Hi Doug I have a quick question here regarding the sg tablesize and retrieval of the supported size via a userspace ioctl.
lpfc defaults to lpfc_sg_seg_cnt:Max Scatter Gather Segment Count (uint) = 64 For sg_io sent from qemu if we exceed 512K I/O we fail, qlogic allows 128 by default. 7:0:2:13 /dev/sdbb 67:80 /dev/sg55 Emulex lpfc LUN [root@dhcp40-131 ~]# sg_dd if=/dev/zero of=/dev/sdbb bpt=0x400 count=0x400 blk_sgio=1 Assume default 'bs' (block size) of 512 bytes writing (SG_IO) on sg device, error: Invalid argument sg_write failed, seek=0 Some error occurred, remaining block count=1024 1024+0 records in 0+0 records out 9:0:1:13 /dev/sdcm 71:240 /dev/sg92 Qlogic qla2xxx LUN [root@dhcp40-131 ~]# sg_dd if=/dev/zero of=/dev/sdcm bpt=0x400 count=0x400 blk_sgio=1 Assume default 'bs' (block size) of 512 bytes 1024+0 records in 1024+0 records out Using ioctl(sg_fd, BLKSECTGET, &max_sectors) from userspace correctly returns the /sys/block/sdcm/queue/max_sectors_kb How can we query the sg tablesize using a userspace ioctl for the sg driver. Figured I would ask you first. Thanks Laurence
