1 /*-
2 * modified for Lites 1.1
3 *
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
6 */
7 /*-
8 * SPDX-License-Identifier: BSD-3-Clause
9 *
10 * Copyright (c) 1982, 1986, 1989, 1993
11 * The Regents of the University of California. All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/conf.h>
41 #include <sys/vnode.h>
42 #include <sys/sdt.h>
43 #include <sys/stat.h>
44 #include <sys/mount.h>
45 #include <sys/sysctl.h>
46 #include <sys/syslog.h>
47 #include <sys/buf.h>
48 #include <sys/endian.h>
49
50 #include <fs/ext2fs/fs.h>
51 #include <fs/ext2fs/inode.h>
52 #include <fs/ext2fs/ext2_mount.h>
53 #include <fs/ext2fs/ext2fs.h>
54 #include <fs/ext2fs/ext2_extern.h>
55
56 SDT_PROVIDER_DEFINE(ext2fs);
57 /*
58 * ext2fs trace probe:
59 * arg0: verbosity. Higher numbers give more verbose messages
60 * arg1: Textual message
61 */
62 SDT_PROBE_DEFINE2(ext2fs, , alloc, trace, "int", "char*");
63 SDT_PROBE_DEFINE3(ext2fs, , alloc, ext2_reallocblks_realloc,
64 "ino_t", "e2fs_lbn_t", "e2fs_lbn_t");
65 SDT_PROBE_DEFINE1(ext2fs, , alloc, ext2_reallocblks_bap, "uint32_t");
66 SDT_PROBE_DEFINE1(ext2fs, , alloc, ext2_reallocblks_blkno, "e2fs_daddr_t");
67 SDT_PROBE_DEFINE2(ext2fs, , alloc, ext2_b_bitmap_validate_error, "char*", "int");
68 SDT_PROBE_DEFINE3(ext2fs, , alloc, ext2_nodealloccg_bmap_corrupted,
69 "int", "daddr_t", "char*");
70 SDT_PROBE_DEFINE2(ext2fs, , alloc, ext2_blkfree_bad_block, "ino_t", "e4fs_daddr_t");
71 SDT_PROBE_DEFINE2(ext2fs, , alloc, ext2_vfree_doublefree, "char*", "ino_t");
72
73 static daddr_t ext2_alloccg(struct inode *, int, daddr_t, int);
74 static daddr_t ext2_clusteralloc(struct inode *, int, daddr_t, int);
75 static u_long ext2_dirpref(struct inode *);
76 static e4fs_daddr_t ext2_hashalloc(struct inode *, int, long, int,
77 daddr_t (*)(struct inode *, int, daddr_t,
78 int));
79 static daddr_t ext2_nodealloccg(struct inode *, int, daddr_t, int);
80 static daddr_t ext2_mapsearch(struct m_ext2fs *, char *, daddr_t);
81
82 /*
83 * Allocate a block in the filesystem.
84 *
85 * A preference may be optionally specified. If a preference is given
86 * the following hierarchy is used to allocate a block:
87 * 1) allocate the requested block.
88 * 2) allocate a rotationally optimal block in the same cylinder.
89 * 3) allocate a block in the same cylinder group.
90 * 4) quadratically rehash into other cylinder groups, until an
91 * available block is located.
92 * If no block preference is given the following hierarchy is used
93 * to allocate a block:
94 * 1) allocate a block in the cylinder group that contains the
95 * inode for the file.
96 * 2) quadratically rehash into other cylinder groups, until an
97 * available block is located.
98 */
99 int
ext2_alloc(struct inode * ip,daddr_t lbn,e4fs_daddr_t bpref,int size,struct ucred * cred,e4fs_daddr_t * bnp)100 ext2_alloc(struct inode *ip, daddr_t lbn, e4fs_daddr_t bpref, int size,
101 struct ucred *cred, e4fs_daddr_t *bnp)
102 {
103 struct m_ext2fs *fs;
104 struct ext2mount *ump;
105 e4fs_daddr_t bno;
106 int cg;
107
108 *bnp = 0;
109 fs = ip->i_e2fs;
110 ump = ip->i_ump;
111 mtx_assert(EXT2_MTX(ump), MA_OWNED);
112 #ifdef INVARIANTS
113 if ((u_int)size > fs->e2fs_bsize || blkoff(fs, size) != 0) {
114 vn_printf(ip->i_devvp, "bsize = %lu, size = %d, fs = %s\n",
115 (long unsigned int)fs->e2fs_bsize, size, fs->e2fs_fsmnt);
116 panic("ext2_alloc: bad size");
117 }
118 if (cred == NOCRED)
119 panic("ext2_alloc: missing credential");
120 #endif /* INVARIANTS */
121 if (size == fs->e2fs_bsize && fs->e2fs_fbcount == 0)
122 goto nospace;
123 if (cred->cr_uid != 0 &&
124 fs->e2fs_fbcount < fs->e2fs_rbcount)
125 goto nospace;
126 if (bpref >= fs->e2fs_bcount)
127 bpref = 0;
128 if (bpref == 0)
129 cg = ino_to_cg(fs, ip->i_number);
130 else
131 cg = dtog(fs, bpref);
132 bno = (daddr_t)ext2_hashalloc(ip, cg, bpref, fs->e2fs_bsize,
133 ext2_alloccg);
134 if (bno > 0) {
135 /* set next_alloc fields as done in block_getblk */
136 ip->i_next_alloc_block = lbn;
137 ip->i_next_alloc_goal = bno;
138
139 ip->i_blocks += btodb(fs->e2fs_bsize);
140 ip->i_flag |= IN_CHANGE | IN_UPDATE;
141 *bnp = bno;
142 return (0);
143 }
144 nospace:
145 EXT2_UNLOCK(ump);
146 SDT_PROBE2(ext2fs, , alloc, trace, 1, "cannot allocate data block");
147 return (ENOSPC);
148 }
149
150 /*
151 * Allocate EA's block for inode.
152 */
153 e4fs_daddr_t
ext2_alloc_meta(struct inode * ip)154 ext2_alloc_meta(struct inode *ip)
155 {
156 struct m_ext2fs *fs;
157 daddr_t blk;
158
159 fs = ip->i_e2fs;
160
161 EXT2_LOCK(ip->i_ump);
162 blk = ext2_hashalloc(ip, ino_to_cg(fs, ip->i_number), 0, fs->e2fs_bsize,
163 ext2_alloccg);
164 if (0 == blk) {
165 EXT2_UNLOCK(ip->i_ump);
166 SDT_PROBE2(ext2fs, , alloc, trace, 1, "cannot allocate meta block");
167 }
168
169 return (blk);
170 }
171
172 /*
173 * Reallocate a sequence of blocks into a contiguous sequence of blocks.
174 *
175 * The vnode and an array of buffer pointers for a range of sequential
176 * logical blocks to be made contiguous is given. The allocator attempts
177 * to find a range of sequential blocks starting as close as possible to
178 * an fs_rotdelay offset from the end of the allocation for the logical
179 * block immediately preceding the current range. If successful, the
180 * physical block numbers in the buffer pointers and in the inode are
181 * changed to reflect the new allocation. If unsuccessful, the allocation
182 * is left unchanged. The success in doing the reallocation is returned.
183 * Note that the error return is not reflected back to the user. Rather
184 * the previous block allocation will be used.
