ext2_vnops.c revision 314937
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 * Copyright (c) 1982, 1986, 1989, 1993
9 *	The Regents of the University of California.  All rights reserved.
10 * (c) UNIX System Laboratories, Inc.
11 * All or some portions of this file are derived from material licensed
12 * to the University of California by American Telephone and Telegraph
13 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
14 * the permission of UNIX System Laboratories, Inc.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 *    notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 *    notice, this list of conditions and the following disclaimer in the
23 *    documentation and/or other materials provided with the distribution.
24 * 4. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 *	@(#)ufs_vnops.c	8.7 (Berkeley) 2/3/94
41 *	@(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
42 * $FreeBSD: stable/10/sys/fs/ext2fs/ext2_vnops.c 314937 2017-03-09 02:47:01Z pfg $
43 */
44
45#include "opt_suiddir.h"
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/stat.h>
53#include <sys/bio.h>
54#include <sys/buf.h>
55#include <sys/endian.h>
56#include <sys/priv.h>
57#include <sys/rwlock.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
68#include <vm/vm.h>
69#include <vm/vm_param.h>
70#include <vm/vm_extern.h>
71#include <vm/vm_object.h>
72#include <vm/vm_page.h>
73#include <vm/vm_pager.h>
74#include <vm/vnode_pager.h>
75
76#include "opt_directio.h"
77
78#include <ufs/ufs/dir.h>
79
80#include <fs/ext2fs/fs.h>
81#include <fs/ext2fs/inode.h>
82#include <fs/ext2fs/ext2_extern.h>
83#include <fs/ext2fs/ext2fs.h>
84#include <fs/ext2fs/ext2_dinode.h>
85#include <fs/ext2fs/ext2_dir.h>
86#include <fs/ext2fs/ext2_mount.h>
87
88static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
89static void ext2_itimes_locked(struct vnode *);
90static int ext4_ext_read(struct vop_read_args *);
91static int ext2_ind_read(struct vop_read_args *);
92
93static vop_access_t	ext2_access;
94static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
95static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
96    struct thread *);
97static vop_close_t	ext2_close;
98static vop_create_t	ext2_create;
99static vop_fsync_t	ext2_fsync;
100static vop_getpages_t	ext2_getpages;
101static vop_getattr_t	ext2_getattr;
102static vop_ioctl_t	ext2_ioctl;
103static vop_link_t	ext2_link;
104static vop_mkdir_t	ext2_mkdir;
105static vop_mknod_t	ext2_mknod;
106static vop_open_t	ext2_open;
107static vop_pathconf_t	ext2_pathconf;
108static vop_print_t	ext2_print;
109static vop_read_t	ext2_read;
110static vop_readlink_t	ext2_readlink;
111static vop_remove_t	ext2_remove;
112static vop_rename_t	ext2_rename;
113static vop_rmdir_t	ext2_rmdir;
114static vop_setattr_t	ext2_setattr;
115static vop_strategy_t	ext2_strategy;
116static vop_symlink_t	ext2_symlink;
117static vop_write_t	ext2_write;
118static vop_vptofh_t	ext2_vptofh;
119static vop_close_t	ext2fifo_close;
120static vop_kqfilter_t	ext2fifo_kqfilter;
121
122/* Global vfs data structures for ext2. */
123struct vop_vector ext2_vnodeops = {
124	.vop_default =		&default_vnodeops,
125	.vop_access =		ext2_access,
126	.vop_bmap =		ext2_bmap,
127	.vop_cachedlookup =	ext2_lookup,
128	.vop_close =		ext2_close,
129	.vop_create =		ext2_create,
130	.vop_fsync =		ext2_fsync,
131	.vop_getpages =		ext2_getpages,
132	.vop_getattr =		ext2_getattr,
133	.vop_inactive =		ext2_inactive,
134	.vop_ioctl =		ext2_ioctl,
135	.vop_link =		ext2_link,
136	.vop_lookup =		vfs_cache_lookup,
137	.vop_mkdir =		ext2_mkdir,
138	.vop_mknod =		ext2_mknod,
139	.vop_open =		ext2_open,
140	.vop_pathconf =		ext2_pathconf,
141	.vop_poll =		vop_stdpoll,
142	.vop_print =		ext2_print,
143	.vop_read =		ext2_read,
144	.vop_readdir =		ext2_readdir,
145	.vop_readlink =		ext2_readlink,
146	.vop_reallocblks =	ext2_reallocblks,
147	.vop_reclaim =		ext2_reclaim,
148	.vop_remove =		ext2_remove,
149	.vop_rename =		ext2_rename,
150	.vop_rmdir =		ext2_rmdir,
151	.vop_setattr =		ext2_setattr,
152	.vop_strategy =		ext2_strategy,
153	.vop_symlink =		ext2_symlink,
154	.vop_write =		ext2_write,
155	.vop_vptofh =		ext2_vptofh,
156};
157
158struct vop_vector ext2_fifoops = {
159	.vop_default =		&fifo_specops,
160	.vop_access =		ext2_access,
161	.vop_close =		ext2fifo_close,
162	.vop_fsync =		ext2_fsync,
163	.vop_getattr =		ext2_getattr,
164	.vop_inactive =		ext2_inactive,
165	.vop_kqfilter =		ext2fifo_kqfilter,
166	.vop_print =		ext2_print,
167	.vop_read =		VOP_PANIC,
168	.vop_reclaim =		ext2_reclaim,
169	.vop_setattr =		ext2_setattr,
170	.vop_write =		VOP_PANIC,
171	.vop_vptofh =		ext2_vptofh,
172};
173
174/*
175 * A virgin directory (no blushing please).
176 * Note that the type and namlen fields are reversed relative to ext2.
177 * Also, we don't use `struct odirtemplate', since it would just cause
178 * endianness problems.
179 */
180static struct dirtemplate mastertemplate = {
181	0, 12, 1, EXT2_FT_DIR, ".",
182	0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
183};
184static struct dirtemplate omastertemplate = {
185	0, 12, 1, EXT2_FT_UNKNOWN, ".",
186	0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
187};
188
189static void
190ext2_itimes_locked(struct vnode *vp)
191{
192	struct inode *ip;
193	struct timespec ts;
194
195	ASSERT_VI_LOCKED(vp, __func__);
196
197	ip = VTOI(vp);
198	if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
199		return;
200	if ((vp->v_type == VBLK || vp->v_type == VCHR))
201		ip->i_flag |= IN_LAZYMOD;
202	else
203		ip->i_flag |= IN_MODIFIED;
204	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
205		vfs_timestamp(&ts);
206		if (ip->i_flag & IN_ACCESS) {
207			ip->i_atime = ts.tv_sec;
208			ip->i_atimensec = ts.tv_nsec;
209		}
210		if (ip->i_flag & IN_UPDATE) {
211			ip->i_mtime = ts.tv_sec;
212			ip->i_mtimensec = ts.tv_nsec;
213			ip->i_modrev++;
214		}
215		if (ip->i_flag & IN_CHANGE) {
216			ip->i_ctime = ts.tv_sec;
217			ip->i_ctimensec = ts.tv_nsec;
218		}
219	}
220	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
221}
222
223void
224ext2_itimes(struct vnode *vp)
225{
226
227	VI_LOCK(vp);
228	ext2_itimes_locked(vp);
229	VI_UNLOCK(vp);
230}
231
232/*
233 * Create a regular file
234 */
235static int
236ext2_create(struct vop_create_args *ap)
237{
238	int error;
239
240	error =
241	    ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
242	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
243	if (error != 0)
244		return (error);
245	if ((ap->a_cnp->cn_flags & MAKEENTRY) != 0)
246		cache_enter(ap->a_dvp, *ap->a_vpp, ap->a_cnp);
247	return (0);
248}
249
250static int
251ext2_open(struct vop_open_args *ap)
252{
253
254	if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
255		return (EOPNOTSUPP);
256
257	/*
258	 * Files marked append-only must be opened for appending.
259	 */
260	if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
261	    (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
262		return (EPERM);
263
264	vnode_create_vobject(ap->a_vp, VTOI(ap->a_vp)->i_size, ap->a_td);
265
266	return (0);
267}
268
269/*
270 * Close called.
271 *
272 * Update the times on the inode.
