Commit Graph

57 Commits

Author SHA1 Message Date
Alexander Motin
d3ab449cfa Remove few more unused variables. 2015-09-26 11:39:54 +00:00
Alexander Motin
9c887a4f86 Remove some duplicate, legacy, dead and questionable code. 2015-09-26 11:28:45 +00:00
Alexander Motin
c53993057b Add support for Control extension mode page. 2015-09-22 14:55:46 +00:00
Alexander Motin
efbf6139a4 Split two command flags with different meaning.
This is only a cosmetical change.
2015-09-19 19:11:59 +00:00
Alexander Motin
6213882769 When reporting TPT UA, report which of thresholds was reached. 2015-09-17 17:00:36 +00:00
Alexander Motin
7ac58230ea Reimplement CTL High Availability.
CTL HA functionality was originally implemented by Copan many years ago,
but large part of the sources was never published.  This change includes
clean room implementation of the missing code and fixes for many bugs.

This code supports dual-node HA with ALUA in four modes:
 - Active/Unavailable without interlink between nodes;
 - Active/Standby with second node handling only basic LUN discovery and
reservation, synchronizing with the first node through the interlink;
 - Active/Active with both nodes processing commands and accessing the
backing storage, synchronizing with the first node through the interlink;
 - Active/Active with second node working as proxy, transfering all
commands to the first node for execution through the interlink.

Unlike original Copan's implementation, depending on specific hardware,
this code uses simple custom TCP-based protocol for interlink.  It has
no authentication, so it should never be enabled on public interfaces.

The code may still need some polishing, but generally it is functional.

Relnotes:	yes
Sponsored by:	iXsystems, Inc.
2015-09-10 12:40:31 +00:00
Alexander Motin
0bcd4ab6ba Move setting of media parameters inside open routines.
This is preparation for possibility to open/close media several times
per LUN life cycle.  While there, rename variables to reduce confusion.
As additional bonus this allows to open read-only media, such as ZFS
snapshots.
2015-09-06 09:54:56 +00:00
Alexander Motin
67ceb24bca Move "ioctl" CAM frontend into separate file.
It has nothing to share with too huge ctl.c other then device descriptor,
but even that may be counted as design error that may be fixed later.
At some point we may even want to have several ioctl ports.
2015-08-15 15:42:21 +00:00
Alexander Motin
2f444d157b Drop "internal" CTL frontend.
Its idea was to be a simple initiator and execute several commands from
kernel level, but FreeBSD never had consumer for that functionality,
while its implementation polluted many unrelated places..
2015-08-15 13:34:38 +00:00
Alexander Motin
f2a20b166a Relax serialization of SYNCHRONIZE CACHE commands.
Before this change SYNCHRONIZE CACHE commands were executed exclusively,
as if they had ORDERED tag.  But looking through SCSI specs I've found
no any reason to be so strict.  For reads this ordering seems pointless.
For writes it looks less obvious, so I left ordering against preceeding
write commands, while following ones are no longer required to wait.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2015-08-05 21:58:32 +00:00
Alexander Motin
7834ea8891 Bring per-port LUN enable/disable code up to date:
- remove last remnants of never implemented multiple targets support;
 - implement missing support for LUN mapping in this area.

Due to existing locking constraints LUN mapping code is practically
unlocked at this point.  Hopefully it is not racy enough to live until
somebody get idea how to call sleeping fronend methods under lock also
taken by the same frontend in non-sleepable context. :(
2015-06-20 12:43:54 +00:00
Alexander Motin
2d8b28765c Introduce separate lock for tokens to reduce ctl_lock scope. 2015-06-20 11:20:25 +00:00
Alexander Motin
2c8cab2a4e Add support for General Statistics and Performance log page.
CTL already collects most of statistics reported there, so why not.

MFC after:	2 weeks
2015-02-11 16:10:31 +00:00
Alexander Motin
920c6cbadc CTL LUN mapping rewrite.
Replace iSCSI-specific LUN mapping mechanism with new one, working for any
ports.  By default all ports are created without LUN mapping, exposing all
CTL LUNs as before.  But, if needed, LUN mapping can be manually set on
per-port basis via ctladm.  For its iSCSI ports ctld does it via ioctl(2).
The next step will be to teach ctld to work with FibreChannel ports also.

Respecting additional flexibility of the new mechanism, ctl.conf now allows
alternative syntax for LUN definition.  LUNs can now be defined in global
context, and then referenced from targets by unique name, as needed.  It
allows same LUN to be exposed several times via multiple targets.

