bp->b_flags has been broken for many years:
a) they didn't set B_BUSY for doing i/o. This has been fatal since
1995/07/25 when biodone() started checking that B_BUSY is set.
b) they didn't set B_INVAL for releasing the buffer. This at best
just put a useless buffer in the LRU queue for a little while.
Fix a couple of spelling errors and complete a couple of function
pointer declarations.
Submitted by: terry (terry lambert)
This is a composite of 3 patch sets submitted by terry.
they are:
New low-level init code that supports loadbal modules better
some cleanups in the namei code to help terry in 16-bit character support
some changes to the mount-root code to make it a little more
modular..
NOTE: mounting root off cdrom or NFS MIGHT be broken as I haven't been able
to test those cases..
certainly mounting root of disk still works just fine..
mfs should work but is untested. (tomorrows task)
The low level init stuff includes a total rewrite of init_main.c
to make it possible for new modules to have an init phase by simply
adding an entry to a TEXT_SET (or is it DATA_SET) list. thus a new module can
be added to the kernel without editing any other files other than the
'files' file.
instead of with none. The first (struct proc *) arg is used if lkmnosys()
if is actually called.
Implement lkmnosys() with the correct number and type of args so that
the first of them can be used and the others won't need to be fixed
lated.
calls.
Found by: gcc -Wstrict-prototypes after I supplied some of the 5000+
missing prototypes. Now I have 9000+ lines of warnings and errors
about bogus conversions of function pointers.
disksort is called at non-interrupt time and can be actively traversing
the list when that happens, there is a very small window of vulnerability.
Close it by protecting disksort with splbio().
Old variant returns 38400 for them, now it returns nearest matched
rounded down, expect speeds in range 0 > speed < 50 rounded up
to not produce hangup.
with interaction pty <-> serial driver with non-standard speed.
So, nothing protect us from garbadge in speed field, expect
checking for < 0 left in tty.c :-(
too much for non-open ptys, but there is normally no problem because the
l_modem(, 0) is a no-op for closed ptys provided the line discipline is
standard and MDMBUF isn't set.
wrong vp's ops vector being used by changing the VOP_LINK's argument order.
The special-case hack doesn't go far enough and breaks the generic
bypass routine used in some non-leaf filesystems. Pointed out by Kirk
McKusick.
Introduce TS_CONNECTED and TS_ZOMBIE states. TS_CONNECTED is set
while a connection is established. It is set while (TS_CARR_ON or
CLOCAL is set) and TS_ZOMBIE is clear. TS_ZOMBIE is set for on to
off transitions of TS_CARR_ON that occur when CLOCAL is clear and
is cleared for off to on transitions of CLOCAL. I/o can only occur
while TS_CONNECTED is set. TS_ZOMBIE prevents further i/o.
Split the input-event sleep address TSA_CARR_ON(tp) into TSA_CARR_ON(tp)
and TSA_HUP_OR_INPUT(tp). The former address is now used only for
off to on carrier transitions and equivalent CLOCAL transitions.
The latter is used for all input events, all carrier transitions
and certain CLOCAL transitions. There are some harmless extra
wakeups for rare connection- related events. Previously there were
too many extra wakeups for non-rare input events.
Drivers now call l_modem() instead of setting TS_CARR_ON directly
to handle even the initial off to on transition of carrier. They
should always have done this. l_modem() now handles TS_CONNECTED
and TS_ZOMBIE as well as TS_CARR_ON.
gnu/isdn/iitty.c:
Set TS_CONNECTED for first open ourself to go with bogusly setting
CLOCAL.
i386/isa/syscons.c, i386/isa/pcvt/pcvt_drv.c:
We fake carrier, so don't also fake CLOCAL.
kern/tty.c:
Testing TS_CONNECTED instead of TS_CARR_ON fixes TIOCCONS forgetting to
test CLOCAL. TS_ISOPEN was tested instead, but that broke when we disabled
the clearing of TS_ISOPEN for certain transitions of CLOCAL.
Testing TS_CONNECTED fixes ttyselect() returning false success for output
to devices in state !TS_CARR_ON && !CLOCAL.
Optimize the other selwakeup() call (this is not related to the other
changes).
kern/tty_pty.c:
ptcopen() can be declared in traditional C now that dev_t isn't short.
Make more functions static.
tty.c:
Use tcflag_t (u_long) and cc_t instead of u_char and int/long.
