| 1 | /* |
| 2 | * Copyright (c) 1992, 1993, 1994 The Regents of the University of California. |
| 3 | * Copyright (c) 1992, 1993, 1994 Jan-Simon Pendry. |
| 4 | * 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 8.18 (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/types.h> |
| 20 | #include <sys/vnode.h> |
| 21 | #include <sys/mount.h> |
| 22 | #include <sys/namei.h> |
| 23 | #include <sys/malloc.h> |
| 24 | #include <sys/buf.h> |
| 25 | #include <sys/queue.h> |
| 26 | #include <miscfs/union/union.h> |
| 27 | |
| 28 | #define FIXUP(un) { \ |
| 29 | if (((un)->un_flags & UN_ULOCK) == 0) { \ |
| 30 | union_fixup(un); \ |
| 31 | } \ |
| 32 | } |
| 33 | |
| 34 | static void |
| 35 | union_fixup(un) |
| 36 | struct union_node *un; |
| 37 | { |
| 38 | |
| 39 | VOP_LOCK(un->un_uppervp); |
| 40 | un->un_flags |= UN_ULOCK; |
| 41 | } |
| 42 | |
| 43 | static int |
| 44 | union_lookup1(udvp, dvpp, vpp, cnp) |
| 45 | struct vnode *udvp; |
| 46 | struct vnode **dvpp; |
| 47 | struct vnode **vpp; |
| 48 | struct componentname *cnp; |
| 49 | { |
| 50 | int error; |
| 51 | struct vnode *tdvp; |
| 52 | struct vnode *dvp; |
| 53 | struct mount *mp; |
| 54 | |
| 55 | dvp = *dvpp; |
| 56 | |
| 57 | /* |
| 58 | * If stepping up the directory tree, check for going |
| 59 | * back across the mount point, in which case do what |
| 60 | * lookup would do by stepping back down the mount |
| 61 | * hierarchy. |
| 62 | */ |
| 63 | if (cnp->cn_flags & ISDOTDOT) { |
| 64 | while ((dvp != udvp) && (dvp->v_flag & VROOT)) { |
| 65 | /* |
| 66 | * Don't do the NOCROSSMOUNT check |
| 67 | * at this level. By definition, |
| 68 | * union fs deals with namespaces, not |
| 69 | * filesystems. |
| 70 | */ |
| 71 | tdvp = dvp; |
| 72 | *dvpp = dvp = dvp->v_mount->mnt_vnodecovered; |
| 73 | vput(tdvp); |
| 74 | VREF(dvp); |
| 75 | VOP_LOCK(dvp); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | error = VOP_LOOKUP(dvp, &tdvp, cnp); |
| 80 | if (error) |
| 81 | return (error); |
| 82 | |
| 83 | /* |
| 84 | * The parent directory will have been unlocked, unless lookup |
| 85 | * found the last component. In which case, re-lock the node |
| 86 | * here to allow it to be unlocked again (phew) in union_lookup. |
| 87 | */ |
| 88 | if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN)) |
| 89 | VOP_LOCK(dvp); |
| 90 | |
| 91 | dvp = tdvp; |
| 92 | |
| 93 | /* |
| 94 | * Lastly check if the current node is a mount point in |
| 95 | * which case walk up the mount hierarchy making sure not to |
| 96 | * bump into the root of the mount tree (ie. dvp != udvp). |
| 97 | */ |
| 98 | while (dvp != udvp && (dvp->v_type == VDIR) && |
| 99 | (mp = dvp->v_mountedhere)) { |
| 100 | |
| 101 | if (mp->mnt_flag & MNT_MLOCK) { |
| 102 | mp->mnt_flag |= MNT_MWAIT; |
| 103 | sleep((caddr_t) mp, PVFS); |
| 104 | continue; |
| 105 | } |
| 106 | |
| 107 | if (error = VFS_ROOT(mp, &tdvp)) { |
| 108 | vput(dvp); |
| 109 | return (error); |
| 110 | } |
| 111 | |
| 112 | vput(dvp); |
| 113 | dvp = tdvp; |
| 114 | } |
| 115 | |
| 116 | *vpp = dvp; |
| 117 | return (0); |
| 118 | } |
| 119 | |
| 120 | int |
| 121 | union_lookup(ap) |
| 122 | struct vop_lookup_args /* { |
| 123 | struct vnodeop_desc *a_desc; |
| 124 | struct vnode *a_dvp; |
| 125 | struct vnode **a_vpp; |
| 126 | struct componentname *a_cnp; |
| 127 | } */ *ap; |
| 128 | { |
| 129 | int error; |
| 130 | int uerror, lerror; |
| 131 | struct vnode *uppervp, *lowervp; |
| 132 | struct vnode *upperdvp, *lowerdvp; |
| 133 | struct vnode *dvp = ap->a_dvp; |
| 134 | struct union_node *dun = VTOUNION(dvp); |
| 135 | struct componentname *cnp = ap->a_cnp; |
| 136 | int lockparent = cnp->cn_flags & LOCKPARENT; |
| 137 | int rdonly = cnp->cn_flags & RDONLY; |
| 138 | struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount); |
| 139 | struct ucred *saved_cred; |
| 140 | |
| 141 | #ifdef notyet |
| 142 | if (cnp->cn_namelen == 3 && |
| 143 | cnp->cn_nameptr[2] == '.' && |
| 144 | cnp->cn_nameptr[1] == '.' && |
| 145 | cnp->cn_nameptr[0] == '.') { |
| 146 | dvp = *ap->a_vpp = LOWERVP(ap->a_dvp); |
| 147 | if (dvp == NULLVP) |
| 148 | return (ENOENT); |
| 149 | VREF(dvp); |
| 150 | VOP_LOCK(dvp); |
| 151 | if (!lockparent || !(cnp->cn_flags & ISLASTCN)) |
| 152 | VOP_UNLOCK(ap->a_dvp); |
| 153 | return (0); |
| 154 | } |
| 155 | #endif |
| 156 | |
| 157 | cnp->cn_flags |= LOCKPARENT; |
| 158 | |
| 159 | upperdvp = dun->un_uppervp; |
| 160 | lowerdvp = dun->un_lowervp; |
| 161 | uppervp = NULLVP; |
| 162 | lowervp = NULLVP; |
| 163 | |
| 164 | /* |
| 165 | * do the lookup in the upper level. |
| 166 | * if that level comsumes additional pathnames, |
| 167 | * then assume that something special is going |
| 168 | * on and just return that vnode. |
| 169 | */ |
| 170 | if (upperdvp != NULLVP) { |
| 171 | FIXUP(dun); |
| 172 | uerror = union_lookup1(um->um_uppervp, &upperdvp, |
| 173 | &uppervp, cnp); |
| 174 | /*if (uppervp == upperdvp) |
| 175 | dun->un_flags |= UN_KLOCK;*/ |
| 176 | |
| 177 | if (cnp->cn_consume != 0) { |
| 178 | *ap->a_vpp = uppervp; |
| 179 | if (!lockparent) |
| 180 | cnp->cn_flags &= ~LOCKPARENT; |
| 181 | return (uerror); |
| 182 | } |
| 183 | } else { |
| 184 | uerror = ENOENT; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * in a similar way to the upper layer, do the lookup |
| 189 | * in the lower layer. this time, if there is some |
| 190 | * component magic going on, then vput whatever we got |
| 191 | * back from the upper layer and return the lower vnode |
| 192 | * instead. |
| 193 | */ |
