miscfs/deadfs/deadfs.h: New home for deadfs-related externs.

XXX regen sys/kern/vnode_if.c and the others

Make dead vfs ops "vfs_statvfs" and "vfs_vptofh" return EOPNOTSUPP.
Both operations may originate from (possible dead) vnodes.

Reported-by: syzbot+eceb203d44457742be3b@syzkaller.appspotmail.com

Remove now unused VV_LOCKSWORK, all file systems support locking.

Remove unused predicates vn_locked() and vn_anylocked().

Welcome to 9.99.95

Switch spec_vnodeop vector to real vnode locking, VV_LOCKSWORK now.

Add "void *extra" argument to vcache_new() so a file system may
pass more information about the file to create.

Welcome to 8.99.30

branches: 1.8.2; 1.8.4;
No need to cache anonymous device vnodes, they will never be looked up.

Set key to (dead_rootmount, 0, NULL) and add assertions.

branches: 1.7.10;
Unfortunately MFS uses v_data of its anonymous device vnode so
it cannot be used as vcache key. Use v_interlock as key ...

Redo previous again, v_specnode is invariant but not unique.

Set "vp->v_data = vp" and use v_data as key.

Use the address of vp->v_specnode as vcache key. It is invariant
over the lifetime of the vnode.

The previous worked by luck, it took the first sizeof(void *) bytes
of struct vnode as key.

Resolves CID 1308957: wrong sizeof()

Add a vfs_newvnode() method to deadfs and use it to create
anonymous device vnodes with bdevvp() and cdevvp().

Implement spec_inactive() and spec_reclaim() to handle these nodes.

Use VFS_PROTOS() for deadfs. Rename dead_mount to dead_rootmount.

branches: 1.2.4; 1.2.6; 1.2.10; 1.2.12;
Change all vfsops to use C99 designated initializers.

No functional changes intended.

Currently dead vnodes still reside on the vnodelist of the file system
they have been removed from.

Create a "dead mount" that takes dead vnodes until they get freed.

Discussed on tech-kern.

miscfs/deadfs/deadfs.h: New home for deadfs-related externs.

XXX regen sys/kern/vnode_if.c and the others

Overhaul of the EVFILT_VNODE kevent(2) filter:

- Centralize vnode kevent handling in the VOP_*() wrappers, rather than
forcing each individual file system to deal with it (except VOP_RENAME(),
because VOP_RENAME() is a mess and we currently have 2 different ways
of handling it; at least it's reasonably well-centralized in the "new"
way).
- Add support for NOTE_OPEN, NOTE_CLOSE, NOTE_CLOSE_WRITE, and NOTE_READ,
compatible with the same events in FreeBSD.
- Track which kevent notifications clients are interested in receiving
to avoid doing work for events no one cares about (avoiding, e.g.
taking locks and traversing the klist to send a NOTE_WRITE when
someone is merely watching for a file to be deleted, for example).

In support of the above:

- Add support in vnode_if.sh for specifying PRE- and POST-op handlers,
to be invoked before and after vop_pre() and vop_post(), respectively.
Basic idea from FreeBSD, but implemented differently.
- Add support in vnode_if.sh for specifying CONTEXT fields in the
vop_*_args structures. These context fields are used to convey information
between the file system VOP function and the VOP wrapper, but do not
occupy an argument slot in the VOP_*() call itself. These context fields
are initialized and subsequently interpreted by PRE- and POST-op handlers.
- Version VOP_REMOVE(), uses the a context field for the file system to report
back the resulting link count of the target vnode. Return this in tmpfs,
udf, nfs, chfs, ext2fs, lfs, and ufs.

NetBSD 9.99.92.

Abolish all the silly indirection macros for initializing vnode ops tables.

These are things of the form #define foofs_op genfs_op, or #define
foofs_op genfs_eopnotsupp, or similar. They serve no purpose besides
obfuscation, and have gotten cutpasted all over everywhere.

- Add a new vnode op: VOP_PARSEPATH.
- Move namei_getcomponent to genfs_vnops.c and call it genfs_parsepath.
- Add a parsepath entry to every vnode ops table.

VOP_PARSEPATH takes a directory vnode to be searched and a complete
following path and chooses how much of that path to consume. To begin
with, all parsepath calls are genfs_parsepath, which locates the first
'/' as always.

Note that the call doesn't take the whole struct componentname, only
the string. The other bits of struct componentname should not be
needed and there's no reason to cause potential complications by
exposing them.

branches: 1.63.10;
UVM locking changes, proposed on tech-kern:

- Change the lock on uvm_object, vm_amap and vm_anon to be a RW lock.
- Break v_interlock and vmobjlock apart. v_interlock remains a mutex.
- Do partial PV list locking in the x86 pmap. Others to follow later.

