1. 16 Jun, 2015 1 commit
    • Nicholas Bellinger's avatar
      target: Drop unnecessary core_tpg_register TFO parameter · bc0c94b1
      Nicholas Bellinger authored
      This patch drops unnecessary target_core_fabric_ops parameter usage
      for core_tpg_register() during fabric driver TFO->fabric_make_tpg()
      se_portal_group creation callback execution.
      
      Instead, use the existing se_wwn->wwn_tf->tf_ops pointer to ensure
      fabric driver is really using the same TFO provided at module_init
      time.
      
      Also go ahead and drop the forward TFO declarations tree-wide, and
      handling the special case for iscsi-target discovery TPG.
      
      Cc: Christoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      bc0c94b1
  2. 01 Jun, 2015 17 commits
    • Nicholas Bellinger's avatar
      target: Drop se_lun->lun_active for existing percpu lun_ref · 9e37d042
      Nicholas Bellinger authored
      With se_port_t and t10_alua_tg_pt_gp_member being absored into se_lun,
      there is no need for an extra atomic_t based reference count for PR
      ALL_TG_PT=1 and ALUA access state transition.
      
      Go ahead and use the existing percpu se_lun->lun_ref instead, and
      convert the two special cases to percpu_ref_tryget_live() to avoid
      se_lun if transport_clear_lun_ref() has already been invoked to
      shutdown the se_lun.
      
      Cc: Christoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      9e37d042
    • Nicholas Bellinger's avatar
      target: Drop lun_sep_lock for se_lun->lun_se_dev RCU usage · 4cc987ea
      Nicholas Bellinger authored
      With se_port and t10_alua_tg_pt_gp_member being absored into se_lun,
      there is no need for an extra lock to protect se_lun->lun_se_dev
      assignment.
      
      This patch also converts backend drivers to use call_rcu() release
      to allow any se_device readers to complete.  The call_rcu() instead
      of kfree_rcu() is required here because se_device is embedded into
      the backend driver specific structure.
      
      Also, convert se_lun->lun_stats to use atomic_long_t within the
      target_complete_ok_work() completion callback, and add FIXME for
      transport_lookup_tmr_lun() with se_lun->lun_ref.
      
      Finally, update sbp_update_unit_directory() special case usage with
      proper rcu_dereference_raw() and configfs symlink comment.
      Reported-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Chris Boot <bootc@bootc.net>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      4cc987ea
    • Christoph Hellwig's avatar
      target: Subsume se_port + t10_alua_tg_pt_gp_member into se_lun · adf653f9
      Christoph Hellwig authored
      This patch eliminates all se_port + t10_alua_tg_pt_gp_member usage,
      and converts current users to direct se_lun pointer dereference.
      
      This includes the removal of core_export_port(), core_release_port()
      core_dev_export() and core_dev_unexport().  Along with conversion
      of special case se_lun pointer dereference within PR ALL_TG_PT=1
      and ALUA access state transition UNIT_ATTENTION handling.
      
      Also, update core_enable_device_list_for_node() to reference the
      new per se_lun->lun_deve_list when creating a new entry, or
      replacing an existing one via RCU.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      adf653f9
    • Bart Van Assche's avatar
      target: Simplify LUN shutdown code · b3eeea66
      Bart Van Assche authored
      Instead of starting a thread from transport_clear_lun_ref() that
      waits for LUN shutdown, wait in that function for LUN shutdown
      to finish. Additionally, change the return type of
      transport_clear_lun_ref() from int to void.
      Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      b3eeea66
    • Christoph Hellwig's avatar
      target: simplify backend attribute implementation · 3effdb90
      Christoph Hellwig authored
      Consolidate the implementation of the backend attributes in a single file
      and single function per attribute show/store function instead of splitting
      it into multiple functions in multiple files.
      
      Also use the proper strto* helpers for exposed data types, add macros to
      implement the store methods for the most common data types and share the
      show methods between the two different attribute implementations.
      
