This code was disabled due to its high memory usage. But now we need this
functionality for cfumass(4) frontend, since USB MS BBB transport does not
support autosense.
MFC after: 2 weeks
When LUN is disabled, SIM starts returning queued ATIOs/INOTs. But at the
same time there can be some ATIOs/INOTs still carrying real new requests.
If we free those, SIM may leak some resources, forever expecting for any
response from us. So try to be careful, separating ATIOs/INOTs carrying
requests which still must be processed, from ATIOs/INOTs completed with
errors which can be freed.
MFC after: 2 weeks
Before this change XCOPY code could allocate memory in chunks up to 16-32MB
(VMware does XCOPY in 4MB chunks by default), that could be difficult for
VM subsystem to do due to KVA fragmentation, that sometimes created huge
allocation delays, blocking any I/O for respective LU for that time.
This change limits allocations down to TPC_MAX_IO_SIZE, which is 1MB now.
1MB is also not a cookie, but ZFS also can do that for large blocks, so
it should be less dramatic. As drawback this increases CPU overhead, but
it still look acceptable comparing to time consumed by ZFS read/write.
MFC after: 1 week
sys/cam/ctl/ctl.c:
In ctl_datamove(), inside CTL_IO_DELAY, add a lun variable and fill
it in before trying to dereference it.
MFC after: 3 days
Sponsored by: Spectra Logic
Before this change MaxCmdSN was reported as CmdSN + delta, that made it
limit number of requests in transmission from the initiator to target,
that was pretty useless. After this change MaxCmdSN limits number of
requests queued to CTL, i.e. maximal queue depth for the initiator.
The default limit is 256 outstanding requests per initiator at a time.
This code uses existing cs_outstanding_ctl_pdus counter to track queue
depth. It's semantics doen't perfectly match, but close enough to not
add another counter. Just don't set the maxtags below 2.
MFC after: 2 weeks
all of them in terms of an sbuf-based back-end, xpt_path_sbuf. This
unifies the implementation, but more importantly it stops the output
fropm being split between 4 or more invocations of printf. The
multiple invocations cause interleaving of the messages on the
console during boot, making the output of disk discovery often
unintelligible. This change helps a lot, but more work is needed.
Reviewed by: ken, mav
Sponsored by: Netflix
If "capacity" LU option is set, ramdisk backend now implements featured
thin provisioned disk, storing data in malloc(9) allocated memory blocks
of pblocksize bytes (default PAGE_SIZE or 4KB). Additionally ~0.2% of LU
size is used for indirection tree (bigger pblocksize reduce the overhead).
Backend supports all unmap and anchor operations. If configured capacity
is overflowed, proper error conditions are reported.
If "capacity" LU option is not set, the backend operates mostly the same
as before without allocating real storage: writes go to nowhere, reads
return zeroes, reporting that all LBAs are unmapped.
This backend is still mostly oriented on testing and benchmarking (it is
still a volatile RAM disk), but now it should allow to run real FS tests,
not only simple dumb dd.
MFC after: 2 weeks
It is only a first step and not perfect, but better then nothing.
The main blocker is CAM target frontend, that can not be unloaded,
since CAM does not have mechanism to unregister periph driver now.
MFC after: 2 weeks
The length of the scsi_set_timestamp_parameters struct was incorrect. LTO-5
drives don't care, but LTO-7 drives do.
Reviewed by: Sam Klopsch
MFC after: 2 weeks
Sponsored by: Spectra Logic Corp
This field has no practical use and never readed. Initiators already
receive respective residual size from frontends. Removed field had
different semantics, which looks useless, and was never passed through
by any frontend.
While there, fix kern_data_resid field support in case of HA, missed in
r312291.
MFC after: 13 days
It seems like kern_data_resid was never really implemented. This change
finally does it. Now frontends update this field while transferring data,
while CTL/backends getting it can more flexibly handle the result.
At this point behavior should not change significantly, still reporting
errors on write overrun, but that may be changed later, if we decide so.
CAM target frontend still does not properly handle overruns due to CAM API
limitations. We may need to add some fields to struct ccb_accept_tio to
pass information about initiator requested transfer size(s).
MFC after: 2 weeks
Replace archaic "busses" with modern form "buses."
Intentionally excluded:
* Old/random drivers I didn't recognize
* Old hardware in general
* Use of "busses" in code as identifiers
No functional change.
http://grammarist.com/spelling/buses-busses/
PR: 216099
Reported by: bltsrc at mail.ru
Sponsored by: Dell EMC Isilon
Instead of collecting statistics for each combination of ports and logical
units, that consumed ~45KB per LU with present number of ports, collect
separate statistics for every port and every logical unit separately, that
consume only 176 bytes per each single LU/port. This reduces struct
ctl_lun size down to just 6KB.
Also new IOCTL API/ABI does not hardcode number of LUs/ports, and should
allow handling of very large quantities.
MFC after: 2 weeks (probably keeping old API enabled for some time)
This array takes 64KB of RAM now, that was more then half of struct ctl_lun
size. If at some point we support more ports, this may need another tune.
MFC after: 2 weeks
The sim_vid, hba_vid, and dev_name fields of struct ccb_pathinq are
fixed-length strings. AFAICT the only place they're read is in
sbin/camcontrol/camcontrol.c, which assumes they'll be null-terminated.
However, the kernel doesn't null-terminate them. A bunch of copy-pasted code
uses strncpy to write them, and doesn't guarantee null-termination. For at
least 4 drivers (mpr, mps, ciss, and hyperv), the hba_vid field actually
overflows. You can see the result by doing "camcontrol negotiate da0 -v".
This change null-terminates those fields everywhere they're set in the
kernel. It also shortens a few strings to ensure they'll fit within the
16-character field.
PR: 215474
Reported by: Coverity
CID: 1009997 1010000 1010001 1010002 1010003 1010004 1010005
CID: 1331519 1010006 1215097 1010007 1288967 1010008 1306000
CID: 1211924 1010009 1010010 1010011 1010012 1010013 1010014
CID: 1147190 1010017 1010016 1010018 1216435 1010020 1010021
CID: 1010022 1009666 1018185 1010023 1010025 1010026 1010027
CID: 1010028 1010029 1010030 1010031 1010033 1018186 1018187
CID: 1010035 1010036 1010042 1010041 1010040 1010039
Reviewed by: imp, sephe, slm
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D9037
Differential Revision: https://reviews.freebsd.org/D9038
observed to fix any actual error, but it's the right thing to do
from the correctness point of view.
