Commit Graph

14 Commits

Author SHA1 Message Date
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
Garrett Wollman
e51d1e8707 Revert poll() for UFS files to traditional behavior where polling for read-
or writability always returns true.  This works around bugs in netscape and
squid, at a minimum.
1997-12-17 14:44:23 +00:00
Garrett Wollman
1cbbd625cc Add support for poll(2) on files. vop_nopoll() now returns POLLNVAL
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.
1997-12-15 03:09:59 +00:00
Bruce Evans
1cd52ec333 Don't include <sys/lock.h> in headers when only `struct simplelock' is
required.  Fixed everything that depended on the pollution.
1997-12-05 19:55:52 +00:00
Bruce Evans
d662024a0d Removed an unused #include.
Fixed a style bug (one of many KNF breakages in vfs_subr.c moved here).
1997-11-18 13:03:48 +00:00
Poul-Henning Kamp
dba3870c10 VFS interior redecoration.
Rename vn_default_error to vop_defaultop all over the place.
Move vn_bwrite from vfs_bio.c to vfs_default.c and call it vop_stdbwrite.
Use vop_null instead of nullop.
Move vop_nopoll from vfs_subr.c to vfs_default.c
Move vop_sharedlock from vfs_subr.c to vfs_default.c
Move vop_nolock from vfs_subr.c to vfs_default.c
Move vop_nounlock from vfs_subr.c to vfs_default.c
Move vop_noislocked from vfs_subr.c to vfs_default.c
Use vop_ebadf instead of *_ebadf.
Add vop_defaultop for getpages on master vnode in MFS.
1997-10-26 20:55:39 +00:00
Poul-Henning Kamp
1b09ae776d Simplify the lease_check stuff. 1997-10-26 20:26:33 +00:00
Poul-Henning Kamp
d54d34b533 Make a set of VOP standard lock, unlock & islocked VOP operators, which
depend on the lock being located at vp->v_data.  Saves 3x3 identical
vop procs, more as the other filesystems becomes lock aware.
1997-10-17 12:36:19 +00:00
Poul-Henning Kamp
e9565321ea VFS clean up "hekto commit"
1.  Add defaults for more VOPs
        VOP_LOCK        vop_nolock
        VOP_ISLOCKED    vop_noislocked
        VOP_UNLOCK      vop_nounlock
    and remove direct reference in filesystems.

2.  Rename the nfsv2 vnop tables to improve sorting order.
1997-10-16 22:01:05 +00:00
Poul-Henning Kamp
987f569678 Another VFS cleanup "kilo commit"
1.  Remove VOP_UPDATE, it is (also) an UFS/{FFS,LFS,EXT2FS,MFS}
    intereface function, and now lives in the ufsmount structure.

2.  Remove VOP_SEEK, it was unused.

3.  Add mode default vops:

    VOP_ADVLOCK          vop_einval
    VOP_CLOSE            vop_null
    VOP_FSYNC            vop_null
    VOP_IOCTL            vop_enotty
    VOP_MMAP             vop_einval
    VOP_OPEN             vop_null
    VOP_PATHCONF         vop_einval
    VOP_READLINK         vop_einval
    VOP_REALLOCBLKS      vop_eopnotsupp

    And remove identical functionality from filesystems

4.   Add vop_stdpathconf, which returns the canonical stuff.  Use
     it in the filesystems.  (XXX: It's probably wrong that specfs
     and fifofs sets this vop, shouldn't it come from the "host"
     filesystem, for instance ufs or cd9660 ?)

5.   Try to make system wide VOP functions have vop_* names.

6.   Initialize the um_* vectors in LFS.

(Recompile your LKMS!!!)
1997-10-16 20:32:40 +00:00
Poul-Henning Kamp
2df896458d Oops. forgot the blasted cvs add.
Pointed hat sent from:	Karl Denninger  <karl@Mcs.Net>
1997-10-16 17:48:22 +00:00