a whole bunch of changes to improve performance and robustness under load:

- remove special treatment of pager_map mappings in pmaps. this is
required now, since I've removed the globals that expose the address range.
pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
no longer any need to special-case it.
- eliminate struct uvm_vnode by moving its fields into struct vnode.
- rewrite the pageout path. the pager is now responsible for handling the
high-level requests instead of only getting control after a bunch of work
has already been done on its behalf. this will allow us to UBCify LFS,
which needs tighter control over its pages than other filesystems do.
writing a page to disk no longer requires making it read-only, which
allows us to write wired pages without causing all kinds of havoc.
- use a new PG_PAGEOUT flag to indicate that a page should be freed
on behalf of the pagedaemon when it's unlocked. this flag is very similar
to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
pageout fails due to eg. an indirect-block buffer being locked.
this allows us to remove the "version" field from struct vm_page,
and together with shrinking "loan_count" from 32 bits to 16,
struct vm_page is now 4 bytes smaller.
- no longer use PG_RELEASED for swap-backed pages. if the page is busy
because it's being paged out, we can't release the swap slot to be
reallocated until that write is complete, but unlike with vnodes we
don't keep a count of in-progress writes so there's no good way to
know when the write is done. instead, when we need to free a busy
swap-backed page, just sleep until we can get it busy ourselves.
- implement a fast-path for extending writes which allows us to avoid
zeroing new pages. this substantially reduces cpu usage.
- encapsulate the data used by the genfs code in a struct genfs_node,
which must be the first element of the filesystem-specific vnode data
for filesystems which use genfs_{get,put}pages().
- eliminate many of the UVM pagerops, since they aren't needed anymore
now that the pager "put" operation is a higher-level operation.
- enhance the genfs code to allow NFS to use the genfs_{get,put}pages
instead of a modified copy.
- clean up struct vnode by removing all the fields that used to be used by
the vfs_cluster.c code (which we don't use anymore with UBC).
- remove kmem_object and mb_object since they were useless.
instead of allocating pages to these objects, we now just allocate
pages with no object. such pages are mapped in the kernel until they
are freed, so we can use the mapping to find the page to free it.
this allows us to remove splvm() protection in several places.

The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.

branches: 1.2.14; 1.2.16; 1.2.18;
Introduce layer library in genfs. This set of files abstracts most of
the functionality of nullfs. The latter is now just a mount & unmount
routine, and a few tables. umapfs borrow most of this infrastructure.

Both fs's are now nfs-exportable.

All layered fs's share a common format to private mount & private
vnode structs (which a particular fs can extend).

Also add genfs_noerr_rele(), a vnode op which will vrele/vput
operand vnodes appropriately.

branches: 1.1.10;
Rework the way kernel include files are installed. In the new method,
as with user-land programs, include files are installed by each directory
in the tree that has includes to install. (This allows more flexibility
as to what gets installed, makes 'partial installs' easier, and gives us
more options as to which machines' includes get installed at any given
time.) The old SYS_INCLUDES={symlinks,copies} behaviours are _both_
still supported, though at least one bug in the 'symlinks' case is
fixed by this change. Include files can't be build before installation,
so directories that have includes as targets (e.g. dev/pci) have to move
those targets into a different Makefile.

dedup the eofs link/symlink methods

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.

- 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: 1.36.6;
accmode should be accmode_t

Introduce genfs_pathconf() and use it for the default case in all filesystems.

Add ACL support for FFS. From FreeBSD.

Add generic genfs_suspendctl() and use it for all file systems.
Layered file systems need work.

branches: 1.32.6; 1.32.10; 1.32.14;
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

branches: 1.31.4;
Fix (harmless) typo in struct genfs_rename_ops::gro_lookup prototype.

branches: 1.30.2;
Implement a genfs_rename abstraction.

First major step in incrementally adapting all the file systems to a
saner rename VOP protocol.

Replace the remaining KAUTH_GENERIC_ISSUSER authorization calls with
something meaningful. All relevant documentation has been updated or
written.

Most of these changes were brought up in the following messages:

http://mail-index.netbsd.org/tech-kern/2012/01/18/msg012490.html
http://mail-index.netbsd.org/tech-kern/2012/01/19/msg012502.html
http://mail-index.netbsd.org/tech-kern/2012/02/17/msg012728.html

Thanks to christos, manu, njoly, and jmmv for input.

Huge thanks to pgoyette for spinning these changes through some build
cycles and ATF.

branches: 1.28.12; 1.28.16; 1.28.18;
Introduce genfs_statvfs() as pretty much a no-info statvfs and
convert several pseudo file systems to use it.

Move the implementation of vaccess() to genfs_can_access(), in line with
the other routines of the same spirit.

Adjust file-system code to use it.

Keep vaccess() for KPI compatibility and to keep element of least
surprise. A "diagnostic" message warning that vaccess() is deprecated will
be printed when it's used (obviously, only in DIAGNOSTIC kernels).

No objections on tech-kern@:

http://mail-index.netbsd.org/tech-kern/2009/06/21/msg005310.html

Extract the open-coded authorization logic for chtimes() from various
file-systems and put it in a single function, genfs_can_chtimes().

This also makes UDF follow the same policy as all other file-systems.

Mailing list reference:

http://mail-index.netbsd.org/tech-kern/2009/04/27/msg004951.html

Add genfs_can_mount() and use it to prevent some more code duplication of
the security checks when mounting a device (VOP_ACCESS() + kauth(9) call)).

Proposed with no objections on tech-kern@:

http://mail-index.netbsd.org/tech-kern/2009/04/20/msg004859.html

The vnode is always expected to be locked, so no locking is done outside
the file-system code.

Per discussion on tech-kern@:

- Replace use of label/goto with returns

- Rename, change prototype of, and move functions from vfs_subr.c to
genfs_vnops.c

branches: 1.23.10; 1.23.18; 1.23.24;
Fix some race conditions in rename.
Introduce a per-FS rename lock and new vfsops to manipulate it.
Get this lock while renaming. Also add another relookup() in do_sys_rename,
which is a hack to kludge around some of the worst deficiencies of
ufs_rename.
reviewed-by: pooka (and an earlier rev by ad)
posted on tech-kern with no objections.

Remove VOP_LEASE. Discussed on tech-kern.

branches: 1.21.8; 1.21.14;
Split the VOP interface part of genfs_putpages() from the code. The new
function that does the work, genfs_do_putpages(), now takes as an argument
a pointer to the page that would be waited on, if PGO_BUSYWAIT were not set.
This allows a consumer, e.g. lfs_putpages(), to perform an action outside
the scope of UVM before sleeping on the page in question.

branches: 1.20.24; 1.20.26; 1.20.30; 1.20.32; 1.20.38;
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: 1.18.2;
Remove __P()

branches: 1.17.2; 1.17.18;
use former genfs_eopnotsupp_rele() as genfs_eopnotsupp(), so that vnodes
are vput()/vrele()d as necessary - some filesystems did use the wrong
one for some ops, and it's just safer to not take the chance

based on suggestion by Bill Studenmund

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

add some compatibility routines to allow mmap() to work non-UBCified
filesystems (in the same non-coherent fashion that they worked before).

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

a whole bunch of changes to improve performance and robustness under load:

- remove special treatment of pager_map mappings in pmaps. this is
required now, since I've removed the globals that expose the address range.
pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
no longer any need to special-case it.
- eliminate struct uvm_vnode by moving its fields into struct vnode.
- rewrite the pageout path. the pager is now responsible for handling the
high-level requests instead of only getting control after a bunch of work
has already been done on its behalf. this will allow us to UBCify LFS,
which needs tighter control over its pages than other filesystems do.
writing a page to disk no longer requires making it read-only, which
allows us to write wired pages without causing all kinds of havoc.
- use a new PG_PAGEOUT flag to indicate that a page should be freed
on behalf of the pagedaemon when it's unlocked. this flag is very similar
to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
pageout fails due to eg. an indirect-block buffer being locked.
this allows us to remove the "version" field from struct vm_page,
and together with shrinking "loan_count" from 32 bits to 16,
struct vm_page is now 4 bytes smaller.
- no longer use PG_RELEASED for swap-backed pages. if the page is busy
because it's being paged out, we can't release the swap slot to be
reallocated until that write is complete, but unlike with vnodes we
don't keep a count of in-progress writes so there's no good way to
know when the write is done. instead, when we need to free a busy
swap-backed page, just sleep until we can get it busy ourselves.
- implement a fast-path for extending writes which allows us to avoid
zeroing new pages. this substantially reduces cpu usage.
- encapsulate the data used by the genfs code in a struct genfs_node,
which must be the first element of the filesystem-specific vnode data
for filesystems which use genfs_{get,put}pages().
- eliminate many of the UVM pagerops, since they aren't needed anymore
now that the pager "put" operation is a higher-level operation.
- enhance the genfs code to allow NFS to use the genfs_{get,put}pages
instead of a modified copy.
- clean up struct vnode by removing all the fields that used to be used by
the vfs_cluster.c code (which we don't use anymore with UBC).
- remove kmem_object and mb_object since they were useless.
instead of allocating pages to these objects, we now just allocate
pages with no object. such pages are mapped in the kernel until they
are freed, so we can use the mapping to find the page to free it.
this allows us to remove splvm() protection in several places.

The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.

branches: 1.12.2; 1.12.4;
add a genfs_mmap() and change all of the disk-based filesystems
to implement VOP_MMAP() with the genfs version, in preparation for
actually using this VOP.

branches: 1.11.2;
Initial integration of the Unified Buffer Cache project.

branches: 1.10.2;
Add support for fcntl(2) to generate VOP_FCNTL calls. Any fcntl
call with F_FSCTL set and F_SETFL calls generate calls to a new
fileop fo_fcntl. Add genfs_fcntl() and soo_fcntl() which return 0
for F_SETFL and EOPNOTSUPP otherwise. Have all leaf filesystems
use genfs_fcntl().

Reviewed by: thorpej
Tested by: wrstuden

Introduce layer library in genfs. This set of files abstracts most of
the functionality of nullfs. The latter is now just a mount & unmount
routine, and a few tables. umapfs borrow most of this infrastructure.

Both fs's are now nfs-exportable.

All layered fs's share a common format to private mount & private
vnode structs (which a particular fs can extend).

Also add genfs_noerr_rele(), a vnode op which will vrele/vput
operand vnodes appropriately.

branches: 1.8.8;
Add genfs_einval(), which does the obvious thing.

create miscfs/genfs/genfs_vnops.c:genfs_enoioctl and make all the other
filesystems use it instead of a private version.

- Rename nqnfs_vop_lease_check() to genfs_lease_check(). If NFSSERVER is
not in the kernel, genfs_lease_check() is simply a no-op. This allows
LKM'd file systems to be exported (previously did not work properly
due to a compile-time decision based on -DNFSSERVER).
- defopt NFSSERVER

Merge with Lite2 + local changes

RCSID Police.

Implement a POSIX compliant genfs VOP_SEEK() and use it in the appropriate
places; by Chris G. Demetriou and myself.

Implement poll(2).

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

uvm: Expand v_size <= v_writesize assertions to help diagnostics.

PR kern/58117

genfs: KASSERT(A && B) -> KASSERT(A); KASSERT(B)

genfs(9): Prune dead branch.

Remove trailing \n from UVMHIST_LOG() format strings.

centralize calls from UVM to radixtree into a few functions.
in those functions, assert that the object lock is held in
the correct mode.

Output offsets in hex for UVMHIST.

genfs_putpages(): when building a cluster make use of pages in the in the
existing uvm_page_array.

- Alter the convention for uvm_page_array slightly, so the basic search
parameters can't change part way through a search: move the "uobj" and
"flags" arguments over to uvm_page_array_init() and store those with the
array.

- With that, detect when it's not possible to find any more pages in the
tree with the given search parameters, and avoid repeated tree lookups if
the caller loops over uvm_page_array_fill_and_peek().

Start trying to reduce cache misses on vm_page during fault processing.

- Make PGO_LOCKED getpages imply PGO_NOBUSY and remove the latter. Mark
pages busy only when there's actually I/O to do.

- When doing COW on a uvm_object, don't mess with neighbouring pages. In
all likelyhood they're already entered.

