xref: /dragonfly/sys/vfs/ext2fs/ext2_vnops.c (revision 55f88487)
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 "opt_suiddir.h"
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/fcntl.h>
53 #include <sys/filio.h>
54 #include <sys/limits.h>
55 #include <sys/stat.h>
56 #include <sys/bio.h>
57 #include <sys/buf2.h>
58 #include <sys/endian.h>
59 #include <sys/priv.h>
60 #include <sys/mount.h>
61 #include <sys/unistd.h>
62 #include <sys/time.h>
63 #include <sys/vnode.h>
64 #include <sys/namei.h>
65 #include <sys/lockf.h>
66 #include <sys/event.h>
67 #include <sys/conf.h>
68 #include <sys/file.h>
69 #include <sys/vmmeter.h>
70 #include <sys/vfsops.h>
71 #include <sys/malloc.h>
72 #include <sys/uio.h>
73 #include <sys/jail.h>
74 
75 #include <vm/vm.h>
76 #include <vm/vm_param.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_object.h>
79 #include <vm/vm_page2.h>
80 #include <vm/vm_pager.h>
81 #include <vm/vnode_pager.h>
82 
83 #include <vfs/ufs/dir.h>
84 #include <vfs/fifofs/fifo.h>
85 
86 #include <vfs/ext2fs/fs.h>
87 #include <vfs/ext2fs/inode.h>
88 #include <vfs/ext2fs/ext2fs.h>
89 #include <vfs/ext2fs/ext2_extern.h>
90 #include <vfs/ext2fs/ext2_dinode.h>
91 #include <vfs/ext2fs/ext2_dir.h>
92 #include <vfs/ext2fs/ext2_mount.h>
93 #include <vfs/ext2fs/ext2_extents.h>
94 
95 SDT_PROVIDER_DECLARE(ext2fs);
96 /*
97  * ext2fs trace probe:
98  * arg0: verbosity. Higher numbers give more verbose messages
99  * arg1: Textual message
100  */
101 SDT_PROBE_DEFINE2(ext2fs, , vnops, trace, "int", "char*");
102 
103 static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
104 
105 static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
106 static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
107     struct thread *);
108 
109 /*
110  * A virgin directory (no blushing please).
111  * Note that the type and namlen fields are reversed relative to ext2.
112  * Also, we don't use `struct odirtemplate', since it would just cause
113  * endianness problems.
114  */
115 static struct dirtemplate mastertemplate = {
116 	0, htole16(12), 1, EXT2_FT_DIR, ".",
117 	0, htole16(DIRBLKSIZ - 12), 2, EXT2_FT_DIR, ".."
118 };
119 static struct dirtemplate omastertemplate = {
120 	0, htole16(12), 1, EXT2_FT_UNKNOWN, ".",
121 	0, htole16(DIRBLKSIZ - 12), 2, EXT2_FT_UNKNOWN, ".."
122 };
123 
124 void
125 ext2_itimes(struct vnode *vp)
126 {
127 	struct inode *ip;
128 	struct timespec ts;
129 
130 	ip = VTOI(vp);
131 	if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
132 		return;
133 	if ((vp->v_type == VBLK || vp->v_type == VCHR))
134 		ip->i_flag |= IN_LAZYMOD;
135 	else
136 		ip->i_flag |= IN_MODIFIED;
137 	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
138 		vfs_timestamp(&ts);
139 		if (ip->i_flag & IN_ACCESS) {
140 			ip->i_atime = ts.tv_sec;
141 			ip->i_atimensec = ts.tv_nsec;
142 		}
143 		if (ip->i_flag & IN_UPDATE) {
144 			ip->i_mtime = ts.tv_sec;
145 			ip->i_mtimensec = ts.tv_nsec;
146 			ip->i_modrev++;
147 		}
148 		if (ip->i_flag & IN_CHANGE) {
149 			ip->i_ctime = ts.tv_sec;
150 			ip->i_ctimensec = ts.tv_nsec;
151 		}
152 	}
153 	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
154 }
155 
156 /*
157  * Create a regular file
158  */
159 static int
160 ext2_create(struct vop_old_create_args *ap)
161 {
162 	int error;
163 
164 	error =
165 	    ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
166 	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
167 	if (error != 0)
168 		return (error);
169 	return (0);
170 }
171 
172 static int
173 ext2_open(struct vop_open_args *ap)
174 {
175 
176 	if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
177 		return (EOPNOTSUPP);
178 
179 	/*
180 	 * Files marked append-only must be opened for appending.
181 	 */
182 	if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
183 	    (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
184 		return (EPERM);
185 
186 	return (vop_stdopen(ap));
187 }
188 
189 /*
190  * Close called.
191  *
192  * Update the times on the inode.
193  */
194 static int
195 ext2_close(struct vop_close_args *ap)
196 {
197 	struct vnode *vp = ap->a_vp;
198 
199 	if (VREFCNT(vp) > 1)
200 		ext2_itimes(vp);
201 	return (vop_stdclose(ap));
202 }
203 
204 static int
205 ext2_access(struct vop_access_args *ap)
206 {
207 	struct vnode *vp = ap->a_vp;
208 	struct inode *ip = VTOI(vp);
209 	int error;
210 
211 	if (vp->v_type == VBLK || vp->v_type == VCHR)
212 		return (EOPNOTSUPP);
213 
214 	error = vop_helper_access(ap, ip->i_uid, ip->i_gid, ip->i_mode,
215 	    ip->i_flags);
216 	return (error);
217 }
218 
219 static int
220 ext2_getattr(struct vop_getattr_args *ap)
221 {
222 	struct vnode *vp = ap->a_vp;
223 	struct inode *ip = VTOI(vp);
224 	struct vattr *vap = ap->a_vap;
225 
226 	ext2_itimes(vp);
227 	/*
228 	 * Copy from inode table
229 	 */
230 	vap->va_fsid = devid_from_dev(ip->i_dev);
231 	vap->va_fileid = ip->i_number;
232 	vap->va_mode = ip->i_mode & ~IFMT;
233 	vap->va_nlink = ip->i_nlink;
234 	vap->va_uid = ip->i_uid;
235 	vap->va_gid = ip->i_gid;
236 	vap->va_size = ip->i_size;
237 	vap->va_atime.tv_sec = ip->i_atime;
238 	vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
239 	vap->va_mtime.tv_sec = ip->i_mtime;
240 	vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
241 	vap->va_ctime.tv_sec = ip->i_ctime;
242 	vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
243 	vap->va_flags = ip->i_flags;
244 	vap->va_gen = ip->i_gen;
245 	vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
246 	vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
247 	vap->va_type = IFTOVT(ip->i_mode);
248 	vap->va_filerev = ip->i_modrev;
249 	return (0);
250 }
251 
252 /*
253  * Set attribute vnode op. called from several syscalls
254  */
255 static int
256 ext2_setattr(struct vop_setattr_args *ap)
257 {
258 	struct vattr *vap = ap->a_vap;
259 	struct vnode *vp = ap->a_vp;
260 	struct inode *ip = VTOI(vp);
261 	struct ucred *cred = ap->a_cred;
262 	struct thread *td = curthread;
263 	int error;
264 
265 	/*
266 	 * Check for unsettable attributes.
267 	 */
268 	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
269 	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
270 	    (vap->va_blocksize != VNOVAL) || (vap->va_rmajor != VNOVAL) ||
271 	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
272 		return (EINVAL);
273 	}
274 	if (vap->va_flags != VNOVAL) {
275 		/* Disallow flags not supported by ext2fs. */
276 		if (vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
277 			return (EOPNOTSUPP);
278 
279 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
280 			return (EROFS);
281 		if (cred->cr_uid != ip->i_uid &&
282 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
283 			return (error);
284 		/*
285 		 * Note that a root chflags becomes a user chflags when
286 		 * we are jailed, unless the jail vfs_chflags sysctl
287 		 * is set.
288 		 */
289 		if (cred->cr_uid == 0 &&
290 		    (!jailed(cred) || PRISON_CAP_ISSET(cred->cr_prison->pr_caps,
291 		    PRISON_CAP_VFS_CHFLAGS))) {
292 			if ((ip->i_flags
293 			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) &&
294 			    securelevel > 0)
295 				return (EPERM);
296 			ip->i_flags = vap->va_flags;
297 		} else {
298 			if (ip->i_flags
299 			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
300 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
301 				return (EPERM);
302 			ip->i_flags &= SF_SETTABLE;
303 			ip->i_flags |= (vap->va_flags & UF_SETTABLE);
304 		}
305 		ip->i_flag |= IN_CHANGE;
306 		if (vap->va_flags & (IMMUTABLE | APPEND))
307 			return (0);
308 	}
309 	if (ip->i_flags & (IMMUTABLE | APPEND))
310 		return (EPERM);
311 	/*
312 	 * Go through the fields and update iff not VNOVAL.
313 	 */
314 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
315 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
316 			return (EROFS);
317 		if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
318 		    td)) != 0)
319 			return (error);
320 	}
321 	if (vap->va_size != VNOVAL) {
322 		/*
323 		 * Disallow write attempts on read-only file systems;
324 		 * unless the file is a socket, fifo, or a block or
325 		 * character device resident on the file system.