185 */
186
187 static SYSCTL_NODE(_vfs, OID_AUTO, ext2fs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
188 "EXT2FS filesystem");
189
190 static int doasyncfree = 1;
191
192 SYSCTL_INT(_vfs_ext2fs, OID_AUTO, doasyncfree, CTLFLAG_RW, &doasyncfree, 0,
193 "Use asynchronous writes to update block pointers when freeing blocks");
194
195 static int doreallocblks = 0;
196
197 SYSCTL_INT(_vfs_ext2fs, OID_AUTO, doreallocblks, CTLFLAG_RW, &doreallocblks, 0, "");
198
199 int
ext2_reallocblks(struct vop_reallocblks_args * ap)200 ext2_reallocblks(struct vop_reallocblks_args *ap)
201 {
202 struct m_ext2fs *fs;
203 struct inode *ip;
204 struct vnode *vp;
205 struct buf *sbp, *ebp;
206 uint32_t *bap, *sbap, *ebap;
207 struct ext2mount *ump;
208 struct cluster_save *buflist;
209 struct indir start_ap[EXT2_NIADDR + 1], end_ap[EXT2_NIADDR + 1], *idp;
210 e2fs_lbn_t start_lbn, end_lbn;
211 int soff;
212 e2fs_daddr_t newblk, blkno;
213 int i, len, start_lvl, end_lvl, pref, ssize;
214
215 if (doreallocblks == 0)
216 return (ENOSPC);
217
218 vp = ap->a_vp;
219 ip = VTOI(vp);
220 fs = ip->i_e2fs;
221 ump = ip->i_ump;
222
223 if (fs->e2fs_contigsumsize <= 0 || ip->i_flag & IN_E4EXTENTS)
224 return (ENOSPC);
225
226 buflist = ap->a_buflist;
227 len = buflist->bs_nchildren;
228 start_lbn = buflist->bs_children[0]->b_lblkno;
229 end_lbn = start_lbn + len - 1;
230 #ifdef INVARIANTS
231 for (i = 1; i < len; i++)
232 if (buflist->bs_children[i]->b_lblkno != start_lbn + i)
233 panic("ext2_reallocblks: non-cluster");
234 #endif
235 /*
236 * If the cluster crosses the boundary for the first indirect
237 * block, leave space for the indirect block. Indirect blocks
238 * are initially laid out in a position after the last direct
239 * block. Block reallocation would usually destroy locality by
240 * moving the indirect block out of the way to make room for
241 * data blocks if we didn't compensate here. We should also do
242 * this for other indirect block boundaries, but it is only
243 * important for the first one.
244 */
245 if (start_lbn < EXT2_NDADDR && end_lbn >= EXT2_NDADDR)
246 return (ENOSPC);
247 /*
248 * If the latest allocation is in a new cylinder group, assume that
249 * the filesystem has decided to move and do not force it back to
250 * the previous cylinder group.
251 */
252 if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) !=
253 dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno)))
254 return (ENOSPC);
255 if (ext2_getlbns(vp, start_lbn, start_ap, &start_lvl) ||
256 ext2_getlbns(vp, end_lbn, end_ap, &end_lvl))
257 return (ENOSPC);
258 /*
259 * Get the starting offset and block map for the first block.
260 */
261 if (start_lvl == 0) {
262 sbap = &ip->i_db[0];
263 soff = start_lbn;
264 } else {
265 idp = &start_ap[start_lvl - 1];
266 if (bread(vp, idp->in_lbn, (int)fs->e2fs_bsize, NOCRED, &sbp)) {
267 brelse(sbp);
268 return (ENOSPC);
269 }
270 sbap = (u_int *)sbp->b_data;
271 soff = idp->in_off;
272 }
273 /*
274 * If the block range spans two block maps, get the second map.
275 */
276 ebap = NULL;
277 if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
278 ssize = len;
279 } else {
280 #ifdef INVARIANTS
281 if (start_ap[start_lvl - 1].in_lbn == idp->in_lbn)
282 panic("ext2_reallocblks: start == end");
283 #endif
284 ssize = len - (idp->in_off + 1);
285 if (bread(vp, idp->in_lbn, (int)fs->e2fs_bsize, NOCRED, &ebp))
286 goto fail;
287 ebap = (u_int *)ebp->b_data;
288 }
289 /*
290 * Find the preferred location for the cluster.
291 */
292 EXT2_LOCK(ump);
293 pref = ext2_blkpref(ip, start_lbn, soff, sbap, 0);
294 /*
295 * Search the block map looking for an allocation of the desired size.
296 */
297 if ((newblk = (e2fs_daddr_t)ext2_hashalloc(ip, dtog(fs, pref), pref,
298 len, ext2_clusteralloc)) == 0) {
299 EXT2_UNLOCK(ump);
300 goto fail;
301 }
302 /*
303 * We have found a new contiguous block.
304 *
305 * First we have to replace the old block pointers with the new
306 * block pointers in the inode and indirect blocks associated
307 * with the file.
308 */
309 SDT_PROBE3(ext2fs, , alloc, ext2_reallocblks_realloc,
310 ip->i_number, start_lbn, end_lbn);
311 blkno = newblk;
312 for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->e2fs_fpb) {
313 if (i == ssize) {
314 bap = ebap;
315 soff = -i;
316 }
317 #ifdef INVARIANTS
318 if (buflist->bs_children[i]->b_blkno != fsbtodb(fs, *bap))
319 panic("ext2_reallocblks: alloc mismatch");
320 #endif
321 SDT_PROBE1(ext2fs, , alloc, ext2_reallocblks_bap, *bap);
322 *bap++ = blkno;
323 }
324 /*
325 * Next we must write out the modified inode and indirect blocks.
326 * For strict correctness, the writes should be synchronous since
327 * the old block values may have been written to disk. In practise
328 * they are almost never written, but if we are concerned about
329 * strict correctness, the `doasyncfree' flag should be set to zero.
330 *
331 * The test on `doasyncfree' should be changed to test a flag
332 * that shows whether the associated buffers and inodes have
333 * been written. The flag should be set when the cluster is
334 * started and cleared whenever the buffer or inode is flushed.
335 * We can then check below to see if it is set, and do the
336 * synchronous write only when it has been cleared.
337 */
338 if (sbap != &ip->i_db[0]) {
339 if (doasyncfree)
340 bdwrite(sbp);
341 else
342 bwrite(sbp);
343 } else {
344 ip->i_flag |= IN_CHANGE | IN_UPDATE;
345 if (!doasyncfree)
346 ext2_update(vp, 1);
347 }
348 if (ssize < len) {
349 if (doasyncfree)
350 bdwrite(ebp);
351 else
352 bwrite(ebp);
353 }
354 /*
355 * Last, free the old blocks and assign the new blocks to the buffers.
356 */
357 for (blkno = newblk, i = 0; i < len; i++, blkno += fs->e2fs_fpb) {
358 ext2_blkfree(ip, dbtofsb(fs, buflist->bs_children[i]->b_blkno),
359 fs->e2fs_bsize);
360 buflist->bs_children[i]->b_blkno = fsbtodb(fs, blkno);
361 SDT_PROBE1(ext2fs, , alloc, ext2_reallocblks_blkno, blkno);
362 }
363
364 return (0);
365
366 fail:
367 if (ssize < len)
368 brelse(ebp);
369 if (sbap != &ip->i_db[0])
370 brelse(sbp);
371 return (ENOSPC);
372 }
373
374 /*
375 * Allocate an inode in the filesystem.
376 *
377 */
378 int
ext2_valloc(struct vnode * pvp,int mode,struct ucred * cred,struct vnode ** vpp)379 ext2_valloc(struct vnode *pvp, int mode, struct ucred *cred, struct vnode **vpp)
380 {
381 struct timespec ts;
382 struct m_ext2fs *fs;
383 struct ext2mount *ump;
384 struct inode *pip;
385 struct inode *ip;
386 struct vnode *vp;
387 struct thread *td;
388 ino_t ino, ipref;
389 int error, cg;
390
391 *vpp = NULL;
392 pip = VTOI(pvp);
393 fs = pip->i_e2fs;
394 ump = pip->i_ump;
395
396 EXT2_LOCK(ump);
397 if (fs->e2fs_ficount == 0)
398 goto noinodes;
399 /*
400 * If it is a directory then obtain a cylinder group based on
401 * ext2_dirpref else obtain it using ino_to_cg. The preferred inode is
402 * always the next inode.
