Whamcloud - gitweb
config: update config.{guess,sub}
[tools/e2fsprogs.git] / e2fsck / super.c
1 /*
2  * e2fsck.c - superblock checks
3  *
4  * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Public
8  * License.
9  * %End-Header%
10  */
11
12 #include "config.h"
13 #ifdef HAVE_ERRNO_H
14 #include <errno.h>
15 #endif
16
17 #ifndef EXT2_SKIP_UUID
18 #include "uuid/uuid.h"
19 #endif
20 #include "e2fsck.h"
21 #include "problem.h"
22
23 #define MIN_CHECK 1
24 #define MAX_CHECK 2
25 #define LOG2_CHECK 4
26
27 static int check_super_value(e2fsck_t ctx, const char *descr,
28                               unsigned long value, int flags,
29                               unsigned long min_val, unsigned long max_val)
30 {
31         struct          problem_context pctx;
32
33         if ((flags & MIN_CHECK && value < min_val) ||
34             (flags & MAX_CHECK && value > max_val) ||
35             (flags & LOG2_CHECK && (value & (value - 1)) != 0)) {
36                 clear_problem_context(&pctx);
37                 pctx.num = value;
38                 pctx.str = descr;
39                 fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
40                 ctx->flags |= E2F_FLAG_ABORT;
41                 return 0;
42         }
43         return 1;
44 }
45
46 static int check_super_value64(e2fsck_t ctx, const char *descr,
47                                 __u64 value, int flags,
48                                 __u64 min_val, __u64 max_val)
49 {
50         struct          problem_context pctx;
51
52         if ((flags & MIN_CHECK && value < min_val) ||
53             (flags & MAX_CHECK && value > max_val) ||
54             (flags & LOG2_CHECK && (value & (value - 1)) != 0)) {
55                 clear_problem_context(&pctx);
56                 pctx.num = value;
57                 pctx.str = descr;
58                 fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
59                 ctx->flags |= E2F_FLAG_ABORT;
60                 return 0;
61         }
62         return 1;
63 }
64
65 /*
66  * helper function to release an inode
67  */
68 struct process_block_struct {
69         e2fsck_t        ctx;
70         char            *buf;
71         struct problem_context *pctx;
72         int             truncating;
73         int             truncate_offset;
74         e2_blkcnt_t     truncate_block;
75         int             truncated_blocks;
76         int             abort;
77         errcode_t       errcode;
78         blk64_t last_cluster;
79         struct ext2_inode_large *inode;
80 };
81
82 static int release_inode_block(ext2_filsys fs,
83                                blk64_t  *block_nr,
84                                e2_blkcnt_t blockcnt,
85                                blk64_t  ref_blk EXT2FS_ATTR((unused)),
86                                int      ref_offset EXT2FS_ATTR((unused)),
87                                void *priv_data)
88 {
89         struct process_block_struct *pb;
90         e2fsck_t                ctx;
91         struct problem_context  *pctx;
92         blk64_t                 blk = *block_nr;
93         blk64_t                 cluster = EXT2FS_B2C(fs, *block_nr);
94         int                     retval = 0;
95
96         pb = (struct process_block_struct *) priv_data;
97         ctx = pb->ctx;
98         pctx = pb->pctx;
99
100         pctx->blk = blk;
101         pctx->blkcount = blockcnt;
102
103         if (blk == 0)
104                 return 0;
105
106         if (pb->last_cluster == cluster)
107                 return 0;
108
109         pb->last_cluster = cluster;
110
111         if ((blk < fs->super->s_first_data_block) ||
112             (blk >= ext2fs_blocks_count(fs->super))) {
113                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_BLOCK_NUM, pctx);
114         return_abort:
115                 pb->abort = 1;
116                 return BLOCK_ABORT;
117         }
118
119         if (!ext2fs_test_block_bitmap2(fs->block_map, blk)) {
120                 fix_problem(ctx, PR_0_ORPHAN_ALREADY_CLEARED_BLOCK, pctx);
121                 goto return_abort;
122         }
123
124         /*
125          * If we are deleting an orphan, then we leave the fields alone.
126          * If we are truncating an orphan, then update the inode fields
127          * and clean up any partial block data.
128          */
129         if (pb->truncating) {
130                 /*
131                  * We only remove indirect blocks if they are
132                  * completely empty.
133                  */
134                 if (blockcnt < 0) {
135                         int     i, limit;
136                         blk_t   *bp;
137
138                         pb->errcode = io_channel_read_blk64(fs->io, blk, 1,
139                                                         pb->buf);
140                         if (pb->errcode)
141                                 goto return_abort;
142
143                         limit = fs->blocksize >> 2;
144                         for (i = 0, bp = (blk_t *) pb->buf;
145                              i < limit;  i++, bp++)
146                                 if (*bp)
147                                         return 0;
148                 }
149                 /*
150                  * We don't remove direct blocks until we've reached
151                  * the truncation block.
152                  */
153                 if (blockcnt >= 0 && blockcnt < pb->truncate_block)
154                         return 0;
155                 /*
156                  * If part of the last block needs truncating, we do
157                  * it here.
158                  */
159                 if ((blockcnt == pb->truncate_block) && pb->truncate_offset) {
160                         pb->errcode = io_channel_read_blk64(fs->io, blk, 1,
161                                                         pb->buf);
162                         if (pb->errcode)
163                                 goto return_abort;
164                         memset(pb->buf + pb->truncate_offset, 0,
165                                fs->blocksize - pb->truncate_offset);
166                         pb->errcode = io_channel_write_blk64(fs->io, blk, 1,
167                                                          pb->buf);
168                         if (pb->errcode)
169                                 goto return_abort;
170                 }
171                 pb->truncated_blocks++;
172                 *block_nr = 0;
173                 retval |= BLOCK_CHANGED;
174         }
175
176         if (ctx->qctx)
177                 quota_data_sub(ctx->qctx, pb->inode, 0, ctx->fs->blocksize);
178         ext2fs_block_alloc_stats2(fs, blk, -1);
179         ctx->free_blocks++;
180         return retval;
181 }
182
183 /*
184  * This function releases an inode.  Returns 1 if an inconsistency was
185  * found.  If the inode has a link count, then it is being truncated and
186  * not deleted.
