Several places were not checking that the parameter list length
was large enough, and thus accessing invalid memory. Zero-length
parameter lists are just a special case of this.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
- instead of (PTR_ERR(file) < 0) just use IS_ERR(file)
- return -EINVAL instead of EINVAL
- all other error returns in target_scsi3_emulate_pr_out() use
"goto out" -- get rid of the one remaining straight "return."
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull scsi-target changes from Nicholas Bellinger:
"There has been lots of work in existing code in a number of areas this
past cycle. The major highlights have been:
* Removal of transport_do_task_sg_chain() from core + fabrics
(Roland)
* target-core: Removal of se_task abstraction from target-core and
enforce hw_max_sectors for pSCSI backends (hch)
* Re-factoring of iscsi-target tx immediate/response queues (agrover)
* Conversion of iscsi-target back to using target core memory
allocation logic (agrover)
We've had one last minute iscsi-target patch go into for-next to
address a nasty regression bug related to the target core allocation
logic conversion from agrover that is not included in friday's
linux-next build, but has been included in this series.
On the new fabric module code front for-3.5, here is a brief status
update for the three currently in flight this round:
* usb-gadget target driver:
Sebastian Siewior's driver for supporting usb-gadget target mode
operation. This will be going out as a separate PULL request from
target-pending/usb-target-merge with subsystem maintainer ACKs. There
is one minor target-core patch in this series required to function.
* sbp ieee-1394/firewire target driver:
Chris Boot's driver for supportting the Serial Block Protocol (SBP)
across IEEE-1394 Firewire hardware. This will be going out as a
separate PULL request from target-pending/sbp-target-merge with two
additional drivers/firewire/ patches w/ subsystem maintainer ACKs.
* qla2xxx LLD target mode infrastructure changes + tcm_qla2xxx:
The Qlogic >= 24xx series HW target mode LLD infrastructure patch-set
and tcm_qla2xxx fabric driver. Support for FC target mode using
qla2xxx LLD code has been officially submitted by Qlogic to James
below, and is currently outstanding but not yet merged into
scsi.git/for-next..
[PATCH 00/22] qla2xxx: Updates for scsi "misc" branch
http://www.spinics.net/lists/linux-scsi/msg59350.html
Note there are *zero* direct dependencies upon this for-next series
for the qla2xxx LLD target + tcm_qla2xxx patches submitted above, and
over the last days the target mode team has been tracking down an
tcm_qla2xxx specific active I/O shutdown bug that appears to now be
almost squashed for 3.5-rc-fixes."
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (47 commits)
iscsi-target: Fix iov_count calculation bug in iscsit_allocate_iovecs
iscsi-target: remove dead code in iscsi_check_valuelist_for_support
target: Handle ATA_16 passthrough for pSCSI backend devices
target: Add MI_REPORT_TARGET_PGS ext. header + implict_trans_secs attribute
target: Fix MAINTENANCE_IN service action CDB checks to use lower 5 bits
target: add support for the WRITE_VERIFY command
target: make target_put_session void
target: cleanup transport_execute_tasks()
target: Remove max_sectors device attribute for modern se_task less code
target: lock => unlock typo in transport_lun_wait_for_tasks
target: Enforce hw_max_sectors for SCF_SCSI_DATA_SG_IO_CDB
target: remove the t_se_count field in struct se_cmd
target: remove the t_task_cdbs_ex_left field in struct se_cmd
target: remove the t_task_cdbs_left field in struct se_cmd
target: remove struct se_task
target: move the state and execute lists to the command
target: simplify command to task linkage
target: always allocate a single task
target: replace ->execute_task with ->execute_cmd
target: remove the task_sectors field in struct se_task
...
This patch addresses a bug in a special case for target core SPC-2 RELEASE
logic where the same physical client (eg: iSCSI InitiatorName) with
differing iSCSI session identifiers (ISID) is allowed to incorrectly release
the same client's SPC-2 reservation from the non reservation holding path.
Note this bug is specific to iscsi-target w/ SPC-2 reservations, and
with the default enforce_pr_isids=1 device attr setting in target-core
controls if a InitiatorName + different ISID reservations are handled
the same as a single iSCSI client entity.
