Commit Graph

1046 Commits

Author SHA1 Message Date
Sagi Grimberg 23a548ee65 iscsi,iser-target: Expose supported protection ops according to t10_pi
iSER will report supported protection operations based on
the tpg attribute t10_pi settings and HCA PI offload capabilities.
If the HCA does not support PI offload or tpg attribute t10_pi is
not set, we fall to SW PI mode.

In order to do that, we move iscsit_get_sup_prot_ops after connection
tpg assignment.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-12 23:32:26 -08:00
Sagi Grimberg 954f23722b iscsi,iser-target: Initiate termination only once
Since commit 0fc4ea701f ("Target/iser: Don't put isert_conn inside
disconnected handler") we put the conn kref in isert_wait_conn, so we
need .wait_conn to be invoked also in the error path.

Introduce call to isert_conn_terminate (called under lock)
which transitions the connection state to TERMINATING and calls
rdma_disconnect. If the state is already teminating, just bail
out back (temination started).

Also, make sure to destroy the connection when getting a connect
error event if didn't get to connected (state UP). Same for the
handling of REJECTED and UNREACHABLE cma events.

Squashed:

iscsi-target: Add call to wait_conn in establishment error flow

Reported-by: Slava Shwartsman <valyushash@gmail.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-12 22:55:22 -08:00
Julia Lawall 13ba564c95 target: remove unneeded array
Delete a local array that is only used to be initialized by memset.

A semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
type T;
@@

{
... when any
-T x[...];
<+... when != x
- memset(x,...);
...+>
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:22 -08:00
Lino Sanfilippo 7f2c53bb95 iscsi-target: fix error path in iscsi_target_init_module()
In iscsi_target_init_module() unwind transport protocol registration in case
that iscsit_load_discovery_tpg() failed.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:22 -08:00
Hannes Reinecke 506787a2c7 tcm_loop: Fix wrong I_T nexus association
tcm_loop has the I_T nexus associated with the HBA. This causes
commands to become misdirected if the HBA has more than one
target portal group; any command is then being sent to the
first target portal group instead of the correct one.

The nexus needs to be associated with the target portal group
instead.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org> # 3.0+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:21 -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 43cf208cbe target: Drop left-over internal dev attribute code
Now that backend drivers are populating their own device attributes,
go ahead and remove left-over definitions + internal attribute list
of device attributes from target_core_configfs.c code

Also update TB_CIT_SETUP(dev_attrib,...) to signal ct_attr = NULL.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:21 -08:00
Nicholas Bellinger 6cfb546bfc target/pscsi: Convert to external pscsi_backend_dev_attrs
This patch converts PSCSI to use an external set of device attributes,
and utilizes target_core_backend_configfs.h macros to generate a default
set of configfs extended-attr handlers.

It calls target_core_setup_sub_cits() to setup the initial config_item_type
based on existing target_core_configfs.c defaults, and using configfs_attribute
for hw_pi_prot_type, hw_block_size, hw_max_sectors, hw_queue_depth populates
pscsi_backend_dev_attrs[]

Only these four hw_* read-only device attributes are exports for PSCSI.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:03 -08:00
Nicholas Bellinger e9f720d63b target/user: Convert to external tcmu_backend_dev_attrs
This patch converts TCM-USER to use an external set of device attributes,
and utilizes target_core_backend_configfs.h macros to generate a default
set of configfs extended-attr handlers.

It calls target_core_setup_sub_cits() to setup the initial config_item_type
based on existing target_core_configfs.c defaults, and using configfs_attribute
generated by DEF_TB_DEFAULT_ATTRIBS(tcmu) populates tcmu_backend_dev_attrs[]

It introduces no function change for existing TCMU device attributes.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:03 -08:00
Nicholas Bellinger 03a627457e target/rd: Convert to external rd_mcp_backend_dev_attrs
This patch converts RAMDISK to use an external set of device attributes,
and utilizes target_core_backend_configfs.h macros to generate a default
set of configfs extended-attr handlers.