- Don't mess with neighbouring VAs that have existing mappings as replacing
those mappings with same can be quite costly.

- Don't enqueue pages for neighbour faults unless not enqueued already, and
don't activate centre pages unless uvmpdpol says its useful.

Also:

- Make PGO_LOCKED getpages on UAOs work more like vnodes: do gang lookup in
the radix tree, and don't allocate new pages.

- Fix many assertion failures around faults/loans with tmpfs.

Process concurrent page faults on individual uvm_objects / vm_amaps in
parallel, where the relevant pages are already in-core. Proposed on
tech-kern.

Temporarily disabled on MP architectures with __HAVE_UNLOCKED_PMAP until
adjustments are made to their pmaps.

Tweak the March 14th change to make page waits interlocked by pg->interlock.
Remove unneeded changes and only deal with the PQ_WANTED flag, to exclude
possible bugs.

Make uvm_pagemarkdirty() responsible for putting vnodes onto the syncer
work list. Proposed on tech-kern@.

Make page waits (WANTED vs BUSY) interlocked by pg->interlock. Gets RW
locks out of the equation for sleep/wakeup, and allows observing+waiting
for busy pages when holding only a read lock. Proposed on tech-kern.

Unused variable.

- Hide the details of SPCF_SHOULDYIELD and related behind a couple of small
functions: preempt_point() and preempt_needed().

- preempt(): if the LWP has exceeded its timeslice in kernel, strip it of
any priority boost gained earlier from blocking.

OR into bp->b_cflags; don't overwrite.

Tighten up the locking around vp->v_iflag a little more after the recent
split of vmobjlock & v_interlock.

v_interlock -> vmobjlock

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.

remove the aiodoned thread. I originally added this to provide a thread context
for doing page cache iodone work, but since then biodone() has changed to
hand off all iodone work to a softint thread, so we no longer need the
special-purpose aiodoned thread.

Merge from yamt-pagecache (after much testing):

- Reduce unnecessary page scan in putpages esp. when an object has a ton of
pages cached but only a few of them are dirty.

- Reduce the number of pmap operations by tracking page dirtiness more
precisely in uvm layer.

branches: 1.83.2;
- Add and use wrapper functions that take and acquire page interlocks, and pairs
of page interlocks. Require that the page interlock be held over calls to
uvm_pageactivate(), uvm_pagewire() and similar.

- Solve the concurrency problem with page replacement state. Rather than
updating the global state synchronously, set an intended state on
individual pages (active, inactive, enqueued, dequeued) while holding the
page interlock. After the interlock is released put the pages on a 128
entry per-CPU queue for their state changes to be made real in batch.
This results in in a ~400 fold decrease in contention on my test system.
Proposed on tech-kern but modified to use the page interlock rather than
atomics to synchronise as it's much easier to maintain that way, and
cheaper.

Rename uvm_page_locked_p() -> uvm_page_owner_locked_p()

genfs_do_putpages(): add a missing call to uvm_page_array_advance().

Spotted by the automated test runs and:

Reported-by: syzbot+adc1f0ce21bcece5307d@syzkaller.appspotmail.com

Correction to previous for DEBUG case.

Fix DEBUG build.

Merge from yamt-pagecache:

- do gang lookup of pages using radixtree.
- remove now unused uvm_object::uo_memq and vm_page::listq.queue.

Break the global uvm_pageqlock into a per-page identity lock and a private
lock for use of the pagedaemon policy code. Discussed on tech-kern.

PR kern/54209: NetBSD 8 large memory performance extremely low
PR kern/54210: NetBSD-8 processes presumably not exiting
PR kern/54727: writing a large file causes unreasonable system behaviour

Defer to synchronous I/O before the aiodone work queue exists.

Fix (harmless) uninitialized variable: 'pg' could be 'endm', in which case
'pg->uobject' would not be initialized. Just invert the two last conditions
of the KASSERT.

ok hannken@

assert that WAPBL journal write lock is actually held when called with
PGO_JOURNALLOCKED or IO_JOURNALLOCKED

suggested by mrg@, thanks

support flag PGO_JOURNALLOCKED also for genfs_getpages()

branches: 1.72.2;
add a genfs method to allow a file system to limit the range of pages
that are given to a single GOP_WRITE() call. needed by ZFS.

branches: 1.71.2;
Update the kernhist(9) kernel history code to address issues identified
in PR kern/52639, as well as some general cleaning-up...

(As proposed on tech-kern@ with additional changes and enhancements.)

Details of changes:

* All history arguments are now stored as uintmax_t values[1], both in
the kernel and in the structures used for exporting the history data
to userland via sysctl(9). This avoids problems on some architectures
where passing a 64-bit (or larger) value to printf(3) can cause it to
process the value as multiple arguments. (This can be particularly
problematic when printf()'s format string is not a literal, since in
that case the compiler cannot know how large each argument should be.)

* Update the data structures used for exporting kernel history data to
include a version number as well as the length of history arguments.

* All [2] existing users of kernhist(9) have had their format strings
updated. Each format specifier now includes an explicit length
modifier 'j' to refer to numeric values of the size of uintmax_t.

* All [2] existing users of kernhist(9) have had their format strings
updated to replace uses of "%p" with "%#jx", and the pointer
arguments are now cast to (uintptr_t) before being subsequently cast
to (uintmax_t). This is needed to avoid compiler warnings about
casting "pointer to integer of a different size."

* All [2] existing users of kernhist(9) have had instances of "%s" or
"%c" format strings replaced with numeric formats; several instances
of mis-match between format string and argument list have been fixed.

* vmstat(1) has been modified to handle the new size of arguments in the
history data as exported by sysctl(9).

* vmstat(1) now provides a warning message if the history requested with
the -u option does not exist (previously, this condition was silently
ignored, with only a single blank line being printed).

* vmstat(1) now checks the version and argument length included in the
data exported via sysctl(9) and exits if they do not match the values
with which vmstat was built.

* The kernhist(9) man-page has been updated to note the additional
requirements imposed on the format strings, along with several other
minor changes and enhancements.

[1] It would have been possible to use an explicit length (for example,
uint64_t) for the history arguments. But that would require another
"rototill" of all the users in the future when we add support for an
architecture that supports a larger size. Also, the printf(3) format
specifiers for explicitly-sized values, such as "%"PRIu64, are much
more verbose (and less aesthetically appealing, IMHO) than simply
using "%ju".

[2] I've tried very hard to find "all [the] existing users of kernhist(9)"
but it is possible that I've missed some of them. I would be glad to
update any stragglers that anyone identifies.

Add missing check for dead or dying vnode to the entry of genfs_getpages().

Operations fstrans_start() and fstrans_start_nowait() now always
use FSTRANS_SHARED as lock type so remove the lock type argument.

File system state FSTRANS_SUSPENDING is now unused so remove it.

Regen vnode_if files.

Ride 8.99.1 less than a hour ago.

branches: 1.68.6;
Clarify meaning of "glocked" argument of genfs_putpages_read.

Simplify genfs_getpages_read async/unlock protocol.

Previously the caller unlocked for error or sync I/O, whereas
genfs_getpages_read unlocked on successful async.

Now caller unlocks in every case, and genfs_getpages_read doesn't
touch the lock.

Change last users of FSTRANS_LAZY to FSTRANS_SHARED and change
genfs_suspendctl() to move from FSTRANS_NORMAL to FSTRANS_SUSPENDED
and vice versa.

Protect genfs_do_putpages() against vnodes disappearing during
a forced mount update from read-write to read-only.

Protect genfs_getpages() against vnodes disappearing during a
forced mount update from read-write to read-only.

branches: 1.63.2;
don't change the loop counts; noted by mrg@

Allow sparc kernels to build with SSP by using a constant PAGE_SIZE...

branches: 1.61.2;
Remove miscfs/syncfs and

- move the syncer into kern/vfs_subr.c.

- change the syncer to process the mountlist and VFS_SYNC as appropriate.

- use an API for mount points similiar to the API for vnodes:
- vfs_syncer_add_to_worklist(struct mount *mp) to add
- vfs_syncer_remove_from_worklist(struct mount *mp) to remove a mount.

No objections on tech-kern@

Fix UVMHIST build.

Pull VOP_BMAP/VOP_STRATEGY loop from getpages into its own function.

No functional change.

In preparation for a gop_read like the existing gop_write.

branches: 1.58.6;
Turn a few __unused into __diagused

Mark a potentially unused variable

Mark a potentially unused (if an arch implements pmap_update as empty
macro) variable accordingly.

branches: 1.55.2; 1.55.4;
don't block on pager map for read-ahead.
reduce code duplication.

change vflushbuf() to take the full FSYNC_* flags.
translate FSYNC_LAZY into PGO_LAZY for VOP_PUTPAGES() so that
genfs_do_io() can set the appropriate io priority for the I/O.
this is the first part of addressing PR 46325.

branches: 1.53.2; 1.53.6; 1.53.8;
typo in a comment

Trim unused headers.

Use the new UVM_KMF_COLORMATCH flag to get a congruent mappings of the user
buffer so we can use unmanaged mappings (pmap_kenter_pa/pmap_kremove).

genfs_do_directio: acquire the lock of page owner for now and fix PR/45177.
Will be revisited to avoid locking dance and be more efficient, e.g. we can
use unmanaged-mapping by allocating with colouring in mind.

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: 1.48.2;
Move some #ifdefs to prevent a code path change when DEBUG .vs. !DEBUG
Solves problem an assert firing when using NFS on MIPS.

G/C unused speedup_syncer() mechanism and thus simplify some code.
Update some comments to reflect the reality. No actual changes to
the (used) syncer logic.

OK ad@

branches: 1.46.2;
Correct an assertion; pointed out by mrg@ and pooka@, thanks.

genfs_do_putpages(): When testing an uobject for dirty or modified
pages skip uninitialized (PG_FAKE) pages (DEBUG only).

Always take the object lock before changing vmpage flags. Fixes a deadlock
where a thread is waiting on "genput" but the page in question is neither
BUSY nor WANTED.

No objections from tech-kern@.

Whitespace.

Genfs_getpages(): Break a deadlock where one thread runs VOP_GETPAGES(),
has busy pages and wants the wapbl lock as reader from wapbl_begin(),
another thread has the wapbl lock as reader and waits for a page from
the first thread. Now a third thread calls wapbl_flush() and wants the
wapbl lock as writer.

Move the wapbl_begin() up to a point where genfs_getpages() has no busy
pages yet.

genfs_getpages: restore vm_page array correctly in PGO_LOCKED error
code path.

replace the earlier workaround for PR 40389 with a better fix.
the earlier change caused data corruption by freeing pages
without invaliding their mappings. instead of the trylock/retry,
just take the genfs-node lock before calling VOP_GETPAGES()
and pass a new flag to tell it that we're already holding this lock.

print more info in the "past eof" panic

in genfs_getpages(), mark the vnode dirty (ie. add to syncer worklist
and set VI_WRMAPDIRTY) after we have busied the pages rather than
before. this prevents other threads calling genfs_do_putpages() from
marking the vnode clean again while we're in the process of creating
new writable mappings, since such threads will wait for the page(s) to
become unbusy before proceeding.
fixes the problem recently reported by hannken@ on tech-kern.

Add vm page flag PG_MARKER and use it to tag dummy marker pages
in genfs_do_putpages() and uao_put().
Use 'v_uobj.uo_npages' to check for an empty memq.
Put some assertions where these marker pages may not appear.

Ok: YAMAMOTO Takashi <yamt@netbsd.org>

branches: 1.36.2; 1.36.4;
Reduce the diff between genfs_getpages() and genfs_do_io(). These should be
merged eventually.

Slightly more descriptive local variable names.

genfs_getpages: Narrow & clarify the context where I/O happens & vmobjlock is dropped.

genfs_getpages: Redo previous with a better goto label.

Revert part which variable initializations within interleaved gotos.

again: if (...) goto err;
void *ptr = alloc();
if (...) goto again;
if (...) goto err1;
...
err1: if (ptr) free(ptr);
err:
return;

This leaks memory if exited with "goto again; -> goto err;".

genfs_getpages: More constification & localization.

genfs_getpages: Constify 2 variables, move one. No functional changes.

genfs_getpages: Constify orignpages. Don't override its meaning by the value
re-calucated from GOP_SIZE(GOP_SIZE_MEM), but assign another variable
(orignmempages).