While there, increase limit for LUNs per target in ctld from 256 to 1024.
Some initiators do not support LUNs above 255, but that is not our problem.

Discussed with:	trasz
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	iXsystems, Inc.
2015-02-01 21:50:28 +00:00
Alexander Motin
bfbfc4a3cb Count consecutive read requests as blocking in CTL for files and ZVOLs.
Technically read requests can be executed in any order or simultaneously
since they are not changing any data.  But ZFS prefetcher goes crasy when
it receives consecutive requests from different threads.  Since prefetcher
works on level of separate blocks, instead of two consecutive 128K requests
it may receive 32 8K requests in mixed order.

This patch is more workaround then a real fix, and it does not fix all of
prefetcher problems, but it improves sequential read speed by 3-4x times
in some configurations.  On the other side it may hurt performance if
some backing store has no prefetch, that is why it is disabled by default
for raw devices.

MFC after:	2 weeks
2014-12-06 20:39:25 +00:00
Alexander Motin
ef8daf3fed Add GET LBA STATUS command support to CTL.
It is implemented for LUNs backed by ZVOLs in "dev" mode and files.
GEOM has no such API, so for LUNs backed by raw devices all LBAs will
be reported as mapped/unknown.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-12-04 11:34:19 +00:00
Alexander Motin
9e52565344 Do not pre-allocate UNIT ATTENTIONs storage for every possible initiator.
Abusing ability of major UAs cover minor ones we may not account UAs for
inactive ports.  Allocate UAs storage for port and start accounting only
after some initiator from that port fetched its first POWER ON OCCURRED.

This reduces per-LUN CTL memory usage from >1MB to less then 100K.

MFC after:	1 month
2014-12-03 15:16:18 +00:00
Alexander Motin
411598df7a Do not pre-allocate reservation keys memory for every possible initiator.
In configurations with many ports, like iSCSI, each LUN is typically
accessed only by limited subset of ports.  Allocating that memory on
demand allows to reduce CTL memory usage from 5.3MB/LUN to 1.3MB/LUN.

MFC after:	1 month
2014-12-03 09:05:53 +00:00
Alexander Motin
77a06f9db0 Convert persis_offset from global variable to softc field. 2014-12-02 12:38:22 +00:00
Alexander Motin
1251a76b12 Replace home-grown CTL IO allocator with UMA.
Old allocator created significant lock congestion protecting its lists
of preallocated I/Os, while UMA provides much better SMP scalability.
The downside of UMA is lack of reliable preallocation, that could guarantee
successful allocation in non-sleepable environments.  But careful code
review shown, that only CAM target frontend really has that requirement.
Fix that making that frontend preallocate and statically bind CTL I/O for
every ATIO/INOT it preallocates any way.  That allows to avoid allocations
in hot I/O path.  Other frontends either may sleep in allocation context
or can properly handle allocation errors.

On 40-core server with 6 ZVOL-backed LUNs and 7 iSCSI client connections
this change increases peak performance from ~700K to >1M IOPS!  Yay! :)

MFC after:	1 month
Sponsored by:	iXsystems, Inc.
2014-11-24 11:37:27 +00:00
Alexander Motin
23b30f5600 Partially reconstruct Active/Standby clusting.
In this mode one head is in Active state, supporting all commands, while
another is in Standby state, supporting only minimal LUN discovery subset.

It is still incomplete since Standby state requires reservation support,
which is impossible to do right without having interlink between heads.
But it allows to run some basic experiments.
2014-11-21 06:27:37 +00:00
Alexander Motin
3275003e03 Synchronize medium rotation rate in legacy Rigid Disk Drive Geometry mode
page with modern Block Device Characteristics VPD page.

MFC after:	1 week
2014-11-07 00:10:07 +00:00
Alexander Motin
c3e7ba3e6d Add to CTL support for logical block provisioning threshold notifications.
For ZVOL-backed LUNs this allows to inform initiators if storage's used or
available spaces get above/below the configured thresholds.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-11-06 00:48:36 +00:00
Alexander Motin
115dc0c762 Reduce code duplication around Write Exclusive persistent reservation.
While there, allow some more commands to pass persistent reservation.

MFC after:	1 week
2014-10-27 09:26:24 +00:00
Alexander Motin
b491e75b4b Allocate buffer for READ BUFFER/WRITE BUFFER commands on demand.
These commands are rare, but consume additional 256KB RAM per LUN.

