CVS log for src/sys/kern/subr_disk.c

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Pull up following revision(s) (requested by riastradh in ticket #284):

	sys/dev/dkwedge/dk.c				1.125-1.158
	sys/kern/subr_disk.c				1.135-1.137
	sys/sys/disk.h					1.78

dk(4): Explain why dk_rawopens can't overflow and assert it.

dk(4): Restore assertions in dklastclose.

We only enter dklastclose if the wedge is open (sc->sc_dk.dk_openmask
!= 0), which can happen only if dkfirstopen has succeeded, in which
case we hold a dk_rawopens reference to the parent that prevents
anyone else from closing it.  Hence sc->sc_parent->dk_rawopens > 0.

On open, sc->sc_parent->dk_rawvp is set to nonnull, and it is only
reset to null on close.  Hence if the parent is still open, as it
must be here, sc->sc_parent->dk_rawvp must be nonnull.

dk(4): Avoid holding dkwedges_lock while allocating array.

This is not great -- we shouldn't be choosing the unit number here
anyway; we should just let autoconf do it for us -- but it's better
than potentially blocking any dk_openlock or dk_rawlock (which are
sometimes held when waiting for dkwedges_lock) for memory allocation.

dk(4): KNF: return (v) -> return v.
No functional change intended.

dk(4): KNF: Whitespace.
No functional change intended.

dk(4): Omit needless void * cast.
No functional change intended.

dk(4): Fix typo in comment: dkstrategy, not dkstragegy.
No functional change intended.

dk(4): ENXIO, not ENODEV, means no such device.
ENXIO is `device not configured', meaning there is no such device.
ENODEV is `operation not supported by device', meaning the device is
there but refuses the operation, like writing to a read-only medium.

Exception: For undefined ioctl commands, it's not ENODEV _or_ ENXIO,
but rather ENOTTY, because why make any of this obvious when you
could make it obscure Unix lore?

dk(4): KNF: Sort includes.
No functional change intended.

dk(4): <sys/rwlock.h> for rwlock(9).

dk(4): Prevent races in access to struct dkwedge_softc::sc_size.
Rules:
1. Only ever increases, never decreases.
   (Decreases require removing and readding the wedge.)
2. Increases are serialized by dk_openlock.
3. Reads can happen unlocked in any context where the softc is valid.

Access is gathered into dkwedge_size* subroutines -- don't touch
sc_size outside these.  For now, we use rwlock(9) to keep the
reasoning simple.  This should be done with atomics on 64-bit
platforms and a seqlock on 32-bit platforms to avoid contention.

However, we can do that in a later change.

dk(4): Move CFDRIVER_DECL and CFATTACH_DECL3_NEW earlier in file.

Follows the pattern of most drivers, and will be necessary for
referencing dk_cd in dk_bdevsw and dk_cdevsw soon, to prevent
open/detach races.
No functional change intended.

dk(4): Don't touch dkwedges or ndkwedges outside dkwedges_lock.

dk(4): Assert parent vp is nonnull before we stash it away.

Let's enable early attribution if this goes wrong.

If it's not the parent's first open, also assert the parent vp is
already nonnull.

dk(4): Assert dkwedges[unit] is the sc we're about to free.

dk(4): Require dk_openlock in dk_set_geometry.

Not strictly necessary but this makes reasoning easier and documents
with an assertion how disk_set_info is serialized.

disk(9): Fix use-after-free race with concurrent disk_set_info.

This can happen with dk(4), which allows wedges to have their size
increased without destroying and recreating the device instance.

Drivers which allow concurrent disk_set_info and disk_ioctl must
serialize disk_set_info with dk_openlock.

dk(4): Add null d_cancel routine to devsw.

This way, dkclose is guaranteed that dkopen, dkread, dkwrite,
dkioctl, &c., have all returned before it runs.  For block opens,
setting d_cancel also guarantees that any buffered writes are flushed
with vinvalbuf before dkclose is called.

dk(4): Fix callout detach race.
1. Set a flag sc_iostop under the lock sc_iolock so dkwedge_detach
   and dkstart don't race over it.
2. Decline to schedule the callout if sc_iostop is set.  The callout
   is already only ever scheduled while the lock is held.
3. Use callout_halt to wait for any concurrent callout to complete.
   At this point, it can't reschedule itself.

Without this change, the callout could be concurrently rescheduling
itself as we issue callout_stop, leading to use-after-free later.

dk(4): Use disk_begindetach and rely on vdevgone to close instances.

The first step is to decide whether we can detach (if forced, yes; if
not forced, only if not already open), and prevent new opens if so.

There's no need to start closing open instances at this point --
we're just making a decision to detach, and preventing new opens by
transitioning state that dkopen will respect[*].

The second step is to force all open instances to close.  This is
done by vdevgone.  By the time vdevgone returns, there can be no open
instances, so if there _were_ any, closing them via vdevgone will
have passed through dklastclose.

