1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/bio.h>
40#include <sys/buf.h>
41#include <sys/proc.h>
42#include <sys/rwlock.h>
43#include <sys/vnode.h>
44#include <sys/mount.h>
45#include <sys/racct.h>
46#include <sys/resourcevar.h>
47#include <sys/stat.h>
48
49#include <vm/vm.h>
50#include <vm/vm_object.h>
51#include <vm/vnode_pager.h>
52
53#include <ufs/ufs/extattr.h>
54#include <ufs/ufs/quota.h>
55#include <ufs/ufs/inode.h>
56#include <ufs/ufs/ufsmount.h>
57#include <ufs/ufs/ufs_extern.h>
58
59static ufs_lbn_t lbn_count(struct ufsmount *, int);
60static int readindir(struct vnode *, ufs_lbn_t, ufs2_daddr_t, struct buf **);
61
62/*
63 * Bmap converts the logical block number of a file to its physical block
64 * number on the disk. The conversion is done by using the logical block
65 * number to index into the array of block pointers described by the dinode.
66 */
67int
68ufs_bmap(
69	struct vop_bmap_args /* {
70		struct vnode *a_vp;
71		daddr_t a_bn;
72		struct bufobj **a_bop;
73		daddr_t *a_bnp;
74		int *a_runp;
75		int *a_runb;
76	} */ *ap)
77{
78	ufs2_daddr_t blkno;
79	int error;
80
81	/*
82	 * Check for underlying vnode requests and ensure that logical
83	 * to physical mapping is requested.
84	 */
85	if (ap->a_bop != NULL)
86		*ap->a_bop = &VFSTOUFS(ap->a_vp->v_mount)->um_devvp->v_bufobj;
87	if (ap->a_bnp == NULL)
88		return (0);
89
90	error = ufs_bmaparray(ap->a_vp, ap->a_bn, &blkno, NULL,
91	    ap->a_runp, ap->a_runb);
92	*ap->a_bnp = blkno;
93	return (error);
94}
95
96static int
97readindir(struct vnode *vp,
98	ufs_lbn_t lbn,
99	ufs2_daddr_t daddr,
100	struct buf **bpp)
101{
102	struct buf *bp;
103	struct mount *mp;
104	struct ufsmount *ump;
105	int error;
106
107	mp = vp->v_mount;
108	ump = VFSTOUFS(mp);
109
110	bp = getblk(vp, lbn, mp->mnt_stat.f_iosize, 0, 0, 0);
111	if ((bp->b_flags & B_CACHE) == 0) {
112		KASSERT(daddr != 0,
113		    ("readindir: indirect block not in cache"));
114
115		bp->b_blkno = blkptrtodb(ump, daddr);
116		bp->b_iocmd = BIO_READ;
117		bp->b_flags &= ~B_INVAL;
118		bp->b_ioflags &= ~BIO_ERROR;
119		vfs_busy_pages(bp, 0);
120		bp->b_iooffset = dbtob(bp->b_blkno);
121		bstrategy(bp);
122#ifdef RACCT
123		if (racct_enable) {
124			PROC_LOCK(curproc);
125			racct_add_buf(curproc, bp, 0);
126			PROC_UNLOCK(curproc);
127		}
128#endif
129		curthread->td_ru.ru_inblock++;
130		error = bufwait(bp);
131		if (error != 0) {
132			brelse(bp);
133			return (error);
134		}
135	}
136	*bpp = bp;
137	return (0);
138}
139
140/*
141 * Indirect blocks are now on the vnode for the file.  They are given negative
142 * logical block numbers.  Indirect blocks are addressed by the negative
143 * address of the first data block to which they point.  Double indirect blocks
144 * are addressed by one less than the address of the first indirect block to
145 * which they point.  Triple indirect blocks are addressed by one less than
146 * the address of the first double indirect block to which they point.
147 *
148 * ufs_bmaparray does the bmap conversion, and if requested returns the
149 * array of logical blocks which must be traversed to get to a block.
150 * Each entry contains the offset into that block that gets you to the
151 * next block and the disk address of the block (if it is assigned).
