e2fsprogs/e2fsck/emptydir.c

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/*
* emptydir.c --- clear empty directory blocks
*
* Copyright (C) 1998 Theodore Ts'o
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*
* This file has the necessary routines to search for empty directory
* blocks and get rid of them.
*/
#include "e2fsck.h"
#include "problem.h"
/*
* For e2fsck.h
*/
struct empty_dir_info_struct {
ext2_dblist empty_dblist;
ext2fs_block_bitmap empty_dir_blocks;
ext2fs_inode_bitmap dir_map;
char *block_buf;
ext2_ino_t ino;
struct ext2_inode inode;
blk_t logblk;
blk_t freed_blocks;
};
typedef struct empty_dir_info_struct *empty_dir_info;
extern empty_dir_info init_empty_dir(e2fsck_t ctx);
extern void free_empty_dirblock(empty_dir_info edi);
extern void add_empty_dirblock(empty_dir_info edi,
struct ext2_db_entry *db);
extern void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi);
empty_dir_info init_empty_dir(e2fsck_t ctx)
{
empty_dir_info edi;
errcode_t retval;
edi = malloc(sizeof(struct empty_dir_info_struct));
if (!edi)
return NULL;
memset(edi, 0, sizeof(struct empty_dir_info_struct));
retval = ext2fs_init_dblist(ctx->fs, &edi->empty_dblist);
if (retval)
goto errout;
retval = ext2fs_allocate_block_bitmap(ctx->fs, _("empty dirblocks"),
&edi->empty_dir_blocks);
if (retval)
goto errout;
retval = ext2fs_allocate_inode_bitmap(ctx->fs, _("empty dir map"),
&edi->dir_map);
if (retval)
goto errout;
return (edi);
errout:
free_empty_dirblock(edi);
return NULL;
}
void free_empty_dirblock(empty_dir_info edi)
{
if (!edi)
return;
if (edi->empty_dblist)
ext2fs_free_dblist(edi->empty_dblist);
if (edi->empty_dir_blocks)
ext2fs_free_block_bitmap(edi->empty_dir_blocks);
if (edi->dir_map)
ext2fs_free_inode_bitmap(edi->dir_map);
memset(edi, 0, sizeof(struct empty_dir_info_struct));
free(edi);
}
void add_empty_dirblock(empty_dir_info edi,
struct ext2_db_entry *db)
{
if (!edi || !db)
return;
if (db->ino == 11)
return; /* Inode number 11 is usually lost+found */
printf(_("Empty directory block %d (#%d) in inode %d\n"),
db->blk, db->blockcnt, db->ino);
ext2fs_mark_block_bitmap(edi->empty_dir_blocks, db->blk);
if (ext2fs_test_inode_bitmap(edi->dir_map, db->ino))
return;
ext2fs_mark_inode_bitmap(edi->dir_map, db->ino);
ext2fs_add_dir_block(edi->empty_dblist, db->ino,
db->blk, db->blockcnt);
}
/*
* Helper function used by fix_directory.
*
* XXX need to finish this. General approach is to use bmap to
* iterate over all of the logical blocks using the bmap function, and
* copy the block reference as necessary. Big question --- what do
* about error recovery?
*
* Also question --- how to free the indirect blocks.
*/
int empty_pass1(ext2_filsys fs, blk_t *block_nr, e2_blkcnt_t blockcnt,
blk_t ref_block, int ref_offset, void *priv_data)
{
empty_dir_info edi = (empty_dir_info) priv_data;
blk_t block, new_block;
errcode_t retval;
if (blockcnt < 0)
return 0;
block = *block_nr;
do {
retval = ext2fs_bmap(fs, edi->ino, &edi->inode,
edi->block_buf, 0, edi->logblk,
&new_block);
if (retval)
return DIRENT_ABORT; /* XXX what to do? */
if (new_block == 0)
break;
edi->logblk++;
} while (ext2fs_test_block_bitmap(edi->empty_dir_blocks, new_block));
if (new_block == block)
return 0;
if (new_block == 0)
edi->freed_blocks++;
*block_nr = new_block;
return BLOCK_CHANGED;
}
static int fix_directory(ext2_filsys fs,
struct ext2_db_entry *db,
void *priv_data)
{
errcode_t retval;
empty_dir_info edi = (empty_dir_info) priv_data;
edi->logblk = 0;
edi->freed_blocks = 0;
edi->ino = db->ino;
retval = ext2fs_read_inode(fs, db->ino, &edi->inode);
if (retval)
return 0;
retval = ext2fs_block_iterate2(fs, db->ino, 0, edi->block_buf,
empty_pass1, edi);
if (retval)
return 0;
if (edi->freed_blocks) {
edi->inode.i_size -= edi->freed_blocks * fs->blocksize;
edi->inode.i_blocks -= edi->freed_blocks *
(fs->blocksize / 512);
(void) ext2fs_write_inode(fs, db->ino, &edi->inode);
}
return 0;
}
void process_empty_dirblock(e2fsck_t ctx, empty_dir_info edi)
{
if (!edi)
return;
edi->block_buf = malloc(ctx->fs->blocksize * 3);
if (edi->block_buf) {
(void) ext2fs_dblist_iterate(edi->empty_dblist,
fix_directory, &edi);
}
free(edi->block_buf);
free_empty_dirblock(edi);
}