| | 1 | /* |
| | 2 | * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry. |
| | 3 | * Copyright (c) 1992, 1993, 1994, 1995 |
| | 4 | * The Regents of the University of California. All rights reserved. |
| | 5 | * |
| | 6 | * This code is derived from software contributed to Berkeley by |
| | 7 | * Jan-Simon Pendry. |
| | 8 | * |
| | 9 | * %sccs.include.redist.c% |
| | 10 | * |
| | 11 | * @(#)union_vnops.c 8.26 (Berkeley) %G% |
| | 12 | */ |
| | 13 | |
| | 14 | #include <sys/param.h> |
| | 15 | #include <sys/systm.h> |
| | 16 | #include <sys/proc.h> |
| | 17 | #include <sys/file.h> |
| | 18 | #include <sys/time.h> |
| | 19 | #include <sys/stat.h> |
| | 20 | #include <sys/types.h> |
| | 21 | #include <sys/vnode.h> |
| | 22 | #include <sys/mount.h> |
| | 23 | #include <sys/namei.h> |
| | 24 | #include <sys/malloc.h> |
| | 25 | #include <sys/buf.h> |
| | 26 | #include <sys/queue.h> |
| | 27 | #include <miscfs/union/union.h> |
| | 28 | |
| | 29 | #define FIXUP(un) { \ |
| | 30 | if (((un)->un_flags & UN_ULOCK) == 0) { \ |
| | 31 | union_fixup(un); \ |
| | 32 | } \ |
| | 33 | } |
| | 34 | |
| | 35 | static void |
| | 36 | union_fixup(un) |
| | 37 | struct union_node *un; |
| | 38 | { |
| | 39 | |
| | 40 | VOP_LOCK(un->un_uppervp); |
| | 41 | un->un_flags |= UN_ULOCK; |
| | 42 | } |
| | 43 | |
| | 44 | static int |
| | 45 | union_lookup1(udvp, dvpp, vpp, cnp) |
| | 46 | struct vnode *udvp; |
| | 47 | struct vnode **dvpp; |
| | 48 | struct vnode **vpp; |
| | 49 | struct componentname *cnp; |
| | 50 | { |
| | 51 | int error; |
| | 52 | struct vnode *tdvp; |
| | 53 | struct vnode *dvp; |
| | 54 | struct mount *mp; |
| | 55 | |
| | 56 | dvp = *dvpp; |
| | 57 | |
| | 58 | /* |
| | 59 | * If stepping up the directory tree, check for going |
| | 60 | * back across the mount point, in which case do what |
| | 61 | * lookup would do by stepping back down the mount |
| | 62 | * hierarchy. |
| | 63 | */ |
| | 64 | if (cnp->cn_flags & ISDOTDOT) { |
| | 65 | while ((dvp != udvp) && (dvp->v_flag & VROOT)) { |
| | 66 | /* |
| | 67 | * Don't do the NOCROSSMOUNT check |
| | 68 | * at this level. By definition, |
| | 69 | * union fs deals with namespaces, not |
| | 70 | * filesystems. |
| | 71 | */ |
| | 72 | tdvp = dvp; |
| | 73 | *dvpp = dvp = dvp->v_mount->mnt_vnodecovered; |
| | 74 | vput(tdvp); |
| | 75 | VREF(dvp); |
| | 76 | VOP_LOCK(dvp); |
| | 77 | } |
| | 78 | } |
| | 79 | |
| | 80 | error = VOP_LOOKUP(dvp, &tdvp, cnp); |
| | 81 | if (error) |
| | 82 | return (error); |
| | 83 | |
| | 84 | /* |
| | 85 | * The parent directory will have been unlocked, unless lookup |
| | 86 | * found the last component. In which case, re-lock the node |
| | 87 | * here to allow it to be unlocked again (phew) in union_lookup. |
| | 88 | */ |
| | 89 | if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN)) |
| | 90 | VOP_LOCK(dvp); |
| | 91 | |
| | 92 | dvp = tdvp; |
| | 93 | |
| | 94 | /* |
| | 95 | * Lastly check if the current node is a mount point in |
| | 96 | * which case walk up the mount hierarchy making sure not to |
| | 97 | * bump into the root of the mount tree (ie. dvp != udvp). |
| | 98 | */ |
| | 99 | while (dvp != udvp && (dvp->v_type == VDIR) && |
| | 100 | (mp = dvp->v_mountedhere)) { |
| | 101 | |
| | 102 | if (mp->mnt_flag & MNT_MLOCK) { |
| | 103 | mp->mnt_flag |= MNT_MWAIT; |
| | 104 | sleep((caddr_t) mp, PVFS); |
| | 105 | continue; |
| | 106 | } |
| | 107 | |
| | 108 | if (error = VFS_ROOT(mp, &tdvp)) { |
| | 109 | vput(dvp); |
| | 110 | return (error); |
| | 111 | } |
| | 112 | |
| | 113 | vput(dvp); |
| | 114 | dvp = tdvp; |
| | 115 | } |
| | 116 | |
| | 117 | *vpp = dvp; |
| | 118 | return (0); |
| | 119 | } |
| | 120 | |
| | 121 | int |
| | 122 | union_lookup(ap) |
| | 123 | struct vop_lookup_args /* { |
| | 124 | struct vnodeop_desc *a_desc; |
| | 125 | struct vnode *a_dvp; |
| | 126 | struct vnode **a_vpp; |
| | 127 | struct componentname *a_cnp; |
| | 128 | } */ *ap; |
| | 129 | { |
| | 130 | int error; |
| | 131 | int uerror, lerror; |
| | 132 | struct vnode *uppervp, *lowervp; |
| | 133 | struct vnode *upperdvp, *lowerdvp; |
| | 134 | struct vnode *dvp = ap->a_dvp; |
| | 135 | struct union_node *dun = VTOUNION(dvp); |
| | 136 | struct componentname *cnp = ap->a_cnp; |
| | 137 | int lockparent = cnp->cn_flags & LOCKPARENT; |
| | 138 | int rdonly = cnp->cn_flags & RDONLY; |
| | 139 | struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount); |
| | 140 | struct ucred *saved_cred; |
| | 141 | int iswhiteout; |
| | 142 | struct vattr va; |
| | 143 | |
| | 144 | #ifdef notyet |
| | 145 | if (cnp->cn_namelen == 3 && |
| | 146 | cnp->cn_nameptr[2] == '.' && |
| | 147 | cnp->cn_nameptr[1] == '.' && |
| | 148 | cnp->cn_nameptr[0] == '.') { |
| | 149 | dvp = *ap->a_vpp = LOWERVP(ap->a_dvp); |
| | 150 | if (dvp == NULLVP) |
| | 151 | return (ENOENT); |
| | 152 | VREF(dvp); |
| | 153 | VOP_LOCK(dvp); |
| | 154 | if (!lockparent || !(cnp->cn_flags & ISLASTCN)) |
| | 155 | VOP_UNLOCK(ap->a_dvp); |
| | 156 | return (0); |
| | 157 | } |
| | 158 | #endif |
| | 159 | |
| | 160 | cnp->cn_flags |= LOCKPARENT; |
| | 161 | |
| | 162 | upperdvp = dun->un_uppervp; |
| | 163 | lowerdvp = dun->un_lowervp; |
| | 164 | uppervp = NULLVP; |
| | 165 | lowervp = NULLVP; |
| | 166 | iswhiteout = 0; |
| | 167 | |
| | 168 | /* |
| | 169 | * do the lookup in the upper level. |
| | 170 | * if that level comsumes additional pathnames, |
| | 171 | * then assume that something special is going |
| | 172 | * on and just return that vnode. |
| | 173 | */ |
| | 174 | if (upperdvp != NULLVP) { |
| | 175 | FIXUP(dun); |
| | 176 | uerror = union_lookup1(um->um_uppervp, &upperdvp, |
| | 177 | &uppervp, cnp); |
| | 178 | /*if (uppervp == upperdvp) |
| | 179 | dun->un_flags |= UN_KLOCK;*/ |
| | 180 | |
| | 181 | if (cnp->cn_consume != 0) { |
| | 182 | *ap->a_vpp = uppervp; |
| | 183 | if (!lockparent) |
| | 184 | cnp->cn_flags &= ~LOCKPARENT; |
| | 185 | return (uerror); |
| | 186 | } |
| | 187 | if (uerror == ENOENT || uerror == EJUSTRETURN) { |
| | 188 | if (cnp->cn_flags & ISWHITEOUT) { |
| | 189 | iswhiteout = 1; |
| | 190 | } else if (lowerdvp != NULLVP) { |
| | 191 | lerror = VOP_GETATTR(upperdvp, &va, |
| | 192 | cnp->cn_cred, cnp->cn_proc); |
| | 193 | if (lerror == 0 && (va.va_flags & OPAQUE)) |
| | 194 | iswhiteout = 1; |
| | 195 | } |
| | 196 | } |
| | 197 | } else { |
| | 198 | uerror = ENOENT; |
| | 199 | } |