403 */
404 if ((mode & IFMT) == IFDIR) {
405 cg = ext2_dirpref(pip);
406 if (fs->e2fs_contigdirs[cg] < 255)
407 fs->e2fs_contigdirs[cg]++;
408 } else {
409 cg = ino_to_cg(fs, pip->i_number);
410 if (fs->e2fs_contigdirs[cg] > 0)
411 fs->e2fs_contigdirs[cg]--;
412 }
413 ipref = cg * fs->e2fs_ipg + 1;
414 ino = (ino_t)ext2_hashalloc(pip, cg, (long)ipref, mode, ext2_nodealloccg);
415 if (ino == 0)
416 goto noinodes;
417
418 td = curthread;
419 error = vfs_hash_get(ump->um_mountp, ino, LK_EXCLUSIVE, td, vpp, NULL, NULL);
420 if (error || *vpp != NULL) {
421 return (error);
422 }
423
424 ip = malloc(sizeof(struct inode), M_EXT2NODE, M_WAITOK | M_ZERO);
425
426 /* Allocate a new vnode/inode. */
427 if ((error = getnewvnode("ext2fs", ump->um_mountp, &ext2_vnodeops, &vp)) != 0) {
428 free(ip, M_EXT2NODE);
429 return (error);
430 }
431
432 lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
433 vp->v_data = ip;
434 ip->i_vnode = vp;
435 ip->i_e2fs = fs = ump->um_e2fs;
436 ip->i_ump = ump;
437 ip->i_number = ino;
438 ip->i_block_group = ino_to_cg(fs, ino);
439 ip->i_next_alloc_block = 0;
440 ip->i_next_alloc_goal = 0;
441
442 error = insmntque(vp, ump->um_mountp);
443 if (error) {
444 free(ip, M_EXT2NODE);
445 return (error);
446 }
447
448 error = vfs_hash_insert(vp, ino, LK_EXCLUSIVE, td, vpp, NULL, NULL);
449 if (error || *vpp != NULL) {
450 *vpp = NULL;
451 free(ip, M_EXT2NODE);
452 return (error);
453 }
454
455 if ((error = ext2_vinit(ump->um_mountp, &ext2_fifoops, &vp)) != 0) {
456 vput(vp);
457 *vpp = NULL;
458 free(ip, M_EXT2NODE);
459 return (error);
460 }
461
462 if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_EXTENTS)
463 && (S_ISREG(mode) || S_ISDIR(mode)))
464 ext4_ext_tree_init(ip);
465 else
466 memset(ip->i_data, 0, sizeof(ip->i_data));
467
468 /*
469 * Set up a new generation number for this inode.
470 * Avoid zero values.
471 */
472 do {
473 ip->i_gen = arc4random();
474 } while (ip->i_gen == 0);
475
476 vfs_timestamp(&ts);
477 ip->i_birthtime = ts.tv_sec;
478 ip->i_birthnsec = ts.tv_nsec;
479
480 vn_set_state(vp, VSTATE_CONSTRUCTED);
481 *vpp = vp;
482
483 return (0);
484
485 noinodes:
486 EXT2_UNLOCK(ump);
487 SDT_PROBE2(ext2fs, , alloc, trace, 1, "out of inodes");
488 return (ENOSPC);
489 }
490
491 /*
492 * 64-bit compatible getters and setters for struct ext2_gd from ext2fs.h
493 */
494 uint64_t
e2fs_gd_get_b_bitmap(struct ext2_gd * gd)495 e2fs_gd_get_b_bitmap(struct ext2_gd *gd)
496 {
497
498 return (((uint64_t)(le32toh(gd->ext4bgd_b_bitmap_hi)) << 32) |
499 le32toh(gd->ext2bgd_b_bitmap));
500 }
501
502 uint64_t
e2fs_gd_get_i_bitmap(struct ext2_gd * gd)503 e2fs_gd_get_i_bitmap(struct ext2_gd *gd)
504 {
505
506 return (((uint64_t)(le32toh(gd->ext4bgd_i_bitmap_hi)) << 32) |
507 le32toh(gd->ext2bgd_i_bitmap));
508 }
509
510 uint64_t
e2fs_gd_get_i_tables(struct ext2_gd * gd)511 e2fs_gd_get_i_tables(struct ext2_gd *gd)
512 {
513
514 return (((uint64_t)(le32toh(gd->ext4bgd_i_tables_hi)) << 32) |
515 le32toh(gd->ext2bgd_i_tables));
516 }
517
518 static uint32_t
e2fs_gd_get_nbfree(struct ext2_gd * gd)519 e2fs_gd_get_nbfree(struct ext2_gd *gd)
520 {
521
522 return (((uint32_t)(le16toh(gd->ext4bgd_nbfree_hi)) << 16) |
523 le16toh(gd->ext2bgd_nbfree));
524 }
525
526 static void
e2fs_gd_set_nbfree(struct ext2_gd * gd,uint32_t val)527 e2fs_gd_set_nbfree(struct ext2_gd *gd, uint32_t val)
528 {
529
530 gd->ext2bgd_nbfree = htole16(val & 0xffff);
531 gd->ext4bgd_nbfree_hi = htole16(val >> 16);
532 }
533
534 static uint32_t
e2fs_gd_get_nifree(struct ext2_gd * gd)535 e2fs_gd_get_nifree(struct ext2_gd *gd)
536 {
537
538 return (((uint32_t)(le16toh(gd->ext4bgd_nifree_hi)) << 16) |
539 le16toh(gd->ext2bgd_nifree));
540 }
541
542 static void
e2fs_gd_set_nifree(struct ext2_gd * gd,uint32_t val)543 e2fs_gd_set_nifree(struct ext2_gd *gd, uint32_t val)
544 {
545
546 gd->ext2bgd_nifree = htole16(val & 0xffff);
547 gd->ext4bgd_nifree_hi = htole16(val >> 16);
548 }
549
550 uint32_t
e2fs_gd_get_ndirs(struct ext2_gd * gd)551 e2fs_gd_get_ndirs(struct ext2_gd *gd)
552 {
553
554 return (((uint32_t)(le16toh(gd->ext4bgd_ndirs_hi)) << 16) |
555 le16toh(gd->ext2bgd_ndirs));
556 }
557
558 static void
e2fs_gd_set_ndirs(struct ext2_gd * gd,uint32_t val)559 e2fs_gd_set_ndirs(struct ext2_gd *gd, uint32_t val)
560 {
561
562 gd->ext2bgd_ndirs = htole16(val & 0xffff);
563 gd->ext4bgd_ndirs_hi = htole16(val >> 16);
564 }
565
566 static uint32_t
e2fs_gd_get_i_unused(struct ext2_gd * gd)567 e2fs_gd_get_i_unused(struct ext2_gd *gd)
568 {
569 return ((uint32_t)(le16toh(gd->ext4bgd_i_unused_hi) << 16) |
570 le16toh(gd->ext4bgd_i_unused));
571 }
572
573 static void
e2fs_gd_set_i_unused(struct ext2_gd * gd,uint32_t val)574 e2fs_gd_set_i_unused(struct ext2_gd *gd, uint32_t val)
575 {
576
577 gd->ext4bgd_i_unused = htole16(val & 0xffff);
578 gd->ext4bgd_i_unused_hi = htole16(val >> 16);
579 }
580
581 /*
582 * Find a cylinder to place a directory.
583 *
584 * The policy implemented by this algorithm is to allocate a
585 * directory inode in the same cylinder group as its parent
586 * directory, but also to reserve space for its files inodes
587 * and data. Restrict the number of directories which may be
588 * allocated one after another in the same cylinder group
589 * without intervening allocation of files.