| 194 | if (lowerdvp != NULLVP) { |
| 195 | int nameiop; |
| 196 | |
| 197 | VOP_LOCK(lowerdvp); |
| 198 | |
| 199 | /* |
| 200 | * Only do a LOOKUP on the bottom node, since |
| 201 | * we won't be making changes to it anyway. |
| 202 | */ |
| 203 | nameiop = cnp->cn_nameiop; |
| 204 | cnp->cn_nameiop = LOOKUP; |
| 205 | if (um->um_op == UNMNT_BELOW) { |
| 206 | saved_cred = cnp->cn_cred; |
| 207 | cnp->cn_cred = um->um_cred; |
| 208 | } |
| 209 | lerror = union_lookup1(um->um_lowervp, &lowerdvp, |
| 210 | &lowervp, cnp); |
| 211 | if (um->um_op == UNMNT_BELOW) |
| 212 | cnp->cn_cred = saved_cred; |
| 213 | cnp->cn_nameiop = nameiop; |
| 214 | |
| 215 | if (lowervp != lowerdvp) |
| 216 | VOP_UNLOCK(lowerdvp); |
| 217 | |
| 218 | if (cnp->cn_consume != 0) { |
| 219 | if (uppervp != NULLVP) { |
| 220 | if (uppervp == upperdvp) |
| 221 | vrele(uppervp); |
| 222 | else |
| 223 | vput(uppervp); |
| 224 | uppervp = NULLVP; |
| 225 | } |
| 226 | *ap->a_vpp = lowervp; |
| 227 | if (!lockparent) |
| 228 | cnp->cn_flags &= ~LOCKPARENT; |
| 229 | return (lerror); |
| 230 | } |
| 231 | } else { |
| 232 | lerror = ENOENT; |
| 233 | if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { |
| 234 | lowervp = LOWERVP(dun->un_pvp); |
| 235 | if (lowervp != NULLVP) { |
| 236 | VREF(lowervp); |
| 237 | VOP_LOCK(lowervp); |
| 238 | lerror = 0; |
| 239 | } |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | if (!lockparent) |
| 244 | cnp->cn_flags &= ~LOCKPARENT; |
| 245 | |
| 246 | /* |
| 247 | * at this point, we have uerror and lerror indicating |
| 248 | * possible errors with the lookups in the upper and lower |
| 249 | * layers. additionally, uppervp and lowervp are (locked) |
| 250 | * references to existing vnodes in the upper and lower layers. |
| 251 | * |
| 252 | * there are now three cases to consider. |
| 253 | * 1. if both layers returned an error, then return whatever |
| 254 | * error the upper layer generated. |
| 255 | * |
| 256 | * 2. if the top layer failed and the bottom layer succeeded |
| 257 | * then two subcases occur. |
| 258 | * a. the bottom vnode is not a directory, in which |
| 259 | * case just return a new union vnode referencing |
| 260 | * an empty top layer and the existing bottom layer. |
| 261 | * b. the bottom vnode is a directory, in which case |
| 262 | * create a new directory in the top-level and |
| 263 | * continue as in case 3. |
| 264 | * |
| 265 | * 3. if the top layer succeeded then return a new union |
| 266 | * vnode referencing whatever the new top layer and |
| 267 | * whatever the bottom layer returned. |
| 268 | */ |
| 269 | |
| 270 | *ap->a_vpp = NULLVP; |
| 271 | |
| 272 | /* case 1. */ |
| 273 | if ((uerror != 0) && (lerror != 0)) { |
| 274 | return (uerror); |
| 275 | } |
| 276 | |
| 277 | /* case 2. */ |
| 278 | if (uerror != 0 /* && (lerror == 0) */ ) { |
| 279 | if (lowervp->v_type == VDIR) { /* case 2b. */ |
| 280 | dun->un_flags &= ~UN_ULOCK; |
| 281 | VOP_UNLOCK(upperdvp); |
| 282 | uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); |
| 283 | VOP_LOCK(upperdvp); |
| 284 | dun->un_flags |= UN_ULOCK; |
| 285 | |
| 286 | if (uerror) { |
| 287 | if (lowervp != NULLVP) { |
| 288 | vput(lowervp); |
| 289 | lowervp = NULLVP; |
| 290 | } |
| 291 | return (uerror); |
| 292 | } |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | if (lowervp != NULLVP) |
| 297 | VOP_UNLOCK(lowervp); |
| 298 | |
| 299 | error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, |
| 300 | uppervp, lowervp); |
| 301 | |
| 302 | if (error) { |
| 303 | if (uppervp != NULLVP) |
| 304 | vput(uppervp); |
| 305 | if (lowervp != NULLVP) |
| 306 | vrele(lowervp); |
| 307 | } else { |
| 308 | if (*ap->a_vpp != dvp) |
| 309 | if (!lockparent || !(cnp->cn_flags & ISLASTCN)) |
| 310 | VOP_UNLOCK(dvp); |
| 311 | } |
| 312 | |
| 313 | return (error); |
| 314 | } |
| 315 | |
| 316 | int |
| 317 | union_create(ap) |
| 318 | struct vop_create_args /* { |
| 319 | struct vnode *a_dvp; |
| 320 | struct vnode **a_vpp; |
| 321 | struct componentname *a_cnp; |
| 322 | struct vattr *a_vap; |
| 323 | } */ *ap; |
| 324 | { |
| 325 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 326 | struct vnode *dvp = un->un_uppervp; |
| 327 | |
| 328 | if (dvp != NULLVP) { |
| 329 | int error; |
| 330 | struct vnode *vp; |
| 331 | |
| 332 | FIXUP(un); |
| 333 | |
| 334 | VREF(dvp); |
| 335 | un->un_flags |= UN_KLOCK; |
| 336 | vput(ap->a_dvp); |
| 337 | error = VOP_CREATE(dvp, &vp, ap->a_cnp, ap->a_vap); |
| 338 | if (error) |
| 339 | return (error); |
| 340 | |
| 341 | error = union_allocvp( |
| 342 | ap->a_vpp, |
| 343 | ap->a_dvp->v_mount, |
| 344 | ap->a_dvp, |
| 345 | NULLVP, |
| 346 | ap->a_cnp, |
| 347 | vp, |
| 348 | NULLVP); |
| 349 | if (error) |
| 350 | vput(vp); |
| 351 | return (error); |
| 352 | } |
| 353 | |
| 354 | vput(ap->a_dvp); |
| 355 | return (EROFS); |
| 356 | } |
| 357 | |
| 358 | int |
| 359 | union_mknod(ap) |
| 360 | struct vop_mknod_args /* { |
| 361 | struct vnode *a_dvp; |
| 362 | struct vnode **a_vpp; |
| 363 | struct componentname *a_cnp; |
| 364 | struct vattr *a_vap; |
| 365 | } */ *ap; |
| 366 | { |
| 367 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 368 | struct vnode *dvp = un->un_uppervp; |
| 369 | |
| 370 | if (dvp != NULLVP) { |
| 371 | int error; |
| 372 | struct vnode *vp; |
| 373 | |
| 374 | FIXUP(un); |
| 375 | |
| 376 | VREF(dvp); |
| 377 | un->un_flags |= UN_KLOCK; |
| 378 | vput(ap->a_dvp); |
| 379 | error = VOP_MKNOD(dvp, &vp, ap->a_cnp, ap->a_vap); |
| 380 | if (error) |
| 381 | return (error); |