MFC after:	1 week
2014-10-26 23:25:42 +00:00
Alexander Motin
218d5d4be2 Implement more functional CTL debug logging.
Setting bits in kern.cam.ctl.debug allows to log errors, commands and some
commands data respectively.

MFC after:	1 week
2014-10-16 08:42:17 +00:00
Alexander Motin
9a0190c9a1 Remove couple Copan's vendor-specific mode pages.
Those pages are highly system-/hardware-specific, the code is incomplete,
and so they hardly can be useful for anybody else.
2014-10-14 11:28:25 +00:00
Alexander Motin
523f047ea2 Some groundwork for later Informational Exceptions support.
This includes support for:
 - Read-Write Error Recovery mode page;
 - Informational Exceptions Control mode page;
 - Logical Block Provisioning mode page;
 - LOG SENSE command.

No real Informational Exceptions features yet. This is only a placeholder.

Sponsored by:	iXsystems, Inc.
2014-10-14 10:14:14 +00:00
Alexander Motin
d70698b372 Add support for READ DEFECT DATA (10/12) commands.
SPC-4 r2 allows to return empty defect list if the list is not supported.
We don't reallu support defect data lists, but this suppresses some errors.

MFC after:	1 week
2014-10-13 14:48:49 +00:00
Alexander Motin
0ca2fdeca2 Store persistent reservation keys as uint64_t instead of uint8_t[8].
This allows to simplify the code and save 512KB of RAM per LUN (8%)
by removing no longer needed "registered" keys flags.
2014-10-10 12:38:53 +00:00
Alexander Motin
5396f4d279 Implement software (mode page) and hardware (config) write protection. 2014-10-08 12:24:24 +00:00
Alexander Motin
2f872218e7 Simplify legacy reservation handling. Drop it on I_T nexus loss. 2014-09-22 07:59:25 +00:00
Alexander Motin
ab55ae255a Implement control over command reordering via options and control mode page.
It allows to bypass range checks between UNMAP and READ/WRITE commands,
which may introduce additional delays while waiting for UNMAP parameters.
READ and WRITE commands are always processed in safe order since their
range checks are almost free.
2014-09-13 10:34:23 +00:00
Alexander Motin
bfa005503c Make ctl_port_mask an array to support more then 32 ports.
Overflow reported by Coverity.

CID:		1229894
MFC after:	3 days
2014-09-10 07:16:17 +00:00
Alexander Motin
55551d0542 Improve cache control support, including DPO/FUA flags and the mode page.
At this moment it works only for files and ZVOLs in device mode since BIOs
have no respective respective cache control flags (DPO/FUA).

MFC after:	1 month
Sponsored by:	iXsystems, Inc.
2014-09-09 11:38:29 +00:00
Alexander Motin
25eee848cd Add support for Windows dialect of EXTENDED COPY command, aka Microsoft ODX.
This allows to avoid extra network traffic when copying files on NTFS iSCSI
disks within one storage host by drag'n'dropping them in Windows Explorer
of Windows 8/2012.  It should also accelerate Hyper-V VM operations, etc.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-08-04 01:16:20 +00:00
Alexander Motin
8cbf9eae6f Increase maximal number of SCSI ports in CTL from 32 to 128.
After I gave each iSCSI target its own port, the old limit appeared to be
not so big.  This change almost proportionally increases per-LUN memory
use, but it is still three times better then it was before r268807.

MFC after:	2 weeks
2014-07-17 21:16:52 +00:00
Alexander Motin
38afa8f733 Reduce per-LUN memory usage from 18MB to 1.8MB.
CTL never had use for CA support code since SPI has gone, and there is no
even frontends supporting that.  But it still was reserving 256 bytes of
memory per LUN per every possible initiator on every possible port.

Wrap unused code with ifdef's in case somebody even need it.

MFC after:	2 weeks
2014-07-17 20:28:51 +00:00
Alexander Motin
984a2ea91f Add support for VMWare dialect of EXTENDED COPY command, aka VAAI Clone.
This allows to clone VMs and move them between LUNs inside one storage
host without generating extra network traffic to the initiator and back,
and without being limited by network bandwidth.

LUNs participating in copy operation should have UNIQUE NAA or EUI IDs set.
For LUNs without these IDs VMWare will use traditional copy operations.

Beware: the above LUN IDs explicitly set to values non-unique from the VM
cluster point of view may cause data corruption if wrong LUN is addressed!

