14 Feb, 2013

2 commits

  • The loop in rd_execute_rw() will never terminate if the
    sg element has a zero size. Or it'll spill over into
    outer space if the sg element is larger than the available
    space.
    So we need to add some safety catches here.

    Cc: Nic Bellinger
    Signed-off-by: Hannes Reinecke
    Signed-off-by: Nicholas Bellinger

    Hannes Reinecke
     
  • Sequential scan of rd_dev->sg_table_array in rd_get_sg_table is
    a serious I/O performance bottleneck for large rd LUNs. Fix this
    by computing the sg_table index directly from page offset because
    all sg_tables (except the last one) have the same number of pages.

    Tested with 90 GiB rd_mcp LUN, where the patch improved maximal
    random R/W IOPS by more than 100-150%, depending on actual
    hardware and SAN setup.

    Signed-off-by: Martin Svec
    Signed-off-by: Nicholas Bellinger

    Martin Svec
     

28 Nov, 2012

1 commit


07 Nov, 2012

5 commits

  • Pass the sense reason as an explicit return value from the I/O submission
    path instead of storing it in struct se_cmd and using negative return
    values. This cleans up a lot of the code pathes, and with the sparse
    annotations for the new sense_reason_t type allows for much better
    error checking.

    (nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
    sense_reason_t with Roland's MODE SELECT changes)

    Signed-off-by: Christoph Hellwig
    Cc: Roland Dreier
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Now that the reservations and ALUA code have been cleaned up there is no need
    for the get_device_rev method, as we only need the standards revision in the
    inquiry data, where we can hardcode it.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • These really are sbc_ops, so name them correctly.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Simplify the code a lot by killing the superflous struct se_subsystem_dev.
    Instead se_device is allocated early on by the backend driver, which allocates
    it as part of its own per-device structure, borrowing the scheme that is for
    example used for inode allocation.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

17 Jul, 2012

2 commits

  • Remove the execute_cmd method in struct se_subsystem_api, and always use the
    one directly in struct se_cmd. To make life simpler for SBC virtual backends
    a struct spc_ops that is passed to sbc_parse_cmd is added. For now it
    only contains an execute_rw member, but more will follow with the subsequent
    commits.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Instead of trying to handle all SCSI command sets in one function
    (transport_generic_cmd_sequencer) call out to the backend driver to perform
    this functionality. For pSCSI a copy of the existing code is used, but for
    all virtual backends we can use a new parse_sbc_cdb helper is used to
    provide a simple SBC emulation.

    For now this setups means a fair amount of duplication between pSCSI and the
    SBC library, but patches later in this series will sort out that problem.

    (nab: Fix up build failure in target_core_pscsi.c)

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

07 May, 2012

3 commits

  • We can use struct se_cmd for everything it did. Make sure to pass the S/G
    list and data direction to the execution function to ease adding back BIDI
    support later on.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Now that we don't split commands the size field in the task is always
    equivalent to the one in the CDB, even in cases where we have two tasks
    due to a BIDI transfer. Just refer the the size in the command instead
    of duplicating it in the task.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • Now that we don't split commands the lba field in the task is always
    equivalent to the one in the CDB, even in cases where we have two tasks
    due to a BIDI transfer. Just refer the the lba in the command instead
    of duplicating it in the task.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

15 Apr, 2012

2 commits


14 Dec, 2011

2 commits

  • The command
    | echo rd_pages=32768 > ramdisk/control

    Does not work because it writes "rd_pages=32768\n" and the parser which
    matches for "rd_pages=%d" does not recognize it due to the \n. One way
    of fixing this would be using "echo -n" instead.
    This patch adds \n to the list of separators so we don't have to use the
    -n argument which I find is more convinient.

    Signed-off-by: Sebastian Andrzej Siewior
    Signed-off-by: Nicholas Bellinger

    Sebastian Andrzej Siewior
     
  • This reorganized the headers under include/target into:

    - target_core_base.h stays as is with all target-wide data stuctures and defines
    - target_core_backend.h contains the whole interface to I/O backends
    - target_core_fabric.h contains the whole interface to fabric modules

    Except for those only the various configfs macro headers stay around.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

06 Dec, 2011

3 commits

  • So the code assumes that the sg list is only a array while in reality
    loopback SGL memory via scsi_cmnd into target-core may be already
    chained. This patch converts ramdisk code to use sg_miter logic from
    scatterlist.h in order to properly support passthrough SGL usage with
    transport_generic_map_mem_to_cmd() via loopback.

    With this patch the bug goes away. However after umount/mount of the
    device my files are gone. So something is still not right. After looking
    at it for a while I decided to rewrite the that part of the code and now
    things do work for me.

