NFS: create completion structure to pass into page_init functions

Factors out the code that will need to change when directio
starts using these code paths.  This will allow directio to use
the generic pagein and flush routines

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

6 files changed, 85 insertions, 51 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 16bc9c47c83e..3ef8fcda1a5f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -300,11 +300,10 @@ extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
 #endif
 
+struct nfs_pgio_completion_ops;
 /* read.c */
-extern void nfs_async_read_error(struct list_head *head);
 extern struct nfs_read_header *nfs_readhdr_alloc(void);
 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
-extern void nfs_read_completion(struct nfs_pgio_header *hdr);
 extern struct nfs_read_data *nfs_readdata_alloc(struct nfs_pgio_header *hdr,
 						unsigned int pagecount);
 extern int nfs_initiate_read(struct rpc_clnt *clnt,
@@ -314,21 +313,21 @@ 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_init_read_mds(struct nfs_pageio_descriptor *pgio,
-		struct inode *inode);
+			struct inode *inode,
+			const struct nfs_pgio_completion_ops *compl_ops);
 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 
 /* write.c */
-extern void nfs_async_write_error(struct list_head *head);
 extern struct nfs_write_header *nfs_writehdr_alloc(void);
 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
 extern struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
 						  unsigned int pagecount);
-extern void nfs_write_completion(struct nfs_pgio_header *hdr);
 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 			     struct nfs_pgio_header *hdr);
 extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
-				  struct inode *inode, int ioflags);
+			struct inode *inode, int ioflags,
+			const struct nfs_pgio_completion_ops *compl_ops);
 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);
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index cd4c038135a7..4cf2a68493e0 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -49,6 +49,7 @@ void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 	hdr->io_start = req_offset(hdr->req);
 	hdr->good_bytes = desc->pg_count;
 	hdr->release = release;
+	hdr->completion_ops = desc->pg_completion_ops;
 }
 
 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
@@ -240,6 +241,7 @@ EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
 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,
 		     size_t bsize,
 		     int io_flags)
 {
@@ -252,6 +254,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
 	desc->pg_recoalesce = 0;
 	desc->pg_inode = inode;
 	desc->pg_ops = pg_ops;
+	desc->pg_completion_ops = compl_ops;
 	desc->pg_ioflags = io_flags;
 	desc->pg_error = 0;
 	desc->pg_lseg = NULL;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index d515f00614cd..b3a0c01718af 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1113,26 +1113,31 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
 
 bool
-pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode)
+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)
 		return false;
-	nfs_pageio_init(pgio, inode, ld->pg_read_ops, server->rsize, 0);
+	nfs_pageio_init(pgio, inode, ld->pg_read_ops, compl_ops,
+			server->rsize, 0);
 	return true;
 }
 
 bool
-pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags)
+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)
 		return false;
-	nfs_pageio_init(pgio, inode, ld->pg_write_ops, server->wsize, ioflags);
+	nfs_pageio_init(pgio, inode, ld->pg_write_ops, compl_ops,
+			server->wsize, ioflags);
 	return true;
 }
 
@@ -1162,13 +1167,15 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
 
-static int pnfs_write_done_resend_to_mds(struct inode *inode, struct list_head *head)
+static int pnfs_write_done_resend_to_mds(struct inode *inode,
+				struct list_head *head,
+				const struct nfs_pgio_completion_ops *compl_ops)
 {
 	struct nfs_pageio_descriptor pgio;
 	LIST_HEAD(failed);
 
 	/* Resend all requests through the MDS */
-	nfs_pageio_init_write_mds(&pgio, inode, FLUSH_STABLE);
+	nfs_pageio_init_write_mds(&pgio, inode, FLUSH_STABLE, compl_ops);
 	while (!list_empty(head)) {
 		struct nfs_page *req = nfs_list_entry(head->next);
 
@@ -1201,7 +1208,8 @@ static void pnfs_ld_handle_write_error(struct nfs_write_data *data)
 	}
 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
 		data->task.tk_status = pnfs_write_done_resend_to_mds(hdr->inode,
-								&hdr->pages);
+							&hdr->pages,
+							hdr->completion_ops);
 }
 
 /*
@@ -1292,7 +1300,7 @@ pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 
 	whdr = nfs_writehdr_alloc();
 	if (!whdr) {
-		nfs_async_write_error(&desc->pg_list);
+		desc->pg_completion_ops->error_cleanup(&hdr->pages);
 		put_lseg(desc->pg_lseg);
 		desc->pg_lseg = NULL;
 		return -ENOMEM;
@@ -1309,18 +1317,20 @@ pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 	} else
 		pnfs_do_multiple_writes(desc, &hdr->rpc_list, desc->pg_ioflags);
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_write_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
 
