for possible buffer overflow problems. Replaced most sprintf()'s
with snprintf(); for others cases, added terminating NUL bytes where
appropriate, replaced constants like "16" with sizeof(), etc.
These changes include several bug fixes, but most changes are for
maintainability's sake. Any instance where it wasn't "immediately
obvious" that a buffer overflow could not occur was made safer.
Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Mike Spengler <mks@networkcs.com>
- Call isa_dmadone() whenever necessary to stop DMA and/or free bounce
buffers. Undead DMA corrupted the malloc freelist fairly consistently
in the following configuration: SLICE kernel, 2 floppy drives, no disk
in fd0, disk in fd1.
- Don't call fdc_reset() from fd_timeout(). Doing so gave an "extra"
interrupt which was usually misinterpreted as being for completion
of the next FDC command; the interrupt for completion of the next
FDC command was then usually misinterpreted... There were further
complications for interrupts latched by the soft-spl mechanism so
that they were delivered after all the h/w interrupts went away.
This caused at least wrong head settle delays and may be why the
FreeBSD floppy driver seems to munch floppies more than most floppy
drivers. The reset was unnecessary anyway in cases that didn't have
the bug described next, since is was repeated a little later for
the IOTIMEDOUT state. The state machine has complications to handle
resets correctly, so just use it.
- Don't call retrier() from fd_timeout(). The IOTIMEDOUT state needs
to be processed next, and it isn't valid to set to that state if
retrier() has aborted the current transfer. Doing so caused null
pointer panics after the previous bug was fixed.
Improved error handling:
- If an i/o is aborted, arrange to reset in the state machine before
doing the next i/o. New fdc flag for this. This fixes spurious
warnings and lengthy busy-waiting for the next i/o.
- Split STARTRECAL into RESETCOMPLETE and STARTRECAL and only check
for the results from reset if we actually reset. This fixes spurious
warnings for other paths to STARTRECAL. [Oops, it may break reset
handling for motor-off resets.]
Cleanups in fd_timeout():
- Renamed to fd_iotimeout() to make it clearer that it is only used
for i/o.
- Don't handle the bp == 0 case. This case can't happen for i/o.
- Don't check for controller-busy. We know it must be.
- Don't print anything. retrier() already prints too much for normal
errors.
- Fudge the state differently so that the state machine advances
fdc->retry and the status is invalid (perhaps this should fudge a
valid state like the one for WP).
- Style fixes.
controller reports a successful seek, it is very unlikely to report
seeking to a cylinder other than the one requested, but we check for
this, and botched the error handling for the requested_cylinder != 0
case. This error happened when the bug fixed in rev.1.52 of <sys/buf.h>
caused the head of buffer queue to change to one starting on a different
cylnder - the requested cylinder was found, but it wasn't what we
thought we requested. The fix is simply to arrange to reset the state
machine.
Corruption of the buffer queue seems to only have been a problem in the
floppy driver. Other drivers dequeue the head of the queue before doing
physical i/o on it, so the corruption at worse broke the elevator sort
order. Dequeueing breaks it anyway.
interupt level events. This needs a lot of cleanup, but has been working
here for a month or two.. originally needed for CAM integration
but that hasn't happenned yet. The probing state machines for each
handler should be replaced by a more generic state-service. It's
still quite messy in there..
There is only cdevsw (which should be renamed in a later edit to deventry
or something). cdevsw contains the union of what were in both bdevsw an
cdevsw entries. The bdevsw[] table stiff exists and is a second pointer
to the cdevsw entry of the device. it's major is in d_bmaj rather than
d_maj. some cleanup still to happen (e.g. dsopen now gets two pointers
to the same cdevsw struct instead of one to a bdevsw and one to a cdevsw).
rawread()/rawwrite() went away as part of this though it's not strictly
the same patch, just that it involves all the same lines in the drivers.
cdroms no longer have write() entries (they did have rawwrite (?)).
tapes no longer have support for bdev operations.
Reviewed by: Eivind Eklund and Mike Smith
Changes suggested by eivind.
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
This code will be turned on with the TWO options
DEVFS and SLICE. (see LINT)
Two labels PRE_DEVFS_SLICE and POST_DEVFS_SLICE will deliniate these changes.
/dev will be automatically mounted by init (thanks phk)
on bootup. See /sys/dev/slice/slice.4 for more info.
All code should act the same without these options enabled.
Mike Smith, Poul Henning Kamp, Soeren, and a few dozen others
This code does not support the following:
bad144 handling.
