History log of /freebsd-10-stable/sys/cam/ata/ata_da.c
Revision Date Author Comments
# 308081 29-Oct-2016 mav

MFC r307507, r307509, r307515:
Consider device as clean even if SYNCHRONIZE CACHE failed.

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.


# 297711 08-Apr-2016 sbruno

Revert svn 297681 as it has been deprecated by svn 297575.

Submitted by: Tomoaki AOKI <junchoon@dec.dakura.ne.jp>


# 297681 07-Apr-2016 sbruno

MFC r297237

Add 4k enabled cam quirks for Samsung SM863 Series SSDs


# 297575 05-Apr-2016 dumbbell

CAM: Generalize 4k quirk to all Samsung MZ7* SSDs

This adds Samsung PM851 to the list. It can be found in Lenovo Thinkpad
T440 for instance.

MFC of: r297370
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>
Differential Revision: https://reviews.freebsd.org/D5753


# 292348 16-Dec-2015 ken

MFC r291716, r291724, r291741, r291742

In addition to those revisions, add this change to a file that is not in
head:

sys/ia64/include/bus.h:
Guard kernel-only parts of the ia64 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.

------------------------------------------------------------------------
r291716 | ken | 2015-12-03 15:54:55 -0500 (Thu, 03 Dec 2015) | 257 lines

Add asynchronous command support to the pass(4) driver, and the new
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

------------------------------------------------------------------------
r291724 | ken | 2015-12-03 17:07:01 -0500 (Thu, 03 Dec 2015) | 6 lines

Fix typos in the camdd(8) usage() function output caused by an error in
my diff filter script.

Sponsored by: Spectra Logic

------------------------------------------------------------------------
r291741 | ken | 2015-12-03 22:38:35 -0500 (Thu, 03 Dec 2015) | 10 lines

Fix g_disk_vlist_limit() to work properly with deletes.

Add a new bp argument to g_disk_maxsegs(), and add a new function,
g_disk_maxsize() tha will properly determine the maximum I/O size for a
delete or non-delete bio.

Submitted by: will
Sponsored by: Spectra Logic

------------------------------------------------------------------------
------------------------------------------------------------------------
r291742 | ken | 2015-12-03 22:44:12 -0500 (Thu, 03 Dec 2015) | 5 lines

Fix a style issue in g_disk_limit().

Noticed by: bdrewery

------------------------------------------------------------------------

Sponsored by: Spectra Logic


# 291497 30-Nov-2015 mav

MFC r289138: Remove legacy CHS geometry from dmesg and unify capacity outputs.


# 290768 13-Nov-2015 mav

MFC r290462: Removed unused malloc types.

Submitted by: Dmitry Luhtionov <dmitryluhtionov@gmail.com>


# 288701 05-Oct-2015 mav

MFC r280845 (by eadler):
Add some additional quirks for various Western Digital Caviar MHDDs


# 288694 05-Oct-2015 mav

MFC r277101 (by imp):
Explain a bit of tricky code dealing with trims and how it prevents
starvation. These side effects aren't obvious without extremely
careful study, and are important to do just so.


# 287286 29-Aug-2015 mav

MFC r287025: Remove some code duplication by using biofinish().


# 286800 15-Aug-2015 mav

MFC r286447:
Don't panic if disk lost TRIM support due to switching to PIO mode.


# 274260 07-Nov-2014 gnn

MFC: 273279

Add new quirks for the latest Samsung SSD, model 850.

Submitted by: sbruno


# 273814 29-Oct-2014 smh

MFC: r273704

Fix CF ERASE breakage caused by 268205.

Sponsored by: Multiplay


# 271238 07-Sep-2014 smh

MFC r256956:
Improve ZFS N-way mirror read performance by using load and locality
information.

MFC r260713:
Fix ZFS mirror code for handling multiple DVA's

Also make the addition of the d_rotation_rate binary compatible. This allows
storage drivers compiled for 10.0 to work by preserving the ABI for disks.

