mirror of
https://github.com/SCST-project/scst.git
synced 2026-08-19 21:56:31 +00:00
Yan Burman
e4c7d430c1
svn+ssh://yanb123@svn.code.sf.net/p/scst/svn/trunk
........
r5536 | vlnb | 2014-05-22 06:06:46 +0300 (Thu, 22 May 2014) | 3 lines
Version changed to 3.1.0-pre1
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r5537 | vlnb | 2014-05-22 06:18:27 +0300 (Thu, 22 May 2014) | 3 lines
Web updates
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r5538 | bvassche | 2014-05-22 10:16:04 +0300 (Thu, 22 May 2014) | 1 line
nightly build: Update kernel versions
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r5539 | vlnb | 2014-05-23 05:20:35 +0300 (Fri, 23 May 2014) | 9 lines
vdisk_nullio: Add "read_zero" attribute
Add an attribute called "read_zero" to vdisk_nullio devices that
controls whether or not READs from a vdisk_nullio device return
zeroed data buffers.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
........
r5543 | bvassche | 2014-05-23 10:33:53 +0300 (Fri, 23 May 2014) | 1 line
RHEL 7 build fixes
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r5545 | bvassche | 2014-05-23 11:36:36 +0300 (Fri, 23 May 2014) | 1 line
scripts/rebuild-rhel-kernel-rpm: Add RHEL 7 RC support
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r5547 | vlnb | 2014-05-24 06:10:34 +0300 (Sat, 24 May 2014) | 3 lines
Optimize read_zero functionality
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r5555 | bvassche | 2014-05-27 14:59:11 +0300 (Tue, 27 May 2014) | 5 lines
qla2x00t: Documentation / source code comment / log messages spelling fix
Change a few occurrences of "conformation" into "confirmation". See also the
QLogic 2500 Series Firmware Interface Specification.
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r5557 | vlnb | 2014-05-30 03:42:34 +0300 (Fri, 30 May 2014) | 5 lines
Small code reorganization.
No functionality changed
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r5558 | vlnb | 2014-05-30 06:00:07 +0300 (Fri, 30 May 2014) | 3 lines
Logging fixes
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r5560 | bvassche | 2014-06-02 18:31:50 +0300 (Mon, 02 Jun 2014) | 1 line
Makefile: Only report which RPMs have been built if "make rpm" is run as a non-privileged user
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r5561 | bvassche | 2014-06-03 09:04:47 +0300 (Tue, 03 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5562 | vlnb | 2014-06-04 04:54:21 +0300 (Wed, 04 Jun 2014) | 3 lines
Decrease max WRITE SAME length for better latencies
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r5563 | vlnb | 2014-06-04 05:16:51 +0300 (Wed, 04 Jun 2014) | 3 lines
Enforce limit on max unmap LBAs
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r5566 | bvassche | 2014-06-04 18:14:22 +0300 (Wed, 04 Jun 2014) | 1 line
ib_srpt: Fix an error message
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r5567 | bvassche | 2014-06-04 18:17:59 +0300 (Wed, 04 Jun 2014) | 1 line
ib_srpt: Avoid triggering a SCSI command timeout after login
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r5568 | bvassche | 2014-06-05 09:34:19 +0300 (Thu, 05 Jun 2014) | 1 line
scst_vdisk: Build fix for kernel versions <= 2.6.32
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r5569 | bvassche | 2014-06-05 09:46:57 +0300 (Thu, 05 Jun 2014) | 1 line
scst_vdisk: Fix a kernel version < 2.6.38 compiler warning
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r5570 | vlnb | 2014-06-06 06:20:26 +0300 (Fri, 06 Jun 2014) | 8 lines
scst_lib: Fix a compiler warning triggered by the WRITE SAME implementation
Avoid for release builds that the compiler reports that the variable
'ws_sg_cnt' is not used.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5571 | vlnb | 2014-06-06 06:22:14 +0300 (Fri, 06 Jun 2014) | 7 lines
nullio_exec_read(): Fix kunmap() argument
The argument of kunmap() is of type struct page *. Detected by smatch.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5572 | vlnb | 2014-06-06 06:24:03 +0300 (Fri, 06 Jun 2014) | 11 lines
scst: Leave out FSF mail address
This avoids that the following checkpatch complaint is triggered:
Do not include the paragraph about writing to the Free Software Foundation's
mailing address from the sample GPL notice. The FSF has changed addresses in
the past, and may do so again. Linux already includes a copy of the GPL.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5573 | vlnb | 2014-06-06 06:26:55 +0300 (Fri, 06 Jun 2014) | 10 lines
scst: Make lockdep_assert_held() easier to use
The lockdep_assert_held() macro is a convenient debugging tool.
However, it is inconvenient to surround each invocation of that
macro by an #ifdef/#endif pair. Hence make it easier to use this
macro with older kernel versions.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5574 | vlnb | 2014-06-07 00:59:24 +0300 (Sat, 07 Jun 2014) | 3 lines
Use limits.discard_zeroes_data to set LBPRZ
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r5575 | bvassche | 2014-06-07 13:46:49 +0300 (Sat, 07 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5577 | bvassche | 2014-06-10 17:16:14 +0300 (Tue, 10 Jun 2014) | 1 line
ib_srpt: Make the test for IB_EVENT_GID_CHANGE support more robust
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r5578 | bvassche | 2014-06-10 17:49:59 +0300 (Tue, 10 Jun 2014) | 1 line
ib_srpt: Make IB_EVENT_GID_CHANGE test independent of the OFED detection code
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r5579 | bvassche | 2014-06-11 13:02:15 +0300 (Wed, 11 Jun 2014) | 1 line
ib_srpt: RHEL 5 build fix
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r5581 | bvassche | 2014-06-11 18:27:06 +0300 (Wed, 11 Jun 2014) | 1 line
regression tests: Sync with a recent sysfs change
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r5582 | bvassche | 2014-06-11 18:27:48 +0300 (Wed, 11 Jun 2014) | 1 line
regression tests: Sort hash keys before comparing
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r5583 | bvassche | 2014-06-11 18:41:01 +0300 (Wed, 11 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5584 | vlnb | 2014-06-11 22:33:18 +0300 (Wed, 11 Jun 2014) | 8 lines
scst: RHEL 5 build fix
Avoid that building the scst kernel module fails on RHEL 5 due to
a missing kvasprintf() implementation.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
........
r5585 | vlnb | 2014-06-11 22:38:10 +0300 (Wed, 11 Jun 2014) | 11 lines
scst: Remove unused variables
Avoid that building scst with W=1 triggers compiler warnings about
variables that are set but not used. See also the documentation of
the gcc compiler flag -Wunused-but-set-variable.
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5586 | vlnb | 2014-06-11 22:39:51 +0300 (Wed, 11 Jun 2014) | 9 lines
scst_lib: Introduce additional temporary variables
Make the code slightly easier to read by introducing temporary
variables for the expressions 'tgt_dev->sess' and 'sess->tgt->tgtt'.
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5587 | vlnb | 2014-06-11 23:57:03 +0300 (Wed, 11 Jun 2014) | 10 lines
scst: Add support for 64-bit LUNs
The datatype of scsi_device.lun will be changed from u32 into u64
in the near future. Update SCST accordingly. These changes have
been implemented such that these are compatible with 32-bit and
64-bit LUNs.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5588 | vlnb | 2014-06-12 00:00:16 +0300 (Thu, 12 Jun 2014) | 9 lines
scst_local: Support LUN numbers >= 16384
Add support for 32-bit LUN numbers. As soon as the patches that add
64-bit LUN support are upstream this patch will also make 64-bit
LUN support available in scst_local.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5589 | vlnb | 2014-06-12 00:42:08 +0300 (Thu, 12 Jun 2014) | 8 lines
scst: Clean up __scst_resume_activity()
Move all management commands from scst_delayed_mgmt_cmd_list to the
active command list during resume instead of only the first one.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
........
r5590 | vlnb | 2014-06-12 01:07:00 +0300 (Thu, 12 Jun 2014) | 9 lines
scst: Introduce scst_lookup_tgt_dev()
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
with some improvements
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r5592 | bvassche | 2014-06-12 11:38:45 +0300 (Thu, 12 Jun 2014) | 7 lines
scst.h: Move definition of swap()
Make sure that the definition of swap() is guarded by
"#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)" only instead
of "#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 28)" and
"#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)".
