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 int below; 87 uid_t uid; 88 gid_t gid; 89 u_short udir; 90 u_short ufile; 91 unionfs_copymode copymode; 92 unionfs_whitemode whitemode; 93 struct nameidata nd, *ndp; 94 struct vattr va; 95 96 UNIONFSDEBUG("unionfs_mount(mp = %p)\n", (void *)mp); 97 98 error = 0; 99 below = 0; 100 uid = 0; 101 gid = 0; 102 udir = 0; 103 ufile = 0; 104 copymode = UNIONFS_TRANSPARENT; /* default */ 105 whitemode = UNIONFS_WHITE_ALWAYS; 106 ndp = &nd; 107 td = curthread; 108 109 if (mp->mnt_flag & MNT_ROOTFS) { 110 vfs_mount_error(mp, "Cannot union mount root filesystem"); 111 return (EOPNOTSUPP); 112 } 113 114 /* 115 * Update is a no operation. 116 */ 117 if (mp->mnt_flag & MNT_UPDATE) { 118 vfs_mount_error(mp, "unionfs does not support mount update"); 119 return (EOPNOTSUPP); 120 } 121 122 /* 123 * Get argument 124 */ 125 error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len); 126 if (error) 127 error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target, 128 &len); 129 if (error || target[len - 1] != '\0') { 130 vfs_mount_error(mp, "Invalid target"); 131 return (EINVAL); 132 } 133 if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0) 134 below = 1; 135 if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) { 136 if (tmp != NULL) 137 udir = (mode_t)strtol(tmp, &ep, 8); 138 if (tmp == NULL || *ep) { 139 vfs_mount_error(mp, "Invalid udir"); 140 return (EINVAL); 141 } 142 udir &= S_IRWXU | S_IRWXG | S_IRWXO; 143 } 144 if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) { 145 if (tmp != NULL) 146 ufile = (mode_t)strtol(tmp, &ep, 8); 147 if (tmp == NULL || *ep) { 148 vfs_mount_error(mp, "Invalid ufile"); 149 return (EINVAL); 150 } 151 ufile &= S_IRWXU | S_IRWXG | S_IRWXO; 152 } 153 /* check umask, uid and gid */ 154 if (udir == 0 && ufile != 0) 155 udir = ufile; 156 if (ufile == 0 && udir != 0) 157 ufile = udir; 158 159 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 160 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 161 if (!error) { 162 if (udir == 0) 163 udir = va.va_mode; 164 if (ufile == 0) 165 ufile = va.va_mode; 166 uid = va.va_uid; 167 gid = va.va_gid; 168 } 169 VOP_UNLOCK(mp->mnt_vnodecovered); 170 if (error) 171 return (error); 172 173 if (mp->mnt_cred->cr_ruid == 0) { /* root only */ 174 if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp, 175 NULL) == 0) { 176 if (tmp != NULL) 177 uid = (uid_t)strtol(tmp, &ep, 10); 178 if (tmp == NULL || *ep) { 179 vfs_mount_error(mp, "Invalid uid"); 180 return (EINVAL); 181 } 182 } 183 if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp, 184 NULL) == 0) { 185 if (tmp != NULL) 186 gid = (gid_t)strtol(tmp, &ep, 10); 187 if (tmp == NULL || *ep) { 188 vfs_mount_error(mp, "Invalid gid"); 189 return (EINVAL); 190 } 191 } 192 if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp, 193 NULL) == 0) { 194 if (tmp == NULL) { 195 vfs_mount_error(mp, "Invalid copymode"); 196 return (EINVAL); 197 } else if (strcasecmp(tmp, "traditional") == 0) 198 copymode = UNIONFS_TRADITIONAL; 199 else if (strcasecmp(tmp, "transparent") == 0) 200 copymode = UNIONFS_TRANSPARENT; 201 else if (strcasecmp(tmp, "masquerade") == 0) 202 copymode = UNIONFS_MASQUERADE; 203 else { 204 vfs_mount_error(mp, "Invalid copymode"); 205 return (EINVAL); 206 } 207 } 208 if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp, 209 NULL) == 0) { 210 if (tmp == NULL) { 211 vfs_mount_error(mp, "Invalid whiteout mode"); 212 return (EINVAL); 213 } else if (strcasecmp(tmp, "always") == 0) 214 whitemode = UNIONFS_WHITE_ALWAYS; 215 