It calls target_core_setup_sub_cits() to setup the initial config_item_type
based on existing target_core_configfs.c defaults, and using configfs_attribute
generated by DEF_TB_DEFAULT_ATTRIBS(rc_mcp) populates rd_mcp_backend_dev_attrs[]

It introduces no functional change for existing RD_MCP device attributes.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:02 -08:00
Nicholas Bellinger b23204970a target/file: Convert to external fileio_backend_dev_attrs
This patch converts FILEIO to use an external set of device attributes,
and utilizes target_core_backend_configfs.h macros to generate a default
set of configfs extended-attr handlers.

It calls target_core_setup_sub_cits() to setup the initial config_item_type
based on existing target_core_configfs.c defaults, and using configfs_attribute
generated by DEF_TB_DEFAULT_ATTRIBS(fileio) populates fileio_backend_dev_attrs[]

It introduces no functional change for existing FILEIO device attributes.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:02 -08:00
Nicholas Bellinger 5645cba011 target/iblock: Convert to external iblock_backend_dev_attrs
This patch converts IBLOCK to use an external set of device attributes,
and utilizes target_core_backend_configfs.h macros to generate a default
set of configfs extended-attr handlers.

It calls target_core_setup_sub_cits() to setup the initial config_item_type
based on existing target_core_configfs.c defaults, and using configfs_attribute
generated by DEF_TB_DEFAULT_ATTRIBS(iblock) populates iblock_backend_dev_attrs[]

It introduces no functional change for existing IBLOCK device attributes.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:36:02 -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 d23ab570bc target: Move dev_stat_cit to struct se_subsystem_api
This patch adds support for dev_stat_cit as an external config_item_type
using TB_CIT_SETUP() helper macro, and sets only ct_group_ops following
existing code.

It updates target_core_make_subdev() + target_core_setup_dev_attrib_cit() +
struct target_backend_cits, and drops left-over target_core_dev_stat_cit
from target_core_configfs.c code and update comments.

This patch introduces no functional change from existing code.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:39 -08:00
Nicholas Bellinger 72aca57bd3 target: Move dev_alua_tg_pt_gps_cit to struct se_subsystem_api
This patch adds support for dev_alua_tg_pt_gps_cit as an external config_item_type
using TB_CIT_SETUP() helper macro, and sets only ct_group_ops following
existing code.

It updates target_core_make_subdev() + target_core_setup_dev_attrib_cit() +
struct target_backend_cits, and drops left-over target_core_dev_alua_tg_pt_gps_cit
from target_core_configfs.c code and update comments.

This patch introduces no functional change from existing code.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:39 -08:00
Nicholas Bellinger f8d389c6f6 target: Move dev_wwn_cit to struct se_subsystem_api
This patch adds support for dev_wwn_cit as an external config_item_type
using TB_CIT_SETUP() helper macro, and sets both ct_item_ops + ct_attr
following existing code.

It updates target_core_make_subdev() + target_core_setup_dev_attrib_cit() +
struct target_backend_cits, and drops left-over target_core_dev_wwn_cit
from target_core_configfs.c code and update comments.

This patch introduces no functional change from existing code.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:39 -08:00
Nicholas Bellinger 91e2e39ba8 target: Move dev_pr_cit to struct se_subsystem_api
This patch adds support for dev_pr_cit as an external config_item_type
using TB_CIT_SETUP() helper macro, and sets both ct_item_ops + ct_attr
following existing code.

It updates target_core_make_subdev() + target_core_setup_dev_attrib_cit() +
struct target_backend_cits, and drops left-over target_core_dev_pr_cit
from target_core_configfs.c code and update comments.

This patch introduces no functional change from existing code.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:39 -08:00
Nicholas Bellinger f79a897efa target: Move dev_attrib_cit to struct se_subsystem_api
This patch adds support for dev_attrib_cit as an external config_item_type
using TB_CIT_SETUP() helper macro, and sets both ct_item_ops + ct_attr
following existing code.

It updates target_core_make_subdev() + target_core_setup_dev_attrib_cit() +
struct target_backend_cits, and drops left-over target_core_dev_attrib_cit
from target_core_configfs.c code and update comments.

This patch introduces no functional change from existing code.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:22 -08:00
Nicholas Bellinger 73112edca9 target: Move dev_cit to struct se_subsystem_api
This patch adds initial support for dev_cit as external config_item_type.

