Commit Graph

60 Commits

Author SHA1 Message Date
Jeff Roberson
c897b81311 Remove references to vm_zone.h and switch over to the new uma API.
Also, remove maxsockets.  If you look carefully you'll notice that the old
zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
Alfred Perlstein
4d77a549fe Remove __P. 2002-03-19 21:25:46 +00:00
Kirk McKusick
a0595d0249 Add a flags parameter to VFS_VGET to pass through the desired
locking flags when acquiring a vnode. The immediate purpose is
to allow polling lock requests (LK_NOWAIT) needed by soft updates
to avoid deadlock when enlisting other processes to help with
the background cleanup. For the future it will allow the use of
shared locks for read access to vnodes. This change touches a
lot of files as it affects most filesystems within the system.
It has been well tested on FFS, loopback, and CD-ROM filesystems.
only lightly on the others, so if you find a problem there, please
let me (mckusick@mckusick.com) know.
2002-03-17 01:25:47 +00:00
Eivind Eklund
eb8e6d5276 Document all functions, global and static variables, and sysctls.
Includes some minor whitespace changes, and re-ordering to be able to document
properly (e.g, grouping of variables and the SYSCTL macro calls for them, where
the documentation has been added.)

Reviewed by:	phk (but all errors are mine)
2002-03-05 15:38:49 +00:00
Matthew Dillon
4f467cb8c1 Fix incorrect double-termination of vm_object. When a vm_object is
terminated and flushes pending dirty pages it is possible for the
object to be ref'd (0->1) and then deref'd (1->0) during termination.
We do not terminate the object a second time.

Document vop_stdgetvobject() to explicitly allow it to be called without
the vnode interlock held (for upcoming sync_msync() and ffs_sync()
performance optimizations)

MFC after:	3 days
2001-10-23 01:23:41 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Matthew Dillon
0cddd8f023 With Alfred's permission, remove vm_mtx in favor of a fine-grained approach
(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
2001-07-04 16:20:28 +00:00
John Baldwin
5bd57bc8b7 Don't release the vm lock just to turn around and grab it again. 2001-05-23 19:51:12 +00:00
Alfred Perlstein
2395531439 Introduce a global lock for the vm subsystem (vm_mtx).
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
Jonathan Lemon
97f6754ff1 When calling poll() on a fd associated with a filesystem, let POLLIN/POLLOUT
behave identically to POLLRDNORM/POLLWRNORM.

Submitted by: bde
PR: 27287
merge after: 1 week
2001-05-14 14:37:25 +00:00
Poul-Henning Kamp
b966319db7 Fix return type of vop_stdputpages()
Noticed by:	rwatson
2001-05-06 17:40:22 +00:00
Poul-Henning Kamp
a62615e59b Implement vop_std{get|put}pages() and add them to the default vop[].
Un-copy&paste all the VOP_{GET|PUT}PAGES() functions which do nothing but
the default.
2001-05-01 08:34:45 +00:00
Poul-Henning Kamp
b7ebffbc08 Add a vop_stdbmap(), and make it part of the default vop vector.
Make 7 filesystems which don't really know about VOP_BMAP rely
on the default vector, rather than more or less complete local
vop_nopbmap() implementations.
2001-04-29 11:48:41 +00:00
Greg Lehey
60fb0ce365 Revert consequences of changes to mount.h, part 2.
Requested by:	bde
2001-04-29 02:45:39 +00:00
Poul-Henning Kamp
a13234bb35 Move the netexport structure from the fs-specific mountstructure
to struct mount.

This makes the "struct netexport *" paramter to the vfs_export
and vfs_checkexport interface unneeded.

Consequently that all non-stacking filesystems can use
vfs_stdcheckexp().

At the same time, make it a pointer to a struct netexport
in struct mount, so that we can remove the bogus AF_MAX
and #include <net/radix.h> from <sys/mount.h>
2001-04-25 07:07:52 +00:00
Greg Lehey
d98dc34f52 Correct #includes to work with fixed sys/mount.h. 2001-04-23 09:05:15 +00:00
Poul-Henning Kamp
f84e29a06c This patch removes the VOP_BWRITE() vector.
VOP_BWRITE() was a hack which made it possible for NFS client
side to use struct buf with non-bio backing.