152 */
153
154int
155ufs_bmaparray(struct vnode *vp,
156	ufs2_daddr_t bn,
157	ufs2_daddr_t *bnp,
158	struct buf *nbp,
159	int *runp,
160	int *runb)
161{
162	struct inode *ip;
163	struct buf *bp;
164	struct ufsmount *ump;
165	struct mount *mp;
166	struct indir a[UFS_NIADDR+1], *ap;
167	ufs2_daddr_t daddr;
168	ufs_lbn_t metalbn;
169	int error, num, maxrun = 0;
170	int *nump;
171
172	ap = NULL;
173	ip = VTOI(vp);
174	mp = vp->v_mount;
175	ump = VFSTOUFS(mp);
176
177	if (runp) {
178		maxrun = mp->mnt_iosize_max / mp->mnt_stat.f_iosize - 1;
179		*runp = 0;
180	}
181
182	if (runb) {
183		*runb = 0;
184	}
185
186	ap = a;
187	nump = &num;
188	error = ufs_getlbns(vp, bn, ap, nump);
189	if (error)
190		return (error);
191
192	num = *nump;
193	if (num == 0) {
194		if (bn >= 0 && bn < UFS_NDADDR) {
195			*bnp = blkptrtodb(ump, DIP(ip, i_db[bn]));
196		} else if (bn < 0 && bn >= -UFS_NXADDR) {
197			*bnp = blkptrtodb(ump, ip->i_din2->di_extb[-1 - bn]);
198			if (*bnp == 0)
199				*bnp = -1;
200			if (nbp == NULL) {
201				/* indirect block not found */
202				return (EINVAL);
203			}
204			nbp->b_xflags |= BX_ALTDATA;
205			return (0);
206		} else {
207			/* blkno out of range */
208			return (EINVAL);
209		}
210		/*
211		 * Since this is FFS independent code, we are out of
212		 * scope for the definitions of BLK_NOCOPY and
213		 * BLK_SNAP, but we do know that they will fall in
214		 * the range 1..um_seqinc, so we use that test and
215		 * return a request for a zeroed out buffer if attempts
216		 * are made to read a BLK_NOCOPY or BLK_SNAP block.
217		 */
218		if (IS_SNAPSHOT(ip) && DIP(ip, i_db[bn]) > 0 &&
219		    DIP(ip, i_db[bn]) < ump->um_seqinc) {
220			*bnp = -1;
221		} else if (*bnp == 0) {
222			*bnp = IS_SNAPSHOT(ip) ? blkptrtodb(ump,
223			    bn * ump->um_seqinc) : -1;
224		} else if (runp) {
225			ufs2_daddr_t bnb = bn;
226			for (++bn; bn < UFS_NDADDR && *runp < maxrun &&
227			    is_sequential(ump, DIP(ip, i_db[bn - 1]),
228			    DIP(ip, i_db[bn]));
229			    ++bn, ++*runp);
230			bn = bnb;
231			if (runb && (bn > 0)) {
232				for (--bn; (bn >= 0) && (*runb < maxrun) &&
233					is_sequential(ump, DIP(ip, i_db[bn]),
234						DIP(ip, i_db[bn+1]));
235						--bn, ++*runb);
236			}
237		}
238		return (0);
239	}
240
241	/* Get disk address out of indirect block array */
242	daddr = DIP(ip, i_ib[ap->in_off]);
243
244	for (bp = NULL, ++ap; --num; ++ap) {
245		/*
246		 * Exit the loop if there is no disk address assigned yet and
247		 * the indirect block isn't in the cache, or if we were
248		 * looking for an indirect block and we've found it.
249		 */
250
251		metalbn = ap->in_lbn;
252		if ((daddr == 0 && !incore(&vp->v_bufobj, metalbn)) || metalbn == bn)
253			break;
254		/*
255		 * If we get here, we've either got the block in the cache
256		 * or we have a disk address for it, go fetch it.
