ufs: fixed signed/unsigned bugs affecting large file systems

Apply these commits from FreeBSD:

commit e870d1e6f97cc73308c11c40684b775bcfa906a2
Author: Kirk McKusick <mckusick@FreeBSD.org>
Date: Wed Feb 10 20:10:35 2010 +0000

This fix corrects a problem in the file system that treats large
inode numbers as negative rather than unsigned. For a default
(16K block) file system, this bug began to show up at a file system
size above about 16Tb.

To fully handle this problem, newfs must be updated to ensure that
it will never create a filesystem with more than 2^32 inodes. That
patch will be forthcoming soon.

Reported by: Scott Burns, John Kilburg, Bruce Evans
Followup by: Jeff Roberson
PR: 133980
MFC after: 2 weeks

commit 81479e688b0f643ffacd3f335b4b4bba460b769d
Author: Kirk McKusick <mckusick@FreeBSD.org>
Date: Thu Feb 11 18:14:53 2010 +0000

One last pass to get all the unsigned comparisons correct.


In additional to the changes from FreeBSD, this commit includes quite a few
related changes to appease -Wsign-compare.

the UFS_EXTATTR option was supposed to affect only UFS1 file systems,
but when the UFS2 extattr code was merged, the UFS_EXTATTR option was
mistakenly changed to affect UFS2 file systems as well. this commit
changes UFS_EXTATTR back to affecting only UFS1 file systems as originally
intended. in UFS2 (or rather UFS2ea in NetBSD), extattrs are a
native feature and are always supported.

Extended attribute support for ffsv2, from FreeBSD.

branches: 1.85.10;
- Cleanup for dynamic sysctl:
- Remove unused *_NAMES macros for sysctl.
- Remove unused *_MAXID for sysctls.
- Move CTL_MACHDEP sysctl definitions for m68k into m68k/include/cpu.h and
use them on all m68k machines.

branches: 1.84.12; 1.84.14;

Sprinkle in a pinch of const, not too much, just enough
to add a little strength without affecting the overall balance...

branches: 1.83.2;
allocate wapbl dealloc registration structures via pool, so that there is more
flexibility with limit handling

branches: 1.82.2;
Disentangle buffer-cached I/O from page-cached I/O in UFS.

Page-cached I/O is used for regular files, and is initiated by VFS
users such as userland and NFS.

Buffer-cached I/O is used for directories and symlinks, and is issued
only internally by UFS.

New UFS routine ufs_bufio replaces vn_rdwr for internal use.
ufs_bufio is implemented by new UFS operations uo_bufrd/uo_bufwr,
which sit in ufs_readwrite.c alongside the VOP_READ/VOP_WRITE
implementations.

I preserved the code as much as possible and will leave further
simplification for future commits. I kept the ulfs_readwrite.c
copypasta close to ufs_readwrite.c in case we ever want to merge them
back; likewise ext2fs_readwrite.c.

No externally visible semantic change. All atf fs tests still pass.

Change ffs to use vcache_new:
- Change ffs_valloc to return an inode number.
- Remove now obsolete UFS operations UFS_VALLOC and UFS_VFREE.
- Make ufs_makeinode private to ufs_vnops.c and pass vattr instead of mode.

branches: 1.80.10;
Add an UFS_SNAPGONE() ufs op replacing the calls
to ffs_snapgone() in ufs_lookup.c.

Ok: David Holland <dholland@netbsd.org>

Welcome to 6.99.22

Implement experimental support to pass notifications that a file
was deleted from the filesystem to the disk driver, commonly
known as "discard" or "trim".
fs/driver support is in ffs and ata wd for now.
This is what was posted here:
http://mail-index.netbsd.org/tech-kern/2012/02/28/msg012813.html
with minor cleanup, and the global switch replaced by a mount option.

branches: 1.78.2; 1.78.12;
Add mount -o extattr option to enable extended attributs (corrently only
for UFS1).
Remove kernel option for EA backing store autocreation and do it by
default. Add a sysctl so that autocreated attriutr size can be modified.

branches: 1.77.2;
Cleanup ffs fsync and make devices on wapbl enabled file systems work here:

- Replace the ugly sync loop in ffs_full_fsync() and ffs_vfs_fsync() with
vflushbuf(). This loop is a relic of softdeps and not needed anymore.

- Add ffs_spec_fsync() for device nodes on ffs file systems that calls
spec_fsync() like all other file systems do and then updates the ctime.

Discussed on tech-kern.

Should fix PRs:
PR #41192 wapbl diagnostic panic during cgdconfig
PR #41977 kernel diagnostic assertion "rw_lock_held(&wl->wl_rwlock)" failed
PR #42149 wapbl locking panic if watching DVD
PR #42551 Lockdebug assert in wapbl when running zpool

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: 1.75.4; 1.75.6; 1.75.8;
PR kern/26878 FFSv2 + softdep = livelock (no free ram)
PR kern/16942 panic with softdep and quotas
PR kern/19565 panic: softdep_write_inodeblock: indirect pointer #1 mismatch
PR kern/26274 softdep panic: allocdirect_merge: ...
PR kern/26374 Long delay before non-root users can write to softdep partitions
PR kern/28621 1.6.x "vp != NULL" panic in ffs_softdep.c:4653 while unmounting a softdep (+quota) filesystem
PR kern/29513 FFS+Softdep panic with unfsck-able file-corruption
PR kern/31544 The ffs softdep code appears to fail to write dirty bits to disk
PR kern/31981 stopping scsi disk can cause panic (softdep)
PR kern/32116 kernel panic in softdep (assertion failure)
PR kern/32532 softdep_trackbufs deadlock
PR kern/37191 softdep: locking against myself
PR kern/40474 Kernel panic after remounting raid root with softdep

Retire softdep, pass 2. As discussed and later formally announced on the
mailing lists.

branches: 1.74.4;
Split ffs_freefile into a frontend for normal cylinder group and for
snapshot use. Adjust ffs_blkfree_common to get the fs instance passed
in, the original commit didn't account blocks in the snapshots
correctly. Assert that ffs_blkfree is used with the primary fs instance
and that ffs_checkfreefile is only used for snapshots. Move the bdwrite
from ffs_blkfree_common into the caller for symmetry. This creates a
redundant write of unmodified data for ffs_blkfree_snap if a double free
of a block happens.

Reviewed and tested by hannken@.

ffs_blkfree is used in two different ways. The normal usage is to free a
block in the cylinder groups of the filesystem. The other user is the
snapshot code, which wants to modify the copied cylinder groups. Use
different frontends to distinguish the cases in preparation for fine
grained locking for cylinder groups.

Split ffs_blkalloc into a frontend that does inode based consistency
checks and a backend that just asserts them. Use the backend in
ffs_wapbl_abort_sync_metadata instead of faking an inode.

Remove XXXUBC code for ffs_reallocblks, that has been conditionalized in
2002 and #if 0'ed in 2005. It would need a considerable amount of work
to bring back and obscures the more important block allocation.

branches: 1.70.2;
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>

Add snapshot support for logging ffs file systems.

- Add UFS_WAPBL_BEGIN() / UFS_WAPBL_END() where needed.

- Expunge WAPBL log inodes from snapshots.

- Ffs_copyonwrite() and ffs_snapblkfree() must run inside a WAPBL transaction.

- Add ffs_gop_write() as a wrapper around genfs_gop_write() that makes sure
genfs_gop_write() gets always called inside a WAPBL transaction.

- Add VOP_PUTPAGES() flag PGO_JOURNALLOCKED to tag calls to VOP_PUTPAGES()
inside a WAPBL transaction.

