ufs_extattr.c revision 252438
1/*- 2 * Copyright (c) 1999-2002 Robert N. M. Watson 3 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed by Robert Watson for the TrustedBSD Project. 7 * 8 * This software was developed for the FreeBSD Project in part by Network 9 * Associates Laboratories, the Security Research Division of Network 10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 11 * as part of the DARPA CHATS research program. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35 36/* 37 * Support for filesystem extended attribute: UFS-specific support functions. 38 */ 39 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD: head/sys/ufs/ufs/ufs_extattr.c 252438 2013-07-01 04:06:40Z gleb $"); 42 43#include "opt_ufs.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/kernel.h> 48#include <sys/namei.h> 49#include <sys/malloc.h> 50#include <sys/fcntl.h> 51#include <sys/priv.h> 52#include <sys/proc.h> 53#include <sys/vnode.h> 54#include <sys/mount.h> 55#include <sys/lock.h> 56#include <sys/dirent.h> 57#include <sys/extattr.h> 58#include <sys/sx.h> 59#include <sys/sysctl.h> 60 61#include <vm/uma.h> 62 63#include <ufs/ufs/dir.h> 64#include <ufs/ufs/extattr.h> 65#include <ufs/ufs/quota.h> 66#include <ufs/ufs/ufsmount.h> 67#include <ufs/ufs/inode.h> 68#include <ufs/ufs/ufs_extern.h> 69 70#ifdef UFS_EXTATTR 71 72static MALLOC_DEFINE(M_UFS_EXTATTR, "ufs_extattr", "ufs extended attribute"); 73 74static int ufs_extattr_sync = 0; 75SYSCTL_INT(_debug, OID_AUTO, ufs_extattr_sync, CTLFLAG_RW, &ufs_extattr_sync, 76 0, ""); 77 78static int ufs_extattr_valid_attrname(int attrnamespace, 79 const char *attrname); 80static int ufs_extattr_enable_with_open(struct ufsmount *ump, 81 struct vnode *vp, int attrnamespace, const char *attrname, 82 struct thread *td); 83static int ufs_extattr_enable(struct ufsmount *ump, int attrnamespace, 84 const char *attrname, struct vnode *backing_vnode, 85 struct thread *td); 86static int ufs_extattr_disable(struct ufsmount *ump, int attrnamespace, 87 const char *attrname, struct thread *td); 88static int ufs_extattr_get(struct vnode *vp, int attrnamespace, 89 const char *name, struct uio *uio, size_t *size, 90 struct ucred *cred, struct thread *td); 91static int ufs_extattr_set(struct vnode *vp, int attrnamespace, 92 const char *name, struct uio *uio, struct ucred *cred, 93 struct thread *td); 94static int ufs_extattr_rm(struct vnode *vp, int attrnamespace, 95 const char *name, struct ucred *cred, struct thread *td); 96#ifdef UFS_EXTATTR_AUTOSTART 97static int ufs_extattr_autostart_locked(struct mount *mp, 98 struct thread *td); 99#endif 100static int ufs_extattr_start_locked(struct ufsmount *ump, 101 struct thread *td); 102 103/* 104 * Per-FS attribute lock protecting attribute operations. 105 * 106 * XXXRW: Perhaps something more fine-grained would be appropriate, but at 107 * the end of the day we're going to contend on the vnode lock for the 108 * backing file anyway. 109 */ 110static void 111ufs_extattr_uepm_lock(struct ufsmount *ump) 112{ 113 114 sx_xlock(&ump->um_extattr.uepm_lock); 115} 116 117static void 118ufs_extattr_uepm_unlock(struct ufsmount *ump) 119{ 120 121 sx_xunlock(&ump->um_extattr.uepm_lock); 122} 123 124/*- 125 * Determine whether the name passed is a valid name for an actual 126 * attribute. 127 * 128 * Invalid currently consists of: 129 * NULL pointer for attrname 130 * zero-length attrname (used to retrieve application attribute list) 131 */ 132static int 133ufs_extattr_valid_attrname(int attrnamespace, const char *attrname) 134{ 135 136 if (attrname == NULL) 137 return (0); 138 if (strlen(attrname) == 0) 139 return (0); 140 return (1); 141} 142 143/* 144 * Locate an attribute given a name and mountpoint. 145 * Must be holding uepm lock for the mount point. 146 */ 147static struct ufs_extattr_list_entry * 148ufs_extattr_find_attr(struct ufsmount *ump, int attrnamespace, 149 const char *attrname) 150{ 151 struct ufs_extattr_list_entry *search_attribute; 152 153 sx_assert(&ump->um_extattr.uepm_lock, SA_XLOCKED); 154 155 for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list); 156 search_attribute != NULL; 157 search_attribute = LIST_NEXT(search_attribute, uele_entries)) { 158 if (!