -133,11 +138,156 @@ nfs_iocounter_wait(struct nfs_io_counter *c)
         return __nfs_iocounter_wait(c);
 }
 
+static int nfs_wait_bit_uninterruptible(void *word)
+{
+        io_schedule();
+        return 0;
+}
+
+/*
+ * nfs_page_group_lock - lock the head of the page group
+ * @req - request in group that is to be locked
+ *
+ * this lock must be held if modifying the page group list
+ */
+void
+nfs_page_group_lock(struct nfs_page *req)
+{
+        struct nfs_page *head = req->wb_head;
+
+        WARN_ON_ONCE(head != head->wb_head);
+
+        wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
+                        nfs_wait_bit_uninterruptible,
+                        TASK_UNINTERRUPTIBLE);
+}
+
+/*
+ * nfs_page_group_unlock - unlock the head of the page group
+ * @req - request in group that is to be unlocked
+ */
+void
+nfs_page_group_unlock(struct nfs_page *req)
+{
+        struct nfs_page *head = req->wb_head;
+
+        WARN_ON_ONCE(head != head->wb_head);
+
+        smp_mb__before_atomic();
+        clear_bit(PG_HEADLOCK, &head->wb_flags);
+        smp_mb__after_atomic();
+        wake_up_bit(&head->wb_flags, PG_HEADLOCK);
+}
+
+/*
+ * nfs_page_group_sync_on_bit_locked
+ *
+ * must be called with page group lock held
+ */
+static bool
+nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
+{
+        struct nfs_page *head = req->wb_head;
+        struct nfs_page *tmp;
+
+        WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
+        WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
+
+        tmp = req->wb_this_page;
+        while (tmp != req) {
+                if (!test_bit(bit, &tmp->wb_flags))
+                        return false;
+                tmp = tmp->wb_this_page;
+        }
+
+        /* true! reset all bits */
+        tmp = req;
+        do {
+                clear_bit(bit, &tmp->wb_flags);
+                tmp = tmp->wb_this_page;
+        } while (tmp != req);
+
+        return true;
+}
+
+/*
+ * nfs_page_group_sync_on_bit - set bit on current request, but only
+ *   return true if the bit is set for all requests in page group
+ * @req - request in page group
+ * @bit - PG_* bit that is used to sync page group
+ */
+bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
+{
+        bool ret;
+
+        nfs_page_group_lock(req);
+        ret = nfs_page_group_sync_on_bit_locked(req, bit);
+        nfs_page_group_unlock(req);
+
+        return ret;
+}
+
+/*
+ * nfs_page_group_init - Initialize the page group linkage for @req
+ * @req - a new nfs request
+ * @prev - the previous request in page group, or NULL if @req is the first
+ *         or only request in the group (the head).
+ */
+static inline void
+nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
+{
+        WARN_ON_ONCE(prev == req);
+
+        if (!prev) {
+                req->wb_head = req;
+                req->wb_this_page = req;
+        } else {
+                WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
+                WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
+                req->wb_head = prev->wb_head;
+                req->wb_this_page = prev->wb_this_page;
+                prev->wb_this_page = req;
+
+                /* grab extra ref 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))
+                        kref_get(&req->wb_kref);
+        }
+}
+
+/*
+ * nfs_page_group_destroy - sync the destruction of page groups
+ * @req - request that no longer needs the page group
+ *
+ * releases the page group reference from each member once all
+ * members have called this function.
+ */
+static void
+nfs_page_group_destroy(struct kref *kref)
+{
+        struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
+        struct nfs_page *tmp, *next;
+
+        if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
+                return;
+
+        tmp = req;
+        do {
+                next = tmp->wb_this_page;
+                /* unlink and free */
+                tmp->wb_this_page = tmp;
+                tmp->wb_head = tmp;
+                nfs_free_request(tmp);
+                tmp = next;
+        } while (tmp != req);
+}
+
 /**
  * nfs_create_request - Create an NFS read/write request.
  * @ctx: open context to use
- * @inode: inode to which the request is attached
  * @page: page to write
+ * @last: last nfs request created for this page group or NULL if head
  * @offset: starting offset within the page for the write
  * @count: number of bytes to read/write
  *
@@ -146,9 +296,9 @@ nfs_iocounter_wait(struct nfs_io_counter *c)
  * User should ensure it is safe to sleep in this function.
  */
 struct nfs_page *
-nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
-                   struct page *page,
-                   unsigned int offset, unsigned int count)
+nfs_create_request(struct nfs_open_context *ctx, struct page *page,
+                   struct nfs_page *last, unsigned int offset,
+                   unsigned int count)
 {
         struct nfs_page         *req;
         struct nfs_lock_context *l_ctx;
@@ -180,6 +330,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
         req->wb_bytes   = count;
         req->wb_context = get_nfs_open_context(ctx);
         kref_init(&req->wb_kref);
+        nfs_page_group_init(req, last);
         return req;
 }
 
@@ -237,16 +388,22 @@ static void nfs_clear_request(struct nfs_page *req)
         }
 }
 
-
 /**
  * nfs_release_request - Release the count on an NFS read/write request
  * @req: request to release
  *
  * Note: Should never be called with the spinlock held!
  */
-static void nfs_free_request(struct kref *kref)
+static void nfs_free_request(struct nfs_page *req)
 {
-        struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
+        WARN_ON_ONCE(req->wb_this_page != req);
+
+        /* extra debug: make sure no sync bits are still set */
+        WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
+        WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
+        WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
+        WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
+        WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
 
         /* Release struct file and open context */
         nfs_clear_request(req);
@@ -255,13 +412,7 @@ static void nfs_free_request(struct kref *kref)
 
 void nfs_release_request(struct nfs_page *req)
 {
-        kref_put(&req->wb_kref, nfs_free_request);
-}
-
-static int nfs_wait_bit_uninterruptible(void *word)
-{
-        io_schedule();
-        return 0;
+        kref_put(&req->wb_kref, nfs_page_group_destroy);
 }
 
 /**
@@ -279,22 +430,249 @@ nfs_wait_on_request(struct nfs_page *req)
                         TASK_UNINTERRUPTIBLE);
 }
 
-bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
+/*
+ * nfs_generic_pg_test - determine if requests can be coalesced
+ * @desc: pointer to descriptor
+ * @prev: previous request in desc, or NULL
+ * @req: this request
+ *
+ * Returns zero if @req can be coalesced into @desc, otherwise it returns
+ * the size of the request.
+ */
+size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
+                           struct nfs_page *prev, struct nfs_page *req)
 {
-        /*
-         * FIXME: ideally we should be able to coalesce all requests
-         * that are not block boundary aligned, but currently this
-         * is problematic for the case of bsize < PAGE_CACHE_SIZE,
-         * since nfs_flush_multi and nfs_pagein_multi assume you
-         * can have only one struct nfs_page.
-         */
-        if (desc->pg_bsize < PAGE_SIZE)
+        if (desc->pg_count > desc->pg_bsize) {
+                /* should never happen */
+                WARN_ON_ONCE(1);
                 return 0;
+        }
 
-        return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
+        return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes);
 }
 EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
 
+static inline struct nfs_rw_header *NFS_RW_HEADER(struct nfs_pgio_header *hdr)
+{
+        return container_of(hdr, struct nfs_rw_header, header);
+}
+
+/**
+ * nfs_rw_header_alloc - Allocate a header for a read or write
+ * @ops: Read or write function vector
+ */
+struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *ops)
+{
+        struct nfs_rw_header *header = ops->rw_alloc_header();
+
+        if (header) {
+                struct nfs_pgio_header *hdr = &header->header;
+
+                INIT_LIST_HEAD(&hdr->pages);
+                spin_lock_init(&hdr->lock);
+                atomic_set(&hdr->refcnt, 0);
+                hdr->rw_ops = ops;
+        }
+        return header;
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_alloc);
+
+/*
+ * nfs_rw_header_free - Free a read or write header
+ * @hdr: The header to free
+ */
+void nfs_rw_header_free(struct nfs_pgio_header *hdr)
+{
+        hdr->rw_ops->rw_free_header(NFS_RW_HEADER(hdr));
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_free);
+
+/**
+ * nfs_pgio_data_alloc - Allocate pageio data
+ * @hdr: The header making a request
+ * @pagecount: Number of pages to create
+ */
+static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
+                                                 unsigned int pagecount)
+{
+        struct nfs_pgio_data *data, *prealloc;
+
+        prealloc = &NFS_RW_HEADER(hdr)->rpc_data;
+        if (prealloc->header == NULL)
+                data = prealloc;
+        else
+                data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                goto out;
+
+        if (nfs_pgarray_set(&data->pages, pagecount)) {
+                data->header = hdr;
+                atomic_inc(&hdr->refcnt);
+        } else {
+                if (data != prealloc)
+                        kfree(data);
+                data = NULL;
+        }
+out:
+        return data;
+}
+
+/**
+ * nfs_pgio_data_release - Properly free pageio data
+ * @data: The data to release
+ */
+void nfs_pgio_data_release(struct nfs_pgio_data *data)
+{
+        struct nfs_pgio_header *hdr = data->header;
+        struct nfs_rw_header *pageio_header = NFS_RW_HEADER(hdr);
+
+        put_nfs_open_context(data->args.context);
+        if (data->pages.pagevec != data->pages.page_array)
+                kfree(data->pages.pagevec);
+        if (data == &pageio_header->rpc_data) {
+                data->header = NULL;
+                data = NULL;
+        }
+        if (atomic_dec_and_test(&hdr->refcnt))
+                hdr->completion_ops->completion(hdr);
+        /* Note: we only free the rpc_task after callbacks are done.
+         * See the comment in rpc_free_task() for why
+         */
+        kfree(data);
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_data_release);
+
+/**
+ * nfs_pgio_rpcsetup - Set up arguments for a pageio call
+ * @data: The pageio data
+ * @count: Number of bytes to read
+ * @offset: Initial offset
+ * @how: How to commit data (writes only)
+ * @cinfo: Commit information for the call (writes only)
+ */
+static void nfs_pgio_rpcsetup(struct nfs_pgio_data *data,
+                              unsigned int count, unsigned int offset,
+                              int how, struct nfs_commit_info *cinfo)
+{
+        struct nfs_page *req = data->header->req;
+
+        /* Set up the RPC argument and reply structs
+         * NB: take care not to mess about with data->commit et al. */
+
+        data->args.fh     = NFS_FH(data->header->inode);
+        data->args.offset = req_offset(req) + offset;
+        /* pnfs_set_layoutcommit needs this */
+        data->mds_offset = data->args.offset;
+        data->args.pgbase = req->wb_pgbase + offset;
+        data->args.pages  = data->pages.pagevec;
+        data->args.count  = count;
+        data->args.context = get_nfs_open_context(req->wb_context);
+        data->args.lock_context = req->wb_lock_context;
+        data->args.stable  = NFS_UNSTABLE;
+        switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
+        case 0:
+                break;
+        case FLUSH_COND_STABLE:
+                if (nfs_reqs_to_commit(cinfo))
+                        break;
+        default:
+                data->args.stable = NFS_FILE_SYNC;
+        }
+
+        data->res.fattr   = &data->fattr;
+        data->res.count   = count;
+        data->res.eof     = 0;
+        data->res.verf    = &data->verf;
+        nfs_fattr_init(&data->fattr);
+}
+
+/**
+ * nfs_pgio_prepare - Prepare pageio data to go over the wire
+ * @task: The current task
+ * @calldata: pageio data to prepare
+ */
+static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
+{
+        struct nfs_pgio_data *data = calldata;
+        int err;
+        err = NFS_PROTO(data->header->inode)->pgio_rpc_prepare(task, data);
+        if (err)
+                rpc_exit(task, err);
+}
+
+int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_data *data,
+                      const struct rpc_call_ops *call_ops, int how, int flags)
+{
+        struct rpc_task *task;
+        struct rpc_message msg = {
+                .rpc_argp = &data->args,
+                .rpc_resp = &data->res,
+                .rpc_cred = data->header->cred,
+        };
+        struct rpc_task_setup task_setup_data = {
+                .rpc_client = clnt,
+                .task = &data->task,
+                .rpc_message = &msg,
+                .callback_ops = call_ops,
+                .callback_data = data,
+                .workqueue = nfsiod_workqueue,
+                .flags = RPC_TASK_ASYNC | flags,
+        };
+        int ret = 0;
+
+        data->header->rw_ops->rw_initiate(data, &msg, &task_setup_data, how);
+
+        dprintk("NFS: %5u initiated pgio call "
+                "(req %s/%llu, %u bytes @ offset %llu)\n",
+                data->task.tk_pid,
+                data->header->inode->i_sb->s_id,
+                (unsigned long long)NFS_FILEID(data->header->inode),
+                data->args.count,
+                (unsigned long long)data->args.offset);
+
+        task = rpc_run_task(&task_setup_data);
+        if (IS_ERR(task)) {
+                ret = PTR_ERR(task);
+                goto out;
+        }
+        if (how & FLUSH_SYNC) {
+                ret = rpc_wait_for_completion_task(task);
+                if (ret == 0)
+                        ret = task->tk_status;
+        }
+        rpc_put_task(task);
+out:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
+
+/**
+ * nfs_pgio_error - Clean up from a pageio error
+ * @desc: IO descriptor
+ * @hdr: pageio header
+ */
+static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
+                          struct nfs_pgio_header *hdr)
+{
+        set_bit(NFS_IOHDR_REDO, &hdr->flags);
+        nfs_pgio_data_release(hdr->data);
+        hdr->data = NULL;
+        desc->pg_completion_ops->error_cleanup(&desc->pg_list);
+        return -ENOMEM;
+}
+
+/**
+ * nfs_pgio_release - Release pageio data
+ * @calldata: The pageio data to release
+ */
+static void nfs_pgio_release(void *calldata)
+{
+        struct nfs_pgio_data *data = calldata;
+        if (data->header->rw_ops->rw_release)
+                data->header->rw_ops->rw_release(data);
+        nfs_pgio_data_release(data);
+}
+
 /**
  * nfs_pageio_init - initialise a page io descriptor
  * @desc: pointer to descriptor
@@ -307,6 +685,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
                      struct inode *inode,
                      const struct nfs_pageio_ops *pg_ops,
                      const struct nfs_pgio_completion_ops *compl_ops,
+                     const struct nfs_rw_ops *rw_ops,
                      size_t bsize,
                      int io_flags)
 {
@@ -320,6 +699,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
         desc->pg_inode = inode;
         desc->pg_ops = pg_ops;
         desc->pg_completion_ops = compl_ops;
+        desc->pg_rw_ops = rw_ops;
         desc->pg_ioflags = io_flags;
         desc->pg_error = 0;
         desc->pg_lseg = NULL;
@@ -328,6 +708,94 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init);
 
