1 files changed, 245 insertions, 265 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index febdade9167..de92b9509d9 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -12,6 +12,7 @@
 #include <linux/pagemap.h>
 #include <linux/file.h>
 #include <linux/writeback.h>
+#include <linux/swap.h>
 
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
@@ -20,7 +21,6 @@
 #include <linux/backing-dev.h>
 
 #include <asm/uaccess.h>
-#include <linux/smp_lock.h>
 
 #include "delegation.h"
 #include "internal.h"
@@ -37,9 +37,8 @@
 static struct nfs_page * nfs_update_request(struct nfs_open_context*,
 					    struct page *,
 					    unsigned int, unsigned int);
-static void nfs_mark_request_dirty(struct nfs_page *req);
-static int nfs_wait_on_write_congestion(struct address_space *, int);
-static long nfs_flush_mapping(struct address_space *mapping, struct writeback_control *wbc, int how);
+static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
+				  struct inode *inode, int ioflags);
 static const struct rpc_call_ops nfs_write_partial_ops;
 static const struct rpc_call_ops nfs_write_full_ops;
 static const struct rpc_call_ops nfs_commit_ops;
@@ -48,8 +47,6 @@ static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;
 static mempool_t *nfs_commit_mempool;
 
-static DECLARE_WAIT_QUEUE_HEAD(nfs_write_congestion);
-
 struct nfs_write_data *nfs_commit_alloc(void)
 {
 	struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
@@ -74,9 +71,8 @@ void nfs_commit_free(struct nfs_write_data *wdata)
 	call_rcu_bh(&wdata->task.u.tk_rcu, nfs_commit_rcu_free);
 }
 
-struct nfs_write_data *nfs_writedata_alloc(size_t len)
+struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
 {
-	unsigned int pagecount = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
 
 	if (p) {
@@ -142,7 +138,7 @@ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int c
 {
 	struct inode *inode = page->mapping->host;
 	loff_t end, i_size = i_size_read(inode);
-	unsigned long end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
+	pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 
 	if (i_size > 0 && page->index < end_index)
 		return;
@@ -204,23 +200,62 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
 static int wb_priority(struct writeback_control *wbc)
 {
 	if (wbc->for_reclaim)
-		return FLUSH_HIGHPRI;
+		return FLUSH_HIGHPRI | FLUSH_STABLE;
 	if (wbc->for_kupdate)
 		return FLUSH_LOWPRI;
 	return 0;
 }
 
 /*
+ * NFS congestion control
+ */
+
+int nfs_congestion_kb;
+
+#define NFS_CONGESTION_ON_THRESH 	(nfs_congestion_kb >> (PAGE_SHIFT-10))
+#define NFS_CONGESTION_OFF_THRESH	\
+	(NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
+
+static int nfs_set_page_writeback(struct page *page)
+{
+	int ret = test_set_page_writeback(page);
+
+	if (!ret) {
+		struct inode *inode = page->mapping->host;
+		struct nfs_server *nfss = NFS_SERVER(inode);
+
+		if (atomic_long_inc_return(&nfss->writeback) >
+				NFS_CONGESTION_ON_THRESH)
+			set_bdi_congested(&nfss->backing_dev_info, WRITE);
+	}
+	return ret;
+}
+
+static void nfs_end_page_writeback(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+
+	end_page_writeback(page);
+	if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) {
+		clear_bdi_congested(&nfss->backing_dev_info, WRITE);
+		congestion_end(WRITE);
+	}
+}
+
+/*
  * Find an associated nfs write request, and prepare to flush it out
  * Returns 1 if there was no write request, or if the request was
  * already tagged by nfs_set_page_dirty.Returns 0 if the request
  * was not tagged.
  * May also return an error if the user signalled nfs_wait_on_request().
  */
-static int nfs_page_mark_flush(struct page *page)
+static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
+				struct page *page)
 {
 	struct nfs_page *req;
-	spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
+	struct nfs_inode *nfsi = NFS_I(page->mapping->host);
+	spinlock_t *req_lock = &nfsi->req_lock;
 	int ret;
 
