ulfs_extattr.c revision 1.10
1 /* $NetBSD: ulfs_extattr.c,v 1.10 2016/06/20 01:44:05 dholland Exp $ */ 2 /* from NetBSD: ufs_extattr.c,v 1.44 2014/11/14 10:09:50 manu */ 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 1.10 2016/06/20 01:44:05 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 /* XXX Why does this need to be recursive? */ 172 if (mutex_owned(&ump->um_extattr.uepm_lock)) { 173 ump->um_extattr.uepm_lockcnt++; 174 return; 175 } 176 mutex_enter(&ump->um_extattr.uepm_lock); 177 } 178 179 static void 180 ulfs_extattr_uepm_unlock(struct ulfsmount *ump) 181 { 182 183 if (ump->um_extattr.uepm_lockcnt != 0) { 184 KASSERT(mutex_owned(&ump->um_extattr.uepm_lock)); 185 ump->um_extattr.uepm_lockcnt--; 186 return; 187 } 188 mutex_exit(&ump->um_extattr.uepm_lock); 189 } 190 191 /*- 192 * Determine whether the name passed is a valid name for an actual 193 * attribute. 194 * 195 * Invalid currently consists of: 196 * NULL pointer for attrname 197 * zero-length attrname (used to retrieve application attribute list) 198 */ 199 static int 200 ulfs_extattr_valid_attrname(int attrnamespace, const char *attrname) 201 { 202 203 if (attrname == NULL) 204 return (0); 205 if (strlen(attrname) == 0) 206 return (0); 207 return (1); 208 } 209 210 /* 211 * Autocreate an attribute storage 212 */ 213 static struct ulfs_extattr_list_entry * 214 ulfs_extattr_autocreate_attr(struct vnode *vp, int attrnamespace, 215 const char *attrname, struct lwp *l) 216 { 217 struct mount *mp = vp->v_mount; 218 struct ulfsmount *ump = VFSTOULFS(mp); 219 struct vnode *backing_vp; 220 struct nameidata nd; 221 struct pathbuf *pb; 222 char *path; 223 struct ulfs_extattr_fileheader uef; 224 struct ulfs_extattr_list_entry *uele; 225 int error; 226 227 path = PNBUF_GET(); 228 229 /* 230 * We only support system and user namespace autocreation 231 */ 232 switch (attrnamespace) { 233 case EXTATTR_NAMESPACE_SYSTEM: 234 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s", 235 mp->mnt_stat.f_mntonname, 236 ULFS_EXTATTR_FSROOTSUBDIR, 237 ULFS_EXTATTR_SUBDIR_SYSTEM, 238 attrname); 239 break; 240 case EXTATTR_NAMESPACE_USER: 241 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s", 242 mp->mnt_stat.f_mntonname, 243 ULFS_EXTATTR_FSROOTSUBDIR, 244 ULFS_EXTATTR_SUBDIR_USER, 245 attrname); 246 break; 247 default: 248 PNBUF_PUT(path); 249 return NULL; 250 break; 251 } 252 253 /* 254 * XXX unlock/lock should only be done when setting extattr 255 * on backing store or one of its parent directory 256 * including root, but we always do it for now. 257 */ 258 KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); 259 VOP_UNLOCK(vp); 260 261 pb = pathbuf_create(path); 262 NDINIT(&nd, CREATE, LOCKPARENT, pb); 263 264 error = vn_open(&nd, O_CREAT|O_RDWR, 0600); 265 266 /* 267 * Reacquire the lock on the vnode 268 */ 269 KASSERT(VOP_ISLOCKED(vp) == 0); 270 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 271 272 if (error != 0) { 273 pathbuf_destroy(pb); 274 PNBUF_PUT(path); 275 return NULL; 276 } 277 278 KASSERT(nd.ni_vp != NULL); 279 KASSERT(VOP_ISLOCKED(nd.ni_vp) == LK_EXCLUSIVE); 280 KASSERT(VOP_ISLOCKED(nd.ni_dvp) == 0); 281 282 /* 283 * backing_vp is the backing store. 284 */ 285 backing_vp = nd.ni_vp; 286 pathbuf_destroy(pb); 287 PNBUF_PUT(path); 288 289 uef.uef_magic = ULFS_EXTATTR_MAGIC; 290 uef.uef_version = ULFS_EXTATTR_VERSION; 291 uef.uef_size = ulfs_extattr_autocreate; 292 293 error = vn_rdwr(UIO_WRITE, backing_vp, &uef, sizeof(uef), 0, 294 UIO_SYSSPACE, IO_NODELOCKED|IO_APPEND, 295 l->l_cred, NULL, l); 296 297 VOP_UNLOCK(backing_vp); 298 299 if (error != 0) { 300 printf("%s: write uef header failed for %s, error = %d\n", 301 __func__, attrname, error); 302 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 303 return NULL; 304 } 305 306 /* 307 * Now enable attribute. 308 */ 309 error = ulfs_extattr_enable(ump,attrnamespace, attrname, backing_vp, l); 310 KASSERT(VOP_ISLOCKED(backing_vp) == 0); 311 312 if (error != 0) { 313 printf("%s: enable %s failed, error %d\n", 314 __func__, attrname, error); 315 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 316 return NULL; 317 } 318 319 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname); 320 if (uele == NULL) { 321 printf("%s: atttribute %s created but not found!\n", 322 __func__, attrname); 323 vn_close(backing_vp, FREAD|FWRITE, l->l_cred); 324 return NULL; 325 } 326 327 printf("%s: EA backing store autocreated for %s\n", 328 mp->mnt_stat.f_mntonname, attrname); 329 330 return uele; 331 } 332 333 /* 334 * Locate an attribute given a name and mountpoint. 335 * Must be holding uepm lock for the mount point. 336 */ 337 static struct ulfs_extattr_list_entry * 338 ulfs_extattr_find_attr(struct ulfsmount *ump, int attrnamespace, 339 const char *attrname) 340 { 341 struct ulfs_extattr_list_entry *search_attribute; 342 343 for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list); 344 search_attribute != NULL; 345 search_attribute = LIST_NEXT(search_attribute, uele_entries)) { 346 if (!