+/**
+ * nfs_pgio_result - Basic pageio error handling
+ * @task: The task that ran
+ * @calldata: Pageio data to check
+ */
+static void nfs_pgio_result(struct rpc_task *task, void *calldata)
+{
+        struct nfs_pgio_data *data = calldata;
+        struct inode *inode = data->header->inode;
+
+        dprintk("NFS: %s: %5u, (status %d)\n", __func__,
+                task->tk_pid, task->tk_status);
+
+        if (data->header->rw_ops->rw_done(task, data, inode) != 0)
+                return;
+        if (task->tk_status < 0)
+                nfs_set_pgio_error(data->header, task->tk_status, data->args.offset);
+        else
+                data->header->rw_ops->rw_result(task, data);
+}
+
+/*
+ * Create an RPC task for the given read or write request and kick it.
+ * The page must have been locked by the caller.
+ *
+ * It may happen that the page we're passed is not marked dirty.
+ * This is the case if nfs_updatepage detects a conflicting request
+ * that has been written but not committed.
+ */
+int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
+                     struct nfs_pgio_header *hdr)
+{
+        struct nfs_page         *req;
+        struct page             **pages;
+        struct nfs_pgio_data    *data;
+        struct list_head *head = &desc->pg_list;
+        struct nfs_commit_info cinfo;
+
+        data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base,
+                                                           desc->pg_count));
+        if (!data)
+                return nfs_pgio_error(desc, hdr);
+
+        nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
+        pages = data->pages.pagevec;
+        while (!list_empty(head)) {
+                req = nfs_list_entry(head->next);
+                nfs_list_remove_request(req);
+                nfs_list_add_request(req, &hdr->pages);
+                *pages++ = req->wb_page;
+        }
+
+        if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
+            (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
+                desc->pg_ioflags &= ~FLUSH_COND_STABLE;
+
+        /* Set up the argument struct */
+        nfs_pgio_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
+        hdr->data = data;
+        desc->pg_rpc_callops = &nfs_pgio_common_ops;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pgio);
+
+static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
+{
+        struct nfs_rw_header *rw_hdr;
+        struct nfs_pgio_header *hdr;
+        int ret;
+
+        rw_hdr = nfs_rw_header_alloc(desc->pg_rw_ops);
+        if (!rw_hdr) {
+                desc->pg_completion_ops->error_cleanup(&desc->pg_list);
+                return -ENOMEM;
+        }
+        hdr = &rw_hdr->header;
+        nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
+        atomic_inc(&hdr->refcnt);
+        ret = nfs_generic_pgio(desc, hdr);
+        if (ret == 0)
+                ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
+                                        hdr->data, desc->pg_rpc_callops,
+                                        desc->pg_ioflags, 0);
+        if (atomic_dec_and_test(&hdr->refcnt))
+                hdr->completion_ops->completion(hdr);
+        return ret;
+}
+
 static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
                 const struct nfs_open_context *ctx2)
 {
@@ -356,18 +824,23 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
                                       struct nfs_page *req,
                                       struct nfs_pageio_descriptor *pgio)
 {
-        if (!nfs_match_open_context(req->wb_context, prev->wb_context))
-                return false;
-        if (req->wb_context->dentry->d_inode->i_flock != NULL &&
-            !nfs_match_lock_context(req->wb_lock_context, prev->wb_lock_context))
-                return false;
-        if (req->wb_pgbase != 0)
-                return false;
-        if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
-                return false;
-        if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
-                return false;
-        return pgio->pg_ops->pg_test(pgio, prev, req);
+        size_t size;
+
+        if (prev) {
+                if (!nfs_match_open_context(req->wb_context, prev->wb_context))
+                        return false;
+                if (req->wb_context->dentry->d_inode->i_flock != NULL &&
+                    !nfs_match_lock_context(req->wb_lock_context,
+                                            prev->wb_lock_context))
+                        return false;
+                if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+                        return false;
+        }
+        size = pgio->pg_ops->pg_test(pgio, prev, req);
+        WARN_ON_ONCE(size > req->wb_bytes);
+        if (size && size < req->wb_bytes)
+                req->wb_bytes = size;
+        return size > 0;
 }
 
 /**
@@ -381,17 +854,16 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
 static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
                                      struct nfs_page *req)
 {
+        struct nfs_page *prev = NULL;
         if (desc->pg_count != 0) {
-                struct nfs_page *prev;
-
                 prev = nfs_list_entry(desc->pg_list.prev);
-                if (!nfs_can_coalesce_requests(prev, req, desc))
-                        return 0;
         } else {
                 if (desc->pg_ops->pg_init)
                         desc->pg_ops->pg_init(desc, req);
                 desc->pg_base = req->wb_pgbase;
         }
+        if (!nfs_can_coalesce_requests(prev, req, desc))
+                return 0;
         nfs_list_remove_request(req);
         nfs_list_add_request(req, &desc->pg_list);
         desc->pg_count += req->wb_bytes;
@@ -421,22 +893,73 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
  * @desc: destination io descriptor
  * @req: request
  *
+ * This may split a request into subrequests which are all part of the
+ * same page group.
+ *
  * Returns true if the request 'req' was successfully coalesced into the
  * existing list of pages 'desc'.
  */
 static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
                            struct nfs_page *req)
 {
-        while (!nfs_pageio_do_add_request(desc, req)) {
-                desc->pg_moreio = 1;
-                nfs_pageio_doio(desc);
-                if (desc->pg_error < 0)
-                        return 0;
-                desc->pg_moreio = 0;
-                if (desc->pg_recoalesce)
-                        return 0;
-        }
+        struct nfs_page *subreq;
+        unsigned int bytes_left = 0;
+        unsigned int offset, pgbase;
+
+        nfs_page_group_lock(req);
+
+        subreq = req;
+        bytes_left = subreq->wb_bytes;
+        offset = subreq->wb_offset;
+        pgbase = subreq->wb_pgbase;
+
+        do {
+                if (!nfs_pageio_do_add_request(desc, subreq)) {
+                        /* make sure pg_test call(s) did nothing */
+                        WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
+                        WARN_ON_ONCE(subreq->wb_offset != offset);
+                        WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
+
+                        nfs_page_group_unlock(req);
+                        desc->pg_moreio = 1;
+                        nfs_pageio_doio(desc);
+                        if (desc->pg_error < 0)
+                                return 0;
+                        desc->pg_moreio = 0;
+                        if (desc->pg_recoalesce)
+                                return 0;
+                        /* retry add_request for this subreq */
+                        nfs_page_group_lock(req);
+                        continue;
+                }
+
+                /* check for buggy pg_test call(s) */
+                WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
+                WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
+                WARN_ON_ONCE(subreq->wb_bytes == 0);
+
+                bytes_left -= subreq->wb_bytes;
+                offset += subreq->wb_bytes;
+                pgbase += subreq->wb_bytes;
+
+                if (bytes_left) {
+                        subreq = nfs_create_request(req->wb_context,
+                                        req->wb_page,
+                                        subreq, pgbase, bytes_left);
+                        if (IS_ERR(subreq))
+                                goto err_ptr;
+                        nfs_lock_request(subreq);
+                        subreq->wb_offset  = offset;
+                        subreq->wb_index = req->wb_index;
+                }
+        } while (bytes_left > 0);
+
+        nfs_page_group_unlock(req);
         return 1;
+err_ptr:
+        desc->pg_error = PTR_ERR(subreq);
+        nfs_page_group_unlock(req);
+        return 0;
 }
 
 static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
@@ -535,3 +1058,13 @@ void nfs_destroy_nfspagecache(void)
         kmem_cache_destroy(nfs_page_cachep);
 }
 