 	spin_lock(req_lock);
@@ -238,19 +273,30 @@ static int nfs_page_mark_flush(struct page *page)
 		 *	 request as dirty (in which case we don't care).
 		 */
 		spin_unlock(req_lock);
+		/* Prevent deadlock! */
+		nfs_pageio_complete(pgio);
 		ret = nfs_wait_on_request(req);
 		nfs_release_request(req);
 		if (ret != 0)
 			return ret;
 		spin_lock(req_lock);
 	}
-	spin_unlock(req_lock);
-	if (test_and_set_bit(PG_FLUSHING, &req->wb_flags) == 0) {
-		nfs_mark_request_dirty(req);
-		set_page_writeback(page);
+	if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {
+		/* This request is marked for commit */
+		spin_unlock(req_lock);
+		nfs_unlock_request(req);
+		nfs_pageio_complete(pgio);
+		return 1;
+	}
+	if (nfs_set_page_writeback(page) != 0) {
+		spin_unlock(req_lock);
+		BUG();
 	}
+	radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index,
+			NFS_PAGE_TAG_WRITEBACK);
 	ret = test_bit(PG_NEED_FLUSH, &req->wb_flags);
-	nfs_unlock_request(req);
+	spin_unlock(req_lock);
+	nfs_pageio_add_request(pgio, req);
 	return ret;
 }
 
@@ -259,6 +305,7 @@ static int nfs_page_mark_flush(struct page *page)
  */
 static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
 {
+	struct nfs_pageio_descriptor mypgio, *pgio;
 	struct nfs_open_context *ctx;
 	struct inode *inode = page->mapping->host;
 	unsigned offset;
@@ -267,7 +314,14 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
 	nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1);
 
-	err = nfs_page_mark_flush(page);
+	if (wbc->for_writepages)
+		pgio = wbc->fs_private;
+	else {
+		nfs_pageio_init_write(&mypgio, inode, wb_priority(wbc));
+		pgio = &mypgio;
+	}
+
+	err = nfs_page_async_flush(pgio, page);
 	if (err <= 0)
 		goto out;
 	err = 0;
@@ -284,12 +338,12 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
 	put_nfs_open_context(ctx);
 	if (err != 0)
 		goto out;
-	err = nfs_page_mark_flush(page);
+	err = nfs_page_async_flush(pgio, page);
 	if (err > 0)
 		err = 0;
 out:
 	if (!wbc->for_writepages)
-		nfs_flush_mapping(page->mapping, wbc, FLUSH_STABLE|wb_priority(wbc));
+		nfs_pageio_complete(pgio);
 	return err;
 }
 
@@ -302,36 +356,23 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
 	return err; 
 }
 
-/*
- * Note: causes nfs_update_request() to block on the assumption
- * 	 that the writeback is generated due to memory pressure.
- */
 int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {
-	struct backing_dev_info *bdi = mapping->backing_dev_info;
 	struct inode *inode = mapping->host;
+	struct nfs_pageio_descriptor pgio;
 	int err;
 
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
+	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
+	wbc->fs_private = &pgio;
 	err = generic_writepages(mapping, wbc);
+	nfs_pageio_complete(&pgio);
 	if (err)
 		return err;
-	while (test_and_set_bit(BDI_write_congested, &bdi->state) != 0) {
-		if (wbc->nonblocking)
-			return 0;
-		nfs_wait_on_write_congestion(mapping, 0);
-	}
-	err = nfs_flush_mapping(mapping, wbc, wb_priority(wbc));
-	if (err < 0)
-		goto out;
-	nfs_add_stats(inode, NFSIOS_WRITEPAGES, err);
-	err = 0;
-out:
-	clear_bit(BDI_write_congested, &bdi->state);
-	wake_up_all(&nfs_write_congestion);
-	congestion_end(WRITE);
-	return err;
+	if (pgio.pg_error)
+		return pgio.pg_error;
+	return 0;
 }
 