| | 200 | |
| | 201 | /* |
| | 202 | * in a similar way to the upper layer, do the lookup |
| | 203 | * in the lower layer. this time, if there is some |
| | 204 | * component magic going on, then vput whatever we got |
| | 205 | * back from the upper layer and return the lower vnode |
| | 206 | * instead. |
| | 207 | */ |
| | 208 | if (lowerdvp != NULLVP && !iswhiteout) { |
| | 209 | int nameiop; |
| | 210 | |
| | 211 | VOP_LOCK(lowerdvp); |
| | 212 | |
| | 213 | /* |
| | 214 | * Only do a LOOKUP on the bottom node, since |
| | 215 | * we won't be making changes to it anyway. |
| | 216 | */ |
| | 217 | nameiop = cnp->cn_nameiop; |
| | 218 | cnp->cn_nameiop = LOOKUP; |
| | 219 | if (um->um_op == UNMNT_BELOW) { |
| | 220 | saved_cred = cnp->cn_cred; |
| | 221 | cnp->cn_cred = um->um_cred; |
| | 222 | } |
| | 223 | lerror = union_lookup1(um->um_lowervp, &lowerdvp, |
| | 224 | &lowervp, cnp); |
| | 225 | if (um->um_op == UNMNT_BELOW) |
| | 226 | cnp->cn_cred = saved_cred; |
| | 227 | cnp->cn_nameiop = nameiop; |
| | 228 | |
| | 229 | if (lowervp != lowerdvp) |
| | 230 | VOP_UNLOCK(lowerdvp); |
| | 231 | |
| | 232 | if (cnp->cn_consume != 0) { |
| | 233 | if (uppervp != NULLVP) { |
| | 234 | if (uppervp == upperdvp) |
| | 235 | vrele(uppervp); |
| | 236 | else |
| | 237 | vput(uppervp); |
| | 238 | uppervp = NULLVP; |
| | 239 | } |
| | 240 | *ap->a_vpp = lowervp; |
| | 241 | if (!lockparent) |
| | 242 | cnp->cn_flags &= ~LOCKPARENT; |
| | 243 | return (lerror); |
| | 244 | } |
| | 245 | } else { |
| | 246 | lerror = ENOENT; |
| | 247 | if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { |
| | 248 | lowervp = LOWERVP(dun->un_pvp); |
| | 249 | if (lowervp != NULLVP) { |
| | 250 | VREF(lowervp); |
| | 251 | VOP_LOCK(lowervp); |
| | 252 | lerror = 0; |
| | 253 | } |
| | 254 | } |
| | 255 | } |
| | 256 | |
| | 257 | if (!lockparent) |
| | 258 | cnp->cn_flags &= ~LOCKPARENT; |
| | 259 | |
| | 260 | /* |
| | 261 | * at this point, we have uerror and lerror indicating |
| | 262 | * possible errors with the lookups in the upper and lower |
| | 263 | * layers. additionally, uppervp and lowervp are (locked) |
| | 264 | * references to existing vnodes in the upper and lower layers. |
| | 265 | * |
| | 266 | * there are now three cases to consider. |
| | 267 | * 1. if both layers returned an error, then return whatever |
| | 268 | * error the upper layer generated. |
| | 269 | * |
| | 270 | * 2. if the top layer failed and the bottom layer succeeded |
| | 271 | * then two subcases occur. |
| | 272 | * a. the bottom vnode is not a directory, in which |
| | 273 | * case just return a new union vnode referencing |
| | 274 | * an empty top layer and the existing bottom layer. |
| | 275 | * b. the bottom vnode is a directory, in which case |
| | 276 | * create a new directory in the top-level and |
| | 277 | * continue as in case 3. |
| | 278 | * |
| | 279 | * 3. if the top layer succeeded then return a new union |
| | 280 | * vnode referencing whatever the new top layer and |
| | 281 | * whatever the bottom layer returned. |
| | 282 | */ |
| | 283 | |
| | 284 | *ap->a_vpp = NULLVP; |
| | 285 | |
| | 286 | /* case 1. */ |
| | 287 | if ((uerror != 0) && (lerror != 0)) { |
| | 288 | return (uerror); |
| | 289 | } |
| | 290 | |
| | 291 | /* case 2. */ |
| | 292 | if (uerror != 0 /* && (lerror == 0) */ ) { |
| | 293 | if (lowervp->v_type == VDIR) { /* case 2b. */ |
| | 294 | dun->un_flags &= ~UN_ULOCK; |
| | 295 | VOP_UNLOCK(upperdvp); |
| | 296 | uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); |
| | 297 | VOP_LOCK(upperdvp); |
| | 298 | dun->un_flags |= UN_ULOCK; |
| | 299 | |
| | 300 | if (uerror) { |
| | 301 | if (lowervp != NULLVP) { |
| | 302 | vput(lowervp); |
| | 303 | lowervp = NULLVP; |
| | 304 | } |
| | 305 | return (uerror); |
| | 306 | } |
| | 307 | } |
| | 308 | } |
| | 309 | |
| | 310 | if (lowervp != NULLVP) |
| | 311 | VOP_UNLOCK(lowervp); |
| | 312 | |
| | 313 | error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, |
| | 314 | uppervp, lowervp, 1); |
| | 315 | |
| | 316 | if (error) { |
| | 317 | if (uppervp != NULLVP) |
| | 318 | vput(uppervp); |
| | 319 | if (lowervp != NULLVP) |
| | 320 | vrele(lowervp); |
| | 321 | } else { |
| | 322 | if (*ap->a_vpp != dvp) |
| | 323 | if (!lockparent || !(cnp->cn_flags & ISLASTCN)) |
| | 324 | VOP_UNLOCK(dvp); |
| | 325 | } |
| | 326 | |
| | 327 | return (error); |
| | 328 | } |
| | 329 | |
| | 330 | int |
| | 331 | union_create(ap) |
| | 332 | struct vop_create_args /* { |
| | 333 | struct vnode *a_dvp; |
| | 334 | struct vnode **a_vpp; |
| | 335 | struct componentname *a_cnp; |
| | 336 | struct vattr *a_vap; |
| | 337 | } */ *ap; |
| | 338 | { |
| | 339 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 340 | struct vnode *dvp = un->un_uppervp; |
| | 341 | |
| | 342 | if (dvp != NULLVP) { |
| | 343 | int error; |
| | 344 | struct vnode *vp; |
| | 345 | struct mount *mp; |
| | 346 | |
| | 347 | FIXUP(un); |
| | 348 | |
| | 349 | VREF(dvp); |
| | 350 | un->un_flags |= UN_KLOCK; |
| | 351 | mp = ap->a_dvp->v_mount; |
| | 352 | vput(ap->a_dvp); |
| | 353 | error = VOP_CREATE(dvp, &vp, ap->a_cnp, ap->a_vap); |
| | 354 | if (error) |
| | 355 | return (error); |
| | 356 | |
| | 357 | error = union_allocvp( |
| | 358 | ap->a_vpp, |
| | 359 | mp, |
| | 360 | NULLVP, |
| | 361 | NULLVP, |
| | 362 | ap->a_cnp, |
| | 363 | vp, |
| | 364 | NULLVP, |
| | 365 | 1); |
| | 366 | if (error) |
| | 367 | vput(vp); |
| | 368 | return (error); |
| | 369 | } |
| | 370 | |
| | 371 | vput(ap->a_dvp); |
| | 372 | return (EROFS); |
| | 373 | } |
| | 374 | |
| | 375 | int |
| | 376 | union_whiteout(ap) |
| | 377 | struct vop_whiteout_args /* { |
| | 378 | struct vnode *a_dvp; |
| | 379 | struct componentname *a_cnp; |
| | 380 | int a_flags; |
| | 381 | } */ *ap; |
| | 382 | { |
| | 383 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 384 | |
| | 385 | if (un->un_uppervp == NULLVP) |
| | 386 | return (EOPNOTSUPP); |
| | 387 | |
| | 388 | FIXUP(un); |
| | 389 | return (VOP_WHITEOUT(un->un_uppervp, ap->a_cnp, ap->a_flags)); |
| | 390 | } |
| | 391 | |
| | 392 | int |
| | 393 | union_mknod(ap) |
| | 394 | struct vop_mknod_args /* { |
| | 395 | struct vnode *a_dvp; |
| | 396 | struct vnode **a_vpp; |
| | 397 | struct componentname *a_cnp; |
| | 398 | struct vattr *a_vap; |
| | 399 | } */ *ap; |
| | 400 | { |
| | 401 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 402 | struct vnode *dvp = un->un_uppervp; |
