pnfs: layoutret_on_setattr

With the objects layout security model, we have object capabilities
that are associated with the layout and we anticipate that the server
will issue a cb_layoutrecall for any setattr that changes security
related attributes (user/group/mode/acl) or truncates the file.

Therefore, the layout is returned before issuing the setattr to avoid
the anticipated cb_layoutrecall.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index c34f7a0e3bc2..af3967a893a1 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -65,6 +65,11 @@ enum {
 	NFS_LAYOUT_DESTROYED,		/* no new use of layout allowed */
 };
 
+enum layoutdriver_policy_flags {
+	/* Should the pNFS client commit and return the layout upon a setattr */
+	PNFS_LAYOUTRET_ON_SETATTR	= 1 << 0,
+};
+
 struct nfs4_deviceid_node;
 
 /* Per-layout driver specific registration structure */
@@ -73,6 +78,7 @@ struct pnfs_layoutdriver_type {
 	const u32 id;
 	const char *name;
 	struct module *owner;
+	unsigned flags;
 
 	struct pnfs_layout_hdr * (*alloc_layout_hdr) (struct inode *inode, gfp_t gfp_flags);
 	void (*free_layout_hdr) (struct pnfs_layout_hdr *);
@@ -258,6 +264,16 @@ static inline void pnfs_clear_request_commit(struct nfs_page *req)
 		put_lseg(req->wb_commit_lseg);
 }
 
+/* Should the pNFS client commit and return the layout upon a setattr */
+static inline bool
+pnfs_ld_layoutret_on_setattr(struct inode *inode)
+{
+	if (!pnfs_enabled_sb(NFS_SERVER(inode)))
+		return false;
+	return NFS_SERVER(inode)->pnfs_curr_ld->flags &
+		PNFS_LAYOUTRET_ON_SETATTR;
+}
+
 static inline int pnfs_return_layout(struct inode *ino)
 {
 	struct nfs_inode *nfsi = NFS_I(ino);
@@ -317,6 +333,12 @@ static inline int pnfs_return_layout(struct inode *ino)
 }
 
 static inline bool
+pnfs_ld_layoutret_on_setattr(struct inode *inode)
+{
+	return false;
+}
+
+static inline bool
 pnfs_roc(struct inode *ino)
 {
 	return false;