Leonard Michlmayr wrote: > Thank you for your reply. > >>> @@ -3700,7 +3701,8 @@ >>> start_blk = start >> inode->i_sb->s_blocksize_bits; >>> - len_blks = len >> inode->i_sb->s_blocksize_bits; >>> + end_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; >>> + len_blks = end_blk - start_blk + 1; >> I don't think this is quite correct either. For example, if blocksize >> is 1024 >> and start is 1023 (start_blk = 0) and len is 2 (end = 1024, end_blk = >> 1) then >> len_blks = 2 which is too much. > > I think that len_blks = 2 is the correct value, because the requested > region extends into 2 blocks (namely 0 and 1). If both blocks are in two > separate extents, then ext4_ext_walk_space should report 2 extents. (If > it's the same extent, only 1 will be reported anyways) > >> I think the right calculation here is: >> >> end_blk = (start + len + inode->i_sb->s_blocksize - 1) >> >> inode->i_sb->s_blocksize_bits; >> len_blks = end_blk - start_blk; >> > > This is exactly the same (provided that len > 0). You can convince > yourself easily that ((blocksize + x) >> blocksize_bits == x >> > blocksize_bits + 1) for any positive x, because the lower bits of > blocksize are all 0. (Your calculation would handle the case len == 0 > right, if that was allowed.) > > Regards > Leonard I was wondering if there is any update on the status of this patch. Thanks ! Warm Regards, Surbhi. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
