| 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 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * 1. Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * 2. Redistributions in binary form must reproduce the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer in the |
| 16 | * documentation and/or other materials provided with the distribution. |
| 17 | * 3. All advertising materials mentioning features or use of this software |
| 18 | * must display the following acknowledgement: |
| 19 | * This product includes software developed by the University of |
| 20 | * California, Berkeley and its contributors. |
| 21 | * 4. Neither the name of the University nor the names of its contributors |
| 22 | * may be used to endorse or promote products derived from this software |
| 23 | * without specific prior written permission. |
| 24 | * |
| 25 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 26 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 29 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 30 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 31 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 32 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 33 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 34 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 35 | * SUCH DAMAGE. |
| 36 | * |
| 37 | * @(#)union_vnops.c 8.32 (Berkeley) 6/23/95 |
| 38 | * $FreeBSD: src/sys/miscfs/union/union_vnops.c,v 1.72 1999/12/15 23:02:14 eivind Exp $ |
| 39 | * $DragonFly: src/sys/vfs/union/union_vnops.c,v 1.36 2006/12/23 00:41:30 swildner Exp $ |
| 40 | */ |
| 41 | |
| 42 | #include <sys/param.h> |
| 43 | #include <sys/systm.h> |
| 44 | #include <sys/proc.h> |
| 45 | #include <sys/fcntl.h> |
| 46 | #include <sys/stat.h> |
| 47 | #include <sys/kernel.h> |
| 48 | #include <sys/vnode.h> |
| 49 | #include <sys/mount.h> |
| 50 | #include <sys/namei.h> |
| 51 | #include <sys/malloc.h> |
| 52 | #include <sys/buf.h> |
| 53 | #include <sys/lock.h> |
| 54 | #include <sys/sysctl.h> |
| 55 | #include "union.h" |
| 56 | |
| 57 | #include <vm/vm.h> |
| 58 | #include <vm/vnode_pager.h> |
| 59 | |
| 60 | #include <vm/vm_page.h> |
| 61 | #include <vm/vm_object.h> |
| 62 | |
| 63 | int uniondebug = 0; |
| 64 | |
| 65 | #if UDEBUG_ENABLED |
| 66 | SYSCTL_INT(_vfs, OID_AUTO, uniondebug, CTLFLAG_RW, &uniondebug, 0, ""); |
| 67 | #else |
| 68 | SYSCTL_INT(_vfs, OID_AUTO, uniondebug, CTLFLAG_RD, &uniondebug, 0, ""); |
| 69 | #endif |
| 70 | |
| 71 | static int union_access (struct vop_access_args *ap); |
| 72 | static int union_advlock (struct vop_advlock_args *ap); |
| 73 | static int union_bmap (struct vop_bmap_args *ap); |
| 74 | static int union_close (struct vop_close_args *ap); |
| 75 | static int union_create (struct vop_old_create_args *ap); |
| 76 | static int union_fsync (struct vop_fsync_args *ap); |
| 77 | static int union_getattr (struct vop_getattr_args *ap); |
| 78 | static int union_inactive (struct vop_inactive_args *ap); |
| 79 | static int union_ioctl (struct vop_ioctl_args *ap); |
| 80 | static int union_link (struct vop_old_link_args *ap); |
| 81 | static int union_lookup (struct vop_old_lookup_args *ap); |
| 82 | static int union_lookup1 (struct vnode *udvp, struct vnode **dvp, |
| 83 | struct vnode **vpp, |
| 84 | struct componentname *cnp); |
| 85 | static int union_mkdir (struct vop_old_mkdir_args *ap); |
| 86 | static int union_mknod (struct vop_old_mknod_args *ap); |
| 87 | static int union_mmap (struct vop_mmap_args *ap); |
| 88 | static int union_open (struct vop_open_args *ap); |
| 89 | static int union_pathconf (struct vop_pathconf_args *ap); |
| 90 | static int union_print (struct vop_print_args *ap); |
| 91 | static int union_read (struct vop_read_args *ap); |
| 92 | static int union_readdir (struct vop_readdir_args *ap); |
| 93 | static int union_readlink (struct vop_readlink_args *ap); |
| 94 | static int union_reclaim (struct vop_reclaim_args *ap); |
| 95 | static int union_remove (struct vop_old_remove_args *ap); |
| 96 | static int union_rename (struct vop_old_rename_args *ap); |
| 97 | static int union_revoke (struct vop_revoke_args *ap); |
| 98 | static int union_rmdir (struct vop_old_rmdir_args *ap); |
| 99 | static int union_poll (struct vop_poll_args *ap); |
| 100 | static int union_setattr (struct vop_setattr_args *ap); |
| 101 | static int union_strategy (struct vop_strategy_args *ap); |
| 102 | static int union_getpages (struct vop_getpages_args *ap); |
| 103 | static int union_putpages (struct vop_putpages_args *ap); |
| 104 | static int union_symlink (struct vop_old_symlink_args *ap); |
| 105 | static int union_whiteout (struct vop_old_whiteout_args *ap); |
| 106 | static int union_write (struct vop_read_args *ap); |
| 107 | |
| 108 | static __inline |
| 109 | struct vnode * |
| 110 | union_lock_upper(struct union_node *un, struct thread *td) |
| 111 | { |
| 112 | struct vnode *uppervp; |
| 113 | |
| 114 | if ((uppervp = un->un_uppervp) != NULL) { |
| 115 | vref(uppervp); |
| 116 | vn_lock(uppervp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); |
| 117 | } |
| 118 | KASSERT((uppervp == NULL || uppervp->v_usecount > 0), ("uppervp usecount is 0")); |
| 119 | return(uppervp); |
| 120 | } |
| 121 | |
| 122 | static __inline |
| 123 | struct vnode * |
| 124 | union_ref_upper(struct union_node *un) |
| 125 | { |
| 126 | struct vnode *uppervp; |
| 127 | |
| 128 | if ((uppervp = un->un_uppervp) != NULL) { |
| 129 | vref(uppervp); |
| 130 | if (uppervp->v_flag & VRECLAIMED) { |
| 131 | vrele(uppervp); |
| 132 | return (NULLVP); |
| 133 | } |
| 134 | } |
| 135 | return (uppervp); |
| 136 | } |
| 137 | |
| 138 | static __inline |
| 139 | void |
| 140 | union_unlock_upper(struct vnode *uppervp, struct thread *td) |
| 141 | { |
| 142 | vput(uppervp); |
| 143 | } |
| 144 | |
| 145 | static __inline |
| 146 | struct vnode * |
| 147 | union_lock_other(struct union_node *un, struct thread *td) |
| 148 | { |
| 149 | struct vnode *vp; |
| 150 | |
| 151 | if (un->un_uppervp != NULL) { |
| 152 | vp = union_lock_upper(un, td); |
| 153 | } else if ((vp = un->un_lowervp) != NULL) { |
| 154 | vref(vp); |
| 155 | vn_lock(vp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); |
| 156 | } |
| 157 | return(vp); |
| 158 | } |
| 159 | |
| 160 | static __inline |
| 161 | void |
| 162 | union_unlock_other(struct vnode *vp, struct thread *td) |
| 163 | { |
| 164 | vput(vp); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * union_lookup: |
| 169 | * |
| 170 | * udvp must be exclusively locked on call and will remain |
| 171 | * exclusively locked on return. This is the mount point |
| 172 | * for out filesystem. |
| 173 | * |
| 174 | * dvp Our base directory, locked and referenced. |
| 175 | * The passed dvp will be dereferenced and unlocked on return |
| 176 | * and a new dvp will be returned which is locked and |
| 177 | * referenced in the same variable. |
| 178 | * |
| 179 | * vpp is filled in with the result if no error occured, |
| 180 | * locked and ref'd. |
| 181 | * |
| 182 | * If an error is returned, *vpp is set to NULLVP. If no |
| 183 | * error occurs, *vpp is returned with a reference and an |
| 184 | * exclusive lock. |
| 185 | */ |
| 186 | |
| 187 | static int |
| 188 | union_lookup1(struct vnode *udvp, struct vnode **pdvp, struct vnode **vpp, |
| 189 | struct componentname *cnp) |
| 190 | { |
| 191 | int error; |
| 192 | struct thread *td = cnp->cn_td; |
| 193 | struct vnode *dvp = *pdvp; |
| 194 | struct vnode *tdvp; |
| 195 | struct mount *mp; |
| 196 | |
| 197 | /* |
| 198 | * If stepping up the directory tree, check for going |
| 199 | * back across the mount point, in which case do what |
| 200 | * lookup would do by stepping back down the mount |
| 201 | * hierarchy. |
| 202 | */ |
