ulfs_extattr.c revision 1.14
1 /* $NetBSD: ulfs_extattr.c,v 1.14 2016/11/09 05:44:42 dholland Exp $ */ 2 /* from NetBSD: ulfs_extattr.c,v 1.48 2016/11/09 05:08:35 dholland Exp */ 3 4 /*- 5 * Copyright (c) 1999-2002 Robert N. M. Watson 6 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 7 * All rights reserved. 8 * 9 * This software was developed by Robert Watson for the TrustedBSD Project. 10 * 11 * This software was developed for the FreeBSD Project in part by Network 12 * Associates Laboratories, the Security Research Division of Network 13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 14 * as part of the DARPA CHATS research program. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 */ 38 39 /* 40 * Support for file system extended attributes on the ULFS1 file system. 41 * 42 * Extended attributes are defined in the form name=value, where name is 43 * a nul-terminated string in the style of a file name, and value is a 44 * binary blob of zero or more bytes. The ULFS1 extended attribute service 45 * layers support for extended attributes onto a backing file, in the style 46 * of the quota implementation, meaning that it requires no underlying format 47 * changes to the file system. This design choice exchanges simplicity, 48 * usability, and easy deployment for performance. 49 */ 50 51 #include <sys/cdefs.h> 52 __KERNEL_RCSID(0, "$NetBSD: ulfs_extattr.c,v 1.14 2016/11/09 05:44:42 dholland Exp $"); 53 54 #ifdef _KERNEL_OPT 55 #include "opt_lfs.h" 56 #endif 57 58 #include <sys/param.h> 59 #include <sys/systm.h> 60 #include <sys/reboot.h> 61 #include <sys/kauth.h> 62 #include <sys/kernel.h> 63 #include <sys/namei.h> 64 #include <sys/kmem.h> 65 #include <sys/fcntl.h> 66 #include <sys/lwp.h> 67 #include <sys/vnode.h> 68 #include <sys/mount.h> 69 #include <sys/lock.h> 70 #include <sys/dirent.h> 71 #include <sys/extattr.h> 72 #include <sys/sysctl.h> 73 74 #include <ufs/lfs/ulfs_extattr.h> 75 #include <ufs/lfs/ulfsmount.h> 76 #include <ufs/lfs/ulfs_inode.h> 77 #include <ufs/lfs/ulfs_bswap.h> 78 #include <ufs/lfs/ulfs_extern.h> 79 80 int ulfs_extattr_sync = 1; 81 int ulfs_extattr_autocreate = 1024; 82 83 static int ulfs_extattr_valid_attrname(int attrnamespace, 84 const char *attrname); 85 static int ulfs_extattr_enable_with_open(struct ulfsmount *ump, 86 struct vnode *vp, int attrnamespace, const char *attrname, 87 struct lwp *l); 88 static int ulfs_extattr_enable(struct ulfsmount *ump, int attrnamespace, 89 const char *attrname, struct vnode *backing_vnode, 90 struct lwp *l); 91 static int ulfs_extattr_disable(struct ulfsmount *ump, int attrnamespace, 92 const char *attrname, struct lwp *l); 93 static int ulfs_extattr_get(struct vnode *vp, int attrnamespace, 94 const char *name, struct uio *uio, size_t *size, 95 kauth_cred_t cred, struct lwp *l); 96 static int ulfs_extattr_list(struct vnode *vp, int attrnamespace, 97 struct uio *uio, size_t *size, int flag, 98 kauth_cred_t cred, struct lwp *l); 99 static int ulfs_extattr_set(struct vnode *vp, int attrnamespace, 100 const char *name, struct uio *uio, kauth_cred_t cred, 101 struct lwp *l); 102 static int ulfs_extattr_rm(struct vnode *vp, int attrnamespace, 103 const char *name, kauth_cred_t cred, struct lwp *l); 104 static struct ulfs_extattr_list_entry *ulfs_extattr_find_attr(struct ulfsmount *, 105 int, const char *); 106 static int ulfs_extattr_get_header(struct vnode *, 107 struct ulfs_extattr_list_entry *, 108 struct ulfs_extattr_header *, off_t *); 109 110 /* 111 * Convert a FreeBSD extended attribute and namespace to a consistent string 112 * representation. 113 * 114 * The returned value, if not NULL, is guaranteed to be an allocated object 115 * of its size as returned by strlen() + 1 and must be freed by the caller. 116 */ 117 static char * 118 from_freebsd_extattr(int attrnamespace, const char *attrname) 119 { 120 const char *namespace; 121 char *attr; 122 size_t len; 123 124 if (attrnamespace == EXTATTR_NAMESPACE_SYSTEM) 125 namespace = "system"; 126 else if (attrnamespace == EXTATTR_NAMESPACE_USER) 127 namespace = "user"; 128 else 129 return NULL; 130 131 /* <namespace>.<attrname>\0 */ 132 len = strlen(namespace) + 1 + strlen(attrname) + 1; 133 134 attr = kmem_alloc(len, KM_SLEEP); 135 136 snprintf(attr, len, "%s.%s", namespace, attrname); 137 138 return attr; 139 } 140 141 /* 142 * Internal wrapper around a conversion-check-free sequence. 143 */ 144 static int 145 internal_extattr_check_cred(vnode_t *vp, int attrnamespace, const char *name, 146 kauth_cred_t cred, int access_mode) 147 { 148 char *attr; 149 int error; 150 151 attr = from_freebsd_extattr(attrnamespace, name); 152 if (attr == NULL) 153 return EINVAL; 154 155 error = extattr_check_cred(vp, attr, cred, access_mode); 156 157 kmem_free(attr, strlen(attr) + 1); 158 159 return error; 160 } 161 162 /* 163 * Per-FS attribute lock protecting attribute operations. 164 * XXX Right now there is a lot of lock contention due to having a single 165 * lock per-FS; really, this should be far more fine-grained. 166 */ 167 static void 168 ulfs_extattr_uepm_lock(struct ulfsmount *ump) 169 { 170 171 /* 172 * XXX This needs to be recursive for the following reasons: 173 * - it is taken in ulfs_extattr_vnode_inactive 174 * - which is called from VOP_INACTIVE 175 * - which can be triggered by any vrele, vput, or vn_close 176 * - several of these can happen while it's held 177 */ 178 if (mutex_owned(&ump->um_extattr.uepm_lock)) { 179 ump->um_extattr.uepm_lockcnt++; 180 return; 181 } 182 mutex_enter(&ump->um_extattr.uepm_lock); 183 } 184 185 static void 186 ulfs_extattr_uepm_unlock(struct ulfsmount *ump) 187 { 188 189 if (ump->um_extattr.uepm_lockcnt != 0) { 190 KASSERT(mutex_owned(&ump->um_extattr.uepm_lock)); 191 ump->um_extattr.uepm_lockcnt--; 192 return; 193 } 194 mutex_exit(&ump->um_extattr.uepm_lock); 195 } 196 197 /*- 198 * Determine whether the name passed is a valid name for an actual 199 * attribute. 