could not compress into clusters. This could result in lots of
wasted clusters while recieving small packets from an interface
that uses clusters for all it's packets.
Patch is partially from BSDi (limiting the size of the copy) and
based on a patch for 4.1 by Ian Dowse <iedowse@maths.tcd.ie> and
myself.
Reviewed by: bmilekic
Obtained From: BSDi
Submitted by: iedowse
- Use the mutex in hardclock to ensure no races between it and
softclock.
- Make softclock be INTR_MPSAFE and provide a flag,
CALLOUT_MPSAFE, which specifies that a callout handler does not
need giant. There is still no way to set this flag when
regstering a callout.
Reviewed by: -smp@, jlemon
Removed most of the hacks that were trying to deal with low-memory
situations prior to now.
The new code is based on the concept that I/O must be able to function in
a low memory situation. All major modules related to I/O (except
networking) have been adjusted to allow allocation out of the system
reserve memory pool. These modules now detect a low memory situation but
rather then block they instead continue to operate, then return resources
to the memory pool instead of cache them or leave them wired.
Code has been added to stall in a low-memory situation prior to a vnode
being locked.
Thus situations where a process blocks in a low-memory condition while
holding a locked vnode have been reduced to near nothing. Not only will
I/O continue to operate, but many prior deadlock conditions simply no
longer exist.
Implement a number of VFS/BIO fixes
(found by Ian): in biodone(), bogus-page replacement code, the loop
was not properly incrementing loop variables prior to a continue
statement. We do not believe this code can be hit anyway but we
aren't taking any chances. We'll turn the whole section into a
panic (as it already is in brelse()) after the release is rolled.
In biodone(), the foff calculation was incorrectly
clamped to the iosize, causing the wrong foff to be calculated
for pages in the case of an I/O error or biodone() called without
initiating I/O. The problem always caused a panic before. Now it
doesn't. The problem is mainly an issue with NFS.
Fixed casts for ~PAGE_MASK. This code worked properly before only
because the calculations use signed arithmatic. Better to properly
extend PAGE_MASK first before inverting it for the 64 bit masking
op.
In brelse(), the bogus_page fixup code was improperly throwing
away the original contents of 'm' when it did the j-loop to
fix the bogus pages. The result was that it would potentially
invalidate parts of the *WRONG* page(!), leading to corruption.
There may still be cases where a background bitmap write is
being duplicated, causing potential corruption. We have identified
a potentially serious bug related to this but the fix is still TBD.
So instead this patch contains a KASSERT to detect the problem
and panic the machine rather then continue to corrupt the filesystem.
The problem does not occur very often.. it is very hard to
reproduce, and it may or may not be the cause of the corruption
people have reported.
Review by: (VFS/BIO: mckusick, Ian Dowse <iedowse@maths.tcd.ie>)
Testing by: (VM/Deadlock) Paul Saab <ps@yahoo-inc.com>
Pre-rfork code assumed inherent locking of a process's file descriptor
array. However, with the advent of rfork() the file descriptor table
could be shared between processes. This patch closes over a dozen
serious race conditions related to one thread manipulating the table
(e.g. closing or dup()ing a descriptor) while another is blocked in
an open(), close(), fcntl(), read(), write(), etc...
PR: kern/11629
Discussed with: Alexander Viro <viro@math.psu.edu>
are in softclock() for a long time. The old code already did an
splx()/slphigh() pair here, I just missed adding in the equivalent mutex
operations on sched_lock earlier.
This makes crash recovery work for stripe sizes that are not multiples of
DEFAULT_REVIVE_BLOCKSIZE (currently 64 kB).
While we're here, fix a few cosmetic nits.
Reviewed by: grog
Sponsored by: Enitel ASA (http://www.enitel.no/)
may block on a mutex while on the sleep queue without corrupting
it.
- Move dropping of Giant to after the acquire of sched_lock.
Tested by: John Hay <jhay@icomtek.csir.co.za>
jhb
instead of DIAGNOSTIC.
- Remove the p_wchan check as it no longer applies since a process may be
switched out during CURSIG() within msleep() or mawait().
- Remove an extra sanity check only needed during the early SMPng work.
with Julian and Archie.
Implement a new ``sizedstring'' parse type for dealing with field pairs
consisting of a uint16_t followed by a data field of that size, and use
this to deal with the data_len and data fields.
Written by: Archie with some input by me
Agreed in principle by: julian
untimeout() not being called with Giant in those functions. For now,
use the sched_lock to protect the callout wheel in softclock() and in
the various timeout and callout functions.
