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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 #ifdef HAVE_ERRNO_H
13 #include <errno.h>
14 #endif
15 
16 #ifndef EXT2_SKIP_UUID
17 #include "uuid/uuid.h"
18 #endif
19 #include "e2fsck.h"
20 #include "problem.h"
21 
22 #define MIN_CHECK 1
23 #define MAX_CHECK 2
24 
check_super_value(e2fsck_t ctx,const char * descr,unsigned long value,int flags,unsigned long min_val,unsigned long max_val)25 static void check_super_value(e2fsck_t ctx, const char *descr,
26 			      unsigned long value, int flags,
27 			      unsigned long min_val, unsigned long max_val)
28 {
29 	struct		problem_context pctx;
30 
31 	if (((flags & MIN_CHECK) && (value < min_val)) ||
32 	    ((flags & MAX_CHECK) && (value > max_val))) {
33 		clear_problem_context(&pctx);
34 		pctx.num = value;
35 		pctx.str = descr;
36 		fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
37 		ctx->flags |= E2F_FLAG_ABORT; /* never get here! */
38 	}
39 }
40 
41 /*
42  * helper function to release an inode
43  */
44 struct process_block_struct {
45 	e2fsck_t 	ctx;
46 	char 		*buf;
47 	struct problem_context *pctx;
48 	int		truncating;
49 	int		truncate_offset;
50 	e2_blkcnt_t	truncate_block;
51 	int		truncated_blocks;
52 	int		abort;
53 	errcode_t	errcode;
54 };
55 
release_inode_block(ext2_filsys fs,blk_t * block_nr,e2_blkcnt_t blockcnt,blk_t ref_blk EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)56 static int release_inode_block(ext2_filsys fs,
57 			       blk_t	*block_nr,
58 			       e2_blkcnt_t blockcnt,
59 			       blk_t	ref_blk EXT2FS_ATTR((unused)),
60 			       int	ref_offset EXT2FS_ATTR((unused)),
61 			       void *priv_data)
62 {
63 	struct process_block_struct *pb;
64 	e2fsck_t 		ctx;
65 	struct problem_context	*pctx;
66 	blk_t			blk = *block_nr;
67 	int			retval = 0;
68 
69 	pb = (struct process_block_struct *) priv_data;
70 	ctx = pb->ctx;
71 	pctx = pb->pctx;
72 
73 	pctx->blk = blk;
74 	pctx->blkcount = blockcnt;
75 
76 	if (HOLE_BLKADDR(blk))
77 		return 0;
78 
79 	if ((blk < fs->super->s_first_data_block) ||
80 	    (blk >= fs->super->s_blocks_count)) {
81 		fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_BLOCK_NUM, pctx);
82 	return_abort:
83 		pb->abort = 1;
84 		return BLOCK_ABORT;
85 	}
86 
87 	if (!ext2fs_test_block_bitmap(fs->block_map, blk)) {
88 		fix_problem(ctx, PR_0_ORPHAN_ALREADY_CLEARED_BLOCK, pctx);
89 		goto return_abort;
90 	}
91 
92 	/*
93 	 * If we are deleting an orphan, then we leave the fields alone.
94 	 * If we are truncating an orphan, then update the inode fields
95 	 * and clean up any partial block data.
96 	 */
97 	if (pb->truncating) {
98 		/*
99 		 * We only remove indirect blocks if they are
100 		 * completely empty.
101 		 */
102 		if (blockcnt < 0) {
103 			int	i, limit;
104 			blk_t	*bp;
105 
106 			pb->errcode = io_channel_read_blk(fs->io, blk, 1,
107 							pb->buf);
108 			if (pb->errcode)
109 				goto return_abort;
110 
111 			limit = fs->blocksize >> 2;
112 			for (i = 0, bp = (blk_t *) pb->buf;
113 			     i < limit;	 i++, bp++)
114 				if (*bp)
115 					return 0;
116 		}
117 		/*
118 		 * We don't remove direct blocks until we've reached
119 		 * the truncation block.
120 		 */
121 		if (blockcnt >= 0 && blockcnt < pb->truncate_block)
122 			return 0;
123 		/*
124 		 * If part of the last block needs truncating, we do
125 		 * it here.
