Lines Matching full:layer
38 .Nd "mount a loopback file system sub-tree; demonstrate the use of a null file system layer"
49 layer, duplicating a sub-tree of the file system
81 all lower-layer vnodes, not just over directory vnodes.
95 Disable metadata caching in the null layer.
96 Some lower-layer file systems may force this option.
108 The null layer has two purposes.
109 First, it serves as a demonstration of layering by providing a layer
113 Second, the null layer can serve as a prototype layer.
114 Since it provides all necessary layer framework,
116 with a null layer.
118 The remainder of this man page examines the null layer as a basis
129 layer will appear in the namespace (mount-point-pn).
131 the null layer is put into place, the contents
135 .Sh OPERATION OF A NULL LAYER
136 The null layer is the minimum file system layer,
137 simply bypassing all possible operations to the lower layer
144 handling by the lower layer.
147 lower-layer equivalents.
149 on the lower layer.
167 they can handle freeing null-layer specific data.
174 Mounting associates the null layer with a lower layer,
180 root of the new null layer.
190 For example, imagine mounting a null layer with
192 mount_nullfs /usr/include /dev/layer/null
196 .Pa /dev/layer/null
198 the root null-node (which was created when the null layer was mounted).
204 to the lower layer which would return a vnode representing
219 a copy of the null layer, rename all files and variables, and
226 The umap layer is an example of a layer descended from the
227 null layer.
231 There are two techniques to invoke operations on a lower layer
236 it is the responsibility of the aliasing layer to make
237 the operation arguments "correct" for the lower layer
238 by mapping a vnode argument to the lower layer.
240 The first approach is to call the aliasing layer's bypass routine.
242 currently being handled on the lower layer.
247 in the null layer.
250 the lower layer with the
254 arbitrary operations on the lower layer.