Add a flag to dk_dump for virtual disk devices.

If a disk is backed by a physical medium other than itself, such as
cgd(4), then it passes DK_DUMP_RECURSIVE to disable the recursion
detection for dk_dump.

If, however, a device represents a physical medium on its own, such
as wd(4), then it passes 0 instead.

With this, I can now dump to dk on cgd on dk on wd.

Drop now unused dk_lookup function.

Protect against multiple inclusion.

do not attach nvme ld as randomness source - device is too fast, it overwhelms
the rndq handling code, and causes system crashes; gathering rnd there is
also bad idea from performance perspective

branches: 1.28.6;
Fix race condition in dksubr, where a dk_start from another thread
or interrupt was ignored while the queue was processed.

Bump kernel revision for changed dk_softc.

revert 1.90 of dksubr.c and change sc_deferred back to simple pointer; the
global sc_busy flag guards against race so it's not actually necessary, and
this place is unlikely to need to be parallelized in near future

discussed with mlelstv@

change sc_deferred to TAILQ (reusing bufq b_actq) to avoid possible buf leak
for MPSAFE drivers

branches: 1.25.2;
support deferral of diskstart to a separate thread.

move entropy gathering into dksubr.

Prevent race condition where two threads can defer a buffer.

Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.

Two changes to the dksubr interface.

- d_diskstart callback now processes a single buffer only.
The new wrapper function dk_start processes the queue,
performs other buffer handling and also provides locking
for the the data structures.

- add d_discard callback to handle device specific function inside
the new dk_discard helper function.

Replace splbio with mutex to protect queue and disk structure.
Refactor common code in dk_strategy and dk_discard into dk_translate.

Adjust and simplify ld(4), cgd(4) and xbd(4) drivers accordingly.

ld(4) now becomes MP_SAFE.

Bump kernel version.

Merge dk_intf and dkdriver interfaces.
Merge common disk driver functionality in ld.c with dksubr.c.
Adjust the two previous users of dk_intf (cgd and xbd) to
the changes.

bump kernel version to 7.99.14

branches: 1.19.4;
As proposed in
https://mail-index.netbsd.org/tech-kern/2014/05/21/msg017098.html
remove dk_start() and dk_iodone() from dksubr.c and move the related code
to the underlying driver.
This increase complexity only marginally: the underlying drivers have
to do the while() loop themselves, but this can now be done properly with
bufq_peek()/bufq_get(), removing the buffer from the queue at the right time.
This handle both the recursion and reordering issues (the reordering
issue is described here:
https://mail-index.netbsd.org/tech-kern/2014/05/19/msg017089.html
the recursion isssue is PR #25240).

Difference with the patch posted to tech-kern@: KASSERT() that the
buffer we remove with bufq_get() is the same as the one we bufq_peek()'d
just before.
Hopefully this will allow more disk drivers to use dksubr.c

branches: 1.18.6;
eliminate dk_geom

phase 1 of disk geometry cleanup:
- centralize the geometry -> plist code so that we don't have
n useless copies of it.

branches: 1.16.2;
Modify dksubr.c to add a function that sets the disk properties in
the drvctl framework. And call this new functionality from cgd(4),
the consumer of dksubr.c. We do this to allow gpt(8) to be able
to label cgd(4) disks. We also add in some DIOCGSECTORSIZE logic
and we ensure that the WEDGE ioctls are not called on either
uninitialised disks or disks which have not been opened for write
access.

branches: 1.15.8; 1.15.12; 1.15.14;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

branches: 1.14.4;
Put the entire expression that DK_BUSY() evaluates to in parentheses
for safety.

Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Allow to pass device_xname() to dk_sc_init() without build error
OK joerg

branches: 1.11.28;
Change dk_lookup() to accept an additional argument of the type enum uio_seg
that tells whether the given path is in user space or kernel space, so it
can tell NDINIT().

While the raidframe calls were ok, both ccd(4) and cgd(4) were passing
pointers to user space data, which leads to strange error on i386, as
reported by Jukka Salmi on current-users.

The issue has been there since last august, I'm actually a bit surprised
that no one in the meantime has used ccd(4) or cgd(4) on an arch where it
would have simply faulted.

branches: 1.10.2; 1.10.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.9.24; 1.9.26; 1.9.30;
merge ktrace-lwp.

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

add wedge support to xbd and cgd.

branches: 1.6.2;
constification fallout

Make this build with "-Wcast-qual -Wshadow".

Modified the dksubr routines to:

o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.