Persistance. (My head is still hurting from the last time we discussed this)
ATAPI flopies are not handled by the SLICE code yet.
When this code is running, all major numbers are arbitrary and COULD
be dynamically assigned. (this is not done, for POLA only)
Minor numbers for disk slices ARE arbitray and dynamically assigned.
This introduce an xxxFS_BOOT for each of the rootable filesystems.
(Presently not required, but encouraged to allow a smooth move of option *FS
to opt_dontuse.h later.)
LFS is temporarily disabled, and will be re-enabled tomorrow.
floppy drive #0, regardless of what the CMOS says. This is intended
as a bandaid for those plagued with Compaq's idea to not announce the
floppy drive on their `Aero' notebook.
Using the device flags is not very nice (in particular since they
aren't per-drive but per-controller), but still looks a lot better to
me than the disgusting guesswork hack that was recently posted to
-hackers.
Doc update will follow shortly.
number of dma overruns/underruns for systems under heavy dma load.
As a side effect, broken enhanced floppy controllers that sometimes
don't detect dma overruns/underruns will give less errors.
Reviewed by: j@uriah.heep.sax.de (J Wunsch)
Hide the bogus FDC ``chip type'' display behind a (mostly) undocumented
option, since people started to trust the bogus claim. Once we're going
to handle 2.88 MB controllers, we have to redo the chip detection, by
now just leave it hidden.
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.
The system boots and can mount UFS filesystems.
Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
Mount_std mounts will not work until the getfsent
library routine is changed.
Reviewed by: various people
Submitted by: Jeffery Hsu <hsu@freebsd.org>
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
appearance of this bug was the malfunctioning -M option in GNU tar (it
worked only by explicitly specifying -L).
Reviewed by: bde, and partially corrected accoring to his comments
Candidate for 2.2, IMHO even for 2.1.6.
Saves about 280 butes of source per driver, 56 bytes in object size
and another 56 bytes moves from data to bss.
No functional change intended nor expected.
GENERIC should be about one k smaller now :-)
quite work yet, so the heart of it is disabled.
Added bdev and cdev args to dsopen().
drivers:
Fixed device names, links, minor numbers and modes.
wd.c:
Started actually supporting devfs.
diskslice.h:
Added devfs tokens to structs (currently 576 of them per disk! :-().
subr_diskslice.c:
Create devfs entries in dsopen() and (unsuccessfully) attempt to make
them go away at the right times. DEVFS is #undefed at the start so
that this shouldn't cause problems.
fd and wt drivers need bounce buffers, so this normally saves 32K-1K
of kernel memory.
Keep track of which DMA channels are busy. isa_dmadone() must now be
called when DMA has finished or been aborted.
Panic for unallocated and too-small (required) bounce buffers.
fd.c:
There will be new warnings about isa_dmadone() not being called after
DMA has been aborted.
sound/dmabuf.c:
isa_dmadone() needs more parameters than are available, so temporarily
use a new interface isa_dmadone_nobounce() to avoid having to worry
about panics for fake parameters. Untested.
most devsw referenced functions are now static, as they are
in the same file as their devsw structure. I've also added DEVFS
support for nearly every device in the system, however
many of the devices have 'incorrect' names under DEVFS
because I couldn't quickly work out the correct naming conventions.
(but devfs won't be coming on line for a month or so anyhow so that doesn't
matter)
If you "OWN" a device which would normally have an entry in /dev
then search for the devfs_add_devsw() entries and munge to make them right..
check out similar devices to see what I might have done in them in you
can't see what's going on..
for a laugh compare conf.c conf.h defore and after... :)
I have not doen DEVFS entries for any DISKSLICE devices yet as that will be
a much more complicated job.. (pass 5 :)
pass 4 will be to make the devsw tables of type (cdevsw * )
rather than (cdevsw)
seems to work here..
complaints to the usual places.. :)
totally dynamic.
this is only the devices in i386/isa
I'll do more tomorrow.
they're completely masked by #ifdef JREMOD at this stage...
the eventual aim is that every driver will do a SYSINIT
at startup BEFORE the probes, which will effectively
link it into the devsw tables etc.