Tested by: Eugene M. Zheganin <emz at norma.perm.ru>
MFC after: 1 month
- Since I/Os are allocates from per-port pools, make allocations store
pointer to CTL softc there, and use it where needed instead of global.
- Created bunch of helper macros to access LUN, port and CTL softc.
MFC after: 2 weeks
We do not have non-volatile memory to really save those values, so we
neither report nor support this capability. Also saved mode pages are
not replicated between HA peers now.
MFC after: 2 weeks
Those two values are not directly related, so make them independent.
This does not change any limits immediately, but makes number of LUNs
per port controllable via tunable/sysctl kern.cam.ctl.lun_map_size.
After this change increasing CTL_MAX_LUNS should be pretty cheap,
and even making it tunable should be easy.
MFC after: 2 weeks
For EXTENDED COPY:
- improve parameters checking to report some errors before copy start;
- forward sense data from copy target as descriptor in case of error;
- report which CSCD reported error in sense key specific information.
For WRITE USING TOKEN:
- pass through real sense data from copy target instead of reporting
our copy error, since for initiator its a "simple" write, not a copy.
MFC after: 2 weeks
- Allow maximal sense size limitation via Control Extension mode page.
- When sense size limited, include descriptors atomically: whole or none.
- Set new SDAT_OVFL bit if some descriptors don't fit the limit.
- Report real written sense length instead of static maximal 252 bytes.
MFC after: 2 weeks
VMware tries to enable this bit to avoid multiple threshold notifications
in case of multiple initiators connected to the same LUN. Unfortunately
their code sends MODE SELECT(6) request with parameter length hardcoded
for the page without any thresholds. Since we have four threshold and our
page is bigger, this attempt fails, that is correct in my understanding.
So all we can do about this now is to report proper error code and hope
VMware fix their code one day.
MFC after: 2 weeks
for INFORMATION field fit into available 4 bytes (has no non-zero bytes
except last 4), as explicitly required by SPC-5 specification.
MFC after: 2 weeks
While CTL still has no real events to report in this way (like SMART),
it is possible to trigger false event by manually setting TEST bit in
Informational Exceptions Control mode page, that can be useful for
initiator testing. This code supports all flavours of IE reporting:
UNIT ATTENTION, RECOVERED ERROR and NO SENSE sense keys, REQUEST SENSE
command and Informational Exceptions log page.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Under kern.cam we have certain sysctls that are per-device, such as the
ones under kern.cam.ada.[0-9]+.*. Add a "device_index" label annotation
to such sysctls, so that the Prometheus metrics exporter will give all
of those metrics the same name. The device number will be added to the
metric name as the "device_index" label.
Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D8775
This adds support to camcontrol(8) and libcam(3) for getting and setting
the time on SCSI protocol drives. This is more commonly found on tape
drives, but is a SPC (SCSI Primary Commands) command, and may be found
on any device that speaks SCSI.
The new camcontrol timestamp subcommand allows getting the current device
time or setting the time to the current system time or any arbitrary time.
sbin/camcontrol/Makefile:
Add timestamp.c.
sbin/camcontrol/camcontrol.8:
Document the new timestamp subcommand.
sbin/camcontrol/camcontrol.c:
Add the timestamp subcommand to camcontrol.
sbin/camcontrol/camcontrol.h:
Add the timestamp() function prototype.
sbin/camcontrol/timestamp.c:
Timestamp setting and reporting functionality.
sys/cam/scsi/scsi_all.c:
Add two new CCB building functions, scsi_set_timestamp() and
scsi_report_timestamp(). Also, add a new helper function,
scsi_create_timestamp().
sys/cam/scsi/scsi_all.h:
Add CDB and parameter data for the the set and report timestamp
commands.
Add function declarations for the new CCB building and helper
functions.
Submitted by: Sam Klopsch
Sponsored by: Spectra Logic
MFC After: 2 weeks
- On control request update all status pages, since they may also be
affected if user enables/disables enclosure slots.
- Periodically update element descriptors too, since there is some
hardware where they are changed dynamically.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
A bug in CAM's serial number hash logic resulted in SATA drives behind a SAS
controller getting removed and readded anytime the drive was rescanned for
any reason.
PR: 212914
Submitted by: kadesai
Reported by: kadesai
Reviewed by: asomers, ken
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
The BUF_TRACKING bio pointer only makes sense for kernel consumers of
CCBs.
PR: 214250
Reported by: trasz@
Reviewed by: imp@, markj@
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8477
It was added in SES-3 spec, and its support required to properly link
the Additional Element Status page data to the original elements.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
is not going to recover until the system is reset. Treat it as a special
case and don't allow it to fall through to quasi-success.
Reviewed by: ken, imp
Obtained from: Netflix
MFC after: 3 days
the components are reset). Therefore retries are pointless. This is very
visible in SATL systems, for example an LSI SAS controller and a SATA HDD/SSD.
Reviewed by: ken
Obtained from: Netflix
MFC after: 3 days
be accessed by root. It uses unsigned ints instead of size_t
to preserve the ABI.
PR: 207627
Submitted by: ryan@ryanday.net (with slight tweaks)
MFC after: 1 month
Upstream the BUF_TRACKING and FULL_BUF_TRACKING buffer debugging code.
This can be handy in tracking down what code touched hung bios and bufs
last. The full history is especially useful, but adds enough bloat that
it shouldn't be enabled in release builds.
Function names (or arbitrary string constants) are tracked in a
fixed-size ring in bufs. Bios gain a pointer to the upper buf for
tracking. SCSI CCBs gain a pointer to the upper bio for tracking.
Reviewed by: markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8366
Previously pass driver just ignored the flag, making random kernel code
access user-space pointer, sometime causing crashes even for correctly
written applications if user-level context was switched or swapped out.
This patch tries to copyin the CDB into kernel space to avoid it.
MFC after: 2 weeks
If device reservation was preempted by other initiator, our sync request
will always fail. Without this change CAM tried to sync cache on every
following device close, including numerous GEOM tasting opens/closes,
causing lots of useless noise in logs.
