Commit Graph

149 Commits

Author SHA1 Message Date
Nicholas Bellinger bd4e2d2907 target: Fix NULL dereference during LUN lookup + active I/O shutdown
When transport_clear_lun_ref() is shutting down a se_lun via
configfs with new I/O in-flight, it's possible to trigger a
NULL pointer dereference in transport_lookup_cmd_lun() due
to the fact percpu_ref_get() doesn't do any __PERCPU_REF_DEAD
checking before incrementing lun->lun_ref.count after
lun->lun_ref has switched to atomic_t mode.

This results in a NULL pointer dereference as LUN shutdown
code in core_tpg_remove_lun() continues running after the
existing ->release() -> core_tpg_lun_ref_release() callback
completes, and clears the RCU protected se_lun->lun_se_dev
pointer.

During the OOPs, the state of lun->lun_ref in the process
which triggered the NULL pointer dereference looks like
the following on v4.1.y stable code:

struct se_lun {
  lun_link_magic = 4294932337,
  lun_status = TRANSPORT_LUN_STATUS_FREE,

  .....

  lun_se_dev = 0x0,
  lun_sep = 0x0,

  .....

  lun_ref = {
    count = {
      counter = 1
    },
    percpu_count_ptr = 3,
    release = 0xffffffffa02fa1e0 <core_tpg_lun_ref_release>,
    confirm_switch = 0x0,
    force_atomic = false,
    rcu = {
      next = 0xffff88154fa1a5d0,
      func = 0xffffffff8137c4c0 <percpu_ref_switch_to_atomic_rcu>
    }
  }
}

To address this bug, use percpu_ref_tryget_live() to ensure
once __PERCPU_REF_DEAD is visable on all CPUs and ->lun_ref
has switched to atomic_t, all new I/Os will fail to obtain
a new lun->lun_ref reference.

Also use an explicit percpu_ref_kill_and_confirm() callback
to block on ->lun_ref_comp to allow the first stage and
associated RCU grace period to complete, and then block on
->lun_ref_shutdown waiting for the final percpu_ref_put()
to drop the last reference via transport_lun_remove_cmd()
before continuing with core_tpg_remove_lun() shutdown.

Reported-by: Rob Millner <rlm@daterainc.com>
Tested-by: Rob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Tested-by: Vaibhav Tandon <vst@datera.io>
Cc: Vaibhav Tandon <vst@datera.io>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-26 16:08:44 -08:00
Bart Van Assche 4f4c6c3ddb target: Remove se_tmr_req.tmr_lun
Member tmr_lun of se_tmr_req is set but not used. Hence remove it.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: Giridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:10 -08:00
Nicholas Bellinger 391e2a6de9 target: Don't BUG_ON during NodeACL dynamic -> explicit conversion
After the v4.2+ RCU conversion to se_node_acl->lun_entry_hlist,
a BUG_ON() was added in core_enable_device_list_for_node() to
detect when the located orig->se_lun_acl contains an existing
se_lun_acl pointer reference.

However, this scenario can happen when a dynamically generated
NodeACL is being converted to an explicit NodeACL, when the
explicit NodeACL contains a different LUN mapping than the
default provided by the WWN endpoint.

So instead of triggering BUG_ON(), go ahead and fail instead
following the original pre RCU conversion logic.

Reported-by: Benjamin ESTRABAUD <ben.estrabaud@mpstor.com>
Cc: Benjamin ESTRABAUD <ben.estrabaud@mpstor.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-08 07:46:31 -08:00
Bart Van Assche 8dcf07be2d target: Minimize #include directives
Remove superfluous #include directives from the include/target/*.h
files. Add missing #include directives to other *.h and *.c files.
Use forward declarations for structures where possible. This
change reduces the build time for make M=drivers/target on my
laptop from 27.1s to 18.7s or by about 30%.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
2016-12-09 10:22:28 -08:00
Mike Christie ea263c7fad target: Fix max_unmap_lba_count calc overflow
max_discard_sectors only 32bits, and some non scsi backend
devices will set this to the max 0xffffffff, so we can end up
overflowing during the max_unmap_lba_count calculation.