After that point, there can be no opens and no I/O operations, so
dk_openmask must already be zero and the bufq must be empty.

Thus, there's no need to have an explicit call to dklastclose (via
dkwedge_cleanup_parent) before or after making the decision to
detach.
[*] Currently access to this state is racy: nothing serializes
    dkwedge_detach's state transition with dkopen's test.  TBD in a
    separate commit shortly.

dk(4): Set .d_cfdriver and .d_devtounit to plug open/detach race.

This way, opening dkN or rdkN will wait if attach or detach is still
in progress, and vdevgone will wake up such pending opens and make
them fail.  So it is no longer possible for a wedge to be detached
after dkopen has already started using it.

For now, we use a custom .d_devtounit function that looks up the
autoconf unit number via the dkwedges array, which conceivably may
use an independent unit numbering system -- nothing guarantees they
match up.  (In practice they will mostly match up, but concurrent
wedge creation could lead to different numbering.)  Eventually this
should be changed so the two numbering systems match, which would let
us delete the new dkunit function and just use dev_minor_unit like
many other drivers can.

dk(4): Take a read-lock on dkwedges_lock if we're only reading.
- dkwedge_find_by_name
- dkwedge_find_by_parent
- dkwedge_print_wnames

dk(4): Omit needless locking in dksize, dkdump.

All the members these use are stable after initialization, except for
the wedge size, which dkwedge_size safely reads a snapshot of without
locking in the caller.

dk(4): dkdump: Simplify.  No functional change intended.

dk(4): Narrow the scope of the device numbering lookup on detach.

Just need it for vdevgone, order relative to other things in detach
doesn't matter.
No functional change intended.

disk(9): Fix missing unlock in error branch in previous change.

dk(4): Fix racy access to sc->sc_dk.dk_openmask in dkwedge_delall1.
Need sc->sc_parent->dk_rawlock for this, as used in dkopen/dkclose.

dk(4): Convert tests to assertions in various devsw operations.
.d_cancel, .d_strategy, .d_read, .d_write, .d_ioctl, and .d_discard
are only ever used between successful .d_open return and entry to
.d_close.  .d_open doesn't return until sc is nonnull and sc_state is
RUNNING, and dkwedge_detach waits for the last .d_close before
setting sc_state to DEAD.  So there is no possibility for sc to be
null or for sc_state to be anything other than RUNNING or DYING.

There is a small functional change here but only in the event of a
race: in the short window between when dkwedge_detach is entered, and
when .d_close runs, any I/O operations (read, write, ioctl, &c.) may
be issued that would have failed with ENXIO before.

This shouldn't matter for anything: disk I/O operations are supposed
to complete reasonably promptly, and these operations _could_ have
begun milliseconds prior, before dkwedge_detach was entered, so it's
not a significant distinction.

Notes:
- .d_open must still contend with trying to open a nonexistent wedge,
  of course.
- .d_close must also contend with closing a nonexistent wedge, in
  case there were two calls to open in quick succession and the first
  failed while the second hadn't yet determined it would fail.
- .d_size and .d_dump are used from ddb without any open/close.

dk(4): Fix lock assertion in size increase: parent's, not wedge's.

dk(4): Rename label for consistency.  No functional change intended.

dk(4): dkclose must handle a dying wedge too to close the parent.

Otherwise the parent open leaks on detach (or revoke) when the wedge
was open and had to be forcibly closed.

Fixes assertion sc->sc_dk.dk_openmask == 0.
ioctl(DIOCRMWEDGES): Delete only idle wedges.

Don't forcibly delete busy wedges.

Fixes accidental destruction of the busy wedge that the root file
system is mounted on, triggered by syzbot's ioctl(DIOCRMWEDGES).

dk(4): Omit needless sc_iopend, sc_dkdrn mechanism.
vdevgone guarantees that all instances are closed by the time it
returns, which in turn guarantees all I/O operations (read, write,
ioctl, &c.) have completed, and, if the block device is open,
vinvalbuf(V_SAVE) -> vflushbuf has completed, which forces all
buffered transfers to be issued and waits for them to complete.
So by the time vdevgone returns, no further transfers can be
submitted and the bufq must be empty.

dk(4): Fix typo: sc_state, not sc_satte.

Had tested a patch series, but not every patch in it, and I
inadvertently fixed the typo in a later patch in the series, not in
the one I committed.

dk(4): Make it clearer that dkopen EROFS branch doesn't leak.
It looked like we may need to sometimes call dklastclose in error
branch for the case of (flags & ~sc->sc_mode & FWRITE) != 0, but it
is not actually possible to reach that case: if the caller requested
read/write, and the parent is read-only, and it is the first time
we've opened the parent, then dkfirstopen will fail with EROFS so we
never get there.

