On Saturday January 1, poonamsbox@xxxxxxxxx wrote: > Respected Sir, > > I am a student from India. I am studying the RAID 0 code > in the linux kernel 2.4.20. I got some problems in > understanding the code, especially in the > raid0_make_request function. I didnt understand the > following statements.. like why the anding is done, and > what is sect_in_chunk. Please if you could tell me the > details, it would be a very great help for me. Please > sir, hoping for some help. > > 258 sect_in_chunk = bh->b_rsector & ((chunk_size<<1) -1); > 259 chunk = (block - zone->zone_offset) / (zone->nb_dev << chunksize_bits); > 260 tmp_dev = zone->dev[(block >> chunksize_bits) % zone->nb_dev]; > 261 rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1) > 262 + sect_in_chunk; "sect_in_chunk" is the number of the target sector within it's chunk. i.e. the remainder when the target sector is divided by the chunk size. If it still doesn't make sense, try writing the code for mapping an array sector number to a (device number + device sector number). Then ask specifically about differences. NeilBrown > > Thanking you in anticipation. > > With Regards, > Poonam Dalya, > PICT,Pune, > INDIA. > - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
