xref: /dragonfly/sys/vfs/ext2fs/ext2_vnops.c (revision c8860c9a)
1 /*-
2  *  modified for EXT2FS support in Lites 1.1
3  *
4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
5  *  University of Utah, Department of Computer Science
6  */
7 /*-
8  * SPDX-License-Identifier: BSD-3-Clause
9  *
10  * Copyright (c) 1982, 1986, 1989, 1993
11  *	The Regents of the University of California.  All rights reserved.
12  * (c) UNIX System Laboratories, Inc.
13  * All or some portions of this file are derived from material licensed
14  * to the University of California by American Telephone and Telegraph
15  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
16  * the permission of UNIX System Laboratories, Inc.
17  *
18  * Redistribution and use in source and binary forms, with or without
19  * modification, are permitted provided that the following conditions
20  * are met:
21  * 1. Redistributions of source code must retain the above copyright
22  *    notice, this list of conditions and the following disclaimer.
23  * 2. Redistributions in binary form must reproduce the above copyright
24  *    notice, this list of conditions and the following disclaimer in the
25  *    documentation and/or other materials provided with the distribution.
26  * 3. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  *	@(#)ufs_vnops.c	8.7 (Berkeley) 2/3/94
43  *	@(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
44  * $FreeBSD$
45  */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
50 #include <sys/fcntl.h>
51 #include <sys/filio.h>
52 #include <sys/limits.h>
53 #include <sys/stat.h>
54 #include <sys/bio.h>
55 #include <sys/buf2.h>
56 #include <sys/endian.h>
57 #include <sys/priv.h>
58 #include <sys/mount.h>
59 #include <sys/unistd.h>
60 #include <sys/time.h>
61 #include <sys/vnode.h>
62 #include <sys/namei.h>
63 #include <sys/lockf.h>
64 #include <sys/event.h>
65 #include <sys/conf.h>
66 #include <sys/file.h>
67 #include <sys/vmmeter.h>
68 #include <sys/vfsops.h>
69 #include <sys/malloc.h>
70 #include <sys/uio.h>
71 #include <sys/jail.h>
72 
73 #include <vm/vm.h>
74 #include <vm/vm_param.h>
75 #include <vm/vm_extern.h>
76 #include <vm/vm_object.h>
77 #include <vm/vm_page2.h>
78 #include <vm/vm_pager.h>
79 #include <vm/vnode_pager.h>
80 
81 #include <vfs/ufs/dir.h>
82 #include <vfs/fifofs/fifo.h>
83 
84 #include <vfs/ext2fs/fs.h>
85 #include <vfs/ext2fs/inode.h>
86 #include <vfs/ext2fs/ext2fs.h>
87 #include <vfs/ext2fs/ext2_extern.h>
88 #include <vfs/ext2fs/ext2_dinode.h>
89 #include <vfs/ext2fs/ext2_dir.h>
90 #include <vfs/ext2fs/ext2_mount.h>
91 #include <vfs/ext2fs/ext2_extents.h>
92 
93 SDT_PROVIDER_DECLARE(ext2fs);
94 /*
95  * ext2fs trace probe:
96  * arg0: verbosity. Higher numbers give more verbose messages
97  * arg1: Textual message
98  */
99 SDT_PROBE_DEFINE2(ext2fs, , vnops, trace, "int", "char*");
100 
101 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
102 
103 static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
104 static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
105     struct thread *);
106 
107 /*
108  * A virgin directory (no blushing please).
109  * Note that the type and namlen fields are reversed relative to ext2.
110  * Also, we don't use `struct odirtemplate', since it would just cause
111  * endianness problems.
112  */
113 static struct dirtemplate mastertemplate = {
114 	0, htole16(12), 1, EXT2_FT_DIR, ".",
115 	0, htole16(DIRBLKSIZ - 12), 2, EXT2_FT_DIR, ".."
116 };
117 static struct dirtemplate omastertemplate = {
118 	0, htole16(12), 1, EXT2_FT_UNKNOWN, ".",
119 	0, htole16(DIRBLKSIZ - 12), 2, EXT2_FT_UNKNOWN, ".."
120 };
121 
122 void
123 ext2_itimes(struct vnode *vp)
124 {
125 	struct inode *ip;
126 	struct timespec ts;
127 
128 	ip = VTOI(vp);
129 	if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
130 		return;
131 	if ((vp->v_type == VBLK || vp->v_type == VCHR))
132 		ip->i_flag |= IN_LAZYMOD;
133 	else
134 		ip->i_flag |= IN_MODIFIED;
135 	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
136 		vfs_timestamp(&ts);
137 		if (ip->i_flag & IN_ACCESS) {
138 			ip->i_atime = ts.tv_sec;
139 			ip->i_atimensec = ts.tv_nsec;
140 		}
141 		if (ip->i_flag & IN_UPDATE) {
142 			ip->i_mtime = ts.tv_sec;
143 			ip->i_mtimensec = ts.tv_nsec;
144 			ip->i_modrev++;
145 		}
146 		if (ip->i_flag & IN_CHANGE) {
147 			ip->i_ctime = ts.tv_sec;
148 			ip->i_ctimensec = ts.tv_nsec;
149 		}
150 	}
151 	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
152 }
153 
154 /*
155  * Create a regular file
156  */
157 static int
158 ext2_create(struct vop_old_create_args *ap)
159 {
160 	int error;
161 
162 	error =
163 	    ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
164 	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
165 	if (error != 0)
166 		return (error);
167 	return (0);
168 }
169 
170 static int
171 ext2_open(struct vop_open_args *ap)
172 {
173 
174 	if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
175 		return (EOPNOTSUPP);
176 
177 	/*
178 	 * Files marked append-only must be opened for appending.
179 	 */
180 	if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
181 	    (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
182 		return (EPERM);
183 
184 	return (vop_stdopen(ap));
185 }
186 
187 /*
188  * Close called.
189  *
190  * Update the times on the inode.
191  */
192 static int
193 ext2_close(struct vop_close_args *ap)
194 {
195 	struct vnode *vp = ap->a_vp;
196 
197 	if (VREFCNT(vp) > 1)
198 		ext2_itimes(vp);
199 	return (vop_stdclose(ap));
200 }
201 
202 static int
203 ext2_access(struct vop_access_args *ap)
204 {
205 	struct vnode *vp = ap->a_vp;
206 	struct inode *ip = VTOI(vp);
207 	int error;
208 
209 	if (vp->v_type == VBLK || vp->v_type == VCHR)
210 		return (EOPNOTSUPP);
211 
212 	error = vop_helper_access(ap, ip->i_uid, ip->i_gid, ip->i_mode,
213 	    ip->i_flags);
214 	return (error);
215 }
216 
217 static int
218 ext2_getattr(struct vop_getattr_args *ap)
219 {
220 	struct vnode *vp = ap->a_vp;
221 	struct inode *ip = VTOI(vp);
222 	struct vattr *vap = ap->a_vap;
223 
224 	ext2_itimes(vp);
225 	/*
226 	 * Copy from inode table
227 	 */
228 	vap->va_fsid = devid_from_dev(ip->i_dev);
229 	vap->va_fileid = ip->i_number;
230 	vap->va_mode = ip->i_mode & ~IFMT;
231 	vap->va_nlink = ip->i_nlink;
232 	vap->va_uid = ip->i_uid;
233 	vap->va_gid = ip->i_gid;
234 	vap->va_size = ip->i_size;
235 	vap->va_atime.tv_sec = ip->i_atime;
236 	vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
237 	vap->va_mtime.tv_sec = ip->i_mtime;
238 	vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
239 	vap->va_ctime.tv_sec = ip->i_ctime;
240 	vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
241 	vap->va_flags = ip->i_flags;
242 	vap->va_gen = ip->i_gen;
243 	vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
244 	vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
245 	vap->va_type = IFTOVT(ip->i_mode);
246 	vap->va_filerev = ip->i_modrev;
247 	return (0);
248 }
249 
250 /*
251  * Set attribute vnode op. called from several syscalls
252  */
253 static int
254 ext2_setattr(struct vop_setattr_args *ap)
255 {
256 	struct vattr *vap = ap->a_vap;
257 	struct vnode *vp = ap->a_vp;
258 	struct inode *ip = VTOI(vp);
259 	struct ucred *cred = ap->a_cred;
260 	struct thread *td = curthread;
261 	int error;
262 
263 	/*
264 	 * Check for unsettable attributes.
265 	 */
266 	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
267 	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
268 	    (vap->va_blocksize != VNOVAL) || (vap->va_rmajor != VNOVAL) ||
269 	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
270 		return (EINVAL);
271 	}
272 	if (vap->va_flags != VNOVAL) {
273 		/* Disallow flags not supported by ext2fs. */
274 		if (vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
275 			return (EOPNOTSUPP);
276 
277 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
278 			return (EROFS);
279 		if (cred->cr_uid != ip->i_uid &&
280 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
281 			return (error);
282 		/*
283 		 * Note that a root chflags becomes a user chflags when
284 		 * we are jailed, unless the jail vfs_chflags sysctl
285 		 * is set.