But this is confusing and it looked like the error branch is wrong,
so let's rearrange the conditional to make it clearer that we cannot
goto out after dkfirstopen has succeeded.  And then assert that the
case cannot happen when we do call dkfirstopen.

dk(4): Need pdk->dk_openlock to read pdk->dk_wedges.

ioctl(DIOCRMWEDGES): Delete only idle wedges.

Don't forcibly delete busy wedges.

Reported-by: syzbot+e46f31fe56e04f567d88@syzkaller.appspotmail.com
https://syzkaller.appspot.com/bug?id=8a00fd7f2e7459748d7a274098180a4708ff0f61

Fixes accidental destruction of the busy wedge that the root file
system is mounted on, triggered by syzbot's ioctl(DIOCRMWEDGES).

disk(9): Fix missing unlock in error branch in previous change.

Reported-by: syzbot+870665adaf8911c0d94d@syzkaller.appspotmail.com
https://syzkaller.appspot.com/bug?id=a4ae17cf66b5bb999182ae77fd3c7ad9ad18c891

disk(9): Fix use-after-free race with concurrent disk_set_info.

This can happen with dk(4), which allows wedges to have their size
increased without destroying and recreating the device instance.

Drivers which allow concurrent disk_set_info and disk_ioctl must
serialize disk_set_info with dk_openlock.

disk(9): New function disklabel_dev_unit.

Maps a dev_t like wd3e to an autoconf instance number like 3, with no
partition.  Same as DISKUNIT macro, but is a symbol whose pointer can
be taken.  Meant for use with struct bdevsw, cdevsw::d_devtounit.

Sync w/ HEAD.

sync with head

move bi-endian disklabel support from the kernel and libsa into libkern.

- dkcksum() and dkcksum_sized() move from subr_disk.c and from
  libsa into libkern/dkcksum.c (which is missing _sized() version),
  using the version from usr.sbin/disklabel.

- swap_disklabel() moves from subr_disk_mbr.c into libkern, now called
  disklabel_swap().  (the sh3 version should be updated to use this.)

- DISKLABEL_EI becomes a first-class option with opt_disklabel.h.

- add libkern.h to libsa/disklabel.c.

this enables future work for bi-endian libsa/ufs.c (relevant for ffsv1,
ffsv2, lfsv1, and lfsv2), as well as making it possible for ports not
using subr_disk_mbr.c to include bi-endian disklabel support (which,
afaict, includes any disk on mbr-supporting platforms that do not have
an mbr as well as disklabel.)

builds successsfully on: alpha, i386, amd64, sun2, sun3, evbarm64,
evbarm64-eb, sparc, and sparc64.  tested in anita on i386 and sparc,
testing in hardware on evbarm64*.

Attach disk info even for zero sized disks.
Slight refactoring.

Update for proplib(3) API changes.

Mostly merge changes from HEAD upto 20200411

Merge changes from current as of 20200406

Pull up following revision(s) (requested by mlelstv in ticket #814):

	sys/dev/scsipi/cd.c: revision 1.343
	sys/kern/subr_disk.c: revision 1.130

Avoid division by zero if label isn't valid.

Allow open of RAWPART even when no medium is loaded.
Keep errors silent if no medium is loaded.

Fixes PR kern/55104

Pull up following revision(s) (requested by mlelstv in ticket #1527):

	sys/dev/scsipi/cd.c: revision 1.343
	sys/kern/subr_disk.c: revision 1.130

Avoid division by zero if label isn't valid.
Allow open of RAWPART even when no medium is loaded.
Keep errors silent if no medium is loaded.
Fixes PR kern/55104

Avoid division by zero if label isn't valid.

Pull up following revision(s) (requested by cnst in ticket #1397):

	sys/kern/subr_disk.c: revision 1.129

kern/subr_disk: bounds_check_with_label: really protect against div by zero

Solves kernel panic in NetBSD 8.1 amd64 on VirtualBox 6.0.12 r133076.

Triggered with an NVMe controller without any actual discs behind it:

nvme0 at pci0 dev 14 function 0: vendor 80ee product 4e56 (rev. 0x00)
nvme0: NVMe 1.2
nvme0: interrupting at ioapic0 pin 22
nvme0: ORCL-VBOX-NVME-VER12, firmware 1.0, serial VB1234-56789
ld0 at nvme0 nsid 1
ld0: 0, 0 cyl, 16 head, 63 sec, 1 bytes/sect x 0 sectors

Code path is reached 4 times during normal boot, each time after wd0a
is already mounted; this patch avoids a crash with a dirty filesystem.

kern/subr_disk: bounds_check_with_label: really protect against div by zero

Solves kernel panic in NetBSD 8.1 amd64 on VirtualBox 6.0.12 r133076.

