Commit Graph

1033 Commits

Author SHA1 Message Date
Pawel Jakub Dawidek
565bc10111 Add a very simple and small GEOM class - ZERO.
It creates very huge provider (41PB) /dev/gzero.
On BIO_READ request it zero-fills bio_data and on BIO_WRITE it does nothing.
You can also set kern.geom.zero.clear sysctl to 0 to do nothing even for
BIO_READ.

I'm using it for performance testing where it is very helpful.

MFC after:	3 days
2005-07-25 10:03:16 +00:00
Poul-Henning Kamp
0322f8dc8d Comment typo 2005-07-20 18:08:16 +00:00
Pawel Jakub Dawidek
0499edf459 Before calling g_orphan_provider(), add G_PF_WITHER flag, so GEOM will know
to destroy it.

PR:		kern/81758
Submitted by:	trasz <trasz@buziaczek.pl>
MFC after:	3 days
2005-07-17 13:15:02 +00:00
Yoshihiro Takahashi
0bf2708b8c Merged from geom_mbr.c revisions 1.62 and 1.66.
- Implement a gctl handler and the verb "write MBR".
2005-07-15 15:29:45 +00:00
Lukas Ertl
7ad68986b8 *) Implement round-robin reads for multiplex volumes.
*) Plug a possible memory leak. [1]

[1] obtained from: pjd@.
2005-07-15 13:38:06 +00:00
Poul-Henning Kamp
1c3cf26412 Implement a gctl handler and the verb "write MBR" which can be used to
update metadata and bootcode while the MBR is in use.

MFC candidate
2005-07-15 08:00:44 +00:00
Pawel Jakub Dawidek
84436f14c4 Add CANCEL command which allows to remove one request from the queue or
all requests from the queue if request number is not given.

Bump version number.

Approved by:	re (scottl)
2005-07-08 21:08:53 +00:00
Pawel Jakub Dawidek
59ddf345d5 After provider creation!! 2005-05-25 15:54:17 +00:00
Pawel Jakub Dawidek
0f2bbe5ba4 - Call root_mount_rel() when provider IS created, not earlier.
This should close the race observed by Daniel Eriksson.
- Remove redundant wakeup().
2005-05-25 13:10:04 +00:00
Pawel Jakub Dawidek
4eafb037f6 Add some debug code to diagnose root-on-mirror problems with recent -current.
Reported by:	Daniel Eriksson
2005-05-23 13:05:07 +00:00
Pawel Jakub Dawidek
d246aa55e7 Correct typo. 2005-05-18 21:53:08 +00:00
Lukas Ertl
0164489c96 When a drive dies, don't call g_wither_geom() directly, but instead
post an event to the geom event queue that will take care of it,
letting outstanding bios finish, and closing the consumers.

Plus some cosmetic clean ups.
2005-05-17 16:38:30 +00:00
Pawel Jakub Dawidek
3ac6c13bd4 cp can't be NULL.
Noticed by:	Coverity Prevent analysis tool
2005-05-11 19:36:56 +00:00
Pawel Jakub Dawidek
b957751627 gp can't be NULL.
Noticed by:	Coverity Prevent analysis tool
2005-05-11 19:35:43 +00:00
Pawel Jakub Dawidek
862f5624ea Add KASSERT() to be sure there is an active component.
Suggested by:	Coverity Prevent analysis tool
2005-05-11 18:13:51 +00:00
Pawel Jakub Dawidek
0a3384a8f8 Check return value.
Found by:	Coverity Prevent analysis tool
2005-05-11 18:07:39 +00:00
Yoshihiro Takahashi
16da54931e Fix signed vs unsigned warning. 2005-05-01 09:44:50 +00:00
Lukas Ertl
bc2d4d6784 Only allow RAID5 plexes to be parity checked.
PR:           kern/80427
Submitty by:  Stijn Hoop <stijn@win.tue.nl>
2005-04-28 13:09:00 +00:00
Pawel Jakub Dawidek
3865ca2e13 Fix provider's size check for 'insert' command.
Before this fix one was able to insert one sector too small provider.