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r5593 | bvassche | 2014-06-12 12:15:50 +0300 (Thu, 12 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5594 | bvassche | 2014-06-12 14:33:00 +0300 (Thu, 12 Jun 2014) | 1 line
ib_srpt: Set MOFED include path correctly if MOFED has been installed with --add-kernel-support
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r5595 | bvassche | 2014-06-12 16:38:38 +0300 (Thu, 12 Jun 2014) | 1 line
ib_srpt: Make non-OFED build work again
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r5596 | vlnb | 2014-06-13 07:52:18 +0300 (Fri, 13 Jun 2014) | 16 lines
scst: Switch from the cpu_*() to the cpumask_*() API
The cpus_*() functions were deprecated via patch "cpumask:
introduce new API, without changing anything" (November 2008,
commit ID 2d3854a37e8b). Hence switch from the cpus_*() API to
the cpumask_*() API.
This patch has the intended side effect of not adding the "[key]"
property to cpumask sysfs attributes that contain the default
cpumask. The current code namely reads uninitialized bits on
systems where nr_cpu_ids < NR_CPUS because cpus_equal() compares
more bits than those that were set by cpumask_copy().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5597 | vlnb | 2014-06-13 08:03:17 +0300 (Fri, 13 Jun 2014) | 3 lines
Forgotten versions updated
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r5598 | bvassche | 2014-06-13 09:55:23 +0300 (Fri, 13 Jun 2014) | 1 line
ib_srpt: Make one_target_per_port the default mode
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r5600 | vlnb | 2014-06-14 01:24:06 +0300 (Sat, 14 Jun 2014) | 9 lines
scst: Avoid that W=1 triggers complaints about unused variables
Avoid that building scst with W=1 triggers compiler warnings about
variables that are set but not used. See also the documentation of
the gcc compiler flag -Wunused-but-set-variable.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
........
r5601 | vlnb | 2014-06-14 01:31:42 +0300 (Sat, 14 Jun 2014) | 8 lines
scst_local: Add close_session() callback function
This is useful for triggering the session reassignment code via
the scst_local driver.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
........
r5602 | vlnb | 2014-06-14 02:57:26 +0300 (Sat, 14 Jun 2014) | 8 lines
scst_pr_read_reservation(): Initialize returned buffer
Avoid that this function returns an uninitialized buffer to the
initiator if buffer_size < 8. Detected by Coverity.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5603 | vlnb | 2014-06-14 02:58:28 +0300 (Sat, 14 Jun 2014) | 5 lines
scst: Help Coverity recognize that vmalloc(0) returns NULL
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5605 | bvassche | 2014-06-14 20:10:58 +0300 (Sat, 14 Jun 2014) | 1 line
fcst: Remove an unused variable
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r5606 | bvassche | 2014-06-14 20:17:56 +0300 (Sat, 14 Jun 2014) | 5 lines
fcst: Move exch_done() calls into ft_cmd_done()
This patch ensures that exch_done() gets called if an fcst
callback returns SCST_TGT_RES_FATAL_ERROR.
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r5607 | bvassche | 2014-06-14 20:18:34 +0300 (Sat, 14 Jun 2014) | 10 lines
fcst: Handle frame send failures properly
Retry sending XFER_RDY, data and response frames if the network
driver reports that sending failed (-ENOMEM) instead of reporting
a kernel warning (WARN_ON(1)). If sending XFER_RDY or data frames
failed for another reason, report this to the initiator as a
write error (ASC = 03; ASCQ = 00 which stands for PERIPHERAL
DEVICE WRITE FAULT). If sending a response frame failed with
another error code than -ENOMEM, do not send a response.
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r5608 | vlnb | 2014-06-17 03:50:46 +0300 (Tue, 17 Jun 2014) | 10 lines
scst: Make access control group removal behavior configurable
SCST rejects removal of an access control group with one or more
sessions with error code -EBUSY. Make it easy to change this
behavior into forcibly closing sessions when an access control
group is removed.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5609 | bvassche | 2014-06-17 09:37:08 +0300 (Tue, 17 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5610 | vlnb | 2014-06-19 06:51:48 +0300 (Thu, 19 Jun 2014) | 3 lines
Update for 3.15 kernels
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r5611 | bvassche | 2014-06-19 10:09:53 +0300 (Thu, 19 Jun 2014) | 1 line
nightly build: Add kernel 3.15 build infrastructure
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r5612 | bvassche | 2014-06-19 15:48:25 +0300 (Thu, 19 Jun 2014) | 1 line
kernel module installation: Skip "depmod" when building an RPM
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r5613 | vlnb | 2014-06-20 07:00:41 +0300 (Fri, 20 Jun 2014) | 8 lines
scst: Convert a loop to keep smatch happy
Avoid that smatch reports the following warning:
scst_init_session() info: loop could be replaced with if statement.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5614 | vlnb | 2014-06-20 07:02:00 +0300 (Fri, 20 Jun 2014) | 13 lines
iscsi-scst: Suppress a compiler warning
Avoid that the following compiler warning is reported when compiling
iscsi-scst:
chap.c: In function 'chap_rand':
chap.c:348:5: warning: ignoring return value of 'read', declared with attribute warn_unused_result [-Wunused-result]
(void)read(fd, &r, sizeof(r));
^
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5615 | vlnb | 2014-06-20 07:03:40 +0300 (Fri, 20 Jun 2014) | 5 lines
scst, iscsi-scst: Fix RHEL 5 compilation warnings
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5616 | vlnb | 2014-06-20 07:05:11 +0300 (Fri, 20 Jun 2014) | 10 lines
scst: Exclude certain locking code from static analysis
Loops with locking statements and also lock and unlock
statements guarded by an if-statement trigger false positive
warnings when analyzing the SCST code with smatch and/or sparse.
Hence exclude such code from static analysis.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5617 | vlnb | 2014-06-20 07:09:11 +0300 (Fri, 20 Jun 2014) | 10 lines
scst: Avoid that sparse complains about unreachable code
Remove the code after BUG() statements to avoid that smatch
complains about unreachable code. Hide the spin_unlock() statements
before BUG() statements for static analysis tools to avoid that
sparse complains about locking imbalances.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5618 | vlnb | 2014-06-20 07:10:40 +0300 (Fri, 20 Jun 2014) | 12 lines
Change BUG_ON(1) into BUG()
With CONFIG_BUG=y both BUG() and BUG_ON(1) halt the system. However,
with CONFIG_BUG=n BUG() halts the system but BUG_ON(1) not. To avoid
such subtleties, change BUG_ON(1) into BUG().
See also patch Josh Triplett, "bug: Make BUG() always stop the machine",
7 April 2014 (commit ID a4b5d580e07875f9be29f62a57c67fbbdbb40ba2).
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5619 | bvassche | 2014-06-20 08:56:36 +0300 (Fri, 20 Jun 2014) | 1 line
nightly build: Add kernel version 3.15.1
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r5620 | vlnb | 2014-06-24 07:45:08 +0300 (Tue, 24 Jun 2014) | 9 lines
scst_vdisk: Split vdisk_exec_inquiry()
Make vdisk_exec_inquiry() easier to read by moving the code
for the implementation of each VPD page into a separate function.