 /*
@@ -354,13 +395,15 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 	}
 	SetPagePrivate(req->wb_page);
 	set_page_private(req->wb_page, (unsigned long)req);
+	if (PageDirty(req->wb_page))
+		set_bit(PG_NEED_FLUSH, &req->wb_flags);
 	nfsi->npages++;
 	atomic_inc(&req->wb_count);
 	return 0;
 }
 
 /*
- * Insert a write request into an inode
+ * Remove a write request from an inode
  */
 static void nfs_inode_remove_request(struct nfs_page *req)
 {
@@ -373,6 +416,8 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 	set_page_private(req->wb_page, 0);
 	ClearPagePrivate(req->wb_page);
 	radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
+	if (test_and_clear_bit(PG_NEED_FLUSH, &req->wb_flags))
+		__set_page_dirty_nobuffers(req->wb_page);
 	nfsi->npages--;
 	if (!nfsi->npages) {
 		spin_unlock(&nfsi->req_lock);
@@ -384,28 +429,9 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 	nfs_release_request(req);
 }
 
-/*
- * Add a request to the inode's dirty list.
- */
-static void
-nfs_mark_request_dirty(struct nfs_page *req)
-{
-	struct inode *inode = req->wb_context->dentry->d_inode;
-	struct nfs_inode *nfsi = NFS_I(inode);
-
-	spin_lock(&nfsi->req_lock);
-	radix_tree_tag_set(&nfsi->nfs_page_tree,
-			req->wb_index, NFS_PAGE_TAG_DIRTY);
-	nfs_list_add_request(req, &nfsi->dirty);
-	nfsi->ndirty++;
-	spin_unlock(&nfsi->req_lock);
-	__mark_inode_dirty(inode, I_DIRTY_PAGES);
-}
-
 static void
 nfs_redirty_request(struct nfs_page *req)
 {
-	clear_bit(PG_FLUSHING, &req->wb_flags);
 	__set_page_dirty_nobuffers(req->wb_page);
 }
 
@@ -415,7 +441,11 @@ nfs_redirty_request(struct nfs_page *req)
 static inline int
 nfs_dirty_request(struct nfs_page *req)
 {
-	return test_bit(PG_FLUSHING, &req->wb_flags) == 0;
+	struct page *page = req->wb_page;
+
+	if (page == NULL || test_bit(PG_NEED_COMMIT, &req->wb_flags))
+		return 0;
+	return !PageWriteback(req->wb_page);
 }
 
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
@@ -431,10 +461,48 @@ nfs_mark_request_commit(struct nfs_page *req)
 	spin_lock(&nfsi->req_lock);
 	nfs_list_add_request(req, &nfsi->commit);
 	nfsi->ncommit++;
+	set_bit(PG_NEED_COMMIT, &(req)->wb_flags);
 	spin_unlock(&nfsi->req_lock);
 	inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
 	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 }
+
+static inline
+int nfs_write_need_commit(struct nfs_write_data *data)
+{
+	return data->verf.committed != NFS_FILE_SYNC;
+}
+
+static inline
+int nfs_reschedule_unstable_write(struct nfs_page *req)
+{
+	if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {
+		nfs_mark_request_commit(req);
+		return 1;
+	}
+	if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) {
+		nfs_redirty_request(req);
+		return 1;
+	}
+	return 0;
+}
+#else
+static inline void
+nfs_mark_request_commit(struct nfs_page *req)
+{
+}
+
+static inline
+int nfs_write_need_commit(struct nfs_write_data *data)
+{
+	return 0;
+}
+
+static inline
+int nfs_reschedule_unstable_write(struct nfs_page *req)
+{
+	return 0;
+}
 #endif
 