Noticed by: tegge
16-bit mode. Technically, pcn_probe() is destructive because once the
chip goes into 32-bit mode, the only way to get it out again is a
hardware reset. And once the device is in 32-bit mode, the lnc driver
won't be able to talk to it. So if pcn_probe() is called before the
lnc probe routine, and pcn_probe() rejects the chip as one it doesn't
support, the lnc driver will be SOL.
I don't like this. I think it's a design flaw that you can't switch
the chip out of 32-bit mode once it's selected. The only 'right'
solution is for the pcn driver to support all of the PCI devices
in 32-bit mode, however I don't have samples of all the PCnet series
cards for testing.
acquire Giant as needed in functions that call mi_switch(). The releases
need to be done outside of the sched_lock to avoid potential deadlocks
from trying to acquire Giant while interrupts are disabled.
Submitted by: witness
linux_rt_sendsig() and restore the same signal mask linux does
in rt_sigreturn(). This gets us saving/restoring all 64-bits of the
linux sigset_t in rt signals.
Reviewed by: marcel
idea to be holding the sched_lock while we are calling it. As such,
release sched_lock before calling CURSIG() in msleep() and mawait() and
reacquire it after CURSIG() returns.
Submitted by: witness
to our native connect(). This is required to deal with the differences
in the way linux handles connects on non-blocking sockets.
This gets the private beta of the Compaq Linux/alpha JDK working
on FreeBSD/alpha
Approved by: marcel
tsleep(). Namely, mawait() takes an extra argument which is a mutex
to drop when going to sleep. Just as with msleep(), if the priority
argument includes the PDROP flag, then the mutex will be dropped and will
not be reacquired when the process wakes up.
- Add in a backwards compatible macro await() that passes in NULL as the
mutex argument to mawait().
except that it uses the MTX_NOSWITCH flag while it releases Giant via
mtx_exit().
- Add a mtx_recursed() primitive. This primitive should only be used on
a mutex owned by the current process. It will return non-zero if the
mutex is recursively owned, or zero otherwise.
- Add two new flags MA_RECURSED and MA_NOTRECURSED that can be used in
conjuction with MA_OWNED to control the assertion checked by mtx_assert().
- Fix some of the KTR tracepoint strings to use %p when displaying the lock
field of a mutex, which is a uintptr_t.
macros which provide the same functionality and are a bit more
efficient, convert use of CIRCLEQ's in netgraph PPP code to TAILQ's.
Reviewed by: Archie Cobbs <archie@dellroad.org>
sched_lock. This is needed for kernel threads that are created before
interrupts are enabled. kthreads created by kld's that are created at
SI_SUB_KLD such as the random kthread.
Tested by: phk
macros which provide the same functionality and are a bit more
efficient, convert use of CIRCLEQ's in resource manager to TAILQ's.
Approved by: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
is to first write the deleted directory entry to disk, second write
the zero'ed inode to disk, and finally to release the freed blocks
and the inode back to the cylinder-group map. As this ordering
requires two disk writes to occur which are normally spaced about
30 seconds apart (except when memory is under duress), it takes
about a minute from the time that a file is deleted until its inode
and data blocks show up in the cylinder-group map for reallocation.
If a file has had only a brief lifetime (less than 30 seconds from
creation to deletion), neither its inode nor its directory entry
may have been written to disk. If its directory entry has not been
written to disk, then we need not wait for that directory block to
be written as the on-disk directory block does not reference the
inode. Similarly, if the allocated inode has never been written to
disk, we do not have to wait for it to be written back either as
its on-disk representation is still zero'ed out. Thus, in the case
of a short lived file, we can simply release the blocks and inode
to the cylinder-group map immediately. As the inode and its blocks
are released immediately, they are immediately available for other
uses. If they are not released for a minute, then other inodes and
blocks must be allocated for short lived files, cluttering up the
vnode and buffer caches. The previous code was a bit too aggressive
in trying to release the blocks and inode back to the cylinder-group
map resulting in their being made available when in fact the inode
on disk had not yet been zero'ed. This patch takes a more conservative
approach to doing the release which avoids doing the release prematurely.
of the data structures to include new members that weren't defined in the
manual I have.
I opted to use Doug Ambrisko's WEP patches since David Cornejo's patches
did not include the necessary changes to ancontrol(8) to actually enable
and use WEP.
