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 #if HAVE_UNISTD_H
  12 #include <unistd.h>
  13 #endif
  14 #include <stdlib.h>
  15 #include <sys/types.h>
  16 #include <sys/time.h>
  17
  18 #include <linux/ext2_fs.h>
  19 #include "ext2fs/ext2fs.h"
  20
  21 struct process_block_struct {
  22         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                          int blockcnt, blk_t ref_block,
  34                          int ref_offset, void *private)
  35 {
  36         struct process_block_struct *pb = private;
  37         errcode_t       retval;
  38         int             ret;
  39         blk_t           block, orig;
  40
  41         block = orig = *block_nr;
  42         ret = 0;
  43
  44         /*
  45          * Let's see if this is one which we need to relocate
  46          */
  47         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  48                 do {
  49                         if (++block >= fs->super->s_blocks_count)
  50                                 block = fs->super->s_first_data_block;
  51                         if (block == orig) {
  52                                 pb->error = ENOSPC;
  53                                 return BLOCK_ABORT;
  54                         }
  55                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  56                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  57
  58                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  59                 if (retval) {
  60                         pb->error = retval;
  61                         return BLOCK_ABORT;
  62                 }
  63                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  64                 if (retval) {
  65                         pb->error = retval;
  66                         return BLOCK_ABORT;
  67                 }
  68                 *block_nr = block;
  69                 ext2fs_mark_block_bitmap(pb->alloc_map, block);
  70                 ret = BLOCK_CHANGED;
  71                 if (pb->flags & EXT2_BMOVE_DEBUG)
  72                         printf("ino=%ld, blockcnt=%d, %ld->%ld\n", pb->ino,
  73                                blockcnt, orig, block);
  74         }
  75         if (pb->add_dir) {
  76                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  77                                               block, blockcnt);
  78                 if (retval) {
  79                         pb->error = retval;
  80                         ret |= BLOCK_ABORT;
  81                 }
  82         }
  83         return ret;
  84 }
  85
  86 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  87                              ext2fs_block_bitmap reserve,
  88                              ext2fs_block_bitmap alloc_map,
  89                              int flags)
  90 {
  91         ino_t   ino;
  92         struct ext2_inode inode;
  93         errcode_t       retval;
  94         struct process_block_struct pb;
  95         ext2_inode_scan scan;
  96         char            *block_buf;
  97
  98         retval = ext2fs_open_inode_scan(fs, 0, &scan);
  99         if (retval)
 100                 return retval;
 101
 102         pb.reserve = reserve;
 103         pb.error = 0;
 104         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 105         pb.flags = flags;
 106
 107         block_buf = malloc(fs->blocksize * 4);
 108         if (!block_buf)
 109                 return ENOMEM;
 110         pb.buf = block_buf + fs->blocksize * 3;
 111
 112         /*
 113          * If GET_DBLIST is set in the flags field, then we should
 114          * gather directory block information while we're doing the
 115          * block move.
 116          */
 117         if (flags & EXT2_BMOVE_GET_DBLIST) {
 118                 if (fs->dblist) {
 119                         ext2fs_free_dblist(fs->dblist);
 120                         fs->dblist = NULL;
 121                 }
 122                 retval = ext2fs_init_dblist(fs, 0);
 123                 if (retval)
 124                         return retval;
 125         }
 126
 127         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 128         if (retval)
 129                 return retval;
 130
 131         while (ino) {
 132                 if ((inode.i_links_count == 0) ||
 133                     !ext2fs_inode_has_valid_blocks(&inode))
 134                         goto next;
 135
 136                 pb.ino = ino;
 137                 pb.inode = &inode;
 138
 139                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 140                               flags & EXT2_BMOVE_GET_DBLIST);
 141
 142                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 143                                               process_block, &pb);
 144                 if (retval)
 145                         return retval;
 146                 if (pb.error)
 147                         return pb.error;
 148
 149         next:
 150                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 151                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 152                         goto next;
 153         }
 154         return 0;
 155 }
 156