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resize2fs.c

/*
 * resize2fs.c --- ext2 main routine
 *
 * Copyright (C) 1997, 1998 by Theodore Ts'o and
 *    PowerQuest, Inc.
 *
 * Copyright (C) 1999, 2000 by Theosore Ts'o
 * 
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

/*
 * Resizing a filesystem consists of the following phases:
 *
 *    1.  Adjust superblock and write out new parts of the inode
 *          table
 *    2.  Determine blocks which need to be relocated, and copy the
 *          contents of blocks from their old locations to the new ones.
 *    3.  Scan the inode table, doing the following:
 *          a.  If blocks have been moved, update the block
 *                pointers in the inodes and indirect blocks to
 *                point at the new block locations.
 *          b.  If parts of the inode table need to be evacuated,
 *                copy inodes from their old locations to their
 *                new ones.
 *          c.  If (b) needs to be done, note which blocks contain
 *                directory information, since we will need to
 *                update the directory information.
 *    4.  Update the directory blocks with the new inode locations.
 *    5.  Move the inode tables, if necessary.
 */

#include "resize2fs.h"

#ifdef __linux__              /* Kludge for debugging */
#define RESIZE2FS_DEBUG
#endif

static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size);
static errcode_t blocks_to_move(ext2_resize_t rfs);
static errcode_t block_mover(ext2_resize_t rfs);
static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
static errcode_t inode_ref_fix(ext2_resize_t rfs);
static errcode_t move_itables(ext2_resize_t rfs);
static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);

/*
 * Some helper CPP macros
 */
#define FS_BLOCK_BM(fs, i) ((fs)->group_desc[(i)].bg_block_bitmap)
#define FS_INODE_BM(fs, i) ((fs)->group_desc[(i)].bg_inode_bitmap)
#define FS_INODE_TB(fs, i) ((fs)->group_desc[(i)].bg_inode_table)

#define IS_BLOCK_BM(fs, i, blk) ((blk) == FS_BLOCK_BM((fs),(i)))
#define IS_INODE_BM(fs, i, blk) ((blk) == FS_INODE_BM((fs),(i)))

#define IS_INODE_TB(fs, i, blk) (((blk) >= FS_INODE_TB((fs), (i))) && \
                         ((blk) < (FS_INODE_TB((fs), (i)) + \
                                 (fs)->inode_blocks_per_group)))



/*
 * This is the top-level routine which does the dirty deed....
 */
errcode_t resize_fs(ext2_filsys fs, blk_t new_size, int flags,
                errcode_t (*progress)(ext2_resize_t rfs, int pass,
                             unsigned long cur,
                             unsigned long max_val))
{
      ext2_resize_t     rfs;
      errcode_t   retval;

      retval = ext2fs_read_bitmaps(fs);
      if (retval)
            return retval;
      
      /*
       * Create the data structure
       */
      retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct),
                        (void **) &rfs);
      if (retval)
            return retval;
      memset(rfs, 0, sizeof(struct ext2_resize_struct));

      rfs->old_fs = fs;
      rfs->flags = flags;
      rfs->itable_buf    = 0;
      rfs->progress = progress;
      retval = ext2fs_dup_handle(fs, &rfs->new_fs);
      if (retval)
            goto errout;

      retval = adjust_superblock(rfs, new_size);
      if (retval)
            goto errout;

      retval = blocks_to_move(rfs);
      if (retval)
            goto errout;

#ifdef RESIZE2FS_DEBUG
      if (rfs->flags & RESIZE_DEBUG_BMOVE)
            printf(_("Number of free blocks: %d/%d, Needed: %d\n"),
                   rfs->old_fs->super->s_free_blocks_count,
                   rfs->new_fs->super->s_free_blocks_count,
                   rfs->needed_blocks);
#endif
      
      retval = block_mover(rfs);
      if (retval)
            goto errout;

      retval = inode_scan_and_fix(rfs);
      if (retval)
            goto errout;

      retval = inode_ref_fix(rfs);
      if (retval)
            goto errout;

      retval = ext2fs_calculate_summary_stats(rfs->new_fs);
      if (retval)
            goto errout;
      
      retval = move_itables(rfs);
      if (retval)
            goto errout;

      retval = ext2fs_close(rfs->new_fs);
      if (retval)
            goto errout;

      rfs->flags = flags;
      
      ext2fs_free(rfs->old_fs);
      if (rfs->itable_buf)
            ext2fs_free_mem((void **) &rfs->itable_buf);
      ext2fs_free_mem((void **) &rfs);
      
      return 0;

errout:
      if (rfs->new_fs)
            ext2fs_free(rfs->new_fs);
      if (rfs->itable_buf)
            ext2fs_free_mem((void **) &rfs->itable_buf);
      ext2fs_free_mem((void **) &rfs);
      return retval;
}

/* --------------------------------------------------------------------
 *
 * Resize processing, phase 1.
 *
 * In this phase we adjust the in-memory superblock information, and
 * initialize any new parts of the inode table.  The new parts of the
 * inode table are created in virgin disk space, so we can abort here
 * without any side effects.
 * --------------------------------------------------------------------
 */