200 * 201 * Invalid currently consists of: 202 * NULL pointer for attrname 203 * zero-length attrname (used to retrieve application attribute list) 204 */ 205 static int 206 ulfs_extattr_valid_attrname(int attrnamespace, const char *attrname) 207 { 208 209 if (attrname == NULL) 210 return (0); 211 if (strlen(attrname) == 0) 212 return (0); 213 return (1); 214 } 215 216 /* 217 * Autocreate an attribute storage 218 */ 219 static int 220 ulfs_extattr_autocreate_attr(struct vnode *vp, int attrnamespace, 221 const char *attrname, struct lwp *l, struct ulfs_extattr_list_entry **uelep) 222 { 223 struct mount *mp = vp->v_mount; 224 struct ulfsmount *ump = VFSTOULFS(mp); 225 struct vnode *backing_vp; 226 struct nameidata nd; 227 struct pathbuf *pb; 228 char *path; 229 struct ulfs_extattr_fileheader uef; 230 struct ulfs_extattr_list_entry *uele; 231 int error; 232 233 path = PNBUF_GET(); 234 235 /* 236 * We only support system and user namespace autocreation 237 */ 238 switch (attrnamespace) { 239 case EXTATTR_NAMESPACE_SYSTEM: 240 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s", 241 mp->mnt_stat.f_mntonname, 242 ULFS_EXTATTR_FSROOTSUBDIR, 243 ULFS_EXTATTR_SUBDIR_SYSTEM, 244 attrname); 245 break; 246 case EXTATTR_NAMESPACE_USER: 247 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s", 248 mp->mnt_stat.f_mntonname, 249 ULFS_EXTATTR_FSROOTSUBDIR, 250 ULFS_EXTATTR_SUBDIR_USER, 251 attrname); 252 break; 253 default: 254 PNBUF_PUT(path); 255 *uelep = NULL; 256 return EINVAL; 257 break; 258 } 259 260 /* 261 * Release extended attribute mount lock, otherwise 262 * we can deadlock with another thread that would lock 263 * vp after we unlock it below, and call 264 * ulfs_extattr_uepm_lock(ump), for instance 265 * in ulfs_getextattr(). 266 */ 267 ulfs_extattr_uepm_unlock(ump); 268 269 /* 270 * XXX unlock/lock should only be done when setting extattr 271 * on backing store or one of its parent directory 272 * including root, but we always do it for now. 273 */ 274 KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); 275 VOP_UNLOCK(vp); 276 277 pb = pathbuf_create(path); 278 NDINIT(&nd, CREATE, LOCKPARENT, pb); 279 280 /* 281 * Since we do not hold ulfs_extattr_uepm_lock anymore, 282 * another thread may race with us for backend creation, 283 * but only one can succeed here thanks to O_EXCL 284 */ 285 error = vn_open(&nd, O_CREAT|O_EXCL|O_RDWR, 0600); 286 287 /* 288 * Reacquire the lock on the vnode 289 */ 290 KASSERT(VOP_ISLOCKED(vp) == 0); 291 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 292 293 ulfs_extattr_uepm_lock(ump); 294 295 if (error != 0) { 296 pathbuf_destroy(pb); 297 PNBUF_PUT(path); 298 *uelep = NULL; 299 return error; 300 } 301 302 KASSERT(nd.ni_vp != NULL); 303 KASSERT(VOP_ISLOCKED(nd.ni_vp) == LK_EXCLUSIVE); 304 KASSERT(VOP_ISLOCKED(nd.ni_dvp) == 0); 305 306 /* 307 * backing_vp is the backing store. 308 */ 309 backing_vp = nd.ni_vp; 310 pathbuf_destroy(pb); 311 PNBUF_PUT(path); 312 313 uef.uef_magic = ULFS_EXTATTR_MAGIC; 314 uef.uef_version = ULFS_EXTATTR_VERSION; 315 uef.uef_size = ulfs_extattr_autocreate; 316 317 error = vn_rdwr(UIO_WRITE, backing_vp, &uef, sizeof(uef), 0, 318 UIO_SYSSPACE, IO_NODELOCKED|IO_APPEND, 319 l->l_cred, NULL, l); 320 321 VOP_UNLOCK(backing_vp); 322 323 if (error != 0) { 324 printf("%s: write uef header failed for %s, error = %d\n", 325 __func__, attrname, error); 326 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 327 *uelep = NULL; 328 return error; 329 } 330 331 /* 332 * Now enable attribute. 333 */ 334 error = ulfs_extattr_enable(ump,attrnamespace, attrname, backing_vp, l); 335 KASSERT(VOP_ISLOCKED(backing_vp) == 0); 336 337 if (error != 0) { 338 printf("%s: enable %s failed, error %d\n", 339 __func__, attrname, error); 340 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 341 *uelep = NULL; 342 return error; 343 } 344 345 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname); 346 if (uele == NULL) { 347 printf("%s: atttribute %s created but not found!\n", 348 __func__, attrname); 349 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 350 *uelep = NULL; 351 return ESRCH; /* really internal error */ 352 } 353 354 printf("%s: EA backing store autocreated for %s\n", 355 mp->mnt_stat.f_mntonname, attrname); 356 357 *uelep = uele; 358 return 0; 359 } 360 361 /* 362 * Locate an attribute given a name and mountpoint. 363 * Must be holding uepm lock for the mount point. 364 */ 365 static struct ulfs_extattr_list_entry * 366 ulfs_extattr_find_attr(struct ulfsmount *ump, int attrnamespace, 367 const char *attrname) 368 { 369 struct ulfs_extattr_list_entry *search_attribute; 370 371 for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list); 372 search_attribute != NULL; 373 search_attribute = LIST_NEXT(search_attribute, uele_entries)) { 374 if (!(strncmp(attrname, search_attribute->uele_attrname, 375 ULFS_EXTATTR_MAXEXTATTRNAME)) && 376 (attrnamespace == search_attribute->uele_attrnamespace)) { 377 return (search_attribute); 378 } 379 } 380 381 return (0); 382 } 383 384 /* 385 * Initialize per-FS structures supporting extended attributes. Do not 386 * start extended attributes yet. 387 */ 388 void 389 ulfs_extattr_uepm_init(struct ulfs_extattr_per_mount *uepm) 390 { 391 392 uepm->uepm_flags = 0; 393 uepm->uepm_lockcnt = 0; 394 395 LIST_INIT(&uepm->uepm_list); 396 mutex_init(&uepm->uepm_lock, MUTEX_DEFAULT, IPL_NONE); 397 uepm->uepm_flags |= ULFS_EXTATTR_UEPM_INITIALIZED; 398 } 399 400 /* 401 * Destroy per-FS structures supporting extended attributes. Assumes 402 * that EAs have already been stopped, and will panic if not. 403 */ 404 void 405 ulfs_extattr_uepm_destroy(struct ulfs_extattr_per_mount *uepm) 406 { 407 408 if (!