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 * $FreeBSD$
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/mount.h>
58#include <sys/unistd.h>
59#include <sys/time.h>
60#include <sys/vnode.h>
61#include <sys/namei.h>
62#include <sys/lockf.h>
63#include <sys/event.h>
64#include <sys/conf.h>
65#include <sys/file.h>
66
67#include <vm/vm.h>
68#include <vm/vm_page.h>
69#include <vm/vm_object.h>
70#include <vm/vm_extern.h>
71#include <vm/vnode_pager.h>
72
73#include "opt_directio.h"
74
75#include <fs/fifofs/fifo.h>
76
77#include <ufs/ufs/dir.h>
78
79#include <fs/ext2fs/fs.h>
80#include <fs/ext2fs/inode.h>
81#include <fs/ext2fs/ext2_extern.h>
82#include <fs/ext2fs/ext2fs.h>
83#include <fs/ext2fs/ext2_dinode.h>
84#include <fs/ext2fs/ext2_dir.h>
85#include <fs/ext2fs/ext2_mount.h>
86
87static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);
88static void ext2_itimes_locked(struct vnode *);
89static int ext4_ext_read(struct vop_read_args *);
90static int ext2_ind_read(struct vop_read_args *);
91
92static vop_access_t	ext2_access;
93static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
94static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
95    struct thread *);
96static vop_close_t	ext2_close;
97static vop_create_t	ext2_create;
98static vop_fsync_t	ext2_fsync;
99static vop_getattr_t	ext2_getattr;
100static vop_ioctl_t	ext2_ioctl;
101static vop_link_t	ext2_link;
102static vop_mkdir_t	ext2_mkdir;
103static vop_mknod_t	ext2_mknod;
104static vop_open_t	ext2_open;
105static vop_pathconf_t	ext2_pathconf;
106static vop_print_t	ext2_print;
107static vop_read_t	ext2_read;
108static vop_readlink_t	ext2_readlink;
109static vop_remove_t	ext2_remove;
110static vop_rename_t	ext2_rename;
111static vop_rmdir_t	ext2_rmdir;
112static vop_setattr_t	ext2_setattr;
113static vop_strategy_t	ext2_strategy;
114static vop_symlink_t	ext2_symlink;
115static vop_write_t	ext2_write;
116static vop_vptofh_t	ext2_vptofh;
117static vop_close_t	ext2fifo_close;
118static vop_kqfilter_t	ext2fifo_kqfilter;
119
120/* Global vfs data structures for ext2. */
121struct vop_vector ext2_vnodeops = {
122	.vop_default =		&default_vnodeops,
123	.vop_access =		ext2_access,
124	.vop_bmap =		ext2_bmap,
125	.vop_cachedlookup =	ext2_lookup,
126	.vop_close =		ext2_close,
127	.vop_create =		ext2_create,
128	.vop_fsync =		ext2_fsync,
129	.vop_getattr =		ext2_getattr,
130	.vop_inactive =		ext2_inactive,
131	.vop_ioctl =		ext2_ioctl,
132	.vop_link =		ext2_link,
133	.vop_lookup =		vfs_cache_lookup,
134	.vop_mkdir =		ext2_mkdir,
135	.vop_mknod =		ext2_mknod,
136	.vop_open =		ext2_open,
137	.vop_pathconf =		ext2_pathconf,
138	.vop_poll =		vop_stdpoll,
139	.vop_print =		ext2_print,
140	.vop_read =		ext2_read,
141	.vop_readdir =		ext2_readdir,
142	.vop_readlink =		ext2_readlink,
143	.vop_reallocblks =	ext2_reallocblks,
144	.vop_reclaim =		ext2_reclaim,
145	.vop_remove =		ext2_remove,
146	.vop_rename =		ext2_rename,
147	.vop_rmdir =		ext2_rmdir,
148	.vop_setattr =		ext2_setattr,
149	.vop_strategy =		ext2_strategy,
150	.vop_symlink =		ext2_symlink,
151	.vop_write =		ext2_write,
152	.vop_vptofh =		ext2_vptofh,
153};
154
155struct vop_vector ext2_fifoops = {
156	.vop_default =		&fifo_specops,
157	.vop_access =		ext2_access,
158	.vop_close =		ext2fifo_close,
159	.vop_fsync =		ext2_fsync,
160	.vop_getattr =		ext2_getattr,
161	.vop_inactive =		ext2_inactive,
162	.vop_kqfilter =		ext2fifo_kqfilter,
163	.vop_print =		ext2_print,
164	.vop_read =		VOP_PANIC,
165	.vop_reclaim =		ext2_reclaim,
166	.vop_setattr =		ext2_setattr,
167	.vop_write =		VOP_PANIC,
168	.vop_vptofh =		ext2_vptofh,
169};
170
171/*
172 * A virgin directory (no blushing please).
173 * Note that the type and namlen fields are reversed relative to ext2.
174 * Also, we don't use `struct odirtemplate', since it would just cause
175 * endianness problems.
176 */
177static struct dirtemplate mastertemplate = {
178	0, 12, 1, EXT2_FT_DIR, ".",
179	0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
180};
181static struct dirtemplate omastertemplate = {
182	0, 12, 1, EXT2_FT_UNKNOWN, ".",
183	0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
184};
185
186static void
187ext2_itimes_locked(struct vnode *vp)
188{
189	struct inode *ip;
190	struct timespec ts;
191
192	ASSERT_VI_LOCKED(vp, __func__);
193
194	ip = VTOI(vp);
195	if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
196		return;
197	if ((vp->v_type == VBLK || vp->v_type == VCHR))
198		ip->i_flag |= IN_LAZYMOD;
199	else
200		ip->i_flag |= IN_MODIFIED;
201	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
202		vfs_timestamp(&ts);
203		if (ip->i_flag & IN_ACCESS) {
204			ip->i_atime = ts.tv_sec;
205			ip->i_atimensec = ts.tv_nsec;
206		}
207		if (ip->i_flag & IN_UPDATE) {
208			ip->i_mtime = ts.tv_sec;
209			ip->i_mtimensec = ts.tv_nsec;
210			ip->i_modrev++;
211		}
212		if (ip->i_flag & IN_CHANGE) {
213			ip->i_ctime = ts.tv_sec;
214			ip->i_ctimensec = ts.tv_nsec;
215		}
216	}
217	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
218}
219
220void
221ext2_itimes(struct vnode *vp)
222{
223
224	VI_LOCK(vp);
225	ext2_itimes_locked(vp);
226	VI_UNLOCK(vp);
227}
228
229/*
230 * Create a regular file
231 */
232static int
233ext2_create(struct vop_create_args *ap)
234{
235	int error;
236
237	error =
238	    ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
239	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
240	if (error)
241		return (error);
242	return (0);
243}
244
245static int
246ext2_open(struct vop_open_args *ap)
247{
248
249	if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
250		return (EOPNOTSUPP);
251
252	/*
253	 * Files marked append-only must be opened for appending.
254	 */
255	if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
256	    (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
257		return (EPERM);
258
259	vnode_create_vobject(ap->a_vp, VTOI(ap->a_vp)->i_size, ap->a_td);
260
261	return (0);
262}
263
264/*
265 * Close called.
266 *
267 * Update the times on the inode.
268 */
269static int
270ext2_close(struct vop_close_args *ap)
271{
272	struct vnode *vp = ap->a_vp;
273
274	VI_LOCK(vp);
275	if (vp->v_usecount > 1)
276		ext2_itimes_locked(vp);
277	VI_UNLOCK(vp);
278	return (0);
279}
280
281static int
282ext2_access(struct vop_access_args *ap)
283{
284	struct vnode *vp = ap->a_vp;
285	struct inode *ip = VTOI(vp);
286	accmode_t accmode = ap->a_accmode;
287	int error;
288
289	if (vp->v_type == VBLK || vp->v_type == VCHR)
290		return (EOPNOTSUPP);
291
292	/*
293	 * Disallow write attempts on read-only file systems;
294	 * unless the file is a socket, fifo, or a block or
295	 * character device resident on the file system.