187  */
188 static int release_inode_blocks(e2fsck_t ctx, ext2_ino_t ino,
189                                 struct ext2_inode_large *inode, char *block_buf,
190                                 struct problem_context *pctx)
191 {
192         struct process_block_struct     pb;
193         ext2_filsys                     fs = ctx->fs;
194         blk64_t                         blk;
195         errcode_t                       retval;
196         __u32                           count;
197
198         if (!ext2fs_inode_has_valid_blocks2(fs, EXT2_INODE(inode)))
199                 return 0;
200
201         pb.buf = block_buf + 3 * ctx->fs->blocksize;
202         pb.ctx = ctx;
203         pb.abort = 0;
204         pb.errcode = 0;
205         pb.pctx = pctx;
206         pb.last_cluster = 0;
207         pb.inode = inode;
208         if (inode->i_links_count) {
209                 pb.truncating = 1;
210                 pb.truncate_block = (e2_blkcnt_t)
211                         ((EXT2_I_SIZE(inode) + fs->blocksize - 1) /
212                          fs->blocksize);
213                 pb.truncate_offset = inode->i_size % fs->blocksize;
214         } else {
215                 pb.truncating = 0;
216                 pb.truncate_block = 0;
217                 pb.truncate_offset = 0;
218         }
219         pb.truncated_blocks = 0;
220         retval = ext2fs_block_iterate3(fs, ino, BLOCK_FLAG_DEPTH_TRAVERSE,
221                                       block_buf, release_inode_block, &pb);
222         if (retval) {
223                 com_err("release_inode_blocks", retval,
224                         _("while calling ext2fs_block_iterate for inode %u"),
225                         ino);
226                 return 1;
227         }
228         if (pb.abort)
229                 return 1;
230
231         /* Refresh the inode since ext2fs_block_iterate may have changed it */
232         e2fsck_read_inode_full(ctx, ino, EXT2_INODE(inode), sizeof(*inode),
233                         "release_inode_blocks");
234
235         if (pb.truncated_blocks)
236                 ext2fs_iblk_sub_blocks(fs, EXT2_INODE(inode),
237                                 pb.truncated_blocks);
238
239         blk = ext2fs_file_acl_block(fs, EXT2_INODE(inode));
240         if (blk) {
241                 retval = ext2fs_adjust_ea_refcount3(fs, blk, block_buf, -1,
242                                 &count, ino);
243                 if (retval == EXT2_ET_BAD_EA_BLOCK_NUM) {
244                         retval = 0;
245                         count = 1;
246                 }
247                 if (retval) {
248                         com_err("release_inode_blocks", retval,
249                 _("while calling ext2fs_adjust_ea_refcount2 for inode %u"),
250                                 ino);
251                         return 1;
252                 }
253                 if (count == 0) {
254                         if (ctx->qctx)
255                                 quota_data_sub(ctx->qctx, inode, 0,
256                                                 ctx->fs->blocksize);
257                         ext2fs_block_alloc_stats2(fs, blk, -1);
258                         ctx->free_blocks++;
259                 }
260                 ext2fs_file_acl_block_set(fs, EXT2_INODE(inode), 0);
261         }
262         return 0;
263 }
264
265 /* Load all quota data in preparation for orphan clearing. */
266 static errcode_t e2fsck_read_all_quotas(e2fsck_t ctx)
267 {
268         ext2_ino_t qf_ino;
269         enum quota_type qtype;
270         errcode_t retval = 0;
271
272         if (!ext2fs_has_feature_quota(ctx->fs->super))
273                 return retval;
274
275         retval = quota_init_context(&ctx->qctx, ctx->fs, 0);
276         if (retval)
277                 return retval;
278
279         for (qtype = 0 ; qtype < MAXQUOTAS; qtype++) {
280                 qf_ino = *quota_sb_inump(ctx->fs->super, qtype);
281                 if (qf_ino == 0)
282                         continue;
283
284                 retval = quota_update_limits(ctx->qctx, qf_ino, qtype);
285                 if (retval)
286                         break;
287         }
288         if (retval)
289                 quota_release_context(&ctx->qctx);
290         return retval;
291 }
292
293 /* Write all the quota info to disk. */
294 static errcode_t e2fsck_write_all_quotas(e2fsck_t ctx)
295 {
296         struct problem_context pctx;
297         enum quota_type qtype;
298
299         if (!ext2fs_has_feature_quota(ctx->fs->super))
300                 return 0;
301
302         clear_problem_context(&pctx);
303         for (qtype = 0 ; qtype < MAXQUOTAS; qtype++) {
304                 pctx.num = qtype;
305                 pctx.errcode = quota_write_inode(ctx->qctx, 1 << qtype);
306                 if (pctx.errcode) {
307                         fix_problem(ctx, PR_6_WRITE_QUOTAS, &pctx);
308                         break;
309                 }
310         }
311
312         quota_release_context(&ctx->qctx);
313         return pctx.errcode;
314 }
315
316 /*
317  * This function releases all of the orphan inodes.  It returns 1 if
318  * it hit some error, and 0 on success.
319  */
320 static int release_orphan_inodes(e2fsck_t ctx)
321 {
322         ext2_filsys fs = ctx->fs;
323         ext2_ino_t      ino, next_ino;
324         struct ext2_inode_large inode;
325         struct problem_context pctx;
326         char *block_buf;
327
328         if ((ino = fs->super->s_last_orphan) == 0)
329                 return 0;
330
331         clear_problem_context(&pctx);
332         pctx.errcode = e2fsck_read_all_quotas(ctx);
333         if (pctx.errcode) {
334                 fix_problem(ctx, PR_0_QUOTA_INIT_CTX, &pctx);
335                 return 1;
336         }
337
338         /*
339          * Win or lose, we won't be using the head of the orphan inode
340          * list again.
341          */
342         fs->super->s_last_orphan = 0;
343         ext2fs_mark_super_dirty(fs);
344
345         /*
346          * If the filesystem contains errors, don't run the orphan
347          * list, since the orphan list can't be trusted; and we're
348          * going to be running a full e2fsck run anyway...