Reviewed by: Simon Burge <simonb@netbsd.org>, Greg Oster <oster@netbsd.org>

PGO_JOURNALLOCKED / ffs_gop_write() part presented on tech-kern@.

Deny read/write access to snapshot vnodes. We use fss(4) to read from
snapshots. With this policy in place:

- Separate the snapshot vnode lock from the snapshot common lock.
Snapshots no longer need recursive vnode locks.

- Use a mutex (si_snaplock) to serialize creation, deletion, reading and
writing of snapshots.

- Move ffs_read() for snapshots into ffs_snapshot.c.

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

While here change ffs_copyonwrite() to fail requests from pagedaemon that need
to copy-on-write.

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: 1.66.2;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.65.2;
ufs/ffs: replace calls to getblk() with ffs_getblk(). Now all buffers
have been run through copy-on-write and async mounts work again.

Fixes PR kern/38820

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

branches: 1.64.2; 1.64.4; 1.64.6;
Replace get/setspecific with a void pointer in struct ufsmount. Use explicit
initialization/finalization of snapshot private data on creation/deletion
of struct ufsmount.
Snapshot mounts no longer may fail silently because kmem_alloc() fails.

Welcome to 4.99.60

Ok: Andrew Doran <ad@netbsd.org>

branches: 1.63.6;
Use pool_cache.

Merge vmlocking2 to head.

branches: 1.61.4;
Remove cn_lwp from struct componentname. curlwp should be used
from on. The NDINIT() macro no longer takes the lwp parameter and
associates the credentials of the calling thread with the namei
structure.

branches: 1.60.2; 1.60.8; 1.60.10;
Move the fstrans-aware lock vnops from ufs to ffs. Other ufs file systems
do not need them.

Ride on 4.99.28

Move snapshot per-mount data from struct ufsmount to mount specific data.
No functional changes.

Welcome to 4.99.28 (struct ufsmount changed size)

branches: 1.58.2; 1.58.4;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

branches: 1.57.2;
Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

remove a duplicated definition of FFS_ITIMES.

branches: 1.55.6; 1.55.8;
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).

branches: 1.54.4;
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: 1.53.4;
integrate kauth.

remove unused FFS_NAMES and LFS_NAMES.

branches: 1.51.2; 1.51.4; 1.51.6; 1.51.8; 1.51.10;
- unify ffs_blkatoff and lfs_blkatoff.
- remove ufs_ops::uo_blkatoff.
- add directory read-ahead code. (disabled for now.)

branches: 1.50.2;
changes for making DIAGNOSTIC not change the kernel ABI:
- for structure fields that are conditionally present,
make those fields always present.
- for functions which are conditionally inline, make them never inline.
- remove some other functions which are conditionally defined but
don't actually do anything anymore.
- make a lock-debugging function conditional on only LOCKDEBUG.

as discussed on tech-kern some time back.

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: 1.47.2;
- access the ffs and ext2fs itimes functions through a pointer, so that
if the filesystem is not compiled in the kernel still links. Probably
a better solution is to use weak symbols.
- move the filesystem-specific itime macros to the filesystem header files.

Use nanotime() to update the time fields in filesystems. Convert the code
from macros to real functions. Original patch and review from chuq.
Note: ext2fs only keeps seconds in the on-disk inode, and msdosfs does not
have enough precision for all fields, so this is not very useful for those
two.

revert the code to expand putpage requests to block boundary.
because:
- it was incomplete in some cases.
- it can confuse pagedaemon.
see PR/15364 for details.

Experimental support for extended attributes on UFS1 file systems, using a
backing file per attribute type indexed by inode number to hold the extended
attributes.

This is working pretty well on my test systems, except for the "autostart"
feature. I need someone with a better handle on the VFS locking protocol
to go over that.

This is a work-in-progress. There are parts of this that could be re-factored
allowing this approach to be used on other types of file systems.

Adapted from FreeBSD.

Use ANSI function decls.

branches: 1.42.2; 1.42.4;
nuke trailing whitespace

branches: 1.41.4; 1.41.6;
While creating a snapshot inodes must be freed from the
snapshot, not from the file system.
ffs_freefile() needs explicit "fs" and "devvp" arguments.

Need to forward-declare "struct timespec" because the new ffs_snapshot()
function declaration refers to it. Fixes build problem of sbin/badsect
for the vax target, which still uses gcc 2.95.3.

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>

Tweak sysctl setup functions (the macros, actually) for use in lkms,
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.

This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.

linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).

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

branches: 1.36.2;
Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue.

Cleanup ffs_sync() which did not synchronously wait when MNT_WAIT
was specified. Clear the work queue when MNT_WAIT is specified.

Result is a clean on-disk file system after ffs_sync(.., MNT_WAIT, ..)

From FreeBSD.

add uuid field to apple ufs volume label

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: 1.32.2;
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.

Add forward declaration of struct lwp instead of struct proc. Sort those
while I'm here.

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 support for UFS2. UFS2 is an enhanced FFS, adding support for
64 bit block pointers, extended attribute storage, and a few
other things.

This commit does not yet include the code to manipulate the extended
storage (for e.g. ACLs), this will be done later.

Originally written by Kirk McKusick and Network Associates Laboratories for
FreeBSD.

ffs_gop_alloc() is not used any more. Remove it.

OK:ed by Konrad Schroder.

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.

Bump daddr_t to 64 bits. Replace it with int32_t in all places where
it was used on-disk, so that on-disk formats remain the same.
Remove ufs_daddr_t and ufs_lbn_t for the time being.

Add multiple inclusion protection for headers. Fix mismatched
variable declarations (missing const's) as needed.

Add support for the Apple UFS variation on ffs
This is the bulk of PR #17345

The general approach is to use a run time deteriminable value
for DIRBLKSIZ. Additional allowances are included for using
MAXSYMLINKLEN with FS_42INODEFMT and a shift in the cylinder group
cluster summary count array. Support is added for managing
the Apple UFS volume label.

for softdep vnodes, always write together the pages for any block that
might have a dependency , since the accounting doesn't work otherwise.
fixes PRs 15364 16336 16448.

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.

add a new VFS op, vfs_reinit, which is called when desiredvnodes is
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.

convert various file systems to use the <sys/queue.h> macros for
their hash tables.

branches: 1.19.2;
remove third argument (`int ns') from ffs_sb_swap(), and let ffs_sb_swap()
determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.

this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).

whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.

FFS_EI should now be a lot more stable.

be consistent and use "u_char" instead of "unsigned char"

branches: 1.17.2; 1.17.6;
Initial integration of the Unified Buffer Cache project.

branches: 1.16.4;
Add a new sysctl variable vfs.ffs.log_changeopt - if this is true,
an optimalization strategy change is logged into syslog. Default
is 0 (to not log). This replaces the recent not quite "right"
change to only log the change if kernel is compiled with DEBUG.

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.

For each leaf filesystem, add appropriate vfs_done routine.

Also remember how many times ffs_init() was called and do
the appropriate initialization on first call only. In ffs_done(),
destroy the resources when called by the last user of ffs code.
Change mfs to call ffs_init()/ffs_done() appropriately.

Fixes to the softdep code from Ethan Solomita <ethan@geocast.com>.
* Fix buffer ordering when it has dependencies.
* Alleviate memory problems.
* Deal with some recursive vnode locks (sigh).
* Fix other bugs.

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

branches: 1.12.4; 1.12.8; 1.12.10; 1.12.14;
Modify vfsops to seperate vfs_fhtovp() into two routines. vfs_fhtovp() now
only handles the file handle to vnode conversion, and a new call,
vfs_checkexp(), performs the export verification.

branches: 1.11.2;
Use the pool allocator and the "nointr" pool page allocator for FFS inodes.

