has been some bitrot and incorrect assumptions in the vfs_bio code. These
problems have manifest themselves worse on NFS type filesystems, but can
still affect local filesystems under certain circumstances. Most of
the problems have involved mmap consistancy, and as a side-effect broke
the vfs.ioopt code. This code might have been committed seperately, but
almost everything is interrelated.
1) Allow (pmap_object_init_pt) prefaulting of buffer-busy pages that
are fully valid.
2) Rather than deactivating erroneously read initial (header) pages in
kern_exec, we now free them.
3) Fix the rundown of non-VMIO buffers that are in an inconsistent
(missing vp) state.
4) Fix the disassociation of pages from buffers in brelse. The previous
code had rotted and was faulty in a couple of important circumstances.
5) Remove a gratuitious buffer wakeup in vfs_vmio_release.
6) Remove a crufty and currently unused cluster mechanism for VBLK
files in vfs_bio_awrite. When the code is functional, I'll add back
a cleaner version.
7) The page busy count wakeups assocated with the buffer cache usage were
incorrectly cleaned up in a previous commit by me. Revert to the
original, correct version, but with a cleaner implementation.
8) The cluster read code now tries to keep data associated with buffers
more aggressively (without breaking the heuristics) when it is presumed
that the read data (buffers) will be soon needed.
9) Change to filesystem lockmgr locks so that they use LK_NOPAUSE. The
delay loop waiting is not useful for filesystem locks, due to the
length of the time intervals.
10) Correct and clean-up spec_getpages.
11) Implement a fully functional nfs_getpages, nfs_putpages.
12) Fix nfs_write so that modifications are coherent with the NFS data on
the server disk (at least as well as NFS seems to allow.)
13) Properly support MS_INVALIDATE on NFS.
14) Properly pass down MS_INVALIDATE to lower levels of the VM code from
vm_map_clean.
15) Better support the notion of pages being busy but valid, so that
fewer in-transit waits occur. (use p->busy more for pageouts instead
of PG_BUSY.) Since the page is fully valid, it is still usable for
reads.
16) It is possible (in error) for cached pages to be busy. Make the
page allocation code handle that case correctly. (It should probably
be a printf or panic, but I want the system to handle coding errors
robustly. I'll probably add a printf.)
17) Correct the design and usage of vm_page_sleep. It didn't handle
consistancy problems very well, so make the design a little less
lofty. After vm_page_sleep, if it ever blocked, it is still important
to relookup the page (if the object generation count changed), and
verify it's status (always.)
18) In vm_pageout.c, vm_pageout_clean had rotted, so clean that up.
19) Push the page busy for writes and VM_PROT_READ into vm_pageout_flush.
20) Fix vm_pager_put_pages and it's descendents to support an int flag
instead of a boolean, so that we can pass down the invalidate bit.
f00f_hack has run.
Use the global r_idt descriptor in f00f_hack when in SMP mode,
so the APs find the relocated interrupt descriptor table.
Submitted by: Partially from David A Adkins <adkin003@tc.umn.edu>
dynamically depending on the line speed(s). This should give the old
sizes and watermarks until drivers are changed.
Display the input watermarks in pstat and sicontrol.
Fix for RTPRIO scheduler to eliminate invalid context switches.
POSIX.4 headers and sysctl variables. Nothing should change
unless POSIX4 is defined or _POSIX_VERSION is set to 199309.
interrupts are masked, and EOI is sent iff the corresponding ISR bit
is set in the local apic. If the CPU cannot obtain the interrupt
service lock (currently the global kernel lock) the interrupt is
forwarded to the CPU holding that lock.
Clock interrupts now have higher priority than other slow interrupts.
the signal handling latency for cpu-bound processes that performs very
few system calls.
The IPI for forcing an additional software trap is no longer dependent upon
BETTER_CLOCK being defined.
than rolling it's own. This means that it now uses the "safe"
exec_map_first_page() to get the ld.so headers rather than risking a panic
on a page fault failure (eg: NFS server goes down).