296	 */
297	if (accmode & VWRITE) {
298		switch (vp->v_type) {
299		case VDIR:
300		case VLNK:
301		case VREG:
302			if (vp->v_mount->mnt_flag & MNT_RDONLY)
303				return (EROFS);
304			break;
305		default:
306			break;
307		}
308	}
309
310	/* If immutable bit set, nobody gets to write it. */
311	if ((accmode & VWRITE) && (ip->i_flags & (SF_IMMUTABLE | SF_SNAPSHOT)))
312		return (EPERM);
313
314	error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
315	    ap->a_accmode, ap->a_cred, NULL);
316	return (error);
317}
318
319static int
320ext2_getattr(struct vop_getattr_args *ap)
321{
322	struct vnode *vp = ap->a_vp;
323	struct inode *ip = VTOI(vp);
324	struct vattr *vap = ap->a_vap;
325
326	ext2_itimes(vp);
327	/*
328	 * Copy from inode table
329	 */
330	vap->va_fsid = dev2udev(ip->i_devvp->v_rdev);
331	vap->va_fileid = ip->i_number;
332	vap->va_mode = ip->i_mode & ~IFMT;
333	vap->va_nlink = ip->i_nlink;
334	vap->va_uid = ip->i_uid;
335	vap->va_gid = ip->i_gid;
336	vap->va_rdev = ip->i_rdev;
337	vap->va_size = ip->i_size;
338	vap->va_atime.tv_sec = ip->i_atime;
339	vap->va_atime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_atimensec : 0;
340	vap->va_mtime.tv_sec = ip->i_mtime;
341	vap->va_mtime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_mtimensec : 0;
342	vap->va_ctime.tv_sec = ip->i_ctime;
343	vap->va_ctime.tv_nsec = E2DI_HAS_XTIME(ip) ? ip->i_ctimensec : 0;
344	if E2DI_HAS_XTIME(ip) {
345		vap->va_birthtime.tv_sec = ip->i_birthtime;
346		vap->va_birthtime.tv_nsec = ip->i_birthnsec;
347	}
348	vap->va_flags = ip->i_flags;
349	vap->va_gen = ip->i_gen;
350	vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
351	vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
352	vap->va_type = IFTOVT(ip->i_mode);
353	vap->va_filerev = ip->i_modrev;
354	return (0);
355}
356
357/*
358 * Set attribute vnode op. called from several syscalls
359 */
360static int
361ext2_setattr(struct vop_setattr_args *ap)
362{
363	struct vattr *vap = ap->a_vap;
364	struct vnode *vp = ap->a_vp;
365	struct inode *ip = VTOI(vp);
366	struct ucred *cred = ap->a_cred;
367	struct thread *td = curthread;
368	int error;
369
370	/*
371	 * Check for unsettable attributes.
372	 */
373	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
374	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
375	    (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
376	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
377		return (EINVAL);
378	}
379	if (vap->va_flags != VNOVAL) {
380		/* Disallow flags not supported by ext2fs. */
381		if(vap->va_flags & ~(SF_APPEND | SF_IMMUTABLE | UF_NODUMP))
382			return (EOPNOTSUPP);
383
384		if (vp->v_mount->mnt_flag & MNT_RDONLY)
385			return (EROFS);
386		/*
387		 * Callers may only modify the file flags on objects they
388		 * have VADMIN rights for.
389		 */
390		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
391			return (error);
392		/*
393		 * Unprivileged processes and privileged processes in
394		 * jail() are not permitted to unset system flags, or
395		 * modify flags if any system flags are set.
396		 * Privileged non-jail processes may not modify system flags
397		 * if securelevel > 0 and any existing system flags are set.
398		 */
399		if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
400			if (ip->i_flags &
401			    (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
402				error = securelevel_gt(cred, 0);
403				if (error)
404					return (error);
405			}
406			ip->i_flags = vap->va_flags;
407		} else {
408			if (ip->i_flags &
409			    (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
410			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
411				return (EPERM);
412			ip->i_flags &= SF_SETTABLE;
413			ip->i_flags |= (vap->va_flags & UF_SETTABLE);
414		}
415		ip->i_flag |= IN_CHANGE;
416		if (ip->i_flags & (IMMUTABLE | APPEND))
417			return (0);
418	}
419	if (ip->i_flags & (IMMUTABLE | APPEND))
420		return (EPERM);
421	/*
422	 * Go through the fields and update iff not VNOVAL.
423	 */
424	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
425		if (vp->v_mount->mnt_flag & MNT_RDONLY)
426			return (EROFS);
427		if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
428		    td)) != 0)
429			return (error);
430	}
431	if (vap->va_size != VNOVAL) {
432		/*
433		 * Disallow write attempts on read-only file systems;
434		 * unless the file is a socket, fifo, or a block or
435		 * character device resident on the file system.
436		 */
437		switch (vp->v_type) {
438		case VDIR:
439			return (EISDIR);
440		case VLNK:
441		case VREG:
442			if (vp->v_mount->mnt_flag & MNT_RDONLY)
443				return (EROFS);
444			break;
445		default:
446			break;
447		}
448		if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
449			return (error);
450	}
451	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
452		if (vp->v_mount->mnt_flag & MNT_RDONLY)
453			return (EROFS);
454		/*
455		 * From utimes(2):
456		 * If times is NULL, ... The caller must be the owner of
457		 * the file, have permission to write the file, or be the
458		 * super-user.
459		 * If times is non-NULL, ... The caller must be the owner of
460		 * the file or be the super-user.
461		 */
462		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
463		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
464		    (error = VOP_ACCESS(vp, VWRITE, cred, td))))
465			return (error);
466		if (vap->va_atime.tv_sec != VNOVAL)
467			ip->i_flag |= IN_ACCESS;
468		if (vap->va_mtime.tv_sec != VNOVAL)
469			ip->i_flag |= IN_CHANGE | IN_UPDATE;
470		ext2_itimes(vp);
471		if (vap->va_atime.tv_sec != VNOVAL) {
472			ip->i_atime = vap->va_atime.tv_sec;
473			ip->i_atimensec = vap->va_atime.tv_nsec;
474		}
475		if (vap->va_mtime.tv_sec != VNOVAL) {
476			ip->i_mtime = vap->va_mtime.tv_sec;
477			ip->i_mtimensec = vap->va_mtime.tv_nsec;
478		}
479		ip->i_birthtime = vap->va_birthtime.tv_sec;
480		ip->i_birthnsec = vap->va_birthtime.tv_nsec;
481		error = ext2_update(vp, 0);
482		if (error)
483			return (error);
484	}
485	error = 0;
486	if (vap->va_mode != (mode_t)VNOVAL) {
487		if (vp->v_mount->mnt_flag & MNT_RDONLY)
488			return (EROFS);
489		error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
490	}
491	return (error);
492}
493
494/*
495 * Change the mode on a file.
496 * Inode must be locked before calling.
497 */
498static int
499ext2_chmod(struct vnode *vp, int mode, struct ucred *cred, struct thread *td)
500{
501	struct inode *ip = VTOI(vp);
502	int error;
503
504	/*
505	 * To modify the permissions on a file, must possess VADMIN
506	 * for that file.
507	 */
508	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
509		return (error);
510	/*
511	 * Privileged processes may set the sticky bit on non-directories,
512	 * as well as set the setgid bit on a file with a group that the
513	 * process is not a member of.
514	 */
515	if (vp->v_type != VDIR && (mode & S_ISTXT)) {
516		error = priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0);
517		if (error)
518			return (EFTYPE);
519	}
520	if (!groupmember(ip->i_gid, cred) && (mode & ISGID)) {
521		error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
522		if (error)
523			return (error);
524	}
525	ip->i_mode &= ~ALLPERMS;
526	ip->i_mode |= (mode & ALLPERMS);
527	ip->i_flag |= IN_CHANGE;
528	return (0);
529}
530
531/*
532 * Perform chown operation on inode ip;
533 * inode must be locked prior to call.
534 */
535static int
536ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
537    struct thread *td)
538{
539	struct inode *ip = VTOI(vp);
540	uid_t ouid;
541	gid_t ogid;
542	int error = 0;
543
544	if (uid == (uid_t)VNOVAL)
545		uid = ip->i_uid;
546	if (gid == (gid_t)VNOVAL)
547		gid = ip->i_gid;
548	/*
549	 * To modify the ownership of a file, must possess VADMIN
550	 * for that file.
551	 */
552	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
553		return (error);
554	/*
555	 * To change the owner of a file, or change the group of a file
556	 * to a group of which we are not a member, the caller must
557	 * have privilege.