590 *
591 * If we allocate a first level directory then force allocation
592 * in another cylinder group.
593 *
594 */
595 static u_long
ext2_dirpref(struct inode * pip)596 ext2_dirpref(struct inode *pip)
597 {
598 struct m_ext2fs *fs;
599 int cg, prefcg, cgsize;
600 uint64_t avgbfree, minbfree;
601 u_int avgifree, avgndir, curdirsize;
602 u_int minifree, maxndir;
603 u_int mincg, minndir;
604 u_int dirsize, maxcontigdirs;
605
606 mtx_assert(EXT2_MTX(pip->i_ump), MA_OWNED);
607 fs = pip->i_e2fs;
608
609 avgifree = fs->e2fs_ficount / fs->e2fs_gcount;
610 avgbfree = fs->e2fs_fbcount / fs->e2fs_gcount;
611 avgndir = fs->e2fs_total_dir / fs->e2fs_gcount;
612
613 /*
614 * Force allocation in another cg if creating a first level dir.
615 */
616 ASSERT_VOP_LOCKED(ITOV(pip), "ext2fs_dirpref");
617 if (ITOV(pip)->v_vflag & VV_ROOT) {
618 prefcg = arc4random() % fs->e2fs_gcount;
619 mincg = prefcg;
620 minndir = fs->e2fs_ipg;
621 for (cg = prefcg; cg < fs->e2fs_gcount; cg++)
622 if (e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) < minndir &&
623 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= avgifree &&
624 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) >= avgbfree) {
625 mincg = cg;
626 minndir = e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]);
627 }
628 for (cg = 0; cg < prefcg; cg++)
629 if (e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) < minndir &&
630 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= avgifree &&
631 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) >= avgbfree) {
632 mincg = cg;
633 minndir = e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]);
634 }
635 return (mincg);
636 }
637 /*
638 * Count various limits which used for
639 * optimal allocation of a directory inode.
640 */
641 maxndir = min(avgndir + fs->e2fs_ipg / 16, fs->e2fs_ipg);
642 minifree = avgifree - avgifree / 4;
643 if (minifree < 1)
644 minifree = 1;
645 minbfree = avgbfree - avgbfree / 4;
646 if (minbfree < 1)
647 minbfree = 1;
648 cgsize = fs->e2fs_fsize * fs->e2fs_fpg;
649 dirsize = AVGDIRSIZE;
650 curdirsize = avgndir ?
651 (cgsize - avgbfree * fs->e2fs_bsize) / avgndir : 0;
652 if (dirsize < curdirsize)
653 dirsize = curdirsize;
654 maxcontigdirs = min((avgbfree * fs->e2fs_bsize) / dirsize, 255);
655 maxcontigdirs = min(maxcontigdirs, fs->e2fs_ipg / AFPDIR);
656 if (maxcontigdirs == 0)
657 maxcontigdirs = 1;
658
659 /*
660 * Limit number of dirs in one cg and reserve space for
661 * regular files, but only if we have no deficit in
662 * inodes or space.
663 */
664 prefcg = ino_to_cg(fs, pip->i_number);
665 for (cg = prefcg; cg < fs->e2fs_gcount; cg++)
666 if (e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) < maxndir &&
667 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= minifree &&
668 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) >= minbfree) {
669 if (fs->e2fs_contigdirs[cg] < maxcontigdirs)
670 return (cg);
671 }
672 for (cg = 0; cg < prefcg; cg++)
673 if (e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) < maxndir &&
674 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= minifree &&
675 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) >= minbfree) {
676 if (fs->e2fs_contigdirs[cg] < maxcontigdirs)
677 return (cg);
678 }
679 /*
680 * This is a backstop when we have deficit in space.
681 */
682 for (cg = prefcg; cg < fs->e2fs_gcount; cg++)
683 if (e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= avgifree)
684 return (cg);
685 for (cg = 0; cg < prefcg; cg++)
686 if (e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) >= avgifree)
687 break;
688 return (cg);
689 }
690
691 /*
692 * Select the desired position for the next block in a file.
693 *
694 * we try to mimic what Remy does in inode_getblk/block_getblk
695 *
696 * we note: blocknr == 0 means that we're about to allocate either
697 * a direct block or a pointer block at the first level of indirection
698 * (In other words, stuff that will go in i_db[] or i_ib[])
699 *
700 * blocknr != 0 means that we're allocating a block that is none
701 * of the above. Then, blocknr tells us the number of the block
702 * that will hold the pointer
703 */
704 e4fs_daddr_t
ext2_blkpref(struct inode * ip,e2fs_lbn_t lbn,int indx,e2fs_daddr_t * bap,e2fs_daddr_t blocknr)705 ext2_blkpref(struct inode *ip, e2fs_lbn_t lbn, int indx, e2fs_daddr_t *bap,
706 e2fs_daddr_t blocknr)
707 {
708 struct m_ext2fs *fs;
709 int tmp;
710
711 fs = ip->i_e2fs;
712
713 mtx_assert(EXT2_MTX(ip->i_ump), MA_OWNED);
714
715 /*
716 * If the next block is actually what we thought it is, then set the
717 * goal to what we thought it should be.
718 */
719 if (ip->i_next_alloc_block == lbn && ip->i_next_alloc_goal != 0)
720 return ip->i_next_alloc_goal;
721
722 /*
723 * Now check whether we were provided with an array that basically
724 * tells us previous blocks to which we want to stay close.
725 */
726 if (bap)
727 for (tmp = indx - 1; tmp >= 0; tmp--)
728 if (bap[tmp])
729 return (le32toh(bap[tmp]));
730
731 /*
732 * Else lets fall back to the blocknr or, if there is none, follow
733 * the rule that a block should be allocated near its inode.
734 */
735 return (blocknr ? blocknr :
736 (e2fs_daddr_t)(ip->i_block_group *
737 EXT2_BLOCKS_PER_GROUP(fs)) + le32toh(fs->e2fs->e2fs_first_dblock));
738 }
739
740 /*
741 * Implement the cylinder overflow algorithm.
742 *
743 * The policy implemented by this algorithm is:
744 * 1) allocate the block in its requested cylinder group.
745 * 2) quadratically rehash on the cylinder group number.
746 * 3) brute force search for a free block.
747 */
748 static e4fs_daddr_t
ext2_hashalloc(struct inode * ip,int cg,long pref,int size,daddr_t (* allocator)(struct inode *,int,daddr_t,int))749 ext2_hashalloc(struct inode *ip, int cg, long pref, int size,
750 daddr_t (*allocator) (struct inode *, int, daddr_t, int))
751 {
752 struct m_ext2fs *fs;
753 e4fs_daddr_t result;
754 int i, icg = cg;
755
756 mtx_assert(EXT2_MTX(ip->i_ump), MA_OWNED);
757 fs = ip->i_e2fs;
758 /*
759 * 1: preferred cylinder group
760 */
761 result = (*allocator)(ip, cg, pref, size);
762 if (result)
763 return (result);
764 /*
765 * 2: quadratic rehash
766 */
767 for (i = 1; i < fs->e2fs_gcount; i *= 2) {
768 cg += i;
769 if (cg >= fs->e2fs_gcount)
770 cg -= fs->e2fs_gcount;
771 result = (*allocator)(ip, cg, 0, size);
772 if (result)
773 return (result);
774 }
775 /*
776 * 3: brute force search
777 * Note that we start at i == 2, since 0 was checked initially,
778 * and 1 is always checked in the quadratic rehash.
