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.
Remove targ_enable()/targ_disable() frontend methods.
Those methods were never implemented, and I believe that their concept is
wrong, since single frontend (SCSI port) can not handle several targets.
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.
Increase CTL_DEVID_LEN from 16 to 64 bytes.
SPC-4 recommends T10 vendor ID based LUN ID was created by concatenating
product name and serial number (and istgt follows that). But product name
is 16 bytes long by itself, so 16 bytes total length is clearly not enough
to fit both.
To keep compatibility with existing configurations, pad short device IDs
to old length of 16, same as before.
This change probably breaks CTL user-level ABI, so control tools should
be rebuilt after this change.
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.
Sponsored by: iXsystems, Inc.
Simplify statistics calculation.
Instead of trying to guess size of disk I/O operations (it just won't work
that way for newly added commands, and is equal to data move size for old
ones), account data move traffic. If disk I/Os are that interesting, then
backends have to account and provide that information.
Block backend already exports the information about disk I/Os via devstat,
so having it here too is excessive.
Allow MODE SENSE commands through Write Exclusive persistent reservation,
as required by SPC-4.
Report that fact in persistent reservation capabilities.
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.
Add some more CTL_FLAG_ABORT check points.
This should allow to abort commands doing mostly disk I/O, such as VERIFY
or WRITE SAME. Before this change CTL_FLAG_ABORT was only checked around
data moves, which for these commands may not happen for a very long time.
Rework session termination in iSCSI target to actually wait
for any outstanding commands to be properly aborted by CTL.
Without it, in some cases (such as files backing the LUNs
stored on failing disk drives), terminating a busy session
would result in panic.
- Add support for SG_GET_SG_TABLESIZE IOCTL to report that we don't support
scatter/gather lists.
- Return error for still unsupported SG 3.x API read/write calls.
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.
Sponsored by: iXsystems, Inc.
Make backends track completion by processed number of sectors instead of
total transfer size.
Commands such as VERIFY or COMPARE AND WRITE may have transfer size not
matching directly to number of sectors.
Format Portal Group Tag same as istgt does -- %4.4x instead of %x.
SPC-4 spec tells it should be "two or more hexadecimal digits".
RFC3720 tells it is 16-bit value.
Allow to use iSCSI immediate data by several ctl_datamove() calls.
While for FreeBSD client that is only a minor optimization, VMWare client
doesn't support additional data requests after all data being sent once as
immediate.
Overhaul CAM SG driver IOCTL interfaces.
Make it really work for native FreeBSD programs. Before this it was broken
for years due to different number of pointer dereferences in Linux and
FreeBSD IOCTL paths, permanently returning errors to FreeBSD programs.
This change breaks the driver FreeBSD IOCTL ABI, making it more strict,
but since it was not working any way -- who bother.
Add shims for 32-bit programs on 64-bit host, translating the argument
of the SG_IO IOCTL for both FreeBSD and Linux ABIs.
With this change I was able to run 32-bit Linux sg3_utils tools and simple
32 and 64-bit FreeBSD test tools on both 32 and 64-bit FreeBSD systems.
Don't denounce peripherals on system shutdown. Together with r267321
(MFCed to stable/10 in r267775), we're now back to the pre-r228483
level of default verbosity. This in turn again typically allows for
reading information that userland might have printed on the screen
before initiating a halt, but still permits to debug potential device
shutdown problems on system shutdown via CAM_DEBUG etc.
Reviewed by: mav
Sponsored by: Bally Wulff Games & Entertainment GmbH
Respect MAXIMUM TRANSFER LENGTH field of Block Limits VPD page.
Nobody yet reported disk supporting I/Os less then our MAXPHYS value, but
since we any way have code to read Block Limits VPD page, that is easy.
Do not reread SCSI disk VPD pages on every device open.
Instead of rereading VPD pages on every device open, do it only on initial
device probe, and in cases when device reported via UNIT ATTENTIONs that
something has changed. Capacity is still rereaded on every open because
it is more critical for operation and more probable to change in run time.
On my tests with Intel 530 SSDs on mps(4) HBA this change reduces time
GEOM needs to retaste the device (that includes few open/close cycles)
from ~150ms to ~30ms.
Remove limits on size of READ/WRITE operations.
Instead of allocating up to 16MB or RAM at once to handle whole I/O,
allocate up to 1MB at a time, but do multiple ctl_datamove() and storage
I/Os if needed.
Make CAM target CTL frontend respect SIM I/O size limitations.
If datamove size is bigger then SIM can handle, or it has more segments
then this code can handle -- split it into several CTIO requests.
Add support for SCSI UNMAP commands to CTL.
This patch adds support for three new SCSI commands: UNMAP, WRITE SAME(10)
and WRITE SAME(16). WRITE SAME commands support both normal write mode
and UNMAP flag. To properly report UNMAP capabilities this patch also adds
support for reporting two new VPD pages: Block limits and Logical Block
Provisioning.
UNMAP support can be enabled per-LUN by adding "-o unmap=on" to `ctladm
create` command line or "option unmap on" to lun sections of /etc/ctl.conf.
At this moment UNMAP supported for ramdisks and device-backed block LUNs.
It was tested to work great with ZFS ZVOLs. For file-backed LUNs UNMAP
support is unfortunately missing due to absence of respective VFS KPI.
Sponsored by: iXsystems, Inc
Replace several instances of -1 with appropriate CAM_*_WILDCARD and types.
It was equal before r259397, but for good or bad, not any more for LUNs.
This change fixes at least CAM debugging.