273 */
274static int
275ext2_close(struct vop_close_args *ap)
276{
277	struct vnode *vp = ap->a_vp;
278
279	VI_LOCK(vp);
280	if (vp->v_usecount > 1)
281		ext2_itimes_locked(vp);
282	VI_UNLOCK(vp);
283	return (0);
284}
285
286static int
287ext2_access(struct vop_access_args *ap)
288{
289	struct vnode *vp = ap->a_vp;
290	struct inode *ip = VTOI(vp);
291	accmode_t accmode = ap->a_accmode;
292	int error;
293
294	if (vp->v_type == VBLK || vp->v_type == VCHR)
295		return (EOPNOTSUPP);
296
297	/*
298	 * Disallow write attempts on read-only file systems;
299	 * unless the file is a socket, fifo, or a block or
300	 * character device resident on the file system.
301	 */
302	if (accmode & VWRITE) {
303		switch (vp->v_type) {
304		case VDIR:
305		case VLNK:
306		case VREG:
307			if (vp->v_mount->mnt_flag & MNT_RDONLY)
308				return (EROFS);
309			break;
310		default:
311			break;
312		}
313	}
314
315	/* If immutable bit set, nobody gets to write it. */
316	if ((accmode & VWRITE) && (ip->i_flags & (SF_IMMUTABLE | SF_SNAPSHOT)))
317		return (EPERM);
318
319	error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
320	    ap->a_accmode, ap->a_cred, NULL);
321	return (error);
322}
323
324static int
325ext2_getattr(struct vop_getattr_args *ap)
326{
327	struct vnode *vp = ap->a_vp;
328	struct inode *ip = VTOI(vp);
329	struct vattr *vap = ap->a_vap;
330
331	ext2_itimes(vp);
332	/*
333	 * Copy from inode table
334	 */
335	vap->va_fsid = dev2udev(ip->i_devvp->v_rdev);
336	vap->va_fileid = ip->i_number;
337	vap->va_mode = ip->i_mode & ~IFMT;
338	vap->va_nlink = ip->i_nlink;
339	vap->va_uid = ip->i_uid;
340	vap->va_gid = ip->i_gid;
341	vap->va_rdev = ip->i_rdev;
342	vap->va_size = ip->i_size;
343	vap->va_atime.tv_sec = ip->i_atime;
344	vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
345	vap->va_mtime.tv_sec = ip->i_mtime;
346	vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
347	vap->va_ctime.tv_sec = ip->i_ctime;
348	vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
349	if E2DI_HAS_XTIME(ip) {
350		vap->va_birthtime.tv_sec = ip->i_birthtime;
351		vap->va_birthtime.tv_nsec = ip->i_birthnsec;
352	}
353	vap->va_flags = ip->i_flags;
354	vap->va_gen = ip->i_gen;
355	vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
356	vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
357	vap->va_type = IFTOVT(ip->i_mode);
358	vap->va_filerev = ip->i_modrev;
359	return (0);
360}
361
362/*
363 * Set attribute vnode op. called from several syscalls
364 */
365static int
366ext2_setattr(struct vop_setattr_args *ap)
367{
368	struct vattr *vap = ap->a_vap;
369	struct vnode *vp = ap->a_vp;
370	struct inode *ip = VTOI(vp);
371	struct ucred *cred = ap->a_cred;
372	struct thread *td = curthread;
373	int error;
374
375	/*
376	 * Check for unsettable attributes.
377	 */
378	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
379	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
380	    (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
381	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
382		return (EINVAL);
383	}
384	if (vap->va_flags != VNOVAL) {
385		/* Disallow flags not supported by ext2fs. */
386		if (vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
387			return (EOPNOTSUPP);
388
389		if (vp->v_mount->mnt_flag & MNT_RDONLY)
390			return (EROFS);
391		/*
392		 * Callers may only modify the file flags on objects they
393		 * have VADMIN rights for.
394		 */
395		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
396			return (error);
397		/*
398		 * Unprivileged processes and privileged processes in
399		 * jail() are not permitted to unset system flags, or
400		 * modify flags if any system flags are set.
401		 * Privileged non-jail processes may not modify system flags
402		 * if securelevel > 0 and any existing system flags are set.
403		 */
404		if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
405			if (ip->i_flags & (SF_IMMUTABLE | SF_APPEND)) {
406				error = securelevel_gt(cred, 0);
407				if (error)
408					return (error);
409			}
410		} else {
411			if (ip->i_flags & (SF_IMMUTABLE | SF_APPEND) ||
412			    ((vap->va_flags ^ ip->i_flags) & SF_SETTABLE))
413				return (EPERM);
414		}
415		ip->i_flags = vap->va_flags;
416		ip->i_flag |= IN_CHANGE;
417		if (ip->i_flags & (IMMUTABLE | APPEND))
418			return (0);
419	}
420	if (ip->i_flags & (IMMUTABLE | APPEND))
421		return (EPERM);
422	/*
423	 * Go through the fields and update iff not VNOVAL.
424	 */
425	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
426		if (vp->v_mount->mnt_flag & MNT_RDONLY)
427			return (EROFS);
428		if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
429		    td)) != 0)
430			return (error);
431	}
432	if (vap->va_size != VNOVAL) {
433		/*
434		 * Disallow write attempts on read-only file systems;
435		 * unless the file is a socket, fifo, or a block or
436		 * character device resident on the file system.
437		 */
438		switch (vp->v_type) {
439		case VDIR:
440			return (EISDIR);
441		case VLNK:
442		case VREG:
443			if (vp->v_mount->mnt_flag & MNT_RDONLY)
444				return (EROFS);
445			break;
446		default:
447			break;
448		}
449		if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
450			return (error);
451	}
452	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
453		if (vp->v_mount->mnt_flag & MNT_RDONLY)
454			return (EROFS);
455		/*
456		 * From utimes(2):
457		 * If times is NULL, ... The caller must be the owner of
458		 * the file, have permission to write the file, or be the
459		 * super-user.
460		 * If times is non-NULL, ... The caller must be the owner of
461		 * the file or be the super-user.
462		 */
463		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
464		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
465		    (error = VOP_ACCESS(vp, VWRITE, cred, td))))
466			return (error);
467		ip->i_flag |= IN_CHANGE | IN_MODIFIED;
468		if (vap->va_atime.tv_sec != VNOVAL) {
469			ip->i_flag &= ~IN_ACCESS;
470			ip->i_atime = vap->va_atime.tv_sec;
471			ip->i_atimensec = vap->va_atime.tv_nsec;
472		}
473		if (vap->va_mtime.tv_sec != VNOVAL) {
474			ip->i_flag &= ~IN_UPDATE;
475			ip->i_mtime = vap->va_mtime.tv_sec;
476			ip->i_mtimensec = vap->va_mtime.tv_nsec;
477		}
478		ip->i_birthtime = vap->va_birthtime.tv_sec;
479		ip->i_birthnsec = vap->va_birthtime.tv_nsec;
480		error = ext2_update(vp, 0);
481		if (error)
482			return (error);
483	}
484	error = 0;
485	if (vap->va_mode != (mode_t)VNOVAL) {
486		if (vp->v_mount->mnt_flag & MNT_RDONLY)
487			return (EROFS);
488		error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
489	}
490	return (error);
491}
492
493/*
494 * Change the mode on a file.
495 * Inode must be locked before calling.
496 */
497static int
498ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
499{
500	struct inode *ip = VTOI(vp);
501	int error;
502
503	/*
504	 * To modify the permissions on a file, must possess VADMIN
505	 * for that file.
506	 */
507	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
508		return (error);
509	/*
510	 * Privileged processes may set the sticky bit on non-directories,
511	 * as well as set the setgid bit on a file with a group that the
512	 * process is not a member of.
513	 */
514	if (vp->v_type != VDIR && (mode & S_ISTXT)) {
515		error = priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0);
516		if (error)
517			return (EFTYPE);
518	}
519	if (!groupmember(ip->i_gid, cred) && (mode & ISGID)) {
520		error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
521		if (error)
522			return (error);
523	}
524	ip->i_mode &= ~ALLPERMS;
525	ip->i_mode |= (mode & ALLPERMS);
526	ip->i_flag |= IN_CHANGE;
527	return (0);
528}
529
530/*
531 * Perform chown operation on inode ip;
532 * inode must be locked prior to call.
533 */
534static int
535ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
536    struct thread *td)
537{
538	struct inode *ip = VTOI(vp);
539	uid_t ouid;
540	gid_t ogid;
541	int error = 0;
542
543	if (uid == (uid_t)VNOVAL)
544		uid = ip->i_uid;
545	if (gid == (gid_t)VNOVAL)
546		gid = ip->i_gid;
547	/*
548	 * To modify the ownership of a file, must possess VADMIN
549	 * for that file.
550	 */
551	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
552		return (error);
553	/*
554	 * To change the owner of a file, or change the group of a file
555	 * to a group of which we are not a member, the caller must
556	 * have privilege.
