xref: /freebsd/sys/ufs/ffs/ffs_vnops.c (revision 66fd12cf4896eb08ad8e7a2627537f84ead84dd3)
1 /*-
2  * SPDX-License-Identifier: (BSD-2-Clause AND BSD-3-Clause)
3  *
4  * Copyright (c) 2002, 2003 Networks Associates Technology, Inc.
5  * All rights reserved.
6  *
7  * This software was developed for the FreeBSD Project by Marshall
8  * Kirk McKusick and Network Associates Laboratories, the Security
9  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
10  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
11  * 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  * Copyright (c) 1982, 1986, 1989, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	from: @(#)ufs_readwrite.c	8.11 (Berkeley) 5/8/95
62  * from: $FreeBSD: .../ufs/ufs_readwrite.c,v 1.96 2002/08/12 09:22:11 phk ...
63  *	@(#)ffs_vnops.c	8.15 (Berkeley) 5/14/95
64  */
65 
66 #include <sys/cdefs.h>
67 __FBSDID("$FreeBSD$");
68 
69 #include "opt_directio.h"
70 #include "opt_ffs.h"
71 #include "opt_ufs.h"
72 
73 #include <sys/param.h>
74 #include <sys/bio.h>
75 #include <sys/systm.h>
76 #include <sys/buf.h>
77 #include <sys/conf.h>
78 #include <sys/extattr.h>
79 #include <sys/kernel.h>
80 #include <sys/limits.h>
81 #include <sys/malloc.h>
82 #include <sys/mount.h>
83 #include <sys/priv.h>
84 #include <sys/rwlock.h>
85 #include <sys/stat.h>
86 #include <sys/sysctl.h>
87 #include <sys/vmmeter.h>
88 #include <sys/vnode.h>
89 
90 #include <vm/vm.h>
91 #include <vm/vm_param.h>
92 #include <vm/vm_extern.h>
93 #include <vm/vm_object.h>
94 #include <vm/vm_page.h>
95 #include <vm/vm_pager.h>
96 #include <vm/vnode_pager.h>
97 
98 #include <ufs/ufs/extattr.h>
99 #include <ufs/ufs/quota.h>
100 #include <ufs/ufs/inode.h>
101 #include <ufs/ufs/ufs_extern.h>
102 #include <ufs/ufs/ufsmount.h>
103 #include <ufs/ufs/dir.h>
104 #ifdef UFS_DIRHASH
105 #include <ufs/ufs/dirhash.h>
106 #endif
107 
108 #include <ufs/ffs/fs.h>
109 #include <ufs/ffs/ffs_extern.h>
110 
111 #define	ALIGNED_TO(ptr, s)	\
112 	(((uintptr_t)(ptr) & (_Alignof(s) - 1)) == 0)
113 
114 #ifdef DIRECTIO
115 extern int	ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone);
116 #endif
117 static vop_fdatasync_t	ffs_fdatasync;
118 static vop_fsync_t	ffs_fsync;
119 static vop_getpages_t	ffs_getpages;
120 static vop_getpages_async_t	ffs_getpages_async;
121 static vop_lock1_t	ffs_lock;
122 #ifdef INVARIANTS
123 static vop_unlock_t	ffs_unlock_debug;
124 #endif
125 static vop_read_t	ffs_read;
126 static vop_write_t	ffs_write;
127 static int	ffs_extread(struct vnode *vp, struct uio *uio, int ioflag);
128 static int	ffs_extwrite(struct vnode *vp, struct uio *uio, int ioflag,
129 		    struct ucred *cred);
130 static vop_strategy_t	ffsext_strategy;
131 static vop_closeextattr_t	ffs_closeextattr;
132 static vop_deleteextattr_t	ffs_deleteextattr;
133 static vop_getextattr_t	ffs_getextattr;
134 static vop_listextattr_t	ffs_listextattr;
135 static vop_openextattr_t	ffs_openextattr;
136 static vop_setextattr_t	ffs_setextattr;
137 static vop_vptofh_t	ffs_vptofh;
138 static vop_vput_pair_t	ffs_vput_pair;
139 
140 /* Global vfs data structures for ufs. */
141 struct vop_vector ffs_vnodeops1 = {
142 	.vop_default =		&ufs_vnodeops,
143 	.vop_fsync =		ffs_fsync,
144 	.vop_fdatasync =	ffs_fdatasync,
145 	.vop_getpages =		ffs_getpages,
146 	.vop_getpages_async =	ffs_getpages_async,
147 	.vop_lock1 =		ffs_lock,
148 #ifdef INVARIANTS
149 	.vop_unlock =		ffs_unlock_debug,
150 #endif
151 	.vop_read =		ffs_read,
152 	.vop_reallocblks =	ffs_reallocblks,
153 	.vop_write =		ffs_write,
154 	.vop_vptofh =		ffs_vptofh,
155 	.vop_vput_pair =	ffs_vput_pair,
156 	.vop_fplookup_vexec =	VOP_EAGAIN,
157 	.vop_fplookup_symlink =	VOP_EAGAIN,
158 };
159 VFS_VOP_VECTOR_REGISTER(ffs_vnodeops1);
160 
161 struct vop_vector ffs_fifoops1 = {
162 	.vop_default =		&ufs_fifoops,
163 	.vop_fsync =		ffs_fsync,
164 	.vop_fdatasync =	ffs_fdatasync,
165 	.vop_lock1 =		ffs_lock,
166 #ifdef INVARIANTS
167 	.vop_unlock =		ffs_unlock_debug,
168 #endif
169 	.vop_vptofh =		ffs_vptofh,
170 	.vop_fplookup_vexec =   VOP_EAGAIN,
171 	.vop_fplookup_symlink = VOP_EAGAIN,
172 };
173 VFS_VOP_VECTOR_REGISTER(ffs_fifoops1);
174 
175 /* Global vfs data structures for ufs. */
176 struct vop_vector ffs_vnodeops2 = {
177 	.vop_default =		&ufs_vnodeops,
178 	.vop_fsync =		ffs_fsync,
179 	.vop_fdatasync =	ffs_fdatasync,
180 	.vop_getpages =		ffs_getpages,
181 	.vop_getpages_async =	ffs_getpages_async,
182 	.vop_lock1 =		ffs_lock,
183 #ifdef INVARIANTS
184 	.vop_unlock =		ffs_unlock_debug,
185 #endif
186 	.vop_read =		ffs_read,
187 	.vop_reallocblks =	ffs_reallocblks,
188 	.vop_write =		ffs_write,
189 	.vop_closeextattr =	ffs_closeextattr,
190 	.vop_deleteextattr =	ffs_deleteextattr,
191 	.vop_getextattr =	ffs_getextattr,
192 	.vop_listextattr =	ffs_listextattr,
193 	.vop_openextattr =	ffs_openextattr,
194 	.vop_setextattr =	ffs_setextattr,
195 	.vop_vptofh =		ffs_vptofh,
196 	.vop_vput_pair =	ffs_vput_pair,
197 	.vop_fplookup_vexec =	VOP_EAGAIN,
198 	.vop_fplookup_symlink =	VOP_EAGAIN,
199 };
200 VFS_VOP_VECTOR_REGISTER(ffs_vnodeops2);
201 
202 struct vop_vector ffs_fifoops2 = {
203 	.vop_default =		&ufs_fifoops,
204 	.vop_fsync =		ffs_fsync,
205 	.vop_fdatasync =	ffs_fdatasync,
206 	.vop_lock1 =		ffs_lock,
207 #ifdef INVARIANTS
208 	.vop_unlock =		ffs_unlock_debug,
209 #endif
210 	.vop_reallocblks =	ffs_reallocblks,
211 	.vop_strategy =		ffsext_strategy,
212 	.vop_closeextattr =	ffs_closeextattr,
213 	.vop_deleteextattr =	ffs_deleteextattr,
214 	.vop_getextattr =	ffs_getextattr,
215 	.vop_listextattr =	ffs_listextattr,
216 	.vop_openextattr =	ffs_openextattr,
217 	.vop_setextattr =	ffs_setextattr,
218 	.vop_vptofh =		ffs_vptofh,
219 	.vop_fplookup_vexec =   VOP_EAGAIN,
220 	.vop_fplookup_symlink = VOP_EAGAIN,
221 };
222 VFS_VOP_VECTOR_REGISTER(ffs_fifoops2);
223 
224 /*
225  * Synch an open file.
226  */
227 /* ARGSUSED */
228 static int
229 ffs_fsync(struct vop_fsync_args *ap)
230 {
231 	struct vnode *vp;
232 	struct bufobj *bo;
233 	int error;
234 
235 	vp = ap->a_vp;
236 	bo = &vp->v_bufobj;
237 retry:
238 	error = ffs_syncvnode(vp, ap->a_waitfor, 0);
239 	if (error)
240 		return (error);
241 	if (ap->a_waitfor == MNT_WAIT && DOINGSOFTDEP(vp)) {
242 		error = softdep_fsync(vp);
243 		if (error)
244 			return (error);
245 
246 		/*
247 		 * The softdep_fsync() function may drop vp lock,
248 		 * allowing for dirty buffers to reappear on the
249 		 * bo_dirty list. Recheck and resync as needed.
250 		 */
251 		BO_LOCK(bo);
252 		if ((vp->v_type == VREG || vp->v_type == VDIR) &&
253 		    (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)) {
254 			BO_UNLOCK(bo);
255 			goto retry;
256 		}
257 		BO_UNLOCK(bo);
258 	}
259 	if (ffs_fsfail_cleanup(VFSTOUFS(vp->v_mount), 0))
260 		return (ENXIO);
261 	return (0);
262 }
263 
264 int
265 ffs_syncvnode(struct vnode *vp, int waitfor, int flags)
266 {
267 	struct inode *ip;
268 	struct bufobj *bo;
269 	struct ufsmount *ump;
270 	struct buf *bp, *nbp;
271 	ufs_lbn_t lbn;
272 	int error, passes, wflag;
273 	bool still_dirty, unlocked, wait;
274 
275 	ip = VTOI(vp);
276 	bo = &vp->v_bufobj;
277 	ump = VFSTOUFS(vp->v_mount);
278 #ifdef WITNESS
279 	wflag = IS_SNAPSHOT(ip) ? LK_NOWITNESS : 0;
280 #else
281 	wflag = 0;
282 #endif
283 
284 	/*
285 	 * When doing MNT_WAIT we must first flush all dependencies
286 	 * on the inode.