else if (strcasecmp(tmp, "whenneeded") == 0) 216 whitemode = UNIONFS_WHITE_WHENNEEDED; 217 else { 218 vfs_mount_error(mp, "Invalid whiteout mode"); 219 return (EINVAL); 220 } 221 } 222 } 223 /* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */ 224 if (copymode == UNIONFS_TRADITIONAL) { 225 uid = mp->mnt_cred->cr_ruid; 226 gid = mp->mnt_cred->cr_rgid; 227 } 228 229 UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid); 230 UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile); 231 UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode); 232 233 /* 234 * Find upper node 235 */ 236 NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, target, td); 237 if ((error = namei(ndp))) 238 return (error); 239 240 NDFREE(ndp, NDF_ONLY_PNBUF); 241 242 /* get root vnodes */ 243 lowerrootvp = mp->mnt_vnodecovered; 244 upperrootvp = ndp->ni_vp; 245 246 /* create unionfs_mount */ 247 ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount), 248 M_UNIONFSMNT, M_WAITOK | M_ZERO); 249 250 /* 251 * Save reference 252 */ 253 if (below) { 254 VOP_UNLOCK(upperrootvp); 255 vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY); 256 ump->um_lowervp = upperrootvp; 257 ump->um_uppervp = lowerrootvp; 258 } else { 259 ump->um_lowervp = lowerrootvp; 260 ump->um_uppervp = upperrootvp; 261 } 262 ump->um_rootvp = NULLVP; 263 ump->um_uid = uid; 264 ump->um_gid = gid; 265 ump->um_udir = udir; 266 ump->um_ufile = ufile; 267 ump->um_copymode = copymode; 268 ump->um_whitemode = whitemode; 269 270 mp->mnt_data = ump; 271 272 /* 273 * Copy upper layer's RDONLY flag. 274 */ 275 mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY; 276 277 /* 278 * Unlock the node 279 */ 280 VOP_UNLOCK(ump->um_uppervp); 281 282 /* 283 * Get the unionfs root vnode. 284 */ 285 error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp, 286 NULLVP, &(ump->um_rootvp), NULL, td); 287 vrele(upperrootvp); 288 if (error) { 289 free(ump, M_UNIONFSMNT); 290 mp->mnt_data = NULL; 291 return (error); 292 } 293 294 MNT_ILOCK(mp); 295 if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) && 296 (ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL)) 297 mp->mnt_flag |= MNT_LOCAL; 298 mp->mnt_kern_flag |= MNTK_NOMSYNC | MNTK_UNIONFS; 299 MNT_IUNLOCK(mp); 300 301 /* 302 * Get new fsid 303 */ 304 vfs_getnewfsid(mp); 305 306 snprintf(mp->mnt_stat.f_mntfromname, MNAMELEN, "<%s>:%s", 307 below ? "below" : "above", target); 308 309 UNIONFSDEBUG("unionfs_mount: from %s, on %s\n", 310 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 311 312 return (0); 313 } 314 315 /* 316 * Free reference to unionfs layer 317 */ 318 static int 319 unionfs_unmount(struct mount *mp, int mntflags) 320 { 321 struct unionfs_mount *ump; 322 int error; 323 int num; 324 int freeing; 325 int flags; 326 327 UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp); 328 329 ump = MOUNTTOUNIONFSMOUNT(mp); 330 flags = 0; 331 332 if (mntflags & MNT_FORCE) 333 flags |= FORCECLOSE; 334 335 /* vflush (no need to call vrele) */ 336 for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) { 337 num = mp->mnt_nvnodelistsize; 338 if (num == freeing) 339 break; 340 freeing = num; 341 } 342 343 if (error) 344 return (error); 345 346 free(ump, M_UNIONFSMNT); 347 mp->mnt_data = NULL; 348 349 return (0); 350 } 351 352 static int 353 unionfs_root(struct mount *mp, int flags, struct vnode **vpp) 354 { 355 struct unionfs_mount *ump; 356 struct vnode *vp; 357 358 ump = MOUNTTOUNIONFSMOUNT(mp); 359 vp = ump->um_rootvp; 360 361 UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n", 362 vp, VOP_ISLOCKED(vp)); 363 364 vref(vp); 365 if (flags & LK_TYPE_MASK) 366 vn_lock(vp, flags); 367 368 *vpp = vp; 369 370 return (0); 371 } 372 373 static int 374 unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg) 375 { 376 struct unionfs_mount *ump; 377 378 ump = MOUNTTOUNIONFSMOUNT(mp); 379 380 /* 381 * Writing is always performed to upper vnode. 