286 		 */
287 		if (cred->cr_uid == 0 &&
288 		    (!jailed(cred) || PRISON_CAP_ISSET(cred->cr_prison->pr_caps,
289 		    PRISON_CAP_VFS_CHFLAGS))) {
290 			if ((ip->i_flags
291 			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) &&
292 			    securelevel > 0)
293 				return (EPERM);
294 			ip->i_flags = vap->va_flags;
295 		} else {
296 			if (ip->i_flags
297 			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
298 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
299 				return (EPERM);
300 			ip->i_flags &= SF_SETTABLE;
301 			ip->i_flags |= (vap->va_flags & UF_SETTABLE);
302 		}
303 		ip->i_flag |= IN_CHANGE;
304 		if (vap->va_flags & (IMMUTABLE | APPEND))
305 			return (0);
306 	}
307 	if (ip->i_flags & (IMMUTABLE | APPEND))
308 		return (EPERM);
309 	/*
310 	 * Go through the fields and update iff not VNOVAL.
311 	 */
312 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
313 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
314 			return (EROFS);
315 		if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
316 		    td)) != 0)
317 			return (error);
318 	}
319 	if (vap->va_size != VNOVAL) {
320 		/*
321 		 * Disallow write attempts on read-only file systems;
322 		 * unless the file is a socket, fifo, or a block or
323 		 * character device resident on the file system.
324 		 */
325 		switch (vp->v_type) {
326 		case VDIR:
327 			return (EISDIR);
328 		case VLNK:
329 		case VREG:
330 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
331 				return (EROFS);
332 			break;
333 		default:
334 			break;
335 		}
336 		if ((error = ext2_truncate(vp, vap->va_size, 0, cred)) != 0)
337 			return (error);
338 	}
339 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
340 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
341 			return (EROFS);
342 		if (cred->cr_uid != ip->i_uid &&
343 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)) &&
344 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
345 		    (error = VOP_EACCESS(vp, VWRITE, cred))))
346 			return (error);
347 		ip->i_flag |= IN_CHANGE | IN_MODIFIED;
348 		if (vap->va_atime.tv_sec != VNOVAL) {
349 			ip->i_flag &= ~IN_ACCESS;
350 			ip->i_atime = vap->va_atime.tv_sec;
351 			ip->i_atimensec = vap->va_atime.tv_nsec;
352 		}
353 		if (vap->va_mtime.tv_sec != VNOVAL) {
354 			ip->i_flag &= ~IN_UPDATE;
355 			ip->i_mtime = vap->va_mtime.tv_sec;
356 			ip->i_mtimensec = vap->va_mtime.tv_nsec;
357 		}
358 		error = ext2_update(vp, 0);
359 		if (error)
360 			return (error);
361 	}
362 	error = 0;
363 	if (vap->va_mode != (mode_t)VNOVAL) {
364 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
365 			return (EROFS);
366 		error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
367 	}
368 	return (error);
369 }
370 
371 /*
372  * Change the mode on a file.
373  * Inode must be locked before calling.
374  */
375 static int
376 ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
377 {
378 	struct inode *ip = VTOI(vp);
379 	int error;
380 
381 	if (cred->cr_uid != ip->i_uid) {
382 		error = priv_check_cred(cred, PRIV_VFS_CHMOD, 0);
383 		if (error)
384 			return (error);
385 	}
386 	if (cred->cr_uid) {
387 		if (vp->v_type != VDIR && (mode & S_ISTXT))
388 			return (EFTYPE);
389 		if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
390 			return (EPERM);
391 	}
392 	ip->i_mode &= ~ALLPERMS;
393 	ip->i_mode |= (mode & ALLPERMS);
394 	ip->i_flag |= IN_CHANGE;
395 	return (0);
396 }
397 
398 /*
399  * Perform chown operation on inode ip;
400  * inode must be locked prior to call.
401  */
402 static int
403 ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
404     struct thread *td)
405 {
406 	struct inode *ip = VTOI(vp);
407 	uid_t ouid;
408 	gid_t ogid;
409 	int error = 0;
410 
411 	if (uid == (uid_t)VNOVAL)
412 		uid = ip->i_uid;
413 	if (gid == (gid_t)VNOVAL)
414 		gid = ip->i_gid;
415 	/*
416 	 * If we don't own the file, are trying to change the owner
417 	 * of the file, or are not a member of the target group,
418 	 * the caller must be superuser or the call fails.
419 	 */
420 	if ((cred->cr_uid != ip->i_uid || uid != ip->i_uid ||
421 	    (gid != ip->i_gid && !(cred->cr_gid == gid ||
422 	    groupmember(gid, cred)))) &&
423 	    (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
424 		return (error);
425 	ogid = ip->i_gid;
426 	ouid = ip->i_uid;
427 	ip->i_gid = gid;
428 	ip->i_uid = uid;
429 	ip->i_flag |= IN_CHANGE;
430 	if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
431 		if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
432 			ip->i_mode &= ~(ISUID | ISGID);
433 	}
434 	return (0);
435 }
436 
437 struct ext2_fsync_bp_info {
438 	struct vnode *vp;
439 	int waitfor;
440 };
441 
442 static int
443 ext2_fsync_bp(struct buf *bp, void *data)
444 {
445 	struct ext2_fsync_bp_info *info = data;
446 
447 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
448 		return (0);
449 	if ((bp->b_flags & B_DELWRI) == 0)
450 		panic("ext2_fsync: not dirty");
451 	bremfree(bp);
452 
453 	/*
454 	 * Wait for I/O associated with indirect blocks to complete,
455 	 * since there is no way to quickly wait for them below.
456 	 */
457 	if (bp->b_vp == info->vp || (info->waitfor & MNT_NOWAIT))
458 		bawrite(bp);
459 	else
460 		bwrite(bp);
461 	return (1);
462 }
463 
464 /*
465  * Synch an open file.
466  */
467 /* ARGSUSED */
468 static int
469 ext2_fsync(struct vop_fsync_args *ap)
470 {
471 	struct ext2_fsync_bp_info info;
472 	struct vnode *vp = ap->a_vp;
473 	int count;
474 
475 	/*
476 	 * XXX why is all this fs specific?
477 	 */
478 
479 	/*
480 	 * Flush all dirty buffers associated with a vnode.
481 	 */
482 	lwkt_gettoken(&vp->v_token);
483 	info.vp = vp;
484 loop:
485 	info.waitfor = ap->a_waitfor;
486 	count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL, ext2_fsync_bp,
487 	    &info);
488 	if (count)
489 		goto loop;
490 
491 	if (ap->a_waitfor == MNT_WAIT) {
492 		bio_track_wait(&vp->v_track_write, 0, 0);
493 #ifdef DIAGNOSTIC
494 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
495 			vprint("ext2_fsync: dirty", vp);
496 			goto loop;
497 		}
498 #endif
499 	}
500 	lwkt_reltoken(&vp->v_token);
501 
502 	return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
503 }
504 
505 /*
506  * Mknod vnode call
507  */
508 /* ARGSUSED */
509 static int
510 ext2_mknod(struct vop_old_mknod_args *ap)
511 {
512 	struct vattr *vap = ap->a_vap;
513 	struct vnode **vpp = ap->a_vpp;
514 	struct inode *ip;
515 	ino_t ino;
516 	int error;
517 
518 	if (vap->va_rmajor != VNOVAL &&
519 	    makeudev(vap->va_rmajor, vap->va_rminor) == NOUDEV) {
520 		return (EINVAL);
521 	}
522 
523 	error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
524 	    ap->a_dvp, vpp, ap->a_cnp);
525 	if (error)
526 		return (error);
527 	ip = VTOI(*vpp);
528 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
529 	if (vap->va_rmajor != VNOVAL) {
530 		/*
531 		 * Want to be able to use this to make badblock
532 		 * inodes, so don't truncate the dev number.
533 		 */
534 		ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
535 	}
536 	/*
537 	 * Remove inode, then reload it through VFS_VGET so it is
538 	 * checked to see if it is an alias of an existing entry in
539 	 * the inode cache.	 XXX I don't believe this is necessary now.
540 	 */
541 	(*vpp)->v_type = VNON;
542 	ino = ip->i_number;	/* Save this before vgone() invalidates ip. */
543 	vgone_vxlocked(*vpp);
544 	vput(*vpp);
545 	error = VFS_VGET(ap->a_dvp->v_mount, NULL, ino, vpp);
546 	if (error) {
547 		*vpp = NULL;
548 		return (error);
549 	}
550 	return (0);
551 }
552 
553 static int
554 ext2_remove(struct vop_old_remove_args *ap)
555 {
556 	struct inode *ip;
557 	struct vnode *vp = ap->a_vp;
558 	struct vnode *dvp = ap->a_dvp;
559 	int error;
560 
561 	ip = VTOI(vp);
562 	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
563 	    (VTOI(dvp)->i_flags & APPEND)) {
564 		error = EPERM;
565 		goto out;
566 	}
567 	error = ext2_dirremove(dvp, ap->a_cnp);
568 	if (error == 0) {
569 		ip->i_nlink--;
570 		ip->i_flag |= IN_CHANGE;
571 	}
572 out:
573 	return (error);
574 }
575 
576 /*
577  * link vnode call
578  */
579 static int
580 ext2_link(struct vop_old_link_args *ap)
581 {
582 	struct vnode *vp = ap->a_vp;
583 	struct vnode *tdvp = ap->a_tdvp;
584 	struct componentname *cnp = ap->a_cnp;
585 	struct inode *ip;
586 	int error;
587 
588 	if (tdvp->v_mount != vp->v_mount) {
589 		error = EXDEV;
590 		goto out2;
591 	}
592 	if (tdvp != vp) {
593 		error = vn_lock(vp, LK_EXCLUSIVE | LK_FAILRECLAIM);
594 		if (error)
595 			goto out2;
596 	}
597 	ip = VTOI(vp);
598 	if ((nlink_t)ip->i_nlink >= EXT4_LINK_MAX) {
599 		error = EMLINK;
600 		goto out;
601 	}
602 	if (ip->i_flags & (IMMUTABLE | APPEND)) {
603 		error = EPERM;
604 		goto out;
605 	}
606 	ip->i_nlink++;
607 	ip->i_flag |= IN_CHANGE;
608 	error = ext2_update(vp, !DOINGASYNC(vp));
609 	if (!error)
610 		error = ext2_direnter(ip, tdvp, cnp);
611 	if (error) {
612 		ip->i_nlink--;
613 		ip->i_flag |= IN_CHANGE;
614 	}
615 out:
616 	if (tdvp != vp)
617 		vn_unlock(vp);
618 out2:
619 	return (error);
620 }
621 
622 static int
623 ext2_inc_nlink(struct inode *ip)
624 {
625 
626 	ip->i_nlink++;
627 
628 	if (S_ISDIR(ip->i_mode) &&
629 	    EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK) &&
630 	    ip->i_nlink > 1) {
631 		if (ip->i_nlink >= EXT4_LINK_MAX || ip->i_nlink == 2)
632 			ip->i_nlink = 1;
633 	} else if (ip->i_nlink > EXT4_LINK_MAX) {
634 		ip->i_nlink--;
635 		return (EMLINK);
636 	}
637 
638 	return (0);
639 }
640 
641 static void
642 ext2_dec_nlink(struct inode *ip)
643 {
644 
645 	if (!S_ISDIR(ip->i_mode) || ip->i_nlink > 2)
646 		ip->i_nlink--;
647 }
648 
649 /*
650  * Rename system call.