287 	 */
288 	if (DOINGSOFTDEP(vp) && waitfor == MNT_WAIT &&
289 	    (error = softdep_sync_metadata(vp)) != 0) {
290 		if (ffs_fsfail_cleanup(ump, error))
291 			error = 0;
292 		return (error);
293 	}
294 
295 	/*
296 	 * Flush all dirty buffers associated with a vnode.
297 	 */
298 	error = 0;
299 	passes = 0;
300 	wait = false;	/* Always do an async pass first. */
301 	unlocked = false;
302 	lbn = lblkno(ITOFS(ip), (ip->i_size + ITOFS(ip)->fs_bsize - 1));
303 	BO_LOCK(bo);
304 loop:
305 	TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
306 		bp->b_vflags &= ~BV_SCANNED;
307 	TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
308 		/*
309 		 * Reasons to skip this buffer: it has already been considered
310 		 * on this pass, the buffer has dependencies that will cause
311 		 * it to be redirtied and it has not already been deferred,
312 		 * or it is already being written.
313 		 */
314 		if ((bp->b_vflags & BV_SCANNED) != 0)
315 			continue;
316 		bp->b_vflags |= BV_SCANNED;
317 		/*
318 		 * Flush indirects in order, if requested.
319 		 *
320 		 * Note that if only datasync is requested, we can
321 		 * skip indirect blocks when softupdates are not
322 		 * active.  Otherwise we must flush them with data,
323 		 * since dependencies prevent data block writes.
324 		 */
325 		if (waitfor == MNT_WAIT && bp->b_lblkno <= -UFS_NDADDR &&
326 		    (lbn_level(bp->b_lblkno) >= passes ||
327 		    ((flags & DATA_ONLY) != 0 && !DOINGSOFTDEP(vp))))
328 			continue;
329 		if (bp->b_lblkno > lbn)
330 			panic("ffs_syncvnode: syncing truncated data.");
331 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL) == 0) {
332 			BO_UNLOCK(bo);
333 		} else if (wait) {
334 			if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
335 			    LK_INTERLOCK | wflag, BO_LOCKPTR(bo)) != 0) {
336 				BO_LOCK(bo);
337 				bp->b_vflags &= ~BV_SCANNED;
338 				goto next_locked;
339 			}
340 		} else
341 			continue;
342 		if ((bp->b_flags & B_DELWRI) == 0)
343 			panic("ffs_fsync: not dirty");
344 		/*
345 		 * Check for dependencies and potentially complete them.
346 		 */
347 		if (!LIST_EMPTY(&bp->b_dep) &&
348 		    (error = softdep_sync_buf(vp, bp,
349 		    wait ? MNT_WAIT : MNT_NOWAIT)) != 0) {
350 			/*
351 			 * Lock order conflict, buffer was already unlocked,
352 			 * and vnode possibly unlocked.
353 			 */
354 			if (error == ERELOOKUP) {
355 				if (vp->v_data == NULL)
356 					return (EBADF);
357 				unlocked = true;
358 				if (DOINGSOFTDEP(vp) && waitfor == MNT_WAIT &&
359 				    (error = softdep_sync_metadata(vp)) != 0) {
360 					if (ffs_fsfail_cleanup(ump, error))
361 						error = 0;
362 					return (unlocked && error == 0 ?
363 					    ERELOOKUP : error);
364 				}
365 				/* Re-evaluate inode size */
366 				lbn = lblkno(ITOFS(ip), (ip->i_size +
367 				    ITOFS(ip)->fs_bsize - 1));
368 				goto next;
369 			}
370 			/* I/O error. */
371 			if (error != EBUSY) {
372 				BUF_UNLOCK(bp);
373 				return (error);
374 			}
375 			/* If we deferred once, don't defer again. */
376 		    	if ((bp->b_flags & B_DEFERRED) == 0) {
377 				bp->b_flags |= B_DEFERRED;
378 				BUF_UNLOCK(bp);
379 				goto next;
380 			}
381 		}
382 		if (wait) {
383 			bremfree(bp);
384 			error = bwrite(bp);
385 			if (ffs_fsfail_cleanup(ump, error))
386 				error = 0;
387 			if (error != 0)
388 				return (error);
389 		} else if ((bp->b_flags & B_CLUSTEROK)) {
390 			(void) vfs_bio_awrite(bp);
391 		} else {
392 			bremfree(bp);
393 			(void) bawrite(bp);
394 		}
395 next:
396 		/*
397 		 * Since we may have slept during the I/O, we need
398 		 * to start from a known point.
399 		 */
400 		BO_LOCK(bo);
401 next_locked:
402 		nbp = TAILQ_FIRST(&bo->bo_dirty.bv_hd);
403 	}
404 	if (waitfor != MNT_WAIT) {
405 		BO_UNLOCK(bo);
406 		if ((flags & NO_INO_UPDT) != 0)
407 			return (unlocked ? ERELOOKUP : 0);
408 		error = ffs_update(vp, 0);
409 		if (error == 0 && unlocked)
410 			error = ERELOOKUP;
411 		return (error);
412 	}
413 	/* Drain IO to see if we're done. */
414 	bufobj_wwait(bo, 0, 0);
415 	/*
416 	 * Block devices associated with filesystems may have new I/O
417 	 * requests posted for them even if the vnode is locked, so no
418 	 * amount of trying will get them clean.  We make several passes
419 	 * as a best effort.
420 	 *
421 	 * Regular files may need multiple passes to flush all dependency
422 	 * work as it is possible that we must write once per indirect
423 	 * level, once for the leaf, and once for the inode and each of
424 	 * these will be done with one sync and one async pass.
425 	 */
426 	if (bo->bo_dirty.bv_cnt > 0) {
427 		if ((flags & DATA_ONLY) == 0) {
428 			still_dirty = true;
429 		} else {
430 			/*
431 			 * For data-only sync, dirty indirect buffers
432 			 * are ignored.
433 			 */
434 			still_dirty = false;
435 			TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
436 				if (bp->b_lblkno > -UFS_NDADDR) {
437 					still_dirty = true;
438 					break;
439 				}
440 			}
441 		}
442 
443 		if (still_dirty) {
444 			/* Write the inode after sync passes to flush deps. */
445 			if (wait && DOINGSOFTDEP(vp) &&
446 			    (flags & NO_INO_UPDT) == 0) {
447 				BO_UNLOCK(bo);
448 				ffs_update(vp, 1);
449 				BO_LOCK(bo);
450 			}
451 			/* switch between sync/async. */
452 			wait = !wait;
453 			if (wait || ++passes < UFS_NIADDR + 2)
454 				goto loop;
455 		}
456 	}
457 	BO_UNLOCK(bo);
458 	error = 0;
459 	if ((flags & DATA_ONLY) == 0) {
460 		if ((flags & NO_INO_UPDT) == 0)
461 			error = ffs_update(vp, 1);
462 		if (DOINGSUJ(vp))
463 			softdep_journal_fsync(VTOI(vp));
464 	} else if ((ip->i_flags & (IN_SIZEMOD | IN_IBLKDATA)) != 0) {
465 		error = ffs_update(vp, 1);
466 	}
467 	if (error == 0 && unlocked)
468 		error = ERELOOKUP;
469 	if (error == 0)
470 		ip->i_flag &= ~IN_NEEDSYNC;
471 	return (error);
472 }
473 
474 static int
475 ffs_fdatasync(struct vop_fdatasync_args *ap)
476 {
477 
478 	return (ffs_syncvnode(ap->a_vp, MNT_WAIT, DATA_ONLY));
479 }
480 
481 static int
482 ffs_lock(
483 	struct vop_lock1_args /* {
484 		struct vnode *a_vp;
485 		int a_flags;
486 		char *file;
487 		int line;
488 	} */ *ap)
489 {
490 #if !defined(NO_FFS_SNAPSHOT) || defined(DIAGNOSTIC)
491 	struct vnode *vp = ap->a_vp;
492 #endif	/* !NO_FFS_SNAPSHOT || DIAGNOSTIC */
493 #ifdef DIAGNOSTIC
494 	struct inode *ip;
495 #endif	/* DIAGNOSTIC */
496 	int result;
497 #ifndef NO_FFS_SNAPSHOT
498 	int flags;
499 	struct lock *lkp;
500 
501 	/*
502 	 * Adaptive spinning mixed with SU leads to trouble. use a giant hammer
503 	 * and only use it when LK_NODDLKTREAT is set. Currently this means it
504 	 * is only used during path lookup.
505 	 */
506 	if ((ap->a_flags & LK_NODDLKTREAT) != 0)
507 		ap->a_flags |= LK_ADAPTIVE;
508 	switch (ap->a_flags & LK_TYPE_MASK) {
509 	case LK_SHARED:
510 	case LK_UPGRADE:
511 	case LK_EXCLUSIVE:
512 		flags = ap->a_flags;
513 		for (;;) {
514 #ifdef DEBUG_VFS_LOCKS
515 			VNPASS(vp->v_holdcnt != 0, vp);
516 #endif	/* DEBUG_VFS_LOCKS */
517 			lkp = vp->v_vnlock;
518 			result = lockmgr_lock_flags(lkp, flags,
519 			    &VI_MTX(vp)->lock_object, ap->a_file, ap->a_line);
520 			if (lkp == vp->v_vnlock || result != 0)
521 				break;
522 			/*
523 			 * Apparent success, except that the vnode
524 			 * mutated between snapshot file vnode and
525 			 * regular file vnode while this process
526 			 * slept.  The lock currently held is not the
527 			 * right lock.  Release it, and try to get the
528 			 * new lock.