779 */
780 cg = (icg + 2) % fs->e2fs_gcount;
781 for (i = 2; i < fs->e2fs_gcount; i++) {
782 result = (*allocator)(ip, cg, 0, size);
783 if (result)
784 return (result);
785 cg++;
786 if (cg == fs->e2fs_gcount)
787 cg = 0;
788 }
789 return (0);
790 }
791
792 static uint64_t
ext2_cg_number_gdb_nometa(struct m_ext2fs * fs,int cg)793 ext2_cg_number_gdb_nometa(struct m_ext2fs *fs, int cg)
794 {
795
796 if (!ext2_cg_has_sb(fs, cg))
797 return (0);
798
799 if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_META_BG))
800 return (le32toh(fs->e2fs->e3fs_first_meta_bg));
801
802 return ((fs->e2fs_gcount + EXT2_DESCS_PER_BLOCK(fs) - 1) /
803 EXT2_DESCS_PER_BLOCK(fs));
804 }
805
806 static uint64_t
ext2_cg_number_gdb_meta(struct m_ext2fs * fs,int cg)807 ext2_cg_number_gdb_meta(struct m_ext2fs *fs, int cg)
808 {
809 unsigned long metagroup;
810 int first, last;
811
812 metagroup = cg / EXT2_DESCS_PER_BLOCK(fs);
813 first = metagroup * EXT2_DESCS_PER_BLOCK(fs);
814 last = first + EXT2_DESCS_PER_BLOCK(fs) - 1;
815
816 if (cg == first || cg == first + 1 || cg == last)
817 return (1);
818
819 return (0);
820 }
821
822 uint64_t
ext2_cg_number_gdb(struct m_ext2fs * fs,int cg)823 ext2_cg_number_gdb(struct m_ext2fs *fs, int cg)
824 {
825 unsigned long first_meta_bg, metagroup;
826
827 first_meta_bg = le32toh(fs->e2fs->e3fs_first_meta_bg);
828 metagroup = cg / EXT2_DESCS_PER_BLOCK(fs);
829
830 if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_META_BG) ||
831 metagroup < first_meta_bg)
832 return (ext2_cg_number_gdb_nometa(fs, cg));
833
834 return ext2_cg_number_gdb_meta(fs, cg);
835 }
836
837 static int
ext2_number_base_meta_blocks(struct m_ext2fs * fs,int cg)838 ext2_number_base_meta_blocks(struct m_ext2fs *fs, int cg)
839 {
840 int number;
841
842 number = ext2_cg_has_sb(fs, cg);
843
844 if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_META_BG) ||
845 cg < le32toh(fs->e2fs->e3fs_first_meta_bg) *
846 EXT2_DESCS_PER_BLOCK(fs)) {
847 if (number) {
848 number += ext2_cg_number_gdb(fs, cg);
849 number += le16toh(fs->e2fs->e2fs_reserved_ngdb);
850 }
851 } else {
852 number += ext2_cg_number_gdb(fs, cg);
853 }
854
855 return (number);
856 }
857
858 static void
ext2_mark_bitmap_end(int start_bit,int end_bit,char * bitmap)859 ext2_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
860 {
861 int i;
862
863 if (start_bit >= end_bit)
864 return;
865
866 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
867 setbit(bitmap, i);
868 if (i < end_bit)
869 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
870 }
871
872 static int
ext2_get_group_number(struct m_ext2fs * fs,e4fs_daddr_t block)873 ext2_get_group_number(struct m_ext2fs *fs, e4fs_daddr_t block)
874 {
875
876 return ((block - le32toh(fs->e2fs->e2fs_first_dblock)) /
877 fs->e2fs_bsize);
878 }
879
880 static int
ext2_block_in_group(struct m_ext2fs * fs,e4fs_daddr_t block,int cg)881 ext2_block_in_group(struct m_ext2fs *fs, e4fs_daddr_t block, int cg)
882 {
883
884 return ((ext2_get_group_number(fs, block) == cg) ? 1 : 0);
885 }
886
887 static int
ext2_cg_block_bitmap_init(struct m_ext2fs * fs,int cg,struct buf * bp)888 ext2_cg_block_bitmap_init(struct m_ext2fs *fs, int cg, struct buf *bp)
889 {
890 int bit, bit_max, inodes_per_block;
891 uint64_t start, tmp;
892
893 if (!(le16toh(fs->e2fs_gd[cg].ext4bgd_flags) & EXT2_BG_BLOCK_UNINIT))
894 return (0);
895
896 memset(bp->b_data, 0, fs->e2fs_bsize);
897
898 bit_max = ext2_number_base_meta_blocks(fs, cg);
899 if ((bit_max >> 3) >= fs->e2fs_bsize)
900 return (EINVAL);
901
902 for (bit = 0; bit < bit_max; bit++)
903 setbit(bp->b_data, bit);
904
905 start = (uint64_t)cg * fs->e2fs_bpg +
906 le32toh(fs->e2fs->e2fs_first_dblock);
907
908 /* Set bits for block and inode bitmaps, and inode table. */
909 tmp = e2fs_gd_get_b_bitmap(&fs->e2fs_gd[cg]);
910 if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG) ||
911 ext2_block_in_group(fs, tmp, cg))
912 setbit(bp->b_data, tmp - start);
913
914 tmp = e2fs_gd_get_i_bitmap(&fs->e2fs_gd[cg]);
915 if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG) ||
916 ext2_block_in_group(fs, tmp, cg))
917 setbit(bp->b_data, tmp - start);
918
919 tmp = e2fs_gd_get_i_tables(&fs->e2fs_gd[cg]);
920 inodes_per_block = fs->e2fs_bsize/EXT2_INODE_SIZE(fs);
921 while( tmp < e2fs_gd_get_i_tables(&fs->e2fs_gd[cg]) +
922 fs->e2fs_ipg / inodes_per_block ) {
923 if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG) ||
924 ext2_block_in_group(fs, tmp, cg))
925 setbit(bp->b_data, tmp - start);
926 tmp++;
927 }
928
929 /*
930 * Also if the number of blocks within the group is less than
931 * the blocksize * 8 ( which is the size of bitmap ), set rest
932 * of the block bitmap to 1
933 */
934 ext2_mark_bitmap_end(fs->e2fs_bpg, fs->e2fs_bsize * 8,
935 bp->b_data);
936
937 /* Clean the flag */
938 fs->e2fs_gd[cg].ext4bgd_flags = htole16(le16toh(
939 fs->e2fs_gd[cg].ext4bgd_flags) & ~EXT2_BG_BLOCK_UNINIT);
940
941 return (0);
942 }
943
944 static int
ext2_b_bitmap_validate(struct m_ext2fs * fs,struct buf * bp,int cg)945 ext2_b_bitmap_validate(struct m_ext2fs *fs, struct buf *bp, int cg)
946 {
947 struct ext2_gd *gd;
948 uint64_t group_first_block;
949 unsigned int offset, max_bit;
950
951 if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG)) {
952 /*
953 * It is not possible to check block bitmap in case of this
954 * feature, because the inode and block bitmaps and inode table
955 * blocks may not be in the group at all.
956 * So, skip check in this case.
957 */
958 return (0);
959 }
960
961 gd = &fs->e2fs_gd[cg];
962 max_bit = fs->e2fs_fpg;
963 group_first_block = ((uint64_t)cg) * fs->e2fs_fpg +
964 le32toh(fs->e2fs->e2fs_first_dblock);
965
966 /* Check block bitmap block number */
967 offset = e2fs_gd_get_b_bitmap(gd) - group_first_block;
968 if (offset >= max_bit || !isset(bp->b_data, offset)) {
969 SDT_PROBE2(ext2fs, , alloc, ext2_b_bitmap_validate_error,
970 "bad block bitmap, group", cg);
971 return (EINVAL);
972 }
973
974 /* Check inode bitmap block number */
975 offset = e2fs_gd_get_i_bitmap(gd) - group_first_block;
976 if (offset >= max_bit || !isset(bp->b_data, offset)) {
977 SDT_PROBE2(ext2fs, , alloc, ext2_b_bitmap_validate_error,
978 "bad inode bitmap", cg);
979 return (EINVAL);
980 }
981
982 /* Check inode table */
983 offset = e2fs_gd_get_i_tables(gd) - group_first_block;
984 if (offset >= max_bit || offset + fs->e2fs_itpg >= max_bit) {
985 SDT_PROBE2(ext2fs, , alloc, ext2_b_bitmap_validate_error,
986 "bad inode table, group", cg);
987 return (EINVAL);
988 }
989
990 return (0);
991 }
992
993 /*
994 * Determine whether a block can be allocated.