651  * 	rename("foo", "bar");
652  * is essentially
653  *	unlink("bar");
654  *	link("foo", "bar");
655  *	unlink("foo");
656  * but ``atomically''.  Can't do full commit without saving state in the
657  * inode on disk which isn't feasible at this time.  Best we can do is
658  * always guarantee the target exists.
659  *
660  * Basic algorithm is:
661  *
662  * 1) Bump link count on source while we're linking it to the
663  *    target.  This also ensure the inode won't be deleted out
664  *    from underneath us while we work (it may be truncated by
665  *    a concurrent `trunc' or `open' for creation).
666  * 2) Link source to destination.  If destination already exists,
667  *    delete it first.
668  * 3) Unlink source reference to inode if still around. If a
669  *    directory was moved and the parent of the destination
670  *    is different from the source, patch the ".." entry in the
671  *    directory.
672  */
673 static int
674 ext2_rename(struct vop_old_rename_args *ap)
675 {
676 	struct vnode *tvp = ap->a_tvp;
677 	struct vnode *tdvp = ap->a_tdvp;
678 	struct vnode *fvp = ap->a_fvp;
679 	struct vnode *fdvp = ap->a_fdvp;
680 	struct componentname *tcnp = ap->a_tcnp;
681 	struct componentname *fcnp = ap->a_fcnp;
682 	struct inode *ip, *xp, *dp;
683 	struct dirtemplate *dirbuf;
684 	int doingdirectory = 0, oldparent = 0, newparent = 0;
685 	int error = 0;
686 	u_char namlen;
687 
688 	/*
689 	 * Check for cross-device rename.
690 	 */
691 	if ((fvp->v_mount != tdvp->v_mount) ||
692 	    (tvp && (fvp->v_mount != tvp->v_mount))) {
693 		error = EXDEV;
694 abortit:
695 		if (tdvp == tvp)
696 			vrele(tdvp);
697 		else
698 			vput(tdvp);
699 		if (tvp)
700 			vput(tvp);
701 		vrele(fdvp);
702 		vrele(fvp);
703 		return (error);
704 	}
705 
706 	if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
707 	    (VTOI(tdvp)->i_flags & APPEND))) {
708 		error = EPERM;
709 		goto abortit;
710 	}
711 
712 	/*
713 	 * Renaming a file to itself has no effect.  The upper layers should
714 	 * not call us in that case.  Temporarily just warn if they do.
715 	 */
716 	if (fvp == tvp) {
717 		SDT_PROBE2(ext2fs, , vnops, trace, 1,
718 		    "rename: fvp == tvp (can't happen)");
719 		error = 0;
720 		goto abortit;
721 	}
722 
723 	if ((error = vn_lock(fvp, LK_EXCLUSIVE | LK_FAILRECLAIM)) != 0)
724 		goto abortit;
725 	dp = VTOI(fdvp);
726 	ip = VTOI(fvp);
727 	if (ip->i_nlink >= EXT4_LINK_MAX &&
728 	    !EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK)) {
729 		vn_unlock(fvp);
730 		error = EMLINK;
731 		goto abortit;
732 	}
733 	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
734 	    || (dp->i_flags & APPEND)) {
735 		vn_unlock(fvp);
736 		error = EPERM;
737 		goto abortit;
738 	}
739 	if ((ip->i_mode & IFMT) == IFDIR) {
740 		/*
741 		 * Avoid ".", "..", and aliases of "." for obvious reasons.
742 		 */
743 		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
744 		    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & CNP_ISDOTDOT ||
745 		    (ip->i_flag & IN_RENAME)) {
746 			vn_unlock(fvp);
747 			error = EINVAL;
748 			goto abortit;
749 		}
750 		ip->i_flag |= IN_RENAME;
751 		oldparent = dp->i_number;
752 		doingdirectory++;
753 	}
754 	//vrele(fdvp); XXX
755 
756 	/*
757 	 * When the target exists, both the directory
758 	 * and target vnodes are returned locked.
759 	 */
760 	dp = VTOI(tdvp);
761 	xp = NULL;
762 	if (tvp)
763 		xp = VTOI(tvp);
764 
765 	/*
766 	 * 1) Bump link count while we're moving stuff
767 	 *    around.  If we crash somewhere before
768 	 *    completing our work, the link count
769 	 *    may be wrong, but correctable.
770 	 */
771 	ext2_inc_nlink(ip);
772 	ip->i_flag |= IN_CHANGE;
773 	if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
774 		vn_unlock(fvp);
775 		goto bad;
776 	}
777 
778 	/*
779 	 * If ".." must be changed (ie the directory gets a new
780 	 * parent) then the source directory must not be in the
781 	 * directory hierarchy above the target, as this would
782 	 * orphan everything below the source directory. Also
783 	 * the user must have write permission in the source so
784 	 * as to be able to change "..". We must repeat the call
785 	 * to namei, as the parent directory is unlocked by the
786 	 * call to checkpath().
787 	 */
788 	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred);
789 	vn_unlock(fvp);
790 
791 	/*
792 	 * tvp (if not NULL) and tdvp are locked.  fvp and fdvp are not.
793 	 * dp and xp are set according to tdvp and tvp.
794 	 */
795 	if (oldparent != dp->i_number)
796 		newparent = dp->i_number;
797 	if (doingdirectory && newparent) {
798 		if (error)	/* write access check above */
799 			goto bad;
800 
801 		/*
802 		 * Prepare for relookup, get rid of xp
803 		 */
804 		if (xp != NULL) {
805 			vput(tvp);
806 			xp = NULL;
807 		}
808 
809 		/*
810 		 * checkpath vput()'s tdvp (VTOI(dp)) on return no matter what,
811 		 * get an extra ref so we wind up with just an unlocked, ref'd
812 		 * tdvp.  The 'out' target skips xp and tdvp cleanups.  Our
813 		 * tdvp is now unlocked so we have to clean it up ourselves.
814 		 */
815 		vref(tdvp);
816 		error = ext2_checkpath(ip, dp, tcnp->cn_cred);
817 		tcnp->cn_flags |= CNP_PDIRUNLOCK;
818 		if (error) {
819 			vrele(tdvp);
820 			goto out;
821 		}
822 		/*
823 		 * relookup no longer messes with the ref count.  An unlocked
824 		 * tdvp must be passed and if no error occurs a locked tdvp
825 		 * will be returned.  We have to use the out target again.
826 		 */
827 		error = relookup(tdvp, &tvp, tcnp);
828 		if (error) {
829 			if (tcnp->cn_flags & CNP_PDIRUNLOCK)
830 				vrele(tdvp);
831 			else
832 				vput(tdvp);
833 			goto out;
834 		}
835 
836 		/*
837 		 * tdvp is locked at this point.  in the RENAME case tvp may
838 		 * be NULL without an error, assign xp accordingly.  The
839 		 * 'bad' target can be used again after this.
840 		 */
841 		dp = VTOI(tdvp);
842 		if (tvp)
843 			xp = VTOI(tvp);
844 	}
845 
846 	/*
847 	 * 2) If target doesn't exist, link the target
848 	 *    to the source and unlink the source.
849 	 *    Otherwise, rewrite the target directory
850 	 *    entry to reference the source inode and
851 	 *    expunge the original entry's existence.
852 	 */
853 	if (xp == NULL) {
854 		if (dp->i_devvp != ip->i_devvp)
855 			panic("ext2_rename: EXDEV");
856 		/*
857 		 * Account for ".." in new directory.
858 		 * When source and destination have the same
859 		 * parent we don't fool with the link count.