529 			 */
530 			lockmgr_unlock(lkp);
531 			if ((flags & (LK_INTERLOCK | LK_NOWAIT)) ==
532 			    (LK_INTERLOCK | LK_NOWAIT))
533 				return (EBUSY);
534 			if ((flags & LK_TYPE_MASK) == LK_UPGRADE)
535 				flags = (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE;
536 			flags &= ~LK_INTERLOCK;
537 		}
538 #ifdef DIAGNOSTIC
539 		switch (ap->a_flags & LK_TYPE_MASK) {
540 		case LK_UPGRADE:
541 		case LK_EXCLUSIVE:
542 			if (result == 0 && vp->v_vnlock->lk_recurse == 0) {
543 				ip = VTOI(vp);
544 				if (ip != NULL)
545 					ip->i_lock_gen++;
546 			}
547 		}
548 #endif	/* DIAGNOSTIC */
549 		break;
550 	default:
551 #ifdef DIAGNOSTIC
552 		if ((ap->a_flags & LK_TYPE_MASK) == LK_DOWNGRADE) {
553 			ip = VTOI(vp);
554 			if (ip != NULL)
555 				ufs_unlock_tracker(ip);
556 		}
557 #endif	/* DIAGNOSTIC */
558 		result = VOP_LOCK1_APV(&ufs_vnodeops, ap);
559 		break;
560 	}
561 #else	/* NO_FFS_SNAPSHOT */
562 	/*
563 	 * See above for an explanation.
564 	 */
565 	if ((ap->a_flags & LK_NODDLKTREAT) != 0)
566 		ap->a_flags |= LK_ADAPTIVE;
567 #ifdef DIAGNOSTIC
568 	if ((ap->a_flags & LK_TYPE_MASK) == LK_DOWNGRADE) {
569 		ip = VTOI(vp);
570 		if (ip != NULL)
571 			ufs_unlock_tracker(ip);
572 	}
573 #endif	/* DIAGNOSTIC */
574 	result =  VOP_LOCK1_APV(&ufs_vnodeops, ap);
575 #endif	/* NO_FFS_SNAPSHOT */
576 #ifdef DIAGNOSTIC
577 	switch (ap->a_flags & LK_TYPE_MASK) {
578 	case LK_UPGRADE:
579 	case LK_EXCLUSIVE:
580 		if (result == 0 && vp->v_vnlock->lk_recurse == 0) {
581 			ip = VTOI(vp);
582 			if (ip != NULL)
583 				ip->i_lock_gen++;
584 		}
585 	}
586 #endif	/* DIAGNOSTIC */
587 	return (result);
588 }
589 
590 #ifdef INVARIANTS
591 static int
592 ffs_unlock_debug(struct vop_unlock_args *ap)
593 {
594 	struct vnode *vp;
595 	struct inode *ip;
596 
597 	vp = ap->a_vp;
598 	ip = VTOI(vp);
599 	if (ip->i_flag & UFS_INODE_FLAG_LAZY_MASK_ASSERTABLE) {
600 		if ((vp->v_mflag & VMP_LAZYLIST) == 0) {
601 			VI_LOCK(vp);
602 			VNASSERT((vp->v_mflag & VMP_LAZYLIST), vp,
603 			    ("%s: modified vnode (%x) not on lazy list",
604 			    __func__, ip->i_flag));
605 			VI_UNLOCK(vp);
606 		}
607 	}
608 	KASSERT(vp->v_type != VDIR || vp->v_vnlock->lk_recurse != 0 ||
609 	    (ip->i_flag & IN_ENDOFF) == 0,
610 	    ("ufs dir vp %p ip %p flags %#x", vp, ip, ip->i_flag));
611 #ifdef DIAGNOSTIC
612 	if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE && ip != NULL &&
613 	    vp->v_vnlock->lk_recurse == 0)
614 		ufs_unlock_tracker(ip);
615 #endif
616 	return (VOP_UNLOCK_APV(&ufs_vnodeops, ap));
617 }
618 #endif
619 
620 static int
621 ffs_read_hole(struct uio *uio, long xfersize, long *size)
622 {
623 	ssize_t saved_resid, tlen;
624 	int error;
625 
626 	while (xfersize > 0) {
627 		tlen = min(xfersize, ZERO_REGION_SIZE);
628 		saved_resid = uio->uio_resid;
629 		error = vn_io_fault_uiomove(__DECONST(void *, zero_region),
630 		    tlen, uio);
631 		if (error != 0)
632 			return (error);
633 		tlen = saved_resid - uio->uio_resid;
634 		xfersize -= tlen;
635 		*size -= tlen;
636 	}
637 	return (0);
638 }
639 
640 /*
641  * Vnode op for reading.
642  */
643 static int
644 ffs_read(
645 	struct vop_read_args /* {
646 		struct vnode *a_vp;
647 		struct uio *a_uio;
648 		int a_ioflag;
649 		struct ucred *a_cred;
650 	} */ *ap)
651 {
652 	struct vnode *vp;
653 	struct inode *ip;
654 	struct uio *uio;
655 	struct fs *fs;
656 	struct buf *bp;
657 	ufs_lbn_t lbn, nextlbn;
658 	off_t bytesinfile;
659 	long size, xfersize, blkoffset;
660 	ssize_t orig_resid;
661 	int bflag, error, ioflag, seqcount;
662 
663 	vp = ap->a_vp;
664 	uio = ap->a_uio;
665 	ioflag = ap->a_ioflag;
666 	if (ap->a_ioflag & IO_EXT)
667 #ifdef notyet
668 		return (ffs_extread(vp, uio, ioflag));
669 #else
670 		panic("ffs_read+IO_EXT");
671 #endif
672 #ifdef DIRECTIO
673 	if ((ioflag & IO_DIRECT) != 0) {
674 		int workdone;
675 
676 		error = ffs_rawread(vp, uio, &workdone);
677 		if (error != 0 || workdone != 0)
678 			return error;
679 	}
680 #endif
681 
682 	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
683 	ip = VTOI(vp);
684 
685 #ifdef INVARIANTS
686 	if (uio->uio_rw != UIO_READ)
687 		panic("ffs_read: mode");
688 
689 	if (vp->v_type == VLNK) {
690 		if ((int)ip->i_size < VFSTOUFS(vp->v_mount)->um_maxsymlinklen)
691 			panic("ffs_read: short symlink");
692 	} else if (vp->v_type != VREG && vp->v_type != VDIR)
693 		panic("ffs_read: type %d",  vp->v_type);
694 #endif
695 	orig_resid = uio->uio_resid;
696 	KASSERT(orig_resid >= 0, ("ffs_read: uio->uio_resid < 0"));
697 	if (orig_resid == 0)
698 		return (0);
699 	KASSERT(uio->uio_offset >= 0, ("ffs_read: uio->uio_offset < 0"));
700 	fs = ITOFS(ip);
701 	if (uio->uio_offset < ip->i_size &&
702 	    uio->uio_offset >= fs->fs_maxfilesize)
703 		return (EOVERFLOW);
704 
705 	bflag = GB_UNMAPPED | (uio->uio_segflg == UIO_NOCOPY ? 0 : GB_NOSPARSE);
706 #ifdef WITNESS
707 	bflag |= IS_SNAPSHOT(ip) ? GB_NOWITNESS : 0;
708 #endif
709 	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
710 		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
711 			break;
712 		lbn = lblkno(fs, uio->uio_offset);
713 		nextlbn = lbn + 1;
714 
715 		/*
716 		 * size of buffer.  The buffer representing the
717 		 * end of the file is rounded up to the size of
718 		 * the block type ( fragment or full block,
719 		 * depending ).
720 		 */
721 		size = blksize(fs, ip, lbn);
722 		blkoffset = blkoff(fs, uio->uio_offset);
723 
724 		/*
725 		 * The amount we want to transfer in this iteration is
726 		 * one FS block less the amount of the data before
727 		 * our startpoint (duh!)
728 		 */
729 		xfersize = fs->fs_bsize - blkoffset;
730 
731 		/*
732 		 * But if we actually want less than the block,
733 		 * or the file doesn't have a whole block more of data,
734 		 * then use the lesser number.
735 		 */
736 		if (uio->uio_resid < xfersize)
737 			xfersize = uio->uio_resid;
738 		if (bytesinfile < xfersize)
739 			xfersize = bytesinfile;
740 
741 		if (lblktosize(fs, nextlbn) >= ip->i_size) {
742 			/*
743 			 * Don't do readahead if this is the end of the file.
744 			 */
745 			error = bread_gb(vp, lbn, size, NOCRED, bflag, &bp);
746 		} else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
747 			/*
748 			 * Otherwise if we are allowed to cluster,
749 			 * grab as much as we can.
750 			 *
751 			 * XXX  This may not be a win if we are not
752 			 * doing sequential access.
753 			 */
754 			error = cluster_read(vp, ip->i_size, lbn,
755 			    size, NOCRED, blkoffset + uio->uio_resid,
756 			    seqcount, bflag, &bp);
757 		} else if (seqcount > 1) {
758 			/*
759 			 * If we are NOT allowed to cluster, then
760 			 * if we appear to be acting sequentially,
761 			 * fire off a request for a readahead
762 			 * as well as a read. Note that the 4th and 5th
763 			 * arguments point to arrays of the size specified in
764 			 * the 6th argument.
765 			 */
766 			u_int nextsize = blksize(fs, ip, nextlbn);
767 			error = breadn_flags(vp, lbn, lbn, size, &nextlbn,
768 			    &nextsize, 1, NOCRED, bflag, NULL, &bp);
769 		} else {
770 			/*
771 			 * Failing all of the above, just read what the
772 			 * user asked for. Interestingly, the same as
773 			 * the first option above.
774 			 */
775 			error = bread_gb(vp, lbn, size, NOCRED, bflag, &bp);
776 		}
777 		if (error == EJUSTRETURN) {
778 			error = ffs_read_hole(uio, xfersize, &size);
779 			if (error == 0)
780 				continue;
781 		}
782 		if (error != 0) {
783 			brelse(bp);
784 			bp = NULL;
785 			break;
786 		}
787 
788 		/*
789 		 * We should only get non-zero b_resid when an I/O error
790 		 * has occurred, which should cause us to break above.
791 		 * However, if the short read did not cause an error,
792 		 * then we want to ensure that we do not uiomove bad
793 		 * or uninitialized data.
794 		 */
795 		size -= bp->b_resid;
796 		if (size < xfersize) {
797 			if (size == 0)
798 				break;
799 			xfersize = size;
800 		}
801 
802 		if (buf_mapped(bp)) {
803 			error = vn_io_fault_uiomove((char *)bp->b_data +
804 			    blkoffset, (int)xfersize, uio);
805 		} else {
806 			error = vn_io_fault_pgmove(bp->b_pages,
807 			    blkoffset + (bp->b_offset & PAGE_MASK),
808 			    (int)xfersize, uio);
809 		}
810 		if (error)
811 			break;
812 
813 		vfs_bio_brelse(bp, ioflag);
814 	}
815 
816 	/*
817 	 * This can only happen in the case of an error
818 	 * because the loop above resets bp to NULL on each iteration
819 	 * and on normal completion has not set a new value into it.
