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 7.1 (Berkeley) 06/23/92 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 #if 0 31 #define DODEBUG(A) A 32 #else 33 #define DODEBUG(A) 34 #endif 35 36 37 38 extern struct vnodeopv_desc *vfs_opv_descs[]; 39 /* a list of lists of vnodeops defns */ 40 extern struct vnodeop_desc *vfs_op_descs[]; 41 /* and the operations they perform */ 42 /* 43 * This code doesn't work if the defn is **vnodop_defns with cc. 44 * The problem is because of the compiler sometimes putting in an 45 * extra level of indirection for arrays. It's an interesting 46 * "feature" of C. 47 */ 48 int vfs_opv_numops; 49 50 typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 51 52 53 54 /* 55 * A miscellaneous routine. 56 * A generic "default" routine that just returns an error. 57 */ 58 int 59 vn_default_error() 60 { 61 return EOPNOTSUPP; 62 } 63 64 65 66 67 /* 68 * vfs_init.c 69 * 70 * Allocate and fill in operations vectors. 71 * 72 * An undocumented feature of this approach to defining 73 * operations is that there can be multiple entries in 74 * vfs_opv_descs for the same operations vector. 75 * This allows third parties to extend the set of operations 76 * supported by another layer in a binary compatibile way. 77 * For example, assume that NFS needed to be modified to support 78 * Ficus. NFS has an entry (probably nfs_vnopdeop_decls) 79 * declaring all the operations NFS supports by default. 80 * Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 81 * listing those new operations Ficus adds to NFS, all without 82 * modifying the NFS code. (Of couse, the OTW NFS protocol 83 * still needs to be munged, but that's a(whole)nother story.) 84 * This is a feature. 85 */ 86 87 void 88 vfs_opv_init() 89 { 90 int i, j, k; 91 struct vnodeop_defn *defnp; 92 int (***opv_desc_vector_p)(); 93 int (**opv_desc_vector)(); 94 struct vnodeopv_entry_desc *opve_descp; 95 96 /* 97 * Allocate the dynamic vectors and fill them in. 98 */ 99 for (i=0; vfs_opv_descs[i]; i++) { 100 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 101 /* 102 * Allocate and init the vector, if it needs it. 103 * Also handle backwards compatibility. 104 */ 105 if (*opv_desc_vector_p == NULL) { 106 /* XXX - shouldn't be M_VNODE */ 107 MALLOC(*opv_desc_vector_p, PFI*, 108 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 109 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 110 DODEBUG(printf("vector at %x allocated\n", opv_desc_vector_p)); 111 }; 112 opv_desc_vector = *opv_desc_vector_p; 113 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 114 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 115 116 /* 117 * Sanity check: is this operation listed 118 * in the list of operations? We check this 119 * by seeing if its offest is zero. Since 120 * the default routine should always be listed 121 * first, it should be the only one with a zero 122 * offset. Any other operation with a zero 123 * offset is probably not listed in 124 * vfs_op_descs, 125 * and so is probably an error. 126 * 127 * A panic here means the layer programmer 128 * has committed the all-too common bug 129 * of adding a new operation to the layer's 130 * list of vnode operations but 131 * not adding the operation to the system-wide 132 * list of supported operations. 133 */ 134 if (opve_descp->opve_op->vdesc_offset == 0 && 135 opve_descp->opve_op->vdesc_offset != 136 VOFFSET(vop_default)) { 137 printf ("error: operation %s not listed in vfs_op_descs.\n", opve_descp->opve_op->vdesc_name); 138 panic ("vfs_opv_init: bad operation"); 139 }; 140 /* 141 * Fill in this entry. 142 */ 143 opv_desc_vector[opve_descp->opve_op->vdesc_offset]= 144 opve_descp->opve_impl; 145 }; 146 }; 147 148 /* 149 * Finally, go back and replace unfilled routines 150 * with their default. (Sigh, an O(n^3) algorithm. I 151 * could make it better, but that'd be work, and n is small.) 152 */ 153 for (i=0; vfs_opv_descs[i]; i++) { 154 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 155 /* 156 * Force every operations vector to have a default routine. 157 */ 158 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 159 panic("vfs_opv_init: operation vector without default routine."); 160 }; 161 for (k=0; k<vfs_opv_numops; k++) 162 if (opv_desc_vector[k] == NULL) 163 opv_desc_vector[k] = 164 opv_desc_vector[VOFFSET(vop_default)]; 165 }; 166 } 167 168 169 170 171 void 172 vfs_op_init() 173 { 174 int i, j; 175 176 DODEBUG(printf ("Vnode_interface_init.\n")); 177 178 /* 179 * Set all vnode vectors to a well known value. 180 */ 181 for (i=0; vfs_opv_descs[i]; i++) 182 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 183 184 vfs_opv_numops = 0; 185 186 /* 187 * Figure out how many ops there are by counting the table, 188 * and assign each its offset. 189 */ 190 for (i=0; vfs_op_descs[i]; i++) { 191 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 192 vfs_opv_numops++; 193 }; 194 195 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 196 } 197 198 199 200 201 202 203 204 /* 205 * Routines having to do with the management of the vnode table. 206 */ 207 struct vnode *vfreeh, **vfreet; 208 extern struct vnodeops dead_vnodeops; 209 extern struct vnodeops spec_vnodeops; 210 extern void vclean(); 211 struct vattr va_null; 212 213 /* 214 * Initialize the vnode structures and initialize each file system type. 215 */ 216 vfsinit() 217 { 218 struct vfsops **vfsp; 219 220 /* 221 * Initialize the vnode name cache 222 */ 223 nchinit(); 224 /* 225 * Build vnode operation vectors. 226 */ 227 vfs_op_init(); 228 vfs_opv_init(); /* finish the job */ 229 /* 230 * Initialize each file system type. 231 */ 232 vattr_null(&va_null); 233 for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) { 234 if (*vfsp == NULL) 235 continue; 236 (*(*vfsp)->vfs_init)(); 237 } 238 } 239