349          */
350         if (fs->super->s_state & EXT2_ERROR_FS) {
351                 if (ctx->qctx)
352                         quota_release_context(&ctx->qctx);
353                 return 0;
354         }
355
356         if ((ino < EXT2_FIRST_INODE(fs->super)) ||
357             (ino > fs->super->s_inodes_count)) {
358                 clear_problem_context(&pctx);
359                 pctx.ino = ino;
360                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
361                 goto err_qctx;
362         }
363
364         block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
365                                                     "block iterate buffer");
366         e2fsck_read_bitmaps(ctx);
367
368         while (ino) {
369                 e2fsck_read_inode_full(ctx, ino, EXT2_INODE(&inode),
370                                 sizeof(inode), "release_orphan_inodes");
371                 clear_problem_context(&pctx);
372                 pctx.ino = ino;
373                 pctx.inode = EXT2_INODE(&inode);
374                 pctx.str = inode.i_links_count ? _("Truncating") :
375                         _("Clearing");
376
377                 fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
378
379                 next_ino = inode.i_dtime;
380                 if (next_ino &&
381                     ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
382                      (next_ino > fs->super->s_inodes_count))) {
383                         pctx.ino = next_ino;
384                         fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
385                         goto err_buf;
386                 }
387
388                 if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
389                         goto err_buf;
390
391                 if (!inode.i_links_count) {
392                         if (ctx->qctx)
393                                 quota_data_inodes(ctx->qctx, &inode, ino, -1);
394                         ext2fs_inode_alloc_stats2(fs, ino, -1,
395                                                   LINUX_S_ISDIR(inode.i_mode));
396                         ctx->free_inodes++;
397                         inode.i_dtime = ctx->now;
398                 } else {
399                         inode.i_dtime = 0;
400                 }
401                 e2fsck_write_inode_full(ctx, ino, EXT2_INODE(&inode),
402                                 sizeof(inode), "delete_file");
403                 ino = next_ino;
404         }
405         ext2fs_free_mem(&block_buf);
406         pctx.errcode = e2fsck_write_all_quotas(ctx);
407         if (pctx.errcode)
408                 goto err;
409         return 0;
410 err_buf:
411         ext2fs_free_mem(&block_buf);
412 err_qctx:
413         if (ctx->qctx)
414                 quota_release_context(&ctx->qctx);
415 err:
416         return 1;
417 }
418
419 /*
420  * Check the resize inode to make sure it is sane.  We check both for
421  * the case where on-line resizing is not enabled (in which case the
422  * resize inode should be cleared) as well as the case where on-line
423  * resizing is enabled.
424  */
425 void check_resize_inode(e2fsck_t ctx)
426 {
427         ext2_filsys fs = ctx->fs;
428         struct ext2_inode inode;
429         struct problem_context  pctx;
430         int             i, gdt_off, ind_off;
431         dgrp_t          j;
432         blk_t           blk, pblk;
433         blk_t           expect; /* for resize inode, which is 32-bit only */
434         __u32           *dind_buf = 0, *ind_buf;
435         errcode_t       retval;
436
437         clear_problem_context(&pctx);
438
439         if (ext2fs_has_feature_resize_inode(fs->super) &&
440             ext2fs_has_feature_meta_bg(fs->super) &&
441             fix_problem(ctx, PR_0_DISABLE_RESIZE_INODE, &pctx)) {
442                 ext2fs_clear_feature_resize_inode(fs->super);
443                 fs->super->s_reserved_gdt_blocks = 0;
444                 ext2fs_mark_super_dirty(fs);
445         }
446
447         /*
448          * If the resize inode feature isn't set, then
449          * s_reserved_gdt_blocks must be zero.
450          */
451         if (!ext2fs_has_feature_resize_inode(fs->super)) {
452                 if (fs->super->s_reserved_gdt_blocks) {
453                         pctx.num = fs->super->s_reserved_gdt_blocks;
454                         if (fix_problem(ctx, PR_0_NONZERO_RESERVED_GDT_BLOCKS,
455                                         &pctx)) {
456                                 fs->super->s_reserved_gdt_blocks = 0;
457                                 ext2fs_mark_super_dirty(fs);
458                         }
459                 }
460         }
461
462         /* Read the resize inode */
463         pctx.ino = EXT2_RESIZE_INO;
464         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
465         if (retval) {
466                 if (ext2fs_has_feature_resize_inode(fs->super))
467                         ctx->flags |= E2F_FLAG_RESIZE_INODE;
468                 return;
469         }
470
471         /*
472          * If the resize inode feature isn't set, check to make sure
473          * the resize inode is cleared; then we're done.