If I'd thought about it more I'd have put that in in this set (damn)
The ioconf lines generated by config will also end up in the
device's own scope as well, so ioconf.c will eventually be gutted
the SYSINIT call to the driver will include a phase where the
driver links it's ioconf line into a chain of such. when this phase is done
then the user can modify them with the boot: -c
config menu if he wants, just like now..
config will put the config lines out in the .h file
(e.g. in aha.h will be the addresses for the aha driver to look.)
as I said this is a very small first step..
the aim of THIS set of edits is to not have to edit conf.c at all when
adding a new device.. the tabe will be a simple skeleton..
when this is done, it will allow other changes to be made,
all teh time still having a fully working kernel tree,
but the logical outcome is the complete REMOVAL of the devsw tables.
By the end of this, linked in drivers will be exactly the same as
run-time loaded drivers, except they JUST HAPPEN to already be linked
and present at startup..
the SYSINIT calls will be the equivalent of the "init" call
made to a newly loaded driver in every respect.
For this edit,
each of the files has the following code inserted into it:
obviously, tailored to suit..
----------------------somewhere at the top:
#ifdef JREMOD
#include <sys/conf.h>
#define CDEV_MAJOR 13
#define BDEV_MAJOR 4
static void sd_devsw_install();
#endif /*JREMOD */
---------------------somewhere that's run during bootup: EVENTUALLY a SYSINIT
#ifdef JREMOD
sd_devsw_install();
#endif /*JREMOD*/
-----------------------at the bottom:
#ifdef JREMOD
struct bdevsw sd_bdevsw =
{ sdopen, sdclose, sdstrategy, sdioctl, /*4*/
sddump, sdsize, 0 };
struct cdevsw sd_cdevsw =
{ sdopen, sdclose, rawread, rawwrite, /*13*/
sdioctl, nostop, nullreset, nodevtotty,/* sd */
seltrue, nommap, sdstrategy };
static sd_devsw_installed = 0;
static void sd_devsw_install()
{
dev_t descript;
if( ! sd_devsw_installed ) {
descript = makedev(CDEV_MAJOR,0);
cdevsw_add(&descript,&sd_cdevsw,NULL);
#if defined(BDEV_MAJOR)
descript = makedev(BDEV_MAJOR,0);
bdevsw_add(&descript,&sd_bdevsw,NULL);
#endif /*BDEV_MAJOR*/
sd_devsw_installed = 1;
}
}
#endif /* JREMOD */
Convert the remaining sysctl stuff to the new way of doing things.
the devconf stuff is the reason for the large number of files.
Cleaned up some compiler warnings while I were there.
floppies must have been random in 2.x since we reintroduced sorting
on b_pblkno on 1995/03/18. Drivers still initialize b_cylin/b_resid
although this is no longer used.
Removed unused, wrong function fdsize(). (Returning 0 means that the
device exists and has size 0, not that the device doesn't exist.
swaponvp() allows for size 0 by stupidly calling the d_psize function
twice if the size isn't 0. setdumpdev() doesn't allow for it.)
Continued removing /* ARGSUSED */ from drivers.
misplaced extern declarations (mostly prototypes of interrupt handlers)
that this exposed. The prototypes should be moved back to the driver
sources when the functions are staticalized.
Added idempotency guards to <machine/conf.h>. "ioconf.h" can't be
included when building LKMs so define a wart in bsd.kmod.mk to help
guard against including it.
to <machine/conf.h>. conf.h was mechanically generated by
`grep ^d_ conf.c >conf.h'. This accounts for part of its ugliness. The
prototypes should be moved back to the driver sources when the functions
are staticalized.
changes to allow devices that don't probe (e.g. /dev/mem)
to create devfs entries
this required giving 'configure' its own SYSINIT entry
so we could duck in just before it with a DEVFS init
and some device inits..
my devfs now looks like:
./misc
./misc/speaker
./misc/mem
./misc/kmem
./misc/null
./misc/zero
./misc/io
./misc/console
./misc/pcaudio
./misc/pcaudioctl
./disks
./disks/rfloppy
./disks/rfloppy/fd0.1440
./disks/rfloppy/fd1.1200
./disks/floppy
./disks/floppy/fd0.1440
./disks/floppy/fd1.1200
also some sligt cleanups.. DEVFS needs a lot of work
but I'm getting back to it..
The ``flags 1'' in the fdc line is now only needed for owners of an
Insight tape (perhaps there aren't any? Mine is disfunctional). All
other probes are safe wrt. to the motor-control line of floppy disk
drives. Document the flag in LINT finally.
For those where it was easy, drivers were also fixed to call
dev_attach() during probe rather than attach (in keeping with the
new design articulated in a mail message five months ago). For
a few that were really easy, correct state tracking was added as well.