Modified cgd to:

o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.

We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.

Addresses PR: kern/24715
(at least according to the submitter.)

branches: 1.3.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

branches: 1.1.2;
A slight abstraction for disks. This is mainly [right now] in
support of the cryptographic disk which I'll be checking in shortly.

Drop now unused dk_lookup function.

Protect against multiple inclusion.

do not attach nvme ld as randomness source - device is too fast, it overwhelms
the rndq handling code, and causes system crashes; gathering rnd there is
also bad idea from performance perspective

branches: 1.28.6;
Fix race condition in dksubr, where a dk_start from another thread
or interrupt was ignored while the queue was processed.

Bump kernel revision for changed dk_softc.

revert 1.90 of dksubr.c and change sc_deferred back to simple pointer; the
global sc_busy flag guards against race so it's not actually necessary, and
this place is unlikely to need to be parallelized in near future

discussed with mlelstv@

change sc_deferred to TAILQ (reusing bufq b_actq) to avoid possible buf leak
for MPSAFE drivers

branches: 1.25.2;
support deferral of diskstart to a separate thread.

move entropy gathering into dksubr.

Prevent race condition where two threads can defer a buffer.

Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.

Two changes to the dksubr interface.

- d_diskstart callback now processes a single buffer only.
The new wrapper function dk_start processes the queue,
performs other buffer handling and also provides locking
for the the data structures.

- add d_discard callback to handle device specific function inside
the new dk_discard helper function.

Replace splbio with mutex to protect queue and disk structure.
Refactor common code in dk_strategy and dk_discard into dk_translate.

Adjust and simplify ld(4), cgd(4) and xbd(4) drivers accordingly.

ld(4) now becomes MP_SAFE.

Bump kernel version.

Merge dk_intf and dkdriver interfaces.
Merge common disk driver functionality in ld.c with dksubr.c.
Adjust the two previous users of dk_intf (cgd and xbd) to
the changes.

bump kernel version to 7.99.14

branches: 1.19.4;
As proposed in
https://mail-index.netbsd.org/tech-kern/2014/05/21/msg017098.html
remove dk_start() and dk_iodone() from dksubr.c and move the related code
to the underlying driver.
This increase complexity only marginally: the underlying drivers have
to do the while() loop themselves, but this can now be done properly with
bufq_peek()/bufq_get(), removing the buffer from the queue at the right time.
This handle both the recursion and reordering issues (the reordering
issue is described here:
https://mail-index.netbsd.org/tech-kern/2014/05/19/msg017089.html
the recursion isssue is PR #25240).

Difference with the patch posted to tech-kern@: KASSERT() that the
buffer we remove with bufq_get() is the same as the one we bufq_peek()'d
just before.
Hopefully this will allow more disk drivers to use dksubr.c

branches: 1.18.6;
eliminate dk_geom

phase 1 of disk geometry cleanup:
- centralize the geometry -> plist code so that we don't have
n useless copies of it.

branches: 1.16.2;
Modify dksubr.c to add a function that sets the disk properties in
the drvctl framework. And call this new functionality from cgd(4),
the consumer of dksubr.c. We do this to allow gpt(8) to be able
to label cgd(4) disks. We also add in some DIOCGSECTORSIZE logic
and we ensure that the WEDGE ioctls are not called on either
uninitialised disks or disks which have not been opened for write
access.

branches: 1.15.8; 1.15.12; 1.15.14;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

branches: 1.14.4;
Put the entire expression that DK_BUSY() evaluates to in parentheses
for safety.

Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Allow to pass device_xname() to dk_sc_init() without build error
OK joerg

branches: 1.11.28;
Change dk_lookup() to accept an additional argument of the type enum uio_seg
that tells whether the given path is in user space or kernel space, so it
can tell NDINIT().

While the raidframe calls were ok, both ccd(4) and cgd(4) were passing
pointers to user space data, which leads to strange error on i386, as
reported by Jukka Salmi on current-users.

The issue has been there since last august, I'm actually a bit surprised
that no one in the meantime has used ccd(4) or cgd(4) on an arch where it
would have simply faulted.

branches: 1.10.2; 1.10.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.9.24; 1.9.26; 1.9.30;
merge ktrace-lwp.

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

add wedge support to xbd and cgd.

branches: 1.6.2;
constification fallout

Make this build with "-Wcast-qual -Wshadow".

Modified the dksubr routines to:

o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.

Modified cgd to:

o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.

We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.

