NFS: rewrite directio write to use async coalesce code

This also has the advantage that it allows directio to use pnfs.
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/internal.h

@@ -320,10 +320,11 @@ 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_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+			struct inode *inode, int ioflags,
+			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 struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
-						  unsigned int pagecount);
 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,
@@ -346,6 +347,15 @@ extern void nfs_init_commit(struct nfs_commit_data *data,
 			    struct list_head *head,
 			    struct pnfs_layout_segment *lseg,
 			    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);
+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,
+			     struct pnfs_layout_segment *lseg,
+			     struct nfs_commit_info *cinfo);
+int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
+			    int how, struct nfs_commit_info *cinfo);
 void nfs_retry_commit(struct list_head *page_list,
 		      struct pnfs_layout_segment *lseg,
 		      struct nfs_commit_info *cinfo);
@@ -365,6 +375,10 @@ extern int nfs_migrate_page(struct address_space *,
 #define nfs_migrate_page NULL
 #endif
 
+/* direct.c */
+void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
+			      struct nfs_direct_req *dreq);
+
 /* nfs4proc.c */
 extern void __nfs4_read_done_cb(struct nfs_read_data *);
 extern void nfs4_reset_read(struct rpc_task *task, struct nfs_read_data *data);

fs/nfs/nfs4filelayout.c

@@ -996,12 +996,9 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
 }
 
 static int
-filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
-			       struct nfs_commit_info *cinfo,
-			       int max)
+transfer_commit_list(struct list_head *src, struct list_head *dst,
+		     struct nfs_commit_info *cinfo, int max)
 {
-	struct list_head *src = &bucket->written;
-	struct list_head *dst = &bucket->committing;
 	struct nfs_page *req, *tmp;
 	int ret = 0;
 
@@ -1014,9 +1011,22 @@ filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
 		nfs_list_add_request(req, dst);
 		ret++;
-		if (ret == max)
+		if ((ret == max) && !cinfo->dreq)
 			break;
 	}
+	return ret;
+}
+
+static int
+filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
+			       struct nfs_commit_info *cinfo,
+			       int max)
+{
+	struct list_head *src = &bucket->written;
+	struct list_head *dst = &bucket->committing;
+	int ret;
+
+	ret = transfer_commit_list(src, dst, cinfo, max);
 	if (ret) {
 		cinfo->ds->nwritten -= ret;
 		cinfo->ds->ncommitting += ret;
@@ -1046,6 +1056,27 @@ static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
 	return rv;
 }
 
+/* Pull everything off the committing lists and dump into @dst */
+static void filelayout_recover_commit_reqs(struct list_head *dst,
+					   struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_bucket *b;
+	int i;
+
+	/* NOTE cinfo->lock is NOT held, relying on fact that this is
+	 * only called on single thread per dreq.
+	 * Can't take the lock because need to do put_lseg
+	 */
+	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+		if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
+			BUG_ON(!list_empty(&b->written));
+			put_lseg(b->wlseg);
+			b->wlseg = NULL;
+		}
+	}
+	cinfo->ds->nwritten = 0;
+}
+
 static unsigned int
 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
 {
@@ -1170,6 +1201,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.mark_request_commit	= filelayout_mark_request_commit,
 	.clear_request_commit	= filelayout_clear_request_commit,
 	.scan_commit_lists	= filelayout_scan_commit_lists,
+	.recover_commit_reqs	= filelayout_recover_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,

fs/nfs/pnfs.h

@@ -102,6 +102,8 @@ struct pnfs_layoutdriver_type {
 				      struct nfs_commit_info *cinfo);
 	int (*scan_commit_lists) (struct nfs_commit_info *cinfo,
 				  int max);
+	void (*recover_commit_reqs) (struct list_head *list,
+				     struct nfs_commit_info *cinfo);
 	int (*commit_pagelist)(struct inode *inode,
 			       struct list_head *mds_pages,
 			       int how,
@@ -323,6 +325,15 @@ pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
 		return NFS_SERVER(inode)->pnfs_curr_ld->scan_commit_lists(cinfo, max);
 }
 
+static inline void
+pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
+			 struct nfs_commit_info *cinfo)
+{
+	if (cinfo->ds == NULL || cinfo->ds->nwritten == 0)
+		return;
+	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
+}
+
 /* Should the pNFS client commit and return the layout upon a setattr */
 static inline bool
 pnfs_ld_layoutret_on_setattr(struct inode *inode)
@@ -456,6 +467,12 @@ pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
 	return 0;
 }
 
+static inline void
+pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
+			 struct nfs_commit_info *cinfo)
+{
+}
+
 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 {
 	return 0;

fs/nfs/write.c

@@ -39,9 +39,6 @@
 /*
  * Local function declarations
  */
-static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc,
-			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;
@@ -87,8 +84,8 @@ struct nfs_write_header *nfs_writehdr_alloc(void)
 	return p;
 }
 
-struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
-					   unsigned int pagecount)
+static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr,
+						  unsigned int pagecount)
 {
 	struct nfs_write_data *data, *prealloc;
 
@@ -518,14 +515,17 @@ void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 		    struct inode *inode,
 		    struct nfs_direct_req *dreq)
 {
-	nfs_init_cinfo_from_inode(cinfo, inode);
+	if (dreq)
+		nfs_init_cinfo_from_dreq(cinfo, dreq);
+	else
+		nfs_init_cinfo_from_inode(cinfo, inode);
 }
 EXPORT_SYMBOL_GPL(nfs_init_cinfo);
 
 /*
  * Add a request to the inode's commit list.
  */
-static void
+void
 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
 			struct nfs_commit_info *cinfo)
 {
@@ -567,7 +567,7 @@ int nfs_write_need_commit(struct nfs_write_data *data)
 }
 
 #else
-static void
+void
 nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
 			struct nfs_commit_info *cinfo)
 {
@@ -632,7 +632,7 @@ nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
 }
 
 /* cinfo->lock held by caller */
-static int
+int
 nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 		     struct nfs_commit_info *cinfo, int max)
 {
@@ -647,7 +647,7 @@ nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 		nfs_request_remove_commit_list(req, cinfo);
 		nfs_list_add_request(req, dst);
 		ret++;
-		if (ret == max)
+		if ((ret == max) && !cinfo->dreq)
 			break;
 	}
 	return ret;
@@ -662,7 +662,7 @@ nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
  * Moves requests from the inode's 'commit' request list.
  * The requests are *not* checked to ensure that they form a contiguous set.
  */
-static int
+int
 nfs_scan_commit(struct inode *inode, struct list_head *dst,
 		struct nfs_commit_info *cinfo)
 {
@@ -686,8 +686,8 @@ static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
 	return 0;
 }
 
-static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst,
-				  struct nfs_commit_info *cinfo)
+int nfs_scan_commit(struct inode *inode, struct list_head *dst,
+		    struct nfs_commit_info *cinfo)
 {
 	return 0;
 }
@@ -1202,9 +1202,9 @@ 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,
-				const struct nfs_pgio_completion_ops *compl_ops)
+void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+			   struct inode *inode, int ioflags,
+			   const struct nfs_pgio_completion_ops *compl_ops)
 {
 	if (!pnfs_pageio_init_write(pgio, inode, ioflags, compl_ops))
 		nfs_pageio_init_write_mds(pgio, inode, ioflags, compl_ops);
@@ -1568,8 +1568,8 @@ static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
 	.error_cleanup = nfs_commit_clear_lock,
 };
 
-static int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
-				   int how, struct nfs_commit_info *cinfo)
+int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
+			    int how, struct nfs_commit_info *cinfo)
 {
 	int status;