| 382 | |
| 383 | if (vp != NULLVP) { |
| 384 | error = union_allocvp( |
| 385 | ap->a_vpp, |
| 386 | ap->a_dvp->v_mount, |
| 387 | ap->a_dvp, |
| 388 | NULLVP, |
| 389 | ap->a_cnp, |
| 390 | vp, |
| 391 | NULLVP); |
| 392 | if (error) |
| 393 | vput(vp); |
| 394 | } |
| 395 | return (error); |
| 396 | } |
| 397 | |
| 398 | vput(ap->a_dvp); |
| 399 | return (EROFS); |
| 400 | } |
| 401 | |
| 402 | int |
| 403 | union_open(ap) |
| 404 | struct vop_open_args /* { |
| 405 | struct vnodeop_desc *a_desc; |
| 406 | struct vnode *a_vp; |
| 407 | int a_mode; |
| 408 | struct ucred *a_cred; |
| 409 | struct proc *a_p; |
| 410 | } */ *ap; |
| 411 | { |
| 412 | struct union_node *un = VTOUNION(ap->a_vp); |
| 413 | struct vnode *tvp; |
| 414 | int mode = ap->a_mode; |
| 415 | struct ucred *cred = ap->a_cred; |
| 416 | struct proc *p = ap->a_p; |
| 417 | int error; |
| 418 | |
| 419 | /* |
| 420 | * If there is an existing upper vp then simply open that. |
| 421 | */ |
| 422 | tvp = un->un_uppervp; |
| 423 | if (tvp == NULLVP) { |
| 424 | /* |
| 425 | * If the lower vnode is being opened for writing, then |
| 426 | * copy the file contents to the upper vnode and open that, |
| 427 | * otherwise can simply open the lower vnode. |
| 428 | */ |
| 429 | tvp = un->un_lowervp; |
| 430 | if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { |
| 431 | error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p); |
| 432 | if (error == 0) |
| 433 | error = VOP_OPEN(un->un_uppervp, mode, cred, p); |
| 434 | return (error); |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * Just open the lower vnode |
| 439 | */ |
| 440 | un->un_openl++; |
| 441 | VOP_LOCK(tvp); |
| 442 | error = VOP_OPEN(tvp, mode, cred, p); |
| 443 | VOP_UNLOCK(tvp); |
| 444 | |
| 445 | return (error); |
| 446 | } |
| 447 | |
| 448 | FIXUP(un); |
| 449 | |
| 450 | error = VOP_OPEN(tvp, mode, cred, p); |
| 451 | |
| 452 | return (error); |
| 453 | } |
| 454 | |
| 455 | int |
| 456 | union_close(ap) |
| 457 | struct vop_close_args /* { |
| 458 | struct vnode *a_vp; |
| 459 | int a_fflag; |
| 460 | struct ucred *a_cred; |
| 461 | struct proc *a_p; |
| 462 | } */ *ap; |
| 463 | { |
| 464 | struct union_node *un = VTOUNION(ap->a_vp); |
| 465 | struct vnode *vp; |
| 466 | |
| 467 | if (un->un_uppervp != NULLVP) { |
| 468 | vp = un->un_uppervp; |
| 469 | } else { |
| 470 | #ifdef UNION_DIAGNOSTIC |
| 471 | if (un->un_openl <= 0) |
| 472 | panic("union: un_openl cnt"); |
| 473 | #endif |
| 474 | --un->un_openl; |
| 475 | vp = un->un_lowervp; |
| 476 | } |
| 477 | |
| 478 | return (VOP_CLOSE(vp, ap->a_fflag, ap->a_cred, ap->a_p)); |
| 479 | } |
| 480 | |
| 481 | /* |
| 482 | * Check access permission on the union vnode. |
| 483 | * The access check being enforced is to check |
| 484 | * against both the underlying vnode, and any |
| 485 | * copied vnode. This ensures that no additional |
| 486 | * file permissions are given away simply because |
| 487 | * the user caused an implicit file copy. |
| 488 | */ |
| 489 | int |
| 490 | union_access(ap) |
| 491 | struct vop_access_args /* { |
| 492 | struct vnodeop_desc *a_desc; |
| 493 | struct vnode *a_vp; |
| 494 | int a_mode; |
| 495 | struct ucred *a_cred; |
| 496 | struct proc *a_p; |
| 497 | } */ *ap; |
| 498 | { |
| 499 | struct union_node *un = VTOUNION(ap->a_vp); |
| 500 | int error = EACCES; |
| 501 | struct vnode *vp; |
| 502 | |
| 503 | if ((vp = un->un_uppervp) != NULLVP) { |
| 504 | FIXUP(un); |
| 505 | return (VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p)); |
| 506 | } |
| 507 | |
| 508 | if ((vp = un->un_lowervp) != NULLVP) { |
| 509 | VOP_LOCK(vp); |
| 510 | error = VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p); |
| 511 | if (error == 0) { |
| 512 | struct union_mount *um = MOUNTTOUNIONMOUNT(vp->v_mount); |
| 513 | |
| 514 | if (um->um_op == UNMNT_BELOW) |
| 515 | error = VOP_ACCESS(vp, ap->a_mode, |
| 516 | um->um_cred, ap->a_p); |
| 517 | } |
| 518 | VOP_UNLOCK(vp); |
| 519 | if (error) |
| 520 | return (error); |
| 521 | } |
| 522 | |
| 523 | return (error); |
| 524 | } |
| 525 | |
| 526 | /* |
| 527 | * We handle getattr only to change the fsid and |
| 528 | * track object sizes |
| 529 | */ |
| 530 | int |
| 531 | union_getattr(ap) |
| 532 | struct vop_getattr_args /* { |
| 533 | struct vnode *a_vp; |
| 534 | struct vattr *a_vap; |
| 535 | struct ucred *a_cred; |
| 536 | struct proc *a_p; |
| 537 | } */ *ap; |
| 538 | { |
| 539 | int error; |
| 540 | struct union_node *un = VTOUNION(ap->a_vp); |
| 541 | struct vnode *vp = un->un_uppervp; |
| 542 | struct vattr *vap; |
| 543 | struct vattr va; |
| 544 | |
| 545 | |
| 546 | /* |
| 547 | * Some programs walk the filesystem hierarchy by counting |
| 548 | * links to directories to avoid stat'ing all the time. |
| 549 | * This means the link count on directories needs to be "correct". |
| 550 | * The only way to do that is to call getattr on both layers |
| 551 | * and fix up the link count. The link count will not necessarily |
| 552 | * be accurate but will be large enough to defeat the tree walkers. |
| 553 | */ |
| 554 | |
| 555 | vap = ap->a_vap; |
| 556 | |
| 557 | vp = un->un_uppervp; |
| 558 | if (vp != NULLVP) { |
| 559 | /* |
| 560 | * It's not clear whether VOP_GETATTR is to be |
| 561 | * called with the vnode locked or not. stat() calls |
| 562 | * it with (vp) locked, and fstat calls it with |
| 563 | * (vp) unlocked. |
| 564 | * In the mean time, compensate here by checking |
| 565 | * the union_node's lock flag. |
| 566 | */ |