(strncmp(attrname, search_attribute->uele_attrname, 347 ULFS_EXTATTR_MAXEXTATTRNAME)) && 348 (attrnamespace == search_attribute->uele_attrnamespace)) { 349 return (search_attribute); 350 } 351 } 352 353 return (0); 354 } 355 356 /* 357 * Initialize per-FS structures supporting extended attributes. Do not 358 * start extended attributes yet. 359 */ 360 void 361 ulfs_extattr_uepm_init(struct ulfs_extattr_per_mount *uepm) 362 { 363 364 uepm->uepm_flags = 0; 365 uepm->uepm_lockcnt = 0; 366 367 LIST_INIT(&uepm->uepm_list); 368 mutex_init(&uepm->uepm_lock, MUTEX_DEFAULT, IPL_NONE); 369 uepm->uepm_flags |= ULFS_EXTATTR_UEPM_INITIALIZED; 370 } 371 372 /* 373 * Destroy per-FS structures supporting extended attributes. Assumes 374 * that EAs have already been stopped, and will panic if not. 375 */ 376 void 377 ulfs_extattr_uepm_destroy(struct ulfs_extattr_per_mount *uepm) 378 { 379 380 if (!(uepm->uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 381 panic("ulfs_extattr_uepm_destroy: not initialized"); 382 383 if ((uepm->uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 384 panic("ulfs_extattr_uepm_destroy: called while still started"); 385 386 /* 387 * It's not clear that either order for the next three lines is 388 * ideal, and it should never be a problem if this is only called 389 * during unmount, and with vfs_busy(). 390 */ 391 uepm->uepm_flags &= ~ULFS_EXTATTR_UEPM_STARTED; 392 uepm->uepm_flags &= ~ULFS_EXTATTR_UEPM_INITIALIZED; 393 mutex_destroy(&uepm->uepm_lock); 394 } 395 396 /* 397 * Start extended attribute support on an FS. 398 */ 399 int 400 ulfs_extattr_start(struct mount *mp, struct lwp *l) 401 { 402 struct ulfsmount *ump; 403 int error = 0; 404 405 ump = VFSTOULFS(mp); 406 407 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 408 ulfs_extattr_uepm_init(&ump->um_extattr); 409 410 ulfs_extattr_uepm_lock(ump); 411 412 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) { 413 error = EOPNOTSUPP; 414 goto unlock; 415 } 416 if (ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED) { 417 error = EBUSY; 418 goto unlock; 419 } 420 421 ump->um_extattr.uepm_flags |= ULFS_EXTATTR_UEPM_STARTED; 422 423 ump->um_extattr.uepm_ucred = l->l_cred; 424 kauth_cred_hold(ump->um_extattr.uepm_ucred); 425 426 unlock: 427 ulfs_extattr_uepm_unlock(ump); 428 429 return (error); 430 } 431 432 /* 433 * Helper routine: given a locked parent directory and filename, return 434 * the locked vnode of the inode associated with the name. Will not 435 * follow symlinks, may return any type of vnode. Lock on parent will 436 * be released even in the event of a failure. In the event that the 437 * target is the parent (i.e., "."), there will be two references and 438 * one lock, requiring the caller to possibly special-case. 439 */ 440 static int 441 ulfs_extattr_lookup(struct vnode *start_dvp, int lockparent, const char *dirname, 442 struct vnode **vp, struct lwp *l) 443 { 444 struct vop_lookup_v2_args vargs; 445 struct componentname cnp; 446 struct vnode *target_vp; 447 char *pnbuf; 448 int error; 449 450 KASSERT(VOP_ISLOCKED(start_dvp) == LK_EXCLUSIVE); 451 452 pnbuf = PNBUF_GET(); 453 454 memset(&cnp, 0, sizeof(cnp)); 455 cnp.cn_nameiop = LOOKUP; 456 cnp.cn_flags = ISLASTCN | lockparent; 457 cnp.cn_cred = l->l_cred; 458 cnp.cn_nameptr = pnbuf; 459 error = copystr(dirname, pnbuf, MAXPATHLEN, &cnp.cn_namelen); 460 if (error) { 461 if (lockparent == 0) { 462 VOP_UNLOCK(start_dvp); 463 } 464 PNBUF_PUT(pnbuf); 465 printf("ulfs_extattr_lookup: copystr failed\n"); 466 return (error); 467 } 468 cnp.cn_namelen--; /* trim nul termination */ 469 vargs.a_desc = NULL; 470 vargs.a_dvp = start_dvp; 471 vargs.a_vpp = &target_vp; 472 vargs.a_cnp = &cnp; 473 error = ulfs_lookup(&vargs); 474 PNBUF_PUT(pnbuf); 475 if (error) { 476 if (lockparent == 0) { 477 VOP_UNLOCK(start_dvp); 478 } 479 return (error); 480 } 481 #if 0 482 if (target_vp == start_dvp) 483 panic("ulfs_extattr_lookup: target_vp == start_dvp"); 484 #endif 485 486 if (target_vp != start_dvp) { 487 error = vn_lock(target_vp, LK_EXCLUSIVE); 488 if (lockparent == 0) 489 VOP_UNLOCK(start_dvp); 490 if (error) { 491 vrele(target_vp); 492 return error; 493 } 494 } 495 496 KASSERT(VOP_ISLOCKED(target_vp) == LK_EXCLUSIVE); 497 *vp = target_vp; 498 return (0); 499 } 500 501 /* 502 * Enable an EA using the passed filesystem, backing vnode, attribute name, 503 * namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp 504 * to be locked when passed in. The vnode will be returned unlocked, 505 * regardless of success/failure of the function. As a result, the caller 506 * will always need to vrele(), but not vput(). 