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5621 | bvassche | 2014-06-24 16:32:18 +0300 (Tue, 24 Jun 2014) | 1 line
ib_srpt: Complain if another ib_srpt.ko kernel module already exists
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r5622 | bvassche | 2014-06-24 16:33:23 +0300 (Tue, 24 Jun 2014) | 2 lines
ib_srpt: Set SCSI residual fields in SRP_CMD reply
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r5624 | bvassche | 2014-06-25 14:50:40 +0300 (Wed, 25 Jun 2014) | 1 line
nightly build: Use http instead of ftp for downloading kernel source code
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r5625 | vlnb | 2014-06-26 00:38:19 +0300 (Thu, 26 Jun 2014) | 5 lines
scst_debug.h: Make EXTRACHECKS_*_ON() statements visible to Coverity
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5626 | vlnb | 2014-06-27 02:26:25 +0300 (Fri, 27 Jun 2014) | 10 lines
scst_vdisk: Three more put_unaligned_*() conversions
Convert three more *(__be16 *)p = cpu_to_be16(v) statements into
put_unaligned_be16(v, p) since the latter is easier to read. Also
convert one "cmd->dev" into "dev" expression. This patch does not
change any functionality.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
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r5627 | bvassche | 2014-06-27 13:32:02 +0300 (Fri, 27 Jun 2014) | 1 line
nightly build: Update kernel versions
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r5628 | bvassche | 2014-06-28 22:56:36 +0300 (Sat, 28 Jun 2014) | 1 line
ib_srpt: Remove existing ib_srpt.ko kernel modules before installation
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r5629 | bvassche | 2014-06-28 22:58:44 +0300 (Sat, 28 Jun 2014) | 6 lines
scst_vdisk: Fix 32-bit build
Avoid 64-bit modulo computations since these result in undefined symbol
errors on 32-bit systems (__moddi3 / __umoddi3). Support sizes >= 2**32
bytes on 32-bit systems.
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r5630 | bvassche | 2014-06-28 23:00:22 +0300 (Sat, 28 Jun 2014) | 1 line
scst.spec.in: Follow-up for r5628
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r5631 | bvassche | 2014-06-28 23:15:45 +0300 (Sat, 28 Jun 2014) | 1 line
scst_local: Avoid that session deletion triggers a kernel warning
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r5647 | bvassche | 2014-06-30 10:18:53 +0300 (Mon, 30 Jun 2014) | 1 line
scst: Build fix for Linux kernel versions 2.6.33 and 2.6.34
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r5648 | bvassche | 2014-06-30 10:28:18 +0300 (Mon, 30 Jun 2014) | 1 line
scst: Build fix for kernel versions <= 2.6.31
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r5649 | bvassche | 2014-06-30 11:40:23 +0300 (Mon, 30 Jun 2014) | 6 lines
scst_vdisk: Fix a checkpatch warning
Address the following checkpatch warning:
char * array declaration might be better as static const
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r5650 | bvassche | 2014-06-30 11:52:06 +0300 (Mon, 30 Jun 2014) | 1 line
nightly build: Correct a kernel version
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r5651 | bvassche | 2014-06-30 12:18:41 +0300 (Mon, 30 Jun 2014) | 1 line
nightly build: Correct a kernel version
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r5654 | bvassche | 2014-07-01 09:38:13 +0300 (Tue, 01 Jul 2014) | 6 lines
scst_vdisk: Fix a checkpatch warning
Avoid that checkpatch reports the following warning:
WARNING: static const char * array should probably be static const char * const
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r5657 | bvassche | 2014-07-01 19:46:12 +0300 (Tue, 01 Jul 2014) | 1 line
nightly build: Update kernel versions
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r5658 | bvassche | 2014-07-03 11:36:48 +0300 (Thu, 03 Jul 2014) | 1 line
scripts/kernel-functions: Handle 3.x.0 kernel versions correctly
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r5659 | bvassche | 2014-07-03 11:42:08 +0300 (Thu, 03 Jul 2014) | 1 line
scripts/generate-patched-kernel: Clean up
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r5661 | bvassche | 2014-07-04 08:39:28 +0300 (Fri, 04 Jul 2014) | 1 line
Make scripts/kernel-functions again compatible with 2.6.x kernels
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r5662 | bvassche | 2014-07-06 11:02:28 +0300 (Sun, 06 Jul 2014) | 1 line
scripts/run-regression-tests: Add command-line option -4 (disable IPv6)
........
git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/iser@5666 d57e44dd-8a1f-0410-8b47-8ef2f437770f
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iSCSI SCST target driver
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========================
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Version 3.1.0, XX XXXXX 2014
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----------------------------
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ISCSI-SCST is a deeply reworked fork of iSCSI Enterprise Target (IET)
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(http://iscsitarget.sourceforge.net). Reasons of the fork were:
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- To be able to use full power of SCST core.
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- To fix all the problems, corner cases issues and iSCSI standard
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violations which IET has.
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See for more info http://iscsi-scst.sourceforge.net.
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This version is compatible with SCST version 2.0.0 and higher.
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Installation if your Linux kernel already has iSCSI-SCST built-in
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-----------------------------------------------------------------
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Simply run "make all", then "make install".
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Installation out of Linux kernel tree
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-------------------------------------
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See HOWTOs in the doc/ subdirectory.
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Only vanilla kernels from kernel.org and RHEL/CentOS 5.2 kernels are
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supported, but it should work on other (vendors') kernels, if you manage
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to successfully compile on them. The main problem with vendor's kernels
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is that they often contain patches, which appear only in the next
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version of the vanilla kernel, therefore it's quite hard to track such
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changes. Thus, if during compilation for some vendor's kernel your
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compiler complains about redefinition of some symbol, you should either
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switch to vanilla kernel, or add or change as necessary the
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corresponding to that symbol "#if LINUX_VERSION_CODE" statement.
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Default sysfs interface supports only kernels 2.6.26 and higher, because
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in 2.6.26 internal kernel's sysfs interface had a major change, which
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made it heavily incompatible with pre-2.6.26 version. But with the
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obsolete procfs interface kernels 2.6.16+ are supported.
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If during compilation you see message like "*** No rule to make target
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`xxx.h', needed by `yyy.o'. Stop.", then your autogenerated
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dependencies don't match your compiler configuration anymore. You should
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run "make extraclean" to remove them. On the next compilation they will
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be regenerated.
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If you experience problems during kernel module load or running, check
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your system and/or kernel logs (or run dmesg command for the few most
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recent kernel messages).
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To use full power of TCP zero-copy transmit functions, especially
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dealing with user space supplied via scst_user module memory, iSCSI-SCST
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needs to be notified when Linux networking finished data transmission.
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For that you should enable CONFIG_TCP_ZERO_COPY_TRANSFER_COMPLETION_NOTIFICATION
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kernel config option. This is highly recommended, but not required.
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Basically, iSCSI-SCST works fine with an unpatched Linux kernel with the
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same or better speed as other open source iSCSI targets, including IET,
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but if you want even better performance you have to patch and rebuild
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the kernel. Without CONFIG_TCP_ZERO_COPY_TRANSFER_COMPLETION_NOTIFICATION
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enabled you will just revert to the original behavior of other open
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source iSCSI targets, when for data transmission:
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- For in-kernel allocated memory (scst_vdisk and pass-through
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handlers) usage of SGV cache on transmit path (READ-type commands)
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will be disabled, but data will still be sent in zero-copy manner.
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- For user space allocated memory (scst_user handler) all transmitted
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data will be additionally copied into temporary TCP buffers. The
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performance hit will be quite noticeable.
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Note, that if your network hardware does not support TX offload
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functions or has them disabled, then TCP zero-copy transmit functions on
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your system will not be used by Linux networking in any case, so
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put_page_callback patch will not be able to improve performance for you.
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You can check your network hardware offload capabilities by command
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"ethtool -k ethX", where X is the network device number. At least
|
|
"tx-checksumming" and "scatter-gather" should be enabled.
|
|
|
|
If you have in your kernel log error messages like:
|
|
|
|
iscsi-scst: ***ERROR*** net_priv isn't NULL and != ref_cmd
|
|
|
|
with the corresponding kernel BUG dump, then put_page_callback patch you
|
|
use isn't sufficient for your kernel. This might be because the kernel
|
|
you use has some additional patches applied, which affect the
|
|
functionality, which put_page_callback patch provides. For example,
|
|
Fedora or Gentoo use kernels, which, although have version number like
|
|
2.6.18, are greatly differ from the "vanilla" kernel 2.6.18,
|
|
maintained by Linus Torvalds for that the put_page_callback patch was
|
|
created. In this case it is recommended either:
|
|
|
|
- Search net/ in your kernel source for "put_page" and "get_page" functions.
|
|
If you find any in some place, except in net/sunrpc/svc.c and
|
|
net/core/pktgen.c, then, most likely, you found the reason of your
|
|
problem. Replace them by "net_put_page" and "net_get_page"
|
|
correspondingly and try again. If the problem is solved, then please
|
|
prepare a new put_page_callback patch and send it to the SCST mailing
|
|
list scst-devel@lists.sourceforge.net.
