1 /*
2  * dirinfo.c --- maintains the directory information table for e2fsck.
3  *
4  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
5  * under the terms of the GNU Public License.
6  */
7 
8 #include "config.h"
9 #include "e2fsck.h"
10 
11 /*
12  * This subroutine is called during pass1 to create a directory info
13  * entry.  During pass1, the passed-in parent is 0; it will get filled
14  * in during pass2.
15  */
e2fsck_add_dx_dir(e2fsck_t ctx,ext2_ino_t ino,int num_blocks)16 void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, int num_blocks)
17 {
18 	struct dx_dir_info *dir;
19 	int		i, j;
20 	errcode_t	retval;
21 	unsigned long	old_size;
22 
23 #if 0
24 	printf("add_dx_dir_info for inode %lu...\n", ino);
25 #endif
26 	if (!ctx->dx_dir_info) {
27 		ctx->dx_dir_info_count = 0;
28 		ctx->dx_dir_info_size = 100; /* Guess */
29 		ctx->dx_dir_info  = (struct dx_dir_info *)
30 			e2fsck_allocate_memory(ctx, ctx->dx_dir_info_size
31 					       * sizeof (struct dx_dir_info),
32 					       "directory map");
33 	}
34 
35 	if (ctx->dx_dir_info_count >= ctx->dx_dir_info_size) {
36 		old_size = ctx->dx_dir_info_size * sizeof(struct dx_dir_info);
37 		ctx->dx_dir_info_size += 10;
38 		retval = ext2fs_resize_mem(old_size, ctx->dx_dir_info_size *
39 					   sizeof(struct dx_dir_info),
40 					   &ctx->dx_dir_info);
41 		if (retval) {
42 			fprintf(stderr, "Couldn't reallocate dx_dir_info "
43 				"structure to %d entries\n",
44 				ctx->dx_dir_info_size);
45 			fatal_error(ctx, 0);
46 			ctx->dx_dir_info_size -= 10;
47 			return;
48 		}
49 	}
50 
51 	/*
52 	 * Normally, add_dx_dir_info is called with each inode in
53 	 * sequential order; but once in a while (like when pass 3
54 	 * needs to recreate the root directory or lost+found
55 	 * directory) it is called out of order.  In those cases, we
56 	 * need to move the dx_dir_info entries down to make room, since
57 	 * the dx_dir_info array needs to be sorted by inode number for
58 	 * get_dx_dir_info()'s sake.
59 	 */
60 	if (ctx->dx_dir_info_count &&
61 	    ctx->dx_dir_info[ctx->dx_dir_info_count-1].ino >= ino) {
62 		for (i = ctx->dx_dir_info_count-1; i > 0; i--)
63 			if (ctx->dx_dir_info[i-1].ino < ino)
64 				break;
65 		dir = &ctx->dx_dir_info[i];
66 		if (dir->ino != ino)
67 			for (j = ctx->dx_dir_info_count++; j > i; j--)
68 				ctx->dx_dir_info[j] = ctx->dx_dir_info[j-1];
69 	} else
70 		dir = &ctx->dx_dir_info[ctx->dx_dir_info_count++];
71 
72 	dir->ino = ino;
73 	dir->numblocks = num_blocks;
74 	dir->hashversion = 0;
75 	dir->dx_block = e2fsck_allocate_memory(ctx, num_blocks
76 				       * sizeof (struct dx_dirblock_info),
77 				       "dx_block info array");
78 
79 }
80 
81 /*
82  * get_dx_dir_info() --- given an inode number, try to find the directory
83  * information entry for it.
84  */
e2fsck_get_dx_dir_info(e2fsck_t ctx,ext2_ino_t ino)85 struct dx_dir_info *e2fsck_get_dx_dir_info(e2fsck_t ctx, ext2_ino_t ino)
86 {
87 	int	low, high, mid;
88 
89 	low = 0;
90 	high = ctx->dx_dir_info_count-1;
91 	if (!ctx->dx_dir_info)
92 		return 0;
93 	if (ino == ctx->dx_dir_info[low].ino)
94 		return &ctx->dx_dir_info[low];
95 	if  (ino == ctx->dx_dir_info[high].ino)
96 		return &ctx->dx_dir_info[high];
97 
98 	while (low < high) {
99 		mid = (low+high)/2;
100 		if (mid == low || mid == high)
101 			break;
102 		if (ino == ctx->dx_dir_info[mid].ino)
103 			return &ctx->dx_dir_info[mid];
104 		if (ino < ctx->dx_dir_info[mid].ino)
105 			high = mid;
106 		else
107 			low = mid;
108 	}
109 	return 0;
110 }
111 
112 /*
113  * Free the dx_dir_info structure when it isn't needed any more.
114  */
e2fsck_free_dx_dir_info(e2fsck_t ctx)115 void e2fsck_free_dx_dir_info(e2fsck_t ctx)
116 {
117 	int	i;
118 	struct dx_dir_info *dir;
119 
120 	if (ctx->dx_dir_info) {
121 		dir = ctx->dx_dir_info;
122 		for (i=0; i < ctx->dx_dir_info_count; i++,dir++) {
123 			if (dir->dx_block) {
124 				ext2fs_free_mem(&dir->dx_block);
125 				dir->dx_block = 0;
126 			}
127 		}
128 		ext2fs_free_mem(&ctx->dx_dir_info);
129 		ctx->dx_dir_info = 0;
130 	}
131 	ctx->dx_dir_info_size = 0;
132 	ctx->dx_dir_info_count = 0;
133 }
134 
135 /*
136  * Return the count of number of directories in the dx_dir_info structure
137  */
e2fsck_get_num_dx_dirinfo(e2fsck_t ctx)138 int e2fsck_get_num_dx_dirinfo(e2fsck_t ctx)
139 {
140 	return ctx->dx_dir_info_count;
141 }
142 
143 /*
144  * A simple interator function
145  */
e2fsck_dx_dir_info_iter(e2fsck_t ctx,int * control)146 struct dx_dir_info *e2fsck_dx_dir_info_iter(e2fsck_t ctx, int *control)
147 {
148 	if (*control >= ctx->dx_dir_info_count)
149 		return 0;
150 
151 	return(ctx->dx_dir_info + (*control)++);
152 }
153