Greetings all, I am studying the conversion code, and maybe somebody can help me with these questions: # btrfs_make_block_groups() I see that this function uses some heuristics to create block groups for BTRFS_BLOCK_GROUP_METADATA and BTRFS_BLOCK_GROUP_DATA. Later, ext2 data blocks are mapped into EXTENT_ITEMs based on their original locations in ext2, as reported by ext2fs_block_iterate2 function. However, it is not ensured later that those EXTENT_ITEMs land into BTRFS_BLOCK_GROUP_DATA only. Later there are some data relocations happening, but still there are EXTENT_ITEMs that map file data and still they live in the BTRFS_BLOCK_GROUP_METADATA block groups. Is this a problem? Or perhaps I am wrong and somehow it is ensured later that these EXTENT_ITEMs are moved into DATA block groups? # create_ext2_image() I see this comment: /* * copy blocks covered by extent #0 to new positions. extent #0 is * special, we can't rely on relocate_extents_range to relocate it. */ Then relocation of blocks up to the end of the first superblock copy happens, and these blocks will be mapped by the ext2 image files that is created. However, it may happen that this area contained some ext2 data block, but relevant btrfs files are not updated at this step. Perhaps they will be updated later in relocate_extents_range() as part of cleaning the BTRFS_BLOCK_GROUP_SYSTEM group? What is special about this "extent#0"? Thanks, Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