| 567 | if (un->un_flags & UN_LOCKED) |
| 568 | FIXUP(un); |
| 569 | |
| 570 | error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); |
| 571 | if (error) |
| 572 | return (error); |
| 573 | union_newsize(ap->a_vp, vap->va_size, VNOVAL); |
| 574 | } |
| 575 | |
| 576 | if (vp == NULLVP) { |
| 577 | vp = un->un_lowervp; |
| 578 | } else if (vp->v_type == VDIR) { |
| 579 | vp = un->un_lowervp; |
| 580 | vap = &va; |
| 581 | } else { |
| 582 | vp = NULLVP; |
| 583 | } |
| 584 | |
| 585 | if (vp != NULLVP) { |
| 586 | VOP_LOCK(vp); |
| 587 | error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p); |
| 588 | VOP_UNLOCK(vp); |
| 589 | if (error) |
| 590 | return (error); |
| 591 | union_newsize(ap->a_vp, VNOVAL, vap->va_size); |
| 592 | } |
| 593 | |
| 594 | if ((vap != ap->a_vap) && (vap->va_type == VDIR)) |
| 595 | ap->a_vap->va_nlink += vap->va_nlink; |
| 596 | |
| 597 | ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; |
| 598 | return (0); |
| 599 | } |
| 600 | |
| 601 | int |
| 602 | union_setattr(ap) |
| 603 | struct vop_setattr_args /* { |
| 604 | struct vnode *a_vp; |
| 605 | struct vattr *a_vap; |
| 606 | struct ucred *a_cred; |
| 607 | struct proc *a_p; |
| 608 | } */ *ap; |
| 609 | { |
| 610 | struct union_node *un = VTOUNION(ap->a_vp); |
| 611 | int error; |
| 612 | |
| 613 | /* |
| 614 | * Handle case of truncating lower object to zero size, |
| 615 | * by creating a zero length upper object. This is to |
| 616 | * handle the case of open with O_TRUNC and O_CREAT. |
| 617 | */ |
| 618 | if ((un->un_uppervp == NULLVP) && |
| 619 | /* assert(un->un_lowervp != NULLVP) */ |
| 620 | (un->un_lowervp->v_type == VREG) && |
| 621 | (ap->a_vap->va_size == 0)) { |
| 622 | struct vnode *vp; |
| 623 | |
| 624 | error = union_vn_create(&vp, un, ap->a_p); |
| 625 | if (error) |
| 626 | return (error); |
| 627 | |
| 628 | /* at this point, uppervp is locked */ |
| 629 | union_newupper(un, vp); |
| 630 | |
| 631 | VOP_UNLOCK(vp); |
| 632 | union_vn_close(un->un_uppervp, FWRITE, ap->a_cred, ap->a_p); |
| 633 | VOP_LOCK(vp); |
| 634 | un->un_flags |= UN_ULOCK; |
| 635 | } |
| 636 | |
| 637 | /* |
| 638 | * Try to set attributes in upper layer, |
| 639 | * otherwise return read-only filesystem error. |
| 640 | */ |
| 641 | if (un->un_uppervp != NULLVP) { |
| 642 | FIXUP(un); |
| 643 | error = VOP_SETATTR(un->un_uppervp, ap->a_vap, |
| 644 | ap->a_cred, ap->a_p); |
| 645 | if ((error == 0) && (ap->a_vap->va_size != VNOVAL)) |
| 646 | union_newsize(ap->a_vp, ap->a_vap->va_size, VNOVAL); |
| 647 | } else { |
| 648 | error = EROFS; |
| 649 | } |
| 650 | |
| 651 | return (error); |
| 652 | } |
| 653 | |
| 654 | int |
| 655 | union_read(ap) |
| 656 | struct vop_read_args /* { |
| 657 | struct vnode *a_vp; |
| 658 | struct uio *a_uio; |
| 659 | int a_ioflag; |
| 660 | struct ucred *a_cred; |
| 661 | } */ *ap; |
| 662 | { |
| 663 | int error; |
| 664 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 665 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 666 | |
| 667 | if (dolock) |
| 668 | VOP_LOCK(vp); |
| 669 | else |
| 670 | FIXUP(VTOUNION(ap->a_vp)); |
| 671 | error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 672 | if (dolock) |
| 673 | VOP_UNLOCK(vp); |
| 674 | |
| 675 | /* |
| 676 | * XXX |
| 677 | * perhaps the size of the underlying object has changed under |
| 678 | * our feet. take advantage of the offset information present |
| 679 | * in the uio structure. |
| 680 | */ |
| 681 | if (error == 0) { |
| 682 | struct union_node *un = VTOUNION(ap->a_vp); |
| 683 | off_t cur = ap->a_uio->uio_offset; |
| 684 | |
| 685 | if (vp == un->un_uppervp) { |
| 686 | if (cur > un->un_uppersz) |
| 687 | union_newsize(ap->a_vp, cur, VNOVAL); |
| 688 | } else { |
| 689 | if (cur > un->un_lowersz) |
| 690 | union_newsize(ap->a_vp, VNOVAL, cur); |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | return (error); |
| 695 | } |
| 696 | |
| 697 | int |
| 698 | union_write(ap) |
| 699 | struct vop_read_args /* { |
| 700 | struct vnode *a_vp; |
| 701 | struct uio *a_uio; |
| 702 | int a_ioflag; |
| 703 | struct ucred *a_cred; |
| 704 | } */ *ap; |
| 705 | { |
| 706 | int error; |
| 707 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 708 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 709 | |
| 710 | if (dolock) |
| 711 | VOP_LOCK(vp); |
| 712 | else |
| 713 | FIXUP(VTOUNION(ap->a_vp)); |
| 714 | error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 715 | if (dolock) |
| 716 | VOP_UNLOCK(vp); |
| 717 | |
| 718 | /* |
| 719 | * the size of the underlying object may be changed by the |
| 720 | * write. |
| 721 | */ |
| 722 | if (error == 0) { |
| 723 | struct union_node *un = VTOUNION(ap->a_vp); |
| 724 | off_t cur = ap->a_uio->uio_offset; |
| 725 | |
| 726 | if (vp == un->un_uppervp) { |
| 727 | if (cur > un->un_uppersz) |
| 728 | union_newsize(ap->a_vp, cur, VNOVAL); |
| 729 | } else { |
| 730 | if (cur > un->un_lowersz) |
| 731 | union_newsize(ap->a_vp, VNOVAL, cur); |
| 732 | } |
| 733 | } |
| 734 | |
| 735 | return (error); |
| 736 | } |
| 737 | |
| 738 | int |
| 739 | union_ioctl(ap) |
| 740 | struct vop_ioctl_args /* { |
| 741 | struct vnode *a_vp; |
| 742 | int a_command; |
| 743 | caddr_t a_data; |
| 744 | int a_fflag; |
| 745 | struct ucred *a_cred; |
| 746 | struct proc *a_p; |
| 747 | } */ *ap; |
| 748 | { |
| 749 | |
| 750 | return (VOP_IOCTL(OTHERVP(ap->a_vp), ap->a_command, ap->a_data, |
| 751 | ap->a_fflag, ap->a_cred, ap->a_p)); |
| 752 | } |
| 753 | |
| 754 | int |
| 755 | union_select(ap) |