326 		 */
327 		switch (vp->v_type) {
328 		case VDIR:
329 			return (EISDIR);
330 		case VLNK:
331 		case VREG:
332 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
333 				return (EROFS);
334 			break;
335 		default:
336 			break;
337 		}
338 		if ((error = ext2_truncate(vp, vap->va_size, 0, cred)) != 0)
339 			return (error);
340 	}
341 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
342 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
343 			return (EROFS);
344 		if (cred->cr_uid != ip->i_uid &&
345 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)) &&
346 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
347 		    (error = VOP_EACCESS(vp, VWRITE, cred))))
348 			return (error);
349 		ip->i_flag |= IN_CHANGE | IN_MODIFIED;
350 		if (vap->va_atime.tv_sec != VNOVAL) {
351 			ip->i_flag &= ~IN_ACCESS;
352 			ip->i_atime = vap->va_atime.tv_sec;
353 			ip->i_atimensec = vap->va_atime.tv_nsec;
354 		}
355 		if (vap->va_mtime.tv_sec != VNOVAL) {
356 			ip->i_flag &= ~IN_UPDATE;
357 			ip->i_mtime = vap->va_mtime.tv_sec;
358 			ip->i_mtimensec = vap->va_mtime.tv_nsec;
359 		}
360 		error = ext2_update(vp, 0);
361 		if (error)
362 			return (error);
363 	}
364 	error = 0;
365 	if (vap->va_mode != (mode_t)VNOVAL) {
366 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
367 			return (EROFS);
368 		error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
369 	}
370 	return (error);
371 }
372 
373 /*
374  * Change the mode on a file.
375  * Inode must be locked before calling.
376  */
377 static int
378 ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
379 {
380 	struct inode *ip = VTOI(vp);
381 	int error;
382 
383 	if (cred->cr_uid != ip->i_uid) {
384 		error = priv_check_cred(cred, PRIV_VFS_CHMOD, 0);
385 		if (error)
386 			return (error);
387 	}
388 	if (cred->cr_uid) {
389 		if (vp->v_type != VDIR && (mode & S_ISTXT))
390 			return (EFTYPE);
391 		if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
392 			return (EPERM);
393 	}
394 	ip->i_mode &= ~ALLPERMS;
395 	ip->i_mode |= (mode & ALLPERMS);
396 	ip->i_flag |= IN_CHANGE;
397 	return (0);
398 }
399 
400 /*
401  * Perform chown operation on inode ip;
402  * inode must be locked prior to call.
403  */
404 static int
405 ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
406     struct thread *td)
407 {
408 	struct inode *ip = VTOI(vp);
409 	uid_t ouid;
410 	gid_t ogid;
411 	int error = 0;
412 
413 	if (uid == (uid_t)VNOVAL)
414 		uid = ip->i_uid;
415 	if (gid == (gid_t)VNOVAL)
416 		gid = ip->i_gid;
417 	/*
418 	 * If we don't own the file, are trying to change the owner
419 	 * of the file, or are not a member of the target group,
420 	 * the caller must be superuser or the call fails.
421 	 */
422 	if ((cred->cr_uid != ip->i_uid || uid != ip->i_uid ||
423 	    (gid != ip->i_gid && !(cred->cr_gid == gid ||
424 	    groupmember(gid, cred)))) &&
425 	    (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
426 		return (error);
427 	ogid = ip->i_gid;
428 	ouid = ip->i_uid;
429 	ip->i_gid = gid;
430 	ip->i_uid = uid;
431 	ip->i_flag |= IN_CHANGE;
432 	if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
433 		if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
434 			ip->i_mode &= ~(ISUID | ISGID);
435 	}
436 	return (0);
437 }
438 
439 struct ext2_fsync_bp_info {
440 	struct vnode *vp;
441 	int waitfor;
442 };
443 
444 static int
445 ext2_fsync_bp(struct buf *bp, void *data)
446 {
447 	struct ext2_fsync_bp_info *info = data;
448 
449 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
450 		return (0);
451 	if ((bp->b_flags & B_DELWRI) == 0)
452 		panic("ext2_fsync: not dirty");
453 	bremfree(bp);
454 
455 	/*
456 	 * Wait for I/O associated with indirect blocks to complete,
457 	 * since there is no way to quickly wait for them below.
458 	 */
459 	if (bp->b_vp == info->vp || (info->waitfor & MNT_NOWAIT))
460 		bawrite(bp);
461 	else
462 		bwrite(bp);
463 	return (1);
464 }
465 
466 /*
467  * Synch an open file.
468  */
469 /* ARGSUSED */
470 static int
471 ext2_fsync(struct vop_fsync_args *ap)
472 {
473 	struct ext2_fsync_bp_info info;
474 	struct vnode *vp = ap->a_vp;
475 	int count;
476 
477 	/*
478 	 * XXX why is all this fs specific?
479 	 */
480 
481 	/*
482 	 * Flush all dirty buffers associated with a vnode.
483 	 */
484 	lwkt_gettoken(&vp->v_token);
485 	info.vp = vp;
486 loop:
487 	info.waitfor = ap->a_waitfor;
488 	count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL, ext2_fsync_bp,
489 	    &info);
490 	if (count)
491 		goto loop;
492 
493 	if (ap->a_waitfor == MNT_WAIT) {
494 		bio_track_wait(&vp->v_track_write, 0, 0);
495 #ifdef DIAGNOSTIC
496 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
497 			vprint("ext2_fsync: dirty", vp);
498 			goto loop;
499 		}
500 #endif
501 	}
502 	lwkt_reltoken(&vp->v_token);
503 
504 	return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
505 }
506 
507 /*
508  * Mknod vnode call
509  */
510 /* ARGSUSED */
511 static int
512 ext2_mknod(struct vop_old_mknod_args *ap)
513 {
514 	struct vattr *vap = ap->a_vap;
515 	struct vnode **vpp = ap->a_vpp;
516 	struct inode *ip;
517 	ino_t ino;
518 	int error;
519 
520 	if (vap->va_rmajor != VNOVAL &&
521 	    makeudev(vap->va_rmajor, vap->va_rminor) == NOUDEV) {
522 		return (EINVAL);
523 	}
524 
525 	error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
526 	    ap->a_dvp, vpp, ap->a_cnp);
527 	if (error)
528 		return (error);
529 	ip = VTOI(*vpp);
530 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
531 	if (vap->va_rmajor != VNOVAL) {
532 		/*
533 		 * Want to be able to use this to make badblock
534 		 * inodes, so don't truncate the dev number.
535 		 */
536 		ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
537 	}
538 	/*
539 	 * Remove inode, then reload it through VFS_VGET so it is
540 	 * checked to see if it is an alias of an existing entry in
541 	 * the inode cache.	 XXX I don't believe this is necessary now.
542 	 */
543 	(*vpp)->v_type = VNON;
544 	ino = ip->i_number;	/* Save this before vgone() invalidates ip. */
545 	vgone_vxlocked(*vpp);
546 	vput(*vpp);
547 	error = VFS_VGET(ap->a_dvp->v_mount, NULL, ino, vpp);
548 	if (error) {
549 		*vpp = NULL;
550 		return (error);
551 	}
552 	return (0);
553 }
554 
555 static int
556 ext2_remove(struct vop_old_remove_args *ap)
557 {
558 	struct inode *ip;
559 	struct vnode *vp = ap->a_vp;
560 	struct vnode *dvp = ap->a_dvp;
561 	int error;
562 
563 	ip = VTOI(vp);
564 	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
565 	    (VTOI(dvp)->i_flags & APPEND)) {
566 		error = EPERM;
567 		goto out;
568 	}
569 	error = ext2_dirremove(dvp, ap->a_cnp);
570 	if (error == 0) {
571 		ip->i_nlink--;
572 		ip->i_flag |= IN_CHANGE;
573 	}
574 out:
575 	return (error);
576 }
577 
578 /*
579  * link vnode call
580  */
581 static int
582 ext2_link(struct vop_old_link_args *ap)
583 {
584 	struct vnode *vp = ap->a_vp;
585 	struct vnode *tdvp = ap->a_tdvp;
586 	struct componentname *cnp = ap->a_cnp;
587 	struct inode *ip;
588 	int error;
589 
590 	if (tdvp->v_mount != vp->v_mount) {
591 		error = EXDEV;
592 		goto out2;
593 	}
594 	if (tdvp != vp) {
595 		error = vn_lock(vp, LK_EXCLUSIVE | LK_FAILRECLAIM);
596 		if (error)
597 			goto out2;
598 	}
599 	ip = VTOI(vp);
600 	if ((nlink_t)ip->i_nlink >= EXT4_LINK_MAX) {
601 		error = EMLINK;
602 		goto out;
603 	}
604 	if (ip->i_flags & (IMMUTABLE | APPEND)) {
605 		error = EPERM;
606 		goto out;
607 	}
608 	ip->i_nlink++;
609 	ip->i_flag |= IN_CHANGE;
610 	error = ext2_update(vp, !DOINGASYNC(vp));
611 	if (!error)
612 		error = ext2_direnter(ip, tdvp, cnp);
613 	if (error) {
614 		ip->i_nlink--;
615 		ip->i_flag |= IN_CHANGE;
616 	}
617 out:
618 	if (tdvp != vp)
619 		vn_unlock(vp);
620 out2:
621 	return (error);
622 }
623 
624 static int
625 ext2_inc_nlink(struct inode *ip)
626 {
627 
628 	ip->i_nlink++;
629 
630 	if (S_ISDIR(ip->i_mode) &&
631 	    EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK) &&
632 	    ip->i_nlink > 1) {
633 		if (ip->i_nlink >= EXT4_LINK_MAX || ip->i_nlink == 2)
634 			ip->i_nlink = 1;
635 	} else if (ip->i_nlink > EXT4_LINK_MAX) {
636 		ip->i_nlink--;
637 		return (EMLINK);
638 	}
639 
640 	return (0);
641 }
642 
643 static void
644 ext2_dec_nlink(struct inode *ip)
645 {
646 
647 	if (!S_ISDIR(ip->i_mode) || ip->i_nlink > 2)
648 		ip->i_nlink--;
649 }
650 
651 /*
652  * Rename system call.