/*
 * This routine adjusts the superblock and other data structures...
 */
static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size)
{
      ext2_filsys fs;
      int         overhead = 0;
      int         rem, adj = 0;
      errcode_t   retval;
      ext2_ino_t  real_end;
      blk_t       blk, group_block;
      unsigned long     i, j;
      int         old_numblocks, numblocks, adjblocks;
      unsigned long     max_group;
      
      fs = rfs->new_fs;
      fs->super->s_blocks_count = new_size;
      ext2fs_mark_super_dirty(fs);
      ext2fs_mark_bb_dirty(fs);
      ext2fs_mark_ib_dirty(fs);

retry:
      fs->group_desc_count = (fs->super->s_blocks_count -
                        fs->super->s_first_data_block +
                        EXT2_BLOCKS_PER_GROUP(fs->super) - 1)
            / EXT2_BLOCKS_PER_GROUP(fs->super);
      if (fs->group_desc_count == 0)
            return EXT2_ET_TOOSMALL;
      fs->desc_blocks = (fs->group_desc_count +
                     EXT2_DESC_PER_BLOCK(fs->super) - 1)
            / EXT2_DESC_PER_BLOCK(fs->super);

      /*
       * Overhead is the number of bookkeeping blocks per group.  It
       * includes the superblock backup, the group descriptor
       * backups, the inode bitmap, the block bitmap, and the inode
       * table.
       *
       * XXX Not all block groups need the descriptor blocks, but
       * being clever is tricky...
       */
      overhead = 3 + fs->desc_blocks + fs->inode_blocks_per_group;
      
      /*
       * See if the last group is big enough to support the
       * necessary data structures.  If not, we need to get rid of
       * it.
       */
      rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) %
            fs->super->s_blocks_per_group;
      if ((fs->group_desc_count == 1) && rem && (rem < overhead))
            return EXT2_ET_TOOSMALL;
      if (rem && (rem < overhead+50)) {
            fs->super->s_blocks_count -= rem;
            goto retry;
      }
      /*
       * Adjust the number of inodes
       */
      fs->super->s_inodes_count = fs->super->s_inodes_per_group *
            fs->group_desc_count;

      /*
       * Adjust the number of free blocks
       */
      blk = rfs->old_fs->super->s_blocks_count;
      if (blk > fs->super->s_blocks_count)
            fs->super->s_free_blocks_count -=
                  (blk - fs->super->s_blocks_count);
      else
            fs->super->s_free_blocks_count +=
                  (fs->super->s_blocks_count - blk);

      /*
       * Adjust the number of reserved blocks
       */
      blk = rfs->old_fs->super->s_r_blocks_count * 100 /
            rfs->old_fs->super->s_blocks_count;
      fs->super->s_r_blocks_count = ((fs->super->s_blocks_count * blk)
                               / 100);

      /*
       * Adjust the bitmaps for size
       */
      retval = ext2fs_resize_inode_bitmap(fs->super->s_inodes_count,
                                  fs->super->s_inodes_count,
                                  fs->inode_map);
      if (retval) goto errout;
      
      real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super)
                 * fs->group_desc_count)) - 1 +
                       fs->super->s_first_data_block;
      retval = ext2fs_resize_block_bitmap(fs->super->s_blocks_count-1,
                                  real_end, fs->block_map);

      if (retval) goto errout;

      /*
       * Reallocate the group descriptors as necessary.
       */
      if (rfs->old_fs->desc_blocks != fs->desc_blocks) {
            retval = ext2fs_resize_mem(rfs->old_fs->desc_blocks *
                                 fs->blocksize,
                                 fs->desc_blocks * fs->blocksize,
                                 (void **) &fs->group_desc);
            if (retval)
                  goto errout;
      }

      /*
       * Check to make sure there are enough inodes
       */
      if ((rfs->old_fs->super->s_inodes_count -
           rfs->old_fs->super->s_free_inodes_count) >
          rfs->new_fs->super->s_inodes_count) {
            retval = ENOSPC;
            goto errout;
      }

      /*
       * If we are shrinking the number block groups, we're done and
       * can exit now.
       */
      if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
            retval = 0;
            goto errout;
      }
      /*
       * Fix the count of the last (old) block group
       */
      old_numblocks = (rfs->old_fs->super->s_blocks_count -
                   rfs->old_fs->super->s_first_data_block) %
                         rfs->old_fs->super->s_blocks_per_group;
      if (!old_numblocks)
            old_numblocks = rfs->old_fs->super->s_blocks_per_group;
      if (rfs->old_fs->group_desc_count == fs->group_desc_count) {
            numblocks = (rfs->new_fs->super->s_blocks_count -
                       rfs->new_fs->super->s_first_data_block) %
                             rfs->new_fs->super->s_blocks_per_group;
            if (!numblocks)
                  numblocks = rfs->new_fs->super->s_blocks_per_group;
      } else
            numblocks = rfs->new_fs->super->s_blocks_per_group;
      i = rfs->old_fs->group_desc_count - 1;
      fs->group_desc[i].bg_free_blocks_count += (numblocks-old_numblocks);
            