(uepm->uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 409 panic("ulfs_extattr_uepm_destroy: not initialized"); 410 411 if ((uepm->uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 412 panic("ulfs_extattr_uepm_destroy: called while still started"); 413 414 /* 415 * It's not clear that either order for the next three lines is 416 * ideal, and it should never be a problem if this is only called 417 * during unmount, and with vfs_busy(). 418 */ 419 uepm->uepm_flags &= ~ULFS_EXTATTR_UEPM_STARTED; 420 uepm->uepm_flags &= ~ULFS_EXTATTR_UEPM_INITIALIZED; 421 mutex_destroy(&uepm->uepm_lock); 422 } 423 424 /* 425 * Start extended attribute support on an FS. 426 */ 427 int 428 ulfs_extattr_start(struct mount *mp, struct lwp *l) 429 { 430 struct ulfsmount *ump; 431 int error = 0; 432 433 ump = VFSTOULFS(mp); 434 435 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 436 ulfs_extattr_uepm_init(&ump->um_extattr); 437 438 ulfs_extattr_uepm_lock(ump); 439 440 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) { 441 error = EOPNOTSUPP; 442 goto unlock; 443 } 444 if (ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED) { 445 error = EBUSY; 446 goto unlock; 447 } 448 449 ump->um_extattr.uepm_flags |= ULFS_EXTATTR_UEPM_STARTED; 450 451 ump->um_extattr.uepm_ucred = l->l_cred; 452 kauth_cred_hold(ump->um_extattr.uepm_ucred); 453 454 unlock: 455 ulfs_extattr_uepm_unlock(ump); 456 457 return (error); 458 } 459 460 /* 461 * Helper routine: given a locked parent directory and filename, return 462 * the locked vnode of the inode associated with the name. Will not 463 * follow symlinks, may return any type of vnode. Lock on parent will 464 * be released even in the event of a failure. In the event that the 465 * target is the parent (i.e., "."), there will be two references and 466 * one lock, requiring the caller to possibly special-case. 467 */ 468 static int 469 ulfs_extattr_lookup(struct vnode *start_dvp, int lockparent, const char *dirname, 470 struct vnode **vp, struct lwp *l) 471 { 472 struct vop_lookup_v2_args vargs; 473 struct componentname cnp; 474 struct vnode *target_vp; 475 char *pnbuf; 476 int error; 477 478 KASSERT(VOP_ISLOCKED(start_dvp) == LK_EXCLUSIVE); 479 480 pnbuf = PNBUF_GET(); 481 482 memset(&cnp, 0, sizeof(cnp)); 483 cnp.cn_nameiop = LOOKUP; 484 cnp.cn_flags = ISLASTCN | lockparent; 485 cnp.cn_cred = l->l_cred; 486 cnp.cn_nameptr = pnbuf; 487 error = copystr(dirname, pnbuf, MAXPATHLEN, &cnp.cn_namelen); 488 if (error) { 489 if (lockparent == 0) { 490 VOP_UNLOCK(start_dvp); 491 } 492 PNBUF_PUT(pnbuf); 493 printf("ulfs_extattr_lookup: copystr failed\n"); 494 return (error); 495 } 496 cnp.cn_namelen--; /* trim nul termination */ 497 vargs.a_desc = NULL; 498 vargs.a_dvp = start_dvp; 499 vargs.a_vpp = &target_vp; 500 vargs.a_cnp = &cnp; 501 error = ulfs_lookup(&vargs); 502 PNBUF_PUT(pnbuf); 503 if (error) { 504 if (lockparent == 0) { 505 VOP_UNLOCK(start_dvp); 506 } 507 return (error); 508 } 509 #if 0 510 if (target_vp == start_dvp) 511 panic("ulfs_extattr_lookup: target_vp == start_dvp"); 512 #endif 513 514 if (target_vp != start_dvp) { 515 error = vn_lock(target_vp, LK_EXCLUSIVE); 516 if (lockparent == 0) 517 VOP_UNLOCK(start_dvp); 518 if (error) { 519 vrele(target_vp); 520 return error; 521 } 522 } 523 524 KASSERT(VOP_ISLOCKED(target_vp) == LK_EXCLUSIVE); 525 *vp = target_vp; 526 return (0); 527 } 528 529 /* 530 * Enable an EA using the passed filesystem, backing vnode, attribute name, 531 * namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp 532 * to be locked when passed in. The vnode will be returned unlocked, 533 * regardless of success/failure of the function. As a result, the caller 534 * will always need to vrele(), but not vput(). 535 */ 536 static int 537 ulfs_extattr_enable_with_open(struct ulfsmount *ump, struct vnode *vp, 538 int attrnamespace, const char *attrname, struct lwp *l) 539 { 540 int error; 541 542 error = VOP_OPEN(vp, FREAD|FWRITE, l->l_cred); 543 if (error) { 544 printf("ulfs_extattr_enable_with_open.VOP_OPEN(): failed " 545 "with %d\n", error); 546 VOP_UNLOCK(vp); 547 return (error); 548 } 549 550 mutex_enter(vp->v_interlock); 551 vp->v_writecount++; 552 mutex_exit(vp->v_interlock); 553 554 vref(vp); 555 556 VOP_UNLOCK(vp); 557 558 error = ulfs_extattr_enable(ump, attrnamespace, attrname, vp, l); 559 if (error != 0) 560 vn_close(vp, FREAD|FWRITE, l->l_cred); 561 return (error); 562 } 563 564 /* 565 * Given a locked directory vnode, iterate over the names in the directory 566 * and use ulfs_extattr_lookup() to retrieve locked vnodes of potential 567 * attribute files. Then invoke ulfs_extattr_enable_with_open() on each 568 * to attempt to start the attribute. Leaves the directory locked on 569 * exit. 570 */ 571 static int 572 ulfs_extattr_iterate_directory(struct ulfsmount *ump, struct vnode *dvp, 573 int attrnamespace, struct lwp *l) 574 { 575 struct vop_readdir_args vargs; 576 struct statvfs *sbp = &ump->um_mountp->mnt_stat; 577 struct dirent *dp, *edp; 578 struct vnode *attr_vp; 579 struct uio auio; 580 struct iovec aiov; 581 char *dirbuf; 582 int error, eofflag = 0; 583 584 if (dvp->v_type != VDIR) 585 return (ENOTDIR); 586 587 dirbuf = kmem_alloc(LFS_DIRBLKSIZ, KM_SLEEP); 588 589 auio.uio_iov = &aiov; 590 auio.uio_iovcnt = 1; 591 auio.uio_rw = UIO_READ; 592 auio.uio_offset = 0; 593 UIO_SETUP_SYSSPACE(&auio); 594 595 vargs.a_desc = NULL; 596 vargs.a_vp = dvp; 597 vargs.a_uio = &auio; 598 vargs.a_cred = l->l_cred; 599 vargs.a_eofflag = &eofflag; 600 vargs.a_ncookies = NULL; 601 vargs.a_cookies = NULL; 602 603 while (!eofflag) { 604 auio.uio_resid = LFS_DIRBLKSIZ; 605 aiov.iov_base = dirbuf; 606 aiov.iov_len = LFS_DIRBLKSIZ; 607 error = ulfs_readdir(&vargs); 608 if (error) { 609 printf("ulfs_extattr_iterate_directory: ulfs_readdir " 610 "%d\n", error); 611 return (error); 612 } 613 614 /* 615 * XXXRW: While in LFS, we always get LFS_DIRBLKSIZ returns from 616 * the directory code on success, on other file systems this 617 * may not be the case. For portability, we should check the 618 * read length on return from ulfs_readdir(). 