Unbreak modules build.

genfs_getpages: Constify & localize more variables.

genfs_getpages: Move local variable declarations that are used only for I/O
to where they're used. This helps to track what's going in this lengthy
function.

genfs_getpages: Localize a few more variables.

genfs_putpages: Localize a few variables. No functional changes.

Use genfs_node_*lock().

Constify some pointers in genfs_getpages() and genfs_do_putpages().

Remove uarea swap-out functionality:

- Addresses the issue described in PR/38828.
- Some simplification in threading and sleepq subsystems.
- Eliminates pmap_collect() and, as a side note, allows pmap optimisations.
- Eliminates XS_CTL_DATA_ONSTACK in scsipi code.
- Avoids few scans on LWP list and thus potentially long holds of proc_lock.
- Cuts ~1.5k lines of code. Reduces amd64 kernel size by ~4k.
- Removes __SWAP_BROKEN cases.

Tested on x86, mips, acorn32 (thanks <mpumford>) and partly tested on
acorn26 (thanks to <bjh21>).

Discussed on <tech-kern>, reviewed by <ad>.

Move genfs_null_putpages() from genfs_io.c to genfs_vnops.c -- it does
not really do i/o.

genfs_getpages: rework 1.18 revision - move uvm_pagermapout() back.
It is useful to make KVA available ASAP. Per discussion with <yamt>.

branches: 1.18.2;
genfs_getpages: move putiobuf() and uvm_pagermapout() outside the glock.
OK by <ad>.

- g/c stale function prototypes.
- rename UVM_PAGE_HASH_PENALTY to UVM_PAGE_TREE_PENALTY.

Check that the filesystem acutally uses WAPBL before initiating a
transaction for the directio case. Fixes PR 39929 and similiar issues
seen with PostgreSQL.

more <sys/buf.h> police

- allocate 8 pointers on the stack to avoid stack overflow in nfs.
- make that 8 a constant
- remove bogus panic

branches: 1.13.2; 1.13.4;
Make genfs_directio() IO_JOURNALLOCKED aware. DirectIO no longer triggers
"locking against myself" panic in wapbl_begin().

Observed and tested by: Frank Kardel <kardel@netbsd.org>

Break a deadlock where one thread has a wapbl transaction, calls VOP_GETPAGES
and wants to busy a page while another thread calls VOP_PUTPAGES on the same
vnode, takes pages busy and wants to start a wapbl transaction.

Reviewed by: Jason Thorpe <thorpej@netbsd.org>

remove always-true conditionals.

constify

Merge the simonb-wapbl branch. From the original branch commit:

Add Wasabi System's WAPBL (Write Ahead Physical Block Logging)
journaling code. Originally written by Darrin B. Jewell while
at Wasabi and updated to -current by Antti Kantee, Andy Doran,
Greg Oster and Simon Burge.

OK'd by core@, releng@.

branches: 1.8.2; 1.8.4;
vm_page: put TAILQ_ENTRY into a union with LIST_ENTRY, so we can use both.

Import writing part of the UDF file system making optical media like CD's
and DVD's behave like floppy discs. Writing is supported upto and including
version 2.01; version 2.50 and 2.60 will follow.

Also extending the UDF implementation to support symbolic links and
hardlinks.

Added are the mmcformat(8) tool to format rewritable CD/DVD discs and
newfs_udf(8).

Limitations:
all operations can be performed on the file system though the
sheduling is currently optimised for archiving workloads.

mv(1)/rename(2) is currently only implemented for non-directories.

branches: 1.6.2; 1.6.4;
Remove a race when pages are released while waiting for fstrans_start().

Fixes PR #38460

branches: 1.5.6; 1.5.8;
genfs_do_putpages: DEBUG checks.

genfs_do_putpages: ensure that we clean the vnode in the case of PGO_RECLAIM.

push pmap_clear_reference calls into pdpolicy code, where reference bits
actually matter.

Merge vmlocking2 to head.

branches: 1.1.4; 1.1.6; 1.1.8; 1.1.10; 1.1.12; 1.1.14; 1.1.16; 1.1.20;
Split I/O-related routines (getpages, putpages, etc.) which are heavily
tied to uvm out of genfs_vnops into genfs_io.c

Update a comment.

Merge from yamt-pagecache (after much testing):

- Reduce unnecessary page scan in putpages esp. when an object has a ton of
pages cached but only a few of them are dirty.

- Reduce the number of pmap operations by tracking page dirtiness more
precisely in uvm layer.

branches: 1.22.2; 1.22.8;
add a genfs method to allow a file system to limit the range of pages
that are given to a single GOP_WRITE() call. needed by ZFS.

branches: 1.21.32;
Add missing declaration of struct vnode.

branches: 1.20.8; 1.20.18;
replace the earlier workaround for PR 40389 with a better fix.
the earlier change caused data corruption by freeing pages
without invaliding their mappings. instead of the trylock/retry,
just take the genfs-node lock before calling VOP_GETPAGES()
and pass a new flag to tell it that we're already holding this lock.

branches: 1.19.2; 1.19.4;
Don't forget to tell the result of rw_tryenter().

Add genfs_node_rdtrylock().

branches: 1.17.8; 1.17.14; 1.17.16;
Import writing part of the UDF file system making optical media like CD's
and DVD's behave like floppy discs. Writing is supported upto and including
version 2.01; version 2.50 and 2.60 will follow.

Also extending the UDF implementation to support symbolic links and
hardlinks.

Added are the mmcformat(8) tool to format rewritable CD/DVD discs and
newfs_udf(8).

Limitations:
all operations can be performed on the file system though the
sheduling is currently optimised for archiving workloads.

mv(1)/rename(2) is currently only implemented for non-directories.

branches: 1.16.38; 1.16.40; 1.16.42; 1.16.44;
Add genfs_node_destroy(). Fixes a lock "leak" seen when running LOCKDEBUG
kernels.

branches: 1.15.2;
Replace some uses of lockmgr() / simplelocks.

add wrapper functions of lockmgr on g_glock.

fix build error in mount_sysvbfs.

add support for O_DIRECT (I/O directly to application memory,
bypassing any kernel caching for file data).

branches: 1.11.8; 1.11.10;
integrate kauth.

some cleanups after the introduction of GOP_SIZE_MEM flag.
- remove GOP_SIZE_READ/GOP_SIZE_WRITE flags.
they have not been used since the change.
- ufs_balloc_range: remove code which has been no-op since the change.
thanks Konrad Schroder for explaining the original intention of the code.
- ffs_gop_size: don't extend past eof, in the case of GOP_SIZE_MEM.
otherwise genfs_getpages end up to allocate pages past eof unnecessarily.

branches: 1.9.4; 1.9.6; 1.9.8; 1.9.10; 1.9.12;
merge ktrace-lwp.

update file timestamps for nfsd loaned-read and mmap.
PR/25279. discussed on tech-kern@.

ensure that vnodes with dirty pages are always on syncer's queue.

- genfs_putpages: wait for i/o completion of PG_RELEASED/PG_PAGEOUT pages by
setting "wasclean" false when encountering them.
suggested by Stephan Uphoff in PR/24596 (1).

- genfs_putpages: write protect pages when cleaning out, if
we're going to take the vnode off the syncer's queue.
uvm_fault: don't write-map pages unless its vnode is already on
the syncer's queue.

fix PR/24596 (3) but in the different way from the suggested fix.
(to keep our current behaviour, ie. not to require explicit msync.
discussed on tech-kern@.)

- genfs_putpages: don't mistakenly take a vnode off the queue
by introducing a generation number in genfs_node.
genfs_getpages: increment the generation number.
suggested by Stephan Uphoff in PR/24596 (2).

- add some assertions.

branches: 1.6.2;
- constify genfs_ops.
- use member designators.

branches: 1.5.14;
fix a bug of lfs.

genfs_getpages() can read in more blocks than it should due to faked filesize
of lfs_gop_size(). it's a security problem and it makes gcc3 "internal error"

to fix this,
- in genfs_getpages(), always calculate diskeof and memeof separately
so that filesystems (in this case, lfs) can use different strategies
for them.
- introduce GOP_SIZE_MEM flag and use it to request in-core filesize.
(it was an intention of GOP_SIZE_READ,
but after the above change _READ is not a straightforward name)

after this, no one uses GOP_SIZE_{READ,WRITE} anymore but leave them for now.

branches: 1.4.2;
Add code to UBCify LFS. This is still behind "#ifdef LFS_UBC" for now
(there are still some details to work out) but expect that to go
away soon. To support these basic changes (creation of lfs_putpages,
lfs_gop_write, mods to lfs_balloc) several other changes were made, to
wit:

* Create a writer daemon kernel thread whose purpose is to handle page
writes for the pagedaemon, but which also takes over some of the
functions of lfs_check(). This thread is started the first time an
LFS is mounted.

* Add a "flags" parameter to GOP_SIZE. Current values are
GOP_SIZE_READ, meaning that the call should return the size of the
in-core version of the file, and GOP_SIZE_WRITE, meaning that it
should return the on-disk size. One of GOP_SIZE_READ or
GOP_SIZE_WRITE must be specified.

* Instead of using malloc(...M_WAITOK) for everything, reserve enough
resources to get by and use malloc(...M_NOWAIT), using the reserves if
necessary. Use the pool subsystem for structures small enough that
this is feasible. This also obsoletes LFS_THROTTLE.

And a few that are not strictly necessary:

* Moves the LFS inode extensions off onto a separately allocated
structure; getting closer to LFS as an LKM. "Welcome to 1.6O."

* Unified GOP_ALLOC between FFS and LFS.

* Update LFS copyright headers to correct values.

* Actually cast to unsigned in lfs_shellsort, like the comment says.

* Keep track of which segments were empty before the previous
checkpoint; any segments that pass two checkpoints both dirty and
empty can be summarily cleaned. Do this. Right now lfs_segclean
still works, but this should be turned into an effectless
compatibility syscall.

branches: 1.3.2;
add some compatibility routines to allow mmap() to work non-UBCified
filesystems (in the same non-coherent fashion that they worked before).

branches: 1.2.2; 1.2.4;
add a forward decl for struct vm_page.

interfaces and structures used by new genfs_{get,put}pages().

Don't use genfs_rename_knote() in the "rename foo over hard-link to itself"
case, which simply results in removing the "from" name; there are assertions
in genfs_rename_knote() that are too strong for that case.

PR kern/56460

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.

genfs_rename: Fix deadlocks in cross-directory cyclic rename.

Reproducer:

A: for (;;) { mkdir("c", 0600); mkdir("c/d", 0600); mkdir("c/d/e", 0600);
rmdir("c/d/e"); rmdir("c/d"); }
B: for (;;) { mkdir("c", 0600); mkdir("c/d", 0600); mkdir("c/d/e", 0600);
rename("c", "c/d/e"); }
C: for (;;) { mkdir("c", 0600); mkdir("c/d", 0600); mkdir("c/d/e", 0600);
rename("c/d/e", "c"); }

Deadlock:

- A holds c and wants to lock d; and either
- B holds . and d and wants to lock c, or
- C holds . and d and wants to lock c.

The problem with these is that genfs_rename_enter_separate in B or C
tried lock order .->d->c->e (in A/B, fdvp->tdvp->fvp->tvp; in A/C,
tdvp->fdvp->tvp->fvp) which violates the ancestor->descendant order
.->c->d->e.

The resolution is to change B to do fdvp->fvp->tdvp->tvp and C to do
tdvp->tvp->fdvp->fvp. But there's an edge case: tvp and fvp might be
the same (hard links), and we can't detect that until after we've
looked them both up -- and in some file systems (I'm looking at you,
ufs), there is no mere lookup operation, only lookup-and-lock, so we
can't even hold the lock on one of tvp or fvp when we look up the
other one if there's a chance they might be the same.

Fortunately the cases
(a) tvp = fvp
(b) tvp or fvp is a directory
are mutually exclusive as long as directories cannot be hard-linked.
In case (a) we can just defer locking {tvp, fvp} until the end, because
it can't possibly have {fdvp or fvp, tdvp or tvp} as descendants. In
case (b) we can just lock them in the order fdvp->fvp->tdvp->tvp or
tdvp->tvp->fdvp->fvp if the first one of {fvp, tvp} is a directory,
because it can't possibly coincide with the second one of {fvp, tvp}.