| 203 | if (cnp->cn_flags & CNP_ISDOTDOT) { |
| 204 | while ((dvp != udvp) && (dvp->v_flag & VROOT)) { |
| 205 | /* |
| 206 | * Don't do the NOCROSSMOUNT check |
| 207 | * at this level. By definition, |
| 208 | * union fs deals with namespaces, not |
| 209 | * filesystems. |
| 210 | */ |
| 211 | tdvp = dvp; |
| 212 | dvp = dvp->v_mount->mnt_vnodecovered; |
| 213 | vref(dvp); |
| 214 | vput(tdvp); |
| 215 | vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * Set return dvp to be the upperdvp 'parent directory. |
| 221 | */ |
| 222 | *pdvp = dvp; |
| 223 | |
| 224 | /* |
| 225 | * If the VOP_LOOKUP call generates an error, tdvp is invalid and no |
| 226 | * changes will have been made to dvp, so we are set to return. |
| 227 | */ |
| 228 | |
| 229 | error = VOP_LOOKUP(dvp, &tdvp, cnp); |
| 230 | if (error) { |
| 231 | UDEBUG(("dvp %p error %d flags %lx\n", dvp, error, cnp->cn_flags)); |
| 232 | *vpp = NULL; |
| 233 | return (error); |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * The parent directory will have been unlocked, unless lookup |
| 238 | * found the last component or if dvp == tdvp (tdvp must be locked). |
| 239 | * |
| 240 | * We want our dvp to remain locked and ref'd. We also want tdvp |
| 241 | * to remain locked and ref'd. |
| 242 | */ |
| 243 | UDEBUG(("parentdir %p result %p flag %lx\n", dvp, tdvp, cnp->cn_flags)); |
| 244 | |
| 245 | #if 0 |
| 246 | if (dvp != tdvp && (cnp->cn_flags & CNP_XXXISLASTCN) == 0) |
| 247 | vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); |
| 248 | #endif |
| 249 | |
| 250 | /* |
| 251 | * Lastly check if the current node is a mount point in |
| 252 | * which case walk up the mount hierarchy making sure not to |
| 253 | * bump into the root of the mount tree (ie. dvp != udvp). |
| 254 | * |
| 255 | * We use dvp as a temporary variable here, it is no longer related |
| 256 | * to the dvp above. However, we have to ensure that both *pdvp and |
| 257 | * tdvp are locked on return. |
| 258 | */ |
| 259 | |
| 260 | dvp = tdvp; |
| 261 | while ( |
| 262 | dvp != udvp && |
| 263 | (dvp->v_type == VDIR) && |
| 264 | (mp = dvp->v_mountedhere) |
| 265 | ) { |
| 266 | int relock_pdvp = 0; |
| 267 | |
| 268 | if (vfs_busy(mp, 0)) |
| 269 | continue; |
| 270 | |
| 271 | if (dvp == *pdvp) |
| 272 | relock_pdvp = 1; |
| 273 | vput(dvp); |
| 274 | dvp = NULL; |
| 275 | error = VFS_ROOT(mp, &dvp); |
| 276 | |
| 277 | vfs_unbusy(mp); |
| 278 | |
| 279 | if (relock_pdvp) |
| 280 | vn_lock(*pdvp, LK_EXCLUSIVE | LK_RETRY); |
| 281 | |
| 282 | if (error) { |
| 283 | *vpp = NULL; |
| 284 | return (error); |
| 285 | } |
| 286 | } |
| 287 | *vpp = dvp; |
| 288 | return (0); |
| 289 | } |
| 290 | |
| 291 | /* |
| 292 | * union_lookup(struct vnode *a_dvp, struct vnode **a_vpp, |
| 293 | * struct componentname *a_cnp) |
| 294 | */ |
| 295 | static int |
| 296 | union_lookup(struct vop_old_lookup_args *ap) |
| 297 | { |
| 298 | int error; |
| 299 | int uerror, lerror; |
| 300 | struct vnode *uppervp, *lowervp; |
| 301 | struct vnode *upperdvp, *lowerdvp; |
| 302 | struct vnode *dvp = ap->a_dvp; /* starting dir */ |
| 303 | struct union_node *dun = VTOUNION(dvp); /* associated union node */ |
| 304 | struct componentname *cnp = ap->a_cnp; |
| 305 | struct thread *td = cnp->cn_td; |
| 306 | int lockparent = cnp->cn_flags & CNP_LOCKPARENT; |
| 307 | struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount); |
| 308 | struct ucred *saved_cred = NULL; |
| 309 | int iswhiteout; |
| 310 | struct vattr va; |
| 311 | |
| 312 | *ap->a_vpp = NULLVP; |
| 313 | |
| 314 | /* |
| 315 | * Disallow write attemps to the filesystem mounted read-only. |
| 316 | */ |
| 317 | if ((dvp->v_mount->mnt_flag & MNT_RDONLY) && |
| 318 | (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME)) { |
| 319 | return (EROFS); |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * For any lookup's we do, always return with the parent locked |
| 324 | */ |
| 325 | cnp->cn_flags |= CNP_LOCKPARENT; |
| 326 | |
| 327 | lowerdvp = dun->un_lowervp; |
| 328 | uppervp = NULLVP; |
| 329 | lowervp = NULLVP; |
| 330 | iswhiteout = 0; |
| 331 | |
| 332 | uerror = ENOENT; |
| 333 | lerror = ENOENT; |
| 334 | |
| 335 | /* |
| 336 | * Get a private lock on uppervp and a reference, effectively |
| 337 | * taking it out of the union_node's control. |
| 338 | * |
| 339 | * We must lock upperdvp while holding our lock on dvp |
| 340 | * to avoid a deadlock. |
| 341 | */ |
| 342 | upperdvp = union_lock_upper(dun, td); |
| 343 | |
| 344 | /* |
| 345 | * do the lookup in the upper level. |
| 346 | * if that level comsumes additional pathnames, |
| 347 | * then assume that something special is going |
| 348 | * on and just return that vnode. |
| 349 | */ |
| 350 | if (upperdvp != NULLVP) { |
| 351 | /* |
| 352 | * We do not have to worry about the DOTDOT case, we've |
| 353 | * already unlocked dvp. |
| 354 | */ |
| 355 | UDEBUG(("A %p\n", upperdvp)); |
| 356 | |
| 357 | /* |
| 358 | * Do the lookup. We must supply a locked and referenced |
| 359 | * upperdvp to the function and will get a new locked and |
| 360 | * referenced upperdvp back with the old having been |
| 361 | * dereferenced. |
| 362 | * |
| 363 | * If an error is returned, uppervp will be NULLVP. If no |
| 364 | * error occurs, uppervp will be the locked and referenced |
| 365 | * return vnode or possibly NULL, depending on what is being |
| 366 | * requested. It is possible that the returned uppervp |
| 367 | * will be the same as upperdvp. |
| 368 | */ |
| 369 | uerror = union_lookup1(um->um_uppervp, &upperdvp, &uppervp, cnp); |
| 370 | UDEBUG(( |
| 371 | "uerror %d upperdvp %p %d/%d, uppervp %p ref=%d/lck=%d\n", |
| 372 | uerror, |
| 373 | upperdvp, |
| 374 | upperdvp->v_usecount, |
| 375 | vn_islocked(upperdvp), |
| 376 | uppervp, |
| 377 | (uppervp ? uppervp->v_usecount : -99), |
| 378 | (uppervp ? vn_islocked(uppervp) : -99) |
| 379 | )); |
| 380 | |
| 381 | /* |
| 382 | * Disallow write attemps to the filesystem mounted read-only. |
| 383 | */ |
| 384 | if (uerror == EJUSTRETURN && |
| 385 | (dvp->v_mount->mnt_flag & MNT_RDONLY) && |
| 386 | (cnp->cn_nameiop == NAMEI_CREATE || cnp->cn_nameiop == NAMEI_RENAME)) { |
| 387 | error = EROFS; |
| 388 | goto out; |
| 389 | } |
| 390 | |
| 391 | /* |
| 392 | * Special case. If cn_consume != 0 skip out. The result |
| 393 | * of the lookup is transfered to our return variable. If |
| 394 | * an error occured we have to throw away the results. |
| 395 | */ |
| 396 | |
| 397 | if (cnp->cn_consume != 0) { |
| 398 | if ((error = uerror) == 0) { |
| 399 | *ap->a_vpp = uppervp; |
| 400 | uppervp = NULL; |
| 401 | } |
| 402 | goto out; |
| 403 | } |
| 404 | |
| 405 | /* |
| 406 | * Calculate whiteout, fall through |
| 407 | */ |
| 408 | |
| 409 | if (uerror == ENOENT || uerror == EJUSTRETURN) { |
| 410 | if (cnp->cn_flags & CNP_ISWHITEOUT) { |
| 411 | iswhiteout = 1; |
| 412 | } else if (lowerdvp != NULLVP) { |
| 413 | int terror; |
| 414 | |
| 415 | terror = VOP_GETATTR(upperdvp, &va); |
| 416 | if (terror == 0 && (va.va_flags & OPAQUE)) |
| 417 | iswhiteout = 1; |
| 418 | } |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * in a similar way to the upper layer, do the lookup |
| 424 | * in the lower layer. this time, if there is some |
| 425 | * component magic going on, then vput whatever we got |
| 426 | * back from the upper layer and return the lower vnode |
| 427 | * instead. |
| 428 | */ |
| 429 | |
| 430 | if (lowerdvp != NULLVP && !iswhiteout) { |
| 431 | int nameiop; |
| 432 | |
| 433 | UDEBUG(("B %p\n", lowerdvp)); |
| 434 | |
| 435 | /* |
| 436 | * Force only LOOKUPs on the lower node, since |
| 437 | * we won't be making changes to it anyway. |
| 438 | */ |
| 439 | nameiop = cnp->cn_nameiop; |
| 440 | cnp->cn_nameiop = NAMEI_LOOKUP; |
