1/*
2 * pass4.c -- pass #4 of e2fsck: Check reference counts
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 * Pass 4 frees the following data structures:
12 * 	- A bitmap of which inodes are in bad blocks.	(inode_bb_map)
13 * 	- A bitmap of which inodes are imagic inodes.	(inode_imagic_map)
14 */
15
16#include "e2fsck.h"
17#include "problem.h"
18#include <ext2fs/ext2_ext_attr.h>
19
20/*
21 * This routine is called when an inode is not connected to the
22 * directory tree.
23 *
24 * This subroutine returns 1 then the caller shouldn't bother with the
25 * rest of the pass 4 tests.
26 */
27static int disconnect_inode(e2fsck_t ctx, ext2_ino_t i,
28			    struct ext2_inode *inode)
29{
30	ext2_filsys fs = ctx->fs;
31	struct problem_context	pctx;
32	__u32 eamagic = 0;
33	int extra_size = 0;
34
35	if (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE) {
36		e2fsck_read_inode_full(ctx, i, inode,EXT2_INODE_SIZE(fs->super),
37				       "pass4: disconnect_inode");
38		extra_size = ((struct ext2_inode_large *)inode)->i_extra_isize;
39	} else {
40		e2fsck_read_inode(ctx, i, inode, "pass4: disconnect_inode");
41	}
42	clear_problem_context(&pctx);
43	pctx.ino = i;
44	pctx.inode = inode;
45
46	if (EXT2_INODE_SIZE(fs->super) -EXT2_GOOD_OLD_INODE_SIZE -extra_size >0)
47		eamagic = *(__u32 *)(((char *)inode) +EXT2_GOOD_OLD_INODE_SIZE +
48				     extra_size);
49	/*
50	 * Offer to delete any zero-length files that does not have
51	 * blocks.  If there is an EA block, it might have useful
52	 * information, so we won't prompt to delete it, but let it be
53	 * reconnected to lost+found.
54	 */
55	if (!inode->i_blocks && eamagic != EXT2_EXT_ATTR_MAGIC &&
56	    (LINUX_S_ISREG(inode->i_mode) || LINUX_S_ISDIR(inode->i_mode))) {
57		if (fix_problem(ctx, PR_4_ZERO_LEN_INODE, &pctx)) {
58			e2fsck_clear_inode(ctx, i, inode, 0,
59					   "disconnect_inode");
60			/*
61			 * Fix up the bitmaps...
62			 */
63			e2fsck_read_bitmaps(ctx);
64			ext2fs_inode_alloc_stats2(fs, i, -1,
65						  LINUX_S_ISDIR(inode->i_mode));
66			return 0;
67		}
68	}
69
70	/*
71	 * Prompt to reconnect.
72	 */
73	if (fix_problem(ctx, PR_4_UNATTACHED_INODE, &pctx)) {
74		if (e2fsck_reconnect_file(ctx, i))
75			ext2fs_unmark_valid(fs);
76	} else {
77		/*
78		 * If we don't attach the inode, then skip the
79		 * i_links_test since there's no point in trying to
80		 * force i_links_count to zero.