      /*
       * If the number of block groups is staying the same, we're
       * done and can exit now.  (If the number block groups is
       * shrinking, we had exited earlier.)
       */
      if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
            retval = 0;
            goto errout;
      }
      /*
       * Initialize the new block group descriptors
       */
      retval = ext2fs_get_mem(fs->blocksize * fs->inode_blocks_per_group,
                        (void **) &rfs->itable_buf);
      if (retval)
            goto errout;

      memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
      group_block = fs->super->s_first_data_block +
            rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;

      adj = rfs->old_fs->group_desc_count;
      max_group = fs->group_desc_count - adj;
      if (rfs->progress) {
            retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
                               0, max_group);
            if (retval)
                  goto errout;
      }
      for (i = rfs->old_fs->group_desc_count;
           i < fs->group_desc_count; i++) {
            memset(&fs->group_desc[i], 0,
                   sizeof(struct ext2_group_desc));
            adjblocks = 0;

            if (i == fs->group_desc_count-1) {
                  numblocks = (fs->super->s_blocks_count -
                             fs->super->s_first_data_block) %
                                   fs->super->s_blocks_per_group;
                  if (!numblocks)
                        numblocks = fs->super->s_blocks_per_group;
            } else
                  numblocks = fs->super->s_blocks_per_group;

            if (ext2fs_bg_has_super(fs, i)) {
                  for (j=0; j < fs->desc_blocks+1; j++)
                        ext2fs_mark_block_bitmap(fs->block_map,
                                           group_block + j);
                  adjblocks = 1 + fs->desc_blocks;
            }
            adjblocks += 2 + fs->inode_blocks_per_group;
            
            numblocks -= adjblocks;
            fs->super->s_free_blocks_count -= adjblocks;
            fs->super->s_free_inodes_count +=
                  fs->super->s_inodes_per_group;
            fs->group_desc[i].bg_free_blocks_count = numblocks;
            fs->group_desc[i].bg_free_inodes_count =
                  fs->super->s_inodes_per_group;
            fs->group_desc[i].bg_used_dirs_count = 0;

            retval = ext2fs_allocate_group_table(fs, i, 0);
            if (retval) goto errout;

            /*
             * Write out the new inode table
             */
            retval = io_channel_write_blk(fs->io,
                                    fs->group_desc[i].bg_inode_table,
                                    fs->inode_blocks_per_group,
                                    rfs->itable_buf);
            if (retval) goto errout;

            io_channel_flush(fs->io);
            if (rfs->progress) {
                  retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
                                     i - adj + 1, max_group);
                  if (retval)
                        goto errout;
            }
            group_block += fs->super->s_blocks_per_group;
      }
      io_channel_flush(fs->io);
      retval = 0;

errout:
      return retval;
}

/* --------------------------------------------------------------------
 *
 * Resize processing, phase 2.
 *
 * In this phase we adjust determine which blocks need to be moved, in
 * blocks_to_move().  We then copy the blocks to their ultimate new
 * destinations using block_mover().  Since we are copying blocks to
 * their new locations, again during this pass we can abort without
 * any problems.
 * --------------------------------------------------------------------
 */

/*
 * This helper function creates a block bitmap with all of the
 * filesystem meta-data blocks.
 */
static errcode_t mark_table_blocks(ext2_filsys fs,
                           ext2fs_block_bitmap *ret_bmap)
{
      blk_t             block, b;
      int               i,j;
      ext2fs_block_bitmap     bmap;
      errcode_t         retval;

      retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"), 
                                    &bmap);
      if (retval)
            return retval;
      
      block = fs->super->s_first_data_block;
      for (i = 0; i < fs->group_desc_count; i++) {
            if (ext2fs_bg_has_super(fs, i)) {
                  /*
                   * Mark this group's copy of the superblock
                   */
                  ext2fs_mark_block_bitmap(bmap, block);
            
                  /*
                   * Mark this group's copy of the descriptors
                   */
                  for (j = 0; j < fs->desc_blocks; j++)
                        ext2fs_mark_block_bitmap(bmap, block + j + 1);
            }
            
            /*
             * Mark the blocks used for the inode table
             */
            for (j = 0, b = fs->group_desc[i].bg_inode_table;
                 j < fs->inode_blocks_per_group;
                 j++, b++)
                  ext2fs_mark_block_bitmap(bmap, b);
                      
            /*
             * Mark block used for the block bitmap 
             */
            ext2fs_mark_block_bitmap(bmap,
                               fs->group_desc[i].bg_block_bitmap);
            /*
             * Mark block used for the inode bitmap 
             */
            ext2fs_mark_block_bitmap(bmap,
                               fs->group_desc[i].bg_inode_bitmap);
            block += fs->super->s_blocks_per_group;
      }
      *ret_bmap = bmap;
      return 0;
}

/*
 * This routine marks and unmarks reserved blocks in the new block
 * bitmap.  It also determines which blocks need to be moved and
 * places this information into the move_blocks bitmap.
 */
static errcode_t blocks_to_move(ext2_resize_t rfs)
{
      int   i, j, max_groups;
      blk_t blk, group_blk;
      unsigned long old_blocks, new_blocks;
      errcode_t   retval;
      ext2_filsys       fs, old_fs;
      ext2fs_block_bitmap     meta_bmap;

      fs = rfs->new_fs;
      old_fs = rfs->old_fs;
      if (old_fs->super->s_blocks_count > fs->super->s_blocks_count)
            fs = rfs->old_fs;
      
      retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
                                    &rfs->reserve_blocks);
      if (retval)
            return retval;

      retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
                                    &rfs->move_blocks);
      if (retval)
            return retval;

      retval = mark_table_blocks(old_fs, &meta_bmap);
      if (retval)
            return retval;

      fs = rfs->new_fs;
      