474          */
475         if (!ext2fs_has_feature_resize_inode(fs->super)) {
476                 for (i=0; i < EXT2_N_BLOCKS; i++) {
477                         if (inode.i_block[i])
478                                 break;
479                 }
480                 if ((i < EXT2_N_BLOCKS) &&
481                     fix_problem(ctx, PR_0_CLEAR_RESIZE_INODE, &pctx)) {
482                         memset(&inode, 0, sizeof(inode));
483                         e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
484                                            "clear_resize");
485                 }
486                 return;
487         }
488
489         /*
490          * The resize inode feature is enabled; check to make sure the
491          * only block in use is the double indirect block
492          */
493         blk = inode.i_block[EXT2_DIND_BLOCK];
494         for (i=0; i < EXT2_N_BLOCKS; i++) {
495                 if (i != EXT2_DIND_BLOCK && inode.i_block[i])
496                         break;
497         }
498         if ((i < EXT2_N_BLOCKS) || !blk || !inode.i_links_count ||
499             !(inode.i_mode & LINUX_S_IFREG) ||
500             (blk < fs->super->s_first_data_block ||
501              blk >= ext2fs_blocks_count(fs->super))) {
502         resize_inode_invalid:
503                 if (fix_problem(ctx, PR_0_RESIZE_INODE_INVALID, &pctx)) {
504                         memset(&inode, 0, sizeof(inode));
505                         e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
506                                            "clear_resize");
507                         ctx->flags |= E2F_FLAG_RESIZE_INODE;
508                 }
509                 if (!(ctx->options & E2F_OPT_READONLY)) {
510                         fs->super->s_state &= ~EXT2_VALID_FS;
511                         ext2fs_mark_super_dirty(fs);
512                 }
513                 goto cleanup;
514         }
515         dind_buf = (__u32 *) e2fsck_allocate_memory(ctx, fs->blocksize * 2,
516                                                     "resize dind buffer");
517         ind_buf = (__u32 *) ((char *) dind_buf + fs->blocksize);
518
519         retval = ext2fs_read_ind_block(fs, blk, dind_buf);
520         if (retval)
521                 goto resize_inode_invalid;
522
523         gdt_off = fs->desc_blocks;
524         pblk = fs->super->s_first_data_block + 1 + fs->desc_blocks;
525         if (fs->blocksize == 1024 && fs->super->s_first_data_block == 0)
526                 pblk++; /* Deal with 1024 blocksize bigalloc fs */
527         for (i = 0; i < fs->super->s_reserved_gdt_blocks / 4;
528              i++, gdt_off++, pblk++) {
529                 gdt_off %= fs->blocksize/4;
530                 if (dind_buf[gdt_off] != pblk)
531                         goto resize_inode_invalid;
532                 retval = ext2fs_read_ind_block(fs, pblk, ind_buf);
533                 if (retval)
534                         goto resize_inode_invalid;
535                 ind_off = 0;
536                 for (j = 1; j < fs->group_desc_count; j++) {
537                         if (!ext2fs_bg_has_super(fs, j))
538                                 continue;
539                         expect = pblk + EXT2_GROUPS_TO_BLOCKS(fs->super, j);
540                         if (ind_buf[ind_off] != expect)
541                                 goto resize_inode_invalid;
542                         ind_off++;
543                 }
544         }
545
546 cleanup:
547         if (dind_buf)
548                 ext2fs_free_mem(&dind_buf);
549
550  }
551
552 /*
553  * This function checks the dirhash signed/unsigned hint if necessary.
554  */
555 static void e2fsck_fix_dirhash_hint(e2fsck_t ctx)
556 {
557         struct ext2_super_block *sb = ctx->fs->super;
558         struct problem_context pctx;
559         char    c;
560
561         if ((ctx->options & E2F_OPT_READONLY) ||
562             !ext2fs_has_feature_dir_index(sb) ||
563             (sb->s_flags & (EXT2_FLAGS_SIGNED_HASH|EXT2_FLAGS_UNSIGNED_HASH)))
564                 return;
565
566         c = (char) 255;
567
568         clear_problem_context(&pctx);
569         if (fix_problem(ctx, PR_0_DIRHASH_HINT, &pctx)) {
570                 if (((int) c) == -1) {
571                         sb->s_flags |= EXT2_FLAGS_SIGNED_HASH;
572                 } else {
573                         sb->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
574                 }
575                 ext2fs_mark_super_dirty(ctx->fs);
576         }
577 }
578
579
580 void check_super_block(e2fsck_t ctx)
581 {
582         ext2_filsys fs = ctx->fs;
583         blk64_t first_block, last_block;
584         struct ext2_super_block *sb = fs->super;
585         unsigned int    ipg_max;
586         problem_t       problem;
587         blk64_t blocks_per_group = fs->super->s_blocks_per_group;
588         __u32   bpg_max, cpg_max;
589         __u64   blks_max;
590         int     inodes_per_block;
591         int     inode_size;
592         int     accept_time_fudge;
593         int     broken_system_clock;
594         dgrp_t  i;
595         blk64_t should_be;
596         struct problem_context  pctx;
597         blk64_t free_blocks = 0;
598         ino_t   free_inodes = 0;
599         int     csum_flag, clear_test_fs_flag;
600
601         inodes_per_block = EXT2_INODES_PER_BLOCK(fs->super);
602         ipg_max = inodes_per_block * (blocks_per_group - 4);
603         if (ipg_max > EXT2_MAX_INODES_PER_GROUP(sb))
604                 ipg_max = EXT2_MAX_INODES_PER_GROUP(sb);
605         cpg_max = 8 * EXT2_BLOCK_SIZE(sb);
606         if (cpg_max > EXT2_MAX_CLUSTERS_PER_GROUP(sb))
607                 cpg_max = EXT2_MAX_CLUSTERS_PER_GROUP(sb);
608         bpg_max = 8 * EXT2_BLOCK_SIZE(sb) * EXT2FS_CLUSTER_RATIO(fs);
609         if (bpg_max > EXT2_MAX_BLOCKS_PER_GROUP(sb))
610                 bpg_max = EXT2_MAX_BLOCKS_PER_GROUP(sb);
611
612         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
613                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
614         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
615                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
616         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
617                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
618
619         blks_max = (1ULL << 32) * EXT2_MAX_BLOCKS_PER_GROUP(fs->super);
620         if (ext2fs_has_feature_64bit(fs->super)) {
621                 if (blks_max > ((1ULL << 48) - 1))
622                         blks_max = (1ULL << 48) - 1;
623         } else {
624                 if (blks_max > ((1ULL << 32) - 1))
625                         blks_max = (1ULL << 32) - 1;
626         }
627
628         clear_problem_context(&pctx);
629
630         /*
631          * Verify the super block constants...
