kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals
kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)
based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe
This merge changes the device switch tables from static array to
dynamically generated by config(8).
- All device switches is defined as a constant structure in device drivers.
- The new grammer ``device-major'' is introduced to ``files''.
device-major <prefix> char <num> [block <num>] [<rules>]
- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.
- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.
- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.
- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.
- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.
inserted into comments. I really think that more testing was required,
but Christos was eager.
+ Add in tape block/file position reporting support.
+ Change the prevent/allow ejection code so that if the device
is close the tape can be ejected. This allows robots to eject
the tape even if the tape isn't at BOT.
+ Don't do a null filemark write if we're reading block position. This
was such an abysmal performance killer that it had to go. Assume
that the tape will DTRT and tell you what the tape position really is
including any buffered data. You are depending on the tape to do
the right thing to report position at all, so the risk factors don't
increase appreciably here. BTW- we only do this for logical block
position. For 'hardware' block position, we still flush.
+ Some substantial tweaking in st_interpret_sense. This essentially duplicates
the FreeBSD driver's exception handling code. This is to try and correctly
handle EOM cases. I'm not sure that this is now correct with respect to
the ENABLE EARLY WARNING code- I hadn't gotten around to validating that.
Add in full 32 bit residuals- this can then be available to an update
MTIOCGET in the future.
+ Make sure we handle SKEY_VOLUME_OVERFLOW correctly.
st0 at atapibus0 drive 1: <Seagate STT8000A, , 5.51> type 1 sequential
removable
Major changes may still happen in order to properly support other ATAPI
tape drives.
This is a completely rewritten scsipi_xfer execution engine, and the
associated changes to HBA drivers. Overview of changes & features:
- All xfers are queued in the mid-layer, rather than doing so in an
ad-hoc fashion in individual adapter drivers.
- Adapter/channel resource management in the mid-layer, avoids even trying
to start running an xfer if the adapter/channel doesn't have the resources.
- Better communication between the mid-layer and the adapters.
- Asynchronous event notification mechanism from adapter to mid-layer and
peripherals.
- Better peripheral queue management: freeze/thaw, sorted requeueing during
recovery, etc.
- Clean separation of peripherals, adapters, and adapter channels (no more
scsipi_link).
- Kernel thread for each scsipi_channel makes error recovery much easier
(no more dealing with interrupt context when recovering from an error).
- Mid-layer support for tagged queueing: commands can have the tag type
set explicitly, tag IDs are allocated in the mid-layer (thus eliminating
the need to use buggy tag ID allocation schemes in many adapter drivers).
- support for QUEUE FULL and CHECK CONDITION status in mid-layer; the command
will be requeued, or a REQUEST SENSE will be sent as appropriate.
Just before the merge syssrc has been tagged with thorpej_scsipi_beforemerge
we have it.
* st_unmount(): reset density to the device default. This prevents using
stale density values after changing to a medium with different density.
Section 9.3.3 of the SCSI specs states that a device shall return the
density value specified in the last succesfull MODE SELECT after an
unload operation, in case it is not able to automatically determine
the density of the new medium.
after all, probing the device for acceptable parameters.
* In st_loadquirks(), copy mode-specific quirks from the quirk table
to `st_softc'; otherwise all such quirks save ST_Q_FORCE_BLKSIZE are ignored.
This is an attempt to allow people to change the default configuration
to try harder at 'mounting' a tape. This allows you to specify, in
seconds, the amount of time a non-control unit open will retry
(once per second) the scsipi_test_unit_ready when it tries to mount
the tape. It also turns off the over-verbose error reporting at
this time unless SCSIDEBUG is set.
The reason this is not enabled as a default is that it's a large change
of behaviour. I find it useful to 'try harder' at mounting a tape in
the tape driver, particularly when loaded via a media changer device
rather than specifying the delays in the backup program.
- `flags' is now gone, replaced with `xs_control' and `xs_status'.
- Massive cleanup of the control flags. Now we explicitly say that
a job is to complete asynchronously, rather than relying on side-effects,
and use a new flag to now that device discovery is being performed.
- Do SCSI device discovery interrupt-driven.
Anyway, just because a drive doesn't support the LOAD (to BOT) command does
not mean that the drive doesn't support the UNLOAD command. Also note and
print errors in rewinds and unloads (and errors in writing closing filemarks
for same).