|
|
|
|
or
|
|
|
|
- Unapply this patch and use iSCSI-SCST without it. Also report this
|
|
problem to the SCST mailing list scst-devel@lists.sourceforge.net.
|
|
|
|
|
|
IMPORTANT: This patch does not support compound pages, so not working with
|
|
========= network drivers using them. Sings of that is either when
|
|
iSCSI-SCST keeps closing connections, because no reply from
|
|
initiator for too long time, or system crashes on NULL
|
|
pointer dereference in iscsi_get_page_callback. You can find
|
|
list of such drivers by searching in drivers/net for
|
|
__GFP_COMP word in their source code.
|
|
|
|
Usage
|
|
-----
|
|
|
|
See HOWTOs in the doc/ subdirectory.
|
|
|
|
If you want to use Intel CRC32 offload and have corresponding hardware,
|
|
you should load crc32c-intel module. Then iSCSI-SCST will do all digest
|
|
calculations using this facility.
|
|
|
|
In 2.0.0 usage of iscsi-scstd.conf as well as iscsi-scst-adm utility is
|
|
obsolete. Use the sysfs interface facilities instead.
|
|
|
|
The flow of iSCSI-SCST inialization should be as the following:
|
|
|
|
1. Load of SCST and iSCSI-SCST kernel modules with necessary module
|
|
parameters, if needed.
|
|
|
|
2. Start iSCSI-SCST service.
|
|
|
|
3. Configure targets, devices, LUNs, etc. either using scstadmin
|
|
(recommended), or using the sysfs interface directly as described below.
|
|
|
|
It is recommended to use TEST UNIT READY ("tur") command to check if
|
|
iSCSI-SCST target is alive in MPIO configurations.
|
|
|
|
Also see SCST README file how to tune for the best performance.
|
|
|
|
CAUTION: Working of target and initiator on the same host isn't fully
|
|
======= supported. See SCST README file for details.
|
|
|
|
|
|
Migration from the obsolete proc interface
|
|
------------------------------------------
|
|
|
|
Sysfs enabled scstadmin supports old procfs config file format, so with
|
|
it you should do the following steps to migrate your proc-based
|
|
configuration to the sysfs interface:
|
|
|
|
1. Load SCST modules
|
|
|
|
2. Run "scstadmin -config old_config_file"
|
|
|
|
3. Start iSCSI-SCST
|
|
|
|
4. Run "scstadmin -write_config new_config_file"
|
|
|
|
5. Check new_config_file and make sure it has everything written
|
|
properly.
|
|
|
|
6. IMPORTANT! Delete /etc/iscsi-scst.conf and forget about it.
|
|
|
|
7. Start using "scstadmin -config new_config_file" to configure both
|
|
SCST and iSCSI-SCST.
|
|
|
|
IMPORTANT: With the sysfs interface the flow of iSCSI-SCST initialization
|
|
========= has changed (see above). Now scstadmin should be run as the FINAL
|
|
step of the initialization and only ONCE.
|
|
|
|
Also it is recommended to convert initiators.allow and initiators.deny
|
|
files to the corresponding sysfs facilities.
|
|
|
|
|
|
Migration from IET
|
|
------------------
|
|
|
|
Scalable Informatics Inc. has developed a pretty simple tool, will
|
|
automatically generate an /etc/scst.conf file from an /etc/ietd.conf
|
|
file, and then restart daemons.
|
|
|
|
Tool is here: http://download.scalableinformatics.com/gen_scst_conf/
|
|
|
|
Just run it on an ietd.conf based iSCSI target:
|
|
|
|
$ chmod +x gen_scst_conf.pl
|
|
$ sudo ./gen_scst_conf.pl
|
|
|
|
and your IET machine should now largely be an iSCSI-SCST machine. With
|
|
the caveat of a few IET elements not being supported.
|
|
|
|
Current limitations are one LUN per target, and not all LUN options
|
|
might be mapped well between the systems. This may change if there is
|
|
demand. For any questions and inquirys feel free to contact Joe Landman
|
|
<landman@scalableinformatics.com> (and please provide a few sample
|
|
ietd.conf files for us to play with).
|
|
|
|
|
|
Sysfs interface
|
|
---------------
|
|
|
|
Starting from 2.0.0 iSCSI-SCST uses sysfs interface. The procfs
|
|
interface is obsolete and will be removed in one of the next versions.
|
|
The sysfs build supports only kernels 2.6.26 and higher, because in
|
|
2.6.26 internal kernel's sysfs interface had a major change, which made
|
|
it heavily incompatible with pre-2.6.26 version. But with the obsolete
|
|
procfs interface kernels 2.6.16+ are supported.
|
|
|
|
Root of SCST sysfs interface is /sys/kernel/scst_tgt. Root of iSCSI-SCST
|
|
is /sys/kernel/scst_tgt/targets/iscsi. It has the following entries:
|
|
|
|
- None, one or more subdirectories for targets with name equal to names
|
|
of the corresponding targets.
|
|
|
|
- IncomingUser[num] - optional one or more attributes containing user
|
|
name and password for incoming discovery user name. Not exist by
|
|
default and can be added through "mgmt" entry, see below.
|
|
|
|
- OutgoingUser - optional attribute containing user name and password
|
|
for outgoing discovery user name. Not exist by default and can be
|
|
added through "mgmt" entry, see below.
|
|
|
|
- iSNSServer - contains name or IP address of iSNS server with optional
|
|
"AccessControl" attribute, which allows to enable iSNS access
|
|
control. Empty by default.
|
|
|
|
- allowed_portal[num] - optional attribute, which specifies, on which
|
|
portals (target's IP addresses) this target will be available. If not
|
|
specified (default) the target will be available on all all portals.
|
|
As soon as at least one allowed_portal specified, the target will be
|
|
accessible for initiators only on the specified portals. There might
|
|
be any number of the allowed_portal attributes. The portals
|
|
specification in the allowed_portal attributes can be a simple
|
|
DOS-type patterns, containing '*' and '?' symbols. '*' means match
|
|
all any symbols, '?' means match only any single symbol. For
|
|
instance, "10.170.77.2" will match "10.170.7?.*". Additionally, you
|
|
can use negative sign '!' to revert the value of the pattern. For
|
|
instance, "10.170.67.2" will match "!10.170.7?.*". See examples
|
|
below.
|
|
|
|
- enabled - using this attribute you can enable or disable iSCSI-SCST
|
|
accept new connections. It allows to finish configuring global
|
|
iSCSI-SCST attributes before it starts accepting new connections. 0
|
|
by default.
|
|
|
|
- open_state - read-only attribute, which allows to see if the user
|
|
space part of iSCSI-SCST connected to the kernel part.
|
|
|
|
- per_portal_acl - if set, makes iSCSI-SCST work in the per-portal
|
|
access control mode. In this mode iSCSI-SCST registers all initiators
|
|
in SCST core as "initiator_name#portal_IP_address" pattern, like
|
|
"iqn.2006-10.net.vlnb:ini#10.170.77.2" for initiator
|
|
iqn.2006-10.net.vlnb connected through portal 10.170.77.2. This mode
|
|
allows to make particular initiators be able to use only particular
|
|
portals on the target and don't see/be able to connect through
|
|
others. See below for more details.
|
|
|
|
- trace_level - allows to enable and disable various tracing
|
|
facilities. See content of this file for help how to use it.
|
|
|
|
- version - read-only attribute, which allows to see version of
|
|
iSCSI-SCST and enabled optional features.
|
|
|
|
- mgmt - main management entry, which allows to configure iSCSI-SCST.
|
|
Namely, add/delete targets as well as add/delete optional global and
|
|
per-target attributes. See content of this file for help how to use
|
|
it.
|
|
|
|
Each iSCSI-SCST sysfs file (attribute) can contain in the last line mark
|
|
"[key]". It is automatically added mark used to allow scstadmin to see
|
|
which attributes it should save in the config file. You can ignore it.
|
|
|
|
Each target subdirectory contains the following entries:
|
|
|
|
- ini_groups - subdirectory defining initiator groups for this target,
|
|
used to define per-initiator access control. See SCST core README for
|
|
more details.
