Both backstores and fabrics use arrays of struct scatterlist to describe
data buffers. However TCM used struct se_mems, basically a linked list
of scatterlist entries. We are able to simplify the code by eliminating
this intermediate data structure and just using struct scatterlist[]
throughout.
Also, moved attachment of task to cmd out of transport_generic_get_task
and into allocate_control_task and allocate_data_tasks. The reasoning
is that it's nonintuitive that get_task should automatically add it to
the cmd's task list -- it should just return an allocated, initialized
task. That's all it should do, based on the function's name, so either the
function shouldn't do it, or the name should change to encapsulate the
entire essence of what it does.
(nab: Fix compile warnings in tcm_fc, and make transport_kmap_first_data_page
honor sg->offset for SGLs from contigious memory with TCM_Loop, and
fix control se_cmd descriptor memory leak)
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Since sectors is not modified, it's more straightforward to do this.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Due to all cdbs' data buffers being referenced by scatterlists, buffers
of more than a page are not contiguous. Instead of handling this in all
control command handlers, we may be able to get away with just limiting
control cdb data buffers to one page. The only control CDBs we handle that
have potentially large data buffers are REPORT LUNS and UNMAP, so if we
didn't want to live with this limitation, they would need to be modified
to walk the pages in the data buffer's sgl.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Previously, some control CDBs did not allocate memory in pages for their
data buffer, but just did a kmalloc. This patch makes all cdbs allocate
pages.
This has the benefit of streamlining some paths that had to behave
differently when we used two allocation methods. The downside is that
all accesses to the data buffer need to kmap it before use, and need to
handle data in page-sized chunks if more than a page is needed for a given
command's data buffer.
Finally, note that cdbs with no data buffers are handled a little
differently. Before, SCSI_NON_DATA_CDBs would not call get_mem at all
(they'd be in the final else in transport_allocate_resources) but now
these will make it into generic_get_mem, but just not allocate any
buffers.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Implement page B1h, Block Device Characteristics, so that we can report
a medium rotation rate of 1 (non-rotating / solid state) if the
is_nonrot device attribute is set; we update the iblock backend to set
this attribute if the underlying Linux block device has its nonrot
flag set.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds SCF_EMULATE_QUEUE_FULL support using -EAGAIN failures
via transport_handle_queue_full() to signal queue full in completion
path TFO->queue_data_in() and TFO->queue_status() callbacks.
This is done using a new se_cmd->transport_qf_callback() to handle
the following queue full exception cases within target core:
*) TRANSPORT_COMPLETE_OK (for completion path queue full)
*) TRANSPORT_COMPLETE_QF_WP (for TRANSPORT_WRITE_PENDING queue full)
*) transport_send_check_condition_and_sense() failure paths in
transport_generic_request_failure() and transport_generic_complete_ok()
All logic is driven using se_device->qf_work_queue -> target_qf_do_work()
to to requeue outstanding se_cmd at the head of se_dev->queue_obj->qobj_list
for transport_processing_thread() execution.
Tested using tcm_qla2xxx with MAX_OUTSTANDING_COMMANDS=128 for FCP READ
to trigger the TRANSPORT_COMPLETE_OK queue full cases, and a simulated
TFO->write_pending() -EAGAIN failure to trigger TRANSPORT_COMPLETE_QF_WP.
Reported-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds a transport_handle_cdb_direct() optimization for mapping
and queueing tasks directly from within fabric processing context by calling
the newly exported transport_generic_new_cmd(). This currently expects to
be called from process context only, and will fail if called within interrupt
context.
This patch also leaves transport_generic_handle_cdb() unmodified for the
moment to function as expected with existing tcm_fc and ib_srpt fabrics,
and will be removed once these have been converted and tested with v4.1
code using transport_handle_cdb_direct().
Based on Andy's original patch here:
[PATCH 39/42] target: Call transport_new_cmd instead of adding to cmd queue
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The release_cmd_to_pool and release_cmd_direct methods are always the same.
Merge them into a single release_cmd method, and clean up the fallout.