| | 403 | |
| | 404 | if (dvp != NULLVP) { |
| | 405 | int error; |
| | 406 | struct vnode *vp; |
| | 407 | struct mount *mp; |
| | 408 | |
| | 409 | FIXUP(un); |
| | 410 | |
| | 411 | VREF(dvp); |
| | 412 | un->un_flags |= UN_KLOCK; |
| | 413 | mp = ap->a_dvp->v_mount; |
| | 414 | vput(ap->a_dvp); |
| | 415 | error = VOP_MKNOD(dvp, &vp, ap->a_cnp, ap->a_vap); |
| | 416 | if (error) |
| | 417 | return (error); |
| | 418 | |
| | 419 | if (vp != NULLVP) { |
| | 420 | error = union_allocvp( |
| | 421 | ap->a_vpp, |
| | 422 | mp, |
| | 423 | NULLVP, |
| | 424 | NULLVP, |
| | 425 | ap->a_cnp, |
| | 426 | vp, |
| | 427 | NULLVP, |
| | 428 | 1); |
| | 429 | if (error) |
| | 430 | vput(vp); |
| | 431 | } |
| | 432 | return (error); |
| | 433 | } |
| | 434 | |
| | 435 | vput(ap->a_dvp); |
| | 436 | return (EROFS); |
| | 437 | } |
| | 438 | |
| | 439 | int |
| | 440 | union_open(ap) |
| | 441 | struct vop_open_args /* { |
| | 442 | struct vnodeop_desc *a_desc; |
| | 443 | struct vnode *a_vp; |
| | 444 | int a_mode; |
| | 445 | struct ucred *a_cred; |
| | 446 | struct proc *a_p; |
| | 447 | } */ *ap; |
| | 448 | { |
| | 449 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 450 | struct vnode *tvp; |
| | 451 | int mode = ap->a_mode; |
| | 452 | struct ucred *cred = ap->a_cred; |
| | 453 | struct proc *p = ap->a_p; |
| | 454 | int error; |
| | 455 | |
| | 456 | /* |
| | 457 | * If there is an existing upper vp then simply open that. |
| | 458 | */ |
| | 459 | tvp = un->un_uppervp; |
| | 460 | if (tvp == NULLVP) { |
| | 461 | /* |
| | 462 | * If the lower vnode is being opened for writing, then |
| | 463 | * copy the file contents to the upper vnode and open that, |
| | 464 | * otherwise can simply open the lower vnode. |
| | 465 | */ |
| | 466 | tvp = un->un_lowervp; |
| | 467 | if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { |
| | 468 | error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p); |
| | 469 | if (error == 0) |
| | 470 | error = VOP_OPEN(un->un_uppervp, mode, cred, p); |
| | 471 | return (error); |
| | 472 | } |
| | 473 | |
| | 474 | /* |
| | 475 | * Just open the lower vnode |
| | 476 | */ |
| | 477 | un->un_openl++; |
| | 478 | VOP_LOCK(tvp); |
| | 479 | error = VOP_OPEN(tvp, mode, cred, p); |
| | 480 | VOP_UNLOCK(tvp); |
| | 481 | |
| | 482 | return (error); |
| | 483 | } |
| | 484 | |
| | 485 | FIXUP(un); |
| | 486 | |
| | 487 | error = VOP_OPEN(tvp, mode, cred, p); |
| | 488 | |
| | 489 | return (error); |
| | 490 | } |
| | 491 | |
| | 492 | int |
| | 493 | union_close(ap) |
| | 494 | struct vop_close_args /* { |
| | 495 | struct vnode *a_vp; |
| | 496 | int a_fflag; |
| | 497 | struct ucred *a_cred; |
| | 498 | struct proc *a_p; |
| | 499 | } */ *ap; |
| | 500 | { |
| | 501 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 502 | struct vnode *vp; |
| | 503 | |
| | 504 | if (un->un_uppervp != NULLVP) { |
| | 505 | vp = un->un_uppervp; |
| | 506 | } else { |
| | 507 | #ifdef UNION_DIAGNOSTIC |
| | 508 | if (un->un_openl <= 0) |
| | 509 | panic("union: un_openl cnt"); |
| | 510 | #endif |
| | 511 | --un->un_openl; |
| | 512 | vp = un->un_lowervp; |
| | 513 | } |
| | 514 | |
| | 515 | return (VOP_CLOSE(vp, ap->a_fflag, ap->a_cred, ap->a_p)); |
| | 516 | } |
| | 517 | |
| | 518 | /* |
| | 519 | * Check access permission on the union vnode. |
| | 520 | * The access check being enforced is to check |
| | 521 | * against both the underlying vnode, and any |
| | 522 | * copied vnode. This ensures that no additional |
| | 523 | * file permissions are given away simply because |
| | 524 | * the user caused an implicit file copy. |
| | 525 | */ |
| | 526 | int |
| | 527 | union_access(ap) |
| | 528 | struct vop_access_args /* { |
| | 529 | struct vnodeop_desc *a_desc; |
| | 530 | struct vnode *a_vp; |
| | 531 | int a_mode; |
| | 532 | struct ucred *a_cred; |
| | 533 | struct proc *a_p; |
| | 534 | } */ *ap; |
| | 535 | { |
| | 536 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 537 | int error = EACCES; |
| | 538 | struct vnode *vp; |
| | 539 | |
| | 540 | if ((vp = un->un_uppervp) != NULLVP) { |
| | 541 | FIXUP(un); |
| | 542 | return (VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p)); |
| | 543 | } |
| | 544 | |
| | 545 | if ((vp = un->un_lowervp) != NULLVP) { |
| | 546 | VOP_LOCK(vp); |
| | 547 | error = VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p); |
| | 548 | if (error == 0) { |
| | 549 | struct union_mount *um = MOUNTTOUNIONMOUNT(vp->v_mount); |
| | 550 | |
| | 551 | if (um->um_op == UNMNT_BELOW) |
| | 552 | error = VOP_ACCESS(vp, ap->a_mode, |
| | 553 | um->um_cred, ap->a_p); |
| | 554 | } |
| | 555 | VOP_UNLOCK(vp); |
| | 556 | if (error) |
| | 557 | return (error); |
| | 558 | } |
| | 559 | |
| | 560 | return (error); |
| | 561 | } |
| | 562 | |
| | 563 | /* |
| | 564 | * We handle getattr only to change the fsid and |
| | 565 | * track object sizes |
| | 566 | */ |
| | 567 | int |
| | 568 | union_getattr(ap) |
| | 569 | struct vop_getattr_args /* { |
| | 570 | struct vnode *a_vp; |
| | 571 | struct vattr *a_vap; |
| | 572 | struct ucred *a_cred; |
| | 573 | struct proc *a_p; |
| | 574 | } */ *ap; |
| | 575 | { |
| | 576 | int error; |
| | 577 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 578 | struct vnode *vp = un->un_uppervp; |
| | 579 | struct vattr *vap; |
| | 580 | struct vattr va; |
| | 581 | |
| | 582 | |
| | 583 | /* |
| | 584 | * Some programs walk the filesystem hierarchy by counting |
| | 585 | * links to directories to avoid stat'ing all the time. |
| | 586 | * This means the link count on directories needs to be "correct". |
| | 587 | * The only way to do that is to call getattr on both layers |
| | 588 | * and fix up the link count. The link count will not necessarily |
| | 589 | * be accurate but will be large enough to defeat the tree walkers. |
| | 590 | */ |
| | 591 | |
| | 592 | vap = ap->a_vap; |
| | 593 | |
| | 594 | vp = un->un_uppervp; |
| | 595 | if (vp != NULLVP) { |
| | 596 | /* |
| | 597 | * It's not clear whether VOP_GETATTR is to be |
| | 598 | * called with the vnode locked or not. stat() calls |
| | 599 | * it with (vp) locked, and fstat calls it with |
| | 600 | * (vp) unlocked. |
| | 601 | * In the mean time, compensate here by checking |
| | 602 | * the union_node's lock flag. |
| | 603 | */ |
| | 604 | if (un->un_flags & UN_LOCKED) |
| | 605 | FIXUP(un); |