    For reference:
    - http://article.gmane.org/gmane.linux.scsi.target.devel/595
    the sg_next() conversion
    - http://article.gmane.org/gmane.linux.scsi.target.devel/602
    the rewrite of the copy code

    (nab: Fix compile warning in rd_MEMCPY)

    Signed-off-by: Sebastian Andrzej Siewior
    Cc: stable@kernel.org
    Signed-off-by: Nicholas Bellinger

    Sebastian Andrzej Siewior
     
  • Breakout rd_MEMCPY_do_task() usage of do_div() to tmp value during
    rd_request->rd_page assignment.

    Signed-off-by: Sebastian Andrzej Siewior
    Signed-off-by: Nicholas Bellinger

    Sebastian Andrzej Siewior
     
  • This patch removes legacy usage of PYX_TRANSPORT_* return codes in a number
    of locations and addresses cases where transport_generic_request_failure()
    was returning the incorrect sense upon CHECK_CONDITION status after the
    v3.1 converson to use errno return codes.

    This includes the conversion of transport_generic_request_failure() to
    process cmd->scsi_sense_reason and handle extra TCM_RESERVATION_CONFLICT
    before calling transport_send_check_condition_and_sense() to queue up
    response status. It also drops PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES legacy
    usgae, and returns TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE w/ a response
    for these cases.

    transport_generic_allocate_tasks(), transport_generic_new_cmd(), backend
    SCF_SCSI_DATA_SG_IO_CDB ->do_task(), and emulated ->execute_task() have
    all been updated to set se_cmd->scsi_sense_reason and return errno codes
    universally upon failure. This includes cmd->scsi_sense_reason assignment
    in target_core_alua.c, target_core_pr.c and target_core_cdb.c emulation code.

    Finally it updates fabric modules to remove the legacy usage, and for
    TFO->new_cmd_map() callers forwards return values outside of fabric code.
    iscsi-target has also been updated to remove a handful of special cases
    related to the cleanup and signaling QUEUE_FULL handling w/ ft_write_pending()

    (v2: Drop extra SCF_SCSI_CDB_EXCEPTION check during failure from
    transport_generic_new_cmd, and re-add missing task->task_error_status
    assignment in transport_complete_task)

    Cc: Christoph Hellwig
    Cc: stable@kernel.org
    Signed-off-by: Nicholas Bellinger

    Nicholas Bellinger
     

24 Oct, 2011

2 commits

  • The most commonly used file, iblock and rd backends have no use for
    a per-task CDB and thus don't need a method to copy it into their
    otherwise unused CDB fields.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     
  • This is a squashed version of the following se_task cleanup patches:

    target: remove the unused task_state_flags field in se_task
    target: remove the unused se_obj_ptr field in se_task
    target: remove the se_dev field in se_task

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

11 Oct, 2011

1 commit


23 Aug, 2011

1 commit

  • Use BUG_ON(x) rather than if(x) BUG();

    The semantic patch that fixes this problem is as follows:
    (http://coccinelle.lip6.fr/)

    //
    @@ identifier x; @@
    -if (x) BUG();
    +BUG_ON(x);

    @@ identifier x; @@
    -if (!x) BUG();
    +BUG_ON(!x);
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: Nicholas Bellinger

    Julia Lawall
     

22 Jul, 2011

4 commits

  • 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
    Reviewed-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Andy Grover
     
  • 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 sgbuf 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
    Reviewed-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Andy Grover
     
  • 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
    Signed-off-by: Roland Dreier
    Signed-off-by: Nicholas Bellinger

    Andy Grover
     
  • 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
    Signed-off-by: Nicholas Bellinger

    Andy Grover
     

24 Mar, 2011

2 commits

  • This patch converts rd_build_device_space() to return errno usage
    for failures in rd_create_virtdevice().

    Signed-off-by: Dan Carpenter
    Signed-off-by: Nicholas A. Bellinger
    Signed-off-by: James Bottomley

    Dan Carpenter
     
  • This patch converts the target_core_store_dev_enable() -> struct
    se_subsystem_api->create_virtdevice() call to return proper ERR_PTR values
    back up to configfs logic during backend dependent struct se_device ENABLE
    exception conditions.

    Along with the change to target_core_configfs.c, this includes converting IBLOCK,
    FILEIO, pSCSI, and RAMDISK_* backend subsystem plugins to obtain upper level
    PTR_ERR return codes (where available), and return via ERR_PTR during a
    *_create_virtdev() failure.

    Reported-by: Fubo Chen
    Signed-off-by: Nicholas A. Bellinger
    Signed-off-by: James Bottomley

    Nicholas Bellinger
     

02 Mar, 2011

1 commit


15 Jan, 2011

1 commit

  • 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
    Signed-off-by: James Bottomley

    Nicholas Bellinger