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 #if EXT2_FLAT_INCLUDES
  22 #include "ext2_fs.h"
  23 #else
  24 #include <linux/ext2_fs.h>
  25 #endif
  26
  27 #include "ext2fsP.h"
  28
  29 struct process_block_struct {
  30         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, blk_t  *block_nr,
  41                          blkcnt_t blockcnt, blk_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         blk_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_bitmap(pb->reserve, block)) {
  57                 do {
  58                         if (++block >= fs->super->s_blocks_count)
  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_bitmap(pb->reserve, block) ||
  65                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  66
  67                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  68                 if (retval) {
  69                         pb->error = retval;
  70                         return BLOCK_ABORT;
  71                 }
  72                 retval = io_channel_write_blk(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_bitmap(pb->alloc_map, block);
  79                 ret = BLOCK_CHANGED;
  80                 if (pb->flags & EXT2_BMOVE_DEBUG)
  81                         printf("ino=%ld, blockcnt=%lld, %d->%d\n", pb->ino,
  82                                blockcnt, orig, block);
  83         }
  84         if (pb->add_dir) {
  85                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  86                                               block, (int) blockcnt);
  87                 if (retval) {
  88                         pb->error = retval;
  89                         ret |= BLOCK_ABORT;
  90                 }
  91         }
  92         return ret;
  93 }
  94
  95 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  96                              ext2fs_block_bitmap reserve,
  97                              ext2fs_block_bitmap alloc_map,
  98                              int flags)
  99 {
 100         ino_t   ino;
 101         struct ext2_inode inode;
 102         errcode_t       retval;
 103         struct process_block_struct pb;
 104         ext2_inode_scan scan;
 105         char            *block_buf;
 106
 107         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 108         if (retval)
 109                 return retval;
 110
 111         pb.reserve = reserve;
 112         pb.error = 0;
 113         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 114         pb.flags = flags;
 115
 116         retval = ext2fs_get_mem(fs->blocksize * 4, (void **) &block_buf);
 117         if (retval)
 118                 return retval;
 119         pb.buf = block_buf + fs->blocksize * 3;
 120
 121         /*
 122          * If GET_DBLIST is set in the flags field, then we should
 123          * gather directory block information while we're doing the
 124          * block move.
 125          */
 126         if (flags & EXT2_BMOVE_GET_DBLIST) {
 127                 if (fs->dblist) {
 128                         ext2fs_free_dblist(fs->dblist);
 129                         fs->dblist = NULL;
 130                 }
 131                 retval = ext2fs_init_dblist(fs, 0);
 132                 if (retval)
 133                         return retval;
 134         }
 135
 136         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 137         if (retval)
 138                 return retval;
 139
 140         while (ino) {
 141                 if ((inode.i_links_count == 0) ||
 142                     !ext2fs_inode_has_valid_blocks(&inode))
 143                         goto next;
 144
 145                 pb.ino = ino;
 146                 pb.inode = &inode;
 147
 148                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 149                               flags & EXT2_BMOVE_GET_DBLIST);
 150
 151                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 152                                               process_block, &pb);
 153                 if (retval)
 154                         return retval;
 155                 if (pb.error)
 156                         return pb.error;
 157
 158         next:
 159                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 160                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 161                         goto next;
 162         }
 163         return 0;
 164 }
 165