619 */ 620 edp = (struct dirent *)&dirbuf[LFS_DIRBLKSIZ]; 621 for (dp = (struct dirent *)dirbuf; dp < edp; ) { 622 if (dp->d_reclen == 0) 623 break; 624 /* Skip "." and ".." */ 625 if (dp->d_name[0] == '.' && 626 (dp->d_name[1] == '\0' || 627 (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) 628 goto next; 629 error = ulfs_extattr_lookup(dvp, LOCKPARENT, 630 dp->d_name, &attr_vp, l); 631 if (error == ENOENT) { 632 goto next; /* keep silent */ 633 } else if (error) { 634 printf("ulfs_extattr_iterate_directory: lookup " 635 "%s %d\n", dp->d_name, error); 636 } else if (attr_vp == dvp) { 637 vrele(attr_vp); 638 } else if (attr_vp->v_type != VREG) { 639 vput(attr_vp); 640 } else { 641 error = ulfs_extattr_enable_with_open(ump, 642 attr_vp, attrnamespace, dp->d_name, l); 643 vrele(attr_vp); 644 if (error) { 645 printf("ulfs_extattr_iterate_directory: " 646 "enable %s %d\n", dp->d_name, 647 error); 648 } else if (bootverbose) { 649 printf("%s: EA %s loaded\n", 650 sbp->f_mntonname, dp->d_name); 651 } 652 } 653 next: 654 dp = (struct dirent *) ((char *)dp + dp->d_reclen); 655 if (dp >= edp) 656 break; 657 } 658 } 659 kmem_free(dirbuf, LFS_DIRBLKSIZ); 660 661 return (0); 662 } 663 664 /* 665 * Auto-start of extended attributes, to be executed (optionally) at 666 * mount-time. 667 */ 668 int 669 ulfs_extattr_autostart(struct mount *mp, struct lwp *l) 670 { 671 struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp; 672 int error; 673 674 /* 675 * Does ULFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root? 676 * If so, automatically start EA's. 677 */ 678 error = VFS_ROOT(mp, &rvp); 679 if (error) { 680 printf("ulfs_extattr_autostart.VFS_ROOT() returned %d\n", 681 error); 682 return (error); 683 } 684 685 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE); 686 687 error = ulfs_extattr_lookup(rvp, 0, 688 ULFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, l); 689 if (error) { 690 /* rvp ref'd but now unlocked */ 691 KASSERT(VOP_ISLOCKED(rvp) == 0); 692 vrele(rvp); 693 return (error); 694 } 695 if (rvp == attr_dvp) { 696 /* Should never happen. */ 697 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE); 698 vrele(attr_dvp); 699 vput(rvp); 700 return (EINVAL); 701 } 702 KASSERT(VOP_ISLOCKED(rvp) == 0); 703 vrele(rvp); 704 705 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 706 707 if (attr_dvp->v_type != VDIR) { 708 printf("ulfs_extattr_autostart: %s != VDIR\n", 709 ULFS_EXTATTR_FSROOTSUBDIR); 710 goto return_vput_attr_dvp; 711 } 712 713 error = ulfs_extattr_start(mp, l); 714 if (error) { 715 printf("ulfs_extattr_autostart: ulfs_extattr_start failed (%d)\n", 716 error); 717 goto return_vput_attr_dvp; 718 } 719 720 /* 721 * Look for two subdirectories: ULFS_EXTATTR_SUBDIR_SYSTEM, 722 * ULFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory, 723 * and start with appropriate type. Failures in either don't 724 * result in an over-all failure. attr_dvp is left locked to 725 * be cleaned up on exit. 726 */ 727 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT, 728 ULFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, l); 729 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 730 if (error == 0) { 731 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE); 732 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp), 733 attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, l); 734 if (error) 735 printf("ulfs_extattr_iterate_directory returned %d\n", 736 error); 737 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE); 738 vput(attr_system_dvp); 739 } 740 741 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT, 742 ULFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, l); 743 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 744 if (error == 0) { 745 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE); 746 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp), 747 attr_user_dvp, EXTATTR_NAMESPACE_USER, l); 748 if (error) 749 printf("ulfs_extattr_iterate_directory returned %d\n", 750 error); 751 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE); 752 vput(attr_user_dvp); 753 } 754 755 /* Mask startup failures in sub-directories. */ 756 error = 0; 757 758 return_vput_attr_dvp: 759 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 760 vput(attr_dvp); 761 762 return (error); 763 } 764 765 /* 766 * Stop extended attribute support on an FS. 767 */ 768 void 769 ulfs_extattr_stop(struct mount *mp, struct lwp *l) 770 { 771 struct ulfs_extattr_list_entry *uele; 772 struct ulfsmount *ump = VFSTOULFS(mp); 773 774 ulfs_extattr_uepm_lock(ump); 775 776 /* 777 * If we haven't been started, no big deal. Just short-circuit 778 * the processing work. 779 */ 780 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) { 781 goto unlock; 782 } 783 784 while (LIST_FIRST(&ump->um_extattr.uepm_list) != NULL) { 785 uele = LIST_FIRST(&ump->um_extattr.uepm_list); 786 ulfs_extattr_disable(ump, uele->uele_attrnamespace, 787 uele->uele_attrname, l); 788 } 789 790 ump->um_extattr.uepm_flags &= ~ULFS_EXTATTR_UEPM_STARTED; 791 792 kauth_cred_free(ump->um_extattr.uepm_ucred); 793 ump->um_extattr.uepm_ucred = NULL; 794 795 unlock: 796 ulfs_extattr_uepm_unlock(ump); 797 } 798 799 /* 800 * Enable a named attribute on the specified filesystem; provide an 801 * unlocked backing vnode to hold the attribute data. 802 */ 803 static int 804 ulfs_extattr_enable(struct ulfsmount *ump, int attrnamespace, 805 const char *attrname, struct vnode *backing_vnode, struct lwp *l) 806 { 807 struct ulfs_extattr_list_entry *attribute; 808 struct iovec aiov; 809 struct uio auio; 810 int