e2fsprogs/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 #if HAVE_UNISTD_H
  12 #include <unistd.h>
  13 #endif
  14 #if HAVE_SYS_TYPES_H
  15 #include <sys/types.h>
  16 #endif
  17
  18 #include "ext2_fs.h"
  19 #include "ext2fsP.h"
  20
  21 struct process_block_struct {
  22         ext2_ino_t              ino;
  23         struct ext2_inode *     inode;
  24         ext2fs_block_bitmap     reserve;
  25         ext2fs_block_bitmap     alloc_map;
  26         errcode_t               error;
  27         char                    *buf;
  28         int                     add_dir;
  29         int                     flags;
  30 };
  31
  32 static int process_block(ext2_filsys fs, blk_t  *block_nr,
  33                          e2_blkcnt_t blockcnt, blk_t ref_block,
  34                          int ref_offset, void *priv_data)
  35 {
  36         struct process_block_struct *pb;
  37         errcode_t       retval;
  38         int             ret;
  39         blk_t           block, orig;
  40
  41         pb = (struct process_block_struct *) priv_data;
  42         block = orig = *block_nr;
  43         ret = 0;
  44
  45         /*
  46          * Let's see if this is one which we need to relocate
  47          */
  48         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  49                 do {
  50                         if (++block >= fs->super->s_blocks_count)
  51                                 block = fs->super->s_first_data_block;
  52                         if (block == orig) {
  53                                 pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  54                                 return BLOCK_ABORT;
  55                         }
  56                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  57                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  58
  59                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  60                 if (retval) {
  61                         pb->error = retval;
  62                         return BLOCK_ABORT;
  63                 }
  64                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  65                 if (retval) {
  66                         pb->error = retval;
  67                         return BLOCK_ABORT;
  68                 }
  69                 *block_nr = block;
  70                 ext2fs_mark_block_bitmap(pb->alloc_map, block);
  71                 ret = BLOCK_CHANGED;
  72                 if (pb->flags & EXT2_BMOVE_DEBUG)
  73                         printf("ino=%ld, blockcnt=%lld, %d->%d\n", pb->ino,
  74                                blockcnt, orig, block);
  75         }
  76         if (pb->add_dir) {
  77                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  78                                               block, (int) blockcnt);
  79                 if (retval) {
  80                         pb->error = retval;
  81                         ret |= BLOCK_ABORT;
  82                 }
  83         }
  84         return ret;
  85 }
  86
  87 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  88                              ext2fs_block_bitmap reserve,
  89                              ext2fs_block_bitmap alloc_map,
  90                              int flags)
  91 {
  92         ext2_ino_t      ino;
  93         struct ext2_inode inode;
  94         errcode_t       retval;
  95         struct process_block_struct pb;
  96         ext2_inode_scan scan;
  97         char            *block_buf;
  98
  99         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 100         if (retval)
 101                 return retval;
 102
 103         pb.reserve = reserve;
 104         pb.error = 0;
 105         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 106         pb.flags = flags;
 107
 108         retval = ext2fs_get_mem(fs->blocksize * 4, &block_buf);
 109         if (retval)
 110                 return retval;
 111         pb.buf = block_buf + fs->blocksize * 3;
 112
 113         /*
 114          * If GET_DBLIST is set in the flags field, then we should
 115          * gather directory block information while we're doing the
 116          * block move.
 117          */
 118         if (flags & EXT2_BMOVE_GET_DBLIST) {
 119                 ext2fs_free_dblist(fs->dblist);
 120                 fs->dblist = NULL;
 121                 retval = ext2fs_init_dblist(fs, 0);
 122                 if (retval)
 123                         return retval;
 124         }
 125
 126         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 127         if (retval)
 128                 return retval;
 129
 130         while (ino) {
 131                 if ((inode.i_links_count == 0) ||
 132                     !ext2fs_inode_has_valid_blocks(&inode))
 133                         goto next;
 134
 135                 pb.ino = ino;
 136                 pb.inode = &inode;
 137
 138                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 139                               flags & EXT2_BMOVE_GET_DBLIST);
 140
 141                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 142                                               process_block, &pb);
 143                 if (retval)
 144                         return retval;
 145                 if (pb.error)
 146                         return pb.error;
 147
 148         next:
 149                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 150                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 151                         goto next;
 152         }
 153         return 0;
 154 }
 155