This fixes a regression caused by my patch:

commit 8a9ebe717a
Author: Mike Christie <mchristi@redhat.com>
Date:   Mon Jan 18 14:09:27 2016 -0600

    target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

which can result in extra discards being sent to due the overflow
causing max_unmap_lba_count to be smaller than what the backing
device can actually support.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:36 -07:00
Andy Grover 03a68b44fa target: Remove enum transport_lunflags_table
se_dev_entry.lun_flags and se_lun.lun_access are only used for keeping
track of read-write vs. read-only state. Since this is an either/or thing
we can represent it as bool, and remove the unneeded enum
transport_lunflags_table, which is left over from when there were more
flags.

Change code that uses this enum to just use true/false, and make it clear
through variable and param names that true means read-only, false means
read-write.

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-03-10 21:48:55 -08:00
Mike Christie 8a9ebe717a target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors
In a couple places we are not converting to/from the Linux
block layer 512 bytes sectors.

1.

The request queue values and what we do are a mismatch of
things:

max_discard_sectors - This is in linux block layer 512 byte
sectors. We are just copying this to max_unmap_lba_count.

discard_granularity - This is in bytes. We are converting it
to Linux block layer 512 byte sectors.

discard_alignment - This is in bytes. We are just copying
this over.

The problem is that the core LIO code exports these values in
spc_emulate_evpd_b0 and we use them to test request arguments
in sbc_execute_unmap, but we never convert to the block size
we export to the initiator. If we are not using 512 byte sectors
then we are exporting the wrong values or are checks are off.
And, for the discard_alignment/bytes case we are just plain messed
up.

2.

blkdev_issue_discard's start and number of sector arguments
are supposed to be in linux block layer 512 byte sectors. We are
currently passing in the values we get from the initiator which
might be based on some other sector size.

There is a similar problem in iblock_execute_write_same where
the bio functions want values in 512 byte sectors but we are
passing in what we got from the initiator.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-01-29 19:29:34 -08:00
Jamie Pocas e6f41633cb target/sbc: Add LBPRZ attribute + control CDB emulation
This change sets the LBPRZ flag in EVPD page b2h and READ CAPACITY (16)
based on a new unmap_zeroes_data device attribute. This flag is set
automatically for iblock based on underlying block device queue's
discard_zeroes_data flag.

Signed-off-by: Jamie Pocas <jamie.pocas@emc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-01-06 13:39:55 -08:00
Nicholas Bellinger 8fa3a86748 target: Make TCM_WRITE_PROTECT failure honor D_SENSE bit
This patch changes transport_lookup_cmd_lun() to obtain
se_lun->lun_ref + se_cmd->se_device rcu_dereference during
TCM_WRITE_PROTECT -> CHECK_CONDITION failure status.

Do this to ensure the active control D_SENSE mode page bit
is being honored.

Reported-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-09-24 23:17:27 -07:00
Nicholas Bellinger 3ccd6e83df target: Fix PR registration + APTPL RCU conversion regression
This patch fixes a v4.2+ regression introduced by commit 79dc9c9e86
where lookup of t10_pr_registration->pr_reg_deve and associated
->pr_kref get was missing from __core_scsi3_do_alloc_registration(),
which is responsible for setting DEF_PR_REG_ACTIVE.

This would result in REGISTER operations completing successfully,
but subsequent core_scsi3_pr_seq_non_holder() checking would fail
with !DEF_PR_REG_ACTIVE -> RESERVATION CONFLICT status.

Update __core_scsi3_add_registration() to drop ->pr_kref reference
after registration and any optional ALL_TG_PT=1 processing has
completed.  Update core_scsi3_decode_spec_i_port() to release
the new parent local_pr_reg->pr_kref as well.

Also, update __core_scsi3_check_aptpl_registration() to perform
the same target_nacl_find_deve() lookup + ->pr_kref get, now that
__core_scsi3_add_registration() expects to drop the reference.