 /*
@@ -442,11 +510,11 @@ nfs_mark_request_commit(struct nfs_page *req)
  *
  * Interruptible by signals only if mounted with intr flag.
  */
-static int nfs_wait_on_requests_locked(struct inode *inode, unsigned long idx_start, unsigned int npages)
+static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_page *req;
-	unsigned long		idx_end, next;
+	pgoff_t idx_end, next;
 	unsigned int		res = 0;
 	int			error;
 
@@ -475,17 +543,6 @@ static int nfs_wait_on_requests_locked(struct inode *inode, unsigned long idx_st
 	return res;
 }
 
-static void nfs_cancel_dirty_list(struct list_head *head)
-{
-	struct nfs_page *req;
-	while(!list_empty(head)) {
-		req = nfs_list_entry(head->next);
-		nfs_list_remove_request(req);
-		nfs_inode_remove_request(req);
-		nfs_clear_page_writeback(req);
-	}
-}
-
 static void nfs_cancel_commit_list(struct list_head *head)
 {
 	struct nfs_page *req;
@@ -494,6 +551,7 @@ static void nfs_cancel_commit_list(struct list_head *head)
 		req = nfs_list_entry(head->next);
 		dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
 		nfs_list_remove_request(req);
+		clear_bit(PG_NEED_COMMIT, &(req)->wb_flags);
 		nfs_inode_remove_request(req);
 		nfs_unlock_request(req);
 	}
@@ -511,7 +569,7 @@ static void nfs_cancel_commit_list(struct list_head *head)
  * The requests are *not* checked to ensure that they form a contiguous set.
  */
 static int
-nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
+nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	int res = 0;
@@ -525,48 +583,12 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_st
 	return res;
 }
 #else
-static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
+static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
 {
 	return 0;
 }
 #endif
 
-static int nfs_wait_on_write_congestion(struct address_space *mapping, int intr)
-{
-	struct backing_dev_info *bdi = mapping->backing_dev_info;
-	DEFINE_WAIT(wait);
-	int ret = 0;
-
-	might_sleep();
-
-	if (!bdi_write_congested(bdi))
-		return 0;
-
-	nfs_inc_stats(mapping->host, NFSIOS_CONGESTIONWAIT);
-
-	if (intr) {
-		struct rpc_clnt *clnt = NFS_CLIENT(mapping->host);
-		sigset_t oldset;
-
-		rpc_clnt_sigmask(clnt, &oldset);
-		prepare_to_wait(&nfs_write_congestion, &wait, TASK_INTERRUPTIBLE);
-		if (bdi_write_congested(bdi)) {
-			if (signalled())
-				ret = -ERESTARTSYS;
-			else
-				schedule();
-		}
-		rpc_clnt_sigunmask(clnt, &oldset);
-	} else {
-		prepare_to_wait(&nfs_write_congestion, &wait, TASK_UNINTERRUPTIBLE);
-		if (bdi_write_congested(bdi))
-			schedule();
-	}
-	finish_wait(&nfs_write_congestion, &wait);
-	return ret;
-}
-
-
 /*
  * Try to update any existing write request, or create one if there is none.
  * In order to match, the request's credentials must match those of
@@ -577,15 +599,14 @@ static int nfs_wait_on_write_congestion(struct address_space *mapping, int intr)
 static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
 		struct page *page, unsigned int offset, unsigned int bytes)
 {
-	struct inode *inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_page		*req, *new = NULL;
-	unsigned long		rqend, end;
+	pgoff_t		rqend, end;
 
 	end = offset + bytes;
 
-	if (nfs_wait_on_write_congestion(page->mapping, NFS_SERVER(inode)->flags & NFS_MOUNT_INTR))
-		return ERR_PTR(-ERESTARTSYS);
 	for (;;) {
 		/* Loop over all inode entries and see if we find
 		 * A request for the page we wish to update
@@ -727,26 +748,12 @@ int nfs_updatepage(struct file *file, struct page *page,
 
 static void nfs_writepage_release(struct nfs_page *req)
 {
-	end_page_writeback(req->wb_page);
 