| | 606 | |
| | 607 | error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); |
| | 608 | if (error) |
| | 609 | return (error); |
| | 610 | union_newsize(ap->a_vp, vap->va_size, VNOVAL); |
| | 611 | } |
| | 612 | |
| | 613 | if (vp == NULLVP) { |
| | 614 | vp = un->un_lowervp; |
| | 615 | } else if (vp->v_type == VDIR) { |
| | 616 | vp = un->un_lowervp; |
| | 617 | vap = &va; |
| | 618 | } else { |
| | 619 | vp = NULLVP; |
| | 620 | } |
| | 621 | |
| | 622 | if (vp != NULLVP) { |
| | 623 | error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); |
| | 624 | if (error) |
| | 625 | return (error); |
| | 626 | union_newsize(ap->a_vp, VNOVAL, vap->va_size); |
| | 627 | } |
| | 628 | |
| | 629 | if ((vap != ap->a_vap) && (vap->va_type == VDIR)) |
| | 630 | ap->a_vap->va_nlink += vap->va_nlink; |
| | 631 | |
| | 632 | ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; |
| | 633 | return (0); |
| | 634 | } |
| | 635 | |
| | 636 | int |
| | 637 | union_setattr(ap) |
| | 638 | struct vop_setattr_args /* { |
| | 639 | struct vnode *a_vp; |
| | 640 | struct vattr *a_vap; |
| | 641 | struct ucred *a_cred; |
| | 642 | struct proc *a_p; |
| | 643 | } */ *ap; |
| | 644 | { |
| | 645 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 646 | int error; |
| | 647 | |
| | 648 | /* |
| | 649 | * Handle case of truncating lower object to zero size, |
| | 650 | * by creating a zero length upper object. This is to |
| | 651 | * handle the case of open with O_TRUNC and O_CREAT. |
| | 652 | */ |
| | 653 | if ((un->un_uppervp == NULLVP) && |
| | 654 | /* assert(un->un_lowervp != NULLVP) */ |
| | 655 | (un->un_lowervp->v_type == VREG)) { |
| | 656 | error = union_copyup(un, (ap->a_vap->va_size != 0), |
| | 657 | ap->a_cred, ap->a_p); |
| | 658 | if (error) |
| | 659 | return (error); |
| | 660 | } |
| | 661 | |
| | 662 | /* |
| | 663 | * Try to set attributes in upper layer, |
| | 664 | * otherwise return read-only filesystem error. |
| | 665 | */ |
| | 666 | if (un->un_uppervp != NULLVP) { |
| | 667 | FIXUP(un); |
| | 668 | error = VOP_SETATTR(un->un_uppervp, ap->a_vap, |
| | 669 | ap->a_cred, ap->a_p); |
| | 670 | if ((error == 0) && (ap->a_vap->va_size != VNOVAL)) |
| | 671 | union_newsize(ap->a_vp, ap->a_vap->va_size, VNOVAL); |
| | 672 | } else { |
| | 673 | error = EROFS; |
| | 674 | } |
| | 675 | |
| | 676 | return (error); |
| | 677 | } |
| | 678 | |
| | 679 | int |
| | 680 | union_read(ap) |
| | 681 | struct vop_read_args /* { |
| | 682 | struct vnode *a_vp; |
| | 683 | struct uio *a_uio; |
| | 684 | int a_ioflag; |
| | 685 | struct ucred *a_cred; |
| | 686 | } */ *ap; |
| | 687 | { |
| | 688 | int error; |
| | 689 | struct vnode *vp = OTHERVP(ap->a_vp); |
| | 690 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| | 691 | |
| | 692 | if (dolock) |
| | 693 | VOP_LOCK(vp); |
| | 694 | else |
| | 695 | FIXUP(VTOUNION(ap->a_vp)); |
| | 696 | error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| | 697 | if (dolock) |
| | 698 | VOP_UNLOCK(vp); |
| | 699 | |
| | 700 | /* |
| | 701 | * XXX |
| | 702 | * perhaps the size of the underlying object has changed under |
| | 703 | * our feet. take advantage of the offset information present |
| | 704 | * in the uio structure. |
| | 705 | */ |
| | 706 | if (error == 0) { |
| | 707 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 708 | off_t cur = ap->a_uio->uio_offset; |
| | 709 | |
| | 710 | if (vp == un->un_uppervp) { |
| | 711 | if (cur > un->un_uppersz) |
| | 712 | union_newsize(ap->a_vp, cur, VNOVAL); |
| | 713 | } else { |
| | 714 | if (cur > un->un_lowersz) |
| | 715 | union_newsize(ap->a_vp, VNOVAL, cur); |
| | 716 | } |
| | 717 | } |
| | 718 | |
| | 719 | return (error); |
| | 720 | } |
| | 721 | |
| | 722 | int |
| | 723 | union_write(ap) |
| | 724 | struct vop_read_args /* { |
| | 725 | struct vnode *a_vp; |
| | 726 | struct uio *a_uio; |
| | 727 | int a_ioflag; |
| | 728 | struct ucred *a_cred; |
| | 729 | } */ *ap; |
| | 730 | { |
| | 731 | int error; |
| | 732 | struct vnode *vp; |
| | 733 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 734 | |
| | 735 | vp = UPPERVP(ap->a_vp); |
| | 736 | if (vp == NULLVP) |
| | 737 | panic("union: missing upper layer in write"); |
| | 738 | |
| | 739 | FIXUP(un); |
| | 740 | error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| | 741 | |
| | 742 | /* |
| | 743 | * the size of the underlying object may be changed by the |
| | 744 | * write. |
| | 745 | */ |
| | 746 | if (error == 0) { |
| | 747 | off_t cur = ap->a_uio->uio_offset; |
| | 748 | |
| | 749 | if (cur > un->un_uppersz) |
| | 750 | union_newsize(ap->a_vp, cur, VNOVAL); |
| | 751 | } |
| | 752 | |
| | 753 | return (error); |
| | 754 | } |
| | 755 | |
| | 756 | union_lease(ap) |
| | 757 | struct vop_lease_args /* { |
| | 758 | struct vnode *a_vp; |
| | 759 | struct proc *a_p; |
| | 760 | struct ucred *a_cred; |
| | 761 | int a_flag; |
| | 762 | } */ *ap; |
| | 763 | { |
| | 764 | |
| | 765 | return (VOP_LEASE(OTHERVP(ap->a_vp), ap->a_p, ap->a_cred, ap->a_flag)); |
| | 766 | } |
| | 767 | |
| | 768 | int |
| | 769 | union_ioctl(ap) |
| | 770 | struct vop_ioctl_args /* { |
| | 771 | struct vnode *a_vp; |
| | 772 | int a_command; |
| | 773 | caddr_t a_data; |
| | 774 | int a_fflag; |
| | 775 | struct ucred *a_cred; |
| | 776 | struct proc *a_p; |
| | 777 | } */ *ap; |
| | 778 | { |
| | 779 | |
| | 780 | return (VOP_IOCTL(OTHERVP(ap->a_vp), ap->a_command, ap->a_data, |
| | 781 | ap->a_fflag, ap->a_cred, ap->a_p)); |
| | 782 | } |
| | 783 | |
| | 784 | int |
| | 785 | union_select(ap) |
| | 786 | struct vop_select_args /* { |
| | 787 | struct vnode *a_vp; |
| | 788 | int a_which; |
| | 789 | int a_fflags; |
| | 790 | struct ucred *a_cred; |
| | 791 | struct proc *a_p; |
| | 792 | } */ *ap; |
| | 793 | { |
| | 794 | |
| | 795 | return (VOP_SELECT(OTHERVP(ap->a_vp), ap->a_which, ap->a_fflags, |
| | 796 | ap->a_cred, ap->a_p)); |
| | 797 | } |
| | 798 | |
| | 799 | int |
| | 800 | union_revoke(ap) |
| | 801 | struct vop_revoke_args /* { |
| | 802 | struct vnode *a_vp; |
| | 803 | int a_flags; |
| | 804 | } */ *ap; |
| | 805 | { |
| | 806 | struct vnode *vp = ap->a_vp; |
| | 807 | |
| | 808 | if (UPPERVP(vp)) |
| | 809 | VOP_REVOKE(UPPERVP(vp), ap->a_flags); |
| | 810 | if (LOWERVP(vp)) |
| | 811 | VOP_REVOKE(UPPERVP(vp), ap->a_flags); |
| | 812 | vgone(vp); |
| | 813 | } |
| | 814 | |
| | 815 | int |
| | 816 | union_mmap(ap) |
