[pnfs] [PATCH 25/38] [v1] pnfs: client layout cache: require layout driver {alloc, free}_lseg

[Benny Halevy]

mandate implementation of the layout driver's alloc_lseg
and free_lseg methods.

Signed-off-by: Benny Halevy <bhalevy at panasas.com>
---
 fs/nfs/pnfs.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c95659b..82b65bc 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -271,6 +271,12 @@ pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 		return NULL;
 	}
 
+	if (!io_ops->alloc_lseg || !io_ops->free_lseg) {
+		printk(KERN_ERR "%s Layout driver must provide "
+		       "alloc_lseg and free_lseg.\n", __FUNCTION__);
+		return NULL;
+	}
+
 	pnfs_mod = kmalloc(sizeof(struct pnfs_module), GFP_KERNEL);
 	if (pnfs_mod != NULL) {
 		dprintk("%s Registering id:%u name:%s\n",
-- 
1.5.3.3