-#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-	if (!PageError(req->wb_page)) {
-		if (NFS_NEED_RESCHED(req)) {
-			nfs_redirty_request(req);
-			goto out;
-		} else if (NFS_NEED_COMMIT(req)) {
-			nfs_mark_request_commit(req);
-			goto out;
-		}
-	}
-	nfs_inode_remove_request(req);
-
-out:
-	nfs_clear_commit(req);
-	nfs_clear_reschedule(req);
-#else
-	nfs_inode_remove_request(req);
-#endif
+	if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) {
+		nfs_end_page_writeback(req->wb_page);
+		nfs_inode_remove_request(req);
+	} else
+		nfs_end_page_writeback(req->wb_page);
 	nfs_clear_page_writeback(req);
 }
 
@@ -823,7 +830,7 @@ static void nfs_execute_write(struct nfs_write_data *data)
  * Generate multiple small requests to write out a single
  * contiguous dirty area on one page.
  */
-static int nfs_flush_multi(struct inode *inode, struct list_head *head, int how)
+static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how)
 {
 	struct nfs_page *req = nfs_list_entry(head->next);
 	struct page *page = req->wb_page;
@@ -835,11 +842,11 @@ static int nfs_flush_multi(struct inode *inode, struct list_head *head, int how)
 
 	nfs_list_remove_request(req);
 
-	nbytes = req->wb_bytes;
+	nbytes = count;
 	do {
 		size_t len = min(nbytes, wsize);
 
-		data = nfs_writedata_alloc(len);
+		data = nfs_writedata_alloc(1);
 		if (!data)
 			goto out_bad;
 		list_add(&data->pages, &list);
@@ -850,23 +857,19 @@ static int nfs_flush_multi(struct inode *inode, struct list_head *head, int how)
 
 	ClearPageError(page);
 	offset = 0;
-	nbytes = req->wb_bytes;
+	nbytes = count;
 	do {
 		data = list_entry(list.next, struct nfs_write_data, pages);
 		list_del_init(&data->pages);
 
 		data->pagevec[0] = page;
 
-		if (nbytes > wsize) {
-			nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
-					wsize, offset, how);
-			offset += wsize;
-			nbytes -= wsize;
-		} else {
-			nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
-					nbytes, offset, how);
-			nbytes = 0;
-		}
+		if (nbytes < wsize)
+			wsize = nbytes;
+		nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
+				   wsize, offset, how);
+		offset += wsize;
+		nbytes -= wsize;
 		nfs_execute_write(data);
 	} while (nbytes != 0);
 
@@ -879,6 +882,7 @@ out_bad:
 		nfs_writedata_release(data);
 	}
 	nfs_redirty_request(req);
+	nfs_end_page_writeback(req->wb_page);
 	nfs_clear_page_writeback(req);
 	return -ENOMEM;
 }
@@ -891,26 +895,23 @@ out_bad:
  * This is the case if nfs_updatepage detects a conflicting request
  * that has been written but not committed.
  */
-static int nfs_flush_one(struct inode *inode, struct list_head *head, int how)
+static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how)
 {
 	struct nfs_page		*req;
 	struct page		**pages;
 	struct nfs_write_data	*data;
-	unsigned int		count;
 
-	data = nfs_writedata_alloc(NFS_SERVER(inode)->wsize);
+	data = nfs_writedata_alloc(npages);
 	if (!data)
 		goto out_bad;
 
 	pages = data->pagevec;
-	count = 0;
 	while (!list_empty(head)) {
 		req = nfs_list_entry(head->next);
 		nfs_list_remove_request(req);
 		nfs_list_add_request(req, &data->pages);
 		ClearPageError(req->wb_page);
 		*pages++ = req->wb_page;
-		count += req->wb_bytes;
 	}
 	req = nfs_list_entry(data->pages.next);
 