The `fd' driver was fixed to correctly fill in the description.
The CPU identify code was fixed to attach a `cpu' device. The code
was also massively reordered to fill in cpu_model with somethingremotely
resembling what identifycpu() prints out. A few bytes saved by using
%b to format the features list rather than lots of ifs.
Report floppy/tape units on seperate lines as fdX:/ftX: to correct lots of
ways the current scheme failed to end the output with \n.
Add controller and/or drive designator to the fron of several messages
that come from this drive. [It's not fun to track down driver messages
using grep over the source tree.]
Reviewed by: joerg
protected drive at open() time has been *totally bogus*! The guy who
submitted it didn't understand all the implications of calling
set_motor(), and the `who' who included the patch into the tree did it
blindly... Pleeeeze, don't commit code to this driver unless you are
really going to understand what it does! This one caused me to pull
out even more hears, and those who know me do know that i ain't got
too many o'them. :-)
now marked busy as long as it's being in non-reset state, and the
drives are busy as long as at least one instance is open.
Also reformat everything to fit into 80 columns again.
Changed my mind wrt. error reporting for a write-protected drive and
an open() with write intent; ENXIO has been too weird, now return EIO.
Some portions of the code need to be rewritten to use tprintf()
instead of simple printf()'s, so the messages will also appear on the
session terminal, however.
floppy driver (or in the hardware?). It turned out to be caused by
spurious interrupts, right after an FDC reset.
Also major cleanup in the low-level structure, there are now functions
performing error-checks for the FDC I/O.
Submitted by: (mostly) Peter Dufault <dufault@FreeBSD.org>
Now floppy tape support is *disabled* unless you specifically
request otherwise. Poul wanted it this way, and I guess I'm not going to argue
though it may seem counter-intuitive. We can always change it back, later.
flags & 0x1. Somebody should build a kernel with this and see if
the floppy-tape damaged people can turn it off properly with userconfig.
I can't reproduce the original problem here.
floppies now. I'm not sure why, but things hang when it gets to the
`changing root to fd0c' part. Without your latest commit, everything works
fine. Maybe you can figure out what you broke after ALPHA! :)
. avoid resetting the FDC every time the last motor is going off;
instead, give it a 60-second period for possible later reactivation.
This prevents us from needing to recalibrate the FDC too often,
but still allows for an ``automagic error recovery', just in case the
controller is absolutely stuck. (Simply wait for 60 seconds, and
try it again.)
. made the floppy head settle time after a seek a constant
that might be overridden by a config option. (Well, actually the
divisor of the settle time). Pepople often reported problems with
their floppies, so i need a simply mechanism that allows them
to play with that value. (I personally cannot find any problem
on *my* drives.)
. implement the FD_DEBUG ioctl command, in case the driver
is compiled with DEBUG turned on.
. removed a bogus parameter from a printf; the remaining warnings
from gcc -Wall seem to be warnings about the %b format gcc cannot
understand
. rearrange Garett's code to fit better in the existing structure
of #define/type/function ordering.
. make everything fit into 79 columns again.
and all SCSI devices (except that it's not done quite the way I want). New
information added includes:
- A text description of the device
- A ``state''---unknown, unconfigured, idle, or busy
- A generic parent device (with support in the m.i. code)
- An interrupt mask type field (which will hopefully go away) so that
. ``doconfig'' can be written
This requires a new version of the `lsdev' program as well (next commit).
so i hope i've finally removed all the occasions where the driver
got stuck when there's no floppy in the drive.
Also attemmpting to omit the error mesage for ``recalib failed''
for the first time, since people tend to be confused about this.
This is needed for having the fdformat program no longer searching
non-public include paths.
Protect the definitions in fdreg.h against double inclusion.
when the drive had been left on a cylinder > 67 after kernel boot. The
most common case for this is booting a kernel that is located on
the inner cylinders of a floppy.
Also removed all occurences of spinwait(), replaced by DELAY.
Nuked a return line saying nothing, this might make Bruce happy 8^)
Submitted by: partially by Bruce Evans
date: 1994/05/22 12:35:38; author: joerg; state: Exp; lines: +6 -6
First round of floppy changes. Try making `fd' more robust.
