| 1 | /* $NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1992, 1993, 1994, 1995 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to Berkeley by |
| 8 | * Jan-Simon Pendry. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * 3. Neither the name of the University nor the names of its contributors |
| 19 | * may be used to endorse or promote products derived from this software |
| 20 | * without specific prior written permission. |
| 21 | * |
| 22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | * |
| 34 | * @(#)union_vnops.c 8.33 (Berkeley) 7/31/95 |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * Copyright (c) 1992, 1993, 1994, 1995 Jan-Simon Pendry. |
| 39 | * |
| 40 | * This code is derived from software contributed to Berkeley by |
| 41 | * Jan-Simon Pendry. |
| 42 | * |
| 43 | * Redistribution and use in source and binary forms, with or without |
| 44 | * modification, are permitted provided that the following conditions |
| 45 | * are met: |
| 46 | * 1. Redistributions of source code must retain the above copyright |
| 47 | * notice, this list of conditions and the following disclaimer. |
| 48 | * 2. Redistributions in binary form must reproduce the above copyright |
| 49 | * notice, this list of conditions and the following disclaimer in the |
| 50 | * documentation and/or other materials provided with the distribution. |
| 51 | * 3. All advertising materials mentioning features or use of this software |
| 52 | * must display the following acknowledgement: |
| 53 | * This product includes software developed by the University of |
| 54 | * California, Berkeley and its contributors. |
| 55 | * 4. Neither the name of the University nor the names of its contributors |
| 56 | * may be used to endorse or promote products derived from this software |
| 57 | * without specific prior written permission. |
| 58 | * |
| 59 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 60 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 61 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 62 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 63 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 64 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 65 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 66 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 67 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 68 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 69 | * SUCH DAMAGE. |
| 70 | * |
| 71 | * @(#)union_vnops.c 8.33 (Berkeley) 7/31/95 |
| 72 | */ |
| 73 | |
| 74 | #include <sys/cdefs.h> |
| 75 | __KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $" ); |
| 76 | |
| 77 | #include <sys/param.h> |
| 78 | #include <sys/systm.h> |
| 79 | #include <sys/proc.h> |
| 80 | #include <sys/file.h> |
| 81 | #include <sys/time.h> |
| 82 | #include <sys/stat.h> |
| 83 | #include <sys/vnode.h> |
| 84 | #include <sys/mount.h> |
| 85 | #include <sys/namei.h> |
| 86 | #include <sys/malloc.h> |
| 87 | #include <sys/buf.h> |
| 88 | #include <sys/queue.h> |
| 89 | #include <sys/lock.h> |
| 90 | #include <sys/kauth.h> |
| 91 | |
| 92 | #include <fs/union/union.h> |
| 93 | #include <miscfs/genfs/genfs.h> |
| 94 | #include <miscfs/specfs/specdev.h> |
| 95 | |
| 96 | int union_lookup(void *); |
| 97 | int union_create(void *); |
| 98 | int union_whiteout(void *); |
| 99 | int union_mknod(void *); |
| 100 | int union_open(void *); |
| 101 | int union_close(void *); |
| 102 | int union_access(void *); |
| 103 | int union_getattr(void *); |
| 104 | int union_setattr(void *); |
| 105 | int union_read(void *); |
| 106 | int union_write(void *); |
| 107 | int union_ioctl(void *); |
| 108 | int union_poll(void *); |
| 109 | int union_revoke(void *); |
| 110 | int union_mmap(void *); |
| 111 | int union_fsync(void *); |
| 112 | int union_seek(void *); |
| 113 | int union_remove(void *); |
| 114 | int union_link(void *); |
| 115 | int union_rename(void *); |
| 116 | int union_mkdir(void *); |
| 117 | int union_rmdir(void *); |
| 118 | int union_symlink(void *); |
| 119 | int union_readdir(void *); |
| 120 | int union_readlink(void *); |
| 121 | int union_abortop(void *); |
| 122 | int union_inactive(void *); |
| 123 | int union_reclaim(void *); |
| 124 | int union_lock(void *); |
| 125 | int union_unlock(void *); |
| 126 | int union_bmap(void *); |
| 127 | int union_print(void *); |
| 128 | int union_islocked(void *); |
| 129 | int union_pathconf(void *); |
| 130 | int union_advlock(void *); |
| 131 | int union_strategy(void *); |
| 132 | int union_bwrite(void *); |
| 133 | int union_getpages(void *); |
| 134 | int union_putpages(void *); |
| 135 | int union_kqfilter(void *); |
| 136 | |
| 137 | static int union_lookup1(struct vnode *, struct vnode **, |
| 138 | struct vnode **, struct componentname *); |
| 139 | |
| 140 | |
| 141 | /* |
| 142 | * Global vfs data structures |
| 143 | */ |
| 144 | int (**union_vnodeop_p)(void *); |
| 145 | const struct vnodeopv_entry_desc union_vnodeop_entries[] = { |
| 146 | { &vop_default_desc, vn_default_error }, |
| 147 | { &vop_lookup_desc, union_lookup }, /* lookup */ |
| 148 | { &vop_create_desc, union_create }, /* create */ |
| 149 | { &vop_whiteout_desc, union_whiteout }, /* whiteout */ |
| 150 | { &vop_mknod_desc, union_mknod }, /* mknod */ |
| 151 | { &vop_open_desc, union_open }, /* open */ |
| 152 | { &vop_close_desc, union_close }, /* close */ |
| 153 | { &vop_access_desc, union_access }, /* access */ |
| 154 | { &vop_getattr_desc, union_getattr }, /* getattr */ |
| 155 | { &vop_setattr_desc, union_setattr }, /* setattr */ |
| 156 | { &vop_read_desc, union_read }, /* read */ |
| 157 | { &vop_write_desc, union_write }, /* write */ |
| 158 | { &vop_fallocate_desc, genfs_eopnotsupp }, /* fallocate */ |
| 159 | { &vop_fdiscard_desc, genfs_eopnotsupp }, /* fdiscard */ |
| 160 | { &vop_ioctl_desc, union_ioctl }, /* ioctl */ |
| 161 | { &vop_poll_desc, union_poll }, /* select */ |
| 162 | { &vop_revoke_desc, union_revoke }, /* revoke */ |
| 163 | { &vop_mmap_desc, union_mmap }, /* mmap */ |
| 164 | { &vop_fsync_desc, union_fsync }, /* fsync */ |
| 165 | { &vop_seek_desc, union_seek }, /* seek */ |
| 166 | { &vop_remove_desc, union_remove }, /* remove */ |
| 167 | { &vop_link_desc, union_link }, /* link */ |
| 168 | { &vop_rename_desc, union_rename }, /* rename */ |
| 169 | { &vop_mkdir_desc, union_mkdir }, /* mkdir */ |
| 170 | { &vop_rmdir_desc, union_rmdir }, /* rmdir */ |
| 171 | { &vop_symlink_desc, union_symlink }, /* symlink */ |
| 172 | { &vop_readdir_desc, union_readdir }, /* readdir */ |
| 173 | { &vop_readlink_desc, union_readlink }, /* readlink */ |
| 174 | { &vop_abortop_desc, union_abortop }, /* abortop */ |
| 175 | { &vop_inactive_desc, union_inactive }, /* inactive */ |
| 176 | { &vop_reclaim_desc, union_reclaim }, /* reclaim */ |
| 177 | { &vop_lock_desc, union_lock }, /* lock */ |
| 178 | { &vop_unlock_desc, union_unlock }, /* unlock */ |
| 179 | { &vop_bmap_desc, union_bmap }, /* bmap */ |
| 180 | { &vop_strategy_desc, union_strategy }, /* strategy */ |
| 181 | { &vop_bwrite_desc, union_bwrite }, /* bwrite */ |
| 182 | { &vop_print_desc, union_print }, /* print */ |
| 183 | { &vop_islocked_desc, union_islocked }, /* islocked */ |
| 184 | { &vop_pathconf_desc, union_pathconf }, /* pathconf */ |
| 185 | { &vop_advlock_desc, union_advlock }, /* advlock */ |
| 186 | { &vop_getpages_desc, union_getpages }, /* getpages */ |
| 187 | { &vop_putpages_desc, union_putpages }, /* putpages */ |
