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 8.1 (Berkeley) 06/10/93 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 struct vnodeop_defn *defnp; 82 int (***opv_desc_vector_p)(); 83 int (**opv_desc_vector)(); 84 struct vnodeopv_entry_desc *opve_descp; 85 86 /* 87 * Allocate the dynamic vectors and fill them in. 88 */ 89 for (i=0; vfs_opv_descs[i]; i++) { 90 opv_desc_vector_p = vfs_opv_descs[i]->opv_desc_vector_p; 91 /* 92 * Allocate and init the vector, if it needs it. 93 * Also handle backwards compatibility. 94 */ 95 if (*opv_desc_vector_p == NULL) { 96 /* XXX - shouldn't be M_VNODE */ 97 MALLOC(*opv_desc_vector_p, PFI*, 98 vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK); 99 bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI)); 100 DODEBUG(printf("vector at %x allocated\n", 101 opv_desc_vector_p)); 102 } 103 opv_desc_vector = *opv_desc_vector_p; 104 for (j=0; vfs_opv_descs[i]->opv_desc_ops[j].opve_op; j++) { 105 opve_descp = &(vfs_opv_descs[i]->opv_desc_ops[j]); 106 107 /* 108 * Sanity check: is this operation listed 109 * in the list of operations? We check this 110 * by seeing if its offest is zero. Since 111 * the default routine should always be listed 112 * first, it should be the only one with a zero 113 * offset. Any other operation with a zero 114 * offset is probably not listed in 115 * vfs_op_descs, and so is probably an error. 116 * 117 * A panic here means the layer programmer 118 * has committed the all-too common bug 119 * of adding a new operation to the layer's 120 * list of vnode operations but 121 * not adding the operation to the system-wide 122 * list of supported operations. 123 */ 124 if (opve_descp->opve_op->vdesc_offset == 0 && 125 opve_descp->opve_op->vdesc_offset != 126 VOFFSET(vop_default)) { 127 printf("operation %s not listed in %s.\n", 128 opve_descp->opve_op->vdesc_name, 129 "vfs_op_descs"); 130 panic ("vfs_opv_init: bad operation"); 131 } 132 /* 133 * Fill in this entry. 134 */ 135 opv_desc_vector[opve_descp->opve_op->vdesc_offset] = 136 opve_descp->opve_impl; 137 } 138 } 139 /* 140 * Finally, go back and replace unfilled routines 141 * with their default. (Sigh, an O(n^3) algorithm. I 142 * could make it better, but that'd be work, and n is small.) 143 */ 144 for (i = 0; vfs_opv_descs[i]; i++) { 145 opv_desc_vector = *(vfs_opv_descs[i]->opv_desc_vector_p); 146 /* 147 * Force every operations vector to have a default routine. 148 */ 149 if (opv_desc_vector[VOFFSET(vop_default)]==NULL) { 150 panic("vfs_opv_init: operation vector without default routine."); 151 } 152 for (k = 0; k<vfs_opv_numops; k++) 153 if (opv_desc_vector[k] == NULL) 154 opv_desc_vector[k] = 155 opv_desc_vector[VOFFSET(vop_default)]; 156 } 157 } 158 159 /* 160 * Initialize known vnode operations vectors. 161 */ 162 void 163 vfs_op_init() 164 { 165 int i, j; 166 167 DODEBUG(printf("Vnode_interface_init.\n")); 168 /* 169 * Set all vnode vectors to a well known value. 170 */ 171 for (i = 0; vfs_opv_descs[i]; i++) 172 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL; 173 /* 174 * Figure out how many ops there are by counting the table, 175 * and assign each its offset. 176 */ 177 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) { 178 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops; 179 vfs_opv_numops++; 180 } 181 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops)); 182 } 183 184 /* 185 * Routines having to do with the management of the vnode table. 186 */ 187 extern struct vnodeops dead_vnodeops; 188 extern struct vnodeops spec_vnodeops; 189 extern void vclean(); 190 struct vattr va_null; 191 192 /* 193 * Initialize the vnode structures and initialize each file system type. 194 */ 195 vfsinit() 196 { 197 struct vfsops **vfsp; 198 199 /* 200 * Initialize the vnode name cache 201 */ 202 nchinit(); 203 /* 204 * Build vnode operation vectors. 205 */ 206 vfs_op_init(); 207 vfs_opv_init(); /* finish the job */ 208 /* 209 * Initialize each file system type. 210 */ 211 vattr_null(&va_null); 212 for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) { 213 if (*vfsp == NULL) 214 continue; 215 (*(*vfsp)->vfs_init)(); 216 } 217 } 218