@@ -924,44 +925,21 @@ static int nfs_flush_one(struct inode *inode, struct list_head *head, int how)
 		struct nfs_page *req = nfs_list_entry(head->next);
 		nfs_list_remove_request(req);
 		nfs_redirty_request(req);
+		nfs_end_page_writeback(req->wb_page);
 		nfs_clear_page_writeback(req);
 	}
 	return -ENOMEM;
 }
 
-static int nfs_flush_list(struct inode *inode, struct list_head *head, int npages, int how)
+static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+				  struct inode *inode, int ioflags)
 {
-	LIST_HEAD(one_request);
-	int (*flush_one)(struct inode *, struct list_head *, int);
-	struct nfs_page	*req;
-	int wpages = NFS_SERVER(inode)->wpages;
 	int wsize = NFS_SERVER(inode)->wsize;
-	int error;
 
-	flush_one = nfs_flush_one;
 	if (wsize < PAGE_CACHE_SIZE)
-		flush_one = nfs_flush_multi;
-	/* For single writes, FLUSH_STABLE is more efficient */
-	if (npages <= wpages && npages == NFS_I(inode)->npages
-			&& nfs_list_entry(head->next)->wb_bytes <= wsize)
-		how |= FLUSH_STABLE;
-
-	do {
-		nfs_coalesce_requests(head, &one_request, wpages);
-		req = nfs_list_entry(one_request.next);
-		error = flush_one(inode, &one_request, how);
-		if (error < 0)
-			goto out_err;
-	} while (!list_empty(head));
-	return 0;
-out_err:
-	while (!list_empty(head)) {
-		req = nfs_list_entry(head->next);
-		nfs_list_remove_request(req);
-		nfs_redirty_request(req);
-		nfs_clear_page_writeback(req);
-	}
-	return error;
+		nfs_pageio_init(pgio, inode, nfs_flush_multi, wsize, ioflags);
+	else
+		nfs_pageio_init(pgio, inode, nfs_flush_one, wsize, ioflags);
 }
 
 /*
@@ -986,22 +964,28 @@ static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata)
 		nfs_set_pageerror(page);
 		req->wb_context->error = task->tk_status;
 		dprintk(", error = %d\n", task->tk_status);
-	} else {
-#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-		if (data->verf.committed < NFS_FILE_SYNC) {
-			if (!NFS_NEED_COMMIT(req)) {
-				nfs_defer_commit(req);
-				memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
-				dprintk(" defer commit\n");
-			} else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) {
-				nfs_defer_reschedule(req);
-				dprintk(" server reboot detected\n");
-			}
-		} else
-#endif
-			dprintk(" OK\n");
+		goto out;
 	}
 
+	if (nfs_write_need_commit(data)) {
+		spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
+
+		spin_lock(req_lock);
+		if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) {
+			/* Do nothing we need to resend the writes */
+		} else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) {
+			memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
+			dprintk(" defer commit\n");
+		} else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) {
+			set_bit(PG_NEED_RESCHED, &req->wb_flags);
+			clear_bit(PG_NEED_COMMIT, &req->wb_flags);
+			dprintk(" server reboot detected\n");
+		}
+		spin_unlock(req_lock);
+	} else
+		dprintk(" OK\n");
+
+out:
 	if (atomic_dec_and_test(&req->wb_complete))
 		nfs_writepage_release(req);
 }
@@ -1042,25 +1026,21 @@ static void nfs_writeback_done_full(struct rpc_task *task, void *calldata)
 		if (task->tk_status < 0) {
 			nfs_set_pageerror(page);
 			req->wb_context->error = task->tk_status;
-			end_page_writeback(page);
-			nfs_inode_remove_request(req);
 			dprintk(", error = %d\n", task->tk_status);
-			goto next;
+			goto remove_request;
 		}
-		end_page_writeback(page);
 