Triggered with an NVMe controller without any actual discs behind it:

nvme0 at pci0 dev 14 function 0: vendor 80ee product 4e56 (rev. 0x00)
nvme0: NVMe 1.2
nvme0: interrupting at ioapic0 pin 22
nvme0: ORCL-VBOX-NVME-VER12, firmware 1.0, serial VB1234-56789
ld0 at nvme0 nsid 1
ld0: 0, 0 cyl, 16 head, 63 sec, 1 bytes/sect x 0 sectors

Code path is reached 4 times during normal boot, each time after wd0a
is already mounted; this patch avoids a crash with a dirty filesystem.

Sync with HEAD

Implement disk_rename()/iostat_rename() to rename a disk.

Use it from zvol_rename_minor() when renaming a ZVOL.

Pull up following revision(s) (requested by martin in ticket #1223):
	sys/sys/dkio.h: revision 1.25
	sys/kern/subr_disk.c: revision 1.123
	sys/dev/dksubr.c: revision 1.107
	sys/dev/ccd.c: revision 1.179
	sys/dev/ofw/ofdisk.c: revision 1.53
Add a disk ioctl DIOCRMWEDGES to remove all wedges of a given disk
(if not busy).

move setdisklabel(9) into a separate file.

one more __func__

Make the DEBUG version compile

centralize setdisklabel(9)

Add a disk ioctl DIOCRMWEDGES to remove all wedges of a given disk
(if not busy).

Synch with HEAD

Fix typo in comment (s/is/if/) - NFC.

update from HEAD

Revert printf return value change.

[syzkaller] Cast all the printf's to (void *)
> as a result of new printf(9) declaration.

Sync with HEAD

remove checks for failure after memory allocation calls that cannot fail:

  kmem_alloc() with KM_SLEEP
  kmem_zalloc() with KM_SLEEP
  percpu_alloc()
  pserialize_create()
  psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

Sync with HEAD

Sync with HEAD

Enhance disk metrics by calculating a weighted sum that is incremented
by the number of concurrent I/O requests. Also introduce a new disk_wait()
function to measure requests waiting in a bufq.
iostat -y now reports data about waiting and active requests.

So far only drivers using dksubr and dk, ccd, wd and xbd collect data about
waiting requests.

pi_bsize must be at least pi_secsize

Allows block device accesses to 4KiB logical sector disks to function on the
vast majority of ports with 2KiB BLKDEV_IOSIZE.

Sync with HEAD

print the disklabel information on error if DIAGNOSTIC.

Sync with HEAD (as of 26th Dec)

Replace DIOCGPART -> DIOCGPARTINFO which returns the data needed instead of
pointers.

Handle sector sizes other than DEV_BSIZE when reading labels.

Sync with HEAD

Pull up following revision(s) (requested by jnemeth in ticket #775):
	share/man/man9/disk.9: revision 1.37
	sys/kern/subr_disk.c: revisions 1.104, 1.105
	sys/dev/dksubr.c: revision 1.56
	sys/sys/dkio.h: revision 1.21
Implement DIOCGMEDIASIZE and DIOCGSECTORSIZE from FreeBSD.
--
clear error for new ioctls.

Pull up following revision(s) (requested by chs in ticket #766):
	sys/kern/subr_disk.c: revision 1.113
in bounds_check_with_*, reject negative block numbers and avoid
a potential overflow in calculating the size of the request.

in bounds_check_with_*, reject negative block numbers and avoid
a potential overflow in calculating the size of the request.

Always fixup zero sector size, even when other geometry values are invalid.

Sync with HEAD

- Use NODEV instead of 0
- Return EBUSY if there was no label

Retire disk_blocksize().

Mention which ioctls need to move to dk_ioctl, and don't allow wedges on
wedges.

make more drivers use disk_ioctl, and add a dev parameter to it so that
we can merge the "easy" disklabel ioctls to it. Ultimately all this will
go do dk_ioctl once all the drivers have been converted.

Centralize wedge ioctls in disk_ioctl.

disk_blocksize and disk_set_info relay the same information
to the disk subsystem.

Make disk_set_info also set blocksize shift values.
Remove every call to disk_blocksize.

Keep disk_blocksize for ABI compatibility, make it also set dg_secsize.

clear error for new ioctls.

Implement DIOCGMEDIASIZE and DIOCGSECTORSIZE from FreeBSD.

Rebase to HEAD as of a few days ago.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

sync with head

use 64bit arithmetic to compute sectors-per-unit

resync from head

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

resync with head

Add an accessor -- ufs_maxphys() -- to check the maximum transfer size
for a given UFS mountpoint, and move the code from mount that finds
the underlying disk and resets the mountpoint max transfer size into a
utility function, ufs_update_maxphys().