| | 817 | struct vop_mmap_args /* { |
| | 818 | struct vnode *a_vp; |
| | 819 | int a_fflags; |
| | 820 | struct ucred *a_cred; |
| | 821 | struct proc *a_p; |
| | 822 | } */ *ap; |
| | 823 | { |
| | 824 | |
| | 825 | return (VOP_MMAP(OTHERVP(ap->a_vp), ap->a_fflags, |
| | 826 | ap->a_cred, ap->a_p)); |
| | 827 | } |
| | 828 | |
| | 829 | int |
| | 830 | union_fsync(ap) |
| | 831 | struct vop_fsync_args /* { |
| | 832 | struct vnode *a_vp; |
| | 833 | struct ucred *a_cred; |
| | 834 | int a_waitfor; |
| | 835 | struct proc *a_p; |
| | 836 | } */ *ap; |
| | 837 | { |
| | 838 | int error = 0; |
| | 839 | struct vnode *targetvp = OTHERVP(ap->a_vp); |
| | 840 | |
| | 841 | if (targetvp != NULLVP) { |
| | 842 | int dolock = (targetvp == LOWERVP(ap->a_vp)); |
| | 843 | |
| | 844 | if (dolock) |
| | 845 | VOP_LOCK(targetvp); |
| | 846 | else |
| | 847 | FIXUP(VTOUNION(ap->a_vp)); |
| | 848 | error = VOP_FSYNC(targetvp, ap->a_cred, |
| | 849 | ap->a_waitfor, ap->a_p); |
| | 850 | if (dolock) |
| | 851 | VOP_UNLOCK(targetvp); |
| | 852 | } |
| | 853 | |
| | 854 | return (error); |
| | 855 | } |
| | 856 | |
| | 857 | int |
| | 858 | union_seek(ap) |
| | 859 | struct vop_seek_args /* { |
| | 860 | struct vnode *a_vp; |
| | 861 | off_t a_oldoff; |
| | 862 | off_t a_newoff; |
| | 863 | struct ucred *a_cred; |
| | 864 | } */ *ap; |
| | 865 | { |
| | 866 | |
| | 867 | return (VOP_SEEK(OTHERVP(ap->a_vp), ap->a_oldoff, ap->a_newoff, ap->a_cred)); |
| | 868 | } |
| | 869 | |
| | 870 | int |
| | 871 | union_remove(ap) |
| | 872 | struct vop_remove_args /* { |
| | 873 | struct vnode *a_dvp; |
| | 874 | struct vnode *a_vp; |
| | 875 | struct componentname *a_cnp; |
| | 876 | } */ *ap; |
| | 877 | { |
| | 878 | int error; |
| | 879 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| | 880 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 881 | |
| | 882 | if (dun->un_uppervp == NULLVP) |
| | 883 | panic("union remove: null upper vnode"); |
| | 884 | |
| | 885 | if (un->un_uppervp != NULLVP) { |
| | 886 | struct vnode *dvp = dun->un_uppervp; |
| | 887 | struct vnode *vp = un->un_uppervp; |
| | 888 | struct componentname *cnp = ap->a_cnp; |
| | 889 | |
| | 890 | FIXUP(dun); |
| | 891 | VREF(dvp); |
| | 892 | dun->un_flags |= UN_KLOCK; |
| | 893 | vput(ap->a_dvp); |
| | 894 | FIXUP(un); |
| | 895 | VREF(vp); |
| | 896 | un->un_flags |= UN_KLOCK; |
| | 897 | vput(ap->a_vp); |
| | 898 | |
| | 899 | if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) |
| | 900 | cnp->cn_flags |= DOWHITEOUT; |
| | 901 | error = VOP_REMOVE(dvp, vp, cnp); |
| | 902 | if (!error) |
| | 903 | union_removed_upper(un); |
| | 904 | } else { |
| | 905 | FIXUP(dun); |
| | 906 | error = union_mkwhiteout( |
| | 907 | MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), |
| | 908 | dun->un_uppervp, ap->a_cnp, un->un_path); |
| | 909 | vput(ap->a_dvp); |
| | 910 | vput(ap->a_vp); |
| | 911 | } |
| | 912 | |
| | 913 | return (error); |
| | 914 | } |
| | 915 | |
| | 916 | int |
| | 917 | union_link(ap) |
| | 918 | struct vop_link_args /* { |
| | 919 | struct vnode *a_vp; |
| | 920 | struct vnode *a_tdvp; |
| | 921 | struct componentname *a_cnp; |
| | 922 | } */ *ap; |
| | 923 | { |
| | 924 | int error = 0; |
| | 925 | struct union_node *un; |
| | 926 | struct vnode *vp; |
| | 927 | struct vnode *tdvp; |
| | 928 | |
| | 929 | un = VTOUNION(ap->a_tdvp); |
| | 930 | |
| | 931 | if (ap->a_tdvp->v_op != ap->a_vp->v_op) { |
| | 932 | vp = ap->a_vp; |
| | 933 | } else { |
| | 934 | struct union_node *tun = VTOUNION(ap->a_vp); |
| | 935 | if (tun->un_uppervp == NULLVP) { |
| | 936 | VOP_LOCK(ap->a_vp); |
| | 937 | if (un->un_uppervp == tun->un_dirvp) { |
| | 938 | un->un_flags &= ~UN_ULOCK; |
| | 939 | VOP_UNLOCK(un->un_uppervp); |
| | 940 | } |
| | 941 | error = union_copyup(tun, 1, ap->a_cnp->cn_cred, |
| | 942 | ap->a_cnp->cn_proc); |
| | 943 | if (un->un_uppervp == tun->un_dirvp) { |
| | 944 | VOP_LOCK(un->un_uppervp); |
| | 945 | un->un_flags |= UN_ULOCK; |
| | 946 | } |
| | 947 | VOP_UNLOCK(ap->a_vp); |
| | 948 | } |
| | 949 | vp = tun->un_uppervp; |
| | 950 | } |
| | 951 | |
| | 952 | tdvp = un->un_uppervp; |
| | 953 | if (tdvp == NULLVP) |
| | 954 | error = EROFS; |
| | 955 | |
| | 956 | if (error) { |
| | 957 | vput(ap->a_tdvp); |
| | 958 | return (error); |
| | 959 | } |
| | 960 | |
| | 961 | FIXUP(un); |
| | 962 | VREF(tdvp); |
| | 963 | un->un_flags |= UN_KLOCK; |
| | 964 | vput(ap->a_tdvp); |
| | 965 | |
| | 966 | return (VOP_LINK(vp, tdvp, ap->a_cnp)); |
| | 967 | } |
| | 968 | |
| | 969 | int |
| | 970 | union_rename(ap) |
| | 971 | struct vop_rename_args /* { |
| | 972 | struct vnode *a_fdvp; |
| | 973 | struct vnode *a_fvp; |
| | 974 | struct componentname *a_fcnp; |
| | 975 | struct vnode *a_tdvp; |
| | 976 | struct vnode *a_tvp; |
| | 977 | struct componentname *a_tcnp; |
| | 978 | } */ *ap; |
| | 979 | { |
| | 980 | int error; |
| | 981 | |
| | 982 | struct vnode *fdvp = ap->a_fdvp; |
| | 983 | struct vnode *fvp = ap->a_fvp; |
| | 984 | struct vnode *tdvp = ap->a_tdvp; |
| | 985 | struct vnode *tvp = ap->a_tvp; |
| | 986 | |
| | 987 | if (fdvp->v_op == union_vnodeop_p) { /* always true */ |
| | 988 | struct union_node *un = VTOUNION(fdvp); |
| | 989 | if (un->un_uppervp == NULLVP) { |
| | 990 | /* |
| | 991 | * this should never happen in normal |
| | 992 | * operation but might if there was |
| | 993 | * a problem creating the top-level shadow |
| | 994 | * directory. |
| | 995 | */ |
| | 996 | error = EXDEV; |
| | 997 | goto bad; |
| | 998 | } |
| | 999 | |
| | 1000 | fdvp = un->un_uppervp; |
| | 1001 | VREF(fdvp); |
| | 1002 | vrele(ap->a_fdvp); |
| | 1003 | } |
| | 1004 | |
| | 1005 | if (fvp->v_op == union_vnodeop_p) { /* always true */ |
| | 1006 | struct union_node *un = VTOUNION(fvp); |
| | 1007 | if (un->un_uppervp == NULLVP) { |
| | 1008 | /* XXX: should do a copyup */ |
| | 1009 | error = EXDEV; |
| | 1010 | goto bad; |
| | 1011 | } |
| | 1012 | |
| | 1013 | if (un->un_lowervp != NULLVP) |
| | 1014 | ap->a_fcnp->cn_flags |= DOWHITEOUT; |
| | 1015 | |
| | 1016 | fvp = un->un_uppervp; |
| | 1017 | VREF(fvp); |
| | 1018 | vrele(ap->a_fvp); |
| | 1019 | } |
| | 1020 | |
| | 1021 | if (tdvp->v_op == union_vnodeop_p) { |
| | 1022 | struct union_node *un = VTOUNION(tdvp); |
| | 1023 | if (un->un_uppervp == NULLVP) { |
| | 1024 | /* |
| | 1025 | * this should never happen in normal |
| | 1026 | * operation but might if there was |