New features:
. ioctl command for setting the drive type (density etc.); restricted
to the super-user
. ioctl for getting/seting `drive options'; currently only option
is FDOPT_NORETRY: inhibit the usual retries; used when verifying
a newly formatted track
Fixes:
. function prototypes
. made all internal functions `static'
. cleaned up & corrected .h files
. restructured, to make the chaotic function sequence more rational
. compiled with -Wall, and cleared all warnings
. introduced a mirror for the (write-only) `digital output register',
to avoid the current kludge
. device probing completed by seeking/recalibrating, and looking
for track 0 being found
. holding the controller down in reset state while it is idle (and
thus saving allot of headaches)
. make requests fail that are not a multiple of the (physical)
sector size
. removed the fixed physical sector size (512 bytes), allowing for any
size the controller could handle (128/256/512/1024 bytes)
. replaced some silly messages
. fixed the TRACE* macro usage, debugging reports should be complete
now again (debugging output is HUGE! though)
. removed fd_timeout for SEEK command; seeks are always reported by
the controller to succeed, since the `success' only refers to the
controller's idea of success - there is no hardware line to tell about
the seek end (other than the `track 0' line)
. catch SENSEI's that report about a `terminated due to READY changed'
status - could happen after a controller reset
. converted ``hz / <something>'' divide operations to divisors that are
powers of two, so gcc can optimize them into shifts
. write/format operations are checked against a write-protected medium
now *prior* starting the operation
. error reports of `invalid command' and `wrong cylinder' will cause
shortcuts in the retrier() now
. fixed a bug in the retrier() causing bogus block numbers to be reported
. fdformat() does care for errors now
Known Bugs:
. no attempts have been made (yet) to improve the performance
. sometimes, bogus ``seek/recalib failed'' messages are logged; this
is still a bug in the driver, but it's not harmful since it's
usually caught by the retrier()
Reviewed by:
Submitted by:
Obtained from:
Added a missing #ifdef INET wrapper in lpt.c
Main change:
Removed the timeout_func_t casts from timeout calls and
correctly defined the timeout routines to conform to
the new format.
lpt.c doesn't have this change.
Reviewed by:
Submitted by:
``changes'' are actually not changes at all, but CVS sometimes has trouble
telling the difference.
This also includes support for second-directory compiles. This is not
quite complete yet, as `config' doesn't yet do the right thing. You can
still make it work trivially, however, by doing the following:
rm /sys/compile
mkdir /usr/obj/sys/compile
ln -s M-. /sys/compile
cd /sys/i386/conf
config MYKERNEL
cd ../../compile/MYKERNEL
ln -s /sys @
rm machine
ln -s @/i386/include machine
make depend
make
1) check va before clearing the page clean flag. Not doing so was
causing the vnode pager error 5 messages when paging from
NFS. (pmap.c)
2) put back interrupt protection in idle_loop. Bruce didn't think
it was necessary, John insists that it is (and I agree). (swtch.s)
3) various improvements to the clustering code (vm_machdep.c). It's
now enabled/used by default.
4) bad disk blocks are now handled properly when doing clustered IOs.
(wd.c, vm_machdep.c)
5) bogus bad block handling fixed in wd.c.
6) algorithm improvements to the pageout/pagescan daemons. It's amazing
how well 4MB machines work now.
Subject: Re: Bugs with floppy drives
Date: Tue, 8 Mar 94 9:11:54 CST
The transfer speed was only set in the retry after error, not when
switching drives.
a binary link-kit. Make all non-optional options (pagers, procfs) standard,
and update LINT to reflect new symtab requirements.
NB: -Wtraditional will henceforth be forgotten. This editing pass was
primarily intended to detect any constructions where the old code might
have been relying on traditional C semantics or syntax. These were all
fixed, and the result of fixing some of them means that -Wall is now a
realistic possibility within a few weeks.
Entries for 800 and 820 fixed.
From vak@kiae.su:
incorporate Joerg Wunsch formatting code
correct handle timeouted operations
fixed entry for 720 media
GAP values changed suitable for possible format code addition.
Read/write GAP always 2 now.
Interleave parameter added for possible format code addition.
Many logical formats added.
720K physical drive added.
Problems: still can't read 720..820 media in 1.44 drive.
800K in HD 5.25in (maximum for DD diskettes)
1.44M in HD 5.25in (for easy distributions)
1.46M in HD 5.25in (maximum for 5.25)
Some cosmetique changes.
Now minor looks like UU DDDDDD, UU - unit, DDDDDD - density.
If density == 0, CMOS-detect format assumed.
Fix attach code for correct work with unknown CMOS
floppy types.
Trick diskerr to handle new minor.
1.722M floppy in 1.44M drive popular format added.
possible end-user errors.
