1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. 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 8.5 (Berkeley) 05/11/95 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/namei.h> 22 #include <sys/ucred.h> 23 #include <sys/buf.h> 24 #include <sys/errno.h> 25 #include <sys/malloc.h> 26 27 /* 28 * Sigh, such primitive tools are these... 29 */ 30 #if 0 31 #define DODEBUG(A) A 32 #else 33 #define DODEBUG(A) 34 #endif 35 36 extern struct vnodeopv_desc *vfs_opv_descs[]; 37 /* a list of lists of vnodeops defns */ 38 extern struct vnodeop_desc *vfs_op_descs[]; 39 /* and the operations they perform */ 40 /* 41 * This code doesn't work if the defn is **vnodop_defns with cc. 42 * The problem is because of the compiler sometimes putting in an 43 * extra level of indirection for arrays. It's an interesting 44 * "feature" of C. 45 */ 46 int vfs_opv_numops; 47 48 typedef (*PFI)(); /* the standard Pointer to a Function returning an Int */ 49 50 /* 51 * A miscellaneous routine. 52 * A generic "default" routine that just returns an error. 53 */ 54 int 55 vn_default_error() 56 { 57 58 return (EOPNOTSUPP); 59 } 60 61 /* 62 * vfs_init.c 63 * 64 * Allocate and fill in operations vectors. 65 * 66 * An undocumented feature of this approach to defining operations is that 67 * there can be multiple entries in vfs_opv_descs for the same operations 68 * vector. This allows third parties to extend the set of operations 69 * supported by another layer in a binary compatibile way. For example, 70 * assume that NFS needed to be modified to support Ficus. NFS has an entry 71 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 72 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 73 * listing those new operations Ficus adds to NFS, all without modifying the 74 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 75 * that is a(whole)nother story.) This is a feature. 76 */ 77 void 78 vfs_opv_init() 79 { 80 int i, j, k; 81 int (***opv_desc_vector_p)(); 82 int (**opv_desc_vector)(); 83 struct vnodeopv_entry_desc *opve_descp; 84 85 /* 86 * Allocate the dynamic vectors and fill them in. 87 */ 88 for (i=0; vfs_opv_descs[i]; i++) { 89 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 90 /* 91 * Allocate and init the vector, if it needs it. 92 * Also handle backwards compatibility. 93 */ 94 if (*opv_desc_vector_p == NULL) { 95 /* XXX - shouldn't be M_VNODE */ 96 MALLOC(*opv_desc_vector_p, PFI*, 97 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 98 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 99 DODEBUG(printf("vector at %x allocated\n", 100 opv_desc_vector_p)); 101 } 102 opv_desc_vector = *opv_desc_vector_p; 103 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 104 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 105 106 /* 107 * Sanity check: is this operation listed 108 * in the list of operations? We check this 109 * by seeing if its offest is zero. Since 110 * the default routine should always be listed 111 * first, it should be the only one with a zero 112 * offset. Any other operation with a zero 113 * offset is probably not listed in 114 * vfs_op_descs, and so is probably an error. 115 * 116 * A panic here means the layer programmer 117 * has committed the all-too common bug 118 * of adding a new operation to the layer's 119 * list of vnode operations but 120 * not adding the operation to the system-wide 121 * list of supported operations. 122 */ 123 if (opve_descp->opve_op->vdesc_offset == 0 && 124 opve_descp->opve_op->vdesc_offset != 125 VOFFSET(vop_default)) { 126 printf("operation %s not listed in %s.\n", 127 opve_descp->opve_op->vdesc_name, 128 "vfs_op_descs"); 129 panic ("vfs_opv_init: bad operation"); 130 } 131 /* 132 * Fill in this entry. 133 */ 134 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 135 opve_descp->opve_impl; 136 } 137 } 138 /* 139 * Finally, go back and replace unfilled routines 140 * with their default. (Sigh, an O(n^3) algorithm. I 141 * could make it better, but that'd be work, and n is small.) 142 */ 143 for (i = 0; vfs_opv_descs[i]; i++) { 144 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 145 /* 146 * Force every operations vector to have a default routine. 147 */ 148 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 149 panic("vfs_opv_init: operation vector without default routine."); 150 } 151 for (k = 0; k<vfs_opv_numops; k++) 152 if (opv_desc_vector[k] == NULL) 153 opv_desc_vector[k] = 154 opv_desc_vector[VOFFSET(vop_default)]; 155 } 156 } 157 158 /* 159 * Initialize known vnode operations vectors. 160 */ 161 void 162 vfs_op_init() 163 { 164 int i; 165 166 DODEBUG(printf("Vnode_interface_init.\n")); 167 /* 168 * Set all vnode vectors to a well known value. 169 */ 170 for (i = 0; vfs_opv_descs[i]; i++) 171 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 172 /* 173 * Figure out how many ops there are by counting the table, 174 * and assign each its offset. 175 */ 176 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 177 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 178 vfs_opv_numops++; 179 } 180 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 181 } 182 183 /* 184 * Routines having to do with the management of the vnode table. 185 */ 186 extern struct vnodeops dead_vnodeops; 187 extern struct vnodeops spec_vnodeops; 188 struct vattr va_null; 189 190 /* 191 * Initialize the vnode structures and initialize each file system type. 192 */ 193 vfsinit() 194 { 195 struct vfsconf *vfsp; 196 int i, maxtypenum; 197 198 /* 199 * Initialize the vnode table 200 */ 201 vntblinit(); 202 /* 203 * Initialize the vnode name cache 204 */ 205 nchinit(); 206 /* 207 * Build vnode operation vectors. 208 */ 209 vfs_op_init(); 210 vfs_opv_init(); /* finish the job */ 211 /* 212 * Initialize each file system type. 213 */ 214 vattr_null(&va_null); 215 maxtypenum = 0; 216 for (vfsp = vfsconf, i = 1; i <= maxvfsconf; i++, vfsp++) { 217 if (i < maxvfsconf) 218 vfsp->vfc_next = vfsp + 1; 219 if (maxtypenum <= vfsp->vfc_typenum) 220 maxtypenum = vfsp->vfc_typenum + 1; 221 (*vfsp->vfc_vfsops->vfs_init)(vfsp); 222 } 223 /* next vfc_typenum to be used */ 224 maxvfsconf = maxtypenum; 225 } 226