      /*
       * If we're shrinking the filesystem, we need to move all of
       * the blocks that don't fit any more
       */
      for (blk = fs->super->s_blocks_count;
           blk < old_fs->super->s_blocks_count; blk++) {
            if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
                !ext2fs_test_block_bitmap(meta_bmap, blk)) {
                  ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
                  rfs->needed_blocks++;
            }
            ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
      }
      
      old_blocks = old_fs->desc_blocks;
      new_blocks = fs->desc_blocks;

      if (old_blocks == new_blocks) {
            retval = 0;
            goto errout;
      }

      max_groups = fs->group_desc_count;
      if (max_groups > old_fs->group_desc_count)
            max_groups = old_fs->group_desc_count;
      group_blk = old_fs->super->s_first_data_block;
      /*
       * If we're reducing the number of descriptor blocks, this
       * makes life easy.  :-)   We just have to mark some extra
       * blocks as free.
       */
      if (old_blocks > new_blocks) {
            for (i = 0; i < max_groups; i++) {
                  if (!ext2fs_bg_has_super(fs, i)) {
                        group_blk += fs->super->s_blocks_per_group;
                        continue;
                  }
                  for (blk = group_blk+1+new_blocks;
                       blk < group_blk+1+old_blocks; blk++) {
                        ext2fs_unmark_block_bitmap(fs->block_map,
                                             blk);
                        rfs->needed_blocks--;
                  }
                  group_blk += fs->super->s_blocks_per_group;
            }
            retval = 0;
            goto errout;
      }
      /*
       * If we're increasing the number of descriptor blocks, life
       * gets interesting....  
       */
      for (i = 0; i < max_groups; i++) {
            if (!ext2fs_bg_has_super(fs, i))
                  goto next_group;

            for (blk = group_blk;
                 blk < group_blk + 1 + new_blocks; blk++) {
                  ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
                  ext2fs_mark_block_bitmap(fs->block_map, blk);

                  /*
                   * Check to see if we overlap with the inode
                   * or block bitmap, or the inode tables.  If
                   * not, and the block is in use, then mark it
                   * as a block to be moved.
                   */
                  if (IS_BLOCK_BM(fs, i, blk)) {
                        FS_BLOCK_BM(fs, i) = 0;
                        rfs->needed_blocks++;
                  } else if (IS_INODE_BM(fs, i, blk)) {
                        FS_INODE_BM(fs, i) = 0;
                        rfs->needed_blocks++;
                  } else if (IS_INODE_TB(fs, i, blk)) {
                        FS_INODE_TB(fs, i) = 0;
                        rfs->needed_blocks++;
                  } else if (ext2fs_test_block_bitmap(old_fs->block_map,
                                              blk) &&
                           !ext2fs_test_block_bitmap(meta_bmap, blk)) {
                        ext2fs_mark_block_bitmap(rfs->move_blocks,
                                           blk);
                        rfs->needed_blocks++;
                  }
            }
            if (fs->group_desc[i].bg_inode_table &&
                fs->group_desc[i].bg_inode_bitmap &&
                fs->group_desc[i].bg_block_bitmap)
                  goto next_group;

            /*
             * Reserve the existing meta blocks that we know
             * aren't to be moved.
             */
            if (fs->group_desc[i].bg_block_bitmap)
                  ext2fs_mark_block_bitmap(rfs->reserve_blocks,
                         fs->group_desc[i].bg_block_bitmap);
            if (fs->group_desc[i].bg_inode_bitmap)
                  ext2fs_mark_block_bitmap(rfs->reserve_blocks,
                         fs->group_desc[i].bg_inode_bitmap);
            if (fs->group_desc[i].bg_inode_table)
                  for (blk = fs->group_desc[i].bg_inode_table, j=0;
                       j < fs->inode_blocks_per_group ; j++, blk++)
                        ext2fs_mark_block_bitmap(rfs->reserve_blocks,
                                           blk);

            /*
             * Allocate the missing data structures
             */
            retval = ext2fs_allocate_group_table(fs, i,
                                         rfs->reserve_blocks);
            if (retval)
                  goto errout;

            /*
             * For those structures that have changed, we need to
             * do bookkeepping.
             */
            if (FS_BLOCK_BM(old_fs, i) !=
                (blk = FS_BLOCK_BM(fs, i))) {
                  ext2fs_mark_block_bitmap(fs->block_map, blk);
                  if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
                      !ext2fs_test_block_bitmap(meta_bmap, blk))
                        ext2fs_mark_block_bitmap(rfs->move_blocks,
                                           blk);
            }
            if (FS_INODE_BM(old_fs, i) !=
                (blk = FS_INODE_BM(fs, i))) {
                  ext2fs_mark_block_bitmap(fs->block_map, blk);
                  if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
                      !ext2fs_test_block_bitmap(meta_bmap, blk))
                        ext2fs_mark_block_bitmap(rfs->move_blocks,
                                           blk);
            }

