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 #include <unistd.h>
  12 #include <stdlib.h>
  13 #include <sys/types.h>
  14 #include <sys/time.h>
  15
  16 #include <linux/ext2_fs.h>
  17 #include "ext2fs/ext2fs.h"
  18
  19 struct process_block_struct {
  20         ino_t                   ino;
  21         struct ext2_inode *     inode;
  22         ext2fs_block_bitmap     reserve;
  23         ext2fs_block_bitmap     alloc_map;
  24         errcode_t               error;
  25         char                    *buf;
  26         int                     add_dir;
  27         int                     flags;
  28 };
  29
  30 static int process_block(ext2_filsys fs, blk_t  *block_nr,
  31                          int blockcnt, blk_t ref_block,
  32                          int ref_offset, void *private)
  33 {
  34         struct process_block_struct *pb = private;
  35         errcode_t       retval;
  36         int             ret;
  37         blk_t           block, orig;
  38
  39         block = orig = *block_nr;
  40         ret = 0;
  41
  42         /*
  43          * Let's see if this is one which we need to relocate
  44          */
  45         if (ext2fs_test_block_bitmap(pb->reserve, block)) {
  46                 do {
  47                         if (++block >= fs->super->s_blocks_count)
  48                                 block = fs->super->s_first_data_block;
  49                         if (block == orig) {
  50                                 pb->error = ENOSPC;
  51                                 return BLOCK_ABORT;
  52                         }
  53                 } while (ext2fs_test_block_bitmap(pb->reserve, block) ||
  54                          ext2fs_test_block_bitmap(pb->alloc_map, block));
  55
  56                 retval = io_channel_read_blk(fs->io, orig, 1, pb->buf);
  57                 if (retval) {
  58                         pb->error = retval;
  59                         return BLOCK_ABORT;
  60                 }
  61                 retval = io_channel_write_blk(fs->io, block, 1, pb->buf);
  62                 if (retval) {
  63                         pb->error = retval;
  64                         return BLOCK_ABORT;
  65                 }
  66                 *block_nr = block;
  67                 ext2fs_mark_block_bitmap(pb->alloc_map, block);
  68                 ret = BLOCK_CHANGED;
  69                 if (pb->flags & EXT2_BMOVE_DEBUG)
  70                         printf("ino=%ld, blockcnt=%d, %ld->%ld\n", pb->ino,
  71                                blockcnt, orig, block);
  72         }
  73         if (pb->add_dir) {
  74                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
  75                                               block, blockcnt);
  76                 if (retval) {
  77                         pb->error = retval;
  78                         ret |= BLOCK_ABORT;
  79                 }
  80         }
  81         return ret;
  82 }
  83
  84 errcode_t ext2fs_move_blocks(ext2_filsys fs,
  85                              ext2fs_block_bitmap reserve,
  86                              ext2fs_block_bitmap alloc_map,
  87                              int flags)
  88 {
  89         ino_t   ino;
  90         struct ext2_inode inode;
  91         errcode_t       retval;
  92         struct process_block_struct pb;
  93         ext2_inode_scan scan;
  94         char            *block_buf;
  95
  96         retval = ext2fs_open_inode_scan(fs, 0, &scan);
  97         if (retval)
  98                 return retval;
  99
 100         pb.reserve = reserve;
 101         pb.error = 0;
 102         pb.alloc_map = alloc_map ? alloc_map : fs->block_map;
 103         pb.flags = flags;
 104
 105         block_buf = malloc(fs->blocksize * 4);
 106         if (!block_buf)
 107                 return ENOMEM;
 108         pb.buf = block_buf + fs->blocksize * 3;
 109
 110         /*
 111          * If GET_DBLIST is set in the flags field, then we should
 112          * gather directory block information while we're doing the
 113          * block move.
 114          */
 115         if (flags & EXT2_BMOVE_GET_DBLIST) {
 116                 if (fs->dblist) {
 117                         ext2fs_free_dblist(fs->dblist);
 118                         fs->dblist = NULL;
 119                 }
 120                 retval = ext2fs_init_dblist(fs, 0);
 121                 if (retval)
 122                         return retval;
 123         }
 124
 125         retval = ext2fs_get_next_inode(scan, &ino, &inode);
 126         if (retval)
 127                 return retval;
 128
 129         while (ino) {
 130                 if ((inode.i_links_count == 0) ||
 131                     !ext2fs_inode_has_valid_blocks(&inode))
 132                         goto next;
 133
 134                 pb.ino = ino;
 135                 pb.inode = &inode;
 136
 137                 pb.add_dir = (LINUX_S_ISDIR(inode.i_mode) &&
 138                               flags & EXT2_BMOVE_GET_DBLIST);
 139
 140                 retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
 141                                               process_block, &pb);
 142                 if (retval)
 143                         return retval;
 144                 if (pb.error)
 145                         return pb.error;
 146
 147         next:
 148                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 149                 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
 150                         goto next;
 151         }
 152         return 0;
 153 }
 154