(nab: fix breakage in transport_generic_free_cmd() parameter build breakage
in drivers/target/tcm_fc/tfc_cmd.c)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains a squashed version to remove unused SCF_* flags:
target: remove the unused SCF_SE_DISABLE_ONLINE_CHECK flag
target: remove the unused SCF_CMD_PASSTHROUGH_NOALLOC flag
target: remove the unused SCF_EMULATE_SYNC_UNMAP flag
target: remove the unused SCF_EMULATE_SYNC_CACHE flag
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains a squashed version of third round series cleanups,
improvements ,and simplfications from Andy and Christoph ahead of the
heavy lifting between round 3 -> 4 for the target core SGL conversion.
This include cleanups to the main target I/O path and other miscellaneous
updates.
target: Replace custom sg<->buf functions with lib funcs
target: Simplify sector limiting code
target: get_cdb should never return NULL
target: Simplify transport_memcpy_se_mem_read_contig
target: Use assignment rather than increment for t_task_cdbs
target: Don't pass dma_size to generic_get_mem
target: Pass sg with type scatterlist in transport_map_sg_to_mem
target: Move task_sg_num next to task_sg in struct se_task
target: inline struct se_transport_task into struct se_cmd
target: Change name & semantics of transport_get_sectors()
target: Remove unused members of se_cmd
target: Rename se_cmd.t_task_cdbs to t_task_list_num
target: Fix some spelling
target: Remove unused var from transport_generic_do_tmr
target: map_sg_to_mem: return sg_count in return value
target/pscsi: Use min_t for sector limits
target/pscsi: Unused param for pscsi_get_bio()
target: Rename get_cdb_count to allocate_tasks
target: Make transport_generic_new_cmd() available for iscsi-target
target: Remove fabric callback to allocate iovecs
target: Fix transport_generic_new_cmd WRITE comment
(hch: Use __GFP_ZERO usage for alloc_pages() usage)
Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the squashed version of second round of target core
cleanups and simplifications and Andy and Co. It also contains a handful
of fixes to address bugs the original series and other minor cleanups.
Here is the condensed shortlog:
target: Remove unneeded casts to void*
target: Rename get_lun_for_{cmd,tmr} to lookup_{cmd,tmr}_lun
target: Make t_task a member of se_cmd, not a pointer
target: Handle functions returning "-2"
target: Use cmd->se_dev over cmd->se_lun->lun_se_dev
target: Embed qr in struct se_cmd
target: Replace embedded struct se_queue_req with a list_head
target: Rename list_heads that are nodes in struct se_cmd to "*_node"
target: Fold transport_device_setup_cmd() into lookup_{tmr,cmd}_lun()
target: Make t_mem_list and t_mem_list_bidi members of t_task
target: Add comment & cleanup transport_map_sg_to_mem()
target: Remove unneeded checks in transport_free_pages()
(Roland: Fix se_queue_req removal leftovers OOPs)
(nab: Fix transport_lookup_tmr_lun failure case)
(nab: Fix list_empty(&cmd->t_task.t_mem_bidi_list) inversion bugs)
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the squashed version of a number of cleanups and
minor fixes from Andy's initial series (round 1) for target core this
past spring. The condensed log looks like:
target: use errno values instead of returning -1 for everything
target: Rename transport_calc_sg_num to transport_init_task_sg
target: Fix leak in error path in transport_init_task_sg
target/pscsi: Remove pscsi_get_sh() usage
target: Make two runtime checks into WARN_ONs
target: Remove hba queue depth and convert to spin_lock_irq usage
target: dev->dev_status_queue_obj is unused
target: Make struct se_queue_req.cmd type struct se_cmd *
target: Remove __transport_get_qr_from_queue()
target: Rename se_dev->g_se_dev_list to se_dev_node
target: Remove struct se_global
target: Simplify scsi mib index table code
target: Make dev_queue_obj a member of se_device instead of a pointer
target: remove extraneous returns at end of void functions
target: Ensure transport_dump_vpd_ident_type returns null-terminated str
target: Function pointers don't need to use '&' to be assigned
target: Fix comment in __transport_execute_tasks()
target: Misc style cleanups
target: rename struct pr_reservation_template to pr_reservation
target: Remove #defines that just perform indirection
target: Inline transport_get_task_from_execute_queue()
target: Minor header comment fixes
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch removes the now unnecessary 'unsigned char *cdb' function
parameter from transport_get_lun_for_cmd(). This also includes updating
lio-target, tcm_loop and tcm_fc usage of transport_get_lun_for_cmd().