| 188 | { &vop_kqfilter_desc, union_kqfilter }, /* kqfilter */ |
| 189 | { NULL, NULL } |
| 190 | }; |
| 191 | const struct vnodeopv_desc union_vnodeop_opv_desc = |
| 192 | { &union_vnodeop_p, union_vnodeop_entries }; |
| 193 | |
| 194 | #define NODE_IS_SPECIAL(vp) \ |
| 195 | ((vp)->v_type == VBLK || (vp)->v_type == VCHR || \ |
| 196 | (vp)->v_type == VSOCK || (vp)->v_type == VFIFO) |
| 197 | |
| 198 | static int |
| 199 | union_lookup1(struct vnode *udvp, struct vnode **dvpp, struct vnode **vpp, |
| 200 | struct componentname *cnp) |
| 201 | { |
| 202 | int error; |
| 203 | struct vnode *tdvp; |
| 204 | struct vnode *dvp; |
| 205 | struct mount *mp; |
| 206 | |
| 207 | dvp = *dvpp; |
| 208 | |
| 209 | /* |
| 210 | * If stepping up the directory tree, check for going |
| 211 | * back across the mount point, in which case do what |
| 212 | * lookup would do by stepping back down the mount |
| 213 | * hierarchy. |
| 214 | */ |
| 215 | if (cnp->cn_flags & ISDOTDOT) { |
| 216 | while ((dvp != udvp) && (dvp->v_vflag & VV_ROOT)) { |
| 217 | /* |
| 218 | * Don't do the NOCROSSMOUNT check |
| 219 | * at this level. By definition, |
| 220 | * union fs deals with namespaces, not |
| 221 | * filesystems. |
| 222 | */ |
| 223 | tdvp = dvp; |
| 224 | *dvpp = dvp = dvp->v_mount->mnt_vnodecovered; |
| 225 | VOP_UNLOCK(tdvp); |
| 226 | vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | error = VOP_LOOKUP(dvp, &tdvp, cnp); |
| 231 | if (error) |
| 232 | return (error); |
| 233 | if (dvp != tdvp) { |
| 234 | if (cnp->cn_flags & ISDOTDOT) |
| 235 | VOP_UNLOCK(dvp); |
| 236 | error = vn_lock(tdvp, LK_EXCLUSIVE); |
| 237 | if (cnp->cn_flags & ISDOTDOT) |
| 238 | vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); |
| 239 | if (error) { |
| 240 | vrele(tdvp); |
| 241 | return error; |
| 242 | } |
| 243 | dvp = tdvp; |
| 244 | } |
| 245 | |
| 246 | /* |
| 247 | * Lastly check if the current node is a mount point in |
| 248 | * which case walk up the mount hierarchy making sure not to |
| 249 | * bump into the root of the mount tree (ie. dvp != udvp). |
| 250 | */ |
| 251 | while (dvp != udvp && (dvp->v_type == VDIR) && |
| 252 | (mp = dvp->v_mountedhere)) { |
| 253 | if (vfs_busy(mp, NULL)) |
| 254 | continue; |
| 255 | vput(dvp); |
| 256 | error = VFS_ROOT(mp, &tdvp); |
| 257 | vfs_unbusy(mp, false, NULL); |
| 258 | if (error) { |
| 259 | return (error); |
| 260 | } |
| 261 | dvp = tdvp; |
| 262 | } |
| 263 | |
| 264 | *vpp = dvp; |
| 265 | return (0); |
| 266 | } |
| 267 | |
| 268 | int |
| 269 | union_lookup(void *v) |
| 270 | { |
| 271 | struct vop_lookup_v2_args /* { |
| 272 | struct vnodeop_desc *a_desc; |
| 273 | struct vnode *a_dvp; |
| 274 | struct vnode **a_vpp; |
| 275 | struct componentname *a_cnp; |
| 276 | } */ *ap = v; |
| 277 | int error; |
| 278 | int uerror, lerror; |
| 279 | struct vnode *uppervp, *lowervp; |
| 280 | struct vnode *upperdvp, *lowerdvp; |
| 281 | struct vnode *dvp = ap->a_dvp; |
| 282 | struct union_node *dun = VTOUNION(dvp); |
| 283 | struct componentname *cnp = ap->a_cnp; |
| 284 | struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount); |
| 285 | kauth_cred_t saved_cred = NULL; |
| 286 | int iswhiteout; |
| 287 | struct vattr va; |
| 288 | |
| 289 | #ifdef notyet |
| 290 | if (cnp->cn_namelen == 3 && |
| 291 | cnp->cn_nameptr[2] == '.' && |
| 292 | cnp->cn_nameptr[1] == '.' && |
| 293 | cnp->cn_nameptr[0] == '.') { |
| 294 | dvp = *ap->a_vpp = LOWERVP(ap->a_dvp); |
| 295 | if (dvp == NULLVP) |
| 296 | return (ENOENT); |
| 297 | vref(dvp); |
| 298 | vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); |
| 299 | return (0); |
| 300 | } |
| 301 | #endif |
| 302 | |
| 303 | if ((cnp->cn_flags & ISLASTCN) && |
| 304 | (dvp->v_mount->mnt_flag & MNT_RDONLY) && |
| 305 | (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) |
| 306 | return (EROFS); |
| 307 | |
| 308 | start: |
| 309 | upperdvp = dun->un_uppervp; |
| 310 | lowerdvp = dun->un_lowervp; |
| 311 | uppervp = NULLVP; |
| 312 | lowervp = NULLVP; |
| 313 | iswhiteout = 0; |
| 314 | |
| 315 | /* |
| 316 | * do the lookup in the upper level. |
| 317 | * if that level comsumes additional pathnames, |
| 318 | * then assume that something special is going |
| 319 | * on and just return that vnode. |
| 320 | */ |
| 321 | if (upperdvp != NULLVP) { |
| 322 | uerror = union_lookup1(um->um_uppervp, &upperdvp, |
| 323 | &uppervp, cnp); |
| 324 | if (cnp->cn_consume != 0) { |
| 325 | if (uppervp != upperdvp) |
| 326 | VOP_UNLOCK(uppervp); |
| 327 | *ap->a_vpp = uppervp; |
| 328 | return (uerror); |
| 329 | } |
| 330 | if (uerror == ENOENT || uerror == EJUSTRETURN) { |
| 331 | if (cnp->cn_flags & ISWHITEOUT) { |
| 332 | iswhiteout = 1; |
| 333 | } else if (lowerdvp != NULLVP) { |
| 334 | lerror = VOP_GETATTR(upperdvp, &va, |
| 335 | cnp->cn_cred); |
| 336 | if (lerror == 0 && (va.va_flags & OPAQUE)) |
| 337 | iswhiteout = 1; |
| 338 | } |
| 339 | } |
| 340 | } else { |
| 341 | uerror = ENOENT; |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * in a similar way to the upper layer, do the lookup |
| 346 | * in the lower layer. this time, if there is some |
| 347 | * component magic going on, then vput whatever we got |
| 348 | * back from the upper layer and return the lower vnode |
| 349 | * instead. |
| 350 | */ |
| 351 | if (lowerdvp != NULLVP && !iswhiteout) { |
| 352 | int nameiop; |
| 353 | |
| 354 | vn_lock(lowerdvp, LK_EXCLUSIVE | LK_RETRY); |
| 355 | |
| 356 | /* |
| 357 | * Only do a LOOKUP on the bottom node, since |
| 358 | * we won't be making changes to it anyway. |
| 359 | */ |
| 360 | nameiop = cnp->cn_nameiop; |
| 361 | cnp->cn_nameiop = LOOKUP; |
| 362 | if (um->um_op == UNMNT_BELOW) { |
| 363 | saved_cred = cnp->cn_cred; |
| 364 | cnp->cn_cred = um->um_cred; |
| 365 | } |
| 366 | |
| 367 | /* |
| 368 | * we shouldn't have to worry about locking interactions |
| 369 | * between the lower layer and our union layer (w.r.t. |
| 370 | * `..' processing) because we don't futz with lowervp |
| 371 | * locks in the union-node instantiation code path. |
| 372 | */ |
| 373 | lerror = union_lookup1(um->um_lowervp, &lowerdvp, |
| 374 | &lowervp, cnp); |
| 375 | if (um->um_op == UNMNT_BELOW) |
| 376 | cnp->cn_cred = saved_cred; |
| 377 | cnp->cn_nameiop = nameiop; |
| 378 | |
| 379 | if (lowervp != lowerdvp) |
| 380 | VOP_UNLOCK(lowerdvp); |
| 381 | |
| 382 | if (cnp->cn_consume != 0) { |
| 383 | if (uppervp != NULLVP) { |
| 384 | if (uppervp == upperdvp) |
| 385 | vrele(uppervp); |
| 386 | else |
| 387 | vput(uppervp); |
| 388 | uppervp = NULLVP; |
| 389 | } |
| 390 | *ap->a_vpp = lowervp; |
| 391 | return (lerror); |
| 392 | } |
| 393 | } else { |
| 394 | lerror = ENOENT; |
| 395 | if ((cnp->cn_flags & ISDOTDOT) && dun->un_pvp != NULLVP) { |
| 396 | lowervp = LOWERVP(dun->un_pvp); |
| 397 | if (lowervp != NULLVP) { |
| 398 | vref(lowervp); |
| 399 | vn_lock(lowervp, LK_EXCLUSIVE | LK_RETRY); |
| 400 | lerror = 0; |
| 401 | } |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | /* |
| 406 | * EJUSTRETURN is used by underlying filesystems to indicate that |
| 407 | * a directory modification op was started successfully. |
| 408 | * This will only happen in the upper layer, since |
| 409 | * the lower layer only does LOOKUPs. |
| 410 | * If this union is mounted read-only, bounce it now. |
| 411 | */ |
| 412 | |
| 413 | if ((uerror == EJUSTRETURN) && (cnp->cn_flags & ISLASTCN) && |
| 414 | (dvp->v_mount->mnt_flag & MNT_RDONLY) && |
