Hmm, is it originated from: (2^32-1) - (2^32-1)%512 = 4294966784 bytes = 8388607 (512-byte) blocks = 0x7fffff for the byte count (of a bio?) is limited by a 32-bit representation (2^32-1) as well just like the block count in the two scsi commands? What about SD_MAX_XFER_BLOCKS then? On 10 March 2016 at 10:32, Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote: >>>>>> "Tom" == Tom Yan <tom.ty89@xxxxxxxxx> writes: > > Tom> Btw, why SD_MAX_WS16_BLOCKS (which is used for both SD_LBP_WS16 and > Tom> SD_LBP_UNMAP) is set to 0x7fffff (23-bit) instead of 0xffffffff > Tom> (32-bit, 4-byte)? > > This limit represents the largest block range we can describe using a > single bio. > > -- > Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html