xref: /openbsd/sys/ufs/ffs/ffs_vnops.c (revision 9ea232b5)
1 /*	$OpenBSD: ffs_vnops.c,v 1.102 2024/02/03 18:51:58 beck Exp $	*/
2 /*	$NetBSD: ffs_vnops.c,v 1.7 1996/05/11 18:27:24 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)ffs_vnops.c	8.10 (Berkeley) 8/10/94
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/resourcevar.h>
38 #include <sys/kernel.h>
39 #include <sys/stat.h>
40 #include <sys/buf.h>
41 #include <sys/mount.h>
42 #include <sys/vnode.h>
43 #include <sys/malloc.h>
44 #include <sys/signalvar.h>
45 #include <sys/pool.h>
46 #include <sys/event.h>
47 #include <sys/specdev.h>
48 
49 #include <miscfs/fifofs/fifo.h>
50 
51 #include <ufs/ufs/quota.h>
52 #include <ufs/ufs/inode.h>
53 #include <ufs/ufs/dir.h>
54 #include <ufs/ufs/ufs_extern.h>
55 #include <ufs/ufs/ufsmount.h>
56 
57 #include <ufs/ffs/fs.h>
58 #include <ufs/ffs/ffs_extern.h>
59 
60 const struct vops ffs_vops = {
61 	.vop_lookup	= ufs_lookup,
62 	.vop_create	= ufs_create,
63 	.vop_mknod	= ufs_mknod,
64 	.vop_open	= ufs_open,
65 	.vop_close	= ufs_close,
66 	.vop_access	= ufs_access,
67 	.vop_getattr	= ufs_getattr,
68 	.vop_setattr	= ufs_setattr,
69 	.vop_read	= ffs_read,
70 	.vop_write	= ffs_write,
71 	.vop_ioctl	= ufs_ioctl,
72 	.vop_kqfilter	= ufs_kqfilter,
73 	.vop_revoke	= vop_generic_revoke,
74 	.vop_fsync	= ffs_fsync,
75 	.vop_remove	= ufs_remove,
76 	.vop_link	= ufs_link,
77 	.vop_rename	= ufs_rename,
78 	.vop_mkdir	= ufs_mkdir,
79 	.vop_rmdir	= ufs_rmdir,
80 	.vop_symlink	= ufs_symlink,
81 	.vop_readdir	= ufs_readdir,
82 	.vop_readlink	= ufs_readlink,
83 	.vop_abortop	= vop_generic_abortop,
84 	.vop_inactive	= ufs_inactive,
85 	.vop_reclaim	= ffs_reclaim,
86 	.vop_lock	= ufs_lock,
87 	.vop_unlock	= ufs_unlock,
88 	.vop_bmap	= ufs_bmap,
89 	.vop_strategy	= ufs_strategy,
90 	.vop_print	= ufs_print,
91 	.vop_islocked	= ufs_islocked,
92 	.vop_pathconf	= ufs_pathconf,
93 	.vop_advlock	= ufs_advlock,
94 	.vop_bwrite	= vop_generic_bwrite
95 };
96 
97 const struct vops ffs_specvops = {
98 	.vop_close	= ufsspec_close,
99 	.vop_access	= ufs_access,
100 	.vop_getattr	= ufs_getattr,
101 	.vop_setattr	= ufs_setattr,
102 	.vop_read	= ufsspec_read,
103 	.vop_write	= ufsspec_write,
104 	.vop_fsync	= ffs_fsync,
105 	.vop_inactive	= ufs_inactive,
106 	.vop_reclaim	= ffs_reclaim,
107 	.vop_lock	= ufs_lock,