| 415 | ((cnp->cn_nameiop == CREATE) || (cnp->cn_nameiop == RENAME))) |
| 416 | uerror = EROFS; |
| 417 | |
| 418 | /* |
| 419 | * at this point, we have uerror and lerror indicating |
| 420 | * possible errors with the lookups in the upper and lower |
| 421 | * layers. additionally, uppervp and lowervp are (locked) |
| 422 | * references to existing vnodes in the upper and lower layers. |
| 423 | * |
| 424 | * there are now three cases to consider. |
| 425 | * 1. if both layers returned an error, then return whatever |
| 426 | * error the upper layer generated. |
| 427 | * |
| 428 | * 2. if the top layer failed and the bottom layer succeeded |
| 429 | * then two subcases occur. |
| 430 | * a. the bottom vnode is not a directory, in which |
| 431 | * case just return a new union vnode referencing |
| 432 | * an empty top layer and the existing bottom layer. |
| 433 | * b. the bottom vnode is a directory, in which case |
| 434 | * create a new directory in the top-level and |
| 435 | * continue as in case 3. |
| 436 | * |
| 437 | * 3. if the top layer succeeded then return a new union |
| 438 | * vnode referencing whatever the new top layer and |
| 439 | * whatever the bottom layer returned. |
| 440 | */ |
| 441 | |
| 442 | *ap->a_vpp = NULLVP; |
| 443 | |
| 444 | |
| 445 | /* case 1. */ |
| 446 | if ((uerror != 0) && (lerror != 0)) { |
| 447 | return (uerror); |
| 448 | } |
| 449 | |
| 450 | /* case 2. */ |
| 451 | if (uerror != 0 /* && (lerror == 0) */ ) { |
| 452 | if (lowervp->v_type == VDIR) { /* case 2b. */ |
| 453 | /* |
| 454 | * We may be racing another process to make the |
| 455 | * upper-level shadow directory. Be careful with |
| 456 | * locks/etc! |
| 457 | * If we have to create a shadow directory and want |
| 458 | * to commit the node we have to restart the lookup |
| 459 | * to get the componentname right. |
| 460 | */ |
| 461 | if (upperdvp) { |
| 462 | VOP_UNLOCK(upperdvp); |
| 463 | uerror = union_mkshadow(um, upperdvp, cnp, |
| 464 | &uppervp); |
| 465 | vn_lock(upperdvp, LK_EXCLUSIVE | LK_RETRY); |
| 466 | if (uerror == 0 && cnp->cn_nameiop != LOOKUP) { |
| 467 | vrele(uppervp); |
| 468 | if (lowervp != NULLVP) |
| 469 | vput(lowervp); |
| 470 | goto start; |
| 471 | } |
| 472 | } |
| 473 | if (uerror) { |
| 474 | if (lowervp != NULLVP) { |
| 475 | vput(lowervp); |
| 476 | lowervp = NULLVP; |
| 477 | } |
| 478 | return (uerror); |
| 479 | } |
| 480 | } |
| 481 | } else { /* uerror == 0 */ |
| 482 | if (uppervp != upperdvp) |
| 483 | VOP_UNLOCK(uppervp); |
| 484 | } |
| 485 | |
| 486 | if (lowervp != NULLVP) |
| 487 | VOP_UNLOCK(lowervp); |
| 488 | |
| 489 | error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp, |
| 490 | uppervp, lowervp, 1); |
| 491 | |
| 492 | if (error) { |
| 493 | if (uppervp != NULLVP) |
| 494 | vrele(uppervp); |
| 495 | if (lowervp != NULLVP) |
| 496 | vrele(lowervp); |
| 497 | return error; |
| 498 | } |
| 499 | |
| 500 | return 0; |
| 501 | } |
| 502 | |
| 503 | int |
| 504 | union_create(void *v) |
| 505 | { |
| 506 | struct vop_create_v3_args /* { |
| 507 | struct vnode *a_dvp; |
| 508 | struct vnode **a_vpp; |
| 509 | struct componentname *a_cnp; |
| 510 | struct vattr *a_vap; |
| 511 | } */ *ap = v; |
| 512 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 513 | struct vnode *dvp = un->un_uppervp; |
| 514 | struct componentname *cnp = ap->a_cnp; |
| 515 | |
| 516 | if (dvp != NULLVP) { |
| 517 | int error; |
| 518 | struct vnode *vp; |
| 519 | struct mount *mp; |
| 520 | |
| 521 | mp = ap->a_dvp->v_mount; |
| 522 | |
| 523 | vp = NULL; |
| 524 | error = VOP_CREATE(dvp, &vp, cnp, ap->a_vap); |
| 525 | if (error) |
| 526 | return (error); |
| 527 | |
| 528 | error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, cnp, vp, |
| 529 | NULLVP, 1); |
| 530 | if (error) |
| 531 | vrele(vp); |
| 532 | return (error); |
| 533 | } |
| 534 | |
| 535 | return (EROFS); |
| 536 | } |
| 537 | |
| 538 | int |
| 539 | union_whiteout(void *v) |
| 540 | { |
| 541 | struct vop_whiteout_args /* { |
| 542 | struct vnode *a_dvp; |
| 543 | struct componentname *a_cnp; |
| 544 | int a_flags; |
| 545 | } */ *ap = v; |
| 546 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 547 | struct componentname *cnp = ap->a_cnp; |
| 548 | |
| 549 | if (un->un_uppervp == NULLVP) |
| 550 | return (EOPNOTSUPP); |
| 551 | |
| 552 | return (VOP_WHITEOUT(un->un_uppervp, cnp, ap->a_flags)); |
| 553 | } |
| 554 | |
| 555 | int |
| 556 | union_mknod(void *v) |
| 557 | { |
| 558 | struct vop_mknod_v3_args /* { |
| 559 | struct vnode *a_dvp; |
| 560 | struct vnode **a_vpp; |
| 561 | struct componentname *a_cnp; |
| 562 | struct vattr *a_vap; |
| 563 | } */ *ap = v; |
| 564 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 565 | struct vnode *dvp = un->un_uppervp; |
| 566 | struct componentname *cnp = ap->a_cnp; |
| 567 | |
| 568 | if (dvp != NULLVP) { |
| 569 | int error; |
| 570 | struct vnode *vp; |
| 571 | struct mount *mp; |
| 572 | |
| 573 | mp = ap->a_dvp->v_mount; |
| 574 | error = VOP_MKNOD(dvp, &vp, cnp, ap->a_vap); |
| 575 | if (error) |
| 576 | return (error); |
| 577 | |
| 578 | error = union_allocvp(ap->a_vpp, mp, NULLVP, NULLVP, |
| 579 | cnp, vp, NULLVP, 1); |
| 580 | if (error) |
| 581 | vrele(vp); |
| 582 | return (error); |
| 583 | } |
| 584 | |
| 585 | return (EROFS); |
| 586 | } |
| 587 | |
| 588 | int |
| 589 | union_open(void *v) |
| 590 | { |
| 591 | struct vop_open_args /* { |
| 592 | struct vnodeop_desc *a_desc; |
| 593 | struct vnode *a_vp; |
| 594 | int a_mode; |
| 595 | kauth_cred_t a_cred; |
| 596 | } */ *ap = v; |
| 597 | struct union_node *un = VTOUNION(ap->a_vp); |
| 598 | struct vnode *tvp; |
| 599 | int mode = ap->a_mode; |
| 600 | kauth_cred_t cred = ap->a_cred; |
| 601 | struct lwp *l = curlwp; |
| 602 | int error; |
| 603 | |
| 604 | /* |
| 605 | * If there is an existing upper vp then simply open that. |
| 606 | */ |
| 607 | tvp = un->un_uppervp; |
| 608 | if (tvp == NULLVP) { |
| 609 | /* |
| 610 | * If the lower vnode is being opened for writing, then |
| 611 | * copy the file contents to the upper vnode and open that, |
| 612 | * otherwise can simply open the lower vnode. |
| 613 | */ |
| 614 | tvp = un->un_lowervp; |
| 615 | if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { |
| 616 | error = union_copyup(un, (mode&O_TRUNC) == 0, cred, l); |
| 617 | if (error == 0) |
| 618 | error = VOP_OPEN(un->un_uppervp, mode, cred); |
| 619 | return (error); |
| 620 | } |
| 621 | |
| 622 | /* |
| 623 | * Just open the lower vnode, but check for nodev mount flag |
| 624 | */ |
| 625 | if ((tvp->v_type == VBLK || tvp->v_type == VCHR) && |
| 626 | (ap->a_vp->v_mount->mnt_flag & MNT_NODEV)) |
| 627 | return ENXIO; |
| 628 | un->un_openl++; |
| 629 | vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY); |
| 630 | error = VOP_OPEN(tvp, mode, cred); |
| 631 | VOP_UNLOCK(tvp); |
| 632 | |
| 633 | return (error); |
| 634 | } |
| 635 | /* |
| 636 | * Just open the upper vnode, checking for nodev mount flag first |
| 637 | */ |
| 638 | if ((tvp->v_type == VBLK || tvp->v_type == VCHR) && |
| 639 | (ap->a_vp->v_mount->mnt_flag & MNT_NODEV)) |
| 640 | return ENXIO; |
| 641 | |
| 642 | error = VOP_OPEN(tvp, mode, cred); |
| 643 | |
| 644 | return (error); |
| 645 | } |
| 646 | |
| 647 | int |
| 648 | union_close(void *v) |
| 649 | { |
| 650 | struct vop_close_args /* { |
| 651 | struct vnode *a_vp; |
| 652 | int a_fflag; |
| 653 | kauth_cred_t a_cred; |
| 654 | } */ *ap = v; |
| 655 | struct union_node *un = VTOUNION(ap->a_vp); |