Approved by: re (gjb)
Sponsored by: Multiplay


# 270313 21-Aug-2014 smh

MFC r269974 - Added 4K quirks for Corsair Force GT and Samsung 840 SSDs

Sponsored by: Multiplay


# 268816 17-Jul-2014 imp

MFC:

>r267118 | imp | 2014-06-05 11:13:42 -0600 (Thu, 05 Jun 2014) | 9 lines
>The code that combines adjacent ranges for BIO_DELETEs to optimize
>trims to the device assumes the list is sorted. Don't apply the
>optimization of not sorting the queue when we have SSDs to the
>delete_queue, since it causes more discard traffic to the drive. While
>one could argue that the higher levels should coalesce the trims,
>that's not done today, so some optimization at this level is needed.
>CR: https://phabric.freebsd.org/D142


# 268815 17-Jul-2014 imp

MFC:

>r268205 | imp | 2014-07-02 23:22:13 -0600 (Wed, 02 Jul 2014) | 9 lines
>Rework the BIO_DELETE code slightly. Always queue the BIO_DELETE
>requests on the trim_queue, even for the CFA ERASE. This allows us, in
>the future, to collapse adjacent requests. Since CFA ERASE is only for
>CF cards, and it is so restrictive in what it can do, the collapse
>code is not presently here. This also brings the ada driver more in
>line with the da driver's treatment of BIO_DELETEs.


# 260475 09-Jan-2014 mav

MFC r256547 (by smh):
Added 4K quirks for Corsair Neutron GTX SSD's


# 260387 06-Jan-2014 scottl

MFC Alexander Motin's direct dispatch, multi-queue, and finer-grained
locking support for CAM

r256826:
Fix several target mode SIMs to not blindly clear ccb_h.flags field of
ATIO CCBs. Not all CCB flags there belong to them.

r256836:
Remove hard limit on number of BIOs handled with one ATA TRIM request.

r256843:
Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

r256888:
Unconditionally acquire periph reference on CCB allocation failure.

r256895:
Fix memory and references leak due to unfreed path.

r256960:
Move CAM_UNQUEUED_INDEX setting to the last moment and under the periph lock.
This fixes race condition with cam_periph_ccbwait(), causing use-after-free.

r256975:
Minor (mostly cosmetical) addition to r256960.

r257054:
Some microoptimizations for da and ada drivers:
- Replace ordered_tag_count counter with single flag;
- From da remove outstanding_cmds counter, duplicating pending_ccbs list;
- From da_softc remove unused links field.

r257482:
Fix lock recursion, triggered by `smartctl -a /dev/adaX`.

r257501:
Make getenv_*() functions and respectively TUNABLE_*_FETCH() macros not
allocate memory and so not require sleepable environment. getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.

r257914:
Some CAM locks polishing:
- Fix LOR and possible lock recursion when handling high-power commands.
Introduce new lock to protect left power quota and list of frozen devices.
- Correct locking around xpt periph creation.
- Remove seems never used XPT_FLAG_OPEN xpt periph flag.

Again, Netflix assisted with testing the merge, but all of the credit goes
to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems


# 260385 06-Jan-2014 scottl

MFC Alexander Motin's GEOM direct dispatch work:

r256603:
Introduce new function devstat_end_transaction_bio_bt(), adding new argument
to specify present time. Use this function to move binuptime() out of lock,
substantially reducing lock congestion when slow timecounter is used.

r256606:
Move g_io_deliver() out of the lock, as required for direct dispatch.
Move g_destroy_bio() out too to reduce lock scope even more.

r256607:
Fix passing uninitialized bio_resid argument to g_trace().

r256610:
Add unmapped I/O support to GEOM RAID.

r256830:
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).

r256880:
Merge GEOM direct dispatch changes from the projects/camlock branch.

When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.

r259247:
Fix bug introduced at r256607. We have to recalculate bp_resid here since
sizes of original and completed requests may differ due to end of media.

Testing of the stable/10 merge was done by Netflix, but all of the credit
goes to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems


# 257049 24-Oct-2013 mav

MFC r256552:
Unify periph invalidation and destruction reporting.
Print message containing device model and serial number on invalidation.

Approved by: re (hrs)


# 288701 05-Oct-2015 mav

MFC r280845 (by eadler):
Add some additional quirks for various Western Digital Caviar MHDDs


# 288694 05-Oct-2015 mav

MFC r277101 (by imp):
Explain a bit of tricky code dealing with trims and how it prevents
starvation. These side effects aren't obvious without extremely
careful study, and are important to do just so.


# 287286 29-Aug-2015 mav

MFC r287025: Remove some code duplication by using biofinish().


# 286800 15-Aug-2015 mav

MFC r286447:
Don't panic if disk lost TRIM support due to switching to PIO mode.


# 274260 07-Nov-2014 gnn

MFC: 273279

Add new quirks for the latest Samsung SSD, model 850.

Submitted by: sbruno


# 273814 29-Oct-2014 smh

MFC: r273704

Fix CF ERASE breakage caused by 268205.

