NFS: Create a generic_pgio function

These functions are almost identical on both the read and write side.
FLUSH_COND_STABLE will never be set for the read path, so leaving it in
the generic code won't hurt anything.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

5 files changed, 106 insertions, 192 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index a4b9e75..365cdb1 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -237,14 +237,10 @@ extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 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 rpc_call_ops nfs_pgio_common_ops;
 struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *);
 void nfs_rw_header_free(struct nfs_pgio_header *);
-struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *, unsigned int);
 void nfs_pgio_data_release(struct nfs_pgio_data *);
-int nfs_pgio_error(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
-void nfs_pgio_rpcsetup(struct nfs_pgio_data *, unsigned int, unsigned int, int,
-		       struct nfs_commit_info *);
+int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
 
 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 {
@@ -410,8 +406,6 @@ extern int nfs_initiate_read(struct rpc_clnt *clnt,
 			     struct nfs_pgio_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);
 
 /* super.c */
@@ -429,8 +423,6 @@ int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 			struct inode *inode, int ioflags, bool force_mds,
 			const struct nfs_pgio_completion_ops *compl_ops);
-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_commit_free(struct nfs_commit_data *p);
 extern int nfs_initiate_write(struct rpc_clnt *clnt,
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index b0a98da..d8d25a4 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -27,6 +27,7 @@
 #define NFSDBG_FACILITY		NFSDBG_PAGECACHE
 
 static struct kmem_cache *nfs_page_cachep;
+static const struct rpc_call_ops nfs_pgio_common_ops;
 
 static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
 {
@@ -338,8 +339,8 @@ EXPORT_SYMBOL_GPL(nfs_rw_header_free);
  * @hdr: The header making a request
  * @pagecount: Number of pages to create
  */
-struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
-					  unsigned int pagecount)
+static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
+						 unsigned int pagecount)
 {
 	struct nfs_pgio_data *data, *prealloc;
 
@@ -396,7 +397,7 @@ EXPORT_SYMBOL_GPL(nfs_pgio_data_release);
  * @how: How to commit data (writes only)
  * @cinfo: Commit information for the call (writes only)
  */
-void nfs_pgio_rpcsetup(struct nfs_pgio_data *data,
+static void nfs_pgio_rpcsetup(struct nfs_pgio_data *data,
 			      unsigned int count, unsigned int offset,
 			      int how, struct nfs_commit_info *cinfo)
 {
@@ -451,7 +452,7 @@ static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
  * @desc: IO descriptor
  * @hdr: pageio header
  */
-int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
+static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
 			  struct nfs_pgio_header *hdr)
 {
 	struct nfs_pgio_data *data;
@@ -534,6 +535,101 @@ static void nfs_pgio_result(struct rpc_task *task, void *calldata)
 		data->header->rw_ops->rw_result(task, data);
 }
 
+/*
+ * Generate multiple small requests to read or write a single
+ * contiguous dirty on one page.
+ */
+static int nfs_pgio_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_pgio_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_pgio_data_alloc(hdr, 1);
+		if (!data)
+			return nfs_pgio_error(desc, hdr);
+		data->pages.pagevec[0] = page;
+		nfs_pgio_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_pgio_common_ops;
+	return 0;
+}
+
+/*
+ * 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.
+ */
+static int nfs_pgio_one(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);
+	list_add(&data->list, &hdr->rpc_list);
+	desc->pg_rpc_callops = &nfs_pgio_common_ops;
+	return 0;
+}
+
+int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
+		     struct nfs_pgio_header *hdr)
+{
+	if (desc->pg_bsize < PAGE_CACHE_SIZE)
+		return nfs_pgio_multi(desc, hdr);
+	return nfs_pgio_one(desc, hdr);
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pgio);
+
 static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
 		const struct nfs_open_context *ctx2)
 {
@@ -741,7 +837,7 @@ void nfs_destroy_nfspagecache(void)
 	kmem_cache_destroy(nfs_page_cachep);
 }
 
-const struct rpc_call_ops nfs_pgio_common_ops = {
+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,
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 54c84c1..0fe6701 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1607,7 +1607,7 @@ 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;
@@ -1766,7 +1766,7 @@ 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;
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 64f8eef..4fcef82 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -237,85 +237,6 @@ static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
 	.completion = nfs_read_completion,
 };
 
-/*
- * 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_pgio_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_pgio_data_alloc(hdr, 1);
-		if (!data)
-			return nfs_pgio_error(desc, hdr);
-		data->pages.pagevec[0] = page;
-		nfs_pgio_rpcsetup(data, len, offset, 0, NULL);
-		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_pgio_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_pgio_data	*data;
-	struct list_head *head = &desc->pg_list;
-
-	data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base,
-							  desc->pg_count));
-	if (!data)
-		return nfs_pgio_error(desc, hdr);
-
-	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_pgio_rpcsetup(data, desc->pg_count, 0, 0, NULL);
-	list_add(&data->list, &hdr->rpc_list);
-	desc->pg_rpc_callops = &nfs_pgio_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_rw_header *rhdr;
@@ -330,7 +251,7 @@ static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 	hdr = &rhdr->header;
 	nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
 	atomic_inc(&hdr->refcnt);
-	ret = nfs_generic_pagein(desc, hdr);
+	ret = nfs_generic_pgio(desc, hdr);
 	if (ret == 0)
 		ret = nfs_do_multiple_reads(&hdr->rpc_list,
 					    desc->pg_rpc_callops);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 02d088b..0e34c70 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1044,101 +1044,6 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
 	.completion = nfs_write_completion,
 };
 
-/*
- * 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_pgio_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_pgio_data_alloc(hdr, 1);
-		if (!data)
-			return nfs_pgio_error(desc, hdr);
-		data->pages.pagevec[0] = page;
-		nfs_pgio_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_pgio_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_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);
-	list_add(&data->list, &hdr->rpc_list);
-	desc->pg_rpc_callops = &nfs_pgio_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_rw_header *whdr;
@@ -1153,7 +1058,7 @@ static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 	hdr = &whdr->header;
 	nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
 	atomic_inc(&hdr->refcnt);
-	ret = nfs_generic_flush(desc, hdr);
+	ret = nfs_generic_pgio(desc, hdr);
 	if (ret == 0)
 		ret = nfs_do_multiple_writes(&hdr->rpc_list,
 					     desc->pg_rpc_callops,