With this change, we can now prove that the locking order is consistent
with the ancestor->descendant partial ordering. Where two nodes are
incommensurate under that partial ordering, they are only ever locked
by rename and there is only ever one rename at a time.

Proof:

- For same-directory renames, genfs_rename_enter_common locks the
directory first and then the children. The order
directory->child[i] is consistent with ancestor->descendant and
child[0]/child[1] are incommensurate.

- For cross-directory renames:

. While a rename is in progress and the fs-wide rename lock is held,
directories can be created or removed but not changed, so the
outcome of gro_genealogy -- which, given fdvp and tdvp, returns
the node N relating fdvp/N/.../tdvp or null if there is none --
can only transition from finding N to not finding N, if one of
the directories is removed while any of the vnodes are unlocked.
Merely creating directories cannot change the ancestry of tdvp,
and concurrent renames are not possible.

Thus, if a gro_genealogy determined the operation to have the
form fdvp/N/.../tdvp, then it might cease to have that form, but
only because tdvp was removed which will harmlessly cause the
rename to fail later on. Similarly, if gro_genealogy determined
the operation _not_ to have the form fdvp/N/.../tdvp then it
can't begin to have that form until after the rename has
completed.

The lock order is,

=> for fdvp/.../tdvp:
1. lock fdvp
2. lookup(/lock/unlock) fvp (consistent with fdvp->fvp)
3. lock fvp if a directory (consistent with fdvp->fvp)
4. lock tdvp (consistent with fdvp->tdvp and possibly fvp->tdvp)
5. lookup(/lock/unlock) tvp (consistent with tdvp->tvp)
6. lock fvp if a nondirectory (fvp->t* or fvp->fdvp is impossible)
7. lock tvp if not fvp (tvp->f* is impossible unless tvp=fvp)

=> for incommensurate fdvp & tdvp, or for tdvp/.../fdvp:
1. lock tdvp
2. lookup(/lock/unlock) tvp (consistent with tdvp->tvp)
3. lock tvp if a directory (consistent with tdvp->tvp)
4. lock fdvp (either incommensurate with tdvp and/or tvp, or
consistent with tdvp(->tvp)->fdvp)
5. lookup(/lock/unlock) fvp (consistent with fdvp->fvp)
6. lock tvp if a nondirectory (tvp->f* or tvp->tdvp is impossible)
7. lock fvp if not tvp (fvp->t* is impossible unless fvp=tvp)

Deadlocks found by hannken@; resolution worked out with dholland@.

XXX I think we could improve concurrency somewhat -- with a likely
big win for applications like tar and rsync that create many files
with temporary names and then rename them to the permanent one in the
same directory -- by making vfs_renamelock a reader/writer lock: any
number of same-directory renames, or exactly one cross-directory
rename, at any one time.

Add ACL support for FFS. From FreeBSD.

branches: 1.3.18;
Remove now redundant calls to fstrans_start()/fstrans_done().

branches: 1.2.6; 1.2.10; 1.2.14;
Move fstrans_start()/fstrans_done() into genfs_insane_rename() to protect
the complete rename operation like we do for all other vnode operations.

branches: 1.1.2; 1.1.4; 1.1.6; 1.1.8; 1.1.10;
Implement a genfs_rename abstraction.

First major step in incrementally adapting all the file systems to a
saner rename VOP protocol.

Handle IMNT_GONE on the file system we want suspended not its
lowest mount we really suspend.

Make mntvnode_lock per-mount, and address false sharing of struct mount.

Attach "mnt_transinfo" to "dead_rootmount" so every mount has a
valid "mnt_transinfo" and remove now unneeded flag IMNT_HAS_TRANS.

Run fstrans_start()/fstrans_done() on dead_rootmount if FSTRANS_DEAD_ENABLED.
Should become the default for DIAGNOSTIC in the future.

Bring back three state file system suspension:

NORMAL -> SUSPENDING -> SUSPENDED

and add operation fstrans_start_lazy() that only blocks while SUSPENDED.

Change vndthread() support operation handle_with_rdwr() to bracket
its file system operations by fstrans_start_lazy() and fstrans_done().

PR kern/53624 (dom0 freeze on domU exit)

branches: 1.7.2; 1.7.8; 1.7.10;
With dounmount() working on a suspended file system remove no longer
needed fields mnt_busynest and mnt_unmounting from struct mount.

Welcome to 7.99.73

Return ENOENT if trying to suspend an unmounted file system.

branches: 1.5.4;
Change last users of FSTRANS_LAZY to FSTRANS_SHARED and change
genfs_suspendctl() to move from FSTRANS_NORMAL to FSTRANS_SUSPENDED
and vice versa.

Add generic genfs_suspendctl() and use it for all file systems.
Layered file systems need work.

branches: 1.3.22; 1.3.40; 1.3.44; 1.3.48;
Introduce genfs_statvfs() as pretty much a no-info statvfs and
convert several pseudo file systems to use it.

Remove clause 3 and 4 from TNF licenses

branches: 1.1.2; 1.1.4; 1.1.10; 1.1.12; 1.1.14; 1.1.16;
Part of the rename patches *doh*

Fix genfs_can_chtimes() to also handle the condition:

If the time pointer is null, then write permission
on the file is also sufficient.

From FreeBSD.

Should fix PR kern/57246 "NFS group permissions regression"

branches: 1.219.4;
dedup the eofs link/symlink methods

Expose groupmember as kauth_cred_groupmember and use it.

Remove now unused genfs_nolock(), genfs_nounlock() and genfs_noislocked().

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.

Mark the EVFILT_VNODE filters MP-safe.

Setting EV_EOF requires modifying kn->kn_flags. However, that relies on
holding the kq_lock of that note's kq. Rather than exposing this directly,
add new knote_set_eof() and knote_clear_eof() functions that handle the
necessary locking and don't leak as many implementation details to modules.

NetBSD 9.99.91

Must hold kn->kn_kq->kq_lock to modify kn->kn_flags.

Change the kqueue filterops::f_isfd field to filterops::f_flags, and
define a flag FILTEROP_ISFD that has the meaning of the prior f_isfd.
Field and flag name aligned with OpenBSD.

This does not constitute a functional or ABI change, as the field location
and size, and the value placed in that field, are the same as the previous
code, but we're bumping __NetBSD_Version__ so 3rd-party module source code
can adapt, as needed.

NetBSD 9.99.89

- 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: 1.210.6;
Round of uvm.h cleanup.

The poorly named uvm.h is generally supposed to be for uvm-internal
users only.

- Narrow it to files that actually need it -- mostly files that need
to query whether curlwp is the pagedaemon, which should maybe be
exposed by an external header.

- Use uvm_extern.h where feasible and uvm_*.h for things not exposed
by it. We should split up uvm_extern.h but this will serve for now
to reduce the uvm.h dependencies.

- Use uvm_stat.h and #ifdef UVMHIST uvm.h for files that use
UVMHIST(ubchist), since ubchist is declared in uvm.h but the
reference evaporates if UVMHIST is not defined, so we reduce header
file dependencies.

- Make uvm_device.h and uvm_swap.h independently includable while
here.

ok chs@

accmode should be accmode_t

Introduce genfs_pathconf() and use it for the default case in all filesystems.

Fix EPERM vs EACCES on chtimes (thanks @hannken)

remove debugging, it is just clutter.

Fix EPERM vs EACCES return.

Add ACL support for FFS. From FreeBSD.

Allow root to access and modify system space extended attributes.
XXX: this routine should not be using the string, but the attribute namespace.
I have fixed this in the ACL code.

Merge from ad-namecache:

- Have a stab at clustering the members of vnode_t and vnode_impl_t in a
more cache-conscious way. With that done, go back to adjusting v_usecount
with atomics and keep vi_lock directly in vnode_impl_t (saves KVA).

- Allow VOP_LOCK(LK_NONE) for the benefit of VFS_VGET() and VFS_ROOT().
Make sure LK_UPGRADE always comes with LK_NOWAIT.

- Make cwdinfo use mostly lockless.

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.

branches: 1.200.2;
Minor vnode locking changes:

- Stop using atomics to maniupulate v_usecount. It was a mistake to begin
with. It doesn't work as intended unless the XLOCK bit is incorporated in
v_usecount and we don't have that any more. When I introduced this 10+
years ago it was to reduce pressure on v_interlock but it doesn't do that,
it just makes stuff disappear from lockstat output and introduces problems
elsewhere. We could do atomic usecounts on vnodes but there has to be a
well thought out scheme.

- Resurrect LK_UPGRADE/LK_DOWNGRADE which will be needed to work effectively
when there is increased use of shared locks on vnodes.

- Allocate the vnode lock using rw_obj_alloc() to reduce false sharing of
struct vnode.

- Put all of the LRU lists into a single cache line, and do not requeue a
vnode if it's already on the correct list and was requeued recently (less
than a second ago).

Kernel build before and after:

119.63s real 1453.16s user 2742.57s system
115.29s real 1401.52s user 2690.94s system

branches: 1.199.4;
Use C99 initializer for filterops

Mostly done with spatch with touchups for indentation

@@
expression a;
identifier b,c,d;
identifier p;
@@
const struct filterops p =
- { a, b, c, d
+ {
+ .f_isfd = a,
+ .f_attach = b,
+ .f_detach = c,
+ .f_event = d,
};

Provide EVFILT_WRITE; this is what FreeBSD does and go wants it.
Makes go unit tests pass.

Locking a layer vnode using the regular bypass routine is no longer
racy. Undo the change from 2017-03-30 11:16:52, commitid eurqbzuGxGRlryLz
and make vi_lock a krwlock_t again.

Now that FSTRANS is part of VOP_*LOCK() remove FSTRANS and vdead_check()
from genfs_.*lock() and assert the vnode state once the vnode is locked.

branches: 1.195.4;
Eliminate now-unused WILLUNLOCK vop flag.

Locking a layer vnode is racy as it may become reclaimed before
calling the operation on the lower vnode.

Replace vi_lock with a rw_obj and change layered file systems
to share the lock with the lower vnode.

Layered file systems now use genfs_lock()/_unlock/_islocked().

Welcome to 7.99.67

branches: 1.193.2;
Move vnode member v_lock as vi_lock to vnode_impl.h.

branches: 1.192.4; 1.192.6; 1.192.8; 1.192.10; 1.192.14;
- Make VI_XLOCK, VI_CLEAN and VI_LOCKSHARE private to kern/vfs_*.c.
- Make vwait() static.
- Add vdead_check() to check a vnode for being or becoming dead.

Discussed on tech-kern.

Welcome to 6.99.38

Restructure genfs_deadlock() and genfs_lock() to always lock before
testing for dead node. Use ISSET() to test flags, add assertions.

Save the mount for fstrans_done() before genfs_unlock() unlocks the node.

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

branches: 1.189.2; 1.189.4;
uid mismatch for file flags changes is expected to fail with EPERM not
EACCES.

Replace the remaining KAUTH_GENERIC_ISSUSER authorization calls with
something meaningful. All relevant documentation has been updated or
written.

Most of these changes were brought up in the following messages:

http://mail-index.netbsd.org/tech-kern/2012/01/18/msg012490.html
http://mail-index.netbsd.org/tech-kern/2012/01/19/msg012502.html
http://mail-index.netbsd.org/tech-kern/2012/02/17/msg012728.html

Thanks to christos, manu, njoly, and jmmv for input.

Huge thanks to pgoyette for spinning these changes through some build
cycles and ATF.

branches: 1.187.2; 1.187.6;
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: 1.186.6;
Extend the range of fstrans transactions to a sequence of vnode operations
on a locked vnode. This leaves a suspended file system and therefore a
snapshot with either all or no operations of such a sequence done.

Abolish the SAVENAME and HASBUF flags. There is now always a buffer,
so the path in a struct componentname is now always valid during VOP
calls.

Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

This removes the need for the SAVENAME and HASBUF namei flags.

replace the earlier workaround for PR 40389 with a better fix.
the earlier change caused data corruption by freeing pages
without invaliding their mappings. instead of the trylock/retry,
just take the genfs-node lock before calling VOP_GETPAGES()
and pass a new flag to tell it that we're already holding this lock.