|
|
|
|
- luns - subdirectory defining LUNs of this target. See SCST core
|
|
README for more details.
|
|
|
|
- sessions - subdirectory containing connected to this target sessions.
|
|
|
|
- IncomingUser[num] - optional one or more attributes containing user
|
|
name and password for incoming user name. Not exist by default and can
|
|
be added through the "mgmt" entry, see above.
|
|
|
|
- OutgoingUser - optional attribute containing user name and password
|
|
for outgoing user name. Not exist by default and can be added through
|
|
the "mgmt" entry, see above.
|
|
|
|
- Entries defining default iSCSI parameters values used during iSCSI
|
|
parameters negotiation. Only entries which can be changed or make
|
|
sense are listed there.
|
|
|
|
- QueuedCommands - defines maximum number of commands queued to any
|
|
session of this target. Default is 32 commands.
|
|
|
|
- NopInInterval - defines interval between NOP-In requests, which the
|
|
target will send on idle connections to check if the initiator is
|
|
still alive. If there is no NOP-Out reply from the initiator in
|
|
NopInTimeout seconds, the corresponding connection will be closed. Default
|
|
is 30 seconds. If it's set to 0, then NOP-In requests are disabled.
|
|
|
|
- NopInTimeout - defines the maximum time in seconds a NOP-In request
|
|
can wait for response from initiator, otherwise the corresponding
|
|
connection will be closed. Default is 30 seconds.
|
|
|
|
- RspTimeout - defines the maximum time in seconds a command can wait for
|
|
response from initiator, otherwise the corresponding connection will
|
|
be closed. Default is 90 seconds.
|
|
|
|
- enabled - using this attribute you can enable or disable iSCSI-SCST
|
|
accept new connections to this target. It allows to finish
|
|
configuring it before it starts accepting new connections. 0 by
|
|
default.
|
|
|
|
- redirect - allows to temporarily or permanently redirect login to the
|
|
target to another portal. Discovery sessions will not be impacted,
|
|
but normal sessions will be redirected before security negotiation.
|
|
The destination should be specified using format "<ip_addr>[:port] temp|perm".
|
|
IPv6 addresses need to be enclosed in [] brackets. To remove
|
|
redirection, provide an empty string. For example:
|
|
echo "10.170.77.2:32600 temp" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/redirect
|
|
will temporarily redirect login to portal 10.170.77.2 and port 32600.
|
|
|
|
- tid - TID of this target.
|
|
|
|
Subdirectory "sessions" contains one subdirectory for each connected
|
|
session with name equal to name of the connected initiator.
|
|
|
|
Each session subdirectory contains the following entries:
|
|
|
|
- One subdirectory for each TCP connection in this session. ISCSI-SCST
|
|
supports 1 connection per session, but the session subdirectory can
|
|
contain several connections: one active and other being closed.
|
|
|
|
- Entries defining negotiated iSCSI parameters. Only parameters which
|
|
can be changed or make sense are listed there.
|
|
|
|
- initiator_name - contains initiator name
|
|
|
|
- sid - contains SID of this session
|
|
|
|
- reinstating - contains reinstatement state of this session
|
|
|
|
- force_close - write-only attribute, which allows to force close this
|
|
session. This is the only writable session attribute.
|
|
|
|
- active_commands - contains number of active, i.e. not yet or being
|
|
executed, SCSI commands in this session.
|
|
|
|
- commands - contains overall number of SCSI commands in this session.
|
|
|
|
Each connection subdirectory contains the following entries:
|
|
|
|
- cid - contains CID of this connection.
|
|
|
|
- ip - contains IP address of the connected initiator.
|
|
|
|
- state - contains processing state of this connection.
|
|
|
|
See SCST README for info about other attributes.
|
|
|
|
Below is a sample script, which configures 1 virtual disk "disk1" using
|
|
/disk1 image and one target iqn.2006-10.net.vlnb:tgt with all default
|
|
parameters:
|
|
|
|
#!/bin/bash
|
|
|
|
modprobe scst
|
|
modprobe scst_vdisk
|
|
|
|
echo "add_device disk1 filename=/disk1; nv_cache=1" >/sys/kernel/scst_tgt/handlers/vdisk_fileio/mgmt
|
|
|
|
service iscsi-scst start
|
|
|
|
echo "add_target iqn.2006-10.net.vlnb:tgt" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add disk1 0" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/mgmt
|
|
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/enabled
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/enabled
|
|
|
|
Below is another sample script, which configures 1 real local SCSI disk
|
|
0:0:1:0 and one target iqn.2006-10.net.vlnb:tgt with all default parameters:
|
|
|
|
#!/bin/bash
|
|
|
|
modprobe scst
|
|
modprobe scst_disk
|
|
|
|
echo "add_device 0:0:1:0" >/sys/kernel/scst_tgt/handlers/dev_disk/mgmt
|
|
|
|
service iscsi-scst start
|
|
|
|
echo "add_target iqn.2006-10.net.vlnb:tgt" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add 0:0:1:0 0" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/mgmt
|
|
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/enabled
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/enabled
|
|
|
|
Below is an advanced sample script, which configures more virtual
|
|
devices of various types, including virtual CDROM and 2 targets, one
|
|
with all default parameters, another one with some not default
|
|
parameters, incoming and outgoing user names for CHAP authentification,
|
|
and special permissions for initiator iqn.2005-03.org.open-iscsi:cacdcd2520,
|
|
which will see another set of devices. Also this sample configures CHAP
|
|
authentication for discovery sessions and iSNS server with access
|
|
control.
|
|
|
|
#!/bin/bash
|
|
|
|
modprobe scst
|
|
modprobe scst_vdisk
|
|
|
|
echo "add_device disk1 filename=/disk1; nv_cache=1" >/sys/kernel/scst_tgt/handlers/vdisk_fileio/mgmt
|
|
echo "add_device disk2 filename=/disk2; blocksize=4096; nv_cache=1" >/sys/kernel/scst_tgt/handlers/vdisk_fileio/mgmt
|
|
echo "add_device blockio filename=/dev/sda5" >/sys/kernel/scst_tgt/handlers/vdisk_blockio/mgmt
|
|
echo "add_device nullio" >/sys/kernel/scst_tgt/handlers/vdisk_nullio/mgmt
|
|
echo "add_device cdrom" >/sys/kernel/scst_tgt/handlers/vcdrom/mgmt
|
|
|
|
service iscsi-scst start
|
|
|
|
echo "192.168.1.16 AccessControl" >/sys/kernel/scst_tgt/targets/iscsi/iSNSServer
|
|
echo "add_attribute IncomingUser joeD 12charsecret" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add_attribute OutgoingUser jackD 12charsecret1" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
echo "add_target iqn.2006-10.net.vlnb:tgt" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
echo "add disk1 0" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/mgmt
|
|
echo "add cdrom 1" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/mgmt
|
|
|
|
echo "add_target iqn.2006-10.net.vlnb:tgt1" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add_target_attribute iqn.2006-10.net.vlnb:tgt1 IncomingUser1 joe2 12charsecret2" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add_target_attribute iqn.2006-10.net.vlnb:tgt1 IncomingUser joe 12charsecret" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "add_target_attribute iqn.2006-10.net.vlnb:tgt1 OutgoingUser jim1 12charpasswd" >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo "No" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/InitialR2T
|
|
echo "Yes" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/ImmediateData
|
|
echo "8192" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/MaxRecvDataSegmentLength
|
|
echo "8192" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/MaxXmitDataSegmentLength
|
|
echo "131072" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/MaxBurstLength
|
|
echo "32768" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/FirstBurstLength
|
|