MFC after:	3 days
2005-04-25 10:41:26 +00:00
Garrett Wollman
d5e3d722df The size of a filesystem may be less than the size of the provider it
resides on.  Fix the special case of the filesystem fragment size not
evenly dividing the size of the provider.  Fixing the general case
probably requires better superblock validation (left as an exercise to
the reader).
2005-04-19 21:55:28 +00:00
Pawel Jakub Dawidek
7979b3683c Remove the hack which allowed to use gmirror for root file system,
use root_mount KPI instead.
2005-04-19 21:47:25 +00:00
Poul-Henning Kamp
d1c712ede2 Call g_waitidle() instead of GEOM using the root_mount_hold() KPI.
GEOM could (and will) get events as a result of drivers coming in
late so a one-shot method is not good enough for GEOM.
2005-04-19 06:23:59 +00:00
Poul-Henning Kamp
73fbaa74e5 Add a named reference-count KPI to hold off mounting of the root filesystem.
While we wait for holds to be released, print a list of who holds us
back once per second.

Use the new KPI from GEOM instead of vfs_mount.c calling g_waitidle().

Use the new KPI also from ata.

With ATAmkIII's newbusification, ata could narrowly miss the window
and ad0 would not exist when we tried to mount root.
2005-04-18 21:21:26 +00:00
Pawel Jakub Dawidek
811787079b Protect against recursive labels creation in simlar way as it is done
in BSD and MBR classes, ie. if provider below us uses the same metadata,
don't create labels based on the metadata.
This allows to create labels on geoms with rank != 1 without hacks.

Tested by:	Chris Elsworth <chris@shagged.org> on sparc64
OK'ed by:	phk
MFC after:	2 weeks
2005-04-12 08:14:15 +00:00
Pawel Jakub Dawidek
cdae843174 Fix a long-standing bug. Error string has to be copyied from the user
process context.

Approved by:	phk
MFC after:	3 days
2005-04-08 09:28:08 +00:00
Pawel Jakub Dawidek
7e0b3120e7 - Add a missing g_io_deliver() in case of allocation failure - we didn't
completed I/O requests here.
- First allocate all needed bios, so if any of allocations fail, we can
  free memory before sending any I/O requests down.

Reported by:	Pawel Malachowski
MFC after:	3 days
2005-04-03 14:55:49 +00:00
Yoshihiro Takahashi
612f970e46 Remove geometry translations here. 2005-03-30 12:59:54 +00:00
Joerg Wunsch
3328bbeef2 Support VTOC volume names. This can be useful to distinguish multiple
disks in a system.  Solaris' format(1m) displays the volume names in
the disk overview.

MFC after:	1 month
2005-03-30 09:33:10 +00:00
Poul-Henning Kamp
9bb329f4e5 fix a "modify after free" bug which is practically impossible to
experience.

Found by:	Coverity (id #540 #541)
2005-03-26 21:07:35 +00:00
Pawel Jakub Dawidek
34cb151796 If an error occurs, clean up before returning from g_raid3_connect_disk(). 2005-03-26 17:24:19 +00:00
Pawel Jakub Dawidek
c2ca10933d Make the code more obvious - when an error occurs in g_mirror_connect_disk(),
detach and destroy consumer before returning.
2005-03-26 17:23:01 +00:00
Pawel Jakub Dawidek
cc6aa917b9 Check for return values.
Submitted by:	sam
Found by:	Coverity Prevent analysis tool
2005-03-26 16:51:19 +00:00
Poul-Henning Kamp
cb7ff8b71d g_read_data() can return NULL, check for it.
Found by:	Coverity (ID#258)
2005-03-18 07:03:56 +00:00
Poul-Henning Kamp
b3fd9b46bb After rejecting the bio request early, return instead of panicing.
Found by:	Coverity (ID#450)
2005-03-18 07:01:31 +00:00
Poul-Henning Kamp
b3b21113a5 Avoid null pointer dereference. 2005-03-18 06:57:58 +00:00
Pawel Jakub Dawidek
42cfb5bada Plug memory leak.
Submitted by:	Ted Unangst
Found by:	Coverity Prevent analysis tool
Approved by:	phk
MFC after:	3 days
2005-03-16 20:48:13 +00:00
Poul-Henning Kamp
20b3501394 forward declare struct disk. 2005-03-15 10:47:38 +00:00
Poul-Henning Kamp
03c02e5cb1 Do not attach MBR on top of an MBR. This removes some confusing
slice names on disks with extended partitions.