+static const struct rpc_call_ops nfs_pgio_common_ops = {
+        .rpc_call_prepare = nfs_pgio_prepare,
+        .rpc_call_done = nfs_pgio_result,
+        .rpc_release = nfs_pgio_release,
+};
+
+const struct nfs_pageio_ops nfs_pgio_rw_ops = {
+        .pg_test = nfs_generic_pg_test,
+        .pg_doio = nfs_generic_pg_pgios,
+};
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index fd9536e494bc..6fdcd233d6f7 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1388,11 +1388,6 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
 
         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-        if (req->wb_offset != req->wb_pgbase) {
-                nfs_pageio_reset_read_mds(pgio);
-                return;
-        }
-
         if (pgio->pg_dreq == NULL)
                 rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
         else
@@ -1417,11 +1412,6 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 {
         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-        if (req->wb_offset != req->wb_pgbase) {
-                nfs_pageio_reset_write_mds(pgio);
-                return;
-        }
-
         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                            req->wb_context,
                                            req_offset(req),
@@ -1434,56 +1424,49 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
 
-void
-pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
-                      const struct nfs_pgio_completion_ops *compl_ops)
-{
-        struct nfs_server *server = NFS_SERVER(inode);
-        struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
-
-        if (ld == NULL)
-                nfs_pageio_init_read(pgio, inode, compl_ops);
-        else
-                nfs_pageio_init(pgio, inode, ld->pg_read_ops, compl_ops, server->rsize, 0);
-}
-
-void
-pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode,
-                       int ioflags,
-                       const struct nfs_pgio_completion_ops *compl_ops)
-{
-        struct nfs_server *server = NFS_SERVER(inode);
-        struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
-
-        if (ld == NULL)
-                nfs_pageio_init_write(pgio, inode, ioflags, compl_ops);
-        else
-                nfs_pageio_init(pgio, inode, ld->pg_write_ops, compl_ops, server->wsize, ioflags);
-}
-
-bool
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+size_t
 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                      struct nfs_page *req)
 {
-        if (pgio->pg_lseg == NULL)
-                return nfs_generic_pg_test(pgio, prev, req);
+        unsigned int size;
+        u64 seg_end, req_start, seg_left;
+
+        size = nfs_generic_pg_test(pgio, prev, req);
+        if (!size)
+                return 0;
 
         /*
-         * Test if a nfs_page is fully contained in the pnfs_layout_range.
-         * Note that this test makes several assumptions:
-         * - that the previous nfs_page in the struct nfs_pageio_descriptor
-         *   is known to lie within the range.
-         *   - that the nfs_page being tested is known to be contiguous with the
-         *   previous nfs_page.
-         *   - Layout ranges are page aligned, so we only have to test the
-         *   start offset of the request.
+         * 'size' contains the number of bytes left in the current page (up
+         * to the original size asked for in @req->wb_bytes).
+         *
+         * Calculate how many bytes are left in the layout segment
+         * and if there are less bytes than 'size', return that instead.
          *
          * Please also note that 'end_offset' is actually the offset of the
          * first byte that lies outside the pnfs_layout_range. FIXME?
          *
          */
-        return req_offset(req) < end_offset(pgio->pg_lseg->pls_range.offset,
-                                         pgio->pg_lseg->pls_range.length);
+        if (pgio->pg_lseg) {
+                seg_end = end_offset(pgio->pg_lseg->pls_range.offset,
+                                     pgio->pg_lseg->pls_range.length);
+                req_start = req_offset(req);
+                WARN_ON_ONCE(req_start > seg_end);
+                /* start of request is past the last byte of this segment */
+                if (req_start >= seg_end)
+                        return 0;
+
+                /* adjust 'size' iff there are fewer bytes left in the
+                 * segment than what nfs_generic_pg_test returned */
+                seg_left = seg_end - req_start;
+                if (seg_left < size)
+                        size = (unsigned int)seg_left;
+        }
+
+        return size;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
 
@@ -1496,7 +1479,7 @@ int pnfs_write_done_resend_to_mds(struct inode *inode,
         LIST_HEAD(failed);
 
         /* Resend all requests through the MDS */
-        nfs_pageio_init_write(&pgio, inode, FLUSH_STABLE, compl_ops);
+        nfs_pageio_init_write(&pgio, inode, FLUSH_STABLE, true, compl_ops);
         pgio.pg_dreq = dreq;
         while (!list_empty(head)) {
                 struct nfs_page *req = nfs_list_entry(head->next);
@@ -1519,7 +1502,7 @@ int pnfs_write_done_resend_to_mds(struct inode *inode,
 }
 EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
 
-static void pnfs_ld_handle_write_error(struct nfs_write_data *data)
+static void pnfs_ld_handle_write_error(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1538,7 +1521,7 @@ static void pnfs_ld_handle_write_error(struct nfs_write_data *data)
 /*
  * Called by non rpc-based layout drivers
  */
-void pnfs_ld_write_done(struct nfs_write_data *data)
+void pnfs_ld_write_done(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1554,7 +1537,7 @@ EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
 
 static void
 pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
-                struct nfs_write_data *data)
+                struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1563,11 +1546,11 @@ pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
                 nfs_pageio_reset_write_mds(desc);
                 desc->pg_recoalesce = 1;
         }
-        nfs_writedata_release(data);
+        nfs_pgio_data_release(data);
 }
 
 static enum pnfs_try_status
-pnfs_try_to_write_data(struct nfs_write_data *wdata,
+pnfs_try_to_write_data(struct nfs_pgio_data *wdata,
                         const struct rpc_call_ops *call_ops,
                         struct pnfs_layout_segment *lseg,
                         int how)
@@ -1589,41 +1572,36 @@ pnfs_try_to_write_data(struct nfs_write_data *wdata,
 }
 
 static void
-pnfs_do_multiple_writes(struct nfs_pageio_descriptor *desc, struct list_head *head, int how)
+pnfs_do_write(struct nfs_pageio_descriptor *desc,
+              struct nfs_pgio_header *hdr, int how)
 {
-        struct nfs_write_data *data;
+        struct nfs_pgio_data *data = hdr->data;
         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
         struct pnfs_layout_segment *lseg = desc->pg_lseg;
+        enum pnfs_try_status trypnfs;
 
         desc->pg_lseg = NULL;
-        while (!list_empty(head)) {
-                enum pnfs_try_status trypnfs;
-
-                data = list_first_entry(head, struct nfs_write_data, list);
-                list_del_init(&data->list);
-
-                trypnfs = pnfs_try_to_write_data(data, call_ops, lseg, how);
-                if (trypnfs == PNFS_NOT_ATTEMPTED)
-                        pnfs_write_through_mds(desc, data);
-        }
+        trypnfs = pnfs_try_to_write_data(data, call_ops, lseg, how);
+        if (trypnfs == PNFS_NOT_ATTEMPTED)
+                pnfs_write_through_mds(desc, data);
         pnfs_put_lseg(lseg);
 }
 
 static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
 {
         pnfs_put_lseg(hdr->lseg);
-        nfs_writehdr_free(hdr);
+        nfs_rw_header_free(hdr);
 }
 EXPORT_SYMBOL_GPL(pnfs_writehdr_free);
 
 int
 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 {
-        struct nfs_write_header *whdr;
+        struct nfs_rw_header *whdr;
         struct nfs_pgio_header *hdr;
         int ret;
 
-        whdr = nfs_writehdr_alloc();
+        whdr = nfs_rw_header_alloc(desc->pg_rw_ops);
         if (!whdr) {
                 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
                 pnfs_put_lseg(desc->pg_lseg);
@@ -1634,12 +1612,12 @@ pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
         nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
         atomic_inc(&hdr->refcnt);
-        ret = nfs_generic_flush(desc, hdr);
+        ret = nfs_generic_pgio(desc, hdr);
         if (ret != 0) {
                 pnfs_put_lseg(desc->pg_lseg);
                 desc->pg_lseg = NULL;
         } else
-                pnfs_do_multiple_writes(desc, &hdr->rpc_list, desc->pg_ioflags);
+                pnfs_do_write(desc, hdr, desc->pg_ioflags);
         if (atomic_dec_and_test(&hdr->refcnt))
                 hdr->completion_ops->completion(hdr);
         return ret;
@@ -1655,7 +1633,7 @@ int pnfs_read_done_resend_to_mds(struct inode *inode,
         LIST_HEAD(failed);
 
         /* Resend all requests through the MDS */
-        nfs_pageio_init_read(&pgio, inode, compl_ops);
+        nfs_pageio_init_read(&pgio, inode, true, compl_ops);
         pgio.pg_dreq = dreq;
         while (!list_empty(head)) {
                 struct nfs_page *req = nfs_list_entry(head->next);
@@ -1674,7 +1652,7 @@ int pnfs_read_done_resend_to_mds(struct inode *inode,
 }
 EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
 
-static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
+static void pnfs_ld_handle_read_error(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1693,7 +1671,7 @@ static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
 /*
  * Called by non rpc-based layout drivers
  */
-void pnfs_ld_read_done(struct nfs_read_data *data)
+void pnfs_ld_read_done(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1709,7 +1687,7 @@ EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
 
 static void
 pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
-                struct nfs_read_data *data)
+                struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
 
@@ -1718,14 +1696,14 @@ pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
                 nfs_pageio_reset_read_mds(desc);
                 desc->pg_recoalesce = 1;
         }
-        nfs_readdata_release(data);
+        nfs_pgio_data_release(data);
 }
 
 /*
  * Call the appropriate parallel I/O subsystem read function.
  */
 static enum pnfs_try_status
-pnfs_try_to_read_data(struct nfs_read_data *rdata,
+pnfs_try_to_read_data(struct nfs_pgio_data *rdata,
                        const struct rpc_call_ops *call_ops,
                        struct pnfs_layout_segment *lseg)
 {
@@ -1747,41 +1725,35 @@ pnfs_try_to_read_data(struct nfs_read_data *rdata,
 }
 
 static void
-pnfs_do_multiple_reads(struct nfs_pageio_descriptor *desc, struct list_head *head)
+pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
 {
-        struct nfs_read_data *data;
+        struct nfs_pgio_data *data = hdr->data;
         const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
         struct pnfs_layout_segment *lseg = desc->pg_lseg;
+        enum pnfs_try_status trypnfs;
 
         desc->pg_lseg = NULL;
-        while (!list_empty(head)) {
-                enum pnfs_try_status trypnfs;
-
-                data = list_first_entry(head, struct nfs_read_data, list);
-                list_del_init(&data->list);
-
-                trypnfs = pnfs_try_to_read_data(data, call_ops, lseg);
-                if (trypnfs == PNFS_NOT_ATTEMPTED)
-                        pnfs_read_through_mds(desc, data);
-        }
+        trypnfs = pnfs_try_to_read_data(data, call_ops, lseg);
+        if (trypnfs == PNFS_NOT_ATTEMPTED)
+                pnfs_read_through_mds(desc, data);
         pnfs_put_lseg(lseg);
 }
 
 static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
 {
         pnfs_put_lseg(hdr->lseg);
-        nfs_readhdr_free(hdr);
+        nfs_rw_header_free(hdr);
 }
 EXPORT_SYMBOL_GPL(pnfs_readhdr_free);
 
 int
 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 {
-        struct nfs_read_header *rhdr;
+        struct nfs_rw_header *rhdr;
         struct nfs_pgio_header *hdr;
         int ret;
 