This patch takes a more general approach and adds a bp->b_op
vector where more methods can be added.

The success of this patch depends on bp->b_op being initialized
all relevant places for some value of "relevant" which is not
easy to determine.  For now the buffers have grown a b_magic
element which will make such issues a tiny bit easier to debug.
2001-04-17 08:56:39 +00:00
Robert Watson
3063207147 o Rename "namespace" argument to "attrnamespace" as namespace is a C++
reserved word.

Submitted by:	jkh
Obtained from:	TrustedBSD Project
2001-03-19 05:44:15 +00:00
Robert Watson
70f3685105 o Change the API and ABI of the Extended Attribute kernel interfaces to
introduce a new argument, "namespace", rather than relying on a first-
  character namespace indicator.  This is in line with more recent
  thinking on EA interfaces on various mailing lists, including the
  posix1e, Linux acl-devel, and trustedbsd-discuss forums.  Two namespaces
  are defined by default, EXTATTR_NAMESPACE_SYSTEM and
  EXTATTR_NAMESPACE_USER, where the primary distinction lies in the
  access control model: user EAs are accessible based on the normal
  MAC and DAC file/directory protections, and system attributes are
  limited to kernel-originated or appropriately privileged userland
  requests.

o These API changes occur at several levels: the namespace argument is
  introduced in the extattr_{get,set}_file() system call interfaces,
  at the vnode operation level in the vop_{get,set}extattr() interfaces,
  and in the UFS extended attribute implementation.  Changes are also
  introduced in the VFS extattrctl() interface (system call, VFS,
  and UFS implementation), where the arguments are modified to include
  a namespace field, as well as modified to advoid direct access to
  userspace variables from below the VFS layer (in the style of recent
  changes to mount by adrian@FreeBSD.org).  This required some cleanup
  and bug fixing regarding VFS locks and the VFS interface, as a vnode
  pointer may now be optionally submitted to the VFS_EXTATTRCTL()
  call.  Updated documentation for the VFS interface will be committed
  shortly.

o In the near future, the auto-starting feature will be updated to
  search two sub-directories to the ".attribute" directory in appropriate
  file systems: "user" and "system" to locate attributes intended for
  those namespaces, as the single filename is no longer sufficient
  to indicate what namespace the attribute is intended for.  Until this
  is committed, all attributes auto-started by UFS will be placed in
  the EXTATTR_NAMESPACE_SYSTEM namespace.

o The default POSIX.1e attribute names for ACLs and Capabilities have
  been updated to no longer include the '$' in their filename.  As such,
  if you're using these features, you'll need to rename the attribute
  backing files to the same names without '$' symbols in front.

o Note that these changes will require changes in userland, which will
  be committed shortly.  These include modifications to the extended
  attribute utilities, as well as to libutil for new namespace
  string conversion routines.  Once the matching userland changes are
  committed, a buildworld is recommended to update all the necessary
  include files and verify that the kernel and userland environments
  are in sync.  Note: If you do not use extended attributes (most people
  won't), upgrading is not imperative although since the system call
  API has changed, the new userland extended attribute code will no longer
  compile with old include files.

o Couple of minor cleanups while I'm there: make more code compilation
  conditional on FFS_EXTATTR, which should recover a bit of space on
  kernels running without EA's, as well as update copyright dates.

Obtained from:	TrustedBSD Project
2001-03-15 02:54:29 +00:00
Bruce Evans
a25f057175 Added a dummy lookup vop. Specfs was broken by removing its dummy
lookup vop so that it defaulted to using vop_eopnotsupp for strange
lookups like the ones for open("/dev/null/", ...) and stat("/dev/null/",
...).  This mainly caused the wrong errno to be returned by vfs syscalls
(EOPNOTSUPP is not in POSIX, and is not documented in connection with
specfs in open.2 and is not documented in stat.2 at all).  Also, lookup
vops are apparently required to set *ap->a_vpp to NULL on error, but
vop_eopnotsupp is too broken to do this.
2001-02-18 02:22:58 +00:00
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
Eivind Eklund
e3c4036b18 Give vop_mmap an untimely death. The opportunity to give it a timely
death timed out in 1996.
2000-11-01 17:57:24 +00:00
John Baldwin
35e0e5b311 Catch up to moving headers:
- machine/ipl.h -> sys/ipl.h
- machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Boris Popov
67e871664b Add a lock structure to vnode structure. Previously it was either allocated
separately (nfs, cd9660 etc) or keept as a first element of structure
referenced by v_data pointer(ffs). Such organization leads to known problems
with stacked filesystems.