echo "1" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/MaxOutstandingR2T
|
|
echo "CRC32C,None" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/HeaderDigest
|
|
echo "CRC32C,None" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/DataDigest
|
|
echo "32" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/QueuedCommands
|
|
|
|
echo "add disk2 0" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/luns/mgmt
|
|
echo "add nullio 26" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/luns/mgmt
|
|
|
|
echo "create special_ini" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/ini_groups/mgmt
|
|
echo "add blockio 0 read_only=1" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/ini_groups/special_ini/luns/mgmt
|
|
echo "add iqn.2005-03.org.open-iscsi:cacdcd2520" >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/ini_groups/special_ini/initiators/mgmt
|
|
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/enabled
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt1/enabled
|
|
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/enabled
|
|
|
|
The resulting overall SCST sysfs hierarchy with an initiator connected to
|
|
both iSCSI-SCST targets will look like:
|
|
|
|
/sys/kernel/scst_tgt
|
|
|-- devices
|
|
| |-- blockio
|
|
| | |-- blocksize
|
|
| | |-- exported
|
|
| | | `-- export0 -> ../../../targets/iscsi/iqn.2006-10.net.vlnb:tgt1/ini_groups/special_ini/luns/0
|
|
| | |-- filename
|
|
| | |-- handler -> ../../handlers/vdisk_blockio
|
|
| | |-- nv_cache
|
|
| | |-- read_only
|
|
| | |-- removable
|
|
| | |-- resync_size
|
|
| | |-- size_mb
|
|
| | |-- t10_dev_id
|
|
| | |-- threads_num
|
|
| | |-- threads_pool_type
|
|
| | |-- type
|
|
| | `-- usn
|
|
| |-- cdrom
|
|
| | |-- exported
|
|
| | | `-- export0 -> ../../../targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/1
|
|
| | |-- filename
|
|
| | |-- handler -> ../../handlers/vcdrom
|
|
| | |-- size_mb
|
|
| | |-- t10_dev_id
|
|
| | |-- threads_num
|
|
| | |-- threads_pool_type
|
|
| | |-- type
|
|
| | `-- usn
|
|
| |-- disk1
|
|
| | |-- blocksize
|
|
| | |-- exported
|
|
| | | `-- export0 -> ../../../targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/0
|
|
| | |-- filename
|
|
| | |-- handler -> ../../handlers/vdisk_fileio
|
|
| | |-- nv_cache
|
|
| | |-- o_direct
|
|
| | |-- read_only
|
|
| | |-- removable
|
|
| | |-- resync_size
|
|
| | |-- size_mb
|
|
| | |-- t10_dev_id
|
|
| | |-- threads_num
|
|
| | |-- threads_pool_type
|
|
| | |-- type
|
|
| | |-- usn
|
|
| | `-- write_through
|
|
| |-- disk2
|
|
| | |-- blocksize
|
|
| | |-- exported
|
|
| | | `-- export0 -> ../../../targets/iscsi/iqn.2006-10.net.vlnb:tgt1/luns/0
|
|
| | |-- filename
|
|
| | |-- handler -> ../../handlers/vdisk_fileio
|
|
| | |-- nv_cache
|
|
| | |-- o_direct
|
|
| | |-- read_only
|
|
| | |-- removable
|
|
| | |-- resync_size
|
|
| | |-- size_mb
|
|
| | |-- t10_dev_id
|
|
| | |-- threads_num
|
|
| | |-- threads_pool_type
|
|
| | |-- type
|
|
| | |-- usn
|
|
| | `-- write_through
|
|
| `-- nullio
|
|
| |-- blocksize
|
|
| |-- exported
|
|
| | `-- export0 -> ../../../targets/iscsi/iqn.2006-10.net.vlnb:tgt1/luns/26
|
|
| |-- handler -> ../../handlers/vdisk_nullio
|
|
| |-- read_only
|
|
| |-- removable
|
|
| |-- size_mb
|
|
| |-- t10_dev_id
|
|
| |-- threads_num
|
|
| |-- threads_pool_type
|
|
| |-- type
|
|
| `-- usn
|
|
|-- handlers
|
|
| |-- vcdrom
|
|
| | |-- cdrom -> ../../devices/cdrom
|
|
| | |-- mgmt
|
|
| | |-- trace_level
|
|
| | `-- type
|
|
| |-- vdisk_blockio
|
|
| | |-- blockio -> ../../devices/blockio
|
|
| | |-- mgmt
|
|
| | |-- trace_level
|
|
| | `-- type
|
|
| |-- vdisk_fileio
|
|
| | |-- disk1 -> ../../devices/disk1
|
|
| | |-- disk2 -> ../../devices/disk2
|
|
| | |-- mgmt
|
|
| | |-- trace_level
|
|
| | `-- type
|
|
| `-- vdisk_nullio
|
|
| |-- mgmt
|
|
| |-- nullio -> ../../devices/nullio
|
|
| |-- trace_level
|
|
| `-- type
|
|
|-- sgv
|
|
| |-- global_stats
|
|
| |-- sgv
|
|
| | `-- stats
|
|
| |-- sgv-clust
|
|
| | `-- stats
|
|
| `-- sgv-dma
|
|
| `-- stats
|
|
|-- targets
|
|
| `-- iscsi
|
|
| |-- IncomingUser
|
|
| |-- OutgoingUser
|
|
| |-- enabled
|
|
| |-- iSNSServer
|
|
| |-- iqn.2006-10.net.vlnb:tgt
|
|
| | |-- DataDigest
|
|
| | |-- FirstBurstLength
|
|
| | |-- HeaderDigest
|
|
| | |-- ImmediateData
|
|
| | |-- InitialR2T
|
|
| | |-- MaxBurstLength
|
|
| | |-- MaxOutstandingR2T
|
|
| | |-- MaxRecvDataSegmentLength
|
|
| | |-- MaxXmitDataSegmentLength
|
|
| | |-- NopInInterval
|
|
| | |-- QueuedCommands
|
|
| | |-- RspTimeout
|
|
| | |-- enabled
|
|
| | |-- ini_groups
|
|
| | | `-- mgmt
|
|
| | |-- luns
|
|
| | | |-- 0
|
|
| | | | |-- device -> ../../../../../devices/disk1
|
|
| | | | `-- read_only
|
|
| | | |-- 1
|
|
| | | | |-- device -> ../../../../../devices/cdrom
|
|
| | | | `-- read_only
|
|
| | | `-- mgmt
|
|
| | |-- per_portal_acl
|
|
| | |-- redirect
|
|
| | |-- rel_tgt_id
|
|
| | |-- sessions
|
|
| | | `-- iqn.2005-03.org.open-iscsi:cacdcd2520
|
|
| | | |-- 10.170.75.2
|
|
| | | | |-- cid
|
|
| | | | |-- ip
|
|
| | | | `-- state
|
|
| | | |-- DataDigest
|
|
| | | |-- FirstBurstLength
|
|
| | | |-- HeaderDigest
|
|
| | | |-- ImmediateData
|
|
| | | |-- InitialR2T
|
|
| | | |-- MaxBurstLength
|
|
| | | |-- MaxOutstandingR2T
|
|
| | | |-- MaxRecvDataSegmentLength
|
|
| | | |-- MaxXmitDataSegmentLength
|
|
| | | |-- active_commands
|
|
| | | |-- commands
|
|
| | | |-- force_close
|
|
| | | |-- initiator_name
|
|
| | | |-- luns -> ../../luns
|
|
| | | |-- reinstating
|
|
| | | `-- sid
|
|
| | `-- tid
|
|
| |-- iqn.2006-10.net.vlnb:tgt1
|
|
| | |-- DataDigest
|
|
| | |-- FirstBurstLength
|
|
| | |-- HeaderDigest
|
|
| | |-- ImmediateData
|
|
| | |-- IncomingUser
|
|
| | |-- IncomingUser1
|
|
| | |-- InitialR2T
|
|
| | |-- MaxBurstLength
|
|
| | |-- MaxOutstandingR2T
|
|
| | |-- MaxRecvDataSegmentLength
|
|
| | |-- MaxXmitDataSegmentLength
|
|
| | |-- OutgoingUser
|
|
| | |-- NopInInterval
|
|
| | |-- QueuedCommands
|
|
| | |-- RspTimeout
|
|
| | |-- enabled
|
|
| | |-- ini_groups
|
|
| | | |-- mgmt
|
|
| | | `-- special_ini
|
|
| | | |-- initiators
|
|
| | | | |-- iqn.2005-03.org.open-iscsi:cacdcd2520
|
|
| | | | `-- mgmt
|
|
| | | `-- luns
|
|
| | | |-- 0
|
|
| | | | |-- device -> ../../../../../../../devices/blockio
|
|
| | | | `-- read_only
|
|
| | | `-- mgmt
|
|
| | |-- luns
|
|
| | | |-- 0
|
|
| | | | |-- device -> ../../../../../devices/disk2
|
|
| | | | `-- read_only
|
|
| | | |-- 26
|
|
| | | | |-- device -> ../../../../../devices/nullio
|
|
| | | | `-- read_only
|
|
| | | `-- mgmt
|
|
| | |-- per_portal_acl
|
|
| | |-- redirect
|
|
| | |-- rel_tgt_id
|
|
| | |-- sessions
|
|
| | | `-- iqn.2005-03.org.open-iscsi:cacdcd2520
|
|
| | | |-- 10.170.75.2
|
|
| | | | |-- cid
|
|
| | | | |-- ip
|
|
| | | | `-- state
|
|
| | | |-- DataDigest
|
|
| | | |-- FirstBurstLength
|
|
| | | |-- HeaderDigest
|
|
| | | |-- ImmediateData
|
|
| | | |-- InitialR2T
|
|
| | | |-- MaxBurstLength
|
|
| | | |-- MaxOutstandingR2T
|
|
| | | |-- MaxRecvDataSegmentLength
|
|
| | | |-- MaxXmitDataSegmentLength
|
|
| | | |-- active_commands
|
|
| | | |-- commands
|
|
| | | |-- force_close
|
|
| | | |-- initiator_name
|
|
| | | |-- luns -> ../../ini_groups/special_ini/luns
|
|
| | | |-- reinstating
|
|
| | | `-- sid
|
|
| | `-- tid
|
|
| |-- mgmt
|
|
| |-- open_state
|
|
| |-- trace_level
|
|
| `-- version
|
|
|-- threads
|
|
|-- trace_level
|
|
`-- version
|
|
|
|
|
|
Configuring iscsi-scst via scstadmin
|
|
------------------------------------
|
|
|
|
All iscsi-scst parameters that were configured in the previous section via the
|
|
sysfs interface can also be set via scstadmin. Here is an example that shows
|
|
how to configure the IP address of the iSNSServer and to enable iSNS access
|
|
control at the same time:
|
|
|
|
# scstadmin -noprompt -set_drv_attr iscsi -attributes iSNSServer="192.168.1.16 AccessControl"
|
|
|
|
Collecting current configuration: done.