(strncmp(attrname, search_attribute->uele_attrname, 159 UFS_EXTATTR_MAXEXTATTRNAME)) && 160 (attrnamespace == search_attribute->uele_attrnamespace)) { 161 return (search_attribute); 162 } 163 } 164 165 return (0); 166} 167 168/* 169 * Initialize per-FS structures supporting extended attributes. Do not 170 * start extended attributes yet. 171 */ 172void 173ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm) 174{ 175 176 uepm->uepm_flags = 0; 177 LIST_INIT(&uepm->uepm_list); 178 sx_init(&uepm->uepm_lock, "ufs_extattr_sx"); 179 uepm->uepm_flags |= UFS_EXTATTR_UEPM_INITIALIZED; 180} 181 182/* 183 * Destroy per-FS structures supporting extended attributes. Assumes 184 * that EAs have already been stopped, and will panic if not. 185 */ 186void 187ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm) 188{ 189 190 if (!(uepm->uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 191 panic("ufs_extattr_uepm_destroy: not initialized"); 192 193 if ((uepm->uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 194 panic("ufs_extattr_uepm_destroy: called while still started"); 195 196 /* 197 * It's not clear that either order for the next two lines is 198 * ideal, and it should never be a problem if this is only called 199 * during unmount, and with vfs_busy(). 200 */ 201 uepm->uepm_flags &= ~UFS_EXTATTR_UEPM_INITIALIZED; 202 sx_destroy(&uepm->uepm_lock); 203} 204 205/* 206 * Start extended attribute support on an FS. 207 */ 208int 209ufs_extattr_start(struct mount *mp, struct thread *td) 210{ 211 struct ufsmount *ump; 212 int error = 0; 213 214 ump = VFSTOUFS(mp); 215 216 ufs_extattr_uepm_lock(ump); 217 error = ufs_extattr_start_locked(ump, td); 218 ufs_extattr_uepm_unlock(ump); 219 return (error); 220} 221 222static int 223ufs_extattr_start_locked(struct ufsmount *ump, struct thread *td) 224{ 225 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 226 return (EOPNOTSUPP); 227 if (ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED) 228 return (EBUSY); 229 230 ump->um_extattr.uepm_flags |= UFS_EXTATTR_UEPM_STARTED; 231 ump->um_extattr.uepm_ucred = crhold(td->td_ucred); 232 return (0); 233} 234 235#ifdef UFS_EXTATTR_AUTOSTART 236/* 237 * Helper routine: given a locked parent directory and filename, return 238 * the locked vnode of the inode associated with the name. Will not 239 * follow symlinks, may return any type of vnode. Lock on parent will 240 * be released even in the event of a failure. In the event that the 241 * target is the parent (i.e., "."), there will be two references and 242 * one lock, requiring the caller to possibly special-case. 243 */ 244#define UE_GETDIR_LOCKPARENT 1 245#define UE_GETDIR_LOCKPARENT_DONT 2 246static int 247ufs_extattr_lookup(struct vnode *start_dvp, int lockparent, char *dirname, 248 struct vnode **vp, struct thread *td) 249{ 250 struct vop_cachedlookup_args vargs; 251 struct componentname cnp; 252 struct vnode *target_vp; 253 int error; 254 255 bzero(&cnp, sizeof(cnp)); 256 cnp.cn_nameiop = LOOKUP; 257 cnp.cn_flags = ISLASTCN; 258 if (lockparent == UE_GETDIR_LOCKPARENT) 259 cnp.cn_flags |= LOCKPARENT; 260 cnp.cn_lkflags = LK_EXCLUSIVE; 261 cnp.cn_thread = td; 262 cnp.cn_cred = td->td_ucred; 263 cnp.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 264 cnp.cn_nameptr = cnp.cn_pnbuf; 265 error = copystr(dirname, cnp.cn_pnbuf, MAXPATHLEN, 266 (size_t *) &cnp.cn_namelen); 267 if (error) { 268 if (lockparent == UE_GETDIR_LOCKPARENT_DONT) { 269 VOP_UNLOCK(start_dvp, 0); 270 } 271 uma_zfree(namei_zone, cnp.cn_pnbuf); 272 printf("ufs_extattr_lookup: copystr failed\n"); 273 return (error); 274 } 275 cnp.cn_namelen--; /* trim nul termination */ 276 vargs.a_gen.a_desc = NULL; 277 vargs.a_dvp = start_dvp; 278 vargs.a_vpp = &target_vp; 279 vargs.a_cnp = &cnp; 280 error = ufs_lookup(&vargs); 281 uma_zfree(namei_zone, cnp.cn_pnbuf); 282 if (error) { 283 /* 284 * Error condition, may have to release the lock on the parent 285 * if ufs_lookup() didn't. 286 */ 287 if (lockparent == UE_GETDIR_LOCKPARENT_DONT) 288 VOP_UNLOCK(start_dvp, 0); 289 290 /* 291 * Check that ufs_lookup() didn't release the lock when we 292 * didn't want it to. 293 */ 294 if (lockparent == UE_GETDIR_LOCKPARENT) 295 ASSERT_VOP_LOCKED(start_dvp, "ufs_extattr_lookup"); 296 297 return (error); 298 } 299/* 300 if (target_vp == start_dvp) 301 panic("ufs_extattr_lookup: target_vp == start_dvp"); 302*/ 303 304 if (target_vp != start_dvp && lockparent == UE_GETDIR_LOCKPARENT_DONT) 305 VOP_UNLOCK(start_dvp, 0); 306 307 if (lockparent == UE_GETDIR_LOCKPARENT) 308 ASSERT_VOP_LOCKED(start_dvp, "ufs_extattr_lookup"); 309 310 /* printf("ufs_extattr_lookup: success\n"); */ 311 *vp = target_vp; 312 return (0); 313} 314#endif /* !UFS_EXTATTR_AUTOSTART */ 315 316/* 317 * Enable an EA using the passed filesystem, backing vnode, attribute name, 318 * namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp 319 * to be locked when passed in. The vnode will be returned unlocked, 320 * regardless of success/failure of the function. As a result, the caller 321 * will always need to vrele(), but not vput(). 