Add a global serial number that counts disk property changes to which
filesystems are meant to accomodate themselves.  Make ufs_maxphys()
check it.  This is a sort of flag-polling interface that avoids callbacks
into the filesystem code, but will require freezing filesystems and
draining in-flight transactions before a decrease in size that is
mandatory (like attaching a disk with a smaller maximum transfer size
as a spare in a RAIDframe set), rather than "advisory", like finding
out set geometry from a RAID controller long after boot and deciding
a smaller transfer size would be optimal, can be signalled.  Still, the
"advisory" case is the common one so this is progress.

Make a bit of an example of RAIDframe by making it bump this new
serial number when disks are added to the subsystem.  I will attack
one of the hardware RAID drivers (probably arcmsr) next.

printflike maintenance.

Don't pass NULL struct dkdriver to disk_init.  That's seriously bogus.

Initial snapshot of work to eliminate 64K MAXPHYS.  Basically works for
physio (I/O to raw devices); needs more doing to get it going with the
filesystems, but it shouldn't damage data.

All work's been done on amd64 so far.  Not hard to add support to other
ports.  If others want to pitch in, one very helpful thing would be to
sort out when and how IDE disks can do 128K or larger transfers, and
adjust the various PCI IDE (or at least ahcisata) drivers and wd.c
accordingly -- it would make testing much easier.  Another very helpful
thing would be to implement a smart minphys() for RAIDframe along the
lines detailed in the MAXPHYS-NOTES file.

sync with head

Pull up following revision(s) (requested by mrg in ticket #1520):
	sys/sys/device.h: revision 1.133
	sys/kern/subr_disk.c: patch
Add helper function that determines the size and block size of a disk device.
For now we query
- the disk label
- the wedge info and data from disk(9)

Pull up following revision(s) (requested by mrg in ticket #1411):
	sys/kern/subr_disk.c: revision 1.100
add some (uint64_t) casts so avoid 32 bit overflows.  this fixes my
3TB disk with 4KB sectors and disklabel (which looks like it would
work upto 16TB.)
idea from mlelstv@.

Pull up following revision(s) (requested by mrg in ticket #1463):
	sys/kern/subr_disk.c: revision 1.100
add some (uint64_t) casts so avoid 32 bit overflows.  this fixes my
3TB disk with 4KB sectors and disklabel (which looks like it would
work upto 16TB.)
idea from mlelstv@.

Sync with HEAD (-D20101022).

add some (uint64_t) casts so avoid 32 bit overflows.  this fixes my
3TB disk with 4KB sectors and disklabel (which looks like it would
work upto 16TB.)

idea from mlelstv@.

sync with head

When truncating a request in bounds_check_with_mediasize() multiply
by the provided sector size instead of 512.
Fixes last bit of PR/31565

u_short -> uint16_t, some KNF.

Sync with HEAD.

sync with head

On second thought, let's call disk_predetach() disk_begindetach().
Verbs are good.

Encapsulate the checks that I do before detaching a disk(9) provider
in a pre-detachment routine, disk_predetach().

Sync with HEAD.

Commit is split, to avoid a "too many arguments" protocol error.

sync with head.

Sync with HEAD.

Pull up following revision(s) (requested by ad in ticket #657):
	sys/kern/subr_disk.c: revision 1.95
	sys/kern/subr_iostat.c: revision 1.17
	sys/sys/disk.h: revision 1.52
	sys/sys/iostat.h: revision 1.10
Add disk_isbusy(), iostat_isbusy().

Add disk_isbusy(), iostat_isbusy().

Sync with HEAD.

malloc -> kmem_alloc

Sync with HEAD.

sync with head.

sync with head.

Remove clause 3 and 4 from TNF licenses

Sync with HEAD.

sync with head.

sync with HEAD

sync with head.

constify dkdriver

Sync with HEAD.

sync with head.

Constify both struct disk->dk_name and the `name' argument to
disk_init().

constify disk->dk_name.

sync with head

sync with HEAD

Sync with HEAD

Merge vmlocking2 to head.

Pull the vmlocking changes into a new branch.

sync with HEAD

sync with head.

Sync with HEAD.

Follow the merge of pmap.c on i386 and amd64 and move
pmap_init_tmp_pgtbl into arch/x86/x86/pmap.c. Modify the ACPI wakeup
code to restore CR4 before jumping back into kernel space as the large
page option might cover that.

sync with head.

Merge disk init changes from the vmlocking branch. These seperate init /
destroy of 'struct disk' from attach / detach.

sync with head.

Sync with buffer cache locking changes. See buf.h/vfs_bio.c for details.
Some minor portions are incomplete and needs to be verified as a whole.

Sync with head.

Sync with HEAD.

- Alter disk attach/detach to fix a panic when closing a vnd device.
- Sync with HEAD.

- Back out the biodone() changes.
- Eliminate B_ERROR (from HEAD).

Sync with HEAD.