Signed-off-by: Bernhard Kohl <bernhard.kohl@gmx.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Make CDB emulation work on commands instead of tasks again as a preparation
of removing tasks completely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch includes the handful of squashed patches for target/iscsi from
Andy's original series into lio-core/master code:
*) Make iscsit_add_reject static
*) Remove unused data_offset_end from iscsi_datain_req
*) Remove "#if 0" stubs
*) Rename iscsi_datain_req to cmd_datain_node
*) Cleanups for built_r2ts_for_cmd()
*) Cleanups for Cleanup build_sendtargets_response()
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull SCSI target updates from Nicholas Bellinger:
"This contains the usual set of updates and bugfixes to target-core +
existing fabric module code, along with a handful of the patches
destined for v3.3 stable.
It also contains the necessary target-core infrastructure pieces
required to run using tcm_qla2xxx.ko WWPNs with the new Qlogic Fibre
Channel fabric module currently queued in target-pending/for-next-merge,
and coming for round 2.
The highlights for this series include:
- Add target_submit_tmr() helper function for fabric task management
(andy)
- Convert tcm_fc to use target_submit_tmr() (andy)
- Replace target core various cmd flags with a transport state (hch)
- Convert loopback to use workqueue submission (hch)
- Convert target core to use array_zalloc for tpg_lun_list (joern)
- Convert target core to use array_zalloc for device_list (joern)
- Add target core support for TMR_ABORT_TASK (nab)
- Add target core se_sess->sess_kref + get/put helpers (nab)
- Add target core se_node_acl->acl_kref for ->acl_free_comp usage
(nab)
- Convert iscsi-target to use target_put_session + sess_kref (nab)
- Fix tcm_fc fc_exch memory leak in ft_send_resp_status (nab)
- Fix ib_srpt srpt_handle_cmd send_ioctx->ioctx_kref leak on
exception (nab)
- Fix target core up handling of short INQUIRY buffers (roland)
- Untangle target-core front-end and back-end meanings of max_sectors
attribute (roland)
- Set loopback residual field for SCSI commands (roland)
- Fix target-core 16-bit target ports for SET TARGET PORT GROUPS
emulation (roland)
Thanks again to Andy, Christoph, Joern, Roland, and everyone who has
contributed this round!"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (64 commits)
ib_srpt: Fix srpt_handle_cmd send_ioctx->ioctx_kref leak on exception
loopback: Fix transport_generic_allocate_tasks error handling
iscsi-target: remove improper externs
iscsi-target: Remove unused variables in iscsi_target_parameters.c
target: remove obvious warnings
target: Use array_zalloc for device_list
target: Use array_zalloc for tpg_lun_list
target: Fix sense code for unsupported SERVICE ACTION IN
target: Remove hack to make READ CAPACITY(10) lie if thin provisioning is enabled
target: Bump core version to v4.1.0-rc2-ml + fabric versions
tcm_fc: Fix fc_exch memory leak in ft_send_resp_status
target: Drop unused legacy target_core_fabric_ops API callers
iscsi-target: Convert to use target_put_session + sess_kref
target: Convert se_node_acl->acl_group removal to use ->acl_kref
target: Add se_node_acl->acl_kref for ->acl_free_comp usage
target: Add se_node_acl->acl_free_comp for NodeACL release path
target: Add se_sess->sess_kref + get/put helpers
target: Convert session_lock to irqsave
target: Fix typo in drivers/target
iscsi-target: Fix dynamic -> explict NodeACL pointer reference
...
Get rid of a bunch of write-only variables. In a number of cases I
suspect actual bugs to be present, so I left all of those for a second
look.
(nab: fix lio-core patch fuzz)
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Turns an order-8 allocation into slab-sized ones, thereby preventing
allocation failures with memory fragmentation.
This likely saves memory as well, as the slab allocator can pack objects
more tightly than the buddy allocator.
(nab: Fix lio-core patch fuzz)
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch addresses a bug with target_check_scsi2_reservation_conflict()
return checking in target_scsi2_reservation_[reserve,release]() that was
preventing CRH=1 operation from silently succeeding in the two special
cases defined by SPC-3, and not failing with reservation conflict status
when dealing with legacy RESERVE/RELEASE + active SPC-3 PR logic.
Also explictly set cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT during
the early non reservation holder failure from pr_ops->t10_seq_non_holder()
check in transport_generic_cmd_sequencer() for fabrics that already expect
it to be set.