| 441 | if (um->um_op == UNMNT_BELOW) { |
| 442 | saved_cred = cnp->cn_cred; |
| 443 | cnp->cn_cred = um->um_cred; |
| 444 | } |
| 445 | |
| 446 | /* |
| 447 | * We shouldn't have to worry about locking interactions |
| 448 | * between the lower layer and our union layer (w.r.t. |
| 449 | * `..' processing) because we don't futz with lowervp |
| 450 | * locks in the union-node instantiation code path. |
| 451 | * |
| 452 | * union_lookup1() requires lowervp to be locked on entry, |
| 453 | * and it will be unlocked on return. The ref count will |
| 454 | * not change. On return lowervp doesn't represent anything |
| 455 | * to us so we NULL it out. |
| 456 | */ |
| 457 | vref(lowerdvp); |
| 458 | vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY); |
| 459 | lerror = union_lookup1(um->um_lowervp, &lowerdvp, &lowervp, cnp); |
| 460 | if (lowerdvp == lowervp) |
| 461 | vrele(lowerdvp); |
| 462 | else |
| 463 | vput(lowerdvp); |
| 464 | lowerdvp = NULL; /* lowerdvp invalid after vput */ |
| 465 | |
| 466 | if (um->um_op == UNMNT_BELOW) |
| 467 | cnp->cn_cred = saved_cred; |
| 468 | cnp->cn_nameiop = nameiop; |
| 469 | |
| 470 | if (cnp->cn_consume != 0 || lerror == EACCES) { |
| 471 | if ((error = lerror) == 0) { |
| 472 | *ap->a_vpp = lowervp; |
| 473 | lowervp = NULL; |
| 474 | } |
| 475 | goto out; |
| 476 | } |
| 477 | } else { |
| 478 | UDEBUG(("C %p\n", lowerdvp)); |
| 479 | if ((cnp->cn_flags & CNP_ISDOTDOT) && dun->un_pvp != NULLVP) { |
| 480 | if ((lowervp = LOWERVP(dun->un_pvp)) != NULL) { |
| 481 | vref(lowervp); |
| 482 | vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY); |
| 483 | lerror = 0; |
| 484 | } |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * Ok. Now we have uerror, uppervp, upperdvp, lerror, and lowervp. |
| 490 | * |
| 491 | * 1. If both layers returned an error, select the upper layer. |
| 492 | * |
| 493 | * 2. If the upper layer faile and the bottom layer succeeded, |
| 494 | * two subcases occur: |
| 495 | * |
| 496 | * a. The bottom vnode is not a directory, in which case |
| 497 | * just return a new union vnode referencing an |
| 498 | * empty top layer and the existing bottom layer. |
| 499 | * |
| 500 | * b. The button vnode is a directory, in which case |
| 501 | * create a new directory in the top layer and |
| 502 | * and fall through to case 3. |
| 503 | * |
| 504 | * 3. If the top layer succeeded then return a new union |
| 505 | * vnode referencing whatever the new top layer and |
| 506 | * whatever the bottom layer returned. |
| 507 | */ |
| 508 | |
| 509 | /* case 1. */ |
| 510 | if ((uerror != 0) && (lerror != 0)) { |
| 511 | error = uerror; |
| 512 | goto out; |
| 513 | } |
| 514 | |
| 515 | /* case 2. */ |
| 516 | if (uerror != 0 /* && (lerror == 0) */ ) { |
| 517 | if (lowervp->v_type == VDIR) { /* case 2b. */ |
| 518 | KASSERT(uppervp == NULL, ("uppervp unexpectedly non-NULL")); |
| 519 | /* |
| 520 | * oops, uppervp has a problem, we may have to shadow. |
| 521 | */ |
| 522 | uerror = union_mkshadow(um, upperdvp, cnp, &uppervp); |
| 523 | if (uerror) { |
| 524 | error = uerror; |
| 525 | goto out; |
| 526 | } |
| 527 | } |
| 528 | } |
| 529 | |
| 530 | /* |
| 531 | * Must call union_allocvp with both the upper and lower vnodes |
| 532 | * referenced and the upper vnode locked. ap->a_vpp is returned |
| 533 | * referenced and locked. lowervp, uppervp, and upperdvp are |
| 534 | * absorbed by union_allocvp() whether it succeeds or fails. |
| 535 | * |
| 536 | * upperdvp is the parent directory of uppervp which may be |
| 537 | * different, depending on the path, from dvp->un_uppervp. That's |
| 538 | * why it is a separate argument. Note that it must be unlocked. |
| 539 | * |
| 540 | * dvp must be locked on entry to the call and will be locked on |
| 541 | * return. |
| 542 | */ |
| 543 | |
| 544 | if (uppervp && uppervp != upperdvp) |
| 545 | vn_unlock(uppervp); |
| 546 | if (lowervp) |
| 547 | vn_unlock(lowervp); |
| 548 | if (upperdvp) |
| 549 | vn_unlock(upperdvp); |
| 550 | |
| 551 | error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, |
| 552 | uppervp, lowervp, 1); |
| 553 | |
| 554 | UDEBUG(("Create %p = %p %p refs=%d\n", *ap->a_vpp, uppervp, lowervp, (*ap->a_vpp) ? ((*ap->a_vpp)->v_usecount) : -99)); |
| 555 | |
| 556 | uppervp = NULL; |
| 557 | upperdvp = NULL; |
| 558 | lowervp = NULL; |
| 559 | |
| 560 | /* |
| 561 | * Termination Code |
| 562 | * |
| 563 | * - put away any extra junk laying around. Note that lowervp |
| 564 | * (if not NULL) will never be the same as *ap->a_vp and |
| 565 | * neither will uppervp, because when we set that state we |
| 566 | * NULL-out lowervp or uppervp. On the otherhand, upperdvp |
| 567 | * may match uppervp or *ap->a_vpp. |
| 568 | * |
| 569 | * - relock/unlock dvp if appropriate. |
| 570 | */ |
| 571 | |
| 572 | out: |
| 573 | if (upperdvp) { |
| 574 | if (upperdvp == uppervp || upperdvp == *ap->a_vpp) |
| 575 | vrele(upperdvp); |
| 576 | else |
| 577 | vput(upperdvp); |
| 578 | } |
| 579 | |
| 580 | if (uppervp) |
| 581 | vput(uppervp); |
| 582 | |
| 583 | if (lowervp) |
| 584 | vput(lowervp); |
| 585 | |
| 586 | /* |
| 587 | * Restore LOCKPARENT state |
| 588 | */ |
| 589 | |
| 590 | if (!lockparent) |
| 591 | cnp->cn_flags &= ~CNP_LOCKPARENT; |
| 592 | |
| 593 | UDEBUG(("Out %d vpp %p/%d lower %p upper %p\n", error, *ap->a_vpp, |
| 594 | ((*ap->a_vpp) ? (*ap->a_vpp)->v_usecount : -99), |
| 595 | lowervp, uppervp)); |
| 596 | |
| 597 | /* |
| 598 | * dvp lock state, determine whether to relock dvp. dvp is expected |
| 599 | * to be locked on return if: |
| 600 | * |
| 601 | * - there was an error (except not EJUSTRETURN), or |
| 602 | * - we hit the last component and lockparent is true |
| 603 | * |
| 604 | * dvp_is_locked is the current state of the dvp lock, not counting |
| 605 | * the possibility that *ap->a_vpp == dvp (in which case it is locked |
| 606 | * anyway). Note that *ap->a_vpp == dvp only if no error occured. |
| 607 | */ |
| 608 | |
| 609 | if (*ap->a_vpp != dvp) { |
| 610 | if ((error == 0 || error == EJUSTRETURN) && !lockparent) { |
| 611 | vn_unlock(dvp); |
| 612 | } |
| 613 | } |
| 614 | |
| 615 | /* |
| 616 | * Diagnostics |
| 617 | */ |
| 618 | |
| 619 | #ifdef DIAGNOSTIC |
| 620 | if (cnp->cn_namelen == 1 && |
| 621 | cnp->cn_nameptr[0] == '.' && |
| 622 | *ap->a_vpp != dvp) { |
| 623 | panic("union_lookup returning . (%p) not same as startdir (%p)", ap->a_vpp, dvp); |
| 624 | } |
| 625 | #endif |
| 626 | |
| 627 | return (error); |
| 628 | } |
| 629 | |
| 630 | /* |
| 631 | * union_create: |
| 632 | * |
| 633 | * a_dvp is locked on entry and remains locked on return. a_vpp is returned |
| 634 | * locked if no error occurs, otherwise it is garbage. |
| 635 | * |
| 636 | * union_create(struct vnode *a_dvp, struct vnode **a_vpp, |
| 637 | * struct componentname *a_cnp, struct vattr *a_vap) |
| 638 | */ |
| 639 | static int |
| 640 | union_create(struct vop_old_create_args *ap) |
| 641 | { |
| 642 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 643 | struct componentname *cnp = ap->a_cnp; |
| 644 | struct thread *td = cnp->cn_td; |
| 645 | struct vnode *dvp; |
| 646 | int error = EROFS; |
| 647 | |
| 648 | if ((dvp = union_lock_upper(dun, td)) != NULL) { |
| 649 | struct vnode *vp; |
| 650 | struct mount *mp; |
| 651 | |
| 652 | error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap); |
| 653 | if (error == 0) { |
| 654 | mp = ap->a_dvp->v_mount; |
| 655 | vn_unlock(vp); |
| 656 | UDEBUG(("ALLOCVP-1 FROM %p REFS %d\n", vp, vp->v_usecount)); |
| 657 | error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, |
| 658 | cnp, vp, NULLVP, 1); |
| 659 | UDEBUG(("ALLOCVP-2B FROM %p REFS %d\n", *ap->a_vpp, vp->v_usecount)); |
| 660 | } |
| 661 | union_unlock_upper(dvp, td); |
| 662 | } |
| 663 | return (error); |