558	 */
559	if (uid != ip->i_uid || (gid != ip->i_gid &&
560	    !groupmember(gid, cred))) {
561		error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
562		if (error)
563			return (error);
564	}
565	ogid = ip->i_gid;
566	ouid = ip->i_uid;
567	ip->i_gid = gid;
568	ip->i_uid = uid;
569	ip->i_flag |= IN_CHANGE;
570	if ((ip->i_mode & (ISUID | ISGID)) && (ouid != uid || ogid != gid)) {
571		if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0) != 0)
572			ip->i_mode &= ~(ISUID | ISGID);
573	}
574	return (0);
575}
576
577/*
578 * Synch an open file.
579 */
580/* ARGSUSED */
581static int
582ext2_fsync(struct vop_fsync_args *ap)
583{
584	/*
585	 * Flush all dirty buffers associated with a vnode.
586	 */
587
588	vop_stdfsync(ap);
589
590	return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
591}
592
593/*
594 * Mknod vnode call
595 */
596/* ARGSUSED */
597static int
598ext2_mknod(struct vop_mknod_args *ap)
599{
600	struct vattr *vap = ap->a_vap;
601	struct vnode **vpp = ap->a_vpp;
602	struct inode *ip;
603	ino_t ino;
604	int error;
605
606	error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
607	    ap->a_dvp, vpp, ap->a_cnp);
608	if (error)
609		return (error);
610	ip = VTOI(*vpp);
611	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
612	if (vap->va_rdev != VNOVAL) {
613		/*
614		 * Want to be able to use this to make badblock
615		 * inodes, so don't truncate the dev number.
616		 */
617		ip->i_rdev = vap->va_rdev;
618	}
619	/*
620	 * Remove inode, then reload it through VFS_VGET so it is
621	 * checked to see if it is an alias of an existing entry in
622	 * the inode cache.	 XXX I don't believe this is necessary now.
623	 */
624	(*vpp)->v_type = VNON;
625	ino = ip->i_number;	/* Save this before vgone() invalidates ip. */
626	vgone(*vpp);
627	vput(*vpp);
628	error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
629	if (error) {
630		*vpp = NULL;
631		return (error);
632	}
633	return (0);
634}
635
636static int
637ext2_remove(struct vop_remove_args *ap)
638{
639	struct inode *ip;
640	struct vnode *vp = ap->a_vp;
641	struct vnode *dvp = ap->a_dvp;
642	int error;
643
644	ip = VTOI(vp);
645	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
646	    (VTOI(dvp)->i_flags & APPEND)) {
647		error = EPERM;
648		goto out;
649	}
650	error = ext2_dirremove(dvp, ap->a_cnp);
651	if (error == 0) {
652		ip->i_nlink--;
653		ip->i_flag |= IN_CHANGE;
654	}
655out:
656	return (error);
657}
658
659/*
660 * link vnode call
661 */
662static int
663ext2_link(struct vop_link_args *ap)
664{
665	struct vnode *vp = ap->a_vp;
666	struct vnode *tdvp = ap->a_tdvp;
667	struct componentname *cnp = ap->a_cnp;
668	struct inode *ip;
669	int error;
670
671#ifdef INVARIANTS
672	if ((cnp->cn_flags & HASBUF) == 0)
673		panic("ext2_link: no name");
674#endif
675	if (tdvp->v_mount != vp->v_mount) {
676		error = EXDEV;
677		goto out;
678	}
679	ip = VTOI(vp);
680	if ((nlink_t)ip->i_nlink >= EXT2_LINK_MAX) {
681		error = EMLINK;
682		goto out;
683	}
684	if (ip->i_flags & (IMMUTABLE | APPEND)) {
685		error = EPERM;
686		goto out;
687	}
688	ip->i_nlink++;
689	ip->i_flag |= IN_CHANGE;
690	error = ext2_update(vp, !DOINGASYNC(vp));
691	if (!error)
692		error = ext2_direnter(ip, tdvp, cnp);
693	if (error) {
694		ip->i_nlink--;
695		ip->i_flag |= IN_CHANGE;
696	}
697out:
698	return (error);
699}
700
701/*
702 * Rename system call.
703 * 	rename("foo", "bar");
704 * is essentially
705 *	unlink("bar");
706 *	link("foo", "bar");
707 *	unlink("foo");
708 * but ``atomically''.  Can't do full commit without saving state in the
709 * inode on disk which isn't feasible at this time.  Best we can do is
710 * always guarantee the target exists.
711 *
712 * Basic algorithm is:
713 *
714 * 1) Bump link count on source while we're linking it to the
715 *    target.  This also ensure the inode won't be deleted out
716 *    from underneath us while we work (it may be truncated by
717 *    a concurrent `trunc' or `open' for creation).
718 * 2) Link source to destination.  If destination already exists,
719 *    delete it first.
720 * 3) Unlink source reference to inode if still around. If a
721 *    directory was moved and the parent of the destination
722 *    is different from the source, patch the ".." entry in the
723 *    directory.
724 */
725static int
726ext2_rename(struct vop_rename_args *ap)
727{
728	struct vnode *tvp = ap->a_tvp;
729	struct vnode *tdvp = ap->a_tdvp;
730	struct vnode *fvp = ap->a_fvp;
731	struct vnode *fdvp = ap->a_fdvp;
732	struct componentname *tcnp = ap->a_tcnp;
733	struct componentname *fcnp = ap->a_fcnp;
734	struct inode *ip, *xp, *dp;
735	struct dirtemplate dirbuf;
736	int doingdirectory = 0, oldparent = 0, newparent = 0;
737	int error = 0;
738	u_char namlen;
739
740#ifdef INVARIANTS
741	if ((tcnp->cn_flags & HASBUF) == 0 ||
742	    (fcnp->cn_flags & HASBUF) == 0)
743		panic("ext2_rename: no name");
744#endif
745	/*
746	 * Check for cross-device rename.
747	 */
748	if ((fvp->v_mount != tdvp->v_mount) ||
749	    (tvp && (fvp->v_mount != tvp->v_mount))) {
750		error = EXDEV;
751abortit:
752		if (tdvp == tvp)
753			vrele(tdvp);
754		else
755			vput(tdvp);
756		if (tvp)
757			vput(tvp);
758		vrele(fdvp);
759		vrele(fvp);
760		return (error);
761	}
762
763	if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
764	    (VTOI(tdvp)->i_flags & APPEND))) {
765		error = EPERM;
766		goto abortit;
767	}
768
769	/*
770	 * Renaming a file to itself has no effect.  The upper layers should
771	 * not call us in that case.  Temporarily just warn if they do.
772	 */
773	if (fvp == tvp) {
774		printf("ext2_rename: fvp == tvp (can't happen)\n");
775		error = 0;
776		goto abortit;
777	}
778
779	if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
780		goto abortit;
781	dp = VTOI(fdvp);
782	ip = VTOI(fvp);
783	if (ip->i_nlink >= EXT2_LINK_MAX) {
784		VOP_UNLOCK(fvp, 0);
785		error = EMLINK;
786		goto abortit;
787	}
788	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
789	    || (dp->i_flags & APPEND)) {
790		VOP_UNLOCK(fvp, 0);
791		error = EPERM;
792		goto abortit;
793	}
794	if ((ip->i_mode & IFMT) == IFDIR) {
795		/*
796		 * Avoid ".", "..", and aliases of "." for obvious reasons.
797		 */
798		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
799		    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
800		    (ip->i_flag & IN_RENAME)) {
801			VOP_UNLOCK(fvp, 0);
802			error = EINVAL;
803			goto abortit;
804		}
805		ip->i_flag |= IN_RENAME;
806		oldparent = dp->i_number;
807		doingdirectory++;
808	}
809	vrele(fdvp);
810
811	/*
812	 * When the target exists, both the directory
813	 * and target vnodes are returned locked.
814	 */
815	dp = VTOI(tdvp);
816	xp = NULL;
817	if (tvp)
818		xp = VTOI(tvp);
819
820	/*
821	 * 1) Bump link count while we're moving stuff
822	 *    around.  If we crash somewhere before
823	 *    completing our work, the link count
824	 *    may be wrong, but correctable.
