ext2fs: Nix trailing whitespace.

don't assign struct pointers to smaller then structure regions of memory.

in all cases here, the later parts of the structure are not actually
accessed, so there are no existing bugs here beyond general UB. for the
ufs ones, this also removes some casts.

found by GCC 12.

s/blity/bility/ in various words, mainly in comments.

Add ACL support for FFS. From FreeBSD.

Merge the remaining changes from the ad-namecache branch, affecting namei()
and getcwd():

- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.

Possible future enhancements:

- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.

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

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

branches: 1.88.16; 1.88.22;
KNF, no functional change

fix bug introduced in rev 1.82 of ext2fs_lookup.c, when ext2fs_add_entry()
was introduced splitting code from ext2fs_direnter() - code used
incorrect new entry size, leading to incomplete entry copy or buffer
overflow; fixed by passing the right size from ext2fs_direnter()

when converting on-disk direntry, only use the on-disk filetype if the feature flag is present

switch code to use the EXT2_HAS_{COMPAT|ROCOMPAT|INCOMPAT}_FEATURE() macros instead of open coding the checks

KNF, no functional changes...

sync with hrishi's git

merge missing function.

actually pass the d_type from the on-disk directory entry to the lookup results

GSoC 2016 (Hrishikesh Goyal): Htree index support from FreeBSD

Use buffer cache, not page cache, to expand directories in ext2fs.

Candidate fix for PR kern/50607, PR port-evbmips/50059.

Formerly VOP_WRITE-->ext2fs_write would automatically dispatch to
this code path for writes to directories, but I broke that in
ext2fs_lookup.c rev. 1.78 when disentangling page-cached and
buffer-cached writes.

This was not a problem in ufs, and I didn't notice it in ext2fs,
because ufs consistently used buffercache(9) directly instead of
using VOP_WRITE sometimes as ext2fs did.

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.

branches: 1.77.4;
Introduce two helper functions to centralise the namecache statistics
in vfs_cache.c. Use consistent locking around the per-cpu data.

Remove ext2fs_checkpath(). It is a relic from the pre-genfs_rename era.

Add a global vnode cache:

- vcache_get() retrieves a referenced and initialised vnode / fs node pair.
- vcache_remove() removes a vnode / fs node pair from the cache.

On cache miss vcache_get() calls new vfs operation vfs_loadvnode() to
initialise a vnode / fs node pair. This call is guaranteed exclusive,
no other thread will try to load this vnode / fs node pair.

Convert ufs/ext2fs, ufs/ffs and ufs/mfs to use this interface.

Remove now unused ufs/ufs_ihash

Discussed on tech-kern.

Welcome to 6.99.41

branches: 1.74.2;
Change vnode operation lookup to return the resulting vnode *vpp unlocked.
Change cache_lookup() to return an unlocked vnode.

Discussed on tech-kern@

Welcome to 6.99.31

branches: 1.73.2;
Stuff UFS_ in front of a few of ufs's symbols to reduce namespace
pollution. Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN -> UFS_MAXSYMLINKLEN
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Sort out ext2fs's misuse of NDADDR and NIADDR; fortunately, these have
the same values in ext2fs and ffs.

No functional change intended.

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

Disentangle the namecache from the internals of namei.

- Move the namecache's hash computation to inside the namecache code,
instead of being spread out all over the place. Remove cn_hash from
struct componentname and delete all uses of it.

- It is no longer necessary (if it ever was) for cache_lookup and
cache_lookup_raw to clear MAKEENTRY from cnp->cn_flags for the cases
that cache_enter already checks for.

- Rearrange the interface of cache_lookup (and cache_lookup_raw) to
make it somewhat simpler, to exclude certain nonexistent error
conditions, and (most importantly) to make it not require write access
to cnp->cn_flags.

This change requires a kernel bump.

branches: 1.70.2;
Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Fix last commit that broke lookup for dot with op DELETE.