257		 */
258		if (bp)
259			bqrelse(bp);
260		error = readindir(vp, metalbn, daddr, &bp);
261		if (error != 0)
262			return (error);
263
264		if (I_IS_UFS1(ip))
265			daddr = ((ufs1_daddr_t *)bp->b_data)[ap->in_off];
266		else
267			daddr = ((ufs2_daddr_t *)bp->b_data)[ap->in_off];
268		if ((error = UFS_CHECK_BLKNO(mp, ip->i_number, daddr,
269		     mp->mnt_stat.f_iosize)) != 0) {
270			bqrelse(bp);
271			return (error);
272		}
273		if (I_IS_UFS1(ip)) {
274			if (num == 1 && daddr && runp) {
275				for (bn = ap->in_off + 1;
276				    bn < MNINDIR(ump) && *runp < maxrun &&
277				    is_sequential(ump,
278				    ((ufs1_daddr_t *)bp->b_data)[bn - 1],
279				    ((ufs1_daddr_t *)bp->b_data)[bn]);
280				    ++bn, ++*runp);
281				bn = ap->in_off;
282				if (runb && bn) {
283					for (--bn; bn >= 0 && *runb < maxrun &&
284					    is_sequential(ump,
285					    ((ufs1_daddr_t *)bp->b_data)[bn],
286					    ((ufs1_daddr_t *)bp->b_data)[bn+1]);
287					    --bn, ++*runb);
288				}
289			}
290			continue;
291		}
292		if (num == 1 && daddr && runp) {
293			for (bn = ap->in_off + 1;
294			    bn < MNINDIR(ump) && *runp < maxrun &&
295			    is_sequential(ump,
296			    ((ufs2_daddr_t *)bp->b_data)[bn - 1],
297			    ((ufs2_daddr_t *)bp->b_data)[bn]);
298			    ++bn, ++*runp);
299			bn = ap->in_off;
300			if (runb && bn) {
301				for (--bn; bn >= 0 && *runb < maxrun &&
302				    is_sequential(ump,
303				    ((ufs2_daddr_t *)bp->b_data)[bn],
304				    ((ufs2_daddr_t *)bp->b_data)[bn + 1]);
305				    --bn, ++*runb);
306			}
307		}
308	}
309	if (bp)
310		bqrelse(bp);
311
312	/*
313	 * Since this is FFS independent code, we are out of scope for the
314	 * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they
315	 * will fall in the range 1..um_seqinc, so we use that test and
316	 * return a request for a zeroed out buffer if attempts are made
317	 * to read a BLK_NOCOPY or BLK_SNAP block.
318	 */
319	if (IS_SNAPSHOT(ip) && daddr > 0 && daddr < ump->um_seqinc){
320		*bnp = -1;
321		return (0);
322	}
323	*bnp = blkptrtodb(ump, daddr);
324	if (*bnp == 0) {
325		if (IS_SNAPSHOT(ip))
326			*bnp = blkptrtodb(ump, bn * ump->um_seqinc);
327		else
328			*bnp = -1;
329	}
330	return (0);
331}
332
333static ufs_lbn_t
334lbn_count(struct ufsmount *ump, int level)
335{
336	ufs_lbn_t blockcnt;
337
338	for (blockcnt = 1; level > 0; level--)
339		blockcnt *= MNINDIR(ump);
340	return (blockcnt);
341}
342
343int
344ufs_bmap_seekdata(struct vnode *vp, off_t *offp)
345{
346	struct buf *bp;
347	struct indir a[UFS_NIADDR + 1], *ap;
348	struct inode *ip;
349	struct mount *mp;
350	struct ufsmount *ump;
351	ufs2_daddr_t bn, daddr, nextbn;
352	uint64_t bsize;
353	off_t numblks;
354	int error, num, num1, off;
355
356	bp = NULL;
357	error = 0;
358	ip = VTOI(vp);
359	mp = vp->v_mount;
360	ump = VFSTOUFS(mp);
361
362	if (vp->v_type != VREG || IS_SNAPSHOT(ip))
363		return (EINVAL);
364	if (*offp < 0 || *offp >= ip->i_size)
365		return (ENXIO);
366
367	/*
368	 * We could have pages on the vnode' object queue which still
369	 * do not have the data blocks allocated.  Convert all dirty
370	 * pages into buffer writes to ensure that we see all
371	 * allocated data.
372	 */
373	vnode_pager_clean_sync(vp);
374
375	bsize = mp->mnt_stat.f_iosize;
376	for (bn = *offp / bsize, numblks = howmany(ip->i_size, bsize);
377	    bn < numblks; bn = nextbn) {
378		if (bn < UFS_NDADDR) {
379			daddr = DIP(ip, i_db[bn]);
380			if (daddr != 0)
381				break;
382			nextbn = bn + 1;
383			continue;
384		}
385
386		ap = a;
387		error = ufs_getlbns(vp, bn, ap, &num);
388		if (error != 0)
389			break;
390		MPASS(num >= 2);
391		daddr = DIP(ip, i_ib[ap->in_off]);
392		ap++, num--;
393		for (nextbn = UFS_NDADDR, num1 = num - 1; num1 > 0; num1--)
394			nextbn += lbn_count(ump, num1);
395		if (daddr == 0) {
396			nextbn += lbn_count(ump, num);
397			continue;
398		}
399
400		for (; daddr != 0 && num > 0; ap++, num--) {
401			if (bp != NULL)
402				bqrelse(bp);
403			error = readindir(vp, ap->in_lbn, daddr, &bp);
404			if (error != 0)
405				return (error);
406
407			/*
408			 * Scan the indirect block until we find a non-zero
409			 * pointer.
