/* $OpenBSD: vfs_init.c,v 1.27 2010/09/10 16:34:08 thib Exp $ */ /* $NetBSD: vfs_init.c,v 1.6 1996/02/09 19:00:58 christos Exp $ */ /* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed * to Berkeley by John Heidemann of the UCLA Ficus project. * * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 */ #include #include #include #include #include #include #include #include #include #include #include #include /* a list of lists of vnodeops defns */ extern struct vnodeopv_desc *vfs_opv_descs[]; /* and the operations they perform */ extern struct vnodeop_desc *vfs_op_descs[]; struct pool namei_pool; /* * This code doesn't work if the defn is **vnodop_defns with cc. * The problem is because of the compiler sometimes putting in an * extra level of indirection for arrays. It's an interesting * "feature" of C. */ int vfs_opv_numops; typedef int (*PFI)(void *); /* * vfs_init.c * * Allocate and fill in operations vectors. * * An undocumented feature of this approach to defining operations is that * there can be multiple entries in vfs_opv_descs for the same operations * vector. This allows third parties to extend the set of operations * supported by another layer in a binary compatible way. For example, * assume that NFS needed to be modified to support Ficus. NFS has an entry * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) * listing those new operations Ficus adds to NFS, all without modifying the * NFS code. (Of course, the OTW NFS protocol still needs to be munged, but * that is a(whole)nother story.) This is a feature. */ /* * Allocate and init the vector, if it needs it. * Also handle backwards compatibility. */ void vfs_opv_init_explicit(struct vnodeopv_desc *vfs_opv_desc) { int (**opv_desc_vector)(void *); struct vnodeopv_entry_desc *opve_descp; opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); if (opv_desc_vector == NULL) { /* XXX - shouldn't be M_VNODE */ opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI), M_VNODE, M_WAITOK|M_ZERO); *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector; } for (opve_descp = vfs_opv_desc->opv_desc_ops; opve_descp->opve_op; opve_descp++) { /* * Sanity check: is this operation listed * in the list of operations? We check this * by seeing if its offset is zero. Since * the default routine should always be listed * first, it should be the only one with a zero * offset. Any other operation with a zero * offset is probably not listed in * vfs_op_descs, and so is probably an error. * * A panic here means the layer programmer * has committed the all-too common bug * of adding a new operation to the layer's * list of vnode operations but * not adding the operation to the system-wide * list of supported operations. */ if (opve_descp->opve_op->vdesc_offset == 0 && opve_descp->opve_op != VDESC(vop_default)) { printf("operation %s not listed in %s.\n", opve_descp->opve_op->vdesc_name, "vfs_op_descs"); panic ("vfs_opv_init: bad operation"); } /* * Fill in this entry. */ opv_desc_vector[opve_descp->opve_op->vdesc_offset] = opve_descp->opve_impl; } } void vfs_opv_init_default(struct vnodeopv_desc *vfs_opv_desc) { int j; int (**opv_desc_vector)(void *); opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); /* * Force every operations vector to have a default routine. */ if (opv_desc_vector[VOFFSET(vop_default)] == NULL) panic("vfs_opv_init: operation vector without default routine."); for (j = 0; j < vfs_opv_numops; j++) if (opv_desc_vector[j] == NULL) opv_desc_vector[j] = opv_desc_vector[VOFFSET(vop_default)]; } /* Initialize known vnode operations vectors. */ void vfs_op_init(void) { int i; /* Set all vnode vectors to a well known value. */ for (i = 0; vfs_opv_descs[i]; i++) *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; /* * Figure out how many ops there are by counting the table, * and assign each its offset. */ for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; vfs_opv_numops++; } /* Allocate the dynamic vectors and fill them in. */ for (i = 0; vfs_opv_descs[i]; i++) vfs_opv_init_explicit(vfs_opv_descs[i]); /* * Finally, go back and replace unfilled routines * with their default. */ for (i = 0; vfs_opv_descs[i]; i++) vfs_opv_init_default(vfs_opv_descs[i]); } /* * Initialize the vnode structures and initialize each file system type. */ void vfsinit(void) { int i; struct vfsconf *vfsconflist; int vfsconflistlen; pool_init(&namei_pool, MAXPATHLEN, 0, 0, 0, "namei", &pool_allocator_nointr); /* * Initialize the vnode table */ vntblinit(); /* * Initialize the vnode name cache */ nchinit(); /* * Build vnode operation vectors. */ vfs_op_init(); /* * Stop using vfsconf and maxvfsconf as a temporary storage, * set them to their correct values now. */ vfsconflist = vfsconf; vfsconflistlen = maxvfsconf; vfsconf = NULL; maxvfsconf = 0; for (i = 0; i < vfsconflistlen; i++) vfs_register(&vfsconflist[i]); }