557	 */
558	if (uid != ip->i_uid || (gid != ip->i_gid &&
559	    !groupmember(gid, cred))) {
560		error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
561		if (error)
562			return (error);
563	}
564	ogid = ip->i_gid;
565	ouid = ip->i_uid;
566	ip->i_gid = gid;
567	ip->i_uid = uid;
568	ip->i_flag |= IN_CHANGE;
569	if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
570		if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
571			ip->i_mode &= ~(ISUID | ISGID);
572	}
573	return (0);
574}
575
576/*
577 * Synch an open file.
578 */
579/* ARGSUSED */
580static int
581ext2_fsync(struct vop_fsync_args *ap)
582{
583	/*
584	 * Flush all dirty buffers associated with a vnode.
585	 */
586
587	vop_stdfsync(ap);
588
589	return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
590}
591
592/*
593 * Mknod vnode call
594 */
595/* ARGSUSED */
596static int
597ext2_mknod(struct vop_mknod_args *ap)
598{
599	struct vattr *vap = ap->a_vap;
600	struct vnode **vpp = ap->a_vpp;
601	struct inode *ip;
602	ino_t ino;
603	int error;
604
605	error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
606	    ap->a_dvp, vpp, ap->a_cnp);
607	if (error)
608		return (error);
609	ip = VTOI(*vpp);
610	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
611	if (vap->va_rdev != VNOVAL) {
612		/*
613		 * Want to be able to use this to make badblock
614		 * inodes, so don't truncate the dev number.
615		 */
616		ip->i_rdev = vap->va_rdev;
617	}
618	/*
619	 * Remove inode, then reload it through VFS_VGET so it is
620	 * checked to see if it is an alias of an existing entry in
621	 * the inode cache.	 XXX I don't believe this is necessary now.
622	 */
623	(*vpp)->v_type = VNON;
624	ino = ip->i_number;	/* Save this before vgone() invalidates ip. */
625	vgone(*vpp);
626	vput(*vpp);
627	error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
628	if (error) {
629		*vpp = NULL;
630		return (error);
631	}
632	return (0);
633}
634
635static int
636ext2_remove(struct vop_remove_args *ap)
637{
638	struct inode *ip;
639	struct vnode *vp = ap->a_vp;
640	struct vnode *dvp = ap->a_dvp;
641	int error;
642
643	ip = VTOI(vp);
644	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
645	    (VTOI(dvp)->i_flags & APPEND)) {
646		error = EPERM;
647		goto out;
648	}
649	error = ext2_dirremove(dvp, ap->a_cnp);
650	if (error == 0) {
651		ip->i_nlink--;
652		ip->i_flag |= IN_CHANGE;
653	}
654out:
655	return (error);
656}
657
658/*
659 * link vnode call
660 */
661static int
662ext2_link(struct vop_link_args *ap)
663{
664	struct vnode *vp = ap->a_vp;
665	struct vnode *tdvp = ap->a_tdvp;
666	struct componentname *cnp = ap->a_cnp;
667	struct inode *ip;
668	int error;
669
670#ifdef INVARIANTS
671	if ((cnp->cn_flags & HASBUF) == 0)
672		panic("ext2_link: no name");
673#endif
674	ip = VTOI(vp);
675	if ((nlink_t)ip->i_nlink >= EXT2_LINK_MAX) {
676		error = EMLINK;
677		goto out;
678	}
679	if (ip->i_flags & (IMMUTABLE | APPEND)) {
680		error = EPERM;
681		goto out;
682	}
683	ip->i_nlink++;
684	ip->i_flag |= IN_CHANGE;
685	error = ext2_update(vp, !DOINGASYNC(vp));
686	if (!error)
687		error = ext2_direnter(ip, tdvp, cnp);
688	if (error) {
689		ip->i_nlink--;
690		ip->i_flag |= IN_CHANGE;
691	}
692out:
693	return (error);
694}
695
696/*
697 * Rename system call.
698 * 	rename("foo", "bar");
699 * is essentially
700 *	unlink("bar");
701 *	link("foo", "bar");
702 *	unlink("foo");
703 * but ``atomically''.  Can't do full commit without saving state in the
704 * inode on disk which isn't feasible at this time.  Best we can do is
705 * always guarantee the target exists.
706 *
707 * Basic algorithm is:
708 *
709 * 1) Bump link count on source while we're linking it to the
710 *    target.  This also ensure the inode won't be deleted out
711 *    from underneath us while we work (it may be truncated by
712 *    a concurrent `trunc' or `open' for creation).
713 * 2) Link source to destination.  If destination already exists,
714 *    delete it first.
715 * 3) Unlink source reference to inode if still around. If a
716 *    directory was moved and the parent of the destination
717 *    is different from the source, patch the ".." entry in the
718 *    directory.
719 */
720static int
721ext2_rename(struct vop_rename_args *ap)
722{
723	struct vnode *tvp = ap->a_tvp;
724	struct vnode *tdvp = ap->a_tdvp;
725	struct vnode *fvp = ap->a_fvp;
726	struct vnode *fdvp = ap->a_fdvp;
727	struct componentname *tcnp = ap->a_tcnp;
728	struct componentname *fcnp = ap->a_fcnp;
729	struct inode *ip, *xp, *dp;
730	struct dirtemplate dirbuf;
731	int doingdirectory = 0, oldparent = 0, newparent = 0;
732	int error = 0;
733	u_char namlen;
734
735#ifdef INVARIANTS
736	if ((tcnp->cn_flags & HASBUF) == 0 ||
737	    (fcnp->cn_flags & HASBUF) == 0)
738		panic("ext2_rename: no name");
739#endif
740	/*
741	 * Check for cross-device rename.
742	 */
743	if ((fvp->v_mount != tdvp->v_mount) ||
744	    (tvp && (fvp->v_mount != tvp->v_mount))) {
745		error = EXDEV;
746abortit:
747		if (tdvp == tvp)
748			vrele(tdvp);
749		else
750			vput(tdvp);
751		if (tvp)
752			vput(tvp);
753		vrele(fdvp);
754		vrele(fvp);
755		return (error);
756	}
757
758	if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
759	    (VTOI(tdvp)->i_flags & APPEND))) {
760		error = EPERM;
761		goto abortit;
762	}
763
764	/*
765	 * Renaming a file to itself has no effect.  The upper layers should
766	 * not call us in that case.  Temporarily just warn if they do.
767	 */
768	if (fvp == tvp) {
769		printf("ext2_rename: fvp == tvp (can't happen)\n");
770		error = 0;
771		goto abortit;
772	}
773
774	if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
775		goto abortit;
776	dp = VTOI(fdvp);
777	ip = VTOI(fvp);
778	if (ip->i_nlink >= EXT2_LINK_MAX) {
779		VOP_UNLOCK(fvp, 0);
780		error = EMLINK;
781		goto abortit;
782	}
783	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
784	    || (dp->i_flags & APPEND)) {
785		VOP_UNLOCK(fvp, 0);
786		error = EPERM;
787		goto abortit;
788	}
789	if ((ip->i_mode & IFMT) == IFDIR) {
790		/*
791		 * Avoid ".", "..", and aliases of "." for obvious reasons.
792		 */
793		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
794		    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
795		    (ip->i_flag & IN_RENAME)) {
796			VOP_UNLOCK(fvp, 0);
797			error = EINVAL;
798			goto abortit;
799		}
800		ip->i_flag |= IN_RENAME;
801		oldparent = dp->i_number;
802		doingdirectory++;
803	}
804	vrele(fdvp);
805
806	/*
807	 * When the target exists, both the directory
808	 * and target vnodes are returned locked.
809	 */
810	dp = VTOI(tdvp);
811	xp = NULL;
812	if (tvp)
813		xp = VTOI(tvp);
814
815	/*
816	 * 1) Bump link count while we're moving stuff
817	 *    around.  If we crash somewhere before
818	 *    completing our work, the link count
819	 *    may be wrong, but correctable.
820	 */
821	ip->i_nlink++;
822	ip->i_flag |= IN_CHANGE;
823	if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
824		VOP_UNLOCK(fvp, 0);
825		goto bad;
826	}
827
828	/*
829	 * If ".." must be changed (ie the directory gets a new
830	 * parent) then the source directory must not be in the
831	 * directory hierarchy above the target, as this would
832	 * orphan everything below the source directory. Also
833	 * the user must have write permission in the source so
834	 * as to be able to change "..". We must repeat the call
835	 * to namei, as the parent directory is unlocked by the
836	 * call to checkpath().