632          */
633         if (!check_super_value(ctx, "inodes_count", sb->s_inodes_count,
634                                MIN_CHECK, 1, 0))
635                 return;
636         if (!check_super_value64(ctx, "blocks_count", ext2fs_blocks_count(sb),
637                                  MIN_CHECK | MAX_CHECK, 1, blks_max))
638                 return;
639         if (!check_super_value(ctx, "first_data_block", sb->s_first_data_block,
640                                MAX_CHECK, 0, ext2fs_blocks_count(sb)))
641                 return;
642         if (!check_super_value(ctx, "log_block_size", sb->s_log_block_size,
643                                MIN_CHECK | MAX_CHECK, 0,
644                                EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE))
645                 return;
646         if (!check_super_value(ctx, "log_cluster_size",
647                                sb->s_log_cluster_size,
648                                MIN_CHECK | MAX_CHECK, sb->s_log_block_size,
649                                (EXT2_MAX_CLUSTER_LOG_SIZE -
650                                 EXT2_MIN_CLUSTER_LOG_SIZE)))
651                 return;
652         if (!check_super_value(ctx, "clusters_per_group",
653                                sb->s_clusters_per_group,
654                                MIN_CHECK | MAX_CHECK, 8, cpg_max))
655                 return;
656         if (!check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
657                                MIN_CHECK | MAX_CHECK, 8, bpg_max))
658                 return;
659         if (!check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
660                                MIN_CHECK | MAX_CHECK, inodes_per_block, ipg_max))
661                 return;
662         if (!check_super_value(ctx, "r_blocks_count", ext2fs_r_blocks_count(sb),
663                                MAX_CHECK, 0, ext2fs_blocks_count(sb) / 2))
664                 return;
665         if (!check_super_value(ctx, "reserved_gdt_blocks",
666                                sb->s_reserved_gdt_blocks, MAX_CHECK, 0,
667                                fs->blocksize / sizeof(__u32)))
668                 return;
669         if (!check_super_value(ctx, "desc_size",
670                                sb->s_desc_size, MAX_CHECK | LOG2_CHECK, 0,
671                                EXT2_MAX_DESC_SIZE))
672                 return;
673
674         should_be = (__u64)sb->s_inodes_per_group * fs->group_desc_count;
675         if (should_be > ~0U) {
676                 pctx.num = should_be;
677                 fix_problem(ctx, PR_0_INODE_COUNT_BIG, &pctx);
678                 ctx->flags |= E2F_FLAG_ABORT;
679                 return;
680         }
681         if (sb->s_inodes_count != should_be) {
682                 pctx.ino = sb->s_inodes_count;
683                 pctx.ino2 = should_be;
684                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
685                         sb->s_inodes_count = should_be;
686                         ext2fs_mark_super_dirty(fs);
687                 } else {
688                         pctx.num = sb->s_inodes_count;
689                         pctx.str = "inodes_count";
690                         fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
691                         ctx->flags |= E2F_FLAG_ABORT;
692                         return;
693                 }
694         }
695         if (sb->s_rev_level > EXT2_GOOD_OLD_REV &&
696             !check_super_value(ctx, "first_ino", sb->s_first_ino,
697                                MIN_CHECK | MAX_CHECK,
698                                EXT2_GOOD_OLD_FIRST_INO, sb->s_inodes_count))
699                 return;
700         inode_size = EXT2_INODE_SIZE(sb);
701         if (!check_super_value(ctx, "inode_size",
702                                inode_size, MIN_CHECK | MAX_CHECK | LOG2_CHECK,
703                                EXT2_GOOD_OLD_INODE_SIZE, fs->blocksize))
704                 return;
705         if (sb->s_blocks_per_group != (sb->s_clusters_per_group *
706                                        EXT2FS_CLUSTER_RATIO(fs))) {
707                 pctx.num = sb->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs);
708                 pctx.str = "block_size";
709                 fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
710                 ctx->flags |= E2F_FLAG_ABORT;
711                 return;
712         }
713
714         if ((ctx->flags & E2F_FLAG_GOT_DEVSIZE) &&
715             (ctx->num_blocks < ext2fs_blocks_count(sb))) {
716                 pctx.blk = ext2fs_blocks_count(sb);
717                 pctx.blk2 = ctx->num_blocks;
718                 if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
719                         ctx->flags |= E2F_FLAG_ABORT;
720                         return;
721                 }
722         }
723
724         should_be = (sb->s_log_block_size == 0 &&
725                      EXT2FS_CLUSTER_RATIO(fs) == 1) ? 1 : 0;
726         if (sb->s_first_data_block != should_be) {
727                 pctx.blk = sb->s_first_data_block;
728                 pctx.blk2 = should_be;
729                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
730                 ctx->flags |= E2F_FLAG_ABORT;
731                 return;
732         }
733
734         if (EXT2_INODE_SIZE(sb) > EXT2_GOOD_OLD_INODE_SIZE) {
735                 unsigned min =
736                         sizeof(((struct ext2_inode_large *) 0)->i_extra_isize) +
737                         sizeof(((struct ext2_inode_large *) 0)->i_checksum_hi);
738                 unsigned max = EXT2_INODE_SIZE(sb) - EXT2_GOOD_OLD_INODE_SIZE;
739                 pctx.num = sb->s_min_extra_isize;
740                 if (sb->s_min_extra_isize &&
741                     (sb->s_min_extra_isize < min ||
742                      sb->s_min_extra_isize > max ||
743                      sb->s_min_extra_isize & 3) &&
744                     fix_problem(ctx, PR_0_BAD_MIN_EXTRA_ISIZE, &pctx)) {
745                         sb->s_min_extra_isize =
746                                 (sizeof(struct ext2_inode_large) -
747                                  EXT2_GOOD_OLD_INODE_SIZE);
748                         ext2fs_mark_super_dirty(fs);
749                 }
750                 pctx.num = sb->s_want_extra_isize;
751                 if (sb->s_want_extra_isize &&
752                     (sb->s_want_extra_isize < min ||
753                      sb->s_want_extra_isize > max ||
754                      sb->s_want_extra_isize & 3) &&
755                     fix_problem(ctx, PR_0_BAD_WANT_EXTRA_ISIZE, &pctx)) {
756                         sb->s_want_extra_isize =
757                                 (sizeof(struct ext2_inode_large) -
758                                  EXT2_GOOD_OLD_INODE_SIZE);
759                         ext2fs_mark_super_dirty(fs);
760                 }
761         }
762                     
763         /* Are metadata_csum and uninit_bg both set? */
764         if (ext2fs_has_feature_metadata_csum(fs->super) &&
765             ext2fs_has_feature_gdt_csum(fs->super) &&
766             fix_problem(ctx, PR_0_META_AND_GDT_CSUM_SET, &pctx)) {
767                 ext2fs_clear_feature_gdt_csum(fs->super);
768                 ext2fs_mark_super_dirty(fs);
769                 for (i = 0; i < fs->group_desc_count; i++)
770                         ext2fs_group_desc_csum_set(fs, i);
771         }
772
773         /* We can't have ^metadata_csum,metadata_csum_seed */
774         if (!ext2fs_has_feature_metadata_csum(fs->super) &&
775             ext2fs_has_feature_csum_seed(fs->super) &&
776             fix_problem(ctx, PR_0_CSUM_SEED_WITHOUT_META_CSUM, &pctx)) {
777                 ext2fs_clear_feature_csum_seed(fs->super);
778                 fs->super->s_checksum_seed = 0;
779                 ext2fs_mark_super_dirty(fs);
780         }
781
782         /* Is 64bit set and extents unset? */
783         if (ext2fs_has_feature_64bit(fs->super) &&
784             !ext2fs_has_feature_extents(fs->super) &&
785             fix_problem(ctx, PR_0_64BIT_WITHOUT_EXTENTS, &pctx)) {
786                 ext2fs_set_feature_extents(fs->super);
787                 ext2fs_mark_super_dirty(fs);
788         }
789
790         /* Did user ask us to convert files to extents? */
791         if (ctx->options & E2F_OPT_CONVERT_BMAP) {
792                 ext2fs_set_feature_extents(fs->super);
793                 ext2fs_mark_super_dirty(fs);
794         }
795
796         if (ext2fs_has_feature_meta_bg(fs->super) &&
797             (fs->super->s_first_meta_bg > fs->desc_blocks)) {
798                 pctx.group = fs->desc_blocks;
799                 pctx.num = fs->super->s_first_meta_bg;
800                 if (fix_problem(ctx, PR_0_FIRST_META_BG_TOO_BIG, &pctx)) {
801                         ext2fs_clear_feature_meta_bg(fs->super);
802                         fs->super->s_first_meta_bg = 0;
803                         ext2fs_mark_super_dirty(fs);
804                 }
805         }
806
807         /*
808          * Verify the group descriptors....