-        rhdr = nfs_readhdr_alloc();
+        rhdr = nfs_rw_header_alloc(desc->pg_rw_ops);
         if (!rhdr) {
                 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
                 ret = -ENOMEM;
@@ -1793,12 +1765,12 @@ pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
         nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
         hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
         atomic_inc(&hdr->refcnt);
-        ret = nfs_generic_pagein(desc, hdr);
+        ret = nfs_generic_pgio(desc, hdr);
         if (ret != 0) {
                 pnfs_put_lseg(desc->pg_lseg);
                 desc->pg_lseg = NULL;
         } else
-                pnfs_do_multiple_reads(desc, &hdr->rpc_list);
+                pnfs_do_read(desc, hdr);
         if (atomic_dec_and_test(&hdr->refcnt))
                 hdr->completion_ops->completion(hdr);
         return ret;
@@ -1848,7 +1820,7 @@ void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
 EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
 
 void
-pnfs_set_layoutcommit(struct nfs_write_data *wdata)
+pnfs_set_layoutcommit(struct nfs_pgio_data *wdata)
 {
         struct nfs_pgio_header *hdr = wdata->header;
         struct inode *inode = hdr->inode;
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index c3058a076596..4fb309a2b4c4 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -113,8 +113,8 @@ struct pnfs_layoutdriver_type {
          * Return PNFS_ATTEMPTED to indicate the layout code has attempted
          * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
          */
-        enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
-        enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);
+        enum pnfs_try_status (*read_pagelist) (struct nfs_pgio_data *nfs_data);
+        enum pnfs_try_status (*write_pagelist) (struct nfs_pgio_data *nfs_data, int how);
 
         void (*free_deviceid_node) (struct nfs4_deviceid_node *);
 
@@ -180,11 +180,6 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
 void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
 
-void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *,
-                           const struct nfs_pgio_completion_ops *);
-void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *,
-                            int, const struct nfs_pgio_completion_ops *);
-
 void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
 void unset_pnfs_layoutdriver(struct nfs_server *);
 void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
@@ -192,7 +187,8 @@ int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
 void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
                                 struct nfs_page *req, u64 wb_size);
 int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
-bool pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, struct nfs_page *req);
+size_t pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
+                            struct nfs_page *prev, struct nfs_page *req);
 void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg);
 struct pnfs_layout_segment *pnfs_layout_process(struct nfs4_layoutget *lgp);
 void pnfs_free_lseg_list(struct list_head *tmp_list);
@@ -217,13 +213,13 @@ bool pnfs_roc(struct inode *ino);
 void pnfs_roc_release(struct inode *ino);
 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
 bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task);
-void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
+void pnfs_set_layoutcommit(struct nfs_pgio_data *wdata);
 void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data);
 int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
 int _pnfs_return_layout(struct inode *);
 int pnfs_commit_and_return_layout(struct inode *);
-void pnfs_ld_write_done(struct nfs_write_data *);
-void pnfs_ld_read_done(struct nfs_read_data *);
+void pnfs_ld_write_done(struct nfs_pgio_data *);
+void pnfs_ld_read_done(struct nfs_pgio_data *);
 struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
                                                struct nfs_open_context *ctx,
                                                loff_t pos,
@@ -461,18 +457,6 @@ static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 {
 }
 
-static inline void pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
-                                         const struct nfs_pgio_completion_ops *compl_ops)
-{
-        nfs_pageio_init_read(pgio, inode, compl_ops);
-}
-
-static inline void pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags,
-                                          const struct nfs_pgio_completion_ops *compl_ops)
-{
-        nfs_pageio_init_write(pgio, inode, ioflags, compl_ops);
-}
-
 static inline int
 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
                  struct nfs_commit_info *cinfo)
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index e55ce9e8b034..c171ce1a8a30 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -578,7 +578,7 @@ nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
         return 0;
 }
 
-static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs_read_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct inode *inode = data->header->inode;
 
@@ -594,18 +594,18 @@ static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
         return 0;
 }
 
-static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
+static void nfs_proc_read_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
 }
 
-static int nfs_proc_read_rpc_prepare(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs_proc_pgio_rpc_prepare(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         rpc_call_start(task);
         return 0;
 }
 
-static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs_write_done(struct rpc_task *task, struct nfs_pgio_data *data)
 {
         struct inode *inode = data->header->inode;
 
@@ -614,19 +614,13 @@ static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
         return 0;
 }
 
-static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
+static void nfs_proc_write_setup(struct nfs_pgio_data *data, struct rpc_message *msg)
 {
         /* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
         data->args.stable = NFS_FILE_SYNC;
         msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
 }
 
-static int nfs_proc_write_rpc_prepare(struct rpc_task *task, struct nfs_write_data *data)
-{
-        rpc_call_start(task);
-        return 0;
-}
-
 static void nfs_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
 {
         BUG();
@@ -734,13 +728,10 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
         .fsinfo         = nfs_proc_fsinfo,
         .pathconf       = nfs_proc_pathconf,
         .decode_dirent  = nfs2_decode_dirent,
+        .pgio_rpc_prepare = nfs_proc_pgio_rpc_prepare,
         .read_setup     = nfs_proc_read_setup,
-        .read_pageio_init = nfs_pageio_init_read,
-        .read_rpc_prepare = nfs_proc_read_rpc_prepare,
         .read_done      = nfs_read_done,
         .write_setup    = nfs_proc_write_setup,
-        .write_pageio_init = nfs_pageio_init_write,
-        .write_rpc_prepare = nfs_proc_write_rpc_prepare,
         .write_done     = nfs_write_done,
         .commit_setup   = nfs_proc_commit_setup,
         .commit_rpc_prepare = nfs_proc_commit_rpc_prepare,
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 411aedda14bb..e818a475ca64 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -24,85 +24,24 @@
 #include "internal.h"
 #include "iostat.h"
 #include "fscache.h"
+#include "pnfs.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PAGECACHE
 
-static const struct nfs_pageio_ops nfs_pageio_read_ops;
-static const struct rpc_call_ops nfs_read_common_ops;
 static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
+static const struct nfs_rw_ops nfs_rw_read_ops;
 
 static struct kmem_cache *nfs_rdata_cachep;
 
-struct nfs_read_header *nfs_readhdr_alloc(void)
+static struct nfs_rw_header *nfs_readhdr_alloc(void)
 {
-        struct nfs_read_header *rhdr;
-
-        rhdr = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
-        if (rhdr) {
-                struct nfs_pgio_header *hdr = &rhdr->header;
-
-                INIT_LIST_HEAD(&hdr->pages);
-                INIT_LIST_HEAD(&hdr->rpc_list);
-                spin_lock_init(&hdr->lock);
-                atomic_set(&hdr->refcnt, 0);
-        }
-        return rhdr;
+        return kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
 }
-EXPORT_SYMBOL_GPL(nfs_readhdr_alloc);
 
-static struct nfs_read_data *nfs_readdata_alloc(struct nfs_pgio_header *hdr,
-                                                unsigned int pagecount)
+static void nfs_readhdr_free(struct nfs_rw_header *rhdr)
 {
-        struct nfs_read_data *data, *prealloc;
-
-        prealloc = &container_of(hdr, struct nfs_read_header, header)->rpc_data;
-        if (prealloc->header == NULL)
-                data = prealloc;
-        else
-                data = kzalloc(sizeof(*data), GFP_KERNEL);
-        if (!data)
-                goto out;
-
-        if (nfs_pgarray_set(&data->pages, pagecount)) {
-                data->header = hdr;
-                atomic_inc(&hdr->refcnt);
-        } else {
-                if (data != prealloc)
-                        kfree(data);
-                data = NULL;
-        }
-out:
-        return data;
-}
-
-void nfs_readhdr_free(struct nfs_pgio_header *hdr)
-{
-        struct nfs_read_header *rhdr = container_of(hdr, struct nfs_read_header, header);
-
         kmem_cache_free(nfs_rdata_cachep, rhdr);
 }
-EXPORT_SYMBOL_GPL(nfs_readhdr_free);
-
-void nfs_readdata_release(struct nfs_read_data *rdata)
-{
-        struct nfs_pgio_header *hdr = rdata->header;
-        struct nfs_read_header *read_header = container_of(hdr, struct nfs_read_header, header);
-
-        put_nfs_open_context(rdata->args.context);
-        if (rdata->pages.pagevec != rdata->pages.page_array)
-                kfree(rdata->pages.pagevec);
-        if (rdata == &read_header->rpc_data) {
-                rdata->header = NULL;
-                rdata = NULL;
-        }
-        if (atomic_dec_and_test(&hdr->refcnt))
-                hdr->completion_ops->completion(hdr);
-        /* Note: we only free the rpc_task after callbacks are done.
-         * See the comment in rpc_free_task() for why
-         */
-        kfree(rdata);
-}
-EXPORT_SYMBOL_GPL(nfs_readdata_release);
 
 static
 int nfs_return_empty_page(struct page *page)
@@ -114,17 +53,24 @@ int nfs_return_empty_page(struct page *page)
 }
 
 void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
-                              struct inode *inode,
+                              struct inode *inode, bool force_mds,
                               const struct nfs_pgio_completion_ops *compl_ops)
 {
-        nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, compl_ops,
-                        NFS_SERVER(inode)->rsize, 0);
+        struct nfs_server *server = NFS_SERVER(inode);
+        const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
+
+#ifdef CONFIG_NFS_V4_1
+        if (server->pnfs_curr_ld && !force_mds)
+                pg_ops = server->pnfs_curr_ld->pg_read_ops;
+#endif
+        nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_read_ops,
+                        server->rsize, 0);
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
 
 void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
 {
-        pgio->pg_ops = &nfs_pageio_read_ops;
+        pgio->pg_ops = &nfs_pgio_rw_ops;
         pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
@@ -139,7 +85,7 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
         len = nfs_page_length(page);
         if (len == 0)
                 return nfs_return_empty_page(page);
-        new = nfs_create_request(ctx, inode, page, 0, len);
+        new = nfs_create_request(ctx, page, NULL, 0, len);
         if (IS_ERR(new)) {
                 unlock_page(page);
                 return PTR_ERR(new);
@@ -147,7 +93,8 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
         if (len < PAGE_CACHE_SIZE)
                 zero_user_segment(page, len, PAGE_CACHE_SIZE);
 
-        NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
+        nfs_pageio_init_read(&pgio, inode, false,
+                             &nfs_async_read_completion_ops);
         nfs_pageio_add_request(&pgio, new);
         nfs_pageio_complete(&pgio);
         NFS_I(inode)->read_io += pgio.pg_bytes_written;
@@ -158,10 +105,16 @@ static void nfs_readpage_release(struct nfs_page *req)
 {
         struct inode *d_inode = req->wb_context->dentry->d_inode;
 
-        if (PageUptodate(req->wb_page))
-                nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
+        dprintk("NFS: read done (%s/%llu %d@%lld)\n", d_inode->i_sb->s_id,
+                (unsigned long long)NFS_FILEID(d_inode), req->wb_bytes,
+                (long long)req_offset(req));
 
-        unlock_page(req->wb_page);
+        if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
+                if (PageUptodate(req->wb_page))
+                        nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
+
+                unlock_page(req->wb_page);
+        }
 
         dprintk("NFS: read done (%s/%Lu %d@%Ld)\n",
                         req->wb_context->dentry->d_inode->i_sb->s_id,
@@ -171,7 +124,12 @@ static void nfs_readpage_release(struct nfs_page *req)
         nfs_release_request(req);
 }
 