While there, increase SYNCHRONIZE CACHE timeout to default value.
MFC after: 2 weeks
CTL itself has no limits on on UNMAP and WRITE SAME sizes. But depending
on backends large requests may take too much time. To avoid that new
configuration options allow to hint initiator maximal sizes it should not
exceed.
MFC after: 2 weeks
KASSERT in cam_ccbq_insert_ccb that only XPT_FC_QUEUED ops are queued,
and XPT_FC_USER_CCB ops are not. Otherwise cam_ccbq_ccb_done may be
skipped.
Bounds check the index used for camq_remove in order to panic instead
of scribble on removal of an out-of-bounds index (e.g. consider the
effect of camq_remove of CAM_UNQUEUED_INDEX).
KASSERT in cam_ccbq_remove_ccb that the ccb removed by index was the
one sought.
Submitted by: Ryan Libby <rlibby@gmail.com>
Reviewed by: imp, mav
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8151
In cam_periph_runccb, cam_periph_ccbwait was using the value of the ccb
pinfo.index and status fields to determine whether the ccb was done,
but these fields are updated without a contending lock and could glitch
into states that would be erroneously interpreted as done. Instead,
have cam_periph_ccbwait look for the explicit result of the function
cam_periph_done.
Submitted by: Ryan Libby <rlibby@gmail.com>
Reviewed by: mav
MFC after: 3 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8020
we have queued up normaliazed to the queue size. Also compute buckets
of latency to help compute, in userland, estimates of Median, P90, P95
and P99 values.
Sponsored by: Netflix, Inc
This eventhandler is mainly used by VMs, e.g. Hyper-V, whose disk
controllers share the disks with the simulated ATA controllers.
Submitted by: Hongjiang Zhang <honzhan microsoft com>
Discussed with: mav
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D7693
Some statuses, such as "ATA pass through information available", are part
part of absolutely normal operation and do not worth reporting.
MFC after: 2 weeks
Decouple the send and receive limits on the amount of data in a single
iSCSI PDU. MaxRecvDataSegmentLength is declarative, not negotiated, and
is direction-specific so there is no reason for both ends to limit
themselves to the same min(initiator, target) value in both directions.
Allow iSCSI drivers to report their send, receive, first burst, and max
burst limits explicitly instead of using hardcoded values or trying to
derive all of them from the receive limit (which was the only limit
reported by the drivers prior to this change).
Display the send and receive limits separately in the userspace iSCSI
utilities.
Reviewed by: jpaetzel@ (earlier version), trasz@
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D7279
[set] notation. This fixes pattern matching for recently added drives
that would set the NCQ Trim being broken incorrectly.
PR: 210686
Tested-by: Tomoaki AOKI
MFC After: 3 days
Uses of commas instead of a semicolons can easily go undetected. The comma
can serve as a statement separator but this shouldn't be abused when
statements are meant to be standalone.
Detected with devel/coccinelle following a hint from DragonFlyBSD.
MFC after: 1 month
per-protocol. This reduces the number scsi symbols references by
cam_xpt significantly, and eliminates all ata / nvme symbols. There's
still some NVME / ATA specific code for dealing with XPT_NVME_IO and
XPT_ATA_IO respectively, and a bunch of scsi-specific code, but this
is progress.
Differential Revision: https://reviews.freebsd.org/D7289
eliminates the need to special case everything in cam_xpt for new
transports. It is now a failure to not have a transport object when
registering the bus as well. You can still, however, create a
transport that's unspecified (XPT_)
Differential Revision: https://reviews.freebsd.org/D7289
cam_periph_releaes_locked() at the end of nvme_probe_start because we
hit an assertion which may be bogus. Instead, leak a periph until we
sort it out. Since these devices don't arrive and depart often, so
this is the lessor of two evils.
MFC after: 1 week
In the case where cam_iosched_init() fails, the ada and da softcs were leaked.
Instead, free them.
Reported by: Coverity
CID: 1356039
Sponsored by: EMC / Isilon Storage Division
sys/cam/scsi/scsi_xpt.c
Strip leading spaces off of a SCSI disk's reported serial number
when populating the CAM serial number. This affects the output of
"diskinfo -v" and the names of /dev/diskid/DISK-* device nodes,
among other things.
SPC5r05 says that the Product Serial Number field from the Unit
Serial Number VPD page is right-aligned. So any leading spaces are
not part of the actual serial number. Most devices don't left-pad
their serial numbers, but some do. In particular, the SN VPD page
that an LSI HBA emulates for a SATA drive contains enough
left-padding to fill a 20-byte field.
UPDATING
Add a note to UPDATING, because some users may have to update
/etc/fstab or geom labels.
Reviewed by: ken, mav
MFC after: Never
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D6516
o Some Samsung drives do not support the ATA READ LOG EXT or READ
LOG DMA EXT commands, despite indicating that they do in their
IDENTIFY data. So, fix this in two ways:
1. Only start the log directory probe (ADA_STATE_LOGDIR) if
the drive claims to be an SMR drive in the first place.
We don't need to do the extra probing for other devices.
This will also serve to prevent problems with other
drives that have the same issue.
2. Add quirks for the two Samsung drives that have been
reported so far (thanks to Oleg Nauman and Alex Petrov).
If there is a reason to do a Read Log later on, we will
know that it doesn't work on these drives.
o Add a quirk entry to mark Seagate Lamarr Drive Managed drives as
drive managed. They don't report this in their Identify data.
sys/cam/ata/ata_da.c:
Add two new quirks:
1. ADA_Q_LOG_BROKEN, for drives that claim to support Read
Log but don't really.
2. ADA_Q_SMR_DM, for drives that are Drive Managed SMR, but
don't report it. This can matter for software that
wants to know when it should make an extra effort to
write sequentially.
Record two Samsung drives that don't support Read Log, and
one Seagate drive that doesn't report that it is a SMR drive.
The Seagate drive is already recorded in the da(4) driver.
We may have to come up with a similar solution in the da(4)
driver for SATA drives that don't properly support Read Log.
In adasetflags(), Dont' set the ADA_FLAG_CAN_LOG bit if the
device has the LOG_BROKEN quirk set. Also, look at the
SMR_DM quirk and set the device type accordingly if it is
actually a drive managed drive.
