Theodore Ts'o | f75c28d | 1998-08-01 04:18:06 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * emptydir.c --- clear empty directory blocks |
| 3 | * |
| 4 | * Copyright (C) 1998 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 | * This file has the necessary routines to search for empty directory |
| 12 | * blocks and get rid of them. |
| 13 | */ |
| 14 | |
| 15 | #include "e2fsck.h" |
| 16 | #include "problem.h" |
| 17 | |
| 18 | /* |
| 19 | * For e2fsck.h |
| 20 | */ |
| 21 | struct empty_dir_info_struct { |
| 22 | ext2_dblist empty_dblist; |
| 23 | ext2fs_block_bitmap empty_dir_blocks; |
| 24 | ext2fs_inode_bitmap dir_map; |
| 25 | char *block_buf; |
| 26 | ino_t ino; |
| 27 | struct ext2_inode inode; |
| 28 | blk_t logblk; |
| 29 | blk_t freed_blocks; |
| 30 | }; |
| 31 | |
| 32 | typedef struct empty_dir_info_struct *empty_dir_info; |
| 33 | |
| 34 | extern empty_dir_info init_empty_dir(e2fsck_t ctx); |
| 35 | extern void free_empty_dirblock(empty_dir_info edi); |
| 36 | extern void add_empty_dirblock(empty_dir_info edi, |
| 37 | struct ext2_db_entry *db); |
| 38 | extern void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi); |
| 39 | |
| 40 | |
| 41 | empty_dir_info init_empty_dir(e2fsck_t ctx) |
| 42 | { |
| 43 | empty_dir_info edi; |
| 44 | errcode_t retval; |
| 45 | |
| 46 | edi = malloc(sizeof(struct empty_dir_info_struct)); |
| 47 | if (!edi) |
| 48 | return NULL; |
| 49 | |
| 50 | memset(edi, 0, sizeof(struct empty_dir_info_struct)); |
| 51 | |
| 52 | retval = ext2fs_init_dblist(ctx->fs, &edi->empty_dblist); |
| 53 | if (retval) |
| 54 | goto errout; |
| 55 | |
| 56 | retval = ext2fs_allocate_block_bitmap(ctx->fs, "empty dirblocks", |
| 57 | &edi->empty_dir_blocks); |
| 58 | if (retval) |
| 59 | goto errout; |
| 60 | |
| 61 | retval = ext2fs_allocate_inode_bitmap(ctx->fs, "empty dir map", |
| 62 | &edi->dir_map); |
| 63 | if (retval) |
| 64 | goto errout; |
| 65 | |
| 66 | return (edi); |
| 67 | |
| 68 | errout: |
| 69 | free_empty_dirblock(edi); |
| 70 | return NULL; |
| 71 | } |
| 72 | |
| 73 | void free_empty_dirblock(empty_dir_info edi) |
| 74 | { |
| 75 | if (!edi) |
| 76 | return; |
| 77 | if (edi->empty_dblist) |
| 78 | ext2fs_free_dblist(edi->empty_dblist); |
| 79 | if (edi->empty_dir_blocks) |
| 80 | ext2fs_free_block_bitmap(edi->empty_dir_blocks); |
| 81 | if (edi->dir_map) |
| 82 | ext2fs_free_inode_bitmap(edi->dir_map); |
| 83 | |
| 84 | memset(edi, 0, sizeof(struct empty_dir_info_struct)); |
| 85 | free(edi); |
| 86 | } |
| 87 | |
| 88 | void add_empty_dirblock(empty_dir_info edi, |
| 89 | struct ext2_db_entry *db) |
| 90 | { |
| 91 | if (!edi || !db) |
| 92 | return; |
| 93 | |
| 94 | if (db->ino == 11) |
| 95 | return; /* Inode number 11 is usually lost+found */ |
| 96 | |
| 97 | printf("Empty directory block %d (#%d) in inode %d\n", |
| 98 | db->blk, db->blockcnt, db->ino); |
| 99 | |
| 100 | ext2fs_mark_block_bitmap(edi->empty_dir_blocks, db->blk); |