653  * 	rename("foo", "bar");
654  * is essentially
655  *	unlink("bar");
656  *	link("foo", "bar");
657  *	unlink("foo");
658  * but ``atomically''.  Can't do full commit without saving state in the
659  * inode on disk which isn't feasible at this time.  Best we can do is
660  * always guarantee the target exists.
661  *
662  * Basic algorithm is:
663  *
664  * 1) Bump link count on source while we're linking it to the
665  *    target.  This also ensure the inode won't be deleted out
666  *    from underneath us while we work (it may be truncated by
667  *    a concurrent `trunc' or `open' for creation).
668  * 2) Link source to destination.  If destination already exists,
669  *    delete it first.
670  * 3) Unlink source reference to inode if still around. If a
671  *    directory was moved and the parent of the destination
672  *    is different from the source, patch the ".." entry in the
673  *    directory.
674  */
675 static int
676 ext2_rename(struct vop_old_rename_args *ap)
677 {
678 	struct vnode *tvp = ap->a_tvp;
679 	struct vnode *tdvp = ap->a_tdvp;
680 	struct vnode *fvp = ap->a_fvp;
681 	struct vnode *fdvp = ap->a_fdvp;
682 	struct componentname *tcnp = ap->a_tcnp;
683 	struct componentname *fcnp = ap->a_fcnp;
684 	struct inode *ip, *xp, *dp;
685 	struct dirtemplate *dirbuf;
686 	int doingdirectory = 0, oldparent = 0, newparent = 0;
687 	int error = 0;
688 	u_char namlen;
689 
690 	/*
691 	 * Check for cross-device rename.
692 	 */
693 	if ((fvp->v_mount != tdvp->v_mount) ||
694 	    (tvp && (fvp->v_mount != tvp->v_mount))) {
695 		error = EXDEV;
696 abortit:
697 		if (tdvp == tvp)
698 			vrele(tdvp);
699 		else
700 			vput(tdvp);
701 		if (tvp)
702 			vput(tvp);
703 		vrele(fdvp);
704 		vrele(fvp);
705 		return (error);
706 	}
707 
708 	if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
709 	    (VTOI(tdvp)->i_flags & APPEND))) {
710 		error = EPERM;
711 		goto abortit;
712 	}
713 
714 	/*
715 	 * Renaming a file to itself has no effect.  The upper layers should
716 	 * not call us in that case.  Temporarily just warn if they do.
717 	 */
718 	if (fvp == tvp) {
719 		SDT_PROBE2(ext2fs, , vnops, trace, 1,
720 		    "rename: fvp == tvp (can't happen)");
721 		error = 0;
722 		goto abortit;
723 	}
724 
725 	if ((error = vn_lock(fvp, LK_EXCLUSIVE | LK_FAILRECLAIM)) != 0)
726 		goto abortit;
727 	dp = VTOI(fdvp);
728 	ip = VTOI(fvp);
729 	if (ip->i_nlink >= EXT4_LINK_MAX &&
730 	    !EXT2_HAS_RO_COMPAT_FEATURE(ip->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK)) {
731 		vn_unlock(fvp);
732 		error = EMLINK;
733 		goto abortit;
734 	}
735 	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
736 	    || (dp->i_flags & APPEND)) {
737 		vn_unlock(fvp);
738 		error = EPERM;
739 		goto abortit;
740 	}
741 	if ((ip->i_mode & IFMT) == IFDIR) {
742 		/*
743 		 * Avoid ".", "..", and aliases of "." for obvious reasons.
744 		 */
745 		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
746 		    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & CNP_ISDOTDOT ||
747 		    (ip->i_flag & IN_RENAME)) {
748 			vn_unlock(fvp);
749 			error = EINVAL;
750 			goto abortit;
751 		}
752 		ip->i_flag |= IN_RENAME;
753 		oldparent = dp->i_number;
754 		doingdirectory++;
755 	}
756 	//vrele(fdvp); XXX
757 
758 	/*
759 	 * When the target exists, both the directory
760 	 * and target vnodes are returned locked.
761 	 */
762 	dp = VTOI(tdvp);
763 	xp = NULL;
764 	if (tvp)
765 		xp = VTOI(tvp);
766 
767 	/*
768 	 * 1) Bump link count while we're moving stuff
769 	 *    around.  If we crash somewhere before
770 	 *    completing our work, the link count
771 	 *    may be wrong, but correctable.
772 	 */
773 	ext2_inc_nlink(ip);
774 	ip->i_flag |= IN_CHANGE;
775 	if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
776 		vn_unlock(fvp);
777 		goto bad;
778 	}
779 
780 	/*
781 	 * If ".." must be changed (ie the directory gets a new
782 	 * parent) then the source directory must not be in the
783 	 * directory hierarchy above the target, as this would
784 	 * orphan everything below the source directory. Also
785 	 * the user must have write permission in the source so
786 	 * as to be able to change "..". We must repeat the call
787 	 * to namei, as the parent directory is unlocked by the
788 	 * call to checkpath().
789 	 */
790 	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred);
791 	vn_unlock(fvp);
792 
793 	/*
794 	 * tvp (if not NULL) and tdvp are locked.  fvp and fdvp are not.
795 	 * dp and xp are set according to tdvp and tvp.
796 	 */
797 	if (oldparent != dp->i_number)
798 		newparent = dp->i_number;
799 	if (doingdirectory && newparent) {
800 		if (error)	/* write access check above */
801 			goto bad;
802 
803 		/*
804 		 * Prepare for relookup, get rid of xp
805 		 */
806 		if (xp != NULL) {
807 			vput(tvp);
808 			xp = NULL;
809 		}
810 
811 		/*
812 		 * checkpath vput()'s tdvp (VTOI(dp)) on return no matter what,
813 		 * get an extra ref so we wind up with just an unlocked, ref'd
814 		 * tdvp.  The 'out' target skips xp and tdvp cleanups.  Our
815 		 * tdvp is now unlocked so we have to clean it up ourselves.
816 		 */
817 		vref(tdvp);
818 		error = ext2_checkpath(ip, dp, tcnp->cn_cred);
819 		tcnp->cn_flags |= CNP_PDIRUNLOCK;
820 		if (error) {
821 			vrele(tdvp);
822 			goto out;
823 		}
824 		/*
825 		 * relookup no longer messes with the ref count.  An unlocked
826 		 * tdvp must be passed and if no error occurs a locked tdvp
827 		 * will be returned.  We have to use the out target again.
828 		 */
829 		error = relookup(tdvp, &tvp, tcnp);
830 		if (error) {
831 			if (tcnp->cn_flags & CNP_PDIRUNLOCK)
832 				vrele(tdvp);
833 			else
834 				vput(tdvp);
835 			goto out;
836 		}
837 
838 		/*
839 		 * tdvp is locked at this point.  in the RENAME case tvp may
840 		 * be NULL without an error, assign xp accordingly.  The
841 		 * 'bad' target can be used again after this.
842 		 */
843 		dp = VTOI(tdvp);
844 		if (tvp)
845 			xp = VTOI(tvp);
846 	}
847 
848 	/*
849 	 * 2) If target doesn't exist, link the target
850 	 *    to the source and unlink the source.
851 	 *    Otherwise, rewrite the target directory
852 	 *    entry to reference the source inode and
853 	 *    expunge the original entry's existence.
854 	 */
855 	if (xp == NULL) {
856 		if (dp->i_devvp != ip->i_devvp)
857 			panic("ext2_rename: EXDEV");
858 		/*
859 		 * Account for ".." in new directory.
860 		 * When source and destination have the same
861 		 * parent we don't fool with the link count.
862 		 */
863 		if (doingdirectory && newparent) {
864 			if ((nlink_t)dp->i_nlink >= LINK_MAX) {
865 				error = EMLINK;
866 				goto bad;
867 			}
868 			error = ext2_inc_nlink(dp);
869 			if (error)
870 				goto bad;
871 
872 			dp->i_flag |= IN_CHANGE;
873 			error = ext2_update(tdvp, !DOINGASYNC(tdvp));
874 			if (error)
875 				goto bad;
876 		}
877 		error = ext2_direnter(ip, tdvp, tcnp);
878 		if (error) {
879 			if (doingdirectory && newparent) {
880 				ext2_dec_nlink(dp);
881 				dp->i_flag |= IN_CHANGE;
882 				(void)ext2_update(tdvp, 1);
883 			}
884 			goto bad;
885 		}
886 		vput(tdvp);
887 	} else {
888 		if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
889 			panic("ext2_rename: EXDEV");
890 		/*
891 		 * Short circuit rename(foo, foo).
892 		 */
893 		if (xp->i_number == ip->i_number)
894 			panic("ext2_rename: same file");
895 		/*
896 		 * If the parent directory is "sticky", then the user must
897 		 * own the parent directory, or the destination of the rename,
898 		 * otherwise the destination may not be changed (except by
899 		 * root). This implements append-only directories.