860 		 */
861 		if (doingdirectory && newparent) {
862 			if ((nlink_t)dp->i_nlink >= LINK_MAX) {
863 				error = EMLINK;
864 				goto bad;
865 			}
866 			error = ext2_inc_nlink(dp);
867 			if (error)
868 				goto bad;
869 
870 			dp->i_flag |= IN_CHANGE;
871 			error = ext2_update(tdvp, !DOINGASYNC(tdvp));
872 			if (error)
873 				goto bad;
874 		}
875 		error = ext2_direnter(ip, tdvp, tcnp);
876 		if (error) {
877 			if (doingdirectory && newparent) {
878 				ext2_dec_nlink(dp);
879 				dp->i_flag |= IN_CHANGE;
880 				(void)ext2_update(tdvp, 1);
881 			}
882 			goto bad;
883 		}
884 		vput(tdvp);
885 	} else {
886 		if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
887 			panic("ext2_rename: EXDEV");
888 		/*
889 		 * Short circuit rename(foo, foo).
890 		 */
891 		if (xp->i_number == ip->i_number)
892 			panic("ext2_rename: same file");
893 		/*
894 		 * If the parent directory is "sticky", then the user must
895 		 * own the parent directory, or the destination of the rename,
896 		 * otherwise the destination may not be changed (except by
897 		 * root). This implements append-only directories.
898 		 */
899 		if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
900 		    tcnp->cn_cred->cr_uid != dp->i_uid &&
901 		    xp->i_uid != tcnp->cn_cred->cr_uid) {
902 			error = EPERM;
903 			goto bad;
904 		}
905 		/*
906 		 * Target must be empty if a directory and have no links
907 		 * to it. Also, ensure source and target are compatible
908 		 * (both directories, or both not directories).
909 		 */
910 		if ((xp->i_mode & IFMT) == IFDIR) {
911 			if (!ext2_dirempty(xp, dp->i_number, tcnp->cn_cred)) {
912 				error = ENOTEMPTY;
913 				goto bad;
914 			}
915 			if (!doingdirectory) {
916 				error = ENOTDIR;
917 				goto bad;
918 			}
919 		} else if (doingdirectory) {
920 			error = EISDIR;
921 			goto bad;
922 		}
923 		error = ext2_dirrewrite(dp, ip, tcnp);
924 		if (error)
925 			goto bad;
926 		/*
927 		 * If the target directory is in the same
928 		 * directory as the source directory,
929 		 * decrement the link count on the parent
930 		 * of the target directory.
931 		 */
932 		if (doingdirectory && !newparent) {
933 			ext2_dec_nlink(dp);
934 			dp->i_flag |= IN_CHANGE;
935 		}
936 		vput(tdvp);
937 		/*
938 		 * Adjust the link count of the target to
939 		 * reflect the dirrewrite above.  If this is
940 		 * a directory it is empty and there are
941 		 * no links to it, so we can squash the inode and
942 		 * any space associated with it.  We disallowed
943 		 * renaming over top of a directory with links to
944 		 * it above, as the remaining link would point to
945 		 * a directory without "." or ".." entries.
946 		 */
947 		ext2_dec_nlink(xp);
948 		if (doingdirectory) {
949 			if (xp->i_nlink > 2)
950 				panic("ext2_rename: linked directory");
951 			error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
952 			    tcnp->cn_cred);
953 			xp->i_nlink = 0;
954 		}
955 		xp->i_flag |= IN_CHANGE;
956 		vput(tvp);
957 		xp = NULL;
958 	}
959 
960 	/*
961 	 * 3) Unlink the source.
962 	 */
963 	fcnp->cn_flags &= ~CNP_MODMASK;
964 	fcnp->cn_flags |= CNP_LOCKPARENT;
965 	//vref(fdvp); XXX
966 	error = relookup(fdvp, &fvp, fcnp);
967 	if (error) {
968 		/*
969 		 * From name has disappeared.
970 		 */
971 		if (doingdirectory)
972 			panic("ext2_rename: lost dir entry");
973 		/* ip->i_flag only sets IN_RENAME if doingdirectory */
974 		vrele(ap->a_fvp);
975 		if (fcnp->cn_flags & CNP_PDIRUNLOCK)
976 			vrele(fdvp);
977 		else
978 			vput(fdvp);
979 		return (0);
980 	}
981 	KKASSERT((fcnp->cn_flags & CNP_PDIRUNLOCK) == 0);
982 
983 	/*
984 	 * This case shouldn't occur
985 	 */
986 	if (fvp == NULL) {
987 		/*
988 		 * From name has disappeared.
989 		 */
990 		if (doingdirectory)
991 			panic("ext2_rename: lost dir entry");
992 		/* ip->i_flag only sets IN_RENAME if doingdirectory */
993 		vrele(ap->a_fvp);
994 		vput(fvp);
995 		vput(fdvp);
996 		return (0);
997 	}
998 
999 	/*
1000 	 * fvp and fdvp are both ref'd and locked.
1001 	 */
1002 	xp = VTOI(fvp);
1003 	dp = VTOI(fdvp);
1004 
1005 	/*
1006 	 * Ensure that the directory entry still exists and has not
1007 	 * changed while the new name has been entered. If the source is
1008 	 * a file then the entry may have been unlinked or renamed. In
1009 	 * either case there is no further work to be done. If the source
1010 	 * is a directory then it cannot have been rmdir'ed; its link
1011 	 * count of three would cause a rmdir to fail with ENOTEMPTY.
1012 	 * The IN_RENAME flag ensures that it cannot be moved by another
1013 	 * rename.
1014 	 */
1015 	if (xp != ip) {
1016 		/*
1017 		 * From name resolves to a different inode.  IN_RENAME is
1018 		 * not sufficient protection against timing window races
1019 		 * so we can't panic here.
1020 		 */
1021 	} else {
1022 		/*
1023 		 * If the source is a directory with a
1024 		 * new parent, the link count of the old
1025 		 * parent directory must be decremented
1026 		 * and ".." set to point to the new parent.
1027 		 */
1028 		if (doingdirectory && newparent) {
1029 			ext2_dec_nlink(dp);
1030 			dp->i_flag |= IN_CHANGE;
1031 			dirbuf = malloc(dp->i_e2fs->e2fs_bsize, M_TEMP, M_WAITOK | M_ZERO);
1032 			error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
1033 			    sizeof (struct dirtemplate), (off_t)0,
1034 			    UIO_SYSSPACE, IO_NODELOCKED,
1035 			    tcnp->cn_cred, NULL);
1036 			if (error == 0) {
1037 				/* Like ufs little-endian: */
1038 				namlen = dirbuf->dotdot_type;
1039 				if (namlen != 2 ||
1040 				    dirbuf->dotdot_name[0] != '.' ||
1041 				    dirbuf->dotdot_name[1] != '.') {
1042 					ext2_dirbad(xp, (doff_t)12,
1043 					    "rename: mangled dir");
1044 				} else {
1045 					dirbuf->dotdot_ino = htole32(newparent);
1046 					/*
1047 					 * dirblock 0 could be htree root,
1048 					 * try both csum update functions.
1049 					 */
1050 					ext2_dirent_csum_set(ip,
1051 					    (struct ext2fs_direct_2 *)dirbuf);
1052 					ext2_dx_csum_set(ip,
1053 					    (struct ext2fs_direct_2 *)dirbuf);
1054 					vn_rdwr(UIO_WRITE, fvp,
1055 					    (caddr_t)&dirbuf,
1056 					    sizeof (struct dirtemplate),
1057 					    (off_t)0, UIO_SYSSPACE,
1058 					    IO_NODELOCKED | IO_SYNC,
1059 					    tcnp->cn_cred, NULL);
1060 				}
1061 			}
1062 			free(dirbuf, M_TEMP);
1063 		}
1064 		error = ext2_dirremove(fdvp, fcnp);
1065 		if (!error) {
1066 			ext2_dec_nlink(xp);
1067 			xp->i_flag |= IN_CHANGE;
1068 		}
1069 		xp->i_flag &= ~IN_RENAME;
1070 	}
1071 	if (dp)
1072 		vput(fdvp);
1073 	if (xp)
1074 		vput(fvp);
1075 	vrele(ap->a_fvp);
1076 	return (error);
1077 
1078 bad:
1079 	if (xp)
1080 		vput(ITOV(xp));
1081 	vput(ITOV(dp));
1082 out:
1083 	if (doingdirectory)
1084 		ip->i_flag &= ~IN_RENAME;
1085 	if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
1086 		ext2_dec_nlink(ip);
1087 		ip->i_flag |= IN_CHANGE;
1088 		ip->i_flag &= ~IN_RENAME;
1089 		vput(fvp);
1090 	} else
1091 		vrele(fvp);
1092 	return (error);
1093 }
1094 
1095 /*
1096  * Mkdir system call
1097  */
1098 static int
1099 ext2_mkdir(struct vop_old_mkdir_args *ap)
1100 {
1101 	struct m_ext2fs *fs;
1102 	struct vnode *dvp = ap->a_dvp;
1103 	struct vattr *vap = ap->a_vap;
1104 	struct componentname *cnp = ap->a_cnp;
1105 	struct inode *ip, *dp;
1106 	struct vnode *tvp;
1107 	struct dirtemplate dirtemplate, *dtp;
1108 	char *buf = NULL;
1109 	int error, dmode;
1110 
1111 	dp = VTOI(dvp);
1112 	if ((nlink_t)dp->i_nlink >= EXT4_LINK_MAX &&
1113 	    !EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK)) {
1114 		error = EMLINK;
1115 		goto out;
1116 	}
1117 	dmode = vap->va_mode & 0777;
1118 	dmode |= IFDIR;
1119 	/*
1120 	 * Must simulate part of ext2_makeinode here to acquire the inode,
1121 	 * but not have it entered in the parent directory. The entry is
1122 	 * made later after writing "." and ".." entries.