Use vn_bwrite, not genfs_nullop, for VOP_BWRITE.

VOP_BWRITE is responsible for calling biodone; can't just leave it
hanging.

XXX pullup

branches: 1.61.12; 1.61.16; 1.61.18;
Change VOP_REMOVE and VOP_RMDIR to preserve lock/ref on dvp.

No change to vp -- the plan is to replace the node by the
componentname in the vop parameters, and let all directory vops do
lookups internally.

Proposed on tech-kern with no objections:
https://mail-index.netbsd.org/tech-kern/2017/04/17/msg021825.html

Make VOP_INACTIVE preserve vnode lock on return.

Discussed on tech-kern:
https://mail-index.netbsd.org/tech-kern/2017/04/01/msg021751.html

Ride 7.99.68, a bumpy bus of incremental vfs improvements!

branches: 1.59.2; 1.59.4;
Uncomment the argument struct declarations in deadfs.

We don't actually use them, but this is the only way the vop
versioning mechanism flags code that needs changing.

Make VOP_LINK return directory still locked and referenced.

Ride 7.99.10 bump.

branches: 1.57.4;
Add VOP_FALLOCATE and VOP_FDISCARD to every vnode ops table I can
find.

The filesystem ones all call genfs_eopnotsupp - right now I am only
implementing the plumbing and we can implement fallocate and/or
fdiscard for files later.

The device ones call spec_fallocate (which is also genfs_eopnotsupp)
and spec_fdiscard, which dispatches to the device-level op.

The fifo ones all call vn_fifo_bypass, which also ends up being
EOPNOTSUPP.

branches: 1.56.2;
The current implementation of vn_lock() is racy. Modification of
the vnode operations vector for active vnodes is unsafe because it
is not known whether deadfs or the original file system will be
called.

- Pass down LK_RETRY to the lock operation (hint for deadfs only).

- Change deadfs lock operation to return ENOENT if LK_RETRY is unset.

- Change all other lock operations to check for dead vnode once
the vnode is locked and unlock and return ENOENT in this case.

With these changes in place vnode lock operations will never succeed
after vclean() has marked the vnode as VI_XLOCK and before vclean()
has changed the operations vector.

Adresses PR kern/37706 (Forced unmount of file systems is unsafe)

Discussed on tech-kern.

Welcome to 6.99.33

Currently dead vnodes still reside on the vnodelist of the file system
they have been removed from.

Create a "dead mount" that takes dead vnodes until they get freed.

Discussed on tech-kern.

Change vnode operation lookup to return the resulting vnode *vpp unlocked.
Change cache_lookup() to return an unlocked vnode.

Discussed on tech-kern@

Welcome to 6.99.31

Change vnode operations create, mknod, mkdir and symlink to keep the
directory node dvp locked on return.

Discussed on tech-kern@

Welcome to 6.99.29

Add missing operations that unlock or dereference their arguments.

Stop checking for a vnode state change -- dead vnodes never change state.

branches: 1.51.2; 1.51.12; 1.51.16;
Welcome to 5.99.53! Merge rmind-uvmplock branch:

- Reorganize locking in UVM and provide extra serialisation for pmap(9).
New lock order: [vmpage-owner-lock] -> pmap-lock.

- Simplify locking in some pmap(9) modules by removing P->V locking.

- Use lock object on vmobjlock (and thus vnode_t::v_interlock) to share
the locks amongst UVM objects where necessary (tmpfs, layerfs, unionfs).

- Rewrite and optimise x86 TLB shootdown code, make it simpler and cleaner.
Add TLBSTATS option for x86 to collect statistics about TLB shootdowns.

- Unify /dev/mem et al in MI code and provide required locking (removes
kernel-lock on some ports). Also, avoid cache-aliasing issues.

Thanks to Andrew Doran and Joerg Sonnenberger, as their initial patches
formed the core changes of this branch.

branches: 1.50.6;
do minimal locking to make assertions like KASSERT(VOP_ISLOCKED(vp)) happy.

LK_INTERLOCK is no longer a valid flag for VOP_LOCK().

branches: 1.48.2; 1.48.4;
ANSIfy another 1261 function definitions.
The only ones left in sys are beyond by sed script!
(or in sys/dist or sys/external)
Mostly they have function pointer parameters.

branches: 1.47.10; 1.47.18; 1.47.24;
Remove VOP_LEASE. Discussed on tech-kern.

