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 a4b9e754756b..365cdb11d0de 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 b0a98daae14c..d8d25a4deb88 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 54c84c128b2b..0fe670189fd1 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 64f8eefec76a..4fcef82d78b4 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 02d088b1d8e4..0e34c7024195 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,