From this point vop_no*lock*() functions maintain only interlock lock.
vop_std*lock*() functions maintain built-in v_lock structure using lockmgr().
vop_sharedlock() is compatible with vop_stdunlock(), but maintains a shared
lock on vnode.

If filesystem wishes to export lockmgr compatible lock, it can put an address
of this lock to v_vnlock field. This indicates that the upper filesystem
can take advantage of it and use single lock structure for entire (or part)
of stack of vnodes. This field shouldn't be examined or modified by VFS code
except for initialization purposes.

Reviewed in general by:	mckusick
2000-09-25 15:24:04 +00:00
Boris Popov
9ff5ce6baf Add three new VOPs: VOP_CREATEVOBJECT, VOP_DESTROYVOBJECT and VOP_GETVOBJECT.
They will be used by nullfs and other stacked filesystems to support full
cache coherency.

Reviewed in general by:	mckusick, dillon
2000-09-12 09:49:08 +00:00
Poul-Henning Kamp
39f70682ae Introduce vop_stdinactive() and make it the default if no vop_inactive
is declared.

Sort and prune a few vop_op[].
2000-08-18 10:01:02 +00:00
Kirk McKusick
f2a2857bb3 Add snapshots to the fast filesystem. Most of the changes support
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.

Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
Poul-Henning Kamp
9626b608de Separate the struct bio related stuff out of <sys/buf.h> into
<sys/bio.h>.

<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.

Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.

Still a few bogus uses of struct buf to track down.

Repocopy by:    peter
2000-05-05 09:59:14 +00:00
Poul-Henning Kamp
8177437d85 Complete the bio/buf divorce for all code below devfs::strategy
Exceptions:
        Vinum untouched.  This means that it cannot be compiled.
        Greg Lehey is on the case.

        CCD not converted yet, casts to struct buf (still safe)

        atapi-cd casts to struct buf to examine B_PHYS
2000-04-15 05:54:02 +00:00
Poul-Henning Kamp
c244d2de43 Move B_ERROR flag to b_ioflags and call it BIO_ERROR.
(Much of this done by script)

Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.

Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.

Add bio_queue field for struct bio aware disksort.

Address a lot of stylistic issues brought up by bde.
2000-04-02 15:24:56 +00:00
Poul-Henning Kamp
21144e3bf1 Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new
field in struct buf: b_iocmd.  The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue.  It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users:  Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
Robert Watson
8f0738756c Fix bde'isms in acl/extattr syscall interface, renaming syscalls to
prettier (?) names, adding some const's around here, et al.

Reviewed by:	bde
2000-01-19 06:07:34 +00:00
Robert Watson
91f37dcba1 Second pass commit to introduce new ACL and Extended Attribute system
calls, vnops, vfsops, both in /kern, and to individual file systems that
require a vfsop_ array entry.

Reviewed by:	eivind
1999-12-19 06:08:07 +00:00
Eivind Eklund
762e6b856c Introduce NDFREE (and remove VOP_ABORTOP) 1999-12-15 23:02:35 +00:00
Eivind Eklund
6bdfe06ad9 Lock reporting and assertion changes.
* lockstatus() and VOP_ISLOCKED() gets a new process argument and a new
  return value: LK_EXCLOTHER, when the lock is held exclusively by another
  process.
* The ASSERT_VOP_(UN)LOCKED family is extended to use what this gives them
* Extend the vnode_if.src format to allow more exact specification than
  locked/unlocked.

This commit should not do any semantic changes unless you are using
DEBUG_VFS_LOCKS.