When deciding whether to go into the LOGDIR probe state,
look to see whether the device claims to be an SMR device.
If not, don't bother with the LOGDIR probe state.
Sponsored by: Spectra Logic
The currently used idiom for clearing the part of a ccb after its
header generates one or two Coverity errors for each time it is
used. All instances generate an Out-of-bounds access (ARRAY_VS_SINGLETON)
error because of the treatment of the header as a two element array,
with a pointer to the non-existent second element being passed as
the starting address to bzero(). Some instances also alsp generate
Out-of-bounds access (OVERRUN) errors, probably because the space
being cleared is larger than the sizeofstruct ccb_hdr).
In addition, this idiom is difficult for humans to understand and
it is error prone. The user has to chose the proper struct ccb_*
type (which does not appear in the surrounding code) for the sizeof()
in the length calculation. I found several instances where the
length was incorrect, which could cause either an actual out of
bounds write, or incompletely clear the ccb.
A better way is to write the code to clear the ccb itself starting
at sizeof(ccb_hdr) bytes from the start of the ccb, and calculate
the length based on the specific type of struct ccb_* being cleared
as specified by the union ccb member being used. The latter can
normally be seen in the nearby code. This is friendlier for Coverity
and other static analysis tools because they will see that the
intent is to clear the trailing part of the ccb.
Wrap all of the boilerplate code in a convenient macro that only
requires a pointer to the desired union ccb member (or a pointer
to the union ccb itself) as an argument.
Reported by: Coverity
CID: 1007578, 1008684, 1009724, 1009773, 1011304, 1011306
CID: 1011307, 1011308, 1011309, 1011310, 1011311, 1011312
CID: 1011313, 1011314, 1011315, 1011316, 1011317, 1011318
CID: 1011319, 1011320, 1011321, 1011322, 1011324, 1011325
CID: 1011326, 1011327, 1011328, 1011329, 1011330, 1011374
CID: 1011390, 1011391, 1011392, 1011393, 1011394, 1011395
CID: 1011396, 1011397, 1011398, 1011399, 1011400, 1011401
CID: 1011402, 1011403, 1011404, 1011405, 1011406, 1011408
CID: 1011409, 1011410, 1011411, 1011412, 1011413, 1011414
CID: 1017461, 1018387, 1086860, 1086874, 1194257, 1229897
CID: 1229968, 1306229, 1306234, 1331282, 1331283, 1331294
CID: 1331295, 1331535, 1331536, 1331539, 1331540, 1341623
CID: 1341624, 1341637, 1341638, 1355264, 1355324
Reviewed by: scottl, ken, delphij, imp
MFH: 1 month
Differential Revision: https://reviews.freebsd.org/D6496
I broke broke the quirk in the ada(4) driver disabling NCQ trim support
in revision 300207. The support flags were set before the quirks were
loaded.
sys/cam/ata/ata_da.c:
Call adasetflags() after loading quirks, so that we'll set the
flags accurately.
Sponsored by: Spectra Logic
utilizing previously unused arg field of struct ccb_notify_acknowledge.
This makes new QUERY TASK, QUERY TASK SET and QUERY ASYNC EVENT requests
really functional for CAM target mode drivers.
This change includes support for SCSI SMR drives (which conform to the
Zoned Block Commands or ZBC spec) and ATA SMR drives (which conform to
the Zoned ATA Command Set or ZAC spec) behind SAS expanders.
This includes full management support through the GEOM BIO interface, and
through a new userland utility, zonectl(8), and through camcontrol(8).
This is now ready for filesystems to use to detect and manage zoned drives.
(There is no work in progress that I know of to use this for ZFS or UFS, if
anyone is interested, let me know and I may have some suggestions.)
Also, improve ATA command passthrough and dispatch support, both via ATA
and ATA passthrough over SCSI.
Also, add support to camcontrol(8) for the ATA Extended Power Conditions
feature set. You can now manage ATA device power states, and set various
idle time thresholds for a drive to enter lower power states.
Note that this change cannot be MFCed in full, because it depends on
changes to the struct bio API that break compatilibity. In order to
avoid breaking the stable API, only changes that don't touch or depend on
the struct bio changes can be merged. For example, the camcontrol(8)
changes don't depend on the new bio API, but zonectl(8) and the probe
changes to the da(4) and ada(4) drivers do depend on it.
Also note that the SMR changes have not yet been tested with an actual
SCSI ZBC device, or a SCSI to ATA translation layer (SAT) that supports
ZBC to ZAC translation. I have not yet gotten a suitable drive or SAT
layer, so any testing help would be appreciated. These changes have been
tested with Seagate Host Aware SATA drives attached to both SAS and SATA
controllers. Also, I do not have any SATA Host Managed devices, and I
suspect that it may take additional (hopefully minor) changes to support
them.
Thanks to Seagate for supplying the test hardware and answering questions.
sbin/camcontrol/Makefile:
Add epc.c and zone.c.
sbin/camcontrol/camcontrol.8:
Document the zone and epc subcommands.
sbin/camcontrol/camcontrol.c:
Add the zone and epc subcommands.
Add auxiliary register support to build_ata_cmd(). Make sure to
set the CAM_ATAIO_NEEDRESULT, CAM_ATAIO_DMA, and CAM_ATAIO_FPDMA
flags as appropriate for ATA commands.
Add a new get_ata_status() function to parse ATA result from SCSI
sense descriptors (for ATA passthrough over SCSI) and ATA I/O
requests.
sbin/camcontrol/camcontrol.h:
Update the build_ata_cmd() prototype
Add get_ata_status(), zone(), and epc().
sbin/camcontrol/epc.c:
Support for ATA Extended Power Conditions features. This includes
support for all features documented in the ACS-4 Revision 12
specification from t13.org (dated February 18, 2016).
The EPC feature set allows putting a drive into a power power mode
immediately, or setting timeouts so that the drive will
automatically enter progressively lower power states after various
idle times.
sbin/camcontrol/fwdownload.c:
Update the firmware download code for the new build_ata_cmd()
arguments.
sbin/camcontrol/zone.c:
Implement support for Shingled Magnetic Recording (SMR) drives
via SCSI Zoned Block Commands (ZBC) and ATA Zoned Device ATA
Command Set (ZAC).