XXX MFS also comes in here for inodes, and used a different malloc type,
but the structure is the same, so we just use the FFS inode pool.

Always include fifos; "not an option any more".

defopt for options FIFO

Add support for reading/writing FFS in non-native byte order, conditioned
to "options FFS_EI". The superblock and inodes (without blk addr) are
byteswapped at disk read/write time, other metadatas are byteswapped
when used (as they are acceeded directly in the buffer cache).
This required the addition of a "um_flags" field to struct ufsmount.
ffs_bswap.c contains superblock and inode byteswap routines also used
by userland utilities.

Merge with Lite2 + local changes

Change the second and third args to struct vfsops' (*vfs_mount)() to
'const char *', and 'void *', respectively. The second arg is taken directly
from user arguments, and is const there, so must be const in the prototypes
and functions. The third arg is also taken directly from user arguments.
It doesn't have to be changed, but since it's cleaner to keep the type
the same as the user arg's type, and I'm already making the 'const char *'
change...

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

ffs prototypes

update for new syscall args description mechanism, and deal safely
with wider types.

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

branches: 1.1.1;
Update to 4.4-Lite fs code, with local changes.

the UFS_EXTATTR option was supposed to affect only UFS1 file systems,
but when the UFS2 extattr code was merged, the UFS_EXTATTR option was
mistakenly changed to affect UFS2 file systems as well. this commit
changes UFS_EXTATTR back to affecting only UFS1 file systems as originally
intended. in UFS2 (or rather UFS2ea in NetBSD), extattrs are a
native feature and are always supported.

Extended attribute support for ffsv2, from FreeBSD.

branches: 1.85.10;
- Cleanup for dynamic sysctl:
- Remove unused *_NAMES macros for sysctl.
- Remove unused *_MAXID for sysctls.
- Move CTL_MACHDEP sysctl definitions for m68k into m68k/include/cpu.h and
use them on all m68k machines.

branches: 1.84.12; 1.84.14;

Sprinkle in a pinch of const, not too much, just enough
to add a little strength without affecting the overall balance...

branches: 1.83.2;
allocate wapbl dealloc registration structures via pool, so that there is more
flexibility with limit handling

branches: 1.82.2;
Disentangle buffer-cached I/O from page-cached I/O in UFS.

Page-cached I/O is used for regular files, and is initiated by VFS
users such as userland and NFS.

Buffer-cached I/O is used for directories and symlinks, and is issued
only internally by UFS.

New UFS routine ufs_bufio replaces vn_rdwr for internal use.
ufs_bufio is implemented by new UFS operations uo_bufrd/uo_bufwr,
which sit in ufs_readwrite.c alongside the VOP_READ/VOP_WRITE
implementations.

I preserved the code as much as possible and will leave further
simplification for future commits. I kept the ulfs_readwrite.c
copypasta close to ufs_readwrite.c in case we ever want to merge them
back; likewise ext2fs_readwrite.c.

No externally visible semantic change. All atf fs tests still pass.

Change ffs to use vcache_new:
- Change ffs_valloc to return an inode number.
- Remove now obsolete UFS operations UFS_VALLOC and UFS_VFREE.
- Make ufs_makeinode private to ufs_vnops.c and pass vattr instead of mode.

branches: 1.80.10;
Add an UFS_SNAPGONE() ufs op replacing the calls
to ffs_snapgone() in ufs_lookup.c.

Ok: David Holland <dholland@netbsd.org>

Welcome to 6.99.22

Implement experimental support to pass notifications that a file
was deleted from the filesystem to the disk driver, commonly
known as "discard" or "trim".
fs/driver support is in ffs and ata wd for now.
This is what was posted here:
http://mail-index.netbsd.org/tech-kern/2012/02/28/msg012813.html
with minor cleanup, and the global switch replaced by a mount option.

branches: 1.78.2; 1.78.12;
Add mount -o extattr option to enable extended attributs (corrently only
for UFS1).
Remove kernel option for EA backing store autocreation and do it by
default. Add a sysctl so that autocreated attriutr size can be modified.

branches: 1.77.2;
Cleanup ffs fsync and make devices on wapbl enabled file systems work here:

- Replace the ugly sync loop in ffs_full_fsync() and ffs_vfs_fsync() with
vflushbuf(). This loop is a relic of softdeps and not needed anymore.

- Add ffs_spec_fsync() for device nodes on ffs file systems that calls
spec_fsync() like all other file systems do and then updates the ctime.

Discussed on tech-kern.

Should fix PRs:
PR #41192 wapbl diagnostic panic during cgdconfig
PR #41977 kernel diagnostic assertion "rw_lock_held(&wl->wl_rwlock)" failed
PR #42149 wapbl locking panic if watching DVD
PR #42551 Lockdebug assert in wapbl when running zpool

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: 1.75.4; 1.75.6; 1.75.8;
PR kern/26878 FFSv2 + softdep = livelock (no free ram)
PR kern/16942 panic with softdep and quotas
PR kern/19565 panic: softdep_write_inodeblock: indirect pointer #1 mismatch
PR kern/26274 softdep panic: allocdirect_merge: ...
PR kern/26374 Long delay before non-root users can write to softdep partitions
PR kern/28621 1.6.x "vp != NULL" panic in ffs_softdep.c:4653 while unmounting a softdep (+quota) filesystem
PR kern/29513 FFS+Softdep panic with unfsck-able file-corruption
PR kern/31544 The ffs softdep code appears to fail to write dirty bits to disk
PR kern/31981 stopping scsi disk can cause panic (softdep)
PR kern/32116 kernel panic in softdep (assertion failure)
PR kern/32532 softdep_trackbufs deadlock
PR kern/37191 softdep: locking against myself
PR kern/40474 Kernel panic after remounting raid root with softdep

Retire softdep, pass 2. As discussed and later formally announced on the
mailing lists.

branches: 1.74.4;
Split ffs_freefile into a frontend for normal cylinder group and for
snapshot use. Adjust ffs_blkfree_common to get the fs instance passed
in, the original commit didn't account blocks in the snapshots
correctly. Assert that ffs_blkfree is used with the primary fs instance
and that ffs_checkfreefile is only used for snapshots. Move the bdwrite
from ffs_blkfree_common into the caller for symmetry. This creates a
redundant write of unmodified data for ffs_blkfree_snap if a double free
of a block happens.

Reviewed and tested by hannken@.

ffs_blkfree is used in two different ways. The normal usage is to free a
block in the cylinder groups of the filesystem. The other user is the
snapshot code, which wants to modify the copied cylinder groups. Use
different frontends to distinguish the cases in preparation for fine
grained locking for cylinder groups.

Split ffs_blkalloc into a frontend that does inode based consistency
checks and a backend that just asserts them. Use the backend in
ffs_wapbl_abort_sync_metadata instead of faking an inode.

Remove XXXUBC code for ffs_reallocblks, that has been conditionalized in
2002 and #if 0'ed in 2005. It would need a considerable amount of work
to bring back and obscures the more important block allocation.

branches: 1.70.2;
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>

Add snapshot support for logging ffs file systems.

- Add UFS_WAPBL_BEGIN() / UFS_WAPBL_END() where needed.

- Expunge WAPBL log inodes from snapshots.

- Ffs_copyonwrite() and ffs_snapblkfree() must run inside a WAPBL transaction.

- Add ffs_gop_write() as a wrapper around genfs_gop_write() that makes sure
genfs_gop_write() gets always called inside a WAPBL transaction.

- Add VOP_PUTPAGES() flag PGO_JOURNALLOCKED to tag calls to VOP_PUTPAGES()
inside a WAPBL transaction.