| 664 | } |
| 665 | |
| 666 | /* |
| 667 | * union_whiteout(struct vnode *a_dvp, struct componentname *a_cnp, |
| 668 | * int a_flags) |
| 669 | */ |
| 670 | static int |
| 671 | union_whiteout(struct vop_old_whiteout_args *ap) |
| 672 | { |
| 673 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 674 | struct componentname *cnp = ap->a_cnp; |
| 675 | struct vnode *uppervp; |
| 676 | int error = EOPNOTSUPP; |
| 677 | |
| 678 | if ((uppervp = union_lock_upper(un, cnp->cn_td)) != NULLVP) { |
| 679 | error = VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags); |
| 680 | union_unlock_upper(uppervp, cnp->cn_td); |
| 681 | } |
| 682 | return(error); |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | * union_mknod: |
| 687 | * |
| 688 | * a_dvp is locked on entry and should remain locked on return. |
| 689 | * a_vpp is garbagre whether an error occurs or not. |
| 690 | * |
| 691 | * union_mknod(struct vnode *a_dvp, struct vnode **a_vpp, |
| 692 | * struct componentname *a_cnp, struct vattr *a_vap) |
| 693 | */ |
| 694 | static int |
| 695 | union_mknod(struct vop_old_mknod_args *ap) |
| 696 | { |
| 697 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 698 | struct componentname *cnp = ap->a_cnp; |
| 699 | struct vnode *dvp; |
| 700 | int error = EROFS; |
| 701 | |
| 702 | if ((dvp = union_lock_upper(dun, cnp->cn_td)) != NULL) { |
| 703 | error = VOP_MKNOD(dvp, ap->a_vpp, cnp, ap->a_vap); |
| 704 | union_unlock_upper(dvp, cnp->cn_td); |
| 705 | } |
| 706 | return (error); |
| 707 | } |
| 708 | |
| 709 | /* |
| 710 | * union_open: |
| 711 | * |
| 712 | * run open VOP. When opening the underlying vnode we have to mimic |
| 713 | * vn_open. What we *really* need to do to avoid screwups if the |
| 714 | * open semantics change is to call vn_open(). For example, ufs blows |
| 715 | * up if you open a file but do not vmio it prior to writing. |
| 716 | * |
| 717 | * union_open(struct vnode *a_vp, int a_mode, |
| 718 | * struct ucred *a_cred, struct thread *a_td) |
| 719 | */ |
| 720 | static int |
| 721 | union_open(struct vop_open_args *ap) |
| 722 | { |
| 723 | struct union_node *un = VTOUNION(ap->a_vp); |
| 724 | struct vnode *tvp; |
| 725 | int mode = ap->a_mode; |
| 726 | struct ucred *cred = ap->a_cred; |
| 727 | struct thread *td = ap->a_td; |
| 728 | int error = 0; |
| 729 | int tvpisupper = 1; |
| 730 | |
| 731 | /* |
| 732 | * If there is an existing upper vp then simply open that. |
| 733 | * The upper vp takes precedence over the lower vp. When opening |
| 734 | * a lower vp for writing copy it to the uppervp and then open the |
| 735 | * uppervp. |
| 736 | * |
| 737 | * At the end of this section tvp will be left locked. |
| 738 | */ |
| 739 | if ((tvp = union_lock_upper(un, td)) == NULLVP) { |
| 740 | /* |
| 741 | * If the lower vnode is being opened for writing, then |
| 742 | * copy the file contents to the upper vnode and open that, |
| 743 | * otherwise can simply open the lower vnode. |
| 744 | */ |
| 745 | tvp = un->un_lowervp; |
| 746 | if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { |
| 747 | int docopy = !(mode & O_TRUNC); |
| 748 | error = union_copyup(un, docopy, cred, td); |
| 749 | tvp = union_lock_upper(un, td); |
| 750 | } else { |
| 751 | un->un_openl++; |
| 752 | vref(tvp); |
| 753 | vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); |
| 754 | tvpisupper = 0; |
| 755 | } |
| 756 | } |
| 757 | |
| 758 | /* |
| 759 | * We are holding the correct vnode, open it. Note |
| 760 | * that in DragonFly, VOP_OPEN is responsible for associating |
| 761 | * a VM object with the vnode if the vnode is mappable or the |
| 762 | * underlying filesystem uses buffer cache calls on it. |
| 763 | */ |
| 764 | if (error == 0) |
| 765 | error = VOP_OPEN(tvp, mode, cred, NULL); |
| 766 | |
| 767 | /* |
| 768 | * Release any locks held |
| 769 | */ |
| 770 | if (tvpisupper) { |
| 771 | if (tvp) |
| 772 | union_unlock_upper(tvp, td); |
| 773 | } else { |
| 774 | vput(tvp); |
| 775 | } |
| 776 | return (error); |
| 777 | } |
| 778 | |
| 779 | /* |
| 780 | * union_close: |
| 781 | * |
| 782 | * It is unclear whether a_vp is passed locked or unlocked. Whatever |
| 783 | * the case we do not change it. |
| 784 | * |
| 785 | * union_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred, |
| 786 | * struct thread *a_td) |
| 787 | */ |
| 788 | static int |
| 789 | union_close(struct vop_close_args *ap) |
| 790 | { |
| 791 | struct union_node *un = VTOUNION(ap->a_vp); |
| 792 | struct vnode *vp; |
| 793 | |
| 794 | if ((vp = un->un_uppervp) == NULLVP) { |
| 795 | #ifdef UNION_DIAGNOSTIC |
| 796 | if (un->un_openl <= 0) |
| 797 | panic("union: un_openl cnt"); |
| 798 | #endif |
| 799 | --un->un_openl; |
| 800 | vp = un->un_lowervp; |
| 801 | } |
| 802 | ap->a_head.a_ops = *vp->v_ops; |
| 803 | ap->a_vp = vp; |
| 804 | return(vop_close_ap(ap)); |
| 805 | } |
| 806 | |
| 807 | /* |
| 808 | * Check access permission on the union vnode. |
| 809 | * The access check being enforced is to check |
| 810 | * against both the underlying vnode, and any |
| 811 | * copied vnode. This ensures that no additional |
| 812 | * file permissions are given away simply because |
| 813 | * the user caused an implicit file copy. |
| 814 | * |
| 815 | * union_access(struct vnode *a_vp, int a_mode, |
| 816 | * struct ucred *a_cred, struct thread *a_td) |
| 817 | */ |
| 818 | static int |
| 819 | union_access(struct vop_access_args *ap) |
| 820 | { |
| 821 | struct union_node *un = VTOUNION(ap->a_vp); |
| 822 | struct thread *td = ap->a_td; |
| 823 | int error = EACCES; |
| 824 | struct vnode *vp; |
| 825 | |
| 826 | /* |
| 827 | * Disallow write attempts on filesystems mounted read-only. |
| 828 | */ |
| 829 | if ((ap->a_mode & VWRITE) && |
| 830 | (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)) { |
| 831 | switch (ap->a_vp->v_type) { |
| 832 | case VREG: |
| 833 | case VDIR: |
| 834 | case VLNK: |
| 835 | return (EROFS); |
| 836 | default: |
| 837 | break; |
| 838 | } |
| 839 | } |
| 840 | |
| 841 | if ((vp = union_lock_upper(un, td)) != NULLVP) { |
| 842 | ap->a_head.a_ops = *vp->v_ops; |
| 843 | ap->a_vp = vp; |
| 844 | error = vop_access_ap(ap); |
| 845 | union_unlock_upper(vp, td); |
| 846 | return(error); |
| 847 | } |
| 848 | |
| 849 | if ((vp = un->un_lowervp) != NULLVP) { |
| 850 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 851 | ap->a_head.a_ops = *vp->v_ops; |
| 852 | ap->a_vp = vp; |
| 853 | |
| 854 | /* |
| 855 | * Remove VWRITE from a_mode if our mount point is RW, because |
| 856 | * we want to allow writes and lowervp may be read-only. |
| 857 | */ |
| 858 | if ((un->un_vnode->v_mount->mnt_flag & MNT_RDONLY) == 0) |
| 859 | ap->a_mode &= ~VWRITE; |
| 860 | |
| 861 | error = vop_access_ap(ap); |
| 862 | if (error == 0) { |
| 863 | struct union_mount *um; |
| 864 | |
| 865 | um = MOUNTTOUNIONMOUNT(un->un_vnode->v_mount); |
| 866 | |
| 867 | if (um->um_op == UNMNT_BELOW) { |
| 868 | ap->a_cred = um->um_cred; |
| 869 | error = vop_access_ap(ap); |
| 870 | } |
| 871 | } |
| 872 | vn_unlock(vp); |
| 873 | } |
| 874 | return(error); |
| 875 | } |
| 876 | |
| 877 | /* |
| 878 | * We handle getattr only to change the fsid and |
| 879 | * track object sizes |
| 880 | * |
| 881 | * It's not clear whether VOP_GETATTR is to be |
| 882 | * called with the vnode locked or not. stat() calls |
| 883 | * it with (vp) locked, and fstat calls it with |
| 884 | * (vp) unlocked. |
| 885 | * |
| 886 | * Because of this we cannot use our normal locking functions |
| 887 | * if we do not intend to lock the main a_vp node. At the moment |
| 888 | * we are running without any specific locking at all, but beware |
| 889 | * to any programmer that care must be taken if locking is added |
| 890 | * to this function. |
| 891 | * |