837	 */
838	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
839	VOP_UNLOCK(fvp, 0);
840	if (oldparent != dp->i_number)
841		newparent = dp->i_number;
842	if (doingdirectory && newparent) {
843		if (error)	/* write access check above */
844			goto bad;
845		if (xp != NULL)
846			vput(tvp);
847		error = ext2_checkpath(ip, dp, tcnp->cn_cred);
848		if (error)
849			goto out;
850		VREF(tdvp);
851		error = relookup(tdvp, &tvp, tcnp);
852		if (error)
853			goto out;
854		vrele(tdvp);
855		dp = VTOI(tdvp);
856		xp = NULL;
857		if (tvp)
858			xp = VTOI(tvp);
859	}
860	/*
861	 * 2) If target doesn't exist, link the target
862	 *    to the source and unlink the source.
863	 *    Otherwise, rewrite the target directory
864	 *    entry to reference the source inode and
865	 *    expunge the original entry's existence.
866	 */
867	if (xp == NULL) {
868		if (dp->i_devvp != ip->i_devvp)
869			panic("ext2_rename: EXDEV");
870		/*
871		 * Account for ".." in new directory.
872		 * When source and destination have the same
873		 * parent we don't fool with the link count.
874		 */
875		if (doingdirectory && newparent) {
876			if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
877				error = EMLINK;
878				goto bad;
879			}
880			dp->i_nlink++;
881			dp->i_flag |= IN_CHANGE;
882			error = ext2_update(tdvp, !DOINGASYNC(tdvp));
883			if (error)
884				goto bad;
885		}
886		error = ext2_direnter(ip, tdvp, tcnp);
887		if (error) {
888			if (doingdirectory && newparent) {
889				dp->i_nlink--;
890				dp->i_flag |= IN_CHANGE;
891				(void)ext2_update(tdvp, 1);
892			}
893			goto bad;
894		}
895		vput(tdvp);
896	} else {
897		if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
898			panic("ext2_rename: EXDEV");
899		/*
900		 * Short circuit rename(foo, foo).
901		 */
902		if (xp->i_number == ip->i_number)
903			panic("ext2_rename: same file");
904		/*
905		 * If the parent directory is "sticky", then the user must
906		 * own the parent directory, or the destination of the rename,
907		 * otherwise the destination may not be changed (except by
908		 * root). This implements append-only directories.
909		 */
910		if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
911		    tcnp->cn_cred->cr_uid != dp->i_uid &&
912		    xp->i_uid != tcnp->cn_cred->cr_uid) {
913			error = EPERM;
914			goto bad;
915		}
916		/*
917		 * Target must be empty if a directory and have no links
918		 * to it. Also, ensure source and target are compatible
919		 * (both directories, or both not directories).
920		 */
921		if ((xp->i_mode & IFMT) == IFDIR) {
922			if (!ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) ||
923			    xp->i_nlink > 2) {
924				error = ENOTEMPTY;
925				goto bad;
926			}
927			if (!doingdirectory) {
928				error = ENOTDIR;
929				goto bad;
930			}
931			cache_purge(tdvp);
932		} else if (doingdirectory) {
933			error = EISDIR;
934			goto bad;
935		}
936		error = ext2_dirrewrite(dp, ip, tcnp);
937		if (error)
938			goto bad;
939		/*
940		 * If the target directory is in the same
941		 * directory as the source directory,
942		 * decrement the link count on the parent
943		 * of the target directory.
944		 */
945		if (doingdirectory && !newparent) {
946			dp->i_nlink--;
947			dp->i_flag |= IN_CHANGE;
948		}
949		vput(tdvp);
950		/*
951		 * Adjust the link count of the target to
952		 * reflect the dirrewrite above.  If this is
953		 * a directory it is empty and there are
954		 * no links to it, so we can squash the inode and
955		 * any space associated with it.  We disallowed
956		 * renaming over top of a directory with links to
957		 * it above, as the remaining link would point to
958		 * a directory without "." or ".." entries.
959		 */
960		xp->i_nlink--;
961		if (doingdirectory) {
962			if (--xp->i_nlink != 0)
963				panic("ext2_rename: linked directory");
964			error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
965			    tcnp->cn_cred, tcnp->cn_thread);
966		}
967		xp->i_flag |= IN_CHANGE;
968		vput(tvp);
969		xp = NULL;
970	}
971
972	/*
973	 * 3) Unlink the source.
974	 */
975	fcnp->cn_flags &= ~MODMASK;
976	fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
977	VREF(fdvp);
978	error = relookup(fdvp, &fvp, fcnp);
979	if (error == 0)
980		vrele(fdvp);
981	if (fvp != NULL) {
982		xp = VTOI(fvp);
983		dp = VTOI(fdvp);
984	} else {
985		/*
986		 * From name has disappeared.  IN_RENAME is not sufficient
987		 * to protect against directory races due to timing windows,
988		 * so we can't panic here.
989		 */
990		vrele(ap->a_fvp);
991		return (0);
992	}
993	/*
994	 * Ensure that the directory entry still exists and has not
995	 * changed while the new name has been entered. If the source is
996	 * a file then the entry may have been unlinked or renamed. In
997	 * either case there is no further work to be done. If the source
998	 * is a directory then it cannot have been rmdir'ed; its link
999	 * count of three would cause a rmdir to fail with ENOTEMPTY.
1000	 * The IN_RENAME flag ensures that it cannot be moved by another
1001	 * rename.
1002	 */
1003	if (xp != ip) {
1004		/*
1005		 * From name resolves to a different inode.  IN_RENAME is
1006		 * not sufficient protection against timing window races
1007		 * so we can't panic here.
1008		 */
1009	} else {
1010		/*
1011		 * If the source is a directory with a
1012		 * new parent, the link count of the old
1013		 * parent directory must be decremented
1014		 * and ".." set to point to the new parent.
1015		 */
1016		if (doingdirectory && newparent) {
1017			dp->i_nlink--;
1018			dp->i_flag |= IN_CHANGE;
1019			error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
1020			    sizeof(struct dirtemplate), (off_t)0,
1021			    UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
1022			    tcnp->cn_cred, NOCRED, NULL, NULL);
1023			if (error == 0) {
1024				/* Like ufs little-endian: */
1025				namlen = dirbuf.dotdot_type;
1026				if (namlen != 2 ||
1027				    dirbuf.dotdot_name[0] != '.' ||
1028				    dirbuf.dotdot_name[1] != '.') {
1029					ext2_dirbad(xp, (doff_t)12,
1030					    "rename: mangled dir");
1031				} else {
1032					dirbuf.dotdot_ino = newparent;
1033					(void)vn_rdwr(UIO_WRITE, fvp,
1034					    (caddr_t)&dirbuf,
1035					    sizeof(struct dirtemplate),
1036					    (off_t)0, UIO_SYSSPACE,
1037					    IO_NODELOCKED | IO_SYNC |
1038					    IO_NOMACCHECK, tcnp->cn_cred,
1039					    NOCRED, NULL, NULL);
1040					cache_purge(fdvp);
1041				}
1042			}
1043		}
1044		error = ext2_dirremove(fdvp, fcnp);
1045		if (!error) {
1046			xp->i_nlink--;
1047			xp->i_flag |= IN_CHANGE;
1048		}
1049		xp->i_flag &= ~IN_RENAME;
1050	}
1051	if (dp)
1052		vput(fdvp);
1053	if (xp)
1054		vput(fvp);
1055	vrele(ap->a_fvp);
1056	return (error);
1057
1058bad:
1059	if (xp)
1060		vput(ITOV(xp));
1061	vput(ITOV(dp));
1062out:
1063	if (doingdirectory)
1064		ip->i_flag &= ~IN_RENAME;
1065	if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
1066		ip->i_nlink--;
1067		ip->i_flag |= IN_CHANGE;
1068		ip->i_flag &= ~IN_RENAME;
1069		vput(fvp);
1070	} else
1071		vrele(fvp);
1072	return (error);
1073}
1074
1075/*
1076 * Mkdir system call
1077 */
1078static int
1079ext2_mkdir(struct vop_mkdir_args *ap)
1080{
1081	struct vnode *dvp = ap->a_dvp;
1082	struct vattr *vap = ap->a_vap;
1083	struct componentname *cnp = ap->a_cnp;
1084	struct inode *ip, *dp;
1085	struct vnode *tvp;
1086	struct dirtemplate dirtemplate, *dtp;
1087	int error, dmode;
1088
1089#ifdef INVARIANTS
1090	if ((cnp->cn_flags & HASBUF) == 0)
1091		panic("ext2_mkdir: no name");
1092#endif
1093	dp = VTOI(dvp);
1094	if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
1095		error = EMLINK;
1096		goto out;
1097	}
1098	dmode = vap->va_mode & 0777;
1099	dmode |= IFDIR;
1100	/*
1101	 * Must simulate part of ext2_makeinode here to acquire the inode,
1102	 * but not have it entered in the parent directory. The entry is
1103	 * made later after writing "." and ".." entries.