-#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-		if (data->args.stable != NFS_UNSTABLE || data->verf.committed == NFS_FILE_SYNC) {
-			nfs_inode_remove_request(req);
-			dprintk(" OK\n");
+		if (nfs_write_need_commit(data)) {
+			memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
+			nfs_mark_request_commit(req);
+			nfs_end_page_writeback(page);
+			dprintk(" marked for commit\n");
 			goto next;
 		}
-		memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf));
-		nfs_mark_request_commit(req);
-		dprintk(" marked for commit\n");
-#else
+		dprintk(" OK\n");
+remove_request:
+		nfs_end_page_writeback(page);
 		nfs_inode_remove_request(req);
-#endif
 	next:
 		nfs_clear_page_writeback(req);
 	}
@@ -1248,6 +1228,7 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)
 	while (!list_empty(&data->pages)) {
 		req = nfs_list_entry(data->pages.next);
 		nfs_list_remove_request(req);
+		clear_bit(PG_NEED_COMMIT, &(req)->wb_flags);
 		dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
 
 		dprintk("NFS: commit (%s/%Ld %d@%Ld)",
@@ -1282,31 +1263,7 @@ static const struct rpc_call_ops nfs_commit_ops = {
 	.rpc_call_done = nfs_commit_done,
 	.rpc_release = nfs_commit_release,
 };
-#else
-static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
-{
-	return 0;
-}
-#endif
-
-static long nfs_flush_mapping(struct address_space *mapping, struct writeback_control *wbc, int how)
-{
-	struct nfs_inode *nfsi = NFS_I(mapping->host);
-	LIST_HEAD(head);
-	long res;
 
-	spin_lock(&nfsi->req_lock);
-	res = nfs_scan_dirty(mapping, wbc, &head);
-	spin_unlock(&nfsi->req_lock);
-	if (res) {
-		int error = nfs_flush_list(mapping->host, &head, res, how);
-		if (error < 0)
-			return error;
-	}
-	return res;
-}
-
-#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 int nfs_commit_inode(struct inode *inode, int how)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
@@ -1323,13 +1280,18 @@ int nfs_commit_inode(struct inode *inode, int how)
 	}
 	return res;
 }
+#else
+static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
+{
+	return 0;
+}
 #endif
 
 long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)
 {
 	struct inode *inode = mapping->host;
 	struct nfs_inode *nfsi = NFS_I(inode);
-	unsigned long idx_start, idx_end;
+	pgoff_t idx_start, idx_end;
 	unsigned int npages = 0;
 	LIST_HEAD(head);
 	int nocommit = how & FLUSH_NOCOMMIT;
@@ -1342,41 +1304,24 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr
 		idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
 		idx_end = wbc->range_end >> PAGE_CACHE_SHIFT;
 		if (idx_end > idx_start) {
-			unsigned long l_npages = 1 + idx_end - idx_start;
+			pgoff_t l_npages = 1 + idx_end - idx_start;
 			npages = l_npages;
 			if (sizeof(npages) != sizeof(l_npages) &&
-					(unsigned long)npages != l_npages)
+					(pgoff_t)npages != l_npages)
 				npages = 0;
 		}
 	}
 	how &= ~FLUSH_NOCOMMIT;
 	spin_lock(&nfsi->req_lock);
 	do {
-		wbc->pages_skipped = 0;
 		ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
 		if (ret != 0)
 			continue;
-		pages = nfs_scan_dirty(mapping, wbc, &head);
-		if (pages != 0) {
-			spin_unlock(&nfsi->req_lock);
-			if (how & FLUSH_INVALIDATE) {
-				nfs_cancel_dirty_list(&head);
-				ret = pages;
-			} else
-				ret = nfs_flush_list(inode, &head, pages, how);
-			spin_lock(&nfsi->req_lock);
-			continue;
-		}
-		if (wbc->pages_skipped != 0)
-			continue;
 		if (nocommit)
 			break;
 		pages = nfs_scan_commit(inode, &head, idx_start, npages);
-		if (pages == 0) {
-			if (wbc->pages_skipped != 0)
-				continue;
+		if (pages == 0)
 			break;
-		}
 		if (how & FLUSH_INVALIDATE) {
 			spin_unlock(&nfsi->req_lock);
 			nfs_cancel_commit_list(&head);
@@ -1408,7 +1353,7 @@ int nfs_wb_all(struct inode *inode)
 	};
 	int ret;
 
