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 "config.h"
  14 #include <stdio.h>
  15 #include <string.h>
  16 #if HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19 #if HAVE_SYS_TYPES_H
  20 #include <sys/types.h>
  21 #endif
  22 #if HAVE_SYS_TIME_H
  23 #include <sys/time.h>
  24 #endif
  25
  26 #include "ext2_fs.h"
  27 #include "ext2fsP.h"
  28
  29 struct process_block_struct {
  30         ext2_ino_t              ino;
  31         struct ext2_inode *     inode;
  32         ext2fs_block_bitmap     reserve;
  33         ext2fs_block_bitmap     alloc_map;
  34         errcode_t               error;
  35         char                    *buf;
  36         int                     add_dir;
  37         int                     flags;
  38 };
  39
  40 static int process_block(ext2_filsys fs, blk64_t *block_nr,
  41                          e2_blkcnt_t blockcnt, blk64_t ref_block,
  42                          int ref_offset, void *priv_data)
  43 {
  44         struct process_block_struct *pb;
  45         errcode_t       retval;
  46         int             ret;
  47         blk64_t         block, orig;
  48
  49         pb = (struct process_block_struct *) priv_data;
  50         block = orig = *block_nr;
  51         ret = 0;
  52
  53         /*
  54          * Let's see if this is one which we need to relocate
  55          */
  56         if (ext2fs_test_block_bitmap2(pb->reserve, block)) {
  57                 do {
  58                         if (++block >= ext2fs_blocks_count(fs->super))
  59                                 block = fs->super->s_first_data_block;
  60                         if (block == orig) {
  61                                 pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  62                                 return BLOCK_ABORT;
  63                         }
  64                 } while (ext2fs_test_block_bitmap2(pb->reserve, block) ||
  65                          ext2fs_test_block_bitmap2(pb->alloc_map, block));
  66
  67                 retval = io_channel_read_blk64(fs->io, orig, 1, pb->buf);
  68                 if (retval) {
  69                         pb->error = retval;
  70                         return BLOCK_ABORT;
  71                 }
  72                 retval = io_channel_write_blk64(fs->io, block, 1, pb->buf);
  73                 if (retval) {
  74                         pb->error = retval;
  75                         return BLOCK_ABORT;
  76                 }
  77                 *block_nr = block;
  78                 ext2fs_mark_block_bitmap2(pb->alloc_map, block);
  79                 ret = BLOCK_CHANGED;
  80                 if (pb->flags & EXT2_BMOVE_DEBUG)
  81                         printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
  82                                (unsigned) pb->ino, blockcnt,
  83                                (unsigned long long) orig,
  84                                (unsigned long long) block);
  85         }
  86         if (pb->add_dir) {
  87                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
  88                                                block, blockcnt);
  89                 if (retval) {
  90                         pb->error = retval;
  91                         ret |= BLOCK_ABORT;
  92                 }
  93         }
  94         return ret;
  95 }
  96
  97 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  98                              ext2fs_block_bitmap reserve,
  99                              ext2fs_block_bitmap alloc_map,
 100                              int flags)
 101 {
 102         ext2_ino_t      ino;
 103         struct ext2_inode inode;
 104         errcode_t       retval;
 105         struct process_block_struct pb;
 106         ext2_inode_scan scan;
 107         char            *block_buf;
 108
 109         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 110         if (retval)
 111                 return retval;
 112
 113         pb.reserve = reserve;
 114         pb.error = 0;
 115         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 116         pb.flags = flags;
 117
 118         retval = ext2fs_get_array(4, fs->blocksize, &block_buf);
 119         if (retval)
 120                 return retval;
 121         pb.buf = block_buf + fs->blocksize * 3;
 122
 123         /*
 124          * If GET_DBLIST is set in the flags field, then we should
 125          * gather directory block information while we're doing the
 126          * block move.
 127          */
 128         if (flags & EXT2_BMOVE_GET_DBLIST) {
 129                 if (fs->dblist) {
 130                         ext2fs_free_dblist(fs->dblist);
 131                         fs->dblist = NULL;
 132                 }
 133                 retval = ext2fs_init_dblist(fs, 0);
 134                 if (retval)
 135                         return retval;
 136         }
 137
 138         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 139         if (retval)
 140                 return retval;
 141
 142         while (ino) {
 143                 if ((inode.i_links_count == 0) ||
 144                     !ext2fs_inode_has_valid_blocks2(fs, &inode))
 145                         goto next;
 146
 147                 pb.ino = ino;
 148                 pb.inode = &inode;
 149
 150                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 151                               flags & EXT2_BMOVE_GET_DBLIST);
 152
 153                 retval = ext2fs_block_iterate3(fs, ino, 0, block_buf,
 154                                                process_block, &pb);
 155                 if (retval)
 156                         return retval;
 157                 if (pb.error)
 158                         return pb.error;
 159
 160         next:
 161                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 162                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 163                         goto next;
 164         }
 165         return 0;
 166 }
 167