Spotted on:	Mother-in-laws computer.
2005-03-14 15:22:18 +00:00
Hajimu UMEMOTO
68527b3aad stop including rijndael-api-fst.h from rijndael.h.
this is required to integrate opencrypto into crypto.
2005-03-11 15:42:51 +00:00
Lukas Ertl
cf01c54cda Remove test for zero sectorsize when tasting. This check doesn't
seem to be necessary anymore, and it prevents tasting a valid drive
when booting with geom_vinum already loaded, since SCSI disks set their
sectorsize not until first opening them.
2005-03-07 19:58:58 +00:00
Poul-Henning Kamp
3b3f38ed7d Add placeholder mutex argument to new_unrhdr(). 2005-03-07 11:05:47 +00:00
Lukas Ertl
9954331c23 Don't allow to synchronize a plex that is already sychronizing.
Reset the 'syncing' flag in case of errors, too.

Some cosmetics.
2005-03-04 16:43:40 +00:00
Pawel Jakub Dawidek
e68909854c - Add md_provsize field to metadata, which will help with
shared-last-sector problem.
  After this change, even if there is more than one provider with the same
  last sector, the proper one will be chosen based on its size.
  It still doesn't fix the 'c' partition problem (when da0s1 can be confused
  with da0s1c) and situation when 'a' partition starts at offset 0
  (then da0s1a can be confused with da0s1 and da0s1c). One can use '-h'
  option there, when creating device or avoid sharing last sector.
  Actually, when providers share the same last sector and their size is equal,
  they provide exactly the same data, so the name (da0s1, da0s1a, da0s1c)
  isn't important at all.
- Provide backward compatibility.
- Update copyright's year.

MFC after:	1 week
2005-02-27 23:07:47 +00:00
Lukas Ertl
d8688e1117 Correctly calculate what to do and how to retry a request to a plex when
the previous one failed and there are more than one plex in the volume.

This could have led to a flood of error messages on the console and
probably a deadlock in certain situations.
2005-02-23 14:59:14 +00:00
Poul-Henning Kamp
dfd4be14bd Try to unbreak the vnode locking around vop_reclaim() (based mostly on
patch from kan@).

Pull bufobj_invalbuf() out of vinvalbuf() and make g_vfs call it on
close.  This is not yet a generally safe function, but for this very
specific use it is safe.  This solves the problem with buffers not
being flushed by unmount or after failed mount attempts.
2005-02-19 11:44:57 +00:00
Lukas Ertl
3608f72533 In case of drive errors, don't close the associated consumer and
detach it, but instead let the geom wither away.

Bump copyright year.
2005-02-17 16:08:36 +00:00
Pawel Jakub Dawidek
07b9f1becd Fix year in copyrights. 2005-02-16 22:26:34 +00:00
Pawel Jakub Dawidek
0218292cdf Update copyright in files changed this year. 2005-02-16 22:14:52 +00:00
Pawel Jakub Dawidek
99394c59ae Fix year in copyrights. 2005-02-16 22:13:22 +00:00
Pawel Jakub Dawidek
ccbef85dd0 Remove mutex asserion from g_gate_find(). We don't want g_gate_list_mtx
mutex to be held here, because we want speed here.
2005-02-16 16:13:56 +00:00
Pawel Jakub Dawidek
f906581296 Remove TDP_GEOM flag from thread after ggate device creation.
This flag means "wait for all pending requests before returning to userland".
There are pending events for sure, because we just created new provider and
other classes want to taste it, but we cannot answer on I/O requests until
we're here.
2005-02-16 16:12:28 +00:00
Pawel Jakub Dawidek
35f855d9f9 Fix typo. We want to unlock mutex here.
Submitted by:	Andreas Kohn <andreas.kohn@gmail.com>
MFC after:	1 week
2005-02-12 16:19:03 +00:00
Poul-Henning Kamp
07e95ed633 Make various random things static 2005-02-10 12:10:35 +00:00
Pawel Jakub Dawidek
e35d3a7828 - Remove g_gate_hold()/g_gate_release() from start/done paths. It saves
4 mutex operations per I/O requests.
- Use only one mutex to protect both (incoming and outgoing) queue.
  As MUTEX_PROFILING(9) shows, there is no big contention for this lock.
- Protect sc_queue_count with queue mutex, instead of doing atomic
  operations on it.
- Remove DROP_GIANT()/PICKUP_GIANT() - ggate is marked as MPSAFE and no
  Giant there.
2005-02-09 08:29:39 +00:00
Dag-Erling Smørgrav
04550802d8 merge from geom_vol_ffs.c rev 1.14 (avoid unaligned I/O requests) 2005-02-08 12:34:11 +00:00
Dag-Erling Smørgrav
363de7f683 Take care not to issue unaligned I/O requests while tasting a provider. 2005-02-08 08:04:23 +00:00
Pawel Jakub Dawidek
662a4e5878 - Use bioq_insert_tail()/bioq_insert_head() instead of bioq_disksort().
- Improve mediasize checking.