| 756 | struct vop_select_args /* { |
| 757 | struct vnode *a_vp; |
| 758 | int a_which; |
| 759 | int a_fflags; |
| 760 | struct ucred *a_cred; |
| 761 | struct proc *a_p; |
| 762 | } */ *ap; |
| 763 | { |
| 764 | |
| 765 | return (VOP_SELECT(OTHERVP(ap->a_vp), ap->a_which, ap->a_fflags, |
| 766 | ap->a_cred, ap->a_p)); |
| 767 | } |
| 768 | |
| 769 | int |
| 770 | union_mmap(ap) |
| 771 | struct vop_mmap_args /* { |
| 772 | struct vnode *a_vp; |
| 773 | int a_fflags; |
| 774 | struct ucred *a_cred; |
| 775 | struct proc *a_p; |
| 776 | } */ *ap; |
| 777 | { |
| 778 | |
| 779 | return (VOP_MMAP(OTHERVP(ap->a_vp), ap->a_fflags, |
| 780 | ap->a_cred, ap->a_p)); |
| 781 | } |
| 782 | |
| 783 | int |
| 784 | union_fsync(ap) |
| 785 | struct vop_fsync_args /* { |
| 786 | struct vnode *a_vp; |
| 787 | struct ucred *a_cred; |
| 788 | int a_waitfor; |
| 789 | struct proc *a_p; |
| 790 | } */ *ap; |
| 791 | { |
| 792 | int error = 0; |
| 793 | struct vnode *targetvp = OTHERVP(ap->a_vp); |
| 794 | |
| 795 | if (targetvp != NULLVP) { |
| 796 | int dolock = (targetvp == LOWERVP(ap->a_vp)); |
| 797 | |
| 798 | if (dolock) |
| 799 | VOP_LOCK(targetvp); |
| 800 | else |
| 801 | FIXUP(VTOUNION(ap->a_vp)); |
| 802 | error = VOP_FSYNC(targetvp, ap->a_cred, |
| 803 | ap->a_waitfor, ap->a_p); |
| 804 | if (dolock) |
| 805 | VOP_UNLOCK(targetvp); |
| 806 | } |
| 807 | |
| 808 | return (error); |
| 809 | } |
| 810 | |
| 811 | int |
| 812 | union_seek(ap) |
| 813 | struct vop_seek_args /* { |
| 814 | struct vnode *a_vp; |
| 815 | off_t a_oldoff; |
| 816 | off_t a_newoff; |
| 817 | struct ucred *a_cred; |
| 818 | } */ *ap; |
| 819 | { |
| 820 | |
| 821 | return (VOP_SEEK(OTHERVP(ap->a_vp), ap->a_oldoff, ap->a_newoff, ap->a_cred)); |
| 822 | } |
| 823 | |
| 824 | int |
| 825 | union_remove(ap) |
| 826 | struct vop_remove_args /* { |
| 827 | struct vnode *a_dvp; |
| 828 | struct vnode *a_vp; |
| 829 | struct componentname *a_cnp; |
| 830 | } */ *ap; |
| 831 | { |
| 832 | int error; |
| 833 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 834 | struct union_node *un = VTOUNION(ap->a_vp); |
| 835 | |
| 836 | if (dun->un_uppervp != NULLVP && un->un_uppervp != NULLVP) { |
| 837 | struct vnode *dvp = dun->un_uppervp; |
| 838 | struct vnode *vp = un->un_uppervp; |
| 839 | |
| 840 | FIXUP(dun); |
| 841 | VREF(dvp); |
| 842 | dun->un_flags |= UN_KLOCK; |
| 843 | vput(ap->a_dvp); |
| 844 | FIXUP(un); |
| 845 | VREF(vp); |
| 846 | un->un_flags |= UN_KLOCK; |
| 847 | vput(ap->a_vp); |
| 848 | |
| 849 | error = VOP_REMOVE(dvp, vp, ap->a_cnp); |
| 850 | if (!error) |
| 851 | union_removed_upper(un); |
| 852 | |
| 853 | /* |
| 854 | * XXX: should create a whiteout here |
| 855 | */ |
| 856 | } else { |
| 857 | /* |
| 858 | * XXX: should create a whiteout here |
| 859 | */ |
| 860 | vput(ap->a_dvp); |
| 861 | vput(ap->a_vp); |
| 862 | error = EROFS; |
| 863 | } |
| 864 | |
| 865 | return (error); |
| 866 | } |
| 867 | |
| 868 | int |
| 869 | union_link(ap) |
| 870 | struct vop_link_args /* { |
| 871 | struct vnode *a_vp; |
| 872 | struct vnode *a_tdvp; |
| 873 | struct componentname *a_cnp; |
| 874 | } */ *ap; |
| 875 | { |
| 876 | int error = 0; |
| 877 | struct union_node *un; |
| 878 | struct vnode *vp; |
| 879 | struct vnode *tdvp; |
| 880 | |
| 881 | un = VTOUNION(ap->a_vp); |
| 882 | |
| 883 | if (ap->a_vp->v_op != ap->a_tdvp->v_op) { |
| 884 | tdvp = ap->a_tdvp; |
| 885 | } else { |
| 886 | struct union_node *tdun = VTOUNION(ap->a_tdvp); |
| 887 | if (tdun->un_uppervp == NULLVP) { |
| 888 | VOP_LOCK(ap->a_tdvp); |
| 889 | if (un->un_uppervp == tdun->un_dirvp) { |
| 890 | un->un_flags &= ~UN_ULOCK; |
| 891 | VOP_UNLOCK(un->un_uppervp); |
| 892 | } |
| 893 | error = union_copyup(tdun, 1, ap->a_cnp->cn_cred, |
| 894 | ap->a_cnp->cn_proc); |
| 895 | if (un->un_uppervp == tdun->un_dirvp) { |
| 896 | VOP_LOCK(un->un_uppervp); |
| 897 | un->un_flags |= UN_ULOCK; |
| 898 | } |
| 899 | VOP_UNLOCK(ap->a_tdvp); |
| 900 | } |
| 901 | tdvp = tdun->un_uppervp; |
| 902 | } |
| 903 | |
| 904 | vp = un->un_uppervp; |
| 905 | if (vp == NULLVP) |
| 906 | error = EROFS; |
| 907 | |
| 908 | if (error) { |
| 909 | vput(ap->a_vp); |
| 910 | return (error); |
| 911 | } |
| 912 | |
| 913 | FIXUP(un); |
| 914 | VREF(vp); |
| 915 | un->un_flags |= UN_KLOCK; |
| 916 | vput(ap->a_vp); |
| 917 | |
| 918 | return (VOP_LINK(vp, tdvp, ap->a_cnp)); |
| 919 | } |
| 920 | |
| 921 | int |
| 922 | union_rename(ap) |
| 923 | struct vop_rename_args /* { |
| 924 | struct vnode *a_fdvp; |
| 925 | struct vnode *a_fvp; |
| 926 | struct componentname *a_fcnp; |
| 927 | struct vnode *a_tdvp; |
| 928 | struct vnode *a_tvp; |
| 929 | struct componentname *a_tcnp; |
| 930 | } */ *ap; |
| 931 | { |
| 932 | int error; |
| 933 | |
| 934 | struct vnode *fdvp = ap->a_fdvp; |
| 935 | struct vnode *fvp = ap->a_fvp; |
| 936 | struct vnode *tdvp = ap->a_tdvp; |
| 937 | struct vnode *tvp = ap->a_tvp; |
| 938 | |
| 939 | if (fdvp->v_op == union_vnodeop_p) { /* always true */ |
| 940 | struct union_node *un = VTOUNION(fdvp); |
| 941 | if (un->un_uppervp == NULLVP) { |
| 942 | error = EROFS; |
| 943 | goto bad; |
| 944 | } |
| 945 | |
| 946 | fdvp = un->un_uppervp; |
| 947 | VREF(fdvp); |
| 948 | vrele(ap->a_fdvp); |
| 949 | } |
| 950 | |
| 951 | if (fvp->v_op == union_vnodeop_p) { /* always true */ |
| 952 | struct union_node *un = VTOUNION(fvp); |
| 953 | if (un->un_uppervp == NULLVP) { |
| 954 | error = EROFS; |
| 955 | goto bad; |
| 956 | } |
| 957 | |
| 958 | fvp = un->un_uppervp; |
| 959 | VREF(fvp); |
| 960 | vrele(ap->a_fvp); |