809          */
810         first_block = sb->s_first_data_block;
811         last_block = ext2fs_blocks_count(sb)-1;
812
813         csum_flag = ext2fs_has_group_desc_csum(fs);
814         for (i = 0; i < fs->group_desc_count; i++) {
815                 pctx.group = i;
816
817                 if (!ext2fs_has_feature_flex_bg(fs->super)) {
818                         first_block = ext2fs_group_first_block2(fs, i);
819                         last_block = ext2fs_group_last_block2(fs, i);
820                 }
821
822                 if ((ext2fs_block_bitmap_loc(fs, i) < first_block) ||
823                     (ext2fs_block_bitmap_loc(fs, i) > last_block)) {
824                         pctx.blk = ext2fs_block_bitmap_loc(fs, i);
825                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx))
826                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
827                 }
828                 if (ext2fs_block_bitmap_loc(fs, i) == 0) {
829                         ctx->invalid_block_bitmap_flag[i]++;
830                         ctx->invalid_bitmaps++;
831                 }
832                 if ((ext2fs_inode_bitmap_loc(fs, i) < first_block) ||
833                     (ext2fs_inode_bitmap_loc(fs, i) > last_block)) {
834                         pctx.blk = ext2fs_inode_bitmap_loc(fs, i);
835                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx))
836                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
837                 }
838                 if (ext2fs_inode_bitmap_loc(fs, i) == 0) {
839                         ctx->invalid_inode_bitmap_flag[i]++;
840                         ctx->invalid_bitmaps++;
841                 }
842                 if ((ext2fs_inode_table_loc(fs, i) < first_block) ||
843                     ((ext2fs_inode_table_loc(fs, i) +
844                       fs->inode_blocks_per_group - 1) > last_block)) {
845                         pctx.blk = ext2fs_inode_table_loc(fs, i);
846                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx))
847                                 ext2fs_inode_table_loc_set(fs, i, 0);
848                 }
849                 if (ext2fs_inode_table_loc(fs, i) == 0) {
850                         ctx->invalid_inode_table_flag[i]++;
851                         ctx->invalid_bitmaps++;
852                 }
853                 free_blocks += ext2fs_bg_free_blocks_count(fs, i);
854                 free_inodes += ext2fs_bg_free_inodes_count(fs, i);
855
856                 if ((ext2fs_bg_free_blocks_count(fs, i) > sb->s_blocks_per_group) ||
857                     (ext2fs_bg_free_inodes_count(fs, i) > sb->s_inodes_per_group) ||
858                     (ext2fs_bg_used_dirs_count(fs, i) > sb->s_inodes_per_group))
859                         ext2fs_unmark_valid(fs);
860
861                 should_be = 0;
862                 if (!ext2fs_group_desc_csum_verify(fs, i)) {
863                         pctx.csum1 = ext2fs_bg_checksum(fs, i);
864                         pctx.csum2 = ext2fs_group_desc_csum(fs, i);
865                         if (fix_problem(ctx, PR_0_GDT_CSUM, &pctx)) {
866                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
867                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
868                                 ext2fs_bg_itable_unused_set(fs, i, 0);
869                                 should_be = 1;
870                         }
871                         ext2fs_unmark_valid(fs);
872                 }
873
874                 if (!csum_flag &&
875                     (ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) ||
876                      ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) ||
877                      ext2fs_bg_itable_unused(fs, i) != 0)) {
878                         if (fix_problem(ctx, PR_0_GDT_UNINIT, &pctx)) {
879                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
880                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
881                                 ext2fs_bg_itable_unused_set(fs, i, 0);
882                                 should_be = 1;
883                         }
884                         ext2fs_unmark_valid(fs);
885                 }
886
887                 if (i == fs->group_desc_count - 1 &&
888                     ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)) {
889                         if (fix_problem(ctx, PR_0_BB_UNINIT_LAST, &pctx)) {
890                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
891                                 should_be = 1;
892                         }
893                         ext2fs_unmark_valid(fs);
894                 }
895
896                 if (csum_flag &&
897                     (ext2fs_bg_itable_unused(fs, i) > ext2fs_bg_free_inodes_count(fs, i) ||
898                      ext2fs_bg_itable_unused(fs, i) > sb->s_inodes_per_group)) {
899                         pctx.blk = ext2fs_bg_itable_unused(fs, i);
900                         if (fix_problem(ctx, PR_0_GDT_ITABLE_UNUSED, &pctx)) {
901                                 ext2fs_bg_itable_unused_set(fs, i, 0);
902                                 should_be = 1;
903                         }
904                         ext2fs_unmark_valid(fs);
905                 }
906
907                 if (should_be)
908                         ext2fs_group_desc_csum_set(fs, i);
909                 /* If the user aborts e2fsck by typing ^C, stop right away */
910                 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
911                         return;
912         }
913
914         ctx->free_blocks = EXT2FS_C2B(fs, free_blocks);
915         ctx->free_inodes = free_inodes;
916
917         if ((ext2fs_free_blocks_count(sb) > ext2fs_blocks_count(sb)) ||
918             (sb->s_free_inodes_count > sb->s_inodes_count))
919                 ext2fs_unmark_valid(fs);
920
921
922         /*
923          * If we have invalid bitmaps, set the error state of the
924          * filesystem.