322 */ 323static int 324ufs_extattr_enable_with_open(struct ufsmount *ump, struct vnode *vp, 325 int attrnamespace, const char *attrname, struct thread *td) 326{ 327 int error; 328 329 error = VOP_OPEN(vp, FREAD|FWRITE, td->td_ucred, td, NULL); 330 if (error) { 331 printf("ufs_extattr_enable_with_open.VOP_OPEN(): failed " 332 "with %d\n", error); 333 VOP_UNLOCK(vp, 0); 334 return (error); 335 } 336 337 VOP_ADD_WRITECOUNT(vp, 1); 338 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, 339 vp->v_writecount); 340 341 vref(vp); 342 343 VOP_UNLOCK(vp, 0); 344 345 error = ufs_extattr_enable(ump, attrnamespace, attrname, vp, td); 346 if (error != 0) 347 vn_close(vp, FREAD|FWRITE, td->td_ucred, td); 348 return (error); 349} 350 351#ifdef UFS_EXTATTR_AUTOSTART 352/* 353 * Given a locked directory vnode, iterate over the names in the directory 354 * and use ufs_extattr_lookup() to retrieve locked vnodes of potential 355 * attribute files. Then invoke ufs_extattr_enable_with_open() on each 356 * to attempt to start the attribute. Leaves the directory locked on 357 * exit. 358 */ 359static int 360ufs_extattr_iterate_directory(struct ufsmount *ump, struct vnode *dvp, 361 int attrnamespace, struct thread *td) 362{ 363 struct vop_readdir_args vargs; 364 struct dirent *dp, *edp; 365 struct vnode *attr_vp; 366 struct uio auio; 367 struct iovec aiov; 368 char *dirbuf; 369 int error, eofflag = 0; 370 371 if (dvp->v_type != VDIR) 372 return (ENOTDIR); 373 374 dirbuf = malloc(DIRBLKSIZ, M_TEMP, M_WAITOK); 375 376 auio.uio_iov = &aiov; 377 auio.uio_iovcnt = 1; 378 auio.uio_rw = UIO_READ; 379 auio.uio_segflg = UIO_SYSSPACE; 380 auio.uio_td = td; 381 auio.uio_offset = 0; 382 383 vargs.a_gen.a_desc = NULL; 384 vargs.a_vp = dvp; 385 vargs.a_uio = &auio; 386 vargs.a_cred = td->td_ucred; 387 vargs.a_eofflag = &eofflag; 388 vargs.a_ncookies = NULL; 389 vargs.a_cookies = NULL; 390 391 while (!eofflag) { 392 auio.uio_resid = DIRBLKSIZ; 393 aiov.iov_base = dirbuf; 394 aiov.iov_len = DIRBLKSIZ; 395 error = ufs_readdir(&vargs); 396 if (error) { 397 printf("ufs_extattr_iterate_directory: ufs_readdir " 398 "%d\n", error); 399 return (error); 400 } 401 402 edp = (struct dirent *)&dirbuf[DIRBLKSIZ - auio.uio_resid]; 403 for (dp = (struct dirent *)dirbuf; dp < edp; ) { 404 if (dp->d_reclen == 0) 405 break; 406 error = ufs_extattr_lookup(dvp, UE_GETDIR_LOCKPARENT, 407 dp->d_name, &attr_vp, td); 408 if (error) { 409 printf("ufs_extattr_iterate_directory: lookup " 410 "%s %d\n", dp->d_name, error); 411 } else if (attr_vp == dvp) { 412 vrele(attr_vp); 413 } else if (attr_vp->v_type != VREG) { 414 vput(attr_vp); 415 } else { 416 error = ufs_extattr_enable_with_open(ump, 417 attr_vp, attrnamespace, dp->d_name, td); 418 vrele(attr_vp); 419 if (error) { 420 printf("ufs_extattr_iterate_directory: " 421 "enable %s %d\n", dp->d_name, 422 error); 423 } else if (bootverbose) { 424 printf("UFS autostarted EA %s\n", 425 dp->d_name); 426 } 427 } 428 dp = (struct dirent *) ((char *)dp + dp->d_reclen); 429 if (dp >= edp) 430 break; 431 } 432 } 433 free(dirbuf, M_TEMP); 434 435 return (0); 436} 437 438/* 439 * Auto-start of extended attributes, to be executed (optionally) at 440 * mount-time. 441 */ 442int 443ufs_extattr_autostart(struct mount *mp, struct thread *td) 444{ 445 struct ufsmount *ump; 446 int error; 447 448 ump = VFSTOUFS(mp); 449 ufs_extattr_uepm_lock(ump); 450 error = ufs_extattr_autostart_locked(mp, td); 451 ufs_extattr_uepm_unlock(ump); 452 return (error); 453} 454 455static int 456ufs_extattr_autostart_locked(struct mount *mp, struct thread *td) 457{ 458 struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp; 459 struct ufsmount *ump = VFSTOUFS(mp); 460 int error; 461 462 /* 463 * UFS_EXTATTR applies only to UFS1, as UFS2 uses native extended 464 * attributes, so don't autostart. 