Reviewed by: Simon Burge <simonb@netbsd.org>, Greg Oster <oster@netbsd.org>

PGO_JOURNALLOCKED / ffs_gop_write() part presented on tech-kern@.

Deny read/write access to snapshot vnodes. We use fss(4) to read from
snapshots. With this policy in place:

- Separate the snapshot vnode lock from the snapshot common lock.
Snapshots no longer need recursive vnode locks.

- Use a mutex (si_snaplock) to serialize creation, deletion, reading and
writing of snapshots.

- Move ffs_read() for snapshots into ffs_snapshot.c.

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

While here change ffs_copyonwrite() to fail requests from pagedaemon that need
to copy-on-write.

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: 1.66.2;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.65.2;
ufs/ffs: replace calls to getblk() with ffs_getblk(). Now all buffers
have been run through copy-on-write and async mounts work again.

Fixes PR kern/38820

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

branches: 1.64.2; 1.64.4; 1.64.6;
Replace get/setspecific with a void pointer in struct ufsmount. Use explicit
initialization/finalization of snapshot private data on creation/deletion
of struct ufsmount.
Snapshot mounts no longer may fail silently because kmem_alloc() fails.

Welcome to 4.99.60

Ok: Andrew Doran <ad@netbsd.org>

branches: 1.63.6;
Use pool_cache.

Merge vmlocking2 to head.

branches: 1.61.4;
Remove cn_lwp from struct componentname. curlwp should be used
from on. The NDINIT() macro no longer takes the lwp parameter and
associates the credentials of the calling thread with the namei
structure.

branches: 1.60.2; 1.60.8; 1.60.10;
Move the fstrans-aware lock vnops from ufs to ffs. Other ufs file systems
do not need them.

Ride on 4.99.28

Move snapshot per-mount data from struct ufsmount to mount specific data.
No functional changes.

Welcome to 4.99.28 (struct ufsmount changed size)

branches: 1.58.2; 1.58.4;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

branches: 1.57.2;
Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

remove a duplicated definition of FFS_ITIMES.

branches: 1.55.6; 1.55.8;
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).

branches: 1.54.4;
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: 1.53.4;
integrate kauth.

remove unused FFS_NAMES and LFS_NAMES.

branches: 1.51.2; 1.51.4; 1.51.6; 1.51.8; 1.51.10;
- unify ffs_blkatoff and lfs_blkatoff.
- remove ufs_ops::uo_blkatoff.
- add directory read-ahead code. (disabled for now.)

branches: 1.50.2;
changes for making DIAGNOSTIC not change the kernel ABI:
- for structure fields that are conditionally present,
make those fields always present.
- for functions which are conditionally inline, make them never inline.
- remove some other functions which are conditionally defined but
don't actually do anything anymore.
- make a lock-debugging function conditional on only LOCKDEBUG.

as discussed on tech-kern some time back.

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: 1.47.2;
- access the ffs and ext2fs itimes functions through a pointer, so that
if the filesystem is not compiled in the kernel still links. Probably
a better solution is to use weak symbols.
- move the filesystem-specific itime macros to the filesystem header files.

Use nanotime() to update the time fields in filesystems. Convert the code
from macros to real functions. Original patch and review from chuq.
Note: ext2fs only keeps seconds in the on-disk inode, and msdosfs does not
have enough precision for all fields, so this is not very useful for those
two.

revert the code to expand putpage requests to block boundary.
because:
- it was incomplete in some cases.
- it can confuse pagedaemon.
see PR/15364 for details.

Experimental support for extended attributes on UFS1 file systems, using a
backing file per attribute type indexed by inode number to hold the extended
attributes.

This is working pretty well on my test systems, except for the "autostart"
feature. I need someone with a better handle on the VFS locking protocol
to go over that.

This is a work-in-progress. There are parts of this that could be re-factored
allowing this approach to be used on other types of file systems.

Adapted from FreeBSD.

Use ANSI function decls.

branches: 1.42.2; 1.42.4;
nuke trailing whitespace

branches: 1.41.4; 1.41.6;
While creating a snapshot inodes must be freed from the
snapshot, not from the file system.
ffs_freefile() needs explicit "fs" and "devvp" arguments.

Need to forward-declare "struct timespec" because the new ffs_snapshot()
function declaration refers to it. Fixes build problem of sbin/badsect
for the vax target, which still uses gcc 2.95.3.

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>

Tweak sysctl setup functions (the macros, actually) for use in lkms,
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.

This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.

linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).

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

branches: 1.36.2;
Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue.

Cleanup ffs_sync() which did not synchronously wait when MNT_WAIT
was specified. Clear the work queue when MNT_WAIT is specified.

Result is a clean on-disk file system after ffs_sync(.., MNT_WAIT, ..)

From FreeBSD.

add uuid field to apple ufs volume label

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: 1.32.2;
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.

Add forward declaration of struct lwp instead of struct proc. Sort those
while I'm here.

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 support for UFS2. UFS2 is an enhanced FFS, adding support for
64 bit block pointers, extended attribute storage, and a few
other things.

This commit does not yet include the code to manipulate the extended
storage (for e.g. ACLs), this will be done later.

Originally written by Kirk McKusick and Network Associates Laboratories for
FreeBSD.

ffs_gop_alloc() is not used any more. Remove it.

OK:ed by Konrad Schroder.

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.

Bump daddr_t to 64 bits. Replace it with int32_t in all places where
it was used on-disk, so that on-disk formats remain the same.
Remove ufs_daddr_t and ufs_lbn_t for the time being.

Add multiple inclusion protection for headers. Fix mismatched
variable declarations (missing const's) as needed.

Add support for the Apple UFS variation on ffs
This is the bulk of PR #17345

The general approach is to use a run time deteriminable value
for DIRBLKSIZ. Additional allowances are included for using
MAXSYMLINKLEN with FS_42INODEFMT and a shift in the cylinder group
cluster summary count array. Support is added for managing
the Apple UFS volume label.

for softdep vnodes, always write together the pages for any block that
might have a dependency , since the accounting doesn't work otherwise.
fixes PRs 15364 16336 16448.

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.

add a new VFS op, vfs_reinit, which is called when desiredvnodes is
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.

convert various file systems to use the <sys/queue.h> macros for
their hash tables.

branches: 1.19.2;
remove third argument (`int ns') from ffs_sb_swap(), and let ffs_sb_swap()
determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.

this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).

whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.

FFS_EI should now be a lot more stable.

be consistent and use "u_char" instead of "unsigned char"

branches: 1.17.2; 1.17.6;
Initial integration of the Unified Buffer Cache project.

branches: 1.16.4;
Add a new sysctl variable vfs.ffs.log_changeopt - if this is true,
an optimalization strategy change is logged into syslog. Default
is 0 (to not log). This replaces the recent not quite "right"
change to only log the change if kernel is compiled with DEBUG.

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.

For each leaf filesystem, add appropriate vfs_done routine.

Also remember how many times ffs_init() was called and do
the appropriate initialization on first call only. In ffs_done(),
destroy the resources when called by the last user of ffs code.
Change mfs to call ffs_init()/ffs_done() appropriately.

Fixes to the softdep code from Ethan Solomita <ethan@geocast.com>.
* Fix buffer ordering when it has dependencies.
* Alleviate memory problems.
* Deal with some recursive vnode locks (sigh).
* Fix other bugs.

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

branches: 1.12.4; 1.12.8; 1.12.10; 1.12.14;
Modify vfsops to seperate vfs_fhtovp() into two routines. vfs_fhtovp() now
only handles the file handle to vnode conversion, and a new call,
vfs_checkexp(), performs the export verification.

branches: 1.11.2;
Use the pool allocator and the "nointr" pool page allocator for FFS inodes.