| | 1027 | * a problem creating the top-level shadow |
| | 1028 | * directory. |
| | 1029 | */ |
| | 1030 | error = EXDEV; |
| | 1031 | goto bad; |
| | 1032 | } |
| | 1033 | |
| | 1034 | tdvp = un->un_uppervp; |
| | 1035 | VREF(tdvp); |
| | 1036 | un->un_flags |= UN_KLOCK; |
| | 1037 | vput(ap->a_tdvp); |
| | 1038 | } |
| | 1039 | |
| | 1040 | if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { |
| | 1041 | struct union_node *un = VTOUNION(tvp); |
| | 1042 | |
| | 1043 | tvp = un->un_uppervp; |
| | 1044 | if (tvp != NULLVP) { |
| | 1045 | VREF(tvp); |
| | 1046 | un->un_flags |= UN_KLOCK; |
| | 1047 | } |
| | 1048 | vput(ap->a_tvp); |
| | 1049 | } |
| | 1050 | |
| | 1051 | return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); |
| | 1052 | |
| | 1053 | bad: |
| | 1054 | vrele(fdvp); |
| | 1055 | vrele(fvp); |
| | 1056 | vput(tdvp); |
| | 1057 | if (tvp != NULLVP) |
| | 1058 | vput(tvp); |
| | 1059 | |
| | 1060 | return (error); |
| | 1061 | } |
| | 1062 | |
| | 1063 | int |
| | 1064 | union_mkdir(ap) |
| | 1065 | struct vop_mkdir_args /* { |
| | 1066 | struct vnode *a_dvp; |
| | 1067 | struct vnode **a_vpp; |
| | 1068 | struct componentname *a_cnp; |
| | 1069 | struct vattr *a_vap; |
| | 1070 | } */ *ap; |
| | 1071 | { |
| | 1072 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 1073 | struct vnode *dvp = un->un_uppervp; |
| | 1074 | |
| | 1075 | if (dvp != NULLVP) { |
| | 1076 | int error; |
| | 1077 | struct vnode *vp; |
| | 1078 | |
| | 1079 | FIXUP(un); |
| | 1080 | VREF(dvp); |
| | 1081 | un->un_flags |= UN_KLOCK; |
| | 1082 | VOP_UNLOCK(ap->a_dvp); |
| | 1083 | error = VOP_MKDIR(dvp, &vp, ap->a_cnp, ap->a_vap); |
| | 1084 | if (error) { |
| | 1085 | vrele(ap->a_dvp); |
| | 1086 | return (error); |
| | 1087 | } |
| | 1088 | |
| | 1089 | error = union_allocvp( |
| | 1090 | ap->a_vpp, |
| | 1091 | ap->a_dvp->v_mount, |
| | 1092 | ap->a_dvp, |
| | 1093 | NULLVP, |
| | 1094 | ap->a_cnp, |
| | 1095 | vp, |
| | 1096 | NULLVP, |
| | 1097 | 1); |
| | 1098 | vrele(ap->a_dvp); |
| | 1099 | if (error) |
| | 1100 | vput(vp); |
| | 1101 | return (error); |
| | 1102 | } |
| | 1103 | |
| | 1104 | vput(ap->a_dvp); |
| | 1105 | return (EROFS); |
| | 1106 | } |
| | 1107 | |
| | 1108 | int |
| | 1109 | union_rmdir(ap) |
| | 1110 | struct vop_rmdir_args /* { |
| | 1111 | struct vnode *a_dvp; |
| | 1112 | struct vnode *a_vp; |
| | 1113 | struct componentname *a_cnp; |
| | 1114 | } */ *ap; |
| | 1115 | { |
| | 1116 | int error; |
| | 1117 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| | 1118 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 1119 | |
| | 1120 | if (dun->un_uppervp == NULLVP) |
| | 1121 | panic("union rmdir: null upper vnode"); |
| | 1122 | |
| | 1123 | if (un->un_uppervp != NULLVP) { |
| | 1124 | struct vnode *dvp = dun->un_uppervp; |
| | 1125 | struct vnode *vp = un->un_uppervp; |
| | 1126 | struct componentname *cnp = ap->a_cnp; |
| | 1127 | |
| | 1128 | FIXUP(dun); |
| | 1129 | VREF(dvp); |
| | 1130 | dun->un_flags |= UN_KLOCK; |
| | 1131 | vput(ap->a_dvp); |
| | 1132 | FIXUP(un); |
| | 1133 | VREF(vp); |
| | 1134 | un->un_flags |= UN_KLOCK; |
| | 1135 | vput(ap->a_vp); |
| | 1136 | |
| | 1137 | if (union_dowhiteout(un, cnp->cn_cred, cnp->cn_proc)) |
| | 1138 | cnp->cn_flags |= DOWHITEOUT; |
| | 1139 | error = VOP_RMDIR(dvp, vp, ap->a_cnp); |
| | 1140 | if (!error) |
| | 1141 | union_removed_upper(un); |
| | 1142 | } else { |
| | 1143 | FIXUP(dun); |
| | 1144 | error = union_mkwhiteout( |
| | 1145 | MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), |
| | 1146 | dun->un_uppervp, ap->a_cnp, un->un_path); |
| | 1147 | vput(ap->a_dvp); |
| | 1148 | vput(ap->a_vp); |
| | 1149 | } |
| | 1150 | |
| | 1151 | return (error); |
| | 1152 | } |
| | 1153 | |
| | 1154 | int |
| | 1155 | union_symlink(ap) |
| | 1156 | struct vop_symlink_args /* { |
| | 1157 | struct vnode *a_dvp; |
| | 1158 | struct vnode **a_vpp; |
| | 1159 | struct componentname *a_cnp; |
| | 1160 | struct vattr *a_vap; |
| | 1161 | char *a_target; |
| | 1162 | } */ *ap; |
| | 1163 | { |
| | 1164 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 1165 | struct vnode *dvp = un->un_uppervp; |
| | 1166 | |
| | 1167 | if (dvp != NULLVP) { |
| | 1168 | int error; |
| | 1169 | struct vnode *vp; |
| | 1170 | struct mount *mp = ap->a_dvp->v_mount; |
| | 1171 | |
| | 1172 | FIXUP(un); |
| | 1173 | VREF(dvp); |
| | 1174 | un->un_flags |= UN_KLOCK; |
| | 1175 | vput(ap->a_dvp); |
| | 1176 | error = VOP_SYMLINK(dvp, &vp, ap->a_cnp, |
| | 1177 | ap->a_vap, ap->a_target); |
| | 1178 | *ap->a_vpp = NULLVP; |
| | 1179 | return (error); |
| | 1180 | } |
| | 1181 | |
| | 1182 | vput(ap->a_dvp); |
| | 1183 | return (EROFS); |
| | 1184 | } |
| | 1185 | |
| | 1186 | /* |
| | 1187 | * union_readdir works in concert with getdirentries and |
| | 1188 | * readdir(3) to provide a list of entries in the unioned |
| | 1189 | * directories. getdirentries is responsible for walking |
| | 1190 | * down the union stack. readdir(3) is responsible for |
| | 1191 | * eliminating duplicate names from the returned data stream. |
| | 1192 | */ |
| | 1193 | int |
| | 1194 | union_readdir(ap) |
| | 1195 | struct vop_readdir_args /* { |
| | 1196 | struct vnodeop_desc *a_desc; |
| | 1197 | struct vnode *a_vp; |
| | 1198 | struct uio *a_uio; |
| | 1199 | struct ucred *a_cred; |
| | 1200 | int *a_eofflag; |
| | 1201 | u_long *a_cookies; |
| | 1202 | int a_ncookies; |
| | 1203 | } */ *ap; |
| | 1204 | { |
| | 1205 | register struct union_node *un = VTOUNION(ap->a_vp); |
| | 1206 | register struct vnode *uvp = un->un_uppervp; |
| | 1207 | |
| | 1208 | if (uvp == NULLVP) |
| | 1209 | return (0); |
| | 1210 | |
| | 1211 | FIXUP(un); |
| | 1212 | ap->a_vp = uvp; |
| | 1213 | return (VOCALL(uvp->v_op, VOFFSET(vop_readdir), ap)); |
| | 1214 | } |
| | 1215 | |
| | 1216 | int |
| | 1217 | union_readlink(ap) |
| | 1218 | struct vop_readlink_args /* { |
| | 1219 | struct vnode *a_vp; |
| | 1220 | struct uio *a_uio; |
| | 1221 | struct ucred *a_cred; |
| | 1222 | } */ *ap; |
| | 1223 | { |
| | 1224 | int error; |
| | 1225 | struct vnode *vp = OTHERVP(ap->a_vp); |
| | 1226 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| | 1227 | |
| | 1228 | if (dolock) |
| | 1229 | VOP_LOCK(vp); |
| | 1230 | else |
| | 1231 | FIXUP(VTOUNION(ap->a_vp)); |
| | 1232 | error = VOP_READLINK(vp, ap->a_uio, ap->a_cred); |
| | 1233 | if (dolock) |
