/* $NetBSD: vfs_init.c,v 1.35 2007/10/10 20:42:26 ad Exp $ */ /*- * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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 8.5 (Berkeley) 5/11/95 */ #include __KERNEL_RCSID(0, "$NetBSD: vfs_init.c,v 1.35 2007/10/10 20:42:26 ad Exp $"); #include #include #include #include #include #include #include #include #include #include #include /* * Sigh, such primitive tools are these... */ #if 0 #define DODEBUG(A) A #else #define DODEBUG(A) #endif /* * The global list of vnode operations. */ extern const struct vnodeop_desc * const vfs_op_descs[]; /* * These vnodeopv_descs are listed here because they are not * associated with any particular file system, and thus cannot * be initialized by vfs_attach(). */ extern const struct vnodeopv_desc dead_vnodeop_opv_desc; extern const struct vnodeopv_desc fifo_vnodeop_opv_desc; extern const struct vnodeopv_desc spec_vnodeop_opv_desc; extern const struct vnodeopv_desc sync_vnodeop_opv_desc; const struct vnodeopv_desc * const vfs_special_vnodeopv_descs[] = { &dead_vnodeop_opv_desc, &fifo_vnodeop_opv_desc, &spec_vnodeop_opv_desc, &sync_vnodeop_opv_desc, NULL, }; struct vfs_list_head vfs_list = /* vfs list */ LIST_HEAD_INITIALIZER(vfs_list); /* * 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. */ typedef int (*PFI)(void *); /* * A miscellaneous routine. * A generic "default" routine that just returns an error. */ /*ARGSUSED*/ int vn_default_error(void *v) { return (EOPNOTSUPP); } /* * 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 compatibile 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 couse, the OTW NFS protocol still needs to be munged, but * that is a(whole)nother story.) This is a feature. */ /* * Init the vector, if it needs it. * Also handle backwards compatibility. */ static void vfs_opv_init_explicit(const struct vnodeopv_desc *vfs_opv_desc) { int (**opv_desc_vector)(void *); const struct vnodeopv_entry_desc *opve_descp; opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p); 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_offset != VOFFSET(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; } } static void vfs_opv_init_default(const 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 < VNODE_OPS_COUNT; j++) if (opv_desc_vector[j] == NULL) opv_desc_vector[j] = opv_desc_vector[VOFFSET(vop_default)]; } void vfs_opv_init(const struct vnodeopv_desc * const *vopvdpp) { int (**opv_desc_vector)(void *); int i; /* * Allocate the vectors. */ for (i = 0; vopvdpp[i] != NULL; i++) { /* XXX - shouldn't be M_VNODE */ opv_desc_vector = malloc(VNODE_OPS_COUNT * sizeof(PFI), M_VNODE, M_WAITOK); memset(opv_desc_vector, 0, VNODE_OPS_COUNT * sizeof(PFI)); *(vopvdpp[i]->opv_desc_vector_p) = opv_desc_vector; DODEBUG(printf("vector at %p allocated\n", opv_desc_vector_p)); } /* * ...and fill them in. */ for (i = 0; vopvdpp[i] != NULL; i++) vfs_opv_init_explicit(vopvdpp[i]); /* * Finally, go back and replace unfilled routines * with their default. */ for (i = 0; vopvdpp[i] != NULL; i++) vfs_opv_init_default(vopvdpp[i]); } void vfs_opv_free(const struct vnodeopv_desc * const *vopvdpp) { int i; /* * Free the vectors allocated in vfs_opv_init(). */ for (i = 0; vopvdpp[i] != NULL; i++) { /* XXX - shouldn't be M_VNODE */ free(*(vopvdpp[i]->opv_desc_vector_p), M_VNODE); *(vopvdpp[i]->opv_desc_vector_p) = NULL; } } #ifdef DEBUG static void vfs_op_check(void) { int i; DODEBUG(printf("Vnode_interface_init.