These specs were developed in concert, and are functionally
identical. The primary differences are due to SCSI and ATA
differences. (SCSI is big endian, ATA is little endian, for
example.)
This includes support for all commands defined in the ZBC and
ZAC specs.
sys/cam/ata/ata_all.c:
Decode a number of additional ATA command names in ata_op_string().
Add a new CCB building function, ata_read_log().
Add ata_zac_mgmt_in() and ata_zac_mgmt_out() CCB building
functions. These support both DMA and NCQ encapsulation.
sys/cam/ata/ata_all.h:
Add prototypes for ata_read_log(), ata_zac_mgmt_out(), and
ata_zac_mgmt_in().
sys/cam/ata/ata_da.c:
Revamp the ada(4) driver to support zoned devices.
Add four new probe states to gather information needed for zone
support.
Add a new adasetflags() function to avoid duplication of large
blocks of flag setting between the async handler and register
functions.
Add new sysctl variables that describe zone support and paramters.
Add support for the new BIO_ZONE bio, and all of its subcommands:
DISK_ZONE_OPEN, DISK_ZONE_CLOSE, DISK_ZONE_FINISH, DISK_ZONE_RWP,
DISK_ZONE_REPORT_ZONES, and DISK_ZONE_GET_PARAMS.
sys/cam/scsi/scsi_all.c:
Add command descriptions for the ZBC IN/OUT commands.
Add descriptions for ZBC Host Managed devices.
Add a new function, scsi_ata_pass() to do ATA passthrough over
SCSI. This will eventually replace scsi_ata_pass_16() -- it
can create the 12, 16, and 32-byte variants of the ATA
PASS-THROUGH command, and supports setting all of the
registers defined as of SAT-4, Revision 5 (March 11, 2016).
Change scsi_ata_identify() to use scsi_ata_pass() instead of
scsi_ata_pass_16().
Add a new scsi_ata_read_log() function to facilitate reading
ATA logs via SCSI.
sys/cam/scsi/scsi_all.h:
Add the new ATA PASS-THROUGH(32) command CDB. Add extended and
variable CDB opcodes.
Add Zoned Block Device Characteristics VPD page.
Add ATA Return SCSI sense descriptor.
Add prototypes for scsi_ata_read_log() and scsi_ata_pass().
sys/cam/scsi/scsi_da.c:
Revamp the da(4) driver to support zoned devices.
Add five new probe states, four of which are needed for ATA
devices.
Add five new sysctl variables that describe zone support and
parameters.
The da(4) driver supports SCSI ZBC devices, as well as ATA ZAC
devices when they are attached via a SCSI to ATA Translation (SAT)
layer. Since ZBC -> ZAC translation is a new feature in the T10
SAT-4 spec, most SATA drives will be supported via ATA commands
sent via the SCSI ATA PASS-THROUGH command. The da(4) driver will
prefer the ZBC interface, if it is available, for performance
reasons, but will use the ATA PASS-THROUGH interface to the ZAC
command set if the SAT layer doesn't support translation yet.
As I mentioned above, ZBC command support is untested.
Add support for the new BIO_ZONE bio, and all of its subcommands:
DISK_ZONE_OPEN, DISK_ZONE_CLOSE, DISK_ZONE_FINISH, DISK_ZONE_RWP,
DISK_ZONE_REPORT_ZONES, and DISK_ZONE_GET_PARAMS.
Add scsi_zbc_in() and scsi_zbc_out() CCB building functions.
Add scsi_ata_zac_mgmt_out() and scsi_ata_zac_mgmt_in() CCB/CDB
building functions. Note that these have return values, unlike
almost all other CCB building functions in CAM. The reason is
that they can fail, depending upon the particular combination
of input parameters. The primary failure case is if the user
wants NCQ, but fails to specify additional CDB storage. NCQ
requires using the 32-byte version of the SCSI ATA PASS-THROUGH
command, and the current CAM CDB size is 16 bytes.
sys/cam/scsi/scsi_da.h:
Add ZBC IN and ZBC OUT CDBs and opcodes.
Add SCSI Report Zones data structures.
Add scsi_zbc_in(), scsi_zbc_out(), scsi_ata_zac_mgmt_out(), and
scsi_ata_zac_mgmt_in() prototypes.
sys/dev/ahci/ahci.c:
Fix SEND / RECEIVE FPDMA QUEUED in the ahci(4) driver.
ahci_setup_fis() previously set the top bits of the sector count
register in the FIS to 0 for FPDMA commands. This is okay for
read and write, because the PRIO field is in the only thing in
those bits, and we don't implement that further up the stack.
But, for SEND and RECEIVE FPDMA QUEUED, the subcommand is in that
byte, so it needs to be transmitted to the drive.
In ahci_setup_fis(), always set the the top 8 bits of the
sector count register. We need it in both the standard
and NCQ / FPDMA cases.
sys/geom/eli/g_eli.c:
Pass BIO_ZONE commands through the GELI class.
sys/geom/geom.h:
Add g_io_zonecmd() prototype.
sys/geom/geom_dev.c:
Add new DIOCZONECMD ioctl, which allows sending zone commands to
disks.
sys/geom/geom_disk.c:
Add support for BIO_ZONE commands.
sys/geom/geom_disk.h:
Add a new flag, DISKFLAG_CANZONE, that indicates that a given
GEOM disk client can handle BIO_ZONE commands.
sys/geom/geom_io.c:
Add a new function, g_io_zonecmd(), that handles execution of
BIO_ZONE commands.
Add permissions check for BIO_ZONE commands.
Add command decoding for BIO_ZONE commands.
sys/geom/geom_subr.c:
Add DDB command decoding for BIO_ZONE commands.
sys/kern/subr_devstat.c:
Record statistics for REPORT ZONES commands. Note that the
number of bytes transferred for REPORT ZONES won't quite match
what is received from the harware. This is because we're
necessarily counting bytes coming from the da(4) / ada(4) drivers,
which are using the disk_zone.h interface to communicate up
the stack. The structure sizes it uses are slightly different
than the SCSI and ATA structure sizes.
sys/sys/ata.h:
Add many bit and structure definitions for ZAC, NCQ, and EPC
command support.
sys/sys/bio.h:
Convert the bio_cmd field to a straight enumeration. This will
yield more space for additional commands in the future. After
change r297955 and other related changes, this is now possible.