            /*
             * The inode table, if we need to relocate it, is
             * handled specially.  We have to reserve the blocks
             * for both the old and the new inode table, since we
             * can't have the inode table be destroyed during the
             * block relocation phase.
             */
            if (FS_INODE_TB(fs, i) == FS_INODE_TB(old_fs, i))
                  goto next_group; /* inode table not moved */

            rfs->needed_blocks += fs->inode_blocks_per_group;

            /*
             * Mark the new inode table as in use in the new block
             * allocation bitmap, and move any blocks that might 
             * be necessary.
             */
            for (blk = fs->group_desc[i].bg_inode_table, j=0;
                 j < fs->inode_blocks_per_group ; j++, blk++) {
                  ext2fs_mark_block_bitmap(fs->block_map, blk);
                  if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
                      !ext2fs_test_block_bitmap(meta_bmap, blk))
                        ext2fs_mark_block_bitmap(rfs->move_blocks,
                                           blk);
            }
            
            /*
             * Make sure the old inode table is reserved in the
             * block reservation bitmap.
             */
            for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
                 j < fs->inode_blocks_per_group ; j++, blk++)
                  ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
            
      next_group:
            group_blk += rfs->new_fs->super->s_blocks_per_group;
      }
      retval = 0;

errout:
      if (meta_bmap)
            ext2fs_free_block_bitmap(meta_bmap);
      
      return retval;
}

/*
 * This helper function tries to allocate a new block.  We try to
 * avoid hitting the original group descriptor blocks at least at
 * first, since we want to make it possible to recover from a badly
 * aborted resize operation as much as possible.
 *
 * In the future, I may further modify this routine to balance out
 * where we get the new blocks across the various block groups.
 * Ideally we would allocate blocks that corresponded with the block
 * group of the containing inode, and keep contiguous blocks
 * together.  However, this very difficult to do efficiently, since we
 * don't have the necessary information up front.
 */

#define AVOID_OLD 1
#define DESPERATION     2

static void init_block_alloc(ext2_resize_t rfs)
{
      rfs->alloc_state = AVOID_OLD;
      rfs->new_blk = rfs->new_fs->super->s_first_data_block;
#if 0
      /* HACK for testing */
      if (rfs->new_fs->super->s_blocks_count >
          rfs->old_fs->super->s_blocks_count)
            rfs->new_blk = rfs->old_fs->super->s_blocks_count;
#endif
}

static blk_t get_new_block(ext2_resize_t rfs)
{
      ext2_filsys fs = rfs->new_fs;
      
      while (1) {
            if (rfs->new_blk >= fs->super->s_blocks_count) {
                  if (rfs->alloc_state == DESPERATION)
                        return 0;

#ifdef RESIZE2FS_DEBUG
                  if (rfs->flags & RESIZE_DEBUG_BMOVE)
                        printf(_("Going into desperation "
                               "mode for block allocations\n"));
#endif                  
                  rfs->alloc_state = DESPERATION;
                  rfs->new_blk = fs->super->s_first_data_block;
                  continue;
            }
            if (ext2fs_test_block_bitmap(fs->block_map, rfs->new_blk) ||
                ext2fs_test_block_bitmap(rfs->reserve_blocks,
                                   rfs->new_blk) ||
                ((rfs->alloc_state == AVOID_OLD) &&
                 (rfs->new_blk < rfs->old_fs->super->s_blocks_count) &&
                 ext2fs_test_block_bitmap(rfs->old_fs->block_map,
                                    rfs->new_blk))) {
                  rfs->new_blk++;
                  continue;
            }
            return rfs->new_blk;
      }
}

static errcode_t block_mover(ext2_resize_t rfs)
{
      blk_t             blk, old_blk, new_blk;
      ext2_filsys       fs = rfs->new_fs;
      ext2_filsys       old_fs = rfs->old_fs;
      errcode_t         retval;
      int               size, c;
      int               to_move, moved;

      new_blk = fs->super->s_first_data_block;
      if (!rfs->itable_buf) {
            retval = ext2fs_get_mem(fs->blocksize *
                              fs->inode_blocks_per_group,
                              (void **) &rfs->itable_buf);
            if (retval)
                  return retval;
      }
      retval = ext2fs_create_extent_table(&rfs->bmap, 0);
      if (retval)
            return retval;