465 */ 466 if (ump->um_fstype != UFS1) 467 return (0); 468 469 /* 470 * Does UFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root? 471 * If so, automatically start EA's. 472 */ 473 error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp); 474 if (error) { 475 printf("ufs_extattr_autostart.VFS_ROOT() returned %d\n", 476 error); 477 return (error); 478 } 479 480 error = ufs_extattr_lookup(rvp, UE_GETDIR_LOCKPARENT_DONT, 481 UFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, td); 482 if (error) { 483 /* rvp ref'd but now unlocked */ 484 vrele(rvp); 485 return (error); 486 } 487 if (rvp == attr_dvp) { 488 /* Should never happen. */ 489 vput(rvp); 490 vrele(attr_dvp); 491 return (EINVAL); 492 } 493 vrele(rvp); 494 495 if (attr_dvp->v_type != VDIR) { 496 printf("ufs_extattr_autostart: %s != VDIR\n", 497 UFS_EXTATTR_FSROOTSUBDIR); 498 goto return_vput_attr_dvp; 499 } 500 501 error = ufs_extattr_start_locked(ump, td); 502 if (error) { 503 printf("ufs_extattr_autostart: ufs_extattr_start failed (%d)\n", 504 error); 505 goto return_vput_attr_dvp; 506 } 507 508 /* 509 * Look for two subdirectories: UFS_EXTATTR_SUBDIR_SYSTEM, 510 * UFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory, 511 * and start with appropriate type. Failures in either don't 512 * result in an over-all failure. attr_dvp is left locked to 513 * be cleaned up on exit. 514 */ 515 error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT, 516 UFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, td); 517 if (!error) { 518 error = ufs_extattr_iterate_directory(VFSTOUFS(mp), 519 attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, td); 520 if (error) 521 printf("ufs_extattr_iterate_directory returned %d\n", 522 error); 523 vput(attr_system_dvp); 524 } 525 526 error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT, 527 UFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, td); 528 if (!error) { 529 error = ufs_extattr_iterate_directory(VFSTOUFS(mp), 530 attr_user_dvp, EXTATTR_NAMESPACE_USER, td); 531 if (error) 532 printf("ufs_extattr_iterate_directory returned %d\n", 533 error); 534 vput(attr_user_dvp); 535 } 536 537 /* Mask startup failures in sub-directories. */ 538 error = 0; 539 540return_vput_attr_dvp: 541 vput(attr_dvp); 542 543 return (error); 544} 545#endif /* !UFS_EXTATTR_AUTOSTART */ 546 547/* 548 * Stop extended attribute support on an FS. 549 */ 550int 551ufs_extattr_stop(struct mount *mp, struct thread *td) 552{ 553 struct ufs_extattr_list_entry *uele; 554 struct ufsmount *ump = VFSTOUFS(mp); 555 int error = 0; 556 557 ufs_extattr_uepm_lock(ump); 558 559 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 560 error = EOPNOTSUPP; 561 goto unlock; 562 } 563 564 while ((uele = LIST_FIRST(&ump->um_extattr.uepm_list)) != NULL) { 565 ufs_extattr_disable(ump, uele->uele_attrnamespace, 566 uele->uele_attrname, td); 567 } 568 569 ump->um_extattr.uepm_flags &= ~UFS_EXTATTR_UEPM_STARTED; 570 571 crfree(ump->um_extattr.uepm_ucred); 572 ump->um_extattr.uepm_ucred = NULL; 573 574unlock: 575 ufs_extattr_uepm_unlock(ump); 576 577 return (error); 578} 579 580/* 581 * Enable a named attribute on the specified filesystem; provide an 582 * unlocked backing vnode to hold the attribute data. 583 */ 584static int 585ufs_extattr_enable(struct ufsmount *ump, int attrnamespace, 586 const char *attrname, struct vnode *backing_vnode, struct thread *td) 587{ 588 struct ufs_extattr_list_entry *attribute; 589 struct iovec aiov; 590 struct uio auio; 591 int error = 0; 592 593 if (!ufs_extattr_valid_attrname(attrnamespace, attrname)) 594 return (EINVAL); 595 if (backing_vnode->v_type != VREG) 596 return (EINVAL); 597 598 attribute = malloc(sizeof(struct ufs_extattr_list_entry), 599 M_UFS_EXTATTR, M_WAITOK); 600 if (attribute == NULL) 601 return (ENOMEM); 602 603 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 604 error = EOPNOTSUPP; 605 goto free_exit; 606 } 607 608 if (ufs_extattr_find_attr(ump, attrnamespace, attrname)) { 609 error = EEXIST; 610 goto free_exit; 611 } 612 613 strncpy(attribute->uele_attrname, attrname, 614 UFS_EXTATTR_MAXEXTATTRNAME); 615 attribute->uele_attrnamespace = attrnamespace; 616 bzero(&attribute->uele_fileheader, 617 sizeof(struct ufs_extattr_fileheader)); 618 619 attribute->uele_backing_vnode = backing_vnode; 620 621 auio.uio_iov = &aiov; 622 auio.uio_iovcnt = 1; 623 aiov.iov_base = (caddr_t) &attribute->uele_fileheader; 624 aiov.iov_len = sizeof(struct ufs_extattr_fileheader); 625 auio.uio_resid = sizeof(struct ufs_extattr_fileheader); 626 auio.uio_offset = (off_t) 0; 627 auio.uio_segflg = UIO_SYSSPACE; 628 auio.uio_rw = UIO_READ; 629 auio.uio_td = td; 630 631 vn_lock(backing_vnode, LK_SHARED | LK_RETRY); 632 error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED, 633 ump->um_extattr.uepm_ucred); 634 635 if (error) 636 goto unlock_free_exit; 637 638 if (auio.uio_resid != 0) { 639 printf("ufs_extattr_enable: malformed attribute header\n"); 640 error = EINVAL; 641 goto unlock_free_exit; 642 } 643 644 if (attribute->uele_fileheader.uef_magic != UFS_EXTATTR_MAGIC) { 645 printf("ufs_extattr_enable: invalid attribute header magic\n"); 646 error = EINVAL; 647 goto unlock_free_exit; 648 } 