Since all the ELF tools go to a lot of trouble to make sure everything
lives in the first page for executables, this is a win. I have not seen
any ELF executable on any system where all the headers didn't fit in the
first page with lots of room to spare.
I have been running variations of this code for some time on my pure ELF
systems.
a complement to all ops that return a vpp, VFS_VRELE. This is
initially only for file systems that implement the following ops
that do a WILLRELE:
vop_create, vop_whiteout, vop_mknod, vop_remove, vop_link,
vop_rename, vop_mkdir, vop_rmdir, vop_symlink
This is initial DNA that doesn't do anything yet. VFS_VRELE is
implemented but not called.
A default vfs_vrele was created for fs implementations that use the
standard vnode management routines.
VFS_VRELE implementations were made for the following file systems:
Standard (vfs_vrele)
ffs mfs nfs msdosfs devfs ext2fs
Custom
union umapfs
Just EOPNOTSUPP
fdesc procfs kernfs portal cd9660
These implementations may change as VOP changes are implemented.
In the next phase, in the vop implementations calls to vrele and the vrele
part of vput will be moved to the top layer vfs_vnops and made visible
to all layers. vput will be replaced by unlock in these cases. Unlocking
will still be done in the per fs layer but the refcount decrement will be
triggered at the top because it doesn't hurt to hold a vnode reference a
little longer. This will have minimal impact on the structure of the
existing code.
This will only be done for vnode arguments that are released by the various
fs vop implementations.
Wider use of VFS_VRELE will likely require restructuring of the code.
Reviewed by: phk, dyson, terry et. al.
Submitted by: Michael Hancock <michaelh@cet.co.jp>
2) Do not unnecessarily force page blocking when paging
pages out.
3) Further improve swap pager performance and correctness,
including fixing the paging in progress deadlock (except
in severe I/O error conditions.)
4) Enable vfs_ioopt=1 as a default.
5) Fix and enable the page prezeroing in SMP mode.
All in all, SMP systems especially should show a significant
improvement in "snappyness."
times consistently wrong (up to 1 tick too late), but recent changes
fixed the setting of the main clock, making other times inconsistent.
The inconsistencies tended to show up as a negative resource usage
for the process that set the time.
Fixed the check for setting the clock backwards. A stale timestamp
(`time') was checked, so it was possible to set the clock backwards
by up to almost 1 tick. Until recently, this bug was compensated
for by setting the clock consistently wrong.
Merged the comment about setting the clock backwards from Lite2.
Removed latency micro-optimizations/speed pessimizations in settime().
microtime() and set_timecounter() are relatively expensive, and
they must be called together with clock updates blocked to get a
consistent `delta', so significant latency optimizations are not
possible.
Removed some stale comments.
in a way identically as before.) I had problems with the system properly
handling the number of vnodes when there is alot of system memory, and the
default VM_KMEM_SIZE. Two new options "VM_KMEM_SIZE_SCALE" and
"VM_KMEM_SIZE_MAX" have been added to support better auto-sizing for systems
with greater than 128MB.
vnodes, therefore vget doesn't need to do so anymore. Other minor
improvements include the temp free vnode queue obeying the VAGE
flag and a printf that warns of to-be-removed code being executed.
Highlights:
* Simple model for underlying hardware.
* Hardware basis for timekeeping can be changed on the fly.
* Only one hardware clock responsible for TOD keeping.
* Provides a real nanotime() function.
* Time granularity: .232E-18 seconds.
* Frequency granularity: .238E-12 s/s
* Frequency adjustment is continuous in time.
* Less overhead for frequency adjustment.
* Improves xntpd performance.
Reviewed by: bde, bde, bde
so_error is set, clear it before returning it. The behavior
introduced in 4.3-Reno (to not clear so_error) causes potentially
transient errors (e.g. ECONNREFUSED if the other end hasn't opened
its socket yet) to be permanent on connected datagram sockets that
are only used for writing.