-/* Note io was page aligned */
+static void nfs_page_group_set_uptodate(struct nfs_page *req)
+{
+        if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
+                SetPageUptodate(req->wb_page);
+}
+
 static void nfs_read_completion(struct nfs_pgio_header *hdr)
 {
         unsigned long bytes = 0;
@@ -181,21 +139,32 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
         while (!list_empty(&hdr->pages)) {
                 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
                 struct page *page = req->wb_page;
+                unsigned long start = req->wb_pgbase;
+                unsigned long end = req->wb_pgbase + req->wb_bytes;
 
                 if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
-                        if (bytes > hdr->good_bytes)
-                                zero_user(page, 0, PAGE_SIZE);
-                        else if (hdr->good_bytes - bytes < PAGE_SIZE)
-                                zero_user_segment(page,
-                                        hdr->good_bytes & ~PAGE_MASK,
-                                        PAGE_SIZE);
+                        /* note: regions of the page not covered by a
+                         * request are zeroed in nfs_readpage_async /
+                         * readpage_async_filler */
+                        if (bytes > hdr->good_bytes) {
+                                /* nothing in this request was good, so zero
+                                 * the full extent of the request */
+                                zero_user_segment(page, start, end);
+
+                        } else if (hdr->good_bytes - bytes < req->wb_bytes) {
+                                /* part of this request has good bytes, but
+                                 * not all. zero the bad bytes */
+                                start += hdr->good_bytes - bytes;
+                                WARN_ON(start < req->wb_pgbase);
+                                zero_user_segment(page, start, end);
+                        }
                 }
                 bytes += req->wb_bytes;
                 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
                         if (bytes <= hdr->good_bytes)
-                                SetPageUptodate(page);
+                                nfs_page_group_set_uptodate(req);
                 } else
-                        SetPageUptodate(page);
+                        nfs_page_group_set_uptodate(req);
                 nfs_list_remove_request(req);
                 nfs_readpage_release(req);
         }
@@ -203,95 +172,14 @@ out:
         hdr->release(hdr);
 }
 
-int nfs_initiate_read(struct rpc_clnt *clnt,
-                      struct nfs_read_data *data,
-                      const struct rpc_call_ops *call_ops, int flags)
+static void nfs_initiate_read(struct nfs_pgio_data *data, struct rpc_message *msg,
+                              struct rpc_task_setup *task_setup_data, int how)
 {
         struct inode *inode = data->header->inode;
         int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
-        struct rpc_task *task;
-        struct rpc_message msg = {
-                .rpc_argp = &data->args,
-                .rpc_resp = &data->res,
-                .rpc_cred = data->header->cred,
-        };
-        struct rpc_task_setup task_setup_data = {
-                .task = &data->task,
-                .rpc_client = clnt,
-                .rpc_message = &msg,
-                .callback_ops = call_ops,
-                .callback_data = data,
-                .workqueue = nfsiod_workqueue,
-                .flags = RPC_TASK_ASYNC | swap_flags | flags,
-        };
 
-        /* Set up the initial task struct. */
-        NFS_PROTO(inode)->read_setup(data, &msg);
-
-        dprintk("NFS: %5u initiated read call (req %s/%llu, %u bytes @ "
-                        "offset %llu)\n",
-                        data->task.tk_pid,
-                        inode->i_sb->s_id,
-                        (unsigned long long)NFS_FILEID(inode),
-                        data->args.count,
-                        (unsigned long long)data->args.offset);
-
-        task = rpc_run_task(&task_setup_data);
-        if (IS_ERR(task))
-                return PTR_ERR(task);
-        rpc_put_task(task);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(nfs_initiate_read);
-
-/*
- * Set up the NFS read request struct
- */
-static void nfs_read_rpcsetup(struct nfs_read_data *data,
-                unsigned int count, unsigned int offset)
-{
-        struct nfs_page *req = data->header->req;
-
-        data->args.fh     = NFS_FH(data->header->inode);
-        data->args.offset = req_offset(req) + offset;
-        data->args.pgbase = req->wb_pgbase + offset;
-        data->args.pages  = data->pages.pagevec;
-        data->args.count  = count;
-        data->args.context = get_nfs_open_context(req->wb_context);
-        data->args.lock_context = req->wb_lock_context;
-
-        data->res.fattr   = &data->fattr;
-        data->res.count   = count;
-        data->res.eof     = 0;
-        nfs_fattr_init(&data->fattr);
-}
-
-static int nfs_do_read(struct nfs_read_data *data,
-                const struct rpc_call_ops *call_ops)
-{
-        struct inode *inode = data->header->inode;
-
-        return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops, 0);
-}
-
-static int
-nfs_do_multiple_reads(struct list_head *head,
-                const struct rpc_call_ops *call_ops)
-{
-        struct nfs_read_data *data;
-        int ret = 0;
-
-        while (!list_empty(head)) {
-                int ret2;
-
-                data = list_first_entry(head, struct nfs_read_data, list);
-                list_del_init(&data->list);
-
-                ret2 = nfs_do_read(data, call_ops);
-                if (ret == 0)
-                        ret = ret2;
-        }
-        return ret;
+        task_setup_data->flags |= swap_flags;
+        NFS_PROTO(inode)->read_setup(data, msg);
 }
 
 static void
@@ -311,143 +199,14 @@ static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
         .completion = nfs_read_completion,
 };
 
-static void nfs_pagein_error(struct nfs_pageio_descriptor *desc,
-                struct nfs_pgio_header *hdr)
-{
-        set_bit(NFS_IOHDR_REDO, &hdr->flags);
-        while (!list_empty(&hdr->rpc_list)) {
-                struct nfs_read_data *data = list_first_entry(&hdr->rpc_list,
-                                struct nfs_read_data, list);
-                list_del(&data->list);
-                nfs_readdata_release(data);
-        }
-        desc->pg_completion_ops->error_cleanup(&desc->pg_list);
-}
-
-/*
- * Generate multiple requests to fill a single page.
- *
- * We optimize to reduce the number of read operations on the wire.  If we
- * detect that we're reading a page, or an area of a page, that is past the
- * end of file, we do not generate NFS read operations but just clear the
- * parts of the page that would have come back zero from the server anyway.
- *
- * We rely on the cached value of i_size to make this determination; another
- * client can fill pages on the server past our cached end-of-file, but we
- * won't see the new data until our attribute cache is updated.  This is more
- * or less conventional NFS client behavior.
- */
-static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc,
-                            struct nfs_pgio_header *hdr)
-{
-        struct nfs_page *req = hdr->req;
-        struct page *page = req->wb_page;
-        struct nfs_read_data *data;
-        size_t rsize = desc->pg_bsize, nbytes;
-        unsigned int offset;
-
-        offset = 0;
-        nbytes = desc->pg_count;
-        do {
-                size_t len = min(nbytes,rsize);
-
-                data = nfs_readdata_alloc(hdr, 1);
-                if (!data) {
-                        nfs_pagein_error(desc, hdr);
-                        return -ENOMEM;
-                }
-                data->pages.pagevec[0] = page;
-                nfs_read_rpcsetup(data, len, offset);
-                list_add(&data->list, &hdr->rpc_list);
-                nbytes -= len;
-                offset += len;
-        } while (nbytes != 0);
-
-        nfs_list_remove_request(req);
-        nfs_list_add_request(req, &hdr->pages);
-        desc->pg_rpc_callops = &nfs_read_common_ops;
-        return 0;
-}
-
-static int nfs_pagein_one(struct nfs_pageio_descriptor *desc,
-                          struct nfs_pgio_header *hdr)
-{
-        struct nfs_page         *req;
-        struct page             **pages;
-        struct nfs_read_data    *data;
-        struct list_head *head = &desc->pg_list;
-
-        data = nfs_readdata_alloc(hdr, nfs_page_array_len(desc->pg_base,
-                                                          desc->pg_count));
-        if (!data) {
-                nfs_pagein_error(desc, hdr);
-                return -ENOMEM;
-        }
-
-        pages = data->pages.pagevec;
-        while (!list_empty(head)) {
-                req = nfs_list_entry(head->next);
-                nfs_list_remove_request(req);
-                nfs_list_add_request(req, &hdr->pages);
-                *pages++ = req->wb_page;
-        }
-
-        nfs_read_rpcsetup(data, desc->pg_count, 0);
-        list_add(&data->list, &hdr->rpc_list);
-        desc->pg_rpc_callops = &nfs_read_common_ops;
-        return 0;
-}
-
-int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
-                       struct nfs_pgio_header *hdr)
-{
-        if (desc->pg_bsize < PAGE_CACHE_SIZE)
-                return nfs_pagein_multi(desc, hdr);
-        return nfs_pagein_one(desc, hdr);
-}
-EXPORT_SYMBOL_GPL(nfs_generic_pagein);
-
-static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
-{
-        struct nfs_read_header *rhdr;
-        struct nfs_pgio_header *hdr;
-        int ret;
-
-        rhdr = nfs_readhdr_alloc();
-        if (!rhdr) {
-                desc->pg_completion_ops->error_cleanup(&desc->pg_list);
-                return -ENOMEM;
-        }
-        hdr = &rhdr->header;
-        nfs_pgheader_init(desc, hdr, nfs_readhdr_free);
-        atomic_inc(&hdr->refcnt);
-        ret = nfs_generic_pagein(desc, hdr);
-        if (ret == 0)
-                ret = nfs_do_multiple_reads(&hdr->rpc_list,
-                                            desc->pg_rpc_callops);
-        if (atomic_dec_and_test(&hdr->refcnt))
-                hdr->completion_ops->completion(hdr);
-        return ret;
-}
-
-static const struct nfs_pageio_ops nfs_pageio_read_ops = {
-        .pg_test = nfs_generic_pg_test,
-        .pg_doio = nfs_generic_pg_readpages,
-};
-
 /*
  * This is the callback from RPC telling us whether a reply was
  * received or some error occurred (timeout or socket shutdown).
  */
-int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
+static int nfs_readpage_done(struct rpc_task *task, struct nfs_pgio_data *data,
+                             struct inode *inode)
 {
-        struct inode *inode = data->header->inode;
-        int status;
-
-        dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid,
-                        task->tk_status);
-
-        status = NFS_PROTO(inode)->read_done(task, data);
+        int status = NFS_PROTO(inode)->read_done(task, data);
         if (status != 0)
                 return status;
 
@@ -460,10 +219,10 @@ int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
         return 0;
 }
 
-static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
+static void nfs_readpage_retry(struct rpc_task *task, struct nfs_pgio_data *data)
 {
-        struct nfs_readargs *argp = &data->args;
-        struct nfs_readres *resp = &data->res;
+        struct nfs_pgio_args *argp = &data->args;
+        struct nfs_pgio_res  *resp = &data->res;
 
         /* This is a short read! */
         nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD);
@@ -480,17 +239,11 @@ static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data
         rpc_restart_call_prepare(task);
 }
 
-static void nfs_readpage_result_common(struct rpc_task *task, void *calldata)
+static void nfs_readpage_result(struct rpc_task *task, struct nfs_pgio_data *data)
 {
-        struct nfs_read_data *data = calldata;
         struct nfs_pgio_header *hdr = data->header;
 