Sponsored by: Multiplay


# 271238 07-Sep-2014 smh

MFC r256956:
Improve ZFS N-way mirror read performance by using load and locality
information.

MFC r260713:
Fix ZFS mirror code for handling multiple DVA's

Also make the addition of the d_rotation_rate binary compatible. This allows
storage drivers compiled for 10.0 to work by preserving the ABI for disks.

Approved by: re (gjb)
Sponsored by: Multiplay


# 270313 21-Aug-2014 smh

MFC r269974 - Added 4K quirks for Corsair Force GT and Samsung 840 SSDs

Sponsored by: Multiplay


# 268816 17-Jul-2014 imp

MFC:

>r267118 | imp | 2014-06-05 11:13:42 -0600 (Thu, 05 Jun 2014) | 9 lines
>The code that combines adjacent ranges for BIO_DELETEs to optimize
>trims to the device assumes the list is sorted. Don't apply the
>optimization of not sorting the queue when we have SSDs to the
>delete_queue, since it causes more discard traffic to the drive. While
>one could argue that the higher levels should coalesce the trims,
>that's not done today, so some optimization at this level is needed.
>CR: https://phabric.freebsd.org/D142


# 268815 17-Jul-2014 imp

MFC:

>r268205 | imp | 2014-07-02 23:22:13 -0600 (Wed, 02 Jul 2014) | 9 lines
>Rework the BIO_DELETE code slightly. Always queue the BIO_DELETE
>requests on the trim_queue, even for the CFA ERASE. This allows us, in
>the future, to collapse adjacent requests. Since CFA ERASE is only for
>CF cards, and it is so restrictive in what it can do, the collapse
>code is not presently here. This also brings the ada driver more in
>line with the da driver's treatment of BIO_DELETEs.


# 260475 09-Jan-2014 mav

MFC r256547 (by smh):
Added 4K quirks for Corsair Neutron GTX SSD's


# 260387 06-Jan-2014 scottl

MFC Alexander Motin's direct dispatch, multi-queue, and finer-grained
locking support for CAM

r256826:
Fix several target mode SIMs to not blindly clear ccb_h.flags field of
ATIO CCBs. Not all CCB flags there belong to them.

r256836:
Remove hard limit on number of BIOs handled with one ATA TRIM request.

r256843:
Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

r256888:
Unconditionally acquire periph reference on CCB allocation failure.

r256895:
Fix memory and references leak due to unfreed path.

r256960:
Move CAM_UNQUEUED_INDEX setting to the last moment and under the periph lock.
This fixes race condition with cam_periph_ccbwait(), causing use-after-free.

r256975:
Minor (mostly cosmetical) addition to r256960.

r257054:
Some microoptimizations for da and ada drivers:
- Replace ordered_tag_count counter with single flag;
- From da remove outstanding_cmds counter, duplicating pending_ccbs list;
- From da_softc remove unused links field.

r257482:
Fix lock recursion, triggered by `smartctl -a /dev/adaX`.

r257501:
Make getenv_*() functions and respectively TUNABLE_*_FETCH() macros not
allocate memory and so not require sleepable environment. getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.

r257914:
Some CAM locks polishing:
- Fix LOR and possible lock recursion when handling high-power commands.
Introduce new lock to protect left power quota and list of frozen devices.
- Correct locking around xpt periph creation.
- Remove seems never used XPT_FLAG_OPEN xpt periph flag.

Again, Netflix assisted with testing the merge, but all of the credit goes
to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems


# 260385 06-Jan-2014 scottl

MFC Alexander Motin's GEOM direct dispatch work:

r256603:
Introduce new function devstat_end_transaction_bio_bt(), adding new argument
to specify present time. Use this function to move binuptime() out of lock,
substantially reducing lock congestion when slow timecounter is used.

r256606:
Move g_io_deliver() out of the lock, as required for direct dispatch.
Move g_destroy_bio() out too to reduce lock scope even more.

r256607:
Fix passing uninitialized bio_resid argument to g_trace().

r256610:
Add unmapped I/O support to GEOM RAID.

r256830:
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).

r256880:
Merge GEOM direct dispatch changes from the projects/camlock branch.

When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.

r259247:
Fix bug introduced at r256607. We have to recalculate bp_resid here since
sizes of original and completed requests may differ due to end of media.

Testing of the stable/10 merge was done by Netflix, but all of the credit
goes to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems


# 257049 24-Oct-2013 mav

MFC r256552:
Unify periph invalidation and destruction reporting.
Print message containing device model and serial number on invalidation.

Approved by: re (hrs)