(soreceive() clears so_error before returning it, as does
getsockopt(...,SO_ERROR,...).)
Submitted by: Van Jacobson <van@ee.lbl.gov>, via a comment in the vat sources.
or shrinking an open partition (by changing the label for a compatibility
slice while partitions on the corresponding real slice are open, or vice
versa).
waslocked = TRUE. This change may fix lockmgr panic in umapfs/nullfs.
PR: 5634
Reviewed by: "John S. Dyson" <toor@dyson.iquest.net>
Suggested by: Bruce Evans <bde@zeta.org.au>
of the various ad-hoc schemes.
2) When bringing in UPAGES, the pmap code needs to do another vm_page_lookup.
3) When appropriate, set the PG_A or PG_M bits a-priori to both avoid some
processor errata, and to minimize redundant processor updating of page
tables.
4) Modify pmap_protect so that it can only remove permissions (as it
originally supported.) The additional capability is not needed.
5) Streamline read-only to read-write page mappings.
6) For pmap_copy_page, don't enable write mapping for source page.
7) Correct and clean-up pmap_incore.
8) Cluster initial kern_exec pagin.
9) Removal of some minor lint from kern_malloc.
10) Correct some ioopt code.
11) Remove some dead code from the MI swapout routine.
12) Correct vm_object_deallocate (to remove backing_object ref.)
13) Fix dead object handling, that had problems under heavy memory load.
14) Add minor vm_page_lookup improvements.
15) Some pages are not in objects, and make sure that the vm_page.c can
properly support such pages.
16) Add some more page deficit handling.
17) Some minor code readability improvements.
Realtime priority has to be restricted for reasons which should be
obvious. However, for idle priority, there is a potential for
system deadlock if an idleprio process gains a lock on a resource
that other processes need (and the idleprio process can't run
due to a CPU-bound normal process). Fix me! XXX
PR: 5639
MUST be PG_BUSY. It is bogus to free a page that isn't busy,
because it is in a state of being "unavailable" when being
freed. The additional advantage is that the page_remove code
has a better cross-check that the page should be busy and
unavailable for other use. There were some minor problems
with the collapse code, and this plugs those subtile "holes."
Also, the vfs_bio code wasn't checking correctly for PG_BUSY
pages. I am going to develop a more consistant scheme for
grabbing pages, busy or otherwise. For now, we are stuck
with the current morass.
If you want to play with it, you can find the final version of the
code in the repository the tag LFS_RETIREMENT.
If somebody makes LFS work again, adding it back is certainly
desireable, but as it is now nobody seems to care much about it,
and it has suffered considerable bitrot since its somewhat haphazard
integration.
R.I.P
Make vfs_bio buffer mgmt work better.
Buffers were being used after brelse.
Make nfs_getpages work independently of other NFS
interfaces. This eliminates some difficult
recursion problems and decreases pagefault
overhead.
Remove an erroneous vfs_unbusy_pages.
Fix a reentrancy problem, with nfs_vinvalbuf when
vnode is already being rundown.
Reassignbuf wasn't being called when needed under
certain circumstances.
(Thanks to Bill Paul for help.)
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.
1) Start using TSM.
Struct procs continue to point to upages structure, after being freed.
Struct vmspace continues to point to pte object and kva space for kstack.
u_map is now superfluous.
2) vm_map's don't need to be reference counted. They always exist either
in the kernel or in a vmspace. The vmspaces are managed by reference
counts.
3) Remove the "wired" vm_map nonsense.
4) No need to keep a cache of kernel stack kva's.
5) Get rid of strange looking ++var, and change to var++.
6) Change more data structures to use our "zone" allocator. Added
struct proc, struct vmspace and struct vnode. This saves a significant
amount of kva space and physical memory. Additionally, this enables
TSM for the zone managed memory.
