lib/ext2fs/bmove.c

   1 /*
   2  * bmove.c --- Move blocks around to make way for a particular
   3  *      filesystem structure.
   4  *
   5  * Copyright (C) 1997 Theodore Ts'o.  This file may be redistributed
   6  * under the terms of the GNU Public License.
   7  */
   8
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <stdlib.h>
  13 #include <sys/types.h>
  14 #include <sys/time.h>
  15
  16 #include <linux/ext2_fs.h>
  17 #include "ext2fs/ext2fs.h"
  18
  19 struct process_block_struct {
  20         ino_t                   ino;
  21         struct ext2_inode *     inode;
  22         ext2fs_block_bitmap     reserve;
  23         errcode_t               error;
  24         char                    *buf;
  25         int                     add_dir;
  26 };
  27
  28 static int process_block(ext2_filsys fs, blk_t  *block_nr,
  29                          int blockcnt, blk_t ref_block,
  30                          int ref_offset, void *private)
  31 {
  32         struct process_block_struct *pb = private;
  33         errcode_t       retval;
  34         int             ret;
  35         blk_t           block, orig;
  36
  37         block = orig = *block_nr;
  38         ret = 0;
  39
  40         /*
  41          * Let's see if this is one which we need to relocate
  42          */
  43         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  44                 do {
  45                         if (++block >= fs->super->s_blocks_count)
  46                                 block = fs->super->s_first_data_block;
  47                         if (block == orig) {
  48                                 pb->error = ENOSPC;
  49                                 return BLOCK_ABORT;
  50                         }
  51                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  52                          ext2fs_test_block_bitmap(fs->block_map, block));
  53
  54                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  55                 if (retval) {
  56                         pb->error = retval;
  57                         return BLOCK_ABORT;
  58                 }
  59                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  60                 if (retval) {
  61                         pb->error = retval;
  62                         return BLOCK_ABORT;
  63                 }
  64                 *block_nr = block;
  65                 ext2fs_mark_block_bitmap(fs->block_map, block);
  66                 ret = BLOCK_CHANGED;
  67                 printf("ino=%ld, blockcnt=%d, %ld->%ld\n", pb->ino,
  68                        blockcnt, orig, block);
  69         }
  70         if (pb->add_dir) {
  71                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  72                                               block, blockcnt);
  73                 if (retval) {
  74                         pb->error = retval;
  75                         ret |= BLOCK_ABORT;
  76                 }
  77         }
  78         return ret;
  79 }
  80
  81 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  82                              ext2fs_block_bitmap reserve,
  83                              int flags)
  84 {
  85         ino_t   ino;
  86         struct ext2_inode inode;
  87         errcode_t       retval;
  88         struct process_block_struct pb;
  89         ext2_inode_scan scan;
  90         char            *block_buf;
  91
  92         retval = ext2fs_open_inode_scan(fs, 0, &scan);
  93         if (retval)
  94                 return retval;
  95
  96         pb.reserve = reserve;
  97         pb.error = 0;
  98
  99         block_buf = malloc(fs->blocksize * 4);
 100         if (!block_buf)
 101                 return ENOMEM;
 102         pb.buf = block_buf + fs->blocksize * 3;
 103
 104         /*
 105          * If GET_DBLIST is set in the flags field, then we should
 106          * gather directory block information while we're doing the
 107          * block move.
 108          */
 109         if (flags & EXT2_BMOVE_GET_DBLIST) {
 110                 if (fs->dblist) {
 111                         ext2fs_free_dblist(fs->dblist);
 112                         fs->dblist = NULL;
 113                 }
 114                 retval = ext2fs_init_dblist(fs, 0);
 115                 if (retval)
 116                         return retval;
 117         }
 118
 119         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 120         if (retval)
 121                 return retval;
 122
 123         while (ino) {
 124                 if ((inode.i_links_count == 0) ||
 125                     !ext2fs_inode_has_valid_blocks(&inode))
 126                         goto next;
 127
 128                 pb.ino = ino;
 129                 pb.inode = &inode;
 130
 131                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 132                               flags & EXT2_BMOVE_GET_DBLIST);
 133
 134                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 135                                               process_block, &pb);
 136                 if (retval)
 137                         return retval;
 138                 if (pb.error)
 139                         return pb.error;
 140
 141         next:
 142                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 143                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 144                         goto next;
 145         }
 146         return 0;
 147 }
 148