900 		 */
901 		if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
902 		    tcnp->cn_cred->cr_uid != dp->i_uid &&
903 		    xp->i_uid != tcnp->cn_cred->cr_uid) {
904 			error = EPERM;
905 			goto bad;
906 		}
907 		/*
908 		 * Target must be empty if a directory and have no links
909 		 * to it. Also, ensure source and target are compatible
910 		 * (both directories, or both not directories).
911 		 */
912 		if ((xp->i_mode & IFMT) == IFDIR) {
913 			if (!ext2_dirempty(xp, dp->i_number, tcnp->cn_cred)) {
914 				error = ENOTEMPTY;
915 				goto bad;
916 			}
917 			if (!doingdirectory) {
918 				error = ENOTDIR;
919 				goto bad;
920 			}
921 		} else if (doingdirectory) {
922 			error = EISDIR;
923 			goto bad;
924 		}
925 		error = ext2_dirrewrite(dp, ip, tcnp);
926 		if (error)
927 			goto bad;
928 		/*
929 		 * If the target directory is in the same
930 		 * directory as the source directory,
931 		 * decrement the link count on the parent
932 		 * of the target directory.
933 		 */
934 		if (doingdirectory && !newparent) {
935 			ext2_dec_nlink(dp);
936 			dp->i_flag |= IN_CHANGE;
937 		}
938 		vput(tdvp);
939 		/*
940 		 * Adjust the link count of the target to
941 		 * reflect the dirrewrite above.  If this is
942 		 * a directory it is empty and there are
943 		 * no links to it, so we can squash the inode and
944 		 * any space associated with it.  We disallowed
945 		 * renaming over top of a directory with links to
946 		 * it above, as the remaining link would point to
947 		 * a directory without "." or ".." entries.
948 		 */
949 		ext2_dec_nlink(xp);
950 		if (doingdirectory) {
951 			if (xp->i_nlink > 2)
952 				panic("ext2_rename: linked directory");
953 			error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
954 			    tcnp->cn_cred);
955 			xp->i_nlink = 0;
956 		}
957 		xp->i_flag |= IN_CHANGE;
958 		vput(tvp);
959 		xp = NULL;
960 	}
961 
962 	/*
963 	 * 3) Unlink the source.
964 	 */
965 	fcnp->cn_flags &= ~CNP_MODMASK;
966 	fcnp->cn_flags |= CNP_LOCKPARENT;
967 	//vref(fdvp); XXX
968 	error = relookup(fdvp, &fvp, fcnp);
969 	if (error) {
970 		/*
971 		 * From name has disappeared.
972 		 */
973 		if (doingdirectory)
974 			panic("ext2_rename: lost dir entry");
975 		/* ip->i_flag only sets IN_RENAME if doingdirectory */
976 		vrele(ap->a_fvp);
977 		if (fcnp->cn_flags & CNP_PDIRUNLOCK)
978 			vrele(fdvp);
979 		else
980 			vput(fdvp);
981 		return (0);
982 	}
983 	KKASSERT((fcnp->cn_flags & CNP_PDIRUNLOCK) == 0);
984 
985 	/*
986 	 * This case shouldn't occur
987 	 */
988 	if (fvp == NULL) {
989 		/*
990 		 * From name has disappeared.
991 		 */
992 		if (doingdirectory)
993 			panic("ext2_rename: lost dir entry");
994 		/* ip->i_flag only sets IN_RENAME if doingdirectory */
995 		vrele(ap->a_fvp);
996 		vput(fvp);
997 		vput(fdvp);
998 		return (0);
999 	}
1000 
1001 	/*
1002 	 * fvp and fdvp are both ref'd and locked.
1003 	 */
1004 	xp = VTOI(fvp);
1005 	dp = VTOI(fdvp);
1006 
1007 	/*
1008 	 * Ensure that the directory entry still exists and has not
1009 	 * changed while the new name has been entered. If the source is
1010 	 * a file then the entry may have been unlinked or renamed. In
1011 	 * either case there is no further work to be done. If the source
1012 	 * is a directory then it cannot have been rmdir'ed; its link
1013 	 * count of three would cause a rmdir to fail with ENOTEMPTY.
1014 	 * The IN_RENAME flag ensures that it cannot be moved by another
1015 	 * rename.
1016 	 */
1017 	if (xp != ip) {
1018 		/*
1019 		 * From name resolves to a different inode.  IN_RENAME is
1020 		 * not sufficient protection against timing window races
1021 		 * so we can't panic here.
1022 		 */
1023 	} else {
1024 		/*
1025 		 * If the source is a directory with a
1026 		 * new parent, the link count of the old
1027 		 * parent directory must be decremented
1028 		 * and ".." set to point to the new parent.
1029 		 */
1030 		if (doingdirectory && newparent) {
1031 			ext2_dec_nlink(dp);
1032 			dp->i_flag |= IN_CHANGE;
1033 			dirbuf = malloc(dp->i_e2fs->e2fs_bsize, M_TEMP, M_WAITOK | M_ZERO);
1034 			error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
1035 			    sizeof (struct dirtemplate), (off_t)0,
1036 			    UIO_SYSSPACE, IO_NODELOCKED,
1037 			    tcnp->cn_cred, NULL);
1038 			if (error == 0) {
1039 				/* Like ufs little-endian: */
1040 				namlen = dirbuf->dotdot_type;
1041 				if (namlen != 2 ||
1042 				    dirbuf->dotdot_name[0] != '.' ||
1043 				    dirbuf->dotdot_name[1] != '.') {
1044 					ext2_dirbad(xp, (doff_t)12,
1045 					    "rename: mangled dir");
1046 				} else {
1047 					dirbuf->dotdot_ino = htole32(newparent);
1048 					/*
1049 					 * dirblock 0 could be htree root,
1050 					 * try both csum update functions.
1051 					 */
1052 					ext2_dirent_csum_set(ip,
1053 					    (struct ext2fs_direct_2 *)dirbuf);
1054 					ext2_dx_csum_set(ip,
1055 					    (struct ext2fs_direct_2 *)dirbuf);
1056 					vn_rdwr(UIO_WRITE, fvp,
1057 					    (caddr_t)&dirbuf,
1058 					    sizeof (struct dirtemplate),
1059 					    (off_t)0, UIO_SYSSPACE,
1060 					    IO_NODELOCKED | IO_SYNC,
1061 					    tcnp->cn_cred, NULL);
1062 				}
1063 			}
1064 			free(dirbuf, M_TEMP);
1065 		}
1066 		error = ext2_dirremove(fdvp, fcnp);
1067 		if (!error) {
1068 			ext2_dec_nlink(xp);
1069 			xp->i_flag |= IN_CHANGE;
1070 		}
1071 		xp->i_flag &= ~IN_RENAME;
1072 	}
1073 	if (dp)
1074 		vput(fdvp);
1075 	if (xp)
1076 		vput(fvp);
1077 	vrele(ap->a_fvp);
1078 	return (error);
1079 
1080 bad:
1081 	if (xp)
1082 		vput(ITOV(xp));
1083 	vput(ITOV(dp));
1084 out:
1085 	if (doingdirectory)
1086 		ip->i_flag &= ~IN_RENAME;
1087 	if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
1088 		ext2_dec_nlink(ip);
1089 		ip->i_flag |= IN_CHANGE;
1090 		ip->i_flag &= ~IN_RENAME;
1091 		vput(fvp);
1092 	} else
1093 		vrele(fvp);
1094 	return (error);
1095 }
1096 
1097 /*
1098  * Mkdir system call
1099  */
1100 static int
1101 ext2_mkdir(struct vop_old_mkdir_args *ap)
1102 {
1103 	struct m_ext2fs *fs;
1104 	struct vnode *dvp = ap->a_dvp;
1105 	struct vattr *vap = ap->a_vap;
1106 	struct componentname *cnp = ap->a_cnp;
1107 	struct inode *ip, *dp;
1108 	struct vnode *tvp;
1109 	struct dirtemplate dirtemplate, *dtp;
1110 	char *buf = NULL;
1111 	int error, dmode;
1112 
1113 	dp = VTOI(dvp);
1114 	if ((nlink_t)dp->i_nlink >= EXT4_LINK_MAX &&
1115 	    !EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK)) {
1116 		error = EMLINK;
1117 		goto out;
1118 	}
1119 	dmode = vap->va_mode & 0777;
1120 	dmode |= IFDIR;
1121 	/*
1122 	 * Must simulate part of ext2_makeinode here to acquire the inode,
1123 	 * but not have it entered in the parent directory. The entry is
1124 	 * made later after writing "." and ".." entries.
1125 	 */
1126 	error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
1127 	if (error)
1128 		goto out;
1129 	ip = VTOI(tvp);
1130 	fs = ip->i_e2fs;
1131 	ip->i_gid = dp->i_gid;
1132 #ifdef SUIDDIR
1133 	{
1134 		/*
1135 		 * if we are hacking owners here, (only do this where told to)
1136 		 * and we are not giving it TOO root, (would subvert quotas)
1137 		 * then go ahead and give it to the other user.
1138 		 * The new directory also inherits the SUID bit.
1139 		 * If user's UID and dir UID are the same,
1140 		 * 'give it away' so that the SUID is still forced on.