XXX MFS also comes in here for inodes, and used a different malloc type,
but the structure is the same, so we just use the FFS inode pool.

Always include fifos; "not an option any more".

defopt for options FIFO

Add support for reading/writing FFS in non-native byte order, conditioned
to "options FFS_EI". The superblock and inodes (without blk addr) are
byteswapped at disk read/write time, other metadatas are byteswapped
when used (as they are acceeded directly in the buffer cache).
This required the addition of a "um_flags" field to struct ufsmount.
ffs_bswap.c contains superblock and inode byteswap routines also used
by userland utilities.

Merge with Lite2 + local changes

Change the second and third args to struct vfsops' (*vfs_mount)() to
'const char *', and 'void *', respectively. The second arg is taken directly
from user arguments, and is const there, so must be const in the prototypes
and functions. The third arg is also taken directly from user arguments.
It doesn't have to be changed, but since it's cleaner to keep the type
the same as the user arg's type, and I'm already making the 'const char *'
change...

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

ffs prototypes

update for new syscall args description mechanism, and deal safely
with wider types.

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

branches: 1.1.1;
Update to 4.4-Lite fs code, with local changes.

Extended attribute support for ffsv2, from FreeBSD.

- Cleanup for dynamic sysctl:
- Remove unused *_NAMES macros for sysctl.
- Remove unused *_MAXID for sysctls.
- Move CTL_MACHDEP sysctl definitions for m68k into m68k/include/cpu.h and
use them on all m68k machines.

branches: 1.84.12; 1.84.14;

Sprinkle in a pinch of const, not too much, just enough
to add a little strength without affecting the overall balance...

branches: 1.83.2;
allocate wapbl dealloc registration structures via pool, so that there is more
flexibility with limit handling

branches: 1.82.2;
Disentangle buffer-cached I/O from page-cached I/O in UFS.

Page-cached I/O is used for regular files, and is initiated by VFS
users such as userland and NFS.

Buffer-cached I/O is used for directories and symlinks, and is issued
only internally by UFS.

New UFS routine ufs_bufio replaces vn_rdwr for internal use.
ufs_bufio is implemented by new UFS operations uo_bufrd/uo_bufwr,
which sit in ufs_readwrite.c alongside the VOP_READ/VOP_WRITE
implementations.

I preserved the code as much as possible and will leave further
simplification for future commits. I kept the ulfs_readwrite.c
copypasta close to ufs_readwrite.c in case we ever want to merge them
back; likewise ext2fs_readwrite.c.

No externally visible semantic change. All atf fs tests still pass.

Change ffs to use vcache_new:
- Change ffs_valloc to return an inode number.
- Remove now obsolete UFS operations UFS_VALLOC and UFS_VFREE.
- Make ufs_makeinode private to ufs_vnops.c and pass vattr instead of mode.

branches: 1.80.10;
Add an UFS_SNAPGONE() ufs op replacing the calls
to ffs_snapgone() in ufs_lookup.c.

Ok: David Holland <dholland@netbsd.org>

Welcome to 6.99.22

Implement experimental support to pass notifications that a file
was deleted from the filesystem to the disk driver, commonly
known as "discard" or "trim".
fs/driver support is in ffs and ata wd for now.
This is what was posted here:
http://mail-index.netbsd.org/tech-kern/2012/02/28/msg012813.html
with minor cleanup, and the global switch replaced by a mount option.

branches: 1.78.2; 1.78.12;
Add mount -o extattr option to enable extended attributs (corrently only
for UFS1).
Remove kernel option for EA backing store autocreation and do it by
default. Add a sysctl so that autocreated attriutr size can be modified.

branches: 1.77.2;
Cleanup ffs fsync and make devices on wapbl enabled file systems work here:

- Replace the ugly sync loop in ffs_full_fsync() and ffs_vfs_fsync() with
vflushbuf(). This loop is a relic of softdeps and not needed anymore.

- Add ffs_spec_fsync() for device nodes on ffs file systems that calls
spec_fsync() like all other file systems do and then updates the ctime.

Discussed on tech-kern.

Should fix PRs:
PR #41192 wapbl diagnostic panic during cgdconfig
PR #41977 kernel diagnostic assertion "rw_lock_held(&wl->wl_rwlock)" failed
PR #42149 wapbl locking panic if watching DVD
PR #42551 Lockdebug assert in wapbl when running zpool

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: 1.75.4; 1.75.6; 1.75.8;
PR kern/26878 FFSv2 + softdep = livelock (no free ram)
PR kern/16942 panic with softdep and quotas
PR kern/19565 panic: softdep_write_inodeblock: indirect pointer #1 mismatch
PR kern/26274 softdep panic: allocdirect_merge: ...
PR kern/26374 Long delay before non-root users can write to softdep partitions
PR kern/28621 1.6.x "vp != NULL" panic in ffs_softdep.c:4653 while unmounting a softdep (+quota) filesystem
PR kern/29513 FFS+Softdep panic with unfsck-able file-corruption
PR kern/31544 The ffs softdep code appears to fail to write dirty bits to disk
PR kern/31981 stopping scsi disk can cause panic (softdep)
PR kern/32116 kernel panic in softdep (assertion failure)
PR kern/32532 softdep_trackbufs deadlock
PR kern/37191 softdep: locking against myself
PR kern/40474 Kernel panic after remounting raid root with softdep

Retire softdep, pass 2. As discussed and later formally announced on the
mailing lists.

branches: 1.74.4;
Split ffs_freefile into a frontend for normal cylinder group and for
snapshot use. Adjust ffs_blkfree_common to get the fs instance passed
in, the original commit didn't account blocks in the snapshots
correctly. Assert that ffs_blkfree is used with the primary fs instance
and that ffs_checkfreefile is only used for snapshots. Move the bdwrite
from ffs_blkfree_common into the caller for symmetry. This creates a
redundant write of unmodified data for ffs_blkfree_snap if a double free
of a block happens.

Reviewed and tested by hannken@.

ffs_blkfree is used in two different ways. The normal usage is to free a
block in the cylinder groups of the filesystem. The other user is the
snapshot code, which wants to modify the copied cylinder groups. Use
different frontends to distinguish the cases in preparation for fine
grained locking for cylinder groups.

Split ffs_blkalloc into a frontend that does inode based consistency
checks and a backend that just asserts them. Use the backend in
ffs_wapbl_abort_sync_metadata instead of faking an inode.

Remove XXXUBC code for ffs_reallocblks, that has been conditionalized in
2002 and #if 0'ed in 2005. It would need a considerable amount of work
to bring back and obscures the more important block allocation.

branches: 1.70.2;
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>

Add snapshot support for logging ffs file systems.

- Add UFS_WAPBL_BEGIN() / UFS_WAPBL_END() where needed.

- Expunge WAPBL log inodes from snapshots.

- Ffs_copyonwrite() and ffs_snapblkfree() must run inside a WAPBL transaction.

- Add ffs_gop_write() as a wrapper around genfs_gop_write() that makes sure
genfs_gop_write() gets always called inside a WAPBL transaction.

- Add VOP_PUTPAGES() flag PGO_JOURNALLOCKED to tag calls to VOP_PUTPAGES()
inside a WAPBL transaction.

Reviewed by: Simon Burge <simonb@netbsd.org>, Greg Oster <oster@netbsd.org>

PGO_JOURNALLOCKED / ffs_gop_write() part presented on tech-kern@.