108 	.vop_unlock	= ufs_unlock,
109 	.vop_print	= ufs_print,
110 	.vop_islocked	= ufs_islocked,
111 
112 	/* XXX: Keep in sync with spec_vops */
113 	.vop_lookup	= vop_generic_lookup,
114 	.vop_create	= vop_generic_badop,
115 	.vop_mknod	= vop_generic_badop,
116 	.vop_open	= spec_open,
117 	.vop_ioctl	= spec_ioctl,
118 	.vop_kqfilter	= spec_kqfilter,
119 	.vop_revoke	= vop_generic_revoke,
120 	.vop_remove	= vop_generic_badop,
121 	.vop_link	= vop_generic_badop,
122 	.vop_rename	= vop_generic_badop,
123 	.vop_mkdir	= vop_generic_badop,
124 	.vop_rmdir	= vop_generic_badop,
125 	.vop_symlink	= vop_generic_badop,
126 	.vop_readdir	= vop_generic_badop,
127 	.vop_readlink	= vop_generic_badop,
128 	.vop_abortop	= vop_generic_badop,
129 	.vop_bmap	= vop_generic_bmap,
130 	.vop_strategy	= spec_strategy,
131 	.vop_pathconf	= spec_pathconf,
132 	.vop_advlock	= spec_advlock,
133 	.vop_bwrite	= vop_generic_bwrite,
134 };
135 
136 #ifdef FIFO
137 const struct vops ffs_fifovops = {
138 	.vop_close	= ufsfifo_close,
139 	.vop_access	= ufs_access,
140 	.vop_getattr	= ufs_getattr,
141 	.vop_setattr	= ufs_setattr,
142 	.vop_read	= ufsfifo_read,
143 	.vop_write	= ufsfifo_write,
144 	.vop_fsync	= ffs_fsync,
145 	.vop_inactive	= ufs_inactive,
146 	.vop_reclaim	= ffsfifo_reclaim,
147 	.vop_lock	= ufs_lock,
148 	.vop_unlock	= ufs_unlock,
149 	.vop_print	= ufs_print,
150 	.vop_islocked	= ufs_islocked,
151 	.vop_bwrite	= vop_generic_bwrite,
152 
153 	/* XXX: Keep in sync with fifo_vops */
154 	.vop_lookup	= vop_generic_lookup,
155 	.vop_create	= vop_generic_badop,
156 	.vop_mknod	= vop_generic_badop,
157 	.vop_open	= fifo_open,
158 	.vop_ioctl	= fifo_ioctl,
159 	.vop_kqfilter	= fifo_kqfilter,
160 	.vop_revoke	= vop_generic_revoke,
161 	.vop_remove	= vop_generic_badop,
162 	.vop_link	= vop_generic_badop,
163 	.vop_rename	= vop_generic_badop,
164 	.vop_mkdir	= vop_generic_badop,
165 	.vop_rmdir	= vop_generic_badop,
166 	.vop_symlink	= vop_generic_badop,
167 	.vop_readdir	= vop_generic_badop,
168 	.vop_readlink	= vop_generic_badop,
169 	.vop_abortop	= vop_generic_badop,
170 	.vop_bmap	= vop_generic_bmap,
171 	.vop_strategy	= vop_generic_badop,
172 	.vop_pathconf	= fifo_pathconf,
173 	.vop_advlock	= fifo_advlock
174 };
175 #endif /* FIFO */
176 
177 /*
178  * Vnode op for reading.