925          */
926         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
927                 sb->s_state &= ~EXT2_VALID_FS;
928                 ext2fs_mark_super_dirty(fs);
929         }
930
931         clear_problem_context(&pctx);
932
933 #ifndef EXT2_SKIP_UUID
934         /*
935          * If the UUID field isn't assigned, assign it.
936          * Skip if checksums are enabled and the filesystem is mounted,
937          * if the id changes under the kernel remounting rw may fail.
938          */
939         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid) &&
940             !ext2fs_has_feature_metadata_csum(ctx->fs->super) &&
941             (!csum_flag || !(ctx->mount_flags & EXT2_MF_MOUNTED))) {
942                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
943                         uuid_generate(sb->s_uuid);
944                         ext2fs_init_csum_seed(fs);
945                         fs->flags |= EXT2_FLAG_DIRTY;
946                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
947                 }
948         }
949 #endif
950
951         /*
952          * Check to see if we should disable the test_fs flag
953          */
954         profile_get_boolean(ctx->profile, "options",
955                             "clear_test_fs_flag", 0, 1,
956                             &clear_test_fs_flag);
957         if (!(ctx->options & E2F_OPT_READONLY) &&
958             clear_test_fs_flag &&
959             (fs->super->s_flags & EXT2_FLAGS_TEST_FILESYS) &&
960             (fs_proc_check("ext4") || check_for_modules("ext4"))) {
961                 if (fix_problem(ctx, PR_0_CLEAR_TESTFS_FLAG, &pctx)) {
962                         fs->super->s_flags &= ~EXT2_FLAGS_TEST_FILESYS;
963                         fs->flags |= EXT2_FLAG_DIRTY;
964                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
965                 }
966         }
967                         
968         /*
969          * For the Hurd, check to see if the filetype option is set,
970          * since it doesn't support it.
971          */
972         if (!(ctx->options & E2F_OPT_READONLY) &&
973             fs->super->s_creator_os == EXT2_OS_HURD &&
974             ext2fs_has_feature_filetype(fs->super)) {
975                 if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
976                         ext2fs_clear_feature_filetype(fs->super);
977                         ext2fs_mark_super_dirty(fs);
978                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
979                 }
980         }
981
982         /*
983          * If we have any of the compatibility flags set, we need to have a
984          * revision 1 filesystem.  Most kernels will not check the flags on
985          * a rev 0 filesystem and we may have corruption issues because of
986          * the incompatible changes to the filesystem.
987          */
988         if (!(ctx->options & E2F_OPT_READONLY) &&
989             fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
990             (fs->super->s_feature_compat ||
991              fs->super->s_feature_ro_compat ||
992              fs->super->s_feature_incompat) &&
993             fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
994                 ext2fs_update_dynamic_rev(fs);
995                 ext2fs_mark_super_dirty(fs);
996                 fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
997         }
998
999         /*
1000          * Clean up any orphan inodes, if present.
1001          */
1002         if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
1003                 fs->super->s_state &= ~EXT2_VALID_FS;
1004                 ext2fs_mark_super_dirty(fs);
1005         }
1006
1007         /*
1008          * Unfortunately, due to Windows' unfortunate design decision
1009          * to configure the hardware clock to tick localtime, instead
1010          * of the more proper and less error-prone UTC time, many
1011          * users end up in the situation where the system clock is
1012          * incorrectly set at the time when e2fsck is run.
1013          *
1014          * Historically this was usually due to some distributions
1015          * having buggy init scripts and/or installers that didn't
1016          * correctly detect this case and take appropriate
1017          * countermeasures.  However, it's still possible, despite the
1018          * best efforts of init script and installer authors to not be
1019          * able to detect this misconfiguration, usually due to a
1020          * buggy or misconfigured virtualization manager or the
1021          * installer not having access to a network time server during
1022          * the installation process.  So by default, we allow the
1023          * superblock times to be fudged by up to 24 hours.  This can
1024          * be disabled by setting options.accept_time_fudge to the
1025          * boolean value of false in e2fsck.conf.  We also support
1026          * options.buggy_init_scripts for backwards compatibility.
1027          */
1028         profile_get_boolean(ctx->profile, "options", "accept_time_fudge",
1029                             0, 1, &accept_time_fudge);
1030         profile_get_boolean(ctx->profile, "options", "buggy_init_scripts",
1031                             0, accept_time_fudge, &accept_time_fudge);
1032         ctx->time_fudge = accept_time_fudge ? 86400 : 0;
1033
1034         profile_get_boolean(ctx->profile, "options", "broken_system_clock",
1035                             0, 0, &broken_system_clock);
1036
1037         /*
1038          * Check to see if the superblock last mount time or last
1039          * write time is in the future.