-static int pnfs_read_done_resend_to_mds(struct inode *inode, struct list_head *head)
+static int pnfs_read_done_resend_to_mds(struct inode *inode,
+				struct list_head *head,
+				const struct nfs_pgio_completion_ops *compl_ops)
 {
 	struct nfs_pageio_descriptor pgio;
 	LIST_HEAD(failed);
 
 	/* Resend all requests through the MDS */
-	nfs_pageio_init_read_mds(&pgio, inode);
+	nfs_pageio_init_read_mds(&pgio, inode, compl_ops);
 	while (!list_empty(head)) {
 		struct nfs_page *req = nfs_list_entry(head->next);
 
@@ -1349,7 +1359,8 @@ static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
 	}
 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
 		data->task.tk_status = pnfs_read_done_resend_to_mds(hdr->inode,
-								&hdr->pages);
+							&hdr->pages,
+							hdr->completion_ops);
 }
 
 /*
@@ -1443,7 +1454,7 @@ pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 
 	rhdr = nfs_readhdr_alloc();
 	if (!rhdr) {
-		nfs_async_read_error(&desc->pg_list);
+		desc->pg_completion_ops->error_cleanup(&desc->pg_list);
 		ret = -ENOMEM;
 		put_lseg(desc->pg_lseg);
 		desc->pg_lseg = NULL;
@@ -1461,7 +1472,7 @@ pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 	} else
 		pnfs_do_multiple_reads(desc, &hdr->rpc_list);
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_read_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 442ebf68eeec..734e4eff7fb0 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -168,8 +168,10 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 void put_lseg(struct pnfs_layout_segment *lseg);
 
-bool pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
-bool pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *, int);
+bool pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *,
+			   const struct nfs_pgio_completion_ops *);
+bool 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 *);
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index c9633b2501bd..5e78af162039 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -31,6 +31,7 @@
 
 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 struct kmem_cache *nfs_rdata_cachep;
 
@@ -95,7 +96,7 @@ void nfs_readdata_release(struct nfs_read_data *rdata)
 	else
 		rdata->header = NULL;
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_read_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 }
 
 static
@@ -108,9 +109,10 @@ int nfs_return_empty_page(struct page *page)
 }
 
 void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
-		struct inode *inode)
+			      struct inode *inode,
+			      const struct nfs_pgio_completion_ops *compl_ops)
 {
-	nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,
+	nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, compl_ops,
 			NFS_SERVER(inode)->rsize, 0);
 }
 
@@ -122,10 +124,11 @@ void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
 EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
 
 static void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
-		struct inode *inode)
+				struct inode *inode,
+				const struct nfs_pgio_completion_ops *compl_ops)
 {
-	if (!pnfs_pageio_init_read(pgio, inode))
-		nfs_pageio_init_read_mds(pgio, inode);
+	if (!pnfs_pageio_init_read(pgio, inode, compl_ops))
+		nfs_pageio_init_read_mds(pgio, inode, compl_ops);
 }
 
 int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
@@ -146,7 +149,7 @@ 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_pageio_init_read(&pgio, inode);
+	nfs_pageio_init_read(&pgio, inode, &nfs_async_read_completion_ops);
 	nfs_pageio_add_request(&pgio, new);
 	nfs_pageio_complete(&pgio);
 	return 0;
@@ -170,7 +173,7 @@ static void nfs_readpage_release(struct nfs_page *req)
 }
 
 /* Note io was page aligned */
-void nfs_read_completion(struct nfs_pgio_header *hdr)
+static void nfs_read_completion(struct nfs_pgio_header *hdr)
 {
 	unsigned long bytes = 0;
 
@@ -300,7 +303,7 @@ nfs_do_multiple_reads(struct list_head *head,
 	return ret;
 }
 
-void
+static void
 nfs_async_read_error(struct list_head *head)
 {
 	struct nfs_page	*req;
@@ -312,6 +315,11 @@ nfs_async_read_error(struct list_head *head)
 	}
 }
 
+static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
+	.error_cleanup = nfs_async_read_error,
+	.completion = nfs_read_completion,
+};
+
 /*
  * Generate multiple requests to fill a single page.
  *
@@ -362,7 +370,7 @@ out_bad:
 		list_del(&data->list);
 		nfs_readdata_release(data);
 	}
-	nfs_async_read_error(&hdr->pages);
+	desc->pg_completion_ops->error_cleanup(&hdr->pages);
 	return -ENOMEM;
 }
 
@@ -378,7 +386,7 @@ static int nfs_pagein_one(struct nfs_pageio_descriptor *desc,
 	data = nfs_readdata_alloc(hdr, nfs_page_array_len(desc->pg_base,
 							  desc->pg_count));
 	if (!data) {
-		nfs_async_read_error(head);
+		desc->pg_completion_ops->error_cleanup(head);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -414,7 +422,7 @@ static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 
 	rhdr = nfs_readhdr_alloc();
 	if (!rhdr) {
-		nfs_async_read_error(&desc->pg_list);
+		desc->pg_completion_ops->error_cleanup(&desc->pg_list);
 		return -ENOMEM;
 	}
 	hdr = &rhdr->header;
@@ -427,7 +435,7 @@ static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
 	else
 		set_bit(NFS_IOHDR_REDO, &hdr->flags);
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_read_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 	return ret;
 }
 