7) Keep ioopt disabled for now.
8) Remove the now bogus "single use" map concept.
9) Use generation counts or id's for data structures residing in TSM, where
it allows us to avoid unneeded restart overhead during traversals, where
blocking might occur.
10) Account better for memory deficits, so the pageout daemon will be able
to make enough memory available (experimental.)
11) Fix some vnode locking problems. (From Tor, I think.)
12) Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp.
(experimental.)
13) Significantly shrink, cleanup, and make slightly faster the vm_fault.c
code. Use generation counts, get rid of unneded collpase operations,
and clean up the cluster code.
14) Make vm_zone more suitable for TSM.
This commit is partially as a result of discussions and contributions from
other people, including DG, Tor Egge, PHK, and probably others that I
have forgotten to attribute (so let me know, if I forgot.)
This is not the infamous, final cleanup of the vnode stuff, but a necessary
step. Vnode mgmt should be correct, but things might still change, and
there is still some missing stuff (like ioopt, and physical backing of
non-merged cache files, debugging of layering concepts.)
a null pointer panic when the pointer for the incorrect process is
NULL. getpriority() was broken in rev.1.27. Rev.1.28 broke the
warning instead of fixing the problem.
PR: 5495
config option in pmap. Fix a problem with faulting in pages. Clean-up
some loose ends in swap pager memory management.
The system should be much more stable, but all subtile bugs aren't fixed yet.
Fix the UIO optimization code.
Fix an assumption in vm_map_insert regarding allocation of swap pagers.
Fix an spl problem in the collapse handling in vm_object_deallocate.
When pages are freed from vnode objects, and the criteria for putting
the associated vnode onto the free list is reached, either put the
vnode onto the list, or put it onto an interrupt safe version of the
list, for further transfer onto the actual free list.
Some minor syntax changes changing pre-decs, pre-incs to post versions.
Remove a bogus timeout (that I added for debugging) from vn_lock.
PHK will likely still have problems with the vnode list management, and
so do I, but it is better than it was.
original BSD code. The association between the vnode and the vm_object
no longer includes reference counts. The major difference is that
vm_object's are no longer freed gratuitiously from the vnode, and so
once an object is created for the vnode, it will last as long as the
vnode does.
When a vnode object reference count is incremented, then the underlying
vnode reference count is incremented also. The two "objects" are now
more intimately related, and so the interactions are now much less
complex.
When vnodes are now normally placed onto the free queue with an object still
attached. The rundown of the object happens at vnode rundown time, and
happens with exactly the same filesystem semantics of the original VFS
code. There is absolutely no need for vnode_pager_uncache and other
travesties like that anymore.
A side-effect of these changes is that SMP locking should be much simpler,
the I/O copyin/copyout optimizations work, NFS should be more ponderable,
and further work on layered filesystems should be less frustrating, because
of the totally coherent management of the vnode objects and vnodes.
Please be careful with your system while running this code, but I would
greatly appreciate feedback as soon a reasonably possible.
of vnodes and objects. There are some metadata performance improvements
that come along with this. There are also a few prototypes added when
the need is noticed. Changes include:
1) Cleaning up vref, vget.
2) Removal of the object cache.
3) Nuke vnode_pager_uncache and friends, because they aren't needed anymore.
4) Correct some missing LK_RETRY's in vn_lock.
5) Correct the page range in the code for msync.
Be gentle, and please give me feedback asap.
for field widths being 2 larger than specified for "%<number>p". Only
printing of null pointers is "wrong" now (it is actually "right", but
inconsistent with printf(3)).
here, but kmem_malloc() is used and it takes the same "flags" as
malloc().
Use the mbuf allocation "flags" M_WAIT and M_DONTWAIT consistently.
