e2fsck/emptydir.c

   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 "config.h"
  16 #include "e2fsck.h"
  17 #include "problem.h"
  18
  19 /*
  20  * For e2fsck.h
  21  */
  22 struct empty_dir_info_struct {
  23         ext2_dblist empty_dblist;
  24         ext2fs_block_bitmap empty_dir_blocks;
  25         ext2fs_inode_bitmap dir_map;
  26         char *block_buf;
  27         ext2_ino_t ino;
  28         struct ext2_inode inode;
  29         blk64_t logblk;
  30         blk64_t freed_blocks;
  31 };
  32
  33 typedef struct empty_dir_info_struct *empty_dir_info;
  34
  35 extern empty_dir_info init_empty_dir(e2fsck_t ctx);
  36 extern void free_empty_dirblock(empty_dir_info edi);
  37 extern void add_empty_dirblock(empty_dir_info edi,
  38                                struct ext2_db_entry2 *db);
  39 extern void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi);
  40
  41
  42 empty_dir_info init_empty_dir(e2fsck_t ctx)
  43 {
  44         empty_dir_info  edi;
  45         errcode_t       retval;
  46
  47         edi = malloc(sizeof(struct empty_dir_info_struct));
  48         if (!edi)
  49                 return NULL;
  50
  51         memset(edi, 0, sizeof(struct empty_dir_info_struct));
  52
  53         retval = ext2fs_init_dblist(ctx->fs, &edi->empty_dblist);
  54         if (retval)
  55                 goto errout;
  56
  57         retval = ext2fs_allocate_block_bitmap(ctx->fs, _("empty dirblocks"),
  58                                               &edi->empty_dir_blocks);
  59         if (retval)
  60                 goto errout;
  61
  62         retval = ext2fs_allocate_inode_bitmap(ctx->fs, _("empty dir map"),
  63                                               &edi->dir_map);
  64         if (retval)
  65                 goto errout;
  66
  67         return (edi);
  68
  69 errout:
  70         free_empty_dirblock(edi);
  71         return NULL;
  72 }
  73
  74 void free_empty_dirblock(empty_dir_info edi)
  75 {
  76         if (!edi)
  77                 return;
  78         if (edi->empty_dblist)
  79                 ext2fs_free_dblist(edi->empty_dblist);
  80         if (edi->empty_dir_blocks)
  81                 ext2fs_free_block_bitmap(edi->empty_dir_blocks);
  82         if (edi->dir_map)
  83                 ext2fs_free_inode_bitmap(edi->dir_map);
  84
  85         memset(edi, 0, sizeof(struct empty_dir_info_struct));
  86         free(edi);
  87 }
  88
  89 void add_empty_dirblock(empty_dir_info edi,
  90                         struct ext2_db_entry2 *db)
  91 {
  92         if (!edi || !db)
  93                 return;
  94
  95         if (db->ino == 11)
  96                 return;         /* Inode number 11 is usually lost+found */
  97
  98         printf(_("Empty directory block %u (#%d) in inode %u\n"),
  99                db->blk, db->blockcnt, db->ino);
 100
 101         ext2fs_mark_block_bitmap2(edi->empty_dir_blocks, db->blk);
 102         if (ext2fs_test_inode_bitmap(edi->dir_map, db->ino))
 103                 return;
 104         ext2fs_mark_inode_bitmap(edi->dir_map, db->ino);
 105
 106         ext2fs_add_dir_block2(edi->empty_dblist, db->ino,
 107                               db->blk, db->blockcnt);
 108 }
 109
 110 /*
 111  * Helper function used by fix_directory.
 112  *
 113  * XXX need to finish this.  General approach is to use bmap to
 114  * iterate over all of the logical blocks using the bmap function, and
 115  * copy the block reference as necessary.  Big question --- what do
 116  * about error recovery?
 117  *
 118  * Also question --- how to free the indirect blocks.
 119  */
 120 int empty_pass1(ext2_filsys fs, blk64_t *block_nr, e2_blkcnt_t blockcnt,
 121                 blk64_t ref_block, int ref_offset, void *priv_data)
 122 {
 123         empty_dir_info edi = (empty_dir_info) priv_data;
 124         blk64_t block, new_block;
 125         errcode_t       retval;
 126
 127         if (blockcnt < 0)
 128                 return 0;
 129         block = *block_nr;
 130         do {
 131                 retval = ext2fs_bmap2(fs, edi->ino, &edi->inode,
 132                                       edi->block_buf, 0, edi->logblk, 0,
 133                                       &new_block);
 134                 if (retval)
 135                         return DIRENT_ABORT;   /* XXX what to do? */
 136                 if (new_block == 0)
 137                         break;
 138                 edi->logblk++;
 139         } while (ext2fs_test_block_bitmap2(edi->empty_dir_blocks, new_block));
 140
 141         if (new_block == block)
 142                 return 0;
 143         if (new_block == 0)
 144                 edi->freed_blocks++;
 145         *block_nr = new_block;
 146         return BLOCK_CHANGED;
 147 }
 148
 149 static int fix_directory(ext2_filsys fs,
 150                          struct ext2_db_entry2 *db,
 151                          void *priv_data)
 152 {
 153         errcode_t       retval;
 154
 155         empty_dir_info edi = (empty_dir_info) priv_data;
 156
 157         edi->logblk = 0;
 158         edi->freed_blocks = 0;
 159         edi->ino = db->ino;
 160
 161         retval = ext2fs_read_inode(fs, db->ino, &edi->inode);
 162         if (retval)
 163                 return 0;
 164
 165         retval = ext2fs_block_iterate3(fs, db->ino, 0, edi->block_buf,
 166                                        empty_pass1, edi);
 167         if (retval)
 168                 return 0;
 169
 170         if (edi->freed_blocks) {
 171                 edi->inode.i_size -= edi->freed_blocks * fs->blocksize;
 172                 ext2fs_iblk_add_blocks(fs, &edi->inode, edi->freed_blocks);
 173                 retval = ext2fs_write_inode(fs, db->ino, &edi->inode);
 174                 if (retval)
 175                         return 0;
 176         }
 177         return 0;
 178 }
 179
 180 void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi)
 181 {
 182         if (!edi)
 183                 return;
 184
 185         edi->block_buf = malloc(ctx->fs->blocksize * 3);
 186
 187         if (edi->block_buf) {
 188                 (void) ext2fs_dblist_iterate2(edi->empty_dblist,
 189                                               fix_directory, &edi);
 190         }
 191         free(edi->block_buf);
 192         free_empty_dirblock(edi);
 193 }
 194