This change by 2-3 times improves performance of misaligned XCOPY and WUT
commands by avoiding unneeded read-modify-write cycles inside ZFS.
MFC after: 1 week
This change by 2-3 times improves performance of misaligned WRITE SAME
commands by avoiding unneeded read-modify-write cycles inside ZFS.
MFC after: 1 week
target iSCSI offload. Add mechanism to query maximum receive data segment
size supported by chosen hardware offload module, and use it in ctld(8)
to determine the value to advertise to the other side.
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
While ctld(8) still does not allow multiple portal groups per target
to be configured, kernel should now be able to handle it.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
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.
sys/cam/scsi/scsi_all.h:
In struct scsi_extended_inquiry_data:
- Increase the length field to 2 bytes, as it is 2 bytes in SPC-4.
- Add bit definitions for the various Activiate Microcode actions.
- Add the Sequential Access Logical Block Protection support bit,
since we need that in the sa(4) driver. (For modifications
that will come later.)
- Add definitions for the various Multi I_T Nexus Microcode
Download modes.
sys/cam/ctl/ctl.c:
As of SPC-4, a single report of "REPORTED LUNS DATA HAS CHANGED"
is to be given per I_T nexus. Once it is reported, the unit
attention condition should be cleared for all LUNS attached to
an I_T nexus.
Previously that only happened when a REPORT LUNS command was
processed.
This behavior may be different (according to SAM-5) when the
UA_INTLCK_CTRL bits are non-zero in the control mode page but
CTL does not currently support that.
So, in view of the spec, whenever we report a LUN inventory
change unit attention, clear it on all LUNs for that
particular I_T nexus.
Add a new function, ctl_clear_ua() that will clear a unit
attention on all LUNs for the given I_T nexus.
One field in the extended inquiry data that we could potentially
report at some point is the maximum supported sense data length.
To do that, we would the SIM to report (via path inquiry
perhaps) how much sense data it is able to send.
Add comments to explain some of the bits that are set in the
Extended Inquiry VPD page.
Add a few comments to make it more clear which functions handle
various VPD pages.
Sponsored by: Spectra Logic
MFC after: 1 week
This could cause data corruption due to accessing wrong LUN in case of
retries on write errors. Failed writes were retried to read LUN.
MFC after: 3 days
If we aggregated status sending with data move and got error, allow status
to be updated and resent again separately. Without this command may stuck
without status sent at all.
MFC after: 2 weeks
While in most cases CTL should correctly fetch those values from backing
storages, there are some initiators (like MS SQL), that may not like large
physical block sizes, even if they are true. For such cases allow override
fetched values with supported ones (like 4K).
MFC after: 1 week
While we don't support MCS, hole in received sequence numbers may mean
only PDU loss. While we don't support lost PDU recovery, terminate the
connection to avoid stuck commands.
While there, improve handling of sequence numbers wrap after 2^32 PDUs.
MFC after: 2 weeks
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
While without UNMAP support there is not much initiator can do about it,
the administrator still better be notified about the storage overflow.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Previously it was supported only for ZVOL-backed LUNs, but now should work
for file-backed LUNs too. Used value in this case is a space occupied by
the backing file, while available value is an available space on file
system. Pool thresholds are still not implemented in this case.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
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.
After recent optimizations this change is no longer blocked by CTL memory
consumption. Those limits are still not free, but much cheaper now.
MFC after: 1 week
Relnotes: yes
Sponsored by: iXsystems, Inc.
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
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
Make CTL core and block backend set success status before initiating last
data move for read commands. Make CAM target and iSCSI frontends detect
such condition and send command status together with data. New I/O flag
allows to skip duplicate status sending on later fe_done() call.
For Fibre Channel this change saves one of three interrupts per read command,
increasing performance from 126K to 160K IOPS. For iSCSI this change saves
one of three PDUs per read command, increasing performance from 1M to 1.2M
IOPS.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
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.