820 	 * so it must have come from a 'break' statement
821 	 */
822 	if (bp != NULL)
823 		vfs_bio_brelse(bp, ioflag);
824 
825 	if ((error == 0 || uio->uio_resid != orig_resid) &&
826 	    (vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
827 		UFS_INODE_SET_FLAG_SHARED(ip, IN_ACCESS);
828 	return (error);
829 }
830 
831 /*
832  * Vnode op for writing.
833  */
834 static int
835 ffs_write(
836 	struct vop_write_args /* {
837 		struct vnode *a_vp;
838 		struct uio *a_uio;
839 		int a_ioflag;
840 		struct ucred *a_cred;
841 	} */ *ap)
842 {
843 	struct vnode *vp;
844 	struct uio *uio;
845 	struct inode *ip;
846 	struct fs *fs;
847 	struct buf *bp;
848 	ufs_lbn_t lbn;
849 	off_t osize;
850 	ssize_t resid, r;
851 	int seqcount;
852 	int blkoffset, error, flags, ioflag, size, xfersize;
853 
854 	vp = ap->a_vp;
855 	if (DOINGSUJ(vp))
856 		softdep_prealloc(vp, MNT_WAIT);
857 	if (vp->v_data == NULL)
858 		return (EBADF);
859 
860 	uio = ap->a_uio;
861 	ioflag = ap->a_ioflag;
862 	if (ap->a_ioflag & IO_EXT)
863 #ifdef notyet
864 		return (ffs_extwrite(vp, uio, ioflag, ap->a_cred));
865 #else
866 		panic("ffs_write+IO_EXT");
867 #endif
868 
869 	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
870 	ip = VTOI(vp);
871 
872 #ifdef INVARIANTS
873 	if (uio->uio_rw != UIO_WRITE)
874 		panic("ffs_write: mode");
875 #endif
876 
877 	switch (vp->v_type) {
878 	case VREG:
879 		if (ioflag & IO_APPEND)
880 			uio->uio_offset = ip->i_size;
881 		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
882 			return (EPERM);
883 		/* FALLTHROUGH */
884 	case VLNK:
885 		break;
886 	case VDIR:
887 		panic("ffs_write: dir write");
888 		break;
889 	default:
890 		panic("ffs_write: type %p %d (%d,%d)", vp, (int)vp->v_type,
891 			(int)uio->uio_offset,
892 			(int)uio->uio_resid
893 		);
894 	}
895 
896 	KASSERT(uio->uio_resid >= 0, ("ffs_write: uio->uio_resid < 0"));
897 	KASSERT(uio->uio_offset >= 0, ("ffs_write: uio->uio_offset < 0"));
898 	fs = ITOFS(ip);
899 
900 	/*
901 	 * Maybe this should be above the vnode op call, but so long as
902 	 * file servers have no limits, I don't think it matters.
903 	 */
904 	error = vn_rlimit_fsizex(vp, uio, fs->fs_maxfilesize, &r,
905 	    uio->uio_td);
906 	if (error != 0) {
907 		vn_rlimit_fsizex_res(uio, r);
908 		return (error);
909 	}
910 
911 	resid = uio->uio_resid;
912 	osize = ip->i_size;
913 	if (seqcount > BA_SEQMAX)
914 		flags = BA_SEQMAX << BA_SEQSHIFT;
915 	else
916 		flags = seqcount << BA_SEQSHIFT;
917 	if (ioflag & IO_SYNC)
918 		flags |= IO_SYNC;
919 	flags |= BA_UNMAPPED;
920 
921 	for (error = 0; uio->uio_resid > 0;) {
922 		lbn = lblkno(fs, uio->uio_offset);
923 		blkoffset = blkoff(fs, uio->uio_offset);
924 		xfersize = fs->fs_bsize - blkoffset;
925 		if (uio->uio_resid < xfersize)
926 			xfersize = uio->uio_resid;
927 		if (uio->uio_offset + xfersize > ip->i_size)
928 			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
929 
930 		/*
931 		 * We must perform a read-before-write if the transfer size
932 		 * does not cover the entire buffer.
933 		 */
934 		if (fs->fs_bsize > xfersize)
935 			flags |= BA_CLRBUF;
936 		else
937 			flags &= ~BA_CLRBUF;
938 /* XXX is uio->uio_offset the right thing here? */
939 		error = UFS_BALLOC(vp, uio->uio_offset, xfersize,
940 		    ap->a_cred, flags, &bp);
941 		if (error != 0) {
942 			vnode_pager_setsize(vp, ip->i_size);
943 			break;
944 		}
945 		if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
946 			bp->b_flags |= B_NOCACHE;
947 
948 		if (uio->uio_offset + xfersize > ip->i_size) {
949 			ip->i_size = uio->uio_offset + xfersize;
950 			DIP_SET(ip, i_size, ip->i_size);
951 			UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
952 		}
953 
954 		size = blksize(fs, ip, lbn) - bp->b_resid;
955 		if (size < xfersize)
956 			xfersize = size;
957 
958 		if (buf_mapped(bp)) {
959 			error = vn_io_fault_uiomove((char *)bp->b_data +
960 			    blkoffset, (int)xfersize, uio);
961 		} else {
962 			error = vn_io_fault_pgmove(bp->b_pages,
963 			    blkoffset + (bp->b_offset & PAGE_MASK),
964 			    (int)xfersize, uio);
965 		}
966 		/*
967 		 * If the buffer is not already filled and we encounter an
968 		 * error while trying to fill it, we have to clear out any
969 		 * garbage data from the pages instantiated for the buffer.
970 		 * If we do not, a failed uiomove() during a write can leave
971 		 * the prior contents of the pages exposed to a userland mmap.
972 		 *
973 		 * Note that we need only clear buffers with a transfer size
974 		 * equal to the block size because buffers with a shorter
975 		 * transfer size were cleared above by the call to UFS_BALLOC()
976 		 * with the BA_CLRBUF flag set.
977 		 *
978 		 * If the source region for uiomove identically mmaps the
979 		 * buffer, uiomove() performed the NOP copy, and the buffer
980 		 * content remains valid because the page fault handler
981 		 * validated the pages.
982 		 */
983 		if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
984 		    fs->fs_bsize == xfersize)
985 			vfs_bio_clrbuf(bp);
986 
987 		vfs_bio_set_flags(bp, ioflag);
988 
989 		/*
990 		 * If IO_SYNC each buffer is written synchronously.  Otherwise
991 		 * if we have a severe page deficiency write the buffer
992 		 * asynchronously.  Otherwise try to cluster, and if that
993 		 * doesn't do it then either do an async write (if O_DIRECT),
994 		 * or a delayed write (if not).
995 		 */
996 		if (ioflag & IO_SYNC) {
997 			(void)bwrite(bp);
998 		} else if (vm_page_count_severe() ||
999 			    buf_dirty_count_severe() ||
1000 			    (ioflag & IO_ASYNC)) {
1001 			bp->b_flags |= B_CLUSTEROK;
1002 			bawrite(bp);
1003 		} else if (xfersize + blkoffset == fs->fs_bsize) {
1004 			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
1005 				bp->b_flags |= B_CLUSTEROK;
1006 				cluster_write(vp, &ip->i_clusterw, bp,
1007 				    ip->i_size, seqcount, GB_UNMAPPED);
1008 			} else {
1009 				bawrite(bp);
1010 			}
1011 		} else if (ioflag & IO_DIRECT) {
1012 			bp->b_flags |= B_CLUSTEROK;
1013 			bawrite(bp);
1014 		} else {
1015 			bp->b_flags |= B_CLUSTEROK;
1016 			bdwrite(bp);
1017 		}
1018 		if (error || xfersize == 0)
1019 			break;
1020 		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
1021 	}
1022 	/*
1023 	 * If we successfully wrote any data, and we are not the superuser
1024 	 * we clear the setuid and setgid bits as a precaution against
1025 	 * tampering.
1026 	 */
1027 	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
1028 	    ap->a_cred) {
1029 		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID)) {
1030 			vn_seqc_write_begin(vp);
1031 			UFS_INODE_SET_MODE(ip, ip->i_mode & ~(ISUID | ISGID));
1032 			DIP_SET(ip, i_mode, ip->i_mode);
1033 			vn_seqc_write_end(vp);
1034 		}
1035 	}
1036 	if (error) {
1037 		if (ioflag & IO_UNIT) {
1038 			(void)ffs_truncate(vp, osize,
1039 			    IO_NORMAL | (ioflag & IO_SYNC), ap->a_cred);
1040 			uio->uio_offset -= resid - uio->uio_resid;
1041 			uio->uio_resid = resid;
1042 		}
1043 	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
1044 		if (!(ioflag & IO_DATASYNC) ||
1045 		    (ip->i_flags & (IN_SIZEMOD | IN_IBLKDATA)))
1046 			error = ffs_update(vp, 1);
1047 		if (ffs_fsfail_cleanup(VFSTOUFS(vp->v_mount), error))
1048 			error = ENXIO;
1049 	}
1050 	vn_rlimit_fsizex_res(uio, r);
1051 	return (error);
1052 }
1053 
1054 /*
1055  * Extended attribute area reading.
1056  */
1057 static int
1058 ffs_extread(struct vnode *vp, struct uio *uio, int ioflag)
1059 {
1060 	struct inode *ip;
1061 	struct ufs2_dinode *dp;
1062 	struct fs *fs;
1063 	struct buf *bp;
1064 	ufs_lbn_t lbn, nextlbn;
1065 	off_t bytesinfile;
1066 	long size, xfersize, blkoffset;
1067 	ssize_t orig_resid;
1068 	int error;
1069 
1070 	ip = VTOI(vp);
1071 	fs = ITOFS(ip);
1072 	dp = ip->i_din2;
1073 
1074 #ifdef INVARIANTS
1075 	if (uio->uio_rw != UIO_READ || fs->fs_magic != FS_UFS2_MAGIC)
1076 		panic("ffs_extread: mode");
1077 
1078 #endif
1079 	orig_resid = uio->uio_resid;
1080 	KASSERT(orig_resid >= 0, ("ffs_extread: uio->uio_resid < 0"));
1081 	if (orig_resid == 0)
1082 		return (0);
1083 	KASSERT(uio->uio_offset >= 0, ("ffs_extread: uio->uio_offset < 0"));
1084 
1085 	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
1086 		if ((bytesinfile = dp->di_extsize - uio->uio_offset) <= 0)
1087 			break;
1088 		lbn = lblkno(fs, uio->uio_offset);
1089 		nextlbn = lbn + 1;
1090 
1091 		/*
1092 		 * size of buffer.  The buffer representing the
1093 		 * end of the file is rounded up to the size of
1094 		 * the block type ( fragment or full block,
1095 		 * depending ).