507 */ 508 static int 509 ulfs_extattr_enable_with_open(struct ulfsmount *ump, struct vnode *vp, 510 int attrnamespace, const char *attrname, struct lwp *l) 511 { 512 int error; 513 514 error = VOP_OPEN(vp, FREAD|FWRITE, l->l_cred); 515 if (error) { 516 printf("ulfs_extattr_enable_with_open.VOP_OPEN(): failed " 517 "with %d\n", error); 518 VOP_UNLOCK(vp); 519 return (error); 520 } 521 522 mutex_enter(vp->v_interlock); 523 vp->v_writecount++; 524 mutex_exit(vp->v_interlock); 525 526 vref(vp); 527 528 VOP_UNLOCK(vp); 529 530 error = ulfs_extattr_enable(ump, attrnamespace, attrname, vp, l); 531 if (error != 0) 532 vn_close(vp, FREAD|FWRITE, l->l_cred); 533 return (error); 534 } 535 536 /* 537 * Given a locked directory vnode, iterate over the names in the directory 538 * and use ulfs_extattr_lookup() to retrieve locked vnodes of potential 539 * attribute files. Then invoke ulfs_extattr_enable_with_open() on each 540 * to attempt to start the attribute. Leaves the directory locked on 541 * exit. 542 */ 543 static int 544 ulfs_extattr_iterate_directory(struct ulfsmount *ump, struct vnode *dvp, 545 int attrnamespace, struct lwp *l) 546 { 547 struct vop_readdir_args vargs; 548 struct statvfs *sbp = &ump->um_mountp->mnt_stat; 549 struct dirent *dp, *edp; 550 struct vnode *attr_vp; 551 struct uio auio; 552 struct iovec aiov; 553 char *dirbuf; 554 int error, eofflag = 0; 555 556 if (dvp->v_type != VDIR) 557 return (ENOTDIR); 558 559 dirbuf = kmem_alloc(LFS_DIRBLKSIZ, KM_SLEEP); 560 561 auio.uio_iov = &aiov; 562 auio.uio_iovcnt = 1; 563 auio.uio_rw = UIO_READ; 564 auio.uio_offset = 0; 565 UIO_SETUP_SYSSPACE(&auio); 566 567 vargs.a_desc = NULL; 568 vargs.a_vp = dvp; 569 vargs.a_uio = &auio; 570 vargs.a_cred = l->l_cred; 571 vargs.a_eofflag = &eofflag; 572 vargs.a_ncookies = NULL; 573 vargs.a_cookies = NULL; 574 575 while (!eofflag) { 576 auio.uio_resid = LFS_DIRBLKSIZ; 577 aiov.iov_base = dirbuf; 578 aiov.iov_len = LFS_DIRBLKSIZ; 579 error = ulfs_readdir(&vargs); 580 if (error) { 581 printf("ulfs_extattr_iterate_directory: ulfs_readdir " 582 "%d\n", error); 583 return (error); 584 } 585 586 /* 587 * XXXRW: While in LFS, we always get LFS_DIRBLKSIZ returns from 588 * the directory code on success, on other file systems this 589 * may not be the case. For portability, we should check the 590 * read length on return from ulfs_readdir(). 591 */ 592 edp = (struct dirent *)&dirbuf[LFS_DIRBLKSIZ]; 593 for (dp = (struct dirent *)dirbuf; dp < edp; ) { 594 if (dp->d_reclen == 0) 595 break; 596 /* Skip "." and ".." */ 597 if (dp->d_name[0] == '.' && 598 (dp->d_name[1] == '\0' || 599 (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) 600 goto next; 601 error = ulfs_extattr_lookup(dvp, LOCKPARENT, 602 dp->d_name, &attr_vp, l); 603 if (error == ENOENT) { 604 goto next; /* keep silent */ 605 } else if (error) { 606 printf("ulfs_extattr_iterate_directory: lookup " 607 "%s %d\n", dp->d_name, error); 608 } else if (attr_vp == dvp) { 609 vrele(attr_vp); 610 } else if (attr_vp->v_type != VREG) { 611 vput(attr_vp); 612 } else { 613 error = ulfs_extattr_enable_with_open(ump, 614 attr_vp, attrnamespace, dp->d_name, l); 615 vrele(attr_vp); 616 if (error) { 617 printf("ulfs_extattr_iterate_directory: " 618 "enable %s %d\n", dp->d_name, 619 error); 620 } else if (bootverbose) { 621 printf("%s: EA %s loaded\n", 622 sbp->f_mntonname, dp->d_name); 623 } 624 } 625 next: 626 dp = (struct dirent *) ((char *)dp + dp->d_reclen); 627 if (dp >= edp) 628 break; 629 } 630 } 631 kmem_free(dirbuf, LFS_DIRBLKSIZ); 632 633 return (0); 634 } 635 636 /* 637 * Auto-start of extended attributes, to be executed (optionally) at 638 * mount-time. 639 */ 640 int 641 ulfs_extattr_autostart(struct mount *mp, struct lwp *l) 642 { 643 struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp; 644 int error; 645 646 /* 647 * Does ULFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root? 648 * If so, automatically start EA's. 649 */ 650 error = VFS_ROOT(mp, &rvp); 651 if (error) { 652 printf("ulfs_extattr_autostart.VFS_ROOT() returned %d\n", 653 error); 654 return (error); 655 } 656 657 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE); 658 659 error = ulfs_extattr_lookup(rvp, 0, 660 ULFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, l); 661 if (error) { 662 /* rvp ref'd but now unlocked */ 663 KASSERT(VOP_ISLOCKED(rvp) == 0); 664 vrele(rvp); 665 return (error); 666 } 667 if (rvp == attr_dvp) { 668 /* Should never happen. */ 669 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE); 670 vrele(attr_dvp); 671 vput(rvp); 672 return (EINVAL); 673 } 674 KASSERT(VOP_ISLOCKED(rvp) == 0); 675 vrele(rvp); 676 677 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 678 679 if (attr_dvp->v_type != VDIR) { 680 printf("ulfs_extattr_autostart: %s != VDIR\n", 681 ULFS_EXTATTR_FSROOTSUBDIR); 682 goto return_vput_attr_dvp; 683 } 684 685 error = ulfs_extattr_start(mp, l); 686 if (error) { 687 printf("ulfs_extattr_autostart: ulfs_extattr_start failed (%d)\n", 688 error); 689 goto return_vput_attr_dvp; 690 } 691 692 /* 693 * Look for two subdirectories: ULFS_EXTATTR_SUBDIR_SYSTEM, 694 * ULFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory, 695 * and start with appropriate type. Failures in either don't 696 * result in an over-all failure. attr_dvp is left locked to 697 * be cleaned up on exit. 698 */ 699 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT, 700 ULFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, l); 701 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 702 if (error == 0) { 703 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE); 704 