1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed 6 * to Berkeley by John Heidemann of the UCLA Ficus project. 7 * 8 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 9 * 10 * %sccs.include.redist.c% 11 * 12 * @(#)vfs_init.c 7.2 (Berkeley) 07/06/92 13 */ 14 15 16 #include <sys/param.h> 17 #include <sys/mount.h> 18 #include <sys/time.h> 19 #include <sys/vnode.h> 20 #include <sys/stat.h> 21 #include <sys/specdev.h> 22 #include <sys/namei.h> 23 #include <sys/ucred.h> 24 #include <sys/buf.h> 25 #include <sys/errno.h> 26 #include <sys/malloc.h> 27 28 /* 29 * Sigh, such primitive tools are these... 30 */ 31 #if 0 32 #define DODEBUG(A) A 33 #else 34 #define DODEBUG(A) 35 #endif 36 37 extern struct vnodeopv_desc *vfs_opv_descs[]; 38 /* a list of lists of vnodeops defns */ 39 extern struct vnodeop_desc *vfs_op_descs[]; 40 /* and the operations they perform */ 41 /* 42 * This code doesn't work if the defn is **vnodop_defns with cc. 43 * The problem is because of the compiler sometimes putting in an 44 * extra level of indirection for arrays. It's an interesting 45 * "feature" of C. 46 */ 47 int vfs_opv_numops; 48 49 typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 50 51 /* 52 * A miscellaneous routine. 53 * A generic "default" routine that just returns an error. 54 */ 55 int 56 vn_default_error() 57 { 58 59 return (EOPNOTSUPP); 60 } 61 62 /* 63 * vfs_init.c 64 * 65 * Allocate and fill in operations vectors. 66 * 67 * An undocumented feature of this approach to defining operations is that 68 * there can be multiple entries in vfs_opv_descs for the same operations 69 * vector. This allows third parties to extend the set of operations 70 * supported by another layer in a binary compatibile way. For example, 71 * assume that NFS needed to be modified to support Ficus. NFS has an entry 72 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 73 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 74 * listing those new operations Ficus adds to NFS, all without modifying the 75 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 76 * that is a(whole)nother story.) This is a feature. 77 */ 78 void 79 vfs_opv_init() 80 { 81 int i, j, k; 82 struct vnodeop_defn *defnp; 83 int (***opv_desc_vector_p)(); 84 int (**opv_desc_vector)(); 85 struct vnodeopv_entry_desc *opve_descp; 86 87 /* 88 * Allocate the dynamic vectors and fill them in. 89 */ 90 for (i=0; vfs_opv_descs[i]; i++) { 91 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 92 /* 93 * Allocate and init the vector, if it needs it. 94 * Also handle backwards compatibility. 95 */ 96 if (*opv_desc_vector_p == NULL) { 97 /* XXX - shouldn't be M_VNODE */ 98 MALLOC(*opv_desc_vector_p, PFI*, 99 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 100 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 101 DODEBUG(printf("vector at %x allocated\n", 102 opv_desc_vector_p)); 103 } 104 opv_desc_vector = *opv_desc_vector_p; 105 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 106 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 107 108 /* 109 * Sanity check: is this operation listed 110 * in the list of operations? We check this 111 * by seeing if its offest is zero. Since 112 * the default routine should always be listed 113 * first, it should be the only one with a zero 114 * offset. Any other operation with a zero 115 * offset is probably not listed in 116 * vfs_op_descs, and so is probably an error. 117 * 118 * A panic here means the layer programmer 119 * has committed the all-too common bug 120 * of adding a new operation to the layer's 121 * list of vnode operations but 122 * not adding the operation to the system-wide 123 * list of supported operations. 124 */ 125 if (opve_descp->opve_op->vdesc_offset == 0 && 126 opve_descp->opve_op->vdesc_offset != 127 VOFFSET(vop_default)) { 128 printf("operation %s not listed in %s.\n", 129 opve_descp->opve_op->vdesc_name, 130 "vfs_op_descs"); 131 panic ("vfs_opv_init: bad operation"); 132 } 133 /* 134 * Fill in this entry. 135 */ 136 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 137 opve_descp->opve_impl; 138 } 139 } 140 /* 141 * Finally, go back and replace unfilled routines 142 * with their default. (Sigh, an O(n^3) algorithm. I 143 * could make it better, but that'd be work, and n is small.) 144 */ 145 for (i = 0; vfs_opv_descs[i]; i++) { 146 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 147 /* 148 * Force every operations vector to have a default routine. 149 */ 150 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 151 panic("vfs_opv_init: operation vector without default routine."); 152 } 153 for (k = 0; k<vfs_opv_numops; k++) 154 if (opv_desc_vector[k] == NULL) 155 opv_desc_vector[k] = 156 opv_desc_vector[VOFFSET(vop_default)]; 157 } 158 } 159 160 /* 161 * Initialize known vnode operations vectors. 162 */ 163 void 164 vfs_op_init() 165 { 166 int i, j; 167 168 DODEBUG(printf("Vnode_interface_init.\n")); 169 /* 170 * Set all vnode vectors to a well known value. 171 */ 172 for (i = 0; vfs_opv_descs[i]; i++) 173 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 174 /* 175 * Figure out how many ops there are by counting the table, 176 * and assign each its offset. 177 */ 178 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 179 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 180 vfs_opv_numops++; 181 } 182 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 183 } 184 185 /* 186 * Routines having to do with the management of the vnode table. 187 */ 188 struct vnode *vfreeh, **vfreet; 189 extern struct vnodeops dead_vnodeops; 190 extern struct vnodeops spec_vnodeops; 191 extern void vclean(); 192 struct vattr va_null; 193 194 /* 195 * Initialize the vnode structures and initialize each file system type. 196 */ 197 vfsinit() 198 { 199 struct vfsops **vfsp; 200 201 /* 202 * Initialize the vnode name cache 203 */ 204 nchinit(); 205 /* 206 * Build vnode operation vectors. 207 */ 208 vfs_op_init(); 209 vfs_opv_init(); /* finish the job */ 210 /* 211 * Initialize each file system type. 212 */ 213 vattr_null(&va_null); 214 for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) { 215 if (*vfsp == NULL) 216 continue; 217 (*(*vfsp)->vfs_init)(); 218 } 219 } 220