Remove vlockmgr(). Generic vnode lock operations now use a rwlock located
in the vnode. All LK_* flags move from sys/lock.h to sys/vnode.h. Calls
to vlockmgr() in file systems get replaced with VOP_LOCK() or VOP_UNLOCK().

Welcome to 5.99.34.

Discussed on tech-kern.

Clean up vnode lock operations pass 2:

VOP_UNLOCK(vp, flags) -> VOP_UNLOCK(vp): Remove the unneeded flags argument.

Welcome to 5.99.32.

Discussed on tech-kern.

genfs_nolock(): LK_INTERLOCK flag no longer possible.

Clean up vnode lock operations:

- VOP_LOCK(vp, flags): Limit the set of allowed flags to LK_EXCLUSIVE,
LK_SHARED and LK_NOWAIT. LK_INTERLOCK is no longer allowed as it
makes no sense here.

- VOP_ISLOCKED(vp): Remove the for some time unused return value
LK_EXCLOTHER. Mark this operation as "diagnostic only".
Making a lock decision based on this operation is no longer allowed.

Discussed on tech-kern.

Change layered file systems to always pass the locking VOP's down to the
leaf file system. Remove now unused member v_vnlock from struct vnode.
Welcome to 5.99.30

Discussed on tech-kern.

Call VOP_ABORTOP in genfs_eopnotsupp. This prevents file system
authors from having to get down on their knees and pray they won't
get POGA'd(*) again.

This plugs componentname leaks in at least smbfs and buggy puffs
servers (buggy servers shouldn't be able to leak kernel memory).

*) principle of greatest astonishment

branches: 1.176.2; 1.176.4;
Don't forget to tell the result of rw_tryenter().

Add genfs_node_rdtrylock().

Allow chown if caller is in the new group.

Disallow chown for files the caller does not own.

Move the implementation of vaccess() to genfs_can_access(), in line with
the other routines of the same spirit.

Adjust file-system code to use it.

Keep vaccess() for KPI compatibility and to keep element of least
surprise. A "diagnostic" message warning that vaccess() is deprecated will
be printed when it's used (obviously, only in DIAGNOSTIC kernels).

No objections on tech-kern@:

http://mail-index.netbsd.org/tech-kern/2009/06/21/msg005310.html

Extract the open-coded authorization logic for chtimes() from various
file-systems and put it in a single function, genfs_can_chtimes().

This also makes UDF follow the same policy as all other file-systems.

Mailing list reference:

http://mail-index.netbsd.org/tech-kern/2009/04/27/msg004951.html

Add genfs_can_mount() and use it to prevent some more code duplication of
the security checks when mounting a device (VOP_ACCESS() + kauth(9) call)).

Proposed with no objections on tech-kern@:

http://mail-index.netbsd.org/tech-kern/2009/04/20/msg004859.html

The vnode is always expected to be locked, so no locking is done outside
the file-system code.

Per discussion on tech-kern@:

- Replace use of label/goto with returns

- Rename, change prototype of, and move functions from vfs_subr.c to
genfs_vnops.c

Move genfs_null_putpages() from genfs_io.c to genfs_vnops.c -- it does
not really do i/o.

branches: 1.167.8; 1.167.10; 1.167.14; 1.167.16; 1.167.18;
Remove clause 3 and 4 from TNF licenses

branches: 1.166.2;
Remove stale include <sys/fstrans.h>.

branches: 1.165.2;
Catch up with descriptor handling changes. See kern_descrip.c revision
1.173 for details.

branches: 1.164.6;
Lock v_knlist with the vnode interlock. PR kern/37881.

Replace struct lock on vnodes with a simpler lock object built on
krwlock_t. This is a step towards removing lockmgr and simplifying
vnode locking. Discussed on tech-kern.

Since VOP_LEASE is gone, remove genfs_lease_check() too. Now my kernel
builds again. :)

Fix v_freelisthd assertion failure during call to vdevdone(). No calling
VOPs without a vnode reference!

Merge vmlocking2 to head.

branches: 1.159.4;
Do not "return 1" from kqfilter for errors. That value is passed
directly to the userland caller and results in a mysterious EPERM.
Instead, return EINVAL or something else sensible depending on the
case.

branches: 1.158.4; 1.158.6;
Split I/O-related routines (getpages, putpages, etc.) which are heavily
tied to uvm out of genfs_vnops into genfs_io.c

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: 1.156.4; 1.156.6; 1.156.8; 1.156.10;
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: 1.155.2;
Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

improve post-ubc file overwrite performance in common cases.
ie. when it's safe, actually overwrite blocks rather than doing
read-modify-write.

also fixes PR/33152 and PR/36303.

Fstrans_start() always returns zero, so change its type to void.

use a cached value of v_size. no functional changes.

Split the VOP interface part of genfs_putpages() from the code. The new
function that does the work, genfs_do_putpages(), now takes as an argument
a pointer to the page that would be waited on, if PGO_BUSYWAIT were not set.
This allows a consumer, e.g. lfs_putpages(), to perform an action outside
the scope of UVM before sleeping on the page in question.

branches: 1.150.2; 1.150.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

TRUE -> true, FALSE -> false

Replace the Mach-derived boolean_t type with the C99 bool type. A
future commit will replace use of TRUE and FALSE with true and false.

Add genfs_node_destroy(). Fixes a lock "leak" seen when running LOCKDEBUG
kernels.

branches: 1.146.2;
Replace some uses of lockmgr() / simplelocks.

Merge newlock2 to head.

Change fstrans enum types to upper case.
No functional change.

From Antti Kantee <pooka@netbsd.org>

New file system suspension API to replace vn_start_write and vn_finished_write.
The suspension helpers are now put into file system specific operations.
This means every file system not supporting these helpers cannot be suspended
and therefore snapshots are no longer possible.

Implemented for file systems of type ffs.

The new API is enabled on a kernel option NEWVNGATE. This option is
not enabled by default in any kernel config.

Presented and discussed on tech-kern with much input from
Bill Studenmund <wrstuden@netbsd.org> and YAMAMOTO Takashi <yamt@netbsd.org>.

Welcome to 4.99.9 (new vfs op vfs_suspendctl).

remove nqnfs.

put ->K loaned pages on the page queue, so that page loaning doesn't
disturb pagedaemon/pdpolicy.

branches: 1.140.2; 1.140.4;
* update comments before putpages(): the vm object is always returned
unlocked instead of locked. chuq agrees
* use slock set to &uobj->vmobjlock also for the last simple lock
operation to be consistent with the rest of the function

instead of const int, use a #define which most of the time will evaluate
in a compile-time constant.

__unused removal on arguments; approved by core.

Replace the LIST structure mp->mnt_vnodelist to a TAILQ structure since all
vnodes were synced and processed backwards. This meant that the last
accessed node was processed first and the earlierst last.

An extra benefit is the removal of the ugly hack from the Berkly days on
LFS.

In the proces, i've also replaced the various variations hand written loops
by the TAILQ_FOREACH() macro's.

add wrapper functions of lockmgr on g_glock.

genfs_getpages: use kmem_zalloc.

genfs_do_io: iodone handler should be called at splbio.

genfs_putpages: don't try to deactivate loaned pages.
reported and tested by Nicolas Joly on current-users@.

genfs_lease_check(): Consume the arguments even if NFSSERVER is not defined.

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

add support for O_DIRECT (I/O directly to application memory,
bypassing any kernel caching for file data).

branches: 1.129.2;
merge yamt-pdpolicy branch.
- separate page replacement policy from the rest of kernel
- implement an alternative replacement policy

branches: 1.128.4;
Use the LWP cached credentials where sane.

- genfs_getpages: in the case of PGO_LOCKED, check if we can acquire
g_glock as suggested by Chuck Silvers on tech-kern@.
- genfs_rel_pages: handle PGO_DONTCARE so that it can be used for the above.

- in genfs_getpages, take g_glock earlier so that it can't be
intervened by truncation.
it also fixes a deadlock. (g_glock vs pages locking order)
- uvm_vnp_setsize: modify v_size while holding v_interlock.

reviewed by Chuck Silvers.

integrate kauth.

genfs_getpages:
- use "overwrite" variable consistently.
- remove a set-only variable.
no functional changes.

some cleanups after the introduction of GOP_SIZE_MEM flag.
- remove GOP_SIZE_READ/GOP_SIZE_WRITE flags.
they have not been used since the change.
- ufs_balloc_range: remove code which has been no-op since the change.
thanks Konrad Schroder for explaining the original intention of the code.
- ffs_gop_size: don't extend past eof, in the case of GOP_SIZE_MEM.
otherwise genfs_getpages end up to allocate pages past eof unnecessarily.

branches: 1.122.2; 1.122.4; 1.122.6;
merge yamt-uio_vmspace branch.

- use vmspace rather than proc or lwp where appropriate.
the latter is more natural to specify an address space.
(and less likely to be abused for random purposes.)
- fix a swdmover race.

branches: 1.121.2; 1.121.4;
Add genfs support for directories and softlinks next to regular files and
block devices.

Discussed on tech-kern and ok'd by Chuck

use nestiobuf api for genfs.

- add simple functions to allocate/free a buffer for i/o.
- make bufpool static.

branches: 1.118.2;
Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

fix lock/unlock mismatch in rev.1.115.
reported by Chris Tribo on current-users@.

merge ktrace-lwp.

genfs_compat_getpages: add minimum support of async get. ie. ignore them.
should fix a crash reported by Jukka Salmi on current-users@.

genfs_gop_write: use devvp directly as genfs_getpages does.

genfs_putpages: initialize marker pages only when needed.

revert rev.1.111 as it isn't necessary or correct.
- currently no one in tree has a problem with zero b_lblkno, afaik.
- this buf is used for "devvp", so it doesn't make sense to
use lbn in the "vp".

Learn genfs that (struct buf *)->b_lblkno allways need to point to the
logical block number of the file instead of allways zero.

merge yamt-readahead branch.

branches: 1.109.2;
genfs_getpages:
- add an assertion.
- call VOP_STRATEGY of underlying vnode directly, rather than
through the filesystem vnode.
- no need to set b_dev here because VOP_STRATEGY will take care of it.

merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.107.2;
Remove Veriexec bits from genfs, don't #if 0 them.

Various fixes from blymn@ and myself.

Also, put genfs changes under #if 0, and don't do per-page fingerprints
until this is properly discussed, as requested by yamt@.

Introduce per-page fingerprints in Veriexec.

This closes a hole pointed out by Thor Lancelot Simon on tech-kern ~3
years ago.

The problem was with running binaries from remote storage, where our
kernel (and Veriexec) has no control over any changes to files.

An attacker could, after the fingerprint has been verified and
program loaded to memory, inject malicious code into the backing
store on the remote storage, followed by a forced flush, causing
a page-in of the malicious data from backing store, bypassing
integrity checks.

Initial implementation by Brett Lymn.

don't write-protect wired pages. pointed by Chuck Silvers.
for now, leave a vnode on the syncer's queue, as suggested by him.

update file timestamps for nfsd loaned-read and mmap.
PR/25279. discussed on tech-kern@.

genfs_putpages: don't bother to clean the vnode unless VONWORKLST.

ensure that vnodes with dirty pages are always on syncer's queue.

- genfs_putpages: wait for i/o completion of PG_RELEASED/PG_PAGEOUT pages by
setting "wasclean" false when encountering them.
suggested by Stephan Uphoff in PR/24596 (1).

- genfs_putpages: write protect pages when cleaning out, if
we're going to take the vnode off the syncer's queue.
uvm_fault: don't write-map pages unless its vnode is already on
the syncer's queue.

fix PR/24596 (3) but in the different way from the suggested fix.
(to keep our current behaviour, ie. not to require explicit msync.
discussed on tech-kern@.)

- genfs_putpages: don't mistakenly take a vnode off the queue
by introducing a generation number in genfs_node.
genfs_getpages: increment the generation number.
suggested by Stephan Uphoff in PR/24596 (2).

- add some assertions.

- introduce PGO_NOBLOCKALLOC and use it for ubc mapping
to prevent unnecessary block allocations in the case that
page size > block size.

