Re: WRITE BUFFER commands through SG_IO getting rounded up to sector past 32k

[Mike Christie <michaelc@cs.wisc.edu>]

Aravind Parchuri wrote:
> My log messages were getting all mixed up, so I cleaned up my little
> test to send just one command at a time. It actually looks like the mid
> layer passes the command through to open-iscsi with the right size the
> first time, but then it sends a second command with request_bufflen = 0.
> 
> I can verify that the command completed on the target just like the
> regular ones did, so there should be no reason for a retry of any sort.
> 
> Here's the log for a 32896 byte command:
> Mar  9 11:27:43 ITX000c292c3c8d kernel: sg_open: dev=0, flags=0x802
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_add_sfp: sfp=0xcbadc000
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_build_reserve: req_size=32768
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_build_indirect:
> buff_size=32768, blk_size=32768
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_add_sfp:   bufflen=32768,
> k_use_sg=1
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_ioctl: sg0, cmd=0x2285
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_common_write:  scsi
> opcode=0x3b, cmd_size=10
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_start_req: dxfer_len=32896
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_build_indirect:
> buff_size=32896, blk_size=33280
> Mar  8 11:27:43 ITX000c292c3c8d kernel: sg_write_xfer: num_xfer=32896,
> iovec_count=0, k_use_sg=2
> Mar  8 11:27:43 ITX000c292c3c8d kernel: iscsi_queuecommand: opcode 3b
> request_bufflen 32896 transfersize 32896

Did you add your own output? Could you enable iscsi debugging? What
kernel is this with and what versions of open-iscsi (upstream or svn or
tarball release)?