Merge vmlocking2 to head.

branches: 1.45.4; 1.45.6; 1.45.10;
Merge from vmlocking:

- Split vnode::v_flag into three fields, depending on field locking.
- simple_lock -> kmutex in a few places.
- Fix some simple locking problems.

branches: 1.44.4; 1.44.6; 1.44.8; 1.44.10;
It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

branches: 1.43.6; 1.43.14;
Teach deadfs about vm object locking for getpages. This avoids
errors resulting from situations where we take a page fault for a
vnode which has been converted a deadfs vnode.

wrstuden ok

a smorgasbord of improvements to vnode locking and path lookup:
- LOCKPARENT is no longer relevant for lookup(), relookup() or VOP_LOOKUP().
these now always return the parent vnode locked. namei() works as before.
lookup() and various other paths no longer acquire vnode locks in the
wrong order via vrele(). fixes PR 32535.
as a nice side effect, path lookup is also up to 25% faster.
- the above allows us to get rid of PDIRUNLOCK.
- also get rid of WANTPARENT (just use LOCKPARENT and unlock it).
- remove an assumption in layer_node_find() that all file systems implement
a recursive VOP_LOCK() (unionfs doesn't).
- require that all file systems supply vfs_vptofh and vfs_fhtovp routines.
fill in eopnotsupp() for file systems that don't support being exported
and remove the checks for NULL. (layerfs calls these without checking.)
- in union_lookup1(), don't change refcounts in the ISDOTDOT case, just
adjust which vnode is locked. fixes PR 33374.
- apply fixes for ufs_rename() from ufs_vnops.c rev. 1.61 to ext2fs_rename().

branches: 1.41.2;
__unused removal on arguments; approved by core.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

branches: 1.39.8; 1.39.10;
integrate kauth.

branches: 1.38.4; 1.38.6; 1.38.8; 1.38.10; 1.38.12;
merge ktrace-lwp.

merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.36.2;
Remove __P()

branches: 1.35.12;
First pass for some caddr_t removal and changes to get rid of it where we
no longer use and/or need it

- removed casts from unionfs, deadfs and fdesc
(there are more to hunt down still)
- changed vfs_quotactl args argumet from caddr_t to void *
- changed vfs_quotactl structures/callers to reflect the api change

Compiled fine and ran for about a day. Approved/reviewed by
christos@netbsd.org and gimpy@netbsd.org.

Make VOP_STRATEGY(bp) a real VOP as discussed on tech-kern.

VOP_STRATEGY(bp) is replaced by one of two new functions:

- VOP_STRATEGY(vp, bp) Call the strategy routine of vp for bp.
- DEV_STRATEGY(bp) Call the d_strategy routine of bp->b_dev for bp.

DEV_STRATEGY(bp) is used only for block-to-block device situations.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.32.16;
add a VOP_PUTPAGES method for all the filesystems that don't have pages,
just unlock the interlock.

add RCSIDs

branches: 1.30.2; 1.30.4; 1.30.8;
make filesystem vnodeop, specop, fifoop and vnodeopv_* arrays const

sleep() -> tsleep()

Register, begone!

Actually nullop is a better idea here

one more tweak: placebo for VOP_LEASE

Add appropriate VOP_FCNTL handlers to deadfs and specfs ops vectors.

branches: 1.24.14; 1.24.20;
Since the interlock has been unlocked, also clear LK_INTERLOCK from
a_flags in order to not confuse the layer that is called through
the following VCALL.

dead_lock() must unlock `v_interlock'.

Merge with Lite2 + local changes

backout previous kprintf changes

printf -> kprintf, sprintf -> ksprintf

Implement poll(2).

Remove some unused variables.

Add a set of generic file system operations that most file systems use.
Also, fix some time stamp bogosities.

GC *_nullop(). Minor nits.

GC dead_nullop().

miscfs prototype changes

Return EOF for old vnodes of tty devices, rather than EIO.

Remove a_fp.

fixed struct comment

be more careful with types, also pull in headers where necessary.

New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD'

Update to 4.4-Lite fs code, with local changes.

fix return type of dead_print

Canonicalize all #includes.

branches: 1.5.2;
Changes to VFS readdir semantics
NFS changes for better cookie support
ISOFS changes for better Rockridge support and support for generation numbers

Add RCS identifiers (this time on the correct side of the branch), and
incorporate recent changes in netbsd-0-9 branch.

branches: 1.3.2;
ANSIfications - removed all implicit function return types and argument
definitions. Ensured that all files include "systm.h" to gain access to
general prototypes. Casts where necessary.

add $Id$ strings, and clean up file headers where necessary

branches: 1.1.1;
Initial revision

miscfs/deadfs/deadfs.h: New home for deadfs-related externs.

XXX regen sys/kern/vnode_if.c and the others