-	ret = generic_writepages(mapping, &wbc);
+	ret = nfs_writepages(mapping, &wbc);
 	if (ret < 0)
 		goto out;
 	ret = nfs_sync_mapping_wait(mapping, &wbc, 0);
@@ -1431,11 +1376,9 @@ int nfs_sync_mapping_range(struct address_space *mapping, loff_t range_start, lo
 	};
 	int ret;
 
-	if (!(how & FLUSH_NOWRITEPAGE)) {
-		ret = generic_writepages(mapping, &wbc);
-		if (ret < 0)
-			goto out;
-	}
+	ret = nfs_writepages(mapping, &wbc);
+	if (ret < 0)
+		goto out;
 	ret = nfs_sync_mapping_wait(mapping, &wbc, how);
 	if (ret >= 0)
 		return 0;
@@ -1458,7 +1401,7 @@ int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
 	int ret;
 
 	BUG_ON(!PageLocked(page));
-	if (!(how & FLUSH_NOWRITEPAGE) && clear_page_dirty_for_io(page)) {
+	if (clear_page_dirty_for_io(page)) {
 		ret = nfs_writepage_locked(page, &wbc);
 		if (ret < 0)
 			goto out;
@@ -1483,15 +1426,32 @@ int nfs_wb_page(struct inode *inode, struct page* page)
 
 int nfs_set_page_dirty(struct page *page)
 {
+	struct address_space *mapping = page->mapping;
+	struct inode *inode;
+	spinlock_t *req_lock;
 	struct nfs_page *req;
+	int ret;
 
-	req = nfs_page_find_request(page);
+	if (!mapping)
+		goto out_raced;
+	inode = mapping->host;
+	if (!inode)
+		goto out_raced;
+	req_lock = &NFS_I(inode)->req_lock;
+	spin_lock(req_lock);
+	req = nfs_page_find_request_locked(page);
 	if (req != NULL) {
 		/* Mark any existing write requests for flushing */
-		set_bit(PG_NEED_FLUSH, &req->wb_flags);
+		ret = !test_and_set_bit(PG_NEED_FLUSH, &req->wb_flags);
+		spin_unlock(req_lock);
 		nfs_release_request(req);
+		return ret;
 	}
-	return __set_page_dirty_nobuffers(page);
+	ret = __set_page_dirty_nobuffers(page);
+	spin_unlock(req_lock);
+	return ret;
+out_raced:
+	return !TestSetPageDirty(page);
 }
 
 
@@ -1514,6 +1474,26 @@ int __init nfs_init_writepagecache(void)
 	if (nfs_commit_mempool == NULL)
 		return -ENOMEM;
 
+	/*
+	 * NFS congestion size, scale with available memory.
+	 *
+	 *  64MB:    8192k
+	 * 128MB:   11585k
+	 * 256MB:   16384k
+	 * 512MB:   23170k
+	 *   1GB:   32768k
+	 *   2GB:   46340k
+	 *   4GB:   65536k
+	 *   8GB:   92681k
+	 *  16GB:  131072k
+	 *
+	 * This allows larger machines to have larger/more transfers.
+	 * Limit the default to 256M
+	 */
+	nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
+	if (nfs_congestion_kb > 256*1024)
+		nfs_congestion_kb = 256*1024;
+
 	return 0;
 }