1 | /* $NetBSD: ufs_bmap.c,v 1.50 2013/01/22 09:39:18 dholland Exp $ */ |
2 | |
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 | * @(#)ufs_bmap.c 8.8 (Berkeley) 8/11/95 |
37 | */ |
38 | |
39 | #include <sys/cdefs.h> |
40 | __KERNEL_RCSID(0, "$NetBSD: ufs_bmap.c,v 1.50 2013/01/22 09:39:18 dholland Exp $" ); |
41 | |
42 | #include <sys/param.h> |
43 | #include <sys/systm.h> |
44 | #include <sys/buf.h> |
45 | #include <sys/proc.h> |
46 | #include <sys/vnode.h> |
47 | #include <sys/mount.h> |
48 | #include <sys/resourcevar.h> |
49 | #include <sys/trace.h> |
50 | #include <sys/fstrans.h> |
51 | |
52 | #include <miscfs/specfs/specdev.h> |
53 | |
54 | #include <ufs/ufs/inode.h> |
55 | #include <ufs/ufs/ufsmount.h> |
56 | #include <ufs/ufs/ufs_extern.h> |
57 | #include <ufs/ufs/ufs_bswap.h> |
58 | |
59 | static bool |
60 | ufs_issequential(const struct ufsmount *ump, daddr_t daddr0, daddr_t daddr1) |
61 | { |
62 | |
63 | /* for ufs, blocks in a hole is not 'contiguous'. */ |
64 | if (daddr0 == 0) |
65 | return false; |
66 | |
67 | return (daddr0 + ump->um_seqinc == daddr1); |
68 | } |
69 | |
70 | /* |
71 | * Bmap converts the logical block number of a file to its physical block |
72 | * number on the disk. The conversion is done by using the logical block |
73 | * number to index into the array of block pointers described by the dinode. |
74 | */ |
75 | int |
76 | ufs_bmap(void *v) |
77 | { |
78 | struct vop_bmap_args /* { |
79 | struct vnode *a_vp; |
80 | daddr_t a_bn; |
81 | struct vnode **a_vpp; |
82 | daddr_t *a_bnp; |
83 | int *a_runp; |
84 | } */ *ap = v; |
85 | int error; |
86 | |
87 | /* |
88 | * Check for underlying vnode requests and ensure that logical |
89 | * to physical mapping is requested. |
90 | */ |
91 | if (ap->a_vpp != NULL) |
92 | *ap->a_vpp = VTOI(ap->a_vp)->i_devvp; |
93 | if (ap->a_bnp == NULL) |
94 | return (0); |
95 | |
96 | fstrans_start(ap->a_vp->v_mount, FSTRANS_SHARED); |
97 | error = ufs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL, |
98 | ap->a_runp, ufs_issequential); |
99 | fstrans_done(ap->a_vp->v_mount); |
100 | return error; |
101 | } |
102 | |
103 | /* |
104 | * Indirect blocks are now on the vnode for the file. They are given negative |
105 | * logical block numbers. Indirect blocks are addressed by the negative |
106 | * address of the first data block to which they point. Double indirect blocks |
107 | * are addressed by one less than the address of the first indirect block to |
108 | * which they point. Triple indirect blocks are addressed by one less than |
109 | * the address of the first double indirect block to which they point. |
110 | * |
111 | * ufs_bmaparray does the bmap conversion, and if requested returns the |
112 | * array of logical blocks which must be traversed to get to a block. |
113 | * Each entry contains the offset into that block that gets you to the |
114 | * next block and the disk address of the block (if it is assigned). |
115 | */ |
116 | |
117 | int |
118 | ufs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, |