There is really only one boolean flag, M_DONTWAIT, but the "flags"
were always treated as enum-like values, except in some places here
where the values are tacitly converted to boolean flags. Treat
them as enum-like values everywhere, except where we tacitly assume
that there are only two values in order to convert them to the
corresponding two kmem_malloc() "flags".
of time that the laptop was suspending. Thus, select() calls that might have
suspended rather than firing at 1hr + "time suspended" since the timer was
posted.
Adding:
options APM_FIXUP_CALLTODO
to the kernel config enables the patch.
[
This patch was slightly modified to use a consistant indent style and
I removed some unused local variables. After this has been tested a
few weeks we'll make the options the default, so for now I'm now
documenting it in LINT. Mike can later if he wants.
]
Reviewed by: Mike Smith <msmith@freebsd.org>
Submitted by: Ken Key <key@cs.utk.edu>
flag is set in the p_pfsflags field. This, essentially, prevents an SUID
proram from hanging after being traced. (E.g., "truss /usr/bin/rlogin" would
fail, but leave rlogin in a stopevent state.) Yet another case where procctl
is (hopefully ;)) no longer needed in the general case.
Reviewed by: bde (thanks bruce :))
Quite amazing that the system runs at all with this bug. Also present in
2.2.5. The bug appears to have come in with changes in rev 1.53.
PR: might fix PR#5313
Submitted by: bde
if one of the new poll types is requested; hopefully this will not break
any existing code. (This is done so that programs have a dependable
way of determining whether a filesystem supports the extended poll types
or not.)
The new poll types added are:
POLLWRITE - file contents may have been modified
POLLNLINK - file was linked, unlinked, or renamed
POLLATTRIB - file's attributes may have been changed
POLLEXTEND - file was extended
Note that the internal operation of poll() means that it is impossible
for two processes to reliably poll for the same event (this could
be fixed but may not be worth it), so it is not possible to rewrite
`tail -f' to use poll at this time.
- A nonprofiling version of s_lock (called s_lock_np) is used
by mcount.
- When profiling is active, more registers are clobbered in
seemingly simple assembly routines. This means that some
callers needed to save/restore extra registers.
- The stack pointer must have space for a 'fake' return address
in idle, to avoid stack underflow.
... fix a bug with orecvfrom() or recvfrom() called with
the MSG_COMPAT flag on kernels compiled with the COMPAT_43 option.
The symptom is that the fromaddr is not correctly returned.
This affects the Linux emulator.
Submitted by: pb@fasterix.freenix.org (Pierre Beyssac)
noticed some major enhancements available for UP situations. The number
of UP TLB flushes is decreased much more than significantly with these
changes. Since a TLB flush appears to cost minimally approx 80 cycles,
this is a "nice" enhancement, equiv to eliminating between 40 and 160
instructions per TLB flush.
Changes include making sure that kernel threads all use the same PTD,
and eliminate unneeded PTD switches at context switch time.
quite a while, but forgot to do so. For now, this code supports
most daemons running as kernel threads in UP kernels, and as
full processes in SMP. We will soon be able to run them as
threads in SMP, but not yet.
Note that an unload facility should be used to call rm_at_exit() (if
procfs is being loaded as an LKM and is subsequently removed), but it
was non-obvious how to do this in the VFS framework.
Reviewed by: Julian Elischer
surprise, procfs actually is optional, and some people truly do generate
kernels without it. Wow. I built a kernel without 'options PROCFS' and
it compiled and linked.
1) Fix the initialization of malloc structure that changed
due to perf opt.
2) Remove unneeded include.
3) An initialization assert added to malloc.