995 *
996 * Check to see if a block of the appropriate size is available,
997 * and if it is, allocate it.
998 */
999 static daddr_t
ext2_alloccg(struct inode * ip,int cg,daddr_t bpref,int size)1000 ext2_alloccg(struct inode *ip, int cg, daddr_t bpref, int size)
1001 {
1002 struct m_ext2fs *fs;
1003 struct buf *bp;
1004 struct ext2mount *ump;
1005 daddr_t bno, runstart, runlen;
1006 int bit, loc, end, error, start;
1007 char *bbp;
1008 /* XXX ondisk32 */
1009 fs = ip->i_e2fs;
1010 ump = ip->i_ump;
1011 if (e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) == 0)
1012 return (0);
1013
1014 EXT2_UNLOCK(ump);
1015 error = bread(ip->i_devvp, fsbtodb(fs,
1016 e2fs_gd_get_b_bitmap(&fs->e2fs_gd[cg])),
1017 (int)fs->e2fs_bsize, NOCRED, &bp);
1018 if (error)
1019 goto fail;
1020
1021 if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) ||
1022 EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
1023 error = ext2_cg_block_bitmap_init(fs, cg, bp);
1024 if (error)
1025 goto fail;
1026
1027 ext2_gd_b_bitmap_csum_set(fs, cg, bp);
1028 }
1029 error = ext2_gd_b_bitmap_csum_verify(fs, cg, bp);
1030 if (error)
1031 goto fail;
1032
1033 error = ext2_b_bitmap_validate(fs,bp, cg);
1034 if (error)
1035 goto fail;
1036
1037 /*
1038 * Check, that another thread did not not allocate the last block in
1039 * this group while we were waiting for the buffer.
1040 */
1041 if (e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) == 0)
1042 goto fail;
1043
1044 bbp = (char *)bp->b_data;
1045
1046 if (dtog(fs, bpref) != cg)
1047 bpref = 0;
1048 if (bpref != 0) {
1049 bpref = dtogd(fs, bpref);
1050 /*
1051 * if the requested block is available, use it
1052 */
1053 if (isclr(bbp, bpref)) {
1054 bno = bpref;
1055 goto gotit;
1056 }
1057 }
1058 /*
1059 * no blocks in the requested cylinder, so take next
1060 * available one in this cylinder group.
1061 * first try to get 8 contigous blocks, then fall back to a single
1062 * block.
1063 */
1064 if (bpref)
1065 start = dtogd(fs, bpref) / NBBY;
1066 else
1067 start = 0;
1068 end = howmany(fs->e2fs_fpg, NBBY);
1069 retry:
1070 runlen = 0;
1071 runstart = 0;
1072 for (loc = start; loc < end; loc++) {
1073 if (bbp[loc] == (char)0xff) {
1074 runlen = 0;
1075 continue;
1076 }
1077
1078 /* Start of a run, find the number of high clear bits. */
1079 if (runlen == 0) {
1080 bit = fls(bbp[loc]);
1081 runlen = NBBY - bit;
1082 runstart = loc * NBBY + bit;
1083 } else if (bbp[loc] == 0) {
1084 /* Continue a run. */
1085 runlen += NBBY;
1086 } else {
1087 /*
1088 * Finish the current run. If it isn't long
1089 * enough, start a new one.
1090 */
1091 bit = ffs(bbp[loc]) - 1;
1092 runlen += bit;
1093 if (runlen >= 8) {
1094 bno = runstart;
1095 goto gotit;
1096 }
1097
1098 /* Run was too short, start a new one. */
1099 bit = fls(bbp[loc]);
1100 runlen = NBBY - bit;
1101 runstart = loc * NBBY + bit;
1102 }
1103
1104 /* If the current run is long enough, use it. */
1105 if (runlen >= 8) {
1106 bno = runstart;
1107 goto gotit;
1108 }
1109 }
1110 if (start != 0) {
1111 end = start;
1112 start = 0;
1113 goto retry;
1114 }
1115 bno = ext2_mapsearch(fs, bbp, bpref);
1116 if (bno < 0)
1117 goto fail;
1118
1119 gotit:
1120 #ifdef INVARIANTS
1121 if (isset(bbp, bno)) {
1122 printf("ext2fs_alloccgblk: cg=%d bno=%jd fs=%s\n",
1123 cg, (intmax_t)bno, fs->e2fs_fsmnt);
1124 panic("ext2fs_alloccg: dup alloc");
1125 }
1126 #endif
1127 setbit(bbp, bno);
1128 EXT2_LOCK(ump);
1129 ext2_clusteracct(fs, bbp, cg, bno, -1);
1130 fs->e2fs_fbcount--;
1131 e2fs_gd_set_nbfree(&fs->e2fs_gd[cg],
1132 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) - 1);
1133 fs->e2fs_fmod = 1;
1134 EXT2_UNLOCK(ump);
1135 ext2_gd_b_bitmap_csum_set(fs, cg, bp);
1136 bdwrite(bp);
1137 return (((uint64_t)cg) * fs->e2fs_fpg +
1138 le32toh(fs->e2fs->e2fs_first_dblock) + bno);
1139
1140 fail:
1141 brelse(bp);
1142 EXT2_LOCK(ump);
1143 return (0);
1144 }
1145
1146 /*
1147 * Determine whether a cluster can be allocated.
1148 */
1149 static daddr_t
ext2_clusteralloc(struct inode * ip,int cg,daddr_t bpref,int len)1150 ext2_clusteralloc(struct inode *ip, int cg, daddr_t bpref, int len)
1151 {
1152 struct m_ext2fs *fs;
1153 struct ext2mount *ump;
1154 struct buf *bp;
1155 char *bbp;
1156 int bit, error, got, i, loc, run;
1157 int32_t *lp;
1158 daddr_t bno;
1159
1160 fs = ip->i_e2fs;
1161 ump = ip->i_ump;
1162
1163 if (fs->e2fs_maxcluster[cg] < len)
1164 return (0);
1165
1166 EXT2_UNLOCK(ump);
1167 error = bread(ip->i_devvp,
1168 fsbtodb(fs, e2fs_gd_get_b_bitmap(&fs->e2fs_gd[cg])),
1169 (int)fs->e2fs_bsize, NOCRED, &bp);
1170 if (error)
1171 goto fail_lock;
1172
1173 bbp = (char *)bp->b_data;
1174 EXT2_LOCK(ump);
1175 /*
1176 * Check to see if a cluster of the needed size (or bigger) is
1177 * available in this cylinder group.
1178 */
1179 lp = &fs->e2fs_clustersum[cg].cs_sum[len];
1180 for (i = len; i <= fs->e2fs_contigsumsize; i++)
1181 if (*lp++ > 0)
1182 break;
1183 if (i > fs->e2fs_contigsumsize) {
1184 /*
1185 * Update the cluster summary information to reflect
1186 * the true maximum-sized cluster so that future cluster
1187 * allocation requests can avoid reading the bitmap only
1188 * to find no cluster.