119 | int *nump, int *runp, ufs_issequential_callback_t is_sequential) |
120 | { |
121 | struct inode *ip; |
122 | struct buf *bp, *cbp; |
123 | struct ufsmount *ump; |
124 | struct mount *mp; |
125 | struct indir a[UFS_NIADDR + 1], *xap; |
126 | daddr_t daddr; |
127 | daddr_t metalbn; |
128 | int error, maxrun = 0, num; |
129 | |
130 | ip = VTOI(vp); |
131 | mp = vp->v_mount; |
132 | ump = ip->i_ump; |
133 | #ifdef DIAGNOSTIC |
134 | if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL)) |
135 | panic("ufs_bmaparray: invalid arguments" ); |
136 | #endif |
137 | |
138 | if (runp) { |
139 | /* |
140 | * XXX |
141 | * If MAXBSIZE is the largest transfer the disks can handle, |
142 | * we probably want maxrun to be 1 block less so that we |
143 | * don't create a block larger than the device can handle. |
144 | */ |
145 | *runp = 0; |
146 | maxrun = MAXPHYS / mp->mnt_stat.f_iosize - 1; |
147 | } |
148 | |
149 | if (bn >= 0 && bn < UFS_NDADDR) { |
150 | if (nump != NULL) |
151 | *nump = 0; |
152 | if (ump->um_fstype == UFS1) |
153 | daddr = ufs_rw32(ip->i_ffs1_db[bn], |
154 | UFS_MPNEEDSWAP(ump)); |
155 | else |
156 | daddr = ufs_rw64(ip->i_ffs2_db[bn], |
157 | UFS_MPNEEDSWAP(ump)); |
158 | *bnp = blkptrtodb(ump, daddr); |
159 | /* |
160 | * Since this is FFS independent code, we are out of |
161 | * scope for the definitions of BLK_NOCOPY and |
162 | * BLK_SNAP, but we do know that they will fall in |
163 | * the range 1..um_seqinc, so we use that test and |
164 | * return a request for a zeroed out buffer if attempts |
165 | * are made to read a BLK_NOCOPY or BLK_SNAP block. |
166 | */ |
167 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) == SF_SNAPSHOT |
168 | && daddr > 0 && |
169 | daddr < ump->um_seqinc) { |
170 | *bnp = -1; |
171 | } else if (*bnp == 0) { |
172 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) |
173 | == SF_SNAPSHOT) { |
174 | *bnp = blkptrtodb(ump, bn * ump->um_seqinc); |
175 | } else { |
176 | *bnp = -1; |
177 | } |
178 | } else if (runp) { |
179 | if (ump->um_fstype == UFS1) { |
180 | for (++bn; bn < UFS_NDADDR && *runp < maxrun && |
181 | is_sequential(ump, |
182 | ufs_rw32(ip->i_ffs1_db[bn - 1], |
183 | UFS_MPNEEDSWAP(ump)), |
184 | ufs_rw32(ip->i_ffs1_db[bn], |
185 | UFS_MPNEEDSWAP(ump))); |
186 | ++bn, ++*runp); |
187 | } else { |
188 | for (++bn; bn < UFS_NDADDR && *runp < maxrun && |
189 | is_sequential(ump, |
190 | ufs_rw64(ip->i_ffs2_db[bn - 1], |
191 | UFS_MPNEEDSWAP(ump)), |
192 | ufs_rw64(ip->i_ffs2_db[bn], |
193 | UFS_MPNEEDSWAP(ump))); |
194 | ++bn, ++*runp); |
195 | } |
196 | } |
197 | return (0); |
198 | } |
199 | |
200 | xap = ap == NULL ? a : ap; |
201 | if (!nump) |
202 | nump = # |
203 | if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0) |
204 | return (error); |
205 | |
206 | num = *nump; |
207 | |
208 | /* Get disk address out of indirect block array */ |
209 | if (ump->um_fstype == UFS1) |
210 | daddr = ufs_rw32(ip->i_ffs1_ib[xap->in_off], |
211 | UFS_MPNEEDSWAP(ump)); |
212 | else |
213 | daddr = ufs_rw64(ip->i_ffs2_ib[xap->in_off], |
214 | UFS_MPNEEDSWAP(ump)); |
215 | |