Submitted by: John Hood <cgull@smoke.marlboro.vt.us>
workaround. Note that this currently eats up two pages extra in the system;
this could be alleviated by aligning idt correctly, and then only dealing with
that (as opposed to the current method of allocated two pages and copying the
IDT table to that, and then setting that to be the IDT table).
or aio_write can return the pid of the new thread. This is due to the
way that return values from system calls being passed by side-effect in
the proc structure now. This commit fixes the problem with aio_read and
aio_write.
remove alot of overly verbose debugging statements.
ioproclist {
int aioprocflags; /* AIO proc flags */
TAILQ_ENTRY(aioproclist) list; /* List of processes */
struct proc *aioproc; /* The AIO thread */
TAILQ_HEAD (,aiocblist) jobtorun; /* suggested job to run */
};
/*
* data-structure for lio signal management
*/
struct aio_liojob {
int lioj_flags;
int lioj_buffer_count;
int lioj_buffer_finished_count;
int lioj_queue_count;
int lioj_queue_finished_count;
struct sigevent lioj_signal; /* signal on all I/O done */
TAILQ_ENTRY (aio_liojob) lioj_list;
struct kaioinfo *lioj_ki;
};
#define LIOJ_SIGNAL 0x1 /* signal on all done (lio) */
#define LIOJ_SIGNAL_POSTED 0x2 /* signal has been posted */
/*
* per process aio data structure
*/
struct kaioinfo {
int kaio_flags; /* per process kaio flags */
int kaio_maxactive_count; /* maximum number of AIOs */
int kaio_active_count; /* number of currently used AIOs */
int kaio_qallowed_count; /* maxiumu size of AIO queue */
int kaio_queue_count; /* size of AIO queue */
int kaio_ballowed_count; /* maximum number of buffers */
int kaio_queue_finished_count; /* number of daemon jobs finished */
int kaio_buffer_count; /* number of physio buffers */
int kaio_buffer_finished_count; /* count of I/O done */
struct proc *kaio_p; /* process that uses this kaio block */
TAILQ_HEAD (,aio_liojob) kaio_liojoblist; /* list of lio jobs */
TAILQ_HEAD (,aiocblist) kaio_jobqueue; /* job queue for process */
TAILQ_HEAD (,aiocblist) kaio_jobdone; /* done queue for process */
TAILQ_HEAD (,aiocblist) kaio_bufqueue; /* buffer job queue for process */
TAILQ_HEAD (,aiocblist) kaio_bufdone; /* buffer done queue for process */
};
#define KAIO_RUNDOWN 0x1 /* process is being run down */
#define KAIO_WAKEUP 0x2 /* wakeup process when there is a significant
event */
TAILQ_HEAD (,aioproclist) aio_freeproc, aio_activeproc;
TAILQ_HEAD(,aiocblist) aio_jobs; /* Async job list */
TAILQ_HEAD(,aiocblist) aio_bufjobs; /* Phys I/O job list */
TAILQ_HEAD(,aiocblist) aio_freejobs; /* Pool of free jobs */
static void aio_init_aioinfo(struct proc *p) ;
static void aio_onceonly(void *) ;
static int aio_free_entry(struct aiocblist *aiocbe);
static void aio_process(struct aiocblist *aiocbe);
static int aio_newproc(void) ;
static int aio_aqueue(struct proc *p, struct aiocb *job, int type) ;
static void aio_physwakeup(struct buf *bp);
static int aio_fphysio(struct proc *p, struct aiocblist *aiocbe, int type);
static int aio_qphysio(struct proc *p, struct aiocblist *iocb);
static void aio_daemon(void *uproc);
SYSINIT(aio, SI_SUB_VFS, SI_ORDER_ANY, aio_onceonly, NULL);
static vm_zone_t kaio_zone=0, aiop_zone=0,
aiocb_zone=0, aiol_zone=0, aiolio_zone=0;
/*
* Single AIOD vmspace shared amongst all of them
*/
static struct vmspace *aiovmspace = NULL;
/*
* Startup initialization
*/
void
aio_onceonly(void *na)
{
TAILQ_INIT(&aio_freeproc);
TAILQ_INIT(&aio_activeproc);
TAILQ_INIT(&aio_jobs);
TAILQ_INIT(&aio_bufjobs);
TAILQ_INIT(&aio_freejobs);
kaio_zone = zinit("AIO", sizeof (struct kaioinfo), 0, 0, 1);
aiop_zone = zinit("AIOP", sizeof (struct aioproclist), 0, 0, 1);
aiocb_zone = zinit("AIOCB", sizeof (struct aiocblist), 0, 0, 1);
aiol_zone = zinit("AIOL", AIO_LISTIO_MAX * sizeof (int), 0, 0, 1);
aiolio_zone = zinit("AIOLIO",
AIO_LISTIO_MAX * sizeof (struct aio_liojob), 0, 0, 1);
aiod_timeout = AIOD_TIMEOUT_DEFAULT;
aiod_lifetime = AIOD_LIFETIME_DEFAULT;
jobrefid = 1;
}
/*
* Init the per-process aioinfo structure.