Deny read/write access to snapshot vnodes. We use fss(4) to read from
snapshots. With this policy in place:

- Separate the snapshot vnode lock from the snapshot common lock.
Snapshots no longer need recursive vnode locks.

- Use a mutex (si_snaplock) to serialize creation, deletion, reading and
writing of snapshots.

- Move ffs_read() for snapshots into ffs_snapshot.c.

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

While here change ffs_copyonwrite() to fail requests from pagedaemon that need
to copy-on-write.

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: 1.66.2;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.65.2;
ufs/ffs: replace calls to getblk() with ffs_getblk(). Now all buffers
have been run through copy-on-write and async mounts work again.

Fixes PR kern/38820

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

branches: 1.64.2; 1.64.4; 1.64.6;
Replace get/setspecific with a void pointer in struct ufsmount. Use explicit
initialization/finalization of snapshot private data on creation/deletion
of struct ufsmount.
Snapshot mounts no longer may fail silently because kmem_alloc() fails.

Welcome to 4.99.60

Ok: Andrew Doran <ad@netbsd.org>

branches: 1.63.6;
Use pool_cache.

Merge vmlocking2 to head.

branches: 1.61.4;
Remove cn_lwp from struct componentname. curlwp should be used
from on. The NDINIT() macro no longer takes the lwp parameter and
associates the credentials of the calling thread with the namei
structure.

branches: 1.60.2; 1.60.8; 1.60.10;
Move the fstrans-aware lock vnops from ufs to ffs. Other ufs file systems
do not need them.

Ride on 4.99.28

Move snapshot per-mount data from struct ufsmount to mount specific data.
No functional changes.

Welcome to 4.99.28 (struct ufsmount changed size)

branches: 1.58.2; 1.58.4;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

branches: 1.57.2;
Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

remove a duplicated definition of FFS_ITIMES.

branches: 1.55.6; 1.55.8;
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).

branches: 1.54.4;
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: 1.53.4;
integrate kauth.

remove unused FFS_NAMES and LFS_NAMES.

branches: 1.51.2; 1.51.4; 1.51.6; 1.51.8; 1.51.10;
- unify ffs_blkatoff and lfs_blkatoff.
- remove ufs_ops::uo_blkatoff.
- add directory read-ahead code. (disabled for now.)

branches: 1.50.2;
changes for making DIAGNOSTIC not change the kernel ABI:
- for structure fields that are conditionally present,
make those fields always present.
- for functions which are conditionally inline, make them never inline.
- remove some other functions which are conditionally defined but
don't actually do anything anymore.
- make a lock-debugging function conditional on only LOCKDEBUG.

as discussed on tech-kern some time back.

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: 1.47.2;
- access the ffs and ext2fs itimes functions through a pointer, so that
if the filesystem is not compiled in the kernel still links. Probably
a better solution is to use weak symbols.
- move the filesystem-specific itime macros to the filesystem header files.

Use nanotime() to update the time fields in filesystems. Convert the code
from macros to real functions. Original patch and review from chuq.
Note: ext2fs only keeps seconds in the on-disk inode, and msdosfs does not
have enough precision for all fields, so this is not very useful for those
two.

revert the code to expand putpage requests to block boundary.
because:
- it was incomplete in some cases.
- it can confuse pagedaemon.
see PR/15364 for details.

Experimental support for extended attributes on UFS1 file systems, using a
backing file per attribute type indexed by inode number to hold the extended
attributes.

This is working pretty well on my test systems, except for the "autostart"
feature. I need someone with a better handle on the VFS locking protocol
to go over that.

This is a work-in-progress. There are parts of this that could be re-factored
allowing this approach to be used on other types of file systems.

Adapted from FreeBSD.

Use ANSI function decls.

branches: 1.42.2; 1.42.4;
nuke trailing whitespace

branches: 1.41.4; 1.41.6;
While creating a snapshot inodes must be freed from the
snapshot, not from the file system.
ffs_freefile() needs explicit "fs" and "devvp" arguments.

Need to forward-declare "struct timespec" because the new ffs_snapshot()
function declaration refers to it. Fixes build problem of sbin/badsect
for the vax target, which still uses gcc 2.95.3.

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>

Tweak sysctl setup functions (the macros, actually) for use in lkms,
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.

This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.

linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).

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

branches: 1.36.2;
Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue.

Cleanup ffs_sync() which did not synchronously wait when MNT_WAIT
was specified. Clear the work queue when MNT_WAIT is specified.

Result is a clean on-disk file system after ffs_sync(.., MNT_WAIT, ..)

From FreeBSD.

add uuid field to apple ufs volume label

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: 1.32.2;
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.

Add forward declaration of struct lwp instead of struct proc. Sort those
while I'm here.

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 support for UFS2. UFS2 is an enhanced FFS, adding support for
64 bit block pointers, extended attribute storage, and a few
other things.

This commit does not yet include the code to manipulate the extended
storage (for e.g. ACLs), this will be done later.

Originally written by Kirk McKusick and Network Associates Laboratories for
FreeBSD.

ffs_gop_alloc() is not used any more. Remove it.

OK:ed by Konrad Schroder.

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.

Bump daddr_t to 64 bits. Replace it with int32_t in all places where
it was used on-disk, so that on-disk formats remain the same.
Remove ufs_daddr_t and ufs_lbn_t for the time being.

Add multiple inclusion protection for headers. Fix mismatched
variable declarations (missing const's) as needed.

Add support for the Apple UFS variation on ffs
This is the bulk of PR #17345

The general approach is to use a run time deteriminable value
for DIRBLKSIZ. Additional allowances are included for using
MAXSYMLINKLEN with FS_42INODEFMT and a shift in the cylinder group
cluster summary count array. Support is added for managing
the Apple UFS volume label.

for softdep vnodes, always write together the pages for any block that
might have a dependency , since the accounting doesn't work otherwise.
fixes PRs 15364 16336 16448.

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.

add a new VFS op, vfs_reinit, which is called when desiredvnodes is
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.

convert various file systems to use the <sys/queue.h> macros for
their hash tables.

branches: 1.19.2;
remove third argument (`int ns') from ffs_sb_swap(), and let ffs_sb_swap()
determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.

this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).

whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.

FFS_EI should now be a lot more stable.

be consistent and use "u_char" instead of "unsigned char"

branches: 1.17.2; 1.17.6;
Initial integration of the Unified Buffer Cache project.

branches: 1.16.4;
Add a new sysctl variable vfs.ffs.log_changeopt - if this is true,
an optimalization strategy change is logged into syslog. Default
is 0 (to not log). This replaces the recent not quite "right"
change to only log the change if kernel is compiled with DEBUG.

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.

For each leaf filesystem, add appropriate vfs_done routine.

Also remember how many times ffs_init() was called and do
the appropriate initialization on first call only. In ffs_done(),
destroy the resources when called by the last user of ffs code.
Change mfs to call ffs_init()/ffs_done() appropriately.

Fixes to the softdep code from Ethan Solomita <ethan@geocast.com>.
* Fix buffer ordering when it has dependencies.
* Alleviate memory problems.
* Deal with some recursive vnode locks (sigh).
* Fix other bugs.

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

branches: 1.12.4; 1.12.8; 1.12.10; 1.12.14;
Modify vfsops to seperate vfs_fhtovp() into two routines. vfs_fhtovp() now
only handles the file handle to vnode conversion, and a new call,
vfs_checkexp(), performs the export verification.

branches: 1.11.2;
Use the pool allocator and the "nointr" pool page allocator for FFS inodes.

XXX MFS also comes in here for inodes, and used a different malloc type,
but the structure is the same, so we just use the FFS inode pool.