126 		 */
127 		if ((blockcnt == pb->truncate_block) && pb->truncate_offset) {
128 			pb->errcode = io_channel_read_blk(fs->io, blk, 1,
129 							pb->buf);
130 			if (pb->errcode)
131 				goto return_abort;
132 			memset(pb->buf + pb->truncate_offset, 0,
133 			       fs->blocksize - pb->truncate_offset);
134 			pb->errcode = io_channel_write_blk(fs->io, blk, 1,
135 							 pb->buf);
136 			if (pb->errcode)
137 				goto return_abort;
138 		}
139 		pb->truncated_blocks++;
140 		*block_nr = 0;
141 		retval |= BLOCK_CHANGED;
142 	}
143 
144 	ext2fs_block_alloc_stats(fs, blk, -1);
145 	return retval;
146 }
147 
148 /*
149  * This function releases an inode.  Returns 1 if an inconsistency was
150  * found.  If the inode has a link count, then it is being truncated and
151  * not deleted.
152  */
release_inode_blocks(e2fsck_t ctx,ext2_ino_t ino,struct ext2_inode * inode,char * block_buf,struct problem_context * pctx)153 static int release_inode_blocks(e2fsck_t ctx, ext2_ino_t ino,
154 				struct ext2_inode *inode, char *block_buf,
155 				struct problem_context *pctx)
156 {
157 	struct process_block_struct 	pb;
158 	ext2_filsys			fs = ctx->fs;
159 	errcode_t			retval;
160 	__u32				count;
161 
162 	if (!ext2fs_inode_has_valid_blocks(inode))
163 		return 0;
164 
165 	pb.buf = block_buf + 3 * ctx->fs->blocksize;
166 	pb.ctx = ctx;
167 	pb.abort = 0;
168 	pb.errcode = 0;
169 	pb.pctx = pctx;
170 	if (inode->i_links_count) {
171 		pb.truncating = 1;
172 		pb.truncate_block = (e2_blkcnt_t)
173 			((((long long)inode->i_size_high << 32) +
174 			  inode->i_size + fs->blocksize - 1) /
175 			 fs->blocksize);
176 		pb.truncate_offset = inode->i_size % fs->blocksize;
177 	} else {
178 		pb.truncating = 0;
179 		pb.truncate_block = 0;
180 		pb.truncate_offset = 0;
181 	}
182 	pb.truncated_blocks = 0;
183 	retval = ext2fs_block_iterate2(fs, ino, BLOCK_FLAG_DEPTH_TRAVERSE,
184 				      block_buf, release_inode_block, &pb);
185 	if (retval) {
186 		com_err("release_inode_blocks", retval,
187 			_("while calling ext2fs_block_iterate for inode %d"),
188 			ino);
189 		return 1;
190 	}
191 	if (pb.abort)
192 		return 1;
193 
194 	/* Refresh the inode since ext2fs_block_iterate may have changed it */
195 	e2fsck_read_inode(ctx, ino, inode, "release_inode_blocks");
196 
197 	if (pb.truncated_blocks)
198 		inode->i_blocks -= pb.truncated_blocks *
199 			(fs->blocksize / 512);
200 
201 	if (inode->i_file_acl) {
202 		retval = ext2fs_adjust_ea_refcount(fs, inode->i_file_acl,
203 						   block_buf, -1, &count);
204 		if (retval == EXT2_ET_BAD_EA_BLOCK_NUM) {
205 			retval = 0;
206 			count = 1;
207 		}
208 		if (retval) {
209 			com_err("release_inode_blocks", retval,
210 		_("while calling ext2fs_adjust_ea_refcount for inode %d"),
211 				ino);
212 			return 1;
213 		}
214 		if (count == 0)
215 			ext2fs_block_alloc_stats(fs, inode->i_file_acl, -1);
216 		inode->i_file_acl = 0;
217 	}
218 	return 0;
219 }
220 
221 /*
222  * This function releases all of the orphan inodes.  It returns 1 if
223  * it hit some error, and 0 on success.
224  */
release_orphan_inodes(e2fsck_t ctx)225 static int release_orphan_inodes(e2fsck_t ctx)
226 {
227 	ext2_filsys fs = ctx->fs;
228 	ext2_ino_t	ino, next_ino;
229 	struct ext2_inode inode;
230 	struct problem_context pctx;
231 	char *block_buf;
232 
233 	if ((ino = fs->super->s_last_orphan) == 0)
234 		return 0;
235 
236 	/*
237 	 * Win or lose, we won't be using the head of the orphan inode
238 	 * list again.
