ext4_getblk
struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
bh = ext4_getblk(handle, inode, block, map_flags);
bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */);
bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
bh = ext4_getblk(handle, ea_inode, block, 0);