Finally, since there are cases when se_dev_entry->se_lun_acl can
still be dereferenced in core_scsi3_lunacl_undepend_item() while
holding ->pr_kref, go ahead and move explicit rcu_assign_pointer()
NULL assignments within core_disable_device_list_for_node() until
after orig->pr_comp finishes.

Reported-by: Scott L. Lykens <scott@lykens.org>
Tested-by: Scott L. Lykens <scott@lykens.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Lee Duncan <lduncan@suse.com>
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-09-24 23:17:07 -07:00
Roland Dreier 9c31820b6a target: Remove cmd->se_ordered_id (unused except debug log lines)
For every command, we set se_ordered_id by doing atomic_inc_return on
dev->dev_ordered_id for the corresponding device.  However, the only
places this value gets used are in pr_debug() calls, which doesn't
seem worth an extra atomic op per IO.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-07-31 00:06:12 -07:00
Chris Zankel b6a54b8d89 target: remove initiatorname field in se_acl_lun
From: Chris Zankel <czankel@purestorage.com>

The initiatorname field in se_acl_lun is only a copy of the same field
in se_node_acl, so remove it and use the version in se_node_acl where
needed (it's actually only used for pr_debug)

Signed-off-by: Chris Zankel <czankel@purestorage.com>
Signed-off-by: Spencer Baugh <spencer.baugh@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-07-30 22:57:30 -07:00
Sagi Grimberg fe052a1810 target: Use struct t10_pi_tuple
Its not a good idea to keep target specific definition of
the same t10-pi tuple.

(Fix v4.2-rc1 patch fuzz - nab)

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-07-06 14:31:50 -07:00
Linus Torvalds 5c755fe142 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "It's been a busy development cycle for target-core in a number of
  different areas.

  The fabric API usage for se_node_acl allocation is now within
  target-core code, dropping the external API callers for all fabric
  drivers tree-wide.

  There is a new conversion to RCU hlists for se_node_acl and
  se_portal_group LUN mappings, that turns fast-past LUN lookup into a
  completely lockless code-path.  It also removes the original
  hard-coded limitation of 256 LUNs per fabric endpoint.

  The configfs attributes for backends can now be shared between core
  and driver code, allowing existing drivers to use common code while
  still allowing flexibility for new backend provided attributes.

  The highlights include:

   - Merge sbc_verify_dif_* into common code (sagi)
   - Remove iscsi-target support for obsolete IFMarker/OFMarker
     (Christophe Vu-Brugier)
   - Add bidi support in target/user backend (ilias + vangelis + agover)
   - Move se_node_acl allocation into target-core code (hch)
   - Add crc_t10dif_update common helper (akinobu + mkp)
   - Handle target-core odd SGL mapping for data transfer memory
     (akinobu)
   - Move transport ID handling into target-core (hch)
   - Move task tag into struct se_cmd + support 64-bit tags (bart)
   - Convert se_node_acl->device_list[] to RCU hlist (nab + hch +
     paulmck)
   - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch +
     paulmck)
   - Simplify target backend driver registration (hch)
   - Consolidate + simplify target backend attribute implementations
     (hch + nab)
   - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch)
   - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab)
   - Drop unnecessary core_tpg_register TFO parameter (nab)
   - Use 64-bit LUNs tree-wide (hannes)
   - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits)
  target: Bump core version to v5.0
  target: remove target_core_configfs.h
  target: remove unused TARGET_CORE_CONFIG_ROOT define
  target: consolidate version defines
  target: implement WRITE_SAME with UNMAP bit using ->execute_unmap
  target: simplify UNMAP handling
  target: replace se_cmd->execute_rw with a protocol_data field
  target/user: Fix inconsistent kmap_atomic/kunmap_atomic
  target: Send UA when changing LUN inventory
  target: Send UA upon LUN RESET tmr completion
  target: Send UA on ALUA target port group change
  target: Convert se_lun->lun_deve_lock to normal spinlock
  target: use 'se_dev_entry' when allocating UAs
  target: Remove 'ua_nacl' pointer from se_ua structure
  target_core_alua: Correct UA handling when switching states
  xen-scsiback: Fix compile warning for 64-bit LUN
  target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
  target: use 64-bit LUNs
  target: Drop duplicate + unused se_dev_check_wce
  target: Drop unnecessary core_tpg_register TFO parameter
  ...
2015-07-04 14:13:43 -07:00
Linus Torvalds acd53127c4 SCSI misc on 20150622
This is the usual grab bag of driver updates (lpfc, hpsa,
 megaraid_sas, cxgbi, be2iscsi) plus an assortment of minor updates.
 There are also one new driver: the Cisco snic; the advansys driver has
 been rewritten to get rid of the warning about converting it to the
 DMA API, the tape statistics patch got in and finally, there's a
 resuffle of SCSI header files to separate more cleanly initiator from
 target mode (and better share the common definitions).
 
