Fix inode table allocation with flexbg

Disordered inode tables may appear when inode_blocks_per_group is lesser
or equal to the number of groups in a flex group.

This bug can be reproduced with:
	mkfs.ext4 -t ext4dev -G512 70G

In that case, you can see with dump2fs that inode tables for groups 510
and 511 are placed just after group 51's inode table instead of being
placed after group 509's inode table.

Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/alloc_tables.c b/lib/ext2fs/alloc_tables.c
index 8c0ecfc..7726eef 100644 (file)
--- a/lib/ext2fs/alloc_tables.c
+++ b/lib/ext2fs/alloc_tables.c
@@ -34,9 +34,10 @@
  * tables can be allocated continously and in order.
  */
 static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk_t start_blk,
-                          ext2fs_block_bitmap bmap, int offset, int size)
+                          ext2fs_block_bitmap bmap, int offset, int size,
+                          int elem_size)
 {
-       int             flexbg, flexbg_size, elem_size;
+       int             flexbg, flexbg_size;
        blk_t           last_blk, first_free = 0;
        dgrp_t          last_grp;
 
@@ -54,10 +55,6 @@ static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk_t start_blk,
         * search is still valid.
         */
        if (start_blk && group % flexbg_size) {
-               if (size > flexbg_size)
-                       elem_size = fs->inode_blocks_per_group;
-               else
-                       elem_size = 1;
                if (ext2fs_test_block_bitmap_range(bmap, start_blk + elem_size,
                                                   size))
                        return start_blk + elem_size;
@@ -126,7 +123,7 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
                if (group && fs->group_desc[group-1].bg_block_bitmap)
                        prev_block = fs->group_desc[group-1].bg_block_bitmap;
                start_blk = flexbg_offset(fs, group, prev_block, bmap,
-                                                0, rem_grps);
+                                                0, rem_grps, 1);
                last_blk = ext2fs_group_last_block(fs, last_grp);
        }
 
@@ -154,7 +151,7 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
                if (group && fs->group_desc[group-1].bg_inode_bitmap)
                        prev_block = fs->group_desc[group-1].bg_inode_bitmap;
                start_blk = flexbg_offset(fs, group, prev_block, bmap,
-                                                flexbg_size, rem_grps);
+                                                flexbg_size, rem_grps, 1);
                last_blk = ext2fs_group_last_block(fs, last_grp);
        }
 
@@ -187,7 +184,8 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
                group_blk = flexbg_offset(fs, group, prev_block, bmap,
                                                 flexbg_size * 2,
                                                 fs->inode_blocks_per_group *
-                                                rem_grps);
+                                                rem_grps,
+                                                fs->inode_blocks_per_group);
                last_blk = ext2fs_group_last_block(fs, last_grp);
        }