source: MondoRescue/trunk/mindi-busybox/e2fsprogs/ext2fs/bb_inode.c@ 904

/*
 * bb_inode.c --- routines to update the bad block inode.
 *
 * WARNING: This routine modifies a lot of state in the filesystem; if
 * this routine returns an error, the bad block inode may be in an
 * inconsistent state.
 *
 * Copyright (C) 1994, 1995 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <time.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#include "ext2_fs.h"
#include "ext2fs.h"

struct set_badblock_record {
    ext2_badblocks_iterate  bb_iter;
    int     bad_block_count;
    blk_t       *ind_blocks;
    int     max_ind_blocks;
    int     ind_blocks_size;
    int     ind_blocks_ptr;
    char        *block_buf;
    errcode_t   err;
};

static int set_bad_block_proc(ext2_filsys fs, blk_t *block_nr,
                  e2_blkcnt_t blockcnt,
                  blk_t ref_block, int ref_offset,
                  void *priv_data);
static int clear_bad_block_proc(ext2_filsys fs, blk_t *block_nr,
                e2_blkcnt_t blockcnt,
                blk_t ref_block, int ref_offset,
                void *priv_data);

/*
 * Given a bad blocks bitmap, update the bad blocks inode to reflect
 * the map.
 */
errcode_t ext2fs_update_bb_inode(ext2_filsys fs, ext2_badblocks_list bb_list)
{
    errcode_t           retval;
    struct set_badblock_record  rec;
    struct ext2_inode       inode;

    EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

    if (!fs->block_map)
        return EXT2_ET_NO_BLOCK_BITMAP;

    rec.bad_block_count = 0;
    rec.ind_blocks_size = rec.ind_blocks_ptr = 0;
    rec.max_ind_blocks = 10;
    retval = ext2fs_get_mem(rec.max_ind_blocks * sizeof(blk_t),
                &rec.ind_blocks);
    if (retval)
        return retval;
    memset(rec.ind_blocks, 0, rec.max_ind_blocks * sizeof(blk_t));
    retval = ext2fs_get_mem(fs->blocksize, &rec.block_buf);
    if (retval)
        goto cleanup;
    memset(rec.block_buf, 0, fs->blocksize);
    rec.err = 0;

    /*
     * First clear the old bad blocks (while saving the indirect blocks)
     */
    retval = ext2fs_block_iterate2(fs, EXT2_BAD_INO,
                       BLOCK_FLAG_DEPTH_TRAVERSE, 0,
                       clear_bad_block_proc, &rec);
    if (retval)
        goto cleanup;
    if (rec.err) {
        retval = rec.err;
        goto cleanup;
    }

    /*
     * Now set the bad blocks!
     *
     * First, mark the bad blocks as used.  This prevents a bad
     * block from being used as an indirecto block for the bad
     * block inode (!).
     */
    if (bb_list) {
        retval = ext2fs_badblocks_list_iterate_begin(bb_list,
                                 &rec.bb_iter);
        if (retval)
            goto cleanup;
        retval = ext2fs_block_iterate2(fs, EXT2_BAD_INO,
                           BLOCK_FLAG_APPEND, 0,
                           set_bad_block_proc, &rec);
        ext2fs_badblocks_list_iterate_end(rec.bb_iter);
        if (retval)
            goto cleanup;
        if (rec.err) {
            retval = rec.err;
            goto cleanup;
        }
    }

    /*
     * Update the bad block inode's mod time and block count
     * field.
     */
    retval = ext2fs_read_inode(fs, EXT2_BAD_INO, &inode);
    if (retval)
        goto cleanup;

    inode.i_atime = inode.i_mtime = time(0);
    if (!inode.i_ctime)
        inode.i_ctime = time(0);
    inode.i_blocks = rec.bad_block_count * (fs->blocksize / 512);
    inode.i_size = rec.bad_block_count * fs->blocksize;

    retval = ext2fs_write_inode(fs, EXT2_BAD_INO, &inode);
    if (retval)
        goto cleanup;

cleanup:
    ext2fs_free_mem(&rec.ind_blocks);
    ext2fs_free_mem(&rec.block_buf);
    return retval;
}