216 | for (bp = NULL, ++xap; --num; ++xap) { |
217 | /* |
218 | * Exit the loop if there is no disk address assigned yet and |
219 | * the indirect block isn't in the cache, or if we were |
220 | * looking for an indirect block and we've found it. |
221 | */ |
222 | |
223 | metalbn = xap->in_lbn; |
224 | if (metalbn == bn) |
225 | break; |
226 | if (daddr == 0) { |
227 | mutex_enter(&bufcache_lock); |
228 | cbp = incore(vp, metalbn); |
229 | mutex_exit(&bufcache_lock); |
230 | if (cbp == NULL) |
231 | break; |
232 | } |
233 | |
234 | /* |
235 | * If we get here, we've either got the block in the cache |
236 | * or we have a disk address for it, go fetch it. |
237 | */ |
238 | if (bp) |
239 | brelse(bp, 0); |
240 | |
241 | xap->in_exists = 1; |
242 | bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0); |
243 | if (bp == NULL) { |
244 | |
245 | /* |
246 | * getblk() above returns NULL only iff we are |
247 | * pagedaemon. See the implementation of getblk |
248 | * for detail. |
249 | */ |
250 | |
251 | return (ENOMEM); |
252 | } |
253 | if (bp->b_oflags & (BO_DONE | BO_DELWRI)) { |
254 | trace(TR_BREADHIT, pack(vp, size), metalbn); |
255 | } |
256 | #ifdef DIAGNOSTIC |
257 | else if (!daddr) |
258 | panic("ufs_bmaparray: indirect block not in cache" ); |
259 | #endif |
260 | else { |
261 | trace(TR_BREADMISS, pack(vp, size), metalbn); |
262 | bp->b_blkno = blkptrtodb(ump, daddr); |
263 | bp->b_flags |= B_READ; |
264 | BIO_SETPRIO(bp, BPRIO_TIMECRITICAL); |
265 | VOP_STRATEGY(vp, bp); |
266 | curlwp->l_ru.ru_inblock++; /* XXX */ |
267 | if ((error = biowait(bp)) != 0) { |
268 | brelse(bp, 0); |
269 | return (error); |
270 | } |
271 | } |
272 | if (ump->um_fstype == UFS1) { |
273 | daddr = ufs_rw32(((u_int32_t *)bp->b_data)[xap->in_off], |
274 | UFS_MPNEEDSWAP(ump)); |
275 | if (num == 1 && daddr && runp) { |
276 | for (bn = xap->in_off + 1; |
277 | bn < MNINDIR(ump) && *runp < maxrun && |
278 | is_sequential(ump, |
279 | ufs_rw32(((int32_t *)bp->b_data)[bn-1], |
280 | UFS_MPNEEDSWAP(ump)), |
281 | ufs_rw32(((int32_t *)bp->b_data)[bn], |
282 | UFS_MPNEEDSWAP(ump))); |
283 | ++bn, ++*runp); |
284 | } |
285 | } else { |
286 | daddr = ufs_rw64(((u_int64_t *)bp->b_data)[xap->in_off], |
287 | UFS_MPNEEDSWAP(ump)); |
288 | if (num == 1 && daddr && runp) { |
289 | for (bn = xap->in_off + 1; |
290 | bn < MNINDIR(ump) && *runp < maxrun && |
291 | is_sequential(ump, |
292 | ufs_rw64(((int64_t *)bp->b_data)[bn-1], |
293 | UFS_MPNEEDSWAP(ump)), |
294 | ufs_rw64(((int64_t *)bp->b_data)[bn], |
295 | UFS_MPNEEDSWAP(ump))); |
296 | ++bn, ++*runp); |
297 | } |
298 | } |
299 | } |
300 | if (bp) |
301 | brelse(bp, 0); |
302 | |
303 | /* |
304 | * Since this is FFS independent code, we are out of scope for the |
305 | * definitions of BLK_NOCOPY and BLK_SNAP, but we do know that they |
306 | * will fall in the range 1..um_seqinc, so we use that test and |
307 | * return a request for a zeroed out buffer if attempts are made |
308 | * to read a BLK_NOCOPY or BLK_SNAP block. |
309 | */ |
310 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) == SF_SNAPSHOT |