| 101 | if (ext2fs_test_inode_bitmap(edi->dir_map, db->ino)) |
| 102 | return; |
| 103 | ext2fs_mark_inode_bitmap(edi->dir_map, db->ino); |
| 104 | |
| 105 | ext2fs_add_dir_block(edi->empty_dblist, db->ino, |
| 106 | db->blk, db->blockcnt); |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * Helper function used by fix_directory. |
| 111 | * |
| 112 | * XXX need to finish this. General approach is to use bmap to |
| 113 | * iterate over all of the logical blocks using the bmap function, and |
| 114 | * copy the block reference as necessary. Big question --- what do |
| 115 | * about error recovery? |
| 116 | * |
| 117 | * Also question --- how to free the indirect blocks. |
| 118 | */ |
| 119 | int empty_pass1(ext2_filsys fs, blk_t *block_nr, e2_blkcnt_t blockcnt, |
| 120 | blk_t ref_block, int ref_offset, void *priv_data) |
| 121 | { |
| 122 | empty_dir_info edi = (empty_dir_info) priv_data; |
| 123 | blk_t block, new_block; |
| 124 | errcode_t retval; |
| 125 | |
| 126 | if (blockcnt < 0) |
| 127 | return 0; |
| 128 | block = *block_nr; |
| 129 | do { |
| 130 | retval = ext2fs_bmap(fs, edi->ino, &edi->inode, |
| 131 | edi->block_buf, 0, edi->logblk, |
| 132 | &new_block); |
| 133 | if (retval) |
| 134 | return DIRENT_ABORT; /* XXX what to do? */ |
| 135 | if (new_block == 0) |
| 136 | break; |
| 137 | edi->logblk++; |
| 138 | } while (ext2fs_test_block_bitmap(edi->empty_dir_blocks, new_block)); |
| 139 | |
| 140 | if (new_block == block) |
| 141 | return 0; |
| 142 | if (new_block == 0) |
| 143 | edi->freed_blocks++; |
| 144 | *block_nr = new_block; |
| 145 | return BLOCK_CHANGED; |
| 146 | } |
| 147 | |
| 148 | static int fix_directory(ext2_filsys fs, |
| 149 | struct ext2_db_entry *db, |
| 150 | void *priv_data) |
| 151 | { |
| 152 | errcode_t retval; |
| 153 | |
| 154 | empty_dir_info edi = (empty_dir_info) priv_data; |
| 155 | |
| 156 | edi->logblk = 0; |
| 157 | edi->freed_blocks = 0; |
| 158 | edi->ino = db->ino; |
| 159 | |
| 160 | retval = ext2fs_read_inode(fs, db->ino, &edi->inode); |
| 161 | if (retval) |
| 162 | return 0; |
| 163 | |
| 164 | retval = ext2fs_block_iterate2(fs, db->ino, 0, edi->block_buf, |
| 165 | empty_pass1, edi); |
| 166 | if (retval) |
| 167 | return 0; |
| 168 | |
| 169 | if (edi->freed_blocks) { |
| 170 | edi->inode.i_size -= edi->freed_blocks * fs->blocksize; |
| 171 | edi->inode.i_blocks -= edi->freed_blocks * |
| 172 | (fs->blocksize / 512); |
| 173 | (void) ext2fs_write_inode(fs, db->ino, &edi->inode); |
| 174 | } |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi) |
| 179 | { |
| 180 | if (!edi) |
| 181 | return; |
| 182 | |
| 183 | edi->block_buf = malloc(ctx->fs->blocksize * 3); |
| 184 | |
| 185 | if (edi->block_buf) { |
| 186 | (void) ext2fs_dblist_iterate(edi->empty_dblist, |
| 187 | fix_directory, &edi); |
| 188 | } |
| 189 | free(edi->block_buf); |
| 190 | free_empty_dirblock(edi); |
| 191 | } |
| 192 | |