we use the flag ISCSI_PDU_NO_CALLBACK and pdu->callback simultaneously, but
check only for one of them in various places. So drop ISCSI_PDU_NO_CALLBACK
and check for pdu->callback != NULL instead.
All PDUs that carried this flag have pdu->callback set to NULL.
Signed-off-by: Peter Lieven <pl@kamp.de>
This seriously breaks qemu NOP timeouts and probably other things.
The reason is that the
define ISCSI_PDU_ERROR_ON_RECONNECT 0x00000016
is masking bits 0x2 and 0x4 as well.
Correctly it should read:
define ISCSI_PDU_ERROR_ON_RECONNECT 0x00000010
However, the better solution for this approach is invoke all callbacks
of PDUs which carry the ISCSI_PDU_DROP_ON_RECONNECT flag. This will
make sure that callbacks of whatever sync tasks are invoked.
This reverts commit 0407cf6aed.
Certain iSCSI commands such as NOP and LOGOUT commands are discarded instead
of re-queued when we have a session failure and reconnect.
Change the LOGOUT command to instead fail with SCSI_STATUS_ERROR when this
happens.
Otherwise, IF we are in iscsi_logout_sync() and we get a session failure
at the same-ish time we may end up automatically re-connecting the
session, but since we have discarded the logout command we will never
get a reply and will hang indefinitely in the event loop for synchronous
commands.
Arguably, we could also just return SCSI_STATUS_GOOD here since
when we perform a logout, we probably don't care too much about how we
disconnected from the server, only that we did disconnect from the server.
That is academic anyway since this only affects the sync API which is only
meant for trivial applications, which will likely not inspect the result
and just do a:
...
iscsi_logout_sync()
iscsi_destroy_context()
...
anyway.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Normal applications want the current behaviour where we have the library
consume any/all of the UnitAttentions that the target may have queued on the
initial connection, but when we reconnect the session after a failure the
library will pass all the UAs back to the application to process.
Some applications, such as the test suite or really trivial applications
might not want to have to deal with handling of UAs and just "make it work".
Those applications can now request that upon any reconnection of the session
that libiscsi will automatically consume any and all UAs and hide them from
the application.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
this variable was introduced for iscsi-test-cu only. This patch
makes it a generic environment variable that can be set per context.
Signed-off-by: Peter Lieven <pl@kamp.de>
If we are reconnecting and the connection is already established we
end up looping forever if there is a socket error before we finish
the login process. Fix this by invoking the reconnect callback if
there is an error and no new reconnect is scheduled.
Signed-off-by: Peter Lieven <pl@kamp.de>
This is a bug that has been there a long time.
When we reconnect and requeue a PDU we must reset the iovectors
for the task. Otherwise, any partially sent/received data when the
command is reconnected would end up containing garbage.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Rework the reconnect logic so we just call iscsi_scsi_command_async()
for the scsi commands we are re-quining instead of poking into the
private fields of the structures themself.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Remove iscsi_allocate_pdu() which is just a wrapper.
Rename iscsi_allocate_pdu_with_itt_flags() to iscsi_allocate_pdu()
and update all callers.
This only removes a wrapper function and contains no logic changes.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
We write unsolicited data-out PDUs from two places;
when we originally write the command in iscsi_scsi_command_async()
but also when we re-queue the PDUs during a session reconnect.
The re-queuing during the session re-connect was recently (almost) fixed
but was still buggy in that it did not correctly clamp the amount of written
data as per first burst length restriction.
This attempts to fix that.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
If we have writes that do not have the Final bit set during reconnect
we must send out any missing data-out PDU.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
clang defaults to c99 so remove inline statements
(http://clang.llvm.org/compatibility.html#inline ) on functions shared
across different translation units.
clang's linker doesn't like major numbers over 255 so change how SOREL
is generated in Makefile.am.
The iSCSI protocol adds padding to a data packet if the data size is not
a multiple of four. The iovector provided by QEMU does not include such
padding, and libiscsi then complains that there was a protocol error.