| 892 | * union_getattr(struct vnode *a_vp, struct vattr *a_vap, |
| 893 | * struct ucred *a_cred, struct thread *a_td) |
| 894 | */ |
| 895 | static int |
| 896 | union_getattr(struct vop_getattr_args *ap) |
| 897 | { |
| 898 | int error; |
| 899 | struct union_node *un = VTOUNION(ap->a_vp); |
| 900 | struct vnode *vp; |
| 901 | struct vattr *vap; |
| 902 | struct vattr va; |
| 903 | |
| 904 | /* |
| 905 | * Some programs walk the filesystem hierarchy by counting |
| 906 | * links to directories to avoid stat'ing all the time. |
| 907 | * This means the link count on directories needs to be "correct". |
| 908 | * The only way to do that is to call getattr on both layers |
| 909 | * and fix up the link count. The link count will not necessarily |
| 910 | * be accurate but will be large enough to defeat the tree walkers. |
| 911 | */ |
| 912 | |
| 913 | vap = ap->a_vap; |
| 914 | |
| 915 | if ((vp = un->un_uppervp) != NULLVP) { |
| 916 | error = VOP_GETATTR(vp, vap); |
| 917 | if (error) |
| 918 | return (error); |
| 919 | /* XXX isn't this dangerouso without a lock? */ |
| 920 | union_newsize(ap->a_vp, vap->va_size, VNOVAL); |
| 921 | } |
| 922 | |
| 923 | if (vp == NULLVP) { |
| 924 | vp = un->un_lowervp; |
| 925 | } else if (vp->v_type == VDIR && un->un_lowervp != NULLVP) { |
| 926 | vp = un->un_lowervp; |
| 927 | vap = &va; |
| 928 | } else { |
| 929 | vp = NULLVP; |
| 930 | } |
| 931 | |
| 932 | if (vp != NULLVP) { |
| 933 | error = VOP_GETATTR(vp, vap); |
| 934 | if (error) |
| 935 | return (error); |
| 936 | /* XXX isn't this dangerous without a lock? */ |
| 937 | union_newsize(ap->a_vp, VNOVAL, vap->va_size); |
| 938 | } |
| 939 | |
| 940 | if ((vap != ap->a_vap) && (vap->va_type == VDIR)) |
| 941 | ap->a_vap->va_nlink += vap->va_nlink; |
| 942 | return (0); |
| 943 | } |
| 944 | |
| 945 | /* |
| 946 | * union_setattr(struct vnode *a_vp, struct vattr *a_vap, |
| 947 | * struct ucred *a_cred, struct thread *a_td) |
| 948 | */ |
| 949 | static int |
| 950 | union_setattr(struct vop_setattr_args *ap) |
| 951 | { |
| 952 | struct union_node *un = VTOUNION(ap->a_vp); |
| 953 | struct thread *td = ap->a_td; |
| 954 | struct vattr *vap = ap->a_vap; |
| 955 | struct vnode *uppervp; |
| 956 | int error; |
| 957 | |
| 958 | /* |
| 959 | * Disallow write attempts on filesystems mounted read-only. |
| 960 | */ |
| 961 | if ((ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) && |
| 962 | (vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL || |
| 963 | vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL || |
| 964 | vap->va_mtime.tv_sec != VNOVAL || |
| 965 | vap->va_mode != (mode_t)VNOVAL)) { |
| 966 | return (EROFS); |
| 967 | } |
| 968 | |
| 969 | /* |
| 970 | * Handle case of truncating lower object to zero size, |
| 971 | * by creating a zero length upper object. This is to |
| 972 | * handle the case of open with O_TRUNC and O_CREAT. |
| 973 | */ |
| 974 | if (un->un_uppervp == NULLVP && (un->un_lowervp->v_type == VREG)) { |
| 975 | error = union_copyup(un, (ap->a_vap->va_size != 0), |
| 976 | ap->a_cred, ap->a_td); |
| 977 | if (error) |
| 978 | return (error); |
| 979 | } |
| 980 | |
| 981 | /* |
| 982 | * Try to set attributes in upper layer, |
| 983 | * otherwise return read-only filesystem error. |
| 984 | */ |
| 985 | error = EROFS; |
| 986 | if ((uppervp = union_lock_upper(un, td)) != NULLVP) { |
| 987 | error = VOP_SETATTR(un->un_uppervp, ap->a_vap, ap->a_cred); |
| 988 | if ((error == 0) && (ap->a_vap->va_size != VNOVAL)) |
| 989 | union_newsize(ap->a_vp, ap->a_vap->va_size, VNOVAL); |
| 990 | union_unlock_upper(uppervp, td); |
| 991 | } |
| 992 | return (error); |
| 993 | } |
| 994 | |
| 995 | /* |
| 996 | * union_getpages: |
| 997 | */ |
| 998 | |
| 999 | static int |
| 1000 | union_getpages(struct vop_getpages_args *ap) |
| 1001 | { |
| 1002 | int r; |
| 1003 | |
| 1004 | r = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, |
| 1005 | ap->a_count, ap->a_reqpage); |
| 1006 | return(r); |
| 1007 | } |
| 1008 | |
| 1009 | /* |
| 1010 | * union_putpages: |
| 1011 | */ |
| 1012 | |
| 1013 | static int |
| 1014 | union_putpages(struct vop_putpages_args *ap) |
| 1015 | { |
| 1016 | int r; |
| 1017 | |
| 1018 | r = vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, |
| 1019 | ap->a_sync, ap->a_rtvals); |
| 1020 | return(r); |
| 1021 | } |
| 1022 | |
| 1023 | /* |
| 1024 | * union_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, |
| 1025 | * struct ucred *a_cred) |
| 1026 | */ |
| 1027 | static int |
| 1028 | union_read(struct vop_read_args *ap) |
| 1029 | { |
| 1030 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1031 | struct thread *td = ap->a_uio->uio_td; |
| 1032 | struct vnode *uvp; |
| 1033 | int error; |
| 1034 | |
| 1035 | uvp = union_lock_other(un, td); |
| 1036 | KASSERT(uvp != NULL, ("union_read: backing vnode missing!")); |
| 1037 | |
| 1038 | if (ap->a_vp->v_flag & VOBJBUF) |
| 1039 | union_vm_coherency(ap->a_vp, ap->a_uio, 0); |
| 1040 | |
| 1041 | error = VOP_READ(uvp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 1042 | union_unlock_other(uvp, td); |
| 1043 | |
| 1044 | /* |
| 1045 | * XXX |
| 1046 | * perhaps the size of the underlying object has changed under |
| 1047 | * our feet. take advantage of the offset information present |
| 1048 | * in the uio structure. |
| 1049 | */ |
| 1050 | if (error == 0) { |
| 1051 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1052 | off_t cur = ap->a_uio->uio_offset; |
| 1053 | |
| 1054 | if (uvp == un->un_uppervp) { |
| 1055 | if (cur > un->un_uppersz) |
| 1056 | union_newsize(ap->a_vp, cur, VNOVAL); |
| 1057 | } else { |
| 1058 | if (cur > un->un_lowersz) |
| 1059 | union_newsize(ap->a_vp, VNOVAL, cur); |
| 1060 | } |
| 1061 | } |
| 1062 | return (error); |
| 1063 | } |
| 1064 | |
| 1065 | /* |
| 1066 | * union_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, |
| 1067 | * struct ucred *a_cred) |
| 1068 | */ |
| 1069 | static int |
| 1070 | union_write(struct vop_read_args *ap) |
| 1071 | { |
| 1072 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1073 | struct thread *td = ap->a_uio->uio_td; |
| 1074 | struct vnode *uppervp; |
| 1075 | int error; |
| 1076 | |
| 1077 | if ((uppervp = union_lock_upper(un, td)) == NULLVP) |
| 1078 | panic("union: missing upper layer in write"); |
| 1079 | |
| 1080 | /* |
| 1081 | * Since our VM pages are associated with our vnode rather then |
| 1082 | * the real vnode, and since we do not run our reads and writes |
| 1083 | * through our own VM cache, we have a VM/VFS coherency problem. |
| 1084 | * We solve them by invalidating or flushing the associated VM |
| 1085 | * pages prior to allowing a normal read or write to occur. |
| 1086 | * |
| 1087 | * VM-backed writes (UIO_NOCOPY) have to be converted to normal |
| 1088 | * writes because we are not cache-coherent. Normal writes need |
| 1089 | * to be made coherent with our VM-backing store, which we do by |
| 1090 | * first flushing any dirty VM pages associated with the write |
| 1091 | * range, and then destroying any clean VM pages associated with |
| 1092 | * the write range. |
| 1093 | */ |
| 1094 | |
| 1095 | if (ap->a_uio->uio_segflg == UIO_NOCOPY) { |
| 1096 | ap->a_uio->uio_segflg = UIO_SYSSPACE; |
| 1097 | } else if (ap->a_vp->v_flag & VOBJBUF) { |
| 1098 | union_vm_coherency(ap->a_vp, ap->a_uio, 1); |
| 1099 | } |
| 1100 | |
| 1101 | error = VOP_WRITE(uppervp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 1102 | |
| 1103 | /* |
| 1104 | * the size of the underlying object may be changed by the |
| 1105 | * write. |
| 1106 | */ |
| 1107 | if (error == 0) { |
| 1108 | off_t cur = ap->a_uio->uio_offset; |
| 1109 | |
| 1110 | if (cur > un->un_uppersz) |
| 1111 | union_newsize(ap->a_vp, cur, VNOVAL); |
| 1112 | } |