Reviewed by: David Holland <dholland@netbsd.org>

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

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

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

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

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

branches: 1.67.2;
converting readdir in ffs ext2fs from malloc(9) to kmem(9)
while there allocate ufs mount structs from kmem(9) too
preceding kmem-vmem-pool-patch

releng@ acknowledged

branches: 1.66.2; 1.66.6;
Pass the ufs_lookup_results pointer around instead of fetching it from
the inode in the guts of ufs. Now, in VOPs where i_crap is used it is
used (directly) only immediately on entry to the VOP call and then
passed around by reference.

Except for rename, which needs explicit sorting out. The code in
ufs_wapbl_rename is unchanged in behavior but I'm increasingly
inclined to think it's wrong.

Currently, ufs_lookup produces five auxiliary results that are left in
the vnode when lookup returns and fished out again later.

1. Create struct ufs_lookup_results to hold these.

2. Call the ufs_lookup_results instance in struct inode "i_crap" to be
clear about exactly what's going on, and to distinguish the lookup
results from respectable members of struct inode.

3. Update references to these members in the directory access
subroutines.

4. Include preliminary infrastructure for checking that the i_crap
being used is still valid when it's used. This doesn't actually do
anything yet.

5. Update the way ufs_wapbl_rename manipulates these elements to use
the new data structures. I have not changed the manipulation; it may
or may not be correct but I continue to suspect that it is not.

The word of the day is "stigmergy".

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

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

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

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

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.61.2; 1.61.4;
The VATTR_NULL/VREF/VHOLD/HOLDRELE() macros lost their will to live
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.

no functional change

Whitespace nits.

Migrate from u_intNN_t to uintNN_t.

kill MALLOC and FREE macros.

Remove an extra semicolon.

add support for 32 bit uid/gid fields in ext2, but only do so for
when the revision is > REV0.

branches: 1.55.12; 1.55.16; 1.55.22; 1.55.24; 1.55.26;
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: 1.54.2;
Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.53.4;
Merge ffs locking & brelse changes from the vmlocking branch.

Avoid stack allocation of large dirent structures in foo_readdir().

branches: 1.51.4; 1.51.6; 1.51.8; 1.51.10;
Don't depend on uvm_extern.h pulling in proc.h.

branches: 1.50.2; 1.50.10;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.49.2;
Merge newlock2 to head.

Consistent usage of KAUTH_GENERIC_ISSUSER.

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

branches: 1.46.2;
__unused removal on arguments; approved by core.

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

branches: 1.44.8; 1.44.10;
integrate kauth.

Coverity CID 1169: Add KASSERT before deref.

Remove dead code, fixing coverity ID 745. nameiop can only be CREATE
or DELETE here. This code got cut-n-pasted from ufs_loolup.c, but
is only used in whiteout support. ext2fs doesn't support whiteout.

don't use MALLOC with a non-constant size; use malloc instead.

branches: 1.40.2; 1.40.4; 1.40.6;
merge yamt-uio_vmspace branch.

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

branches: 1.39.2; 1.39.4; 1.39.6;
merge ktrace-lwp.

branches: 1.38.2;
merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.37.2;
* Remove __P()
* Use ANSI function declarations on ext2fs and mfs

Don't overload MAXNAMLEN, use a separate constant for each filesystem type.

64 bit inode changes.

branches: 1.34.2;
Ensure that we change the size of the vnode at the same time as
we change the size of the inode, and use ext2fs_size uniformly.
This fixes a crash that occurs when I create a directory, then
move it, all on an ext2 filesystem.

- sprinkle const
- avoid shadow variables.

nuke trailing whitespace

Add support for large files (>2GB).
Like Linux, automagically convert old filesystem to use this,
if they are already at revision 1.
For revision 0, just punt (unlike Linux; makes me a bit too nervous.)

There should be an option to fsck_ext2fs to upgrade revision 0 to revision 1.

Reviewd by Manuel (bouyer@).

branches: 1.30.4; 1.30.6;
There's no need to pass a proc value when using UIO_SYSSPACE with
vn_rdwr(9) and uiomove(9).