1123 	 */
1124 	error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
1125 	if (error)
1126 		goto out;
1127 	ip = VTOI(tvp);
1128 	fs = ip->i_e2fs;
1129 	ip->i_gid = dp->i_gid;
1130 #ifdef SUIDDIR
1131 	{
1132 		/*
1133 		 * if we are hacking owners here, (only do this where told to)
1134 		 * and we are not giving it TOO root, (would subvert quotas)
1135 		 * then go ahead and give it to the other user.
1136 		 * The new directory also inherits the SUID bit.
1137 		 * If user's UID and dir UID are the same,
1138 		 * 'give it away' so that the SUID is still forced on.
1139 		 */
1140 		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1141 		    (dp->i_mode & ISUID) && dp->i_uid) {
1142 			dmode |= ISUID;
1143 			ip->i_uid = dp->i_uid;
1144 		} else {
1145 			ip->i_uid = cnp->cn_cred->cr_uid;
1146 		}
1147 	}
1148 #else
1149 	ip->i_uid = cnp->cn_cred->cr_uid;
1150 #endif
1151 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1152 	ip->i_mode = dmode;
1153 	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
1154 	ip->i_nlink = 2;
1155 	if (cnp->cn_flags & CNP_ISWHITEOUT)
1156 		ip->i_flags |= UF_OPAQUE;
1157 	error = ext2_update(tvp, 1);
1158 
1159 	/*
1160 	 * The vnode must have a VM object in order to issue buffer cache
1161 	 * ops on it.
1162 	 */
1163 	vinitvmio(tvp, 0, PAGE_SIZE, -1);
1164 
1165 	/*
1166 	 * Bump link count in parent directory
1167 	 * to reflect work done below.  Should
1168 	 * be done before reference is created
1169 	 * so reparation is possible if we crash.
1170 	 */
1171 	ext2_inc_nlink(dp);
1172 	dp->i_flag |= IN_CHANGE;
1173 	error = ext2_update(dvp, !DOINGASYNC(dvp));
1174 	if (error)
1175 		goto bad;
1176 
1177 	/* Initialize directory with "." and ".." from static template. */
1178 	if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1179 	    EXT2F_INCOMPAT_FTYPE))
1180 		dtp = &mastertemplate;
1181 	else
1182 		dtp = &omastertemplate;
1183 	dirtemplate = *dtp;
1184 	dirtemplate.dot_ino = htole32(ip->i_number);
1185 	dirtemplate.dotdot_ino = htole32(dp->i_number);
1186 	/*
1187 	 * note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE so let's
1188 	 * just redefine it - for this function only
1189 	 */
1190 #undef  DIRBLKSIZ
1191 #define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
1192 	dirtemplate.dotdot_reclen = htole16(DIRBLKSIZ - 12);
1193 	buf = malloc(DIRBLKSIZ, M_TEMP, M_WAITOK | M_ZERO);
1194 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
1195 		dirtemplate.dotdot_reclen =
1196 		    htole16(le16toh(dirtemplate.dotdot_reclen) -
1197 		    sizeof(struct ext2fs_direct_tail));
1198 		ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, DIRBLKSIZ));
1199 	}
1200 	memcpy(buf, &dirtemplate, sizeof(dirtemplate));
1201 	ext2_dirent_csum_set(ip, (struct ext2fs_direct_2 *)buf);
1202 	error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)buf,
1203 	    DIRBLKSIZ, (off_t)0, UIO_SYSSPACE,
1204 	    IO_NODELOCKED | IO_SYNC, cnp->cn_cred, NULL);
1205 	if (error) {
1206 		ext2_dec_nlink(dp);
1207 		dp->i_flag |= IN_CHANGE;
1208 		goto bad;
1209 	}
1210 	if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
1211 		/* XXX should grow with balloc() */
1212 		panic("ext2_mkdir: blksize");
1213 	else {
1214 		ip->i_size = DIRBLKSIZ;
1215 		ip->i_flag |= IN_CHANGE;
1216 	}
1217 
1218 	/* Directory set up, now install its entry in the parent directory. */
1219 	error = ext2_direnter(ip, dvp, cnp);
1220 	if (error) {
1221 		ext2_dec_nlink(dp);
1222 		dp->i_flag |= IN_CHANGE;
1223 	}
1224 bad:
1225 	/*
1226 	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
1227 	 * for us because we set the link count to 0.
1228 	 */
1229 	if (error) {
1230 		ip->i_nlink = 0;
1231 		ip->i_flag |= IN_CHANGE;
1232 		vput(tvp);
1233 	} else
1234 		*ap->a_vpp = tvp;
1235 out:
1236 	free(buf, M_TEMP);
1237 	return (error);
1238 #undef  DIRBLKSIZ
1239 #define DIRBLKSIZ  DEV_BSIZE
1240 }
1241 
1242 /*
1243  * Rmdir system call.
1244  */
1245 static int
1246 ext2_rmdir(struct vop_old_rmdir_args *ap)
1247 {
1248 	struct vnode *vp = ap->a_vp;
1249 	struct vnode *dvp = ap->a_dvp;
1250 	struct componentname *cnp = ap->a_cnp;
1251 	struct inode *ip, *dp;
1252 	int error;
1253 
1254 	ip = VTOI(vp);
1255 	dp = VTOI(dvp);
1256 
1257 	/*
1258 	 * Verify the directory is empty (and valid).
1259 	 * (Rmdir ".." won't be valid since
1260 	 *  ".." will contain a reference to
1261 	 *  the current directory and thus be
1262 	 *  non-empty.)
1263 	 */
1264 	if (!ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
1265 		error = ENOTEMPTY;
1266 		goto out;
1267 	}
1268 	if ((dp->i_flags & APPEND)
1269 	    || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1270 		error = EPERM;
1271 		goto out;
1272 	}
1273 	/*
1274 	 * Delete reference to directory before purging
1275 	 * inode.  If we crash in between, the directory
1276 	 * will be reattached to lost+found,
1277 	 */
1278 	error = ext2_dirremove(dvp, cnp);
1279 	if (error)
1280 		goto out;
1281 	ext2_dec_nlink(dp);
1282 	dp->i_flag |= IN_CHANGE;
1283 	vn_unlock(dvp);
1284 	/*
1285 	 * Truncate inode.  The only stuff left
1286 	 * in the directory is "." and "..".
1287 	 */
1288 	ip->i_nlink = 0;
1289 	error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred);
1290 	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1291 out:
1292 	return (error);
1293 }
1294 
1295 /*
1296  * symlink -- make a symbolic link
1297  */
1298 static int
1299 ext2_symlink(struct vop_old_symlink_args *ap)
1300 {
1301 	struct vnode *vp, **vpp = ap->a_vpp;
1302 	struct inode *ip;
1303 	int len, error;
1304 
1305 	error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
1306 	    vpp, ap->a_cnp);
1307 	if (error)
1308 		return (error);
1309 	vp = *vpp;
1310 	len = strlen(ap->a_target);
1311 	if (len < vp->v_mount->mnt_maxsymlinklen) {
1312 		ip = VTOI(vp);
1313 		bcopy(ap->a_target, (char *)ip->i_shortlink, len);
1314 		ip->i_size = len;
1315 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
1316 	} else {
1317 		/*
1318 		 * Make sure we have a VM object in order to use
1319 		 * the buffer cache.
1320 		 */
1321 		if (vp->v_object == NULL)
1322 			vinitvmio(vp, 0, PAGE_SIZE, -1);
1323 
1324 		error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
1325 		    UIO_SYSSPACE, IO_NODELOCKED, ap->a_cnp->cn_cred, NULL);
1326 	}
1327 	if (error)
1328 		vput(vp);
1329 	return (error);
1330 }
1331 
1332 /*
1333  * Return target name of a symbolic link
1334  */
1335 static int
1336 ext2_readlink(struct vop_readlink_args *ap)
1337 {
1338 	struct vnode *vp = ap->a_vp;
1339 	struct inode *ip = VTOI(vp);
1340 	int isize;
1341 
1342 	isize = ip->i_size;
1343 	if (isize < vp->v_mount->mnt_maxsymlinklen) {
1344 		uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
1345 		return (0);
1346 	}
1347 	return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
1348 }
1349 
1350 /*
1351  * Calculate the logical to physical mapping if not done already,
1352  * then call the device strategy routine.
1353  *
1354  * In order to be able to swap to a file, the ext2_bmaparray() operation may not
1355  * deadlock on memory.  See ext2_bmap() for details.
1356  */
1357 static int
1358 ext2_strategy(struct vop_strategy_args *ap)
1359 {
1360 	struct bio *bio = ap->a_bio;
1361 	struct bio *nbio;
1362 	struct buf *bp = bio->bio_buf;
1363 	struct vnode *vp = ap->a_vp;
1364 	struct inode *ip;
1365 	int error;
1366 
1367 	ip = VTOI(vp);
1368 	if (vp->v_type == VBLK || vp->v_type == VCHR)
1369 		panic("ext2_strategy: spec");
1370 	nbio = push_bio(bio);
1371 	if (nbio->bio_offset == NOOFFSET) {
1372 		error = VOP_BMAP(vp, bio->bio_offset, &nbio->bio_offset, NULL,
1373 		    NULL, bp->b_cmd);
1374 		if (error) {
1375 			bp->b_error = error;
1376 			bp->b_flags |= B_ERROR;
1377 			/* I/O was never started on nbio, must biodone(bio) */
1378 			biodone(bio);
1379 			return (error);
1380 		}
1381 		if (nbio->bio_offset == NOOFFSET)
1382 			vfs_bio_clrbuf(bp);
1383 	}
1384 	if (nbio->bio_offset == NOOFFSET) {
1385 		/* I/O was never started on nbio, must biodone(bio) */
1386 		biodone(bio);
1387 		return (0);
1388 	}
1389 	vn_strategy(ip->i_devvp, nbio);
1390 	return (0);
1391 }
1392 
1393 /*
1394  * Print out the contents of an inode.