825	 */
826	ip->i_nlink++;
827	ip->i_flag |= IN_CHANGE;
828	if ((error = ext2_update(fvp, !DOINGASYNC(fvp))) != 0) {
829		VOP_UNLOCK(fvp, 0);
830		goto bad;
831	}
832
833	/*
834	 * If ".." must be changed (ie the directory gets a new
835	 * parent) then the source directory must not be in the
836	 * directory hierarchy above the target, as this would
837	 * orphan everything below the source directory. Also
838	 * the user must have write permission in the source so
839	 * as to be able to change "..". We must repeat the call
840	 * to namei, as the parent directory is unlocked by the
841	 * call to checkpath().
842	 */
843	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
844	VOP_UNLOCK(fvp, 0);
845	if (oldparent != dp->i_number)
846		newparent = dp->i_number;
847	if (doingdirectory && newparent) {
848		if (error)	/* write access check above */
849			goto bad;
850		if (xp != NULL)
851			vput(tvp);
852		error = ext2_checkpath(ip, dp, tcnp->cn_cred);
853		if (error)
854			goto out;
855		VREF(tdvp);
856		error = relookup(tdvp, &tvp, tcnp);
857		if (error)
858			goto out;
859		vrele(tdvp);
860		dp = VTOI(tdvp);
861		xp = NULL;
862		if (tvp)
863			xp = VTOI(tvp);
864	}
865	/*
866	 * 2) If target doesn't exist, link the target
867	 *    to the source and unlink the source.
868	 *    Otherwise, rewrite the target directory
869	 *    entry to reference the source inode and
870	 *    expunge the original entry's existence.
871	 */
872	if (xp == NULL) {
873		if (dp->i_devvp != ip->i_devvp)
874			panic("ext2_rename: EXDEV");
875		/*
876		 * Account for ".." in new directory.
877		 * When source and destination have the same
878		 * parent we don't fool with the link count.
879		 */
880		if (doingdirectory && newparent) {
881			if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
882				error = EMLINK;
883				goto bad;
884			}
885			dp->i_nlink++;
886			dp->i_flag |= IN_CHANGE;
887			error = ext2_update(tdvp, !DOINGASYNC(tdvp));
888			if (error)
889				goto bad;
890		}
891		error = ext2_direnter(ip, tdvp, tcnp);
892		if (error) {
893			if (doingdirectory && newparent) {
894				dp->i_nlink--;
895				dp->i_flag |= IN_CHANGE;
896				(void)ext2_update(tdvp, 1);
897			}
898			goto bad;
899		}
900		vput(tdvp);
901	} else {
902		if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
903		       panic("ext2_rename: EXDEV");
904		/*
905		 * Short circuit rename(foo, foo).
906		 */
907		if (xp->i_number == ip->i_number)
908			panic("ext2_rename: same file");
909		/*
910		 * If the parent directory is "sticky", then the user must
911		 * own the parent directory, or the destination of the rename,
912		 * otherwise the destination may not be changed (except by
913		 * root). This implements append-only directories.
914		 */
915		if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
916		    tcnp->cn_cred->cr_uid != dp->i_uid &&
917		    xp->i_uid != tcnp->cn_cred->cr_uid) {
918			error = EPERM;
919			goto bad;
920		}
921		/*
922		 * Target must be empty if a directory and have no links
923		 * to it. Also, ensure source and target are compatible
924		 * (both directories, or both not directories).
925		 */
926		if ((xp->i_mode&IFMT) == IFDIR) {
927			if (! ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) ||
928			    xp->i_nlink > 2) {
929				error = ENOTEMPTY;
930				goto bad;
931			}
932			if (!doingdirectory) {
933				error = ENOTDIR;
934				goto bad;
935			}
936			cache_purge(tdvp);
937		} else if (doingdirectory) {
938			error = EISDIR;
939			goto bad;
940		}
941		error = ext2_dirrewrite(dp, ip, tcnp);
942		if (error)
943			goto bad;
944		/*
945		 * If the target directory is in the same
946		 * directory as the source directory,
947		 * decrement the link count on the parent
948		 * of the target directory.
949		 */
950		if (doingdirectory && !newparent) {
951			dp->i_nlink--;
952			dp->i_flag |= IN_CHANGE;
953		}
954		vput(tdvp);
955		/*
956		 * Adjust the link count of the target to
957		 * reflect the dirrewrite above.  If this is
958		 * a directory it is empty and there are
959		 * no links to it, so we can squash the inode and
960		 * any space associated with it.  We disallowed
961		 * renaming over top of a directory with links to
962		 * it above, as the remaining link would point to
963		 * a directory without "." or ".." entries.
964		 */
965		xp->i_nlink--;
966		if (doingdirectory) {
967			if (--xp->i_nlink != 0)
968				panic("ext2_rename: linked directory");
969			error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
970			    tcnp->cn_cred, tcnp->cn_thread);
971		}
972		xp->i_flag |= IN_CHANGE;
973		vput(tvp);
974		xp = NULL;
975	}
976
977	/*
978	 * 3) Unlink the source.
979	 */
980	fcnp->cn_flags &= ~MODMASK;
981	fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
982	VREF(fdvp);
983	error = relookup(fdvp, &fvp, fcnp);
984	if (error == 0)
985		vrele(fdvp);
986	if (fvp != NULL) {
987		xp = VTOI(fvp);
988		dp = VTOI(fdvp);
989	} else {
990		/*
991		 * From name has disappeared.
992		 */
993		if (doingdirectory)
994			panic("ext2_rename: lost dir entry");
995		vrele(ap->a_fvp);
996		return (0);
997	}
998	/*
999	 * Ensure that the directory entry still exists and has not
1000	 * changed while the new name has been entered. If the source is
1001	 * a file then the entry may have been unlinked or renamed. In
1002	 * either case there is no further work to be done. If the source
1003	 * is a directory then it cannot have been rmdir'ed; its link
1004	 * count of three would cause a rmdir to fail with ENOTEMPTY.
1005	 * The IN_RENAME flag ensures that it cannot be moved by another
1006	 * rename.
1007	 */
1008	if (xp != ip) {
1009		if (doingdirectory)
1010			panic("ext2_rename: lost dir entry");
1011	} else {
1012		/*
1013		 * If the source is a directory with a
1014		 * new parent, the link count of the old
1015		 * parent directory must be decremented
1016		 * and ".." set to point to the new parent.
1017		 */
1018		if (doingdirectory && newparent) {
1019			dp->i_nlink--;
1020			dp->i_flag |= IN_CHANGE;
1021			error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
1022				sizeof(struct dirtemplate), (off_t)0,
1023				UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
1024				tcnp->cn_cred, NOCRED, NULL, NULL);
1025			if (error == 0) {
1026				/* Like ufs little-endian: */
1027				namlen = dirbuf.dotdot_type;
1028				if (namlen != 2 ||
1029				    dirbuf.dotdot_name[0] != '.' ||
1030				    dirbuf.dotdot_name[1] != '.') {
1031					ext2_dirbad(xp, (doff_t)12,
1032					    "rename: mangled dir");
1033				} else {
1034					dirbuf.dotdot_ino = newparent;
1035					(void) vn_rdwr(UIO_WRITE, fvp,
1036					    (caddr_t)&dirbuf,
1037					    sizeof(struct dirtemplate),
1038					    (off_t)0, UIO_SYSSPACE,
1039					    IO_NODELOCKED | IO_SYNC |
1040					    IO_NOMACCHECK, tcnp->cn_cred,
1041					    NOCRED, NULL, NULL);
1042					cache_purge(fdvp);
1043				}
1044			}
1045		}
1046		error = ext2_dirremove(fdvp, fcnp);
1047		if (!error) {
1048			xp->i_nlink--;
1049			xp->i_flag |= IN_CHANGE;
1050		}
1051		xp->i_flag &= ~IN_RENAME;
1052	}
1053	if (dp)
1054		vput(fdvp);
1055	if (xp)
1056		vput(fvp);
1057	vrele(ap->a_fvp);
1058	return (error);
1059
1060bad:
1061	if (xp)
1062		vput(ITOV(xp));
1063	vput(ITOV(dp));
1064out:
1065	if (doingdirectory)
1066		ip->i_flag &= ~IN_RENAME;
1067	if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
1068		ip->i_nlink--;
1069		ip->i_flag |= IN_CHANGE;
1070		ip->i_flag &= ~IN_RENAME;
1071		vput(fvp);
1072	} else
1073		vrele(fvp);
1074	return (error);
1075}
1076
1077/*
1078 * Mkdir system call
1079 */
1080static int
1081ext2_mkdir(struct vop_mkdir_args *ap)
1082{
1083	struct vnode *dvp = ap->a_dvp;
1084	struct vattr *vap = ap->a_vap;
1085	struct componentname *cnp = ap->a_cnp;
1086	struct inode *ip, *dp;
1087	struct vnode *tvp;
1088	struct dirtemplate dirtemplate, *dtp;
1089	int error, dmode;
1090
1091#ifdef INVARIANTS
1092	if ((cnp->cn_flags & HASBUF) == 0)
1093		panic("ext2_mkdir: no name");
1094#endif
1095	dp = VTOI(dvp);
1096	if ((nlink_t)dp->i_nlink >= EXT2_LINK_MAX) {
1097		error = EMLINK;
1098		goto out;
1099	}
1100	dmode = vap->va_mode & 0777;
1101	dmode |= IFDIR;
1102	/*
1103	 * Must simulate part of ext2_makeinode here to acquire the inode,
1104	 * but not have it entered in the parent directory. The entry is
1105	 * made later after writing "." and ".." entries.