| 656 | struct vnode *vp; |
| 657 | int error; |
| 658 | bool do_lock; |
| 659 | |
| 660 | vp = un->un_uppervp; |
| 661 | if (vp != NULLVP) { |
| 662 | do_lock = false; |
| 663 | } else { |
| 664 | KASSERT(un->un_openl > 0); |
| 665 | --un->un_openl; |
| 666 | vp = un->un_lowervp; |
| 667 | do_lock = true; |
| 668 | } |
| 669 | |
| 670 | KASSERT(vp != NULLVP); |
| 671 | ap->a_vp = vp; |
| 672 | if (do_lock) |
| 673 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 674 | error = VCALL(vp, VOFFSET(vop_close), ap); |
| 675 | if (do_lock) |
| 676 | VOP_UNLOCK(vp); |
| 677 | |
| 678 | return error; |
| 679 | } |
| 680 | |
| 681 | /* |
| 682 | * Check access permission on the union vnode. |
| 683 | * The access check being enforced is to check |
| 684 | * against both the underlying vnode, and any |
| 685 | * copied vnode. This ensures that no additional |
| 686 | * file permissions are given away simply because |
| 687 | * the user caused an implicit file copy. |
| 688 | */ |
| 689 | int |
| 690 | union_access(void *v) |
| 691 | { |
| 692 | struct vop_access_args /* { |
| 693 | struct vnodeop_desc *a_desc; |
| 694 | struct vnode *a_vp; |
| 695 | int a_mode; |
| 696 | kauth_cred_t a_cred; |
| 697 | } */ *ap = v; |
| 698 | struct vnode *vp = ap->a_vp; |
| 699 | struct union_node *un = VTOUNION(vp); |
| 700 | int error = EACCES; |
| 701 | struct union_mount *um = MOUNTTOUNIONMOUNT(vp->v_mount); |
| 702 | |
| 703 | /* |
| 704 | * Disallow write attempts on read-only file systems; |
| 705 | * unless the file is a socket, fifo, or a block or |
| 706 | * character device resident on the file system. |
| 707 | */ |
| 708 | if (ap->a_mode & VWRITE) { |
| 709 | switch (vp->v_type) { |
| 710 | case VDIR: |
| 711 | case VLNK: |
| 712 | case VREG: |
| 713 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 714 | return (EROFS); |
| 715 | break; |
| 716 | case VBAD: |
| 717 | case VBLK: |
| 718 | case VCHR: |
| 719 | case VSOCK: |
| 720 | case VFIFO: |
| 721 | case VNON: |
| 722 | default: |
| 723 | break; |
| 724 | } |
| 725 | } |
| 726 | |
| 727 | |
| 728 | if ((vp = un->un_uppervp) != NULLVP) { |
| 729 | ap->a_vp = vp; |
| 730 | return (VCALL(vp, VOFFSET(vop_access), ap)); |
| 731 | } |
| 732 | |
| 733 | if ((vp = un->un_lowervp) != NULLVP) { |
| 734 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 735 | ap->a_vp = vp; |
| 736 | error = VCALL(vp, VOFFSET(vop_access), ap); |
| 737 | if (error == 0) { |
| 738 | if (um->um_op == UNMNT_BELOW) { |
| 739 | ap->a_cred = um->um_cred; |
| 740 | error = VCALL(vp, VOFFSET(vop_access), ap); |
| 741 | } |
| 742 | } |
| 743 | VOP_UNLOCK(vp); |
| 744 | if (error) |
| 745 | return (error); |
| 746 | } |
| 747 | |
| 748 | return (error); |
| 749 | } |
| 750 | |
| 751 | /* |
| 752 | * We handle getattr only to change the fsid and |
| 753 | * track object sizes |
| 754 | */ |
| 755 | int |
| 756 | union_getattr(void *v) |
| 757 | { |
| 758 | struct vop_getattr_args /* { |
| 759 | struct vnode *a_vp; |
| 760 | struct vattr *a_vap; |
| 761 | kauth_cred_t a_cred; |
| 762 | } */ *ap = v; |
| 763 | int error; |
| 764 | struct union_node *un = VTOUNION(ap->a_vp); |
| 765 | struct vnode *vp = un->un_uppervp; |
| 766 | struct vattr *vap; |
| 767 | struct vattr va; |
| 768 | |
| 769 | |
| 770 | /* |
| 771 | * Some programs walk the filesystem hierarchy by counting |
| 772 | * links to directories to avoid stat'ing all the time. |
| 773 | * This means the link count on directories needs to be "correct". |
| 774 | * The only way to do that is to call getattr on both layers |
| 775 | * and fix up the link count. The link count will not necessarily |
| 776 | * be accurate but will be large enough to defeat the tree walkers. |
| 777 | * |
| 778 | * To make life more interesting, some filesystems don't keep |
| 779 | * track of link counts in the expected way, and return a |
| 780 | * link count of `1' for those directories; if either of the |
| 781 | * component directories returns a link count of `1', we return a 1. |
| 782 | */ |
| 783 | |
| 784 | vap = ap->a_vap; |
| 785 | |
| 786 | vp = un->un_uppervp; |
| 787 | if (vp != NULLVP) { |
| 788 | error = VOP_GETATTR(vp, vap, ap->a_cred); |
| 789 | if (error) |
| 790 | return (error); |
| 791 | mutex_enter(&un->un_lock); |
| 792 | union_newsize(ap->a_vp, vap->va_size, VNOVAL); |
| 793 | } |
| 794 | |
| 795 | if (vp == NULLVP) { |
| 796 | vp = un->un_lowervp; |
| 797 | } else if (vp->v_type == VDIR) { |
| 798 | vp = un->un_lowervp; |
| 799 | if (vp != NULLVP) |
| 800 | vap = &va; |
| 801 | } else { |
| 802 | vp = NULLVP; |
| 803 | } |
| 804 | |
| 805 | if (vp != NULLVP) { |
| 806 | if (vp == un->un_lowervp) |
| 807 | vn_lock(vp, LK_SHARED | LK_RETRY); |
| 808 | error = VOP_GETATTR(vp, vap, ap->a_cred); |
| 809 | if (vp == un->un_lowervp) |
| 810 | VOP_UNLOCK(vp); |
| 811 | if (error) |
| 812 | return (error); |
| 813 | mutex_enter(&un->un_lock); |
| 814 | union_newsize(ap->a_vp, VNOVAL, vap->va_size); |
| 815 | } |
| 816 | |
| 817 | if ((vap != ap->a_vap) && (vap->va_type == VDIR)) { |
| 818 | /* |
| 819 | * Link count manipulation: |
| 820 | * - If both return "2", return 2 (no subdirs) |
| 821 | * - If one or the other return "1", return "1" (ENOCLUE) |
| 822 | */ |
| 823 | if ((ap->a_vap->va_nlink == 2) && |
| 824 | (vap->va_nlink == 2)) |
| 825 | ; |
| 826 | else if (ap->a_vap->va_nlink != 1) { |
| 827 | if (vap->va_nlink == 1) |
| 828 | ap->a_vap->va_nlink = 1; |
| 829 | else |
| 830 | ap->a_vap->va_nlink += vap->va_nlink; |
| 831 | } |
| 832 | } |
| 833 | ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0]; |
| 834 | return (0); |
| 835 | } |
| 836 | |
| 837 | int |
| 838 | union_setattr(void *v) |
| 839 | { |
| 840 | struct vop_setattr_args /* { |
| 841 | struct vnode *a_vp; |
| 842 | struct vattr *a_vap; |
| 843 | kauth_cred_t a_cred; |
| 844 | } */ *ap = v; |
| 845 | struct vattr *vap = ap->a_vap; |
| 846 | struct vnode *vp = ap->a_vp; |
| 847 | struct union_node *un = VTOUNION(vp); |
| 848 | bool size_only; /* All but va_size are VNOVAL. */ |
| 849 | int error; |
| 850 | |
| 851 | size_only = (vap->va_flags == VNOVAL && vap->va_uid == (uid_t)VNOVAL && |
| 852 | vap->va_gid == (gid_t)VNOVAL && vap->va_atime.tv_sec == VNOVAL && |
| 853 | vap->va_mtime.tv_sec == VNOVAL && vap->va_mode == (mode_t)VNOVAL); |
| 854 | |
| 855 | if (!size_only && (vp->v_mount->mnt_flag & MNT_RDONLY)) |
| 856 | return (EROFS); |
| 857 | if (vap->va_size != VNOVAL) { |
| 858 | switch (vp->v_type) { |
| 859 | case VDIR: |
| 860 | return (EISDIR); |
| 861 | case VCHR: |
| 862 | case VBLK: |
| 863 | case VSOCK: |
| 864 | case VFIFO: |
| 865 | break; |
| 866 | case VREG: |
| 867 | case VLNK: |
| 868 | default: |
| 869 | /* |
| 870 | * Disallow write attempts if the filesystem is |
| 871 | * mounted read-only. |
| 872 | */ |
| 873 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 874 | return (EROFS); |
| 875 | } |
| 876 | } |
| 877 | |
| 878 | /* |
| 879 | * Handle case of truncating lower object to zero size, |
| 880 | * by creating a zero length upper object. This is to |
| 881 | * handle the case of open with O_TRUNC and O_CREAT. |
| 882 | */ |
| 883 | if ((un->un_uppervp == NULLVP) && |
| 884 | /* assert(un->un_lowervp != NULLVP) */ |
| 885 | (un->un_lowervp->v_type == VREG)) { |
| 886 | error = union_copyup(un, (vap->va_size != 0), |
| 887 | ap->a_cred, curlwp); |
| 888 | if (error) |
| 889 | return (error); |
| 890 | } |
| 891 | |
| 892 | /* |