1141 		 */
1142 		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1143 		    (dp->i_mode & ISUID) && dp->i_uid) {
1144 			dmode |= ISUID;
1145 			ip->i_uid = dp->i_uid;
1146 		} else {
1147 			ip->i_uid = cnp->cn_cred->cr_uid;
1148 		}
1149 	}
1150 #else
1151 	ip->i_uid = cnp->cn_cred->cr_uid;
1152 #endif
1153 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1154 	ip->i_mode = dmode;
1155 	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
1156 	ip->i_nlink = 2;
1157 	if (cnp->cn_flags & CNP_ISWHITEOUT)
1158 		ip->i_flags |= UF_OPAQUE;
1159 	error = ext2_update(tvp, 1);
1160 
1161 	/*
1162 	 * The vnode must have a VM object in order to issue buffer cache
1163 	 * ops on it.
1164 	 */
1165 	vinitvmio(tvp, 0, PAGE_SIZE, -1);
1166 
1167 	/*
1168 	 * Bump link count in parent directory
1169 	 * to reflect work done below.  Should
1170 	 * be done before reference is created
1171 	 * so reparation is possible if we crash.
1172 	 */
1173 	ext2_inc_nlink(dp);
1174 	dp->i_flag |= IN_CHANGE;
1175 	error = ext2_update(dvp, !DOINGASYNC(dvp));
1176 	if (error)
1177 		goto bad;
1178 
1179 	/* Initialize directory with "." and ".." from static template. */
1180 	if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1181 	    EXT2F_INCOMPAT_FTYPE))
1182 		dtp = &mastertemplate;
1183 	else
1184 		dtp = &omastertemplate;
1185 	dirtemplate = *dtp;
1186 	dirtemplate.dot_ino = htole32(ip->i_number);
1187 	dirtemplate.dotdot_ino = htole32(dp->i_number);
1188 	/*
1189 	 * note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE so let's
1190 	 * just redefine it - for this function only
1191 	 */
1192 #undef  DIRBLKSIZ
1193 #define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
1194 	dirtemplate.dotdot_reclen = htole16(DIRBLKSIZ - 12);
1195 	buf = malloc(DIRBLKSIZ, M_TEMP, M_WAITOK | M_ZERO);
1196 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
1197 		dirtemplate.dotdot_reclen =
1198 		    htole16(le16toh(dirtemplate.dotdot_reclen) -
1199 		    sizeof(struct ext2fs_direct_tail));
1200 		ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, DIRBLKSIZ));
1201 	}
1202 	memcpy(buf, &dirtemplate, sizeof(dirtemplate));
1203 	ext2_dirent_csum_set(ip, (struct ext2fs_direct_2 *)buf);
1204 	error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)buf,
1205 	    DIRBLKSIZ, (off_t)0, UIO_SYSSPACE,
1206 	    IO_NODELOCKED | IO_SYNC, cnp->cn_cred, NULL);
1207 	if (error) {
1208 		ext2_dec_nlink(dp);
1209 		dp->i_flag |= IN_CHANGE;
1210 		goto bad;
1211 	}
1212 	if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
1213 		/* XXX should grow with balloc() */
1214 		panic("ext2_mkdir: blksize");
1215 	else {
1216 		ip->i_size = DIRBLKSIZ;
1217 		ip->i_flag |= IN_CHANGE;
1218 	}
1219 
1220 	/* Directory set up, now install its entry in the parent directory. */
1221 	error = ext2_direnter(ip, dvp, cnp);
1222 	if (error) {
1223 		ext2_dec_nlink(dp);
1224 		dp->i_flag |= IN_CHANGE;
1225 	}
1226 bad:
1227 	/*
1228 	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
1229 	 * for us because we set the link count to 0.
1230 	 */
1231 	if (error) {
1232 		ip->i_nlink = 0;
1233 		ip->i_flag |= IN_CHANGE;
1234 		vput(tvp);
1235 	} else
1236 		*ap->a_vpp = tvp;
1237 out:
1238 	free(buf, M_TEMP);
1239 	return (error);
1240 #undef  DIRBLKSIZ
1241 #define DIRBLKSIZ  DEV_BSIZE
1242 }
1243 
1244 /*
1245  * Rmdir system call.
1246  */
1247 static int
1248 ext2_rmdir(struct vop_old_rmdir_args *ap)
1249 {
1250 	struct vnode *vp = ap->a_vp;
1251 	struct vnode *dvp = ap->a_dvp;
1252 	struct componentname *cnp = ap->a_cnp;
1253 	struct inode *ip, *dp;
1254 	int error;
1255 
1256 	ip = VTOI(vp);
1257 	dp = VTOI(dvp);
1258 
1259 	/*
1260 	 * Verify the directory is empty (and valid).
1261 	 * (Rmdir ".." won't be valid since
1262 	 *  ".." will contain a reference to
1263 	 *  the current directory and thus be
1264 	 *  non-empty.)
1265 	 */
1266 	if (!ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
1267 		error = ENOTEMPTY;
1268 		goto out;
1269 	}
1270 	if ((dp->i_flags & APPEND)
1271 	    || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1272 		error = EPERM;
1273 		goto out;
1274 	}
1275 	/*
1276 	 * Delete reference to directory before purging
1277 	 * inode.  If we crash in between, the directory
1278 	 * will be reattached to lost+found,
1279 	 */
1280 	error = ext2_dirremove(dvp, cnp);
1281 	if (error)
1282 		goto out;
1283 	ext2_dec_nlink(dp);
1284 	dp->i_flag |= IN_CHANGE;
1285 	vn_unlock(dvp);
1286 	/*
1287 	 * Truncate inode.  The only stuff left
1288 	 * in the directory is "." and "..".
1289 	 */
1290 	ip->i_nlink = 0;
1291 	error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred);
1292 	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1293 out:
1294 	return (error);
1295 }
1296 
1297 /*
1298  * symlink -- make a symbolic link
1299  */
1300 static int
1301 ext2_symlink(struct vop_old_symlink_args *ap)
1302 {
1303 	struct vnode *vp, **vpp = ap->a_vpp;
1304 	struct inode *ip;
1305 	int len, error;
1306 
1307 	error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
1308 	    vpp, ap->a_cnp);
1309 	if (error)
1310 		return (error);
1311 	vp = *vpp;
1312 	len = strlen(ap->a_target);
1313 	if (len < vp->v_mount->mnt_maxsymlinklen) {
1314 		ip = VTOI(vp);
1315 		bcopy(ap->a_target, (char *)ip->i_shortlink, len);
1316 		ip->i_size = len;
1317 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
1318 	} else {
1319 		/*
1320 		 * Make sure we have a VM object in order to use
1321 		 * the buffer cache.
1322 		 */
1323 		if (vp->v_object == NULL)
1324 			vinitvmio(vp, 0, PAGE_SIZE, -1);
1325 
1326 		error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
1327 		    UIO_SYSSPACE, IO_NODELOCKED, ap->a_cnp->cn_cred, NULL);
1328 	}
1329 	if (error)
1330 		vput(vp);
1331 	return (error);
1332 }
1333 
1334 /*
1335  * Return target name of a symbolic link
1336  */
1337 static int
1338 ext2_readlink(struct vop_readlink_args *ap)
1339 {
1340 	struct vnode *vp = ap->a_vp;
1341 	struct inode *ip = VTOI(vp);
1342 	int isize;
1343 
1344 	isize = ip->i_size;
1345 	if (isize < vp->v_mount->mnt_maxsymlinklen) {
1346 		uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
1347 		return (0);
1348 	}
1349 	return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
1350 }
1351 
1352 /*
1353  * Calculate the logical to physical mapping if not done already,
1354  * then call the device strategy routine.
1355  *
1356  * In order to be able to swap to a file, the ext2_bmaparray() operation may not
1357  * deadlock on memory.  See ext2_bmap() for details.
1358  */
1359 static int
1360 ext2_strategy(struct vop_strategy_args *ap)
1361 {
1362 	struct bio *bio = ap->a_bio;
1363 	struct bio *nbio;
1364 	struct buf *bp = bio->bio_buf;
1365 	struct vnode *vp = ap->a_vp;
1366 	struct inode *ip;
1367 	int error;
1368 
1369 	ip = VTOI(vp);
1370 	if (vp->v_type == VBLK || vp->v_type == VCHR)
1371 		panic("ext2_strategy: spec");
1372 	nbio = push_bio(bio);
1373 	if (nbio->bio_offset == NOOFFSET) {
1374 		error = VOP_BMAP(vp, bio->bio_offset, &nbio->bio_offset, NULL,
1375 		    NULL, bp->b_cmd);
1376 		if (error) {
1377 			bp->b_error = error;
1378 			bp->b_flags |= B_ERROR;
1379 			/* I/O was never started on nbio, must biodone(bio) */
1380 			biodone(bio);
1381 			return (error);
1382 		}
1383 		if (nbio->bio_offset == NOOFFSET)
1384 			vfs_bio_clrbuf(bp);
1385 	}
1386 	if (nbio->bio_offset == NOOFFSET) {
1387 		/* I/O was never started on nbio, must biodone(bio) */
1388 		biodone(bio);
1389 		return (0);
1390 	}
1391 	vn_strategy(ip->i_devvp, nbio);
1392 	return (0);
1393 }
1394 
1395 /*
1396  * Print out the contents of an inode.