1104	 */
1105	error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
1106	if (error)
1107		goto out;
1108	ip = VTOI(tvp);
1109	ip->i_gid = dp->i_gid;
1110#ifdef SUIDDIR
1111	{
1112		/*
1113		 * if we are hacking owners here, (only do this where told to)
1114		 * and we are not giving it TOO root, (would subvert quotas)
1115		 * then go ahead and give it to the other user.
1116		 * The new directory also inherits the SUID bit.
1117		 * If user's UID and dir UID are the same,
1118		 * 'give it away' so that the SUID is still forced on.
1119		 */
1120		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1121		    (dp->i_mode & ISUID) && dp->i_uid) {
1122			dmode |= ISUID;
1123			ip->i_uid = dp->i_uid;
1124		} else {
1125			ip->i_uid = cnp->cn_cred->cr_uid;
1126		}
1127	}
1128#else
1129	ip->i_uid = cnp->cn_cred->cr_uid;
1130#endif
1131	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1132	ip->i_mode = dmode;
1133	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
1134	ip->i_nlink = 2;
1135	if (cnp->cn_flags & ISWHITEOUT)
1136		ip->i_flags |= UF_OPAQUE;
1137	error = ext2_update(tvp, 1);
1138
1139	/*
1140	 * Bump link count in parent directory
1141	 * to reflect work done below.  Should
1142	 * be done before reference is created
1143	 * so reparation is possible if we crash.
1144	 */
1145	dp->i_nlink++;
1146	dp->i_flag |= IN_CHANGE;
1147	error = ext2_update(dvp, !DOINGASYNC(dvp));
1148	if (error)
1149		goto bad;
1150
1151	/* Initialize directory with "." and ".." from static template. */
1152	if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1153	    EXT2F_INCOMPAT_FTYPE))
1154		dtp = &mastertemplate;
1155	else
1156		dtp = &omastertemplate;
1157	dirtemplate = *dtp;
1158	dirtemplate.dot_ino = ip->i_number;
1159	dirtemplate.dotdot_ino = dp->i_number;
1160	/*
1161	 * note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE so let's
1162	 * just redefine it - for this function only
1163	 */
1164#undef  DIRBLKSIZ
1165#define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
1166	dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
1167	error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
1168	    sizeof(dirtemplate), (off_t)0, UIO_SYSSPACE,
1169	    IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
1170	    NULL, NULL);
1171	if (error) {
1172		dp->i_nlink--;
1173		dp->i_flag |= IN_CHANGE;
1174		goto bad;
1175	}
1176	if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
1177		/* XXX should grow with balloc() */
1178		panic("ext2_mkdir: blksize");
1179	else {
1180		ip->i_size = DIRBLKSIZ;
1181		ip->i_flag |= IN_CHANGE;
1182	}
1183
1184	/* Directory set up, now install its entry in the parent directory. */
1185	error = ext2_direnter(ip, dvp, cnp);
1186	if (error) {
1187		dp->i_nlink--;
1188		dp->i_flag |= IN_CHANGE;
1189	}
1190bad:
1191	/*
1192	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
1193	 * for us because we set the link count to 0.
1194	 */
1195	if (error) {
1196		ip->i_nlink = 0;
1197		ip->i_flag |= IN_CHANGE;
1198		vput(tvp);
1199	} else
1200		*ap->a_vpp = tvp;
1201out:
1202	return (error);
1203#undef  DIRBLKSIZ
1204#define DIRBLKSIZ  DEV_BSIZE
1205}
1206
1207/*
1208 * Rmdir system call.
1209 */
1210static int
1211ext2_rmdir(struct vop_rmdir_args *ap)
1212{
1213	struct vnode *vp = ap->a_vp;
1214	struct vnode *dvp = ap->a_dvp;
1215	struct componentname *cnp = ap->a_cnp;
1216	struct inode *ip, *dp;
1217	int error;
1218
1219	ip = VTOI(vp);
1220	dp = VTOI(dvp);
1221
1222	/*
1223	 * Verify the directory is empty (and valid).
1224	 * (Rmdir ".." won't be valid since
1225	 *  ".." will contain a reference to
1226	 *  the current directory and thus be
1227	 *  non-empty.)
1228	 */
1229	if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
1230		error = ENOTEMPTY;
1231		goto out;
1232	}
1233	if ((dp->i_flags & APPEND)
1234	    || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1235		error = EPERM;
1236		goto out;
1237	}
1238	/*
1239	 * Delete reference to directory before purging
1240	 * inode.  If we crash in between, the directory
1241	 * will be reattached to lost+found,
1242	 */
1243	error = ext2_dirremove(dvp, cnp);
1244	if (error)
1245		goto out;
1246	dp->i_nlink--;
1247	dp->i_flag |= IN_CHANGE;
1248	cache_purge(dvp);
1249	VOP_UNLOCK(dvp, 0);
1250	/*
1251	 * Truncate inode.  The only stuff left
1252	 * in the directory is "." and "..".  The
1253	 * "." reference is inconsequential since
1254	 * we're quashing it.  The ".." reference
1255	 * has already been adjusted above.  We've
1256	 * removed the "." reference and the reference
1257	 * in the parent directory, but there may be
1258	 * other hard links so decrement by 2 and
1259	 * worry about them later.
1260	 */
1261	ip->i_nlink -= 2;
1262	error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
1263	    cnp->cn_thread);
1264	cache_purge(ITOV(ip));
1265	if (vn_lock(dvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1266		VOP_UNLOCK(vp, 0);
1267		vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1268		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1269	}
1270out:
1271	return (error);
1272}
1273
1274/*
1275 * symlink -- make a symbolic link
1276 */
1277static int
1278ext2_symlink(struct vop_symlink_args *ap)
1279{
1280	struct vnode *vp, **vpp = ap->a_vpp;
1281	struct inode *ip;
1282	int len, error;
1283
1284	error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
1285	    vpp, ap->a_cnp);
1286	if (error)
1287		return (error);
1288	vp = *vpp;
1289	len = strlen(ap->a_target);
1290	if (len < vp->v_mount->mnt_maxsymlinklen) {
1291		ip = VTOI(vp);
1292		bcopy(ap->a_target, (char *)ip->i_shortlink, len);
1293		ip->i_size = len;
1294		ip->i_flag |= IN_CHANGE | IN_UPDATE;
1295	} else
1296		error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
1297		    UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
1298		    ap->a_cnp->cn_cred, NOCRED, NULL, NULL);
1299	if (error)
1300		vput(vp);
1301	return (error);
1302}
1303
1304/*
1305 * Return target name of a symbolic link
1306 */
1307static int
1308ext2_readlink(struct vop_readlink_args *ap)
1309{
1310	struct vnode *vp = ap->a_vp;
1311	struct inode *ip = VTOI(vp);
1312	int isize;
1313
1314	isize = ip->i_size;
1315	if (isize < vp->v_mount->mnt_maxsymlinklen) {
1316		uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
1317		return (0);
1318	}
1319	return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
1320}
1321
1322/*
1323 * Calculate the logical to physical mapping if not done already,
1324 * then call the device strategy routine.
1325 *
1326 * In order to be able to swap to a file, the ext2_bmaparray() operation may not
1327 * deadlock on memory.  See ext2_bmap() for details.
1328 */
1329static int
1330ext2_strategy(struct vop_strategy_args *ap)
1331{
1332	struct buf *bp = ap->a_bp;
1333	struct vnode *vp = ap->a_vp;
1334	struct bufobj *bo;
1335	daddr_t blkno;
1336	int error;
1337
1338	if (vp->v_type == VBLK || vp->v_type == VCHR)
1339		panic("ext2_strategy: spec");
1340	if (bp->b_blkno == bp->b_lblkno) {
1341		error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
1342		bp->b_blkno = blkno;
1343		if (error) {
1344			bp->b_error = error;
1345			bp->b_ioflags |= BIO_ERROR;
1346			bufdone(bp);
1347			return (0);
1348		}
1349		if ((long)bp->b_blkno == -1)
1350			vfs_bio_clrbuf(bp);
1351	}
1352	if ((long)bp->b_blkno == -1) {
1353		bufdone(bp);
1354		return (0);
1355	}
1356	bp->b_iooffset = dbtob(bp->b_blkno);
1357	bo = VFSTOEXT2(vp->v_mount)->um_bo;
1358	BO_STRATEGY(bo, bp);
1359	return (0);
1360}
1361
1362/*
1363 * Print out the contents of an inode.