81		 */
82		ext2fs_unmark_valid(fs);
83		return 1;
84	}
85	return 0;
86}
87
88
89void e2fsck_pass4(e2fsck_t ctx)
90{
91	ext2_filsys fs = ctx->fs;
92	ext2_ino_t	i;
93	struct ext2_inode	*inode;
94#ifdef RESOURCE_TRACK
95	struct resource_track	rtrack;
96#endif
97	struct problem_context	pctx;
98	__u16	link_count, link_counted;
99	char	*buf = 0;
100	int	group, maxgroup;
101
102	init_resource_track(&rtrack, ctx->fs->io);
103
104#ifdef MTRACE
105	mtrace_print("Pass 4");
106#endif
107
108	clear_problem_context(&pctx);
109
110	if (!(ctx->options & E2F_OPT_PREEN))
111		fix_problem(ctx, PR_4_PASS_HEADER, &pctx);
112
113	group = 0;
114	maxgroup = fs->group_desc_count;
115	if (ctx->progress)
116		if ((ctx->progress)(ctx, 4, 0, maxgroup))
117			return;
118
119	inode = e2fsck_allocate_memory(ctx, EXT2_INODE_SIZE(fs->super),
120				       "scratch inode");
121
122	/* Protect loop from wrap-around if s_inodes_count maxed */
123	for (i=1; i <= fs->super->s_inodes_count && i > 0; i++) {
124		int isdir = ext2fs_test_inode_bitmap(ctx->inode_dir_map, i);
125
126		if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
127			goto errout;
128		if ((i % fs->super->s_inodes_per_group) == 0) {
129			group++;
130			if (ctx->progress)
131				if ((ctx->progress)(ctx, 4, group, maxgroup))
132					goto errout;
133		}
134		if (i == EXT2_BAD_INO ||
135		    (i > EXT2_ROOT_INO && i < EXT2_FIRST_INODE(fs->super)))
136			continue;
137		if (!(ext2fs_test_inode_bitmap(ctx->inode_used_map, i)) ||
138		    (ctx->inode_imagic_map &&
139		     ext2fs_test_inode_bitmap(ctx->inode_imagic_map, i)) ||
140		    (ctx->inode_bb_map &&
141		     ext2fs_test_inode_bitmap(ctx->inode_bb_map, i)))
142			continue;
143		ext2fs_icount_fetch(ctx->inode_link_info, i, &link_count);
144		ext2fs_icount_fetch(ctx->inode_count, i, &link_counted);
145		if (link_counted == 0) {
146			if (!buf)
147				buf = e2fsck_allocate_memory(ctx,
148				     fs->blocksize, "bad_inode buffer");
149			if (e2fsck_process_bad_inode(ctx, 0, i, buf))
150				continue;
151			if (disconnect_inode(ctx, i, inode))
152				continue;
153			ext2fs_icount_fetch(ctx->inode_link_info, i,
154					    &link_count);
155			ext2fs_icount_fetch(ctx->inode_count, i,
156					    &link_counted);
157		}
158		if (isdir && (link_counted > EXT2_LINK_MAX))
159			link_counted = 1;
160		if (link_counted != link_count) {
161			e2fsck_read_inode(ctx, i, inode, "pass4");
162			pctx.ino = i;
163			pctx.inode = inode;
164			if ((link_count != inode->i_links_count) && !isdir &&
165			    (inode->i_links_count <= EXT2_LINK_MAX)) {
166				pctx.num = link_count;
167				fix_problem(ctx,
168					    PR_4_INCONSISTENT_COUNT, &pctx);
169			}
170			pctx.num = link_counted;
171			/* i_link_count was previously exceeded, but no longer
172			 * is, fix this but don't consider it an error */
173			if ((isdir && link_counted > 1 &&
174			     (inode->i_flags & EXT2_INDEX_FL) &&
175			     link_count == 1 && !(ctx->options & E2F_OPT_NO)) ||
176			    fix_problem(ctx, PR_4_BAD_REF_COUNT, &pctx)) {
177				inode->i_links_count = link_counted;
178				e2fsck_write_inode(ctx, i, inode, "pass4");
179			}
180		}
181	}
182	ext2fs_free_icount(ctx->inode_link_info); ctx->inode_link_info = 0;
183	ext2fs_free_icount(ctx->inode_count); ctx->inode_count = 0;
184	ext2fs_free_inode_bitmap(ctx->inode_bb_map);
185	ctx->inode_bb_map = 0;
186	ext2fs_free_inode_bitmap(ctx->inode_imagic_map);
187	ctx->inode_imagic_map = 0;
188errout:
189	if (buf)
190		ext2fs_free_mem(&buf);
191
192	ext2fs_free_mem(&inode);
193	print_resource_track(ctx, _("Pass 4"), &rtrack, ctx->fs->io);
194}
195
196