This includes a new struct target_backend_cits to hold the external CITs
within struct se_subsystem_api, and target_core_setup_sub_cits() to be
used by backend drivers ahead of transport_subsystem_register().

It adds a TB_CIT_SETUP() helper following target_core_fabric_configfs.c
to perform the config_item_type assignments.

Also, drop left-over target_core_dev_cit from target_core_configfs.c code
and update comments.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:22 -08:00
Markus Elfring 2ed37f6c9b target: Deletion of unnecessary checks before the function call "module_put"
The module_put() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:21 -08:00
Roland Dreier e7b7af6e98 target: Fix target_core_register_fabric() for built-in fabric modules
If we try to create a fabric directory in configfs for one of the
default hard-coded fabric modules (iscsi and loopback), and that
fabric is actually built into the kernel, then the operation will
spuriously fail because request_module() (for the code that's already
linked into the kernel) fails.

Fix this by running the autoprobing code only if an initial
target_core_get_fabric() fails.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-12-01 21:35:13 -08:00
Steven Allen b6932ee35f target: return CONFLICT only when SA key unmatched
PREEMPT (and PREEMPT AND ABORT) should return CONFLICT iff a specified
SERVICE ACTION RESERVATION KEY is specified and matches no existing
persistent reservation.

Without this patch, a PREEMPT will return CONFLICT if either all
reservations are held by the initiator (self preemption) or there is
nothing to preempt. According to the spec, both of these cases should
succeed.

Signed-off-by: Steven Allen <steven.allen@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-11-02 22:04:57 -08:00
Steven Allen f2774f430e iscsi-target: return the correct port in SendTargets
The fact that a target is published on the any address has no bearing on
which port(s) it is published. SendTargets should always send the
portal's port, not the port used for discovery.

Signed-off-by: Steven Allen <steven.allen@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-28 13:54:18 -07:00
Roland Dreier 885e7b0e18 target: Don't call TFO->write_pending if data_length == 0
If an initiator sends a zero-length command (e.g. TEST UNIT READY) but
sets the transfer direction in the transport layer to indicate a
data-out phase, we still shouldn't try to transfer data.  At best it's
a NOP, and depending on the transport, we might crash on an
uninitialized sg list.

Reported-by: Craig Watson <craig.watson@vanguard-rugged.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org> # 3.1
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-28 13:54:15 -07:00
Linus Torvalds c3351dfabf Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "Here are the target updates for v3.18-rc2 code.  These where
  originally destined for -rc1, but due to the combination of travel
  last week for KVM Forum and my mistake of taking the three week merge
  window literally, the pull request slipped..  Apologies for that.

  Things where reasonably quiet this round.  The highlights include:

   - New userspace backend driver (target_core_user.ko) by Shaohua Li
     and Andy Grover
   - A number of cleanups in target, iscsi-taret and qla_target code
     from Joern Engel
   - Fix an OOPs related to queue full handling with CHECK_CONDITION
     status from Quinn Tran
   - Fix to disable TX completion interrupt coalescing in iser-target,
     that was causing problems on some hardware
   - Fix for PR APTPL metadata handling with demo-mode ACLs

  I'm most excited about the new backend driver that uses UIO + shared
  memory ring to dispatch I/O and control commands into user-space.
  This was probably the most requested feature by users over the last
  couple of years, and opens up a new area of development + porting of
  existing user-space storage applications to LIO.  Thanks to Shaohua +
  Andy for making this happen.