1364 */
1365static int
1366ext2_print(struct vop_print_args *ap)
1367{
1368	struct vnode *vp = ap->a_vp;
1369	struct inode *ip = VTOI(vp);
1370
1371	vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
1372	if (vp->v_type == VFIFO)
1373		fifo_printinfo(vp);
1374	printf("\n");
1375	return (0);
1376}
1377
1378/*
1379 * Close wrapper for fifos.
1380 *
1381 * Update the times on the inode then do device close.
1382 */
1383static int
1384ext2fifo_close(struct vop_close_args *ap)
1385{
1386	struct vnode *vp = ap->a_vp;
1387
1388	VI_LOCK(vp);
1389	if (vp->v_usecount > 1)
1390		ext2_itimes_locked(vp);
1391	VI_UNLOCK(vp);
1392	return (fifo_specops.vop_close(ap));
1393}
1394
1395/*
1396 * Kqfilter wrapper for fifos.
1397 *
1398 * Fall through to ext2 kqfilter routines if needed
1399 */
1400static int
1401ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
1402{
1403	int error;
1404
1405	error = fifo_specops.vop_kqfilter(ap);
1406	if (error)
1407		error = vfs_kqfilter(ap);
1408	return (error);
1409}
1410
1411/*
1412 * Return POSIX pathconf information applicable to ext2 filesystems.
1413 */
1414static int
1415ext2_pathconf(struct vop_pathconf_args *ap)
1416{
1417	int error = 0;
1418
1419	switch (ap->a_name) {
1420	case _PC_LINK_MAX:
1421		*ap->a_retval = EXT2_LINK_MAX;
1422		break;
1423	case _PC_NAME_MAX:
1424		*ap->a_retval = NAME_MAX;
1425		break;
1426	case _PC_PATH_MAX:
1427		*ap->a_retval = PATH_MAX;
1428		break;
1429	case _PC_PIPE_BUF:
1430		*ap->a_retval = PIPE_BUF;
1431		break;
1432	case _PC_CHOWN_RESTRICTED:
1433		*ap->a_retval = 1;
1434		break;
1435	case _PC_NO_TRUNC:
1436		*ap->a_retval = 1;
1437		break;
1438	case _PC_MIN_HOLE_SIZE:
1439		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1440		break;
1441	case _PC_ASYNC_IO:
1442		/* _PC_ASYNC_IO should have been handled by upper layers. */
1443		KASSERT(0, ("_PC_ASYNC_IO should not get here"));
1444		error = EINVAL;
1445		break;
1446	case _PC_PRIO_IO:
1447		*ap->a_retval = 0;
1448		break;
1449	case _PC_SYNC_IO:
1450		*ap->a_retval = 0;
1451		break;
1452	case _PC_ALLOC_SIZE_MIN:
1453		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
1454		break;
1455	case _PC_FILESIZEBITS:
1456		*ap->a_retval = 64;
1457		break;
1458	case _PC_REC_INCR_XFER_SIZE:
1459		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1460		break;
1461	case _PC_REC_MAX_XFER_SIZE:
1462		*ap->a_retval = -1;	/* means ``unlimited'' */
1463		break;
1464	case _PC_REC_MIN_XFER_SIZE:
1465		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1466		break;
1467	case _PC_REC_XFER_ALIGN:
1468		*ap->a_retval = PAGE_SIZE;
1469		break;
1470	case _PC_SYMLINK_MAX:
1471		*ap->a_retval = MAXPATHLEN;
1472		break;
1473
1474	default:
1475		error = EINVAL;
1476		break;
1477	}
1478	return (error);
1479}
1480
1481/*
1482 * Vnode pointer to File handle
1483 */
1484/* ARGSUSED */
1485static int
1486ext2_vptofh(struct vop_vptofh_args *ap)
1487{
1488	struct inode *ip;
1489	struct ufid *ufhp;
1490
1491	ip = VTOI(ap->a_vp);
1492	ufhp = (struct ufid *)ap->a_fhp;
1493	ufhp->ufid_len = sizeof(struct ufid);
1494	ufhp->ufid_ino = ip->i_number;
1495	ufhp->ufid_gen = ip->i_gen;
1496	return (0);
1497}
1498
1499/*
1500 * Initialize the vnode associated with a new inode, handle aliased
1501 * vnodes.
1502 */
1503int
1504ext2_vinit(struct mount *mntp, struct vop_vector *fifoops, struct vnode **vpp)
1505{
1506	struct inode *ip;
1507	struct vnode *vp;
1508
1509	vp = *vpp;
1510	ip = VTOI(vp);
1511	vp->v_type = IFTOVT(ip->i_mode);
1512	if (vp->v_type == VFIFO)
1513		vp->v_op = fifoops;
1514
1515	if (ip->i_number == EXT2_ROOTINO)
1516		vp->v_vflag |= VV_ROOT;
1517	ip->i_modrev = init_va_filerev();
1518	*vpp = vp;
1519	return (0);
1520}
1521
1522/*
1523 * Allocate a new inode.
1524 */
1525static int
1526ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
1527    struct componentname *cnp)
1528{
1529	struct inode *ip, *pdir;
1530	struct vnode *tvp;
1531	int error;
1532
1533	pdir = VTOI(dvp);
1534#ifdef INVARIANTS
1535	if ((cnp->cn_flags & HASBUF) == 0)
1536		panic("ext2_makeinode: no name");
1537#endif
1538	*vpp = NULL;
1539	if ((mode & IFMT) == 0)
1540		mode |= IFREG;
1541
1542	error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
1543	if (error) {
1544		return (error);
1545	}
1546	ip = VTOI(tvp);
1547	ip->i_gid = pdir->i_gid;
1548#ifdef SUIDDIR
1549	{
1550		/*
1551		 * if we are
1552		 * not the owner of the directory,
1553		 * and we are hacking owners here, (only do this where told to)
1554		 * and we are not giving it TOO root, (would subvert quotas)
1555		 * then go ahead and give it to the other user.
1556		 * Note that this drops off the execute bits for security.
1557		 */
1558		if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1559		    (pdir->i_mode & ISUID) &&
1560		    (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
1561			ip->i_uid = pdir->i_uid;
1562			mode &= ~07111;
1563		} else {
1564			ip->i_uid = cnp->cn_cred->cr_uid;
1565		}
1566	}
1567#else
1568	ip->i_uid = cnp->cn_cred->cr_uid;
1569#endif
1570	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1571	ip->i_mode = mode;
1572	tvp->v_type = IFTOVT(mode);	/* Rest init'd in getnewvnode(). */
1573	ip->i_nlink = 1;
1574	if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
1575		if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
1576			ip->i_mode &= ~ISGID;
1577	}
1578
1579	if (cnp->cn_flags & ISWHITEOUT)
1580		ip->i_flags |= UF_OPAQUE;
1581
1582	/*
1583	 * Make sure inode goes to disk before directory entry.
1584	 */
1585	error = ext2_update(tvp, !DOINGASYNC(tvp));
1586	if (error)
1587		goto bad;
1588	error = ext2_direnter(ip, dvp, cnp);
1589	if (error)
1590		goto bad;
1591
1592	*vpp = tvp;
1593	return (0);
1594
1595bad:
1596	/*
1597	 * Write error occurred trying to update the inode
1598	 * or the directory so must deallocate the inode.
1599	 */
1600	ip->i_nlink = 0;
1601	ip->i_flag |= IN_CHANGE;
1602	vput(tvp);
1603	return (error);
1604}
1605
1606/*
1607 * Vnode op for reading.
1608 */
1609static int
1610ext2_read(struct vop_read_args *ap)
1611{
1612	struct vnode *vp;
1613	struct inode *ip;
1614	int error;
1615
1616	vp = ap->a_vp;
1617	ip = VTOI(vp);
1618
1619	/* EXT4_EXT_LOCK(ip); */
1620	if (ip->i_flag & IN_E4EXTENTS)
1621		error = ext4_ext_read(ap);
1622	else
1623		error = ext2_ind_read(ap);
1624	/* EXT4_EXT_UNLOCK(ip); */
1625	return (error);
1626}
1627
1628/*
1629 * Vnode op for reading.