MFC after:	1 week
2005-02-05 00:30:08 +00:00
Poul-Henning Kamp
3ad9f7c2c5 When dumping to a unpartitioned disk, make sure to chop the
length of the dump area accordingly.

Run into by:	scottl
2005-01-29 16:49:43 +00:00
Jeff Roberson
1907e62037 - If mpsafevfs is off, acquire giant around all calls to bufdone().
Sponsored by:   Isilon Systems, Inc.
2005-01-28 16:04:44 +00:00
Poul-Henning Kamp
84a6975215 Introduce and use g_vfs_close(). 2005-01-25 15:52:04 +00:00
Poul-Henning Kamp
bc0fc6fcc3 Create a correctly sized vnode objects for disk devices. 2005-01-24 22:41:21 +00:00
Jeff Roberson
e9f3e3f8ca - Don't acquire giant around calls to bufdone().
Sponsored By:   Isilon Systems, Inc.
2005-01-24 10:47:46 +00:00
Lukas Ertl
f9b7569c09 Only report state changes of subdisks and plexes when there's
really a state change.

Reword the info a bit.
2005-01-21 18:27:23 +00:00
Lukas Ertl
0d93122102 Don't initialize error with ENXIO as we might end up here when
the plex has no more consumers (e.g. orphaning).
2005-01-21 18:24:20 +00:00
Pawel Jakub Dawidek
857d14cbc9 Protect against recursive slices creation in simlar way as it is done
in BSD class, ie. if provider below us uses the same metadata, don't
create slices based on the metadata.
This allows to create slices on geoms with rank != 1 without hacks.

Discussed with:	phk
Approved by:	phk
MFC after:	2 weeks
2005-01-20 22:14:05 +00:00
Lukas Ertl
eba5b9dfce Rename synchronization and initialization threads and prefix them
with 'gv_' for consistency.
2005-01-19 14:49:26 +00:00
Lukas Ertl
f11c507c45 Although an object may already be known in the configuration, it's
worker thread may have been destroyed (e.g. during orphaning).

Make sure that objects get back their worker threads when they get a
new geom.
2005-01-19 14:08:16 +00:00
Lukas Ertl
3b6cdf438a Reset object flags after killing off an object's worker thread. 2005-01-19 13:57:09 +00:00
Poul-Henning Kamp
e8cde1ac6f Discontinue zero-length g_ctl arguments as "just give him this pointer"
transfers.  The necessary context for calling copyin() isn't available
anyway and automatic code-validation chokes on this.
2005-01-17 07:14:24 +00:00
Poul-Henning Kamp
032bc81d4d CAM will sometimes remove a disk again even before it finished being
initialized.  We already cancel the pending events but we need to not
dereference the geom pointer which never got set different from NULL.
2005-01-14 21:05:35 +00:00
Pawel Jakub Dawidek
080361d6b8 Introduce a new GEOM class - SHSEC. It provides sharing secret between
the given providers. Without even one of the configured components there
should be no way to get the secret.

Supported by:	WHEEL Sp. z o.o.
		http://www.wheel.pl
2005-01-11 18:06:44 +00:00
Poul-Henning Kamp
6ef8480a88 Add BO_SYNC() and add a default which uses the secret vnode pointer
and VOP_FSYNC() for now.
2005-01-11 10:43:08 +00:00
Pawel Jakub Dawidek
437566858a Increase default synchronization speed.
MFC after: 3 days
2005-01-09 14:43:39 +00:00
Warner Losh
fa521b0366 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 18:27:30 +00:00
Pawel Jakub Dawidek
ea973705b3 - Fix 'rebuild' command - it can no longer relay on retaste event
(we ignore it).
- Remove code used for handling spoil events, as spoiling is not possible
  anymore, because we keep consumers open for writing all the time.