- ufs_balloc_range: use VM_PROT_WRITE+PGO_NOBLOCKALLOC rather than
VM_PROT_READ.

genfs_getpages: don't forget to put the vnode onto the syncer's work queue
even in the case of PGO_LOCKED.

branches: 1.98.2;
- constify genfs_ops.
- use member designators.

- sprinkle const
- avoid shadowed variables.

branches: 1.96.2;
nuke trailing whitespace

undo the part of rev. 1.93 that turned the past-EOF check into an assertion.
read() can't request pages past EOF, but mmap() can. apparently I had
disengaged the brain when I said that was ok.

Extend fsync_range(2) to support the FDISKSYNC flag, which requests
that the sync be propogated out through the disk drive caches.

branches: 1.93.2;
-in the read-ahead code, avoid to issue read requests at/past EOF
-because noone should request reads past EOF, or writes past EOF which
are not explicitely marked as file-extending (PGO_PASTEOF), turn
a boundary check into a KASSERT
approved by Chuck Silvers

branches: 1.92.2;
check for _KERNEL_OPT around opt include

Backout previous; seeing many busy page on the pageq is normal.

So that not to leave pages busy unnecessarily, bound to specified region
when building cluster if we aren't pagedaemon and clean entire cluster
if we are pagedaemon.

Count obj pages freed by pagedaemon.

There's no need to pass a proc value when using UIO_SYSSPACE with
vn_rdwr(9) and uiomove(9).

OK'd by Jason Thorpe

- remove a comment which is no longer true.
- add "XXX vn_lock" comments where we can call VOP_READ/WRITE
without vnode lock held. (genfs_compat_*)

Add ffs internal snapshots. Written by Marshall Kirk McKusick for FreeBSD.

- Not enabled by default. Needs kernel option FFS_SNAPSHOT.
- Change parameters of ffs_blkfree.
- Let the copy-on-write functions return an error so spec_strategy
may fail if the copy-on-write fails.
- Change genfs_*lock*() to use vp->v_vnlock instead of &vp->v_lock.
- Add flag B_METAONLY to VOP_BALLOC to return indirect block buffer.
- Add a function ffs_checkfreefile needed for snapshot creation.
- Add special handling of snapshot files:
Snapshots may not be opened for writing and the attributes are read-only.
Use the mtime as the time this snapshot was taken.
Deny mtime updates for snapshot files.
- Add function transferlockers to transfer any waiting processes from
one lock to another.
- Add vfsop VFS_SNAPSHOT to take a snapshot and make it accessible through
a vnode.
- Add snapshot support to ls, fsck_ffs and dump.

Welcome to 2.0F.

Approved by: Jason R. Thorpe <thorpej@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.

store a i/o priority hint in struct buf for buffer queue discipline.

genfs_revoke: use ltsleep() to release the vnode spin lock to avoid a
sleep/wakeup race.

fix a bug of lfs.

genfs_getpages() can read in more blocks than it should due to faked filesize
of lfs_gop_size(). it's a security problem and it makes gcc3 "internal error"

to fix this,
- in genfs_getpages(), always calculate diskeof and memeof separately
so that filesystems (in this case, lfs) can use different strategies
for them.
- introduce GOP_SIZE_MEM flag and use it to request in-core filesize.
(it was an intention of GOP_SIZE_READ,
but after the above change _READ is not a straightforward name)

after this, no one uses GOP_SIZE_{READ,WRITE} anymore but leave them for now.

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

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

branches: 1.80.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Micro-optimisation- move the "pgs == NULL" check from the previous
change to immediately after the malloc call. This can't fail in
the non-malloc case.

Reviewd by YAMAMOTO Takashi.

genfs_getpages: if number of pages requested is >16,
use malloc/free for array of pointers to vm_page.
otherwise, use on-stack array as used to.
this change fixes assertion failure when nfsd gets a big read request
that isn't aligned with filesystem block.
discussed on tech-kern.

Correct use of MAXBSIZE where MAXPHYS was intended. This is a necessary
first step towards per-device MAXPHYS, and has the beneficial side effect
of allowing clustering to MAXPHYS even on systems that need to run with
a reduced MAXBSIZE to get more metadata buffers.

use former genfs_eopnotsupp_rele() as genfs_eopnotsupp(), so that vnodes
are vput()/vrele()d as necessary - some filesystems did use the wrong
one for some ops, and it's just safer to not take the chance

based on suggestion by Bill Studenmund

improve genfs_eopnotsupp_rele() so that's usable for vop_rename,
which uses WILLPUT for member which may be NULL
handle correctly dvp == vp case for WILLPUT members, so this works
for vop_remove, vop_rename

thanks Bill Studenmund for code&comments on this

Add a new BUF_INIT() macro which initializes b_dep and b_interlock, and
use it. This fixes a few places where either b_dep or b_interlock were
not properly initialized.

Add code to UBCify LFS. This is still behind "#ifdef LFS_UBC" for now
(there are still some details to work out) but expect that to go
away soon. To support these basic changes (creation of lfs_putpages,
lfs_gop_write, mods to lfs_balloc) several other changes were made, to
wit:

* Create a writer daemon kernel thread whose purpose is to handle page
writes for the pagedaemon, but which also takes over some of the
functions of lfs_check(). This thread is started the first time an
LFS is mounted.

* Add a "flags" parameter to GOP_SIZE. Current values are
GOP_SIZE_READ, meaning that the call should return the size of the
in-core version of the file, and GOP_SIZE_WRITE, meaning that it
should return the on-disk size. One of GOP_SIZE_READ or
GOP_SIZE_WRITE must be specified.

* Instead of using malloc(...M_WAITOK) for everything, reserve enough
resources to get by and use malloc(...M_NOWAIT), using the reserves if
necessary. Use the pool subsystem for structures small enough that
this is feasible. This also obsoletes LFS_THROTTLE.

And a few that are not strictly necessary:

* Moves the LFS inode extensions off onto a separately allocated
structure; getting closer to LFS as an LKM. "Welcome to 1.6O."

* Unified GOP_ALLOC between FFS and LFS.

* Update LFS copyright headers to correct values.

* Actually cast to unsigned in lfs_shellsort, like the comment says.

* Keep track of which segments were empty before the previous
checkpoint; any segments that pass two checkpoints both dirty and
empty can be summarily cleaned. Do this. Right now lfs_segclean
still works, but this should be turned into an effectless
compatibility syscall.

Make the buffer cache code MP-safe.

step 3. Assign lwp properly if null, so that we can PHOLD without segfaulting.

Merge the nathanw_sa branch.

genfs_compat_gop_write: set uio_iovcnt correctly.

use B_ASYNC for children of nested buffers in genfs_getpages.
ok'ed by Chuck Silvers.

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

Use B_ASYNC in the !PGO_SYNCIO case. Gets back most, if not all, NFS
read throughput performance lost since the introduction of UBC. Spotted
by YAMAMOTO Takashi, many thanks to him.

Add missing pageq lock while uvm_pagefree() is called (either directly
or indirectly). Reviewed by chuq.

branches: 1.63.2;
Just give up to do readahead rather than waiting busy pages.
While I'm here, added few patchable variable so that one can
easily measure readahead behaviour.

branches: 1.62.2;
Protect v_synclist with splbio(); note that LIST_REMOVE is not an idempotent
operation if more than one LIST_REMOVE happens on interrupt, so both the test
for VONWORKLIST and the LIST_REMOVE(vp, v_synclist) need to be in splbio().

Redo rev. 1.57 a bit different way; don't use `tpg' since it may be freed.
Subtract the number of pages behind us when calculating new offset instead.

Don't modify the local variable `n' in genfs_putpages(). It should contain
the number of elements in the page array at the beginning of every iteration.

When traversing by list, if the page next to us is a page in the cluster,
advance the pointer.

- In genfs_putpages(), no need to restrict the cluster within the given
region.
- In uvm_aio_aiodone(), remove assertions no longer true.

Since npages may includes number of pages behind us, we can't use it to
update current offset. Instead, use the last page in the run of pages
to calculate new offset.

Stylistic change; introduce new local variable and use it instead of
sprinkling different expression to test if we're pagedaemon.

We don't need to re-activate page in genfs_putpages() when GOP_WRITE returns
ENOMEM (temporary memory shortage) since it is already handled in
uvm_aio_aiodone() for both async/sync case. Discussed with chuq.

genfs_{compat_}getpages(): For PGO_LOCKED request, it is safe to return
read only page if it was due to read fault. This avoid many unnecessary
read fault introduced by recent nfs_bio.c change. Reviewed by chuq.

KNF and other misc. cosmetic changes.

in genfs_compat_getpages(), clear any part of a page that
VOP_READ() doesn't fill in (eg. because it's past EOF).

Convert ioctl code to use EPASSTHROUGH instead of -1 or ENOTTY for
indicating an unhandled "command". ERESTART is -1, which can lead to
confusion. ERESTART has been moved to -3 and EPASSTHROUGH has been
placed at -4. No ioctl code should now return -1 anywhere. The
ioctl() system call is now properly restartable.

don't yield the cpu in genfs_putpages() if we're the pagedaemon.
pointed out by enami. fixes PR 15784.

fix two problems:
- when yielding the cpu while using the vnode's page list, use a marker page
to keep our place in the list (like the other cases where we drop the lock).
- wait until no one else has the page busy before deciding if the page needs
to be cleaned. a page will be dirty while it's being initialized but will
be marked clean before PG_BUSY is cleared.
both found by enami.

Don't bother to subtract 0.

Don't leave junk in pgs[] array since it will be passed to uvn_findpages()
again.

in genfs_putpages():
- yield the cpu if we've taken too long.
- when traversing by offset, skip over any pages that we clustered.

in genfs_gop_write(), actually set the B_ASYNC flag on buffers that we're
not going to wait for. this doesn't matter for real devices since we call
VOP_STRATEGY() directly, but NFS uses this flag to decide whether or not
to hand the buffer off to an nfsiod thread.

in genfs_putpages(), we must wait for any pending write i/os to complete
if the putpages request is synchronous.

add some compatibility routines to allow mmap() to work non-UBCified
filesystems (in the same non-coherent fashion that they worked before).

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

PR/14781: Matthew Fredette: Clamp the number of read-ahead pages to 16 because
other code has this limit. Also while I am here, convert the magic 16 into
a #define constant and use it in the appropriate places. This is a temporary
fix, since all this read-ahead business is XXXUBC anyway.

add RCSIDs

branches: 1.39.2;
s/genfs_do_putpages/genfs_gop_write/ in uvmhist.

when zeroing pages past EOF, don't zero the page containing EOF if it
already contains valid data. should fix PRs 13361 and 13436.

a whole bunch of changes to improve performance and robustness under load:

- remove special treatment of pager_map mappings in pmaps. this is
required now, since I've removed the globals that expose the address range.
pager_map now uses pmap_kenter_pa() instead of pmap_enter(), so there's
no longer any need to special-case it.
- eliminate struct uvm_vnode by moving its fields into struct vnode.
- rewrite the pageout path. the pager is now responsible for handling the
high-level requests instead of only getting control after a bunch of work
has already been done on its behalf. this will allow us to UBCify LFS,
which needs tighter control over its pages than other filesystems do.
writing a page to disk no longer requires making it read-only, which
allows us to write wired pages without causing all kinds of havoc.
- use a new PG_PAGEOUT flag to indicate that a page should be freed
on behalf of the pagedaemon when it's unlocked. this flag is very similar
to PG_RELEASED, but unlike PG_RELEASED, PG_PAGEOUT can be cleared if the
pageout fails due to eg. an indirect-block buffer being locked.
this allows us to remove the "version" field from struct vm_page,
and together with shrinking "loan_count" from 32 bits to 16,
struct vm_page is now 4 bytes smaller.
- no longer use PG_RELEASED for swap-backed pages. if the page is busy
because it's being paged out, we can't release the swap slot to be
reallocated until that write is complete, but unlike with vnodes we
don't keep a count of in-progress writes so there's no good way to
know when the write is done. instead, when we need to free a busy
swap-backed page, just sleep until we can get it busy ourselves.
- implement a fast-path for extending writes which allows us to avoid
zeroing new pages. this substantially reduces cpu usage.
- encapsulate the data used by the genfs code in a struct genfs_node,
which must be the first element of the filesystem-specific vnode data
for filesystems which use genfs_{get,put}pages().
- eliminate many of the UVM pagerops, since they aren't needed anymore
now that the pager "put" operation is a higher-level operation.
- enhance the genfs code to allow NFS to use the genfs_{get,put}pages
instead of a modified copy.
- clean up struct vnode by removing all the fields that used to be used by
the vfs_cluster.c code (which we don't use anymore with UBC).
- remove kmem_object and mb_object since they were useless.
instead of allocating pages to these objects, we now just allocate
pages with no object. such pages are mapped in the kernel until they
are freed, so we can use the mapping to find the page to free it.
this allows us to remove splvm() protection in several places.