|
|
|
|
|
|
-> Making requested changes.
|
|
-> Done, 0 change(s) made.
|
|
|
|
All done.
|
|
|
|
# scstadmin -list_drv_attr iscsi
|
|
|
|
Collecting current configuration: done.
|
|
|
|
Attribute Value Writable KEY
|
|
------------------------------------------------------------
|
|
iSNSServer 127.0.0.1 AccessControl Yes Yes
|
|
|
|
Dynamic attributes available
|
|
----------------------------
|
|
OutgoingUser
|
|
IncomingUser
|
|
|
|
All done.
|
|
|
|
|
|
Advanced initiators access control
|
|
----------------------------------
|
|
|
|
ISCSI-SCST allows you to optionally control visibility and accessibility
|
|
of your target and its portals (IP addresses) to remote initiators. This
|
|
control includes both the target's portals SendTargets discovery as well
|
|
as regular LUNs access.
|
|
|
|
This facility supersedes the obsolete initiators.[allow,deny] method,
|
|
which is going to be removed in one of the future versions.
|
|
|
|
This facility is available only in the sysfs build of iSCSI-SCST.
|
|
|
|
By default, all portals are available for the initiators.
|
|
|
|
1. If you want to enable/disable one or more target's portals for all
|
|
initiators, you should define one ore more allowed_portal attributes.
|
|
For example:
|
|
|
|
echo 'add_target_attribute iqn.2006-10.net.vlnb:tgt allowed_portal 10.170.77.2' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
will enable only portal 10.170.77.2 and disable all other portals
|
|
|
|
echo 'add_target_attribute iqn.2006-10.net.vlnb:tgt allowed_portal 10.170.77.2' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo 'add_target_attribute iqn.2006-10.net.vlnb:tgt allowed_portal 10.170.75.2' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
will enable only portals 10.170.77.2 and 10.170.75.2 and disable all
|
|
other portals.
|
|
|
|
echo 'add_target_attribute iqn.2006-10.net.vlnb:tgt allowed_portal 10.170.7?.2' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
will enable only portals 10.170.7x.2 and disable all other portals.
|
|
|
|
echo 'add_target_attribute iqn.2006-10.net.vlnb:tgt allowed_portal !*' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
|
|
will disable all portals.
|
|
|
|
2. If you want to want to allow only only specific set of initiators be
|
|
able to connect to your target, you should don't add any default LUNs
|
|
for the target and create for allowed initiators a security group to
|
|
which they will be assigned.
|
|
|
|
For example, we want initiator iqn.2005-03.org.vlnb:cacdcd2520 and only
|
|
it be able to access target iqn.2006-10.net.vlnb:tgt:
|
|
|
|
echo 'add_target iqn.2006-10.net.vlnb:tgt' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo 'create allowed_ini' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/mgmt
|
|
echo 'add dev1 0' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/allowed_ini/luns/mgmt
|
|
echo 'add iqn.2005-03.org.vlnb:cacdcd2520' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/allowed_ini/initiators/mgmt
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/enabled
|
|
|
|
Since there will be no default LUNs for the target, all initiators other
|
|
than iqn.2005-03.org.vlnb:cacdcd2520 will be blocked from accessing it.
|
|
|
|
Alternatively, you can create an empty security group and filter out in
|
|
it all initiators except the allowed one:
|
|
|
|
echo 'add_target iqn.2006-10.net.vlnb:tgt' >/sys/kernel/scst_tgt/targets/iscsi/mgmt
|
|
echo 'add dev1 0' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/luns/mgmt
|
|
echo 'create denied_inis' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/mgmt
|
|
echo 'add !iqn.2005-03.org.vlnb:cacdcd2520' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/denied_inis/initiators/mgmt
|
|
echo 1 >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/enabled
|
|
|
|
3. If you want to enable/disable one or more target's portals for
|
|
particular initiators, you should set per_portal_acl attribute to 1 and
|
|
specify SCST access control to those initiators. If an SCST security
|
|
group doesn't have any LUNs, all the initiator, which should be assigned
|
|
to it, will not see this target and/or its portal. For example:
|
|
|
|
(We assume that an empty group "BLOCKING_GROUP" is already created by for
|
|
target iqn.2006-10.net.vlnb:tgt by command (see above for more information):
|
|
"echo 'create BLOCKING_GROUP' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/mgmt)
|
|
|
|
echo 'add iqn.2005-03.org.vlnb:cacdcd2520#10.170.77.2' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/BLOCKING_GROUP/initiators/mgmt
|
|
|
|
will block access of initiator iqn.2005-03.org.vlnb:cacdcd2520 to
|
|
target iqn.2006-10.net.vlnb:tgt portal 10.170.77.2.
|
|
|
|
Another example:
|
|
|
|
echo 'add iqn.2005-03.org.vlnb:cacdcd2520*' >/sys/kernel/scst_tgt/targets/iscsi/iqn.2006-10.net.vlnb:tgt/ini_groups/BLOCKING_GROUP/initiators/mgmt
|
|
|
|
will block access of initiator iqn.2005-03.org.vlnb:cacdcd2520 to
|
|
all target iqn.2006-10.net.vlnb:tgt portals.
|
|
|
|
|
|
Troubleshooting
|
|
---------------
|
|
|
|
If you have any problems, start troubleshooting from looking at the
|
|
kernel and system logs. In the kernel log iSCSI-SCST and SCST core send
|
|
their messages, in the system log iscsi-scstd sends its messages. In
|
|
most Linux distributions both those logs are put to /var/log/messages
|
|
file.
|
|
|
|
Then, it might be helpful to increase level of logging. For kernel
|
|
modules you should make the debug build, by either running "make 2debug"
|
|
if you work with SCST SVN tree, or by enabling the corresponding
|
|
debug symbols (see below).
|
|
|
|
If after looking on the logs the reason of your problem is still unclear
|
|
for you, report to SCST mailing list scst-devel@lists.sourceforge.net.
