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2011-07-22target: Bump version to v4.1.0-rc1-mlNicholas Bellinger1-1/+1
This patch bumps the target core version to v4.1.0-rc1 now that we are in sync with upstream lio-core-2.6.git/master Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-22target: remove custom hex2bin() implementationAndy Shevchenko1-1/+0
This patch drops transport_asciihex_to_binaryhex() in favor of proper hex2bin usage from include/linux/kernel.h:hex2bin() Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-22target: Update QUEUE ALGORITHM MODIFIER control page defaultNicholas Bellinger3-0/+4
This patch adds the default 'Unrestricted reordering allowed' for SCSI control mode page QUEUE ALGORITHM MODIFIER on a per se_device basis in target_modesense_control() following spc4r23. This includes a new emuluate_rest_reord configfs attribute that currently (only) accepts zero to signal 'Unrestricted reordering allowed' in control mode page usage by the backend target device. Reported-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
2011-07-22target: ->map_task_SG conversion to ->map_control_SG and ->map_data_SGNicholas Bellinger1-2/+6
This patch breaks up the ->map_task_SG() backend call into two seperate ->map_control_SG() and ->map_data_SG() in order to better address IBLOCK and pSCSI. IBLOCK only allocates bios for ->map_data_SG(), and pSCSI will allocate a struct request for both cases. This patch fixes incorrect usage of ->map_task_SG() for all se_cmd descriptors in transport_generic_new_cmd() by moving the call into it's proper location directly inside of transport_allocate_data_tasks() Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-22target: Follow up core updates from AGrover and HCH (round 4)Andy Grover2-7/+2
This patch contains the squashed version of forth round series cleanups from Andy and Christoph following the post heavy lifting in the preceeding: 'Eliminate usage of struct se_mem' and 'Make all control CDBs scatter-gather' changes. This also includes a conversion of target core and the v3.0 mainline fabric modules (loopback and tcm_fc) to use pr_debug and the CONFIG_DYNAMIC_DEBUG infrastructure! These have been squashed into this third and final round for v3.1. target: Remove ifdeffed code in t_g_process_write target: Remove direct ramdisk code target: Rename task_sg_num to task_sg_nents target: Remove custom debug macros for pr_debug. Use pr_err(). target: Remove custom debug macros in mainline fabrics target: Set WSNZ=1 in block limits VPD. Abort if WRITE_SAME sectors = 0 target: Remove transport do_se_mem_map callback target: Further simplify transport_free_pages target: Redo task allocation return value handling target: Remove extra parentheses target: change alloc_task call to take *cdb, not *cmd (nab: Fix bogus struct file assignments in fd_do_readv and fd_do_writev) Signed-off-by: Andy Grover <agrover@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-22target: Eliminate usage of struct se_memAndy Grover1-4/+6
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>
2011-07-22target: Pass 2nd param of transport_split_cdb by valueAndy Grover1-1/+1
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>
2011-07-22target: Enforce 1 page max for control cdb buffer sizesAndy Grover1-0/+1
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>
2011-07-22target: Make all control CDBs scatter-gatherAndy Grover2-8/+3
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>
2011-07-22target: Implement Block Device Characteristics VPD pageRoland Dreier3-0/+4
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>
2011-07-22target: Add SCF_EMULATE_QUEUE_FULL -> transport_handle_queue_fullNicholas Bellinger1-0/+9
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>
2011-07-22target: Add transport_handle_cdb_direct optimizationNicholas Bellinger1-0/+1
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>
2011-07-22target: merge release_cmd methodsChristoph Hellwig2-4/+3
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>
2011-07-22target: remove the unused SCF_* flagsChristoph Hellwig1-4/+0
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>
2011-07-22target: remove the always-noop ->new_cmd_failure methodChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-22target: Updates from AGrover and HCH (round 3)Andy Grover3-64/+49
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>
2011-07-22target: More core cleanups from AGrover (round 2)Andy Grover3-12/+10
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>
2011-07-22target: Core cleanups from AGrover (round 1)Andy Grover2-85/+16
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>
2011-07-22target: Remove unnecessary *cdb transport_get_lun_for_cmd parameterNicholas Bellinger1-1/+1
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>
2011-05-24[SCSI] target: Convert REPORT_LUNs to use int_to_scsilunNicholas Bellinger1-1/+0
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>
2011-05-24[SCSI] target: Fix bug with task_sg chained transport_free_dev_tasks releaseNicholas Bellinger2-0/+2
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>
2011-03-31Fix common misspellingsLucas De Marchi2-4/+4
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-23[SCSI] target: add initial statisticsNicholas Bellinger2-2/+37
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>
2011-03-23[SCSI] target: update version to v4.0.0-rc7-mlNicholas Bellinger1-1/+1
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-03-23[SCSI] target: Convert TMR REQ/RSP definitions to target namespaceNicholas Bellinger1-30/+22
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>
2011-03-23[SCSI] target: Remove spurious double cast from structure macro accessorsNicholas Bellinger1-11/+11
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>
2011-03-23[SCSI] target: Minor sparse warning fixes and annotationsDan Carpenter3-8/+12
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>
2011-02-28[SCSI] target: Fix t_transport_aborted handling in LUN_RESET + active I/O ↵Nicholas Bellinger1-0/+2
shutdown 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>
2011-02-12[SCSI] target: fix use after free detected by SLUB poisonNicholas Bellinger1-0/+1
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>
2011-02-12[SCSI] target: Remove procfs based target_core_mib.c codeNicholas Bellinger2-6/+23
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>
2011-01-14[SCSI] target: Add LIO target core v4.0.0-rc6Nicholas Bellinger10-0/+1860
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>