Now:
1) on physical 1.2 can open logical 1.2, 720, 360H
2) on physical 1.44 can open logical 1.44, 720
3) on physical 360 can open logical 360
All other variants refused.
C-style improved in this check, multiply if's changed to switch.
More work to add 720K floppy support.
Restore good old dependance of device and floppy type.
Now:
fd?a == 1.44
fd?b == 1.2
fd?c == 720
fd?d == 360 in HD
fd?e == 360
Add more strict size check in Fdopen, not it refuse:
1) Attempt to open any type expect fd?e, if you have only 360K drive.
2) Attempt to open fd?a if you have only 1.2 drive.
From: <dec@lazarus.nrtc.northrop.com>
Changes between EPSILON and RELEASE of FreeBSD have again caused
the kernel to not see my floppy disk drives. I don't know what happened,
'cause I don't see any changes to fd.c, but here is an old fix that
I have applied to the probe routine which will solve the problem (at
least for me). Since this is a rather brute-force solution - I understand
if you want to ignore it...
[Upgrading to pre-Beta FreeBSD caused this on my system. -AM]
Date: Thu, 16 Sep 93 01:35:10 +1000
Julian writes:
>In fact DEVIDLE and FINDWORK ended up being basically equivalent.
>the bit I wonder about, is the returning of 0.. What (other than
>another request from somewhere else in the kernel) is going to start
>work on the next item on the queue?
I think removing FINDWORK would make things clearer.
Nothing much is going to start work on the next item. However, it is
pointless to continue processing the queue for the same unready drive.
Aborting all reads and trying harder to perform all writes would be
better.
Julian writes.
> no, actually it should be:
> fdt = fd_data[FDUNIT(minor(dev))].ft;
Fixed.
From: bde@kralizec.zeta.org.au (Bruce Evans)
Date: Thu, 16 Sep 93 22:56:01 +1000
The fd driver reported the wrong cylinder/head/sector numbers after an
error (ST3 is only valid after a sense-drive command), and didn't report
fs block numbers (diskerr was not used).
There was an old problem with writes to block fd devices. Try this:
1. write protect floppy in fd0.
2. tar cf /dev/fd0a /dev/null. Repeat a few times. Later writes tend to
terminate earlier.
3. un-write protect floppy.
4. repeat step 2. The writes tend to return 0, 2048, 4096, ... and then
succeed.
This was caused by a bug in vfs__bios.c. (The bug is fixed in NetBSD's
vfs_bio.c.) fd.c sets bp->b_resid to nonzero after an error. vfs__bios.c
was not initializing bp->b_resid. This causes some writes to terminate
early (e.g., writes to block devices; see spec_write()).
Related funnies:
1. Nothing tries to write the residual bytes.
2. The wd driver sets bp->b_resid to 0 after an error, so there's no
way anything else could write the residual bytes.
3. I use the block fd device for tar because the raw device seemed to
have more bugs long ago, and because it ought to be able to handle
buffering more transparently (I don't want to have to know the
device size). But spec_write() always uses the size BLKDEV_IOSIZE
== 2048 which is too small. For disks it should use the size of
one track (rounded down to meet the next track boundary or the i/o
size). Here it would help if the DIOCGPART ioctl worked. But
DIOCGPART is not implemented for floppies, and the disk size is
ignored except for partitions of type FS_BSDFFS.
Bruce
message for Bruces changes:
>From: bde@kralizec.zeta.org.au (Bruce Evans)
>Subject: fixes for fd driver
I think I've fixed some bugs in the 0.2.4 fd driver.
1. The main cause of hangs was that there was no timeout for seeks. So
attempting i/o with no floppy in the drive hung iff a seek was required.
2. Opens of unattached drives were allowed. The kernel usually paniced
soon after due to a bad pointer.
3. Some timeout functions ran at splclock() instead of splbio(). This
may not have mattered.
4. The state machine was left in a funny state after a timeout.
5. Some function headers were new-style.
6. I picked up some code posted the other day to implement label ioctls.
Now `disklabel fd0' works. See a comment for how to modify conf.c.
reinitialized between while loops. Added comments about what was going
on in the out_fdc routine.
out_fdc now returns if the direction bit is not set in time instead of
trying to wait for MRQ to get cleared.
way of doing things. There still remain several drivers that need to
be updated. Also added a compile-time option to pccons to switch the
control and caps-lock keys (REVERSE_CAPS_CTRL) - added for my personal
sanity.