\n")); /* * Check offset of each op. */ for (i = 0; vfs_op_descs[i]; i++) { if (vfs_op_descs[i]->vdesc_offset != i) panic("vfs_op_check: vfs_op_desc[] offset mismatch"); } if (i != VNODE_OPS_COUNT) { panic("vfs_op_check: vnode ops count mismatch (%d != %d)", i, VNODE_OPS_COUNT); } DODEBUG(printf ("vfs_opv_numops=%d\n", VNODE_OPS_COUNT)); } #endif /* DEBUG */ /* * Initialize the vnode structures and initialize each file system type. */ void vfsinit(void) { __link_set_decl(vfsops, struct vfsops); struct vfsops * const *vfsp; /* * Initialize the namei pathname buffer pool and cache. */ pool_init(&pnbuf_pool, MAXPATHLEN, 0, 0, 0, "pnbufpl", &pool_allocator_nointr, IPL_NONE); pool_cache_init(&pnbuf_cache, &pnbuf_pool, NULL, NULL, NULL); /* * Initialize the vnode table */ vntblinit(); /* * Initialize the vnode name cache */ nchinit(); #ifdef DEBUG /* * Check the list of vnode operations. */ vfs_op_check(); #endif /* * Initialize the special vnode operations. */ vfs_opv_init(vfs_special_vnodeopv_descs); /* * Establish each file system which was statically * included in the kernel. */ __link_set_foreach(vfsp, vfsops) { if (vfs_attach(*vfsp)) { printf("multiple `%s' file systems", (*vfsp)->vfs_name); panic("vfsinit"); } } } /* * Drop a reference to a file system type. */ void vfs_delref(struct vfsops *vfs) { mutex_enter(&vfs_list_lock); vfs->vfs_refcount--; mutex_exit(&vfs_list_lock); } /* * Establish a file system and initialize it. */ int vfs_attach(struct vfsops *vfs) { struct vfsops *v; int error = 0; mutex_enter(&vfs_list_lock); /* * Make sure this file system doesn't already exist. */ LIST_FOREACH(v, &vfs_list, vfs_list) { if (strcmp(vfs->vfs_name, v->vfs_name) == 0) { error = EEXIST; goto out; } } /* * Initialize the vnode operations for this file system. */ vfs_opv_init(vfs->vfs_opv_descs); /* * Now initialize the file system itself. */ (*vfs->vfs_init)(); /* * ...and link it into the kernel's list. */ LIST_INSERT_HEAD(&vfs_list, vfs, vfs_list); /* * Sanity: make sure the reference count is 0. */ vfs->vfs_refcount = 0; out: mutex_exit(&vfs_list_lock); return (error); } /* * Remove a file system from the kernel. */ int vfs_detach(struct vfsops *vfs) { struct vfsops *v; int error = 0; mutex_enter(&vfs_list_lock); /* * Make sure no one is using the filesystem. */ if (vfs->vfs_refcount != 0) { error = EBUSY; goto out; } /* * ...and remove it from the kernel's list. */ LIST_FOREACH(v, &vfs_list, vfs_list) { if (v == vfs) { LIST_REMOVE(v, vfs_list); break; } } if (v == NULL) { error = ESRCH; goto out; } /* * Now run the file system-specific cleanups. */ (*vfs->vfs_done)(); /* * Free the vnode operations vector. */ vfs_opv_free(vfs->vfs_opv_descs); out: mutex_exit(&vfs_list_lock); return (error); } void vfs_reinit(void) { struct vfsops *vfs; mutex_enter(&vfs_list_lock); LIST_FOREACH(vfs, &vfs_list, vfs_list) { if (vfs->vfs_reinit) { vfs->vfs_refcount++; mutex_exit(&vfs_list_lock); (*vfs->vfs_reinit)(); mutex_enter(&vfs_list_lock); vfs->vfs_refcount--; } } mutex_exit(&vfs_list_lock); }