-        /* Note the only returns of nfs_readpage_result are 0 and -EAGAIN */
-        if (nfs_readpage_result(task, data) != 0)
-                return;
-        if (task->tk_status < 0)
-                nfs_set_pgio_error(hdr, task->tk_status, data->args.offset);
-        else if (data->res.eof) {
+        if (data->res.eof) {
                 loff_t bound;
 
                 bound = data->args.offset + data->res.count;
@@ -505,26 +258,6 @@ static void nfs_readpage_result_common(struct rpc_task *task, void *calldata)
                 nfs_readpage_retry(task, data);
 }
 
-static void nfs_readpage_release_common(void *calldata)
-{
-        nfs_readdata_release(calldata);
-}
-
-void nfs_read_prepare(struct rpc_task *task, void *calldata)
-{
-        struct nfs_read_data *data = calldata;
-        int err;
-        err = NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data);
-        if (err)
-                rpc_exit(task, err);
-}
-
-static const struct rpc_call_ops nfs_read_common_ops = {
-        .rpc_call_prepare = nfs_read_prepare,
-        .rpc_call_done = nfs_readpage_result_common,
-        .rpc_release = nfs_readpage_release_common,
-};
-
 /*
  * Read a page over NFS.
  * We read the page synchronously in the following case:
@@ -592,7 +325,6 @@ static int
 readpage_async_filler(void *data, struct page *page)
 {
         struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
-        struct inode *inode = page_file_mapping(page)->host;
         struct nfs_page *new;
         unsigned int len;
         int error;
@@ -601,7 +333,7 @@ readpage_async_filler(void *data, struct page *page)
         if (len == 0)
                 return nfs_return_empty_page(page);
 
-        new = nfs_create_request(desc->ctx, inode, page, 0, len);
+        new = nfs_create_request(desc->ctx, page, NULL, 0, len);
         if (IS_ERR(new))
                 goto out_error;
 
@@ -654,7 +386,8 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
         if (ret == 0)
                 goto read_complete; /* all pages were read */
 
-        NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
+        nfs_pageio_init_read(&pgio, inode, false,
+                             &nfs_async_read_completion_ops);
 
         ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
 
@@ -671,7 +404,7 @@ out:
 int __init nfs_init_readpagecache(void)
 {
         nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
-                                             sizeof(struct nfs_read_header),
+                                             sizeof(struct nfs_rw_header),
                                              0, SLAB_HWCACHE_ALIGN,
                                              NULL);
         if (nfs_rdata_cachep == NULL)
@@ -684,3 +417,12 @@ void nfs_destroy_readpagecache(void)
 {
         kmem_cache_destroy(nfs_rdata_cachep);
 }
+
+static const struct nfs_rw_ops nfs_rw_read_ops = {
+        .rw_mode                = FMODE_READ,
+        .rw_alloc_header        = nfs_readhdr_alloc,
+        .rw_free_header         = nfs_readhdr_free,
+        .rw_done                = nfs_readpage_done,
+        .rw_result              = nfs_readpage_result,
+        .rw_initiate            = nfs_initiate_read,
+};
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 2cb56943e232..084af1060d79 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2180,11 +2180,23 @@ out_no_address:
         return -EINVAL;
 }
 
+#define NFS_MOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
+                | NFS_MOUNT_SECURE \
+                | NFS_MOUNT_TCP \
+                | NFS_MOUNT_VER3 \
+                | NFS_MOUNT_KERBEROS \
+                | NFS_MOUNT_NONLM \
+                | NFS_MOUNT_BROKEN_SUID \
+                | NFS_MOUNT_STRICTLOCK \
+                | NFS_MOUNT_UNSHARED \
+                | NFS_MOUNT_NORESVPORT \
+                | NFS_MOUNT_LEGACY_INTERFACE)
+
 static int
 nfs_compare_remount_data(struct nfs_server *nfss,
                          struct nfs_parsed_mount_data *data)
 {
-        if (data->flags != nfss->flags ||
+        if ((data->flags ^ nfss->flags) & NFS_MOUNT_CMP_FLAGMASK ||
             data->rsize != nfss->rsize ||
             data->wsize != nfss->wsize ||
             data->version != nfss->nfs_client->rpc_ops->version ||
@@ -2248,6 +2260,7 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
         data->version = nfsvers;
         data->minorversion = nfss->nfs_client->cl_minorversion;
+        data->net = current->nsproxy->net_ns;
         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
                 data->nfs_server.addrlen);
 
@@ -2347,18 +2360,6 @@ void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
         nfs_initialise_sb(sb);
 }
 
-#define NFS_MOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
-                | NFS_MOUNT_SECURE \
-                | NFS_MOUNT_TCP \
-                | NFS_MOUNT_VER3 \
-                | NFS_MOUNT_KERBEROS \
-                | NFS_MOUNT_NONLM \
-                | NFS_MOUNT_BROKEN_SUID \
-                | NFS_MOUNT_STRICTLOCK \
-                | NFS_MOUNT_UNSHARED \
-                | NFS_MOUNT_NORESVPORT \
-                | NFS_MOUNT_LEGACY_INTERFACE)
-
 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
 {
         const struct nfs_server *a = s->s_fs_info;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index ffb9459f180b..3ee5af4e738e 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -42,10 +42,10 @@
  * Local function declarations
  */
 static void nfs_redirty_request(struct nfs_page *req);
-static const struct rpc_call_ops nfs_write_common_ops;
 static const struct rpc_call_ops nfs_commit_ops;
 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
+static const struct nfs_rw_ops nfs_rw_write_ops;
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;
@@ -70,76 +70,19 @@ void nfs_commit_free(struct nfs_commit_data *p)
 }
 EXPORT_SYMBOL_GPL(nfs_commit_free);
 
-struct nfs_write_header *nfs_writehdr_alloc(void)
+static struct nfs_rw_header *nfs_writehdr_alloc(void)
 {
-        struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
-
-        if (p) {
-                struct nfs_pgio_header *hdr = &p->header;
+        struct nfs_rw_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
 
+        if (p)
                 memset(p, 0, sizeof(*p));
-                INIT_LIST_HEAD(&hdr->pages);
-                INIT_LIST_HEAD(&hdr->rpc_list);
-                spin_lock_init(&hdr->lock);
-                atomic_set(&hdr->refcnt, 0);
-                hdr->verf = &p->verf;
-        }
         return p;
 }
-EXPORT_SYMBOL_GPL(nfs_writehdr_alloc);
-
-static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
-                                                  unsigned int pagecount)
-{
-        struct nfs_write_data *data, *prealloc;
-
-        prealloc = &container_of(hdr, struct nfs_write_header, header)->rpc_data;
-        if (prealloc->header == NULL)
-                data = prealloc;
-        else
-                data = kzalloc(sizeof(*data), GFP_KERNEL);
-        if (!data)
-                goto out;
-
-        if (nfs_pgarray_set(&data->pages, pagecount)) {
-                data->header = hdr;
-                atomic_inc(&hdr->refcnt);
-        } else {
-                if (data != prealloc)
-                        kfree(data);
-                data = NULL;
-        }
-out:
-        return data;
-}
 
-void nfs_writehdr_free(struct nfs_pgio_header *hdr)
+static void nfs_writehdr_free(struct nfs_rw_header *whdr)
 {
-        struct nfs_write_header *whdr = container_of(hdr, struct nfs_write_header, header);
         mempool_free(whdr, nfs_wdata_mempool);
 }
-EXPORT_SYMBOL_GPL(nfs_writehdr_free);
-
-void nfs_writedata_release(struct nfs_write_data *wdata)
-{
-        struct nfs_pgio_header *hdr = wdata->header;
-        struct nfs_write_header *write_header = container_of(hdr, struct nfs_write_header, header);
-
-        put_nfs_open_context(wdata->args.context);
-        if (wdata->pages.pagevec != wdata->pages.page_array)
-                kfree(wdata->pages.pagevec);
-        if (wdata == &write_header->rpc_data) {
-                wdata->header = NULL;
-                wdata = NULL;
-        }
-        if (atomic_dec_and_test(&hdr->refcnt))
-                hdr->completion_ops->completion(hdr);
-        /* Note: we only free the rpc_task after callbacks are done.
-         * See the comment in rpc_free_task() for why
-         */
-        kfree(wdata);
-}
-EXPORT_SYMBOL_GPL(nfs_writedata_release);
 
 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
 {
@@ -211,18 +154,78 @@ static void nfs_set_pageerror(struct page *page)
         nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page));
 }
 
+/*
+ * nfs_page_group_search_locked
+ * @head - head request of page group
+ * @page_offset - offset into page
+ *
+ * Search page group with head @head to find a request that contains the
+ * page offset @page_offset.
+ *
+ * Returns a pointer to the first matching nfs request, or NULL if no
+ * match is found.
+ *
+ * Must be called with the page group lock held
+ */
+static struct nfs_page *
+nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
+{
+        struct nfs_page *req;
+
+        WARN_ON_ONCE(head != head->wb_head);
+        WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags));
+
+        req = head;
+        do {
+                if (page_offset >= req->wb_pgbase &&
+                    page_offset < (req->wb_pgbase + req->wb_bytes))
+                        return req;
+
+                req = req->wb_this_page;
+        } while (req != head);
+
+        return NULL;
+}
+
+/*
+ * nfs_page_group_covers_page
+ * @head - head request of page group
+ *
+ * Return true if the page group with head @head covers the whole page,
+ * returns false otherwise
+ */
+static bool nfs_page_group_covers_page(struct nfs_page *req)
+{
+        struct nfs_page *tmp;
+        unsigned int pos = 0;
+        unsigned int len = nfs_page_length(req->wb_page);
+
+        nfs_page_group_lock(req);
+
+        do {
+                tmp = nfs_page_group_search_locked(req->wb_head, pos);
+                if (tmp) {
+                        /* no way this should happen */
+                        WARN_ON_ONCE(tmp->wb_pgbase != pos);
+                        pos += tmp->wb_bytes - (pos - tmp->wb_pgbase);
+                }
+        } while (tmp && pos < len);
+
+        nfs_page_group_unlock(req);
+        WARN_ON_ONCE(pos > len);
+        return pos == len;
+}
+
 /* We can set the PG_uptodate flag if we see that a write request
  * covers the full page.
  */
-static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
+static void nfs_mark_uptodate(struct nfs_page *req)
 {
-        if (PageUptodate(page))
-                return;
-        if (base != 0)
+        if (PageUptodate(req->wb_page))
                 return;
-        if (count != nfs_page_length(page))
+        if (!nfs_page_group_covers_page(req))
                 return;
-        SetPageUptodate(page);
+        SetPageUptodate(req->wb_page);
 }
 
 static int wb_priority(struct writeback_control *wbc)
@@ -258,12 +261,15 @@ static void nfs_set_page_writeback(struct page *page)
         }
 }
 
-static void nfs_end_page_writeback(struct page *page)
+static void nfs_end_page_writeback(struct nfs_page *req)
 {
-        struct inode *inode = page_file_mapping(page)->host;
+        struct inode *inode = page_file_mapping(req->wb_page)->host;
         struct nfs_server *nfss = NFS_SERVER(inode);
 
