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