179  */
180 int
181 ffs_read(void *v)
182 {
183 	struct vop_read_args *ap = v;
184 	struct vnode *vp;
185 	struct inode *ip;
186 	struct uio *uio;
187 	struct fs *fs;
188 	struct buf *bp;
189 	daddr_t lbn, nextlbn;
190 	off_t bytesinfile;
191 	int size, xfersize, blkoffset;
192 	mode_t mode;
193 	int error;
194 
195 	vp = ap->a_vp;
196 	ip = VTOI(vp);
197 	mode = DIP(ip, mode);
198 	uio = ap->a_uio;
199 
200 #ifdef DIAGNOSTIC
201 	if (uio->uio_rw != UIO_READ)
202 		panic("ffs_read: mode");
203 
204 	if (vp->v_type == VLNK) {
205 		if (DIP(ip, size) < ip->i_ump->um_maxsymlinklen)
206 			panic("ffs_read: short symlink");
207 	} else if (vp->v_type != VREG && vp->v_type != VDIR)
208 		panic("ffs_read: type %d", vp->v_type);
209 #endif
210 	fs = ip->i_fs;
211 	if (uio->uio_offset < 0)
212 		return (EINVAL);
213 	if (uio->uio_resid == 0)
214 		return (0);
215 
216 	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
217 		if ((bytesinfile = DIP(ip, size) - uio->uio_offset) <= 0)
218 			break;
219 		lbn = lblkno(fs, uio->uio_offset);
220 		nextlbn = lbn + 1;
221 		size = fs->fs_bsize;	/* WAS blksize(fs, ip, lbn); */
222 		blkoffset = blkoff(fs, uio->uio_offset);
223 		xfersize = fs->fs_bsize - blkoffset;
224 		if (uio->uio_resid < xfersize)
225 			xfersize = uio->uio_resid;
226 		if (bytesinfile < xfersize)
227 			xfersize = bytesinfile;
228 
229 		if (lblktosize(fs, nextlbn) >= DIP(ip, size))
230 			error = bread(vp, lbn, size, &bp);
231 		else if (lbn - 1 == ip->i_ci.ci_lastr ||
232 		    uio->uio_resid > xfersize) {
233 			error = bread_cluster(vp, lbn, size, &bp);
234 		} else
235 			error = bread(vp, lbn, size, &bp);
236 
237 		if (error)
238 			break;
239 		ip->i_ci.ci_lastr = lbn;
240 
241 		/*
242 		 * We should only get non-zero b_resid when an I/O error
243 		 * has occurred, which should cause us to break above.
244 		 * However, if the short read did not cause an error,
245 		 * then we want to ensure that we do not uiomove bad
246 		 * or uninitialized data.
247 		 */
248 		size -= bp->b_resid;
249 		if (size < xfersize) {
250 			if (size == 0)
251 				break;
252 			xfersize = size;
253 		}
254 		error = uiomove(bp->b_data + blkoffset, xfersize, uio);
255 		if (error)
256 			break;
257 		brelse(bp);
258 	}
259 	if (bp != NULL)
260 		brelse(bp);
261 	if (!(vp->v_mount->mnt_flag & MNT_NOATIME) ||
262 	    (ip->i_flag & (IN_CHANGE | IN_UPDATE))) {
263 		ip->i_flag |= IN_ACCESS;
264 	}
265 	return (error);
266 }
267 
268 /*
269  * Vnode op for writing.
270  */
271 int
272 ffs_write(void *v)
273 {
274 	struct vop_write_args *ap = v;
275 	struct vnode *vp;
276 	struct uio *uio;
277 	struct inode *ip;
278 	struct fs *fs;
279 	struct buf *bp;
280 	daddr_t lbn;
281 	off_t osize;
282 	int blkoffset, error, extended, flags, ioflag, size, xfersize;
283 	size_t resid;
284 	ssize_t overrun;
285 
286 	extended = 0;
287 	ioflag = ap->a_ioflag;
288 	uio = ap->a_uio;
289 	vp = ap->a_vp;
290 	ip = VTOI(vp);
291 
292 #ifdef DIAGNOSTIC
293 	if (uio->uio_rw != UIO_WRITE)
294 		panic("ffs_write: mode");
295 #endif
296 
297 	/*
298 	 * If writing 0 bytes, succeed and do not change
299 	 * update time or file offset (standards compliance)
300 	 */
301 	if (uio->uio_resid == 0)
302 		return (0);
303 
304 	switch (vp->v_type) {
305 	case VREG:
306 		if (ioflag & IO_APPEND)
307 			uio->uio_offset = DIP(ip, size);
308 		if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
309 			return (EPERM);
310 		/* FALLTHROUGH */
311 	case VLNK:
312 		break;
