An iser target may send iscsi NO-OP PDUs as soon as it marks the iSER
iSCSI session as fully operative. This means that there is window
where there are no posted receive buffers on the initiator side, so
it's possible for the iSER RC connection to break because of RNR NAK /
retry errors. To fix this, rely on the flags bits in the login
request to have FFP (0x3) in the lower nibble as a marker for the
final login request, and post an initial chunk of receive buffers
before sending that login request instead of after getting the login
response.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
We allocate the login dma buffers in iser_verbs.c as part of
alloc_ib_conn_resources(), however we are freeing them in
iser_initiator.c as part of iser_free_rx_descriptors(). This is
needlessly confusing. We have an alloc_rx_descriptors() and it
doesn't alloc something that the free_rx_descriptors() frees, and we
have an alloc_ib_conn_resources() that allocs something not freed by
free_ib_conn_resources(). Clean that up.
Signed-off-by: Doug Ledford <dledford@redhat.com>
[ Fix build error in iser_free_ib_conn_res(). - Or ]
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The driver counted on the transactional nature of iSCSI login/text
flows and used the same buffer for both the request and the response.
We also went further and did DMA mapping only once, with
DMA_FROM_DEVICE, which violates the DMA mapping API. Fix that by
using different buffers, one for requests and one for responses, and
use the correct DMA mapping direction for each.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
RFC3270 mandates that iSCSI PDUs are padded to the closest integer
number of four byte words. Fix the iser code to support that on both
the TX/RX flows.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This patch renames the following iscsi_proto.h structures to avoid
namespace issues with drivers/target/iscsi/iscsi_target_core.h:
*) struct iscsi_cmd -> struct iscsi_scsi_req
*) struct iscsi_cmd_rsp -> struct iscsi_scsi_rsp
*) struct iscsi_login -> struct iscsi_login_req
This patch includes useful ISCSI_FLAG_LOGIN_[CURRENT,NEXT]_STAGE*,
and ISCSI_FLAG_SNACK_TYPE_* definitions used by iscsi_target_mod, and
fixes the incorrect definition of struct iscsi_snack to following
RFC-3720 Section 10.16. SNACK Request.
Also, this patch updates libiscsi, iSER, be2iscsi, and bn2xi to
use the updated structure definitions in a handful of locations.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Currently the iSER receive completion flow takes the session lock
twice. Optimize it to avoid the first one by letting
iser_task_rdma_finalize() be called only from the cleanup_task
callback invoked by iscsi_free_task, thus reducing the contention on
the session lock between the scsi command submission to the scsi
command completion flows.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
libiscsi passthrough mode invokes the transport xmit calls directly
without first going through an internal queue, unlike the other mode,
which uses a queue and a xmitworker thread. Now that the "cant_sleep"
prerequisite of iscsi_host_alloc is met, move to use it. Handling
xmit errors is now done by the passthrough flow of libiscsi. Since
the queue/worker aren't used in this mode, the code that schedules the
xmitworker is removed.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Remove unnecessary checks for the IB connection state and for QP
overflow, as conn state changes are reported by iSER to libiscsi and
handled there. QP overflow is theoretically possible only when
unsolicited data-outs are used; anyway it's being checked and handled
by HW drivers.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Two minor flows in iSER's data path still use allocations; move them
to be atomic as a preperation step towards moving to use libiscsi
passthrough mode.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Simplify and shrink the logic/code used for the send descriptors.
Changes include removing struct iser_dto (an unnecessary abstraction),
using struct iser_regd_buf only for handling SCSI commands, using
dma_sync instead of dma_map/unmap, etc.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Now that both the posting and reaping of receive buffers is done in
the completion path, the counter of outstanding buffers not be atomic.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Currently, the recv buffer posting logic is based on the transactional
nature of iSER which allows for posting a buffer before sending a PDU.
Change this to post only when the number of outstanding recv buffers
is below a water mark and in a batched manner, thus simplifying and
optimizing the data path. Use a pre-allocated ring of recv buffers
instead of allocating from kmem cache. A special treatment is given
to the login response buffer whose size must be 8K unlike the size of
buffers used for any other purpose which is 128 bytes.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
We will make a major change in the recv buffer posting logic, after
which the problem commit bba7ebb "avoid recv buffer exhaustion caused
by unexpected PDUs" comes to solve doesn't exist any more, so revert it.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
We were using the shost work queue which ended up being
a little akward since all iscsi hosts need a thread for
scanning, but only drivers hooked into libiscsi need
a workqueue for transmitting. So this patch moves the
xmit workqueue to the lib.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This just converts iser to new alloc_pdu api. It still
preallocates the pdu, so there is no difference.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
iSCSI/iSER targets may send PDUs without a prior request from the
initiator. RFC 5046 refers to these PDUs as "unexpected". NOP-In PDUs
with itt=RESERVED and Asynchronous Message PDUs occupy this category.
The amount of active "unexpected" PDU's an iSER target may have at any
time is governed by the MaxOutstandingUnexpectedPDUs key, which is not
yet supported.
Currently when an iSER target sends an "unexpected" PDU, the
initiators recv buffer consumed by the PDU is not replaced. If over
initial_post_recv_bufs_num "unexpected" PDUs are received then the
receive queue will run out of receive work requests entirely.