Converting to an enumeration will also prevent use as a bitmask
in the future.
sys/sys/disk.h:
Define the DIOCZONECMD ioctl.
sys/sys/disk_zone.h:
Add a new API for managing zoned disks. This is very close to
the SCSI ZBC and ATA ZAC standards, but uses integers in native
byte order instead of big endian (SCSI) or little endian (ATA)
byte arrays.
This is intended to offer to the complete feature set of the ZBC
and ZAC disk management without requiring the application developer
to include SCSI or ATA headers. We also use one set of headers
for ioctl consumers and kernel bio-level consumers.
sys/sys/param.h:
Bump __FreeBSD_version for sys/bio.h command changes, and inclusion
of SMR support.
usr.sbin/Makefile:
Add the zonectl utility.
usr.sbin/diskinfo/diskinfo.c
Add disk zoning capability to the 'diskinfo -v' output.
usr.sbin/zonectl/Makefile:
Add zonectl makefile.
usr.sbin/zonectl/zonectl.8
zonectl(8) man page.
usr.sbin/zonectl/zonectl.c
The zonectl(8) utility. This allows managing SCSI or ATA zoned
disks via the disk_zone.h API. You can report zones, reset write
pointers, get parameters, etc.
Sponsored by: Spectra Logic
Differential Revision: https://reviews.freebsd.org/D6147
Reviewed by: wblock (documentation)
There were at least two places where M_NOWAIT was used without NULL check.
This change should fix NULL-dereference panic there and possibly improve
operation in other ways under memory pressure.
MFC after: 2 weeks
This makes it possible to manually force updating capacity data
after the disk got resized. Without it it might be neccessary to
reboot before FreeBSD notices updated disk size under eg VMWare.
Discussed with: imp@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6108
Although usually small, values produced by nitems() are unsigned.
By unsigning the corresponding indexes we avoid signed vs unsigned
comparisons. This may have some effect on performance, although given the
small sizes the effect will not be perceivable and it makes the code
clearer.
can handle it, and add the code to add it to the FIS that's sent to
the drive. The mvs driver is the only other ATA driver in the system,
and its hardware doesn't appear to support setting the Auxiliary
register.
Differential Revision: https://reviews.freebsd.org/D5598
transactions, but that value isn't used. It's bogusly used to report
in devstat, due to a cut and paste error from SCSI. Mark it as unused
in cam_fill_ataio. Reclaim the memory as a new ata_flags. In addition,
tag_id and init_id are completely unused, so reclaim those as 'unused'
now too. These were needlessly copied when ata was split from scsi.
This allows us, in the future, to create structures that can
communicate AUXILIARY regsiter to the SIMs, which cannot be done now.
Differential Revision: https://reviews.freebsd.org/D5598
* Samsung 843T Series SSDs (MZ7WD*)
* Samsung PM851 Series SSDs (MZ7TE*)
* Samsung PM853T Series SSDs (MZ7GE*)
as known having broken NCQ TRIM support as they appear to be based on
the same controller technology as the 840 and 850 series.
I've had at least one report of the PM853 being broken, so err on the
side of caution for the above drives. The PM863/SM863 appears to be
based on a newer controller, so give it the benefit of the doubt.
2015). Correct the M500 firmware versions. EU07 was the engineering
test version, not the release version with the fix. MU07 is the
release version. It's the only Micron firmware version to actually
work. Remove support for EU07.
This brings the blacklist into parity with the Linux blacklist as of
4.5, except for the Micron M500 MU07 entry. I personally tested the
MU07 firmware on 12 machines running 6 drives each with no corruption
in the past 6 months with Netflix production loads. Prior versions of
the M500 firmware wouldn't last more than a few days.
Sponsored by: Netflix, Inc.
periph level. When a relevant error is reported to the periph, some
amplifying information is gathered, and the error and information are fed
to devctl with the attributes / keys system=CAM, subsystem=periph. The
'type' key will be either 'error' or 'timeout', and based on this, various
other keys are also populated.
The purpose of this is to provide a concise mechanism for error reporting
that is less noisy than the system console but higher in resolution and
fidelity than simple sysctl counters. We will be using it at Netflix to
populate a structured log and database to track errors and error trends
across our world-wide population of drives.
Submitted by: imp, scottl
Approved by: kenm
MFC after: 3 days
Sponsored by: Netflix
Differential Revision: D5943
as before. The common scheduling bits have moved from inline code in
each of the CAM periph drivers into a library that implements the
default scheduling.
In addition, a number of rate-limiting and I/O preference options can
be enabled by adding CAM_IOSCHED_NETFLIX to your config file. A number
of extra stats are also maintained. CAM_IOSCHED_NETFLIX isn't on by
default because it uses a separate BIO_READ and BIO_WRITE queue, so
doesn't honor BIO_ORDERED between these two types of operations. We
already didn't honor it for BIO_DELETE, and we don't depend on
BIO_ORDERED between reads and writes anywhere in the system (it is
currently used with BIO_FLUSH in ZFS to make sure some writes are
complete before others start and as a poor-man's soft dependency in
one place in UFS where we won't be issuing READs until after the
operation completes). However, out of an abundance of caution, it
isn't enabled by default.
Plus, this also brings in NCQ TRIM support for those SSDs that support
it. A black list is also provided for known rogues that use NCQ trim
as an excuse to corrupt the drive. It was difficult to separate out
into a separate commit.
This code has run in production at Netflix for over a year now.
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D4609
_string variants on top of this. This requires a change to the function
signature of ata_res_sbuf(). Its use in the tree seems to be very limited,
and the change makes it more consistent with the rest of the API.
Reviewed by: imp, mav, kenm
Sponsored by: Netflix
Differential Revision: D5940
Improve over the solution in r297527:
Instead of attempting to initialize all the possible cases, just
move the check nearer to the case where it makes sense.
CID: 1006486
Reviewed by: ken
MFC after: 2 weeks
If there is an error different from ERESTART, there is some
chance that we may end up accessing an uninitialized value. This
doesn't seem likely/possible but initialize announce_buf[0],
just in case.
CID: 1006486
This adds Samsung PM851 to the list. It can be found in Lenovo Thinkpad
T440 for instance.