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-07-16 15:57:17 +00:00
Alexander Motin
4d877c4148 Merge several equal serialization indexes. 2014-07-13 06:01:23 +00:00
Alexander Motin
604e257984 Teach ctl_add_initiator() to dynamically allocate IIDs from pool.
If port passed negative IID value, the function will try to allocate IID
from the pool of unused, based on passed wwpn or name arguments.  It does
all its best to make IID unique and persistent across reconnects.

This makes persistent reservation properly work for iSCSI.  Previously,
in case of reconnects, reservation could be unexpectedly lost, or even
migrate between intiators.
2014-07-07 09:37:22 +00:00
Alexander Motin
69d7b87790 Make REPORT TARGET PORT GROUPS command report realistic data instead of
hardcoded garbage.
2014-07-06 07:02:36 +00:00
Alexander Motin
027e5269c9 Burry devid port method, which was a gross hack.
Instead make ports provide wanted port and target IDs, and LUNs provide
wanted LUN IDs.  After that core Device ID VPD code only had to link all
of them together and add relative port and port group numbers.

LUN ID for iSCSI LUNs no longer created by CTL, but by ctld, and passed
to CTL as "scsiname" LUN option.  This makes LUNs to report the same set
of IDs, independently from the port through which it is accessed, as
required by SCSI specifications.
2014-07-05 19:30:20 +00:00
Alexander Motin
92168f4c01 Separate concepts of frontend and port.
Before iSCSI implementation CTL had no knowledge about frontend drivers,
it had only frontends, which really were ports (alike to LUNs, if comparing
to backends).  But iSCSI added there ioctl() method, which does not belong
to frontend as a port, but belongs to a frontend driver.
2014-07-04 19:27:06 +00:00
Alexander Motin
25c9d5e593 Add support for REPORT TIMESTAMP command.
MFC after:	2 weeks
2014-07-01 16:52:41 +00:00
Alexander Motin
1b08cb4ee7 Add more formal and strict command parsing and validation.
For every supported command define CDB length and mask of bits that are
allowed to be set.  This allows to remove bunch of checks through the code
and still make the validation more strict.  To properly do it for commands
supporting multiple service actions, formalize their parsing by adding
subtables for each of such commands.

As visible effect, this change allows to add support for REPORT SUPPORTED
OPERATION CODES command, reporting to client all the data about supported
SCSI commands, except timeouts.

MFC after:	2 weeks
2014-07-01 15:05:23 +00:00
Alexander Motin
85165a3f70 Add READ BUFFER and improve WRITE BUFFER SCSI commands support.
This gives some use to 512KB per-LUN buffers, allocated for Copan-specific
processor code and not used.  It allows, for example, to test transport
performance and/or correctness without accessing the media, as supported
by Linux version of sg3_utils.

MFC after:	2 weeks
2014-06-26 08:56:36 +00:00
Alexander Motin
3a8ce4a36b Introduce fine-grained CTL locking to improve SMP scalability.
Split global ctl_lock, historically protecting most of CTL context:
 - remaining ctl_lock now protects lists of fronends and backends;
 - per-LUN lun_lock(s) protect LUN-specific information;
 - per-thread queue_lock(s) protect request queues.
This allows to radically reduce congestion on ctl_lock.

Create multiple worker threads, depending on number of CPUs, and assign
each LUN to one of them.  This allows to spread load between multiple CPUs,
still avoiging congestion on queues and LUNs locks.

On 40-core server, exporting 5 LUNs, each backed by gstripe of SATA SSDs,
accessed via 6 iSCSI connections, this change improves peak request rate
from 250K to 680K IOPS.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-06-25 17:02:01 +00:00
Alexander Motin
50fe38b6b8 Execute task management request directly in ctl_queue() context.
From one side it allows to remove CTL_FLAG_TASK_PENDING flag, handling of
which significantly complicates fine-grained locking.  From the other side
it reduces task management requests latency even below then that flag could.
As downside, it denies task management code to sleep, but that is not needed
any way now.

Discussed with:	ken
2014-06-19 13:19:35 +00:00
Alexander Motin
11b569f7cb Add support for VERIFY(10/12/16) and COMPARE AND WRITE SCSI commands.
Make data_submit backends method support not only read and write requests,
but also two new ones: verify and compare.  Verify just checks readability
of the data in specified location without transferring them outside.
Compare reads the specified data and compares them to received data,
returning error if they are different.

VERIFY(10/12/16) commands request either verify or compare from backend,
depending on BYTCHK CDB field.  COMPARE AND WRITE command executed in two
stages: first it requests compare, and then, if succeesed, requests write.
Atomicity of operation is guarantied by CTL request ordering code.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2014-06-16 11:00:14 +00:00