OK'd by Jason Thorpe

Fixing age old cruft:
* Rather than using mnt_maxsymlinklen to indicate that a file systems returns
d_type fields(!), add a new internal flag, IMNT_DTYPE.

Add 3 new elements to ufsmount:
* um_maxsymlinklen, replaces mnt_maxsymlinklen (which never should have existed
in the first place).
* um_dirblksiz, which tracks the current directory block size, eliminating the
FS-specific checks littered throughout the code. This may be used later to
make the block size variable.
* um_maxfilesize, which is the maximum file size, possibly adjusted lower due
to implementation issues.

Sync some bug fixes from FFS into ext2fs, particularly:
* ffs_lookup.c 1.21, 1.28, 1.33, 1.48
* ffs_inode.c 1.43, 1.44, 1.45, 1.66, 1.67
* ffs_vnops.c 1.84, 1.85, 1.86

Clean up some crappy pointer frobnication.

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

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

branches: 1.27.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

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

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

Bump the kernel rev up to 1.6V

Add 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.

eliminate i_ino from in-core inode
and use local variable instead.

ok'ed by Frank van der Linden.

Avoid strict-alias warnings.

remove trailing \n in panic(). approved perry.

Spell '[Rr]ight' correctly. From Jim Bernard.

#if 0 a test that is always false (and the XXX comment above it
indicates so).

branches: 1.18.8; 1.18.10;
add RCSID

remove #include <ufs/ufs/quota.h> where it was just to appease
<ufs/ufs/inode.h>, since the latter now includes the former. leave the former
in source that obviously uses specific bits of it (for completeness.)

branches: 1.16.2; 1.16.6; 1.16.10;
MALLOC()/FREE() are not to be used for variable sized allocations.

Remove register declarations.

Correct (minor) bogons in filetype option support, and add support
for sparse_super option

First cut at ext2fs rev 1 support (as of mke2fs 1.18): supports the filetype
option read/write and the sparse option read-only.

branches: 1.12.2;
Adapt to cache_lookup() changes.

Tested by: jdolecek
Rewieved by: wrstuden

Pull in changes which parallel rev 1.22 -> 1.25 of ufs_lookup().

Add PDIRUNLOCK support.

branches: 1.9.4;
- intentation
- sync LK_* flags with ffs/ufs

Fix copyright '\t' -> ' '

bzero->memset, bcopy->memcpy, bcmp->memcmp

fix to accomodate change in vn_rdwr prototype

Merge with Lite2 + local changes

Update for 64 bits directory cookies.

Add byte-swapping functions (bswap16, bswap32, bswap64) to libkern.
Only assembly version for i386 bswap16 and bswap32 for now (bswap64 uses
bswap32). Contribution of assembly versions of these are welcome.
Add byte-swapping of ext2fs metadata for big-endian systems.
Tested on i386 and sparc.

Fix bad cut&paste from ufs code: we can't align uio_resid to a directory
block size boundary, because size of the returned dir entry may be bigger than
the one read.

branches: 1.1.4;
The ext2fs layer, based on the ffs/ufs one. Uses a few functions from
sys/ufs/ufs/

don't assign struct pointers to smaller then structure regions of memory.

in all cases here, the later parts of the structure are not actually
accessed, so there are no existing bugs here beyond general UB. for the
ufs ones, this also removes some casts.

found by GCC 12.

s/blity/bility/ in various words, mainly in comments.

Add ACL support for FFS. From FreeBSD.

Merge the remaining changes from the ad-namecache branch, affecting namei()
and getcwd():

- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.

Possible future enhancements:

- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.

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

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

branches: 1.88.16; 1.88.22;
KNF, no functional change

fix bug introduced in rev 1.82 of ext2fs_lookup.c, when ext2fs_add_entry()
was introduced splitting code from ext2fs_direnter() - code used
incorrect new entry size, leading to incomplete entry copy or buffer
overflow; fixed by passing the right size from ext2fs_direnter()

when converting on-disk direntry, only use the on-disk filetype if the feature flag is present

switch code to use the EXT2_HAS_{COMPAT|ROCOMPAT|INCOMPAT}_FEATURE() macros instead of open coding the checks

KNF, no functional changes...

sync with hrishi's git

merge missing function.

actually pass the d_type from the on-disk directory entry to the lookup results

GSoC 2016 (Hrishikesh Goyal): Htree index support from FreeBSD

Use buffer cache, not page cache, to expand directories in ext2fs.

