1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1994, 1995 The Regents of the University of California. 5 * Copyright (c) 1994, 1995 Jan-Simon Pendry. 6 * Copyright (c) 2005, 2006, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc. 7 * Copyright (c) 2006, 2012 Daichi Goto <daichi@freebsd.org> 8 * All rights reserved. 9 * 10 * This code is derived from software donated to Berkeley by 11 * Jan-Simon Pendry. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. 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_vfsops.c 8.20 (Berkeley) 5/20/95 38 * $FreeBSD$ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kdb.h> 44 #include <sys/fcntl.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mount.h> 49 #include <sys/namei.h> 50 #include <sys/proc.h> 51 #include <sys/vnode.h> 52 #include <sys/stat.h> 53 54 #include <fs/unionfs/union.h> 55 56 static MALLOC_DEFINE(M_UNIONFSMNT, "UNIONFS mount", "UNIONFS mount structure"); 57 58 static vfs_fhtovp_t unionfs_fhtovp; 59 static vfs_checkexp_t unionfs_checkexp; 60 static vfs_mount_t unionfs_domount; 61 static vfs_quotactl_t unionfs_quotactl; 62 static vfs_root_t unionfs_root; 63 static vfs_sync_t unionfs_sync; 64 static vfs_statfs_t unionfs_statfs; 65 static vfs_unmount_t unionfs_unmount; 66 static vfs_vget_t unionfs_vget; 67 static vfs_extattrctl_t unionfs_extattrctl; 68 69 static struct vfsops unionfs_vfsops; 70 71 /* 72 * Mount unionfs layer. 73 */ 74 static int 75 unionfs_domount(struct mount *mp) 76 { 77 int error; 78 struct vnode *lowerrootvp; 79 struct vnode *upperrootvp; 80 struct unionfs_mount *ump; 81 struct thread *td; 82 char *target; 83 char *tmp; 84 char *ep; 85 int len; 86 size_t done; 87 int below; 88 uid_t uid; 89 gid_t gid; 90 u_short udir; 91 u_short ufile; 92 unionfs_copymode copymode; 93 unionfs_whitemode whitemode; 94 struct nameidata nd, *ndp; 95 struct vattr va; 96 97 UNIONFSDEBUG("unionfs_mount(mp = %p)\n", (void *)mp); 98 99 error = 0; 100 below = 0; 101 uid = 0; 102 gid = 0; 103 udir = 0; 104 ufile = 0; 105 copymode = UNIONFS_TRANSPARENT; /* default */ 106 whitemode = UNIONFS_WHITE_ALWAYS; 107 ndp = &nd; 108 td = curthread; 109 110 if (mp->mnt_flag & MNT_ROOTFS) { 111 vfs_mount_error(mp, "Cannot union mount root filesystem"); 112 return (EOPNOTSUPP); 113 } 114 115 /* 116 * Update is a no operation. 117 */ 118 if (mp->mnt_flag & MNT_UPDATE) { 119 vfs_mount_error(mp, "unionfs does not support mount update"); 120 return (EOPNOTSUPP); 121 } 122 123 /* 124 * Get argument 125 */ 126 error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len); 127 if (error) 128 error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target, 129 &len); 130 if (error || target[len - 1] != '\0') { 131 vfs_mount_error(mp, "Invalid target"); 132 return (EINVAL); 133 } 134 if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0) 135 below = 1; 136 if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) { 137 if (tmp != NULL) 138 udir = (mode_t)strtol(tmp, &ep, 8); 139 if (tmp == NULL || *ep) { 140 vfs_mount_error(mp, "Invalid udir"); 141 return (EINVAL); 142 } 143 udir &= S_IRWXU | S_IRWXG | S_IRWXO; 144 } 145 if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) { 146 if (tmp != NULL) 147 ufile = (mode_t)strtol(tmp, &ep, 8); 148 if (tmp == NULL || *ep) { 149 vfs_mount_error(mp, "Invalid ufile"); 150 return (EINVAL); 151 } 152 ufile &= S_IRWXU | S_IRWXG | S_IRWXO; 153 } 154 /* check umask, uid and gid */ 155 if (udir == 0 && ufile != 0) 156 udir = ufile; 157 if (ufile == 0 && udir != 0) 158 ufile = udir; 159 160 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 161 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 162 if (!error) { 163 if (udir == 0) 164 udir = va.va_mode; 165 if (ufile == 0) 166 ufile = va.va_mode; 167 uid = va.va_uid; 168 gid = va.va_gid; 169 } 170 VOP_UNLOCK(mp->mnt_vnodecovered, LK_RELEASE); 171 if (error) 172 return (error); 173 174 if (mp->mnt_cred->cr_ruid == 0) { /* root only */ 175 if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp, 176 NULL) == 0) { 177 if (tmp != NULL) 178 uid = (uid_t)strtol(tmp, &ep, 10); 179 if (tmp == NULL || *ep) { 180 vfs_mount_error(mp, "Invalid