NOTE: I don't currently have access to an Aironet card, so I can't test
any of this. Everything compiles and close scrutiny doesn't reveal any
obvious problems, but Murphy's Law applies. This means I will probably
leave these changes in -current for a bit longer than usual until I'm
sure they work right.
linux_sigset_t by updating the linux_sigframe struct so as to include
linux's "extramask" field. This field contains the upper 32-bits of
the sigset. extramask sits behind a linux_fpstate struct, which I've
defined primarily for padding purposes.
While we're here, define LINUX_NSIG in terms of LINUX_NBPW (32) and
LINUX_NSIG_WORDS (2).
This fixes problems where threaded apps would accumulate a large
number of zombies. This was happening because the exit signal resides
in the upper 32-bits of the sigset and was never getting unmasked by
the manager thread after the first child exited.
PR: misc/18530 (may be related, originator not yet contacted)
Reviewed by: marcel
This allows us to successfully attach early Storage Dimension cards.
Allocate mailboxes for the 742A bellow the 16MB limit. Although these
cards seem to be able to deal with all other types of data anywhere
in a 32bit address space, 24bit addresses are required for mailboxes.
bt_eisa.c:
Add device IDs for all Storage Dimension products I could
find from their web site.
Thanks to Ted Mittelstaed for loaning me the equipment to diagnose
and fix these problems.
anything and it's likely to be faster on alphas.
Also, add EXT_MOD_TYPE for modules that want to add their own ext_type and
are not network drivers (so they don't use EXT_NET_DRV).
The prior version in the tree was repo-copied from Duncan Barclay's
cvs tree.
Also add $FreeBSD$
Submitted by: Duncan Barclay
Committed-via: raylan link with two webgear cards.
boot problems..
However this demands that dangerously dedicated disks use an
offset of at least 10 from the start to not overwrite the
raid config sector on the HPT...
Shutdown the card when a catastrophic error occurs. This quenches
any interrupts stemming from the card.
aic7xxx_inline.h:
Return instead of processing additional interrupt state
after handling a catastrophic error. We now shutdown the
chip in this case in the hopes that the system can live
without this controller. The shutdown process invalidates any
other interrupt state.
aic7xxx.seq:
Only attempt to clear SCSIBUSL on Ultra2 controllers. The
clearing is workaround for a selection timeout bug on U2/U160
controllers and happens to be illegal on aic7770 (EISA/VL)
controllers.
and which indicates that the ext_buf is to be marked READ-ONLY.
Also introduce M_WRITABLE() macro, which will return true if:
* M_RDONLY is _not_ set AND:
* either mbuf has no ext_buf attached OR it has an ext_buf attached but the ref
count is NOT above 1.
sf_bufs (sendfile) are marked M_RDONLY.
Now code determining whether an mbuf's data area is "shared" or not can be
made to use this instead of doing its own (often incorrect) thing.
Submitted by: bmilekic, dwmalone, and Ian Dowse
Reviewed by: dwmalone, jlemon
to determine whether the given mbuf has a cluster (or some other type of
external storage) attached to it.
Note: This code should eventually be made to use M_WRITABLE() to determine
whether or not a copy should be made.
Reviewed by: jlemon
instead.
Also, fix a small set of "avail." If we're setting `avail,' we shouldn't
be re-checking whether m_flags is M_EXT, because we know that it is, as if
it wasn't, we would have already returned several lines above.
Reviewed by: jlemon
whether the given ext_buf is shared.
* Have the sf_bufs be setup with the mbuf subsystem using MEXTADD() with the
two new arguments.
Note: m_pulldown() is somewhat crotchy; the added comment explains the
situation.
Reviewed by: jlemon
could debug processes after the commit that introduced the typo.
Security is good, but security is not always the same as turning things
off :-).
PR: kern/22711
Obtained from: brooks@one-eyed-alien.net
mainly cut-n-pasted from the i386 port, except for the method of setting
the child's stack which is the only MD part of this function.
I've tested with the example apps shipped with the linux threads source
code (ex1-ex6) and with several binary builds of Mozilla.
- No signal translation is needed. Our signals match the OSF/1 signals
- an OSF/1 sigset_t is 64 bits. Make certain to use all 64-bits of it.
We'd previously only used the lower 32 bits. This was mostly harmless
as I don't know of an OSF/1 apps which use any signals > 31. However,
the alpha Linux ABI uses the osf/1 signal routines and threaded linux
apps tyically use signals 32 and 33 to comminicate with the manager
thread, so it is important we preserve the upper 32-bits.
Reviewed by: marcel (at least in principal)
numerous error recovery buglets.