239 	 */
240 	fs->super->s_last_orphan = 0;
241 	ext2fs_mark_super_dirty(fs);
242 
243 	/*
244 	 * If the filesystem contains errors, don't run the orphan
245 	 * list, since the orphan list can't be trusted; and we're
246 	 * going to be running a full e2fsck run anyway...
247 	 */
248 	if (fs->super->s_state & EXT2_ERROR_FS)
249 		return 0;
250 
251 	if ((ino < EXT2_FIRST_INODE(fs->super)) ||
252 	    (ino > fs->super->s_inodes_count)) {
253 		clear_problem_context(&pctx);
254 		pctx.ino = ino;
255 		fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
256 		return 1;
257 	}
258 
259 	block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
260 						    "block iterate buffer");
261 	e2fsck_read_bitmaps(ctx);
262 
263 	while (ino) {
264 		e2fsck_read_inode(ctx, ino, &inode, "release_orphan_inodes");
265 		clear_problem_context(&pctx);
266 		pctx.ino = ino;
267 		pctx.inode = &inode;
268 		pctx.str = inode.i_links_count ? _("Truncating") :
269 			_("Clearing");
270 
271 		fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
272 
273 		next_ino = inode.i_dtime;
274 		if (next_ino &&
275 		    ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
276 		     (next_ino > fs->super->s_inodes_count))) {
277 			pctx.ino = next_ino;
278 			fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
279 			goto return_abort;
280 		}
281 
282 		if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
283 			goto return_abort;
284 
285 		if (!inode.i_links_count) {
286 			ext2fs_inode_alloc_stats2(fs, ino, -1,
287 						  LINUX_S_ISDIR(inode.i_mode));
288 			inode.i_dtime = ctx->now;
289 		} else {
290 			inode.i_dtime = 0;
291 		}
292 		e2fsck_write_inode(ctx, ino, &inode, "delete_file");
293 		ino = next_ino;
294 	}
295 	ext2fs_free_mem(&block_buf);
296 	return 0;
297 return_abort:
298 	ext2fs_free_mem(&block_buf);
299 	return 1;
300 }
301 
302 /*
303  * Check the resize inode to make sure it is sane.  We check both for
304  * the case where on-line resizing is not enabled (in which case the
305  * resize inode should be cleared) as well as the case where on-line
306  * resizing is enabled.
307  */
check_resize_inode(e2fsck_t ctx)308 static void check_resize_inode(e2fsck_t ctx)
309 {
310 	ext2_filsys fs = ctx->fs;
311 	struct ext2_inode inode;
312 	struct problem_context	pctx;
313 	int		i, gdt_off, ind_off;
314 	dgrp_t		j;
315 	blk_t		blk, pblk, expect;
316 	__u32 		*dind_buf = 0, *ind_buf;
317 	errcode_t	retval;
318 
319 	clear_problem_context(&pctx);
320 
321 	/*
322 	 * If the resize inode feature isn't set, then
323 	 * s_reserved_gdt_blocks must be zero.
324 	 */
325 	if (!(fs->super->s_feature_compat &
326 	      EXT2_FEATURE_COMPAT_RESIZE_INODE)) {
327 		if (fs->super->s_reserved_gdt_blocks) {
328 			pctx.num = fs->super->s_reserved_gdt_blocks;
329 			if (fix_problem(ctx, PR_0_NONZERO_RESERVED_GDT_BLOCKS,
330 					&pctx)) {
331 				fs->super->s_reserved_gdt_blocks = 0;
332 				ext2fs_mark_super_dirty(fs);
333 			}
334 		}
335 	}
336 
337 	/* Read the resize inode */
338 	pctx.ino = EXT2_RESIZE_INO;
339 	retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
340 	if (retval) {
341 		if (fs->super->s_feature_compat &
342 		    EXT2_FEATURE_COMPAT_RESIZE_INODE)
343 			ctx->flags |= E2F_FLAG_RESIZE_INODE;
344 		return;
345 	}
346 
347 	/*
348 	 * If the resize inode feature isn't set, check to make sure
349 	 * the resize inode is cleared; then we're done.