      (Fix bogus store_pi_prot_format flag=0 return value - nab)
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      3effdb90
    • Christoph Hellwig's avatar
      target: consolidate backend attribute implementations · 5873c4d1
      Christoph Hellwig authored
      Provide a common sets of dev_attrib attributes for all devices using the
      generic SPC/SBC parsers, and a second one with the minimal required read-only
      attributes for passthrough devices.  The later is only used by pscsi for now,
      but will be wired up for the full-passthrough TCMU use case as well.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      5873c4d1
    • Christoph Hellwig's avatar
      target: simplify backend driver registration · 0a06d430
      Christoph Hellwig authored
      Rewrite the backend driver registration based on what we did to the fabric
      drivers:  introduce a read-only struct target_bakckend_ops that the driver
      registers, which is then instanciate as a struct target_backend by the
      core.  This allows the ops vector to be smaller and allows us to mark it
      const.  At the same time the registration function can set up the
      configfs attributes, avoiding the need to add additional boilerplate code
      for that to the drivers.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      0a06d430
    • Nicholas Bellinger's avatar
      target: Drop left-over se_lun->lun_status · 46247737
      Nicholas Bellinger authored
      Now that se_portal_group->tpg_lun_hlist is a RCU protected hlist,
      go ahead and drop the left-over lun->lun_status usage.
      Reported-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      46247737
    • Nicholas Bellinger's avatar
      target: Only reset specific dynamic entries during lun_group creation · df9766ca
      Nicholas Bellinger authored
      This patch changes core_tpg_add_node_to_devs() to avoid unnecessarly
      resetting every se_dev_entry in se_node_acl->tpg_lun_hlist when the
      operation is driven by an explicit configfs se_lun->lun_group creation
      via core_dev_add_lun() to only update a single se_lun.
      
      Otherwise for the second core_tpg_check_initiator_node_acl() case, go
      ahead and continue to scan the full set of currently active se_lun in
      se_portal_group->tpg_lun_hlist.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      df9766ca
    • Nicholas Bellinger's avatar
      target: Drop unused se_lun->lun_acl_list · 84786546
      Nicholas Bellinger authored
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      84786546
    • Nicholas Bellinger's avatar
      target: Convert core_tpg_deregister to use list splice · 22793de5
      Nicholas Bellinger authored
      This patch converts core_tpg_deregister() to perform a list splice
      for any remaining dynamically generated se_node_acls attached to
      se_tpg, before calling kfree(nacl) to free memory.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      22793de5
    • Nicholas Bellinger's avatar
      target: Convert se_tpg->acl_node_lock to ->acl_node_mutex · 403edd78
      Nicholas Bellinger authored
      This patch converts se_tpg->acl_node_lock to struct mutex, so that
      ->acl_node_acl walkers in core_clear_lun_from_tpg() can block when
      calling core_disable_device_list_for_node().
      
      It also updates core_dev_add_lun() to hold ->acl_node_mutex when
      calling core_tpg_add_node_to_devs() to build ->lun_entry_hlist
      for dynamically generated se_node_acl.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      403edd78
    • Nicholas Bellinger's avatar
      target: Convert se_portal_group->tpg_lun_list[] to RCU hlist · 6bb82612
      Nicholas Bellinger authored
      This patch converts the fixed size se_portal_group->tpg_lun_list[]
      to use modern RCU with hlist_head in order to support an arbitary
      number of se_lun ports per target endpoint.
      
      It includes dropping core_tpg_alloc_lun() from core_dev_add_lun(),
      and calling it directly from target_fabric_make_lun() to allocate
      a new se_lun.  And add a new target_fabric_port_release() configfs
      item callback to invoke kfree_rcu() to release memory during
      se_lun->lun_group shutdown.
      
      Also now that se_node_acl->lun_entry_hlist is using RCU, convert
      existing tpg_lun_lock to struct mutex so core_tpg_add_node_to_devs()
      can perform RCU updater logic without releasing ->tpg_lun_mutex.
      
