e2fsck, libext2fs: support for bigalloc file systems with a blocksize of 1024

Filesystems with a blocksize of 1024 have the superblock starting at
block #1.  However, the first data block in the superblock is 0 to
simplify the cluster calculations.  So we must compensate for this in
a number of places, mostly in the ext2fs library, but also in e2fsck.

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

e2fsck/super.c

@@ -400,6 +400,8 @@ void check_resize_inode(e2fsck_t ctx)
 
 	gdt_off = fs->desc_blocks;
 	pblk = fs->super->s_first_data_block + 1 + fs->desc_blocks;
+	if (fs->blocksize == 1024 && fs->super->s_first_data_block == 0)
+		pblk++;	/* Deal with 1024 blocksize bigalloc fs */
 	for (i = 0; i < fs->super->s_reserved_gdt_blocks / 4;
 	     i++, gdt_off++, pblk++) {
 		gdt_off %= fs->blocksize/4;
@@ -555,7 +557,8 @@ void check_super_block(e2fsck_t ctx)
 		}
 	}
 
-	should_be = (sb->s_log_block_size == 0) ? 1 : 0;
+	should_be = (sb->s_log_block_size == 0 &&
+		     EXT2FS_CLUSTER_RATIO(fs) == 1) ? 1 : 0;
 	if (sb->s_first_data_block != should_be) {
 		pctx.blk = sb->s_first_data_block;
 		pctx.blk2 = should_be;

lib/ext2fs/alloc_sb.c

@@ -59,6 +59,9 @@ int ext2fs_reserve_super_and_bgd(ext2_filsys fs,
 
 	if (super_blk || (group == 0))
 		ext2fs_mark_block_bitmap2(bmap, super_blk);
+	if ((group == 0) && (fs->blocksize == 1024) &&
+	    EXT2FS_CLUSTER_RATIO(fs) > 1)
+		ext2fs_mark_block_bitmap2(bmap, 0);
 
 	if (old_desc_blk) {
 		if (fs->super->s_reserved_gdt_blocks && fs->block_map == bmap)

lib/ext2fs/alloc_tables.c

@@ -35,45 +35,43 @@
  * tables can be allocated continously and in order.
  */
 static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
-			     ext2fs_block_bitmap bmap, int offset, int size,
+			     ext2fs_block_bitmap bmap, int rem_grp,
 			     int elem_size)
 {
-	int		flexbg, flexbg_size;
+	int		flexbg, flexbg_size, size;
 	blk64_t		last_blk, first_free = 0;
 	dgrp_t	       	last_grp;
 
-	flexbg_size = 1 << fs->super->s_log_groups_per_flex;
+	size = rem_grp * elem_size;
-	flexbg = group / flexbg_size;
 
 	if (size > (int) (fs->super->s_blocks_per_group / 8))
 		size = (int) fs->super->s_blocks_per_group / 8;
 
-	if (offset)
-		offset -= 1;
-
 	/*
 	 * Don't do a long search if the previous block
 	 * search is still valid.
 	 */
-	if (start_blk && group % flexbg_size) {
+	if (start_blk && ext2fs_test_block_bitmap_range2(bmap, start_blk,
-		if (ext2fs_test_block_bitmap_range2(bmap, start_blk + elem_size,
+							 elem_size))
-						   size))
+		return start_blk;
-			return start_blk + elem_size;
-	}
 
 	start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg);
 	last_grp = group | (flexbg_size - 1);
-	if (last_grp > fs->group_desc_count)
+	if (last_grp > fs->group_desc_count-1)
-		last_grp = fs->group_desc_count;
+		last_grp = fs->group_desc_count-1;
 	last_blk = ext2fs_group_last_block2(fs, last_grp);
 
 	/* Find the first available block */
-	if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, 1, bmap,
+	if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, size,
-				   &first_free))
+				    bmap, &first_free) == 0)
 		return first_free;
 
-	if (ext2fs_get_free_blocks2(fs, first_free + offset, last_blk, size,
+	if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, elem_size,
-				   bmap, &first_free))
+				   bmap, &first_free) == 0)
+		return first_free;
+
+	if (ext2fs_get_free_blocks2(fs, 0, last_blk, elem_size, bmap,
+				    &first_free) == 0)
 		return first_free;
 
 	return first_free;
@@ -98,9 +96,9 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
 	    fs->super->s_log_groups_per_flex) {
 		flexbg_size = 1 << fs->super->s_log_groups_per_flex;
 		last_grp = group | (flexbg_size - 1);
-		rem_grps = last_grp - group;
+		if (last_grp > fs->group_desc_count-1)
-		if (last_grp > fs->group_desc_count)
+			last_grp = fs->group_desc_count-1;
-			last_grp = fs->group_desc_count;
+		rem_grps = last_grp - group + 1;
 	}
 
 	/*
@@ -122,10 +120,10 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
 	if (flexbg_size) {
 		blk64_t prev_block = 0;
 