| | 1234 | VOP_UNLOCK(vp); |
| | 1235 | |
| | 1236 | return (error); |
| | 1237 | } |
| | 1238 | |
| | 1239 | int |
| | 1240 | union_abortop(ap) |
| | 1241 | struct vop_abortop_args /* { |
| | 1242 | struct vnode *a_dvp; |
| | 1243 | struct componentname *a_cnp; |
| | 1244 | } */ *ap; |
| | 1245 | { |
| | 1246 | int error; |
| | 1247 | struct vnode *vp = OTHERVP(ap->a_dvp); |
| | 1248 | struct union_node *un = VTOUNION(ap->a_dvp); |
| | 1249 | int islocked = un->un_flags & UN_LOCKED; |
| | 1250 | int dolock = (vp == LOWERVP(ap->a_dvp)); |
| | 1251 | |
| | 1252 | if (islocked) { |
| | 1253 | if (dolock) |
| | 1254 | VOP_LOCK(vp); |
| | 1255 | else |
| | 1256 | FIXUP(VTOUNION(ap->a_dvp)); |
| | 1257 | } |
| | 1258 | error = VOP_ABORTOP(vp, ap->a_cnp); |
| | 1259 | if (islocked && dolock) |
| | 1260 | VOP_UNLOCK(vp); |
| | 1261 | |
| | 1262 | return (error); |
| | 1263 | } |
| | 1264 | |
| | 1265 | int |
| | 1266 | union_inactive(ap) |
| | 1267 | struct vop_inactive_args /* { |
| | 1268 | struct vnode *a_vp; |
| | 1269 | } */ *ap; |
| | 1270 | { |
| | 1271 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 1272 | struct vnode **vpp; |
| | 1273 | |
| | 1274 | /* |
| | 1275 | * Do nothing (and _don't_ bypass). |
| | 1276 | * Wait to vrele lowervp until reclaim, |
| | 1277 | * so that until then our union_node is in the |
| | 1278 | * cache and reusable. |
| | 1279 | * |
| | 1280 | * NEEDSWORK: Someday, consider inactive'ing |
| | 1281 | * the lowervp and then trying to reactivate it |
| | 1282 | * with capabilities (v_id) |
| | 1283 | * like they do in the name lookup cache code. |
| | 1284 | * That's too much work for now. |
| | 1285 | */ |
| | 1286 | |
| | 1287 | #ifdef UNION_DIAGNOSTIC |
| | 1288 | if (un->un_flags & UN_LOCKED) |
| | 1289 | panic("union: inactivating locked node"); |
| | 1290 | if (un->un_flags & UN_ULOCK) |
| | 1291 | panic("union: inactivating w/locked upper node"); |
| | 1292 | #endif |
| | 1293 | |
| | 1294 | if (un->un_dircache != 0) { |
| | 1295 | for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) |
| | 1296 | vrele(*vpp); |
| | 1297 | free(un->un_dircache, M_TEMP); |
| | 1298 | un->un_dircache = 0; |
| | 1299 | } |
| | 1300 | |
| | 1301 | if ((un->un_flags & UN_CACHED) == 0) |
| | 1302 | vgone(ap->a_vp); |
| | 1303 | |
| | 1304 | return (0); |
| | 1305 | } |
| | 1306 | |
| | 1307 | int |
| | 1308 | union_reclaim(ap) |
| | 1309 | struct vop_reclaim_args /* { |
| | 1310 | struct vnode *a_vp; |
| | 1311 | } */ *ap; |
| | 1312 | { |
| | 1313 | |
| | 1314 | union_freevp(ap->a_vp); |
| | 1315 | |
| | 1316 | return (0); |
| | 1317 | } |
| | 1318 | |
| | 1319 | int |
| | 1320 | union_lock(ap) |
| | 1321 | struct vop_lock_args *ap; |
| | 1322 | { |
| | 1323 | struct vnode *vp = ap->a_vp; |
| | 1324 | struct union_node *un; |
| | 1325 | |
| | 1326 | start: |
| | 1327 | while (vp->v_flag & VXLOCK) { |
| | 1328 | vp->v_flag |= VXWANT; |
| | 1329 | sleep((caddr_t)vp, PINOD); |
| | 1330 | } |
| | 1331 | |
| | 1332 | un = VTOUNION(vp); |
| | 1333 | |
| | 1334 | if (un->un_uppervp != NULLVP) { |
| | 1335 | if (((un->un_flags & UN_ULOCK) == 0) && |
| | 1336 | (vp->v_usecount != 0)) { |
| | 1337 | VOP_LOCK(un->un_uppervp); |
| | 1338 | un->un_flags |= UN_ULOCK; |
| | 1339 | } |
| | 1340 | #ifdef DIAGNOSTIC |
| | 1341 | if (un->un_flags & UN_KLOCK) { |
| | 1342 | vprint("union: dangling klock", vp); |
| | 1343 | panic("union: dangling upper lock (%lx)", vp); |
| | 1344 | } |
| | 1345 | #endif |
| | 1346 | } |
| | 1347 | |
| | 1348 | if (un->un_flags & UN_LOCKED) { |
| | 1349 | #ifdef DIAGNOSTIC |
| | 1350 | if (curproc && un->un_pid == curproc->p_pid && |
| | 1351 | un->un_pid > -1 && curproc->p_pid > -1) |
| | 1352 | panic("union: locking against myself"); |
| | 1353 | #endif |
| | 1354 | un->un_flags |= UN_WANT; |
| | 1355 | sleep((caddr_t) &un->un_flags, PINOD); |
| | 1356 | goto start; |
| | 1357 | } |
| | 1358 | |
| | 1359 | #ifdef DIAGNOSTIC |
| | 1360 | if (curproc) |
| | 1361 | un->un_pid = curproc->p_pid; |
| | 1362 | else |
| | 1363 | un->un_pid = -1; |
| | 1364 | #endif |
| | 1365 | |
| | 1366 | un->un_flags |= UN_LOCKED; |
| | 1367 | return (0); |
| | 1368 | } |
| | 1369 | |
| | 1370 | /* |
| | 1371 | * When operations want to vput() a union node yet retain a lock on |
| | 1372 | * the upper vnode (say, to do some further operations like link(), |
| | 1373 | * mkdir(), ...), they set UN_KLOCK on the union node, then call |
| | 1374 | * vput() which calls VOP_UNLOCK() and comes here. union_unlock() |
| | 1375 | * unlocks the union node (leaving the upper vnode alone), clears the |
| | 1376 | * KLOCK flag, and then returns to vput(). The caller then does whatever |
| | 1377 | * is left to do with the upper vnode, and ensures that it gets unlocked. |
| | 1378 | * |
| | 1379 | * If UN_KLOCK isn't set, then the upper vnode is unlocked here. |
| | 1380 | */ |
| | 1381 | int |
| | 1382 | union_unlock(ap) |
| | 1383 | struct vop_lock_args *ap; |
| | 1384 | { |
| | 1385 | struct union_node *un = VTOUNION(ap->a_vp); |
| | 1386 | |
| | 1387 | #ifdef DIAGNOSTIC |
| | 1388 | if ((un->un_flags & UN_LOCKED) == 0) |
| | 1389 | panic("union: unlock unlocked node"); |
| | 1390 | if (curproc && un->un_pid != curproc->p_pid && |
| | 1391 | curproc->p_pid > -1 && un->un_pid > -1) |
| | 1392 | panic("union: unlocking other process's union node"); |
| | 1393 | #endif |
| | 1394 | |
| | 1395 | un->un_flags &= ~UN_LOCKED; |
| | 1396 | |
| | 1397 | if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK) |
| | 1398 | VOP_UNLOCK(un->un_uppervp); |
| | 1399 | |
| | 1400 | un->un_flags &= ~(UN_ULOCK|UN_KLOCK); |
| | 1401 | |
| | 1402 | if (un->un_flags & UN_WANT) { |
| | 1403 | un->un_flags &= ~UN_WANT; |
| | 1404 | wakeup((caddr_t) &un->un_flags); |
| | 1405 | } |
| | 1406 | |
| | 1407 | #ifdef DIAGNOSTIC |
| | 1408 | un->un_pid = 0; |
| | 1409 | #endif |
| | 1410 | |
| | 1411 | return (0); |
| | 1412 | } |
| | 1413 | |
| | 1414 | int |
| | 1415 | union_bmap(ap) |
| | 1416 | struct vop_bmap_args /* { |
| | 1417 | struct vnode *a_vp; |
| | 1418 | daddr_t a_bn; |
| | 1419 | struct vnode **a_vpp; |
| | 1420 | daddr_t *a_bnp; |
| | 1421 | int *a_runp; |
| | 1422 | } */ *ap; |
| | 1423 | { |
| | 1424 | int error; |
| | 1425 | struct vnode *vp = OTHERVP(ap->a_vp); |
| | 1426 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| | 1427 | |
| | 1428 | if (dolock) |
| | 1429 | VOP_LOCK(vp); |