This bug was originally introduced in mainline commit:
commit eacac00ce5
Author: Christoph Hellwig <hch@infradead.org>
Date: Thu Nov 3 17:50:40 2011 -0400
target: split core_scsi2_emulate_crh
Reported-by: Martin Svec <martin.svec@zoner.cz>
Cc: Martin Svec <martin.svec@zoner.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Instead of
static struct list_head foo;
static struct mutex bar;
...
INIT_LIST_HEAD(&foo);
mutex_init(&bar);
just do
static LIST_HEAD(foo);
static DEFINE_MUTEX(bar);
Also remove some superfluous struct list_head and spinlock_t
initialization calls where the variables are already defined using
macros that initialize them.
This saves a decent amount of compiled code too:
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-178 (-178)
function old new delta
target_core_init_configfs 898 850 -48
core_scsi3_emulate_pro_preempt 1742 1683 -59
iscsi_thread_set_init 159 88 -71
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We need to handle >1 page control cdbs, so extend the code to do a vmap
if bigger than 1 page. It seems like kmap() is still preferable if just
a page, fewer TLB shootdowns(?), so keep using that when possible.
Rename function pair for their new scope.
Signed-off-by: Andy Grover <agrover@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Initiators that aren't the active reservation holder should be able to
do a PERSISTENT RESERVE IN command in all cases, so add it to the list
of allowed CDBs in core_scsi3_pr_seq_non_holder().
Signed-off-by: Marco Sanvido <marco@purestorage.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The comments quote the right parts of the spec:
* d) Establish a unit attention condition for the
* initiator port associated with every I_T nexus
* that lost its registration other than the I_T
* nexus on which the PERSISTENT RESERVE OUT command
* was received, with the additional sense code set
* to REGISTRATIONS PREEMPTED.
and
* e) Establish a unit attention condition for the initiator
* port associated with every I_T nexus that lost its
* persistent reservation and/or registration, with the
* additional sense code set to REGISTRATIONS PREEMPTED;
but the actual code accidentally uses ASCQ_2AH_RESERVATIONS_PREEMPTED
instead of ASCQ_2AH_REGISTRATIONS_PREEMPTED. Fix this.
Signed-off-by: Marco Sanvido <marco@purestorage.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This reorganized the headers under include/target into:
- target_core_base.h stays as is with all target-wide data stuctures and defines
- target_core_backend.h contains the whole interface to I/O backends
- target_core_fabric.h contains the whole interface to fabric modules
Except for those only the various configfs macro headers stay around.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Create a new headers, drivers/target/target_core_internal.h that is supposed
to hold all target_core-internal prototypes. Move all non-exported includes
from include/target to it, and merge the smaller prototype-only includes
inside drivers/target into it as well. Mark functions that were found to
not be called outside their implementation file static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch removes legacy usage of PYX_TRANSPORT_* return codes in a number
of locations and addresses cases where transport_generic_request_failure()
was returning the incorrect sense upon CHECK_CONDITION status after the
v3.1 converson to use errno return codes.
This includes the conversion of transport_generic_request_failure() to
process cmd->scsi_sense_reason and handle extra TCM_RESERVATION_CONFLICT
before calling transport_send_check_condition_and_sense() to queue up
response status. It also drops PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES legacy
usgae, and returns TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE w/ a response
for these cases.
transport_generic_allocate_tasks(), transport_generic_new_cmd(), backend
SCF_SCSI_DATA_SG_IO_CDB ->do_task(), and emulated ->execute_task() have
all been updated to set se_cmd->scsi_sense_reason and return errno codes
universally upon failure. This includes cmd->scsi_sense_reason assignment
in target_core_alua.c, target_core_pr.c and target_core_cdb.c emulation code.
Finally it updates fabric modules to remove the legacy usage, and for
TFO->new_cmd_map() callers forwards return values outside of fabric code.
iscsi-target has also been updated to remove a handful of special cases
related to the cleanup and signaling QUEUE_FULL handling w/ ft_write_pending()
(v2: Drop extra SCF_SCSI_CDB_EXCEPTION check during failure from
transport_generic_new_cmd, and re-add missing task->task_error_status
assignment in transport_complete_task)
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
All ->execute_task instances now need to complete the I/O explicitly,
which can either happen synchronously or asynchronously.
Note that a lot of the CDB emulations appear to return success even if
some lowlevel operations failed. Given that this is an existing issue
this patch doesn't change that fact.