      /*
       * The first step is to figure out where all of the blocks
       * will go.
       */
      to_move = moved = 0;
      init_block_alloc(rfs);
      for (blk = old_fs->super->s_first_data_block;
           blk < old_fs->super->s_blocks_count; blk++) {
            if (!ext2fs_test_block_bitmap(old_fs->block_map, blk))
                  continue;
            if (!ext2fs_test_block_bitmap(rfs->move_blocks, blk))
                  continue;

            new_blk = get_new_block(rfs);
            if (!new_blk) {
                  retval = ENOSPC;
                  goto errout;
            }
            ext2fs_mark_block_bitmap(fs->block_map, new_blk);
            ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
            to_move++;
      }
      
      if (to_move == 0) {
            retval = 0;
            goto errout;
      }

      /*
       * Step two is to actually move the blocks
       */
      retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
      if (retval) goto errout;

      if (rfs->progress) {
            retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
                               0, to_move);
            if (retval)
                  goto errout;
      }
      while (1) {
            retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
            if (retval) goto errout;
            if (!size)
                  break;
#ifdef RESIZE2FS_DEBUG
            if (rfs->flags & RESIZE_DEBUG_BMOVE)
                  printf(_("Moving %d blocks %u->%u\n"), size,
                         old_blk, new_blk);
#endif
            do {
                  c = size;
                  if (c > fs->inode_blocks_per_group)
                        c = fs->inode_blocks_per_group;
                  retval = io_channel_read_blk(fs->io, old_blk, c,
                                         rfs->itable_buf);
                  if (retval) goto errout;
                  retval = io_channel_write_blk(fs->io, new_blk, c,
                                          rfs->itable_buf);
                  if (retval) goto errout;
                  size -= c;
                  new_blk += c;
                  old_blk += c;
                  moved += c;
                  if (rfs->progress) {
                        io_channel_flush(fs->io);
                        retval = (rfs->progress)(rfs,
                                    E2_RSZ_BLOCK_RELOC_PASS,
                                    moved, to_move);
                        if (retval)
                              goto errout;
                  }
            } while (size > 0);
            io_channel_flush(fs->io);
      }

errout:
      return retval;
}


/* --------------------------------------------------------------------
 *
 * Resize processing, phase 3
 *
 * --------------------------------------------------------------------
 */


struct process_block_struct {
      ext2_resize_t           rfs;
      ext2_ino_t        ino;
      struct ext2_inode *     inode;
      errcode_t         error;
      int               is_dir;
      int               changed;
};

static int process_block(ext2_filsys fs, blk_t  *block_nr,
                   e2_blkcnt_t blockcnt, blk_t ref_block,
                   int ref_offset, void *priv_data)
{
      struct process_block_struct *pb;
      errcode_t   retval;
      blk_t       block, new_block;
      int         ret = 0;

      pb = (struct process_block_struct *) priv_data;
      block = *block_nr;
      if (pb->rfs->bmap) {
            new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
            if (new_block) {
                  *block_nr = new_block;
                  ret |= BLOCK_CHANGED;
                  pb->changed = 1;
#ifdef RESIZE2FS_DEBUG
                  if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
                        printf(_("ino=%u, blockcnt=%lld, %u->%u\n"), 
                               pb->ino, blockcnt, block, new_block);
#endif
                  block = new_block;
            }
      }
      if (pb->is_dir) {
            retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
                                    block, (int) blockcnt);
            if (retval) {
                  pb->error = retval;
                  ret |= BLOCK_ABORT;
            }
      }
      return ret;
}

/*
 * Progress callback
 */
static errcode_t progress_callback(ext2_filsys fs, ext2_inode_scan scan,
                           dgrp_t group, void * priv_data)
{
      ext2_resize_t rfs = (ext2_resize_t) priv_data;
      errcode_t         retval;

      /*
       * This check is to protect against old ext2 libraries.  It
       * shouldn't be needed against new libraries.
       */
      if ((group+1) == 0)
            return 0;

      if (rfs->progress) {
            io_channel_flush(fs->io);
            retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
                               group+1, fs->group_desc_count);
            if (retval)
                  return retval;
      }
      
      return 0;
}

static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
{
      struct process_block_struct   pb;
      ext2_ino_t        ino, new_inode;
      struct ext2_inode       inode;
      ext2_inode_scan   scan = NULL;
      errcode_t         retval;
      int               group;
      char              *block_buf = 0;
      ext2_ino_t        start_to_move;
      blk_t             orig_size;
      
      if ((rfs->old_fs->group_desc_count <=
           rfs->new_fs->group_desc_count) &&
          !rfs->bmap)
            return 0;

      /*
       * Save the original size of the old filesystem, and
       * temporarily set the size to be the new size if the new size
       * is larger.  We need to do this to avoid catching an error
       * by the block iterator routines
       */
      orig_size = rfs->old_fs->super->s_blocks_count;
      if (orig_size < rfs->new_fs->super->s_blocks_count)
            rfs->old_fs->super->s_blocks_count =
                  rfs->new_fs->super->s_blocks_count;

      retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
      if (retval) goto errout;

      retval = ext2fs_init_dblist(rfs->old_fs, 0);
      if (retval) goto errout;
      retval = ext2fs_get_mem(rfs->old_fs->blocksize * 3,
                        (void **) &block_buf);
      if (retval) goto errout;

      start_to_move = (rfs->new_fs->group_desc_count *
                   rfs->new_fs->super->s_inodes_per_group);
      
      if (rfs->progress) {
            retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
                               0, rfs->old_fs->group_desc_count);
            if (retval)
                  goto errout;
      }
      ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
      pb.rfs = rfs;
      pb.inode = &inode;
      pb.error = 0;
      new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
      /*
       * First, copy all of the inodes that need to be moved
       * elsewhere in the inode table
       */
      while (1) {
            retval = ext2fs_get_next_inode(scan, &ino, &inode);
            if (retval) goto errout;
            if (!ino)
                  break;

            if (inode.i_links_count == 0)
                  continue; /* inode not in use */

            pb.is_dir = LINUX_S_ISDIR(inode.i_mode);
            pb.changed = 0;

            if (ext2fs_inode_has_valid_blocks(&inode) &&
                (rfs->bmap || pb.is_dir)) {
                  pb.ino = ino;
                  retval = ext2fs_block_iterate2(rfs->old_fs,
                                           ino, 0, block_buf,
                                           process_block, &pb);
                  if (retval)
                        goto errout;
                  if (pb.error) {
                        retval = pb.error;
                        goto errout;
                  }
            }

            if (ino <= start_to_move)
                  continue; /* Don't need to move it. */