1106	 */
1107	error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
1108	if (error)
1109		goto out;
1110	ip = VTOI(tvp);
1111	ip->i_gid = dp->i_gid;
1112#ifdef SUIDDIR
1113	{
1114		/*
1115		 * if we are hacking owners here, (only do this where told to)
1116		 * and we are not giving it TOO root, (would subvert quotas)
1117		 * then go ahead and give it to the other user.
1118		 * The new directory also inherits the SUID bit.
1119		 * If user's UID and dir UID are the same,
1120		 * 'give it away' so that the SUID is still forced on.
1121		 */
1122		if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1123		   (dp->i_mode & ISUID) && dp->i_uid) {
1124			dmode |= ISUID;
1125			ip->i_uid = dp->i_uid;
1126		} else {
1127			ip->i_uid = cnp->cn_cred->cr_uid;
1128		}
1129	}
1130#else
1131	ip->i_uid = cnp->cn_cred->cr_uid;
1132#endif
1133	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1134	ip->i_mode = dmode;
1135	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
1136	ip->i_nlink = 2;
1137	if (cnp->cn_flags & ISWHITEOUT)
1138		ip->i_flags |= UF_OPAQUE;
1139	error = ext2_update(tvp, 1);
1140
1141	/*
1142	 * Bump link count in parent directory
1143	 * to reflect work done below.  Should
1144	 * be done before reference is created
1145	 * so reparation is possible if we crash.
1146	 */
1147	dp->i_nlink++;
1148	dp->i_flag |= IN_CHANGE;
1149	error = ext2_update(dvp, !DOINGASYNC(dvp));
1150	if (error)
1151		goto bad;
1152
1153	/* Initialize directory with "." and ".." from static template. */
1154	if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs,
1155	    EXT2F_INCOMPAT_FTYPE))
1156		dtp = &mastertemplate;
1157	else
1158		dtp = &omastertemplate;
1159	dirtemplate = *dtp;
1160	dirtemplate.dot_ino = ip->i_number;
1161	dirtemplate.dotdot_ino = dp->i_number;
1162	/* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE
1163	 * so let's just redefine it - for this function only
1164	 */
1165#undef  DIRBLKSIZ
1166#define DIRBLKSIZ  VTOI(dvp)->i_e2fs->e2fs_bsize
1167	dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
1168	error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
1169	    sizeof(dirtemplate), (off_t)0, UIO_SYSSPACE,
1170	    IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
1171	    NULL, NULL);
1172	if (error) {
1173		dp->i_nlink--;
1174		dp->i_flag |= IN_CHANGE;
1175		goto bad;
1176	}
1177	if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
1178		/* XXX should grow with balloc() */
1179		panic("ext2_mkdir: blksize");
1180	else {
1181		ip->i_size = DIRBLKSIZ;
1182		ip->i_flag |= IN_CHANGE;
1183	}
1184
1185	/* Directory set up, now install its entry in the parent directory. */
1186	error = ext2_direnter(ip, dvp, cnp);
1187	if (error) {
1188		dp->i_nlink--;
1189		dp->i_flag |= IN_CHANGE;
1190	}
1191bad:
1192	/*
1193	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
1194	 * for us because we set the link count to 0.
1195	 */
1196	if (error) {
1197		ip->i_nlink = 0;
1198		ip->i_flag |= IN_CHANGE;
1199		vput(tvp);
1200	} else
1201		*ap->a_vpp = tvp;
1202out:
1203	return (error);
1204#undef  DIRBLKSIZ
1205#define DIRBLKSIZ  DEV_BSIZE
1206}
1207
1208/*
1209 * Rmdir system call.
1210 */
1211static int
1212ext2_rmdir(struct vop_rmdir_args *ap)
1213{
1214	struct vnode *vp = ap->a_vp;
1215	struct vnode *dvp = ap->a_dvp;
1216	struct componentname *cnp = ap->a_cnp;
1217	struct inode *ip, *dp;
1218	int error;
1219
1220	ip = VTOI(vp);
1221	dp = VTOI(dvp);
1222
1223	/*
1224	 * Verify the directory is empty (and valid).
1225	 * (Rmdir ".." won't be valid since
1226	 *  ".." will contain a reference to
1227	 *  the current directory and thus be
1228	 *  non-empty.)
1229	 */
1230	error = 0;
1231	if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
1232		error = ENOTEMPTY;
1233		goto out;
1234	}
1235	if ((dp->i_flags & APPEND)
1236	    || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1237		error = EPERM;
1238		goto out;
1239	}
1240	/*
1241	 * Delete reference to directory before purging
1242	 * inode.  If we crash in between, the directory
1243	 * will be reattached to lost+found,
1244	 */
1245	error = ext2_dirremove(dvp, cnp);
1246	if (error)
1247		goto out;
1248	dp->i_nlink--;
1249	dp->i_flag |= IN_CHANGE;
1250	cache_purge(dvp);
1251	VOP_UNLOCK(dvp, 0);
1252	/*
1253	 * Truncate inode.  The only stuff left
1254	 * in the directory is "." and "..".  The
1255	 * "." reference is inconsequential since
1256	 * we're quashing it.  The ".." reference
1257	 * has already been adjusted above.  We've
1258	 * removed the "." reference and the reference
1259	 * in the parent directory, but there may be
1260	 * other hard links so decrement by 2 and
1261	 * worry about them later.
1262	 */
1263	ip->i_nlink -= 2;
1264	error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred,
1265	    cnp->cn_thread);
1266	cache_purge(ITOV(ip));
1267	if (vn_lock(dvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1268		VOP_UNLOCK(vp, 0);
1269		vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1270		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1271	}
1272out:
1273	return (error);
1274}
1275
1276/*
1277 * symlink -- make a symbolic link
1278 */
1279static int
1280ext2_symlink(struct vop_symlink_args *ap)
1281{
1282	struct vnode *vp, **vpp = ap->a_vpp;
1283	struct inode *ip;
1284	int len, error;
1285
1286	error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
1287	    vpp, ap->a_cnp);
1288	if (error)
1289		return (error);
1290	vp = *vpp;
1291	len = strlen(ap->a_target);
1292	if (len < vp->v_mount->mnt_maxsymlinklen) {
1293		ip = VTOI(vp);
1294		bcopy(ap->a_target, (char *)ip->i_shortlink, len);
1295		ip->i_size = len;
1296		ip->i_flag |= IN_CHANGE | IN_UPDATE;
1297	} else
1298		error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
1299		    UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
1300		    ap->a_cnp->cn_cred, NOCRED, NULL, NULL);
1301	if (error)
1302		vput(vp);
1303	return (error);
1304}
1305
1306/*
1307 * Return target name of a symbolic link
1308 */
1309static int
1310ext2_readlink(struct vop_readlink_args *ap)
1311{
1312	struct vnode *vp = ap->a_vp;
1313	struct inode *ip = VTOI(vp);
1314	int isize;
1315
1316	isize = ip->i_size;
1317	if (isize < vp->v_mount->mnt_maxsymlinklen) {
1318		uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
1319		return (0);
1320	}
1321	return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
1322}
1323
1324/*
1325 * Calculate the logical to physical mapping if not done already,
1326 * then call the device strategy routine.
1327 *
1328 * In order to be able to swap to a file, the ext2_bmaparray() operation may not
1329 * deadlock on memory.  See ext2_bmap() for details.