(nab: Adding missing switch breaks in PR-IN + PR_OUT)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We want to be able to handle all CDBs through it and remove hacks like
always using the first task in a CDB in target_report_luns.
Also rename the callback to ->execute_task to better describe its use.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Split core_scsi2_emulate_crh into one routine each for the
PERSISTENT_RESERVE_IN and PERSISTENT_RESERVE_OUT side.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Split core_scsi2_emulate_crh into one routine each for the reserve and
release side. The common code now is in a helper called by both
routines.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/target/.
This patch removes them.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
With qla2xxx, acl_node_lock is taken inside qla2xxx's hardware_lock,
which is taken in hardirq context. This means acl_node_lock must become
an IRQ-disabling lock; in particular this fixes lockdep warnings along
the lines of
======================================================
[ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
(&(&se_tpg->acl_node_lock)->rlock){+.....}, at: [<ffffffffa026f872>] transport_deregister_session+0x92/0x140 [target_core_mod]
and this task is already holding:
(&(&ha->hardware_lock)->rlock){-.-...}, at: [<ffffffffa017c5e7>] qla_tgt_stop_phase1+0x57/0x2c0 [qla2xxx]
which would create a new lock dependency:
(&(&ha->hardware_lock)->rlock){-.-...} -> (&(&se_tpg->acl_node_lock)->rlock){+.....}
but this new dependency connects a HARDIRQ-irq-safe lock:
(&(&ha->hardware_lock)->rlock){-.-...}
to a HARDIRQ-irq-unsafe lock:
(&(&se_tpg->acl_node_lock)->rlock){+.....}
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the squashed version of forth round series cleanups
from Andy and Christoph following the post heavy lifting in the preceeding:
'Eliminate usage of struct se_mem' and 'Make all control CDBs scatter-gather'
changes. This also includes a conversion of target core and the v3.0
mainline fabric modules (loopback and tcm_fc) to use pr_debug and the
CONFIG_DYNAMIC_DEBUG infrastructure!
These have been squashed into this third and final round for v3.1.
target: Remove ifdeffed code in t_g_process_write
target: Remove direct ramdisk code
target: Rename task_sg_num to task_sg_nents
target: Remove custom debug macros for pr_debug. Use pr_err().
target: Remove custom debug macros in mainline fabrics
target: Set WSNZ=1 in block limits VPD. Abort if WRITE_SAME sectors = 0
target: Remove transport do_se_mem_map callback
target: Further simplify transport_free_pages
target: Redo task allocation return value handling
target: Remove extra parentheses
target: change alloc_task call to take *cdb, not *cmd
(nab: Fix bogus struct file assignments in fd_do_readv and fd_do_writev)
Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Previously, some control CDBs did not allocate memory in pages for their
data buffer, but just did a kmalloc. This patch makes all cdbs allocate
pages.
This has the benefit of streamlining some paths that had to behave
differently when we used two allocation methods. The downside is that
all accesses to the data buffer need to kmap it before use, and need to
handle data in page-sized chunks if more than a page is needed for a given
command's data buffer.
Finally, note that cdbs with no data buffers are handled a little
differently. Before, SCSI_NON_DATA_CDBs would not call get_mem at all
(they'd be in the final else in transport_allocate_resources) but now
these will make it into generic_get_mem, but just not allocate any
buffers.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains a squashed version of third round series cleanups,
improvements ,and simplfications from Andy and Christoph ahead of the
heavy lifting between round 3 -> 4 for the target core SGL conversion.
This include cleanups to the main target I/O path and other miscellaneous
updates.
target: Replace custom sg<->buf functions with lib funcs
target: Simplify sector limiting code
target: get_cdb should never return NULL
target: Simplify transport_memcpy_se_mem_read_contig
target: Use assignment rather than increment for t_task_cdbs
target: Don't pass dma_size to generic_get_mem
target: Pass sg with type scatterlist in transport_map_sg_to_mem
target: Move task_sg_num next to task_sg in struct se_task
target: inline struct se_transport_task into struct se_cmd
target: Change name & semantics of transport_get_sectors()
target: Remove unused members of se_cmd
target: Rename se_cmd.t_task_cdbs to t_task_list_num
target: Fix some spelling
target: Remove unused var from transport_generic_do_tmr
target: map_sg_to_mem: return sg_count in return value
target/pscsi: Use min_t for sector limits
target/pscsi: Unused param for pscsi_get_bio()
target: Rename get_cdb_count to allocate_tasks
target: Make transport_generic_new_cmd() available for iscsi-target
target: Remove fabric callback to allocate iovecs
target: Fix transport_generic_new_cmd WRITE comment
(hch: Use __GFP_ZERO usage for alloc_pages() usage)
Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the squashed version of second round of target core
cleanups and simplifications and Andy and Co. It also contains a handful
of fixes to address bugs the original series and other minor cleanups.
