[PATCH 14/26] pnfs_submit: use fsdata to pass lseg

[Fred Isaman <iisaman@netapp.com>]

Preparing for LAYUTGET invocation in nfs_write_begin to be the
only invocation in the write path.

It isn't used at all yet, but it should be properly referenced/dereferenced

Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
 fs/nfs/file.c |   21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 03601d2..e308244 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -414,12 +414,17 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	struct page *page;
 	int once_thru = 0;
+	struct pnfs_layout_segment *lseg;
 
 	dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
 		file->f_path.dentry->d_parent->d_name.name,
 		file->f_path.dentry->d_name.name,
 		mapping->host->i_ino, len, (long long) pos);
 
+	pnfs_update_layout(mapping->host,
+			   nfs_file_open_context(file),
+			   NFS4_MAX_UINT64, 0, IOMODE_RW,
+			   &lseg);
 start:
 	/*
 	 * Prevent starvation issues if someone is doing a consistency
@@ -428,11 +433,13 @@ start:
 	ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
 			nfs_wait_bit_killable, TASK_KILLABLE);
 	if (ret)
-		return ret;
+		goto out;
 
 	page = grab_cache_page_write_begin(mapping, index, flags);
-	if (!page)
-		return -ENOMEM;
+	if (!page) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	*pagep = page;
 
 	ret = nfs_flush_incompatible(file, page);
@@ -447,6 +454,12 @@ start:
 		if (!ret)
 			goto start;
 	}
+	*fsdata = lseg;
+ out:
+	if (ret) {
+		put_lseg(lseg);
+		*fsdata = NULL;
+	}
 	return ret;
 }
 
@@ -456,6 +469,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 {
 	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 	int status;
+	struct pnfs_layout_segment *lseg = fsdata;
 
 	dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
 		file->f_path.dentry->d_parent->d_name.name,
@@ -486,6 +500,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 
 	unlock_page(page);
 	page_cache_release(page);
+	put_lseg(lseg);
 
 	if (status < 0)
 		return status;
-- 
1.6.6.1