There are now several places in the on-disk format that we are accessing
split 64-bit and 32-bit words with helper functions (e.g.
ext4_free_{blocks,inodes}_count()), but there is no easy way to ensure
that we are accessing them correctly.There were several cases in the recently-ported uninit-groups patch that were missing these checks, and there may be others already in the code. I propose that we do something akin to the __le32 and __be32 types to detect cases where these are improperly accessed. Something like __ll32 and __lh32 for the low and high parts of the word (similarly __ll16 and __lh16) that are cast to __le32 and __le16 respectively in the helper function/macro before being passed to le32_to_cpu() and friends. The alternative is to rename the "low" parts of the field explicitly, so any incorrect code gets a compile error instead of silently working for any filesystem < 16TB in size. I can find the following split fields in ext4_fs.h: __le16 l_i_file_acl_high; __le16 l_i_uid_high; /* these 2 fields */ __le16 l_i_gid_high; /* were reserved2[0] */ #define i_size_high i_dir_acl __le32 s_blocks_count_hi; /* Blocks count */ __le32 s_r_blocks_count_hi; /* Reserved blocks count */ __le32 s_free_blocks_count_hi; /* Free blocks count */ __le32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */ __le32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */ __le32 bg_inode_table_hi; /* Inodes table block MSB */ We should just rename i_dir_acl to i_size_high permanently, and allow directories to use i_size_high as is done for regular files. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