* The aioinfo limits are set per-process for user limit (resource) management.
*/
void
aio_init_aioinfo(struct proc *p)
{
struct kaioinfo *ki;
if (p->p_aioinfo == NULL) {
ki = zalloc(kaio_zone);
p->p_aioinfo = ki
support was missing in the previous version of the AIO code. More
tunables added, and very efficient support for VCHR files has been added.
Kernel threads are not used for VCHR files, all work for such files is
done for the requesting process directly. Some attempt has been made to
charge the requesting process for resource utilization, but more work
is needed. aio_fsync is still missing (but the original fsync system
call can be used for now.) aio_cancel is essentially a noop, but that
is okay per POSIX. More aio_cancel functionality can be added later,
if it is found to be needed.
The functions implemented include:
aio_read, aio_write, lio_listio, aio_error, aio_return,
aio_cancel, aio_suspend.
The code has been implemented to support the POSIX spec 1003.1b
(formerly known as POSIX 1003.4 spec) features of the above. The
async I/O features are truly async, with the VCHR mode of operation
being essentially the same as physio (for appropriate files) for
maximum efficiency. This code also supports the signal capability,
is highly tunable, allowing management of resource usage, and
has been written to allow a per process usage quota.
Both the O'Reilly POSIX.4 book and the actual POSIX 1003.1b document
were the reference specs used. Any filedescriptor can be used with
these new system calls. I know of no exceptions where these
system calls will not work. (TTY's will also probably work.)
this results in a few functions becoming static, and
the SYSINITs being close to the code they are related to.
setting up the dump device is with dumpsys() and
kicking off the scheduler is with the scheduler.
Mounting root is with the code that does it.
Reviewed by: phk
b_flags, and this patch removes unneeded modifications. Only the needed b_flags
bits are modified now. (Specifically, it is usually wrong to zero b_flags.)
Submitted by: bde@freebsd.org
Fixed overflow of FFLAGS() in fcntl(F_SETFL, ...). This was not
a security hole, but gave wrong results for silly flags values.
E.g., it make fcntl(F_SETFL, -1) equivalent to fcntl(F_SETFL, 0).
POSIX requires ignoring the open mode bits in fcntl() (even if
they would be invalid for open()).
Use OID_AUTO instead of a magic number for the debug.syncprt sysctl.
(This sysctl doesn't actually work. FreeBSD nuked it, but parts
of it were mismerged from Lite2. It is not very good, but better
than nothing.)
`mount -u'. This only matters for `mount -u' competing with unmounts.
If I understand the locking correctly: if mount() blocks, then unmount()
may run and set mp->kern_flag for the same mp. Then unmount() blocks
waiting for mount() to finish. When unmount() continues, its MNTK flags
(MNTK_UNMOUNT and MNTK_MWAIT) may have been clobbered.
Didn't fix old bugs:
- restoring mp->mnt_kern_flag is wrong for the same reasons in the error
case.
- the error case of unmount() seems to be broken too:
(a) MNTK_UNMOUNT gets clobbered, although another unmount() may have
set it. Perhaps it shouldn't be set until after the full lock is
aquired.
(b) MNTK_MWAIT isn't honoured.
Fixed a nearby style bug.