Many thanks to Tor Egge for his assistance in diagnosing problems with
the error recovery code.
aic7xxx.c:
Report missed bus free events using their own sequencer interrupt
code to avoid confusion with other "bad phase" interrupts.
Remove a delay used in debugging. This delay could only be hit
in certain, very extreme, error recovery scenarios.
Handle transceiver state changes correctly. You can now
plug an SE device into a hot-plug LVD bus without hanging
the controller.
When stepping through a critical section, panic if we step
more than a reasonable number of times.
After a bus reset, disable bus reset interupts until we either
our first attempt to (re)select another device, or another device
attemps to select us. This removes the need to busy wait in
kernel for the scsi reset line to fall yet still ensures we
see any reset events that impact the state of either our initiator
or target roles. Before this change, we had the potential of
servicing a "storm" of reset interrupts if the reset line was
held for a significant amount of time.
Indicate the current sequencer address whenever we dump the
card's state.
aic7xxx.reg:
Transceiver state change register definitions.
Add the missed bussfree sequencer interrupt code.
Re-enable the scsi reset interrupt if it has been
disabled before every attempt to (re)select a device
and when we have been selected as a target.
When being (re)selected, check to see if the selection
dissappeared just after we enabled our bus free interrupt.
If the bus has gone free again, go back to the idle loop
and wait for another selection.
Note two locations where we should change our behavior
if ATN is still raised. If ATN is raised during the
presentation of a command complete or disconnect message,
we should ignore the message and expect the target to put
us in msgout phase. We don't currently do this as it
requires some code re-arrangement so that critical sections
can be properly placed around our handling of these two
events. Otherwise, we cannot guarantee that the check of
ATN is atomic relative to our acking of the message in
byte (the kernel could assert ATN).
Only set the IDENTIFY_SEEN flag after we have settled
on the SCB for this transaction. The kernel looks at
this flag before assuming that SCB_TAG is valid. This
avoids confusion during certain types of error recovery.
Add a critical section around findSCB. We cannot allow
the kernel to remove an entry from the disconnected
list while we are traversing it. Ditto for get_free_or_disc_scb.
aic7xxx_freebsd.c:
Only assume that SCB_TAG is accurate if IDENTIFY_SEEN is
set in SEQ_FLAGS.
Fix a typo that caused us to execute some code for the
non-SCB paging case when paging SCBs. This only occurred
during error recovery.
block bitmaps before unmount() completes. They were written using
bdwrite(), so they were normally written less than 32 seconds after
unmount(), but this is too late if the media is removed or the system
is rebooted soon after unmount(). sync()ing before unmount() didn't
help, because ext2fs uses buggy private caching for these blocks --
it doesn't even bdwrite() them until they are uncached or the filesystem
is unmounted. sync()ing after unmount() didn't help, because sync()
only applies to (vnodes for) mounted filesystems.
PR: 22726
As of this patchset, the loader builds (under NetBSD/macppc), boots, interacts
and talks to BOOTP/NFS servers.
(main.c was moved from boot/ofw/libofw to boot/ofw/common but has no revision
history)
Reviewed by: obrien
This brings the loader up to the point where I can compile it under
NetBSD/macppc and have it boot, interact and talk to NFS servers.
sys/boot/ofw/libofw/main.c has been deleted (it has no revision history) and
replaced with sys/boot/ofw/common/main.c
Reviewed by: obrien
device tree and resource manager contents. This is the kernel side of
the upcoming libdevinfo, which will expose this information to userspace
applications in a trivial fashion.
Remove the now-obsolete DEVICE_SYSCTLS code.
syscall compare against a variable sv_minsigstksz in struct
sysentvec as to properly take the size of the machine- and
ABI dependent struct sigframe into account.
The SVR4 and iBCS2 modules continue to have a minsigstksz of
8192 to preserve behavior. The real values (if different) are
not known at this time. Other ABI modules use the real
values.
The native MINSIGSTKSZ is now defined as follows:
Arch MINSIGSTKSZ
---- -----------
alpha 4096
i386 2048
ia64 12288
Reviewed by: mjacob
Suggested by: bde
This code has help us comprehence ACPI spec .
Contributors of this code is as follows(except for FreeBSD commiter):
Yasuo Yokoyama,
Munehiro Matsuda,
and ALL acpi-jp@jp.freebsd.org people.
Thanks.
R.I.P.
for an interrupt to enable/disable from the vector (and GID too, if we
had multiple GIDs)- so, stupidly for now, search for the right mcpcia's
softc so we have the right base address for the bridge CSR to apply
IRQ bit-twiddle's to. Alas- this doesn't yet allow us to run, but it's
the right direction.