1189 */
1190 lp = &fs->e2fs_clustersum[cg].cs_sum[len - 1];
1191 for (i = len - 1; i > 0; i--)
1192 if (*lp-- > 0)
1193 break;
1194 fs->e2fs_maxcluster[cg] = i;
1195 goto fail;
1196 }
1197 EXT2_UNLOCK(ump);
1198
1199 /* Search the bitmap to find a big enough cluster like in FFS. */
1200 if (dtog(fs, bpref) != cg)
1201 bpref = 0;
1202 if (bpref != 0)
1203 bpref = dtogd(fs, bpref);
1204 loc = bpref / NBBY;
1205 bit = 1 << (bpref % NBBY);
1206 for (run = 0, got = bpref; got < fs->e2fs_fpg; got++) {
1207 if ((bbp[loc] & bit) != 0)
1208 run = 0;
1209 else {
1210 run++;
1211 if (run == len)
1212 break;
1213 }
1214 if ((got & (NBBY - 1)) != (NBBY - 1))
1215 bit <<= 1;
1216 else {
1217 loc++;
1218 bit = 1;
1219 }
1220 }
1221
1222 if (got >= fs->e2fs_fpg)
1223 goto fail_lock;
1224
1225 /* Allocate the cluster that we found. */
1226 for (i = 1; i < len; i++)
1227 if (!isclr(bbp, got - run + i))
1228 panic("ext2_clusteralloc: map mismatch");
1229
1230 bno = got - run + 1;
1231 if (bno >= fs->e2fs_fpg)
1232 panic("ext2_clusteralloc: allocated out of group");
1233
1234 EXT2_LOCK(ump);
1235 for (i = 0; i < len; i += fs->e2fs_fpb) {
1236 setbit(bbp, bno + i);
1237 ext2_clusteracct(fs, bbp, cg, bno + i, -1);
1238 fs->e2fs_fbcount--;
1239 e2fs_gd_set_nbfree(&fs->e2fs_gd[cg],
1240 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) - 1);
1241 }
1242 fs->e2fs_fmod = 1;
1243 EXT2_UNLOCK(ump);
1244
1245 bdwrite(bp);
1246 return (cg * fs->e2fs_fpg + le32toh(fs->e2fs->e2fs_first_dblock)
1247 + bno);
1248
1249 fail_lock:
1250 EXT2_LOCK(ump);
1251 fail:
1252 brelse(bp);
1253 return (0);
1254 }
1255
1256 static int
ext2_zero_inode_table(struct inode * ip,int cg)1257 ext2_zero_inode_table(struct inode *ip, int cg)
1258 {
1259 struct m_ext2fs *fs;
1260 struct buf *bp;
1261 int i, all_blks, used_blks;
1262
1263 fs = ip->i_e2fs;
1264
1265 if (le16toh(fs->e2fs_gd[cg].ext4bgd_flags) & EXT2_BG_INODE_ZEROED)
1266 return (0);
1267
1268 all_blks = le16toh(fs->e2fs->e2fs_inode_size) * fs->e2fs_ipg /
1269 fs->e2fs_bsize;
1270
1271 used_blks = howmany(fs->e2fs_ipg -
1272 e2fs_gd_get_i_unused(&fs->e2fs_gd[cg]),
1273 fs->e2fs_bsize / EXT2_INODE_SIZE(fs));
1274
1275 for (i = 0; i < all_blks - used_blks; i++) {
1276 bp = getblk(ip->i_devvp, fsbtodb(fs,
1277 e2fs_gd_get_i_tables(&fs->e2fs_gd[cg]) + used_blks + i),
1278 fs->e2fs_bsize, 0, 0, 0);
1279 if (!bp)
1280 return (EIO);
1281
1282 vfs_bio_bzero_buf(bp, 0, fs->e2fs_bsize);
1283 bawrite(bp);
1284 }
1285
1286 fs->e2fs_gd[cg].ext4bgd_flags = htole16(le16toh(
1287 fs->e2fs_gd[cg].ext4bgd_flags) | EXT2_BG_INODE_ZEROED);
1288
1289 return (0);
1290 }
1291
1292 static void
ext2_fix_bitmap_tail(unsigned char * bitmap,int first,int last)1293 ext2_fix_bitmap_tail(unsigned char *bitmap, int first, int last)
1294 {
1295 int i;
1296
1297 for (i = first; i <= last; i++)
1298 bitmap[i] = 0xff;
1299 }
1300
1301 /*
1302 * Determine whether an inode can be allocated.
1303 *
1304 * Check to see if an inode is available, and if it is,
1305 * allocate it using tode in the specified cylinder group.
1306 */
1307 static daddr_t
ext2_nodealloccg(struct inode * ip,int cg,daddr_t ipref,int mode)1308 ext2_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode)
1309 {
1310 struct m_ext2fs *fs;
1311 struct buf *bp;
1312 struct ext2mount *ump;
1313 int error, start, len, ifree, ibytes;
1314 char *ibp, *loc;
1315
1316 ipref--; /* to avoid a lot of (ipref -1) */
1317 if (ipref == -1)
1318 ipref = 0;
1319 fs = ip->i_e2fs;
1320 ump = ip->i_ump;
1321 if (e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) == 0)
1322 return (0);
1323 EXT2_UNLOCK(ump);
1324 error = bread(ip->i_devvp, fsbtodb(fs,
1325 e2fs_gd_get_i_bitmap(&fs->e2fs_gd[cg])),
1326 (int)fs->e2fs_bsize, NOCRED, &bp);
1327 if (error) {
1328 EXT2_LOCK(ump);
1329 return (0);
1330 }
1331 if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) ||
1332 EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
1333 if (le16toh(fs->e2fs_gd[cg].ext4bgd_flags) &
1334 EXT2_BG_INODE_UNINIT) {
1335 ibytes = fs->e2fs_ipg / 8;
1336 memset(bp->b_data, 0, ibytes - 1);
1337 ext2_fix_bitmap_tail(bp->b_data, ibytes,
1338 fs->e2fs_bsize - 1);
1339 fs->e2fs_gd[cg].ext4bgd_flags = htole16(le16toh(
1340 fs->e2fs_gd[cg].ext4bgd_flags) &
1341 ~EXT2_BG_INODE_UNINIT);
1342 }
1343 ext2_gd_i_bitmap_csum_set(fs, cg, bp);
1344 error = ext2_zero_inode_table(ip, cg);
1345 if (error) {
1346 brelse(bp);
1347 EXT2_LOCK(ump);
1348 return (0);
1349 }
1350 }
1351 error = ext2_gd_i_bitmap_csum_verify(fs, cg, bp);
1352 if (error) {
1353 brelse(bp);
1354 EXT2_LOCK(ump);
1355 return (0);
1356 }
1357 if (e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) == 0) {
1358 /*
1359 * Another thread allocated the last i-node in this
1360 * group while we were waiting for the buffer.
1361 */
1362 brelse(bp);
1363 EXT2_LOCK(ump);
1364 return (0);
1365 }
1366 ibp = (char *)bp->b_data;
1367 if (ipref) {
1368 ipref %= fs->e2fs_ipg;
1369 if (isclr(ibp, ipref))
1370 goto gotit;
1371 }
1372 start = ipref / NBBY;
1373 len = howmany(fs->e2fs_ipg - ipref, NBBY);
1374 loc = memcchr(&ibp[start], 0xff, len);
1375 if (loc == NULL) {
1376 len = start + 1;
1377 start = 0;
1378 loc = memcchr(&ibp[start], 0xff, len);
1379 if (loc == NULL) {
1380 SDT_PROBE3(ext2fs, , alloc,
1381 ext2_nodealloccg_bmap_corrupted, cg, ipref,
1382 fs->e2fs_fsmnt);
1383 brelse(bp);
1384 EXT2_LOCK(ump);
1385 return (0);
1386 }
1387 }
1388 ipref = (loc - ibp) * NBBY + ffs(~*loc) - 1;
1389 gotit:
1390 setbit(ibp, ipref);
1391 EXT2_LOCK(ump);
1392 e2fs_gd_set_nifree(&fs->e2fs_gd[cg],
1393 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) - 1);
1394 if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) ||
1395 EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
1396 ifree = fs->e2fs_ipg - e2fs_gd_get_i_unused(&fs->e2fs_gd[cg]);
1397 if (ipref + 1 > ifree)
1398 e2fs_gd_set_i_unused(&fs->e2fs_gd[cg],
1399 fs->e2fs_ipg - (ipref + 1));
1400 }
1401 fs->e2fs_ficount--;
1402 fs->e2fs_fmod = 1;
1403 if ((mode & IFMT) == IFDIR) {
1404 e2fs_gd_set_ndirs(&fs->e2fs_gd[cg],
1405 e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) + 1);
1406 fs->e2fs_total_dir++;
1407 }
1408 EXT2_UNLOCK(ump);
1409 ext2_gd_i_bitmap_csum_set(fs, cg, bp);
1410 bdwrite(bp);
1411 return ((uint64_t)cg * fs->e2fs_ipg + ipref + 1);
1412 }
1413
1414 /*
1415 * Free a block or fragment.