649 650 if (attribute->uele_fileheader.uef_version != UFS_EXTATTR_VERSION) { 651 printf("ufs_extattr_enable: incorrect attribute header " 652 "version\n"); 653 error = EINVAL; 654 goto unlock_free_exit; 655 } 656 657 ASSERT_VOP_LOCKED(backing_vnode, "ufs_extattr_enable"); 658 LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute, 659 uele_entries); 660 661 VOP_UNLOCK(backing_vnode, 0); 662 return (0); 663 664unlock_free_exit: 665 VOP_UNLOCK(backing_vnode, 0); 666 667free_exit: 668 free(attribute, M_UFS_EXTATTR); 669 return (error); 670} 671 672/* 673 * Disable extended attribute support on an FS. 674 */ 675static int 676ufs_extattr_disable(struct ufsmount *ump, int attrnamespace, 677 const char *attrname, struct thread *td) 678{ 679 struct ufs_extattr_list_entry *uele; 680 int error = 0; 681 682 if (!ufs_extattr_valid_attrname(attrnamespace, attrname)) 683 return (EINVAL); 684 685 uele = ufs_extattr_find_attr(ump, attrnamespace, attrname); 686 if (!uele) 687 return (ENOATTR); 688 689 LIST_REMOVE(uele, uele_entries); 690 691 vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_RETRY); 692 ASSERT_VOP_LOCKED(uele->uele_backing_vnode, "ufs_extattr_disable"); 693 VOP_UNLOCK(uele->uele_backing_vnode, 0); 694 error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE, 695 td->td_ucred, td); 696 697 free(uele, M_UFS_EXTATTR); 698 699 return (error); 700} 701 702/* 703 * VFS call to manage extended attributes in UFS. If filename_vp is 704 * non-NULL, it must be passed in locked, and regardless of errors in 705 * processing, will be unlocked. 706 */ 707int 708ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 709 int attrnamespace, const char *attrname) 710{ 711 struct ufsmount *ump = VFSTOUFS(mp); 712 struct thread *td = curthread; 713 int error; 714 715 /* 716 * Processes with privilege, but in jail, are not allowed to 717 * configure extended attributes. 718 */ 719 error = priv_check(td, PRIV_UFS_EXTATTRCTL); 720 if (error) { 721 if (filename_vp != NULL) 722 VOP_UNLOCK(filename_vp, 0); 723 return (error); 724 } 725 726 /* 727 * We only allow extattrctl(2) on UFS1 file systems, as UFS2 uses 728 * native extended attributes. 729 */ 730 if (ump->um_fstype != UFS1) { 731 if (filename_vp != NULL) 732 VOP_UNLOCK(filename_vp, 0); 733 return (EOPNOTSUPP); 734 } 735 736 switch(cmd) { 737 case UFS_EXTATTR_CMD_START: 738 if (filename_vp != NULL) { 739 VOP_UNLOCK(filename_vp, 0); 740 return (EINVAL); 741 } 742 if (attrname != NULL) 743 return (EINVAL); 744 745 error = ufs_extattr_start(mp, td); 746 747 return (error); 748 749 case UFS_EXTATTR_CMD_STOP: 750 if (filename_vp != NULL) { 751 VOP_UNLOCK(filename_vp, 0); 752 return (EINVAL); 753 } 754 if (attrname != NULL) 755 return (EINVAL); 756 757 error = ufs_extattr_stop(mp, td); 758 759 return (error); 760 761 case UFS_EXTATTR_CMD_ENABLE: 762 763 if (filename_vp == NULL) 764 return (EINVAL); 765 if (attrname == NULL) { 766 VOP_UNLOCK(filename_vp, 0); 767 return (EINVAL); 768 } 769 770 /* 771 * ufs_extattr_enable_with_open() will always unlock the 772 * vnode, regardless of failure. 773 */ 774 ufs_extattr_uepm_lock(ump); 775 error = ufs_extattr_enable_with_open(ump, filename_vp, 776 attrnamespace, attrname, td); 777 ufs_extattr_uepm_unlock(ump); 778 779 return (error); 780 781 case UFS_EXTATTR_CMD_DISABLE: 782 783 if (filename_vp != NULL) { 784 VOP_UNLOCK(filename_vp, 0); 785 return (EINVAL); 786 } 787 if (attrname == NULL) 788 return (EINVAL); 789 790 ufs_extattr_uepm_lock(ump); 791 error = ufs_extattr_disable(ump, attrnamespace, attrname, 792 td); 793 ufs_extattr_uepm_unlock(ump); 794 795 return (error); 796 797 default: 798 return (EINVAL); 799 } 800} 801 802/* 803 * Vnode operating to retrieve a named extended attribute. 804 */ 805int 806ufs_getextattr(struct vop_getextattr_args *ap) 807/* 808vop_getextattr { 809 IN struct vnode *a_vp; 810 IN int a_attrnamespace; 811 IN const char *a_name; 812 INOUT struct uio *a_uio; 813 OUT size_t *a_size; 814 IN struct ucred *a_cred; 815 IN struct thread *a_td; 816}; 817*/ 818{ 819 struct mount *mp = ap->a_vp->v_mount; 820 struct ufsmount *ump = VFSTOUFS(mp); 821 int error; 822 823 ufs_extattr_uepm_lock(ump); 824 825 error = ufs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name, 826 ap->a_uio, ap->a_size, ap->a_cred, ap->a_td); 827 828 ufs_extattr_uepm_unlock(ump); 829 830 return (error); 831} 832 833/* 834 * Real work associated with retrieving a named attribute--assumes that 835 * the attribute lock has already been grabbed. 