Candidate fix for PR kern/50607, PR port-evbmips/50059.

Formerly VOP_WRITE-->ext2fs_write would automatically dispatch to
this code path for writes to directories, but I broke that in
ext2fs_lookup.c rev. 1.78 when disentangling page-cached and
buffer-cached writes.

This was not a problem in ufs, and I didn't notice it in ext2fs,
because ufs consistently used buffercache(9) directly instead of
using VOP_WRITE sometimes as ext2fs did.

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.

branches: 1.77.4;
Introduce two helper functions to centralise the namecache statistics
in vfs_cache.c. Use consistent locking around the per-cpu data.

Remove ext2fs_checkpath(). It is a relic from the pre-genfs_rename era.

Add a global vnode cache:

- vcache_get() retrieves a referenced and initialised vnode / fs node pair.
- vcache_remove() removes a vnode / fs node pair from the cache.

On cache miss vcache_get() calls new vfs operation vfs_loadvnode() to
initialise a vnode / fs node pair. This call is guaranteed exclusive,
no other thread will try to load this vnode / fs node pair.

Convert ufs/ext2fs, ufs/ffs and ufs/mfs to use this interface.

Remove now unused ufs/ufs_ihash

Discussed on tech-kern.

Welcome to 6.99.41

branches: 1.74.2;
Change vnode operation lookup to return the resulting vnode *vpp unlocked.
Change cache_lookup() to return an unlocked vnode.

Discussed on tech-kern@

Welcome to 6.99.31

branches: 1.73.2;
Stuff UFS_ in front of a few of ufs's symbols to reduce namespace
pollution. Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN -> UFS_MAXSYMLINKLEN
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Sort out ext2fs's misuse of NDADDR and NIADDR; fortunately, these have
the same values in ext2fs and ffs.

No functional change intended.

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

Disentangle the namecache from the internals of namei.

- Move the namecache's hash computation to inside the namecache code,
instead of being spread out all over the place. Remove cn_hash from
struct componentname and delete all uses of it.

- It is no longer necessary (if it ever was) for cache_lookup and
cache_lookup_raw to clear MAKEENTRY from cnp->cn_flags for the cases
that cache_enter already checks for.

- Rearrange the interface of cache_lookup (and cache_lookup_raw) to
make it somewhat simpler, to exclude certain nonexistent error
conditions, and (most importantly) to make it not require write access
to cnp->cn_flags.

This change requires a kernel bump.

branches: 1.70.2;
Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Fix last commit that broke lookup for dot with op DELETE.

Reviewed by: David Holland <dholland@netbsd.org>

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

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

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

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

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

branches: 1.67.2;
converting readdir in ffs ext2fs from malloc(9) to kmem(9)
while there allocate ufs mount structs from kmem(9) too
preceding kmem-vmem-pool-patch

releng@ acknowledged

branches: 1.66.2; 1.66.6;
Pass the ufs_lookup_results pointer around instead of fetching it from
the inode in the guts of ufs. Now, in VOPs where i_crap is used it is
used (directly) only immediately on entry to the VOP call and then
passed around by reference.

Except for rename, which needs explicit sorting out. The code in
ufs_wapbl_rename is unchanged in behavior but I'm increasingly
inclined to think it's wrong.

Currently, ufs_lookup produces five auxiliary results that are left in
the vnode when lookup returns and fished out again later.

1. Create struct ufs_lookup_results to hold these.

2. Call the ufs_lookup_results instance in struct inode "i_crap" to be
clear about exactly what's going on, and to distinguish the lookup
results from respectable members of struct inode.