error = 0; 811 812 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname)) 813 return (EINVAL); 814 if (backing_vnode->v_type != VREG) 815 return (EINVAL); 816 817 attribute = kmem_zalloc(sizeof(*attribute), KM_SLEEP); 818 819 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) { 820 error = EOPNOTSUPP; 821 goto free_exit; 822 } 823 824 if (ulfs_extattr_find_attr(ump, attrnamespace, attrname)) { 825 error = EEXIST; 826 goto free_exit; 827 } 828 829 strncpy(attribute->uele_attrname, attrname, 830 ULFS_EXTATTR_MAXEXTATTRNAME); 831 attribute->uele_attrnamespace = attrnamespace; 832 memset(&attribute->uele_fileheader, 0, 833 sizeof(struct ulfs_extattr_fileheader)); 834 835 attribute->uele_backing_vnode = backing_vnode; 836 837 auio.uio_iov = &aiov; 838 auio.uio_iovcnt = 1; 839 aiov.iov_base = (void *) &attribute->uele_fileheader; 840 aiov.iov_len = sizeof(struct ulfs_extattr_fileheader); 841 auio.uio_resid = sizeof(struct ulfs_extattr_fileheader); 842 auio.uio_offset = (off_t) 0; 843 auio.uio_rw = UIO_READ; 844 UIO_SETUP_SYSSPACE(&auio); 845 846 vn_lock(backing_vnode, LK_SHARED | LK_RETRY); 847 error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED, 848 ump->um_extattr.uepm_ucred); 849 850 if (error) 851 goto unlock_free_exit; 852 853 if (auio.uio_resid != 0) { 854 printf("ulfs_extattr_enable: malformed attribute header\n"); 855 error = EINVAL; 856 goto unlock_free_exit; 857 } 858 859 /* 860 * Try to determine the byte order of the attribute file. 861 */ 862 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) { 863 attribute->uele_flags |= UELE_F_NEEDSWAP; 864 attribute->uele_fileheader.uef_magic = 865 ulfs_rw32(attribute->uele_fileheader.uef_magic, 866 UELE_NEEDSWAP(attribute)); 867 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) { 868 printf("ulfs_extattr_enable: invalid attribute header " 869 "magic\n"); 870 error = EINVAL; 871 goto unlock_free_exit; 872 } 873 } 874 attribute->uele_fileheader.uef_version = 875 ulfs_rw32(attribute->uele_fileheader.uef_version, 876 UELE_NEEDSWAP(attribute)); 877 attribute->uele_fileheader.uef_size = 878 ulfs_rw32(attribute->uele_fileheader.uef_size, 879 UELE_NEEDSWAP(attribute)); 880 881 if (attribute->uele_fileheader.uef_version != ULFS_EXTATTR_VERSION) { 882 printf("ulfs_extattr_enable: incorrect attribute header " 883 "version\n"); 884 error = EINVAL; 885 goto unlock_free_exit; 886 } 887 888 LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute, 889 uele_entries); 890 891 VOP_UNLOCK(backing_vnode); 892 return (0); 893 894 unlock_free_exit: 895 VOP_UNLOCK(backing_vnode); 896 897 free_exit: 898 kmem_free(attribute, sizeof(*attribute)); 899 return (error); 900 } 901 902 /* 903 * Disable extended attribute support on an FS. 904 */ 905 static int 906 ulfs_extattr_disable(struct ulfsmount *ump, int attrnamespace, 907 const char *attrname, struct lwp *l) 908 { 909 struct ulfs_extattr_list_entry *uele; 910 int error = 0; 911 912 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname)) 913 return (EINVAL); 914 915 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname); 916 if (!uele) 917 return (ENODATA); 918 919 LIST_REMOVE(uele, uele_entries); 920 921 error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE, 922 l->l_cred); 923 924 kmem_free(uele, sizeof(*uele)); 925 926 return (error); 927 } 928 929 /* 930 * VFS call to manage extended attributes in ULFS. If filename_vp is 931 * non-NULL, it must be passed in locked, and regardless of errors in 932 * processing, will be unlocked. 933 */ 934 int 935 ulfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 936 int attrnamespace, const char *attrname) 937 { 938 struct lwp *l = curlwp; 939 struct ulfsmount *ump = VFSTOULFS(mp); 940 int error; 941 942 /* 943 * Only privileged processes can configure extended attributes. 944 */ 945 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_EXTATTR, 946 0, mp, NULL, NULL); 947 if (error) { 948 if (filename_vp != NULL) 949 VOP_UNLOCK(filename_vp); 950 return (error); 951 } 952 953 switch(cmd) { 954 case ULFS_EXTATTR_CMD_START: 955 if (filename_vp != NULL) { 956 VOP_UNLOCK(filename_vp); 957 return (EINVAL); 958 } 959 if (attrname != NULL) 960 return (EINVAL); 961 962 error = ulfs_extattr_autostart(mp, l); 963 return (error); 964 965 case ULFS_EXTATTR_CMD_STOP: 966 if (filename_vp != NULL) { 967 VOP_UNLOCK(filename_vp); 968 return (EINVAL); 969 } 970 if (attrname != NULL) 971 return (EINVAL); 972 973 ulfs_extattr_stop(mp, l); 974 return (0); 975 976 case ULFS_EXTATTR_CMD_ENABLE: 977 if (filename_vp == NULL) 978 return (EINVAL); 979 if (attrname == NULL) { 980 VOP_UNLOCK(filename_vp); 981 return (EINVAL); 982 } 983 984 /* 985 * ulfs_extattr_enable_with_open() will always unlock the 986 * vnode, regardless of failure. 987 */ 988 ulfs_extattr_uepm_lock(ump); 989 error = ulfs_extattr_enable_with_open(ump, filename_vp, 990 attrnamespace, attrname, l); 991 ulfs_extattr_uepm_unlock(ump); 992 return (error); 993 994 case ULFS_EXTATTR_CMD_DISABLE: 995 if (filename_vp != NULL) { 996 VOP_UNLOCK(filename_vp); 997 return (EINVAL); 998 } 999 if (attrname == NULL) 1000 return (EINVAL); 1001 1002 ulfs_extattr_uepm_lock(ump); 1003 error = ulfs_extattr_disable(ump, attrnamespace, attrname, l); 1004 ulfs_extattr_uepm_unlock(ump); 1005 return (error); 1006 1007 default: 1008 return (EINVAL); 1009 } 1010 } 1011 1012 /* 1013 * Read extended attribute header for a given vnode and attribute. 1014 * Backing vnode should be locked and unlocked by caller. 1015 */ 1016 static int 1017 ulfs_extattr_get_header(struct vnode *vp, struct ulfs_extattr_list_entry *uele, 1018 struct ulfs_extattr_header *ueh, off_t *bap) 1019 { 1020 struct mount *mp = vp->v_mount; 1021 struct ulfsmount *ump = VFSTOULFS(mp); 1022 struct inode *ip = VTOI(vp); 1023 off_t base_offset; 1024 struct iovec aiov; 1025 struct uio aio; 1026 int error; 1027 1028 /* 1029 * Find base offset of header in file based on file header size, and 1030 * data header size + maximum data size, indexed by inode number. 