| 893 | * Try to set attributes in upper layer, ignore size change to zero |
| 894 | * for devices to handle O_TRUNC and return read-only filesystem error |
| 895 | * otherwise. |
| 896 | */ |
| 897 | if (un->un_uppervp != NULLVP) { |
| 898 | error = VOP_SETATTR(un->un_uppervp, vap, ap->a_cred); |
| 899 | if ((error == 0) && (vap->va_size != VNOVAL)) { |
| 900 | mutex_enter(&un->un_lock); |
| 901 | union_newsize(ap->a_vp, vap->va_size, VNOVAL); |
| 902 | } |
| 903 | } else { |
| 904 | KASSERT(un->un_lowervp != NULLVP); |
| 905 | if (NODE_IS_SPECIAL(un->un_lowervp)) { |
| 906 | if (size_only && |
| 907 | (vap->va_size == 0 || vap->va_size == VNOVAL)) |
| 908 | error = 0; |
| 909 | else |
| 910 | error = EROFS; |
| 911 | } else { |
| 912 | error = EROFS; |
| 913 | } |
| 914 | } |
| 915 | |
| 916 | return (error); |
| 917 | } |
| 918 | |
| 919 | int |
| 920 | union_read(void *v) |
| 921 | { |
| 922 | struct vop_read_args /* { |
| 923 | struct vnode *a_vp; |
| 924 | struct uio *a_uio; |
| 925 | int a_ioflag; |
| 926 | kauth_cred_t a_cred; |
| 927 | } */ *ap = v; |
| 928 | int error; |
| 929 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 930 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 931 | |
| 932 | if (dolock) |
| 933 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 934 | error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 935 | if (dolock) |
| 936 | VOP_UNLOCK(vp); |
| 937 | |
| 938 | /* |
| 939 | * XXX |
| 940 | * perhaps the size of the underlying object has changed under |
| 941 | * our feet. take advantage of the offset information present |
| 942 | * in the uio structure. |
| 943 | */ |
| 944 | if (error == 0) { |
| 945 | struct union_node *un = VTOUNION(ap->a_vp); |
| 946 | off_t cur = ap->a_uio->uio_offset; |
| 947 | off_t usz = VNOVAL, lsz = VNOVAL; |
| 948 | |
| 949 | mutex_enter(&un->un_lock); |
| 950 | if (vp == un->un_uppervp) { |
| 951 | if (cur > un->un_uppersz) |
| 952 | usz = cur; |
| 953 | } else { |
| 954 | if (cur > un->un_lowersz) |
| 955 | lsz = cur; |
| 956 | } |
| 957 | |
| 958 | if (usz != VNOVAL || lsz != VNOVAL) |
| 959 | union_newsize(ap->a_vp, usz, lsz); |
| 960 | else |
| 961 | mutex_exit(&un->un_lock); |
| 962 | } |
| 963 | |
| 964 | return (error); |
| 965 | } |
| 966 | |
| 967 | int |
| 968 | union_write(void *v) |
| 969 | { |
| 970 | struct vop_read_args /* { |
| 971 | struct vnode *a_vp; |
| 972 | struct uio *a_uio; |
| 973 | int a_ioflag; |
| 974 | kauth_cred_t a_cred; |
| 975 | } */ *ap = v; |
| 976 | int error; |
| 977 | struct vnode *vp; |
| 978 | struct union_node *un = VTOUNION(ap->a_vp); |
| 979 | |
| 980 | vp = UPPERVP(ap->a_vp); |
| 981 | if (vp == NULLVP) { |
| 982 | vp = LOWERVP(ap->a_vp); |
| 983 | if (NODE_IS_SPECIAL(vp)) { |
| 984 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 985 | error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, |
| 986 | ap->a_cred); |
| 987 | VOP_UNLOCK(vp); |
| 988 | return error; |
| 989 | } |
| 990 | panic("union: missing upper layer in write" ); |
| 991 | } |
| 992 | |
| 993 | error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred); |
| 994 | |
| 995 | /* |
| 996 | * the size of the underlying object may be changed by the |
| 997 | * write. |
| 998 | */ |
| 999 | if (error == 0) { |
| 1000 | off_t cur = ap->a_uio->uio_offset; |
| 1001 | |
| 1002 | mutex_enter(&un->un_lock); |
| 1003 | if (cur > un->un_uppersz) |
| 1004 | union_newsize(ap->a_vp, cur, VNOVAL); |
| 1005 | else |
| 1006 | mutex_exit(&un->un_lock); |
| 1007 | } |
| 1008 | |
| 1009 | return (error); |
| 1010 | } |
| 1011 | |
| 1012 | int |
| 1013 | union_ioctl(void *v) |
| 1014 | { |
| 1015 | struct vop_ioctl_args /* { |
| 1016 | struct vnode *a_vp; |
| 1017 | int a_command; |
| 1018 | void *a_data; |
| 1019 | int a_fflag; |
| 1020 | kauth_cred_t a_cred; |
| 1021 | } */ *ap = v; |
| 1022 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1023 | |
| 1024 | ap->a_vp = ovp; |
| 1025 | return (VCALL(ovp, VOFFSET(vop_ioctl), ap)); |
| 1026 | } |
| 1027 | |
| 1028 | int |
| 1029 | union_poll(void *v) |
| 1030 | { |
| 1031 | struct vop_poll_args /* { |
| 1032 | struct vnode *a_vp; |
| 1033 | int a_events; |
| 1034 | } */ *ap = v; |
| 1035 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1036 | |
| 1037 | ap->a_vp = ovp; |
| 1038 | return (VCALL(ovp, VOFFSET(vop_poll), ap)); |
| 1039 | } |
| 1040 | |
| 1041 | int |
| 1042 | union_revoke(void *v) |
| 1043 | { |
| 1044 | struct vop_revoke_args /* { |
| 1045 | struct vnode *a_vp; |
| 1046 | int a_flags; |
| 1047 | struct proc *a_p; |
| 1048 | } */ *ap = v; |
| 1049 | struct vnode *vp = ap->a_vp; |
| 1050 | |
| 1051 | if (UPPERVP(vp)) |
| 1052 | VOP_REVOKE(UPPERVP(vp), ap->a_flags); |
| 1053 | if (LOWERVP(vp)) |
| 1054 | VOP_REVOKE(LOWERVP(vp), ap->a_flags); |
| 1055 | vgone(vp); /* XXXAD?? */ |
| 1056 | return (0); |
| 1057 | } |
| 1058 | |
| 1059 | int |
| 1060 | union_mmap(void *v) |
| 1061 | { |
| 1062 | struct vop_mmap_args /* { |
| 1063 | struct vnode *a_vp; |
| 1064 | vm_prot_t a_prot; |
| 1065 | kauth_cred_t a_cred; |
| 1066 | } */ *ap = v; |
| 1067 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1068 | |
| 1069 | ap->a_vp = ovp; |
| 1070 | return (VCALL(ovp, VOFFSET(vop_mmap), ap)); |
| 1071 | } |
| 1072 | |
| 1073 | int |
| 1074 | union_fsync(void *v) |
| 1075 | { |
| 1076 | struct vop_fsync_args /* { |
| 1077 | struct vnode *a_vp; |
| 1078 | kauth_cred_t a_cred; |
| 1079 | int a_flags; |
| 1080 | off_t offhi; |
| 1081 | off_t offlo; |
| 1082 | } */ *ap = v; |
| 1083 | int error = 0; |
| 1084 | struct vnode *targetvp; |
| 1085 | |
| 1086 | /* |
| 1087 | * If vinvalbuf is calling us, it's a "shallow fsync" -- don't |
| 1088 | * bother syncing the underlying vnodes, since (a) they'll be |
| 1089 | * fsync'ed when reclaimed and (b) we could deadlock if |
| 1090 | * they're locked; otherwise, pass it through to the |
| 1091 | * underlying layer. |
| 1092 | */ |
| 1093 | if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR) { |
| 1094 | error = spec_fsync(v); |
| 1095 | if (error) |
| 1096 | return error; |
| 1097 | } |
| 1098 | |
| 1099 | if (ap->a_flags & FSYNC_RECLAIM) |
| 1100 | return 0; |
| 1101 | |
| 1102 | targetvp = OTHERVP(ap->a_vp); |
| 1103 | if (targetvp != NULLVP) { |
| 1104 | int dolock = (targetvp == LOWERVP(ap->a_vp)); |
| 1105 | |
| 1106 | if (dolock) |
| 1107 | vn_lock(targetvp, LK_EXCLUSIVE | LK_RETRY); |
| 1108 | error = VOP_FSYNC(targetvp, ap->a_cred, ap->a_flags, |
| 1109 | ap->a_offlo, ap->a_offhi); |
| 1110 | if (dolock) |
| 1111 | VOP_UNLOCK(targetvp); |
| 1112 | } |
| 1113 | |
| 1114 | return (error); |
| 1115 | } |
| 1116 | |
| 1117 | int |
| 1118 | union_seek(void *v) |
| 1119 | { |
| 1120 | struct vop_seek_args /* { |
| 1121 | struct vnode *a_vp; |
| 1122 | off_t a_oldoff; |
| 1123 | off_t a_newoff; |
| 1124 | kauth_cred_t a_cred; |
| 1125 | } */ *ap = v; |
| 1126 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1127 | |
| 1128 | ap->a_vp = ovp; |
| 1129 | return (VCALL(ovp, VOFFSET(vop_seek), ap)); |
| 1130 | } |
| 1131 | |
| 1132 | int |
| 1133 | union_remove(void *v) |
| 1134 | { |
| 1135 | struct vop_remove_args /* { |
| 1136 | struct vnode *a_dvp; |
| 1137 | struct vnode *a_vp; |
| 1138 | struct componentname *a_cnp; |
| 1139 | } */ *ap = v; |
| 1140 | int error; |
| 1141 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1142 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1143 | struct componentname *cnp = ap->a_cnp; |
| 1144 | |
| 1145 | if (dun->un_uppervp == NULLVP) |