It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

file subr_disk.c was added on branch matt-mips64 on 2007-07-29 12:15:46 +0000

It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

Replace some uses of lockmgr().

Sync with head.

Sync with head.

Extract common code from i386, xen, and sparc64, creating
config_handle_wedges() and read_disk_sectors().  On x86, handle_wedges()
is a thin wrapper for config_handle_wedges().  Share opendisk()
across architectures.

Add kernel code in support of specifying a root partition by wedge
name.  E.g., root specifications "wedge:wd0a", "wedge:David's Root
Volume" are possible.  (Patches for config(1) coming soon.)

In support of moving disks between architectures (esp. i386 <->
evbmips), I've written a routine convertdisklabel() that ensures
that the raw partition is at RAW_DISK by following these steps:

        0 If we have read a disklabel that has a RAW_PART with
          p_offset == 0 and p_size != 0, then use that raw partition.

        1 If we have read a disklabel that has both partitions 'c'
          and 'd', and RAW_PART has p_offset != 0 or p_size == 0,
          but the other partition is suitable for a raw partition
          (p_offset == 0, p_size != 0), then swap the two partitions
          and use the new raw partition.

        2 If the architecture's raw partition is 'd', and if there
          is no partition 'd', but there is a partition 'c' that
          is suitable for a raw partition, then copy partition 'c'
          to partition 'd'.

        3 Determine the drive's last sector, using either the
          d_secperunit the drive reported, or by guessing (0x1fffffff).
          If we cannot read the drive's last sector, then fail.

        4 If we have read a disklabel that has no partition slot
          RAW_PART, then create a partition RAW_PART.  Make it span
          the whole drive.

        5 If there are fewer than MAXPARTITIONS partitions,
          then "slide" the unsuitable raw partition RAW_PART, and
          subsequent partitions, into partition slots RAW_PART+1
          and subsequent slots.  Create a raw partition at RAW_PART.
          Make it span the whole drive.

The convertdisklabel() procedure can probably stand to be simplified,
but it ought to deal with all but an extraordinarily broken disklabel,
now.

i386: compiled and tested, sparc64: compiled, evbmips: compiled.

Sync with HEAD.

Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

Split the disklabel checksum function into two, so we can pass the
length separately.
Use this for foreign-endianess labels in wedge autodiscovery, and
calculate the checksum of those before we swap various fields in the
label.

Sync with head.

sync with head.

sync with head.

Replace the myriad copies of bounds_check_with_label() with a single MI
version.

Add disk_blocksize(9) so that disk drivers can record the physical
block size of a disk if it is different to DEV_BSIZE. Right now this
simply initialises dk_blkshift and dk_byteshift according to the
supplied block size. This information is used in the MI version of
bounds_check_with_label().

Sync with head.

- Add a new disk ioctl (DIOCGDISKINFO) to get the disk-info dictionary
  for the disk.
- Add a new function, disk_ioctl(), that does generic disk ioctl handling.
  DIOCGDISKINFO is handled here now, and others will be added in the future.
- In the wd driver, fill in the dk_info member of struct disk and use the
  new disk_ioctl() function.

sync with head

- Define disk information, disk geometry, and disk partition dictionary
  schemas.  Disk information and disk geometry are designed to replace
  information currently conveyed to user space using struct disklabel.
- Add a dk_info member to struct disk; a reference to a disk information
  dictionary.  This dictionary is to be allocated and the reference stored
  in struct disk by individual drivers.
- disk_detach0() will release dk_info if non-NULL.
- Convert the wd(4) driver to stash geometry and other disk properties
  as the "disk-info" property in its properties dictionary.  This needs
  some cleanup, but will serve as an example of what to do with other
  disk drivers.

sync with head

sync with head.

Change iostat_alloc() to take the parent pointer and the name directly, so
that callers are not responsible for initializing the fields. Store the name
inside the struct instead of maintaining a pointer to external storage, or
leaked memory (nfs case).

sync with head.

sync with head.

Sync with head.

merge FreeBSD timecounters from branch simonb-timecounters
- struct timeval time is gone
  time.tv_sec -> time_second
- struct timeval mono_time is gone
  mono_time.tv_sec -> time_uptime
- access to time via
	{get,}{micro,nano,bin}time()
	get* versions are fast but less precise
- support NTP nanokernel implementation (NTP API 4)
- further reading:
  Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
  NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html

Merge 2006-05-24 NetBSD-current into the "peter-altq" branch.

sync with head.

sync with head

Sync with head.

iostat_find/disk_find: constify and simplify.

remove some unnecessary #include.

whitespace.

Prefix iostat structure elements with io_

sync with head.

Make i/o statistics collection more generic, include tape drives and
nfs mounts in the set of devices that statistics will be reported on.

Adapt for timecounters: mostly use get*time() and use "time_second"
instead of "time.tv_sec".

u_intN_t -> uintN_t

merge ktrace-lwp.