/*
 * Helper function for update_bb_inode()
 *
 * Clear the bad blocks in the bad block inode, while saving the
 * indirect blocks.
 */
#ifdef __TURBOC__
# pragma argsused
#endif
static int clear_bad_block_proc(ext2_filsys fs, blk_t *block_nr,
                e2_blkcnt_t blockcnt,
                blk_t ref_block EXT2FS_ATTR((unused)),
                int ref_offset EXT2FS_ATTR((unused)),
                void *priv_data)
{
    struct set_badblock_record *rec = (struct set_badblock_record *)
        priv_data;
    errcode_t   retval;
    unsigned long   old_size;

    if (!*block_nr)
        return 0;

    /*
     * If the block number is outrageous, clear it and ignore it.
     */
    if (*block_nr >= fs->super->s_blocks_count ||
        *block_nr < fs->super->s_first_data_block) {
        *block_nr = 0;
        return BLOCK_CHANGED;
    }

    if (blockcnt < 0) {
        if (rec->ind_blocks_size >= rec->max_ind_blocks) {
            old_size = rec->max_ind_blocks * sizeof(blk_t);
            rec->max_ind_blocks += 10;
            retval = ext2fs_resize_mem(old_size,
                   rec->max_ind_blocks * sizeof(blk_t),
                   &rec->ind_blocks);
            if (retval) {
                rec->max_ind_blocks -= 10;
                rec->err = retval;
                return BLOCK_ABORT;
            }
        }
        rec->ind_blocks[rec->ind_blocks_size++] = *block_nr;
    }

    /*
     * Mark the block as unused, and update accounting information
     */
    ext2fs_block_alloc_stats(fs, *block_nr, -1);

    *block_nr = 0;
    return BLOCK_CHANGED;
}


/*
 * Helper function for update_bb_inode()
 *
 * Set the block list in the bad block inode, using the supplied bitmap.
 */
#ifdef __TURBOC__
 #pragma argsused
#endif
static int set_bad_block_proc(ext2_filsys fs, blk_t *block_nr,
                  e2_blkcnt_t blockcnt,
                  blk_t ref_block EXT2FS_ATTR((unused)),
                  int ref_offset EXT2FS_ATTR((unused)),
                  void *priv_data)
{
    struct set_badblock_record *rec = (struct set_badblock_record *)
        priv_data;
    errcode_t   retval;
    blk_t       blk;

    if (blockcnt >= 0) {
        /*
         * Get the next bad block.
         */
        if (!ext2fs_badblocks_list_iterate(rec->bb_iter, &blk))
            return BLOCK_ABORT;
        rec->bad_block_count++;
    } else {
        /*
         * An indirect block; fetch a block from the
         * previously used indirect block list.  The block
         * most be not marked as used; if so, get another one.
         * If we run out of reserved indirect blocks, allocate
         * a new one.
         */
    retry:
        if (rec->ind_blocks_ptr < rec->ind_blocks_size) {
            blk = rec->ind_blocks[rec->ind_blocks_ptr++];
            if (ext2fs_test_block_bitmap(fs->block_map, blk))
                goto retry;
        } else {
            retval = ext2fs_new_block(fs, 0, 0, &blk);
            if (retval) {
                rec->err = retval;
                return BLOCK_ABORT;
            }
        }
        retval = io_channel_write_blk(fs->io, blk, 1, rec->block_buf);
        if (retval) {
            rec->err = retval;
            return BLOCK_ABORT;
        }
    }

    /*
     * Update block counts
     */
    ext2fs_block_alloc_stats(fs, blk, +1);

    *block_nr = blk;
    return BLOCK_CHANGED;
}