[pnfs] [PATCH 7/8] pnfs: pnfs_modify_new_request

[Fred Isaman]

Add hook into nfs_page initialization to allow for setting of
PG_USE_PNFS.

Signed-off-by: Fred Isaman <iisaman at citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy at panasas.com>
---
 fs/nfs/pagelist.c         |    1 +
 fs/nfs/pnfs.c             |   19 +++++++++++++++++++
 fs/nfs/pnfs.h             |   15 +++++++++++++++
 include/linux/nfs4_pnfs.h |    3 +++
 4 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 43634d3..04f9fd6 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -87,6 +87,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
 	req->wb_bytes   = count;
 	req->wb_context = get_nfs_open_context(ctx);
 	kref_init(&req->wb_kref);
+	pnfs_modify_new_request(req, fsdata);
 	return req;
 }
 
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 14760c2..c964beb 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1925,6 +1925,25 @@ out_unlock:
 	goto out;
 }
 
+/* Note that fsdata != NULL */
+void _pnfs_modify_new_write_request(struct nfs_page *req,
+				    struct pnfs_fsdata *fsdata)
+{
+	struct inode *inode = req->wb_page->mapping->host;
+	struct pnfs_layout_segment *lseg = NULL;
+	loff_t pos;
+	unsigned count;
+
+	pos = ((loff_t)req->wb_index << PAGE_CACHE_SHIFT) + req->wb_offset;
+	count = req->wb_bytes;
+	lseg = pnfs_find_get_lseg(inode, pos, count, IOMODE_RW);
+	if (lseg) {
+		if (fsdata->ok_to_use_pnfs)
+			set_bit(PG_USE_PNFS, &req->wb_flags);
+		put_lseg(lseg);
+	}
+}
+
 void pnfs_free_request_data(struct nfs_page *req)
 {
 	struct layoutdriver_io_operations *lo;
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index edbe85f..d6fca00 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -64,6 +64,8 @@ int _pnfs_write_begin(struct inode *inode, struct page *page,
 		      loff_t pos, unsigned len, void **fsdata);
 int _pnfs_do_flush(struct inode *inode, struct nfs_page *req,
 		   struct pnfs_fsdata *fsdata);
+void _pnfs_modify_new_write_request(struct nfs_page *req,
+				    struct pnfs_fsdata *fsdata);
 
 #define PNFS_EXISTS_LDIO_OP(srv, opname) ((srv)->pnfs_curr_ld &&	\
 				     (srv)->pnfs_curr_ld->ld_io_ops &&	\
@@ -155,6 +157,14 @@ static inline void pnfs_redirty_request(struct nfs_page *req)
 	clear_bit(PG_USE_PNFS, &req->wb_flags);
 }
 
+static inline void pnfs_modify_new_request(struct nfs_page *req,
+					   void *fsdata)
+{
+	if (fsdata)
+		_pnfs_modify_new_write_request(req, fsdata);
+	/* Should we do something (like set PG_USE_PNFS) if !fsdata ? */
+}
+
 #else  /* CONFIG_PNFS */
 
 static inline int pnfs_try_to_read_data(struct nfs_read_data *data,
@@ -194,6 +204,11 @@ static inline void pnfs_redirty_request(struct nfs_page *req)
 {
 }
 
+static inline void pnfs_modify_new_request(struct nfs_page *req,
+					   void *fsdata)
+{
+}
+
 #endif /* CONFIG_PNFS */
 
 #endif /* FS_NFS_PNFS_H */
diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
index 4233dee..e893ca6 100644
--- a/include/linux/nfs4_pnfs.h
+++ b/include/linux/nfs4_pnfs.h
@@ -141,6 +141,9 @@ struct layoutdriver_io_operations {
 	int (*write_begin) (struct pnfs_layout_segment *lseg, struct page *page,
 			    loff_t pos, unsigned count,
 			    struct pnfs_fsdata *fsdata);
+	void (*new_request)(struct pnfs_layout_segment *lseg,
+			    struct nfs_page *req, loff_t pos, unsigned count,
+			    struct pnfs_fsdata *fsdata);
 	void (*free_request_data) (struct nfs_page *);
 
 
-- 
1.5.3.3