1096 		 */
1097 		size = sblksize(fs, dp->di_extsize, lbn);
1098 		blkoffset = blkoff(fs, uio->uio_offset);
1099 
1100 		/*
1101 		 * The amount we want to transfer in this iteration is
1102 		 * one FS block less the amount of the data before
1103 		 * our startpoint (duh!)
1104 		 */
1105 		xfersize = fs->fs_bsize - blkoffset;
1106 
1107 		/*
1108 		 * But if we actually want less than the block,
1109 		 * or the file doesn't have a whole block more of data,
1110 		 * then use the lesser number.
1111 		 */
1112 		if (uio->uio_resid < xfersize)
1113 			xfersize = uio->uio_resid;
1114 		if (bytesinfile < xfersize)
1115 			xfersize = bytesinfile;
1116 
1117 		if (lblktosize(fs, nextlbn) >= dp->di_extsize) {
1118 			/*
1119 			 * Don't do readahead if this is the end of the info.
1120 			 */
1121 			error = bread(vp, -1 - lbn, size, NOCRED, &bp);
1122 		} else {
1123 			/*
1124 			 * If we have a second block, then
1125 			 * fire off a request for a readahead
1126 			 * as well as a read. Note that the 4th and 5th
1127 			 * arguments point to arrays of the size specified in
1128 			 * the 6th argument.
1129 			 */
1130 			u_int nextsize = sblksize(fs, dp->di_extsize, nextlbn);
1131 
1132 			nextlbn = -1 - nextlbn;
1133 			error = breadn(vp, -1 - lbn,
1134 			    size, &nextlbn, &nextsize, 1, NOCRED, &bp);
1135 		}
1136 		if (error) {
1137 			brelse(bp);
1138 			bp = NULL;
1139 			break;
1140 		}
1141 
1142 		/*
1143 		 * We should only get non-zero b_resid when an I/O error
1144 		 * has occurred, which should cause us to break above.
1145 		 * However, if the short read did not cause an error,
1146 		 * then we want to ensure that we do not uiomove bad
1147 		 * or uninitialized data.
1148 		 */
1149 		size -= bp->b_resid;
1150 		if (size < xfersize) {
1151 			if (size == 0)
1152 				break;
1153 			xfersize = size;
1154 		}
1155 
1156 		error = uiomove((char *)bp->b_data + blkoffset,
1157 					(int)xfersize, uio);
1158 		if (error)
1159 			break;
1160 		vfs_bio_brelse(bp, ioflag);
1161 	}
1162 
1163 	/*
1164 	 * This can only happen in the case of an error
1165 	 * because the loop above resets bp to NULL on each iteration
1166 	 * and on normal completion has not set a new value into it.
1167 	 * so it must have come from a 'break' statement
1168 	 */
1169 	if (bp != NULL)
1170 		vfs_bio_brelse(bp, ioflag);
1171 	return (error);
1172 }
1173 
1174 /*
1175  * Extended attribute area writing.
1176  */
1177 static int
1178 ffs_extwrite(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *ucred)
1179 {
1180 	struct inode *ip;
1181 	struct ufs2_dinode *dp;
1182 	struct fs *fs;
1183 	struct buf *bp;
1184 	ufs_lbn_t lbn;
1185 	off_t osize;
1186 	ssize_t resid;
1187 	int blkoffset, error, flags, size, xfersize;
1188 
1189 	ip = VTOI(vp);
1190 	fs = ITOFS(ip);
1191 	dp = ip->i_din2;
1192 
1193 #ifdef INVARIANTS
1194 	if (uio->uio_rw != UIO_WRITE || fs->fs_magic != FS_UFS2_MAGIC)
1195 		panic("ffs_extwrite: mode");
1196 #endif
1197 
1198 	if (ioflag & IO_APPEND)
1199 		uio->uio_offset = dp->di_extsize;
1200 	KASSERT(uio->uio_offset >= 0, ("ffs_extwrite: uio->uio_offset < 0"));
1201 	KASSERT(uio->uio_resid >= 0, ("ffs_extwrite: uio->uio_resid < 0"));
1202 	if ((uoff_t)uio->uio_offset + uio->uio_resid >
1203 	    UFS_NXADDR * fs->fs_bsize)
1204 		return (EFBIG);
1205 
1206 	resid = uio->uio_resid;
1207 	osize = dp->di_extsize;
1208 	flags = IO_EXT;
1209 	if (ioflag & IO_SYNC)
1210 		flags |= IO_SYNC;
1211 
1212 	for (error = 0; uio->uio_resid > 0;) {
1213 		lbn = lblkno(fs, uio->uio_offset);
1214 		blkoffset = blkoff(fs, uio->uio_offset);
1215 		xfersize = fs->fs_bsize - blkoffset;
1216 		if (uio->uio_resid < xfersize)
1217 			xfersize = uio->uio_resid;
1218 
1219 		/*
1220 		 * We must perform a read-before-write if the transfer size
1221 		 * does not cover the entire buffer.
1222 		 */
1223 		if (fs->fs_bsize > xfersize)
1224 			flags |= BA_CLRBUF;
1225 		else
1226 			flags &= ~BA_CLRBUF;
1227 		error = UFS_BALLOC(vp, uio->uio_offset, xfersize,
1228 		    ucred, flags, &bp);
1229 		if (error != 0)
1230 			break;
1231 		/*
1232 		 * If the buffer is not valid we have to clear out any
1233 		 * garbage data from the pages instantiated for the buffer.
1234 		 * If we do not, a failed uiomove() during a write can leave
1235 		 * the prior contents of the pages exposed to a userland
1236 		 * mmap().  XXX deal with uiomove() errors a better way.
1237 		 */
1238 		if ((bp->b_flags & B_CACHE) == 0 && fs->fs_bsize <= xfersize)
1239 			vfs_bio_clrbuf(bp);
1240 
1241 		if (uio->uio_offset + xfersize > dp->di_extsize) {
1242 			dp->di_extsize = uio->uio_offset + xfersize;
1243 			UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
1244 		}
1245 
1246 		size = sblksize(fs, dp->di_extsize, lbn) - bp->b_resid;
1247 		if (size < xfersize)
1248 			xfersize = size;
1249 
1250 		error =
1251 		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
1252 
1253 		vfs_bio_set_flags(bp, ioflag);
1254 
1255 		/*
1256 		 * If IO_SYNC each buffer is written synchronously.  Otherwise
1257 		 * if we have a severe page deficiency write the buffer
1258 		 * asynchronously.  Otherwise try to cluster, and if that
1259 		 * doesn't do it then either do an async write (if O_DIRECT),
1260 		 * or a delayed write (if not).
1261 		 */
1262 		if (ioflag & IO_SYNC) {
1263 			(void)bwrite(bp);
1264 		} else if (vm_page_count_severe() ||
1265 			    buf_dirty_count_severe() ||
1266 			    xfersize + blkoffset == fs->fs_bsize ||
1267 			    (ioflag & (IO_ASYNC | IO_DIRECT)))
1268 			bawrite(bp);
1269 		else
1270 			bdwrite(bp);
1271 		if (error || xfersize == 0)
1272 			break;
1273 		UFS_INODE_SET_FLAG(ip, IN_CHANGE);
1274 	}
1275 	/*
1276 	 * If we successfully wrote any data, and we are not the superuser
1277 	 * we clear the setuid and setgid bits as a precaution against
1278 	 * tampering.
1279 	 */
1280 	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid && ucred) {
1281 		if (priv_check_cred(ucred, PRIV_VFS_RETAINSUGID)) {
1282 			vn_seqc_write_begin(vp);
1283 			UFS_INODE_SET_MODE(ip, ip->i_mode & ~(ISUID | ISGID));
1284 			dp->di_mode = ip->i_mode;
1285 			vn_seqc_write_end(vp);
1286 		}
1287 	}
1288 	if (error) {
1289 		if (ioflag & IO_UNIT) {
1290 			(void)ffs_truncate(vp, osize,
1291 			    IO_EXT | (ioflag&IO_SYNC), ucred);
1292 			uio->uio_offset -= resid - uio->uio_resid;
1293 			uio->uio_resid = resid;
1294 		}
1295 	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC))
1296 		error = ffs_update(vp, 1);
1297 	return (error);
1298 }
1299 
1300 /*
1301  * Vnode operating to retrieve a named extended attribute.
1302  *
1303  * Locate a particular EA (nspace:name) in the area (ptr:length), and return
1304  * the length of the EA, and possibly the pointer to the entry and to the data.