836 */ 837static int 838ufs_extattr_get(struct vnode *vp, int attrnamespace, const char *name, 839 struct uio *uio, size_t *size, struct ucred *cred, struct thread *td) 840{ 841 struct ufs_extattr_list_entry *attribute; 842 struct ufs_extattr_header ueh; 843 struct iovec local_aiov; 844 struct uio local_aio; 845 struct mount *mp = vp->v_mount; 846 struct ufsmount *ump = VFSTOUFS(mp); 847 struct inode *ip = VTOI(vp); 848 off_t base_offset; 849 size_t len, old_len; 850 int error = 0; 851 852 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 853 return (EOPNOTSUPP); 854 855 if (strlen(name) == 0) 856 return (EINVAL); 857 858 error = extattr_check_cred(vp, attrnamespace, cred, td, VREAD); 859 if (error) 860 return (error); 861 862 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 863 if (!attribute) 864 return (ENOATTR); 865 866 /* 867 * Allow only offsets of zero to encourage the read/replace 868 * extended attribute semantic. Otherwise we can't guarantee 869 * atomicity, as we don't provide locks for extended attributes. 870 */ 871 if (uio != NULL && uio->uio_offset != 0) 872 return (ENXIO); 873 874 /* 875 * Find base offset of header in file based on file header size, and 876 * data header size + maximum data size, indexed by inode number. 877 */ 878 base_offset = sizeof(struct ufs_extattr_fileheader) + 879 ip->i_number * (sizeof(struct ufs_extattr_header) + 880 attribute->uele_fileheader.uef_size); 881 882 /* 883 * Read in the data header to see if the data is defined, and if so 884 * how much. 885 */ 886 bzero(&ueh, sizeof(struct ufs_extattr_header)); 887 local_aiov.iov_base = (caddr_t) &ueh; 888 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 889 local_aio.uio_iov = &local_aiov; 890 local_aio.uio_iovcnt = 1; 891 local_aio.uio_rw = UIO_READ; 892 local_aio.uio_segflg = UIO_SYSSPACE; 893 local_aio.uio_td = td; 894 local_aio.uio_offset = base_offset; 895 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 896 897 /* 898 * Acquire locks. 899 * 900 * Don't need to get a lock on the backing file if the getattr is 901 * being applied to the backing file, as the lock is already held. 902 */ 903 if (attribute->uele_backing_vnode != vp) 904 vn_lock(attribute->uele_backing_vnode, LK_SHARED | LK_RETRY); 905 906 error = VOP_READ(attribute->uele_backing_vnode, &local_aio, 907 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 908 if (error) 909 goto vopunlock_exit; 910 911 /* Defined? */ 912 if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) { 913 error = ENOATTR; 914 goto vopunlock_exit; 915 } 916 917 /* Valid for the current inode generation? */ 918 if (ueh.ueh_i_gen != ip->i_gen) { 919 /* 920 * The inode itself has a different generation number 921 * than the attribute data. For now, the best solution 922 * is to coerce this to undefined, and let it get cleaned 923 * up by the next write or extattrctl clean. 924 */ 925 printf("ufs_extattr_get (%s): inode number inconsistency (%d, %ju)\n", 926 mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (uintmax_t)ip->i_gen); 927 error = ENOATTR; 928 goto vopunlock_exit; 929 } 930 931 /* Local size consistency check. */ 932 if (ueh.ueh_len > attribute->uele_fileheader.uef_size) { 933 error = ENXIO; 934 goto vopunlock_exit; 935 } 936 937 /* Return full data size if caller requested it. */ 938 if (size != NULL) 939 *size = ueh.ueh_len; 940 941 /* Return data if the caller requested it. */ 942 if (uio != NULL) { 943 /* Allow for offset into the attribute data. */ 944 uio->uio_offset = base_offset + sizeof(struct 945 ufs_extattr_header); 946 947 /* 948 * Figure out maximum to transfer -- use buffer size and 949 * local data limit. 950 */ 951 len = MIN(uio->uio_resid, ueh.ueh_len); 952 old_len = uio->uio_resid; 953 uio->uio_resid = len; 954 955 error = VOP_READ(attribute->uele_backing_vnode, uio, 956 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 957 if (error) 958 goto vopunlock_exit; 959 960 uio->uio_resid = old_len - (len - uio->uio_resid); 961 } 962 963vopunlock_exit: 964 965 if (uio != NULL) 966 uio->uio_offset = 0; 967 968 if (attribute->uele_backing_vnode != vp) 969 VOP_UNLOCK(attribute->uele_backing_vnode, 0); 970 971 return (error); 972} 973 974/* 975 * Vnode operation to remove a named attribute. 976 */ 977int 978ufs_deleteextattr(struct vop_deleteextattr_args *ap) 979/* 980vop_deleteextattr { 981 IN struct vnode *a_vp; 982 IN int a_attrnamespace; 983 IN const char *a_name; 984 IN struct ucred *a_cred; 985 IN struct thread *a_td; 986}; 987*/ 988{ 989 struct mount *mp = ap->a_vp->v_mount; 990 struct ufsmount *ump = VFSTOUFS(mp); 991 int error; 992 993 ufs_extattr_uepm_lock(ump); 994 995 error = ufs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name, 996 ap->a_cred, ap->a_td); 997 998 999 ufs_extattr_uepm_unlock(ump); 1000 1001 return (error); 1002} 1003 1004/* 1005 * Vnode operation to set a named attribute. 