Always include fifos; "not an option any more".

defopt for options FIFO

Add support for reading/writing FFS in non-native byte order, conditioned
to "options FFS_EI". The superblock and inodes (without blk addr) are
byteswapped at disk read/write time, other metadatas are byteswapped
when used (as they are acceeded directly in the buffer cache).
This required the addition of a "um_flags" field to struct ufsmount.
ffs_bswap.c contains superblock and inode byteswap routines also used
by userland utilities.

Merge with Lite2 + local changes

Change the second and third args to struct vfsops' (*vfs_mount)() to
'const char *', and 'void *', respectively. The second arg is taken directly
from user arguments, and is const there, so must be const in the prototypes
and functions. The third arg is also taken directly from user arguments.
It doesn't have to be changed, but since it's cleaner to keep the type
the same as the user arg's type, and I'm already making the 'const char *'
change...

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

ffs prototypes

update for new syscall args description mechanism, and deal safely
with wider types.

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

branches: 1.1.1;
Update to 4.4-Lite fs code, with local changes.

- Cleanup for dynamic sysctl:
- Remove unused *_NAMES macros for sysctl.
- Remove unused *_MAXID for sysctls.
- Move CTL_MACHDEP sysctl definitions for m68k into m68k/include/cpu.h and
use them on all m68k machines.

branches: 1.84.12;

Sprinkle in a pinch of const, not too much, just enough
to add a little strength without affecting the overall balance...

branches: 1.83.2;
allocate wapbl dealloc registration structures via pool, so that there is more
flexibility with limit handling

branches: 1.82.2;
Disentangle buffer-cached I/O from page-cached I/O in UFS.

Page-cached I/O is used for regular files, and is initiated by VFS
users such as userland and NFS.

Buffer-cached I/O is used for directories and symlinks, and is issued
only internally by UFS.

New UFS routine ufs_bufio replaces vn_rdwr for internal use.
ufs_bufio is implemented by new UFS operations uo_bufrd/uo_bufwr,
which sit in ufs_readwrite.c alongside the VOP_READ/VOP_WRITE
implementations.

I preserved the code as much as possible and will leave further
simplification for future commits. I kept the ulfs_readwrite.c
copypasta close to ufs_readwrite.c in case we ever want to merge them
back; likewise ext2fs_readwrite.c.

No externally visible semantic change. All atf fs tests still pass.

Change ffs to use vcache_new:
- Change ffs_valloc to return an inode number.
- Remove now obsolete UFS operations UFS_VALLOC and UFS_VFREE.
- Make ufs_makeinode private to ufs_vnops.c and pass vattr instead of mode.

branches: 1.80.10;
Add an UFS_SNAPGONE() ufs op replacing the calls
to ffs_snapgone() in ufs_lookup.c.

Ok: David Holland <dholland@netbsd.org>

Welcome to 6.99.22

Implement experimental support to pass notifications that a file
was deleted from the filesystem to the disk driver, commonly
known as "discard" or "trim".
fs/driver support is in ffs and ata wd for now.
This is what was posted here:
http://mail-index.netbsd.org/tech-kern/2012/02/28/msg012813.html
with minor cleanup, and the global switch replaced by a mount option.

branches: 1.78.2; 1.78.12;
Add mount -o extattr option to enable extended attributs (corrently only
for UFS1).
Remove kernel option for EA backing store autocreation and do it by
default. Add a sysctl so that autocreated attriutr size can be modified.

branches: 1.77.2;
Cleanup ffs fsync and make devices on wapbl enabled file systems work here:

- Replace the ugly sync loop in ffs_full_fsync() and ffs_vfs_fsync() with
vflushbuf(). This loop is a relic of softdeps and not needed anymore.

- Add ffs_spec_fsync() for device nodes on ffs file systems that calls
spec_fsync() like all other file systems do and then updates the ctime.

Discussed on tech-kern.

Should fix PRs:
PR #41192 wapbl diagnostic panic during cgdconfig
PR #41977 kernel diagnostic assertion "rw_lock_held(&wl->wl_rwlock)" failed
PR #42149 wapbl locking panic if watching DVD
PR #42551 Lockdebug assert in wapbl when running zpool

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: 1.75.4; 1.75.6; 1.75.8;
PR kern/26878 FFSv2 + softdep = livelock (no free ram)
PR kern/16942 panic with softdep and quotas
PR kern/19565 panic: softdep_write_inodeblock: indirect pointer #1 mismatch
PR kern/26274 softdep panic: allocdirect_merge: ...
PR kern/26374 Long delay before non-root users can write to softdep partitions
PR kern/28621 1.6.x "vp != NULL" panic in ffs_softdep.c:4653 while unmounting a softdep (+quota) filesystem
PR kern/29513 FFS+Softdep panic with unfsck-able file-corruption
PR kern/31544 The ffs softdep code appears to fail to write dirty bits to disk
PR kern/31981 stopping scsi disk can cause panic (softdep)
PR kern/32116 kernel panic in softdep (assertion failure)
PR kern/32532 softdep_trackbufs deadlock
PR kern/37191 softdep: locking against myself
PR kern/40474 Kernel panic after remounting raid root with softdep

Retire softdep, pass 2. As discussed and later formally announced on the
mailing lists.

branches: 1.74.4;
Split ffs_freefile into a frontend for normal cylinder group and for
snapshot use. Adjust ffs_blkfree_common to get the fs instance passed
in, the original commit didn't account blocks in the snapshots
correctly. Assert that ffs_blkfree is used with the primary fs instance
and that ffs_checkfreefile is only used for snapshots. Move the bdwrite
from ffs_blkfree_common into the caller for symmetry. This creates a
redundant write of unmodified data for ffs_blkfree_snap if a double free
of a block happens.

Reviewed and tested by hannken@.

ffs_blkfree is used in two different ways. The normal usage is to free a
block in the cylinder groups of the filesystem. The other user is the
snapshot code, which wants to modify the copied cylinder groups. Use
different frontends to distinguish the cases in preparation for fine
grained locking for cylinder groups.

Split ffs_blkalloc into a frontend that does inode based consistency
checks and a backend that just asserts them. Use the backend in
ffs_wapbl_abort_sync_metadata instead of faking an inode.

Remove XXXUBC code for ffs_reallocblks, that has been conditionalized in
2002 and #if 0'ed in 2005. It would need a considerable amount of work
to bring back and obscures the more important block allocation.

branches: 1.70.2;
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>

Add snapshot support for logging ffs file systems.

- Add UFS_WAPBL_BEGIN() / UFS_WAPBL_END() where needed.

- Expunge WAPBL log inodes from snapshots.

- Ffs_copyonwrite() and ffs_snapblkfree() must run inside a WAPBL transaction.

- Add ffs_gop_write() as a wrapper around genfs_gop_write() that makes sure
genfs_gop_write() gets always called inside a WAPBL transaction.

- Add VOP_PUTPAGES() flag PGO_JOURNALLOCKED to tag calls to VOP_PUTPAGES()
inside a WAPBL transaction.

Reviewed by: Simon Burge <simonb@netbsd.org>, Greg Oster <oster@netbsd.org>

PGO_JOURNALLOCKED / ffs_gop_write() part presented on tech-kern@.

Deny read/write access to snapshot vnodes. We use fss(4) to read from
snapshots. With this policy in place:

- Separate the snapshot vnode lock from the snapshot common lock.
Snapshots no longer need recursive vnode locks.

- Use a mutex (si_snaplock) to serialize creation, deletion, reading and
writing of snapshots.

- Move ffs_read() for snapshots into ffs_snapshot.c.

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

While here change ffs_copyonwrite() to fail requests from pagedaemon that need
to copy-on-write.