Reviewed by: Kevin Bowling <kevin.bowling@kev009.com>,
Jason Wolfe <j@nitrology.com>
Approved by: Kevin Bowling <kevin.bowling@kev009.com>,
Jason Wolfe <j@nitrology.com>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D5753
the if statement it pairs with). While not an error today, a careless
edit in the future could cause problems (though given the nature of
this specific code, the problems quite likely would be some variation
of "most direct access SCSI storage devices won't attach," which is
unlikely to go unnoticed).
PVS-Studio: V705
and a retry is scheduled.
Instead of leaving the device queue frozen, unfreeze the device queue so
that the retry can happen.
Sponsored by: Spectra Logic
MFC after: 3 days
Add #defines for ATA_WRITE_UNCORRECTABLE48 and its features. Update the
decoding in ATACAM to recognize the new values. Also improve command
decoding for a few other commands (SMART, NOP, SET_FEATURES). Bring the
decoding in ata(4) up to parity with ATACAM.
Reviewed by: mav, imp
MFC after: 1 month
Sponsored by: Panasas, Inc.
Differential Revision: https://reviews.freebsd.org/D5181
- Use SDT_PROBE<N>() instead of SDT_PROBE(). This has no functional effect
at the moment, but will be needed for some future changes.
- Don't hardcode the module component of the probe identifier. This is
set automatically by the SDT framework.
MFC after: 1 week
r259397 (it contained the CAM_EXTLUN_VALID bit) and I added the
same type name with a different set of values back in r291716.
The old ccb_xflags enumeration still exists in FreeBSD stable/10.
Shift all of the new values by one bit to avoid compatibility
issues when merged to stable/10.
MFC after: 3 days
Sponsored by: Spectra Logic
camdd(8) utility.
CCBs may be queued to the driver via the new CAMIOQUEUE ioctl, and
completed CCBs may be retrieved via the CAMIOGET ioctl. User
processes can use poll(2) or kevent(2) to get notification when
I/O has completed.
While the existing CAMIOCOMMAND blocking ioctl interface only
supports user virtual data pointers in a CCB (generally only
one per CCB), the new CAMIOQUEUE ioctl supports user virtual and
physical address pointers, as well as user virtual and physical
scatter/gather lists. This allows user applications to have more
flexibility in their data handling operations.
Kernel memory for data transferred via the queued interface is
allocated from the zone allocator in MAXPHYS sized chunks, and user
data is copied in and out. This is likely faster than the
vmapbuf()/vunmapbuf() method used by the CAMIOCOMMAND ioctl in
configurations with many processors (there are more TLB shootdowns
caused by the mapping/unmapping operation) but may not be as fast
as running with unmapped I/O.
The new memory handling model for user requests also allows
applications to send CCBs with request sizes that are larger than
MAXPHYS. The pass(4) driver now limits queued requests to the I/O
size listed by the SIM driver in the maxio field in the Path
Inquiry (XPT_PATH_INQ) CCB.
There are some things things would be good to add:
1. Come up with a way to do unmapped I/O on multiple buffers.
Currently the unmapped I/O interface operates on a struct bio,
which includes only one address and length. It would be nice
to be able to send an unmapped scatter/gather list down to
busdma. This would allow eliminating the copy we currently do
for data.
2. Add an ioctl to list currently outstanding CCBs in the various
queues.
3. Add an ioctl to cancel a request, or use the XPT_ABORT CCB to do
that.
4. Test physical address support. Virtual pointers and scatter
gather lists have been tested, but I have not yet tested
physical addresses or scatter/gather lists.
5. Investigate multiple queue support. At the moment there is one
queue of commands per pass(4) device. If multiple processes
open the device, they will submit I/O into the same queue and
get events for the same completions. This is probably the right
model for most applications, but it is something that could be
changed later on.
Also, add a new utility, camdd(8) that uses the asynchronous pass(4)
driver interface.
This utility is intended to be a basic data transfer/copy utility,
a simple benchmark utility, and an example of how to use the
asynchronous pass(4) interface.
It can copy data to and from pass(4) devices using any target queue
depth, starting offset and blocksize for the input and ouptut devices.
It currently only supports SCSI devices, but could be easily extended
to support ATA devices.
It can also copy data to and from regular files, block devices, tape
devices, pipes, stdin, and stdout. It does not support queueing
multiple commands to any of those targets, since it uses the standard
read(2)/write(2)/writev(2)/readv(2) system calls.
The I/O is done by two threads, one for the reader and one for the
writer. The reader thread sends completed read requests to the
writer thread in strictly sequential order, even if they complete
out of order. That could be modified later on for random I/O patterns
or slightly out of order I/O.
camdd(8) uses kqueue(2)/kevent(2) to get I/O completion events from
the pass(4) driver and also to send request notifications internally.
For pass(4) devcies, camdd(8) uses a single buffer (CAM_DATA_VADDR)
per CAM CCB on the reading side, and a scatter/gather list
(CAM_DATA_SG) on the writing side. In addition to testing both
interfaces, this makes any potential reblocking of I/O easier. No
data is copied between the reader and the writer, but rather the
reader's buffers are split into multiple I/O requests or combined
into a single I/O request depending on the input and output blocksize.
For the file I/O path, camdd(8) also uses a single buffer (read(2),
write(2), pread(2) or pwrite(2)) on reads, and a scatter/gather list
(readv(2), writev(2), preadv(2), pwritev(2)) on writes.
Things that would be nice to do for camdd(8) eventually:
1. Add support for I/O pattern generation. Patterns like all
zeros, all ones, LBA-based patterns, random patterns, etc. Right
Now you can always use /dev/zero, /dev/random, etc.
2. Add support for a "sink" mode, so we do only reads with no
writes. Right now, you can use /dev/null.
3. Add support for automatic queue depth probing, so that we can
figure out the right queue depth on the input and output side
for maximum throughput. At the moment it defaults to 6.
4. Add support for SATA device passthrough I/O.
5. Add support for random LBAs and/or lengths on the input and
output sides.
6. Track average per-I/O latency and busy time. The busy time
and latency could also feed in to the automatic queue depth
determination.
sys/cam/scsi/scsi_pass.h:
Define two new ioctls, CAMIOQUEUE and CAMIOGET, that queue
and fetch asynchronous CAM CCBs respectively.
