release/src/router/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
  22 struct 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
  33 static 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
  88 errcode_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 }