[PATCH 2/5] pNFS: recoalesce when ld read pagelist fails

[Peng Tao <bergwolf@gmail.com>]

For pnfs pagelist read failure, we need to pg_recoalesce and resend
IO to mds.

Signed-off-by: Peng Tao <peng_tao@emc.com>
---
 fs/nfs/internal.h |    2 ++
 fs/nfs/pnfs.c     |   18 ++++++++++++++----
 fs/nfs/read.c     |    3 ++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 62f183d..78b662e 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -307,6 +307,8 @@ extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 		struct list_head *head);
 extern int do_nfs_writepage(struct page *page, struct writeback_control *wbc,
 		struct nfs_pageio_descriptor *pgio);
+extern void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+		struct inode *inode);
 extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
 		struct inode *inode, int ioflags);
 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 08aba45..66fc854 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1300,7 +1300,7 @@ EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
 int
 pnfs_ld_read_done(struct nfs_read_data *data)
 {
-	int status;
+	struct nfs_pageio_descriptor pgio;
 
 	if (!data->pnfs_error) {
 		__nfs4_read_done_cb(data);
@@ -1309,11 +1309,21 @@ pnfs_ld_read_done(struct nfs_read_data *data)
 		return 0;
 	}
 
+	put_lseg(data->lseg);
+	data->lseg = NULL;
 	dprintk("%s: pnfs_error=%d, retry via MDS\n", __func__,
 		data->pnfs_error);
-	status = nfs_initiate_read(data, NFS_CLIENT(data->inode),
-				   data->mds_ops);
-	return status ? : -EAGAIN;
+	nfs_pageio_init_read_mds(&pgio, data->inode);
+	pgio.pg_recoalesce = 1;
+	while (!list_empty(&data->pages)) {
+		struct nfs_page *req = nfs_list_entry(data->pages.next);
+
+		nfs_pageio_add_request(&pgio, req);
+	}
+	nfs_pageio_complete(&pgio);
+	nfs_readdata_release(data);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
 
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 2171c04..2484131 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -112,12 +112,13 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
 	}
 }
 
-static void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
 		struct inode *inode)
 {
 	nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,
 			NFS_SERVER(inode)->rsize, 0);
 }
+EXPORT_SYMBOL_GPL(nfs_pageio_init_read_mds);
 
 void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
 {
-- 
1.7.1.262.g5ef3d