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp), 705 attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, l); 706 if (error) 707 printf("ulfs_extattr_iterate_directory returned %d\n", 708 error); 709 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE); 710 vput(attr_system_dvp); 711 } 712 713 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT, 714 ULFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, l); 715 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 716 if (error == 0) { 717 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE); 718 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp), 719 attr_user_dvp, EXTATTR_NAMESPACE_USER, l); 720 if (error) 721 printf("ulfs_extattr_iterate_directory returned %d\n", 722 error); 723 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE); 724 vput(attr_user_dvp); 725 } 726 727 /* Mask startup failures in sub-directories. */ 728 error = 0; 729 730 return_vput_attr_dvp: 731 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE); 732 vput(attr_dvp); 733 734 return (error); 735 } 736 737 /* 738 * Stop extended attribute support on an FS. 739 */ 740 void 741 ulfs_extattr_stop(struct mount *mp, struct lwp *l) 742 { 743 struct ulfs_extattr_list_entry *uele; 744 struct ulfsmount *ump = VFSTOULFS(mp); 745 746 ulfs_extattr_uepm_lock(ump); 747 748 /* 749 * If we haven't been started, no big deal. Just short-circuit 750 * the processing work. 751 */ 752 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) { 753 goto unlock; 754 } 755 756 while (LIST_FIRST(&ump->um_extattr.uepm_list) != NULL) { 757 uele = LIST_FIRST(&ump->um_extattr.uepm_list); 758 ulfs_extattr_disable(ump, uele->uele_attrnamespace, 759 uele->uele_attrname, l); 760 } 761 762 ump->um_extattr.uepm_flags &= ~ULFS_EXTATTR_UEPM_STARTED; 763 764 kauth_cred_free(ump->um_extattr.uepm_ucred); 765 ump->um_extattr.uepm_ucred = NULL; 766 767 unlock: 768 ulfs_extattr_uepm_unlock(ump); 769 } 770 771 /* 772 * Enable a named attribute on the specified filesystem; provide an 773 * unlocked backing vnode to hold the attribute data. 774 */ 775 static int 776 ulfs_extattr_enable(struct ulfsmount *ump, int attrnamespace, 777 const char *attrname, struct vnode *backing_vnode, struct lwp *l) 778 { 779 struct ulfs_extattr_list_entry *attribute; 780 struct iovec aiov; 781 struct uio auio; 782 int error = 0; 783 784 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname)) 785 return (EINVAL); 786 if (backing_vnode->v_type != VREG) 787 return (EINVAL); 788 789 attribute = kmem_zalloc(sizeof(*attribute), KM_SLEEP); 790 791 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) { 792 error = EOPNOTSUPP; 793 goto free_exit; 794 } 795 796 if (ulfs_extattr_find_attr(ump, attrnamespace, attrname)) { 797 error = EEXIST; 798 goto free_exit; 799 } 800 801 strncpy(attribute->uele_attrname, attrname, 802 ULFS_EXTATTR_MAXEXTATTRNAME); 803 attribute->uele_attrnamespace = attrnamespace; 804 memset(&attribute->uele_fileheader, 0, 805 sizeof(struct ulfs_extattr_fileheader)); 806 807 attribute->uele_backing_vnode = backing_vnode; 808 809 auio.uio_iov = &aiov; 810 auio.uio_iovcnt = 1; 811 aiov.iov_base = (void *) &attribute->uele_fileheader; 812 aiov.iov_len = sizeof(struct ulfs_extattr_fileheader); 813 auio.uio_resid = sizeof(struct ulfs_extattr_fileheader); 814 auio.uio_offset = (off_t) 0; 815 auio.uio_rw = UIO_READ; 816 UIO_SETUP_SYSSPACE(&auio); 817 818 vn_lock(backing_vnode, LK_SHARED | LK_RETRY); 819 error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED, 820 ump->um_extattr.uepm_ucred); 821 822 if (error) 823 goto unlock_free_exit; 824 825 if (auio.uio_resid != 0) { 826 printf("ulfs_extattr_enable: malformed attribute header\n"); 827 error = EINVAL; 828 goto unlock_free_exit; 829 } 830 831 /* 832 * Try to determine the byte order of the attribute file. 833 */ 834 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) { 835 attribute->uele_flags |= UELE_F_NEEDSWAP; 836 attribute->uele_fileheader.uef_magic = 837 ulfs_rw32(attribute->uele_fileheader.uef_magic, 838 UELE_NEEDSWAP(attribute)); 839 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) { 840 printf("ulfs_extattr_enable: invalid attribute header " 841 "magic\n"); 842 error = EINVAL; 843 goto unlock_free_exit; 844 } 845 } 846 attribute->uele_fileheader.uef_version = 847 ulfs_rw32(attribute->uele_fileheader.uef_version, 848 UELE_NEEDSWAP(attribute)); 849 attribute->uele_fileheader.uef_size = 850 ulfs_rw32(attribute->uele_fileheader.uef_size, 851 UELE_NEEDSWAP(attribute)); 852 853 if (attribute->uele_fileheader.uef_version != ULFS_EXTATTR_VERSION) { 854 printf("ulfs_extattr_enable: incorrect attribute header " 855 "version\n"); 856 error = EINVAL; 857 goto unlock_free_exit; 858 } 859 860 LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute, 861 uele_entries); 862 863 VOP_UNLOCK(backing_vnode); 864 return (0); 865 866 unlock_free_exit: 867 VOP_UNLOCK(backing_vnode); 868 869 free_exit: 870 kmem_free(attribute, sizeof(*attribute)); 871 return (error); 872 } 873 874 /* 875 * Disable extended attribute support on an FS. 876 */ 877 static int 878 ulfs_extattr_disable(struct ulfsmount *ump, int attrnamespace, 879 const char *attrname, struct lwp *l) 880 { 881 struct ulfs_extattr_list_entry *uele; 882 int error = 0; 883 884 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname)) 885 return (EINVAL); 886 887 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname); 888 if (!uele) 889 return (ENODATA); 890 891 LIST_REMOVE(uele, uele_entries); 892 893 error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE, 894 l->l_cred); 895 896 kmem_free(uele, sizeof(*uele)); 897 898 return (error); 899 } 900 901 /* 902 * VFS call to manage extended attributes in ULFS. If filename_vp is 903 * non-NULL, it must be passed in locked, and regardless of errors in 904 * processing, will be unlocked. 