313 	case VDIR:
314 		if ((ioflag & IO_SYNC) == 0)
315 			panic("ffs_write: nonsync dir write");
316 		break;
317 	default:
318 		panic("ffs_write: type %d", vp->v_type);
319 	}
320 
321 	fs = ip->i_fs;
322 	if (uio->uio_offset < 0 ||
323 	    (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
324 		return (EFBIG);
325 
326 	/* do the filesize rlimit check */
327 	if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
328 		return (error);
329 
330 	resid = uio->uio_resid;
331 	osize = DIP(ip, size);
332 	flags = ioflag & IO_SYNC ? B_SYNC : 0;
333 
334 	for (error = 0; uio->uio_resid > 0;) {
335 		lbn = lblkno(fs, uio->uio_offset);
336 		blkoffset = blkoff(fs, uio->uio_offset);
337 		xfersize = fs->fs_bsize - blkoffset;
338 		if (uio->uio_resid < xfersize)
339 			xfersize = uio->uio_resid;
340 		if (fs->fs_bsize > xfersize)
341 			flags |= B_CLRBUF;
342 		else
343 			flags &= ~B_CLRBUF;
344 
345 		if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
346 			 ap->a_cred, flags, &bp)) != 0)
347 			break;
348 		if (uio->uio_offset + xfersize > DIP(ip, size)) {
349 			DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
350 			uvm_vnp_setsize(vp, DIP(ip, size));
351 			extended = 1;
352 		}
353 		(void)uvm_vnp_uncache(vp);
354 
355 		size = blksize(fs, ip, lbn) - bp->b_resid;
356 		if (size < xfersize)
357 			xfersize = size;
358 
359 		error = uiomove(bp->b_data + blkoffset, xfersize, uio);
360 		/*
361 		 * If the buffer is not already filled and we encounter an
362 		 * error while trying to fill it, we have to clear out any
363 		 * garbage data from the pages instantiated for the buffer.
364 		 * If we do not, a failed uiomove() during a write can leave
365 		 * the prior contents of the pages exposed to a userland mmap.
366 		 *
367 		 * Note that we don't need to clear buffers that were
368 		 * allocated with the B_CLRBUF flag set.
369                  */
370 		if (error != 0 && !(flags & B_CLRBUF))
371 			memset(bp->b_data + blkoffset, 0, xfersize);
372 
373 		if (ioflag & IO_NOCACHE)
374 			bp->b_flags |= B_NOCACHE;
375 
376 		if (ioflag & IO_SYNC)
377 			(void)bwrite(bp);
378 		else if (xfersize + blkoffset == fs->fs_bsize) {
379 			bawrite(bp);
380 		} else
381 			bdwrite(bp);
382 
383 		if (error || xfersize == 0)
384 			break;
385 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
386 	}
387 	/*
388 	 * If we successfully wrote any data, and we are not the superuser
389 	 * we clear the setuid and setgid bits as a precaution against
390 	 * tampering.
391 	 */
392 	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0 &&
393 	    !vnoperm(vp))
394 		DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
395 	if (resid > uio->uio_resid)
396 		VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
397 	if (error) {
398 		if (ioflag & IO_UNIT) {
399 			(void)UFS_TRUNCATE(ip, osize,
400 			    ioflag & IO_SYNC, ap->a_cred);
401 			uio->uio_offset -= resid - uio->uio_resid;
402 			uio->uio_resid = resid;
403 		}
404 	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
405 		error = UFS_UPDATE(ip, 1);
406 	}
407 	/* correct the result for writes clamped by vn_fsizechk() */
408 	uio->uio_resid += overrun;
409 	return (error);
410 }
411 
412 /*
413  * Synch an open file.
414  */
415 int
416 ffs_fsync(void *v)
417 {
418 	struct vop_fsync_args *ap = v;
419 	struct vnode *vp = ap->a_vp;
420 	struct buf *bp, *nbp;
421 	int s, error, passes, skipmeta;
422 
423 	/*
424 	 * Flush all dirty buffers associated with a vnode.
