LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/bmove.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * bmove.c --- Move blocks around to make way for a particular
   4 *      filesystem structure.
   5 *
   6 * Copyright (C) 1997 Theodore Ts'o.  This file may be redistributed
   7 * under the terms of the GNU Public License.
   8 */
   9
  10#include <stdio.h>
  11#include <string.h>
  12#if HAVE_UNISTD_H
  13#include <unistd.h>
  14#endif
  15#if HAVE_SYS_TYPES_H
  16#include <sys/types.h>
  17#endif
  18
  19#include "ext2_fs.h"
  20#include "ext2fsP.h"
  21
  22struct process_block_struct {
  23        ext2_ino_t              ino;
  24        struct ext2_inode *     inode;
  25        ext2fs_block_bitmap     reserve;
  26        ext2fs_block_bitmap     alloc_map;
  27        errcode_t               error;
  28        char                    *buf;
  29        int                     add_dir;
  30        int                     flags;
  31};
  32
  33static int process_block(ext2_filsys fs, blk_t  *block_nr,
  34                         e2_blkcnt_t blockcnt, blk_t ref_block,
  35                         int ref_offset, void *priv_data)
  36{
  37        struct process_block_struct *pb;
  38        errcode_t       retval;
  39        int             ret;
  40        blk_t           block, orig;
  41
  42        pb = (struct process_block_struct *) priv_data;
  43        block = orig = *block_nr;
  44        ret = 0;
  45
  46        /*
  47         * Let's see if this is one which we need to relocate
  48         */
  49        if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  50                do {
  51                        if (++block >= fs->super->s_blocks_count)
  52                                block = fs->super->s_first_data_block;
  53                        if (block == orig) {
  54                                pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  55                                return BLOCK_ABORT;
  56                        }
  57                } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  58                         ext2fs_test_block_bitmap(pb->alloc_map, block));
  59
  60                retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  61                if (retval) {
  62                        pb->error = retval;
  63                        return BLOCK_ABORT;
  64                }
  65                retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  66                if (retval) {
  67                        pb->error = retval;
  68                        return BLOCK_ABORT;
  69                }
  70                *block_nr = block;
  71                ext2fs_mark_block_bitmap(pb->alloc_map, block);
  72                ret = BLOCK_CHANGED;
  73                if (pb->flags & EXT2_BMOVE_DEBUG)
  74                        printf("ino=%ld, blockcnt=%lld, %d->%d\n", pb->ino,
  75                               blockcnt, orig, block);
  76        }
  77        if (pb->add_dir) {
  78                retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  79                                              block, (int) blockcnt);
  80                if (retval) {
  81                        pb->error = retval;
  82                        ret |= BLOCK_ABORT;
  83                }
  84        }
  85        return ret;
  86}
  87
  88errcode_t ext2fs_move_blocks(ext2_filsys fs,
  89                             ext2fs_block_bitmap reserve,
  90                             ext2fs_block_bitmap alloc_map,
  91                             int flags)
  92{
  93        ext2_ino_t      ino;
  94        struct ext2_inode inode;
  95        errcode_t       retval;
  96        struct process_block_struct pb;
  97        ext2_inode_scan scan;
  98        char            *block_buf;
  99
 100        retval = ext2fs_open_inode_scan(fs, 0, &scan);
 101        if (retval)
 102                return retval;
 103
 104        pb.reserve = reserve;
 105        pb.error = 0;
 106        pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 107        pb.flags = flags;
 108
 109        retval = ext2fs_get_mem(fs->blocksize * 4, &block_buf);
 110        if (retval)
 111                return retval;
 112        pb.buf = block_buf + fs->blocksize * 3;
 113
 114        /*
 115         * If GET_DBLIST is set in the flags field, then we should
 116         * gather directory block information while we're doing the
 117         * block move.
 118         */
 119        if (flags & EXT2_BMOVE_GET_DBLIST) {
 120                ext2fs_free_dblist(fs->dblist);
 121                fs->dblist = NULL;
 122                retval = ext2fs_init_dblist(fs, 0);
 123                if (retval)
 124                        return retval;
 125        }
 126
 127        retval = ext2fs_get_next_inode(scan, &ino, &inode);
 128        if (retval)
 129                return retval;
 130
 131        while (ino) {
 132                if ((inode.i_links_count == 0) ||
 133                    !ext2fs_inode_has_valid_blocks(&inode))
 134                        goto next;
 135
 136                pb.ino = ino;
 137                pb.inode = &inode;
 138
 139                pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 140                              flags & EXT2_BMOVE_GET_DBLIST);
 141
 142                retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 143                                              process_block, &pb);
 144                if (retval)
 145                        return retval;
 146                if (pb.error)
 147                        return pb.error;
 148
 149        next:
 150                retval = ext2fs_get_next_inode(scan, &ino, &inode);
 151                if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 152                        goto next;
 153        }
 154        return 0;
 155}
 156