MFC after:	4 days
2005-01-04 12:15:21 +00:00
Pawel Jakub Dawidek
da84416791 Spoiling is now not possible, because we keep consumers open for writing
all the time. Remove unused code then.

MFC after:	4 days
2005-01-04 12:11:49 +00:00
Pawel Jakub Dawidek
fd6d312082 Fix 'rebuild' command (we ignore retaste event now, so don't relay on it). 2005-01-03 19:42:37 +00:00
Pawel Jakub Dawidek
cdca9c06d9 Remove unused #include. 2005-01-03 12:53:10 +00:00
John Baldwin
63710c4d35 Stop explicitly touching td_base_pri outside of the scheduler and simply
set a thread's priority via sched_prio() when that is the desired action.
The schedulers will start managing td_base_pri internally shortly.
2004-12-30 20:29:58 +00:00
Pawel Jakub Dawidek
7f456a7d61 Remove debug code. 2004-12-28 21:52:45 +00:00
Pawel Jakub Dawidek
a245a5483c - Add genid field to the metadata which will allow to improve reliability a bit.
After this change, when component is disconnected because of an I/O error,
  it will not be connected and synchronized automatically, it will be logged
  as broken and skipped. Autosynchronization can occur, when component is
  disconnected (on orphan event) and connected again - there were no I/O
  error, so there is no need to not connected the component, but when there were
  writes while it wasn't connected, it will be synchronized.
  This fix cases, when component is disconnected because of I/O error and can be
  connected again and again.
- Bump version number.
- Implement backward compatibility mechanism. After this change when metadata in
  old version is detected, it is automatically upgraded to the new (current)
  version.
2004-12-25 19:17:47 +00:00
Pawel Jakub Dawidek
538ff5ee7a Update disk->d_genid field when increasing sc->sc_genid. 2004-12-23 21:15:15 +00:00
Pawel Jakub Dawidek
9a9f504132 - Add genid field to the metadata which will allow to improve reliability a bit.
After this change, when component is disconnected because of an I/O error,
  it will not be connected and synchronized automatically, it will be logged
  as broken and skipped. Autosynchronization can occur, when component is
  disconnected (on orphan event) and connected again - there were no I/O
  error, so there is no need to not connected the component, but when there were
  writes while it wasn't connected, it will be synchronized.
  This fix cases, when component is disconnected because of I/O error and can be
  connected again and again.
- Bump version number.
- Add version change history.
- Implement backward compatibility mechanism. After this change when metadata in
  old version is detected, it is automatically upgraded to the new (current)
  version.
2004-12-22 23:09:32 +00:00
Pawel Jakub Dawidek
4485f00081 Now, when force device destruction is done on shutdown, hide warning,
that device cannot be destroyed immediately, under debug=1.

Suggested by:	simon
2004-12-21 19:50:18 +00:00
Pawel Jakub Dawidek
d97d5ee931 Improve reliability and clean up code a bit.
For more details check src/sys/geom/mirror/g_mirror.c rev.1.47,1.48,1.49,1.50.
2004-12-21 19:30:59 +00:00
Pawel Jakub Dawidek
f663832b75 This should not be permitted, but some GEOM classes held the topology lock
while doing g_(read|write)_data() (e.g. BSD). This can cause a deadlock
in MIRROR class. Not sure if this is safe to drop the topology lock in BSD
class, so change the code in MIRROR class to avoid this deadlock.
2004-12-21 18:42:51 +00:00
Pawel Jakub Dawidek
54bab03f04 Implement g_topology_try_lock().
No objection from:	phk
2004-12-21 18:32:46 +00:00
Pawel Jakub Dawidek
dc7d54e7b3 Remove unused variables. 2004-12-19 23:55:49 +00:00
Pawel Jakub Dawidek
a2a7b44de0 - Argument 'flags' in g_mirror_destroy_consumer() function is unsed -
mark it as such.
- Before closing consumer check if it is open. It can be closed here
  when g_mirror_connect_disk() fails on g_access().
2004-12-19 23:33:59 +00:00
Pawel Jakub Dawidek
9eec299fab Some major cleanups.
Keeping consumers open when device is closed is very hard. We need to
open consumers sometimes to update metadata, etc.
Many hacks was introduced in the past to made it possible. You cannot
be sure that you can open consumer for writing always, even if you think
it should be allowed. If one of the mirror components is for example da0
and you try to open it, you can get EPERM when da0s1 is opened for reading
(because BSD class opens consumers (da0) with an extra 'e' bit set).
Waiting for the events queue to be empty may do the trick, but it makes
code much uglier (as you cannot always call g_waitidle()), it doesn't
solve all edge cases and it can introduce deadlocks if there are events
in the queue that wait for gmirror.