410			 */
411			off = ap->in_off;
412			do {
413				daddr = I_IS_UFS1(ip) ?
414				    ((ufs1_daddr_t *)bp->b_data)[off] :
415				    ((ufs2_daddr_t *)bp->b_data)[off];
416			} while (daddr == 0 && ++off < MNINDIR(ump));
417			nextbn += off * lbn_count(ump, num - 1);
418
419			/*
420			 * We need to recompute the LBNs of indirect
421			 * blocks, so restart with the updated block offset.
422			 */
423			if (off != ap->in_off)
424				break;
425		}
426		if (num == 0) {
427			/*
428			 * We found a data block.
429			 */
430			bn = nextbn;
431			break;
432		}
433	}
434	if (bp != NULL)
435		bqrelse(bp);
436	if (bn >= numblks)
437		error = ENXIO;
438	if (error == 0 && *offp < bn * bsize)
439		*offp = bn * bsize;
440	return (error);
441}
442
443/*
444 * Create an array of logical block number/offset pairs which represent the
445 * path of indirect blocks required to access a data block.  The first "pair"
446 * contains the logical block number of the appropriate single, double or
447 * triple indirect block and the offset into the inode indirect block array.
448 * Note, the logical block number of the inode single/double/triple indirect
449 * block appears twice in the array, once with the offset into the i_ib and
450 * once with the offset into the page itself.
451 */
452int
453ufs_getlbns(struct vnode *vp,
454	ufs2_daddr_t bn,
455	struct indir *ap,
456	int *nump)
457{
458	ufs2_daddr_t blockcnt;
459	ufs_lbn_t metalbn, realbn;
460	struct ufsmount *ump;
461	int i, numlevels, off;
462
463	ump = VFSTOUFS(vp->v_mount);
464	if (nump)
465		*nump = 0;
466	numlevels = 0;
467	realbn = bn;
468	if (bn < 0)
469		bn = -bn;
470
471	/* The first UFS_NDADDR blocks are direct blocks. */
472	if (bn < UFS_NDADDR)
473		return (0);
474
475	/*
476	 * Determine the number of levels of indirection.  After this loop
477	 * is done, blockcnt indicates the number of data blocks possible
478	 * at the previous level of indirection, and UFS_NIADDR - i is the
479	 * number of levels of indirection needed to locate the requested block.
480	 */
481	for (blockcnt = 1, i = UFS_NIADDR, bn -= UFS_NDADDR; ;
482	    i--, bn -= blockcnt) {
483		if (i == 0)
484			return (EFBIG);
485		blockcnt *= MNINDIR(ump);
486		if (bn < blockcnt)
487			break;
488	}
489
490	/* Calculate the address of the first meta-block. */
491	if (realbn >= 0)
492		metalbn = -(realbn - bn + UFS_NIADDR - i);
493	else
494		metalbn = -(-realbn - bn + UFS_NIADDR - i);
495
496	/*
497	 * At each iteration, off is the offset into the bap array which is
498	 * an array of disk addresses at the current level of indirection.
499	 * The logical block number and the offset in that block are stored
500	 * into the argument array.
501	 */
502	ap->in_lbn = metalbn;
503	ap->in_off = off = UFS_NIADDR - i;
504	ap++;
505	for (++numlevels; i <= UFS_NIADDR; i++) {
506		/* If searching for a meta-data block, quit when found. */
507		if (metalbn == realbn)
508			break;
509
510		blockcnt /= MNINDIR(ump);
511		off = (bn / blockcnt) % MNINDIR(ump);
512
513		++numlevels;
514		ap->in_lbn = metalbn;
515		ap->in_off = off;
516		++ap;
517
518		metalbn -= -1 + off * blockcnt;
519	}
520	if (nump)
521		*nump = numlevels;
522	return (0);
523}
524