| | 1430 | else |
| | 1431 | FIXUP(VTOUNION(ap->a_vp)); |
| | 1432 | error = VOP_BMAP(vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp); |
| | 1433 | if (dolock) |
| | 1434 | VOP_UNLOCK(vp); |
| | 1435 | |
| | 1436 | return (error); |
| | 1437 | } |
| | 1438 | |
| | 1439 | int |
| | 1440 | union_print(ap) |
| | 1441 | struct vop_print_args /* { |
| | 1442 | struct vnode *a_vp; |
| | 1443 | } */ *ap; |
| | 1444 | { |
| | 1445 | struct vnode *vp = ap->a_vp; |
| | 1446 | |
| | 1447 | printf("\ttag VT_UNION, vp=%x, uppervp=%x, lowervp=%x\n", |
| | 1448 | vp, UPPERVP(vp), LOWERVP(vp)); |
| | 1449 | if (UPPERVP(vp) != NULLVP) |
| | 1450 | vprint("union: upper", UPPERVP(vp)); |
| | 1451 | if (LOWERVP(vp) != NULLVP) |
| | 1452 | vprint("union: lower", LOWERVP(vp)); |
| | 1453 | |
| | 1454 | return (0); |
| | 1455 | } |
| | 1456 | |
| | 1457 | int |
| | 1458 | union_islocked(ap) |
| | 1459 | struct vop_islocked_args /* { |
| | 1460 | struct vnode *a_vp; |
| | 1461 | } */ *ap; |
| | 1462 | { |
| | 1463 | |
| | 1464 | return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 0); |
| | 1465 | } |
| | 1466 | |
| | 1467 | int |
| | 1468 | union_pathconf(ap) |
| | 1469 | struct vop_pathconf_args /* { |
| | 1470 | struct vnode *a_vp; |
| | 1471 | int a_name; |
| | 1472 | int *a_retval; |
| | 1473 | } */ *ap; |
| | 1474 | { |
| | 1475 | int error; |
| | 1476 | struct vnode *vp = OTHERVP(ap->a_vp); |
| | 1477 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| | 1478 | |
| | 1479 | if (dolock) |
| | 1480 | VOP_LOCK(vp); |
| | 1481 | else |
| | 1482 | FIXUP(VTOUNION(ap->a_vp)); |
| | 1483 | error = VOP_PATHCONF(vp, ap->a_name, ap->a_retval); |
| | 1484 | if (dolock) |
| | 1485 | VOP_UNLOCK(vp); |
| | 1486 | |
| | 1487 | return (error); |
| | 1488 | } |
| | 1489 | |
| | 1490 | int |
| | 1491 | union_advlock(ap) |
| | 1492 | struct vop_advlock_args /* { |
| | 1493 | struct vnode *a_vp; |
| | 1494 | caddr_t a_id; |
| | 1495 | int a_op; |
| | 1496 | struct flock *a_fl; |
| | 1497 | int a_flags; |
| | 1498 | } */ *ap; |
| | 1499 | { |
| | 1500 | |
| | 1501 | return (VOP_ADVLOCK(OTHERVP(ap->a_vp), ap->a_id, ap->a_op, |
| | 1502 | ap->a_fl, ap->a_flags)); |
| | 1503 | } |
| | 1504 | |
| | 1505 | |
| | 1506 | /* |
| | 1507 | * XXX - vop_strategy must be hand coded because it has no |
| | 1508 | * vnode in its arguments. |
| | 1509 | * This goes away with a merged VM/buffer cache. |
| | 1510 | */ |
| | 1511 | int |
| | 1512 | union_strategy(ap) |
| | 1513 | struct vop_strategy_args /* { |
| | 1514 | struct buf *a_bp; |
| | 1515 | } */ *ap; |
| | 1516 | { |
| | 1517 | struct buf *bp = ap->a_bp; |
| | 1518 | int error; |
| | 1519 | struct vnode *savedvp; |
| | 1520 | |
| | 1521 | savedvp = bp->b_vp; |
| | 1522 | bp->b_vp = OTHERVP(bp->b_vp); |
| | 1523 | |
| | 1524 | #ifdef DIAGNOSTIC |
| | 1525 | if (bp->b_vp == NULLVP) |
| | 1526 | panic("union_strategy: nil vp"); |
| | 1527 | if (((bp->b_flags & B_READ) == 0) && |
| | 1528 | (bp->b_vp == LOWERVP(savedvp))) |
| | 1529 | panic("union_strategy: writing to lowervp"); |
| | 1530 | #endif |
| | 1531 | |
| | 1532 | error = VOP_STRATEGY(bp); |
| | 1533 | bp->b_vp = savedvp; |
| | 1534 | |
| | 1535 | return (error); |
| | 1536 | } |
| | 1537 | |
| | 1538 | /* |
| | 1539 | * Global vfs data structures |
| | 1540 | */ |
| | 1541 | int (**union_vnodeop_p)(); |
| | 1542 | struct vnodeopv_entry_desc union_vnodeop_entries[] = { |
| | 1543 | { &vop_default_desc, vn_default_error }, |
| | 1544 | { &vop_lookup_desc, union_lookup }, /* lookup */ |
| | 1545 | { &vop_create_desc, union_create }, /* create */ |
| | 1546 | { &vop_whiteout_desc, union_whiteout }, /* whiteout */ |
| | 1547 | { &vop_mknod_desc, union_mknod }, /* mknod */ |
| | 1548 | { &vop_open_desc, union_open }, /* open */ |
| | 1549 | { &vop_close_desc, union_close }, /* close */ |
| | 1550 | { &vop_access_desc, union_access }, /* access */ |
| | 1551 | { &vop_getattr_desc, union_getattr }, /* getattr */ |
| | 1552 | { &vop_setattr_desc, union_setattr }, /* setattr */ |
| | 1553 | { &vop_read_desc, union_read }, /* read */ |
| | 1554 | { &vop_write_desc, union_write }, /* write */ |
| | 1555 | { &vop_lease_desc, union_lease }, /* lease */ |
| | 1556 | { &vop_ioctl_desc, union_ioctl }, /* ioctl */ |
| | 1557 | { &vop_select_desc, union_select }, /* select */ |
| | 1558 | { &vop_revoke_desc, union_revoke }, /* revoke */ |
| | 1559 | { &vop_mmap_desc, union_mmap }, /* mmap */ |
| | 1560 | { &vop_fsync_desc, union_fsync }, /* fsync */ |
| | 1561 | { &vop_seek_desc, union_seek }, /* seek */ |
| | 1562 | { &vop_remove_desc, union_remove }, /* remove */ |
| | 1563 | { &vop_link_desc, union_link }, /* link */ |
| | 1564 | { &vop_rename_desc, union_rename }, /* rename */ |
| | 1565 | { &vop_mkdir_desc, union_mkdir }, /* mkdir */ |
| | 1566 | { &vop_rmdir_desc, union_rmdir }, /* rmdir */ |
| | 1567 | { &vop_symlink_desc, union_symlink }, /* symlink */ |
| | 1568 | { &vop_readdir_desc, union_readdir }, /* readdir */ |
| | 1569 | { &vop_readlink_desc, union_readlink }, /* readlink */ |
| | 1570 | { &vop_abortop_desc, union_abortop }, /* abortop */ |
| | 1571 | { &vop_inactive_desc, union_inactive }, /* inactive */ |
| | 1572 | { &vop_reclaim_desc, union_reclaim }, /* reclaim */ |
| | 1573 | { &vop_lock_desc, union_lock }, /* lock */ |
| | 1574 | { &vop_unlock_desc, union_unlock }, /* unlock */ |
| | 1575 | { &vop_bmap_desc, union_bmap }, /* bmap */ |
| | 1576 | { &vop_strategy_desc, union_strategy }, /* strategy */ |
| | 1577 | { &vop_print_desc, union_print }, /* print */ |
| | 1578 | { &vop_islocked_desc, union_islocked }, /* islocked */ |
| | 1579 | { &vop_pathconf_desc, union_pathconf }, /* pathconf */ |
| | 1580 | { &vop_advlock_desc, union_advlock }, /* advlock */ |
| | 1581 | #ifdef notdef |
| | 1582 | { &vop_blkatoff_desc, union_blkatoff }, /* blkatoff */ |
| | 1583 | { &vop_valloc_desc, union_valloc }, /* valloc */ |
| | 1584 | { &vop_vfree_desc, union_vfree }, /* vfree */ |
| | 1585 | { &vop_truncate_desc, union_truncate }, /* truncate */ |
| | 1586 | { &vop_update_desc, union_update }, /* update */ |
| | 1587 | { &vop_bwrite_desc, union_bwrite }, /* bwrite */ |
| | 1588 | #endif |
| | 1589 | { (struct vnodeop_desc*)NULL, (int(*)())NULL } |
| | 1590 | }; |
| | 1591 | struct vnodeopv_desc union_vnodeop_opv_desc = |
| | 1592 | { &union_vnodeop_p, union_vnodeop_entries }; |
projects / unix-history / blame_incremental