905 */ 906 int 907 ulfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 908 int attrnamespace, const char *attrname) 909 { 910 struct lwp *l = curlwp; 911 struct ulfsmount *ump = VFSTOULFS(mp); 912 int error; 913 914 /* 915 * Only privileged processes can configure extended attributes. 916 */ 917 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_EXTATTR, 918 0, mp, NULL, NULL); 919 if (error) { 920 if (filename_vp != NULL) 921 VOP_UNLOCK(filename_vp); 922 return (error); 923 } 924 925 switch(cmd) { 926 case ULFS_EXTATTR_CMD_START: 927 if (filename_vp != NULL) { 928 VOP_UNLOCK(filename_vp); 929 return (EINVAL); 930 } 931 if (attrname != NULL) 932 return (EINVAL); 933 934 error = ulfs_extattr_autostart(mp, l); 935 return (error); 936 937 case ULFS_EXTATTR_CMD_STOP: 938 if (filename_vp != NULL) { 939 VOP_UNLOCK(filename_vp); 940 return (EINVAL); 941 } 942 if (attrname != NULL) 943 return (EINVAL); 944 945 ulfs_extattr_stop(mp, l); 946 return (0); 947 948 case ULFS_EXTATTR_CMD_ENABLE: 949 if (filename_vp == NULL) 950 return (EINVAL); 951 if (attrname == NULL) { 952 VOP_UNLOCK(filename_vp); 953 return (EINVAL); 954 } 955 956 /* 957 * ulfs_extattr_enable_with_open() will always unlock the 958 * vnode, regardless of failure. 959 */ 960 ulfs_extattr_uepm_lock(ump); 961 error = ulfs_extattr_enable_with_open(ump, filename_vp, 962 attrnamespace, attrname, l); 963 ulfs_extattr_uepm_unlock(ump); 964 return (error); 965 966 case ULFS_EXTATTR_CMD_DISABLE: 967 if (filename_vp != NULL) { 968 VOP_UNLOCK(filename_vp); 969 return (EINVAL); 970 } 971 if (attrname == NULL) 972 return (EINVAL); 973 974 ulfs_extattr_uepm_lock(ump); 975 error = ulfs_extattr_disable(ump, attrnamespace, attrname, l); 976 ulfs_extattr_uepm_unlock(ump); 977 return (error); 978 979 default: 980 return (EINVAL); 981 } 982 } 983 984 /* 985 * Read extended attribute header for a given vnode and attribute. 986 * Backing vnode should be locked and unlocked by caller. 987 */ 988 static int 989 ulfs_extattr_get_header(struct vnode *vp, struct ulfs_extattr_list_entry *uele, 990 struct ulfs_extattr_header *ueh, off_t *bap) 991 { 992 struct mount *mp = vp->v_mount; 993 struct ulfsmount *ump = VFSTOULFS(mp); 994 struct inode *ip = VTOI(vp); 995 off_t base_offset; 996 struct iovec aiov; 997 struct uio aio; 998 int error; 999 1000 /* 1001 * Find base offset of header in file based on file header size, and 1002 * data header size + maximum data size, indexed by inode number. 1003 */ 1004 base_offset = sizeof(struct ulfs_extattr_fileheader) + 1005 ip->i_number * (sizeof(struct ulfs_extattr_header) + 1006 uele->uele_fileheader.uef_size); 1007 1008 /* 1009 * Read in the data header to see if the data is defined, and if so 1010 * how much. 1011 */ 1012 memset(ueh, 0, sizeof(struct ulfs_extattr_header)); 1013 aiov.iov_base = ueh; 1014 aiov.iov_len = sizeof(struct ulfs_extattr_header); 1015 aio.uio_iov = &aiov; 1016 aio.uio_iovcnt = 1; 1017 aio.uio_rw = UIO_READ; 1018 aio.uio_offset = base_offset; 1019 aio.uio_resid = sizeof(struct ulfs_extattr_header); 1020 UIO_SETUP_SYSSPACE(&aio); 1021 1022 error = VOP_READ(uele->uele_backing_vnode, &aio, 1023 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1024 if (error) 1025 return error; 1026 1027 /* 1028 * Attribute headers are kept in file system byte order. 1029 * XXX What about the blob of data? 1030 */ 1031 ueh->ueh_flags = ulfs_rw32(ueh->ueh_flags, UELE_NEEDSWAP(uele)); 1032 ueh->ueh_len = ulfs_rw32(ueh->ueh_len, UELE_NEEDSWAP(uele)); 1033 ueh->ueh_i_gen = ulfs_rw32(ueh->ueh_i_gen, UELE_NEEDSWAP(uele)); 1034 1035 /* Defined? */ 1036 if ((ueh->ueh_flags & ULFS_EXTATTR_ATTR_FLAG_INUSE) == 0) 1037 return ENODATA; 1038 1039 /* Valid for the current inode generation? */ 1040 if (ueh->ueh_i_gen != ip->i_gen) { 1041 /* 1042 * The inode itself has a different generation number 1043 * than the uele data. For now, the best solution 1044 * is to coerce this to undefined, and let it get cleaned 1045 * up by the next write or extattrctl clean. 1046 */ 1047 printf("%s (%s): inode gen inconsistency (%u, %jd)\n", 1048 __func__, mp->mnt_stat.f_mntonname, ueh->ueh_i_gen, 1049 (intmax_t)ip->i_gen); 1050 return ENODATA; 1051 } 1052 1053 /* Local size consistency check. */ 1054 if (ueh->ueh_len > uele->uele_fileheader.uef_size) 1055 return ENXIO; 1056 1057 /* Return base offset */ 1058 if (bap != NULL) 1059 *bap = base_offset; 1060 1061 return 0; 1062 } 1063 1064 /* 1065 * Vnode operation to retrieve a named extended attribute. 