@@ -652,7 +660,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
 	if (ret == 0)
 		goto read_complete; /* all pages were read */
 
-	nfs_pageio_init_read(&pgio, inode);
+	nfs_pageio_init_read(&pgio, inode, &nfs_async_read_completion_ops);
 
 	ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
 
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 076075eb676c..150397279b8d 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -40,10 +40,12 @@
  * Local function declarations
  */
 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
-				  struct inode *inode, int ioflags);
+			struct inode *inode, int ioflags,
+			const struct nfs_pgio_completion_ops *compl_ops);
 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 struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;
@@ -128,7 +130,7 @@ void nfs_writedata_release(struct nfs_write_data *wdata)
 	else
 		wdata->header = NULL;
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_write_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 }
 
 static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
@@ -337,7 +339,8 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
 	struct nfs_pageio_descriptor pgio;
 	int err;
 
-	nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc));
+	nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc),
+			      &nfs_async_write_completion_ops);
 	err = nfs_do_writepage(page, wbc, &pgio);
 	nfs_pageio_complete(&pgio);
 	if (err < 0)
@@ -380,7 +383,8 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
-	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
+	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc),
+			      &nfs_async_write_completion_ops);
 	err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
 	nfs_pageio_complete(&pgio);
 
@@ -558,7 +562,7 @@ int nfs_write_need_commit(struct nfs_write_data *data)
 
 #endif
 
-void nfs_write_completion(struct nfs_pgio_header *hdr)
+static void nfs_write_completion(struct nfs_pgio_header *hdr)
 {
 	unsigned long bytes = 0;
 
@@ -1000,7 +1004,7 @@ static void nfs_redirty_request(struct nfs_page *req)
 	nfs_end_page_writeback(page);
 }
 
-void nfs_async_write_error(struct list_head *head)
+static void nfs_async_write_error(struct list_head *head)
 {
 	struct nfs_page	*req;
 
@@ -1011,6 +1015,11 @@ void nfs_async_write_error(struct list_head *head)
 	}
 }
 
+static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
+	.error_cleanup = nfs_async_write_error,
+	.completion = nfs_write_completion,
+};
+
 /*
  * Generate multiple small requests to write out a single
  * contiguous dirty area on one page.
@@ -1060,7 +1069,7 @@ out_bad:
 		list_del(&data->list);
 		nfs_writedata_release(data);
 	}
-	nfs_async_write_error(&hdr->pages);
+	desc->pg_completion_ops->error_cleanup(&hdr->pages);
 	return -ENOMEM;
 }
 
@@ -1084,7 +1093,7 @@ static int nfs_flush_one(struct nfs_pageio_descriptor *desc,
 	data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base,
 							   desc->pg_count));
 	if (!data) {
-		nfs_async_write_error(head);
+		desc->pg_completion_ops->error_cleanup(head);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -1125,7 +1134,7 @@ static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 
 	whdr = nfs_writehdr_alloc();
 	if (!whdr) {
-		nfs_async_write_error(&desc->pg_list);
+		desc->pg_completion_ops->error_cleanup(&hdr->pages);
 		return -ENOMEM;
 	}
 	hdr = &whdr->header;
@@ -1139,7 +1148,7 @@ static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 	else
 		set_bit(NFS_IOHDR_REDO, &hdr->flags);
 	if (atomic_dec_and_test(&hdr->refcnt))
-		nfs_write_completion(hdr);
+		hdr->completion_ops->completion(hdr);
 	return ret;
 }
 
@@ -1149,9 +1158,10 @@ static const struct nfs_pageio_ops nfs_pageio_write_ops = {
 };
 
 void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
-				  struct inode *inode, int ioflags)
+			       struct inode *inode, int ioflags,
+			       const struct nfs_pgio_completion_ops *compl_ops)
 {
-	nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops,
+	nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops,
 				NFS_SERVER(inode)->wsize, ioflags);
 }
 
@@ -1163,10 +1173,11 @@ void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
 EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
 
 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
-				  struct inode *inode, int ioflags)
+				struct inode *inode, int ioflags,
+				const struct nfs_pgio_completion_ops *compl_ops)
 {
-	if (!pnfs_pageio_init_write(pgio, inode, ioflags))
-		nfs_pageio_init_write_mds(pgio, inode, ioflags);
+	if (!pnfs_pageio_init_write(pgio, inode, ioflags, compl_ops))
+		nfs_pageio_init_write_mds(pgio, inode, ioflags, compl_ops);
 }
 
 void nfs_write_prepare(struct rpc_task *task, void *calldata)