1397  */
1398 static int
1399 ext2_print(struct vop_print_args *ap)
1400 {
1401 	struct vnode *vp = ap->a_vp;
1402 	struct inode *ip = VTOI(vp);
1403 
1404 	printf("tag VT_EXT2FS, ino %lu, on dev %s (%d, %d)",
1405 	    (u_long)ip->i_number, devtoname(ip->i_dev), major(ip->i_dev),
1406 	    minor(ip->i_dev));
1407 	if (vp->v_type == VFIFO)
1408 		fifo_printinfo(vp);
1409 	lockmgr_printinfo(&vp->v_lock);
1410 	printf("\n");
1411 	return (0);
1412 }
1413 
1414 /*
1415  * Read wrapper for fifos.
1416  */
1417 static
1418 int
1419 ext2fifo_read(struct vop_read_args *ap)
1420 {
1421 	int error, resid;
1422 	struct inode *ip;
1423 	struct uio *uio;
1424 
1425 	uio = ap->a_uio;
1426 	resid = uio->uio_resid;
1427 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1428 	ip = VTOI(ap->a_vp);
1429 	if ((ap->a_vp->v_mount->mnt_flag & MNT_NOATIME) == 0 && ip != NULL &&
1430 	    (uio->uio_resid != resid || (error == 0 && resid != 0)))
1431 		VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
1432 	return (error);
1433 }
1434 
1435 /*
1436  * Write wrapper for fifos.
1437  */
1438 static
1439 int
1440 ext2fifo_write(struct vop_write_args *ap)
1441 {
1442 	int error, resid;
1443 	struct inode *ip;
1444 	struct uio *uio;
1445 
1446 	uio = ap->a_uio;
1447 	resid = uio->uio_resid;
1448 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1449 	ip = VTOI(ap->a_vp);
1450 	if (ip != NULL && (uio->uio_resid != resid || (error == 0 && resid != 0)))
1451 		VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
1452 	return (error);
1453 }
1454 
1455 /*
1456  * Close wrapper for fifos.
1457  *
1458  * Update the times on the inode then do device close.
1459  */
1460 static int
1461 ext2fifo_close(struct vop_close_args *ap)
1462 {
1463 	struct vnode *vp = ap->a_vp;
1464 
1465 	if (VREFCNT(vp) > 1)
1466 		ext2_itimes(vp);
1467 	return (VOCALL(&fifo_vnode_vops, &ap->a_head));
1468 }
1469 
1470 static void
1471 filt_ext2detach(struct knote *kn)
1472 {
1473 	struct vnode *vp = (struct vnode *)kn->kn_hook;
1474 
1475 	lwkt_gettoken(&vp->v_token);
1476 	knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1477 	lwkt_reltoken(&vp->v_token);
1478 }
1479 
1480 /*ARGSUSED*/
1481 static int
1482 filt_ext2read(struct knote *kn, long hint)
1483 {
1484 	struct vnode *vp = (struct vnode *)kn->kn_hook;
1485 	struct inode *ip = VTOI(vp);
1486 	off_t off;
1487 
1488 	/*
1489 	 * filesystem is gone, so set the EOF flag and schedule
1490 	 * the knote for deletion.
1491 	 */
1492 	if (hint == NOTE_REVOKE) {
1493 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1494 		return (1);
1495 	}
1496         off = ip->i_size - kn->kn_fp->f_offset;
1497 	kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
1498 	if (kn->kn_sfflags & NOTE_OLDAPI)
1499 		return (1);
1500         return (kn->kn_data != 0);
1501 }
1502 
1503 /*ARGSUSED*/
1504 static int
1505 filt_ext2write(struct knote *kn, long hint)
1506 {
1507 	/*
1508 	 * filesystem is gone, so set the EOF flag and schedule
1509 	 * the knote for deletion.
1510 	 */
1511 	if (hint == NOTE_REVOKE)
1512 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1513 
1514         kn->kn_data = 0;
1515         return (1);
1516 }
1517 
1518 static int
1519 filt_ext2vnode(struct knote *kn, long hint)
1520 {
1521 	if (kn->kn_sfflags & hint)
1522 		kn->kn_fflags |= hint;
1523 	if (hint == NOTE_REVOKE) {
1524 		kn->kn_flags |= (EV_EOF | EV_NODATA);
1525 		return (1);
1526 	}
1527 	return (kn->kn_fflags != 0);
1528 }
1529 
1530 static struct filterops ext2read_filtops =
1531 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2read };
1532 static struct filterops ext2write_filtops =
1533 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2write };
1534 static struct filterops ext2vnode_filtops =
1535 	{ FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, filt_ext2detach, filt_ext2vnode };
1536 
1537 static int
1538 ext2_kqfilter(struct vop_kqfilter_args *ap)
1539 {
1540 	struct vnode *vp = ap->a_vp;
1541 	struct knote *kn = ap->a_kn;
1542 
1543 	switch (kn->kn_filter) {
1544 	case EVFILT_READ:
1545 		kn->kn_fop = &ext2read_filtops;
1546 		break;
1547 	case EVFILT_WRITE:
1548 		kn->kn_fop = &ext2write_filtops;
1549 		break;
1550 	case EVFILT_VNODE:
1551 		kn->kn_fop = &ext2vnode_filtops;
1552 		break;
1553 	default:
1554 		return (EOPNOTSUPP);
1555 	}
1556 
1557 	kn->kn_hook = (caddr_t)vp;
1558 
1559 	/* XXX: kq token actually protects the list */
1560 	lwkt_gettoken(&vp->v_token);
1561 	knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1562 	lwkt_reltoken(&vp->v_token);
1563 
1564 	return (0);
1565 }
1566 
1567 /*
1568  * Kqfilter wrapper for fifos.
1569  *
1570  * Fall through to ext2 kqfilter routines if needed
1571  */
1572 static int
1573 ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
1574 {
1575 	int error;
1576 
1577 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
1578 	if (error)
1579 		error = ext2_kqfilter(ap);
1580 	return (error);
1581 }
1582 
1583 /*
1584  * Return POSIX pathconf information applicable to ext2 filesystems.
1585  */
1586 static int
1587 ext2_pathconf(struct vop_pathconf_args *ap)
1588 {
1589 	int error = 0;
1590 
1591 	switch (ap->a_name) {
1592 	case _PC_LINK_MAX:
1593 		if (EXT2_HAS_RO_COMPAT_FEATURE(VTOI(ap->a_vp)->i_e2fs,
1594 		    EXT2F_ROCOMPAT_DIR_NLINK))
1595 			*ap->a_retval = INT_MAX;
1596 		else
1597 			*ap->a_retval = EXT4_LINK_MAX;
1598 		break;
1599 	case _PC_NAME_MAX:
1600 		*ap->a_retval = NAME_MAX;
1601 		break;
1602 	case _PC_PATH_MAX:
1603 		*ap->a_retval = PATH_MAX;
1604 		break;
1605 	case _PC_PIPE_BUF:
1606 		if (ap->a_vp->v_type == VDIR || ap->a_vp->v_type == VFIFO)
1607 			*ap->a_retval = PIPE_BUF;
1608 		else
1609 			error = EINVAL;
1610 		break;
1611 	case _PC_CHOWN_RESTRICTED:
1612 		*ap->a_retval = 1;
1613 		break;
1614 	case _PC_NO_TRUNC:
1615 		*ap->a_retval = 1;
1616 		break;
1617 	case _PC_MIN_HOLE_SIZE:
1618 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1619 		break;
1620 	case _PC_PRIO_IO:
1621 		*ap->a_retval = 0;
1622 		break;
1623 	case _PC_SYNC_IO:
1624 		*ap->a_retval = 0;
1625 		break;
1626 	case _PC_ALLOC_SIZE_MIN:
1627 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
1628 		break;
1629 	case _PC_FILESIZEBITS:
1630 		*ap->a_retval = 64;
1631 		break;
1632 	case _PC_REC_INCR_XFER_SIZE:
1633 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1634 		break;
1635 	case _PC_REC_MAX_XFER_SIZE:
1636 		*ap->a_retval = -1;	/* means ``unlimited'' */
1637 		break;
1638 	case _PC_REC_MIN_XFER_SIZE:
1639 		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1640 		break;
1641 	case _PC_REC_XFER_ALIGN:
1642 		*ap->a_retval = PAGE_SIZE;
1643 		break;
1644 	case _PC_SYMLINK_MAX:
1645 		*ap->a_retval = MAXPATHLEN;
1646 		break;
1647 
1648 	default:
1649 		error = vop_stdpathconf(ap);
1650 		break;
1651 	}
1652 	return (error);
1653 }
1654 
1655 /*
1656  * Initialize the vnode associated with a new inode, handle aliased vnodes.
1657  */
1658 int
1659 ext2_vinit(struct mount *mntp, struct vnode **vpp)
1660 {
1661 	struct inode *ip;
1662 	struct vnode *vp;
1663 
1664 	vp = *vpp;
1665 	ip = VTOI(vp);
1666 
1667 	switch (vp->v_type = IFTOVT(ip->i_mode)) {
1668 	case VCHR:
1669 	case VBLK:
1670 		vp->v_ops = &mntp->mnt_vn_spec_ops;
1671 		addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
1672 		break;
1673 	case VFIFO:
1674 		vp->v_ops = &mntp->mnt_vn_fifo_ops;
1675 		break;
1676 	case VDIR:
1677 	case VREG:
1678 		vinitvmio(vp, ip->i_size, PAGE_SIZE, -1); /* XXX */
1679 		break;
1680 	case VLNK:
1681 		if ((ip->i_size >= vp->v_mount->mnt_maxsymlinklen) &&
1682 		    ip->i_blocks != 0) {
1683 			vinitvmio(vp, ip->i_size, PAGE_SIZE, -1);
1684 		}
1685 		break;
1686 	default:
1687 		break;
1688 	}
1689 
1690 	/*
1691 	 * Only unallocated inodes should be of type VNON.