350 	 */
351 	if (!(fs->super->s_feature_compat &
352 	      EXT2_FEATURE_COMPAT_RESIZE_INODE)) {
353 		for (i=0; i < EXT2_N_BLOCKS; i++) {
354 			if (inode.i_block[i])
355 				break;
356 		}
357 		if ((i < EXT2_N_BLOCKS) &&
358 		    fix_problem(ctx, PR_0_CLEAR_RESIZE_INODE, &pctx)) {
359 			memset(&inode, 0, sizeof(inode));
360 			e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
361 					   "clear_resize");
362 		}
363 		return;
364 	}
365 
366 	/*
367 	 * The resize inode feature is enabled; check to make sure the
368 	 * only block in use is the double indirect block
369 	 */
370 	blk = inode.i_block[EXT2_DIND_BLOCK];
371 	for (i=0; i < EXT2_N_BLOCKS; i++) {
372 		if (i != EXT2_DIND_BLOCK && inode.i_block[i])
373 			break;
374 	}
375 	if ((i < EXT2_N_BLOCKS) || !blk || !inode.i_links_count ||
376 	    !(inode.i_mode & LINUX_S_IFREG) ||
377 	    (blk < fs->super->s_first_data_block ||
378 	     blk >= fs->super->s_blocks_count)) {
379 	resize_inode_invalid:
380 		if (fix_problem(ctx, PR_0_RESIZE_INODE_INVALID, &pctx)) {
381 			memset(&inode, 0, sizeof(inode));
382 			e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
383 					   "clear_resize");
384 			ctx->flags |= E2F_FLAG_RESIZE_INODE;
385 		}
386 		if (!(ctx->options & E2F_OPT_READONLY)) {
387 			fs->super->s_state &= ~EXT2_VALID_FS;
388 			ext2fs_mark_super_dirty(fs);
389 		}
390 		goto cleanup;
391 	}
392 	dind_buf = (__u32 *) e2fsck_allocate_memory(ctx, fs->blocksize * 2,
393 						    "resize dind buffer");
394 	ind_buf = (__u32 *) ((char *) dind_buf + fs->blocksize);
395 
396 	retval = ext2fs_read_ind_block(fs, blk, dind_buf);
397 	if (retval)
398 		goto resize_inode_invalid;
399 
400 	gdt_off = fs->desc_blocks;
401 	pblk = fs->super->s_first_data_block + 1 + fs->desc_blocks;
402 	for (i = 0; i < fs->super->s_reserved_gdt_blocks / 4;
403 	     i++, gdt_off++, pblk++) {
404 		gdt_off %= fs->blocksize/4;
405 		if (dind_buf[gdt_off] != pblk)
406 			goto resize_inode_invalid;
407 		retval = ext2fs_read_ind_block(fs, pblk, ind_buf);
408 		if (retval)
409 			goto resize_inode_invalid;
410 		ind_off = 0;
411 		for (j = 1; j < fs->group_desc_count; j++) {
412 			if (!ext2fs_bg_has_super(fs, j))
413 				continue;
414 			expect = pblk + (j * fs->super->s_blocks_per_group);
415 			if (ind_buf[ind_off] != expect)
416 				goto resize_inode_invalid;
417 			ind_off++;
418 		}
419 	}
420 
421 cleanup:
422 	if (dind_buf)
423 		ext2fs_free_mem(&dind_buf);
424 
425  }
426 
427 /*
428  * This function checks the dirhash signed/unsigned hint if necessary.