Although these ioctls do not have a declared argument, they
both take a union ccb pointer. If we declare a size here,
the ioctl code in sys/kern/sys_generic.c will malloc and free
a buffer for either the CCB or the CCB pointer (depending on
how it is declared). Since we have to keep a copy of the
CCB (which is fairly large) anyway, having the ioctl malloc
and free a CCB for each call is wasteful.
sys/cam/scsi/scsi_pass.c:
Add asynchronous CCB support.
Add two new ioctls, CAMIOQUEUE and CAMIOGET.
CAMIOQUEUE adds a CCB to the incoming queue. The CCB is
executed immediately (and moved to the active queue) if it
is an immediate CCB, but otherwise it will be executed
in passstart() when a CCB is available from the transport layer.
When CCBs are completed (because they are immediate or
passdone() if they are queued), they are put on the done
queue.
If we get the final close on the device before all pending
I/O is complete, all active I/O is moved to the abandoned
queue and we increment the peripheral reference count so
that the peripheral driver instance doesn't go away before
all pending I/O is done.
The new passcreatezone() function is called on the first
call to the CAMIOQUEUE ioctl on a given device to allocate
the UMA zones for I/O requests and S/G list buffers. This
may be good to move off to a taskqueue at some point.
The new passmemsetup() function allocates memory and
scatter/gather lists to hold the user's data, and copies
in any data that needs to be written. For virtual pointers
(CAM_DATA_VADDR), the kernel buffer is malloced from the
new pass(4) driver malloc bucket. For virtual
scatter/gather lists (CAM_DATA_SG), buffers are allocated
from a new per-pass(9) UMA zone in MAXPHYS-sized chunks.
Physical pointers are passed in unchanged. We have support
for up to 16 scatter/gather segments (for the user and
kernel S/G lists) in the default struct pass_io_req, so
requests with longer S/G lists require an extra kernel malloc.
The new passcopysglist() function copies a user scatter/gather
list to a kernel scatter/gather list. The number of elements
in each list may be different, but (obviously) the amount of data
stored has to be identical.
The new passmemdone() function copies data out for the
CAM_DATA_VADDR and CAM_DATA_SG cases.
The new passiocleanup() function restores data pointers in
user CCBs and frees memory.
Add new functions to support kqueue(2)/kevent(2):
passreadfilt() tells kevent whether or not the done
queue is empty.
passkqfilter() adds a knote to our list.
passreadfiltdetach() removes a knote from our list.
Add a new function, passpoll(), for poll(2)/select(2)
to use.
Add devstat(9) support for the queued CCB path.
sys/cam/ata/ata_da.c:
Add support for the BIO_VLIST bio type.
sys/cam/cam_ccb.h:
Add a new enumeration for the xflags field in the CCB header.
(This doesn't change the CCB header, just adds an enumeration to
use.)
sys/cam/cam_xpt.c:
Add a new function, xpt_setup_ccb_flags(), that allows specifying
CCB flags.
sys/cam/cam_xpt.h:
Add a prototype for xpt_setup_ccb_flags().
sys/cam/scsi/scsi_da.c:
Add support for BIO_VLIST.
sys/dev/md/md.c:
Add BIO_VLIST support to md(4).
sys/geom/geom_disk.c:
Add BIO_VLIST support to the GEOM disk class. Re-factor the I/O size
limiting code in g_disk_start() a bit.
sys/kern/subr_bus_dma.c:
Change _bus_dmamap_load_vlist() to take a starting offset and
length.
Add a new function, _bus_dmamap_load_pages(), that will load a list
of physical pages starting at an offset.
Update _bus_dmamap_load_bio() to allow loading BIO_VLIST bios.
Allow unmapped I/O to start at an offset.
sys/kern/subr_uio.c:
Add two new functions, physcopyin_vlist() and physcopyout_vlist().
sys/pc98/include/bus.h:
Guard kernel-only parts of the pc98 machine/bus.h header with
#ifdef _KERNEL.
This allows userland programs to include <machine/bus.h> to get the
definition of bus_addr_t and bus_size_t.
sys/sys/bio.h:
Add a new bio flag, BIO_VLIST.
sys/sys/uio.h:
Add prototypes for physcopyin_vlist() and physcopyout_vlist().
share/man/man4/pass.4:
Document the CAMIOQUEUE and CAMIOGET ioctls.
usr.sbin/Makefile:
Add camdd.
usr.sbin/camdd/Makefile:
Add a makefile for camdd(8).
usr.sbin/camdd/camdd.8:
Man page for camdd(8).
usr.sbin/camdd/camdd.c:
The new camdd(8) utility.
Sponsored by: Spectra Logic
MFC after: 1 week
sesX device number may change between reboots, so to properly identify
the instance we need more data. Name and ID reported here may mach ones
reported by SCSI device, but that is not really required by specs.
MFC after: 1 week
Sponsored by: iXsystems, Inc.
- Introduce "ha_shared" port option, which being set to "on" moves the
port into separate port group, shared between HA nodes. This allows to
better handle cases when iSCSI portals are bound to CARP address that can
dynamically move between nodes. Some initiators (at least VMware) don't
detect that after iSCSI reconnect they've attached to different SCSI port
from different port group, that totally breakes ALUA status parsing.
In theory, I believe, it should be enough to have different iSCSI portal
group tags on different nodes to make initiators detect this condition,
but it seems like VMware ignores those values, and even full LUN retaste
forced by UA does not help.
- Make CTL report up to three port groups: 1 -- non-HA mode or ports
with "ha_shared" option set, 2 -- HA node 1, 3 -- HA node 2.
- Report Transitioning state for all port groups when HA interlink is
connected, but neither of nodes is primary for the LUN.
MFC after: 2 weeks
This change allows to decode respective functions in isp(4) in target mode
and pass them through CAM to CTL. Unfortunately neither CAM nor isp(4)
support returning response info for those task management functions now.
On the other side I just have no initiator to test this functionality.
This allows to set delete method via tunable, before device capabilities
are known. Also allow ZERO method for devices not reporting LBP, if user
explicitly requests it -- it may be useful if storage supports compression
and WRITE SAME, but does not support UNMAP.
MFC after: 2 weeks
I am not sure what for it was done. Now open routine should automatically
fall back to read-only if open for writing is impossible. In such case
attempt to upgrade to write sounds strange.
MFC after: 1 week