1692 	 */
1693 	if (ip->i_mode != 0 && vp->v_type == VNON)
1694 		return (EINVAL);
1695 
1696 	if (ip->i_number == EXT2_ROOTINO)
1697 		vp->v_flag |= VROOT;
1698 	/*
1699 	 * Initialize modrev times.
1700 	 */
1701 	ip->i_modrev = init_va_filerev();
1702 	*vpp = vp;
1703 	return (0);
1704 }
1705 
1706 /*
1707  * Allocate a new inode.
1708  */
1709 static int
1710 ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
1711     struct componentname *cnp)
1712 {
1713 	struct inode *ip, *pdir;
1714 	struct vnode *tvp;
1715 	int error;
1716 
1717 	pdir = VTOI(dvp);
1718 	*vpp = NULL;
1719 	if ((mode & IFMT) == 0)
1720 		mode |= IFREG;
1721 
1722 	error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
1723 	if (error) {
1724 		return (error);
1725 	}
1726 	ip = VTOI(tvp);
1727 	ip->i_gid = pdir->i_gid;
1728 #ifdef SUIDDIR
1729 	{
1730 		/*
1731 		 * if we are
1732 		 * not the owner of the directory,
1733 		 * and we are hacking owners here, (only do this where told to)
1734 		 * and we are not giving it TOO root, (would subvert quotas)
1735 		 * then go ahead and give it to the other user.
1736 		 * Note that this drops off the execute bits for security.
1737 		 */
1738 		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1739 		    (pdir->i_mode & ISUID) &&
1740 		    (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
1741 			ip->i_uid = pdir->i_uid;
1742 			mode &= ~07111;
1743 		} else {
1744 			ip->i_uid = cnp->cn_cred->cr_uid;
1745 		}
1746 	}
1747 #else
1748 	ip->i_uid = cnp->cn_cred->cr_uid;
1749 #endif
1750 	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1751 	ip->i_mode = mode;
1752 	tvp->v_type = IFTOVT(mode);	/* Rest init'd in getnewvnode(). */
1753 	ip->i_nlink = 1;
1754 	if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
1755 		if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
1756 			ip->i_mode &= ~ISGID;
1757 	}
1758 
1759 	if (cnp->cn_flags & CNP_ISWHITEOUT)
1760 		ip->i_flags |= UF_OPAQUE;
1761 
1762 	/*
1763 	 * Regular files and directories need VM objects.  Softlinks do
1764 	 * not (not immediately anyway).
1765 	 */
1766 	if (tvp->v_type == VREG || tvp->v_type == VDIR)
1767 		vinitvmio(tvp, 0, PAGE_SIZE, -1);
1768 
1769 	/*
1770 	 * Make sure inode goes to disk before directory entry.
1771 	 */
1772 	error = ext2_update(tvp, !DOINGASYNC(tvp));
1773 	if (error)
1774 		goto bad;
1775 
1776 	error = ext2_direnter(ip, dvp, cnp);
1777 	if (error)
1778 		goto bad;
1779 
1780 	*vpp = tvp;
1781 	return (0);
1782 
1783 bad:
1784 	/*
1785 	 * Write error occurred trying to update the inode
1786 	 * or the directory so must deallocate the inode.
1787 	 */
1788 	ip->i_nlink = 0;
1789 	ip->i_flag |= IN_CHANGE;
1790 	vput(tvp);
1791 	return (error);
1792 }
1793 
1794 /*
1795  * Vnode op for reading.
1796  */
1797 static int
1798 ext2_read(struct vop_read_args *ap)
1799 {
1800 	struct vnode *vp;
1801 	struct inode *ip;
1802 	struct uio *uio;
1803 	struct m_ext2fs *fs;
1804 	struct buf *bp;
1805 	daddr_t lbn;
1806 	off_t nextlbn;
1807 	off_t nextloffset;
1808 	off_t bytesinfile;
1809 	long size, xfersize, blkoffset;
1810 	int error, orig_resid, seqcount;
1811 	int ioflag;
1812 
1813 	vp = ap->a_vp;
1814 	uio = ap->a_uio;
1815 	ioflag = ap->a_ioflag;
1816 
1817 	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
1818 	ip = VTOI(vp);
1819 
1820 #ifdef INVARIANTS
1821 	if (uio->uio_rw != UIO_READ)
1822 		panic("%s: mode", "ext2_read");
1823 
1824 	if (vp->v_type == VLNK) {
1825 		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
1826 			panic("%s: short symlink", "ext2_read");
1827 	} else if (vp->v_type != VREG && vp->v_type != VDIR)
1828 		panic("%s: type %d", "ext2_read", vp->v_type);
1829 #endif
1830 	orig_resid = uio->uio_resid;
1831 	KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
1832 	if (orig_resid == 0)
1833 		return (0);
1834 	KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
1835 	fs = ip->i_e2fs;
1836 	if (uio->uio_offset < ip->i_size &&
1837 	    uio->uio_offset >= fs->e2fs_maxfilesize)
1838 		return (EOVERFLOW);
1839 
1840 	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
1841 		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1842 			break;
1843 		lbn = lblkno(fs, uio->uio_offset);
1844 		nextlbn = lbn + 1;
1845 		nextloffset = lblktodoff(fs, nextlbn);
1846 		size = blksize(fs, ip, lbn);
1847 		blkoffset = blkoff(fs, uio->uio_offset);
1848 
1849 		xfersize = fs->e2fs_fsize - blkoffset;
1850 		if (uio->uio_resid < xfersize)
1851 			xfersize = uio->uio_resid;
1852 		if (bytesinfile < xfersize)
1853 			xfersize = bytesinfile;
1854 
1855 		if (nextloffset >= ip->i_size)
1856 			error = bread(vp, lblktodoff(fs, lbn), size, &bp);
1857 		else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
1858 			error = cluster_read(vp, (off_t)ip->i_size,
1859 			    lblktodoff(fs, lbn), size, uio->uio_resid,
1860 			    (ap->a_ioflag >> IO_SEQSHIFT) * MAXBSIZE, &bp);
1861 		} else if (seqcount > 1) {
1862 			u_int nextsize = blksize(fs, ip, nextlbn);
1863 
1864 			error = breadn(vp, lblktodoff(fs, lbn), size,
1865 			    &nextloffset, &nextsize, 1, &bp);
1866 		} else
1867 			error = bread(vp, lblktodoff(fs, lbn), size, &bp);
1868 		if (error) {
1869 			brelse(bp);
1870 			bp = NULL;
1871 			break;
1872 		}
1873 
1874 		/*
1875 		 * We should only get non-zero b_resid when an I/O error
1876 		 * has occurred, which should cause us to break above.
1877 		 * However, if the short read did not cause an error,
1878 		 * then we want to ensure that we do not uiomove bad
1879 		 * or uninitialized data.
1880 		 */
1881 		size -= bp->b_resid;
1882 		if (size < xfersize) {
1883 			if (size == 0)
1884 				break;
1885 			xfersize = size;
1886 		}
1887 		error = uiomove((char *)bp->b_data + blkoffset,
1888 		    (int)xfersize, uio);
1889 		if (error)
1890 			break;
1891 		bqrelse(bp);
1892 	}
1893 
1894 	/*
1895 	 * This can only happen in the case of an error because the loop
1896 	 * above resets bp to NULL on each iteration and on normal
1897 	 * completion has not set a new value into it. so it must have come
1898 	 * from a 'break' statement
1899 	 */
1900 	if (bp != NULL)
1901 		bqrelse(bp);
1902 
1903 	if ((error == 0 || uio->uio_resid != orig_resid) &&
1904 	    (vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
1905 		ip->i_flag |= IN_ACCESS;
1906 	return (error);
1907 }
1908 
1909 /*
1910  * Vnode op for writing.
1911  */
1912 static int
1913 ext2_write(struct vop_write_args *ap)
1914 {
1915 	struct vnode *vp;
1916 	struct uio *uio;
1917 	struct inode *ip;
1918 	struct m_ext2fs *fs;
1919 	struct buf *bp;
1920 	struct thread *td;
1921 	daddr_t lbn;
1922 	off_t osize;
1923 	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
1924 
1925 	ioflag = ap->a_ioflag;
1926 	uio = ap->a_uio;
1927 	vp = ap->a_vp;
1928 
1929 	seqcount = ioflag >> IO_SEQSHIFT;
1930 	ip = VTOI(vp);
1931 
1932 #ifdef INVARIANTS
1933 	if (uio->uio_rw != UIO_WRITE)
1934 		panic("%s: mode", "ext2_write");
1935 #endif
1936 
1937 	switch (vp->v_type) {
1938 	case VREG:
1939 		if (ioflag & IO_APPEND)
1940 			uio->uio_offset = ip->i_size;
1941 		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
1942 			return (EPERM);
1943 		/* FALLTHROUGH */
1944 	case VLNK:
1945 		break;
1946 	case VDIR:
1947 		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
1948 		if ((ioflag & IO_SYNC) == 0)
1949 			panic("ext2_write: nonsync dir write");
1950 		break;
1951 	default:
1952 		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
1953 		    vp->v_type, (intmax_t)uio->uio_offset,
1954 		    (intmax_t)uio->uio_resid);
1955 	}
1956 
1957 	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
1958 	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
1959 	fs = ip->i_e2fs;
1960 	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
1961 		return (EFBIG);
1962 	/*
1963 	 * Maybe this should be above the vnode op call, but so long as
1964 	 * file servers have no limits, I don't think it matters.