 Signed-off-by: James Bottomley <JBottomley@Odin.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This is the usual grab bag of driver updates (lpfc, hpsa,
  megaraid_sas, cxgbi, be2iscsi) plus an assortment of minor updates.

  There is also one new driver: the Cisco snic.  The advansys driver has
  been rewritten to get rid of the warning about converting it to the
  DMA API, the tape statistics patch got in and finally, there's a
  resuffle of SCSI header files to separate more cleanly initiator from
  target mode (and better share the common definitions)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (156 commits)
  snic: driver for Cisco SCSI HBA
  qla2xxx: Fix indentation
  qla2xxx: Comment out unreachable code
  fusion: remove dead MTRR code
  advansys: fix compilation errors and warnings when CONFIG_PCI is not set
  mptsas: fix depth param in scsi_track_queue_full
  megaraid: fix irq setup process regression
  lpfc: Update version to 10.7.0.0 for upstream patch set.
  lpfc: Fix to drop PLOGIs from fabric node till LOGO processing completes
  lpfc: Fix scsi task management error message.
  lpfc: Fix cq_id masking problem.
  lpfc: Fix scsi prep dma buf error.
  lpfc: Add support for using block multi-queue
  lpfc: Devices are not discovered during takeaway/giveback testing
  lpfc: Fix vport deletion failure.
  lpfc: Check for active portpeerbeacon.
  lpfc: Update driver version for upstream patch set 10.6.0.1.
  lpfc: Change buffer pool empty message to miscellaneous category
  lpfc: Fix incorrect log message reported for empty FCF record.
  lpfc: Fix rport leak.
  ...
2015-06-23 15:55:44 -07:00
Hannes Reinecke 7c0d0d51d2 target: Send UA when changing LUN inventory
When changind the LUN inventory via core_enable_device_list_for_node()
or core_disable_device_list_for_node() a REPORTED LUNS DATA HAS CHANGED
UA should be send.

(Convert to target_luns_data_has_changed helper usage - hch)

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-23 00:43:02 -07:00
Nicholas Bellinger 1adff1b3a7 target: Convert se_lun->lun_deve_lock to normal spinlock
This patch converts se_lun->lun_deve_lock acquire/release access
to use a normal, non bottom-half spin_lock_t for protecting
se_lun->lun_deve_list access.

Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-22 23:54:10 -07:00
Hannes Reinecke 196e2e2aa3 target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
LUN allocation is now fully dynamic, so there is no need to
artificially restrain the number of exported LUNs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-15 23:26:03 -07:00
Hannes Reinecke f2d3068020 target: use 64-bit LUNs
As we're now using a list to hold the LUNs the target core
can now converted to use 64-bit LUNs internally.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-15 23:26:01 -07:00
Nicholas Bellinger e34d366273 target: Drop duplicate + unused se_dev_check_wce
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-15 23:25:59 -07:00
Bart Van Assche ba92999252 target: Minimize SCSI header #include directives
Only include SCSI initiator header files in target code that needs
these header files, namely the SCSI pass-through code and the tcm_loop
driver. Change SCSI_SENSE_BUFFERSIZE into TRANSPORT_SENSE_BUFFER in
target code because the former is intended for initiator code and the
latter for target code. With this patch the only initiator include
directives in target code that remain are as follows:

$ git grep -nHE 'include .scsi/(scsi.h|scsi_host.h|scsi_device.h|scsi_cmnd.h)' drivers/target drivers/infiniband/ulp/{isert,srpt} drivers/usb/gadget/legacy/tcm_*.[ch] drivers/{vhost,xen} include/{target,trace/events/target.h}
drivers/target/loopback/tcm_loop.c:29:#include <scsi/scsi.h>
drivers/target/loopback/tcm_loop.c:31:#include <scsi/scsi_host.h>
drivers/target/loopback/tcm_loop.c:32:#include <scsi/scsi_device.h>
drivers/target/loopback/tcm_loop.c:33:#include <scsi/scsi_cmnd.h>
drivers/target/target_core_pscsi.c:39:#include <scsi/scsi_device.h>
drivers/target/target_core_pscsi.c:40:#include <scsi/scsi_host.h>
drivers/xen/xen-scsiback.c:52:#include <scsi/scsi_host.h> /* SG_ALL */

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-06-02 08:03:25 -07:00
Nicholas Bellinger 4cc987eaff target: Drop lun_sep_lock for se_lun->lun_se_dev RCU usage
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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Chris Boot <bootc@bootc.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:27:38 -07:00
Christoph Hellwig adf653f92f target: Subsume se_port + t10_alua_tg_pt_gp_member into se_lun
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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:26:38 -07:00
Bart Van Assche b3eeea6619 target: Simplify LUN shutdown code
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: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:25:39 -07:00
Christoph Hellwig 3effdb9094 target: simplify backend attribute implementation
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:25:38 -07:00
Christoph Hellwig 0a06d4309d target: simplify backend driver registration
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:25:34 -07:00
Nicholas Bellinger df9766ca9d target: Only reset specific dynamic entries during lun_group creation
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: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:25:15 -07:00
Nicholas Bellinger 84786546b6 target: Drop unused se_lun->lun_acl_list
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:25:04 -07:00
Nicholas Bellinger 403edd78a2 target: Convert se_tpg->acl_node_lock to ->acl_node_mutex
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: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:24:44 -07:00
Nicholas Bellinger 6bb826121b target: Convert se_portal_group->tpg_lun_list[] to RCU hlist
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: Hannes 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: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:24:33 -07:00
Nicholas Bellinger 80bfdfa924 target/pr: Use atomic bitop for se_dev_entry->deve_flags reservation check
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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:24:00 -07:00
Nicholas Bellinger 29a05deebf target: Convert se_node_acl->device_list[] to RCU hlist
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: Hannes 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: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:23:46 -07:00
Christophe Vu-Brugier 3a40dede1f target: fix a log message in se_dev_set_emulate_rest_reord()
Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30 22:42:40 -07:00
Christoph Hellwig 814e5b4518 target: fix DPO and FUA bit checks
Drivers may override the WCE flag, in which case the DPOFUA flag in
MODE SENSE might differ from the check used to reject invalid FUA
bits in sbc_check_dpofua.  Also now that we reject invalid FUA
bits early there is no need to duplicate the same buggy check
down in the fileio code.

As the DPOFUA flag controls th support for FUA bits on read and
write commands as well as DPO key off all the checks off a single
helper, and deprecate the emulate_dpo and emulate_fua_read attributs.

This fixes various failures in the libiscsi testsuite.

Personally I'd prefer to also remove the emulate_fua_write attribute
as there is no good reason to disable it, but I'll leave that for
a separate discussion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30 22:41:44 -07:00
Andy Grover a3541703eb target: Use a PASSTHROUGH flag instead of transport_types
It seems like we only care if a transport is passthrough or not. Convert
transport_type to a flags field and replace TRANSPORT_PLUGIN_* with a
flag, TRANSPORT_FLAG_PASSTHROUGH.

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30 19:58:11 -07:00
Andy Grover 7bfea53b5c target: Move passthrough CDB parsing into a common function
Aside from whether they handle BIDI ops or not, parsing of the CDB by
kernel and user SCSI passthrough modules should be identical. Move this
into a new passthrough_parse_cdb() and call it from tcm-pscsi and tcm-user.

Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30 19:57:59 -07:00
Andy Grover 86d65dc4fe target: Allow userspace to write 1 to attrib/emulate_fua_write
Before 4.0, reading attrib/emulate_fua_write has returned 1. Saved
configs created on a pre-4.0 kernel will try to write that back when
restoring LIO configuration. This should succeed with no effect,
and issue a warning.

See https://bugzilla.redhat.com/show_bug.cgi?id=1206184

Reported-by: Yanko Kaneti <yaneti@declera.com>
Reported-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-04-01 21:42:51 -07:00
Christophe Vu-Brugier 9bc6548f37 target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
A check that rejects a CDB with FUA bit set if no write cache is
emulated was added by the following commit:

  fde9f50 target: Add sanity checks for DPO/FUA bit usage

The condition is as follows:

  if (!dev->dev_attrib.emulate_fua_write ||
      !dev->dev_attrib.emulate_write_cache)

However, this check is wrong if the backend device supports WCE but
"emulate_write_cache" is disabled.

This patch uses se_dev_check_wce() (previously named
spc_check_dev_wce) to invoke transport->get_write_cache() if the
device has a write cache or check the "emulate_write_cache" attribute
otherwise.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-03-19 23:26:46 -07:00
Nicholas Bellinger 5f7da044f8 target: Fix virtual LUN=0 target_configure_device failure OOPs
This patch fixes a NULL pointer dereference triggered by a late
target_configure_device() -> alloc_workqueue() failure that results
in target_free_device() being called with DF_CONFIGURED already set,
which subsequently OOPses in destroy_workqueue() code.

Currently this only happens at modprobe target_core_mod time when
core_dev_setup_virtual_lun0() -> target_configure_device() fails,
and the explicit target_free_device() gets called.

To address this bug originally introduced by commit 0fd97ccf45, go
ahead and move DF_CONFIGURED to end of target_configure_device()
code to handle this special failure case.

Reported-by: Claudio Fleiner <cmf@daterainc.com>
Cc: Claudio Fleiner <cmf@daterainc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-03-19 23:26:44 -07:00
Nicholas Bellinger 4b36b68ca8 target: Disallow changing of WRITE cache/FUA attrs after export
Now that incoming FUA=1 bit check is enforced for backends with FUA or
WCE disabled, go ahead and disallow the changing of related backend
attributes when active fabric exports exist.

This is required to avoid potential failures with existing initiator
LUN registrations that have been previously created with FUA=1.

Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-03-19 23:01:04 -07:00
Nicholas Bellinger 7216dc077d target: Drop left-over fabric_max_sectors attribute
Now that fabric_max_sectors is no longer used to enforce the maximum
I/O size, go ahead and drop it's left-over usage in target-core and
associated backend drivers.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-01-09 15:22:05 -08:00
Nicholas Bellinger 046ba64285 target: Drop arbitrary maximum I/O size limit
This patch drops the arbitrary maximum I/O size limit in sbc_parse_cdb(),
which currently for fabric_max_sectors is hardcoded to 8192 (4 MB for 512
byte sector devices), and for hw_max_sectors is a backend driver dependent
value.

This limit is problematic because Linux initiators have only recently
started to honor block limits MAXIMUM TRANSFER LENGTH, and other non-Linux
based initiators (eg: MSFT Fibre Channel) can also generate I/Os larger
than 4 MB in size.

Currently when this happens, the following message will appear on the
target resulting in I/Os being returned with non recoverable status:

  SCSI OP 28h with too big sectors 16384 exceeds fabric_max_sectors: 8192

Instead, drop both [fabric,hw]_max_sector checks in sbc_parse_cdb(),
and convert the existing hw_max_sectors into a purely informational
attribute used to represent the granuality that backend driver and/or
subsystem code is splitting I/Os upon.

