When a writing to a command-provided buffer we need to ensure
that we're not writing past the end of it.
At the same time we need to continue processing as typically
the final data length (ie the required size of the buffer)
need to be returned.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Referrals need an LBA map, which needs to be kept
consistent across all target port groups. So
instead of tying the map to the target port groups
I've implemented a single attribute containing the
entire map.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Add infrastructure for referrals.
v2 changes:
- Fix unsigned long long division in core_alua_state_lba_dependent on
32-bit (Fengguang + Chen + Hannes)
- Fix compile warning in core_alua_state_lba_dependent (nab)
- Convert segment_* + sectors variables in core_alua_state_lba_dependent
to u64 (Hannes)
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Use a workqueue for processing ALUA state transitions; this allows
us to process implicit delay properly.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
During state transition we should be storing both the original
and the pending state.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We should only allocate ALUA metadata if we're actually going
to write them.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
As we now can modify the list of supported states we need to
validate the requested ALUA state when doing a state transition.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The supported ALUA states might be different for individual
devices, so store it in a separate field.
(nab: Remove unnecessary line continuation)
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Rename ALUA_ACCESS_STATE_OPTMIZED to
ALUA_ACCESS_STATE_OPTIMIZED.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Update copyright ownership/year information for target-core,
loopback, iscsi-target, tcm_qla2xx, vhost and iser-target.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a >= v3.9+ regression in __core_scsi3_write_aptpl_to_file()
+ core_alua_write_tpg_metadata() write-out, where a return value of -EIO was
incorrectly being returned upon success.
This bug was originally introduced in:
commit 0e9b10a90f
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat Feb 23 15:22:43 2013 -0500
target: writev() on single-element vector is pointless
However, given that the return of core_scsi3_update_and_write_aptpl()
was not used to determine if a command should be returned with non GOOD
status, this bug was not being triggered in PR logic until v3.11-rc1 by
commit:
commit 459f213ba1
Author: Andy Grover <agrover@redhat.com>
Date: Thu May 16 10:41:02 2013 -0700
target: Allocate aptpl_buf inside update_and_write_aptpl()
So, go ahead and only return -EIO if kernel_write() returned a
negative value.
Reported-by: Gera Kazakov <gkazakov@msn.com>
Signed-off-by: Gera Kazakov <gkazakov@msn.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Grover <agrover@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds an check for a non-existent port->sep_alua_tg_pt_gp_mem
within target_alua_state_check(), which is not present for internally
dispatched EXTENDED_COPY WRITE I/O to the destination target port.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>
The usage of strict_strtoul() and strict_strtoull() is not preferred,
because strict_strtoul() and strict_strtoull() are obsolete. Thus,
kstrtoul() and kstrtoull() should be used.
v2: Fix incorrect return in ft_add_tpg (Fengguang)
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a bug where a handful of informational / control CDBs
that should be allowed during ALUA access state Standby/Offline/Transition
where incorrectly returning CHECK_CONDITION + ASCQ_04H_ALUA_TG_PT_*.
This includes INQUIRY + REPORT_LUNS, which would end up preventing LUN
registration when LUN scanning occured during these ALUA access states.
Cc: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
... in other news:
filp_open() can't return a struct file with NULL dentry
filp_open() can't return a struct file negative dentry
filp_close() of something that never had been in any descriptor
tables is pointless - fput() is all you need
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The compiler complained about uninitialized variables, so
use TCM_NO_SENSE here.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@risingtidesystems.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
v2: Use correct target_core_stat.c 2006 copyright year
v3: Drop extra unnessary legal verbage from header (hch)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Fix a bug introduced with patch "target: pass sense_reason as a return value"
in for-3.8 code where only target port groups with TPGS_EXPLICT_ALUA set
need to be allowed to perform explictly ALUA.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values. This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.
(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We always support ALUA for virtual backends, and never for physical ones. Simplify
the code to just deal with these two cases and remove the superflous abstractions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Simplify the code a lot by killing the superflous struct se_subsystem_dev.
Instead se_device is allocated early on by the backend driver, which allocates
it as part of its own per-device structure, borrowing the scheme that is for
example used for inode allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Correct spelling typo in printk and comment within drivers/target.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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>
The error paths in target_emulate_set_target_port_groups() are all
essentially "rc = -EINVAL; goto out;" but the code at "out:" ignores
rc and always returns success. This means that even if eg explicit
ALUA is turned off, the initiator will always see a good SCSI status
for SET TARGET PORT GROUPS.
Fix this by returning rc as is intended. It appears this bug was
added by the following patch:
commit 05d1c7c0d0
Author: Andy Grover <agrover@redhat.com>
Date: Wed Jul 20 19:13:28 2011 +0000
target: Make all control CDBs scatter-gather
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds support for ALUA MI_REPORT_TARGET_PGS extended header
format defined within SPC-4. It changes target core ALUA emulation logic
within target_emulate_report_target_port_groups() to support both the
extended and original length only header formats.
It includes adding a new 'implict_trans_secs' attribute for each ALUA
target port group to control the value returned to the application client
for an recommended implict translation timeout in seconds. By default
this value is currently set to zero, and limited up to 255 by virtue of
using a single byte in the extended header format.
This value is used by target_emulate_report_target_port_groups() within
the extended header logic to set IMPLICIT TRANSITION TIME as defined by
spc4r30.
Cc: Hannes Reinecke <hare@suse.de>
Cc: Rob Evers <revers@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes the MAINTENANCE_IN service action type checks to only
look at the proper lower 5 bits of cdb byte 1. This addresses the case
where MI_REPORT_TARGET_PGS w/ extended header using the upper three bits of
cdb byte 1 was not processed correctly in transport_generic_cmd_sequencer,
as well as the three cases for standby, unavailable, and transition ALUA
primary access state checks.
Also add MAINTENANCE_IN to the excluded list in transport_generic_prepare_cdb()
to prevent the PARAMETER DATA FORMAT bits from being cleared.
Cc: Hannes Reinecke <hare@suse.de>
Cc: Rob Evers <revers@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
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>
The old code did (MSB << 8) & 0xff, which always evaluates to 0. Just use
get_unaligned_be16() so we don't have to worry about whether our open-coded
version is correct or not.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
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>
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>
Some are never used, some are set but never read, dev_hoq_count is
incremented and decremented, but never read.
Signed-off-by: Joern Engel <joern@logfs.org>
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>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
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>
This patch fixes a bug with the handling of REPORT TARGET PORT GROUPS
containing a smaller allocation length than the payload requires causing
memory writes beyond the end of the buffer. This patch checks for the
minimum 4 byte length for the response payload length, and also checks
upon each loop of T10_ALUA(su_dev)->tg_pt_gps_list to ensure the Target
port group and Target port descriptor list is able to fit into the
remaining allocation length.
If the response payload exceeds the allocation length length, then rd_len
is still increments to indicate to the initiator that the payload has
been truncated.
Reported-by: Roland Dreier <roland@purestorage.com>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
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>
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>
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>