Reported-by: Fubo Chen <fubo.chen@gmail.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
This patch converts transport_core_report_lun_response() to use
drivers/scsi/scsi_scan.c:int_to_scsilun instead of using the
struct target_core_fabric_ops->pack_lun() fabric provided API vector.
It also removes the tfo->pack_lun check from target_fabric_tf_ops_check()
and removes from struct target_core_fabric_ops->pack_lun() from
target_core_fabric_ops.h, and the following mainline scsi-misc fabric
modules:
*) tcm_loop: Drop tcm_loop_pack_lun() usage
*) tcm_fc: Drop ft_pack_lun() usage
Reported-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <jbottomley@parallels.com>
This patch addresses a bug in the target core release path for HW
operation where transport_free_dev_tasks() was incorrectly being called
from transport_lun_remove_cmd() while releasing a se_cmd reference and
calling struct target_core_fabric_ops->queue_data_in().
This would result in a OOPs with HW target mode when the release of
se_task->task_sg[] would happen before pci_unmap_sg() can be called in
HW target mode fabric module code. This patch addresses the issue by
moving transport_free_dev_tasks() from transport_lun_remove_cmd() into
transport_generic_free_cmd(), and adding TRANSPORT_FREE_CMD_INTR and
transport_generic_free_cmd_intr() to allow se_cmd descriptor release
to happen fromfrom within transport_processing_thread() process context
when release of se_cmd is not possible from HW interrupt context.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>
This patch adds a target_core_mib.c statistics conversion for
backend context struct se_subsystem_dev + struct se_device config_group
based statistics in target_core_device.c using CONFIGFS_EATTR()
based struct config_item_types from target_core_stat.c code.
The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_dev, scsi_lu, and scsi_tgt_dev output
from within individual:
/sys/kernel/config/target/core/$HBA/DEV/
The legacy procfs output now appear as individual configfs attributes under:
*) $HBA/$DEV/statistics/scsi_dev:
|-- indx
|-- inst
|-- ports
`-- role
*) $HBA/$DEV/statistics/scsi_lu:
|-- creation_time
|-- dev
|-- dev_type
|-- full_stat
|-- hs_num_cmds
|-- indx
|-- inst
|-- lu_name
|-- lun
|-- num_cmds
|-- prod
|-- read_mbytes
|-- resets
|-- rev
|-- state_bit
|-- status
|-- vend
`-- write_mbytes
*) $HBA/$DEV/statistics/scsi_tgt_dev:
|-- indx
|-- inst
|-- non_access_lus
|-- num_lus
|-- resets
`-- status
The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_port, scsi_tgt_port and scsi_transport
output from within individual:
/sys/kernel/config/target/fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/
The legacy procfs output now appear as individual configfs attributes under:
*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_port
|-- busy_count
|-- dev
|-- indx
|-- inst
`-- role
*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_tgt_port
|-- dev
|-- hs_in_cmds
|-- in_cmds
|-- indx
|-- inst
|-- name
|-- port_index
|-- read_mbytes
`-- write_mbytes
*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_transport
|-- dev_name
|-- device
|-- indx
`-- inst
The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_att_intr_port and scsi_auth_intr output
from within individual:
/sys/kernel/config/target/fabric/$WWN/tpgt_$TPGT/acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/
The legacy procfs output now appear as individual configfs attributes under:
*) acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/scsi_att_intr_port
|-- dev
|-- indx
|-- inst
|-- port
|-- port_auth_indx
`-- port_ident
*) acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/scsi_auth_intr
|-- att_count
|-- creation_time
|-- dev
|-- dev_or_port
|-- hs_num_cmds
|-- indx
|-- inst
|-- intr_name
|-- map_indx
|-- num_cmds
|-- port
|-- read_mbytes
|-- row_status
`-- write_mbytes
Also, this includes adding struct target_fabric_configfs_template->
tfc_wwn_fabric_stats_cit and ->tfc_tpg_nacl_stat_cit respectively for
use during target_core_fabric_configfs.c:target_fabric_setup_cits()
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch changes include/target/target_core_tmr.h code to use
target specific 'TMR_*' prefixed definitions for fabric independent
SCSI Task Management Request/Request naming in include/scsi/scsi.h
definitions for mainline target code.