  Also another honorable mention, a new Xen PV SCSI driver was merged
  via the xen/tip.git tree recently, which puts us now at 10 target
  drivers in upstream! Thanks to David Vrabel + Juergen Gross for their
  work to get this code merged"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (40 commits)
  target/file: fix inclusive vfs_fsync_range() end
  iser-target: Disable TX completion interrupt coalescing
  target: Add force_pr_aptpl device attribute
  target: Fix APTPL metadata handling for dynamic MappedLUNs
  qla_target: don't delete changed nacls
  target/user: Recalculate pad size inside is_ring_space_avail()
  tcm_loop: Fixup tag handling
  iser-target: Fix smatch warning
  target/user: Fix up smatch warnings in tcmu_netlink_event
  target: Add a user-passthrough backstore
  target: Add documentation on the target userspace pass-through driver
  uio: Export definition of struct uio_device
  target: Remove unneeded check in sbc_parse_cdb
  target: Fix queue full status NULL pointer for SCF_TRANSPORT_TASK_SENSE
  qla_target: rearrange struct qla_tgt_prm
  qla_target: improve qlt_unmap_sg()
  qla_target: make some global functions static
  qla_target: remove unused parameter
  target: simplify core_tmr_abort_task
  target: encapsulate smp_mb__after_atomic()
  ...
2014-10-21 13:06:38 -07:00
Linus Torvalds d3dc366bba Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block
Pull core block layer changes from Jens Axboe:
 "This is the core block IO pull request for 3.18.  Apart from the new
  and improved flush machinery for blk-mq, this is all mostly bug fixes
  and cleanups.

   - blk-mq timeout updates and fixes from Christoph.

   - Removal of REQ_END, also from Christoph.  We pass it through the
     ->queue_rq() hook for blk-mq instead, freeing up one of the request
     bits.  The space was overly tight on 32-bit, so Martin also killed
     REQ_KERNEL since it's no longer used.

   - blk integrity updates and fixes from Martin and Gu Zheng.

   - Update to the flush machinery for blk-mq from Ming Lei.  Now we
     have a per hardware context flush request, which both cleans up the
     code should scale better for flush intensive workloads on blk-mq.

   - Improve the error printing, from Rob Elliott.

   - Backing device improvements and cleanups from Tejun.

   - Fixup of a misplaced rq_complete() tracepoint from Hannes.

   - Make blk_get_request() return error pointers, fixing up issues
     where we NULL deref when a device goes bad or missing.  From Joe
     Lawrence.

   - Prep work for drastically reducing the memory consumption of dm
     devices from Junichi Nomura.  This allows creating clone bio sets
     without preallocating a lot of memory.

   - Fix a blk-mq hang on certain combinations of queue depths and
     hardware queues from me.

   - Limit memory consumption for blk-mq devices for crash dump
     scenarios and drivers that use crazy high depths (certain SCSI
     shared tag setups).  We now just use a single queue and limited
     depth for that"

* 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits)
  block: Remove REQ_KERNEL
  blk-mq: allocate cpumask on the home node
  bio-integrity: remove the needless fail handle of bip_slab creating
  block: include func name in __get_request prints
  block: make blk_update_request print prefix match ratelimited prefix
  blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
  block: fix alignment_offset math that assumes io_min is a power-of-2
  blk-mq: Make bt_clear_tag() easier to read
  blk-mq: fix potential hang if rolling wakeup depth is too high
  block: add bioset_create_nobvec()
  block: use bio_clone_fast() in blk_rq_prep_clone()
  block: misplaced rq_complete tracepoint
  sd: Honor block layer integrity handling flags
  block: Replace strnicmp with strncasecmp
  block: Add T10 Protection Information functions
  block: Don't merge requests if integrity flags differ
  block: Integrity checksum flag
  block: Relocate bio integrity flags
  block: Add a disk flag to block integrity profile
  block: Add prefix to block integrity profile flags
  ...
2014-10-18 11:53:51 -07:00
Zach Brown 62d3ab49b8 target/file: fix inclusive vfs_fsync_range() end
Both of the file target's calls to vfs_fsync_range() got the end offset
off by one.  The range is inclusive, not exclusive.  It would sync a bit
more data than was required.

The sync path already tested the length of the range and fell back to
LLONG_MAX so I copied that pattern in the rw path.

This is untested. I found the errors by inspection while following other
code.

Signed-off-by: Zach Brown <zab@zabbo.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-07 23:05:07 -07:00
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
Andy Grover f56574a2b5 target/user: Recalculate pad size inside is_ring_space_avail()
If more than one thread is waiting for command ring space that includes
a PAD, then if the first one finishes (inserts a PAD and a CMD at the
start of the cmd ring) then the second one will incorrectly think it still
needs to insert a PAD (i.e. cmdr_space_needed is now wrong.) This will
lead to it asking for more space than it actually needs, and then inserting
a PAD somewhere else than at the end -- not what we want.