| 1146 | panic("union remove: null upper vnode" ); |
| 1147 | |
| 1148 | if (un->un_uppervp != NULLVP) { |
| 1149 | struct vnode *dvp = dun->un_uppervp; |
| 1150 | struct vnode *vp = un->un_uppervp; |
| 1151 | |
| 1152 | /* |
| 1153 | * Account for VOP_REMOVE to vrele dvp and vp. |
| 1154 | * Note: VOP_REMOVE will unlock dvp and vp. |
| 1155 | */ |
| 1156 | vref(dvp); |
| 1157 | vref(vp); |
| 1158 | if (union_dowhiteout(un, cnp->cn_cred)) |
| 1159 | cnp->cn_flags |= DOWHITEOUT; |
| 1160 | error = VOP_REMOVE(dvp, vp, cnp); |
| 1161 | if (!error) |
| 1162 | union_removed_upper(un); |
| 1163 | vrele(ap->a_dvp); |
| 1164 | vrele(ap->a_vp); |
| 1165 | } else { |
| 1166 | error = union_mkwhiteout( |
| 1167 | MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), |
| 1168 | dun->un_uppervp, ap->a_cnp, un); |
| 1169 | vput(ap->a_dvp); |
| 1170 | vput(ap->a_vp); |
| 1171 | } |
| 1172 | |
| 1173 | return (error); |
| 1174 | } |
| 1175 | |
| 1176 | int |
| 1177 | union_link(void *v) |
| 1178 | { |
| 1179 | struct vop_link_v2_args /* { |
| 1180 | struct vnode *a_dvp; |
| 1181 | struct vnode *a_vp; |
| 1182 | struct componentname *a_cnp; |
| 1183 | } */ *ap = v; |
| 1184 | int error = 0; |
| 1185 | struct componentname *cnp = ap->a_cnp; |
| 1186 | struct union_node *dun; |
| 1187 | struct vnode *vp; |
| 1188 | struct vnode *dvp; |
| 1189 | |
| 1190 | dun = VTOUNION(ap->a_dvp); |
| 1191 | |
| 1192 | KASSERT((ap->a_cnp->cn_flags & LOCKPARENT) != 0); |
| 1193 | |
| 1194 | if (ap->a_dvp->v_op != ap->a_vp->v_op) { |
| 1195 | vp = ap->a_vp; |
| 1196 | } else { |
| 1197 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1198 | if (un->un_uppervp == NULLVP) { |
| 1199 | const bool droplock = (dun->un_uppervp == un->un_dirvp); |
| 1200 | |
| 1201 | /* |
| 1202 | * Needs to be copied before we can link it. |
| 1203 | */ |
| 1204 | vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); |
| 1205 | if (droplock) |
| 1206 | VOP_UNLOCK(dun->un_uppervp); |
| 1207 | error = union_copyup(un, 1, cnp->cn_cred, curlwp); |
| 1208 | if (droplock) { |
| 1209 | vn_lock(dun->un_uppervp, |
| 1210 | LK_EXCLUSIVE | LK_RETRY); |
| 1211 | /* |
| 1212 | * During copyup, we dropped the lock on the |
| 1213 | * dir and invalidated any saved namei lookup |
| 1214 | * state for the directory we'll be entering |
| 1215 | * the link in. We need to re-run the lookup |
| 1216 | * in that directory to reset any state needed |
| 1217 | * for VOP_LINK. |
| 1218 | * Call relookup on the union-layer to reset |
| 1219 | * the state. |
| 1220 | */ |
| 1221 | vp = NULLVP; |
| 1222 | if (dun->un_uppervp == NULLVP) |
| 1223 | panic("union: null upperdvp?" ); |
| 1224 | error = relookup(ap->a_dvp, &vp, ap->a_cnp, 0); |
| 1225 | if (error) { |
| 1226 | VOP_UNLOCK(ap->a_vp); |
| 1227 | return EROFS; /* ? */ |
| 1228 | } |
| 1229 | if (vp != NULLVP) { |
| 1230 | /* |
| 1231 | * The name we want to create has |
| 1232 | * mysteriously appeared (a race?) |
| 1233 | */ |
| 1234 | error = EEXIST; |
| 1235 | VOP_UNLOCK(ap->a_vp); |
| 1236 | vput(vp); |
| 1237 | return (error); |
| 1238 | } |
| 1239 | } |
| 1240 | VOP_UNLOCK(ap->a_vp); |
| 1241 | } |
| 1242 | vp = un->un_uppervp; |
| 1243 | } |
| 1244 | |
| 1245 | dvp = dun->un_uppervp; |
| 1246 | if (dvp == NULLVP) |
| 1247 | error = EROFS; |
| 1248 | |
| 1249 | if (error) |
| 1250 | return (error); |
| 1251 | |
| 1252 | return VOP_LINK(dvp, vp, cnp); |
| 1253 | } |
| 1254 | |
| 1255 | int |
| 1256 | union_rename(void *v) |
| 1257 | { |
| 1258 | struct vop_rename_args /* { |
| 1259 | struct vnode *a_fdvp; |
| 1260 | struct vnode *a_fvp; |
| 1261 | struct componentname *a_fcnp; |
| 1262 | struct vnode *a_tdvp; |
| 1263 | struct vnode *a_tvp; |
| 1264 | struct componentname *a_tcnp; |
| 1265 | } */ *ap = v; |
| 1266 | int error; |
| 1267 | |
| 1268 | struct vnode *fdvp = ap->a_fdvp; |
| 1269 | struct vnode *fvp = ap->a_fvp; |
| 1270 | struct vnode *tdvp = ap->a_tdvp; |
| 1271 | struct vnode *tvp = ap->a_tvp; |
| 1272 | |
| 1273 | /* |
| 1274 | * Account for VOP_RENAME to vrele all nodes. |
| 1275 | * Note: VOP_RENAME will unlock tdvp. |
| 1276 | */ |
| 1277 | |
| 1278 | if (fdvp->v_op == union_vnodeop_p) { /* always true */ |
| 1279 | struct union_node *un = VTOUNION(fdvp); |
| 1280 | if (un->un_uppervp == NULLVP) { |
| 1281 | /* |
| 1282 | * this should never happen in normal |
| 1283 | * operation but might if there was |
| 1284 | * a problem creating the top-level shadow |
| 1285 | * directory. |
| 1286 | */ |
| 1287 | error = EXDEV; |
| 1288 | goto bad; |
| 1289 | } |
| 1290 | |
| 1291 | fdvp = un->un_uppervp; |
| 1292 | vref(fdvp); |
| 1293 | } |
| 1294 | |
| 1295 | if (fvp->v_op == union_vnodeop_p) { /* always true */ |
| 1296 | struct union_node *un = VTOUNION(fvp); |
| 1297 | if (un->un_uppervp == NULLVP) { |
| 1298 | /* XXX: should do a copyup */ |
| 1299 | error = EXDEV; |
| 1300 | goto bad; |
| 1301 | } |
| 1302 | |
| 1303 | if (un->un_lowervp != NULLVP) |
| 1304 | ap->a_fcnp->cn_flags |= DOWHITEOUT; |
| 1305 | |
| 1306 | fvp = un->un_uppervp; |
| 1307 | vref(fvp); |
| 1308 | } |
| 1309 | |
| 1310 | if (tdvp->v_op == union_vnodeop_p) { |
| 1311 | struct union_node *un = VTOUNION(tdvp); |
| 1312 | if (un->un_uppervp == NULLVP) { |
| 1313 | /* |
| 1314 | * this should never happen in normal |
| 1315 | * operation but might if there was |
| 1316 | * a problem creating the top-level shadow |
| 1317 | * directory. |
| 1318 | */ |
| 1319 | error = EXDEV; |
| 1320 | goto bad; |
| 1321 | } |
| 1322 | |
| 1323 | tdvp = un->un_uppervp; |
| 1324 | vref(tdvp); |
| 1325 | } |
| 1326 | |
| 1327 | if (tvp != NULLVP && tvp->v_op == union_vnodeop_p) { |
| 1328 | struct union_node *un = VTOUNION(tvp); |
| 1329 | |
| 1330 | tvp = un->un_uppervp; |
| 1331 | if (tvp != NULLVP) { |
| 1332 | vref(tvp); |
| 1333 | } |
| 1334 | } |
| 1335 | |
| 1336 | error = VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp); |
| 1337 | goto out; |
| 1338 | |
| 1339 | bad: |
| 1340 | vput(tdvp); |
| 1341 | if (tvp != NULLVP) |
| 1342 | vput(tvp); |
| 1343 | vrele(fdvp); |
| 1344 | vrele(fvp); |
| 1345 | |
| 1346 | out: |
| 1347 | if (fdvp != ap->a_fdvp) { |
| 1348 | vrele(ap->a_fdvp); |
| 1349 | } |
| 1350 | if (fvp != ap->a_fvp) { |
| 1351 | vrele(ap->a_fvp); |
| 1352 | } |
| 1353 | if (tdvp != ap->a_tdvp) { |
| 1354 | vrele(ap->a_tdvp); |
| 1355 | } |
| 1356 | if (tvp != ap->a_tvp) { |
| 1357 | vrele(ap->a_tvp); |
| 1358 | } |
| 1359 | return (error); |
| 1360 | } |
| 1361 | |
| 1362 | int |
| 1363 | union_mkdir(void *v) |
| 1364 | { |
| 1365 | struct vop_mkdir_v3_args /* { |
| 1366 | struct vnode *a_dvp; |
| 1367 | struct vnode **a_vpp; |
| 1368 | struct componentname *a_cnp; |
| 1369 | struct vattr *a_vap; |
| 1370 | } */ *ap = v; |
| 1371 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 1372 | struct vnode *dvp = un->un_uppervp; |
| 1373 | struct componentname *cnp = ap->a_cnp; |
| 1374 | |
| 1375 | if (dvp != NULLVP) { |
| 1376 | int error; |
| 1377 | struct vnode *vp; |
| 1378 | |
| 1379 | vp = NULL; |
| 1380 | error = VOP_MKDIR(dvp, &vp, cnp, ap->a_vap); |
| 1381 | if (error) { |
| 1382 | vrele(ap->a_dvp); |
| 1383 | return (error); |
| 1384 | } |
| 1385 | |
| 1386 | error = union_allocvp(ap->a_vpp, ap->a_dvp->v_mount, ap->a_dvp, |
| 1387 | NULLVP, cnp, vp, NULLVP, 1); |
| 1388 | if (error) |
| 1389 | vrele(vp); |
| 1390 | return (error); |
| 1391 | } |
| 1392 | |
| 1393 | return (EROFS); |
| 1394 | } |
| 1395 | |
| 1396 | int |
| 1397 | union_rmdir(void *v) |
| 1398 | { |