-		if (group && ext2fs_block_bitmap_loc(fs, group - 1))
+		if (group % flexbg_size)
-			prev_block = ext2fs_block_bitmap_loc(fs, group - 1);
+			prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
 		start_blk = flexbg_offset(fs, group, prev_block, bmap,
-						 0, rem_grps, 1);
+					  rem_grps, 1);
 		last_blk = ext2fs_group_last_block2(fs, last_grp);
 	}
 
@@ -150,10 +148,13 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
 
 	if (flexbg_size) {
 		blk64_t prev_block = 0;
-		if (group && ext2fs_inode_bitmap_loc(fs, group - 1))
+		if (group % flexbg_size)
-			prev_block = ext2fs_inode_bitmap_loc(fs, group - 1);
+			prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
+		else
+			prev_block = ext2fs_block_bitmap_loc(fs, group) +
+				flexbg_size;
 		start_blk = flexbg_offset(fs, group, prev_block, bmap,
-						 flexbg_size, rem_grps, 1);
+					  rem_grps, 1);
 		last_blk = ext2fs_group_last_block2(fs, last_grp);
 	}
 
@@ -181,15 +182,16 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
 	 */
 	if (flexbg_size) {
 		blk64_t prev_block = 0;
-		if (group && ext2fs_inode_table_loc(fs, group - 1))
+
-			prev_block = ext2fs_inode_table_loc(fs, group - 1);
+		if (group % flexbg_size)
-		if (last_grp == fs->group_desc_count)
+			prev_block = ext2fs_inode_table_loc(fs, group - 1) +
-			rem_grps = last_grp - group;
+				fs->inode_blocks_per_group;
+		else
+			prev_block = ext2fs_inode_bitmap_loc(fs, group) +
+				flexbg_size;
+
 		group_blk = flexbg_offset(fs, group, prev_block, bmap,
-						 flexbg_size * 2,
+					  rem_grps, fs->inode_blocks_per_group);
-						 fs->inode_blocks_per_group *
-						 rem_grps,
-						 fs->inode_blocks_per_group);
 		last_blk = ext2fs_group_last_block2(fs, last_grp);
 	}
 

lib/ext2fs/closefs.c

@@ -73,6 +73,8 @@ errcode_t ext2fs_super_and_bgd_loc2(ext2_filsys fs,
 	int	has_super;
 
 	group_block = ext2fs_group_first_block2(fs, group);
+	if (group_block == 0 && fs->blocksize == 1024)
+		group_block = 1; /* Deal with 1024 blocksize && bigalloc */
 
 	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 		old_desc_blocks = fs->super->s_first_meta_bg;

lib/ext2fs/openfs.c

@@ -322,6 +322,8 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
 		goto cleanup;
 	if (!group_block)
 		group_block = fs->super->s_first_data_block;
+	if (group_block == 0 && fs->blocksize == 1024)
+		group_block = 1; /* Deal with 1024 blocksize && bigalloc */
 	dest = (char *) fs->group_desc;
 	groups_per_block = EXT2_DESC_PER_BLOCK(fs->super);
 	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)

lib/ext2fs/res_gdt.c

@@ -67,7 +67,7 @@ errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
 	unsigned long long	apb, inode_size;
 	/* FIXME-64 - can't deal with extents */
 	blk_t			dindir_blk, rsv_off, gdt_off, gdt_blk;
-	int			dindir_dirty = 0, inode_dirty = 0;
+	int			dindir_dirty = 0, inode_dirty = 0, sb_blk = 0;
 
 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
@@ -82,6 +82,15 @@ errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
 	if (retval)
 		goto out_free;
 
+	/*
+	 * File systems with a blocksize of 1024 and bigalloc have
+	 * sb->s_first_data_block of 0; yet the superblock is still at
+	 * block #1.  We compensate for it here.
+	 */
+	sb_blk = sb->s_first_data_block;
+	if (fs->blocksize == 1024 && sb_blk == 0)
+		sb_blk = 1;
+
 	/* Maximum possible file size (we donly use the dindirect blocks) */
 	apb = EXT2_ADDR_PER_BLOCK(sb);
 	if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
@@ -92,7 +101,7 @@ errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
 		if (retval)
 			goto out_inode;
 	} else {
-		blk_t goal = sb->s_first_data_block + fs->desc_blocks +
+		blk_t goal = sb_blk + fs->desc_blocks +
 			sb->s_reserved_gdt_blocks + 2 +
 			fs->inode_blocks_per_group;
 
@@ -120,7 +129,7 @@ errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
 	}
 
 	for (rsv_off = 0, gdt_off = fs->desc_blocks,
-	     gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks;
+	     gdt_blk = sb_blk + 1 + fs->desc_blocks;
 	     rsv_off < sb->s_reserved_gdt_blocks;
 	     rsv_off++, gdt_off++, gdt_blk++) {
 		unsigned int three = 1, five = 5, seven = 7;