Addresses PR: kern/24715
(at least according to the submitter.)

branches: 1.3.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

branches: 1.1.2;
A slight abstraction for disks. This is mainly [right now] in
support of the cryptographic disk which I'll be checking in shortly.

Protect against multiple inclusion.

do not attach nvme ld as randomness source - device is too fast, it overwhelms
the rndq handling code, and causes system crashes; gathering rnd there is
also bad idea from performance perspective

branches: 1.28.6;
Fix race condition in dksubr, where a dk_start from another thread
or interrupt was ignored while the queue was processed.

Bump kernel revision for changed dk_softc.

revert 1.90 of dksubr.c and change sc_deferred back to simple pointer; the
global sc_busy flag guards against race so it's not actually necessary, and
this place is unlikely to need to be parallelized in near future

discussed with mlelstv@

change sc_deferred to TAILQ (reusing bufq b_actq) to avoid possible buf leak
for MPSAFE drivers

branches: 1.25.2;
support deferral of diskstart to a separate thread.

move entropy gathering into dksubr.

Prevent race condition where two threads can defer a buffer.

Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.

Two changes to the dksubr interface.

- d_diskstart callback now processes a single buffer only.
The new wrapper function dk_start processes the queue,
performs other buffer handling and also provides locking
for the the data structures.

- add d_discard callback to handle device specific function inside
the new dk_discard helper function.

Replace splbio with mutex to protect queue and disk structure.
Refactor common code in dk_strategy and dk_discard into dk_translate.

Adjust and simplify ld(4), cgd(4) and xbd(4) drivers accordingly.

ld(4) now becomes MP_SAFE.

Bump kernel version.

Merge dk_intf and dkdriver interfaces.
Merge common disk driver functionality in ld.c with dksubr.c.
Adjust the two previous users of dk_intf (cgd and xbd) to
the changes.

bump kernel version to 7.99.14

branches: 1.19.4;
As proposed in
https://mail-index.netbsd.org/tech-kern/2014/05/21/msg017098.html
remove dk_start() and dk_iodone() from dksubr.c and move the related code
to the underlying driver.
This increase complexity only marginally: the underlying drivers have
to do the while() loop themselves, but this can now be done properly with
bufq_peek()/bufq_get(), removing the buffer from the queue at the right time.
This handle both the recursion and reordering issues (the reordering
issue is described here:
https://mail-index.netbsd.org/tech-kern/2014/05/19/msg017089.html
the recursion isssue is PR #25240).

Difference with the patch posted to tech-kern@: KASSERT() that the
buffer we remove with bufq_get() is the same as the one we bufq_peek()'d
just before.
Hopefully this will allow more disk drivers to use dksubr.c

branches: 1.18.6;
eliminate dk_geom

phase 1 of disk geometry cleanup:
- centralize the geometry -> plist code so that we don't have
n useless copies of it.

branches: 1.16.2;
Modify dksubr.c to add a function that sets the disk properties in
the drvctl framework. And call this new functionality from cgd(4),
the consumer of dksubr.c. We do this to allow gpt(8) to be able
to label cgd(4) disks. We also add in some DIOCGSECTORSIZE logic
and we ensure that the WEDGE ioctls are not called on either
uninitialised disks or disks which have not been opened for write
access.

branches: 1.15.8; 1.15.12; 1.15.14;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

branches: 1.14.4;
Put the entire expression that DK_BUSY() evaluates to in parentheses
for safety.

Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Allow to pass device_xname() to dk_sc_init() without build error
OK joerg

branches: 1.11.28;
Change dk_lookup() to accept an additional argument of the type enum uio_seg
that tells whether the given path is in user space or kernel space, so it
can tell NDINIT().

While the raidframe calls were ok, both ccd(4) and cgd(4) were passing
pointers to user space data, which leads to strange error on i386, as
reported by Jukka Salmi on current-users.

The issue has been there since last august, I'm actually a bit surprised
that no one in the meantime has used ccd(4) or cgd(4) on an arch where it
would have simply faulted.

branches: 1.10.2; 1.10.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.9.24; 1.9.26; 1.9.30;
merge ktrace-lwp.

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

add wedge support to xbd and cgd.

branches: 1.6.2;
constification fallout

Make this build with "-Wcast-qual -Wshadow".

Modified the dksubr routines to:

o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.

Modified cgd to:

o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.

We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.