429  */
e2fsck_fix_dirhash_hint(e2fsck_t ctx)430 static void e2fsck_fix_dirhash_hint(e2fsck_t ctx)
431 {
432 	struct ext2_super_block *sb = ctx->fs->super;
433 	struct problem_context pctx;
434 	char	c;
435 
436 	if ((ctx->options & E2F_OPT_READONLY) ||
437 	    !(sb->s_feature_compat & EXT2_FEATURE_COMPAT_DIR_INDEX) ||
438 	    (sb->s_flags & (EXT2_FLAGS_SIGNED_HASH|EXT2_FLAGS_UNSIGNED_HASH)))
439 		return;
440 
441 	c = (char) 255;
442 
443 	clear_problem_context(&pctx);
444 	if (fix_problem(ctx, PR_0_DIRHASH_HINT, &pctx)) {
445 		if (((int) c) == -1) {
446 			sb->s_flags |= EXT2_FLAGS_SIGNED_HASH;
447 		} else {
448 			sb->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
449 		}
450 		ext2fs_mark_super_dirty(ctx->fs);
451 	}
452 }
453 
454 
check_super_block(e2fsck_t ctx)455 void check_super_block(e2fsck_t ctx)
456 {
457 	ext2_filsys fs = ctx->fs;
458 	blk_t	first_block, last_block;
459 	struct ext2_super_block *sb = fs->super;
460 	struct ext2_group_desc *gd;
461 	blk_t	blocks_per_group = fs->super->s_blocks_per_group;
462 	blk_t	bpg_max;
463 	int	inodes_per_block;
464 	int	ipg_max;
465 	int	inode_size;
466 	int	buggy_init_scripts;
467 	dgrp_t	i;
468 	blk_t	should_be;
469 	struct problem_context	pctx;
470 	__u32	free_blocks = 0, free_inodes = 0;
471 
472 	inodes_per_block = EXT2_INODES_PER_BLOCK(fs->super);
473 	ipg_max = inodes_per_block * (blocks_per_group - 4);
474 	if (ipg_max > EXT2_MAX_INODES_PER_GROUP(sb))
475 		ipg_max = EXT2_MAX_INODES_PER_GROUP(sb);
476 	bpg_max = 8 * EXT2_BLOCK_SIZE(sb);
477 	if (bpg_max > EXT2_MAX_BLOCKS_PER_GROUP(sb))
478 		bpg_max = EXT2_MAX_BLOCKS_PER_GROUP(sb);
479 
480 	ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
481 		 sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
482 	ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
483 		 sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
484 	ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
485 		sizeof(int) * fs->group_desc_count, "invalid_inode_table");
486 
487 	clear_problem_context(&pctx);
488 
489 	/*
490 	 * Verify the super block constants...
491 	 */
492 	check_super_value(ctx, "inodes_count", sb->s_inodes_count,
493 			  MIN_CHECK, 1, 0);
494 	check_super_value(ctx, "blocks_count", sb->s_blocks_count,
495 			  MIN_CHECK, 1, 0);
496 	check_super_value(ctx, "first_data_block", sb->s_first_data_block,
497 			  MAX_CHECK, 0, sb->s_blocks_count);
498 	check_super_value(ctx, "log_block_size", sb->s_log_block_size,
499 			  MIN_CHECK | MAX_CHECK, 0,
500 			  EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE);
501 	check_super_value(ctx, "log_frag_size", sb->s_log_frag_size,
502 			  MIN_CHECK | MAX_CHECK, 0, sb->s_log_block_size);
503 	check_super_value(ctx, "frags_per_group", sb->s_frags_per_group,
504 			  MIN_CHECK | MAX_CHECK, sb->s_blocks_per_group,
505 			  bpg_max);
506 	check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
507 			  MIN_CHECK | MAX_CHECK, 8, bpg_max);
508 	check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
509 			  MIN_CHECK | MAX_CHECK, inodes_per_block, ipg_max);
510 	check_super_value(ctx, "r_blocks_count", sb->s_r_blocks_count,
511 			  MAX_CHECK, 0, sb->s_blocks_count / 2);
512 	check_super_value(ctx, "reserved_gdt_blocks",
513 			  sb->s_reserved_gdt_blocks, MAX_CHECK, 0,
514 			  fs->blocksize/4);
515 	inode_size = EXT2_INODE_SIZE(sb);
516 	check_super_value(ctx, "inode_size",
517 			  inode_size, MIN_CHECK | MAX_CHECK,
518 			  EXT2_GOOD_OLD_INODE_SIZE, fs->blocksize);
519 	if (inode_size & (inode_size - 1)) {
520 		pctx.num = inode_size;
521 		pctx.str = "inode_size";
522 		fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
523 		ctx->flags |= E2F_FLAG_ABORT; /* never get here! */
524 		return;
525 	}
526 
527 	if ((ctx->flags & E2F_FLAG_GOT_DEVSIZE) &&
528 	    (ctx->num_blocks < sb->s_blocks_count)) {
529 		pctx.blk = sb->s_blocks_count;
530 		pctx.blk2 = ctx->num_blocks;
531 		if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
532 			ctx->flags |= E2F_FLAG_ABORT;
533 			return;
534 		}
535 	}
536 
537 	if (sb->s_log_block_size != (__u32) sb->s_log_frag_size) {
538 		pctx.blk = EXT2_BLOCK_SIZE(sb);
539 		pctx.blk2 = EXT2_FRAG_SIZE(sb);
540 		fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
541 		ctx->flags |= E2F_FLAG_ABORT;
542 		return;
543 	}
544 
545 	should_be = sb->s_frags_per_group >>
546 		(sb->s_log_block_size - sb->s_log_frag_size);
547 	if (sb->s_blocks_per_group != should_be) {
548 		pctx.blk = sb->s_blocks_per_group;
549 		pctx.blk2 = should_be;
550 		fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
551 		ctx->flags |= E2F_FLAG_ABORT;
552 		return;
553 	}
554 
555 	should_be = (sb->s_log_block_size == 0) ? 1 : 0;
556 	if (sb->s_first_data_block != should_be) {
557 		pctx.blk = sb->s_first_data_block;
558 		pctx.blk2 = should_be;
559 		fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
560 		ctx->flags |= E2F_FLAG_ABORT;
561 		return;
562 	}
563 
564 	should_be = sb->s_inodes_per_group * fs->group_desc_count;
565 	if (sb->s_inodes_count != should_be) {
566 		pctx.ino = sb->s_inodes_count;
567 		pctx.ino2 = should_be;
568 		if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
569 			sb->s_inodes_count = should_be;
570 			ext2fs_mark_super_dirty(fs);
571 		}
572 	}
573 
574 	/*
575 	 * Verify the group descriptors....