1416 *
1417 */
1418 void
ext2_blkfree(struct inode * ip,e4fs_daddr_t bno,long size)1419 ext2_blkfree(struct inode *ip, e4fs_daddr_t bno, long size)
1420 {
1421 struct m_ext2fs *fs;
1422 struct buf *bp;
1423 struct ext2mount *ump;
1424 int cg, error;
1425 char *bbp;
1426
1427 fs = ip->i_e2fs;
1428 ump = ip->i_ump;
1429 cg = dtog(fs, bno);
1430 if (bno >= fs->e2fs_bcount) {
1431 SDT_PROBE2(ext2fs, , alloc, ext2_blkfree_bad_block,
1432 ip->i_number, bno);
1433 return;
1434 }
1435 error = bread(ip->i_devvp,
1436 fsbtodb(fs, e2fs_gd_get_b_bitmap(&fs->e2fs_gd[cg])),
1437 (int)fs->e2fs_bsize, NOCRED, &bp);
1438 if (error) {
1439 return;
1440 }
1441 bbp = (char *)bp->b_data;
1442 bno = dtogd(fs, bno);
1443 if (isclr(bbp, bno)) {
1444 panic("ext2_blkfree: freeing free block %lld, fs=%s",
1445 (long long)bno, fs->e2fs_fsmnt);
1446 }
1447 clrbit(bbp, bno);
1448 EXT2_LOCK(ump);
1449 ext2_clusteracct(fs, bbp, cg, bno, 1);
1450 fs->e2fs_fbcount++;
1451 e2fs_gd_set_nbfree(&fs->e2fs_gd[cg],
1452 e2fs_gd_get_nbfree(&fs->e2fs_gd[cg]) + 1);
1453 fs->e2fs_fmod = 1;
1454 EXT2_UNLOCK(ump);
1455 ext2_gd_b_bitmap_csum_set(fs, cg, bp);
1456 bdwrite(bp);
1457 }
1458
1459 /*
1460 * Free an inode.
1461 *
1462 */
1463 int
ext2_vfree(struct vnode * pvp,ino_t ino,int mode)1464 ext2_vfree(struct vnode *pvp, ino_t ino, int mode)
1465 {
1466 struct m_ext2fs *fs;
1467 struct inode *pip;
1468 struct buf *bp;
1469 struct ext2mount *ump;
1470 int error, cg;
1471 char *ibp;
1472
1473 pip = VTOI(pvp);
1474 fs = pip->i_e2fs;
1475 ump = pip->i_ump;
1476 if ((u_int)ino > fs->e2fs_ipg * fs->e2fs_gcount)
1477 panic("ext2_vfree: range: devvp = %p, ino = %ju, fs = %s",
1478 pip->i_devvp, (uintmax_t)ino, fs->e2fs_fsmnt);
1479
1480 cg = ino_to_cg(fs, ino);
1481 error = bread(pip->i_devvp,
1482 fsbtodb(fs, e2fs_gd_get_i_bitmap(&fs->e2fs_gd[cg])),
1483 (int)fs->e2fs_bsize, NOCRED, &bp);
1484 if (error) {
1485 return (0);
1486 }
1487 ibp = (char *)bp->b_data;
1488 ino = (ino - 1) % fs->e2fs_ipg;
1489 if (isclr(ibp, ino)) {
1490 SDT_PROBE2(ext2fs, , alloc, ext2_vfree_doublefree,
1491 fs->e2fs_fsmnt, ino);
1492 if (fs->e2fs_ronly == 0)
1493 panic("ext2_vfree: freeing free inode");
1494 }
1495 clrbit(ibp, ino);
1496 EXT2_LOCK(ump);
1497 fs->e2fs_ficount++;
1498 e2fs_gd_set_nifree(&fs->e2fs_gd[cg],
1499 e2fs_gd_get_nifree(&fs->e2fs_gd[cg]) + 1);
1500 if ((mode & IFMT) == IFDIR) {
1501 e2fs_gd_set_ndirs(&fs->e2fs_gd[cg],
1502 e2fs_gd_get_ndirs(&fs->e2fs_gd[cg]) - 1);
1503 fs->e2fs_total_dir--;
1504 }
1505 fs->e2fs_fmod = 1;
1506 EXT2_UNLOCK(ump);
1507 ext2_gd_i_bitmap_csum_set(fs, cg, bp);
1508 bdwrite(bp);
1509 return (0);
1510 }
1511
1512 /*
1513 * Find a block in the specified cylinder group.
1514 *
1515 * It is a panic if a request is made to find a block if none are
1516 * available.
1517 */
1518 static daddr_t
ext2_mapsearch(struct m_ext2fs * fs,char * bbp,daddr_t bpref)1519 ext2_mapsearch(struct m_ext2fs *fs, char *bbp, daddr_t bpref)
1520 {
1521 char *loc;
1522 int start, len;
1523
1524 /*
1525 * find the fragment by searching through the free block
1526 * map for an appropriate bit pattern
1527 */
1528 if (bpref)
1529 start = dtogd(fs, bpref) / NBBY;
1530 else
1531 start = 0;
1532 len = howmany(fs->e2fs_fpg, NBBY) - start;
1533 loc = memcchr(&bbp[start], 0xff, len);
1534 if (loc == NULL) {
1535 len = start + 1;
1536 start = 0;
1537 loc = memcchr(&bbp[start], 0xff, len);
1538 if (loc == NULL) {
1539 panic("ext2_mapsearch: map corrupted: start=%d, len=%d,"
1540 "fs=%s", start, len, fs->e2fs_fsmnt);
1541 /* NOTREACHED */
1542 }
1543 }
1544 return ((loc - bbp) * NBBY + ffs(~*loc) - 1);
1545 }
1546
1547 int
ext2_cg_has_sb(struct m_ext2fs * fs,int cg)1548 ext2_cg_has_sb(struct m_ext2fs *fs, int cg)
1549 {
1550 int a3, a5, a7;
1551
1552 if (cg == 0)
1553 return (1);
1554
1555 if (EXT2_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_SPARSESUPER2)) {
1556 if (cg == le32toh(fs->e2fs->e4fs_backup_bgs[0]) ||
1557 cg == le32toh(fs->e2fs->e4fs_backup_bgs[1]))
1558 return (1);
1559 return (0);
1560 }
1561
1562 if ((cg <= 1) ||
1563 !EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_SPARSESUPER))
1564 return (1);
1565
1566 if (!(cg & 1))
1567 return (0);
1568
1569 for (a3 = 3, a5 = 5, a7 = 7;
1570 a3 <= cg || a5 <= cg || a7 <= cg;
1571 a3 *= 3, a5 *= 5, a7 *= 7)
1572 if (cg == a3 || cg == a5 || cg == a7)
1573 return (1);
1574 return (0);
1575 }
1576