1006 */ 1007int 1008ufs_setextattr(struct vop_setextattr_args *ap) 1009/* 1010vop_setextattr { 1011 IN struct vnode *a_vp; 1012 IN int a_attrnamespace; 1013 IN const char *a_name; 1014 INOUT struct uio *a_uio; 1015 IN struct ucred *a_cred; 1016 IN struct thread *a_td; 1017}; 1018*/ 1019{ 1020 struct mount *mp = ap->a_vp->v_mount; 1021 struct ufsmount *ump = VFSTOUFS(mp); 1022 int error; 1023 1024 /* 1025 * XXX: No longer a supported way to delete extended attributes. 1026 */ 1027 if (ap->a_uio == NULL) 1028 return (EINVAL); 1029 1030 ufs_extattr_uepm_lock(ump); 1031 1032 error = ufs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1033 ap->a_uio, ap->a_cred, ap->a_td); 1034 1035 ufs_extattr_uepm_unlock(ump); 1036 1037 return (error); 1038} 1039 1040/* 1041 * Real work associated with setting a vnode's extended attributes; 1042 * assumes that the attribute lock has already been grabbed. 1043 */ 1044static int 1045ufs_extattr_set(struct vnode *vp, int attrnamespace, const char *name, 1046 struct uio *uio, struct ucred *cred, struct thread *td) 1047{ 1048 struct ufs_extattr_list_entry *attribute; 1049 struct ufs_extattr_header ueh; 1050 struct iovec local_aiov; 1051 struct uio local_aio; 1052 struct mount *mp = vp->v_mount; 1053 struct ufsmount *ump = VFSTOUFS(mp); 1054 struct inode *ip = VTOI(vp); 1055 off_t base_offset; 1056 int error = 0, ioflag; 1057 1058 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1059 return (EROFS); 1060 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 1061 return (EOPNOTSUPP); 1062 if (!ufs_extattr_valid_attrname(attrnamespace, name)) 1063 return (EINVAL); 1064 1065 error = extattr_check_cred(vp, attrnamespace, cred, td, VWRITE); 1066 if (error) 1067 return (error); 1068 1069 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 1070 if (!attribute) 1071 return (ENOATTR); 1072 1073 /* 1074 * Early rejection of invalid offsets/length. 1075 * Reject: any offset but 0 (replace) 1076 * Any size greater than attribute size limit 1077 */ 1078 if (uio->uio_offset != 0 || 1079 uio->uio_resid > attribute->uele_fileheader.uef_size) 1080 return (ENXIO); 1081 1082 /* 1083 * Find base offset of header in file based on file header size, and 1084 * data header size + maximum data size, indexed by inode number. 1085 */ 1086 base_offset = sizeof(struct ufs_extattr_fileheader) + 1087 ip->i_number * (sizeof(struct ufs_extattr_header) + 1088 attribute->uele_fileheader.uef_size); 1089 1090 /* 1091 * Write out a data header for the data. 1092 */ 1093 ueh.ueh_len = uio->uio_resid; 1094 ueh.ueh_flags = UFS_EXTATTR_ATTR_FLAG_INUSE; 1095 ueh.ueh_i_gen = ip->i_gen; 1096 local_aiov.iov_base = (caddr_t) &ueh; 1097 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1098 local_aio.uio_iov = &local_aiov; 1099 local_aio.uio_iovcnt = 1; 1100 local_aio.uio_rw = UIO_WRITE; 1101 local_aio.uio_segflg = UIO_SYSSPACE; 1102 local_aio.uio_td = td; 1103 local_aio.uio_offset = base_offset; 1104 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1105 1106 /* 1107 * Acquire locks. 1108 * 1109 * Don't need to get a lock on the backing file if the setattr is 1110 * being applied to the backing file, as the lock is already held. 1111 */ 1112 if (attribute->uele_backing_vnode != vp) 1113 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1114 1115 ioflag = IO_NODELOCKED; 1116 if (ufs_extattr_sync) 1117 ioflag |= IO_SYNC; 1118 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1119 ump->um_extattr.uepm_ucred); 1120 if (error) 1121 goto vopunlock_exit; 1122 1123 if (local_aio.uio_resid != 0) { 1124 error = ENXIO; 1125 goto vopunlock_exit; 1126 } 1127 1128 /* 1129 * Write out user data. 1130 */ 1131 uio->uio_offset = base_offset + sizeof(struct ufs_extattr_header); 1132 1133 ioflag = IO_NODELOCKED; 1134 if (ufs_extattr_sync) 1135 ioflag |= IO_SYNC; 1136 error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag, 1137 ump->um_extattr.uepm_ucred); 1138 1139vopunlock_exit: 1140 uio->uio_offset = 0; 1141 1142 if (attribute->uele_backing_vnode != vp) 1143 VOP_UNLOCK(attribute->uele_backing_vnode, 0); 1144 1145 return (error); 1146} 1147 1148/* 1149 * Real work associated with removing an extended attribute from a vnode. 1150 * Assumes the attribute lock has already been grabbed. 