This patch moves the pad calculation inside is_ring_space_available() so
in the above scenario the second thread would then ask for space not
including a PAD. The patch also inserts a PAD op based upon an up-to-date
cmd_head, instead of the potentially stale value.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-03 11:16:12 -07:00
Hannes Reinecke 6375f89082 tcm_loop: Fixup tag handling
The SCSI command tag is set to the tag assigned from the block
layer, not the SCSI-II tag message. So we need to convert
it into the correct SCSI-II tag message based on the
device flags, not the tag value itself.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-03 11:16:12 -07:00
Nicholas Bellinger 6e14eab90a target/user: Fix up smatch warnings in tcmu_netlink_event
This patch fixes up the following unused return smatch warnings:

  drivers/target/target_core_user.c:778 tcmu_netlink_event warn: unused return: ret = nla_put_string()
  drivers/target/target_core_user.c:780 tcmu_netlink_event warn: unused `return: ret = nla_put_u32()

(Fix up missing semicolon: grover)

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-03 11:16:11 -07:00
Andy Grover 7c9e7a6fe1 target: Add a user-passthrough backstore
Add a LIO storage engine that presents commands to userspace for execution.
This would allow more complex backstores to be implemented out-of-kernel,
and also make experimentation a-la FUSE (but at the SCSI level -- "SUSE"?)
possible.

It uses a mmap()able UIO device per LUN to share a command ring and data
area. The commands are raw SCSI CDBs and iovs for in/out data. The command
ring is also reused for returning scsi command status and optional sense
data.

This implementation is based on Shaohua Li's earlier version but heavily
modified. Differences include:

* Shared memory allocated by kernel, not locked-down user pages
* Single ring for command request and response
* Offsets instead of embedded pointers
* Generic SCSI CDB passthrough instead of per-cmd specialization in ring
  format.
* Uses UIO device instead of anon_file passed in mailbox.
* Optional in-kernel handling of some commands.

The main reason for these differences is to permit greater resiliency
if the user process dies or hangs.

Things not yet implemented (on purpose):

* Zero copy. The data area is flexible enough to allow page flipping or
  backend-allocated pages to be used by fabrics, but it's not clear these
  are performance wins. Can come later.
* Out-of-order command completion by userspace. Possible to add by just
  allowing userspace to change cmd_id in rsp cmd entries, but currently
  not supported.
* No locks between kernel cmd submission and completion routines. Sounds
  like it's possible, but this can come later.
* Sparse allocation of mmaped area. Current code vmallocs the whole thing.
  If the mapped area was larger and not fully mapped then the driver would
  have more freedom to change cmd and data area sizes based on demand.

Current code open issues:

* The use of idrs may be overkill -- we maybe can replace them with a
  simple counter to generate cmd_ids, and a hash table to get a cmd_id's
  associated pointer.
* Use of a free-running counter for cmd ring instead of explicit modulo
  math. This would require power-of-2 cmd ring size.

(Add kconfig depends NET - Randy)

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-03 11:15:20 -07:00
Andy Grover 20959c4b40 target: Remove unneeded check in sbc_parse_cdb
The check of SCF_SCSI_DATA_CDB seems to be a remnant from before hch's
refactoring of this function. There are no places where that flag is set
that cmd->execute_cmd isn't also set.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-02 21:35:53 -07:00
Quinn Tran 082f58ac4a target: Fix queue full status NULL pointer for SCF_TRANSPORT_TASK_SENSE
During temporary resource starvation at lower transport layer, command
is placed on queue full retry path, which expose this problem.  The TCM
queue full handling of SCF_TRANSPORT_TASK_SENSE currently sends the same
cmd twice to lower layer.  The 1st time led to cmd normal free path.
The 2nd time cause Null pointer access.