| 1113 | union_unlock_upper(uppervp, td); |
| 1114 | return (error); |
| 1115 | } |
| 1116 | |
| 1117 | /* |
| 1118 | * union_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, |
| 1119 | * struct ucred *a_cred, struct thread *a_td) |
| 1120 | */ |
| 1121 | static int |
| 1122 | union_ioctl(struct vop_ioctl_args *ap) |
| 1123 | { |
| 1124 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1125 | |
| 1126 | ap->a_head.a_ops = *ovp->v_ops; |
| 1127 | ap->a_vp = ovp; |
| 1128 | return(vop_ioctl_ap(ap)); |
| 1129 | } |
| 1130 | |
| 1131 | /* |
| 1132 | * union_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred, |
| 1133 | * struct thread *a_td) |
| 1134 | */ |
| 1135 | static int |
| 1136 | union_poll(struct vop_poll_args *ap) |
| 1137 | { |
| 1138 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1139 | |
| 1140 | ap->a_head.a_ops = *ovp->v_ops; |
| 1141 | ap->a_vp = ovp; |
| 1142 | return(vop_poll_ap(ap)); |
| 1143 | } |
| 1144 | |
| 1145 | /* |
| 1146 | * union_revoke(struct vnode *a_vp, int a_flags, struct thread *a_td) |
| 1147 | */ |
| 1148 | static int |
| 1149 | union_revoke(struct vop_revoke_args *ap) |
| 1150 | { |
| 1151 | struct vnode *vp = ap->a_vp; |
| 1152 | struct vnode *vx; |
| 1153 | |
| 1154 | if ((vx = UPPERVP(vp)) != NULL) { |
| 1155 | vx_get(vx); |
| 1156 | VOP_REVOKE(vx, ap->a_flags); |
| 1157 | vx_put(vx); |
| 1158 | } |
| 1159 | if ((vx = LOWERVP(vp)) != NULL) { |
| 1160 | vx_get(vx); |
| 1161 | VOP_REVOKE(vx, ap->a_flags); |
| 1162 | vx_put(vx); |
| 1163 | } |
| 1164 | vgone(vp); |
| 1165 | return (0); |
| 1166 | } |
| 1167 | |
| 1168 | /* |
| 1169 | * union_mmap(struct vnode *a_vp, int a_fflags, struct ucred *a_cred, |
| 1170 | * struct thread *a_td) |
| 1171 | */ |
| 1172 | static int |
| 1173 | union_mmap(struct vop_mmap_args *ap) |
| 1174 | { |
| 1175 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1176 | |
| 1177 | ap->a_head.a_ops = *ovp->v_ops; |
| 1178 | ap->a_vp = ovp; |
| 1179 | return (vop_mmap_ap(ap)); |
| 1180 | } |
| 1181 | |
| 1182 | /* |
| 1183 | * union_fsync(struct vnode *a_vp, struct ucred *a_cred, int a_waitfor, |
| 1184 | * struct thread *a_td) |
| 1185 | */ |
| 1186 | static int |
| 1187 | union_fsync(struct vop_fsync_args *ap) |
| 1188 | { |
| 1189 | int error = 0; |
| 1190 | struct thread *td = ap->a_td; |
| 1191 | struct vnode *targetvp; |
| 1192 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1193 | |
| 1194 | if ((targetvp = union_lock_other(un, td)) != NULLVP) { |
| 1195 | error = VOP_FSYNC(targetvp, ap->a_waitfor); |
| 1196 | union_unlock_other(targetvp, td); |
| 1197 | } |
| 1198 | |
| 1199 | return (error); |
| 1200 | } |
| 1201 | |
| 1202 | /* |
| 1203 | * union_remove: |
| 1204 | * |
| 1205 | * Remove the specified cnp. The dvp and vp are passed to us locked |
| 1206 | * and must remain locked on return. |
| 1207 | * |
| 1208 | * union_remove(struct vnode *a_dvp, struct vnode *a_vp, |
| 1209 | * struct componentname *a_cnp) |
| 1210 | */ |
| 1211 | static int |
| 1212 | union_remove(struct vop_old_remove_args *ap) |
| 1213 | { |
| 1214 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1215 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1216 | struct componentname *cnp = ap->a_cnp; |
| 1217 | struct thread *td = cnp->cn_td; |
| 1218 | struct vnode *uppervp; |
| 1219 | struct vnode *upperdvp; |
| 1220 | int error; |
| 1221 | |
| 1222 | if ((upperdvp = union_lock_upper(dun, td)) == NULLVP) |
| 1223 | panic("union remove: null upper vnode"); |
| 1224 | |
| 1225 | if ((uppervp = union_lock_upper(un, td)) != NULLVP) { |
| 1226 | if (union_dowhiteout(un, cnp->cn_cred, td)) |
| 1227 | cnp->cn_flags |= CNP_DOWHITEOUT; |
| 1228 | error = VOP_REMOVE(upperdvp, uppervp, cnp); |
| 1229 | #if 0 |
| 1230 | /* XXX */ |
| 1231 | if (!error) |
| 1232 | union_removed_upper(un); |
| 1233 | #endif |
| 1234 | union_unlock_upper(uppervp, td); |
| 1235 | } else { |
| 1236 | error = union_mkwhiteout( |
| 1237 | MOUNTTOUNIONMOUNT(ap->a_dvp->v_mount), |
| 1238 | upperdvp, ap->a_cnp, un->un_path); |
| 1239 | } |
| 1240 | union_unlock_upper(upperdvp, td); |
| 1241 | return (error); |
| 1242 | } |
| 1243 | |
| 1244 | /* |
| 1245 | * union_link: |
| 1246 | * |
| 1247 | * tdvp will be locked on entry, vp will not be locked on entry. |
| 1248 | * tdvp should remain locked on return and vp should remain unlocked |
| 1249 | * on return. |
| 1250 | * |
| 1251 | * union_link(struct vnode *a_tdvp, struct vnode *a_vp, |
| 1252 | * struct componentname *a_cnp) |
| 1253 | */ |
| 1254 | static int |
| 1255 | union_link(struct vop_old_link_args *ap) |
| 1256 | { |
| 1257 | struct componentname *cnp = ap->a_cnp; |
| 1258 | struct thread *td = cnp->cn_td; |
| 1259 | struct union_node *dun = VTOUNION(ap->a_tdvp); |
| 1260 | struct vnode *vp; |
| 1261 | struct vnode *tdvp; |
| 1262 | int error = 0; |
| 1263 | |
| 1264 | if (ap->a_tdvp->v_ops != ap->a_vp->v_ops) { |
| 1265 | vp = ap->a_vp; |
| 1266 | } else { |
| 1267 | struct union_node *tun = VTOUNION(ap->a_vp); |
| 1268 | |
| 1269 | if (tun->un_uppervp == NULLVP) { |
| 1270 | vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); |
| 1271 | #if 0 |
| 1272 | if (dun->un_uppervp == tun->un_dirvp) { |
| 1273 | if (dun->un_flags & UN_ULOCK) { |
| 1274 | dun->un_flags &= ~UN_ULOCK; |
| 1275 | vn_unlock(dun->un_uppervp); |
| 1276 | } |
| 1277 | } |
| 1278 | #endif |
| 1279 | error = union_copyup(tun, 1, cnp->cn_cred, td); |
| 1280 | #if 0 |
| 1281 | if (dun->un_uppervp == tun->un_dirvp) { |
| 1282 | vn_lock(dun->un_uppervp, |
| 1283 | LK_EXCLUSIVE | LK_RETRY); |
| 1284 | dun->un_flags |= UN_ULOCK; |
| 1285 | } |
| 1286 | #endif |
| 1287 | vn_unlock(ap->a_vp); |
| 1288 | } |
| 1289 | vp = tun->un_uppervp; |
| 1290 | } |
| 1291 | |
| 1292 | if (error) |
| 1293 | return (error); |
| 1294 | |
| 1295 | /* |
| 1296 | * Make sure upper is locked, then unlock the union directory we were |
| 1297 | * called with to avoid a deadlock while we are calling VOP_LINK on |
| 1298 | * the upper (with tdvp locked and vp not locked). Our ap->a_tdvp |
| 1299 | * is expected to be locked on return. |
| 1300 | */ |
| 1301 | |
| 1302 | if ((tdvp = union_lock_upper(dun, td)) == NULLVP) |
| 1303 | return (EROFS); |
| 1304 | |
| 1305 | vn_unlock(ap->a_tdvp); /* unlock calling node */ |
| 1306 | error = VOP_LINK(tdvp, vp, cnp); /* call link on upper */ |
| 1307 | |
| 1308 | /* |
| 1309 | * We have to unlock tdvp prior to relocking our calling node in |
| 1310 | * order to avoid a deadlock. |
| 1311 | */ |
| 1312 | union_unlock_upper(tdvp, td); |
| 1313 | vn_lock(ap->a_tdvp, LK_EXCLUSIVE | LK_RETRY); |
| 1314 | return (error); |
| 1315 | } |
| 1316 | |
| 1317 | /* |
| 1318 | * union_rename(struct vnode *a_fdvp, struct vnode *a_fvp, |
| 1319 | * struct componentname *a_fcnp, struct vnode *a_tdvp, |
| 1320 | * struct vnode *a_tvp, struct componentname *a_tcnp) |
| 1321 | */ |
| 1322 | static int |
| 1323 | union_rename(struct vop_old_rename_args *ap) |
| 1324 | { |
| 1325 | int error; |
| 1326 | struct vnode *fdvp = ap->a_fdvp; |
| 1327 | struct vnode *fvp = ap->a_fvp; |
| 1328 | struct vnode *tdvp = ap->a_tdvp; |
| 1329 | struct vnode *tvp = ap->a_tvp; |
| 1330 | |
| 1331 | /* |
| 1332 | * Figure out what fdvp to pass to our upper or lower vnode. If we |
| 1333 | * replace the fdvp, release the original one and ref the new one. |
| 1334 | */ |
| 1335 | |
| 1336 | if (fdvp->v_tag == VT_UNION) { /* always true */ |
| 1337 | struct union_node *un = VTOUNION(fdvp); |
| 1338 | if (un->un_uppervp == NULLVP) { |
| 1339 | /* |
| 1340 | * this should never happen in normal |
| 1341 | * operation but might if there was |
| 1342 | * a problem creating the top-level shadow |
| 1343 | * directory. |
| 1344 | */ |
| 1345 | error = EXDEV; |
| 1346 | goto bad; |
| 1347 | } |
| 1348 | fdvp = un->un_uppervp; |