Addresses PR: kern/24715
(at least according to the submitter.)

branches: 1.3.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

branches: 1.1.2;
A slight abstraction for disks. This is mainly [right now] in
support of the cryptographic disk which I'll be checking in shortly.

do not attach nvme ld as randomness source - device is too fast, it overwhelms
the rndq handling code, and causes system crashes; gathering rnd there is
also bad idea from performance perspective

Fix race condition in dksubr, where a dk_start from another thread
or interrupt was ignored while the queue was processed.

Bump kernel revision for changed dk_softc.

revert 1.90 of dksubr.c and change sc_deferred back to simple pointer; the
global sc_busy flag guards against race so it's not actually necessary, and
this place is unlikely to need to be parallelized in near future

discussed with mlelstv@

change sc_deferred to TAILQ (reusing bufq b_actq) to avoid possible buf leak
for MPSAFE drivers

branches: 1.25.2;
support deferral of diskstart to a separate thread.

move entropy gathering into dksubr.

Prevent race condition where two threads can defer a buffer.

Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.

Two changes to the dksubr interface.

- d_diskstart callback now processes a single buffer only.
The new wrapper function dk_start processes the queue,
performs other buffer handling and also provides locking
for the the data structures.

- add d_discard callback to handle device specific function inside
the new dk_discard helper function.

Replace splbio with mutex to protect queue and disk structure.
Refactor common code in dk_strategy and dk_discard into dk_translate.

Adjust and simplify ld(4), cgd(4) and xbd(4) drivers accordingly.

ld(4) now becomes MP_SAFE.

Bump kernel version.

Merge dk_intf and dkdriver interfaces.
Merge common disk driver functionality in ld.c with dksubr.c.
Adjust the two previous users of dk_intf (cgd and xbd) to
the changes.

bump kernel version to 7.99.14

branches: 1.19.4;
As proposed in
https://mail-index.netbsd.org/tech-kern/2014/05/21/msg017098.html
remove dk_start() and dk_iodone() from dksubr.c and move the related code
to the underlying driver.
This increase complexity only marginally: the underlying drivers have
to do the while() loop themselves, but this can now be done properly with
bufq_peek()/bufq_get(), removing the buffer from the queue at the right time.
This handle both the recursion and reordering issues (the reordering
issue is described here:
https://mail-index.netbsd.org/tech-kern/2014/05/19/msg017089.html
the recursion isssue is PR #25240).

Difference with the patch posted to tech-kern@: KASSERT() that the
buffer we remove with bufq_get() is the same as the one we bufq_peek()'d
just before.
Hopefully this will allow more disk drivers to use dksubr.c

branches: 1.18.6;
eliminate dk_geom

phase 1 of disk geometry cleanup:
- centralize the geometry -> plist code so that we don't have
n useless copies of it.

branches: 1.16.2;
Modify dksubr.c to add a function that sets the disk properties in
the drvctl framework. And call this new functionality from cgd(4),
the consumer of dksubr.c. We do this to allow gpt(8) to be able
to label cgd(4) disks. We also add in some DIOCGSECTORSIZE logic
and we ensure that the WEDGE ioctls are not called on either
uninitialised disks or disks which have not been opened for write
access.

branches: 1.15.8; 1.15.12; 1.15.14;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

branches: 1.14.4;
Put the entire expression that DK_BUSY() evaluates to in parentheses
for safety.

Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Allow to pass device_xname() to dk_sc_init() without build error
OK joerg

branches: 1.11.28;
Change dk_lookup() to accept an additional argument of the type enum uio_seg
that tells whether the given path is in user space or kernel space, so it
can tell NDINIT().

While the raidframe calls were ok, both ccd(4) and cgd(4) were passing
pointers to user space data, which leads to strange error on i386, as
reported by Jukka Salmi on current-users.

The issue has been there since last august, I'm actually a bit surprised
that no one in the meantime has used ccd(4) or cgd(4) on an arch where it
would have simply faulted.

branches: 1.10.2; 1.10.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.9.24; 1.9.26; 1.9.30;
merge ktrace-lwp.

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

add wedge support to xbd and cgd.

branches: 1.6.2;
constification fallout

Make this build with "-Wcast-qual -Wshadow".

Modified the dksubr routines to:

o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.

Modified cgd to:

o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.

We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.

Addresses PR: kern/24715
(at least according to the submitter.)

branches: 1.3.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

branches: 1.1.2;
A slight abstraction for disks. This is mainly [right now] in
support of the cryptographic disk which I'll be checking in shortly.

Fix race condition in dksubr, where a dk_start from another thread
or interrupt was ignored while the queue was processed.