| 1399 | struct vop_rmdir_args /* { |
| 1400 | struct vnode *a_dvp; |
| 1401 | struct vnode *a_vp; |
| 1402 | struct componentname *a_cnp; |
| 1403 | } */ *ap = v; |
| 1404 | int error; |
| 1405 | struct union_node *dun = VTOUNION(ap->a_dvp); |
| 1406 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1407 | struct componentname *cnp = ap->a_cnp; |
| 1408 | |
| 1409 | if (dun->un_uppervp == NULLVP) |
| 1410 | panic("union rmdir: null upper vnode" ); |
| 1411 | |
| 1412 | error = union_check_rmdir(un, cnp->cn_cred); |
| 1413 | if (error) { |
| 1414 | vput(ap->a_dvp); |
| 1415 | vput(ap->a_vp); |
| 1416 | return error; |
| 1417 | } |
| 1418 | |
| 1419 | if (un->un_uppervp != NULLVP) { |
| 1420 | struct vnode *dvp = dun->un_uppervp; |
| 1421 | struct vnode *vp = un->un_uppervp; |
| 1422 | |
| 1423 | /* |
| 1424 | * Account for VOP_RMDIR to vrele dvp and vp. |
| 1425 | * Note: VOP_RMDIR will unlock dvp and vp. |
| 1426 | */ |
| 1427 | vref(dvp); |
| 1428 | vref(vp); |
| 1429 | if (union_dowhiteout(un, cnp->cn_cred)) |
| 1430 | cnp->cn_flags |= DOWHITEOUT; |
| 1431 | error = VOP_RMDIR(dvp, vp, ap->a_cnp); |
| 1432 | if (!error) |
| 1433 | union_removed_upper(un); |
| 1434 | vrele(ap->a_dvp); |
| 1435 | vrele(ap->a_vp); |
| 1436 | } else { |
| 1437 | error = union_mkwhiteout( |
| 1438 | MOUNTTOUNIONMOUNT(UNIONTOV(dun)->v_mount), |
| 1439 | dun->un_uppervp, ap->a_cnp, un); |
| 1440 | vput(ap->a_dvp); |
| 1441 | vput(ap->a_vp); |
| 1442 | } |
| 1443 | |
| 1444 | return (error); |
| 1445 | } |
| 1446 | |
| 1447 | int |
| 1448 | union_symlink(void *v) |
| 1449 | { |
| 1450 | struct vop_symlink_v3_args /* { |
| 1451 | struct vnode *a_dvp; |
| 1452 | struct vnode **a_vpp; |
| 1453 | struct componentname *a_cnp; |
| 1454 | struct vattr *a_vap; |
| 1455 | char *a_target; |
| 1456 | } */ *ap = v; |
| 1457 | struct union_node *un = VTOUNION(ap->a_dvp); |
| 1458 | struct vnode *dvp = un->un_uppervp; |
| 1459 | struct componentname *cnp = ap->a_cnp; |
| 1460 | |
| 1461 | if (dvp != NULLVP) { |
| 1462 | int error; |
| 1463 | |
| 1464 | error = VOP_SYMLINK(dvp, ap->a_vpp, cnp, ap->a_vap, |
| 1465 | ap->a_target); |
| 1466 | return (error); |
| 1467 | } |
| 1468 | |
| 1469 | return (EROFS); |
| 1470 | } |
| 1471 | |
| 1472 | /* |
| 1473 | * union_readdir works in concert with getdirentries and |
| 1474 | * readdir(3) to provide a list of entries in the unioned |
| 1475 | * directories. getdirentries is responsible for walking |
| 1476 | * down the union stack. readdir(3) is responsible for |
| 1477 | * eliminating duplicate names from the returned data stream. |
| 1478 | */ |
| 1479 | int |
| 1480 | union_readdir(void *v) |
| 1481 | { |
| 1482 | struct vop_readdir_args /* { |
| 1483 | struct vnodeop_desc *a_desc; |
| 1484 | struct vnode *a_vp; |
| 1485 | struct uio *a_uio; |
| 1486 | kauth_cred_t a_cred; |
| 1487 | int *a_eofflag; |
| 1488 | u_long *a_cookies; |
| 1489 | int a_ncookies; |
| 1490 | } */ *ap = v; |
| 1491 | struct union_node *un = VTOUNION(ap->a_vp); |
| 1492 | struct vnode *uvp = un->un_uppervp; |
| 1493 | |
| 1494 | if (uvp == NULLVP) |
| 1495 | return (0); |
| 1496 | |
| 1497 | ap->a_vp = uvp; |
| 1498 | return (VCALL(uvp, VOFFSET(vop_readdir), ap)); |
| 1499 | } |
| 1500 | |
| 1501 | int |
| 1502 | union_readlink(void *v) |
| 1503 | { |
| 1504 | struct vop_readlink_args /* { |
| 1505 | struct vnode *a_vp; |
| 1506 | struct uio *a_uio; |
| 1507 | kauth_cred_t a_cred; |
| 1508 | } */ *ap = v; |
| 1509 | int error; |
| 1510 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1511 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1512 | |
| 1513 | if (dolock) |
| 1514 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 1515 | ap->a_vp = vp; |
| 1516 | error = VCALL(vp, VOFFSET(vop_readlink), ap); |
| 1517 | if (dolock) |
| 1518 | VOP_UNLOCK(vp); |
| 1519 | |
| 1520 | return (error); |
| 1521 | } |
| 1522 | |
| 1523 | int |
| 1524 | union_abortop(void *v) |
| 1525 | { |
| 1526 | struct vop_abortop_args /* { |
| 1527 | struct vnode *a_dvp; |
| 1528 | struct componentname *a_cnp; |
| 1529 | } */ *ap = v; |
| 1530 | |
| 1531 | KASSERT(UPPERVP(ap->a_dvp) != NULL); |
| 1532 | |
| 1533 | ap->a_dvp = UPPERVP(ap->a_dvp); |
| 1534 | return VCALL(ap->a_dvp, VOFFSET(vop_abortop), ap); |
| 1535 | } |
| 1536 | |
| 1537 | int |
| 1538 | union_inactive(void *v) |
| 1539 | { |
| 1540 | struct vop_inactive_args /* { |
| 1541 | const struct vnodeop_desc *a_desc; |
| 1542 | struct vnode *a_vp; |
| 1543 | bool *a_recycle; |
| 1544 | } */ *ap = v; |
| 1545 | struct vnode *vp = ap->a_vp; |
| 1546 | struct union_node *un = VTOUNION(vp); |
| 1547 | struct vnode **vpp; |
| 1548 | |
| 1549 | /* |
| 1550 | * Do nothing (and _don't_ bypass). |
| 1551 | * Wait to vrele lowervp until reclaim, |
| 1552 | * so that until then our union_node is in the |
| 1553 | * cache and reusable. |
| 1554 | * |
| 1555 | * NEEDSWORK: Someday, consider inactive'ing |
| 1556 | * the lowervp and then trying to reactivate it |
| 1557 | * with capabilities (v_id) |
| 1558 | * like they do in the name lookup cache code. |
| 1559 | * That's too much work for now. |
| 1560 | */ |
| 1561 | |
| 1562 | if (un->un_dircache != 0) { |
| 1563 | for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) |
| 1564 | vrele(*vpp); |
| 1565 | free(un->un_dircache, M_TEMP); |
| 1566 | un->un_dircache = 0; |
| 1567 | } |
| 1568 | |
| 1569 | *ap->a_recycle = ((un->un_cflags & UN_CACHED) == 0); |
| 1570 | VOP_UNLOCK(vp); |
| 1571 | |
| 1572 | return (0); |
| 1573 | } |
| 1574 | |
| 1575 | int |
| 1576 | union_reclaim(void *v) |
| 1577 | { |
| 1578 | struct vop_reclaim_args /* { |
| 1579 | struct vnode *a_vp; |
| 1580 | } */ *ap = v; |
| 1581 | |
| 1582 | union_freevp(ap->a_vp); |
| 1583 | |
| 1584 | return (0); |
| 1585 | } |
| 1586 | |
| 1587 | static int |
| 1588 | union_lock1(struct vnode *vp, struct vnode *lockvp, int flags) |
| 1589 | { |
| 1590 | struct vop_lock_args ap; |
| 1591 | |
| 1592 | if (lockvp == vp) { |
| 1593 | ap.a_vp = vp; |
| 1594 | ap.a_flags = flags; |
| 1595 | return genfs_lock(&ap); |
| 1596 | } else |
| 1597 | return VOP_LOCK(lockvp, flags); |
| 1598 | } |
| 1599 | |
| 1600 | static int |
| 1601 | union_unlock1(struct vnode *vp, struct vnode *lockvp) |
| 1602 | { |
| 1603 | struct vop_unlock_args ap; |
| 1604 | |
| 1605 | if (lockvp == vp) { |
| 1606 | ap.a_vp = vp; |
| 1607 | return genfs_unlock(&ap); |
| 1608 | } else |
| 1609 | return VOP_UNLOCK(lockvp); |
| 1610 | } |
| 1611 | |
| 1612 | int |
| 1613 | union_lock(void *v) |
| 1614 | { |
| 1615 | struct vop_lock_args /* { |
| 1616 | struct vnode *a_vp; |
| 1617 | int a_flags; |
| 1618 | } */ *ap = v; |
| 1619 | struct vnode *vp = ap->a_vp, *lockvp; |
| 1620 | struct union_node *un = VTOUNION(vp); |
| 1621 | int flags = ap->a_flags; |
| 1622 | int error; |
| 1623 | |
| 1624 | if ((flags & LK_NOWAIT) != 0) { |
| 1625 | if (!mutex_tryenter(&un->un_lock)) |
| 1626 | return EBUSY; |
| 1627 | lockvp = LOCKVP(vp); |
| 1628 | error = union_lock1(vp, lockvp, flags); |
| 1629 | mutex_exit(&un->un_lock); |
| 1630 | if (error) |
| 1631 | return error; |
| 1632 | if (mutex_tryenter(vp->v_interlock)) { |
| 1633 | error = vdead_check(vp, VDEAD_NOWAIT); |
| 1634 | mutex_exit(vp->v_interlock); |
| 1635 | } else |
| 1636 | error = EBUSY; |
| 1637 | if (error) |
| 1638 | union_unlock1(vp, lockvp); |
| 1639 | return error; |
| 1640 | } |
| 1641 | |
| 1642 | mutex_enter(&un->un_lock); |
| 1643 | for (;;) { |
| 1644 | lockvp = LOCKVP(vp); |
| 1645 | mutex_exit(&un->un_lock); |