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Reported-by: Fubo Chen <fubo.chen@gmail.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch addresses the majority of sparse warnings and adds
proper locking annotations. It also fixes the dubious one-bit signed
bitfield, for which the signed one-bit types can be 0 or -1 which can
cause a problem if someone ever checks if (foo->lu_gp_assoc == 1).
The current code is fine because everyone just checks zero vs non-zero.
But Sparse complains about it so lets change it. The warnings look like
this:
include/target/target_core_base.h:228:26: error: dubious one-bit signed bitfield
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Fubo Chen <fubo.chen@gmail.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch addresses two outstanding bugs related to
T_TASK(cmd)->t_transport_aborted handling during TMR LUN_RESET and
active I/O shutdown.
This first involves adding two explict t_transport_aborted=1
assignments in core_tmr_lun_reset() in order to signal the task has
been aborted, and updating transport_generic_wait_for_tasks() to skip
sleeping when t_transport_aborted=1 has been set. This fixes an issue
where transport_generic_wait_for_tasks() would end up sleeping
indefinately when called from fabric module context while TMR
LUN_RESET was happening with long outstanding backend struct se_task
not yet being completed.
The second adds a missing call to
transport_remove_task_from_execute_queue() when
task->task_execute_queue=1 is set in order to fix an OOPs when
task->t_execute_list has not been dropped. It also fixes the same
case in transport_processing_shutdown() to prevent the issue from
happening during active I/O struct se_device shutdown.
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch moves a large number of memory release paths inside of the
configfs callback target_core_hba_item_ops->release() called from
within fs/configfs/item.c: config_item_cleanup() context. This patch
resolves the SLUB 'Poison overwritten' warnings.
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch removes the legacy procfs based target_core_mib.c code,
and moves the necessary scsi_index_tables functions and defines into
target_core_transport.c and target_core_base.h code to allow existing
fabric independent statistics to function.
This includes the removal of a handful of 'atomic_t mib_ref_count'
counters used in struct se_node_acl, se_session and se_hba to prevent
removal while using seq_list procfs walking logic.
[jejb: fix up compile failures]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
LIO target is a full featured in-kernel target framework with the
following feature set:
High-performance, non-blocking, multithreaded architecture with SIMD
support.
Advanced SCSI feature set:
* Persistent Reservations (PRs)
* Asymmetric Logical Unit Assignment (ALUA)
* Protocol and intra-nexus multiplexing, load-balancing and failover (MC/S)
* Full Error Recovery (ERL=0,1,2)
* Active/active task migration and session continuation (ERL=2)
* Thin LUN provisioning (UNMAP and WRITE_SAMExx)
Multiprotocol target plugins
Storage media independence:
* Virtualization of all storage media; transparent mapping of IO to LUNs
* No hard limits on number of LUNs per Target; maximum LUN size ~750 TB
* Backstores: SATA, SAS, SCSI, BluRay, DVD, FLASH, USB, ramdisk, etc.
Standards compliance:
* Full compliance with IETF (RFC 3720)
* Full implementation of SPC-4 PRs and ALUA
Significant code cleanups done by Christoph Hellwig.
[jejb: fix up for new block bdev exclusive interface. Minor fixes from
Randy Dunlap and Dan Carpenter.]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Andy Grover