1630 */
1631static int
1632ext2_ind_read(struct vop_read_args *ap)
1633{
1634	struct vnode *vp;
1635	struct inode *ip;
1636	struct uio *uio;
1637	struct m_ext2fs *fs;
1638	struct buf *bp;
1639	daddr_t lbn, nextlbn;
1640	off_t bytesinfile;
1641	long size, xfersize, blkoffset;
1642	int error, orig_resid, seqcount;
1643	int ioflag;
1644
1645	vp = ap->a_vp;
1646	uio = ap->a_uio;
1647	ioflag = ap->a_ioflag;
1648
1649	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
1650	ip = VTOI(vp);
1651
1652#ifdef INVARIANTS
1653	if (uio->uio_rw != UIO_READ)
1654		panic("%s: mode", "ext2_read");
1655
1656	if (vp->v_type == VLNK) {
1657		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
1658			panic("%s: short symlink", "ext2_read");
1659	} else if (vp->v_type != VREG && vp->v_type != VDIR)
1660		panic("%s: type %d", "ext2_read", vp->v_type);
1661#endif
1662	orig_resid = uio->uio_resid;
1663	KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
1664	if (orig_resid == 0)
1665		return (0);
1666	KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
1667	fs = ip->i_e2fs;
1668	if (uio->uio_offset < ip->i_size &&
1669	    uio->uio_offset >= fs->e2fs_maxfilesize)
1670		return (EOVERFLOW);
1671
1672	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
1673		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1674			break;
1675		lbn = lblkno(fs, uio->uio_offset);
1676		nextlbn = lbn + 1;
1677		size = blksize(fs, ip, lbn);
1678		blkoffset = blkoff(fs, uio->uio_offset);
1679
1680		xfersize = fs->e2fs_fsize - blkoffset;
1681		if (uio->uio_resid < xfersize)
1682			xfersize = uio->uio_resid;
1683		if (bytesinfile < xfersize)
1684			xfersize = bytesinfile;
1685
1686		if (lblktosize(fs, nextlbn) >= ip->i_size)
1687			error = bread(vp, lbn, size, NOCRED, &bp);
1688		else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
1689			error = cluster_read(vp, ip->i_size, lbn, size,
1690			    NOCRED, blkoffset + uio->uio_resid, seqcount,
1691			    0, &bp);
1692		} else if (seqcount > 1) {
1693			u_int nextsize = blksize(fs, ip, nextlbn);
1694
1695			error = breadn(vp, lbn,
1696			    size, &nextlbn, &nextsize, 1, NOCRED, &bp);
1697		} else
1698			error = bread(vp, lbn, size, NOCRED, &bp);
1699		if (error) {
1700			brelse(bp);
1701			bp = NULL;
1702			break;
1703		}
1704
1705		/*
1706		 * If IO_DIRECT then set B_DIRECT for the buffer.  This
1707		 * will cause us to attempt to release the buffer later on
1708		 * and will cause the buffer cache to attempt to free the
1709		 * underlying pages.
1710		 */
1711		if (ioflag & IO_DIRECT)
1712			bp->b_flags |= B_DIRECT;
1713
1714		/*
1715		 * We should only get non-zero b_resid when an I/O error
1716		 * has occurred, which should cause us to break above.
1717		 * However, if the short read did not cause an error,
1718		 * then we want to ensure that we do not uiomove bad
1719		 * or uninitialized data.
1720		 */
1721		size -= bp->b_resid;
1722		if (size < xfersize) {
1723			if (size == 0)
1724				break;
1725			xfersize = size;
1726		}
1727		error = uiomove((char *)bp->b_data + blkoffset,
1728		    (int)xfersize, uio);
1729		if (error)
1730			break;
1731
1732		if (ioflag & (IO_VMIO|IO_DIRECT)) {
1733			/*
1734			 * If it's VMIO or direct I/O, then we don't
1735			 * need the buf, mark it available for
1736			 * freeing. If it's non-direct VMIO, the VM has
1737			 * the data.
1738			 */
1739			bp->b_flags |= B_RELBUF;
1740			brelse(bp);
1741		} else {
1742			/*
1743			 * Otherwise let whoever
1744			 * made the request take care of
1745			 * freeing it. We just queue
1746			 * it onto another list.
1747			 */
1748			bqrelse(bp);
1749		}
1750	}
1751
1752	/*
1753	 * This can only happen in the case of an error because the loop
1754	 * above resets bp to NULL on each iteration and on normal
1755	 * completion has not set a new value into it. so it must have come
1756	 * from a 'break' statement
1757	 */
1758	if (bp != NULL) {
1759		if (ioflag & (IO_VMIO|IO_DIRECT)) {
1760			bp->b_flags |= B_RELBUF;
1761			brelse(bp);
1762		} else {
1763			bqrelse(bp);
1764		}
1765	}
1766
1767	if ((error == 0 || uio->uio_resid != orig_resid) &&
1768	    (vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
1769		ip->i_flag |= IN_ACCESS;
1770	return (error);
1771}
1772
1773static int
1774ext2_ioctl(struct vop_ioctl_args *ap)
1775{
1776
1777	switch (ap->a_command) {
1778	case FIOSEEKDATA:
1779	case FIOSEEKHOLE:
1780		return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
1781		    (off_t *)ap->a_data, ap->a_cred));
1782	default:
1783		return (ENOTTY);
1784	}
1785}
1786
1787/*
1788 * this function handles ext4 extents block mapping
1789 */
1790static int
1791ext4_ext_read(struct vop_read_args *ap)
1792{
1793	static unsigned char zeroes[EXT2_MAX_BLOCK_SIZE];
1794	struct vnode *vp;
1795	struct inode *ip;
1796	struct uio *uio;
1797	struct m_ext2fs *fs;
1798	struct buf *bp;
1799	struct ext4_extent nex, *ep;
1800	struct ext4_extent_path path;
1801	daddr_t lbn, newblk;
1802	off_t bytesinfile;
1803	int cache_type;
1804	ssize_t orig_resid;
1805	int error;
1806	long size, xfersize, blkoffset;
1807
1808	vp = ap->a_vp;
1809	ip = VTOI(vp);
1810	uio = ap->a_uio;
1811	memset(&path, 0, sizeof(path));
1812
1813	orig_resid = uio->uio_resid;
1814	KASSERT(orig_resid >= 0, ("%s: uio->uio_resid < 0", __func__));
1815	if (orig_resid == 0)
1816		return (0);
1817	KASSERT(uio->uio_offset >= 0, ("%s: uio->uio_offset < 0", __func__));
1818	fs = ip->i_e2fs;
1819	if (uio->uio_offset < ip->i_size && uio->uio_offset >= fs->e2fs_maxfilesize)
1820		return (EOVERFLOW);
1821
1822	while (uio->uio_resid > 0) {
1823		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1824			break;
1825		lbn = lblkno(fs, uio->uio_offset);
1826		size = blksize(fs, ip, lbn);
1827		blkoffset = blkoff(fs, uio->uio_offset);
1828
1829		xfersize = fs->e2fs_fsize - blkoffset;
1830		xfersize = MIN(xfersize, uio->uio_resid);
1831		xfersize = MIN(xfersize, bytesinfile);
1832
1833		/* get block from ext4 extent cache */
1834		cache_type = ext4_ext_in_cache(ip, lbn, &nex);
1835		switch (cache_type) {
1836		case EXT4_EXT_CACHE_NO:
1837			ext4_ext_find_extent(fs, ip, lbn, &path);
1838			if (path.ep_is_sparse)
1839				ep = &path.ep_sparse_ext;
1840			else
1841				ep = path.ep_ext;
1842			if (ep == NULL)
1843				return (EIO);
1844
1845			ext4_ext_put_cache(ip, ep,
1846			    path.ep_is_sparse ? EXT4_EXT_CACHE_GAP : EXT4_EXT_CACHE_IN);
1847
1848			newblk = lbn - ep->e_blk + (ep->e_start_lo |
1849			    (daddr_t)ep->e_start_hi << 32);
1850
1851			if (path.ep_bp != NULL) {
1852				brelse(path.ep_bp);
1853				path.ep_bp = NULL;
1854			}
1855			break;
1856
1857		case EXT4_EXT_CACHE_GAP:
1858			/* block has not been allocated yet */
1859			break;
1860
1861		case EXT4_EXT_CACHE_IN:
1862			newblk = lbn - nex.e_blk + (nex.e_start_lo |
1863			    (daddr_t)nex.e_start_hi << 32);
1864			break;
1865
1866		default:
1867			panic("%s: invalid cache type", __func__);
1868		}
1869
1870		if (cache_type == EXT4_EXT_CACHE_GAP ||
1871		    (cache_type == EXT4_EXT_CACHE_NO && path.ep_is_sparse)) {
1872			if (xfersize > sizeof(zeroes))
1873				xfersize = sizeof(zeroes);
1874			error = uiomove(zeroes, xfersize, uio);
1875			if (error)
1876				return (error);
1877		} else {
1878			error = bread(ip->i_devvp, fsbtodb(fs, newblk), size,
1879			    NOCRED, &bp);
1880			if (error) {
1881				brelse(bp);
1882				return (error);
1883			}
1884
1885			size -= bp->b_resid;
1886			if (size < xfersize) {
1887				if (size == 0) {
1888					bqrelse(bp);
1889					break;
1890				}
1891				xfersize = size;
1892			}
1893			error = uiomove(bp->b_data + blkoffset, xfersize, uio);
1894			bqrelse(bp);
1895			if (error)
1896				return (error);
1897		}
1898	}
1899
1900	return (0);
1901}
1902
1903/*
1904 * Vnode op for writing.