1395  */
1396 static int
1397 ext2_print(struct vop_print_args *ap)
1398 {
1399 	struct vnode *vp = ap->a_vp;
1400 	struct inode *ip = VTOI(vp);
1401 
1402 	printf("tag VT_EXT2FS, ino %lu, on dev %s (%d, %d)",
1403 	    (u_long)ip->i_number, devtoname(ip->i_dev), major(ip->i_dev),
1404 	    minor(ip->i_dev));
1405 	if (vp->v_type == VFIFO)
1406 		fifo_printinfo(vp);
1407 	lockmgr_printinfo(&vp->v_lock);
1408 	printf("\n");
1409 	return (0);
1410 }
1411 
1412 /*
1413  * Read wrapper for fifos.
1414  */
1415 static
1416 int
1417 ext2fifo_read(struct vop_read_args *ap)
1418 {
1419 	int error, resid;
1420 	struct inode *ip;
1421 	struct uio *uio;
1422 
1423 	uio = ap->a_uio;
1424 	resid = uio->uio_resid;
1425 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1426 	ip = VTOI(ap->a_vp);
1427 	if ((ap->a_vp->v_mount->mnt_flag & MNT_NOATIME) == 0 && ip != NULL &&
1428 	    (uio->uio_resid != resid || (error == 0 && resid != 0)))
1429 		VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
1430 	return (error);
1431 }
1432 
1433 /*
1434  * Write wrapper for fifos.
1435  */
1436 static
1437 int
1438 ext2fifo_write(struct vop_write_args *ap)
1439 {
1440 	int error, resid;
1441 	struct inode *ip;
1442 	struct uio *uio;
1443 
1444 	uio = ap->a_uio;
1445 	resid = uio->uio_resid;
1446 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1447 	ip = VTOI(ap->a_vp);
1448 	if (ip != NULL && (uio->uio_resid != resid || (error == 0 && resid != 0)))
1449 		VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
1450 	return (error);
1451 }
1452 
1453 /*
1454  * Close wrapper for fifos.
1455  *
1456  * Update the times on the inode then do device close.
1457  */
1458 static int
1459 ext2fifo_close(struct vop_close_args *ap)
1460 {
1461 	struct vnode *vp = ap->a_vp;
1462 
1463 	if (VREFCNT(vp) > 1)
1464 		ext2_itimes(vp);
1465 	return (VOCALL(&fifo_vnode_vops, &ap->a_head));
1466 }
1467 
1468 static void
1469 filt_ext2detach(struct knote *kn)
1470 {
1471 	struct vnode *vp = (struct vnode *)kn->kn_hook;
1472 
1473 	lwkt_gettoken(&vp->v_token);
1474 	knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1475 	lwkt_reltoken(&vp->v_token);
1476 }
1477 
1478 /*ARGSUSED*/
1479 static int
1480 filt_ext2read(struct knote *kn, long hint)
1481 {
1482 	struct vnode *vp = (struct vnode *)kn->kn_hook;
1483 	struct inode *ip = VTOI(vp);
1484 	off_t off;
1485 
1486 	/*
1487 	 * filesystem is gone, so set the EOF flag and schedule
1488 	 * the knote for deletion.
1489 	 */
1490 	if (hint == NOTE_REVOKE) {
1491 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1492 		return (1);
1493 	}
1494         off = ip->i_size - kn->kn_fp->f_offset;
1495 	kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
1496 	if (kn->kn_sfflags & NOTE_OLDAPI)
1497 		return (1);
1498         return (kn->kn_data != 0);
1499 }
1500 
1501 /*ARGSUSED*/
1502 static int
1503 filt_ext2write(struct knote *kn, long hint)
1504 {
1505 	/*
1506 	 * filesystem is gone, so set the EOF flag and schedule
1507 	 * the knote for deletion.
1508 	 */
1509 	if (hint == NOTE_REVOKE)
1510 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1511 
1512         kn->kn_data = 0;
1513         return (1);
1514 }
1515 
1516 static int
1517 filt_ext2vnode(struct knote *kn, long hint)
1518 {
1519 	if (kn->kn_sfflags & hint)
1520 		kn->kn_fflags |= hint;
1521 	if (hint == NOTE_REVOKE) {
1522 		kn->kn_flags |= (EV_EOF | EV_NODATA);
1523 		return (1);
1524 	}
1525 	return (kn->kn_fflags != 0);
1526 }
1527 
1528 static struct filterops ext2read_filtops =
1529 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2read };
1530 static struct filterops ext2write_filtops =
1531 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2write };
1532 static struct filterops ext2vnode_filtops =
1533 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2vnode };
1534 
1535 static int
1536 ext2_kqfilter(struct vop_kqfilter_args *ap)
1537 {
1538 	struct vnode *vp = ap->a_vp;
1539 	struct knote *kn = ap->a_kn;
1540 
1541 	switch (kn->kn_filter) {
1542 	case EVFILT_READ:
1543 		kn->kn_fop = &ext2read_filtops;
1544 		break;
1545 	case EVFILT_WRITE:
1546 		kn->kn_fop = &ext2write_filtops;
1547 		break;
1548 	case EVFILT_VNODE:
1549 		kn->kn_fop = &ext2vnode_filtops;
1550 		break;
1551 	default:
1552 		return (EOPNOTSUPP);
1553 	}
1554 
1555 	kn->kn_hook = (caddr_t)vp;
1556 
1557 	/* XXX: kq token actually protects the list */
1558 	lwkt_gettoken(&vp->v_token);
1559 	knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1560 	lwkt_reltoken(&vp->v_token);
1561 
1562 	return (0);
1563 }
1564 
1565 /*
1566  * Kqfilter wrapper for fifos.
1567  *
1568  * Fall through to ext2 kqfilter routines if needed
1569  */
1570 static int
1571 ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
1572 {
1573 	int error;
1574 
1575 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1576 	if (error)
1577 		error = ext2_kqfilter(ap);
1578 	return (error);
1579 }
1580 
1581 /*
1582  * Return POSIX pathconf information applicable to ext2 filesystems.
1583  */
1584 static int
1585 ext2_pathconf(struct vop_pathconf_args *ap)
1586 {
1587 	int error = 0;
1588 
1589 	switch (ap->a_name) {
1590 	case _PC_LINK_MAX:
1591 		if (EXT2_HAS_RO_COMPAT_FEATURE(VTOI(ap->a_vp)->i_e2fs,
1592 		    EXT2F_ROCOMPAT_DIR_NLINK))
1593 			*ap->a_retval = INT_MAX;
1594 		else
1595 			*ap->a_retval = EXT4_LINK_MAX;
1596 		break;
1597 	case _PC_NAME_MAX:
1598 		*ap->a_retval = NAME_MAX;
1599 		break;
1600 	case _PC_PATH_MAX:
1601 		*ap->a_retval = PATH_MAX;
1602 		break;
1603 	case _PC_PIPE_BUF:
1604 		if (ap->a_vp->v_type == VDIR || ap->a_vp->v_type == VFIFO)
1605 			*ap->a_retval = PIPE_BUF;
1606 		else
1607 			error = EINVAL;
1608 		break;
1609 	case _PC_CHOWN_RESTRICTED:
1610 		*ap->a_retval = 1;
1611 		break;
1612 	case _PC_NO_TRUNC:
1613 		*ap->a_retval = 1;
1614 		break;
1615 	case _PC_MIN_HOLE_SIZE:
1616 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1617 		break;
1618 	case _PC_PRIO_IO:
1619 		*ap->a_retval = 0;
1620 		break;
1621 	case _PC_SYNC_IO:
1622 		*ap->a_retval = 0;
1623 		break;
1624 	case _PC_ALLOC_SIZE_MIN:
1625 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
1626 		break;
1627 	case _PC_FILESIZEBITS:
1628 		*ap->a_retval = 64;
1629 		break;
1630 	case _PC_REC_INCR_XFER_SIZE:
1631 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1632 		break;
1633 	case _PC_REC_MAX_XFER_SIZE:
1634 		*ap->a_retval = -1;	/* means ``unlimited'' */
1635 		break;
1636 	case _PC_REC_MIN_XFER_SIZE:
1637 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1638 		break;
1639 	case _PC_REC_XFER_ALIGN:
1640 		*ap->a_retval = PAGE_SIZE;
1641 		break;
1642 	case _PC_SYMLINK_MAX:
1643 		*ap->a_retval = MAXPATHLEN;
1644 		break;
1645 
1646 	default:
1647 		error = vop_stdpathconf(ap);
1648 		break;
1649 	}
1650 	return (error);
1651 }
1652 
1653 /*
1654  * Initialize the vnode associated with a new inode, handle aliased vnodes.
