piecemeal, middle-of-file writes for NFS. These hacks have caused no
end of trouble, especially when combined with mmap(). I've removed
them. Instead, NFS will issue a read-before-write to fully
instantiate the struct buf containing the write. NFS does, however,
optimize piecemeal appends to files. For most common file operations,
you will not notice the difference. The sole remaining fragment in
the VFS/BIO system is b_dirtyoff/end, which NFS uses to avoid cache
coherency issues with read-merge-write style operations. NFS also
optimizes the write-covers-entire-buffer case by avoiding the
read-before-write. There is quite a bit of room for further
optimization in these areas.
The VM system marks pages fully-valid (AKA vm_page_t->valid =
VM_PAGE_BITS_ALL) in several places, most noteably in vm_fault. This
is not correct operation. The vm_pager_get_pages() code is now
responsible for marking VM pages all-valid. A number of VM helper
routines have been added to aid in zeroing-out the invalid portions of
a VM page prior to the page being marked all-valid. This operation is
necessary to properly support mmap(). The zeroing occurs most often
when dealing with file-EOF situations. Several bugs have been fixed
in the NFS subsystem, including bits handling file and directory EOF
situations and buf->b_flags consistancy issues relating to clearing
B_ERROR & B_INVAL, and handling B_DONE.
getblk() and allocbuf() have been rewritten. B_CACHE operation is now
formally defined in comments and more straightforward in
implementation. B_CACHE for VMIO buffers is based on the validity of
the backing store. B_CACHE for non-VMIO buffers is based simply on
whether the buffer is B_INVAL or not (B_CACHE set if B_INVAL clear,
and vise-versa). biodone() is now responsible for setting B_CACHE
when a successful read completes. B_CACHE is also set when a bdwrite()
is initiated and when a bwrite() is initiated. VFS VOP_BWRITE
routines (there are only two - nfs_bwrite() and bwrite()) are now
expected to set B_CACHE. This means that bowrite() and bawrite() also
set B_CACHE indirectly.
There are a number of places in the code which were previously using
buf->b_bufsize (which is DEV_BSIZE aligned) when they should have
been using buf->b_bcount. These have been fixed. getblk() now clears
B_DONE on return because the rest of the system is so bad about
dealing with B_DONE.
Major fixes to NFS/TCP have been made. A server-side bug could cause
requests to be lost by the server due to nfs_realign() overwriting
other rpc's in the same TCP mbuf chain. The server's kernel must be
recompiled to get the benefit of the fixes.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.
For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".
Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.
Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.
It generally does what one would expect, but setting up a jail
still takes a little knowledge.
A few notes:
I have no scripts for setting up a jail, don't ask me for them.
The IP number should be an alias on one of the interfaces.
mount a /proc in each jail, it will make ps more useable.
/proc/<pid>/status tells the hostname of the prison for
jailed processes.
Quotas are only sensible if you have a mountpoint per prison.
There are no privisions for stopping resource-hogging.
Some "#ifdef INET" and similar may be missing (send patches!)
If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!
Tools, comments, patches & documentation most welcome.
Have fun...
Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/
1:
s/suser/suser_xxx/
2:
Add new function: suser(struct proc *), prototyped in <sys/proc.h>.
3:
s/suser_xxx(\([a-zA-Z0-9_]*\)->p_ucred, \&\1->p_acflag)/suser(\1)/
The remaining suser_xxx() calls will be scrutinized and dealt with
later.
There may be some unneeded #include <sys/cred.h>, but they are left
as an exercise for Bruce.
More changes to the suser() API will come along with the "jail" code.
routine was [ab]used for two different things, and you couldn't tell from
the wait channel which one had wedged.
Catch a few things missing from NFS_NOSERVER.
This makes it possible to change the sysctl tree at runtime.
* Change KLD to find and register any sysctl nodes contained in the loaded
file and to unregister them when the file is unloaded.