| 1349 | vref(fdvp); |
| 1350 | vrele(ap->a_fdvp); |
| 1351 | } |
| 1352 | |
| 1353 | /* |
| 1354 | * Figure out what fvp to pass to our upper or lower vnode. If we |
| 1355 | * replace the fvp, release the original one and ref the new one. |
| 1356 | */ |
| 1357 | |
| 1358 | if (fvp->v_tag == VT_UNION) { /* always true */ |
| 1359 | struct union_node *un = VTOUNION(fvp); |
| 1360 | #if 0 |
| 1361 | struct union_mount *um = MOUNTTOUNIONMOUNT(fvp->v_mount); |
| 1362 | #endif |
| 1363 | |
| 1364 | if (un->un_uppervp == NULLVP) { |
| 1365 | switch(fvp->v_type) { |
| 1366 | case VREG: |
| 1367 | vn_lock(un->un_vnode, LK_EXCLUSIVE | LK_RETRY); |
| 1368 | error = union_copyup(un, 1, ap->a_fcnp->cn_cred, ap->a_fcnp->cn_td); |
| 1369 | vn_unlock(un->un_vnode); |
| 1370 | if (error) |
| 1371 | goto bad; |
| 1372 | break; |
| 1373 | case VDIR: |
| 1374 | /* |
| 1375 | * XXX not yet. |
| 1376 | * |
| 1377 | * There is only one way to rename a directory |
| 1378 | * based in the lowervp, and that is to copy |
| 1379 | * the entire directory hierarchy. Otherwise |
| 1380 | * it would not last across a reboot. |
| 1381 | */ |
| 1382 | #if 0 |
| 1383 | vrele(fvp); |
| 1384 | fvp = NULL; |
| 1385 | vn_lock(fdvp, LK_EXCLUSIVE | LK_RETRY); |
| 1386 | error = union_mkshadow(um, fdvp, |
| 1387 | ap->a_fcnp, &un->un_uppervp); |
| 1388 | vn_unlock(fdvp); |
| 1389 | if (un->un_uppervp) |
| 1390 | vn_unlock(un->un_uppervp); |
| 1391 | if (error) |
| 1392 | goto bad; |
| 1393 | break; |
| 1394 | #endif |
| 1395 | default: |
| 1396 | error = EXDEV; |
| 1397 | goto bad; |
| 1398 | } |
| 1399 | } |
| 1400 | |
| 1401 | if (un->un_lowervp != NULLVP) |
| 1402 | ap->a_fcnp->cn_flags |= CNP_DOWHITEOUT; |
| 1403 | fvp = un->un_uppervp; |
| 1404 | vref(fvp); |
| 1405 | vrele(ap->a_fvp); |
| 1406 | } |
| 1407 | |
| 1408 | /* |
| 1409 | * Figure out what tdvp (destination directory) to pass to the |
| 1410 | * lower level. If we replace it with uppervp, we need to vput the |
| 1411 | * old one. The exclusive lock is transfered to what we will pass |
| 1412 | * down in the VOP_RENAME and we replace uppervp with a simple |
| 1413 | * reference. |
| 1414 | */ |
| 1415 | |
| 1416 | if (tdvp->v_tag == VT_UNION) { |
| 1417 | struct union_node *un = VTOUNION(tdvp); |
| 1418 | |
| 1419 | if (un->un_uppervp == NULLVP) { |
| 1420 | /* |
| 1421 | * this should never happen in normal |
| 1422 | * operation but might if there was |
| 1423 | * a problem creating the top-level shadow |
| 1424 | * directory. |
| 1425 | */ |
| 1426 | error = EXDEV; |
| 1427 | goto bad; |
| 1428 | } |
| 1429 | |
| 1430 | /* |
| 1431 | * new tdvp is a lock and reference on uppervp, put away |
| 1432 | * the old tdvp. |
| 1433 | */ |
| 1434 | tdvp = union_lock_upper(un, ap->a_tcnp->cn_td); |
| 1435 | vput(ap->a_tdvp); |
| 1436 | } |
| 1437 | |
| 1438 | /* |
| 1439 | * Figure out what tvp (destination file) to pass to the |
| 1440 | * lower level. |
| 1441 | * |
| 1442 | * If the uppervp file does not exist put away the (wrong) |
| 1443 | * file and change tvp to NULL. |
| 1444 | */ |
| 1445 | |
| 1446 | if (tvp != NULLVP && tvp->v_tag == VT_UNION) { |
| 1447 | struct union_node *un = VTOUNION(tvp); |
| 1448 | |
| 1449 | tvp = union_lock_upper(un, ap->a_tcnp->cn_td); |
| 1450 | vput(ap->a_tvp); |
| 1451 | /* note: tvp may be NULL */ |
| 1452 | } |
| 1453 | |
| 1454 | /* |
| 1455 | * VOP_RENAME releases/vputs prior to returning, so we have no |
| 1456 | * cleanup to do. |
| 1457 | */ |
| 1458 | |
| 1459 | return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp)); |
| 1460 | |
| 1461 | /* |
| 1462 | * Error. We still have to release / vput the various elements. |
| 1463 | */ |
| 1464 | |
| 1465 | bad: |
| 1466 | vrele(fdvp); |
| 1467 | if (fvp) |
| 1468 | vrele(fvp); |
| 1469 | vput(tdvp); |
| 1470 | if (tvp != NULLVP) { |
| 1471 | if (tvp != tdvp) |
| 1472 | vput(tvp); |
| 1473 | else |
| 1474 | vrele(tvp); |
| 1475 | } |
| 1476 | return (error); |
| 1477 | } |
| 1478 | |
| 1479 | /* |
| 1480 | * union_mkdir(struct vnode *a_dvp, struct vnode **a_vpp, |
| 1481 | * struct componentname *a_cnp, struct vattr *a_vap) |
| 1482 | */ |
| 1483 | static int |
| 1484 | union_mkdir(struct vop_old_mkdir_args *ap) |
| 1485 | { |
| 1486 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1487 | struct componentname *cnp = ap->a_cnp; |
| 1488 | struct thread *td = cnp->cn_td; |
| 1489 | struct vnode *upperdvp; |
| 1490 | int error = EROFS; |
| 1491 | |
| 1492 | if ((upperdvp = union_lock_upper(dun, td)) != NULLVP) { |
| 1493 | struct vnode *vp; |
| 1494 | |
| 1495 | error = VOP_MKDIR(upperdvp, &vp, cnp, ap->a_vap); |
| 1496 | union_unlock_upper(upperdvp, td); |
| 1497 | |
| 1498 | if (error == 0) { |
| 1499 | vn_unlock(vp); |
| 1500 | UDEBUG(("ALLOCVP-2 FROM %p REFS %d\n", vp, vp->v_usecount)); |
| 1501 | error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, |
| 1502 | ap->a_dvp, NULLVP, cnp, vp, NULLVP, 1); |
| 1503 | UDEBUG(("ALLOCVP-2B FROM %p REFS %d\n", *ap->a_vpp, vp->v_usecount)); |
| 1504 | } |
| 1505 | } |
| 1506 | return (error); |
| 1507 | } |
| 1508 | |
| 1509 | /* |
| 1510 | * union_rmdir(struct vnode *a_dvp, struct vnode *a_vp, |
| 1511 | * struct componentname *a_cnp) |
| 1512 | */ |
| 1513 | static int |
| 1514 | union_rmdir(struct vop_old_rmdir_args *ap) |
| 1515 | { |
| 1516 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1517 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1518 | struct componentname *cnp = ap->a_cnp; |
| 1519 | struct thread *td = cnp->cn_td; |
| 1520 | struct vnode *upperdvp; |
| 1521 | struct vnode *uppervp; |
| 1522 | int error; |
| 1523 | |
| 1524 | if ((upperdvp = union_lock_upper(dun, td)) == NULLVP) |
| 1525 | panic("union rmdir: null upper vnode"); |
| 1526 | |
| 1527 | if ((uppervp = union_lock_upper(un, td)) != NULLVP) { |
| 1528 | if (union_dowhiteout(un, cnp->cn_cred, td)) |
| 1529 | cnp->cn_flags |= CNP_DOWHITEOUT; |
| 1530 | error = VOP_RMDIR(upperdvp, uppervp, ap->a_cnp); |
| 1531 | union_unlock_upper(uppervp, td); |
| 1532 | } else { |
| 1533 | error = union_mkwhiteout( |
| 1534 | MOUNTTOUNIONMOUNT(ap->a_dvp->v_mount), |
| 1535 | dun->un_uppervp, ap->a_cnp, un->un_path); |
| 1536 | } |
| 1537 | union_unlock_upper(upperdvp, td); |
| 1538 | return (error); |
| 1539 | } |
| 1540 | |
| 1541 | /* |
| 1542 | * union_symlink: |
| 1543 | * |
| 1544 | * dvp is locked on entry and remains locked on return. a_vpp is garbage |
| 1545 | * (unused). |
| 1546 | * |
| 1547 | * union_symlink(struct vnode *a_dvp, struct vnode **a_vpp, |
| 1548 | * struct componentname *a_cnp, struct vattr *a_vap, |
| 1549 | * char *a_target) |
| 1550 | */ |
| 1551 | static int |
| 1552 | union_symlink(struct vop_old_symlink_args *ap) |
| 1553 | { |
| 1554 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1555 | struct componentname *cnp = ap->a_cnp; |
| 1556 | struct thread *td = cnp->cn_td; |
| 1557 | struct vnode *dvp; |
| 1558 | int error = EROFS; |
| 1559 | |
| 1560 | if ((dvp = union_lock_upper(dun, td)) != NULLVP) { |
| 1561 | error = VOP_SYMLINK(dvp, ap->a_vpp, cnp, ap->a_vap, |
| 1562 | ap->a_target); |
| 1563 | union_unlock_upper(dvp, td); |
| 1564 | } |
| 1565 | return (error); |
| 1566 | } |
| 1567 | |
| 1568 | /* |
| 1569 | * union_readdir works in concert with getdirentries and |
| 1570 | * readdir(3) to provide a list of entries in the unioned |
| 1571 | * directories. getdirentries is responsible for walking |
| 1572 | * down the union stack. readdir(3) is responsible for |
| 1573 | * eliminating duplicate names from the returned data stream. |
| 1574 | * |
| 1575 | * union_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, |
| 1576 | * int *a_eofflag, u_long *a_cookies, int a_ncookies) |
| 1577 | */ |
| 1578 | static int |
| 1579 | union_readdir(struct vop_readdir_args *ap) |