1655  */
1656 int
1657 ext2_vinit(struct mount *mntp, struct vnode **vpp)
1658 {
1659 	struct inode *ip;
1660 	struct vnode *vp;
1661 
1662 	vp = *vpp;
1663 	ip = VTOI(vp);
1664 
1665 	switch (vp->v_type = IFTOVT(ip->i_mode)) {
1666 	case VCHR:
1667 	case VBLK:
1668 		vp->v_ops = &mntp->mnt_vn_spec_ops;
1669 		addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
1670 		break;
1671 	case VFIFO:
1672 		vp->v_ops = &mntp->mnt_vn_fifo_ops;
1673 		break;
1674 	case VDIR:
1675 	case VREG:
1676 		vinitvmio(vp, ip->i_size, PAGE_SIZE, -1); /* XXX */
1677 		break;
1678 	case VLNK:
1679 		if ((ip->i_size >= vp->v_mount->mnt_maxsymlinklen) &&
1680 		    ip->i_blocks != 0) {
1681 			vinitvmio(vp, ip->i_size, PAGE_SIZE, -1);
1682 		}
1683 		break;
1684 	default:
1685 		break;
1686 	}
1687 
1688 	/*
1689 	 * Only unallocated inodes should be of type VNON.
1690 	 */
1691 	if (ip->i_mode != 0 && vp->v_type == VNON)
1692 		return (EINVAL);
1693 
1694 	if (ip->i_number == EXT2_ROOTINO)
1695 		vp->v_flag |= VROOT;
1696 	/*
1697 	 * Initialize modrev times.
1698 	 */
1699 	ip->i_modrev = init_va_filerev();
1700 	*vpp = vp;
1701 	return (0);
1702 }
1703 
1704 /*
1705  * Allocate a new inode.
1706  */
1707 static int
1708 ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
1709     struct componentname *cnp)
1710 {
1711 	struct inode *ip, *pdir;
1712 	struct vnode *tvp;
1713 	int error;
1714 
1715 	pdir = VTOI(dvp);
1716 	*vpp = NULL;
1717 	if ((mode & IFMT) == 0)
1718 		mode |= IFREG;
1719 
1720 	error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
1721 	if (error) {
1722 		return (error);
1723 	}
1724 	ip = VTOI(tvp);
1725 	ip->i_gid = pdir->i_gid;
1726 #ifdef SUIDDIR
1727 	{
1728 		/*
1729 		 * if we are
1730 		 * not the owner of the directory,
1731 		 * and we are hacking owners here, (only do this where told to)
1732 		 * and we are not giving it TOO root, (would subvert quotas)
1733 		 * then go ahead and give it to the other user.
1734 		 * Note that this drops off the execute bits for security.
1735 		 */
1736 		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1737 		    (pdir->i_mode & ISUID) &&
1738 		    (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
1739 			ip->i_uid = pdir->i_uid;
1740 			mode &= ~07111;
1741 		} else {
1742 			ip->i_uid = cnp->cn_cred->cr_uid;
1743 		}
1744 	}
1745 #else
1746 	ip->i_uid = cnp->cn_cred->cr_uid;
1747 #endif
1748 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1749 	ip->i_mode = mode;
1750 	tvp->v_type = IFTOVT(mode);	/* Rest init'd in getnewvnode(). */
1751 	ip->i_nlink = 1;
1752 	if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
1753 		if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
1754 			ip->i_mode &= ~ISGID;
1755 	}
1756 
1757 	if (cnp->cn_flags & CNP_ISWHITEOUT)
1758 		ip->i_flags |= UF_OPAQUE;
1759 
1760 	/*
1761 	 * Regular files and directories need VM objects.  Softlinks do
1762 	 * not (not immediately anyway).
1763 	 */
1764 	if (tvp->v_type == VREG || tvp->v_type == VDIR)
1765 		vinitvmio(tvp, 0, PAGE_SIZE, -1);
1766 
1767 	/*
1768 	 * Make sure inode goes to disk before directory entry.
1769 	 */
1770 	error = ext2_update(tvp, !DOINGASYNC(tvp));
1771 	if (error)
1772 		goto bad;
1773 
1774 	error = ext2_direnter(ip, dvp, cnp);
1775 	if (error)
1776 		goto bad;
1777 
1778 	*vpp = tvp;
1779 	return (0);
1780 
1781 bad:
1782 	/*
1783 	 * Write error occurred trying to update the inode
1784 	 * or the directory so must deallocate the inode.
1785 	 */
1786 	ip->i_nlink = 0;
1787 	ip->i_flag |= IN_CHANGE;
1788 	vput(tvp);
1789 	return (error);
1790 }
1791 
1792 /*
1793  * Vnode op for reading.
1794  */
1795 static int
1796 ext2_read(struct vop_read_args *ap)
1797 {
1798 	struct vnode *vp;
1799 	struct inode *ip;
1800 	struct uio *uio;
1801 	struct m_ext2fs *fs;
1802 	struct buf *bp;
1803 	daddr_t lbn;
1804 	off_t nextlbn;
1805 	off_t nextloffset;
1806 	off_t bytesinfile;
1807 	long size, xfersize, blkoffset;
1808 	int error, orig_resid, seqcount;
1809 	int ioflag;
1810 
1811 	vp = ap->a_vp;
1812 	uio = ap->a_uio;
1813 	ioflag = ap->a_ioflag;
1814 
1815 	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
1816 	ip = VTOI(vp);
1817 
1818 #ifdef INVARIANTS
1819 	if (uio->uio_rw != UIO_READ)
1820 		panic("%s: mode", "ext2_read");
1821 
1822 	if (vp->v_type == VLNK) {
1823 		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
1824 			panic("%s: short symlink", "ext2_read");
1825 	} else if (vp->v_type != VREG && vp->v_type != VDIR)
1826 		panic("%s: type %d", "ext2_read", vp->v_type);
1827 #endif
1828 	orig_resid = uio->uio_resid;
1829 	KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
1830 	if (orig_resid == 0)
1831 		return (0);
1832 	KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
1833 	fs = ip->i_e2fs;
1834 	if (uio->uio_offset < ip->i_size &&
1835 	    uio->uio_offset >= fs->e2fs_maxfilesize)
1836 		return (EOVERFLOW);
1837 
1838 	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
1839 		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1840 			break;
1841 		lbn = lblkno(fs, uio->uio_offset);
1842 		nextlbn = lbn + 1;
1843 		nextloffset = lblktodoff(fs, nextlbn);
1844 		size = blksize(fs, ip, lbn);
1845 		blkoffset = blkoff(fs, uio->uio_offset);
1846 
1847 		xfersize = fs->e2fs_fsize - blkoffset;
1848 		if (uio->uio_resid < xfersize)
1849 			xfersize = uio->uio_resid;
1850 		if (bytesinfile < xfersize)
1851 			xfersize = bytesinfile;
1852 
1853 		if (nextloffset >= ip->i_size)
1854 			error = bread(vp, lblktodoff(fs, lbn), size, &bp);
1855 		else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
1856 			error = cluster_read(vp, (off_t)ip->i_size,
1857 			    lblktodoff(fs, lbn), size, uio->uio_resid,
1858 			    (ap->a_ioflag >> IO_SEQSHIFT) * MAXBSIZE, &bp);
1859 		} else if (seqcount > 1) {
1860 			u_int nextsize = blksize(fs, ip, nextlbn);
1861 
1862 			error = breadn(vp, lblktodoff(fs, lbn), size,
1863 			    &nextloffset, &nextsize, 1, &bp);
1864 		} else
1865 			error = bread(vp, lblktodoff(fs, lbn), size, &bp);
1866 		if (error) {
1867 			brelse(bp);
1868 			bp = NULL;
1869 			break;
1870 		}
1871 
1872 		/*
1873 		 * We should only get non-zero b_resid when an I/O error
1874 		 * has occurred, which should cause us to break above.
1875 		 * However, if the short read did not cause an error,
1876 		 * then we want to ensure that we do not uiomove bad
1877 		 * or uninitialized data.
1878 		 */
1879 		size -= bp->b_resid;
1880 		if (size < xfersize) {
1881 			if (size == 0)
1882 				break;
1883 			xfersize = size;
1884 		}
1885 		error = uiomove((char *)bp->b_data + blkoffset,
1886 		    (int)xfersize, uio);
1887 		if (error)
1888 			break;
1889 		bqrelse(bp);
1890 	}
1891 
1892 	/*
1893 	 * This can only happen in the case of an error because the loop
1894 	 * above resets bp to NULL on each iteration and on normal
1895 	 * completion has not set a new value into it. so it must have come
1896 	 * from a 'break' statement
1897 	 */
1898 	if (bp != NULL)
1899 		bqrelse(bp);
1900 
1901 	if ((error == 0 || uio->uio_resid != orig_resid) &&
1902 	    (vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
1903 		ip->i_flag |= IN_ACCESS;
1904 	return (error);
1905 }
1906 
1907 /*
1908  * Vnode op for writing.
1909  */
1910 static int
1911 ext2_write(struct vop_write_args *ap)
1912 {
1913 	struct vnode *vp;
1914 	struct uio *uio;
1915 	struct inode *ip;
1916 	struct m_ext2fs *fs;
1917 	struct buf *bp;
1918 	struct thread *td;
1919 	daddr_t lbn;
1920 	off_t osize;
1921 	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
1922 
1923 	ioflag = ap->a_ioflag;
1924 	uio = ap->a_uio;
1925 	vp = ap->a_vp;
1926 
1927 	seqcount = ioflag >> IO_SEQSHIFT;
1928 	ip = VTOI(vp);
1929 
1930 #ifdef INVARIANTS
1931 	if (uio->uio_rw != UIO_WRITE)
1932 		panic("%s: mode", "ext2_write");
1933 #endif
1934 
1935 	switch (vp->v_type) {
1936 	case VREG:
1937 		if (ioflag & IO_APPEND)
1938 			uio->uio_offset = ip->i_size;
1939 		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
1940 			return (EPERM);
1941 		/* FALLTHROUGH */
1942 	case VLNK:
1943 		break;
1944 	case VDIR:
1945 		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
1946 		if ((ioflag & IO_SYNC) == 0)
1947 			panic("ext2_write: nonsync dir write");
1948 		break;
1949 	default:
1950 		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
1951 		    vp->v_type, (intmax_t)uio->uio_offset,
1952 		    (intmax_t)uio->uio_resid);
1953 	}
1954 
1955 	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
1956 	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
1957 	fs = ip->i_e2fs;
1958 	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
1959 		return (EFBIG);
1960 	/*
1961 	 * Maybe this should be above the vnode op call, but so long as
1962 	 * file servers have no limits, I don't think it matters.