-        end_page_writeback(page);
+        if (!nfs_page_group_sync_on_bit(req, PG_WB_END))
+                return;
+
+        end_page_writeback(req->wb_page);
         if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
                 clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
 }
@@ -354,10 +360,8 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
         struct nfs_pageio_descriptor pgio;
         int err;
 
-        NFS_PROTO(page_file_mapping(page)->host)->write_pageio_init(&pgio,
-                                                          page->mapping->host,
-                                                          wb_priority(wbc),
-                                                          &nfs_async_write_completion_ops);
+        nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc),
+                                false, &nfs_async_write_completion_ops);
         err = nfs_do_writepage(page, wbc, &pgio);
         nfs_pageio_complete(&pgio);
         if (err < 0)
@@ -400,7 +404,8 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 
         nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
-        NFS_PROTO(inode)->write_pageio_init(&pgio, inode, wb_priority(wbc), &nfs_async_write_completion_ops);
+        nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,
+                                &nfs_async_write_completion_ops);
         err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
         nfs_pageio_complete(&pgio);
 
@@ -425,6 +430,8 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
 
+        WARN_ON_ONCE(req->wb_this_page != req);
+
         /* Lock the request! */
         nfs_lock_request(req);
 
@@ -441,6 +448,7 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
                 set_page_private(req->wb_page, (unsigned long)req);
         }
         nfsi->npages++;
+        set_bit(PG_INODE_REF, &req->wb_flags);
         kref_get(&req->wb_kref);
         spin_unlock(&inode->i_lock);
 }
@@ -452,15 +460,20 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 {
         struct inode *inode = req->wb_context->dentry->d_inode;
         struct nfs_inode *nfsi = NFS_I(inode);
+        struct nfs_page *head;
 
-        spin_lock(&inode->i_lock);
-        if (likely(!PageSwapCache(req->wb_page))) {
-                set_page_private(req->wb_page, 0);
-                ClearPagePrivate(req->wb_page);
-                clear_bit(PG_MAPPED, &req->wb_flags);
+        if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
+                head = req->wb_head;
+
+                spin_lock(&inode->i_lock);
+                if (likely(!PageSwapCache(head->wb_page))) {
+                        set_page_private(head->wb_page, 0);
+                        ClearPagePrivate(head->wb_page);
+                        clear_bit(PG_MAPPED, &head->wb_flags);
+                }
+                nfsi->npages--;
+                spin_unlock(&inode->i_lock);
         }
-        nfsi->npages--;
-        spin_unlock(&inode->i_lock);
         nfs_release_request(req);
 }
 
@@ -583,7 +596,7 @@ nfs_clear_request_commit(struct nfs_page *req)
 }
 
 static inline
-int nfs_write_need_commit(struct nfs_write_data *data)
+int nfs_write_need_commit(struct nfs_pgio_data *data)
 {
         if (data->verf.committed == NFS_DATA_SYNC)
                 return data->header->lseg == NULL;
@@ -614,7 +627,7 @@ nfs_clear_request_commit(struct nfs_page *req)
 }
 
 static inline
-int nfs_write_need_commit(struct nfs_write_data *data)
+int nfs_write_need_commit(struct nfs_pgio_data *data)
 {
         return 0;
 }
@@ -625,6 +638,7 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
 {
         struct nfs_commit_info cinfo;
         unsigned long bytes = 0;
+        bool do_destroy;
 
         if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
                 goto out;
@@ -645,7 +659,7 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
                         goto next;
                 }
                 if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) {
-                        memcpy(&req->wb_verf, &hdr->verf->verifier, sizeof(req->wb_verf));
+                        memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
                         nfs_mark_request_commit(req, hdr->lseg, &cinfo);
                         goto next;
                 }
@@ -653,7 +667,8 @@ remove_req:
                 nfs_inode_remove_request(req);
 next:
                 nfs_unlock_request(req);
-                nfs_end_page_writeback(req->wb_page);
+                nfs_end_page_writeback(req);
+                do_destroy = !test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags);
                 nfs_release_request(req);
         }
 out:
@@ -661,7 +676,7 @@ out:
 }
 
 #if  IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
-static unsigned long
+unsigned long
 nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
 {
         return cinfo->mds->ncommit;
@@ -718,7 +733,7 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst,
 }
 
 #else
-static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
+unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
 {
         return 0;
 }
@@ -758,6 +773,10 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 if (req == NULL)
                         goto out_unlock;
 
+                /* should be handled by nfs_flush_incompatible */
+                WARN_ON_ONCE(req->wb_head != req);
+                WARN_ON_ONCE(req->wb_this_page != req);
+
                 rqend = req->wb_offset + req->wb_bytes;
                 /*
                  * Tell the caller to flush out the request if
@@ -819,7 +838,7 @@ static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
         req = nfs_try_to_update_request(inode, page, offset, bytes);
         if (req != NULL)
                 goto out;
-        req = nfs_create_request(ctx, inode, page, offset, bytes);
+        req = nfs_create_request(ctx, page, NULL, offset, bytes);
         if (IS_ERR(req))
                 goto out;
         nfs_inode_add_request(inode, req);
@@ -837,7 +856,7 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
                 return PTR_ERR(req);
         /* Update file length */
         nfs_grow_file(page, offset, count);
-        nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes);
+        nfs_mark_uptodate(req);
         nfs_mark_request_dirty(req);
         nfs_unlock_and_release_request(req);
         return 0;
@@ -863,6 +882,8 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
                         return 0;
                 l_ctx = req->wb_lock_context;
                 do_flush = req->wb_page != page || req->wb_context != ctx;
+                /* for now, flush if more than 1 request in page_group */
+                do_flush |= req->wb_this_page != req;
                 if (l_ctx && ctx->dentry->d_inode->i_flock != NULL) {
                         do_flush |= l_ctx->lockowner.l_owner != current->files
                                 || l_ctx->lockowner.l_pid != current->tgid;
@@ -990,126 +1011,17 @@ static int flush_task_priority(int how)
         return RPC_PRIORITY_NORMAL;
 }
 
-int nfs_initiate_write(struct rpc_clnt *clnt,
-                       struct nfs_write_data *data,
-                       const struct rpc_call_ops *call_ops,
-                       int how, int flags)
+static void nfs_initiate_write(struct nfs_pgio_data *data, struct rpc_message *msg,
+                               struct rpc_task_setup *task_setup_data, int how)
 {
         struct inode *inode = data->header->inode;
         int priority = flush_task_priority(how);
-        struct rpc_task *task;
-        struct rpc_message msg = {
-                .rpc_argp = &data->args,
-                .rpc_resp = &data->res,
-                .rpc_cred = data->header->cred,
-        };
-        struct rpc_task_setup task_setup_data = {
-                .rpc_client = clnt,
-                .task = &data->task,
-                .rpc_message = &msg,
-                .callback_ops = call_ops,
-                .callback_data = data,
-                .workqueue = nfsiod_workqueue,
-                .flags = RPC_TASK_ASYNC | flags,
-                .priority = priority,
-        };
-        int ret = 0;
-
-        /* Set up the initial task struct.  */
-        NFS_PROTO(inode)->write_setup(data, &msg);
 
-        dprintk("NFS: %5u initiated write call "
-                "(req %s/%llu, %u bytes @ offset %llu)\n",
-                data->task.tk_pid,
-                inode->i_sb->s_id,
-                (unsigned long long)NFS_FILEID(inode),
-                data->args.count,
-                (unsigned long long)data->args.offset);
+        task_setup_data->priority = priority;
+        NFS_PROTO(inode)->write_setup(data, msg);
 
         nfs4_state_protect_write(NFS_SERVER(inode)->nfs_client,
-                                 &task_setup_data.rpc_client, &msg, data);
-
-        task = rpc_run_task(&task_setup_data);
-        if (IS_ERR(task)) {
-                ret = PTR_ERR(task);
-                goto out;
-        }
-        if (how & FLUSH_SYNC) {
-                ret = rpc_wait_for_completion_task(task);
-                if (ret == 0)
-                        ret = task->tk_status;
-        }
-        rpc_put_task(task);
-out:
-        return ret;
-}
-EXPORT_SYMBOL_GPL(nfs_initiate_write);
-
-/*
- * Set up the argument/result storage required for the RPC call.
- */
-static void nfs_write_rpcsetup(struct nfs_write_data *data,
-                unsigned int count, unsigned int offset,
-                int how, struct nfs_commit_info *cinfo)
-{
-        struct nfs_page *req = data->header->req;
-
-        /* Set up the RPC argument and reply structs
-         * NB: take care not to mess about with data->commit et al. */
-
-        data->args.fh     = NFS_FH(data->header->inode);
-        data->args.offset = req_offset(req) + offset;
-        /* pnfs_set_layoutcommit needs this */
-        data->mds_offset = data->args.offset;
-        data->args.pgbase = req->wb_pgbase + offset;
-        data->args.pages  = data->pages.pagevec;
-        data->args.count  = count;
-        data->args.context = get_nfs_open_context(req->wb_context);
-        data->args.lock_context = req->wb_lock_context;
-        data->args.stable  = NFS_UNSTABLE;
-        switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
-        case 0:
-                break;
-        case FLUSH_COND_STABLE:
-                if (nfs_reqs_to_commit(cinfo))
-                        break;
-        default:
-                data->args.stable = NFS_FILE_SYNC;
-        }
-
-        data->res.fattr   = &data->fattr;
-        data->res.count   = count;
-        data->res.verf    = &data->verf;
-        nfs_fattr_init(&data->fattr);
-}
-
-static int nfs_do_write(struct nfs_write_data *data,
-                const struct rpc_call_ops *call_ops,
-                int how)
-{
-        struct inode *inode = data->header->inode;
-
-        return nfs_initiate_write(NFS_CLIENT(inode), data, call_ops, how, 0);
-}
-
-static int nfs_do_multiple_writes(struct list_head *head,
-                const struct rpc_call_ops *call_ops,
-                int how)
-{
-        struct nfs_write_data *data;
-        int ret = 0;
-
-        while (!list_empty(head)) {
-                int ret2;
-
-                data = list_first_entry(head, struct nfs_write_data, list);
-                list_del_init(&data->list);
-                
-                ret2 = nfs_do_write(data, call_ops, how);
-                 if (ret == 0)
-                         ret = ret2;
-        }
-        return ret;
+                                 &task_setup_data->rpc_client, msg, data);
 }
 
 /* If a nfs_flush_* function fails, it should remove reqs from @head and
@@ -1120,7 +1032,7 @@ static void nfs_redirty_request(struct nfs_page *req)
 {
         nfs_mark_request_dirty(req);
         nfs_unlock_request(req);
-        nfs_end_page_writeback(req->wb_page);
+        nfs_end_page_writeback(req);
         nfs_release_request(req);
 }
 
@@ -1140,173 +1052,30 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
         .completion = nfs_write_completion,
 };
 