1031 */ 1032 base_offset = sizeof(struct ulfs_extattr_fileheader) + 1033 ip->i_number * (sizeof(struct ulfs_extattr_header) + 1034 uele->uele_fileheader.uef_size); 1035 1036 /* 1037 * Read in the data header to see if the data is defined, and if so 1038 * how much. 1039 */ 1040 memset(ueh, 0, sizeof(struct ulfs_extattr_header)); 1041 aiov.iov_base = ueh; 1042 aiov.iov_len = sizeof(struct ulfs_extattr_header); 1043 aio.uio_iov = &aiov; 1044 aio.uio_iovcnt = 1; 1045 aio.uio_rw = UIO_READ; 1046 aio.uio_offset = base_offset; 1047 aio.uio_resid = sizeof(struct ulfs_extattr_header); 1048 UIO_SETUP_SYSSPACE(&aio); 1049 1050 error = VOP_READ(uele->uele_backing_vnode, &aio, 1051 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1052 if (error) 1053 return error; 1054 1055 /* 1056 * Attribute headers are kept in file system byte order. 1057 * XXX What about the blob of data? 1058 */ 1059 ueh->ueh_flags = ulfs_rw32(ueh->ueh_flags, UELE_NEEDSWAP(uele)); 1060 ueh->ueh_len = ulfs_rw32(ueh->ueh_len, UELE_NEEDSWAP(uele)); 1061 ueh->ueh_i_gen = ulfs_rw32(ueh->ueh_i_gen, UELE_NEEDSWAP(uele)); 1062 1063 /* Defined? */ 1064 if ((ueh->ueh_flags & ULFS_EXTATTR_ATTR_FLAG_INUSE) == 0) 1065 return ENODATA; 1066 1067 /* Valid for the current inode generation? */ 1068 if (ueh->ueh_i_gen != ip->i_gen) { 1069 /* 1070 * The inode itself has a different generation number 1071 * than the uele data. For now, the best solution 1072 * is to coerce this to undefined, and let it get cleaned 1073 * up by the next write or extattrctl clean. 1074 */ 1075 printf("%s (%s): inode gen inconsistency (%u, %jd)\n", 1076 __func__, mp->mnt_stat.f_mntonname, ueh->ueh_i_gen, 1077 (intmax_t)ip->i_gen); 1078 return ENODATA; 1079 } 1080 1081 /* Local size consistency check. */ 1082 if (ueh->ueh_len > uele->uele_fileheader.uef_size) 1083 return ENXIO; 1084 1085 /* Return base offset */ 1086 if (bap != NULL) 1087 *bap = base_offset; 1088 1089 return 0; 1090 } 1091 1092 /* 1093 * Vnode operation to retrieve a named extended attribute. 1094 */ 1095 int 1096 ulfs_getextattr(struct vop_getextattr_args *ap) 1097 /* 1098 vop_getextattr { 1099 IN struct vnode *a_vp; 1100 IN int a_attrnamespace; 1101 IN const char *a_name; 1102 INOUT struct uio *a_uio; 1103 OUT size_t *a_size; 1104 IN kauth_cred_t a_cred; 1105 }; 1106 */ 1107 { 1108 struct mount *mp = ap->a_vp->v_mount; 1109 struct ulfsmount *ump = VFSTOULFS(mp); 1110 int error; 1111 1112 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1113 return (EOPNOTSUPP); 1114 1115 ulfs_extattr_uepm_lock(ump); 1116 1117 error = ulfs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1118 ap->a_uio, ap->a_size, ap->a_cred, curlwp); 1119 1120 ulfs_extattr_uepm_unlock(ump); 1121 1122 return (error); 1123 } 1124 1125 /* 1126 * Real work associated with retrieving a named attribute--assumes that 1127 * the attribute lock has already been grabbed. 1128 */ 1129 static int 1130 ulfs_extattr_get(struct vnode *vp, int attrnamespace, const char *name, 1131 struct uio *uio, size_t *size, kauth_cred_t cred, struct lwp *l) 1132 { 1133 struct ulfs_extattr_list_entry *attribute; 1134 struct ulfs_extattr_header ueh; 1135 struct mount *mp = vp->v_mount; 1136 struct ulfsmount *ump = VFSTOULFS(mp); 1137 off_t base_offset; 1138 size_t len, old_len; 1139 int error = 0; 1140 1141 if (strlen(name) == 0) 1142 return (EINVAL); 1143 1144 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1145 VREAD); 1146 if (error) 1147 return (error); 1148 1149 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1150 if (!attribute) 1151 return (ENODATA); 1152 1153 /* 1154 * Allow only offsets of zero to encourage the read/replace 1155 * extended attribute semantic. Otherwise we can't guarantee 1156 * atomicity, as we don't provide locks for extended attributes. 1157 */ 1158 if (uio != NULL && uio->uio_offset != 0) 1159 return (ENXIO); 1160 1161 /* 1162 * Don't need to get a lock on the backing file if the getattr is 1163 * being applied to the backing file, as the lock is already held. 1164 */ 1165 if (attribute->uele_backing_vnode != vp) 1166 vn_lock(attribute->uele_backing_vnode, LK_SHARED | LK_RETRY); 1167 1168 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset); 1169 if (error) 1170 goto vopunlock_exit; 1171 1172 /* Return full data size if caller requested it. */ 1173 if (size != NULL) 1174 *size = ueh.ueh_len; 1175 1176 /* Return data if the caller requested it. */ 1177 if (uio != NULL) { 1178 /* Allow for offset into the attribute data. */ 1179 uio->uio_offset = base_offset + sizeof(struct 1180 ulfs_extattr_header); 1181 1182 /* 1183 * Figure out maximum to transfer -- use buffer size and 1184 * local data limit. 1185 */ 1186 len = MIN(uio->uio_resid, ueh.ueh_len); 1187 old_len = uio->uio_resid; 1188 uio->uio_resid = len; 1189 1190 error = VOP_READ(attribute->uele_backing_vnode, uio, 1191 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1192 if (error) 1193 goto vopunlock_exit; 1194 1195 uio->uio_resid = old_len - (len - uio->uio_resid); 1196 } 1197 1198 vopunlock_exit: 1199 1200 if (uio != NULL) 1201 uio->uio_offset = 0; 1202 1203 if (attribute->uele_backing_vnode != vp) 1204 VOP_UNLOCK(attribute->uele_backing_vnode); 1205 1206 return (error); 1207 } 1208 1209 /* 1210 * Vnode operation to list extended attribute for a vnode 1211 */ 1212 int 1213 ulfs_listextattr(struct vop_listextattr_args *ap) 1214 /* 1215 vop_listextattr { 1216 IN struct vnode *a_vp; 1217 IN int a_attrnamespace; 1218 INOUT struct uio *a_uio; 1219 OUT size_t *a_size; 1220 IN int flag; 1221 IN kauth_cred_t a_cred; 1222 struct proc *a_p; 1223 }; 1224 */ 1225 { 1226 struct mount *mp = ap->a_vp->v_mount; 1227 struct ulfsmount *ump = VFSTOULFS(mp); 1228 int error; 1229 1230 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1231 return (EOPNOTSUPP); 1232 1233 ulfs_extattr_uepm_lock(ump); 1234 1235 error = ulfs_extattr_list(ap->a_vp, ap->a_attrnamespace, 1236 ap->a_uio, ap->a_size, ap->a_flag, ap->a_cred, curlwp); 1237 1238 ulfs_extattr_uepm_unlock(ump); 1239 1240 return (error); 1241 } 1242 1243 /* 1244 * Real work associated with retrieving list of attributes--assumes that 1245 * the attribute lock has already been grabbed. 