| 961 | } |
| 962 | |
| 963 | if (tdvp->v_op == union_vnodeop_p) { |
| 964 | struct union_node *un = VTOUNION(tdvp); |
| 965 | if (un->un_uppervp == NULLVP) { |
| 966 | /* |
| 967 | * this should never happen in normal |
| 968 | * operation but might if there was |
| 969 | * a problem creating the top-level shadow |
| 970 | * directory. |
| 971 | */ |
| 972 | error = EROFS; |
| 973 | goto bad; |
| 974 | } |
| 975 | |
| 976 | tdvp = un->un_uppervp; |
| 977 | VREF(tdvp); |
| 978 | un->un_flags |= UN_KLOCK; |
| 979 | vput(ap->a_tdvp); |
| 980 | } |
| 981 | |
| 982 | if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { |
| 983 | struct union_node *un = VTOUNION(tvp); |
| 984 | |
| 985 | tvp = un->un_uppervp; |
| 986 | if (tvp != NULLVP) { |
| 987 | VREF(tvp); |
| 988 | un->un_flags |= UN_KLOCK; |
| 989 | } |
| 990 | vput(ap->a_tvp); |
| 991 | } |
| 992 | |
| 993 | return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); |
| 994 | |
| 995 | bad: |
| 996 | vrele(fdvp); |
| 997 | vrele(fvp); |
| 998 | vput(tdvp); |
| 999 | if (tvp != NULLVP) |
| 1000 | vput(tvp); |
| 1001 | |
| 1002 | return (error); |
| 1003 | } |
| 1004 | |
| 1005 | int |
| 1006 | union_mkdir(ap) |
| 1007 | struct vop_mkdir_args /* { |
| 1008 | struct vnode *a_dvp; |
| 1009 | struct vnode **a_vpp; |
| 1010 | struct componentname *a_cnp; |
| 1011 | struct vattr *a_vap; |
| 1012 | } */ *ap; |
| 1013 | { |
| 1014 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 1015 | struct vnode *dvp = un->un_uppervp; |
| 1016 | |
| 1017 | if (dvp != NULLVP) { |
| 1018 | int error; |
| 1019 | struct vnode *vp; |
| 1020 | |
| 1021 | FIXUP(un); |
| 1022 | VREF(dvp); |
| 1023 | un->un_flags |= UN_KLOCK; |
| 1024 | vput(ap->a_dvp); |
| 1025 | error = VOP_MKDIR(dvp, &vp, ap->a_cnp, ap->a_vap); |
| 1026 | if (error) |
| 1027 | return (error); |
| 1028 | |
| 1029 | error = union_allocvp( |
| 1030 | ap->a_vpp, |
| 1031 | ap->a_dvp->v_mount, |
| 1032 | ap->a_dvp, |
| 1033 | NULLVP, |
| 1034 | ap->a_cnp, |
| 1035 | vp, |
| 1036 | NULLVP); |
| 1037 | if (error) |
| 1038 | vput(vp); |
| 1039 | return (error); |
| 1040 | } |
| 1041 | |
| 1042 | vput(ap->a_dvp); |
| 1043 | return (EROFS); |
| 1044 | } |
| 1045 | |
| 1046 | int |
| 1047 | union_rmdir(ap) |
| 1048 | struct vop_rmdir_args /* { |
| 1049 | struct vnode *a_dvp; |
| 1050 | struct vnode *a_vp; |
| 1051 | struct componentname *a_cnp; |
| 1052 | } */ *ap; |
| 1053 | { |
| 1054 | int error; |
| 1055 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1056 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1057 | |
| 1058 | if (dun->un_uppervp != NULLVP && un->un_uppervp != NULLVP) { |
| 1059 | struct vnode *dvp = dun->un_uppervp; |
| 1060 | struct vnode *vp = un->un_uppervp; |
| 1061 | |
| 1062 | FIXUP(dun); |
| 1063 | VREF(dvp); |
| 1064 | dun->un_flags |= UN_KLOCK; |
| 1065 | vput(ap->a_dvp); |
| 1066 | FIXUP(un); |
| 1067 | VREF(vp); |
| 1068 | un->un_flags |= UN_KLOCK; |
| 1069 | vput(ap->a_vp); |
| 1070 | |
| 1071 | error = VOP_RMDIR(dvp, vp, ap->a_cnp); |
| 1072 | if (!error) |
| 1073 | union_removed_upper(un); |
| 1074 | |
| 1075 | /* |
| 1076 | * XXX: should create a whiteout here |
| 1077 | */ |
| 1078 | } else { |
| 1079 | /* |
| 1080 | * XXX: should create a whiteout here |
| 1081 | */ |
| 1082 | vput(ap->a_dvp); |
| 1083 | vput(ap->a_vp); |
| 1084 | error = EROFS; |
| 1085 | } |
| 1086 | |
| 1087 | return (error); |
| 1088 | } |
| 1089 | |
| 1090 | int |
| 1091 | union_symlink(ap) |
| 1092 | struct vop_symlink_args /* { |
| 1093 | struct vnode *a_dvp; |
| 1094 | struct vnode **a_vpp; |
| 1095 | struct componentname *a_cnp; |
| 1096 | struct vattr *a_vap; |
| 1097 | char *a_target; |
| 1098 | } */ *ap; |
| 1099 | { |
| 1100 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 1101 | struct vnode *dvp = un->un_uppervp; |
| 1102 | |
| 1103 | if (dvp != NULLVP) { |
| 1104 | int error; |
| 1105 | struct vnode *vp; |
| 1106 | struct mount *mp = ap->a_dvp->v_mount; |
| 1107 | |
| 1108 | FIXUP(un); |
| 1109 | VREF(dvp); |
| 1110 | un->un_flags |= UN_KLOCK; |
| 1111 | vput(ap->a_dvp); |
| 1112 | error = VOP_SYMLINK(dvp, &vp, ap->a_cnp, |
| 1113 | ap->a_vap, ap->a_target); |
| 1114 | *ap->a_vpp = NULLVP; |
| 1115 | return (error); |
| 1116 | } |
| 1117 | |
| 1118 | vput(ap->a_dvp); |
| 1119 | return (EROFS); |
| 1120 | } |
| 1121 | |
| 1122 | /* |
| 1123 | * union_readdir works in concert with getdirentries and |
| 1124 | * readdir(3) to provide a list of entries in the unioned |
| 1125 | * directories. getdirentries is responsible for walking |
| 1126 | * down the union stack. readdir(3) is responsible for |
| 1127 | * eliminating duplicate names from the returned data stream. |
| 1128 | */ |
| 1129 | int |
| 1130 | union_readdir(ap) |
| 1131 | struct vop_readdir_args /* { |
| 1132 | struct vnodeop_desc *a_desc; |
| 1133 | struct vnode *a_vp; |
| 1134 | struct uio *a_uio; |
| 1135 | struct ucred *a_cred; |
| 1136 | int *a_eofflag; |
| 1137 | u_long *a_cookies; |
| 1138 | int a_ncookies; |
| 1139 | } */ *ap; |
| 1140 | { |
| 1141 | register struct union_node *un = VTOUNION(ap->a_vp); |
| 1142 | register struct vnode *uvp = un->un_uppervp; |
| 1143 | |
| 1144 | if (uvp == NULLVP) |
| 1145 | return (0); |
| 1146 | |
| 1147 | FIXUP(un); |
| 1148 | ap->a_vp = uvp; |
| 1149 | return (VOCALL(uvp->v_op, VOFFSET(vop_readdir), ap)); |
| 1150 | } |
| 1151 | |
| 1152 | int |
| 1153 | union_readlink(ap) |
| 1154 | struct vop_readlink_args /* { |
| 1155 | struct vnode *a_vp; |
| 1156 | struct uio *a_uio; |
| 1157 | struct ucred *a_cred; |