The sum of all these changes improves write throughput on my
decstation 5000/200 to within 1% of the rate of NetBSD 1.5
and reduces the elapsed time for "make release" of a NetBSD 1.5
source tree on my 128MB pc to 10% less than a 1.5 kernel took.

branches: 1.36.2;
make genfs get/put work for block devices as well:
- the "fs bshift" for block devices is always DEV_BSHIFT.
- retrieve the device vnode from VOP_BMAP() and use that to set b_dev
in page i/o buffers.

branches: 1.35.2;
be sure to allocate dirty zeroed pages to cover blocks we allocate
to resolve a write fault. fixes PR 13201.
also, be sure to allocate blocks for write faults to holes even if
the page is already in memory. fixes PR 13189.

add a genfs_mmap() and change all of the disk-based filesystems
to implement VOP_MMAP() with the genfs version, in preparation for
actually using this VOP.

replace vm_page_t with struct vm_page *.

eliminate the VM_PAGER_* error codes in favor of the traditional E* codes.
the mapping is:

VM_PAGER_OK 0
VM_PAGER_BAD <unused>
VM_PAGER_FAIL <unused>
VM_PAGER_PEND 0 (see below)
VM_PAGER_ERROR EIO
VM_PAGER_AGAIN EAGAIN
VM_PAGER_UNLOCK EBUSY
VM_PAGER_REFAULT ERESTART

for async i/o requests, it used to be possible for the request to
be convert to sync, and the pager would return VM_PAGER_OK or VM_PAGER_PEND
to indicate whether the caller should perform post-i/o cleanup.
this is no longer allowed; pagers must now return 0 to indicate that
the async i/o was successfully started, and the caller never needs to
worry about doing the post-i/o cleanup.

branches: 1.31.2;
in genfs_getpages(), don't try to optimize zeroing past EOF.
fixes PR 12297.

distinguish between a file's in-memory EOF (which marks the offset at
which we disallow creation of page cache pages) and its on-disk EOF
(which marks the offset at which there is not (yet) data on disk that
we need to read when creating pages). for requests with PGO_PASTEOF,
the in-memory EOF maybe be much larger than the on-disk EOF.

fix a couple more bugs:
- in genfs_getpages(), unbusy any pages that we don't free in the error path.
- in genfs_putpages(), if we get a bmap error, record that in the master buf.

Oops, removal unintenionally commited debug code.

Format arg nit.

fix several bugs:
- in the cases where we skip over the i/o loop, increment npages by ridx
so that when the cleanup code starts processing the pgs array at index 0
it'll actually process all of the pages.
- process the PG_RELEASED flag when unbusying pages.
- add some missing MP locking.
- use MIN() and MAX() instead of min() and max() since the latter are
functions which take arguments of type "int" but we call them with
values of type "off_t", so the values could be truncated.
- in the PGO_PASTEOF case, use the larger of the current file size and the
end of the requested range of pages as the file size for this request.
this fixes some problems with sparsing writes to large offsets.

Cast lbn to off_t in a few places, to avoid daddr_t overflow and all sorts
of havoc. From Bill Sommerfeld.

several bugs:
- in genfs_getpages() don't start read-ahead if we get an error on the
sync read, and always start read-ahead after the range of the sync read
if we do any at all.
- off-by-one error in genfs_size().

only zero the part of the page after EOF if we're actually
initializing the page.

allow building without SOFTDEP by adding the pageiodone hook to bio_ops.

Initial integration of the Unified Buffer Cache project.

Adapt for VOP_FSYNC parameter change.

Convert namei pathname buffer allocation to use the pool allocator.

branches: 1.18.2;
Stylistic change.

branches: 1.17.2;
Change the sementics of the last parameter from a boolean ("waitfor") to
a set of flags ("flags"). Two flags are defined, UPDATE_WAIT and
UPDATE_DIROP.

Under the old semantics, VOP_UPDATE would block if waitfor were set,
under the assumption that directory operations should be done
synchronously. At least LFS and FFS+softdep do not make this
assumption; FFS+softdep got around the problem by enclosing all relevant
calls to VOP_UPDATE in a "if(!DOINGSOFTDEP(vp))", while LFS simply
ignored waitfor, one of the reasons why NFS-serving an LFS filesystem
did not work properly.

Under the new semantics, the UPDATE_DIROP flag is a hint to the
fs-specific update routine that the call comes from a dirop routine, and
should be wait for, or not, accordingly.

Closes PR#8996.

Register, begone!

Add Kirk McKusick's soft updates code to the trunk. Not enabled by
default, as the copyright on the main file (ffs_softdep.c) is such
that is has been put into gnusrc. options SOFTDEP will pull this
in. This code also contains the trickle syncer.

Bump version number to 1.4O

Remove some mentioned members in the vop {un}lock args struct that we
do not actually have.

branches: 1.13.2; 1.13.4; 1.13.6;
Add support for fcntl(2) to generate VOP_FCNTL calls. Any fcntl
call with F_FSCTL set and F_SETFL calls generate calls to a new
fileop fo_fcntl. Add genfs_fcntl() and soo_fcntl() which return 0
for F_SETFL and EOPNOTSUPP otherwise. Have all leaf filesystems
use genfs_fcntl().

Reviewed by: thorpej
Tested by: wrstuden

Introduce layer library in genfs. This set of files abstracts most of
the functionality of nullfs. The latter is now just a mount & unmount
routine, and a few tables. umapfs borrow most of this infrastructure.

Both fs's are now nfs-exportable.

All layered fs's share a common format to private mount & private
vnode structs (which a particular fs can extend).

Also add genfs_noerr_rele(), a vnode op which will vrele/vput
operand vnodes appropriately.

branches: 1.11.4;
Pass null pointers to VOP_UPDATE rather than having all the callers fetch the
current time themselves.

Add genfs_einval(), which does the obvious thing.

create miscfs/genfs/genfs_vnops.c:genfs_enoioctl and make all the other
filesystems use it instead of a private version.

- Rename nqnfs_vop_lease_check() to genfs_lease_check(). If NFSSERVER is
not in the kernel, genfs_lease_check() is simply a no-op. This allows
LKM'd file systems to be exported (previously did not work properly
due to a compile-time decision based on -DNFSSERVER).
- defopt NFSSERVER

* Convert fsync vnode operator implementations and usage from the old
waitfor argument and MNT_WAIT/MNT_NOWAIT to flags and FSYNC_WAIT.
* In genfs_fsync(), honor the FSYNC_NODATA flag.

Merge with Lite2 + local changes

RCSID Police.

Implement a POSIX compliant genfs VOP_SEEK() and use it in the appropriate
places; by Chris G. Demetriou and myself.

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.

Field "layerm_vfs" of "struct layer_mount" got superseded by "mnt_lower".
Adapt consumers and remove the now unused field.

Ride 7.99.68

branches: 1.16.4; 1.16.8; 1.16.12;
Change field "layerm_tag" to correct type "enum vtagtype".

CID 1216449: Mixing enum types

Change layerfs from hashlist to vcache.
Make VI_LOCKSHARE public again.

Ride 6.99.43

branches: 1.14.18; 1.14.32;
Change layered file systems to always pass the locking VOP's down to the
leaf file system. Remove now unused member v_vnlock from struct vnode.
Welcome to 5.99.30

Discussed on tech-kern.

branches: 1.13.10; 1.13.30; 1.13.32;
Replace struct lock on vnodes with a simpler lock object built on
krwlock_t. This is a step towards removing lockmgr and simplifying
vnode locking. Discussed on tech-kern.

branches: 1.12.4;
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: 1.11.30; 1.11.44; 1.11.46; 1.11.48;
merge ktrace-lwp.

Follow compat naming tradition: rename compat_export_args to export_args30.

Apply the NFS exports list rototill patch:

- Remove all NFS related stuff from file system specific code.
- Drop the vfs_checkexp hook and generalize it in the new nfs_check_export
function, thus removing redundancy from all file systems.
- Move all NFS export-related stuff from kern/vfs_subr.c to the new
file sys/nfs/nfs_export.c. The former was becoming large and its code
is always compiled, regardless of the build options. Using the latter,
the code is only compiled in when NFSSERVER is enabled. While doing this,
also make some functions in nfs_subs.c conditional to NFSSERVER.
- Add a new command in nfssvc(2), called NFSSVC_SETEXPORTSLIST, that takes a
path and a set of export entries. At the moment it can only clear the
exports list or append entries, one by one, but it is done in a way that
allows setting the whole set of entries atomically in the future (see the
comment in mountd_set_exports_list or in doc/TODO).
- Change mountd(8) to use the nfssvc(2) system call instead of mount(2) so
that it becomes file system agnostic. In fact, all this whole thing was
done to remove a 'XXX' block from this utility!
- Change the mount*, newfs and fsck* userland utilities to not deal with NFS
exports initialization; done internally by the kernel when initializing
the NFS support for each file system.
- Implement an interface for VFS (called VFS hooks) so that several kernel
subsystems can run arbitrary code upon receipt of specific VFS events.
At the moment, this only provides support for unmount and is used to
destroy NFS exports lists from the file systems being unmounted, though it
has room for extension.

Thanks go to yamt@, chs@, thorpej@, wrstuden@ and others for their comments
and advice in the development of this patch.

Remove __P()

Provide a sysctl (vfs.layerfs.debug) to control verbose output when
LAYERFS_DIAGNOSTIC is turned on.

branches: 1.6.12;
Since VOP_UPCALL() has been a long time in coming, add this partial
fix for layered-file-removal. It will work for the case of accessing
and deleting a file through the layered file system. Accessing via
the layer and deleting on the underlying still won't work, nor will
accessing via complicated structures (like two umap layers over a
given file systems).

We still need VOP_UPCALL(), but this is better than things were before.

This patch has been discussed off & on for a while. This incarnation
was tested by hannken at netbsd dot org.

branches: 1.5.2;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

branches: 1.4.22;
Typos in comments (misc/13133 by Michael K. Sanders)

branches: 1.3.6;
Delete redundant decl of layer_node_create(), it's in layer_extern.h.

Fix doubled 'the's in comments.

branches: 1.1.2; 1.1.4;
Introduce layer library in genfs. This set of files abstracts most of
the functionality of nullfs. The latter is now just a mount & unmount
routine, and a few tables. umapfs borrow most of this infrastructure.

Both fs's are now nfs-exportable.

All layered fs's share a common format to private mount & private
vnode structs (which a particular fs can extend).

Also add genfs_noerr_rele(), a vnode op which will vrele/vput
operand vnodes appropriately.

VFS_VGET(), VFS_ROOT(), VFS_FHTOVP(): give them a "int lktype" argument, to
allow us to get shared locks (or no lock) on the returned vnode. Matches
FreeBSD.

branches: 1.40.6; 1.40.12;
Locking a layer vnode using the regular bypass routine is no longer
racy. Undo the change from 2017-03-30 11:16:52, commitid eurqbzuGxGRlryLz
and make vi_lock a krwlock_t again.

branches: 1.39.6;
Locking a layer vnode is racy as it may become reclaimed before
calling the operation on the lower vnode.

Replace vi_lock with a rw_obj and change layered file systems
to share the lock with the lower vnode.

Layered file systems now use genfs_lock()/_unlock/_islocked().

Welcome to 7.99.67

Add generic genfs_suspendctl() and use it for all file systems.
Layered file systems need work.

Handle v_writecount from layer_open(), layer_close() and layer_revoke()
so lower file system vnodes get marked as open for writing.

branches: 1.36.4; 1.36.8; 1.36.12;
Change layerfs from hashlist to vcache.
Make VI_LOCKSHARE public again.