1040          */
1041         if (!broken_system_clock &&
1042             !(ctx->flags & E2F_FLAG_TIME_INSANE) &&
1043             fs->super->s_mtime > (__u32) ctx->now) {
1044                 pctx.num = fs->super->s_mtime;
1045                 problem = PR_0_FUTURE_SB_LAST_MOUNT;
1046                 if (fs->super->s_mtime <= (__u32) ctx->now + ctx->time_fudge)
1047                         problem = PR_0_FUTURE_SB_LAST_MOUNT_FUDGED;
1048                 if (fix_problem(ctx, problem, &pctx)) {
1049                         fs->super->s_mtime = ctx->now;
1050                         fs->flags |= EXT2_FLAG_DIRTY;
1051                 }
1052         }
1053         if (!broken_system_clock &&
1054             !(ctx->flags & E2F_FLAG_TIME_INSANE) &&
1055             fs->super->s_wtime > (__u32) ctx->now) {
1056                 pctx.num = fs->super->s_wtime;
1057                 problem = PR_0_FUTURE_SB_LAST_WRITE;
1058                 if (fs->super->s_wtime <= (__u32) ctx->now + ctx->time_fudge)
1059                         problem = PR_0_FUTURE_SB_LAST_WRITE_FUDGED;
1060                 if (fix_problem(ctx, problem, &pctx)) {
1061                         fs->super->s_wtime = ctx->now;
1062                         fs->flags |= EXT2_FLAG_DIRTY;
1063                 }
1064         }
1065
1066         e2fsck_validate_quota_inodes(ctx);
1067
1068         /*
1069          * Move the ext3 journal file, if necessary.
1070          */
1071         e2fsck_move_ext3_journal(ctx);
1072
1073         /*
1074          * Fix journal hint, if necessary
1075          */
1076         e2fsck_fix_ext3_journal_hint(ctx);
1077
1078         /*
1079          * Add dirhash hint if necessary
1080          */
1081         e2fsck_fix_dirhash_hint(ctx);
1082
1083         /*
1084          * Hide quota inodes if necessary.
1085          */
1086         e2fsck_hide_quota(ctx);
1087
1088         return;
1089 }
1090
1091 /*
1092  * Check to see if we should backup the master sb to the backup super
1093  * blocks.  Returns non-zero if the sb should be backed up.
1094  */
1095
1096 /*
1097  * A few flags are set on the fly by the kernel, but only in the
1098  * primary superblock.  This is actually a bad thing, and we should
1099  * try to discourage it in the future.  In particular, for the newer
1100  * ext4 files, especially EXT4_FEATURE_RO_COMPAT_DIR_NLINK and
1101  * EXT3_FEATURE_INCOMPAT_EXTENTS.  So some of these may go away in the
1102  * future.  EXT3_FEATURE_INCOMPAT_RECOVER may also get set when
1103  * copying the primary superblock during online resize.
1104  *
1105  * The kernel will set EXT2_FEATURE_COMPAT_EXT_ATTR, but
1106  * unfortunately, we shouldn't ignore it since if it's not set in the
1107  * backup, the extended attributes in the filesystem will be stripped
1108  * away.
1109  */
1110 #define FEATURE_RO_COMPAT_IGNORE        (EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
1111                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
1112 #define FEATURE_INCOMPAT_IGNORE         (EXT3_FEATURE_INCOMPAT_EXTENTS| \
1113                                          EXT3_FEATURE_INCOMPAT_RECOVER)
1114
1115 int check_backup_super_block(e2fsck_t ctx)
1116 {
1117         ext2_filsys     fs = ctx->fs;
1118         errcode_t       retval;
1119         dgrp_t          g;
1120         blk64_t         sb;
1121         int             ret = 0;
1122         char            buf[SUPERBLOCK_SIZE];
1123         struct ext2_super_block *backup_sb;
1124
1125         /*
1126          * If we are already writing out the backup blocks, then we
1127          * don't need to test.  Also, if the filesystem is invalid, or
1128          * the check was aborted or cancelled, we also don't want to
1129          * do the backup.  If the filesystem was opened read-only then
1130          * we can't do the backup.
1131          */
1132         if (((fs->flags & EXT2_FLAG_MASTER_SB_ONLY) == 0) ||
1133             !ext2fs_test_valid(fs) ||
1134             (fs->super->s_state & EXT2_ERROR_FS) ||
1135             (ctx->flags & (E2F_FLAG_ABORT | E2F_FLAG_CANCEL)) ||
1136             (ctx->options & E2F_OPT_READONLY))
1137                 return 0;
1138
1139         for (g = 1; g < fs->group_desc_count; g++) {
1140                 if (!ext2fs_bg_has_super(fs, g))
1141                         continue;
1142
1143                 sb = ext2fs_group_first_block2(fs, g);
1144
1145                 retval = io_channel_read_blk(fs->io, sb, -SUPERBLOCK_SIZE,
1146                                              buf);
1147                 if (retval)
1148                         continue;
1149                 backup_sb = (struct ext2_super_block *) buf;
1150 #ifdef WORDS_BIGENDIAN
1151                 ext2fs_swap_super(backup_sb);
1152 #endif
1153                 if ((backup_sb->s_magic != EXT2_SUPER_MAGIC) ||
1154                     (backup_sb->s_rev_level > EXT2_LIB_CURRENT_REV) ||
1155                     ((backup_sb->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) >
1156                      EXT2_MAX_BLOCK_LOG_SIZE) ||
1157                     (EXT2_INODE_SIZE(backup_sb) < EXT2_GOOD_OLD_INODE_SIZE))
1158                         continue;
1159
1160 #define SUPER_INCOMPAT_DIFFERENT(x)     \
1161         ((fs->super->x & ~FEATURE_INCOMPAT_IGNORE) !=   \
1162          (backup_sb->x & ~FEATURE_INCOMPAT_IGNORE))
1163 #define SUPER_RO_COMPAT_DIFFERENT(x)    \
1164         ((fs->super->x & ~FEATURE_RO_COMPAT_IGNORE) !=  \
1165          (backup_sb->x & ~FEATURE_RO_COMPAT_IGNORE))
1166 #define SUPER_DIFFERENT(x)              \
1167         (fs->super->x != backup_sb->x)
1168
1169                 if (SUPER_DIFFERENT(s_feature_compat) ||
1170                     SUPER_INCOMPAT_DIFFERENT(s_feature_incompat) ||
1171                     SUPER_RO_COMPAT_DIFFERENT(s_feature_ro_compat) ||
1172                     SUPER_DIFFERENT(s_blocks_count) ||
1173                     SUPER_DIFFERENT(s_blocks_count_hi) ||
1174                     SUPER_DIFFERENT(s_inodes_count) ||
1175                     memcmp(fs->super->s_uuid, backup_sb->s_uuid,
1176                            sizeof(fs->super->s_uuid)))
1177                         ret = 1;
1178                 break;
1179         }
1180         return ret;
1181 }