Conversion of LIO-Target to use include/scsi/iscsi_proto.h defs

Nicholas A. Bellinger
2010-08-19T22:49:31Z

Greetings mnc and tomo,

So as per our discussions last week, I will be moving forward with the
conversion of the LIO-Target iSCSI fabric module v4 to use protocol and
PDU include/scsi/iscsi_proto.h. As mnc and I agreed privately, this is
going to the right level of integration for v2.6.37, as making libiscsi
target mode aware does not really make for a target mode iSCSI stack
sense due to the amount of logic in place for kernel <-> user with the
Open-iSCSI initiator.

So aside from the main tedious work that will be involved in actually
producing a patch for this on my end, I did notice one immediate item
that will cause an extra headache.. This involves the struct
iscsi_init_* and struct iscsi_target* structure definitions in:

http://git.kernel.org/?p=linux/kernel/git/nab/lio-core-2.6.git;a=blob;f=drivers/target/lio-target/iscsi_protocol.h;hb=refs/heads/lio-4.0

namely that they all have trailing 'u32 header_digest' member that a
decent amount of utility code in iscsi_target.c and iscsi_target_util.c
currently depends upon.

So, assuming that the conversion of all struct iscsi_init_* and struct
iscsi_target* to use include/scsi/iscsi_proto.h defs just involves
checking structure size and renaming the member use in
drivers/target/lio-target, would it be acceptable to do something like:

/* iSCSI PDU Header */
struct iscsi_cmd {
uint8_t opcode;
uint8_t flags;
__be16 rsvd2;
uint8_t hlength;
uint8_t dlength[3];
uint8_t lun[8];
itt_t itt; /* Initiator Task Tag */
__be32 data_length;
__be32 cmdsn;
__be32 exp_statsn;
uint8_t cdb[ISCSI_CDB_SIZE]; /* SCSI Command Block */
/* Additional Data (Command Dependent) */
#ifdef ISCSI_TARGET_MODE
__be32 header_digest;
#endif
};

for the existing PDU defs in iscsi_proto.h in order to the pain
of having to convert this over in existing LIO-Target fabric module
code..? This really help me alot.

Thanks!

--nab