Ride 6.99.43

branches: 1.35.2;
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

branches: 1.34.6; 1.34.10;
Change the syscall API for quotas over to the new non-proplib one.

- struct vfs_quotactl_args -> struct quotactl_args
- add sys/stdint.h to sys/quotactl.h for clean userland build
- install sys/quotactl.h in /usr/include
- update set lists for same
- add new marshalling code in libquota
- add new unmarshalling code in vfs_syscalls.c
- discard proplib interpreter code in vfs_quotactl.c
- add dispatching code for the 14 quotactl ops in vfs_quotactl.c
- mark the proplib quotactl syscall obsolete
- add a new syscall number for the new quotactl syscall
- change the name of the syscall to __quotactl()
- remove the decl of the old quotactl from quota/quotaprop.h
- add a decl of the new quotactl to sys/quotactl.h
- update the libc build
- update ktruss
- remove proplib marshalling code from libquota
- update copy of syscall table in gdb ppc sources
- hack rumphijack to accomodate new quotactl name (as I recall,
pooka wanted such a name change to simplify something, but I
don't really see what/how)

This change appears to require a kernel version bump for rumpish
reasons.

Remove the extra op argument to VFS_QUOTACTL() - the op is now stored
purely in the args structure.

This change requires a kernel version bump.

Introduce struct vfs_quotactl_args. Use it.

This change uglifies vfs_quotactl some in order to make room for
moving operation-specific but FS-independent logic out of ufs_quota.c.

Note: this change requires a kernel version bump.

Move the proplib-based quota command dispatching (that is, the code
that knows the magic string names for the allowed actions) out of
UFS-specific code and to fs-independent code.

This introduces QUOTACTL_* operation codes and changes the signature
of VFS_QUOTACTL() again for compile safety.

Note: this change requires a kernel version bump.

Move the code for iterating over the multiple RPC calls in a quota
proplib XML packet to vfs_quotactl.c out of sys/ufs/ufs.

Add a dummy extra arg to VFS_QUOTACTL for compile safety.

Note: this change requires a kernel version bump.

branches: 1.29.2; 1.29.6;
Change VOP_BWRITE() to take a vnode as its first argument like all other
VOPs do. Layered file systems no longer have to modify bp->b_vp and run
into trouble when an async VOP_BWRITE() uses the wrong vnode.

- change all occurences of VOP_BWRITE(bp) to VOP_BWRITE(bp->b_vp, bp).
- remove layer_bwrite().
- welcome to 5.99.55

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

merge the bouyer-quota2 branch. This adds a new on-disk format
to store disk quota usage and limits, integrated with ffs
metadata. Usage is checked by fsck_ffs (no more quotacheck)
and is covered by the WAPBL journal. Enabled with kernel
option QUOTA2 (added where QUOTA was enabled in kernel config files),
turned on with tunefs(8) on a per-filesystem
basis. mount_mfs(8) can also turn quotas on.

See http://mail-index.netbsd.org/tech-kern/2011/02/19/msg010025.html
for details.

branches: 1.27.2; 1.27.4;
Add layer_revoke() that adjusts the lower vnode use count to be at least as
high as the upper vnode count before passing down the VOP_REVOKE().

This way vclean() check for active (vp->v_usecount > 1) vnodes gets it right.

Should fix PR kern/43456.

LK_INTERLOCK is no longer a valid flag for VOP_LOCK(). This makes
layer_*lock*() obsolete. Remove them and handle lock operations
with the generic bypass function.

Ride 5.99.34.

Slightly clean-up layerfs and nullfs: update the big description more to
the reality (remove duplicate one in nullfs, merge some differences from
it), KNF, improve and update some comments, add few KASSERT()s, remove
unused declarations, avoid double inclusion of headers, misc.

No functional changes.

branches: 1.24.10; 1.24.30; 1.24.32;
Fix some race conditions in rename.
Introduce a per-FS rename lock and new vfsops to manipulate it.
Get this lock while renaming. Also add another relookup() in do_sys_rename,
which is a hack to kludge around some of the worst deficiencies of
ufs_rename.
reviewed-by: pooka (and an earlier rev by ad)
posted on tech-kern with no objections.

Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.22.28; 1.22.30; 1.22.36;
Fix alignement problems for fhandle_t, exposed by gcc4.1.

While touching all vptofh/fhtovp functions, get rid of VFS_MAXFIDSIZ,
version the getfh(2) syscall and explicitly pass the size available in
the filehandle from userland.

Discussed on tech-kern, with lots of help from yamt (thanks!).

branches: 1.21.4;
integrate kauth.

branches: 1.20.4; 1.20.6; 1.20.8; 1.20.10; 1.20.12;
merge ktrace-lwp.

Apply the NFS exports list rototill patch:

- Remove all NFS related stuff from file system specific code.
- Drop the vfs_checkexp hook and generalize it in the new nfs_check_export
function, thus removing redundancy from all file systems.
- Move all NFS export-related stuff from kern/vfs_subr.c to the new
file sys/nfs/nfs_export.c. The former was becoming large and its code
is always compiled, regardless of the build options. Using the latter,
the code is only compiled in when NFSSERVER is enabled. While doing this,
also make some functions in nfs_subs.c conditional to NFSSERVER.
- Add a new command in nfssvc(2), called NFSSVC_SETEXPORTSLIST, that takes a
path and a set of export entries. At the moment it can only clear the
exports list or append entries, one by one, but it is done in a way that
allows setting the whole set of entries atomically in the future (see the
comment in mountd_set_exports_list or in doc/TODO).
- Change mountd(8) to use the nfssvc(2) system call instead of mount(2) so
that it becomes file system agnostic. In fact, all this whole thing was
done to remove a 'XXX' block from this utility!
- Change the mount*, newfs and fsck* userland utilities to not deal with NFS
exports initialization; done internally by the kernel when initializing
the NFS support for each file system.
- Implement an interface for VFS (called VFS hooks) so that several kernel
subsystems can run arbitrary code upon receipt of specific VFS events.
At the moment, this only provides support for unmount and is used to
destroy NFS exports lists from the file systems being unmounted, though it
has room for extension.

Thanks go to yamt@, chs@, thorpej@, wrstuden@ and others for their comments
and advice in the development of this patch.

Remove __P()

branches: 1.17.12;
Do LAYERFS_REMOVED for vop_rmdir.

Reviewed by: Bill Studenmund <wrstuden@netbsd.org>

do a LAYERFS_REMOVED hack for vop_rename as well.

Add layerfs_snapshot() as a handler routine for VFS_SNAPSHOT() calls
through a layered file system.

Note: we don't actually support snapshots through a layered file system,
and this routine returns an error. However we: 1) have clearly documented
what needs fixing (which isn't trivial to fix) and 2) if we do fix
this, all layered file systems can take advantage of it at once.

Since VOP_UPCALL() has been a long time in coming, add this partial
fix for layered-file-removal. It will work for the case of accessing
and deleting a file through the layered file system. Accessing via
the layer and deleting on the underlying still won't work, nor will
accessing via complicated structures (like two umap layers over a
given file systems).

We still need VOP_UPCALL(), but this is better than things were before.

This patch has been discussed off & on for a while. This incarnation
was tested by hannken at netbsd dot org.

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.

Replace the statfs() family of system calls with statvfs().
Retain binary compatibility.

branches: 1.11.2;
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.

Dynamic sysctl.

Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.

Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.

All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.

PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.

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

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

branches: 1.8.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Undo part of the ktrace/lwp changes. In particular:
* Remove the "lwp *" argument that was added to vget(). Turns out
that nothing actually used it!
* Remove the "lwp *" arguments that were added to VFS_ROOT(), VFS_VGET(),
and VFS_FHTOVP(); all they did was pass it to vget() (which, as noted
above, didn't use it).
* Remove all of the "lwp *" arguments to internal functions that were added
just to appease the above.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

add VOP_GETPAGES and VOP_PUTPAGES methods for layered filesystems.
drop the interlock on the upper layer, acquire the interlock on the
lower layer.

branches: 1.4.2;
Typos in comments (misc/13133 by Michael K. Sanders)

branches: 1.3.6;
Add new VFS op routine - vfs_done and call it on filesystem detach
in vfs_detach(). vfs_done may free global filesystem's resources,
typically those allocated in respective filesystem's init function.
Needed so those filesystems which went in via LKM have a chance to
clean after themselves before unloading. This fixes random panics
when LKM for filesystem using pools was loaded and unloaded several
times.

For each leaf filesystem, add appropriate vfs_done routine.

Fix doubled 'the's in comments.

branches: 1.1.2; 1.1.4;
Introduce layer library in genfs. This set of files abstracts most of
the functionality of nullfs. The latter is now just a mount & unmount
routine, and a few tables. umapfs borrow most of this infrastructure.

Both fs's are now nfs-exportable.

All layered fs's share a common format to private mount & private
vnode structs (which a particular fs can extend).

Also add genfs_noerr_rele(), a vnode op which will vrele/vput
operand vnodes appropriately.

fix various typos in comments and output/log messages.

Replace most uses of vp->v_usecount with a call to vrefcnt(vp), a function
that hides the details and does atomic_load_relaxed(). Signature matches
FreeBSD.

branches: 1.37.20; 1.37.30;
Do not uselessly include <sys/malloc.h>.

branches: 1.36.2;
Change layerfs from hashlist to vcache.
Make VI_LOCKSHARE public again.

Ride 6.99.43

branches: 1.35.2;
Change layerfs_vget(), layerfs_fhtovp() and the various layer xxx_mount()
functions to unlock/relock the node for the call to layer_node_create().

Finally remove dirty hacks (LK_NOWAIT, kpause) from layer_node_find().

When layer_node_alloc() finds another thread already inserted the node
into the hashlist and discards the now unneeded node it will raise a
panic "dead but not clean".

Reorder the initialization and use ungetnewvnode() to discard the node.

Allow layer_node_create() with unlocked lower node and change
layer_bypass() to enter nodes from creation operations unlocked.

branches: 1.32.2; 1.32.12; 1.32.16;
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: 1.31.6;
Make holding v_interlock mandatory for callers of vget().

Announced some time ago on tech-kern.

Slightly clean-up layerfs and nullfs: update the big description more to
the reality (remove duplicate one in nullfs, merge some differences from
it), KNF, improve and update some comments, add few KASSERT()s, remove
unused declarations, avoid double inclusion of headers, misc.

No functional changes.

Change layered file systems to always pass the locking VOP's down to the
leaf file system. Remove now unused member v_vnlock from struct vnode.
Welcome to 5.99.30

Discussed on tech-kern.

branches: 1.28.2; 1.28.4;
The VATTR_NULL/VREF/VHOLD/HOLDRELE() macros lost their will to live
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.

no functional change

ansify function definitions

Change about 4500 of the K&R function definitions to ANSI ones.
There are still about 1600 left, but they have ',' or /* ... */
in the actual variable definitions - which my awk script doesn't handle.
There are also many that need () -> (void).
(The script does handle misordered arguments.)

branches: 1.25.10; 1.25.18; 1.25.24;
specfs changes for PR kern/37717 (raidclose() is no longer called on
shutdown). There are still problems with device access and a PR will be
filed.

- Kill checkalias(). Allow multiple vnodes to reference a single device.

- Don't play dangerous tricks with block vnodes to ensure that only one
vnode can describe a block device. Instead, prohibit concurrent opens of
block devices. As a bonus remove the unreliable code that prevents
multiple file system mounts on the same device. It's no longer needed.

- Track opens by vnode and by device. Issue cdev_close() when the last open
goes away, instead of abusing vnode::v_usecount to tell if the device is
open.

layer_node_find: if we find a node being cleaned out, then ignore it and
continue. A thread trying to clean out the extant layer vnode needs to
acquire the shared lock (i.e. the lower vnode's lock), which our caller
already holds. To allow the cleaning to succeed the current thread must make
progress. So, for a brief time more than one vnode in a layered file system
may refer to a single vnode in the lower file system.

Merge vmlocking2 to head.

branches: 1.22.4; 1.22.6; 1.22.10;
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: 1.21.6; 1.21.18; 1.21.20; 1.21.22;
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().