1965 	 */
1966 	td = uio->uio_td;
1967 	if (vp->v_type == VREG && td && td->td_proc &&
1968 	    uio->uio_offset + uio->uio_resid >
1969 	    td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
1970 		lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
1971 		return (EFBIG);
1972 	}
1973 
1974 	resid = uio->uio_resid;
1975 	osize = ip->i_size;
1976 	if (seqcount > BA_SEQMAX)
1977 		flags = BA_SEQMAX << BA_SEQSHIFT;
1978 	else
1979 		flags = seqcount << BA_SEQSHIFT;
1980 	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
1981 		flags |= IO_SYNC;
1982 
1983 	for (error = 0; uio->uio_resid > 0;) {
1984 		lbn = lblkno(fs, uio->uio_offset);
1985 		blkoffset = blkoff(fs, uio->uio_offset);
1986 		xfersize = fs->e2fs_fsize - blkoffset;
1987 		if (uio->uio_resid < xfersize)
1988 			xfersize = uio->uio_resid;
1989 		if (uio->uio_offset + xfersize > ip->i_size)
1990 			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
1991 
1992 		/*
1993 		 * We must perform a read-before-write if the transfer size
1994 		 * does not cover the entire buffer.
1995 		 */
1996 		if (fs->e2fs_bsize > xfersize)
1997 			flags |= BA_CLRBUF;
1998 		else
1999 			flags &= ~BA_CLRBUF;
2000 		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
2001 		    ap->a_cred, &bp, flags);
2002 		if (error != 0)
2003 			break;
2004 
2005 		if ((ioflag & (IO_SYNC | IO_INVAL)) == (IO_SYNC | IO_INVAL))
2006 			bp->b_flags |= B_NOCACHE;
2007 		if (uio->uio_offset + xfersize > ip->i_size)
2008 			ip->i_size = uio->uio_offset + xfersize;
2009 		size = blksize(fs, ip, lbn) - bp->b_resid;
2010 		if (size < xfersize)
2011 			xfersize = size;
2012 
2013 		error =
2014 		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
2015 		if ((ioflag & IO_VMIO) &&
2016 		    LIST_FIRST(&bp->b_dep) == NULL) /* in ext2fs? */
2017 			bp->b_flags |= B_RELBUF;
2018 		/*
2019 		 * If the buffer is not already filled and we encounter an
2020 		 * error while trying to fill it, we have to clear out any
2021 		 * garbage data from the pages instantiated for the buffer.
2022 		 * If we do not, a failed uiomove() during a write can leave
2023 		 * the prior contents of the pages exposed to a userland mmap.
2024 		 *
2025 		 * Note that we need only clear buffers with a transfer size
2026 		 * equal to the block size because buffers with a shorter
2027 		 * transfer size were cleared above by the call to ext2_balloc()
2028 		 * with the BA_CLRBUF flag set.
2029 		 *
2030 		 * If the source region for uiomove identically mmaps the
2031 		 * buffer, uiomove() performed the NOP copy, and the buffer
2032 		 * content remains valid because the page fault handler
2033 		 * validated the pages.
2034 		 */
2035 		if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
2036 		    fs->e2fs_bsize == xfersize)
2037 			vfs_bio_clrbuf(bp);
2038 
2039 		/*
2040 		 * If IO_SYNC each buffer is written synchronously.  Otherwise
2041 		 * if we have a severe page deficiency write the buffer
2042 		 * asynchronously.  Otherwise try to cluster, and if that
2043 		 * doesn't do it then either do an async write (if O_DIRECT),
2044 		 * or a delayed write (if not).
2045 		 */
2046 		if (ioflag & IO_SYNC) {
2047 			(void)bwrite(bp);
2048 		} else if (vm_paging_severe() ||
2049 			   buf_dirty_count_severe() ||
2050 			   (ioflag & IO_ASYNC))
2051 		{
2052 			bp->b_flags |= B_CLUSTEROK;
2053 			bawrite(bp);
2054 		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
2055 			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
2056 				bp->b_flags |= B_CLUSTEROK;
2057 				cluster_write(bp, (off_t)ip->i_size,
2058 				    vp->v_mount->mnt_stat.f_iosize, seqcount);
2059 			} else {
2060 				bawrite(bp);
2061 			}
2062 		} else if (ioflag & IO_DIRECT) {
2063 			bp->b_flags |= B_CLUSTEROK;
2064 			bawrite(bp);
2065 		} else {
2066 			bp->b_flags |= B_CLUSTEROK;
2067 			bdwrite(bp);
2068 		}
2069 		if (error || xfersize == 0)
2070 			break;
2071 	}
2072 	/*
2073 	 * If we successfully wrote any data, and we are not the superuser
2074 	 * we clear the setuid and setgid bits as a precaution against
2075 	 * tampering.
2076 	 */
2077 	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
2078 	    ap->a_cred) {
2079 		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
2080 			ip->i_mode &= ~(ISUID | ISGID);
2081 	}
2082 	if (error) {
2083 		if (ioflag & IO_UNIT) {
2084 			(void)ext2_truncate(vp, osize, ioflag & IO_SYNC,
2085 			    ap->a_cred);
2086 			uio->uio_offset -= resid - uio->uio_resid;
2087 			uio->uio_resid = resid;
2088 		}
2089 	}
2090 	if (uio->uio_resid != resid) {
2091 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
2092 		if (ioflag & IO_SYNC)
2093 			error = ext2_update(vp, 1);
2094 	}
2095 	return (error);
2096 }
2097 
2098 /* Global vfs data structures for ext2. */
2099 struct vop_ops ext2_vnodeops = {
2100 	.vop_default =		vop_defaultop,
2101 	.vop_access =		ext2_access,
2102 	.vop_bmap =		ext2_bmap,
2103 	.vop_old_lookup =	ext2_lookup,
2104 	.vop_close =		ext2_close,
2105 	.vop_old_create =	ext2_create,
2106 	.vop_fsync =		ext2_fsync,
2107 	.vop_getpages =		vop_stdgetpages,
2108 	.vop_putpages =		vop_stdputpages,
2109 	.vop_getattr =		ext2_getattr,
2110 	.vop_inactive =		ext2_inactive,
2111 	.vop_old_link =		ext2_link,
2112 	.vop_old_lookup =	ext2_lookup,
2113 	.vop_old_mkdir =	ext2_mkdir,
2114 	.vop_old_mknod =	ext2_mknod,
2115 	.vop_open =		ext2_open,
2116 	.vop_pathconf =		ext2_pathconf,
2117 	.vop_print =		ext2_print,
2118 	.vop_read =		ext2_read,
2119 	.vop_readdir =		ext2_readdir,
2120 	.vop_readlink =		ext2_readlink,
2121 	.vop_reallocblks =	ext2_reallocblks,
2122 	.vop_reclaim =		ext2_reclaim,
2123 	.vop_old_remove =	ext2_remove,
2124 	.vop_old_rename =	ext2_rename,
2125 	.vop_old_rmdir =	ext2_rmdir,
2126 	.vop_setattr =		ext2_setattr,
2127 	.vop_strategy =		ext2_strategy,
2128 	.vop_old_symlink =	ext2_symlink,
2129 	.vop_write =		ext2_write,
2130 };
2131 
2132 struct vop_ops ext2_specops = {
2133 	.vop_default =		vop_defaultop,
2134 	.vop_access =		ext2_access,
2135 	.vop_close =		ext2_close,
2136 	.vop_fsync =		ext2_fsync,
2137 	.vop_getattr =		ext2_getattr,
2138 	.vop_inactive =		ext2_inactive,
2139 	.vop_pathconf =		ext2_pathconf,
2140 	.vop_print =		ext2_print,
2141 	.vop_read =		vop_stdnoread,
2142 	.vop_reclaim =		ext2_reclaim,
2143 	.vop_setattr =		ext2_setattr,
2144 	.vop_write =		vop_stdnowrite
2145 };
2146 
2147 struct vop_ops ext2_fifoops = {
2148 	.vop_default =		fifo_vnoperate,
2149 	.vop_access =		ext2_access,
2150 	.vop_close =		ext2fifo_close,
2151 	.vop_fsync =		ext2_fsync,
2152 	.vop_getattr =		ext2_getattr,
2153 	.vop_inactive =		ext2_inactive,
2154 	.vop_kqfilter =		ext2fifo_kqfilter,
2155 	.vop_pathconf =		ext2_pathconf,
2156 	.vop_print =		ext2_print,
2157 	.vop_read =		ext2fifo_read,
2158 	.vop_reclaim =		ext2_reclaim,
2159 	.vop_setattr =		ext2_setattr,
2160 	.vop_write =		ext2fifo_write
2161 };
2162 
2163 VNODEOP_SET(ext2_vnodeops);
2164 VNODEOP_SET(ext2_specops);
2165 VNODEOP_SET(ext2_fifoops);
2166