resize2fs: fix 32-bit overflow when calculating the number of free blocks

This caused the free blocks count in the superblock to be incorrect
after resizing a 64-bit file system if the number of free blocks
overflowed a 32-bit value.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index 0407e41..d9501f9 100644 (file)
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -1795,7 +1795,8 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
        ext2_ino_t      ino;
        unsigned int    group = 0;
        unsigned int    count = 0;
-       int             total_free = 0;
+       blk64_t         total_blocks_free = 0;
+       int             total_inodes_free = 0;
        int             group_free = 0;
        int             uninit = 0;
        blk64_t         super_blk, old_desc_blk, new_desc_blk;
@@ -1827,7 +1828,7 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
                          + fs->inode_blocks_per_group))))) ||
                    (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
                        group_free++;
-                       total_free++;
+                       total_blocks_free++;
                }
                count++;
                if ((count == fs->super->s_blocks_per_group) ||
@@ -1851,13 +1852,12 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
                                        fs->super->s_reserved_gdt_blocks;
                }
        }
-       ext2fs_free_blocks_count_set(fs->super, total_free);
+       ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
 
        /*
         * Next, calculate the inode statistics
         */
        group_free = 0;
-       total_free = 0;
        count = 0;
        group = 0;
 
@@ -1867,7 +1867,7 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
                if (uninit ||
                    !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
                        group_free++;
-                       total_free++;
+                       total_inodes_free++;
                }
                count++;
                if ((count == fs->super->s_inodes_per_group) ||
@@ -1882,7 +1882,7 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
                        uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
                }
        }
-       fs->super->s_free_inodes_count = total_free;
+       fs->super->s_free_inodes_count = total_inodes_free;
        ext2fs_mark_super_dirty(fs);
        return 0;
 }