1066 */ 1067 int 1068 ulfs_getextattr(struct vop_getextattr_args *ap) 1069 /* 1070 vop_getextattr { 1071 IN struct vnode *a_vp; 1072 IN int a_attrnamespace; 1073 IN const char *a_name; 1074 INOUT struct uio *a_uio; 1075 OUT size_t *a_size; 1076 IN kauth_cred_t a_cred; 1077 }; 1078 */ 1079 { 1080 struct mount *mp = ap->a_vp->v_mount; 1081 struct ulfsmount *ump = VFSTOULFS(mp); 1082 int error; 1083 1084 ulfs_extattr_uepm_lock(ump); 1085 1086 error = ulfs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1087 ap->a_uio, ap->a_size, ap->a_cred, curlwp); 1088 1089 ulfs_extattr_uepm_unlock(ump); 1090 1091 return (error); 1092 } 1093 1094 /* 1095 * Real work associated with retrieving a named attribute--assumes that 1096 * the attribute lock has already been grabbed. 1097 */ 1098 static int 1099 ulfs_extattr_get(struct vnode *vp, int attrnamespace, const char *name, 1100 struct uio *uio, size_t *size, kauth_cred_t cred, struct lwp *l) 1101 { 1102 struct ulfs_extattr_list_entry *attribute; 1103 struct ulfs_extattr_header ueh; 1104 struct mount *mp = vp->v_mount; 1105 struct ulfsmount *ump = VFSTOULFS(mp); 1106 off_t base_offset; 1107 size_t len, old_len; 1108 int error = 0; 1109 1110 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1111 return (EOPNOTSUPP); 1112 1113 if (strlen(name) == 0) 1114 return (EINVAL); 1115 1116 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1117 VREAD); 1118 if (error) 1119 return (error); 1120 1121 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1122 if (!attribute) 1123 return (ENODATA); 1124 1125 /* 1126 * Allow only offsets of zero to encourage the read/replace 1127 * extended attribute semantic. Otherwise we can't guarantee 1128 * atomicity, as we don't provide locks for extended attributes. 1129 */ 1130 if (uio != NULL && uio->uio_offset != 0) 1131 return (ENXIO); 1132 1133 /* 1134 * Don't need to get a lock on the backing file if the getattr is 1135 * being applied to the backing file, as the lock is already held. 1136 */ 1137 if (attribute->uele_backing_vnode != vp) 1138 vn_lock(attribute->uele_backing_vnode, LK_SHARED | LK_RETRY); 1139 1140 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset); 1141 if (error) 1142 goto vopunlock_exit; 1143 1144 /* Return full data size if caller requested it. */ 1145 if (size != NULL) 1146 *size = ueh.ueh_len; 1147 1148 /* Return data if the caller requested it. */ 1149 if (uio != NULL) { 1150 /* Allow for offset into the attribute data. */ 1151 uio->uio_offset = base_offset + sizeof(struct 1152 ulfs_extattr_header); 1153 1154 /* 1155 * Figure out maximum to transfer -- use buffer size and 1156 * local data limit. 1157 */ 1158 len = MIN(uio->uio_resid, ueh.ueh_len); 1159 old_len = uio->uio_resid; 1160 uio->uio_resid = len; 1161 1162 error = VOP_READ(attribute->uele_backing_vnode, uio, 1163 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1164 if (error) 1165 goto vopunlock_exit; 1166 1167 uio->uio_resid = old_len - (len - uio->uio_resid); 1168 } 1169 1170 vopunlock_exit: 1171 1172 if (uio != NULL) 1173 uio->uio_offset = 0; 1174 1175 if (attribute->uele_backing_vnode != vp) 1176 VOP_UNLOCK(attribute->uele_backing_vnode); 1177 1178 return (error); 1179 } 1180 1181 /* 1182 * Vnode operation to list extended attribute for a vnode 1183 */ 1184 int 1185 ulfs_listextattr(struct vop_listextattr_args *ap) 1186 /* 1187 vop_listextattr { 1188 IN struct vnode *a_vp; 1189 IN int a_attrnamespace; 1190 INOUT struct uio *a_uio; 1191 OUT size_t *a_size; 1192 IN int flag; 1193 IN kauth_cred_t a_cred; 1194 struct proc *a_p; 1195 }; 1196 */ 1197 { 1198 struct mount *mp = ap->a_vp->v_mount; 1199 struct ulfsmount *ump = VFSTOULFS(mp); 1200 int error; 1201 1202 ulfs_extattr_uepm_lock(ump); 1203 1204 error = ulfs_extattr_list(ap->a_vp, ap->a_attrnamespace, 1205 ap->a_uio, ap->a_size, ap->a_flag, ap->a_cred, curlwp); 1206 1207 ulfs_extattr_uepm_unlock(ump); 1208 1209 return (error); 1210 } 1211 1212 /* 1213 * Real work associated with retrieving list of attributes--assumes that 1214 * the attribute lock has already been grabbed. 1215 */ 1216 static int 1217 ulfs_extattr_list(struct vnode *vp, int attrnamespace, 1218 struct uio *uio, size_t *size, int flag, 1219 kauth_cred_t cred, struct lwp *l) 1220 { 1221 struct ulfs_extattr_list_entry *uele; 1222 struct ulfs_extattr_header ueh; 1223 struct mount *mp = vp->v_mount; 1224 struct ulfsmount *ump = VFSTOULFS(mp); 1225 size_t listsize = 0; 1226 int error = 0; 1227 1228 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1229 return (EOPNOTSUPP); 1230 1231 /* 1232 * XXX: We can move this inside the loop and iterate on individual 1233 * attributes. 