|
|
|
|
|
|
Work if target's backstorage or link is too slow
|
|
------------------------------------------------
|
|
|
|
In some cases you can experience I/O stalls or see in the kernel log
|
|
abort or reset messages. It can happen under high I/O load, when your
|
|
target's backstorage gets overloaded, or working over a slow link, when
|
|
the link can't serve all the queued commands on time,
|
|
|
|
To workaround it you can reduce QueuedCommands parameter for the
|
|
corresponding target to some lower value, like 8 (default is 32).
|
|
|
|
Also see SCST README file for more details about that issue and ways to
|
|
prevent it.
|
|
|
|
|
|
Performance advices
|
|
-------------------
|
|
|
|
1. If you use Windows XP or Windows 2003+ as initiators, you can
|
|
consider to decrease TcpAckFrequency parameter to 1. See
|
|
http://support.microsoft.com/kb/328890/ or google for "TcpAckFrequency"
|
|
for more details.
|
|
|
|
2. See how to get the maximum throughput from iSCSI, for instance, at
|
|
http://virtualgeek.typepad.com/virtual_geek/2009/01/a-multivendor-post-to-help-our-mutual-iscsi-customers-using-vmware.html.
|
|
It's about VMware, but its recommendations apply to other environments
|
|
as well.
|
|
|
|
3. ISCSI initiators from pre-CentOS/RHEL 5 reported to have some
|
|
performance problems. If you use it, it is strongly advised to upgrade.
|
|
|
|
4. If you are going to use your target in an VM environment, for
|
|
instance as a shared storage with VMware, make sure all your VMs
|
|
connected to the target via *separate* sessions, i.e. each VM has own
|
|
connection to the target, not all VMs connected using a single
|
|
connection. You can check it using SCST proc or sysfs interface. If you
|
|
miss it, you can greatly loose performance of parallel access to your
|
|
target from different VMs. This isn't related to the case if your VMs
|
|
are using the same shared storage, like with VMFS, for instance. In this
|
|
case all your VM hosts will be connected to the target via separate
|
|
sessions, which is enough.
|
|
|
|
5. Many dual port network adapters are not able to transfer data
|
|
simultaneously on both ports, i.e. they transfer data via both ports on
|
|
the same speed as via any single port. Thus, using such adapters in MPIO
|
|
configuration can't improve performance. To allow MPIO to have double
|
|
performance you should either use separate network adapters, or find a
|
|
dual-port adapter capable to to transfer data simultaneously on both
|
|
ports. You can check it by running 2 iperf's through both ports in
|
|
parallel.
|
|
|
|
6. Since network offload works much better in the write direction, than
|
|
for reading (simplifying, in the read direction often there's additional
|
|
data copy) in many cases with 10GbE in a single initiator-target pair
|
|
the initiator's CPU is a bottleneck, so you can see the initiator can
|
|
read data on much slower rate, than write. You can check it by watching
|
|
*each particular* CPU load to find out if any of them is close to 100%
|
|
load, including IRQ processing load. Note, many tools like vmstat give
|
|
aggregate load on all CPUs, so with 4 cores 25% corresponds to 100% load
|
|
of any single CPU.
|
|
|
|
7. For high speed network adapters it can be better if you configure
|
|
them to serve connections, e.g., from initiator on CPU0 and from
|
|
initiator Y on CPU1. Then you can bind threads processing them also to
|
|
CPU0 and CPU1 correspondingly using cpu_mask attribute of their targets
|
|
or security groups. In NUMA-like configurations it can signficantly
|
|
boost IOPS performance.
|
|
|
|
8. See SCST core's README for more advices. Especially pay attention to
|
|
have io_grouping_type option set correctly.
|
|
|
|
|
|
Compilation options
|
|
-------------------
|
|
|
|
There are the following compilation options, that could be commented
|
|
in/out in the kernel's module Makefile:
|
|
|
|
- CONFIG_SCST_DEBUG - turns on some debugging code, including some logging.
|
|
Makes the driver considerably bigger and slower, producing large amount of
|
|
log data.
|
|
|
|
- CONFIG_SCST_TRACING - turns on ability to log events. Makes the driver
|
|
considerably bigger and leads to some performance loss.
|
|
|
|
- CONFIG_SCST_EXTRACHECKS - adds extra validity checks in the various places.
|
|
|
|
- CONFIG_SCST_ISCSI_DEBUG_DIGEST_FAILURES - simulates digest failures in
|
|
random places.
|
|
|
|
|
|
Creating version of put_page_callback patch for your kernel
|
|
-----------------------------------------------------------
|
|
|
|
If you need your own version of put_page_callback patch for your custom
|
|
kernel, for which there is no prepared version, you can create it
|
|
yourself. This is pretty mechanical work, you don't need to understand
|
|
how it works, you only need to do the following two steps:
|
|
|
|
1. Apply the closest version of put_page_callback-<kernel-version>.patch
|
|
on your kernel. Resolve only failed hunks from include/ and
|
|
net/core/utils.c, ignore other failures.
|
|
|
|
2. Search net/ in your kernel source for "put_page" and "get_page"
|
|
functions. Replace them by "net_put_page" and "net_get_page"
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|
correspondingly.
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|
|
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For vanilla kernels that should be all. Then please send your new
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|
put_page_callback-<kernel-version>.patch to the SCST mailing list
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scst-devel@lists.sourceforge.net.
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|
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|
But some out of tree drivers (some versions of DRBD and Intel e1000 are
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|
reported to do so) use own pages referencing on the TX path, so they
|
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should be modified the same way as above as well. (No need to modify RX
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|
path, because put_page_callback logic used by SCST only on the TX path.)
|
|
|
|
In case of DRBD, if you don't do this modification, you can specify
|
|
disable_sendpage parameter for drbd module. But in this case it might be
|
|
better for performance simply not apply put_page_callback patch.
|
|
|
|
|
|
Background information about zero-copy data sending
|
|
---------------------------------------------------
|
|
|
|
As explained above the most efficient operation of the iSCSI-SCST target
|
|
driver is achieved when the following two conditions are met:
|
|
* Data is sent from target to initiator in a zero-copy fashion.
|
|
* Data buffers are cached for reuse (by the so-called sgv pool).
|
|
Unfortunately the zero-copy API in the Linux kernel (proto.sendpage() /
|
|
tcp_sendpage()) does not yet support completion notifications. Hence the
|
|
put_page_callback patch which adds completion notification support to
|
|
tcp_sendpage(). However, since the put_page_callback patch increases the size
|
|
of the page structure in the Linux kernel that patch is considered
|
|
unacceptable for integration in the mainline kernel [1]. Another approach,
|
|
called skb paged fragment destructors, might get merged in the mainline kernel
|
|
in the future. Version five of that patch series has been posted in May 2012
|
|
[2].
|
|
|
|
Notes:
|
|
* The current implementation of scst_user is such that iSCSI-SCST only sends
|
|
data allocated by scst_user in a zero-copy fashion if the put_page_callback
|
|
patch has been applied. This holds even if scst_user did not use the sgv
|
|
pool to allocate a data buffer.
|
|
* Zero-copy sending is only possible with network interface drivers that
|
|
support scatter/gather and checksumming (NETIF_F_SG and NETIF_F_ALL_CSUM
|
|
respectively).
|
|
|
|
References:
|
|
[1] James Bottomley, Linux Kernel Mailing List, December 2008,
|
|
http://lkml.org/lkml/2008/12/11/213.
|
|
[2] Ian Campbell, [PATCH v5 0/9] skb paged fragment destructors, May 3 2012,
|
|
linux-netdev, http://marc.info/?l=linux-netdev&m=133605705111948&w=2.
|
|
|
|
|
|
Credits
|
|
-------
|
|
|
|
Thanks to:
|
|
|
|
* Ming Zhang <blackmagic02881@gmail.com> for fixes
|
|
|
|
* Krzysztof Blaszkowski <kb@sysmikro.com.pl> for many fixes
|
|
|
|
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> for comments and help in
|
|
debugging
|
|
|
|
* Tomasz Chmielewski <mangoo@wpkg.org> for testing and suggestions
|
|
|
|
* Bart Van Assche <bvanassche@acm.org> for a lot of help
|
|
|
|
Vladislav Bolkhovitin <vst@vlnb.net>, http://scst.sourceforge.net
|
|
|