Here is the condensed shortlog:
target: Remove unneeded casts to void*
target: Rename get_lun_for_{cmd,tmr} to lookup_{cmd,tmr}_lun
target: Make t_task a member of se_cmd, not a pointer
target: Handle functions returning "-2"
target: Use cmd->se_dev over cmd->se_lun->lun_se_dev
target: Embed qr in struct se_cmd
target: Replace embedded struct se_queue_req with a list_head
target: Rename list_heads that are nodes in struct se_cmd to "*_node"
target: Fold transport_device_setup_cmd() into lookup_{tmr,cmd}_lun()
target: Make t_mem_list and t_mem_list_bidi members of t_task
target: Add comment & cleanup transport_map_sg_to_mem()
target: Remove unneeded checks in transport_free_pages()
(Roland: Fix se_queue_req removal leftovers OOPs)
(nab: Fix transport_lookup_tmr_lun failure case)
(nab: Fix list_empty(&cmd->t_task.t_mem_bidi_list) inversion bugs)
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the squashed version of a number of cleanups and
minor fixes from Andy's initial series (round 1) for target core this
past spring. The condensed log looks like:
target: use errno values instead of returning -1 for everything
target: Rename transport_calc_sg_num to transport_init_task_sg
target: Fix leak in error path in transport_init_task_sg
target/pscsi: Remove pscsi_get_sh() usage
target: Make two runtime checks into WARN_ONs
target: Remove hba queue depth and convert to spin_lock_irq usage
target: dev->dev_status_queue_obj is unused
target: Make struct se_queue_req.cmd type struct se_cmd *
target: Remove __transport_get_qr_from_queue()
target: Rename se_dev->g_se_dev_list to se_dev_node
target: Remove struct se_global
target: Simplify scsi mib index table code
target: Make dev_queue_obj a member of se_device instead of a pointer
target: remove extraneous returns at end of void functions
target: Ensure transport_dump_vpd_ident_type returns null-terminated str
target: Function pointers don't need to use '&' to be assigned
target: Fix comment in __transport_execute_tasks()
target: Misc style cleanups
target: rename struct pr_reservation_template to pr_reservation
target: Remove #defines that just perform indirection
target: Inline transport_get_task_from_execute_queue()
target: Minor header comment fixes
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a number of cases in target core using an incorrectly
if (strlen(foo) > SOME_MAX_SIZE)
As strlen() returns the number of characters in the string not counting
the NULL character at the end. So if you do something like:
char buf[10];
if (strlen("0123456789") > 10)
return -ETOOLONG;
snprintf(buf, 10, "0123456789");
printf("%s\n", buf);
then the last "9" gets chopped off and only "012345678" is printed.
Plus I threw in one small related cleanup.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
LIO target is a full featured in-kernel target framework with the
following feature set:
High-performance, non-blocking, multithreaded architecture with SIMD
support.
Advanced SCSI feature set:
* Persistent Reservations (PRs)
* Asymmetric Logical Unit Assignment (ALUA)
* Protocol and intra-nexus multiplexing, load-balancing and failover (MC/S)
* Full Error Recovery (ERL=0,1,2)
* Active/active task migration and session continuation (ERL=2)
* Thin LUN provisioning (UNMAP and WRITE_SAMExx)
Multiprotocol target plugins
Storage media independence:
* Virtualization of all storage media; transparent mapping of IO to LUNs
* No hard limits on number of LUNs per Target; maximum LUN size ~750 TB
* Backstores: SATA, SAS, SCSI, BluRay, DVD, FLASH, USB, ramdisk, etc.
Standards compliance:
* Full compliance with IETF (RFC 3720)
* Full implementation of SPC-4 PRs and ALUA
Significant code cleanups done by Christoph Hellwig.
[jejb: fix up for new block bdev exclusive interface. Minor fixes from
Randy Dunlap and Dan Carpenter.]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
