null_vnops.c (32929) | null_vnops.c (35256) |
---|---|
1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without --- 23 unchanged lines hidden (view full) --- 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92 | 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John Heidemann of the UCLA Ficus project. 7 * 8 * Redistribution and use in source and binary forms, with or without --- 23 unchanged lines hidden (view full) --- 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95 37 * 38 * Ancestors: 39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92 |
40 * $Id: null_vnops.c,v 1.25 1997/10/21 21:01:34 roberto Exp $ | 40 * $Id: null_vnops.c,v 1.26 1998/01/31 07:23:13 eivind Exp $ |
41 * ...and... 42 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 43 * | 41 * ...and... 42 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project 43 * |
44 * $Id: null_vnops.c,v 1.25 1997/10/21 21:01:34 roberto Exp $ | 44 * $Id: null_vnops.c,v 1.26 1998/01/31 07:23:13 eivind Exp $ |
45 */ 46 47/* 48 * Null Layer 49 * 50 * (See mount_null(8) for more information.) 51 * 52 * The null layer duplicates a portion of the file system 53 * name space under a new name. In this respect, it is 54 * similar to the loopback file system. It differs from 55 * the loopback fs in two respects: it is implemented using | 45 */ 46 47/* 48 * Null Layer 49 * 50 * (See mount_null(8) for more information.) 51 * 52 * The null layer duplicates a portion of the file system 53 * name space under a new name. In this respect, it is 54 * similar to the loopback file system. It differs from 55 * the loopback fs in two respects: it is implemented using |
56 * a stackable layers techniques, and it's "null-node"s stack above | 56 * a stackable layers techniques, and its "null-node"s stack above |
57 * all lower-layer vnodes, not just over directory vnodes. 58 * 59 * The null layer has two purposes. First, it serves as a demonstration 60 * of layering by proving a layer which does nothing. (It actually 61 * does everything the loopback file system does, which is slightly 62 * more than nothing.) Second, the null layer can serve as a prototype 63 * layer. Since it provides all necessary layer framework, 64 * new file system layers can be created very easily be starting --- 603 unchanged lines hidden --- | 57 * all lower-layer vnodes, not just over directory vnodes. 58 * 59 * The null layer has two purposes. First, it serves as a demonstration 60 * of layering by proving a layer which does nothing. (It actually 61 * does everything the loopback file system does, which is slightly 62 * more than nothing.) Second, the null layer can serve as a prototype 63 * layer. Since it provides all necessary layer framework, 64 * new file system layers can be created very easily be starting --- 603 unchanged lines hidden --- |