pnfs: add set-clear layoutdriver interface

To allow layout driver to issue getdevicelist at mount time, and clean up
at umount time.

[fixup non NFS_V4_1 set_pnfs_layoutdriver definition]
[pnfs: pass mntfh down the init_pnfs path]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 7074394944a9..bddd8b997e18 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -80,6 +80,9 @@ struct pnfs_layoutdriver_type {
         struct module *owner;
         unsigned flags;
 
+        int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
+        int (*clear_layoutdriver) (struct nfs_server *);
+
         struct pnfs_layout_hdr * (*alloc_layout_hdr) (struct inode *inode, gfp_t gfp_flags);
         void (*free_layout_hdr) (struct pnfs_layout_hdr *);
 
@@ -167,7 +170,7 @@ 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);
 
-void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
+void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
 void unset_pnfs_layoutdriver(struct nfs_server *);
 void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
 int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
@@ -374,7 +377,8 @@ pnfs_roc_drain(struct inode *ino, u32 *barrier)
         return false;
 }
 
-static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
+static inline void set_pnfs_layoutdriver(struct nfs_server *s,
+                                         const struct nfs_fh *mntfh, u32 id);
 {
 }