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 #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 <linux/ext2_fs.h>
  22 #include "ext2fs/ext2fs.h"
  23
  24 struct process_block_struct {
  25         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                          int blockcnt, blk_t ref_block,
  37                          int ref_offset, void *private)
  38 {
  39         struct process_block_struct *pb = private;
  40         errcode_t       retval;
  41         int             ret;
  42         blk_t           block, orig;
  43
  44         block = orig = *block_nr;
  45         ret = 0;
  46
  47         /*
  48          * Let's see if this is one which we need to relocate
  49          */
  50         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  51                 do {
  52                         if (++block >= fs->super->s_blocks_count)
  53                                 block = fs->super->s_first_data_block;
  54                         if (block == orig) {
  55                                 pb->error = EXT2_ET_BLOCK_ALLOC_FAIL;
  56                                 return BLOCK_ABORT;
  57                         }
  58                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  59                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  60
  61                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  62                 if (retval) {
  63                         pb->error = retval;
  64                         return BLOCK_ABORT;
  65                 }
  66                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  67                 if (retval) {
  68                         pb->error = retval;
  69                         return BLOCK_ABORT;
  70                 }
  71                 *block_nr = block;
  72                 ext2fs_mark_block_bitmap(pb->alloc_map, block);
  73                 ret = BLOCK_CHANGED;
  74                 if (pb->flags & EXT2_BMOVE_DEBUG)
  75                         printf("ino=%ld, blockcnt=%d, %d->%d\n", pb->ino,
  76                                blockcnt, orig, block);
  77         }
  78         if (pb->add_dir) {
  79                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  80                                               block, blockcnt);
  81                 if (retval) {
  82                         pb->error = retval;
  83                         ret |= BLOCK_ABORT;
  84                 }
  85         }
  86         return ret;
  87 }
  88
  89 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  90                              ext2fs_block_bitmap reserve,
  91                              ext2fs_block_bitmap alloc_map,
  92                              int flags)
  93 {
  94         ino_t   ino;
  95         struct ext2_inode inode;
  96         errcode_t       retval;
  97         struct process_block_struct pb;
  98         ext2_inode_scan scan;
  99         char            *block_buf;
 100
 101         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 102         if (retval)
 103                 return retval;
 104
 105         pb.reserve = reserve;
 106         pb.error = 0;
 107         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 108         pb.flags = flags;
 109
 110         retval = ext2fs_get_mem(fs->blocksize * 4, (void **) &block_buf);
 111         if (retval)
 112                 return retval;
 113         pb.buf = block_buf + fs->blocksize * 3;
 114
 115         /*
 116          * If GET_DBLIST is set in the flags field, then we should
 117          * gather directory block information while we're doing the
 118          * block move.
 119          */
 120         if (flags & EXT2_BMOVE_GET_DBLIST) {
 121                 if (fs->dblist) {
 122                         ext2fs_free_dblist(fs->dblist);
 123                         fs->dblist = NULL;
 124                 }
 125                 retval = ext2fs_init_dblist(fs, 0);
 126                 if (retval)
 127                         return retval;
 128         }
 129
 130         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 131         if (retval)
 132                 return retval;
 133
 134         while (ino) {
 135                 if ((inode.i_links_count == 0) ||
 136                     !ext2fs_inode_has_valid_blocks(&inode))
 137                         goto next;
 138
 139                 pb.ino = ino;
 140                 pb.inode = &inode;
 141
 142                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 143                               flags & EXT2_BMOVE_GET_DBLIST);
 144
 145                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 146                                               process_block, &pb);
 147                 if (retval)
 148                         return retval;
 149                 if (pb.error)
 150                         return pb.error;
 151
 152         next:
 153                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 154                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 155                         goto next;
 156         }
 157         return 0;
 158 }
 159