diff options
Diffstat (limited to 'fs/nfs/pnfs.c')
-rw-r--r-- | fs/nfs/pnfs.c | 88 |
1 files changed, 86 insertions, 2 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index b483026e82aa..cf795625610e 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 @@ set_pnfs_layoutdriver(struct nfs_server *server, u32 id) 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 @@ out_no_driver: 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); |