Reviewed by: Archie Cobbs <archie@whistle.com>,
Peter Wemm <peter@netplex.com.au> (well they looked at it anyway)
changes to the VM system to support the new swapper, VM bug
fixes, several VM optimizations, and some additional revamping of the
VM code. The specific bug fixes will be documented with additional
forced commits. This commit is somewhat rough in regards to code
cleanup issues.
Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
second argument. np_size is a 64 bit int, so is the second arg. This
might have caused needless 2G/4G file size problems.
I believe it was Bruce who queried this.
sure that this is necessary to be a sync write here since a VOP_FSYNC()
follows and it will schedule, sort and complete the writes that the
vm_object_page_clean() started (as I think I understand things).
is less than NFS_MINPACKET or greater than NFS_MAXPACKET in size, it
barfs and, I think, drops the connection.
However, there's no guarantee that in a multi-fragment RPC, all the
fragments will be at least as large as NFS_MINPACKET.
In fact, with the version of "tclnfs" we have here, which supports NFS
over TCP, at least when built under SunOS 4.1.3 (i.e., with 4.1.3's
user-mode ONC RPC library), I can *repeatably* cause "tclnfs" to send a
request with more than one fragment, one of which is only 8 bytes long.
I just do a 3877-byte write to a file, at an offset of 0.
The check that "slp->ns_reclen" is greater than or equal to
NFS_MINPACKET serves no useful purpose - if the NFS server code can't
handle packets < NFS_MINPACKET bytes, it can't handle them over *any*
protocol, so the check has to be done above the RPC-over-TCP layer - and
should be removed.
Obtained from: Fix from Guy Harris, forwarded by Rick Macklem.
detachment of vfs sysctls. Unloading of vfs LKMs doesn't actually
work for any vfs, since it leaves garbage pointers to memory
allocation control structures.
when nfs is an LKM. Declare it in a header file. Don't forget to use
it in non-Lite2 code. Initialize it to -1 instead of to 0, since 0
will soon be the mount type number for the first vfs loaded.
NetBSD uses strcmp() to avoid this ugly global.
another specialized mbuf type in the process. Also clean up some
of the cruft surrounding IPFW, multicast routing, RSVP, and other
ill-explored corners.
interface congestion (eg: nfs over a ppp link, etc). Don't log these
for UDP mounts, and don't cause syscalls to fail with EINTR.
This stops the 'nfs send error 55' warnings.
If the error is because the system is really hosed, this is the least
of your problems...
respectively. Most of the longs should probably have been
u_longs, but this changes is just to prevent warnings about
casts between pointers and integers of different sizes, not
to fix poorly chosen types.
NFS_*TIMO should possibly be converted to sysctl vars (jkh's suggestion),
but in some cases it looks like nfs keeps a copy of the value in a struct
hash sizes are already ifdef'd KERNEL, so there aren't userland inpact
from them...
NFS_MINATTRTIMO VREG attrib cache timeout in sec
NFS_MAXATTRTIMO
NFS_MINDIRATTRTIMO VDIR attrib cache timeout in sec
NFS_MAXDIRATTRTIMO
NFS_GATHERDELAY Default write gather delay (msec)
NFS_UIDHASHSIZ Tune the size of nfssvc_sock with this
NFS_WDELAYHASHSIZ and with this
NFS_MUIDHASHSIZ Tune the size of nfsmount with this
NFS_NOSERVER (already documented in LINT)
NFS_DEBUG turn on NFS debugging
also, because NFS_ROOT is used by very different files, it has been
renamed to opt_nfsroot.h instead of the old opt_nfs.h....
Pre-2.8 versions of gcc generate a call to __divdi3() for all 64-bit
signed divisions, but egcs optimizes them to a shift and fixup when
the divisor is a constant power of 2. Unfortunately, it generates
a call to __cmpdi2() for the fixup, although all except possibly
ancient versions of gcc and egcs do ordinary 64-bit comparisons
inline.
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.
it just makes more work. We pass a copy of the uid/gid with the
credentials. (although, this may need to be revisited if a non AUTHUNIX
authentication method (such as NFSKERB) ever gets implemented).
Obtained from: NetBSD