Bump kernel revision for changed dk_softc.

revert 1.90 of dksubr.c and change sc_deferred back to simple pointer; the
global sc_busy flag guards against race so it's not actually necessary, and
this place is unlikely to need to be parallelized in near future

discussed with mlelstv@

change sc_deferred to TAILQ (reusing bufq b_actq) to avoid possible buf leak
for MPSAFE drivers

branches: 1.25.2;
support deferral of diskstart to a separate thread.

move entropy gathering into dksubr.

Prevent race condition where two threads can defer a buffer.

Make dksubr use a spin-mutex again, since some drivers still call dk_done
from hardware interrupt. Instead, release mutex while calling start routine.

The buffer peek/use/get sequence which can no longer be atomic. So consume
the buffer directly and on error privately save and retry the buffer later.
The dk_drain function is used to flush such a deferred buffer together with
the buffer queue.
Adjust drivers to use dk_drain.

Fix an error path where dk_done was called while the lock was already held.

Two changes to the dksubr interface.

- d_diskstart callback now processes a single buffer only.
The new wrapper function dk_start processes the queue,
performs other buffer handling and also provides locking
for the the data structures.

- add d_discard callback to handle device specific function inside
the new dk_discard helper function.

Replace splbio with mutex to protect queue and disk structure.
Refactor common code in dk_strategy and dk_discard into dk_translate.

Adjust and simplify ld(4), cgd(4) and xbd(4) drivers accordingly.

ld(4) now becomes MP_SAFE.

Bump kernel version.

Merge dk_intf and dkdriver interfaces.
Merge common disk driver functionality in ld.c with dksubr.c.
Adjust the two previous users of dk_intf (cgd and xbd) to
the changes.

bump kernel version to 7.99.14

branches: 1.19.4;
As proposed in
https://mail-index.netbsd.org/tech-kern/2014/05/21/msg017098.html
remove dk_start() and dk_iodone() from dksubr.c and move the related code
to the underlying driver.
This increase complexity only marginally: the underlying drivers have
to do the while() loop themselves, but this can now be done properly with
bufq_peek()/bufq_get(), removing the buffer from the queue at the right time.
This handle both the recursion and reordering issues (the reordering
issue is described here:
https://mail-index.netbsd.org/tech-kern/2014/05/19/msg017089.html
the recursion isssue is PR #25240).

Difference with the patch posted to tech-kern@: KASSERT() that the
buffer we remove with bufq_get() is the same as the one we bufq_peek()'d
just before.
Hopefully this will allow more disk drivers to use dksubr.c

branches: 1.18.6;
eliminate dk_geom

phase 1 of disk geometry cleanup:
- centralize the geometry -> plist code so that we don't have
n useless copies of it.

branches: 1.16.2;
Modify dksubr.c to add a function that sets the disk properties in
the drvctl framework. And call this new functionality from cgd(4),
the consumer of dksubr.c. We do this to allow gpt(8) to be able
to label cgd(4) disks. We also add in some DIOCGSECTORSIZE logic
and we ensure that the WEDGE ioctls are not called on either
uninitialised disks or disks which have not been opened for write
access.

branches: 1.15.8; 1.15.12; 1.15.14;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

branches: 1.14.4;
Put the entire expression that DK_BUSY() evaluates to in parentheses
for safety.

Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Allow to pass device_xname() to dk_sc_init() without build error
OK joerg

branches: 1.11.28;
Change dk_lookup() to accept an additional argument of the type enum uio_seg
that tells whether the given path is in user space or kernel space, so it
can tell NDINIT().

While the raidframe calls were ok, both ccd(4) and cgd(4) were passing
pointers to user space data, which leads to strange error on i386, as
reported by Jukka Salmi on current-users.

The issue has been there since last august, I'm actually a bit surprised
that no one in the meantime has used ccd(4) or cgd(4) on an arch where it
would have simply faulted.

branches: 1.10.2; 1.10.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.9.24; 1.9.26; 1.9.30;
merge ktrace-lwp.

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

add wedge support to xbd and cgd.

branches: 1.6.2;
constification fallout

Make this build with "-Wcast-qual -Wshadow".

Modified the dksubr routines to:

o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.

Modified cgd to:

o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.

We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.

Addresses PR: kern/24715
(at least according to the submitter.)

branches: 1.3.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

branches: 1.1.2;
A slight abstraction for disks. This is mainly [right now] in
support of the cryptographic disk which I'll be checking in shortly.