Sync with HEAD. Here we go again...

- 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)

introduce a variant of disk_attach/detach, for pseudo disks
which is opened by user before being attached.

- add const.
- remove unnecessary casts.
- add __UNCONST casts and mark them with XXXUNCONST as necessary.

sync with -current

Pull up revision 1.68 (requested by yamt in ticket #112):
introduce a function to drain bufq and use it where appropriate.

Sync with HEAD.

introduce a function to drain bufq and use it where appropriate.

sync with head.

Sync with HEAD.

Change the 'sz' variable in bounds_check_* to int64_t to avoid overflows
when a very large blocknumber is passed in.

Sunc with HEAD.

Change an if/panic statement to a KASSERT and disable a chatty printf.

Sync with HEAD.

lookup bufq using link_set rather than a switch statement.

Sync with HEAD.

move buffer queue related stuffs from buf.h to their own header, bufq.h.

Sync with HEAD

- Eliminate the need to call disk_init().
- disk_count needs to be protected with disklist_slock, too.

move i/o schedulers to their own files.
namely, from kern/subr_disk.c to kern/bufq_{fcfs,disksort,readprio,priocscan}.c.

Work-in-progress implementation of "wedges", a new way to represent
partitions in the NetBSD kernel.  See discussion on tech-kern for details.

Fix the sync with head I botched.

Sync with HEAD.

Sync with HEAD

- add a function prototype.
- consitify.

change the way to handle NEW_BUFQ_STRATEGY option.
instead of putting #ifdefs into each drivers,
use a global variable to indicate default strategy.

XXX should have a way to specify other strategies.

add a new bufq strategy, BUFQ_PRIOCSCAN (per-priority CSCAN).
discussed on tech-kern@

rev.1.55 didn't handle BUFQ_SORT_CYLINDER case correctly.
pointed by Juergen Hannken-Illjes.  patch provided by him.

Make sure buf_inorder() returns a value under all conditions.

buf_inorder: deal with 64-bit daddr_t correctly.

Dynamic sysctl.

Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al.  Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.

Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded.  Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.

All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.

PS - I'm sorry, but there's a distinct lack of documentation at the
moment.  I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

CONSTCONT should have been CONSTCOND

Fix error message for 64bit daddr_t

Add a bounds_check_with_mediasize function, which is intended
for checking RAW_PART transfers (and later raw disk devices).

Catch up to -current

Factor out the COMPAT_16 code.

- do the COMPAT_16 dance in sysctl_diskstats() for the where == NULL case
  as well.  pointed out by enami@.
- defflag COMPAT_16.

repair backwards compatibility with netbsd 1.6 - if we are not given the
wanted sizeof(struct disk_sysctl), use the old size.  for non-COMPAT_16,
however, we return EINVAL so that all future programs are forced into
passing the wanted size.  1.6 iostat(8) works with -current kernel again.

as seen on tech-kern.

When calculating the space needed for the data, use the supplied
userland structure size (if passed in).
Use the supplied userland structure size (if passed in) to check if
there is enough room to copyout the next structure.

implement separate read/write disk statistics:
	- disk_unbusy() gets a new parameter to tell the IO direction.
	- struct disk_sysctl gets 4 new members for read/write bytes/transfers.
	when processing hw.diskstats, add the read&write bytes/transfers for
	the old combined stats to attempt to keep backwards compatibility.

unfortunately, due to multiple bugs, this will cause new kernels and old
vmstat/iostat/systat programs to fail.  however, the next time this is
change it will not fail again.

this is just the kernel portion.

Make this works with QUEUEDEBUG defined; don't use queue pointer after
removing an element from queue.

Cosmetic changes.

Catch up to -current.

sync kqueue branch with HEAD

catch up with -current.

Remove the old device buffer queue interface.

Approved by: Jason R. Thorpe <thorpej@wasabisystems.com>

catch up with -current.

Catch up to -current.

The buffer returned by BUFQ_PEEK must remain the same until BUFQ_GET is
called. It may be used as the "current" buffer.

Pull up revision 1.38 (requested by yamt in ticket #536):
constify diskerr().

Rename bufq_init() to bufq_alloc().
Add bufq_free() to remove a buffer queue.
Avoid MALLOC while holding a spinlock.

From Chuck Silvers.

catch up with -current.

Implement a new device buffer queue interface.
One basic struct, a function to setup a queue with a specific strategy and
three macros to put buf's into the queue, get and remove the next buf or
get the next buf without removal.

The BUFQ_XXX interface will be removed in the future.
The B_ORDERED flag is not longer supported.

Approved by: Jason R. Thorpe <thorpej@wasabisystems.com>

catch up with -current.

constify diskerr().

Catch up with -current.

Catch up to -current.

Use sizeof correctly.  Fixes PR#15613.