1330 */
1331static int
1332ext2_strategy(struct vop_strategy_args *ap)
1333{
1334	struct buf *bp = ap->a_bp;
1335	struct vnode *vp = ap->a_vp;
1336	struct inode *ip;
1337	struct bufobj *bo;
1338	daddr_t blkno;
1339	int error;
1340
1341	ip = VTOI(vp);
1342	if (vp->v_type == VBLK || vp->v_type == VCHR)
1343		panic("ext2_strategy: spec");
1344	if (bp->b_blkno == bp->b_lblkno) {
1345		error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
1346		bp->b_blkno = blkno;
1347		if (error) {
1348			bp->b_error = error;
1349			bp->b_ioflags |= BIO_ERROR;
1350			bufdone(bp);
1351			return (0);
1352		}
1353		if ((long)bp->b_blkno == -1)
1354			vfs_bio_clrbuf(bp);
1355	}
1356	if ((long)bp->b_blkno == -1) {
1357		bufdone(bp);
1358		return (0);
1359	}
1360	bp->b_iooffset = dbtob(bp->b_blkno);
1361	bo = VFSTOEXT2(vp->v_mount)->um_bo;
1362	BO_STRATEGY(bo, bp);
1363	return (0);
1364}
1365
1366/*
1367 * Print out the contents of an inode.
1368 */
1369static int
1370ext2_print(struct vop_print_args *ap)
1371{
1372	struct vnode *vp = ap->a_vp;
1373	struct inode *ip = VTOI(vp);
1374
1375	vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
1376	if (vp->v_type == VFIFO)
1377		fifo_printinfo(vp);
1378	printf("\n");
1379	return (0);
1380}
1381
1382/*
1383 * Close wrapper for fifos.
1384 *
1385 * Update the times on the inode then do device close.
1386 */
1387static int
1388ext2fifo_close(struct vop_close_args *ap)
1389{
1390	struct vnode *vp = ap->a_vp;
1391
1392	VI_LOCK(vp);
1393	if (vp->v_usecount > 1)
1394		ext2_itimes_locked(vp);
1395	VI_UNLOCK(vp);
1396	return (fifo_specops.vop_close(ap));
1397}
1398
1399/*
1400 * Kqfilter wrapper for fifos.
1401 *
1402 * Fall through to ext2 kqfilter routines if needed
1403 */
1404static int
1405ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
1406{
1407	int error;
1408
1409	error = fifo_specops.vop_kqfilter(ap);
1410	if (error)
1411		error = vfs_kqfilter(ap);
1412	return (error);
1413}
1414
1415/*
1416 * Return POSIX pathconf information applicable to ext2 filesystems.
1417 */
1418static int
1419ext2_pathconf(struct vop_pathconf_args *ap)
1420{
1421	int error = 0;
1422
1423	switch (ap->a_name) {
1424	case _PC_LINK_MAX:
1425		*ap->a_retval = EXT2_LINK_MAX;
1426		break;
1427	case _PC_NAME_MAX:
1428		*ap->a_retval = NAME_MAX;
1429		break;
1430	case _PC_PATH_MAX:
1431		*ap->a_retval = PATH_MAX;
1432		break;
1433	case _PC_PIPE_BUF:
1434		*ap->a_retval = PIPE_BUF;
1435		break;
1436	case _PC_CHOWN_RESTRICTED:
1437		*ap->a_retval = 1;
1438		break;
1439	case _PC_NO_TRUNC:
1440		*ap->a_retval = 1;
1441		break;
1442	case _PC_MIN_HOLE_SIZE:
1443		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1444		break;
1445	case _PC_ASYNC_IO:
1446		/* _PC_ASYNC_IO should have been handled by upper layers. */
1447		KASSERT(0, ("_PC_ASYNC_IO should not get here"));
1448		error = EINVAL;
1449		break;
1450	case _PC_PRIO_IO:
1451		*ap->a_retval = 0;
1452		break;
1453	case _PC_SYNC_IO:
1454		*ap->a_retval = 0;
1455		break;
1456	case _PC_ALLOC_SIZE_MIN:
1457		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
1458		break;
1459	case _PC_FILESIZEBITS:
1460		*ap->a_retval = 64;
1461		break;
1462	case _PC_REC_INCR_XFER_SIZE:
1463		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1464		break;
1465	case _PC_REC_MAX_XFER_SIZE:
1466		*ap->a_retval = -1; /* means ``unlimited'' */
1467		break;
1468	case _PC_REC_MIN_XFER_SIZE:
1469		*ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
1470		break;
1471	case _PC_REC_XFER_ALIGN:
1472		*ap->a_retval = PAGE_SIZE;
1473		break;
1474	case _PC_SYMLINK_MAX:
1475		*ap->a_retval = MAXPATHLEN;
1476		break;
1477
1478	default:
1479		error = EINVAL;
1480		break;
1481	}
1482	return (error);
1483}
1484
1485/*
1486 * Vnode pointer to File handle
1487 */
1488/* ARGSUSED */
1489static int
1490ext2_vptofh(struct vop_vptofh_args *ap)
1491{
1492	struct inode *ip;
1493	struct ufid *ufhp;
1494
1495	ip = VTOI(ap->a_vp);
1496	ufhp = (struct ufid *)ap->a_fhp;
1497	ufhp->ufid_len = sizeof(struct ufid);
1498	ufhp->ufid_ino = ip->i_number;
1499	ufhp->ufid_gen = ip->i_gen;
1500	return (0);
1501}
1502
1503/*
1504 * Initialize the vnode associated with a new inode, handle aliased
1505 * vnodes.
1506 */
1507int
1508ext2_vinit(struct mount *mntp, struct vop_vector *fifoops, struct vnode **vpp)
1509{
1510	struct inode *ip;
1511	struct vnode *vp;
1512
1513	vp = *vpp;
1514	ip = VTOI(vp);
1515	vp->v_type = IFTOVT(ip->i_mode);
1516	if (vp->v_type == VFIFO)
1517		vp->v_op = fifoops;
1518
1519	if (ip->i_number == EXT2_ROOTINO)
1520		vp->v_vflag |= VV_ROOT;
1521	ip->i_modrev = init_va_filerev();
1522	*vpp = vp;
1523	return (0);
1524}
1525
1526/*
1527 * Allocate a new inode.
1528 */
1529static int
1530ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
1531    struct componentname *cnp)
1532{
1533	struct inode *ip, *pdir;
1534	struct vnode *tvp;
1535	int error;
1536
1537	pdir = VTOI(dvp);
1538#ifdef INVARIANTS
1539	if ((cnp->cn_flags & HASBUF) == 0)
1540		panic("ext2_makeinode: no name");
1541#endif
1542	*vpp = NULL;
1543	if ((mode & IFMT) == 0)
1544		mode |= IFREG;
1545
1546	error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
1547	if (error) {
1548		return (error);
1549	}
1550	ip = VTOI(tvp);
1551	ip->i_gid = pdir->i_gid;
1552#ifdef SUIDDIR
1553	{
1554		/*
1555		 * if we are
1556		 * not the owner of the directory,
1557		 * and we are hacking owners here, (only do this where told to)
1558		 * and we are not giving it TOO root, (would subvert quotas)
1559		 * then go ahead and give it to the other user.
1560		 * Note that this drops off the execute bits for security.
1561		 */
1562		if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
1563		     (pdir->i_mode & ISUID) &&
1564		     (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
1565			ip->i_uid = pdir->i_uid;
1566			mode &= ~07111;
1567		} else {
1568			ip->i_uid = cnp->cn_cred->cr_uid;
1569		}
1570	}
1571#else
1572	ip->i_uid = cnp->cn_cred->cr_uid;
1573#endif
1574	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
1575	ip->i_mode = mode;
1576	tvp->v_type = IFTOVT(mode);	/* Rest init'd in getnewvnode(). */
1577	ip->i_nlink = 1;
1578	if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred)) {
1579		if (priv_check_cred(cnp->cn_cred, PRIV_VFS_RETAINSUGID, 0))
1580			ip->i_mode &= ~ISGID;
1581	}
1582
1583	if (cnp->cn_flags & ISWHITEOUT)
1584		ip->i_flags |= UF_OPAQUE;
1585
1586	/*
1587	 * Make sure inode goes to disk before directory entry.
