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 #if HAVE_SYS_TIME_H
  18 #include <sys/time.h>
  19 #endif
  20
  21 #include "ext2_fs.h"
  22 #include "ext2fsP.h"
  23
  24 struct process_block_struct {
  25         ext2_ino_t              ino;
  26         struct ext2_inode *     inode;
  27         ext2fs_block_bitmap     reserve;
  28         ext2fs_block_bitmap     alloc_map;
  29         errcode_t               error;
  30         char                    *buf;
  31         int                     add_dir;
  32         int                     flags;
  33 };
  34
  35 static int process_block(ext2_filsys fs, blk_t  *block_nr,
  36                          e2_blkcnt_t blockcnt, blk_t ref_block,
  37                          int ref_offset, void *priv_data)
  38 {
  39         struct process_block_struct *pb;
  40         errcode_t       retval;
  41         int             ret;
  42         blk_t           block, orig;
  43
  44         pb = (struct process_block_struct *) priv_data;
  45         block = orig = *block_nr;
  46         ret = 0;
  47
  48         /*
  49          * Let's see if this is one which we need to relocate
  50          */
  51         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  52                 do {
  53                         if (++block >= fs->super->s_blocks_count)
  54                                 block = fs->super->s_first_data_block;
  55                         if (block == orig) {
  56                                 pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  57                                 return BLOCK_ABORT;
  58                         }
  59                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  60                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  61
  62                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  63                 if (retval) {
  64                         pb->error = retval;
  65                         return BLOCK_ABORT;
  66                 }
  67                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  68                 if (retval) {
  69                         pb->error = retval;
  70                         return BLOCK_ABORT;
  71                 }
  72                 *block_nr = block;
  73                 ext2fs_mark_block_bitmap(pb->alloc_map, block);
  74                 ret = BLOCK_CHANGED;
  75                 if (pb->flags & EXT2_BMOVE_DEBUG)
  76                         printf("ino=%ld, blockcnt=%lld, %d->%d\n", pb->ino,
  77                                blockcnt, orig, block);
  78         }
  79         if (pb->add_dir) {
  80                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  81                                               block, (int) blockcnt);
  82                 if (retval) {
  83                         pb->error = retval;
  84                         ret |= BLOCK_ABORT;
  85                 }
  86         }
  87         return ret;
  88 }
  89
  90 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  91                              ext2fs_block_bitmap reserve,
  92                              ext2fs_block_bitmap alloc_map,
  93                              int flags)
  94 {
  95         ext2_ino_t      ino;
  96         struct ext2_inode inode;
  97         errcode_t       retval;
  98         struct process_block_struct pb;
  99         ext2_inode_scan scan;
 100         char            *block_buf;
 101
 102         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 103         if (retval)
 104                 return retval;
 105
 106         pb.reserve = reserve;
 107         pb.error = 0;
 108         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 109         pb.flags = flags;
 110
 111         retval = ext2fs_get_mem(fs->blocksize * 4, &block_buf);
 112         if (retval)
 113                 return retval;
 114         pb.buf = block_buf + fs->blocksize * 3;
 115
 116         /*
 117          * If GET_DBLIST is set in the flags field, then we should
 118          * gather directory block information while we're doing the
 119          * block move.
 120          */
 121         if (flags & EXT2_BMOVE_GET_DBLIST) {
 122                 if (fs->dblist) {
 123                         ext2fs_free_dblist(fs->dblist);
 124                         fs->dblist = NULL;
 125                 }
 126                 retval = ext2fs_init_dblist(fs, 0);
 127                 if (retval)
 128                         return retval;
 129         }
 130
 131         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 132         if (retval)
 133                 return retval;
 134
 135         while (ino) {
 136                 if ((inode.i_links_count == 0) ||
 137                     !ext2fs_inode_has_valid_blocks(&inode))
 138                         goto next;
 139
 140                 pb.ino = ino;
 141                 pb.inode = &inode;
 142
 143                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 144                               flags & EXT2_BMOVE_GET_DBLIST);
 145
 146                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 147                                               process_block, &pb);
 148                 if (retval)
 149                         return retval;
 150                 if (pb.error)
 151                         return pb.error;
 152
 153         next:
 154                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 155                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 156                         goto next;
 157         }
 158         return 0;
 159 }
 160