This regression bug was originally introduced v3.1-rc code in the
following commit:

commit e057f53308
Author: Christoph Hellwig <hch@infradead.org>
Date:   Mon Oct 17 13:56:41 2011 -0400

    target: remove the transport_qf_callback se_cmd callback

Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:39:30 -07:00
Joern Engel f81ccb489a target: simplify core_tmr_abort_task
list_for_each_entry_safe is necessary if list objects are deleted from
the list while traversing it.  Not the case here, so we can use the base
list_for_each_entry variant.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:39:10 -07:00
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
Joern Engel 74ed7e6228 target: remove some smp_mb__after_atomic()s
atomic_inc_return() already does an implicit memory barrier and the
second case was moved from an atomic to a plain flag operation.  If a
barrier were needed in the second case, it would have to be smp_mb(),
not a variant optimized away for x86 and other architectures.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:38:57 -07:00
Joern Engel 8f83269048 target: simplify core_tmr_release_req()
And while at it, do minimal coding style fixes in the area.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01 14:38:57 -07:00
Andy Grover 9c7d6154bc target: Remove core_tpg_release_virtual_lun0 function
Simple and just called from one place.

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 14:38:57 -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
Andy Grover cc83881f2c target: core_tpg_post_dellun can return void
Nothing in it can raise an error.

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 14:38:41 -07:00
Tejun Heo 2aad2a86f6 percpu_ref: add PERCPU_REF_INIT_* flags
With the recent addition of percpu_ref_reinit(), percpu_ref now can be
used as a persistent switch which can be turned on and off repeatedly
where turning off maps to killing the ref and waiting for it to drain;
however, there currently isn't a way to initialize a percpu_ref in its
off (killed and drained) state, which can be inconvenient for certain
persistent switch use cases.

Similarly, percpu_ref_switch_to_atomic/percpu() allow dynamic
selection of operation mode; however, currently a newly initialized
percpu_ref is always in percpu mode making it impossible to avoid the
latency overhead of switching to atomic mode.

This patch adds @flags to percpu_ref_init() and implements the
following flags.

* PERCPU_REF_INIT_ATOMIC	: start ref in atomic mode
* PERCPU_REF_INIT_DEAD		: start ref killed and drained

These flags should be able to serve the above two use cases.

v2: target_core_tpg.c conversion was missing.  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
2014-09-24 13:31:50 -04:00
Tejun Heo d06efebf0c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18
This is to receive 0a30288da1 ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall.  The
commit reverted and patches to implement proper fix will be added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
2014-09-24 13:00:21 -04:00
Joern Engel c435285df1 target: fix unused shift in core_scsi3_pri_report_capabilities
Clearly a right-shift was meant.  Effectively doesn't make a difference,
as add_len is hard-coded to 8 and the high byte will be zero no matter
which way you shift.  But I hate leaving bad examples for others to
copy.

Found by coverity.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 15:23:00 -07:00
Joern Engel ce31c1b0dc target: correctly handle match_int errors in FILEIO + PSCSI
This patch correctly handles match_int() errors in FILEIO + PSCSI
backend parameter parsing, which can potentially fail due to a
memory allocation failure or invalid argument.

Found by coverity.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 15:20:57 -07:00
Joern Engel 68edbce4fb target: fix pr_out length in iscsi_parse_pr_out_transport_id
Old code in iscsi_parse_pr_out_transport_id() was obviously buggy
and effectively ignored the high byte.

Found by coverity.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 15:17:35 -07:00
Joern Engel 1481473b56 target: simplify target_fabric_make_lun error path
Coverity complained that lun_cg has been dereferenced in all paths
leading to NULL check.  It didn't mention that only a single path could
lead there and the code can be simplified even further.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 15:11:28 -07:00
Joern Engel da0abaee47 target: Fix memory leak on error in target_fabric_make_mappedlun
This patch fixes a memory leak on error in target_fabric_make_mappedlun(),
where se_lun_acl memory does not get released on exit.

Found by coverity.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 14:34:50 -07:00
Joern Engel 8d2135592d target: Fix possible memory leak in aptpl_metadata parsing
Each case of match_strdup could leak memory if the same argument was
present before.  I am not too concerned, as it would require a
non-sensical combination like "target_lun=foo target_lun=bar", done
with root privileges and even then leak just a few bytes per instance.

But arg_p is different, as it will always leak memory.  Let's plug that
one.  And while at it, replace some &args[0] with args.

Found by coverity.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-09-17 14:16:54 -07:00