1963 	 */
1964 	td = uio->uio_td;
1965 	if (vp->v_type == VREG && td && td->td_proc &&
1966 	    uio->uio_offset + uio->uio_resid >
1967 	    td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
1968 		lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
1969 		return (EFBIG);
1970 	}
1971 
1972 	resid = uio->uio_resid;
1973 	osize = ip->i_size;
1974 	if (seqcount > BA_SEQMAX)
1975 		flags = BA_SEQMAX << BA_SEQSHIFT;
1976 	else
1977 		flags = seqcount << BA_SEQSHIFT;
1978 	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
1979 		flags |= IO_SYNC;
1980 
1981 	for (error = 0; uio->uio_resid > 0;) {
1982 		lbn = lblkno(fs, uio->uio_offset);
1983 		blkoffset = blkoff(fs, uio->uio_offset);
1984 		xfersize = fs->e2fs_fsize - blkoffset;
1985 		if (uio->uio_resid < xfersize)
1986 			xfersize = uio->uio_resid;
1987 		if (uio->uio_offset + xfersize > ip->i_size)
1988 			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
1989 
1990 		/*
1991 		 * We must perform a read-before-write if the transfer size
1992 		 * does not cover the entire buffer.
1993 		 */
1994 		if (fs->e2fs_bsize > xfersize)
1995 			flags |= BA_CLRBUF;
1996 		else
1997 			flags &= ~BA_CLRBUF;
1998 		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
1999 		    ap->a_cred, &bp, flags);
2000 		if (error != 0)
2001 			break;
2002 
2003 		if ((ioflag & (IO_SYNC | IO_INVAL)) == (IO_SYNC | IO_INVAL))
2004 			bp->b_flags |= B_NOCACHE;
2005 		if (uio->uio_offset + xfersize > ip->i_size)
2006 			ip->i_size = uio->uio_offset + xfersize;
2007 		size = blksize(fs, ip, lbn) - bp->b_resid;
2008 		if (size < xfersize)
2009 			xfersize = size;
2010 
2011 		error =
2012 		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
2013 		if ((ioflag & IO_VMIO) &&
2014 		    LIST_FIRST(&bp->b_dep) == NULL) /* in ext2fs? */
2015 			bp->b_flags |= B_RELBUF;
2016 		/*
2017 		 * If the buffer is not already filled and we encounter an
2018 		 * error while trying to fill it, we have to clear out any
2019 		 * garbage data from the pages instantiated for the buffer.
2020 		 * If we do not, a failed uiomove() during a write can leave
2021 		 * the prior contents of the pages exposed to a userland mmap.
2022 		 *
2023 		 * Note that we need only clear buffers with a transfer size
2024 		 * equal to the block size because buffers with a shorter
2025 		 * transfer size were cleared above by the call to ext2_balloc()
2026 		 * with the BA_CLRBUF flag set.
2027 		 *
2028 		 * If the source region for uiomove identically mmaps the
2029 		 * buffer, uiomove() performed the NOP copy, and the buffer
2030 		 * content remains valid because the page fault handler
2031 		 * validated the pages.
2032 		 */
2033 		if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
2034 		    fs->e2fs_bsize == xfersize)
2035 			vfs_bio_clrbuf(bp);
2036 
2037 		/*
2038 		 * If IO_SYNC each buffer is written synchronously.  Otherwise
2039 		 * if we have a severe page deficiency write the buffer
2040 		 * asynchronously.  Otherwise try to cluster, and if that
2041 		 * doesn't do it then either do an async write (if O_DIRECT),
2042 		 * or a delayed write (if not).
2043 		 */
2044 		if (ioflag & IO_SYNC) {
2045 			(void)bwrite(bp);
2046 		} else if (vm_paging_severe() ||
2047 			   buf_dirty_count_severe() ||
2048 			   (ioflag & IO_ASYNC))
2049 		{
2050 			bp->b_flags |= B_CLUSTEROK;
2051 			bawrite(bp);
2052 		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
2053 			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
2054 				bp->b_flags |= B_CLUSTEROK;
2055 				cluster_write(bp, (off_t)ip->i_size,
2056 				    vp->v_mount->mnt_stat.f_iosize, seqcount);
2057 			} else {
2058 				bawrite(bp);
2059 			}
2060 		} else if (ioflag & IO_DIRECT) {
2061 			bp->b_flags |= B_CLUSTEROK;
2062 			bawrite(bp);
2063 		} else {
2064 			bp->b_flags |= B_CLUSTEROK;
2065 			bdwrite(bp);
2066 		}
2067 		if (error || xfersize == 0)
2068 			break;
2069 	}
2070 	/*
2071 	 * If we successfully wrote any data, and we are not the superuser
2072 	 * we clear the setuid and setgid bits as a precaution against
2073 	 * tampering.
2074 	 */
2075 	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
2076 	    ap->a_cred) {
2077 		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
2078 			ip->i_mode &= ~(ISUID | ISGID);
2079 	}
2080 	if (error) {
2081 		if (ioflag & IO_UNIT) {
2082 			(void)ext2_truncate(vp, osize, ioflag & IO_SYNC,
2083 			    ap->a_cred);
2084 			uio->uio_offset -= resid - uio->uio_resid;
2085 			uio->uio_resid = resid;
2086 		}
2087 	}
2088 	if (uio->uio_resid != resid) {
2089 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
2090 		if (ioflag & IO_SYNC)
2091 			error = ext2_update(vp, 1);
2092 	}
2093 	return (error);
2094 }
2095 
2096 /* Global vfs data structures for ext2. */
2097 struct vop_ops ext2_vnodeops = {
2098 	.vop_default =		vop_defaultop,
2099 	.vop_access =		ext2_access,
2100 	.vop_bmap =		ext2_bmap,
2101 	.vop_old_lookup =	ext2_lookup,
2102 	.vop_close =		ext2_close,
2103 	.vop_old_create =	ext2_create,
2104 	.vop_fsync =		ext2_fsync,
2105 	.vop_getpages =		vop_stdgetpages,
2106 	.vop_putpages =		vop_stdputpages,
2107 	.vop_getattr =		ext2_getattr,
2108 	.vop_inactive =		ext2_inactive,
2109 	.vop_old_link =		ext2_link,
2110 	.vop_old_lookup =	ext2_lookup,
2111 	.vop_old_mkdir =	ext2_mkdir,
2112 	.vop_old_mknod =	ext2_mknod,
2113 	.vop_open =		ext2_open,
2114 	.vop_pathconf =		ext2_pathconf,
2115 	.vop_print =		ext2_print,
2116 	.vop_read =		ext2_read,
2117 	.vop_readdir =		ext2_readdir,
2118 	.vop_readlink =		ext2_readlink,
2119 	.vop_reallocblks =	ext2_reallocblks,
2120 	.vop_reclaim =		ext2_reclaim,
2121 	.vop_old_remove =	ext2_remove,
2122 	.vop_old_rename =	ext2_rename,
2123 	.vop_old_rmdir =	ext2_rmdir,
2124 	.vop_setattr =		ext2_setattr,
2125 	.vop_strategy =		ext2_strategy,
2126 	.vop_old_symlink =	ext2_symlink,
2127 	.vop_write =		ext2_write,
2128 };
2129 
2130 struct vop_ops ext2_specops = {
2131 	.vop_default =		vop_defaultop,
2132 	.vop_access =		ext2_access,
2133 	.vop_close =		ext2_close,
2134 	.vop_fsync =		ext2_fsync,
2135 	.vop_getattr =		ext2_getattr,
2136 	.vop_inactive =		ext2_inactive,
2137 	.vop_pathconf =		ext2_pathconf,
2138 	.vop_print =		ext2_print,
2139 	.vop_read =		vop_stdnoread,
2140 	.vop_reclaim =		ext2_reclaim,
2141 	.vop_setattr =		ext2_setattr,
2142 	.vop_write =		vop_stdnowrite
2143 };
2144 
2145 struct vop_ops ext2_fifoops = {
2146 	.vop_default =		fifo_vnoperate,
2147 	.vop_access =		ext2_access,
2148 	.vop_close =		ext2fifo_close,
2149 	.vop_fsync =		ext2_fsync,
2150 	.vop_getattr =		ext2_getattr,
2151 	.vop_inactive =		ext2_inactive,
2152 	.vop_kqfilter =		ext2fifo_kqfilter,
2153 	.vop_pathconf =		ext2_pathconf,
2154 	.vop_print =		ext2_print,
2155 	.vop_read =		ext2fifo_read,
2156 	.vop_reclaim =		ext2_reclaim,
2157 	.vop_setattr =		ext2_setattr,
2158 	.vop_write =		ext2fifo_write
2159 };
2160 
2161 VNODEOP_SET(ext2_vnodeops);
2162 VNODEOP_SET(ext2_specops);
2163 VNODEOP_SET(ext2_fifoops);
2164