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 "NFS: %s id 0 is reserved\n", __func__); return status; } if (!ld_type->alloc_lseg || !ld_type->free_lseg) { printk(KERN_ERR "NFS: %s Layout driver must provide " "alloc_lseg and free_lseg.\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 "NFS: %s Module with id %d already loaded!\n", __func__, ld_type->id); } spin_unlock(&pnfs_spinlock); return status; }
static struct pnfs_layoutdriver_type * find_pnfs_driver(u32 id) { struct pnfs_layoutdriver_type *local; spin_lock(&pnfs_spinlock); local = find_pnfs_driver_locked(id); spin_unlock(&pnfs_spinlock); return local; }
static struct pnfs_layoutdriver_type * find_pnfs_driver(u32 id) { struct pnfs_layoutdriver_type *local; spin_lock(&pnfs_spinlock); local = find_pnfs_driver_locked(id); if (local != NULL && !try_module_get(local->owner)) { dprintk("%s: Could not grab reference on module\n", __func__); local = NULL; } spin_unlock(&pnfs_spinlock); return local; }