1588	 */
1589	error = ext2_update(tvp, !DOINGASYNC(tvp));
1590	if (error)
1591		goto bad;
1592	error = ext2_direnter(ip, dvp, cnp);
1593	if (error)
1594		goto bad;
1595
1596	*vpp = tvp;
1597	return (0);
1598
1599bad:
1600	/*
1601	 * Write error occurred trying to update the inode
1602	 * or the directory so must deallocate the inode.
1603	 */
1604	ip->i_nlink = 0;
1605	ip->i_flag |= IN_CHANGE;
1606	vput(tvp);
1607	return (error);
1608}
1609
1610/*
1611 * Vnode op for reading.
1612 */
1613static int
1614ext2_read(struct vop_read_args *ap)
1615{
1616	struct vnode *vp;
1617	struct inode *ip;
1618	int error;
1619
1620	vp = ap->a_vp;
1621	ip = VTOI(vp);
1622
1623	/*EXT4_EXT_LOCK(ip);*/
1624	if (ip->i_flag & IN_E4EXTENTS)
1625		error = ext4_ext_read(ap);
1626	else
1627		error = ext2_ind_read(ap);
1628	/*EXT4_EXT_UNLOCK(ip);*/
1629	return (error);
1630}
1631
1632/*
1633 * Vnode op for reading.
1634 */
1635static int
1636ext2_ind_read(struct vop_read_args *ap)
1637{
1638	struct vnode *vp;
1639	struct inode *ip;
1640	struct uio *uio;
1641	struct m_ext2fs *fs;
1642	struct buf *bp;
1643	daddr_t lbn, nextlbn;
1644	off_t bytesinfile;
1645	long size, xfersize, blkoffset;
1646	int error, orig_resid, seqcount;
1647	int ioflag;
1648
1649	vp = ap->a_vp;
1650	uio = ap->a_uio;
1651	ioflag = ap->a_ioflag;
1652
1653	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
1654	ip = VTOI(vp);
1655
1656#ifdef INVARIANTS
1657	if (uio->uio_rw != UIO_READ)
1658		panic("%s: mode", "ext2_read");
1659
1660	if (vp->v_type == VLNK) {
1661		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
1662			panic("%s: short symlink", "ext2_read");
1663	} else if (vp->v_type != VREG && vp->v_type != VDIR)
1664		panic("%s: type %d", "ext2_read", vp->v_type);
1665#endif
1666	orig_resid = uio->uio_resid;
1667	KASSERT(orig_resid >= 0, ("ext2_read: uio->uio_resid < 0"));
1668	if (orig_resid == 0)
1669		return (0);
1670	KASSERT(uio->uio_offset >= 0, ("ext2_read: uio->uio_offset < 0"));
1671	fs = ip->i_e2fs;
1672	if (uio->uio_offset < ip->i_size &&
1673	    uio->uio_offset >= fs->e2fs_maxfilesize)
1674	    	return (EOVERFLOW);
1675
1676	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
1677		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1678			break;
1679		lbn = lblkno(fs, uio->uio_offset);
1680		nextlbn = lbn + 1;
1681		size = blksize(fs, ip, lbn);
1682		blkoffset = blkoff(fs, uio->uio_offset);
1683
1684		xfersize = fs->e2fs_fsize - blkoffset;
1685		if (uio->uio_resid < xfersize)
1686			xfersize = uio->uio_resid;
1687		if (bytesinfile < xfersize)
1688			xfersize = bytesinfile;
1689
1690		if (lblktosize(fs, nextlbn) >= ip->i_size)
1691			error = bread(vp, lbn, size, NOCRED, &bp);
1692		else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0)
1693			error = cluster_read(vp, ip->i_size, lbn, size,
1694			    NOCRED, blkoffset + uio->uio_resid, seqcount, &bp);
1695		else if (seqcount > 1) {
1696			u_int nextsize = blksize(fs, ip, nextlbn);
1697			error = breadn(vp, lbn,
1698			    size, &nextlbn, &nextsize, 1, NOCRED, &bp);
1699		} else
1700			error = bread(vp, lbn, size, NOCRED, &bp);
1701		if (error) {
1702			brelse(bp);
1703			bp = NULL;
1704			break;
1705		}
1706
1707		/*
1708		 * If IO_DIRECT then set B_DIRECT for the buffer.  This
1709		 * will cause us to attempt to release the buffer later on
1710		 * and will cause the buffer cache to attempt to free the
1711		 * underlying pages.
1712		 */
1713		if (ioflag & IO_DIRECT)
1714			bp->b_flags |= B_DIRECT;
1715
1716		/*
1717		 * We should only get non-zero b_resid when an I/O error
1718		 * has occurred, which should cause us to break above.
1719		 * However, if the short read did not cause an error,
1720		 * then we want to ensure that we do not uiomove bad
1721		 * or uninitialized data.
1722		 */
1723		size -= bp->b_resid;
1724		if (size < xfersize) {
1725			if (size == 0)
1726				break;
1727			xfersize = size;
1728		}
1729		error = uiomove((char *)bp->b_data + blkoffset,
1730			(int)xfersize, uio);
1731		if (error)
1732			break;
1733
1734		if (ioflag & (IO_VMIO|IO_DIRECT)) {
1735			/*
1736			 * If it's VMIO or direct I/O, then we don't
1737			 * need the buf, mark it available for
1738			 * freeing. If it's non-direct VMIO, the VM has
1739			 * the data.
1740			 */
1741			bp->b_flags |= B_RELBUF;
1742			brelse(bp);
1743		} else {
1744			/*
1745			 * Otherwise let whoever
1746			 * made the request take care of
1747			 * freeing it. We just queue
1748			 * it onto another list.
1749			 */
1750			bqrelse(bp);
1751		}
1752	}
1753
1754	/*
1755	 * This can only happen in the case of an error
1756	 * because the loop above resets bp to NULL on each iteration
1757	 * and on normal completion has not set a new value into it.
1758	 * so it must have come from a 'break' statement
1759	 */
1760	if (bp != NULL) {
1761		if (ioflag & (IO_VMIO|IO_DIRECT)) {
1762			bp->b_flags |= B_RELBUF;
1763			brelse(bp);
1764		} else {
1765			bqrelse(bp);
1766		}
1767	}
1768
1769	if ((error == 0 || uio->uio_resid != orig_resid) &&
1770	    (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
1771		ip->i_flag |= IN_ACCESS;
1772	return (error);
1773}
1774
1775static int
1776ext2_ioctl(struct vop_ioctl_args *ap)
1777{
1778
1779	switch (ap->a_command) {
1780	case FIOSEEKDATA:
1781	case FIOSEEKHOLE:
1782		return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
1783		    (off_t *)ap->a_data, ap->a_cred));
1784	default:
1785		return (ENOTTY);
1786	}
1787}
1788
1789/*
1790 * this function handles ext4 extents block mapping
1791 */
1792static int
1793ext4_ext_read(struct vop_read_args *ap)
1794{
1795	struct vnode *vp;
1796	struct inode *ip;
1797	struct uio *uio;
1798	struct m_ext2fs *fs;
1799	struct buf *bp;
1800	struct ext4_extent nex, *ep;
1801	struct ext4_extent_path path;
1802	daddr_t lbn, newblk;
1803	off_t bytesinfile;
1804	int cache_type;
1805	ssize_t orig_resid;
1806	int error;
1807	long size, xfersize, blkoffset;
1808
1809	vp = ap->a_vp;
1810	ip = VTOI(vp);
1811	uio = ap->a_uio;
1812	memset(&path, 0, sizeof(path));
1813
1814	orig_resid = uio->uio_resid;
1815	KASSERT(orig_resid >= 0, ("%s: uio->uio_resid < 0", __func__));
1816	if (orig_resid == 0)
1817		return (0);
1818	KASSERT(uio->uio_offset >= 0, ("%s: uio->uio_offset < 0", __func__));
1819	fs = ip->i_e2fs;
1820	if (uio->uio_offset < ip->i_size && uio->uio_offset >= fs->e2fs_maxfilesize)
1821		return (EOVERFLOW);
1822
1823	while (uio->uio_resid > 0) {
1824		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
1825			break;
1826		lbn = lblkno(fs, uio->uio_offset);
1827		size = blksize(fs, ip, lbn);
1828		blkoffset = blkoff(fs, uio->uio_offset);
1829
1830		xfersize = fs->e2fs_fsize - blkoffset;
1831		xfersize = MIN(xfersize, uio->uio_resid);
1832		xfersize = MIN(xfersize, bytesinfile);
1833
1834		/* get block from ext4 extent cache */
1835		cache_type = ext4_ext_in_cache(ip, lbn, &nex);
1836		switch (cache_type) {
1837		case EXT4_EXT_CACHE_NO:
1838			ext4_ext_find_extent(fs, ip, lbn, &path);
1839			ep = path.ep_ext;
1840			if (ep == NULL)
1841				return (EIO);
1842
1843			ext4_ext_put_cache(ip, ep, EXT4_EXT_CACHE_IN);
1844
1845			newblk = lbn - ep->e_blk + (ep->e_start_lo |
1846			    (daddr_t)ep->e_start_hi << 32);
1847
1848			if (path.ep_bp != NULL) {
1849				brelse(path.ep_bp);
1850				path.ep_bp = NULL;
1851			}
1852			break;
1853
1854		case EXT4_EXT_CACHE_GAP:
1855			/* block has not been allocated yet */
1856			return (0);
1857
1858		case EXT4_EXT_CACHE_IN:
1859			newblk = lbn - nex.e_blk + (nex.e_start_lo |
1860			    (daddr_t)nex.e_start_hi << 32);
1861			break;
1862
1863		default:
1864			panic("%s: invalid cache type", __func__);
1865		}
1866
1867		error = bread(ip->i_devvp, fsbtodb(fs, newblk), size, NOCRED, &bp);
1868		if (error) {
1869			brelse(bp);
1870			return (error);
1871		}
1872
1873		size -= bp->b_resid;
1874		if (size < xfersize) {
1875			if (size == 0) {
1876				bqrelse(bp);
1877				break;
1878			}
1879			xfersize = size;
1880		}
1881		error = uiomove(bp->b_data + blkoffset, (int)xfersize, uio);
1882		bqrelse(bp);
1883		if (error)
1884			return (error);
1885	}
1886
1887	return (0);
1888}
1889
1890/*
1891 * Vnode op for writing.