| 1158 | } */ *ap; |
| 1159 | { |
| 1160 | int error; |
| 1161 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1162 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1163 | |
| 1164 | if (dolock) |
| 1165 | VOP_LOCK(vp); |
| 1166 | else |
| 1167 | FIXUP(VTOUNION(ap->a_vp)); |
| 1168 | error = VOP_READLINK(vp, ap->a_uio, ap->a_cred); |
| 1169 | if (dolock) |
| 1170 | VOP_UNLOCK(vp); |
| 1171 | |
| 1172 | return (error); |
| 1173 | } |
| 1174 | |
| 1175 | int |
| 1176 | union_abortop(ap) |
| 1177 | struct vop_abortop_args /* { |
| 1178 | struct vnode *a_dvp; |
| 1179 | struct componentname *a_cnp; |
| 1180 | } */ *ap; |
| 1181 | { |
| 1182 | int error; |
| 1183 | struct vnode *vp = OTHERVP(ap->a_dvp); |
| 1184 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 1185 | int islocked = un->un_flags & UN_LOCKED; |
| 1186 | int dolock = (vp == LOWERVP(ap->a_dvp)); |
| 1187 | |
| 1188 | if (islocked) { |
| 1189 | if (dolock) |
| 1190 | VOP_LOCK(vp); |
| 1191 | else |
| 1192 | FIXUP(VTOUNION(ap->a_dvp)); |
| 1193 | } |
| 1194 | error = VOP_ABORTOP(vp, ap->a_cnp); |
| 1195 | if (islocked && dolock) |
| 1196 | VOP_UNLOCK(vp); |
| 1197 | |
| 1198 | return (error); |
| 1199 | } |
| 1200 | |
| 1201 | int |
| 1202 | union_inactive(ap) |
| 1203 | struct vop_inactive_args /* { |
| 1204 | struct vnode *a_vp; |
| 1205 | } */ *ap; |
| 1206 | { |
| 1207 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1208 | |
| 1209 | /* |
| 1210 | * Do nothing (and _don't_ bypass). |
| 1211 | * Wait to vrele lowervp until reclaim, |
| 1212 | * so that until then our union_node is in the |
| 1213 | * cache and reusable. |
| 1214 | * |
| 1215 | * NEEDSWORK: Someday, consider inactive'ing |
| 1216 | * the lowervp and then trying to reactivate it |
| 1217 | * with capabilities (v_id) |
| 1218 | * like they do in the name lookup cache code. |
| 1219 | * That's too much work for now. |
| 1220 | */ |
| 1221 | |
| 1222 | #ifdef UNION_DIAGNOSTIC |
| 1223 | if (un->un_flags & UN_LOCKED) |
| 1224 | panic("union: inactivating locked node"); |
| 1225 | if (un->un_flags & UN_ULOCK) |
| 1226 | panic("union: inactivating w/locked upper node"); |
| 1227 | #endif |
| 1228 | |
| 1229 | if ((un->un_flags & UN_CACHED) == 0) |
| 1230 | vgone(ap->a_vp); |
| 1231 | |
| 1232 | return (0); |
| 1233 | } |
| 1234 | |
| 1235 | int |
| 1236 | union_reclaim(ap) |
| 1237 | struct vop_reclaim_args /* { |
| 1238 | struct vnode *a_vp; |
| 1239 | } */ *ap; |
| 1240 | { |
| 1241 | |
| 1242 | union_freevp(ap->a_vp); |
| 1243 | |
| 1244 | return (0); |
| 1245 | } |
| 1246 | |
| 1247 | int |
| 1248 | union_lock(ap) |
| 1249 | struct vop_lock_args *ap; |
| 1250 | { |
| 1251 | struct vnode *vp = ap->a_vp; |
| 1252 | struct union_node *un; |
| 1253 | |
| 1254 | start: |
| 1255 | while (vp->v_flag & VXLOCK) { |
| 1256 | vp->v_flag |= VXWANT; |
| 1257 | sleep((caddr_t)vp, PINOD); |
| 1258 | } |
| 1259 | |
| 1260 | un = VTOUNION(vp); |
| 1261 | |
| 1262 | if (un->un_uppervp != NULLVP) { |
| 1263 | if (((un->un_flags & UN_ULOCK) == 0) && |
| 1264 | (vp->v_usecount != 0)) { |
| 1265 | un->un_flags |= UN_ULOCK; |
| 1266 | VOP_LOCK(un->un_uppervp); |
| 1267 | } |
| 1268 | #ifdef DIAGNOSTIC |
| 1269 | if (un->un_flags & UN_KLOCK) |
| 1270 | panic("union: dangling upper lock"); |
| 1271 | #endif |
| 1272 | } |
| 1273 | |
| 1274 | if (un->un_flags & UN_LOCKED) { |
| 1275 | #ifdef DIAGNOSTIC |
| 1276 | if (curproc && un->un_pid == curproc->p_pid && |
| 1277 | un->un_pid > -1 && curproc->p_pid > -1) |
| 1278 | panic("union: locking against myself"); |
| 1279 | #endif |
| 1280 | un->un_flags |= UN_WANT; |
| 1281 | sleep((caddr_t) &un->un_flags, PINOD); |
| 1282 | goto start; |
| 1283 | } |
| 1284 | |
| 1285 | #ifdef DIAGNOSTIC |
| 1286 | if (curproc) |
| 1287 | un->un_pid = curproc->p_pid; |
| 1288 | else |
| 1289 | un->un_pid = -1; |
| 1290 | #endif |
| 1291 | |
| 1292 | un->un_flags |= UN_LOCKED; |
| 1293 | return (0); |
| 1294 | } |
| 1295 | |
| 1296 | int |
| 1297 | union_unlock(ap) |
| 1298 | struct vop_lock_args *ap; |
| 1299 | { |
| 1300 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1301 | |
| 1302 | #ifdef DIAGNOSTIC |
| 1303 | if ((un->un_flags & UN_LOCKED) == 0) |
| 1304 | panic("union: unlock unlocked node"); |
| 1305 | if (curproc && un->un_pid != curproc->p_pid && |
| 1306 | curproc->p_pid > -1 && un->un_pid > -1) |
| 1307 | panic("union: unlocking other process's union node"); |
| 1308 | #endif |
| 1309 | |
| 1310 | un->un_flags &= ~UN_LOCKED; |
| 1311 | |
| 1312 | if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK) |
| 1313 | VOP_UNLOCK(un->un_uppervp); |
| 1314 | |
| 1315 | un->un_flags &= ~(UN_ULOCK|UN_KLOCK); |
| 1316 | |
| 1317 | if (un->un_flags & UN_WANT) { |
| 1318 | un->un_flags &= ~UN_WANT; |
| 1319 | wakeup((caddr_t) &un->un_flags); |
| 1320 | } |
| 1321 | |
| 1322 | #ifdef DIAGNOSTIC |
| 1323 | un->un_pid = 0; |
| 1324 | #endif |
| 1325 | |
| 1326 | return (0); |
| 1327 | } |
| 1328 | |
| 1329 | int |
| 1330 | union_bmap(ap) |
| 1331 | struct vop_bmap_args /* { |
| 1332 | struct vnode *a_vp; |
| 1333 | daddr_t a_bn; |
| 1334 | struct vnode **a_vpp; |
| 1335 | daddr_t *a_bnp; |
| 1336 | int *a_runp; |
| 1337 | } */ *ap; |
| 1338 | { |
| 1339 | int error; |
| 1340 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1341 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1342 | |
| 1343 | if (dolock) |
| 1344 | VOP_LOCK(vp); |
| 1345 | else |
| 1346 | FIXUP(VTOUNION(ap->a_vp)); |
| 1347 | error = VOP_BMAP(vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp); |