311 | && daddr > 0 && daddr < ump->um_seqinc) { |
312 | *bnp = -1; |
313 | return (0); |
314 | } |
315 | *bnp = blkptrtodb(ump, daddr); |
316 | if (*bnp == 0) { |
317 | if ((ip->i_flags & (SF_SNAPSHOT | SF_SNAPINVAL)) |
318 | == SF_SNAPSHOT) { |
319 | *bnp = blkptrtodb(ump, bn * ump->um_seqinc); |
320 | } else { |
321 | *bnp = -1; |
322 | } |
323 | } |
324 | return (0); |
325 | } |
326 | |
327 | /* |
328 | * Create an array of logical block number/offset pairs which represent the |
329 | * path of indirect blocks required to access a data block. The first "pair" |
330 | * contains the logical block number of the appropriate single, double or |
331 | * triple indirect block and the offset into the inode indirect block array. |
332 | * Note, the logical block number of the inode single/double/triple indirect |
333 | * block appears twice in the array, once with the offset into the i_ffs1_ib and |
334 | * once with the offset into the page itself. |
335 | */ |
336 | int |
337 | ufs_getlbns(struct vnode *vp, daddr_t bn, struct indir *ap, int *nump) |
338 | { |
339 | daddr_t metalbn, realbn; |
340 | struct ufsmount *ump; |
341 | int64_t blockcnt; |
342 | int lbc; |
343 | int i, numlevels, off; |
344 | |
345 | ump = VFSTOUFS(vp->v_mount); |
346 | if (nump) |
347 | *nump = 0; |
348 | numlevels = 0; |
349 | realbn = bn; |
350 | if (bn < 0) |
351 | bn = -bn; |
352 | KASSERT(bn >= UFS_NDADDR); |
353 | |
354 | /* |
355 | * Determine the number of levels of indirection. After this loop |
356 | * is done, blockcnt indicates the number of data blocks possible |
357 | * at the given level of indirection, and UFS_NIADDR - i is the number |
358 | * of levels of indirection needed to locate the requested block. |
359 | */ |
360 | |
361 | bn -= UFS_NDADDR; |
362 | for (lbc = 0, i = UFS_NIADDR;; i--, bn -= blockcnt) { |
363 | if (i == 0) |
364 | return (EFBIG); |
365 | |
366 | lbc += ump->um_lognindir; |
367 | blockcnt = (int64_t)1 << lbc; |
368 | |
369 | if (bn < blockcnt) |
370 | break; |
371 | } |
372 | |
373 | /* Calculate the address of the first meta-block. */ |
374 | metalbn = -((realbn >= 0 ? realbn : -realbn) - bn + UFS_NIADDR - i); |
375 | |
376 | /* |
377 | * At each iteration, off is the offset into the bap array which is |
378 | * an array of disk addresses at the current level of indirection. |
379 | * The logical block number and the offset in that block are stored |
380 | * into the argument array. |
381 | */ |
382 | ap->in_lbn = metalbn; |
383 | ap->in_off = off = UFS_NIADDR - i; |
384 | ap->in_exists = 0; |
385 | ap++; |
386 | for (++numlevels; i <= UFS_NIADDR; i++) { |
387 | /* If searching for a meta-data block, quit when found. */ |
388 | if (metalbn == realbn) |
389 | break; |
390 | |
391 | lbc -= ump->um_lognindir; |
392 | off = (bn >> lbc) & (MNINDIR(ump) - 1); |
393 | |
394 | ++numlevels; |
395 | ap->in_lbn = metalbn; |
396 | ap->in_off = off; |
397 | ap->in_exists = 0; |
398 | ++ap; |
399 | |
400 | metalbn -= -1 + ((int64_t)off << lbc); |
401 | } |
402 | if (nump) |
403 | *nump = numlevels; |
404 | return (0); |
405 | } |
406 | |