1246 */ 1247 static int 1248 ulfs_extattr_list(struct vnode *vp, int attrnamespace, 1249 struct uio *uio, size_t *size, int flag, 1250 kauth_cred_t cred, struct lwp *l) 1251 { 1252 struct ulfs_extattr_list_entry *uele; 1253 struct ulfs_extattr_header ueh; 1254 struct mount *mp = vp->v_mount; 1255 struct ulfsmount *ump = VFSTOULFS(mp); 1256 size_t listsize = 0; 1257 int error = 0; 1258 1259 /* 1260 * XXX: We can move this inside the loop and iterate on individual 1261 * attributes. 1262 */ 1263 error = internal_extattr_check_cred(vp, attrnamespace, "", cred, 1264 VREAD); 1265 if (error) 1266 return (error); 1267 1268 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) { 1269 unsigned char attrnamelen; 1270 1271 if (uele->uele_attrnamespace != attrnamespace) 1272 continue; 1273 1274 error = ulfs_extattr_get_header(vp, uele, &ueh, NULL); 1275 if (error == ENODATA) 1276 continue; 1277 if (error != 0) 1278 return error; 1279 1280 /* 1281 * Don't need to get a lock on the backing file if 1282 * the listattr is being applied to the backing file, 1283 * as the lock is already held. 1284 */ 1285 if (uele->uele_backing_vnode != vp) 1286 vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_RETRY); 1287 1288 /* 1289 * +1 for trailing NUL (listxattr flavor) 1290 * or leading name length (extattr_list_file flavor) 1291 */ 1292 attrnamelen = strlen(uele->uele_attrname); 1293 listsize += attrnamelen + 1; 1294 1295 /* Return data if the caller requested it. */ 1296 if (uio != NULL) { 1297 /* 1298 * We support two flavors. Either NUL-terminated 1299 * strings (a la listxattr), or non NUL-terminated, 1300 * one byte length prefixed strings (for 1301 * extattr_list_file). EXTATTR_LIST_LENPREFIX switches 1302 * that second behavior. 1303 */ 1304 if (flag & EXTATTR_LIST_LENPREFIX) { 1305 uint8_t len = (uint8_t)attrnamelen; 1306 1307 /* Copy leading name length */ 1308 error = uiomove(&len, sizeof(len), uio); 1309 if (error != 0) 1310 break; 1311 } else { 1312 /* Include trailing NULL */ 1313 attrnamelen++; 1314 } 1315 1316 error = uiomove(uele->uele_attrname, 1317 (size_t)attrnamelen, uio); 1318 if (error != 0) 1319 break; 1320 } 1321 1322 if (uele->uele_backing_vnode != vp) 1323 VOP_UNLOCK(uele->uele_backing_vnode); 1324 1325 if (error != 0) 1326 return error; 1327 } 1328 1329 if (uio != NULL) 1330 uio->uio_offset = 0; 1331 1332 /* Return full data size if caller requested it. */ 1333 if (size != NULL) 1334 *size = listsize; 1335 1336 return 0; 1337 } 1338 1339 /* 1340 * Vnode operation to remove a named attribute. 1341 */ 1342 int 1343 ulfs_deleteextattr(struct vop_deleteextattr_args *ap) 1344 /* 1345 vop_deleteextattr { 1346 IN struct vnode *a_vp; 1347 IN int a_attrnamespace; 1348 IN const char *a_name; 1349 IN kauth_cred_t a_cred; 1350 }; 1351 */ 1352 { 1353 struct mount *mp = ap->a_vp->v_mount; 1354 struct ulfsmount *ump = VFSTOULFS(mp); 1355 int error; 1356 1357 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1358 return (EOPNOTSUPP); 1359 1360 ulfs_extattr_uepm_lock(ump); 1361 1362 error = ulfs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1363 ap->a_cred, curlwp); 1364 1365 ulfs_extattr_uepm_unlock(ump); 1366 1367 return (error); 1368 } 1369 1370 /* 1371 * Vnode operation to set a named attribute. 1372 */ 1373 int 1374 ulfs_setextattr(struct vop_setextattr_args *ap) 1375 /* 1376 vop_setextattr { 1377 IN struct vnode *a_vp; 1378 IN int a_attrnamespace; 1379 IN const char *a_name; 1380 INOUT struct uio *a_uio; 1381 IN kauth_cred_t a_cred; 1382 }; 1383 */ 1384 { 1385 struct mount *mp = ap->a_vp->v_mount; 1386 struct ulfsmount *ump = VFSTOULFS(mp); 1387 int error; 1388 1389 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1390 return (EOPNOTSUPP); 1391 1392 ulfs_extattr_uepm_lock(ump); 1393 1394 /* 1395 * XXX: No longer a supported way to delete extended attributes. 1396 */ 1397 if (ap->a_uio == NULL) { 1398 ulfs_extattr_uepm_unlock(ump); 1399 return (EINVAL); 1400 } 1401 1402 error = ulfs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1403 ap->a_uio, ap->a_cred, curlwp); 1404 1405 ulfs_extattr_uepm_unlock(ump); 1406 1407 return (error); 1408 } 1409 1410 /* 1411 * Real work associated with setting a vnode's extended attributes; 1412 * assumes that the attribute lock has already been grabbed. 1413 */ 1414 static int 1415 ulfs_extattr_set(struct vnode *vp, int attrnamespace, const char *name, 1416 struct uio *uio, kauth_cred_t cred, struct lwp *l) 1417 { 1418 struct ulfs_extattr_list_entry *attribute; 1419 struct ulfs_extattr_header ueh; 1420 struct iovec local_aiov; 1421 struct uio local_aio; 1422 struct mount *mp = vp->v_mount; 1423 struct ulfsmount *ump = VFSTOULFS(mp); 1424 struct inode *ip = VTOI(vp); 1425 off_t base_offset; 1426 int error = 0, ioflag; 1427 1428 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1429 return (EROFS); 1430 1431 if (!ulfs_extattr_valid_attrname(attrnamespace, name)) 1432 return (EINVAL); 1433 1434 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1435 VWRITE); 1436 if (error) 1437 return (error); 1438 1439 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1440 if (!attribute) { 1441 error = ulfs_extattr_autocreate_attr(vp, attrnamespace, 1442 name, l, &attribute); 1443 if (error == EEXIST) { 1444 /* Another thread raced us for backend creation */ 1445 error = 0; 1446 attribute = 1447 ulfs_extattr_find_attr(ump, attrnamespace, name); 1448 } 1449 1450 if (error || !attribute) 1451 return ENODATA; 1452 } 1453 1454 /* 1455 * Early rejection of invalid offsets/length. 