1305  */
1306 static int
1307 ffs_findextattr(u_char *ptr, u_int length, int nspace, const char *name,
1308     struct extattr **eapp, u_char **eac)
1309 {
1310 	struct extattr *eap, *eaend;
1311 	size_t nlen;
1312 
1313 	nlen = strlen(name);
1314 	KASSERT(ALIGNED_TO(ptr, struct extattr), ("unaligned"));
1315 	eap = (struct extattr *)ptr;
1316 	eaend = (struct extattr *)(ptr + length);
1317 	for (; eap < eaend; eap = EXTATTR_NEXT(eap)) {
1318 		KASSERT(EXTATTR_NEXT(eap) <= eaend,
1319 		    ("extattr next %p beyond %p", EXTATTR_NEXT(eap), eaend));
1320 		if (eap->ea_namespace != nspace || eap->ea_namelength != nlen
1321 		    || memcmp(eap->ea_name, name, nlen) != 0)
1322 			continue;
1323 		if (eapp != NULL)
1324 			*eapp = eap;
1325 		if (eac != NULL)
1326 			*eac = EXTATTR_CONTENT(eap);
1327 		return (EXTATTR_CONTENT_SIZE(eap));
1328 	}
1329 	return (-1);
1330 }
1331 
1332 static int
1333 ffs_rdextattr(u_char **p, struct vnode *vp, struct thread *td)
1334 {
1335 	const struct extattr *eap, *eaend, *eapnext;
1336 	struct inode *ip;
1337 	struct ufs2_dinode *dp;
1338 	struct fs *fs;
1339 	struct uio luio;
1340 	struct iovec liovec;
1341 	u_int easize;
1342 	int error;
1343 	u_char *eae;
1344 
1345 	ip = VTOI(vp);
1346 	fs = ITOFS(ip);
1347 	dp = ip->i_din2;
1348 	easize = dp->di_extsize;
1349 	if ((uoff_t)easize > UFS_NXADDR * fs->fs_bsize)
1350 		return (EFBIG);
1351 
1352 	eae = malloc(easize, M_TEMP, M_WAITOK);
1353 
1354 	liovec.iov_base = eae;
1355 	liovec.iov_len = easize;
1356 	luio.uio_iov = &liovec;
1357 	luio.uio_iovcnt = 1;
1358 	luio.uio_offset = 0;
1359 	luio.uio_resid = easize;
1360 	luio.uio_segflg = UIO_SYSSPACE;
1361 	luio.uio_rw = UIO_READ;
1362 	luio.uio_td = td;
1363 
1364 	error = ffs_extread(vp, &luio, IO_EXT | IO_SYNC);
1365 	if (error) {
1366 		free(eae, M_TEMP);
1367 		return (error);
1368 	}
1369 	/* Validate disk xattrfile contents. */
1370 	for (eap = (void *)eae, eaend = (void *)(eae + easize); eap < eaend;
1371 	    eap = eapnext) {
1372 		/* Detect zeroed out tail */
1373 		if (eap->ea_length < sizeof(*eap) || eap->ea_length == 0) {
1374 			easize = (const u_char *)eap - eae;
1375 			break;
1376 		}
1377 
1378 		eapnext = EXTATTR_NEXT(eap);
1379 		/* Bogusly long entry. */
1380 		if (eapnext > eaend) {
1381 			free(eae, M_TEMP);
1382 			return (EINTEGRITY);
1383 		}
1384 	}
1385 	ip->i_ea_len = easize;
1386 	*p = eae;
1387 	return (0);
1388 }
1389 
1390 static void
1391 ffs_lock_ea(struct vnode *vp)
1392 {
1393 	struct inode *ip;
1394 
1395 	ip = VTOI(vp);
1396 	VI_LOCK(vp);
1397 	while (ip->i_flag & IN_EA_LOCKED) {
1398 		UFS_INODE_SET_FLAG(ip, IN_EA_LOCKWAIT);
1399 		msleep(&ip->i_ea_refs, &vp->v_interlock, PINOD + 2, "ufs_ea",
1400 		    0);
1401 	}
1402 	UFS_INODE_SET_FLAG(ip, IN_EA_LOCKED);
1403 	VI_UNLOCK(vp);
1404 }
1405 
1406 static void
1407 ffs_unlock_ea(struct vnode *vp)
1408 {
1409 	struct inode *ip;
1410 
1411 	ip = VTOI(vp);
1412 	VI_LOCK(vp);
1413 	if (ip->i_flag & IN_EA_LOCKWAIT)
1414 		wakeup(&ip->i_ea_refs);
1415 	ip->i_flag &= ~(IN_EA_LOCKED | IN_EA_LOCKWAIT);
1416 	VI_UNLOCK(vp);
1417 }
1418 
1419 static int
1420 ffs_open_ea(struct vnode *vp, struct ucred *cred, struct thread *td)
1421 {
1422 	struct inode *ip;
1423 	int error;
1424 
1425 	ip = VTOI(vp);
1426 
1427 	ffs_lock_ea(vp);
1428 	if (ip->i_ea_area != NULL) {
1429 		ip->i_ea_refs++;
1430 		ffs_unlock_ea(vp);
1431 		return (0);
1432 	}
1433 	error = ffs_rdextattr(&ip->i_ea_area, vp, td);
1434 	if (error) {
1435 		ffs_unlock_ea(vp);
1436 		return (error);
1437 	}
1438 	ip->i_ea_error = 0;
1439 	ip->i_ea_refs++;
1440 	ffs_unlock_ea(vp);
1441 	return (0);
1442 }
1443 
1444 /*
1445  * Vnode extattr transaction commit/abort
1446  */
1447 static int
1448 ffs_close_ea(struct vnode *vp, int commit, struct ucred *cred, struct thread *td)
1449 {
1450 	struct inode *ip;
1451 	struct uio luio;
1452 	struct iovec *liovec;
1453 	struct ufs2_dinode *dp;
1454 	size_t ea_len, tlen;
1455 	int error, i, lcnt;
1456 	bool truncate;
1457 
1458 	ip = VTOI(vp);
1459 
1460 	ffs_lock_ea(vp);
1461 	if (ip->i_ea_area == NULL) {
1462 		ffs_unlock_ea(vp);
1463 		return (EINVAL);
1464 	}
1465 	dp = ip->i_din2;
1466 	error = ip->i_ea_error;
1467 	truncate = false;
1468 	if (commit && error == 0) {
1469 		ASSERT_VOP_ELOCKED(vp, "ffs_close_ea commit");
1470 		if (cred == NOCRED)
1471 			cred =  vp->v_mount->mnt_cred;
1472 
1473 		ea_len = MAX(ip->i_ea_len, dp->di_extsize);
1474 		for (lcnt = 1, tlen = ea_len - ip->i_ea_len; tlen > 0;) {
1475 			tlen -= MIN(ZERO_REGION_SIZE, tlen);
1476 			lcnt++;
1477 		}
1478 
1479 		liovec = __builtin_alloca(lcnt * sizeof(struct iovec));
1480 		luio.uio_iovcnt = lcnt;
1481 
1482 		liovec[0].iov_base = ip->i_ea_area;
1483 		liovec[0].iov_len = ip->i_ea_len;
1484 		for (i = 1, tlen = ea_len - ip->i_ea_len; i < lcnt; i++) {
1485 			liovec[i].iov_base = __DECONST(void *, zero_region);
1486 			liovec[i].iov_len = MIN(ZERO_REGION_SIZE, tlen);
1487 			tlen -= liovec[i].iov_len;
1488 		}
1489 		MPASS(tlen == 0);
1490 
1491 		luio.uio_iov = liovec;
1492 		luio.uio_offset = 0;
1493 		luio.uio_resid = ea_len;
1494 		luio.uio_segflg = UIO_SYSSPACE;
1495 		luio.uio_rw = UIO_WRITE;
1496 		luio.uio_td = td;
1497 		error = ffs_extwrite(vp, &luio, IO_EXT | IO_SYNC, cred);
1498 		if (error == 0 && ip->i_ea_len == 0)
1499 			truncate = true;
1500 	}
1501 	if (--ip->i_ea_refs == 0) {
1502 		free(ip->i_ea_area, M_TEMP);
1503 		ip->i_ea_area = NULL;
1504 		ip->i_ea_len = 0;
1505 		ip->i_ea_error = 0;
1506 	}
1507 	ffs_unlock_ea(vp);
1508 
1509 	if (truncate)
1510 		ffs_truncate(vp, 0, IO_EXT, cred);
1511 	return (error);
1512 }
1513 
1514 /*
1515  * Vnode extattr strategy routine for fifos.
1516  *
1517  * We need to check for a read or write of the external attributes.
1518  * Otherwise we just fall through and do the usual thing.
1519  */
1520 static int
1521 ffsext_strategy(
1522 	struct vop_strategy_args /* {
1523 		struct vnodeop_desc *a_desc;
1524 		struct vnode *a_vp;
1525 		struct buf *a_bp;
1526 	} */ *ap)
1527 {
1528 	struct vnode *vp;
1529 	daddr_t lbn;
1530 
1531 	vp = ap->a_vp;
1532 	lbn = ap->a_bp->b_lblkno;
1533 	if (I_IS_UFS2(VTOI(vp)) && lbn < 0 && lbn >= -UFS_NXADDR)
1534 		return (VOP_STRATEGY_APV(&ufs_vnodeops, ap));
1535 	if (vp->v_type == VFIFO)
1536 		return (VOP_STRATEGY_APV(&ufs_fifoops, ap));
1537 	panic("spec nodes went here");
1538 }
1539 
1540 /*
1541  * Vnode extattr transaction commit/abort
1542  */
1543 static int
1544 ffs_openextattr(
1545 	struct vop_openextattr_args /* {
1546 		struct vnodeop_desc *a_desc;
1547 		struct vnode *a_vp;
1548 		IN struct ucred *a_cred;
1549 		IN struct thread *a_td;
1550 	} */ *ap)
1551 {
1552 
1553 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
1554 		return (EOPNOTSUPP);
1555 
1556 	return (ffs_open_ea(ap->a_vp, ap->a_cred, ap->a_td));
1557 }
1558 
1559 /*
1560  * Vnode extattr transaction commit/abort
1561  */
1562 static int
1563 ffs_closeextattr(
1564 	struct vop_closeextattr_args /* {
1565 		struct vnodeop_desc *a_desc;
1566 		struct vnode *a_vp;
1567 		int a_commit;
1568 		IN struct ucred *a_cred;
1569 		IN struct thread *a_td;
1570 	} */ *ap)
1571 {
1572 	struct vnode *vp;
1573 
1574 	vp = ap->a_vp;
1575 	if (vp->v_type == VCHR || vp->v_type == VBLK)
1576 		return (EOPNOTSUPP);
1577 	if (ap->a_commit && (vp->v_mount->mnt_flag & MNT_RDONLY) != 0)
1578 		return (EROFS);
1579 
1580 	if (ap->a_commit && DOINGSUJ(vp)) {
1581 		ASSERT_VOP_ELOCKED(vp, "ffs_closeextattr commit");
1582 		softdep_prealloc(vp, MNT_WAIT);
1583 		if (vp->v_data == NULL)
1584 			return (EBADF);
1585 	}
1586 	return (ffs_close_ea(vp, ap->a_commit, ap->a_cred, ap->a_td));
1587 }
1588 
1589 /*
1590  * Vnode operation to remove a named attribute.
