Ricardo Labiaga | 85e174b | 2010-10-20 00:17:58 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * pNFS functions to call and manage layout drivers. |
| 3 | * |
| 4 | * Copyright (c) 2002 [year of first publication] |
| 5 | * The Regents of the University of Michigan |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * Dean Hildebrand <dhildebz@umich.edu> |
| 9 | * |
| 10 | * Permission is granted to use, copy, create derivative works, and |
| 11 | * redistribute this software and such derivative works for any purpose, |
| 12 | * so long as the name of the University of Michigan is not used in |
| 13 | * any advertising or publicity pertaining to the use or distribution |
| 14 | * of this software without specific, written prior authorization. If |
| 15 | * the above copyright notice or any other identification of the |
| 16 | * University of Michigan is included in any copy of any portion of |
| 17 | * this software, then the disclaimer below must also be included. |
| 18 | * |
| 19 | * This software is provided as is, without representation or warranty |
| 20 | * of any kind either express or implied, including without limitation |
| 21 | * the implied warranties of merchantability, fitness for a particular |
| 22 | * purpose, or noninfringement. The Regents of the University of |
| 23 | * Michigan shall not be liable for any damages, including special, |
| 24 | * indirect, incidental, or consequential damages, with respect to any |
| 25 | * claim arising out of or in connection with the use of the software, |
| 26 | * even if it has been or is hereafter advised of the possibility of |
| 27 | * such damages. |
| 28 | */ |
| 29 | |
| 30 | #include <linux/nfs_fs.h> |
| 31 | #include "pnfs.h" |
| 32 | |
| 33 | #define NFSDBG_FACILITY NFSDBG_PNFS |
| 34 | |
| 35 | /* STUB that returns the equivalent of "no module found" */ |
| 36 | static struct pnfs_layoutdriver_type * |
| 37 | find_pnfs_driver(u32 id) |
| 38 | { |
| 39 | return NULL; |
| 40 | } |
| 41 | |
| 42 | void |
| 43 | unset_pnfs_layoutdriver(struct nfs_server *nfss) |
| 44 | { |
| 45 | nfss->pnfs_curr_ld = NULL; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Try to set the server's pnfs module to the pnfs layout type specified by id. |
| 50 | * Currently only one pNFS layout driver per filesystem is supported. |
| 51 | * |
| 52 | * @id layout type. Zero (illegal layout type) indicates pNFS not in use. |
| 53 | */ |
| 54 | void |
| 55 | set_pnfs_layoutdriver(struct nfs_server *server, u32 id) |
| 56 | { |
| 57 | struct pnfs_layoutdriver_type *ld_type = NULL; |
| 58 | |
| 59 | if (id == 0) |
| 60 | goto out_no_driver; |
| 61 | if (!(server->nfs_client->cl_exchange_flags & |
| 62 | (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) { |
| 63 | printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__, |
| 64 | id, server->nfs_client->cl_exchange_flags); |
| 65 | goto out_no_driver; |
| 66 | } |
| 67 | ld_type = find_pnfs_driver(id); |
| 68 | if (!ld_type) { |
| 69 | request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id); |
| 70 | ld_type = find_pnfs_driver(id); |
| 71 | if (!ld_type) { |
| 72 | dprintk("%s: No pNFS module found for %u.\n", |
| 73 | __func__, id); |
| 74 | goto out_no_driver; |
| 75 | } |
| 76 | } |
| 77 | server->pnfs_curr_ld = ld_type; |
| 78 | dprintk("%s: pNFS module for %u set\n", __func__, id); |
| 79 | return; |
| 80 | |
| 81 | out_no_driver: |
| 82 | dprintk("%s: Using NFSv4 I/O\n", __func__); |
| 83 | server->pnfs_curr_ld = NULL; |
| 84 | } |