Don't record values that are only evaluated once.
Compare ints using imin(), not min(). min() is for comparing u_ints.
Old versions of tty.c used the type-safe but multiple-evaluation-unsafe
macro MIN(). The args are apparently never negative; otherwise this
change would be non-cosmetic.
Don't repeat the loop test in ttywait().
tty.h:
Improve English in and formatting of comments.
Use input buffer watermarks of TTYHOG-512 (high) and (high)*7/8
(low) instead of TTYHOG/2 (high) and TTYHOG/5 (low) to agree with
some drivers. 512 is magic and some things depended on TTYHOG/2
>= TTYHOG-512 to work; now they depend on the 512 magic not changing
and TTYHOG-512 being significantly larger than 0. This should be
handled in ttsetwater().
Separate the decision about whether to do input flow control from
doing it. ttyblock() now just starts input flow control (hardware
and/or software) and there is a new function ttyunblock() to stop
it. The decisions are the same except for the watermark changes
and allowing for input expansion for PARMRK.
When flushing input, try harder at first to send a start character
if required, but give up if the first attempt fails.
cy.c, rc.c, sio.c:
Simplify: let ttyinput() handle input flow control if it is not
being bypassed. Use ttyblock() to start flow control otherwise.
rc.c:
Use same input flow control test as elsewhere: test in a more
efficient order and start flow control at >= highwater instead of
at > highwater.
string as possible and return ENOMEM if the entire string cannot
be returned. This brings the routines in line with how the man
page says they work, and how the calling routines are expecting
them to work. This allows the dummy uname() routine in libc to
obtain the version string, since the kernel version string is
longer than that normally returned by the uname() routine.
This is 3/4 of the fix for PR# 462.
Reviewed by: Bruce Evans
as is required to be POSIXLY_CORRECT and "right". I interpret
"referring to a directory" as being a directory or becoming a
directory. E.g., the trailing slashes in mkdir("/nonesuch/"),
rename("/tmp", /nonesuch/") and link("/tmp", "/root_can_like_dirs/")
are ignored because the target will become a directory if the
syscall succeeds. A trailing slash on a symlink causes the symlink
to be followed (this is a bug if the symlink doesn't point to a
directory; fix later).
queues for TIOCSETA[W]. Swapping an even number of times broke
the queue resource limits. This would have broken CRTSCTS flow
control if the clist slush list was used up.
Don'concatenate the queues for TIOCSETA[W] if one of the queues
has a resource limit of 0. Concatenation would cause a panic if
one of the queues is nonempty and the other is limited to length
0. This may have caused panics in PPPDISC.
Wake up readers after all transitions of ICANON. When ICANON is
turned off it is quite likely that characters will become available
to be read.
Reduce indentation near these changes.
on output below low water) and TS_SO_OCOMPLETE (sleep on output complete).
Most of the support for this has already been committed. Drivers should
call ttwwakeup() to handle wakeups whenever output is below low water
(and some output event causes this condition to be checked) or TS_BUSY is
cleared.
tty.c:
Fix the livelock in ttywait() properly by sleeping on output complete, not
on output below low water.
Use ttwwakeup() instead of separate select and output wakeups for all
wakeups of writers.
Add wakeups of writers for output flushes and carrier/clocal transitions.
Don't go to sleep in ttycheckoutq() if ttstart() reduces the queue to below
low water.
Use the timeout built into tsleep() in ttycheckoutq().
Optimize the select wakeup in ttwwakeup(). It seems reasonable to know
too much about the internals of tp->t_wsel now that the knowledge is
localised in tty.c.
Remove nullmodem().
It may be useful to have a null modem routine, but nullmodem()
wasn't one. nullmodem() was identical to ttymodem() except it
didn't implement MDMBUF (carrier) flow control, didn't do any
wakeups for off to on carrier transitions, and didn't flush the
i/o queues for on to off carrier transitions (flushing has the side
effect of waking up readers and writers) although it did generate
SIGHUPs. The wakeups must normally be done even if nullmodem() is
null in case something is sleeping waiting for a carrier transition.
In any case, the wakeups should be harmless. They may cause bogus
results for select(), but select() is already bogus for nonstandard
line disciplines.
different types of panics/inconsistencies with NFS clients.
Cleared PG_WANTED where appropriate.
Added checks for buffer busy in allocbuf and biodone.
Reviewed by: John Dyson
