For writes that span across multiple DATA-OUT segments we have to
increment the DATASN field for each segment.
We didnt use to, and most targets were perfectly happy, ignoring that the DATASN was constant 0 for every DATAOUT we sent.
LIO however does check this and did cause it to reject the libiscsi test tool.
(This is something we should write a iscsi test for so we can flag all non-LIO targets as broken and needing to be fixed)
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Harmonize the signatures for READ10/WRITE10 to match the ones for READ12/16 and WRITE12/16
This breaks the API/ABI so this forces the next version of the library to bump the major version to 2.0
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
It is not real zero-copy since the data is still copied in the kernel,
but it avoids copying the data inside libiscsi as well as in the callback.
For SCSI tasks that will return data from the target, the application can now
specify application buffers for libiscsi to read the data directly into.
This is done by calling scsi_task_add_data_in_buffer(task, ...
These buffers need not be linear, you can specify different areas to read into
by calling this function several times.
See examples/iscsiclient.c for an example.
dont pick task up from the argument, since this callback can be invoked
from places where we dont have/know the task strucutre and it is thus NULL.
Instead pick it up from scsi_cbstruct.
This prevents a SEGV when processing REJECT to SCSI commands.
(the scsi command callback dereferences the task pointer)
Add a mechanism where residual overflow/underflow can be reportad back to
the application
We probably need somethinf for bidir residuals at some stage too
We dotn need two interfaces that only diuffer in whether they return a pointer or NULL vs an semiidentical interface that returns 0 or <0
All uses of _async() for scsi tasks should be replaced with the equivalent _task() function instead
These functions are also async functions for SCSI commands but they return
a task structure or NULL.
This task structure can be used in task management functions to abort the task or a whole task set.
LBA is uint32_t for read/write10
Also store the lba/numblocks arguments in the task structure for read10/write10
This makes it much easier to implement a fully async "read lots/write lots"
applications.
Update the "send scsi command" fucntion to honour
"FirstBurstLength" so that we only send this many bytes as unsolicited data.
The wait for a train of R2T from the target to clock out additional
busrts of data until the full task data has been sent to the Target.
We should now honour, and handle the case of
ImmediateData=No
InitialR2T=No
correctly for targets that are limited on receiveing data too fast.