1591  */
1592 static int
1593 ffs_deleteextattr(
1594 	struct vop_deleteextattr_args /* {
1595 		IN struct vnode *a_vp;
1596 		IN int a_attrnamespace;
1597 		IN const char *a_name;
1598 		IN struct ucred *a_cred;
1599 		IN struct thread *a_td;
1600 	} */ *ap)
1601 {
1602 	struct vnode *vp;
1603 	struct inode *ip;
1604 	struct extattr *eap;
1605 	uint32_t ul;
1606 	int olen, error, i, easize;
1607 	u_char *eae;
1608 	void *tmp;
1609 
1610 	vp = ap->a_vp;
1611 	ip = VTOI(vp);
1612 
1613 	if (vp->v_type == VCHR || vp->v_type == VBLK)
1614 		return (EOPNOTSUPP);
1615 	if (strlen(ap->a_name) == 0)
1616 		return (EINVAL);
1617 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1618 		return (EROFS);
1619 
1620 	error = extattr_check_cred(vp, ap->a_attrnamespace,
1621 	    ap->a_cred, ap->a_td, VWRITE);
1622 	if (error) {
1623 		/*
1624 		 * ffs_lock_ea is not needed there, because the vnode
1625 		 * must be exclusively locked.
1626 		 */
1627 		if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
1628 			ip->i_ea_error = error;
1629 		return (error);
1630 	}
1631 
1632 	if (DOINGSUJ(vp)) {
1633 		ASSERT_VOP_ELOCKED(vp, "ffs_deleteextattr");
1634 		softdep_prealloc(vp, MNT_WAIT);
1635 		if (vp->v_data == NULL)
1636 			return (EBADF);
1637 	}
1638 
1639 	error = ffs_open_ea(vp, ap->a_cred, ap->a_td);
1640 	if (error)
1641 		return (error);
1642 
1643 	/* CEM: delete could be done in-place instead */
1644 	eae = malloc(ip->i_ea_len, M_TEMP, M_WAITOK);
1645 	bcopy(ip->i_ea_area, eae, ip->i_ea_len);
1646 	easize = ip->i_ea_len;
1647 
1648 	olen = ffs_findextattr(eae, easize, ap->a_attrnamespace, ap->a_name,
1649 	    &eap, NULL);
1650 	if (olen == -1) {
1651 		/* delete but nonexistent */
1652 		free(eae, M_TEMP);
1653 		ffs_close_ea(vp, 0, ap->a_cred, ap->a_td);
1654 		return (ENOATTR);
1655 	}
1656 	ul = eap->ea_length;
1657 	i = (u_char *)EXTATTR_NEXT(eap) - eae;
1658 	bcopy(EXTATTR_NEXT(eap), eap, easize - i);
1659 	easize -= ul;
1660 
1661 	tmp = ip->i_ea_area;
1662 	ip->i_ea_area = eae;
1663 	ip->i_ea_len = easize;
1664 	free(tmp, M_TEMP);
1665 	error = ffs_close_ea(vp, 1, ap->a_cred, ap->a_td);
1666 	return (error);
1667 }
1668 
1669 /*
1670  * Vnode operation to retrieve a named extended attribute.
1671  */
1672 static int
1673 ffs_getextattr(
1674 	struct vop_getextattr_args /* {
1675 		IN struct vnode *a_vp;
1676 		IN int a_attrnamespace;
1677 		IN const char *a_name;
1678 		INOUT struct uio *a_uio;
1679 		OUT size_t *a_size;
1680 		IN struct ucred *a_cred;
1681 		IN struct thread *a_td;
1682 	} */ *ap)
1683 {
1684 	struct inode *ip;
1685 	u_char *eae, *p;
1686 	unsigned easize;
1687 	int error, ealen;
1688 
1689 	ip = VTOI(ap->a_vp);
1690 
1691 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
1692 		return (EOPNOTSUPP);
1693 
1694 	error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
1695 	    ap->a_cred, ap->a_td, VREAD);
1696 	if (error)
1697 		return (error);
1698 
1699 	error = ffs_open_ea(ap->a_vp, ap->a_cred, ap->a_td);
1700 	if (error)
1701 		return (error);
1702 
1703 	eae = ip->i_ea_area;
1704 	easize = ip->i_ea_len;
1705 
1706 	ealen = ffs_findextattr(eae, easize, ap->a_attrnamespace, ap->a_name,
1707 	    NULL, &p);
1708 	if (ealen >= 0) {
1709 		error = 0;
1710 		if (ap->a_size != NULL)
1711 			*ap->a_size = ealen;
1712 		else if (ap->a_uio != NULL)
1713 			error = uiomove(p, ealen, ap->a_uio);
1714 	} else
1715 		error = ENOATTR;
1716 
1717 	ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
1718 	return (error);
1719 }
1720 
1721 /*
1722  * Vnode operation to retrieve extended attributes on a vnode.
1723  */
1724 static int
1725 ffs_listextattr(
1726 	struct vop_listextattr_args /* {
1727 		IN struct vnode *a_vp;
1728 		IN int a_attrnamespace;
1729 		INOUT struct uio *a_uio;
1730 		OUT size_t *a_size;
1731 		IN struct ucred *a_cred;
1732 		IN struct thread *a_td;
1733 	} */ *ap)
1734 {
1735 	struct inode *ip;
1736 	struct extattr *eap, *eaend;
1737 	int error, ealen;
1738 
1739 	ip = VTOI(ap->a_vp);
1740 
1741 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
1742 		return (EOPNOTSUPP);
1743 
1744 	error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
1745 	    ap->a_cred, ap->a_td, VREAD);
1746 	if (error)
1747 		return (error);
1748 
1749 	error = ffs_open_ea(ap->a_vp, ap->a_cred, ap->a_td);
1750 	if (error)
1751 		return (error);
1752 
1753 	error = 0;
1754 	if (ap->a_size != NULL)
1755 		*ap->a_size = 0;
1756 
1757 	KASSERT(ALIGNED_TO(ip->i_ea_area, struct extattr), ("unaligned"));
1758 	eap = (struct extattr *)ip->i_ea_area;
1759 	eaend = (struct extattr *)(ip->i_ea_area + ip->i_ea_len);
1760 	for (; error == 0 && eap < eaend; eap = EXTATTR_NEXT(eap)) {
1761 		KASSERT(EXTATTR_NEXT(eap) <= eaend,
1762 		    ("extattr next %p beyond %p", EXTATTR_NEXT(eap), eaend));
1763 		if (eap->ea_namespace != ap->a_attrnamespace)
1764 			continue;
1765 
1766 		ealen = eap->ea_namelength;
1767 		if (ap->a_size != NULL)
1768 			*ap->a_size += ealen + 1;
1769 		else if (ap->a_uio != NULL)
1770 			error = uiomove(&eap->ea_namelength, ealen + 1,
1771 			    ap->a_uio);
1772 	}
1773 
1774 	ffs_close_ea(ap->a_vp, 0, ap->a_cred, ap->a_td);
1775 	return (error);
1776 }
1777 
1778 /*
1779  * Vnode operation to set a named attribute.
1780  */
1781 static int
1782 ffs_setextattr(
1783 	struct vop_setextattr_args /* {
1784 		IN struct vnode *a_vp;
1785 		IN int a_attrnamespace;
1786 		IN const char *a_name;
1787 		INOUT struct uio *a_uio;
1788 		IN struct ucred *a_cred;
1789 		IN struct thread *a_td;
1790 	} */ *ap)
1791 {
1792 	struct vnode *vp;
1793 	struct inode *ip;
1794 	struct fs *fs;
1795 	struct extattr *eap;
1796 	uint32_t ealength, ul;
1797 	ssize_t ealen;
1798 	int olen, eapad1, eapad2, error, i, easize;
1799 	u_char *eae;
1800 	void *tmp;
1801 
1802 	vp = ap->a_vp;
1803 	ip = VTOI(vp);
1804 	fs = ITOFS(ip);
1805 
1806 	if (vp->v_type == VCHR || vp->v_type == VBLK)
1807 		return (EOPNOTSUPP);
1808 	if (strlen(ap->a_name) == 0)
1809 		return (EINVAL);
1810 
1811 	/* XXX Now unsupported API to delete EAs using NULL uio. */
1812 	if (ap->a_uio == NULL)
1813 		return (EOPNOTSUPP);
1814 
1815 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1816 		return (EROFS);
1817 
1818 	ealen = ap->a_uio->uio_resid;
1819 	if (ealen < 0 || ealen > lblktosize(fs, UFS_NXADDR))
1820 		return (EINVAL);
1821 
1822 	error = extattr_check_cred(vp, ap->a_attrnamespace,
1823 	    ap->a_cred, ap->a_td, VWRITE);
1824 	if (error) {
1825 		/*
1826 		 * ffs_lock_ea is not needed there, because the vnode
1827 		 * must be exclusively locked.
1828 		 */
1829 		if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
1830 			ip->i_ea_error = error;
1831 		return (error);
1832 	}
1833 
1834 	if (DOINGSUJ(vp)) {
1835 		ASSERT_VOP_ELOCKED(vp, "ffs_deleteextattr");
1836 		softdep_prealloc(vp, MNT_WAIT);
1837 		if (vp->v_data == NULL)
1838 			return (EBADF);
1839 	}
1840 
1841 	error = ffs_open_ea(vp, ap->a_cred, ap->a_td);
1842 	if (error)
1843 		return (error);
1844 
1845 	ealength = sizeof(uint32_t) + 3 + strlen(ap->a_name);
1846 	eapad1 = roundup2(ealength, 8) - ealength;
1847 	eapad2 = roundup2(ealen, 8) - ealen;
1848 	ealength += eapad1 + ealen + eapad2;
1849 
1850 	/*
1851 	 * CEM: rewrites of the same size or smaller could be done in-place
1852 	 * instead.  (We don't acquire any fine-grained locks in here either,
1853 	 * so we could also do bigger writes in-place.)