| 1646 | error = union_lock1(vp, lockvp, flags); |
| 1647 | if (error != 0) |
| 1648 | return error; |
| 1649 | mutex_enter(&un->un_lock); |
| 1650 | if (lockvp == LOCKVP(vp)) |
| 1651 | break; |
| 1652 | union_unlock1(vp, lockvp); |
| 1653 | } |
| 1654 | mutex_exit(&un->un_lock); |
| 1655 | |
| 1656 | mutex_enter(vp->v_interlock); |
| 1657 | error = vdead_check(vp, VDEAD_NOWAIT); |
| 1658 | if (error) { |
| 1659 | union_unlock1(vp, lockvp); |
| 1660 | error = vdead_check(vp, 0); |
| 1661 | KASSERT(error == ENOENT); |
| 1662 | } |
| 1663 | mutex_exit(vp->v_interlock); |
| 1664 | return error; |
| 1665 | } |
| 1666 | |
| 1667 | int |
| 1668 | union_unlock(void *v) |
| 1669 | { |
| 1670 | struct vop_unlock_args /* { |
| 1671 | struct vnode *a_vp; |
| 1672 | int a_flags; |
| 1673 | } */ *ap = v; |
| 1674 | struct vnode *vp = ap->a_vp, *lockvp; |
| 1675 | |
| 1676 | lockvp = LOCKVP(vp); |
| 1677 | union_unlock1(vp, lockvp); |
| 1678 | |
| 1679 | return 0; |
| 1680 | } |
| 1681 | |
| 1682 | int |
| 1683 | union_bmap(void *v) |
| 1684 | { |
| 1685 | struct vop_bmap_args /* { |
| 1686 | struct vnode *a_vp; |
| 1687 | daddr_t a_bn; |
| 1688 | struct vnode **a_vpp; |
| 1689 | daddr_t *a_bnp; |
| 1690 | int *a_runp; |
| 1691 | } */ *ap = v; |
| 1692 | int error; |
| 1693 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1694 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1695 | |
| 1696 | if (dolock) |
| 1697 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 1698 | ap->a_vp = vp; |
| 1699 | error = VCALL(vp, VOFFSET(vop_bmap), ap); |
| 1700 | if (dolock) |
| 1701 | VOP_UNLOCK(vp); |
| 1702 | |
| 1703 | return (error); |
| 1704 | } |
| 1705 | |
| 1706 | int |
| 1707 | union_print(void *v) |
| 1708 | { |
| 1709 | struct vop_print_args /* { |
| 1710 | struct vnode *a_vp; |
| 1711 | } */ *ap = v; |
| 1712 | struct vnode *vp = ap->a_vp; |
| 1713 | |
| 1714 | printf("\ttag VT_UNION, vp=%p, uppervp=%p, lowervp=%p\n" , |
| 1715 | vp, UPPERVP(vp), LOWERVP(vp)); |
| 1716 | if (UPPERVP(vp) != NULLVP) |
| 1717 | vprint("union: upper" , UPPERVP(vp)); |
| 1718 | if (LOWERVP(vp) != NULLVP) |
| 1719 | vprint("union: lower" , LOWERVP(vp)); |
| 1720 | if (VTOUNION(vp)->un_dircache) { |
| 1721 | struct vnode **vpp; |
| 1722 | for (vpp = VTOUNION(vp)->un_dircache; *vpp != NULLVP; vpp++) |
| 1723 | vprint("dircache:" , *vpp); |
| 1724 | } |
| 1725 | |
| 1726 | return (0); |
| 1727 | } |
| 1728 | |
| 1729 | int |
| 1730 | union_islocked(void *v) |
| 1731 | { |
| 1732 | struct vop_islocked_args /* { |
| 1733 | struct vnode *a_vp; |
| 1734 | } */ *ap = v; |
| 1735 | struct vnode *vp; |
| 1736 | struct union_node *un; |
| 1737 | |
| 1738 | un = VTOUNION(ap->a_vp); |
| 1739 | mutex_enter(&un->un_lock); |
| 1740 | vp = LOCKVP(ap->a_vp); |
| 1741 | mutex_exit(&un->un_lock); |
| 1742 | |
| 1743 | if (vp == ap->a_vp) |
| 1744 | return genfs_islocked(ap); |
| 1745 | else |
| 1746 | return VOP_ISLOCKED(vp); |
| 1747 | } |
| 1748 | |
| 1749 | int |
| 1750 | union_pathconf(void *v) |
| 1751 | { |
| 1752 | struct vop_pathconf_args /* { |
| 1753 | struct vnode *a_vp; |
| 1754 | int a_name; |
| 1755 | int *a_retval; |
| 1756 | } */ *ap = v; |
| 1757 | int error; |
| 1758 | struct vnode *vp = OTHERVP(ap->a_vp); |
| 1759 | int dolock = (vp == LOWERVP(ap->a_vp)); |
| 1760 | |
| 1761 | if (dolock) |
| 1762 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 1763 | ap->a_vp = vp; |
| 1764 | error = VCALL(vp, VOFFSET(vop_pathconf), ap); |
| 1765 | if (dolock) |
| 1766 | VOP_UNLOCK(vp); |
| 1767 | |
| 1768 | return (error); |
| 1769 | } |
| 1770 | |
| 1771 | int |
| 1772 | union_advlock(void *v) |
| 1773 | { |
| 1774 | struct vop_advlock_args /* { |
| 1775 | struct vnode *a_vp; |
| 1776 | void *a_id; |
| 1777 | int a_op; |
| 1778 | struct flock *a_fl; |
| 1779 | int a_flags; |
| 1780 | } */ *ap = v; |
| 1781 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1782 | |
| 1783 | ap->a_vp = ovp; |
| 1784 | return (VCALL(ovp, VOFFSET(vop_advlock), ap)); |
| 1785 | } |
| 1786 | |
| 1787 | int |
| 1788 | union_strategy(void *v) |
| 1789 | { |
| 1790 | struct vop_strategy_args /* { |
| 1791 | struct vnode *a_vp; |
| 1792 | struct buf *a_bp; |
| 1793 | } */ *ap = v; |
| 1794 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1795 | struct buf *bp = ap->a_bp; |
| 1796 | |
| 1797 | KASSERT(ovp != NULLVP); |
| 1798 | if (!NODE_IS_SPECIAL(ovp)) |
| 1799 | KASSERT((bp->b_flags & B_READ) || ovp != LOWERVP(bp->b_vp)); |
| 1800 | |
| 1801 | return (VOP_STRATEGY(ovp, bp)); |
| 1802 | } |
| 1803 | |
| 1804 | int |
| 1805 | union_bwrite(void *v) |
| 1806 | { |
| 1807 | struct vop_bwrite_args /* { |
| 1808 | struct vnode *a_vp; |
| 1809 | struct buf *a_bp; |
| 1810 | } */ *ap = v; |
| 1811 | struct vnode *ovp = OTHERVP(ap->a_vp); |
| 1812 | struct buf *bp = ap->a_bp; |
| 1813 | |
| 1814 | KASSERT(ovp != NULLVP); |
| 1815 | if (!NODE_IS_SPECIAL(ovp)) |
| 1816 | KASSERT((bp->b_flags & B_READ) || ovp != LOWERVP(bp->b_vp)); |
| 1817 | |
| 1818 | return (VOP_BWRITE(ovp, bp)); |
| 1819 | } |
| 1820 | |
| 1821 | int |
| 1822 | union_getpages(void *v) |
| 1823 | { |
| 1824 | struct vop_getpages_args /* { |
| 1825 | struct vnode *a_vp; |
| 1826 | voff_t a_offset; |
| 1827 | struct vm_page **a_m; |
| 1828 | int *a_count; |
| 1829 | int a_centeridx; |
| 1830 | vm_prot_t a_access_type; |
| 1831 | int a_advice; |
| 1832 | int a_flags; |
| 1833 | } */ *ap = v; |
| 1834 | struct vnode *vp = ap->a_vp; |
| 1835 | |
| 1836 | KASSERT(mutex_owned(vp->v_interlock)); |
| 1837 | |
| 1838 | if (ap->a_flags & PGO_LOCKED) { |
| 1839 | return EBUSY; |
| 1840 | } |
| 1841 | ap->a_vp = OTHERVP(vp); |
| 1842 | KASSERT(vp->v_interlock == ap->a_vp->v_interlock); |
| 1843 | |
| 1844 | /* Just pass the request on to the underlying layer. */ |
| 1845 | return VCALL(ap->a_vp, VOFFSET(vop_getpages), ap); |
| 1846 | } |
| 1847 | |
| 1848 | int |
| 1849 | union_putpages(void *v) |
| 1850 | { |
| 1851 | struct vop_putpages_args /* { |
| 1852 | struct vnode *a_vp; |
| 1853 | voff_t a_offlo; |
| 1854 | voff_t a_offhi; |
| 1855 | int a_flags; |
| 1856 | } */ *ap = v; |
| 1857 | struct vnode *vp = ap->a_vp; |
| 1858 | |
| 1859 | KASSERT(mutex_owned(vp->v_interlock)); |
| 1860 | |
| 1861 | ap->a_vp = OTHERVP(vp); |
| 1862 | KASSERT(vp->v_interlock == ap->a_vp->v_interlock); |
| 1863 | |
| 1864 | if (ap->a_flags & PGO_RECLAIM) { |
| 1865 | mutex_exit(vp->v_interlock); |
| 1866 | return 0; |
| 1867 | } |
| 1868 | |
| 1869 | /* Just pass the request on to the underlying layer. */ |
| 1870 | return VCALL(ap->a_vp, VOFFSET(vop_putpages), ap); |
| 1871 | } |
| 1872 | |
| 1873 | int |
| 1874 | union_kqfilter(void *v) |
| 1875 | { |
| 1876 | struct vop_kqfilter_args /* { |
| 1877 | struct vnode *a_vp; |
| 1878 | struct knote *a_kn; |
| 1879 | } */ *ap = v; |
| 1880 | int error; |
| 1881 | |
| 1882 | /* |
| 1883 | * We watch either the upper layer file (if it already exists), |
| 1884 | * or the lower layer one. If there is lower layer file only |
| 1885 | * at this moment, we will keep watching that lower layer file |
| 1886 | * even if upper layer file would be created later on. |
| 1887 | */ |
| 1888 | if (UPPERVP(ap->a_vp)) |
| 1889 | error = VOP_KQFILTER(UPPERVP(ap->a_vp), ap->a_kn); |
| 1890 | else if (LOWERVP(ap->a_vp)) |
| 1891 | error = VOP_KQFILTER(LOWERVP(ap->a_vp), ap->a_kn); |
| 1892 | else { |
| 1893 | /* panic? */ |
| 1894 | error = EOPNOTSUPP; |
| 1895 | } |
| 1896 | |
| 1897 | return (error); |
| 1898 | } |
| 1899 | |