- Wrap long line.
- Remove unnecessary semi-colon.

Sync w/ -current.

Remember to update the "size copied" counter in sysctl_diskstats().

Use TAILQ_FOREACH().

Implement the hw.disknames and hw.diskstats sysctl's that have been listed
in <sys/sysctl.h> since day one but never implemented.

Sync kqueue branch with -current.

Catch up to -current.

Use cached pointer to next buf instead of re-fetching it.  GCC actually
generates different code.

Catch up to -current.

add RCSID

Commit my "devvp" changes to the thorpej-devvp branch.  This
replaces the use of dev_t in most places with a struct vnode *.

This will form the basic infrastructure for real cloning device
support (besides being architecurally cleaner -- it'll be good
to get away from using numbers to represent objects).

Catch up with -current.

ANSIfy.

Update thorpej_scsipi to -current as of a month ago

Get rid of register declarations.

Fix a bug in disksort_*() which caused non-optimal ordering when multiple
active partitions were on a single spindle.  Add a b_rawblkno member to
struct buf which contains the non-partition-relative block number to sort
by.

The decision that `disksort_cylinder' uses to decide if the buffer needs
to go to the inversion list is incomplete. If the cylinders are equal
block numbers must be checked.

This caused lockups if some buffers with the same cylinder were cycling
through the list, as it may happen with softdep enabled.

Fixes PR #9197.

- Add a B_ORDERED flag to communicate to drivers that an I/O request should
  be issued/completed in order; that is, provide a barrier for I/O queues.
- Change the buffer driver queue links to a TAILQ, rather than using
  a home-grown equivalent.  Provide BUFQ_*() macros to manipulate buffer
  queues; these deal with the barrier provided by B_ORDERED.
- Update disksort() accordingly, and provide 3 versions:
	- disksort_cylinder(): historical disksort(), which keys on
	  b_cylinder (and b_blkno for the case when b_cylinder matches).
	- disksort_blkno(): sorts only on b_blkno.  Essentially the
	  same as disksort_cylinder(), but with fewer comparisons.
	- disksort_tail(): requests are simply inserted into the queue
	  at the tail.  This is provided as an option so that drivers
	  can simply have a pointer to the appropriate sort function.
  Note that disksort() now pays attention to B_ORDERED.

Initial commit of recent changes to make DEV_BSIZE go away.

Runs on i386, needs work on other arch's. Main kernel routines should be
fine, but a number of the stand programs need help.

cd, fd, ccd, wd, and sd have been updated. sd has been tested with non-512
byte block devices. vnd, raidframe, and lfs need work.

Non 2**n block support is automatic for LKM's and conditional for kernels
on "options NON_PO2_BLOCKS".

PR kern/7033 (Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>): use
device minor to unit/partition macros from sys/disklabel.h

Abolition of bcopy, ovbcopy, bcmp, and bzero, phase one.
  bcopy(x, y, z) ->  memcpy(y, x, z)
ovbcopy(x, y, z) -> memmove(y, x, z)
   bcmp(x, y, z) ->  memcmp(x, y, z)
  bzero(x, y)    ->  memset(x, 0, y)

Rearrange disk_detach() slightly, and make a small run-time cosmetic
change in disk_unbusy().

Update marc-pcmcia branch from trunk.

Copyright assigned to The NetBSD Foundation.

removed #ifdef tahoe

backout previous kprintf change

printf -> kprintf, sprintf -> ksprintf

Remove old-style disk instrumentation code.

Fix printf() formats.

More proto fixes

New generic disk framework.  Highlights:

	- New metrics handling.  Metrics are now kept in the new
	  `struct disk'.  Busy time is now stored as a timeval, and
	  transfer count in bytes.

	- Storage for disklabels is now dynamically allocated, so that
	  the size of the disk structure is not machine-dependent.

	- Several new functions for attaching and detaching disks, and
	  handling metrics calculation.

Old-style instrumentation is still supported in drivers that did it before.
However, old-style instrumentation is being deprecated, and will go away
once the userland utilities are updated for the new framework.

For usage and architectural details, see the forthcoming disk(9) manual
page.

Move the old-style disk instrumentation "structures" to a central location
(sys/kern/subr_disk.c) and note that they should/will be deperecated.

Make definition of b_cylinder global.

New RCS ID's, take two.  they're more aesthecially pleasant, and use 'NetBSD'

Update to 4.4-Lite.

Don't need back pointers for disksort().

Remove another use of b_actl.

Use b_actf, not av_forw.

remove warning

Get rid of disklabel indirection functions.

Canonicalize all #includes.

Canonicalize all #includes.

delete hopping-functions cpu_{read,write,set}disklabel()

Strategy functions return void.

Add \n to end of error message.

more disklabel changes

add rcs ids, and clean up headers where necessary

initial import of 386bsd-0.1 sources

Initial revision