This patch fixes this by reading the padding in a separate "recv"
system call. These packets anyway do not happen in the data path,
where the packet size is a multiple of 512.
This fixes QEMU's scsi-generic backend, which triggered the problem when
the target sent a 66-byte INQUIRY response.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch finally introduces a small allocation pool
which recycles all the small portions of memory that
are used for headers and pdu structures. This was
the initial idea behind wrapping all memory functions
in libiscsi.
The results of booting are test system up to the login
prompt are quite impressive:
BEFORE:
libiscsi:5 memory is clean at iscsi_destroy_context() after 10712 mallocs, 18 realloc(s) and 10712 free(s)
AFTER:
libiscsi:5 memory is clean at iscsi_destroy_context() after 41 mallocs, 18 realloc(s), 41 free(s) and 10584 reused small allocations
Signed-off-by: Peter Lieven <pl@kamp.de>
Default to 0 meaning no timeout.
Implement a test for iSCS to test what happens if we send a command
with CMDSN being higher than the target allows.
In this case we dont strictly know what will happen, just that what should
NOT happen is the target responding with success.
But we have to be prepared for any kind of failure, including a timeout,
scsi sense, or even iscsi reject or session failure.
This patch adds support for read/writev to directly read and write
from/to iovectors. Before this patch on read and write from/to socket
the operation was limited by the iovec boundaries. If there is enough
data in the buffer or enough buffer space available its now possible
to transfer the whole data in one atomic operaion.
Signed-off-by: Peter Lieven <pl@kamp.de>
We where modifying out_offset and out_len in iscsi_write_to_socket().
If the packet that was being sent before reconnect was a write command
the was a significant change that out_offset and out_len where already
touched. When requeing the packet after reconnect we where
sending garbage!
Signed-off-by: Peter Lieven <pl@kamp.de>
This patch adds the abilitiy to libiscsi to count the number
of consecutive outstanding NOPs.
With this ability its fairly easy to implement a keepalive
check with NOPs in your application.
Periodically (e.g. every 5 secs) create a NOP-Out with:
iscsi_nop_out_async(iscsi, NULL, NULL, 0, NULL);
At that time check the number of consecutive missing NOP-Ins
with
iscsi_get_nops_in_flight(iscsi) > N.
Where N is the number of missing NOP-Ins you will allow.
Please note that it is legitime for the Target to ignore
a NOP if the load is very high as those packet are mark
as IMMEDIATE.
Signed-off-by: Peter Lieven <pl@kamp.de>
Just like DATA_OUT we should just discard NOPs instead of requeueing them
on session reconnect.
Add new flag that to indicate this behaviour on reconnect and set it for
both data out and nops
In specific situation it might be useful to give up if a reconnect
is not successful or after a given number reconnect retries.
This patch adds the ability to change that. The default remains
the same: retry forever.
Signed-off-by: Peter Lieven <pl@kamp.de>
A storage might sent an R2T response for a WRITE command while
we still sending out the WRITE command PDU. This is especially
the case when the command PDU carries immediata data.
Without this patch the R2T response will get lost as
the cmdpdu for the R2T cannot be found in iscsi_process_pdu()
leading to a deadlock.
Signed-off-by: Peter Lieven <pl@kamp.de>
The send logic was completely broken for any cases except
ISCSI_INITIAL_R2T_NO and ISCSI_IMMEDIATE_DATA_YES.
The final flag was set wrong or no data was sent.
It was also broken if the data did not fit into the cmd_pdu as
the consecutive pdus did not have the scsi_cbdata set which
lead to a segfault in iscsi_get_user_out_buffer().
Unfortunately we need to include scsi-lowlevel.h again in iscsi-private.h.
This should be fixed asap by introduction of an iscsi_task struct
to avoid to store iscsi relevant data in the scsi_task.
Signed-off-by: Peter Lieven <pl@kamp.de>
Conflicts:
lib/iscsi-command.c
Signed-off-by: Peter Lieven <pl@kamp.de>