uid"); 181 return (EINVAL); 182 } 183 } 184 if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp, 185 NULL) == 0) { 186 if (tmp != NULL) 187 gid = (gid_t)strtol(tmp, &ep, 10); 188 if (tmp == NULL || *ep) { 189 vfs_mount_error(mp, "Invalid gid"); 190 return (EINVAL); 191 } 192 } 193 if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp, 194 NULL) == 0) { 195 if (tmp == NULL) { 196 vfs_mount_error(mp, "Invalid copymode"); 197 return (EINVAL); 198 } else if (strcasecmp(tmp, "traditional") == 0) 199 copymode = UNIONFS_TRADITIONAL; 200 else if (strcasecmp(tmp, "transparent") == 0) 201 copymode = UNIONFS_TRANSPARENT; 202 else if (strcasecmp(tmp, "masquerade") == 0) 203 copymode = UNIONFS_MASQUERADE; 204 else { 205 vfs_mount_error(mp, "Invalid copymode"); 206 return (EINVAL); 207 } 208 } 209 if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp, 210 NULL) == 0) { 211 if (tmp == NULL) { 212 vfs_mount_error(mp, "Invalid whiteout mode"); 213 return (EINVAL); 214 } else if (strcasecmp(tmp, "always") == 0) 215 whitemode = UNIONFS_WHITE_ALWAYS; 216 else if (strcasecmp(tmp, "whenneeded") == 0) 217 whitemode = UNIONFS_WHITE_WHENNEEDED; 218 else { 219 vfs_mount_error(mp, "Invalid whiteout mode"); 220 return (EINVAL); 221 } 222 } 223 } 224 /* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */ 225 if (copymode == UNIONFS_TRADITIONAL) { 226 uid = mp->mnt_cred->cr_ruid; 227 gid = mp->mnt_cred->cr_rgid; 228 } 229 230 UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid); 231 UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile); 232 UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode); 233 234 /* 235 * Find upper node 236 */ 237 NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, target, td); 238 if ((error = namei(ndp))) 239 return (error); 240 241 NDFREE(ndp, NDF_ONLY_PNBUF); 242 243 /* get root vnodes */ 244 lowerrootvp = mp->mnt_vnodecovered; 245 upperrootvp = ndp->ni_vp; 246 247 /* create unionfs_mount */ 248 ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount), 249 M_UNIONFSMNT, M_WAITOK | M_ZERO); 250 251 /* 252 * Save reference 253 */ 254 if (below) { 255 VOP_UNLOCK(upperrootvp, LK_RELEASE); 256 vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY); 257 ump->um_lowervp = upperrootvp; 258 ump->um_uppervp = lowerrootvp; 259 } else { 260 ump->um_lowervp = lowerrootvp; 261 ump->um_uppervp = upperrootvp; 262 } 263 ump->um_rootvp = NULLVP; 264 ump->um_uid = uid; 265 ump->um_gid = gid; 266 ump->um_udir = udir; 267 ump->um_ufile = ufile; 268 ump->um_copymode = copymode; 269 ump->um_whitemode = whitemode; 270 271 mp->mnt_data = ump; 272 273 /* 274 * Copy upper layer's RDONLY flag. 275 */ 276 mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY; 277 278 /* 279 * Unlock the node 280 */ 281 VOP_UNLOCK(ump->um_uppervp, LK_RELEASE); 282 283 /* 284 * Get the unionfs root vnode. 285 */ 286 error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp, 287 NULLVP, &(ump->um_rootvp), NULL, td); 288 vrele(upperrootvp); 289 if (error) { 290 free(ump, M_UNIONFSMNT); 291 mp->mnt_data = NULL; 292 return (error); 293 } 294 295 MNT_ILOCK(mp); 296 if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) && 297 (ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL)) 298 mp->mnt_flag |= MNT_LOCAL; 299 MNT_IUNLOCK(mp); 300 301 /* 302 * Get new fsid 303 */ 304 vfs_getnewfsid(mp); 305 306 len = MNAMELEN - 1; 307 tmp = mp->mnt_stat.f_mntfromname; 308 copystr((below ? "<below>:" : "<above>:"), tmp, len, &done); 309 len -= done - 1; 310 tmp += done - 1; 311 copystr(target, tmp, len, NULL); 312 313 UNIONFSDEBUG("unionfs_mount: from %s, on %s\n", 314 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 315 316 return (0); 317 } 318 319 /* 320 * Free reference to unionfs layer 321 */ 322 static int 323 unionfs_unmount(struct mount *mp, int mntflags) 324 { 325 struct unionfs_mount *ump; 326 int error; 327 int num; 328 int freeing; 329 int flags; 330 331 UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp); 332 333 ump = MOUNTTOUNIONFSMOUNT(mp); 334 flags = 0; 335 336 if (mntflags & MNT_FORCE) 337 flags |= FORCECLOSE; 338 339 /* vflush (no need