1892 */
1893static int
1894ext2_write(struct vop_write_args *ap)
1895{
1896	struct vnode *vp;
1897	struct uio *uio;
1898	struct inode *ip;
1899	struct m_ext2fs *fs;
1900	struct buf *bp;
1901	daddr_t lbn;
1902	off_t osize;
1903	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;
1904
1905	ioflag = ap->a_ioflag;
1906	uio = ap->a_uio;
1907	vp = ap->a_vp;
1908
1909	seqcount = ioflag >> IO_SEQSHIFT;
1910	ip = VTOI(vp);
1911
1912#ifdef INVARIANTS
1913	if (uio->uio_rw != UIO_WRITE)
1914		panic("%s: mode", "ext2_write");
1915#endif
1916
1917	switch (vp->v_type) {
1918	case VREG:
1919		if (ioflag & IO_APPEND)
1920			uio->uio_offset = ip->i_size;
1921		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
1922			return (EPERM);
1923		/* FALLTHROUGH */
1924	case VLNK:
1925		break;
1926	case VDIR:
1927		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
1928		if ((ioflag & IO_SYNC) == 0)
1929		panic("ext2_write: nonsync dir write");
1930		break;
1931	default:
1932		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
1933		    vp->v_type, (intmax_t)uio->uio_offset,
1934		    (intmax_t)uio->uio_resid);
1935	}
1936
1937	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
1938	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
1939	fs = ip->i_e2fs;
1940	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
1941		return (EFBIG);
1942	/*
1943	 * Maybe this should be above the vnode op call, but so long as
1944	 * file servers have no limits, I don't think it matters.
1945	 */
1946	if (vn_rlimit_fsize(vp, uio, uio->uio_td))
1947		return (EFBIG);
1948
1949	resid = uio->uio_resid;
1950	osize = ip->i_size;
1951	if (seqcount > BA_SEQMAX)
1952		flags = BA_SEQMAX << BA_SEQSHIFT;
1953	else
1954		flags = seqcount << BA_SEQSHIFT;
1955	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
1956		flags |= IO_SYNC;
1957
1958	for (error = 0; uio->uio_resid > 0;) {
1959		lbn = lblkno(fs, uio->uio_offset);
1960		blkoffset = blkoff(fs, uio->uio_offset);
1961		xfersize = fs->e2fs_fsize - blkoffset;
1962		if (uio->uio_resid < xfersize)
1963			xfersize = uio->uio_resid;
1964		if (uio->uio_offset + xfersize > ip->i_size)
1965			vnode_pager_setsize(vp, uio->uio_offset + xfersize);
1966
1967		/*
1968		 * We must perform a read-before-write if the transfer size
1969		 * does not cover the entire buffer.
1970		 */
1971		if (fs->e2fs_bsize > xfersize)
1972			flags |= BA_CLRBUF;
1973		else
1974			flags &= ~BA_CLRBUF;
1975		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
1976		    ap->a_cred, &bp, flags);
1977		if (error != 0)
1978			break;
1979
1980		if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
1981			bp->b_flags |= B_NOCACHE;
1982		if (uio->uio_offset + xfersize > ip->i_size)
1983			ip->i_size = uio->uio_offset + xfersize;
1984		size = blksize(fs, ip, lbn) - bp->b_resid;
1985		if (size < xfersize)
1986			xfersize = size;
1987
1988		error =
1989		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
1990		/*
1991		 * If the buffer is not already filled and we encounter an
1992		 * error while trying to fill it, we have to clear out any
1993		 * garbage data from the pages instantiated for the buffer.
1994		 * If we do not, a failed uiomove() during a write can leave
1995		 * the prior contents of the pages exposed to a userland mmap.
1996		 *
1997		 * Note that we need only clear buffers with a transfer size
1998		 * equal to the block size because buffers with a shorter
1999		 * transfer size were cleared above by the call to ext2_balloc()
2000		 * with the BA_CLRBUF flag set.
2001		 *
2002		 * If the source region for uiomove identically mmaps the
2003		 * buffer, uiomove() performed the NOP copy, and the buffer
2004		 * content remains valid because the page fault handler
2005		 * validated the pages.
2006		 */
2007		if (error != 0 && (bp->b_flags & B_CACHE) == 0 &&
2008		    fs->e2fs_bsize == xfersize)
2009			vfs_bio_clrbuf(bp);
2010		if (ioflag & (IO_VMIO|IO_DIRECT)) {
2011			bp->b_flags |= B_RELBUF;
2012		}
2013
2014		/*
2015		 * If IO_SYNC each buffer is written synchronously.  Otherwise
2016		 * if we have a severe page deficiency write the buffer
2017		 * asynchronously.  Otherwise try to cluster, and if that
2018		 * doesn't do it then either do an async write (if O_DIRECT),
2019		 * or a delayed write (if not).
2020		 */
2021		if (ioflag & IO_SYNC) {
2022			(void)bwrite(bp);
2023		} else if (vm_page_count_severe() ||
2024		    buf_dirty_count_severe() ||
2025		    (ioflag & IO_ASYNC)) {
2026			bp->b_flags |= B_CLUSTEROK;
2027			bawrite(bp);
2028		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
2029			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
2030				bp->b_flags |= B_CLUSTEROK;
2031				cluster_write(vp, bp, ip->i_size, seqcount);
2032			} else {
2033				bawrite(bp);
2034			}
2035		} else if (ioflag & IO_DIRECT) {
2036			bp->b_flags |= B_CLUSTEROK;
2037			bawrite(bp);
2038		} else {
2039			bp->b_flags |= B_CLUSTEROK;
2040			bdwrite(bp);
2041		}
2042		if (error || xfersize == 0)
2043			break;
2044	}
2045	/*
2046	 * If we successfully wrote any data, and we are not the superuser
2047	 * we clear the setuid and setgid bits as a precaution against
2048	 * tampering.
2049	 */
2050	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
2051	    ap->a_cred) {
2052		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
2053			ip->i_mode &= ~(ISUID | ISGID);
2054	}
2055	if (error) {
2056		if (ioflag & IO_UNIT) {
2057			(void)ext2_truncate(vp, osize,
2058			    ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
2059			uio->uio_offset -= resid - uio->uio_resid;
2060			uio->uio_resid = resid;
2061		}
2062	}
2063	if (uio->uio_resid != resid) {
2064		ip->i_flag |= IN_CHANGE | IN_UPDATE;
2065		if (ioflag & IO_SYNC)
2066			error = ext2_update(vp, 1);
2067	}
2068	return (error);
2069}
2070