| 1580 | { |
| 1581 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1582 | struct thread *td = ap->a_uio->uio_td; |
| 1583 | struct vnode *uvp; |
| 1584 | int error = 0; |
| 1585 | |
| 1586 | if ((uvp = union_ref_upper(un)) != NULLVP) { |
| 1587 | ap->a_head.a_ops = *uvp->v_ops; |
| 1588 | ap->a_vp = uvp; |
| 1589 | error = vop_readdir_ap(ap); |
| 1590 | vrele(uvp); |
| 1591 | } |
| 1592 | return(error); |
| 1593 | } |
| 1594 | |
| 1595 | /* |
| 1596 | * union_readlink(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred) |
| 1597 | */ |
| 1598 | static int |
| 1599 | union_readlink(struct vop_readlink_args *ap) |
| 1600 | { |
| 1601 | int error; |
| 1602 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1603 | struct uio *uio = ap->a_uio; |
| 1604 | struct thread *td = uio->uio_td; |
| 1605 | struct vnode *vp; |
| 1606 | |
| 1607 | vp = union_lock_other(un, td); |
| 1608 | KASSERT(vp != NULL, ("union_readlink: backing vnode missing!")); |
| 1609 | |
| 1610 | ap->a_head.a_ops = *vp->v_ops; |
| 1611 | ap->a_vp = vp; |
| 1612 | error = vop_readlink_ap(ap); |
| 1613 | union_unlock_other(vp, td); |
| 1614 | |
| 1615 | return (error); |
| 1616 | } |
| 1617 | |
| 1618 | /* |
| 1619 | * union_inactive: |
| 1620 | * |
| 1621 | * Called with the vnode locked. We are expected to unlock the vnode. |
| 1622 | * |
| 1623 | * union_inactive(struct vnode *a_vp, struct thread *a_td) |
| 1624 | */ |
| 1625 | static int |
| 1626 | union_inactive(struct vop_inactive_args *ap) |
| 1627 | { |
| 1628 | struct vnode *vp = ap->a_vp; |
| 1629 | /*struct thread *td = ap->a_td;*/ |
| 1630 | struct union_node *un = VTOUNION(vp); |
| 1631 | struct vnode **vpp; |
| 1632 | |
| 1633 | /* |
| 1634 | * Do nothing (and _don't_ bypass). |
| 1635 | * Wait to vrele lowervp until reclaim, |
| 1636 | * so that until then our union_node is in the |
| 1637 | * cache and reusable. |
| 1638 | * |
| 1639 | * NEEDSWORK: Someday, consider inactive'ing |
| 1640 | * the lowervp and then trying to reactivate it |
| 1641 | * with capabilities (v_id) |
| 1642 | * like they do in the name lookup cache code. |
| 1643 | * That's too much work for now. |
| 1644 | */ |
| 1645 | |
| 1646 | if (un->un_dircache != 0) { |
| 1647 | for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) |
| 1648 | vrele(*vpp); |
| 1649 | kfree (un->un_dircache, M_TEMP); |
| 1650 | un->un_dircache = 0; |
| 1651 | } |
| 1652 | |
| 1653 | #if 0 |
| 1654 | if ((un->un_flags & UN_ULOCK) && un->un_uppervp) { |
| 1655 | un->un_flags &= ~UN_ULOCK; |
| 1656 | vn_unlock(un->un_uppervp); |
| 1657 | } |
| 1658 | #endif |
| 1659 | |
| 1660 | if ((un->un_flags & UN_CACHED) == 0) |
| 1661 | vgone(vp); |
| 1662 | |
| 1663 | return (0); |
| 1664 | } |
| 1665 | |
| 1666 | /* |
| 1667 | * union_reclaim(struct vnode *a_vp) |
| 1668 | */ |
| 1669 | static int |
| 1670 | union_reclaim(struct vop_reclaim_args *ap) |
| 1671 | { |
| 1672 | union_freevp(ap->a_vp); |
| 1673 | |
| 1674 | return (0); |
| 1675 | } |
| 1676 | |
| 1677 | /* |
| 1678 | * union_bmap: |
| 1679 | * |
| 1680 | * There isn't much we can do. We cannot push through to the real vnode |
| 1681 | * to get to the underlying device because this will bypass data |
| 1682 | * cached by the real vnode. |
| 1683 | * |
| 1684 | * For some reason we cannot return the 'real' vnode either, it seems |
| 1685 | * to blow up memory maps. |
| 1686 | * |
| 1687 | * union_bmap(struct vnode *a_vp, off_t a_loffset, struct vnode **a_vpp, |
| 1688 | * off_t *a_doffsetp, int *a_runp, int *a_runb) |
| 1689 | */ |
| 1690 | static int |
| 1691 | union_bmap(struct vop_bmap_args *ap) |
| 1692 | { |
| 1693 | return(EOPNOTSUPP); |
| 1694 | } |
| 1695 | |
| 1696 | /* |
| 1697 | * union_print(struct vnode *a_vp) |
| 1698 | */ |
| 1699 | static int |
| 1700 | union_print(struct vop_print_args *ap) |
| 1701 | { |
| 1702 | struct vnode *vp = ap->a_vp; |
| 1703 | |
| 1704 | kprintf("\ttag VT_UNION, vp=%p, uppervp=%p, lowervp=%p\n", |
| 1705 | vp, UPPERVP(vp), LOWERVP(vp)); |
| 1706 | if (UPPERVP(vp) != NULLVP) |
| 1707 | vprint("union: upper", UPPERVP(vp)); |
| 1708 | if (LOWERVP(vp) != NULLVP) |
| 1709 | vprint("union: lower", LOWERVP(vp)); |
| 1710 | |
| 1711 | return (0); |
| 1712 | } |
| 1713 | |
| 1714 | /* |
| 1715 | * union_pathconf(struct vnode *a_vp, int a_name, int *a_retval) |
| 1716 | */ |
| 1717 | static int |
| 1718 | union_pathconf(struct vop_pathconf_args *ap) |
| 1719 | { |
| 1720 | int error; |
| 1721 | struct thread *td = curthread; /* XXX */ |
| 1722 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1723 | struct vnode *vp; |
| 1724 | |
| 1725 | vp = union_lock_other(un, td); |
| 1726 | KASSERT(vp != NULL, ("union_pathconf: backing vnode missing!")); |
| 1727 | |
| 1728 | ap->a_head.a_ops = *vp->v_ops; |
| 1729 | ap->a_vp = vp; |
| 1730 | error = vop_pathconf_ap(ap); |
| 1731 | union_unlock_other(vp, td); |
| 1732 | |
| 1733 | return (error); |
| 1734 | } |
| 1735 | |
| 1736 | /* |
| 1737 | * union_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, |
| 1738 | * struct flock *a_fl, int a_flags) |
| 1739 | */ |
| 1740 | static int |
| 1741 | union_advlock(struct vop_advlock_args *ap) |
| 1742 | { |
| 1743 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1744 | |
| 1745 | ap->a_head.a_ops = *ovp->v_ops; |
| 1746 | ap->a_vp = ovp; |
| 1747 | return (vop_advlock_ap(ap)); |
| 1748 | } |
| 1749 | |
| 1750 | |
| 1751 | /* |
| 1752 | * XXX - vop_strategy must be hand coded because it has no |
| 1753 | * YYY - and it is not coherent with anything |
| 1754 | * |
| 1755 | * vnode in its arguments. |
| 1756 | * This goes away with a merged VM/buffer cache. |
| 1757 | * |
| 1758 | * union_strategy(struct vnode *a_vp, struct bio *a_bio) |
| 1759 | */ |
| 1760 | static int |
| 1761 | union_strategy(struct vop_strategy_args *ap) |
| 1762 | { |
| 1763 | struct bio *bio = ap->a_bio; |
| 1764 | struct buf *bp = bio->bio_buf; |
| 1765 | struct vnode *othervp = OTHERVP(ap->a_vp); |
| 1766 | |
| 1767 | #ifdef DIAGNOSTIC |
| 1768 | if (othervp == NULLVP) |
| 1769 | panic("union_strategy: nil vp"); |
| 1770 | if (bp->b_cmd != BUF_CMD_READ && (othervp == LOWERVP(ap->a_vp))) |
| 1771 | panic("union_strategy: writing to lowervp"); |
| 1772 | #endif |
| 1773 | return (vn_strategy(othervp, bio)); |
| 1774 | } |
| 1775 | |
| 1776 | /* |
| 1777 | * Global vfs data structures |
| 1778 | */ |
| 1779 | struct vop_ops union_vnode_vops = { |
| 1780 | .vop_default = vop_defaultop, |
| 1781 | .vop_access = union_access, |
| 1782 | .vop_advlock = union_advlock, |
| 1783 | .vop_bmap = union_bmap, |
| 1784 | .vop_close = union_close, |
| 1785 | .vop_old_create = union_create, |
| 1786 | .vop_fsync = union_fsync, |
| 1787 | .vop_getpages = union_getpages, |
| 1788 | .vop_putpages = union_putpages, |
| 1789 | .vop_getattr = union_getattr, |
| 1790 | .vop_inactive = union_inactive, |
| 1791 | .vop_ioctl = union_ioctl, |
| 1792 | .vop_old_link = union_link, |
| 1793 | .vop_old_lookup = union_lookup, |
| 1794 | .vop_old_mkdir = union_mkdir, |
| 1795 | .vop_old_mknod = union_mknod, |
| 1796 | .vop_mmap = union_mmap, |
| 1797 | .vop_open = union_open, |
| 1798 | .vop_pathconf = union_pathconf, |
| 1799 | .vop_poll = union_poll, |
| 1800 | .vop_print = union_print, |
| 1801 | .vop_read = union_read, |
| 1802 | .vop_readdir = union_readdir, |
| 1803 | .vop_readlink = union_readlink, |
| 1804 | .vop_reclaim = union_reclaim, |
| 1805 | .vop_old_remove = union_remove, |
| 1806 | .vop_old_rename = union_rename, |
| 1807 | .vop_revoke = union_revoke, |
| 1808 | .vop_old_rmdir = union_rmdir, |
| 1809 | .vop_setattr = union_setattr, |
| 1810 | .vop_strategy = union_strategy, |
| 1811 | .vop_old_symlink = union_symlink, |
| 1812 | .vop_old_whiteout = union_whiteout, |
| 1813 | .vop_write = union_write |
| 1814 | }; |
| 1815 | |