            /*
             * Find a new inode
             */
            while (1) { 
                  if (!ext2fs_test_inode_bitmap(rfs->new_fs->inode_map, 
                                          new_inode))
                        break;
                  new_inode++;
                  if (new_inode > rfs->new_fs->super->s_inodes_count) {
                        retval = ENOSPC;
                        goto errout;
                  }
            }
            ext2fs_mark_inode_bitmap(rfs->new_fs->inode_map, new_inode);
            if (pb.changed) {
                  /* Get the new version of the inode */
                  retval = ext2fs_read_inode(rfs->old_fs, ino, &inode);
                  if (retval) goto errout;
            }
            retval = ext2fs_write_inode(rfs->old_fs, new_inode, &inode);
            if (retval) goto errout;

            group = (new_inode-1) / EXT2_INODES_PER_GROUP(rfs->new_fs->super);
            if (LINUX_S_ISDIR(inode.i_mode))
                  rfs->new_fs->group_desc[group].bg_used_dirs_count++;
            
#ifdef RESIZE2FS_DEBUG
            if (rfs->flags & RESIZE_DEBUG_INODEMAP)
                  printf(_("Inode moved %u->%u\n"), ino, new_inode);
#endif
            if (!rfs->imap) {
                  retval = ext2fs_create_extent_table(&rfs->imap, 0);
                  if (retval)
                        goto errout;
            }
            ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
      }
      io_channel_flush(rfs->old_fs->io);

errout:
      rfs->old_fs->super->s_blocks_count = orig_size;
      if (rfs->bmap) {
            ext2fs_free_extent_table(rfs->bmap);
            rfs->bmap = 0;
      }
      if (scan)
            ext2fs_close_inode_scan(scan);
      if (block_buf)
            ext2fs_free_mem((void **) &block_buf);
      return retval;
}

/* --------------------------------------------------------------------
 *
 * Resize processing, phase 4.
 *
 * --------------------------------------------------------------------
 */

struct istruct {
      ext2_resize_t rfs;
      errcode_t   err;
      unsigned long     max_dirs;
      int         num;
};

static int check_and_change_inodes(ext2_ino_t dir, int entry,
                           struct ext2_dir_entry *dirent, int offset,
                           int      blocksize, char *buf, void *priv_data)
{
      struct istruct *is = (struct istruct *) priv_data;
      ext2_ino_t  new_inode;

      if (is->rfs->progress && offset == 0) {
            io_channel_flush(is->rfs->old_fs->io);
            is->err = (is->rfs->progress)(is->rfs,
                                    E2_RSZ_INODE_REF_UPD_PASS,
                                    ++is->num, is->max_dirs);
            if (is->err)
                  return DIRENT_ABORT;
      }

      if (!dirent->inode)
            return 0;

      new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);

      if (!new_inode)
            return 0;
#ifdef RESIZE2FS_DEBUG
      if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
            printf(_("Inode translate (dir=%u, name=%.*s, %u->%u)\n"),
                   dir, dirent->name_len, dirent->name,
                   dirent->inode, new_inode);
#endif

      dirent->inode = new_inode;

      return DIRENT_CHANGED;
}

static errcode_t inode_ref_fix(ext2_resize_t rfs)
{
      errcode_t         retval;
      struct istruct          is;
      
      if (!rfs->imap)
            return 0;
       
      /*
       * Now, we iterate over all of the directories to update the
       * inode references
       */
      is.num = 0;
      is.max_dirs = ext2fs_dblist_count(rfs->old_fs->dblist);
      is.rfs = rfs;
      is.err = 0;

      if (rfs->progress) {
            retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
                               0, is.max_dirs);
            if (retval)
                  goto errout;
      }
      
      retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
                                 DIRENT_FLAG_INCLUDE_EMPTY, 0,
                                 check_and_change_inodes, &is);
      if (retval)
            goto errout;
      if (is.err) {
            retval = is.err;
            goto errout;
      }

errout:
      ext2fs_free_extent_table(rfs->imap);
      rfs->imap = 0;
      return retval;
}


/* --------------------------------------------------------------------
 *
 * Resize processing, phase 5.
 *
 * In this phase we actually move the inode table around, and then
 * update the summary statistics.  This is scary, since aborting here
 * will potentially scramble the filesystem.  (We are moving the
 * inode tables around in place, and so the potential for lost data,
 * or at the very least scrambling the mapping between filenames and
 * inode numbers is very high in case of a power failure here.)
 * --------------------------------------------------------------------
 */