I removed those hacks. Now all consumers are open r1w1e1 always, even if
device is closed. Maybe it is less clean from GEOM perspective, but simpify
code a lot and make it much more reliable.
The only issue was retaste event which is sent when we close consumers
opened for writing. I ignore retaste event by not detaching consumer
immediately (so retaste event is not send to my class) and sending event
right after it to detach and destroy consumer.
2004-12-19 23:12:00 +00:00
Pawel Jakub Dawidek
c37e2f9bbf Don't quit on first failure, just skip failures. 2004-12-19 22:58:25 +00:00
Christian Brueffer
44d086bde6 Fix typo in a comment.
MFC after:	3 days
2004-12-15 12:18:41 +00:00
Pawel Jakub Dawidek
89dd8e5326 bioq_insert_head() function is already in subr_disk.c. 2004-12-13 13:02:06 +00:00
Poul-Henning Kamp
2221dbebce Pass the file->flags down to geom ioctl handlers.
Reject certain ioctls if write permission is not indicated.

Bump geom API version.

Reported by:	Ruben de Groot <mail25@bzerk.org>
2004-12-12 10:09:05 +00:00
Pawel Jakub Dawidek
53ed4e0d54 - Turn off 'fast' mode by default and increase maximum memory to consume
when this mode is used.
- Manual page update.
2004-12-09 12:26:47 +00:00
Marcel Moolenaar
9055ed836a o Don't limit GPT as a rank 2 provider. Allow it to be connected
anywhere in the DAG. This includes configurations that are not
   allowed by the EFI specification.
o  Reject a GPT partition table if it's not preceeded by a PMBR.
   There's no need to preserve the MBR partitioning anymore as GPT
   is mature and with the first bullet extending the applicability
   of GPT, it's better to be a bit more strict.
2004-12-05 06:02:21 +00:00
Pawel Jakub Dawidek
afd05d741f When initializing device, set d_softc and d_no fields for all components,
because we know it then and we need it when inserting a component which
wasn't destroyed while device was running.

Reported by:	Michael Handler <handler@grendel.net>
MFC after:	1 week
2004-12-04 21:20:59 +00:00
Warner Losh
3bc18cb767 Add observations of the Linux98 and Grub/98 boot loaders. These
observations lead me to believe that the convetion for pc98 boot
loaders is to have a jump unstruction, followed by a string, followed
by code.  The jump usually doesn't have a nop after it and usually the
string is NUL terminated, but Grub/98 breaks both of these rules.

# I looked for, but failed to find the Minux boot blocks for PC-9801 port.
2004-11-30 09:40:11 +00:00
Warner Losh
696ac86f2c Reject tasting of this provider if the sector size isn't a multiple of
512.  If I had an audio cdrom in my cd player when I booted my system,
I'd get a panic from geom because you can't read 8192 bytes from an
audio cdrom.

Remove XXX comment about IPL1 and replace it with some information
from my soon to be published web page on the pc98 disk layout.  The
IPL1 test was the result of an observation of a disk with FreeBSD's
boot0 program.  It was testing part of an area what appears to be
reserved for a boot loader name, which comes after a jump over this
area.  I don't yet know if it is required to be any specific jump
instruction, or if the destination has to be location 11. [1]

[1] FreeBSD Press No. 13, page 115, poorly translated by myself.  The
picture there shows offset 8 as the destination of the jump, but
FreeBSD's boot0 program has three padding NULs after the IPL1 name and
uses a 16-bit 'jmp' instruction.
2004-11-30 08:00:14 +00:00
Poul-Henning Kamp
d4dbba5f83 Fix a long standing bug in geom_mbr which is only now exposed by the
correct open/close behaviour of filesystems:

When an ioctl to modify the MBR arrives, we cannot take for granted that
we have the consumer open.

The symptom is that one cannot run 'boot0cfg -s2 /dev/ad0' in single-user
mode because / is the only open partition in only open r1w0e1.

If it is not, we attempt to increase the write count by one and
decrease it again afterwards.

Presumably most if not all other slices suffer from the same problem.
2004-11-28 20:57:25 +00:00