Previously we had to include <machine/param.h> or <sys/param.h> bogusly
due to the fact that <sys/socket.h> CMSG macros needed the ALIGN macro,
which was defined in param.h. However, including param.h was a disaster
for namespace pollution.
This solution, as contributed by shin a while ago, fixes it elegantly
by wrapping the definitions around some namespace pollution preventer
definitions.
This patch was long overdue.
This should allow any network programmer to use <sys/socket.h> as
before.
PR: 19971, 20530
Submitted by: Martin Kaeske <MartinKaeske@lausitz.net>
Mark Andrews <Mark.Andrews@nominum.com>
Patch submitted by: shin
Reviewed by: bde
systems.
From the PR:
When 'probe.slot' is PCI_SLOTMAX (== 31) and 'probe.func' is 7,
call to 'pci_cfgread()' here and machine suddenly hangs up.
I don't know why... (or 450GX chipset's bug?)
PR: i386/20379
Submitted by: Masayuki FUKUI <fukui@sonic.nm.fujitsu.co.jp>
comments on the same line like so:
device foo # FooInc Brand NetEther cards
Also, move the wireless NIC cards to their own section.
Add commented out wl driver in wireless section.
Remove obsolete or redundant comments about some of the wireless cards
that used to apply but don't since we've removed 'at foobus'.
There should be no functional changes in this change.
happen when the vm system maps past the end of an object or tries
to map a zero length object, the pmap layer misses the fact that
offsets wrap into negative numbers and we get stuck.
Found by: Joost Pol aka Nohican <nohican@marcella.niets.org>
Submitted by: tegge
When the printer is turned off the pipe write will cause and error,
which causes lpd to close the device and reopen it to clear the error.
After a short while the device will disappear from the bus but lpd will
have opened the ulpt0 port by then. ulpt_status will check for status
without checking the sc->dying flag and panic the kernel when the device
finally disappears from the bus.
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
also
- sync with netbsd
- fix a bug that miscalculates tx cell counts when the pointer size isn't 4
tested both ENI and Adaptec cards on both i386 and alpha.
function declared in kern_ktr.c. The only inline checks left are the
checks that compare KTR_COMPILE with the supplied mask and thus should
be optimized away into either nothing or a direct call to ktr_tracepoint().
- Move several KTR-related options to opt_ktr.h now that they are only
needed by kern_ktr.c and not by ktr.h.
- Add in the ktr_verbose functionality if KTR_EXTEND is turned on. If the
global variable 'ktr_verbose' is non-zero, then KTR messages will be
dumped to the console. This variable can be set by either kernel code
or via the 'debug.ktr_verbose' sysctl. It defaults to off unless the
KTR_VERBOSE kernel option is specified in which case it defaults to on.
This can be useful when the machine locks up spinning in a loop with
interrupts disabled as you might be able to see what it is doing when it
locks up.
Requested by: phk
interface. In addition to using newbus, it also uses bus_space rather
than inb/outb to make it MI. The grody static softc allocation stuff
has been removed as well.
When restarting the sequencer, ensure that the SCBCNT register
is 0. A non-zero count will prevent the setting of the CCSCBDIR
bit in any future dma operations. The only time CCSCBCNT would
be non-zero is if we happened to halt the dma during a reset,
but even that should never happen. Better safe than sorry.
When a command completes before the target responds to an
ATN for a recovery command, we now notify the kernel so that
any recovery operation requeued in the qinfifo can be removed
safely. In the past, we did this in ahc_done(), but ahc_done()
may be called without the card paused. This also avoids a
recursive call to ahc_search_qinifo() which could have occurred if
ahc_search_qinififo() happened to be the routine to complete
a recovery action.
Fix 8bit math used for adjusting the qinfifo. The index must
be wrapped properly within the 256 entry array. We rely on the
fact that qinfifonext is a uint8_t in most cases to handle
this wrap, but we missed a few spots where the resultant
calculation was promoted to an int.
Change the way that we deal with aborting the first or second
entry from the qinfifo. We now swap the first entry in the
qinfifo with the "next queued scb" to force the sequencer
to see an abort collision if we ever touch the qinififo while
the sequencer is mid SCB dma.
aic7xxx.reg:
Add new MKMSG_FAILED sequencer interrupt. This displaced
the BOGUS_TAG interrupt used in some previous sequencer code
debugging.
aic7xxx.seq:
Increment our position in the qinfifo only once the dma
is complete and we have verified that the queue has not
been changed during our DMA. This simplifies code in the
kernel.
