NFSv4.1: pnfs: full mount/umount infrastructure
Allow a module implementing a layout type to register, and
have its mount/umount routines called for filesystems that
the server declares support it.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Bian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b483026..cf79562 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -32,16 +32,51 @@
#define NFSDBG_FACILITY NFSDBG_PNFS
-/* STUB that returns the equivalent of "no module found" */
+/* Locking:
+ *
+ * pnfs_spinlock:
+ * protects pnfs_modules_tbl.
+ */
+static DEFINE_SPINLOCK(pnfs_spinlock);
+
+/*
+ * pnfs_modules_tbl holds all pnfs modules
+ */
+static LIST_HEAD(pnfs_modules_tbl);
+
+/* Return the registered pnfs layout driver module matching given id */
+static struct pnfs_layoutdriver_type *
+find_pnfs_driver_locked(u32 id)
+{
+ struct pnfs_layoutdriver_type *local;
+
+ list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
+ if (local->id == id)
+ goto out;
+ local = NULL;
+out:
+ dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
+ return local;
+}
+
static struct pnfs_layoutdriver_type *
find_pnfs_driver(u32 id)
{
- return NULL;
+ struct pnfs_layoutdriver_type *local;
+
+ spin_lock(&pnfs_spinlock);
+ local = find_pnfs_driver_locked(id);
+ spin_unlock(&pnfs_spinlock);
+ return local;
}
void
unset_pnfs_layoutdriver(struct nfs_server *nfss)
{
+ if (nfss->pnfs_curr_ld) {
+ nfss->pnfs_curr_ld->uninitialize_mountpoint(nfss);
+ module_put(nfss->pnfs_curr_ld->owner);
+ }
nfss->pnfs_curr_ld = NULL;
}
@@ -74,7 +109,18 @@
goto out_no_driver;
}
}
+ if (!try_module_get(ld_type->owner)) {
+ dprintk("%s: Could not grab reference on module\n", __func__);
+ goto out_no_driver;
+ }
server->pnfs_curr_ld = ld_type;
+ if (ld_type->initialize_mountpoint(server)) {
+ printk(KERN_ERR
+ "%s: Error initializing mount point for layout driver %u.\n",
+ __func__, id);
+ module_put(ld_type->owner);
+ goto out_no_driver;
+ }
dprintk("%s: pNFS module for %u set\n", __func__, id);
return;
@@ -82,3 +128,41 @@
dprintk("%s: Using NFSv4 I/O\n", __func__);
server->pnfs_curr_ld = NULL;
}
+
+int
+pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
+{
+ int status = -EINVAL;
+ struct pnfs_layoutdriver_type *tmp;
+
+ if (ld_type->id == 0) {
+ printk(KERN_ERR "%s id 0 is reserved\n", __func__);
+ return status;
+ }
+
+ spin_lock(&pnfs_spinlock);
+ tmp = find_pnfs_driver_locked(ld_type->id);
+ if (!tmp) {
+ list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
+ status = 0;
+ dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
+ ld_type->name);
+ } else {
+ printk(KERN_ERR "%s Module with id %d already loaded!\n",
+ __func__, ld_type->id);
+ }
+ spin_unlock(&pnfs_spinlock);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
+
+void
+pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
+{
+ dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
+ spin_lock(&pnfs_spinlock);
+ list_del(&ld_type->pnfs_tblid);
+ spin_unlock(&pnfs_spinlock);
+}
+EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);