Also, update FILEIO with an explicit FD_MAX_BYTES check in fd_execute_rw()
to deal with the one special iovec limitiation case.

v2 changes:
  - Drop hw_max_sectors check in sbc_parse_cdb()

Reported-by: Lance Gropper <lance.gropper@qosserver.com>
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org # 3.4
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-01-09 15:21:40 -08:00
Nicholas Bellinger 4b2f57e5ce target: Drop left-over PHBA_PDEV set attr checks
Now that PSCSI is only exposing four hw_* read-only device attributes,
go ahead and drop the left-over -> legacy PHBA_PDEV checks in various
se_dev_set_* code, since it's now only used by virtual devices.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:21 -08:00
Nicholas Bellinger d30cd1238c target: Add EXPORT_SYMBOL for existing se_dev_set_*
Now that target_core_backend_configfs.h macros will be using these
se_dev_set attribute functions externally to allow backend drivers
to populate different attributes, go ahead and add EXPORT_SYMBOL()
for the existing default set of 30 device attributes.

Also update target_core_backend.h with proper function prototypes.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:02 -08:00
Nicholas Bellinger 92404e609a target: Add force_pr_aptpl device attribute
This patch adds a force_pr_aptpl device attribute used to force SPC-3 PR
Activate Persistence across Target Power Loss (APTPL) operation.  This
makes PR metadata write-out occur during state change regardless if new
PERSISTENT_RESERVE_OUT CDBs have their APTPL feature bit set.

This is useful during H/A failover in active/passive setups where all PR
state is being re-created on a different node, driven by configfs backend
device + export layout and pre-loaded $DEV/pr/res_aptpl_metadata.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-04 05:41:20 +00:00
Nicholas Bellinger e24805637d target: Fix APTPL metadata handling for dynamic MappedLUNs
This patch fixes a bug in handling of SPC-3 PR Activate Persistence
across Target Power Loss (APTPL) logic where re-creation of state for
MappedLUNs from dynamically generated NodeACLs did not occur during
I_T Nexus establishment.

It adds the missing core_scsi3_check_aptpl_registration() call during
core_tpg_check_initiator_node_acl() -> core_tpg_add_node_to_devs() in
order to replay any pre-loaded APTPL metadata state associated with
the newly connected SCSI Initiator Port.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-04 05:40:19 +00:00
Joern Engel 33940d0993 target: encapsulate smp_mb__after_atomic()
The target code has a rather generous helping of smp_mb__after_atomic()
throughout the code base.  Most atomic operations were followed by one
and none were preceded by smp_mb__before_atomic(), nor accompanied by a
comment explaining the need for a barrier.

Instead of trying to prove for every case whether or not it is needed,
this patch introduces atomic_inc_mb() and atomic_dec_mb(), which
explicitly include the memory barriers before and after the atomic
operation.  For now they are defined in a target header, although they
could be of general use.

Most of the existing atomic/mb combinations were replaced by the new
helpers.  In a few cases the atomic was sandwiched in
spin_lock/spin_unlock and I simply removed the barrier.

I suspect that in most cases the correct conversion would have been to
drop the barrier.  I also suspect that a few cases exist where a) the
barrier was necessary and b) a second barrier before the atomic would
have been necessary and got added by this patch.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:39:06 -07:00
Andy Grover cd9d7cbaec target: Change core_dev_del_lun to take a se_lun instead of unpacked_lun
Remove core_tpg_pre_dellun entirely, since we don't need to get/check
a pointer we already have.

Nothing else can return an error, so core_dev_del_lun can return void.

Rename core_tpg_post_dellun to remove_lun - a clearer name, now that
pre_dellun is gone.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:38:48 -07:00
Nicholas Bellinger 83ff42fcce target: Fix left-over se_lun->lun_sep pointer OOPs
This patch fixes a left-over se_lun->lun_sep pointer OOPs when one
of the /sys/kernel/config/target/$FABRIC/$WWPN/$TPGT/lun/$LUN/alua*
attributes is accessed after the $DEVICE symlink has been removed.

To address this bug, go ahead and clear se_lun->lun_sep memory in
core_dev_unexport(), so that the existing checks for show/store
ALUA attributes in target_core_fabric_configfs.c work as expected.

Reported-by: Sebastian Herbszt <herbszt@gmx.de>
Tested-by: Sebastian Herbszt <herbszt@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-06-26 20:56:49 -07:00
Linus Torvalds 776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00