1234 */ 1235 error = internal_extattr_check_cred(vp, attrnamespace, "", cred, 1236 VREAD); 1237 if (error) 1238 return (error); 1239 1240 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) { 1241 unsigned char attrnamelen; 1242 1243 if (uele->uele_attrnamespace != attrnamespace) 1244 continue; 1245 1246 error = ulfs_extattr_get_header(vp, uele, &ueh, NULL); 1247 if (error == ENODATA) 1248 continue; 1249 if (error != 0) 1250 return error; 1251 1252 /* 1253 * Don't need to get a lock on the backing file if 1254 * the listattr is being applied to the backing file, 1255 * as the lock is already held. 1256 */ 1257 if (uele->uele_backing_vnode != vp) 1258 vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_RETRY); 1259 1260 /* 1261 * +1 for trailing NUL (listxattr flavor) 1262 * or leading name length (extattr_list_file flavor) 1263 */ 1264 attrnamelen = strlen(uele->uele_attrname); 1265 listsize += attrnamelen + 1; 1266 1267 /* Return data if the caller requested it. */ 1268 if (uio != NULL) { 1269 /* 1270 * We support two flavors. Either NUL-terminated 1271 * strings (a la listxattr), or non NUL-terminated, 1272 * one byte length prefixed strings (for 1273 * extattr_list_file). EXTATTR_LIST_LENPREFIX switches 1274 * that second behavior. 1275 */ 1276 if (flag & EXTATTR_LIST_LENPREFIX) { 1277 uint8_t len = (uint8_t)attrnamelen; 1278 1279 /* Copy leading name length */ 1280 error = uiomove(&len, sizeof(len), uio); 1281 if (error != 0) 1282 break; 1283 } else { 1284 /* Include trailing NULL */ 1285 attrnamelen++; 1286 } 1287 1288 error = uiomove(uele->uele_attrname, 1289 (size_t)attrnamelen, uio); 1290 if (error != 0) 1291 break; 1292 } 1293 1294 if (uele->uele_backing_vnode != vp) 1295 VOP_UNLOCK(uele->uele_backing_vnode); 1296 1297 if (error != 0) 1298 return error; 1299 } 1300 1301 if (uio != NULL) 1302 uio->uio_offset = 0; 1303 1304 /* Return full data size if caller requested it. */ 1305 if (size != NULL) 1306 *size = listsize; 1307 1308 return 0; 1309 } 1310 1311 /* 1312 * Vnode operation to remove a named attribute. 1313 */ 1314 int 1315 ulfs_deleteextattr(struct vop_deleteextattr_args *ap) 1316 /* 1317 vop_deleteextattr { 1318 IN struct vnode *a_vp; 1319 IN int a_attrnamespace; 1320 IN const char *a_name; 1321 IN kauth_cred_t a_cred; 1322 }; 1323 */ 1324 { 1325 struct mount *mp = ap->a_vp->v_mount; 1326 struct ulfsmount *ump = VFSTOULFS(mp); 1327 int error; 1328 1329 ulfs_extattr_uepm_lock(ump); 1330 1331 error = ulfs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1332 ap->a_cred, curlwp); 1333 1334 ulfs_extattr_uepm_unlock(ump); 1335 1336 return (error); 1337 } 1338 1339 /* 1340 * Vnode operation to set a named attribute. 1341 */ 1342 int 1343 ulfs_setextattr(struct vop_setextattr_args *ap) 1344 /* 1345 vop_setextattr { 1346 IN struct vnode *a_vp; 1347 IN int a_attrnamespace; 1348 IN const char *a_name; 1349 INOUT struct uio *a_uio; 1350 IN kauth_cred_t a_cred; 1351 }; 1352 */ 1353 { 1354 struct mount *mp = ap->a_vp->v_mount; 1355 struct ulfsmount *ump = VFSTOULFS(mp); 1356 int error; 1357 1358 ulfs_extattr_uepm_lock(ump); 1359 1360 /* 1361 * XXX: No longer a supported way to delete extended attributes. 1362 */ 1363 if (ap->a_uio == NULL) { 1364 ulfs_extattr_uepm_unlock(ump); 1365 return (EINVAL); 1366 } 1367 1368 error = ulfs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1369 ap->a_uio, ap->a_cred, curlwp); 1370 1371 ulfs_extattr_uepm_unlock(ump); 1372 1373 return (error); 1374 } 1375 1376 /* 1377 * Real work associated with setting a vnode's extended attributes; 1378 * assumes that the attribute lock has already been grabbed. 1379 */ 1380 static int 1381 ulfs_extattr_set(struct vnode *vp, int attrnamespace, const char *name, 1382 struct uio *uio, kauth_cred_t cred, struct lwp *l) 1383 { 1384 struct ulfs_extattr_list_entry *attribute; 1385 struct ulfs_extattr_header ueh; 1386 struct iovec local_aiov; 1387 struct uio local_aio; 1388 struct mount *mp = vp->v_mount; 1389 struct ulfsmount *ump = VFSTOULFS(mp); 1390 struct inode *ip = VTOI(vp); 1391 off_t base_offset; 1392 int error = 0, ioflag; 1393 1394 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1395 return (EROFS); 1396 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1397 return (EOPNOTSUPP); 1398 if (!ulfs_extattr_valid_attrname(attrnamespace, name)) 1399 return (EINVAL); 1400 1401 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1402 VWRITE); 1403 if (error) 1404 return (error); 1405 1406 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1407 if (!attribute) { 1408 attribute = ulfs_extattr_autocreate_attr(vp, attrnamespace, 1409 name, l); 1410 if (!attribute) 1411 return (ENODATA); 1412 } 1413 1414 /* 1415 * Early rejection of invalid offsets/length. 1416 * Reject: any offset but 0 (replace) 1417 * Any size greater than attribute size limit 1418 */ 1419 if (uio->uio_offset != 0 || 1420 uio->uio_resid > attribute->uele_fileheader.uef_size) 1421 return (ENXIO); 1422 1423 /* 1424 * Find base offset of header in file based on file header size, and 1425 * data header size + maximum data size, indexed by inode number. 