382 */ 383 return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg)); 384 } 385 386 static int 387 unionfs_statfs(struct mount *mp, struct statfs *sbp) 388 { 389 struct unionfs_mount *ump; 390 int error; 391 struct statfs *mstat; 392 uint64_t lbsize; 393 394 ump = MOUNTTOUNIONFSMOUNT(mp); 395 396 UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n", 397 (void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp); 398 399 mstat = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK | M_ZERO); 400 401 error = VFS_STATFS(ump->um_lowervp->v_mount, mstat); 402 if (error) { 403 free(mstat, M_STATFS); 404 return (error); 405 } 406 407 /* now copy across the "interesting" information and fake the rest */ 408 sbp->f_blocks = mstat->f_blocks; 409 sbp->f_files = mstat->f_files; 410 411 lbsize = mstat->f_bsize; 412 413 error = VFS_STATFS(ump->um_uppervp->v_mount, mstat); 414 if (error) { 415 free(mstat, M_STATFS); 416 return (error); 417 } 418 419 420 /* 421 * The FS type etc is copy from upper vfs. 422 * (write able vfs have priority) 423 */ 424 sbp->f_type = mstat->f_type; 425 sbp->f_flags = mstat->f_flags; 426 sbp->f_bsize = mstat->f_bsize; 427 sbp->f_iosize = mstat->f_iosize; 428 429 if (mstat->f_bsize != lbsize) 430 sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) / 431 mstat->f_bsize; 432 433 sbp->f_blocks += mstat->f_blocks; 434 sbp->f_bfree = mstat->f_bfree; 435 sbp->f_bavail = mstat->f_bavail; 436 sbp->f_files += mstat->f_files; 437 sbp->f_ffree = mstat->f_ffree; 438 439 free(mstat, M_STATFS); 440 return (0); 441 } 442 443 static int 444 unionfs_sync(struct mount *mp, int waitfor) 445 { 446 /* nothing to do */ 447 return (0); 448 } 449 450 static int 451 unionfs_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp) 452 { 453 return (EOPNOTSUPP); 454 } 455 456 static int 457 unionfs_fhtovp(struct mount *mp, struct fid *fidp, int flags, 458 struct vnode **vpp) 459 { 460 return (EOPNOTSUPP); 461 } 462 463 static int 464 unionfs_checkexp(struct mount *mp, struct sockaddr *nam, uint64_t *extflagsp, 465 struct ucred **credanonp, int *numsecflavors, int *secflavors) 466 { 467 return (EOPNOTSUPP); 468 } 469 470 static int 471 unionfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 472 int namespace, const char *attrname) 473 { 474 struct unionfs_mount *ump; 475 struct unionfs_node *unp; 476 477 ump = MOUNTTOUNIONFSMOUNT(mp); 478 unp = VTOUNIONFS(filename_vp); 479 480 if (unp->un_uppervp != NULLVP) { 481 return (VFS_EXTATTRCTL(ump->um_uppervp->v_mount, cmd, 482 unp->un_uppervp, namespace, attrname)); 483 } else { 484 return (VFS_EXTATTRCTL(ump->um_lowervp->v_mount, cmd, 485 unp->un_lowervp, namespace, attrname)); 486 } 487 } 488 489 static struct vfsops unionfs_vfsops = { 490 .vfs_checkexp = unionfs_checkexp, 491 .vfs_extattrctl = unionfs_extattrctl, 492 .vfs_fhtovp = unionfs_fhtovp, 493 .vfs_init = unionfs_init, 494 .vfs_mount = unionfs_domount, 495 .vfs_quotactl = unionfs_quotactl, 496 .vfs_root = unionfs_root, 497 .vfs_statfs = unionfs_statfs, 498 .vfs_sync = unionfs_sync, 499 .vfs_uninit = unionfs_uninit, 500 .vfs_unmount = unionfs_unmount, 501 .vfs_vget = unionfs_vget, 502 }; 503 504 VFS_SET(unionfs_vfsops, unionfs, VFCF_LOOPBACK); 505