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.
   6  *
   7  * %Begin-Header%
   8  * This file may be redistributed under the terms of the GNU Library
   9  * General Public License, version 2.
  10  * %End-Header%
  11  */
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #if HAVE_SYS_TYPES_H
  19 #include <sys/types.h>
  20 #endif
  21 #if HAVE_SYS_TIME_H
  22 #include <sys/time.h>
  23 #endif
  24
  25 #include "ext2_fs.h"
  26 #include "ext2fsP.h"
  27
  28 struct process_block_struct {
  29         ext2_ino_t              ino;
  30         struct ext2_inode *     inode;
  31         ext2fs_block_bitmap     reserve;
  32         ext2fs_block_bitmap     alloc_map;
  33         errcode_t               error;
  34         char                    *buf;
  35         int                     add_dir;
  36         int                     flags;
  37 };
  38
  39 static int process_block(ext2_filsys fs, blk64_t *block_nr,
  40                          e2_blkcnt_t blockcnt, blk64_t ref_block,
  41                          int ref_offset, void *priv_data)
  42 {
  43         struct process_block_struct *pb;
  44         errcode_t       retval;
  45         int             ret;
  46         blk64_t         block, orig;
  47
  48         pb = (struct process_block_struct *) priv_data;
  49         block = orig = *block_nr;
  50         ret = 0;
  51
  52         /*
  53          * Let's see if this is one which we need to relocate
  54          */
  55         if (ext2fs_test_block_bitmap2(pb->reserve, block)) {
  56                 do {
  57                         if (++block >= ext2fs_blocks_count(fs->super))
  58                                 block = fs->super->s_first_data_block;
  59                         if (block == orig) {
  60                                 pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  61                                 return BLOCK_ABORT;
  62                         }
  63                 } while (ext2fs_test_block_bitmap2(pb->reserve, block) ||
  64                          ext2fs_test_block_bitmap2(pb->alloc_map, block));
  65
  66                 retval = io_channel_read_blk64(fs->io, orig, 1, pb->buf);
  67                 if (retval) {
  68                         pb->error = retval;
  69                         return BLOCK_ABORT;
  70                 }
  71                 retval = io_channel_write_blk64(fs->io, block, 1, pb->buf);
  72                 if (retval) {
  73                         pb->error = retval;
  74                         return BLOCK_ABORT;
  75                 }
  76                 *block_nr = block;
  77                 ext2fs_mark_block_bitmap2(pb->alloc_map, block);
  78                 ret = BLOCK_CHANGED;
  79                 if (pb->flags & EXT2_BMOVE_DEBUG)
  80                         printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
  81                                (unsigned) pb->ino, blockcnt,
  82                                (unsigned long long) orig,
  83                                (unsigned long long) block);
  84         }
  85         if (pb->add_dir) {
  86                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
  87                                                block, blockcnt);
  88                 if (retval) {
  89                         pb->error = retval;
  90                         ret |= BLOCK_ABORT;
  91                 }
  92         }
  93         return ret;
  94 }
  95
  96 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  97                              ext2fs_block_bitmap reserve,
  98                              ext2fs_block_bitmap alloc_map,
  99                              int flags)
 100 {
 101         ext2_ino_t      ino;
 102         struct ext2_inode inode;
 103         errcode_t       retval;
 104         struct process_block_struct pb;
 105         ext2_inode_scan scan;
 106         char            *block_buf;
 107
 108         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 109         if (retval)
 110                 return retval;
 111
 112         pb.reserve = reserve;
 113         pb.error = 0;
 114         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 115         pb.flags = flags;
 116
 117         retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
 118         if (retval)
 119                 return retval;
 120         pb.buf = block_buf + fs->blocksize * 3;
 121
 122         /*
 123          * If GET_DBLIST is set in the flags field, then we should
 124          * gather directory block information while we're doing the
 125          * block move.
 126          */
 127         if (flags & EXT2_BMOVE_GET_DBLIST) {
 128                 if (fs->dblist) {
 129                         ext2fs_free_dblist(fs->dblist);
 130                         fs->dblist = NULL;
 131                 }
 132                 retval = ext2fs_init_dblist(fs, 0);
 133                 if (retval)
 134                         return retval;
 135         }
 136
 137         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 138         if (retval)
 139                 return retval;
 140
 141         while (ino) {
 142                 if ((inode.i_links_count == 0) ||
 143                     !ext2fs_inode_has_valid_blocks(&inode))
 144                         goto next;
 145
 146                 pb.ino = ino;
 147                 pb.inode = &inode;
 148
 149                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 150                               flags & EXT2_BMOVE_GET_DBLIST);
 151
 152                 retval = ext2fs_block_iterate3(fs, ino, 0, block_buf,
 153                                                process_block, &pb);
 154                 if (retval)
 155                         return retval;
 156                 if (pb.error)
 157                         return pb.error;
 158
 159         next:
 160                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 161                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 162                         goto next;
 163         }
 164         return 0;
 165 }
 166