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: 1.66.2;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.65.2;
ufs/ffs: replace calls to getblk() with ffs_getblk(). Now all buffers
have been run through copy-on-write and async mounts work again.

Fixes PR kern/38820

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

branches: 1.64.2; 1.64.4; 1.64.6;
Replace get/setspecific with a void pointer in struct ufsmount. Use explicit
initialization/finalization of snapshot private data on creation/deletion
of struct ufsmount.
Snapshot mounts no longer may fail silently because kmem_alloc() fails.

Welcome to 4.99.60

Ok: Andrew Doran <ad@netbsd.org>

branches: 1.63.6;
Use pool_cache.

Merge vmlocking2 to head.

branches: 1.61.4;
Remove cn_lwp from struct componentname. curlwp should be used
from on. The NDINIT() macro no longer takes the lwp parameter and
associates the credentials of the calling thread with the namei
structure.

branches: 1.60.2; 1.60.8; 1.60.10;
Move the fstrans-aware lock vnops from ufs to ffs. Other ufs file systems
do not need them.

Ride on 4.99.28

Move snapshot per-mount data from struct ufsmount to mount specific data.
No functional changes.

Welcome to 4.99.28 (struct ufsmount changed size)

branches: 1.58.2; 1.58.4;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

branches: 1.57.2;
Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

remove a duplicated definition of FFS_ITIMES.

branches: 1.55.6; 1.55.8;
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).

branches: 1.54.4;
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: 1.53.4;
integrate kauth.

remove unused FFS_NAMES and LFS_NAMES.

branches: 1.51.2; 1.51.4; 1.51.6; 1.51.8; 1.51.10;
- unify ffs_blkatoff and lfs_blkatoff.
- remove ufs_ops::uo_blkatoff.
- add directory read-ahead code. (disabled for now.)

branches: 1.50.2;
changes for making DIAGNOSTIC not change the kernel ABI:
- for structure fields that are conditionally present,
make those fields always present.
- for functions which are conditionally inline, make them never inline.
- remove some other functions which are conditionally defined but
don't actually do anything anymore.
- make a lock-debugging function conditional on only LOCKDEBUG.

as discussed on tech-kern some time back.

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: 1.47.2;
- access the ffs and ext2fs itimes functions through a pointer, so that
if the filesystem is not compiled in the kernel still links. Probably
a better solution is to use weak symbols.
- move the filesystem-specific itime macros to the filesystem header files.

Use nanotime() to update the time fields in filesystems. Convert the code
from macros to real functions. Original patch and review from chuq.
Note: ext2fs only keeps seconds in the on-disk inode, and msdosfs does not
have enough precision for all fields, so this is not very useful for those
two.

revert the code to expand putpage requests to block boundary.
because:
- it was incomplete in some cases.
- it can confuse pagedaemon.
see PR/15364 for details.

Experimental support for extended attributes on UFS1 file systems, using a
backing file per attribute type indexed by inode number to hold the extended
attributes.

This is working pretty well on my test systems, except for the "autostart"
feature. I need someone with a better handle on the VFS locking protocol
to go over that.

This is a work-in-progress. There are parts of this that could be re-factored
allowing this approach to be used on other types of file systems.

Adapted from FreeBSD.

Use ANSI function decls.

branches: 1.42.2; 1.42.4;
nuke trailing whitespace

branches: 1.41.4; 1.41.6;
While creating a snapshot inodes must be freed from the
snapshot, not from the file system.
ffs_freefile() needs explicit "fs" and "devvp" arguments.

Need to forward-declare "struct timespec" because the new ffs_snapshot()
function declaration refers to it. Fixes build problem of sbin/badsect
for the vax target, which still uses gcc 2.95.3.

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>

Tweak sysctl setup functions (the macros, actually) for use in lkms,
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.

This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.

linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).

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

branches: 1.36.2;
Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue.

Cleanup ffs_sync() which did not synchronously wait when MNT_WAIT
was specified. Clear the work queue when MNT_WAIT is specified.

Result is a clean on-disk file system after ffs_sync(.., MNT_WAIT, ..)

From FreeBSD.

add uuid field to apple ufs volume label

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: 1.32.2;
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.

Add forward declaration of struct lwp instead of struct proc. Sort those
while I'm here.

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 support for UFS2. UFS2 is an enhanced FFS, adding support for
64 bit block pointers, extended attribute storage, and a few
other things.

This commit does not yet include the code to manipulate the extended
storage (for e.g. ACLs), this will be done later.

Originally written by Kirk McKusick and Network Associates Laboratories for
FreeBSD.

ffs_gop_alloc() is not used any more. Remove it.

OK:ed by Konrad Schroder.

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.

Bump daddr_t to 64 bits. Replace it with int32_t in all places where
it was used on-disk, so that on-disk formats remain the same.
Remove ufs_daddr_t and ufs_lbn_t for the time being.

Add multiple inclusion protection for headers. Fix mismatched
variable declarations (missing const's) as needed.

Add support for the Apple UFS variation on ffs
This is the bulk of PR #17345

The general approach is to use a run time deteriminable value
for DIRBLKSIZ. Additional allowances are included for using
MAXSYMLINKLEN with FS_42INODEFMT and a shift in the cylinder group
cluster summary count array. Support is added for managing
the Apple UFS volume label.

for softdep vnodes, always write together the pages for any block that
might have a dependency , since the accounting doesn't work otherwise.
fixes PRs 15364 16336 16448.

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.

add a new VFS op, vfs_reinit, which is called when desiredvnodes is
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.

convert various file systems to use the <sys/queue.h> macros for
their hash tables.

branches: 1.19.2;
remove third argument (`int ns') from ffs_sb_swap(), and let ffs_sb_swap()
determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.

this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).

whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.

FFS_EI should now be a lot more stable.

be consistent and use "u_char" instead of "unsigned char"

branches: 1.17.2; 1.17.6;
Initial integration of the Unified Buffer Cache project.

branches: 1.16.4;
Add a new sysctl variable vfs.ffs.log_changeopt - if this is true,
an optimalization strategy change is logged into syslog. Default
is 0 (to not log). This replaces the recent not quite "right"
change to only log the change if kernel is compiled with DEBUG.

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.

For each leaf filesystem, add appropriate vfs_done routine.

Also remember how many times ffs_init() was called and do
the appropriate initialization on first call only. In ffs_done(),
destroy the resources when called by the last user of ffs code.
Change mfs to call ffs_init()/ffs_done() appropriately.

Fixes to the softdep code from Ethan Solomita <ethan@geocast.com>.
* Fix buffer ordering when it has dependencies.
* Alleviate memory problems.
* Deal with some recursive vnode locks (sigh).
* Fix other bugs.

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

branches: 1.12.4; 1.12.8; 1.12.10; 1.12.14;
Modify vfsops to seperate vfs_fhtovp() into two routines. vfs_fhtovp() now
only handles the file handle to vnode conversion, and a new call,
vfs_checkexp(), performs the export verification.

branches: 1.11.2;
Use the pool allocator and the "nointr" pool page allocator for FFS inodes.

XXX MFS also comes in here for inodes, and used a different malloc type,
but the structure is the same, so we just use the FFS inode pool.

Always include fifos; "not an option any more".

defopt for options FIFO

Add support for reading/writing FFS in non-native byte order, conditioned
to "options FFS_EI". The superblock and inodes (without blk addr) are
byteswapped at disk read/write time, other metadatas are byteswapped
when used (as they are acceeded directly in the buffer cache).
This required the addition of a "um_flags" field to struct ufsmount.
ffs_bswap.c contains superblock and inode byteswap routines also used
by userland utilities.

Merge with Lite2 + local changes