1854 	 */
1855 	eae = malloc(ip->i_ea_len + ealength, M_TEMP, M_WAITOK);
1856 	bcopy(ip->i_ea_area, eae, ip->i_ea_len);
1857 	easize = ip->i_ea_len;
1858 
1859 	olen = ffs_findextattr(eae, easize, ap->a_attrnamespace, ap->a_name,
1860 	    &eap, NULL);
1861         if (olen == -1) {
1862 		/* new, append at end */
1863 		KASSERT(ALIGNED_TO(eae + easize, struct extattr),
1864 		    ("unaligned"));
1865 		eap = (struct extattr *)(eae + easize);
1866 		easize += ealength;
1867 	} else {
1868 		ul = eap->ea_length;
1869 		i = (u_char *)EXTATTR_NEXT(eap) - eae;
1870 		if (ul != ealength) {
1871 			bcopy(EXTATTR_NEXT(eap), (u_char *)eap + ealength,
1872 			    easize - i);
1873 			easize += (ealength - ul);
1874 		}
1875 	}
1876 	if (easize > lblktosize(fs, UFS_NXADDR)) {
1877 		free(eae, M_TEMP);
1878 		ffs_close_ea(vp, 0, ap->a_cred, ap->a_td);
1879 		if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
1880 			ip->i_ea_error = ENOSPC;
1881 		return (ENOSPC);
1882 	}
1883 	eap->ea_length = ealength;
1884 	eap->ea_namespace = ap->a_attrnamespace;
1885 	eap->ea_contentpadlen = eapad2;
1886 	eap->ea_namelength = strlen(ap->a_name);
1887 	memcpy(eap->ea_name, ap->a_name, strlen(ap->a_name));
1888 	bzero(&eap->ea_name[strlen(ap->a_name)], eapad1);
1889 	error = uiomove(EXTATTR_CONTENT(eap), ealen, ap->a_uio);
1890 	if (error) {
1891 		free(eae, M_TEMP);
1892 		ffs_close_ea(vp, 0, ap->a_cred, ap->a_td);
1893 		if (ip->i_ea_area != NULL && ip->i_ea_error == 0)
1894 			ip->i_ea_error = error;
1895 		return (error);
1896 	}
1897 	bzero((u_char *)EXTATTR_CONTENT(eap) + ealen, eapad2);
1898 
1899 	tmp = ip->i_ea_area;
1900 	ip->i_ea_area = eae;
1901 	ip->i_ea_len = easize;
1902 	free(tmp, M_TEMP);
1903 	error = ffs_close_ea(vp, 1, ap->a_cred, ap->a_td);
1904 	return (error);
1905 }
1906 
1907 /*
1908  * Vnode pointer to File handle
1909  */
1910 static int
1911 ffs_vptofh(
1912 	struct vop_vptofh_args /* {
1913 		IN struct vnode *a_vp;
1914 		IN struct fid *a_fhp;
1915 	} */ *ap)
1916 {
1917 	struct inode *ip;
1918 	struct ufid *ufhp;
1919 
1920 	ip = VTOI(ap->a_vp);
1921 	ufhp = (struct ufid *)ap->a_fhp;
1922 	ufhp->ufid_len = sizeof(struct ufid);
1923 	ufhp->ufid_ino = ip->i_number;
1924 	ufhp->ufid_gen = ip->i_gen;
1925 	return (0);
1926 }
1927 
1928 SYSCTL_DECL(_vfs_ffs);
1929 static int use_buf_pager = 1;
1930 SYSCTL_INT(_vfs_ffs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN, &use_buf_pager, 0,
1931     "Always use buffer pager instead of bmap");
1932 
1933 static daddr_t
1934 ffs_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
1935 {
1936 
1937 	return (lblkno(VFSTOUFS(vp->v_mount)->um_fs, off));
1938 }
1939 
1940 static int
1941 ffs_gbp_getblksz(struct vnode *vp, daddr_t lbn, long *sz)
1942 {
1943 
1944 	*sz = blksize(VFSTOUFS(vp->v_mount)->um_fs, VTOI(vp), lbn);
1945 	return (0);
1946 }
1947 
1948 static int
1949 ffs_getpages(struct vop_getpages_args *ap)
1950 {
1951 	struct vnode *vp;
1952 	struct ufsmount *um;
1953 
1954 	vp = ap->a_vp;
1955 	um = VFSTOUFS(vp->v_mount);
1956 
1957 	if (!use_buf_pager && um->um_devvp->v_bufobj.bo_bsize <= PAGE_SIZE)
1958 		return (vnode_pager_generic_getpages(vp, ap->a_m, ap->a_count,
1959 		    ap->a_rbehind, ap->a_rahead, NULL, NULL));
1960 	return (vfs_bio_getpages(vp, ap->a_m, ap->a_count, ap->a_rbehind,
1961 	    ap->a_rahead, ffs_gbp_getblkno, ffs_gbp_getblksz));
1962 }
1963 
1964 static int
1965 ffs_getpages_async(struct vop_getpages_async_args *ap)
1966 {
1967 	struct vnode *vp;
1968 	struct ufsmount *um;
1969 	bool do_iodone;
1970 	int error;
1971 
1972 	vp = ap->a_vp;
1973 	um = VFSTOUFS(vp->v_mount);
1974 	do_iodone = true;
1975 
1976 	if (um->um_devvp->v_bufobj.bo_bsize <= PAGE_SIZE) {
1977 		error = vnode_pager_generic_getpages(vp, ap->a_m, ap->a_count,
1978 		    ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg);
1979 		if (error == 0)
1980 			do_iodone = false;
1981 	} else {
1982 		error = vfs_bio_getpages(vp, ap->a_m, ap->a_count,
1983 		    ap->a_rbehind, ap->a_rahead, ffs_gbp_getblkno,
1984 		    ffs_gbp_getblksz);
1985 	}
1986 	if (do_iodone && ap->a_iodone != NULL)
1987 		ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
1988 
1989 	return (error);
1990 }
1991 
1992 static int
1993 ffs_vput_pair(struct vop_vput_pair_args *ap)
1994 {
1995 	struct mount *mp;
1996 	struct vnode *dvp, *vp, *vp1, **vpp;
1997 	struct inode *dp, *ip;
1998 	ino_t ip_ino;
1999 	u_int64_t ip_gen;
2000 	int error, vp_locked;
2001 
2002 	dvp = ap->a_dvp;
2003 	dp = VTOI(dvp);
2004 	vpp = ap->a_vpp;
2005 	vp = vpp != NULL ? *vpp : NULL;
2006 
2007 	if ((dp->i_flag & (IN_NEEDSYNC | IN_ENDOFF)) == 0) {
2008 		vput(dvp);
2009 		if (vp != NULL && ap->a_unlock_vp)
2010 			vput(vp);
2011 		return (0);
2012 	}
2013 
2014 	mp = dvp->v_mount;
2015 	if (vp != NULL) {
2016 		if (ap->a_unlock_vp) {
2017 			vput(vp);
2018 		} else {
2019 			MPASS(vp->v_type != VNON);
2020 			vp_locked = VOP_ISLOCKED(vp);
2021 			ip = VTOI(vp);
2022 			ip_ino = ip->i_number;
2023 			ip_gen = ip->i_gen;
2024 			VOP_UNLOCK(vp);
2025 		}
2026 	}
2027 
2028 	/*
2029 	 * If compaction or fsync was requested do it in ffs_vput_pair()
2030 	 * now that other locks are no longer held.
2031          */
2032 	if ((dp->i_flag & IN_ENDOFF) != 0) {
2033 		VNASSERT(I_ENDOFF(dp) != 0 && I_ENDOFF(dp) < dp->i_size, dvp,
2034 		    ("IN_ENDOFF set but I_ENDOFF() is not"));
2035 		dp->i_flag &= ~IN_ENDOFF;
2036 		error = UFS_TRUNCATE(dvp, (off_t)I_ENDOFF(dp), IO_NORMAL |
2037 		    (DOINGASYNC(dvp) ? 0 : IO_SYNC), curthread->td_ucred);
2038 		if (error != 0 && error != ERELOOKUP) {
2039 			if (!ffs_fsfail_cleanup(VFSTOUFS(mp), error)) {
2040 				vn_printf(dvp,
2041 				    "IN_ENDOFF: failed to truncate, "
2042 				    "error %d\n", error);
2043 			}
2044 #ifdef UFS_DIRHASH
2045 			ufsdirhash_free(dp);
2046 #endif
2047 		}
2048 		SET_I_ENDOFF(dp, 0);
2049 	}
2050 	if ((dp->i_flag & IN_NEEDSYNC) != 0) {
2051 		do {
2052 			error = ffs_syncvnode(dvp, MNT_WAIT, 0);
2053 		} while (error == ERELOOKUP);
2054 	}
2055 
2056 	vput(dvp);
2057 
2058 	if (vp == NULL || ap->a_unlock_vp)
2059 		return (0);
2060 	MPASS(mp != NULL);
2061 
2062 	/*
2063 	 * It is possible that vp is reclaimed at this point. Only
2064 	 * routines that call us with a_unlock_vp == false can find
2065 	 * that their vp has been reclaimed. There are three areas
2066 	 * that are affected:
2067 	 * 1) vn_open_cred() - later VOPs could fail, but
2068 	 *    dead_open() returns 0 to simulate successful open.
2069 	 * 2) ffs_snapshot() - creation of snapshot fails with EBADF.
2070 	 * 3) NFS server (several places) - code is prepared to detect
2071 	 *    and respond to dead vnodes by returning ESTALE.
2072 	 */
2073 	VOP_LOCK(vp, vp_locked | LK_RETRY);
2074 	if (IS_UFS(vp))
2075 		return (0);
2076 
2077 	/*
2078 	 * Try harder to recover from reclaimed vp if reclaim was not
2079 	 * because underlying inode was cleared.  We saved inode
2080 	 * number and inode generation, so we can try to reinstantiate
2081 	 * exactly same version of inode.  If this fails, return
2082 	 * original doomed vnode and let caller to handle
2083 	 * consequences.
2084 	 *
2085 	 * Note that callers must keep write started around
2086 	 * VOP_VPUT_PAIR() calls, so it is safe to use mp without
2087 	 * busying it.
2088 	 */
2089 	VOP_UNLOCK(vp);
2090 	error = ffs_inotovp(mp, ip_ino, ip_gen, LK_EXCLUSIVE, &vp1,
2091 	    FFSV_REPLACE_DOOMED);
2092 	if (error != 0) {
2093 		VOP_LOCK(vp, vp_locked | LK_RETRY);
2094 	} else {
2095 		vrele(vp);
2096 		*vpp = vp1;
2097 	}
2098 	return (error);
2099 }
2100