resize2fs: don't free in-use clusters when moving blocks

When we're moving blocks around the filesystem, ensure that freeing
the old blocks only frees the clusters if they're not in use by other
metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 63 insertions, 9 deletions

diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index caff422b..6b9ca095 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -909,12 +909,12 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	int		j, has_super;
 	dgrp_t		i, max_groups, g;
 	blk64_t		blk, group_blk;
-	blk64_t		old_blocks, new_blocks;
+	blk64_t		old_blocks, new_blocks, group_end, cluster_freed;
 	blk64_t		new_size;
 	unsigned int	meta_bg, meta_bg_size;
 	errcode_t	retval;
 	ext2_filsys 	fs, old_fs;
-	ext2fs_block_bitmap	meta_bmap;
+	ext2fs_block_bitmap	meta_bmap, new_meta_bmap = NULL;
 	int		flex_bg;
 
 	fs = rfs->new_fs;
@@ -1026,15 +1026,42 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	 * blocks as free.
 	 */
 	if (old_blocks > new_blocks) {
+		if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+			retval = ext2fs_allocate_block_bitmap(fs,
+							_("new meta blocks"),
+							&new_meta_bmap);
+			if (retval)
+				goto errout;
+
+			retval = mark_table_blocks(fs, new_meta_bmap);
+			if (retval)
+				goto errout;
+		}
+
 		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_block_alloc_stats2(fs, blk, -1);
+			group_end = group_blk + 1 + old_blocks;
+			for (blk = group_blk + 1 + new_blocks;
+			     blk < group_end;) {
+				if (new_meta_bmap == NULL ||
+				    !ext2fs_test_block_bitmap2(new_meta_bmap,
+							       blk)) {
+					cluster_freed =
+						EXT2FS_CLUSTER_RATIO(fs) -
+						(blk &
+						 EXT2FS_CLUSTER_MASK(fs));
+					if (cluster_freed > group_end - blk)
+						cluster_freed = group_end - blk;
+					ext2fs_block_alloc_stats2(fs, blk, -1);
+					blk += EXT2FS_CLUSTER_RATIO(fs);
+					rfs->needed_blocks -= cluster_freed;
+					continue;
+				}
 				rfs->needed_blocks--;
+				blk++;
 			}
 			group_blk += fs->super->s_blocks_per_group;
 		}
@@ -1180,6 +1207,8 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
 	retval = 0;
 
 errout:
+	if (new_meta_bmap)
+		ext2fs_free_block_bitmap(new_meta_bmap);
 	if (meta_bmap)
 		ext2fs_free_block_bitmap(meta_bmap);
 
@@ -1779,9 +1808,10 @@ static errcode_t move_itables(ext2_resize_t rfs)
 	dgrp_t		i, max_groups;
 	ext2_filsys	fs = rfs->new_fs;
 	char		*cp;
-	blk64_t		old_blk, new_blk, blk;
+	blk64_t		old_blk, new_blk, blk, cluster_freed;
 	errcode_t	retval;
 	int		j, to_move, moved;
+	ext2fs_block_bitmap	new_bmap = NULL;
 
 	max_groups = fs->group_desc_count;
 	if (max_groups > rfs->old_fs->group_desc_count)
@@ -1794,6 +1824,17 @@ static errcode_t move_itables(ext2_resize_t rfs)
 			return retval;
 	}
 
+	if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+		retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
+						      &new_bmap);
+		if (retval)
+			return retval;
+
+		retval = mark_table_blocks(fs, new_bmap);
+		if (retval)
+			goto errout;
+	}
+
 	/*
 	 * Figure out how many inode tables we need to move
 	 */
@@ -1871,8 +1912,19 @@ static errcode_t move_itables(ext2_resize_t rfs)
 		}
 
 		for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
-		     j < fs->inode_blocks_per_group ; j++, blk++)
-			ext2fs_block_alloc_stats2(fs, blk, -1);
+		     j < fs->inode_blocks_per_group;) {
+			if (new_bmap == NULL ||
+			    !ext2fs_test_block_bitmap2(new_bmap, blk)) {
+				ext2fs_block_alloc_stats2(fs, blk, -1);
+				cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
+						(blk & EXT2FS_CLUSTER_MASK(fs));
+				blk += cluster_freed;
+				j += cluster_freed;
+				continue;
+			}
+			blk++;
+			j++;
+		}
 
 		ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
 		ext2fs_group_desc_csum_set(rfs->old_fs, i);
@@ -1892,9 +1944,11 @@ static errcode_t move_itables(ext2_resize_t rfs)
 	if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
 		printf("Inode table move finished.\n");
 #endif
-	return 0;
+	retval = 0;
 
 errout:
+	if (new_bmap)
+		ext2fs_free_block_bitmap(new_bmap);
 	return retval;
 }