1151 */ 1152static int 1153ufs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name, 1154 struct ucred *cred, struct thread *td) 1155{ 1156 struct ufs_extattr_list_entry *attribute; 1157 struct ufs_extattr_header ueh; 1158 struct iovec local_aiov; 1159 struct uio local_aio; 1160 struct mount *mp = vp->v_mount; 1161 struct ufsmount *ump = VFSTOUFS(mp); 1162 struct inode *ip = VTOI(vp); 1163 off_t base_offset; 1164 int error = 0, ioflag; 1165 1166 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1167 return (EROFS); 1168 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 1169 return (EOPNOTSUPP); 1170 if (!ufs_extattr_valid_attrname(attrnamespace, name)) 1171 return (EINVAL); 1172 1173 error = extattr_check_cred(vp, attrnamespace, cred, td, VWRITE); 1174 if (error) 1175 return (error); 1176 1177 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 1178 if (!attribute) 1179 return (ENOATTR); 1180 1181 /* 1182 * Find base offset of header in file based on file header size, and 1183 * data header size + maximum data size, indexed by inode number. 1184 */ 1185 base_offset = sizeof(struct ufs_extattr_fileheader) + 1186 ip->i_number * (sizeof(struct ufs_extattr_header) + 1187 attribute->uele_fileheader.uef_size); 1188 1189 /* 1190 * Check to see if currently defined. 1191 */ 1192 bzero(&ueh, sizeof(struct ufs_extattr_header)); 1193 1194 local_aiov.iov_base = (caddr_t) &ueh; 1195 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1196 local_aio.uio_iov = &local_aiov; 1197 local_aio.uio_iovcnt = 1; 1198 local_aio.uio_rw = UIO_READ; 1199 local_aio.uio_segflg = UIO_SYSSPACE; 1200 local_aio.uio_td = td; 1201 local_aio.uio_offset = base_offset; 1202 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1203 1204 /* 1205 * Don't need to get the lock on the backing vnode if the vnode we're 1206 * modifying is it, as we already hold the lock. 1207 */ 1208 if (attribute->uele_backing_vnode != vp) 1209 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1210 1211 error = VOP_READ(attribute->uele_backing_vnode, &local_aio, 1212 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1213 if (error) 1214 goto vopunlock_exit; 1215 1216 /* Defined? */ 1217 if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) { 1218 error = ENOATTR; 1219 goto vopunlock_exit; 1220 } 1221 1222 /* Valid for the current inode generation? */ 1223 if (ueh.ueh_i_gen != ip->i_gen) { 1224 /* 1225 * The inode itself has a different generation number than 1226 * the attribute data. For now, the best solution is to 1227 * coerce this to undefined, and let it get cleaned up by 1228 * the next write or extattrctl clean. 1229 */ 1230 printf("ufs_extattr_rm (%s): inode number inconsistency (%d, %jd)\n", 1231 mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (intmax_t)ip->i_gen); 1232 error = ENOATTR; 1233 goto vopunlock_exit; 1234 } 1235 1236 /* Flag it as not in use. */ 1237 ueh.ueh_flags = 0; 1238 ueh.ueh_len = 0; 1239 1240 local_aiov.iov_base = (caddr_t) &ueh; 1241 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1242 local_aio.uio_iov = &local_aiov; 1243 local_aio.uio_iovcnt = 1; 1244 local_aio.uio_rw = UIO_WRITE; 1245 local_aio.uio_segflg = UIO_SYSSPACE; 1246 local_aio.uio_td = td; 1247 local_aio.uio_offset = base_offset; 1248 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1249 1250 ioflag = IO_NODELOCKED; 1251 if (ufs_extattr_sync) 1252 ioflag |= IO_SYNC; 1253 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1254 ump->um_extattr.uepm_ucred); 1255 if (error) 1256 goto vopunlock_exit; 1257 1258 if (local_aio.uio_resid != 0) 1259 error = ENXIO; 1260 1261vopunlock_exit: 1262 VOP_UNLOCK(attribute->uele_backing_vnode, 0); 1263 1264 return (error); 1265} 1266 1267/* 1268 * Called by UFS when an inode is no longer active and should have its 1269 * attributes stripped. 1270 */ 1271void 1272ufs_extattr_vnode_inactive(struct vnode *vp, struct thread *td) 1273{ 1274 struct ufs_extattr_list_entry *uele; 1275 struct mount *mp = vp->v_mount; 1276 struct ufsmount *ump = VFSTOUFS(mp); 1277 1278 /* 1279 * In that case, we cannot lock. We should not have any active vnodes 1280 * on the fs if this is not yet initialized but is going to be, so 1281 * this can go unlocked. 1282 */ 1283 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 1284 return; 1285 1286 ufs_extattr_uepm_lock(ump); 1287 1288 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 1289 ufs_extattr_uepm_unlock(ump); 1290 return; 1291 } 1292 1293 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) 1294 ufs_extattr_rm(vp, uele->uele_attrnamespace, 1295 uele->uele_attrname, NULL, td); 1296 1297 ufs_extattr_uepm_unlock(ump); 1298} 1299 1300#endif /* !UFS_EXTATTR */ 1301