1426 */ 1427 base_offset = sizeof(struct ulfs_extattr_fileheader) + 1428 ip->i_number * (sizeof(struct ulfs_extattr_header) + 1429 attribute->uele_fileheader.uef_size); 1430 1431 /* 1432 * Write out a data header for the data. 1433 */ 1434 ueh.ueh_len = ulfs_rw32((uint32_t) uio->uio_resid, 1435 UELE_NEEDSWAP(attribute)); 1436 ueh.ueh_flags = ulfs_rw32(ULFS_EXTATTR_ATTR_FLAG_INUSE, 1437 UELE_NEEDSWAP(attribute)); 1438 ueh.ueh_i_gen = ulfs_rw32(ip->i_gen, UELE_NEEDSWAP(attribute)); 1439 local_aiov.iov_base = &ueh; 1440 local_aiov.iov_len = sizeof(struct ulfs_extattr_header); 1441 local_aio.uio_iov = &local_aiov; 1442 local_aio.uio_iovcnt = 1; 1443 local_aio.uio_rw = UIO_WRITE; 1444 local_aio.uio_offset = base_offset; 1445 local_aio.uio_resid = sizeof(struct ulfs_extattr_header); 1446 UIO_SETUP_SYSSPACE(&local_aio); 1447 1448 /* 1449 * Don't need to get a lock on the backing file if the setattr is 1450 * being applied to the backing file, as the lock is already held. 1451 */ 1452 if (attribute->uele_backing_vnode != vp) 1453 vn_lock(attribute->uele_backing_vnode, 1454 LK_EXCLUSIVE | LK_RETRY); 1455 1456 ioflag = IO_NODELOCKED; 1457 if (ulfs_extattr_sync) 1458 ioflag |= IO_SYNC; 1459 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1460 ump->um_extattr.uepm_ucred); 1461 if (error) 1462 goto vopunlock_exit; 1463 1464 if (local_aio.uio_resid != 0) { 1465 error = ENXIO; 1466 goto vopunlock_exit; 1467 } 1468 1469 /* 1470 * Write out user data. 1471 * XXX NOT ATOMIC WITH RESPECT TO THE HEADER. 1472 */ 1473 uio->uio_offset = base_offset + sizeof(struct ulfs_extattr_header); 1474 1475 ioflag = IO_NODELOCKED; 1476 if (ulfs_extattr_sync) 1477 ioflag |= IO_SYNC; 1478 error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag, 1479 ump->um_extattr.uepm_ucred); 1480 1481 vopunlock_exit: 1482 uio->uio_offset = 0; 1483 1484 if (attribute->uele_backing_vnode != vp) 1485 VOP_UNLOCK(attribute->uele_backing_vnode); 1486 1487 return (error); 1488 } 1489 1490 /* 1491 * Real work associated with removing an extended attribute from a vnode. 1492 * Assumes the attribute lock has already been grabbed. 1493 */ 1494 static int 1495 ulfs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name, 1496 kauth_cred_t cred, struct lwp *l) 1497 { 1498 struct ulfs_extattr_list_entry *attribute; 1499 struct ulfs_extattr_header ueh; 1500 struct mount *mp = vp->v_mount; 1501 struct ulfsmount *ump = VFSTOULFS(mp); 1502 struct iovec local_aiov; 1503 struct uio local_aio; 1504 off_t base_offset; 1505 int error = 0, ioflag; 1506 1507 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1508 return (EROFS); 1509 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) 1510 return (EOPNOTSUPP); 1511 if (!ulfs_extattr_valid_attrname(attrnamespace, name)) 1512 return (EINVAL); 1513 1514 error = internal_extattr_check_cred(vp, attrnamespace, name, cred, 1515 VWRITE); 1516 if (error) 1517 return (error); 1518 1519 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name); 1520 if (!attribute) 1521 return (ENODATA); 1522 1523 /* 1524 * Don't need to get a lock on the backing file if the getattr is 1525 * being applied to the backing file, as the lock is already held. 1526 */ 1527 if (attribute->uele_backing_vnode != vp) 1528 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1529 1530 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset); 1531 if (error) 1532 goto vopunlock_exit; 1533 1534 /* Flag it as not in use. */ 1535 ueh.ueh_flags = 0; /* No need to byte swap 0 */ 1536 ueh.ueh_len = 0; /* ...ditto... */ 1537 1538 local_aiov.iov_base = &ueh; 1539 local_aiov.iov_len = sizeof(struct ulfs_extattr_header); 1540 local_aio.uio_iov = &local_aiov; 1541 local_aio.uio_iovcnt = 1; 1542 local_aio.uio_rw = UIO_WRITE; 1543 local_aio.uio_offset = base_offset; 1544 local_aio.uio_resid = sizeof(struct ulfs_extattr_header); 1545 UIO_SETUP_SYSSPACE(&local_aio); 1546 1547 ioflag = IO_NODELOCKED; 1548 if (ulfs_extattr_sync) 1549 ioflag |= IO_SYNC; 1550 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1551 ump->um_extattr.uepm_ucred); 1552 if (error) 1553 goto vopunlock_exit; 1554 1555 if (local_aio.uio_resid != 0) 1556 error = ENXIO; 1557 1558 vopunlock_exit: 1559 VOP_UNLOCK(attribute->uele_backing_vnode); 1560 1561 return (error); 1562 } 1563 1564 /* 1565 * Called by ULFS when an inode is no longer active and should have its 1566 * attributes stripped. 1567 */ 1568 void 1569 ulfs_extattr_vnode_inactive(struct vnode *vp, struct lwp *l) 1570 { 1571 struct ulfs_extattr_list_entry *uele; 1572 struct mount *mp = vp->v_mount; 1573 struct ulfsmount *ump = VFSTOULFS(mp); 1574 1575 /* 1576 * In that case, we cannot lock. We should not have any active vnodes 1577 * on the fs if this is not yet initialized but is going to be, so 1578 * this can go unlocked. 1579 */ 1580 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) 1581 return; 1582 1583 ulfs_extattr_uepm_lock(ump); 1584 1585 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) { 1586 ulfs_extattr_uepm_unlock(ump); 1587 return; 1588 } 1589 1590 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) 1591 ulfs_extattr_rm(vp, uele->uele_attrnamespace, 1592 uele->uele_attrname, lwp0.l_cred, l); 1593 1594 ulfs_extattr_uepm_unlock(ump); 1595 } 1596 1597 void 1598 ulfs_extattr_init(void) 1599 { 1600 1601 } 1602 1603 void 1604 ulfs_extattr_done(void) 1605 { 1606 1607 } 1608
Indexes created Sun Sep 28 16:09:52 GMT 2025