ext4_mkfs: merge fill_bgroups and write_bgroups into one function

Previous implementation might alloc a lot of memory to hold
block group descriptors. Now only one block group descriptor
is allocated. However, this might have some performance consequences.

diff --git a/src/ext4_mkfs.c b/src/ext4_mkfs.c
index 0718ebc534e2d04096d6f21348b8fd8690acb569..c32193ad713fb35cdf3a59955a15a4ad880471fe 100644 (file)
--- a/src/ext4_mkfs.c
+++ b/src/ext4_mkfs.c
@@ -180,7 +180,7 @@ static int create_fs_aux_info(struct fs_aux_info *aux_info,
        if (!aux_info->sb)
                return ENOMEM;
 
-       aux_info->bg_desc = calloc(aux_info->groups, sizeof(struct ext4_bgroup));
+       aux_info->bg_desc = calloc(1, sizeof(struct ext4_bgroup));
        if (!aux_info->bg_desc)
                return ENOMEM;
 
@@ -294,16 +294,20 @@ static void fill_in_sb(struct fs_aux_info *aux_info, struct ext4_mkfs_info *info
        sb->flags = to_le32(EXT4_SUPERBLOCK_FLAGS_SIGNED_HASH);
 }
 
-static void fill_bgroups(struct fs_aux_info *aux_info,
+
+
+static int write_bgroups(struct ext4_blockdev *bd, struct fs_aux_info *aux_info,
                         struct ext4_mkfs_info *info)
 {
-       uint32_t i;
-
+       int r = EOK;
+       uint32_t i, j;
        uint32_t bg_free_blk = 0;
        uint64_t sb_free_blk = 0;
+       struct ext4_block b;
 
-       for (i = 0; i < aux_info->groups; i++) {
+       uint32_t block_size = ext4_sb_get_block_size(aux_info->sb);
 
+       for (i = 0; i < aux_info->groups; i++) {
                uint64_t bg_start_block = aux_info->first_data_block +
                        aux_info->first_data_block + i * info->blocks_per_group;
                uint32_t blk_off = 0;
@@ -324,85 +328,63 @@ static void fill_bgroups(struct fs_aux_info *aux_info,
                        bg_free_blk -= aux_info->bg_desc_blocks;
                }
 
-               ext4_bg_set_block_bitmap(&aux_info->bg_desc[i], aux_info->sb,
+               ext4_bg_set_block_bitmap(aux_info->bg_desc, aux_info->sb,
                                bg_start_block + blk_off + 1);
 
-               ext4_bg_set_inode_bitmap(&aux_info->bg_desc[i], aux_info->sb,
+               ext4_bg_set_inode_bitmap(aux_info->bg_desc, aux_info->sb,
                                bg_start_block + blk_off + 2);
 
-               ext4_bg_set_inode_table_first_block(&aux_info->bg_desc[i],
+               ext4_bg_set_inode_table_first_block(aux_info->bg_desc,
                                aux_info->sb,
                                bg_start_block + blk_off + 3);
 
-               ext4_bg_set_free_blocks_count(&aux_info->bg_desc[i],
+               ext4_bg_set_free_blocks_count(aux_info->bg_desc,
                                aux_info->sb, bg_free_blk);
 
-               ext4_bg_set_free_inodes_count(&aux_info->bg_desc[i],
+               ext4_bg_set_free_inodes_count(aux_info->bg_desc,
                                aux_info->sb, aux_info->sb->inodes_per_group);
 
-               ext4_bg_set_used_dirs_count(&aux_info->bg_desc[i], aux_info->sb,
+               ext4_bg_set_used_dirs_count(aux_info->bg_desc, aux_info->sb,
                                            0);
 
-               ext4_bg_set_flag(&aux_info->bg_desc[i],
+               ext4_bg_set_flag(aux_info->bg_desc,
                                EXT4_BLOCK_GROUP_BLOCK_UNINIT |
                                EXT4_BLOCK_GROUP_INODE_UNINIT);
 
                sb_free_blk += bg_free_blk;
-       }
 
-       ext4_sb_set_free_blocks_cnt(aux_info->sb, sb_free_blk);
-}
 
+               for (j = 0; j < aux_info->groups; j++) {
+                       uint64_t bg_start_block = aux_info->first_data_block +
+                                                 j * info->blocks_per_group;
+                       uint32_t blk_off = 0;
 
-static int write_bgroups(struct ext4_blockdev *bd, struct fs_aux_info *aux_info,
-                        struct ext4_mkfs_info *info)
-{
-       int r = EOK;
-       uint32_t i;
-       struct ext4_block b;
-       for (i = 0; i < aux_info->groups; i++) {
-               uint64_t bg_start_block = aux_info->first_data_block +
-                       + i * info->blocks_per_group;
-               uint32_t blk_off = 0;
+                       blk_off += aux_info->bg_desc_blocks;
+                       if (has_superblock(info, j)) {
+                               bg_start_block++;
+                               blk_off += info->bg_desc_reserve_blocks;
+                       }
 
-               blk_off += aux_info->bg_desc_blocks;
-               if (has_superblock(info, i)) {
-                       bg_start_block++;
-                       blk_off += info->bg_desc_reserve_blocks;
-               }
 
-               uint32_t block_size = ext4_sb_get_block_size(aux_info->sb);
-               uint32_t dsc_pos = 0;
-               uint32_t dsc_id = 0;
-               uint32_t dsc_size = ext4_sb_get_desc_size(aux_info->sb);
-               uint32_t dsc_blk_cnt = aux_info->bg_desc_blocks;
-               uint64_t dsc_blk = bg_start_block;
+                       uint32_t dsc_pos = 0;
+                       uint32_t dsc_size = ext4_sb_get_desc_size(aux_info->sb);
+                       uint64_t dsc_blk = bg_start_block +
+                                          i * dsc_size / block_size;
 
-               while (dsc_blk_cnt--) {
-                       r = ext4_block_get(bd, &b, dsc_blk++);
+                       r = ext4_block_get(bd, &b, dsc_blk);
                        if (r != EOK)
                                return r;
 
-                       dsc_pos = 0;
-                       while (dsc_pos + dsc_size <= block_size) {
-                               memcpy(b.data + dsc_pos,
-                                      &aux_info->bg_desc[dsc_id],
-                                      dsc_size);
+                       dsc_pos = (i * dsc_size) % block_size;
+                       memcpy(b.data + dsc_pos,
+                                       aux_info->bg_desc,
+                                       dsc_size);
 
-                               dsc_pos += dsc_size;
-                               dsc_id++;
-
-                               if (dsc_id == aux_info->groups)
-                                       break;
-                       }
 
                        ext4_bcache_set_dirty(b.buf);
                        r = ext4_block_set(bd, &b);
                        if (r != EOK)
                                return r;
-
-                       if (dsc_id == aux_info->groups)
-                               break;
                }
 
                r = ext4_block_get_noread(bd, &b, bg_start_block + blk_off + 1);
@@ -423,7 +405,7 @@ static int write_bgroups(struct ext4_blockdev *bd, struct fs_aux_info *aux_info,
                        return r;
        }
 
-
+       ext4_sb_set_free_blocks_cnt(aux_info->sb, sb_free_blk);
        return r;
 }
 
@@ -492,8 +474,6 @@ static int mkfs_initial(struct ext4_blockdev *bd, struct ext4_mkfs_info *info)
                goto Finish;
 
        fill_in_sb(&aux_info, info);
-       fill_bgroups(&aux_info, info);
-
 
        r = write_bgroups(bd, &aux_info, info);
        if (r != EOK)