This patch ensures recv buffers consumed by "unexpected" PDUs are
replaced in the next iser_post_receive_control() call.
Signed-off-by: David Disseldorp <ddiss@sgi.com>
Signed-off-by: Ken Sandars <ksandars@sgi.com>
Acked-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (102 commits)
[SCSI] scsi_dh: fix kconfig related build errors
[SCSI] sym53c8xx: Fix bogus sym_que_entry re-implementation of container_of
[SCSI] scsi_cmnd.h: remove double inclusion of linux/blkdev.h
[SCSI] make struct scsi_{host,target}_type static
[SCSI] fix locking in host use of blk_plug_device()
[SCSI] zfcp: Cleanup external header file
[SCSI] zfcp: Cleanup code in zfcp_erp.c
[SCSI] zfcp: zfcp_fsf cleanup.
[SCSI] zfcp: consolidate sysfs things into one file.
[SCSI] zfcp: Cleanup of code in zfcp_aux.c
[SCSI] zfcp: Cleanup of code in zfcp_scsi.c
[SCSI] zfcp: Move status accessors from zfcp to SCSI include file.
[SCSI] zfcp: Small QDIO cleanups
[SCSI] zfcp: Adapter reopen for large number of unsolicited status
[SCSI] zfcp: Fix error checking for ELS ADISC requests
[SCSI] zfcp: wait until adapter is finished with ERP during auto-port
[SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver
[SCSI] sg: Add target reset support
[SCSI] lib: Add support for the T10 (SCSI) Data Integrity Field CRC
[SCSI] sd: Move scsi_disk() accessor function to sd.h
...
The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.
We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.
This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This handles the iscsi_cmd_task rename and renames
the iser cmd task to iser task.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Convert ib_iser to support merged tasks.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Currently to get a ctask from the session cmd array, you have to
know to use the itt modifier. To make this easier on LLDs and
so in the future we can easilly kill the session array and use
the host shared map instead, this patch adds a nice wrapper
to strip the itt into a session->cmds index and return a ctask.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The itt field in struct iscsi_data is not defined with any particular
endianness. open-iscsi should use it as-is without byte-swapping it.
This fixes sparse warnings coming from doing ntohl(hdr->itt).
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits)
[SCSI] usbstorage: use last_sector_bug flag universally
[SCSI] libsas: abstract STP task status into a function
[SCSI] ultrastor: clean up inline asm warnings
[SCSI] aic7xxx: fix firmware build
[SCSI] aacraid: fib context lock for management ioctls
[SCSI] ch: remove forward declarations
[SCSI] ch: fix device minor number management bug
[SCSI] ch: handle class_device_create failure properly
[SCSI] NCR5380: fix section mismatch
[SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices
[SCSI] IB/iSER: add logical unit reset support
[SCSI] don't use __GFP_DMA for sense buffers if not required
[SCSI] use dynamically allocated sense buffer
[SCSI] scsi.h: add macro for enclosure bit of inquiry data
[SCSI] sd: add fix for devices with last sector access problems
[SCSI] fix pcmcia compile problem
[SCSI] aacraid: add Voodoo Lite class of cards.
[SCSI] aacraid: add new driver features flags
[SCSI] qla2xxx: Update version number to 8.02.00-k7.
[SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command.
...
There is not need to block the session during logout. Since
we are going to fail the commands that were blocked just fail them
immediately instead.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
<asm/scatterlist.h> is not needed because everyplace it appears,
<linux/scatterlist.h> also appears. <asm/io.h> is not needed because
nothing seems to be using device IO anyway.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
iscsi_iser: convert to use the data buffer accessors
- remove the unnecessary map_single path.
- convert to use the new accessors for the sg lists and the
parameters.
TODO: use scsi_for_each_sg().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The SCSI midlayer may abort a command that was already sent. If the
initiator is still trying to send the command (or data-out PDUs for
that command), the QP may time out after the midlayer times
out. Therefore, when aborting the command, iSER may still have
references for the command's buffers. When sending these PDUs, the
sends will complete with an error and their resources will be released
then.
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This patch renames DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH to avoid
confusion with the drivers default values (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH
is the iscsi RFC specific default).
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
iSER limits the number of outstanding PDUs to send. When this threshold
is reached, it should return an error code (-ENOBUFS) instead of setting
the suspend_tx bit (which should be used only by libiscsi).
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Remove variables that are set but then never looked at in the iSER
initiator. These cleanups came from David Binderman's list of "set
but never used" warnings from icc.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
iSER uses the DMA mapping api to map the page holding the
SCSI command data to the HCA DMA address space. When the
command data is not aligned for RDMA, the data is copied
to/from an allocated buffer which in turn is used for
executing this command. The pages associated with the
command must be unmapped before being touched.
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
iSER uses a data transaction object (struct iser_dto) as part
of its IB data descriptors (struct iser_desc) management.
It also uses a hierarchy of connection structures pointing to
each other. A DTO may exist even after the iscsi_iser connection
pointed by it is destroyed (eg one that is bound to a post
receive buffer which was flushed by the IB HW). Hence DTOs need
point to the lowest connection, which is struct iser_conn.
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This file contains the iSER initiator processing of iSCSI PDUs - controls,
commands and data-outs along with processing of TX and RX completions.
It interacts with the lower level iser code doing the memory registration
and and the cma and verbs calls.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