576 	 */
577 	first_block =  sb->s_first_data_block;
578 
579 	for (i = 0, gd=fs->group_desc; i < fs->group_desc_count; i++, gd++) {
580 		pctx.group = i;
581 
582 		first_block = ext2fs_group_first_block(fs, i);
583 		last_block = ext2fs_group_last_block(fs, i);
584 
585 		if ((gd->bg_block_bitmap < first_block) ||
586 		    (gd->bg_block_bitmap > last_block)) {
587 			pctx.blk = gd->bg_block_bitmap;
588 			if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx))
589 				gd->bg_block_bitmap = 0;
590 		}
591 		if (gd->bg_block_bitmap == 0) {
592 			ctx->invalid_block_bitmap_flag[i]++;
593 			ctx->invalid_bitmaps++;
594 		}
595 		if ((gd->bg_inode_bitmap < first_block) ||
596 		    (gd->bg_inode_bitmap > last_block)) {
597 			pctx.blk = gd->bg_inode_bitmap;
598 			if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx))
599 				gd->bg_inode_bitmap = 0;
600 		}
601 		if (gd->bg_inode_bitmap == 0) {
602 			ctx->invalid_inode_bitmap_flag[i]++;
603 			ctx->invalid_bitmaps++;
604 		}
605 		if ((gd->bg_inode_table < first_block) ||
606 		    ((gd->bg_inode_table +
607 		      fs->inode_blocks_per_group - 1) > last_block)) {
608 			pctx.blk = gd->bg_inode_table;
609 			if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx))
610 				gd->bg_inode_table = 0;
611 		}
612 		if (gd->bg_inode_table == 0) {
613 			ctx->invalid_inode_table_flag[i]++;
614 			ctx->invalid_bitmaps++;
615 		}
616 		free_blocks += gd->bg_free_blocks_count;
617 		free_inodes += gd->bg_free_inodes_count;
618 
619 		if ((gd->bg_free_blocks_count > sb->s_blocks_per_group) ||
620 		    (gd->bg_free_inodes_count > sb->s_inodes_per_group) ||
621 		    (gd->bg_used_dirs_count > sb->s_inodes_per_group))
622 			ext2fs_unmark_valid(fs);
623 
624 	}
625 
626 	/*
627 	 * Update the global counts from the block group counts.  This
628 	 * is needed for an experimental patch which eliminates
629 	 * locking the entire filesystem when allocating blocks or
630 	 * inodes; if the filesystem is not unmounted cleanly, the
631 	 * global counts may not be accurate.
632 	 */
633 	if ((free_blocks != sb->s_free_blocks_count) ||
634 	    (free_inodes != sb->s_free_inodes_count)) {
635 		if (ctx->options & E2F_OPT_READONLY)
636 			ext2fs_unmark_valid(fs);
637 		else {
638 			sb->s_free_blocks_count = free_blocks;
639 			sb->s_free_inodes_count = free_inodes;
640 			ext2fs_mark_super_dirty(fs);
641 		}
642 	}
643 
644 	if ((sb->s_free_blocks_count > sb->s_blocks_count) ||
645 	    (sb->s_free_inodes_count > sb->s_inodes_count))
646 		ext2fs_unmark_valid(fs);
647 
648 
649 	/*
650 	 * If we have invalid bitmaps, set the error state of the
651 	 * filesystem.