Discussed with:	grog, mch, peter, phk
Reviewed by:	peter
1999-12-11 16:13:02 +00:00
Poul-Henning Kamp
0c974a1f16 Make vop_panic() a little more informative. 1999-11-07 15:09:49 +00:00
Alfred Perlstein
c24fda81c9 Seperate the export check in VFS_FHTOVP, exports are now checked via
VFS_CHECKEXP.

Add fh(open|stat|stafs) syscalls to allow userland to query filesystems
based on (network) filehandle.

Obtained from:	NetBSD
1999-09-11 00:46:08 +00:00
Alfred Perlstein
5a5fccc8e7 All unimplemented VFS ops now have entries in kern/vfs_default.c that return
reasonable defaults.

This avoids confusing and ugly casting to eopnotsupp or making dummy functions.
Bogus casting of filesystem sysctls to eopnotsupp() have been removed.

This should make *_vfsops.c more readable and reduce bloat.

Reviewed by:	msmith, eivind
Approved by:	phk
Tested by:	Jeroen Ruigrok/Asmodai <asmodai@wxs.nl>
1999-09-07 22:42:38 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Gary Palmer
0625ba2fc3 Add Id strings 1999-06-17 23:42:45 +00:00
Alan Cox
4221e284a3 The VFS/BIO subsystem contained a number of hacks in order to optimize
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>
1999-05-02 23:57:16 +00:00
Bruce Evans
a5c9bce777 Added a used #include (don't depend on "vnode_if.h" including <sys/buf.h>). 1999-02-25 15:54:06 +00:00
Eivind Eklund
15a1057c46 Add 'options DEBUG_LOCKS', which stores extra information in struct
lock, and add some macros and function parameters to make sure that
the information get to the point where it can be put in the lock
structure.

While I'm here, add DEBUG_VFS_LOCKS to LINT.
1999-01-20 14:49:12 +00:00
Peter Wemm
4e61198e8f Make the vnode opv vector construction fully dynamic. Previously we
leaked memory on each unload and were limited to items referenced in
the kernel copy of vnode_if.c.  Now a kernel module is free to create
it's own VOP_FOO() routines and the rest of the system will happily
deal with it, including passthrough layers like union/umap/etc.

Have VFS_SET() call a common vfs_modevent() handler rather than
inline duplicating the common code all over the place.

Have VNODEOP_SET() have the vnodeops removed at unload time (assuming a
module) so that the vop_t ** vector is reclaimed.

Slightly adjust the vop_t ** vectors so that calling slot 0 is a panic
rather than a page fault.  This could happen if VOP_something() was called
without *any* handlers being present anywhere (including in vfs_default.c).
slot 1 becomes the default vector for the vnodeop table.

TODO: reclaim zones on unload (eg: nfs code)
1998-11-10 09:04:09 +00:00
Julian Elischer
fd5d1124e2 VOP_STRATEGY grows an (struct vnode *) argument
as the value in b_vp is often not really what you want.
(and needs to be frobbed). more cleanups will follow this.
Reviewed by: Bruce Evans <bde@freebsd.org>
1998-07-04 20:45:42 +00:00
Mike Smith
79cc756d8b As described by the submitter:
Reverse the VFS_VRELE patch.  Reference counting of vnodes does not need
to be done per-fs.  I noticed this while fixing vfs layering violations.
Doing reference counting in generic code is also the preference cited by
John Heidemann in recent discussions with him.

The implementation of alternative vnode management per-fs is still a valid
requirement for some filesystems but will be revisited sometime later,
most likely using a different framework.

Submitted by:	Michael Hancock <michaelh@cet.co.jp>
1998-05-06 05:29:41 +00:00
John Dyson
8f9110f6a1 This mega-commit is meant to fix numerous interrelated problems. There
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.
1998-03-07 21:37:31 +00:00
Mike Smith
34bdbbd0de The intent is to get rid of WILLRELE in vnode_if.src by making
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>
1998-03-01 22:46:53 +00:00
John Dyson
95e5e988e0 Make our v_usecount vnode reference count work identically to the
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.
1998-01-06 05:26:17 +00:00