Protect against "instruction creep" when issuing a pausing
sequencer interrupt. On at least the 7890/91/96/97, the
sequencer will coast after issuing the interrupt for up
to two instructions. In the past we delt with this by
using carefully placed nops. Now we call a routine to
issue the interrupt followed by a nop and a ret.
Tell the kernel should an SCB complete with the MK_MESSAGE
flag still set. This means the target ignored our ATN request.
Clear the channel twice as we exit the data phase. On the
aic7890/91, the S/G preload logic may require the second
clearing to get the last S/G out of the FIFO.
aic7xxx_freebsd.c:
Don't bother searching the qinfifo for a doubly queued
recovery scb in ahc_done. This case is handled by the
core driver now.
Free the path used to issue async callbacks after the callback
is complete.
aic7xxx_inline.h:
Split the SCB queue routine into a routine that swaps
the SCB with the "next queued SCB" and a routine that
calls the swapping routine and notifies the card of
the new SCB. The swapping routine is now also used by
ahc_search_qinfifo.
The offset field in struct dirent was set to the offset of
the next dirent in rev 1.36. The offset was calculated from
the current offset and the record length. This offset does
not necessarily match the real offset when we are using
cookies. Therefore, also use the cookies to set the offset
field in struct dirent if we're using cookies to iterate
through the dirents.
circuit generates too much jitter to be used directly as xmit clock.
Don't miscount pending bytes in weird error conditions.
Drop the rest of a packet if we run out of tx-md's.
Trig the xmit-frame signal on rising edge, this fixed the one-bit-too-late
position of the HDLC frames in E1 mode.
wakeup all of the sleeping threads when we free only one buffer. This
avoids us having to needlessly try again (and fail, and go back to
sleep) for all the threads sleeping. We will now only wakeup the
thread we know will succeed.
Reviewed by: green
only be checked if the system is currently performing New Reno style
fast recovery. However, this value was being checked regardless of the
NR state, with the end result being that the congestion window was never
opened.
Change the logic to check t_dupack instead; the only code path that
allows it to be nonzero at this point is NewReno, so if it is nonzero,
we are in fast recovery mode and should not touch the congestion window.
Tested by: phk
pollution in <sys/mutex.h>. This was half fixed in rev.1.3 of
midwayreg.h. The pollution exposed the bug that this driver was using
toy versions of the bus space macros under FreeBSD. Disabling the
toy versions made this driver compile but dependent on the pollution.
There was still a toy version of bus_space_read_1() in unreachable code.
namespace pollution in <sys/mutex.h>. This was half fixed in rev.1.3
of midwayreg.h. The pollution exposed the bug that this driver was
using toy versions of the bus space macros under FreeBSD. Disabling
the toy versions made this driver compile and maybe support PIO space,
but dependent on the pollution.
ufs_vnops.c:
1) i_ino was confused with i_number, so the inode number passed to
VFS_VGET() was usually wrong (usually 0U).
2) ip was dereferenced after vgone() freed it, so the inode number
passed to VFS_VGET() was sometimes not even wrong.
Bug (1) was usually fatal in ext2_mknod(), since ext2fs doesn't have
space for inode 0 on the disk; ino_to_fsba() subtracts 1 from the
inode number, so inode number 0U gives a way out of bounds array
index. Bug(1) was usually harmless in ufs_mknod(); ino_to_fsba()
doesn't subtract 1, and VFS_VGET() reads suitable garbage (all 0's?)
from the disk for the invalid inode number 0U; ufs_mknod() returns
a wrong vnode, but most callers just vput() it; the correct vnode is
eventually obtained by an implicit VFS_VGET() just like it used to be.
Bug (2) usually doesn't happen.
freelist. Should now be thread-friendly, in part.
Note: More work is needed in uipc_syscalls.c, but it will have to wait until
the socket locking issues are at least 80% implemented and committed.
CDs.
With audio CDs, you can't just do a READ(10) call on most drives without
first setting the blocksize with a mode select command. The disklabel code
does a read of the first sector of the media to find a label if it exists.
This caused drives to return an error when an audio CD was in the drive,
due to the problem described above.
The solution is to read the table of contents on the CD, and only attempt
to read the disklabel if the first track is a data track.
This works on all the various CD and DVD media I have tried, but further
testing (especially with Video CDs and other mode 2 media) will be
needed to determine if this is a universal solution.
