diff options
Diffstat (limited to 'sbin/mount_null/mount_null.8')
| -rw-r--r-- | sbin/mount_null/mount_null.8 | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/sbin/mount_null/mount_null.8 b/sbin/mount_null/mount_null.8 index 2f2807bdca8..63f31d15f7c 100644 --- a/sbin/mount_null/mount_null.8 +++ b/sbin/mount_null/mount_null.8 @@ -1,4 +1,4 @@ -.\" $OpenBSD: mount_null.8,v 1.8 1999/05/23 14:11:18 aaron Exp $ +.\" $OpenBSD: mount_null.8,v 1.9 1999/06/04 02:45:18 aaron Exp $ .\" $NetBSD: mount_null.8,v 1.4 1996/04/10 20:57:19 thorpej Exp $ .\" .\" Copyright (c) 1992, 1993, 1994 @@ -85,7 +85,7 @@ for constructing new layers. .\" .\" .Sh INSTANTIATING NEW NULL LAYERS -New null layers are created with +New null layers are created with .Nm mount_null . .Nm takes two arguments: the pathname @@ -110,8 +110,8 @@ on the lower layer. Finally, it replaces the null-nodes in the arguments and, if a vnode is returned by the operation, stacks a null-node on top of the returned vnode. .Pp -Although bypass handles most operations, -.Em vop_getattr , +Although bypass handles most operations, +.Em vop_getattr , .Em vop_inactive , .Em vop_reclaim , and @@ -140,7 +140,7 @@ are created as a result of vnode operations on this or other null vnode stacks. .Pp New vnode stacks come into existence as a result of -an operation which returns a vnode. +an operation which returns a vnode. The bypass routine stacks a null-node above the new vnode before returning it to the caller. .Pp @@ -149,26 +149,26 @@ For example, imagine mounting a null layer with mount_null /usr/include /dev/layer/null .Ed .Pp -Changing directory to +Changing directory to .Pa /dev/layer/null will assign the root null-node (which was created when the null layer was mounted). -Now consider opening +Now consider opening .Pa sys . A .Em vop_lookup would be done on the root null-node. This operation would bypass through -to the lower layer which would return a vnode representing -the UFS +to the lower layer which would return a vnode representing +the UFS .Pa sys . Null_bypass then builds a null-node -aliasing the UFS +aliasing the UFS .Pa sys and returns this to the caller. -Later operations on the null-node +Later operations on the null-node .Pa sys -will repeat this +will repeat this process when constructing other vnode stacks. .\" .\" @@ -176,16 +176,16 @@ process when constructing other vnode stacks. One of the easiest ways to construct new file system layers is to make a copy of the null layer, rename all files and variables, and then begin modifyng the copy. -.Xr sed 1 +.Xr sed 1 can be used to easily rename all variables. .Pp -The umap layer is an example of a layer descended from the +The umap layer is an example of a layer descended from the null layer. .\" .\" .Sh INVOKING OPERATIONS ON LOWER LAYERS -There are two techniques to invoke operations on a lower layer +There are two techniques to invoke operations on a lower layer when the operation cannot be completely bypassed. Each method is appropriate in different situations. In both cases, it is the responsibility of the aliasing layer to make @@ -196,7 +196,7 @@ The first approach is to call the aliasing layer's bypass routine. This method is most suitable when you wish to invoke the operation currently being handled on the lower layer. It has the advantage the bypass routine already must do argument mapping. -An example of this is +An example of this is .Em null_getattrs in the null layer. .Pp |