to call vrele) */ 340 for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) { 341 num = mp->mnt_nvnodelistsize; 342 if (num == freeing) 343 break; 344 freeing = num; 345 } 346 347 if (error) 348 return (error); 349 350 free(ump, M_UNIONFSMNT); 351 mp->mnt_data = NULL; 352 353 return (0); 354 } 355 356 static int 357 unionfs_root(struct mount *mp, int flags, struct vnode **vpp) 358 { 359 struct unionfs_mount *ump; 360 struct vnode *vp; 361 362 ump = MOUNTTOUNIONFSMOUNT(mp); 363 vp = ump->um_rootvp; 364 365 UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n", 366 vp, VOP_ISLOCKED(vp)); 367 368 vref(vp); 369 if (flags & LK_TYPE_MASK) 370 vn_lock(vp, flags); 371 372 *vpp = vp; 373 374 return (0); 375 } 376 377 static int 378 unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg) 379 { 380 struct unionfs_mount *ump; 381 382 ump = MOUNTTOUNIONFSMOUNT(mp); 383 384 /* 385 * Writing is always performed to upper vnode. 386 */ 387 return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg)); 388 } 389 390 static int 391 unionfs_statfs(struct mount *mp, struct statfs *sbp) 392 { 393 struct unionfs_mount *ump; 394 int error; 395 struct statfs *mstat; 396 uint64_t lbsize; 397 398 ump = MOUNTTOUNIONFSMOUNT(mp); 399 400 UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n", 401 (void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp); 402 403 mstat = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK | M_ZERO); 404 405 error = VFS_STATFS(ump->um_lowervp->v_mount, mstat); 406 if (error) { 407 free(mstat, M_STATFS); 408 return (error); 409 } 410 411 /* now copy across the "interesting" information and fake the rest */ 412 sbp->f_blocks = mstat->f_blocks; 413 sbp->f_files = mstat->f_files; 414 415 lbsize = mstat->f_bsize; 416 417 error = VFS_STATFS(ump->um_uppervp->v_mount, mstat); 418 if (error) { 419 free(mstat, M_STATFS); 420 return (error); 421 } 422 423 424 /* 425 * The FS type etc is copy from upper vfs. 426 * (write able vfs have priority) 427 */ 428 sbp->f_type = mstat->f_type; 429 sbp->f_flags = mstat->f_flags; 430 sbp->f_bsize = mstat->f_bsize; 431 sbp->f_iosize = mstat->f_iosize; 432 433 if (mstat->f_bsize != lbsize) 434 sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) / 435 mstat->f_bsize; 436 437 sbp->f_blocks += mstat->f_blocks; 438 sbp->f_bfree = mstat->f_bfree; 439 sbp->f_bavail = mstat->f_bavail; 440 sbp->f_files += mstat->f_files; 441 sbp->f_ffree = mstat->f_ffree; 442 443 free(mstat, M_STATFS); 444 return (0); 445 } 446 447 static int 448 unionfs_sync(struct mount *mp, int waitfor) 449 { 450 /* nothing to do */ 451 return (0); 452 } 453 454 static int 455 unionfs_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp) 456 { 457 return (EOPNOTSUPP); 458 } 459 460 static int 461 unionfs_fhtovp(struct mount *mp, struct fid *fidp, int flags, 462 struct vnode **vpp) 463 { 464 return (EOPNOTSUPP); 465 } 466 467 static int 468 unionfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp, 469 struct ucred **credanonp, int *numsecflavors, int **secflavors) 470 { 471 return (EOPNOTSUPP); 472 } 473 474 static int 475 unionfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 476 int namespace, const char *attrname) 477 { 478 struct unionfs_mount *ump; 479 struct unionfs_node *unp; 480 481 ump = MOUNTTOUNIONFSMOUNT(mp); 482 unp = VTOUNIONFS(filename_vp); 483 484 if (unp->un_uppervp != NULLVP) { 485 return (VFS_EXTATTRCTL(ump->um_uppervp->v_mount, cmd, 486 unp->un_uppervp, namespace, attrname)); 487 } else { 488 return (VFS_EXTATTRCTL(ump->um_lowervp->v_mount, cmd, 489 unp->un_lowervp, namespace, attrname)); 490 } 491 } 492 493 static struct vfsops unionfs_vfsops = { 494 .vfs_checkexp = unionfs_checkexp, 495 .vfs_extattrctl = unionfs_extattrctl, 496 .vfs_fhtovp = unionfs_fhtovp, 497 .vfs_init = unionfs_init, 498 .vfs_mount = unionfs_domount, 499 .vfs_quotactl = unionfs_quotactl, 500 .vfs_root = unionfs_root, 501 .vfs_statfs = unionfs_statfs, 502 .vfs_sync = unionfs_sync, 503 .vfs_uninit = unionfs_uninit, 504 .vfs_unmount = unionfs_unmount, 505 .vfs_vget = unionfs_vget, 506 }; 507 508 VFS_SET(unionfs_vfsops, unionfs, VFCF_LOOPBACK); 509