      Also, drop core_tpg_clear_object_luns() and it's single consumer
      in iscsi-target, which is duplicating TPG LUN shutdown logic and
      is current code results in a NOP.
      
      Finally, sbp-target and xen-scsiback fabric driver conversions are
      included, which are required due to the non-standard way they use
      ->tpg_lun_hlist.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Chris Boot <bootc@bootc.net>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      6bb82612
    • Christoph Hellwig's avatar
      target/pr: cleanup core_scsi3_pr_seq_non_holder · 9fcb57f3
      Christoph Hellwig authored
      Clean up the mess of registered variables, and pass the isid mismatch
      flag explicitly instead of overloading the registration type.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      9fcb57f3
    • Nicholas Bellinger's avatar
      target/pr: Change alloc_registration to avoid pr_reg_tg_pt_lun · 79dc9c9e
      Nicholas Bellinger authored
      This patch changes __core_scsi3_do_alloc_registration() code to
      drop pr_reg->pr_reg_tg_pt_lun pointer usage in favor of a new
      pr_reg RPTI + existing pr_reg->pr_aptpl_target_lun used by
      APTPL metadata logic.
      
      It also includes changes to REGISTER, REGISTER_AND_MOVE and APTPL
      feature bit codepaths to use rcu_dereference_check() with the
      expected non-zero se_dev_entry->pr_kref reference held.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      79dc9c9e
    • Nicholas Bellinger's avatar
      target/pr: Use atomic bitop for se_dev_entry->deve_flags reservation check · 80bfdfa9
      Nicholas Bellinger authored
      This patch converts the core_scsi3_pr_seq_non_holder() check for non
      reservation holding registrations to use an atomic bitop in ->deve_flags
      to determine if a registration is currently active.
      
      It also includes associated a set_bit() in __core_scsi3_add_registration()
      and clear_bit() in __core_scsi3_free_registration(), if se_dev_entry still
      exists, and has not already been released via se_dev_entry shutdown path
      in core_disable_device_list_for_node().
      
      Also, clear_bit in core_disable_device_list_for_node as well to ensure
      the read-critical path in core_scsi3_pr_seq_non_holder() picks up the
      new state, preceeding the final kfree_rcu() call.
      Reported-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      80bfdfa9
    • Nicholas Bellinger's avatar
      target: Convert se_node_acl->device_list[] to RCU hlist · 29a05dee
      Nicholas Bellinger authored
      This patch converts se_node_acl->device_list[] table for mappedluns
      to modern RCU hlist_head usage in order to support an arbitrary number
      of node_acl lun mappings.
      
      It converts transport_lookup_*_lun() fast-path code to use RCU read path
      primitives when looking up se_dev_entry.  It adds a new hlist_head at
      se_node_acl->lun_entry_hlist for this purpose.
      
      For transport_lookup_cmd_lun() code, it works with existing per-cpu
      se_lun->lun_ref when associating se_cmd with se_lun + se_device.
      Also, go ahead and update core_create_device_list_for_node() +
      core_free_device_list_for_node() to use ->lun_entry_hlist.
      
      It also converts se_dev_entry->pr_ref_count access to use modern
      struct kref counting, and updates core_disable_device_list_for_node()
      to kref_put() and block on se_deve->pr_comp waiting for outstanding PR
      special-case PR references to drop, then invoke kfree_rcu() to wait
      for the RCU grace period to complete before releasing memory.
      
      So now that se_node_acl->lun_entry_hlist fast path access uses RCU
      protected pointers, go ahead and convert remaining non-fast path
      RCU updater code using ->lun_entry_lock to struct mutex to allow
      callers to block while walking se_node_acl->lun_entry_hlist.
      
      Finally drop the left-over core_clear_initiator_node_from_tpg() that
      originally cleared lun_access during se_node_acl shutdown, as post
      RCU conversion it now becomes duplicated logic.
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      29a05dee
  3. 31 May, 2015 22 commits