652 	 */
653 	if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
654 		sb->s_state &= ~EXT2_VALID_FS;
655 		ext2fs_mark_super_dirty(fs);
656 	}
657 
658 	clear_problem_context(&pctx);
659 
660 #ifndef EXT2_SKIP_UUID
661 	/*
662 	 * If the UUID field isn't assigned, assign it.
663 	 */
664 	if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid)) {
665 		if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
666 			uuid_generate(sb->s_uuid);
667 			ext2fs_mark_super_dirty(fs);
668 			fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
669 		}
670 	}
671 #endif
672 
673 	/*
674 	 * For the Hurd, check to see if the filetype option is set,
675 	 * since it doesn't support it.
676 	 */
677 	if (!(ctx->options & E2F_OPT_READONLY) &&
678 	    fs->super->s_creator_os == EXT2_OS_HURD &&
679 	    (fs->super->s_feature_incompat &
680 	     EXT2_FEATURE_INCOMPAT_FILETYPE)) {
681 		if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
682 			fs->super->s_feature_incompat &=
683 				~EXT2_FEATURE_INCOMPAT_FILETYPE;
684 			ext2fs_mark_super_dirty(fs);
685 			fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
686 		}
687 	}
688 
689 	/*
690 	 * If we have any of the compatibility flags set, we need to have a
691 	 * revision 1 filesystem.  Most kernels will not check the flags on
692 	 * a rev 0 filesystem and we may have corruption issues because of
693 	 * the incompatible changes to the filesystem.
694 	 */
695 	if (!(ctx->options & E2F_OPT_READONLY) &&
696 	    fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
697 	    (fs->super->s_feature_compat ||
698 	     fs->super->s_feature_ro_compat ||
699 	     fs->super->s_feature_incompat) &&
700 	    fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
701 		ext2fs_update_dynamic_rev(fs);
702 		ext2fs_mark_super_dirty(fs);
703 		fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
704 	}
705 
706 	check_resize_inode(ctx);
707 
708 	/*
709 	 * Clean up any orphan inodes, if present.
710 	 */
711 	if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
712 		fs->super->s_state &= ~EXT2_VALID_FS;
713 		ext2fs_mark_super_dirty(fs);
714 	}
715 
716 	/*
717 	 * Some buggy distributions (such as Ubuntu) have init scripts
718 	 * and/or installers which fail to correctly set the system
719 	 * clock before running e2fsck and/or formatting the
720 	 * filesystem initially.  Normally this happens because the
721 	 * hardware clock is ticking localtime, instead of the more
722 	 * proper and less error-prone UTC time.  So while the kernel
723 	 * is booting, the system time (which in Linux systems always
724 	 * ticks in UTC time) is set from the hardware clock, but
725 	 * since the hardware clock is ticking localtime, the system
726 	 * time is incorrect.  Unfortunately, some buggy distributions
727 	 * do not correct this before running e2fsck.  If this option
728 	 * is set to a boolean value of true, we attempt to work
729 	 * around this situation by allowing the superblock last write
730 	 * time, last mount time, and last check time to be in the
731 	 * future by up to 24 hours.
732 	 */
733 	profile_get_boolean(ctx->profile, "options", "buggy_init_scripts",
734 			    0, 0, &buggy_init_scripts);
735 	ctx->time_fudge = buggy_init_scripts ? 86400 : 0;
736 
737 	/*
738 	 * Check to see if the superblock last mount time or last
739 	 * write time is in the future.
740 	 */
741 	if (fs->super->s_mtime > (__u32) ctx->now + ctx->time_fudge) {
742 		pctx.num = fs->super->s_mtime;
743 		if (fix_problem(ctx, PR_0_FUTURE_SB_LAST_MOUNT, &pctx)) {
744 			fs->super->s_mtime = ctx->now;
745 			ext2fs_mark_super_dirty(fs);
746 		}
747 	}
748 	if (fs->super->s_wtime > (__u32) ctx->now + ctx->time_fudge) {
749 		pctx.num = fs->super->s_wtime;
750 		if (fix_problem(ctx, PR_0_FUTURE_SB_LAST_WRITE, &pctx)) {
751 			fs->super->s_wtime = ctx->now;
752 			ext2fs_mark_super_dirty(fs);
753 		}
754 	}
755 
756 	/*
757 	 * Move the ext3 journal file, if necessary.