425 	 */
426 	passes = NIADDR + 1;
427 	skipmeta = 0;
428 	if (ap->a_waitfor == MNT_WAIT)
429 		skipmeta = 1;
430 	s = splbio();
431 loop:
432 	LIST_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) {
433 		bp->b_flags &= ~B_SCANNED;
434 	}
435 	LIST_FOREACH_SAFE(bp, &vp->v_dirtyblkhd, b_vnbufs, nbp) {
436 		/*
437 		 * Reasons to skip this buffer: it has already been considered
438 		 * on this pass, this pass is the first time through on a
439 		 * synchronous flush request and the buffer being considered
440 		 * is metadata, the buffer has dependencies that will cause
441 		 * it to be redirtied and it has not already been deferred,
442 		 * or it is already being written.
443 		 */
444 		if (bp->b_flags & (B_BUSY | B_SCANNED))
445 			continue;
446 		if ((bp->b_flags & B_DELWRI) == 0)
447 			panic("ffs_fsync: not dirty");
448 		if (skipmeta && bp->b_lblkno < 0)
449 			continue;
450 
451 		bremfree(bp);
452 		buf_acquire(bp);
453 		bp->b_flags |= B_SCANNED;
454 		splx(s);
455 		/*
456 		 * On our final pass through, do all I/O synchronously
457 		 * so that we can find out if our flush is failing
458 		 * because of write errors.
459 		 */
460 		if (passes > 0 || ap->a_waitfor != MNT_WAIT)
461 			(void) bawrite(bp);
462 		else if ((error = bwrite(bp)) != 0)
463 			return (error);
464 		s = splbio();
465 		/*
466 		 * Since we may have slept during the I/O, we need
467 		 * to start from a known point.
468 		 */
469 		nbp = LIST_FIRST(&vp->v_dirtyblkhd);
470 	}
471 	if (skipmeta) {
472 		skipmeta = 0;
473 		goto loop;
474 	}
475 	if (ap->a_waitfor == MNT_WAIT) {
476 		vwaitforio(vp, 0, "ffs_fsync", INFSLP);
477 
478 		/*
479 		 * Ensure that any filesystem metadata associated
480 		 * with the vnode has been written.
481 		 */
482 		splx(s);
483 		/* XXX softdep was here. reconsider this locking dance */
484 		s = splbio();
485 		if (!LIST_EMPTY(&vp->v_dirtyblkhd)) {
486 			/*
487 			 * Block devices associated with filesystems may
488 			 * have new I/O requests posted for them even if
489 			 * the vnode is locked, so no amount of trying will
490 			 * get them clean. Thus we give block devices a
491 			 * good effort, then just give up. For all other file
492 			 * types, go around and try again until it is clean.
493 			 */
494 			if (passes > 0) {
495 				passes -= 1;
496 				goto loop;
497 			}
498 #ifdef DIAGNOSTIC
499 			if (vp->v_type != VBLK)
500 				vprint("ffs_fsync: dirty", vp);
501 #endif
502 		}
503 	}
504 	splx(s);
505 	return (UFS_UPDATE(VTOI(vp), ap->a_waitfor == MNT_WAIT));
506 }
507 
508 /*
509  * Reclaim an inode so that it can be used for other purposes.
510  */
511 int
512 ffs_reclaim(void *v)
513 {
514 	struct vop_reclaim_args *ap = v;
515 	struct vnode *vp = ap->a_vp;
516 	struct inode *ip = VTOI(vp);
517 	int error;
518 
519 	if ((error = ufs_reclaim(vp)) != 0)
520 		return (error);
521 
522 	if (ip->i_din1 != NULL) {
523 #ifdef FFS2
524 		if (ip->i_ump->um_fstype == UM_UFS2)
525 			pool_put(&ffs_dinode2_pool, ip->i_din2);
526 		else
527 #endif
528 			pool_put(&ffs_dinode1_pool, ip->i_din1);
529 	}
530 
531 	pool_put(&ffs_ino_pool, ip);
532 
533 	vp->v_data = NULL;
534 
535 	return (0);
536 }
537 
538 #ifdef FIFO
539 int
540 ffsfifo_reclaim(void *v)
541 {
542 	fifo_reclaim(v);
543 	return (ffs_reclaim(v));
544 }
545 #endif
546