1456 * Reject: any offset but 0 (replace) 1457 * Any size greater than attribute size limit 1458 */ 1459 if (uio->uio_offset != 0 || 1460 uio->uio_resid > attribute->uele_fileheader.uef_size) 1461 return (ENXIO); 1462 1463 /* 1464 * Find base offset of header in file based on file header size, and 1465 * data header size + maximum data size, indexed by inode number. 1466 */ 1467 base_offset = sizeof(struct ulfs_extattr_fileheader) + 1468 ip->i_number * (sizeof(struct ulfs_extattr_header) + 1469 attribute->uele_fileheader.uef_size); 1470 1471 /* 1472 * Write out a data header for the data. 1473 */ 1474 ueh.ueh_len = ulfs_rw32((uint32_t) uio->uio_resid, 1475 UELE_NEEDSWAP(attribute)); 1476 ueh.ueh_flags = ulfs_rw32(ULFS_EXTATTR_ATTR_FLAG_INUSE, 1477 UELE_NEEDSWAP(attribute)); 1478 ueh.ueh_i_gen = ulfs_rw32(ip->i_gen, UELE_NEEDSWAP(attribute)); 1479 local_aiov.iov_base = &ueh; 1480 local_aiov.iov_len = sizeof(struct ulfs_extattr_header); 1481 local_aio.uio_iov = &local_aiov; 1482 local_aio.uio_iovcnt = 1; 1483 local_aio.uio_rw = UIO_WRITE; 1484 local_aio.uio_offset = base_offset; 1485 local_aio.uio_resid = sizeof(struct ulfs_extattr_header); 1486 UIO_SETUP_SYSSPACE(&local_aio); 1487 1488 /* 1489 * Don't need to get a lock on the backing file if the setattr is 1490 * being applied to the backing file, as the lock is already held. 1491 */ 1492 if (attribute->uele_backing_vnode != vp) 1493 vn_lock(attribute->uele_backing_vnode, 1494 LK_EXCLUSIVE | LK_RETRY); 1495 1496 ioflag = IO_NODELOCKED; 1497 if (ulfs_extattr_sync) 1498 ioflag |= IO_SYNC; 1499 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1500 ump->um_extattr.uepm_ucred); 1501 if (error) 1502 goto vopunlock_exit; 1503 1504 if (local_aio.uio_resid != 0) { 1505 error = ENXIO; 1506 goto vopunlock_exit; 1507 } 1508 1509 /* 1510 * Write out user data. 1511 * XXX NOT ATOMIC WITH RESPECT TO THE HEADER. 1512 */ 1513 uio->uio_offset = base_offset + sizeof(struct ulfs_extattr_header); 1514 1515 ioflag = IO_NODELOCKED; 1516 if (ulfs_extattr_sync) 1517 ioflag |= IO_SYNC; 1518 error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag, 1519 ump->um_extattr.uepm_ucred); 1520 1521 vopunlock_exit: 1522 uio->uio_offset = 0; 1523 1524 if (attribute->uele_backing_vnode != vp) 1525 VOP_UNLOCK(attribute->uele_backing_vnode); 1526 1527 return (error); 1528 } 1529 1530 /* 1531 * Real work associated with removing an extended attribute from a vnode. 1532 * Assumes the attribute lock has already been grabbed. 1533 */ 1534 static int 1535 ulfs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name, 1536 kauth_cred_t cred, struct lwp *l) 1537 { 1538 struct ulfs_extattr_list_entry *attribute; 1539 struct ulfs_extattr_header ueh; 1540 struct mount *mp = vp->v_mount; 1541 struct ulfsmount *ump = VFSTOULFS(mp); 1542 struct iovec local_aiov; 1543 struct uio local_aio; 1544 off_t base_offset; 1545 int error = 0, ioflag; 1546 1547 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1548 return (EROFS); 1549 1550 if (!ulfs_extattr_valid_attrname(attrnamespace, name)) 1551 return (EINVAL); 1552 1553 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1554 VWRITE); 1555 if (error) 1556 return (error); 1557 1558 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1559 if (!attribute) 1560 return (ENODATA); 1561 1562 /* 1563 * Don't need to get a lock on the backing file if the getattr is 1564 * being applied to the backing file, as the lock is already held. 1565 */ 1566 if (attribute->uele_backing_vnode != vp) 1567 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1568 1569 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset); 1570 if (error) 1571 goto vopunlock_exit; 1572 1573 /* Flag it as not in use. */ 1574 ueh.ueh_flags = 0; /* No need to byte swap 0 */ 1575 ueh.ueh_len = 0; /* ...ditto... */ 1576 1577 local_aiov.iov_base = &ueh; 1578 local_aiov.iov_len = sizeof(struct ulfs_extattr_header); 1579 local_aio.uio_iov = &local_aiov; 1580 local_aio.uio_iovcnt = 1; 1581 local_aio.uio_rw = UIO_WRITE; 1582 local_aio.uio_offset = base_offset; 1583 local_aio.uio_resid = sizeof(struct ulfs_extattr_header); 1584 UIO_SETUP_SYSSPACE(&local_aio); 1585 1586 ioflag = IO_NODELOCKED; 1587 if (ulfs_extattr_sync) 1588 ioflag |= IO_SYNC; 1589 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1590 ump->um_extattr.uepm_ucred); 1591 if (error) 1592 goto vopunlock_exit; 1593 1594 if (local_aio.uio_resid != 0) 1595 error = ENXIO; 1596 1597 vopunlock_exit: 1598 VOP_UNLOCK(attribute->uele_backing_vnode); 1599 1600 return (error); 1601 } 1602 1603 /* 1604 * Called by ULFS when an inode is no longer active and should have its 1605 * attributes stripped. 1606 */ 1607 void 1608 ulfs_extattr_vnode_inactive(struct vnode *vp, struct lwp *l) 1609 { 1610 struct ulfs_extattr_list_entry *uele; 1611 struct mount *mp = vp->v_mount; 1612 struct ulfsmount *ump = VFSTOULFS(mp); 1613 1614 /* 1615 * In that case, we cannot lock. We should not have any active vnodes 1616 * on the fs if this is not yet initialized but is going to be, so 1617 * this can go unlocked. 1618 */ 1619 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 1620 return; 1621 1622 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1623 return; 1624 1625 ulfs_extattr_uepm_lock(ump); 1626 1627 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) 1628 ulfs_extattr_rm(vp, uele->uele_attrnamespace, 1629 uele->uele_attrname, lwp0.l_cred, l); 1630 1631 ulfs_extattr_uepm_unlock(ump); 1632 } 1633 1634 void 1635 ulfs_extattr_init(void) 1636 { 1637 1638 } 1639 1640 void 1641 ulfs_extattr_done(void) 1642 { 1643 1644 } 1645
Indexes created Fri Sep 26 20:09:58 GMT 2025