-static void nfs_flush_error(struct nfs_pageio_descriptor *desc,
-                struct nfs_pgio_header *hdr)
-{
-        set_bit(NFS_IOHDR_REDO, &hdr->flags);
-        while (!list_empty(&hdr->rpc_list)) {
-                struct nfs_write_data *data = list_first_entry(&hdr->rpc_list,
-                                struct nfs_write_data, list);
-                list_del(&data->list);
-                nfs_writedata_release(data);
-        }
-        desc->pg_completion_ops->error_cleanup(&desc->pg_list);
-}
-
-/*
- * Generate multiple small requests to write out a single
- * contiguous dirty area on one page.
- */
-static int nfs_flush_multi(struct nfs_pageio_descriptor *desc,
-                           struct nfs_pgio_header *hdr)
-{
-        struct nfs_page *req = hdr->req;
-        struct page *page = req->wb_page;
-        struct nfs_write_data *data;
-        size_t wsize = desc->pg_bsize, nbytes;
-        unsigned int offset;
-        int requests = 0;
-        struct nfs_commit_info cinfo;
-
-        nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
-
-        if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
-            (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) ||
-             desc->pg_count > wsize))
-                desc->pg_ioflags &= ~FLUSH_COND_STABLE;
-
-
-        offset = 0;
-        nbytes = desc->pg_count;
-        do {
-                size_t len = min(nbytes, wsize);
-
-                data = nfs_writedata_alloc(hdr, 1);
-                if (!data) {
-                        nfs_flush_error(desc, hdr);
-                        return -ENOMEM;
-                }
-                data->pages.pagevec[0] = page;
-                nfs_write_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo);
-                list_add(&data->list, &hdr->rpc_list);
-                requests++;
-                nbytes -= len;
-                offset += len;
-        } while (nbytes != 0);
-        nfs_list_remove_request(req);
-        nfs_list_add_request(req, &hdr->pages);
-        desc->pg_rpc_callops = &nfs_write_common_ops;
-        return 0;
-}
-
-/*
- * Create an RPC task for the given write request and kick it.
- * The page must have been locked by the caller.
- *
- * It may happen that the page we're passed is not marked dirty.
- * This is the case if nfs_updatepage detects a conflicting request
- * that has been written but not committed.
- */
-static int nfs_flush_one(struct nfs_pageio_descriptor *desc,
-                         struct nfs_pgio_header *hdr)
-{
-        struct nfs_page         *req;
-        struct page             **pages;
-        struct nfs_write_data   *data;
-        struct list_head *head = &desc->pg_list;
-        struct nfs_commit_info cinfo;
-
-        data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base,
-                                                           desc->pg_count));
-        if (!data) {
-                nfs_flush_error(desc, hdr);
-                return -ENOMEM;
-        }
-
-        nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
-        pages = data->pages.pagevec;
-        while (!list_empty(head)) {
-                req = nfs_list_entry(head->next);
-                nfs_list_remove_request(req);
-                nfs_list_add_request(req, &hdr->pages);
-                *pages++ = req->wb_page;
-        }
-
-        if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
-            (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
-                desc->pg_ioflags &= ~FLUSH_COND_STABLE;
-
-        /* Set up the argument struct */
-        nfs_write_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
-        list_add(&data->list, &hdr->rpc_list);
-        desc->pg_rpc_callops = &nfs_write_common_ops;
-        return 0;
-}
-
-int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
-                      struct nfs_pgio_header *hdr)
-{
-        if (desc->pg_bsize < PAGE_CACHE_SIZE)
-                return nfs_flush_multi(desc, hdr);
-        return nfs_flush_one(desc, hdr);
-}
-EXPORT_SYMBOL_GPL(nfs_generic_flush);
-
-static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
-{
-        struct nfs_write_header *whdr;
-        struct nfs_pgio_header *hdr;
-        int ret;
-
-        whdr = nfs_writehdr_alloc();
-        if (!whdr) {
-                desc->pg_completion_ops->error_cleanup(&desc->pg_list);
-                return -ENOMEM;
-        }
-        hdr = &whdr->header;
-        nfs_pgheader_init(desc, hdr, nfs_writehdr_free);
-        atomic_inc(&hdr->refcnt);
-        ret = nfs_generic_flush(desc, hdr);
-        if (ret == 0)
-                ret = nfs_do_multiple_writes(&hdr->rpc_list,
-                                             desc->pg_rpc_callops,
-                                             desc->pg_ioflags);
-        if (atomic_dec_and_test(&hdr->refcnt))
-                hdr->completion_ops->completion(hdr);
-        return ret;
-}
-
-static const struct nfs_pageio_ops nfs_pageio_write_ops = {
-        .pg_test = nfs_generic_pg_test,
-        .pg_doio = nfs_generic_pg_writepages,
-};
-
 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
-                               struct inode *inode, int ioflags,
+                               struct inode *inode, int ioflags, bool force_mds,
                                const struct nfs_pgio_completion_ops *compl_ops)
 {
-        nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops,
-                                NFS_SERVER(inode)->wsize, ioflags);
+        struct nfs_server *server = NFS_SERVER(inode);
+        const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
+
+#ifdef CONFIG_NFS_V4_1
+        if (server->pnfs_curr_ld && !force_mds)
+                pg_ops = server->pnfs_curr_ld->pg_write_ops;
+#endif
+        nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
+                        server->wsize, ioflags);
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
 
 void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
 {
-        pgio->pg_ops = &nfs_pageio_write_ops;
+        pgio->pg_ops = &nfs_pgio_rw_ops;
         pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
 
 
-void nfs_write_prepare(struct rpc_task *task, void *calldata)
-{
-        struct nfs_write_data *data = calldata;
-        int err;
-        err = NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data);
-        if (err)
-                rpc_exit(task, err);
-}
-
 void nfs_commit_prepare(struct rpc_task *task, void *calldata)
 {
         struct nfs_commit_data *data = calldata;
@@ -1314,23 +1083,8 @@ void nfs_commit_prepare(struct rpc_task *task, void *calldata)
         NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
 }
 
-/*
- * Handle a write reply that flushes a whole page.
- *
- * FIXME: There is an inherent race with invalidate_inode_pages and
- *        writebacks since the page->count is kept > 1 for as long
- *        as the page has a write request pending.
- */
-static void nfs_writeback_done_common(struct rpc_task *task, void *calldata)
-{
-        struct nfs_write_data   *data = calldata;
-
-        nfs_writeback_done(task, data);
-}
-
-static void nfs_writeback_release_common(void *calldata)
+static void nfs_writeback_release_common(struct nfs_pgio_data *data)
 {
-        struct nfs_write_data   *data = calldata;
         struct nfs_pgio_header *hdr = data->header;
         int status = data->task.tk_status;
 
@@ -1339,34 +1093,46 @@ static void nfs_writeback_release_common(void *calldata)
                 if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags))
                         ; /* Do nothing */
                 else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags))
-                        memcpy(hdr->verf, &data->verf, sizeof(*hdr->verf));
-                else if (memcmp(hdr->verf, &data->verf, sizeof(*hdr->verf)))
+                        memcpy(&hdr->verf, &data->verf, sizeof(hdr->verf));
+                else if (memcmp(&hdr->verf, &data->verf, sizeof(hdr->verf)))
                         set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags);
                 spin_unlock(&hdr->lock);
         }
-        nfs_writedata_release(data);
 }
 
-static const struct rpc_call_ops nfs_write_common_ops = {
-        .rpc_call_prepare = nfs_write_prepare,
-        .rpc_call_done = nfs_writeback_done_common,
-        .rpc_release = nfs_writeback_release_common,
-};
+/*
+ * Special version of should_remove_suid() that ignores capabilities.
+ */
+static int nfs_should_remove_suid(const struct inode *inode)
+{
+        umode_t mode = inode->i_mode;
+        int kill = 0;
+
+        /* suid always must be killed */
+        if (unlikely(mode & S_ISUID))
+                kill = ATTR_KILL_SUID;
 
+        /*
+         * sgid without any exec bits is just a mandatory locking mark; leave
+         * it alone.  If some exec bits are set, it's a real sgid; kill it.
+         */
+        if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
+                kill |= ATTR_KILL_SGID;
+
+        if (unlikely(kill && S_ISREG(mode)))
+                return kill;
+
+        return 0;
+}
 
 /*
  * This function is called when the WRITE call is complete.
  */
-void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
+static int nfs_writeback_done(struct rpc_task *task, struct nfs_pgio_data *data,
+                              struct inode *inode)
 {
-        struct nfs_writeargs    *argp = &data->args;
-        struct nfs_writeres     *resp = &data->res;
-        struct inode            *inode = data->header->inode;
         int status;
 
-        dprintk("NFS: %5u nfs_writeback_done (status %d)\n",
-                task->tk_pid, task->tk_status);
-
         /*
          * ->write_done will attempt to use post-op attributes to detect
          * conflicting writes by other clients.  A strict interpretation
@@ -1376,11 +1142,11 @@ void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
          */
         status = NFS_PROTO(inode)->write_done(task, data);
         if (status != 0)
-                return;
-        nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, resp->count);
+                return status;
+        nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, data->res.count);
 
 #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4)
-        if (resp->verf->committed < argp->stable && task->tk_status >= 0) {
+        if (data->res.verf->committed < data->args.stable && task->tk_status >= 0) {
                 /* We tried a write call, but the server did not
                  * commit data to stable storage even though we
                  * requested it.
@@ -1396,18 +1162,31 @@ void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data)
                         dprintk("NFS:       faulty NFS server %s:"
                                 " (committed = %d) != (stable = %d)\n",
                                 NFS_SERVER(inode)->nfs_client->cl_hostname,
-                                resp->verf->committed, argp->stable);
+                                data->res.verf->committed, data->args.stable);
                         complain = jiffies + 300 * HZ;
                 }
         }
 #endif
-        if (task->tk_status < 0)
-                nfs_set_pgio_error(data->header, task->tk_status, argp->offset);
-        else if (resp->count < argp->count) {
+
+        /* Deal with the suid/sgid bit corner case */
+        if (nfs_should_remove_suid(inode))
+                nfs_mark_for_revalidate(inode);
+        return 0;
+}
+
+/*
+ * This function is called when the WRITE call is complete.
+ */
+static void nfs_writeback_result(struct rpc_task *task, struct nfs_pgio_data *data)
+{
+        struct nfs_pgio_args    *argp = &data->args;
+        struct nfs_pgio_res     *resp = &data->res;
+
+        if (resp->count < argp->count) {
                 static unsigned long    complain;
 
                 /* This a short write! */
-                nfs_inc_stats(inode, NFSIOS_SHORTWRITE);
+                nfs_inc_stats(data->header->inode, NFSIOS_SHORTWRITE);
 
                 /* Has the server at least made some progress? */
                 if (resp->count == 0) {
@@ -1874,7 +1653,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
 int __init nfs_init_writepagecache(void)
 {
         nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
-                                             sizeof(struct nfs_write_header),
+                                             sizeof(struct nfs_rw_header),
                                              0, SLAB_HWCACHE_ALIGN,
                                              NULL);
         if (nfs_wdata_cachep == NULL)
@@ -1936,3 +1715,12 @@ void nfs_destroy_writepagecache(void)
         kmem_cache_destroy(nfs_wdata_cachep);
 }
 
+static const struct nfs_rw_ops nfs_rw_write_ops = {
+        .rw_mode                = FMODE_WRITE,
+        .rw_alloc_header        = nfs_writehdr_alloc,
+        .rw_free_header         = nfs_writehdr_free,
+        .rw_release             = nfs_writeback_release_common,
+        .rw_done                = nfs_writeback_done,
+        .rw_result              = nfs_writeback_result,
+        .rw_initiate            = nfs_initiate_write,
+};