758 	 */
759 	e2fsck_move_ext3_journal(ctx);
760 
761 	/*
762 	 * Fix journal hint, if necessary
763 	 */
764 	e2fsck_fix_ext3_journal_hint(ctx);
765 
766 	/*
767 	 * Add dirhash hint if necessary
768 	 */
769 	e2fsck_fix_dirhash_hint(ctx);
770 
771 	return;
772 }
773 
774 /*
775  * Check to see if we should backup the master sb to the backup super
776  * blocks.  Returns non-zero if the sb should be backed up.
777  */
778 
779 /*
780  * A few flags are set on the fly by the kernel, but only in the
781  * primary superblock.  This is actually a bad thing, and we should
782  * try to discourage it in the future.  In particular, for the newer
783  * ext4 files, especially EXT4_FEATURE_RO_COMPAT_DIR_NLINK and
784  * EXT3_FEATURE_INCOMPAT_EXTENTS.  So some of these may go away in the
785  * future.
786  *
787  * The kernel will set EXT2_FEATURE_COMPAT_EXT_ATTR, but
788  * unfortunately, we shouldn't ignore it since if it's not set in the
789  * backup, the extended attributes in the filesystem will be stripped
790  * away.
791  */
792 #define FEATURE_RO_COMPAT_IGNORE	(EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
793 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
794 #define FEATURE_INCOMPAT_IGNORE		(EXT3_FEATURE_INCOMPAT_EXTENTS)
795 
check_backup_super_block(e2fsck_t ctx)796 int check_backup_super_block(e2fsck_t ctx)
797 {
798 	ext2_filsys	fs = ctx->fs;
799 	ext2_filsys	tfs = 0;
800 	io_manager	io_ptr;
801 	errcode_t	retval;
802 	dgrp_t		g;
803 	blk_t		sb;
804 	int		ret = 0;
805 
806 	/*
807 	 * If we are already writing out the backup blocks, then we
808 	 * don't need to test.  Also, if the filesystem is invalid, or
809 	 * the check was aborted or cancelled, we also don't want to
810 	 * do the backup.  If the filesystem was opened read-only then
811 	 * we can't do the backup.
812 	 */
813 	if (((fs->flags & EXT2_FLAG_MASTER_SB_ONLY) == 0) ||
814 	    !ext2fs_test_valid(fs) ||
815 	    (fs->super->s_state & EXT2_ERROR_FS) ||
816 	    (ctx->flags & (E2F_FLAG_ABORT | E2F_FLAG_CANCEL)) ||
817 	    (ctx->options & E2F_OPT_READONLY))
818 		return 0;
819 
820 	for (g = 1; g < fs->group_desc_count; g++) {
821 		if (!ext2fs_bg_has_super(fs, g))
822 			continue;
823 
824 		sb = fs->super->s_first_data_block +
825 			(g * fs->super->s_blocks_per_group);
826 
827 		retval = ext2fs_open(ctx->filesystem_name, 0,
828 				     sb, fs->blocksize,
829 				     fs->io->manager, &tfs);
830 		if (retval) {
831 			tfs = 0;
832 			continue;
833 		}
834 
835 #define SUPER_INCOMPAT_DIFFERENT(x)	\
836 	(( fs->super->x & ~FEATURE_INCOMPAT_IGNORE) !=	\
837 	 (tfs->super->x & ~FEATURE_INCOMPAT_IGNORE))
838 #define SUPER_RO_COMPAT_DIFFERENT(x)	\
839 	(( fs->super->x & ~FEATURE_RO_COMPAT_IGNORE) !=	\
840 	 (tfs->super->x & ~FEATURE_RO_COMPAT_IGNORE))
841 #define SUPER_DIFFERENT(x)		\
842 	(fs->super->x != tfs->super->x)
843 
844 		if (SUPER_DIFFERENT(s_feature_compat) ||
845 		    SUPER_INCOMPAT_DIFFERENT(s_feature_incompat) ||
846 		    SUPER_RO_COMPAT_DIFFERENT(s_feature_ro_compat) ||
847 		    SUPER_DIFFERENT(s_blocks_count) ||
848 		    SUPER_DIFFERENT(s_inodes_count) ||
849 		    memcmp(fs->super->s_uuid, tfs->super->s_uuid,
850 			   sizeof(fs->super->s_uuid)))
851 			ret = 1;
852 		ext2fs_close(tfs);
853 		break;
854 	}
855 	return ret;
856 }
857