1905 */
1906static int
1907ext2_write(struct vop_write_args *ap)
1908{
1909	struct vnode *vp;
1910	struct uio *uio;
1911	struct inode *ip;
1912	struct m_ext2fs *fs;
1913	struct buf *bp;
1914	daddr_t lbn;
1915	off_t osize;
1916	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
1917
1918	ioflag = ap->a_ioflag;
1919	uio = ap->a_uio;
1920	vp = ap->a_vp;
1921
1922	seqcount = ioflag >> IO_SEQSHIFT;
1923	ip = VTOI(vp);
1924
1925#ifdef INVARIANTS
1926	if (uio->uio_rw != UIO_WRITE)
1927		panic("%s: mode", "ext2_write");
1928#endif
1929
1930	switch (vp->v_type) {
1931	case VREG:
1932		if (ioflag & IO_APPEND)
1933			uio->uio_offset = ip->i_size;
1934		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
1935			return (EPERM);
1936		/* FALLTHROUGH */
1937	case VLNK:
1938		break;
1939	case VDIR:
1940		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
1941		if ((ioflag & IO_SYNC) == 0)
1942			panic("ext2_write: nonsync dir write");
1943		break;
1944	default:
1945		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
1946		    vp->v_type, (intmax_t)uio->uio_offset,
1947		    (intmax_t)uio->uio_resid);
1948	}
1949
1950	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
1951	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
1952	fs = ip->i_e2fs;
1953	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
1954		return (EFBIG);
1955	/*
1956	 * Maybe this should be above the vnode op call, but so long as
1957	 * file servers have no limits, I don't think it matters.
1958	 */
1959	if (vn_rlimit_fsize(vp, uio, uio->uio_td))
1960		return (EFBIG);
1961
1962	resid = uio->uio_resid;
1963	osize = ip->i_size;
1964	if (seqcount > BA_SEQMAX)
1965		flags = BA_SEQMAX << BA_SEQSHIFT;
1966	else
1967		flags = seqcount << BA_SEQSHIFT;
1968	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
1969		flags |= IO_SYNC;
1970
1971	for (error = 0; uio->uio_resid > 0;) {
1972		lbn = lblkno(fs, uio->uio_offset);
1973		blkoffset = blkoff(fs, uio->uio_offset);
1974		xfersize = fs->e2fs_fsize - blkoffset;
1975		if (uio->uio_resid < xfersize)
1976			xfersize = uio->uio_resid;
1977		if (uio->uio_offset + xfersize > ip->i_size)
1978			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
1979
1980		/*
1981		 * We must perform a read-before-write if the transfer size
1982		 * does not cover the entire buffer.
1983		 */
1984		if (fs->e2fs_bsize > xfersize)
1985			flags |= BA_CLRBUF;
1986		else
1987			flags &= ~BA_CLRBUF;
1988		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
1989		    ap->a_cred, &bp, flags);
1990		if (error != 0)
1991			break;
1992
1993		if ((ioflag & (IO_SYNC | IO_INVAL)) == (IO_SYNC | IO_INVAL))
1994			bp->b_flags |= B_NOCACHE;
1995		if (uio->uio_offset + xfersize > ip->i_size)
1996			ip->i_size = uio->uio_offset + xfersize;
1997		size = blksize(fs, ip, lbn) - bp->b_resid;
1998		if (size < xfersize)
1999			xfersize = size;
2000
2001		error =
2002		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
2003		/*
2004		 * If the buffer is not already filled and we encounter an
2005		 * error while trying to fill it, we have to clear out any
2006		 * garbage data from the pages instantiated for the buffer.
2007		 * If we do not, a failed uiomove() during a write can leave
2008		 * the prior contents of the pages exposed to a userland mmap.
2009		 *
2010		 * Note that we need only clear buffers with a transfer size
2011		 * equal to the block size because buffers with a shorter
2012		 * transfer size were cleared above by the call to ext2_balloc()
2013		 * with the BA_CLRBUF flag set.
2014		 *
2015		 * If the source region for uiomove identically mmaps the
2016		 * buffer, uiomove() performed the NOP copy, and the buffer
2017		 * content remains valid because the page fault handler
2018		 * validated the pages.
2019		 */
2020		if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
2021		    fs->e2fs_bsize == xfersize)
2022			vfs_bio_clrbuf(bp);
2023		if (ioflag & (IO_VMIO|IO_DIRECT)) {
2024			bp->b_flags |= B_RELBUF;
2025		}
2026
2027		/*
2028		 * If IO_SYNC each buffer is written synchronously.  Otherwise
2029		 * if we have a severe page deficiency write the buffer
2030		 * asynchronously.  Otherwise try to cluster, and if that
2031		 * doesn't do it then either do an async write (if O_DIRECT),
2032		 * or a delayed write (if not).
2033		 */
2034		if (ioflag & IO_SYNC) {
2035			(void)bwrite(bp);
2036		} else if (vm_page_count_severe() ||
2037			    buf_dirty_count_severe() ||
2038		    (ioflag & IO_ASYNC)) {
2039			bp->b_flags |= B_CLUSTEROK;
2040			bawrite(bp);
2041		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
2042			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
2043				bp->b_flags |= B_CLUSTEROK;
2044				cluster_write(vp, bp, ip->i_size, seqcount, 0);
2045			} else {
2046				bawrite(bp);
2047			}
2048		} else if (ioflag & IO_DIRECT) {
2049			bp->b_flags |= B_CLUSTEROK;
2050			bawrite(bp);
2051		} else {
2052			bp->b_flags |= B_CLUSTEROK;
2053			bdwrite(bp);
2054		}
2055		if (error || xfersize == 0)
2056			break;
2057	}
2058	/*
2059	 * If we successfully wrote any data, and we are not the superuser
2060	 * we clear the setuid and setgid bits as a precaution against
2061	 * tampering.
2062	 */
2063	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
2064	    ap->a_cred) {
2065		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
2066			ip->i_mode &= ~(ISUID | ISGID);
2067	}
2068	if (error) {
2069		if (ioflag & IO_UNIT) {
2070			(void)ext2_truncate(vp, osize,
2071			    ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
2072			uio->uio_offset -= resid - uio->uio_resid;
2073			uio->uio_resid = resid;
2074		}
2075	}
2076	if (uio->uio_resid != resid) {
2077		ip->i_flag |= IN_CHANGE | IN_UPDATE;
2078		if (ioflag & IO_SYNC)
2079			error = ext2_update(vp, 1);
2080	}
2081	return (error);
2082}
2083
2084/*
2085 * get page routine
2086 */
2087static int
2088ext2_getpages(struct vop_getpages_args *ap)
2089{
2090	int i;
2091	vm_page_t mreq;
2092	int pcount;
2093
2094	pcount = round_page(ap->a_count) / PAGE_SIZE;
2095	mreq = ap->a_m[ap->a_reqpage];
2096
2097	/*
2098	 * if ANY DEV_BSIZE blocks are valid on a large filesystem block,
2099	 * then the entire page is valid.  Since the page may be mapped,
2100	 * user programs might reference data beyond the actual end of file
2101	 * occuring within the page.  We have to zero that data.
2102	 */
2103	VM_OBJECT_WLOCK(mreq->object);
2104	if (mreq->valid) {
2105		if (mreq->valid != VM_PAGE_BITS_ALL)
2106			vm_page_zero_invalid(mreq, TRUE);
2107		for (i = 0; i < pcount; i++) {
2108			if (i != ap->a_reqpage) {
2109				vm_page_lock(ap->a_m[i]);
2110				vm_page_free(ap->a_m[i]);
2111				vm_page_unlock(ap->a_m[i]);
2112			}
2113		}
2114		VM_OBJECT_WUNLOCK(mreq->object);
2115		return VM_PAGER_OK;
2116	}
2117	VM_OBJECT_WUNLOCK(mreq->object);
2118
2119	return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
2120					    ap->a_count,
2121					    ap->a_reqpage);
2122}
2123