| 1348 | if (dolock) |
| 1349 | VOP_UNLOCK(vp); |
| 1350 | |
| 1351 | return (error); |
| 1352 | } |
| 1353 | |
| 1354 | int |
| 1355 | union_print(ap) |
| 1356 | struct vop_print_args /* { |
| 1357 | struct vnode *a_vp; |
| 1358 | } */ *ap; |
| 1359 | { |
| 1360 | struct vnode *vp = ap->a_vp; |
| 1361 | |
| 1362 | printf("\ttag VT_UNION, vp=%x, uppervp=%x, lowervp=%x\n", |
| 1363 | vp, UPPERVP(vp), LOWERVP(vp)); |
| 1364 | return (0); |
| 1365 | } |
| 1366 | |
| 1367 | int |
| 1368 | union_islocked(ap) |
| 1369 | struct vop_islocked_args /* { |
| 1370 | struct vnode *a_vp; |
| 1371 | } */ *ap; |
| 1372 | { |
| 1373 | |
| 1374 | return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 0); |
| 1375 | } |
| 1376 | |
| 1377 | int |
| 1378 | union_pathconf(ap) |
| 1379 | struct vop_pathconf_args /* { |
| 1380 | struct vnode *a_vp; |
| 1381 | int a_name; |
| 1382 | int *a_retval; |
| 1383 | } */ *ap; |
| 1384 | { |
| 1385 | int error; |
| 1386 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1387 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1388 | |
| 1389 | if (dolock) |
| 1390 | VOP_LOCK(vp); |
| 1391 | else |
| 1392 | FIXUP(VTOUNION(ap->a_vp)); |
| 1393 | error = VOP_PATHCONF(vp, ap->a_name, ap->a_retval); |
| 1394 | if (dolock) |
| 1395 | VOP_UNLOCK(vp); |
| 1396 | |
| 1397 | return (error); |
| 1398 | } |
| 1399 | |
| 1400 | int |
| 1401 | union_advlock(ap) |
| 1402 | struct vop_advlock_args /* { |
| 1403 | struct vnode *a_vp; |
| 1404 | caddr_t a_id; |
| 1405 | int a_op; |
| 1406 | struct flock *a_fl; |
| 1407 | int a_flags; |
| 1408 | } */ *ap; |
| 1409 | { |
| 1410 | |
| 1411 | return (VOP_ADVLOCK(OTHERVP(ap->a_vp), ap->a_id, ap->a_op, |
| 1412 | ap->a_fl, ap->a_flags)); |
| 1413 | } |
| 1414 | |
| 1415 | |
| 1416 | /* |
| 1417 | * XXX - vop_strategy must be hand coded because it has no |
| 1418 | * vnode in its arguments. |
| 1419 | * This goes away with a merged VM/buffer cache. |
| 1420 | */ |
| 1421 | int |
| 1422 | union_strategy(ap) |
| 1423 | struct vop_strategy_args /* { |
| 1424 | struct buf *a_bp; |
| 1425 | } */ *ap; |
| 1426 | { |
| 1427 | struct buf *bp = ap->a_bp; |
| 1428 | int error; |
| 1429 | struct vnode *savedvp; |
| 1430 | |
| 1431 | savedvp = bp->b_vp; |
| 1432 | bp->b_vp = OTHERVP(bp->b_vp); |
| 1433 | |
| 1434 | #ifdef DIAGNOSTIC |
| 1435 | if (bp->b_vp == NULLVP) |
| 1436 | panic("union_strategy: nil vp"); |
| 1437 | if (((bp->b_flags & B_READ) == 0) && |
| 1438 | (bp->b_vp == LOWERVP(savedvp))) |
| 1439 | panic("union_strategy: writing to lowervp"); |
| 1440 | #endif |
| 1441 | |
| 1442 | error = VOP_STRATEGY(bp); |
| 1443 | bp->b_vp = savedvp; |
| 1444 | |
| 1445 | return (error); |
| 1446 | } |
| 1447 | |
| 1448 | /* |
| 1449 | * Global vfs data structures |
| 1450 | */ |
| 1451 | int (**union_vnodeop_p)(); |
| 1452 | struct vnodeopv_entry_desc union_vnodeop_entries[] = { |
| 1453 | { &vop_default_desc, vn_default_error }, |
| 1454 | { &vop_lookup_desc, union_lookup }, /* lookup */ |
| 1455 | { &vop_create_desc, union_create }, /* create */ |
| 1456 | { &vop_mknod_desc, union_mknod }, /* mknod */ |
| 1457 | { &vop_open_desc, union_open }, /* open */ |
| 1458 | { &vop_close_desc, union_close }, /* close */ |
| 1459 | { &vop_access_desc, union_access }, /* access */ |
| 1460 | { &vop_getattr_desc, union_getattr }, /* getattr */ |
| 1461 | { &vop_setattr_desc, union_setattr }, /* setattr */ |
| 1462 | { &vop_read_desc, union_read }, /* read */ |
| 1463 | { &vop_write_desc, union_write }, /* write */ |
| 1464 | { &vop_ioctl_desc, union_ioctl }, /* ioctl */ |
| 1465 | { &vop_select_desc, union_select }, /* select */ |
| 1466 | { &vop_mmap_desc, union_mmap }, /* mmap */ |
| 1467 | { &vop_fsync_desc, union_fsync }, /* fsync */ |
| 1468 | { &vop_seek_desc, union_seek }, /* seek */ |
| 1469 | { &vop_remove_desc, union_remove }, /* remove */ |
| 1470 | { &vop_link_desc, union_link }, /* link */ |
| 1471 | { &vop_rename_desc, union_rename }, /* rename */ |
| 1472 | { &vop_mkdir_desc, union_mkdir }, /* mkdir */ |
| 1473 | { &vop_rmdir_desc, union_rmdir }, /* rmdir */ |
| 1474 | { &vop_symlink_desc, union_symlink }, /* symlink */ |
| 1475 | { &vop_readdir_desc, union_readdir }, /* readdir */ |
| 1476 | { &vop_readlink_desc, union_readlink }, /* readlink */ |
| 1477 | { &vop_abortop_desc, union_abortop }, /* abortop */ |
| 1478 | { &vop_inactive_desc, union_inactive }, /* inactive */ |
| 1479 | { &vop_reclaim_desc, union_reclaim }, /* reclaim */ |
| 1480 | { &vop_lock_desc, union_lock }, /* lock */ |
| 1481 | { &vop_unlock_desc, union_unlock }, /* unlock */ |
| 1482 | { &vop_bmap_desc, union_bmap }, /* bmap */ |
| 1483 | { &vop_strategy_desc, union_strategy }, /* strategy */ |
| 1484 | { &vop_print_desc, union_print }, /* print */ |
| 1485 | { &vop_islocked_desc, union_islocked }, /* islocked */ |
| 1486 | { &vop_pathconf_desc, union_pathconf }, /* pathconf */ |
| 1487 | { &vop_advlock_desc, union_advlock }, /* advlock */ |
| 1488 | #ifdef notdef |
| 1489 | { &vop_blkatoff_desc, union_blkatoff }, /* blkatoff */ |
| 1490 | { &vop_valloc_desc, union_valloc }, /* valloc */ |
| 1491 | { &vop_vfree_desc, union_vfree }, /* vfree */ |
| 1492 | { &vop_truncate_desc, union_truncate }, /* truncate */ |
| 1493 | { &vop_update_desc, union_update }, /* update */ |
| 1494 | { &vop_bwrite_desc, union_bwrite }, /* bwrite */ |
| 1495 | #endif |
| 1496 | { (struct vnodeop_desc*)NULL, (int(*)())NULL } |
| 1497 | }; |
| 1498 | struct vnodeopv_desc union_vnodeop_opv_desc = |
| 1499 | { &union_vnodeop_p, union_vnodeop_entries }; |