/*
 * A very scary routine --- this one moves the inode table around!!!
 *
 * After this you have to use the rfs->new_fs file handle to read and
 * write inodes.
 */
static errcode_t move_itables(ext2_resize_t rfs)
{
      int         i, n, num, max_groups, size, diff;
      ext2_filsys fs = rfs->new_fs;
      char        *cp;
      blk_t       old_blk, new_blk;
      errcode_t   retval;
      int         to_move, moved;

      max_groups = fs->group_desc_count;
      if (max_groups > rfs->old_fs->group_desc_count)
            max_groups = rfs->old_fs->group_desc_count;

      size = fs->blocksize * fs->inode_blocks_per_group;
      if (!rfs->itable_buf) {
            retval = ext2fs_get_mem(size, (void **) &rfs->itable_buf);
            if (retval)
                  return retval;
      }

      /*
       * Figure out how many inode tables we need to move
       */
      to_move = moved = 0;
      for (i=0; i < max_groups; i++)
            if (rfs->old_fs->group_desc[i].bg_inode_table !=
                fs->group_desc[i].bg_inode_table)
                  to_move++;

      if (to_move == 0)
            return 0;

      if (rfs->progress) {
            retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
                               0, to_move);
            if (retval)
                  goto errout;
      }

      rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;

      for (i=0; i < max_groups; i++) {
            old_blk = rfs->old_fs->group_desc[i].bg_inode_table;
            new_blk = fs->group_desc[i].bg_inode_table;
            diff = new_blk - old_blk;
            
#ifdef RESIZE2FS_DEBUG
            if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 
                  printf(_("Itable move group %d block "
                         "%u->%u (diff %d)\n"), 
                         i, old_blk, new_blk, diff);
#endif
            
            if (!diff)
                  continue;

            retval = io_channel_read_blk(fs->io, old_blk,
                                   fs->inode_blocks_per_group,
                                   rfs->itable_buf);
            if (retval) 
                  goto errout;
            /*
             * The end of the inode table segment often contains
             * all zeros, and we're often only moving the inode
             * table down a block or two.  If so, we can optimize
             * things by not rewriting blocks that we know to be zero
             * already.
             */
            for (cp = rfs->itable_buf+size, n=0; n < size; n++, cp--)
                  if (*cp)
                        break;
            n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
#ifdef RESIZE2FS_DEBUG
            if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 
                  printf(_("%d blocks of zeros...\n"), n);
#endif
            num = fs->inode_blocks_per_group;
            if (n > diff)
                  num -= n;

            retval = io_channel_write_blk(fs->io, new_blk,
                                    num, rfs->itable_buf);
            if (retval) {
                  io_channel_write_blk(fs->io, old_blk,
                                   num, rfs->itable_buf);
                  goto errout;
            }
            if (n > diff) {
                  retval = io_channel_write_blk(fs->io,
                        old_blk + fs->inode_blocks_per_group,
                        diff, (rfs->itable_buf +
                             (fs->inode_blocks_per_group - diff) *
                             fs->blocksize));
                  if (retval)
                        goto errout;
            }
            rfs->old_fs->group_desc[i].bg_inode_table = new_blk;
            ext2fs_mark_super_dirty(rfs->old_fs);
            if (rfs->progress) {
                  ext2fs_flush(rfs->old_fs);
                  retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
                                     ++moved, to_move);
                  if (retval)
                        goto errout;
            }
      }
      ext2fs_flush(fs);
#ifdef RESIZE2FS_DEBUG
      if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 
            printf(_("Inode table move finished.\n"));
#endif
      return 0;
      
errout:
      return retval;
}

/*
 * Finally, recalculate the summary information
 */
static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
{
      blk_t       blk;
      ext2_ino_t  ino;
      int         group = 0;
      int         count = 0;
      int         total_free = 0;
      int         group_free = 0;

      /*
       * First calculate the block statistics
       */
      for (blk = fs->super->s_first_data_block;
           blk < fs->super->s_blocks_count; blk++) {
            if (!ext2fs_fast_test_block_bitmap(fs->block_map, blk)) {
                  group_free++;
                  total_free++;
            }
            count++;
            if ((count == fs->super->s_blocks_per_group) ||
                (blk == fs->super->s_blocks_count-1)) {
                  fs->group_desc[group++].bg_free_blocks_count =
                        group_free;
                  count = 0;
                  group_free = 0;
            }
      }
      fs->super->s_free_blocks_count = total_free;
      
      /*
       * Next, calculate the inode statistics
       */
      group_free = 0;
      total_free = 0;
      count = 0;
      group = 0;
      for (ino = 1; ino <= fs->super->s_inodes_count; ino++) {
            if (!ext2fs_fast_test_inode_bitmap(fs->inode_map, ino)) {
                  group_free++;
                  total_free++;
            }
            count++;
            if ((count == fs->super->s_inodes_per_group) ||
                (ino == fs->super->s_inodes_count)) {
                  fs->group_desc[group++].bg_free_inodes_count =
                        group_free;
                  count = 0;
                  group_free = 0;
            }
      }
      fs->super->s_free_inodes_count = total_free;
      ext2fs_mark_super_dirty(fs);
      return 0;
}

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