3. Update references to these members in the directory access
subroutines.

4. Include preliminary infrastructure for checking that the i_crap
being used is still valid when it's used. This doesn't actually do
anything yet.

5. Update the way ufs_wapbl_rename manipulates these elements to use
the new data structures. I have not changed the manipulation; it may
or may not be correct but I continue to suspect that it is not.

The word of the day is "stigmergy".

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

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

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

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

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.61.2; 1.61.4;
The VATTR_NULL/VREF/VHOLD/HOLDRELE() macros lost their will to live
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.

no functional change

Whitespace nits.

Migrate from u_intNN_t to uintNN_t.

kill MALLOC and FREE macros.

Remove an extra semicolon.

add support for 32 bit uid/gid fields in ext2, but only do so for
when the revision is > REV0.

branches: 1.55.12; 1.55.16; 1.55.22; 1.55.24; 1.55.26;
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: 1.54.2;
Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.53.4;
Merge ffs locking & brelse changes from the vmlocking branch.

Avoid stack allocation of large dirent structures in foo_readdir().

branches: 1.51.4; 1.51.6; 1.51.8; 1.51.10;
Don't depend on uvm_extern.h pulling in proc.h.

branches: 1.50.2; 1.50.10;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.49.2;
Merge newlock2 to head.

Consistent usage of KAUTH_GENERIC_ISSUSER.

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

branches: 1.46.2;
__unused removal on arguments; approved by core.

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

branches: 1.44.8; 1.44.10;
integrate kauth.

Coverity CID 1169: Add KASSERT before deref.

Remove dead code, fixing coverity ID 745. nameiop can only be CREATE
or DELETE here. This code got cut-n-pasted from ufs_loolup.c, but
is only used in whiteout support. ext2fs doesn't support whiteout.

don't use MALLOC with a non-constant size; use malloc instead.

branches: 1.40.2; 1.40.4; 1.40.6;
merge yamt-uio_vmspace branch.

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

branches: 1.39.2; 1.39.4; 1.39.6;
merge ktrace-lwp.

branches: 1.38.2;
merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.37.2;
* Remove __P()
* Use ANSI function declarations on ext2fs and mfs

Don't overload MAXNAMLEN, use a separate constant for each filesystem type.

64 bit inode changes.

branches: 1.34.2;
Ensure that we change the size of the vnode at the same time as
we change the size of the inode, and use ext2fs_size uniformly.
This fixes a crash that occurs when I create a directory, then
move it, all on an ext2 filesystem.

- sprinkle const
- avoid shadow variables.

nuke trailing whitespace

Add support for large files (>2GB).
Like Linux, automagically convert old filesystem to use this,
if they are already at revision 1.
For revision 0, just punt (unlike Linux; makes me a bit too nervous.)

There should be an option to fsck_ext2fs to upgrade revision 0 to revision 1.

Reviewd by Manuel (bouyer@).

branches: 1.30.4; 1.30.6;
There's no need to pass a proc value when using UIO_SYSSPACE with
vn_rdwr(9) and uiomove(9).

OK'd by Jason Thorpe

Fixing age old cruft:
* Rather than using mnt_maxsymlinklen to indicate that a file systems returns
d_type fields(!), add a new internal flag, IMNT_DTYPE.

Add 3 new elements to ufsmount:
* um_maxsymlinklen, replaces mnt_maxsymlinklen (which never should have existed
in the first place).
* um_dirblksiz, which tracks the current directory block size, eliminating the
FS-specific checks littered throughout the code. This may be used later to
make the block size variable.
* um_maxfilesize, which is the maximum file size, possibly adjusted lower due
to implementation issues.

Sync some bug fixes from FFS into ext2fs, particularly:
* ffs_lookup.c 1.21, 1.28, 1.33, 1.48
* ffs_inode.c 1.43, 1.44, 1.45, 1.66, 1.67
* ffs_vnops.c 1.84, 1.85, 1.86

Clean up some crappy pointer frobnication.

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

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

branches: 1.27.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

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

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

Bump the kernel rev up to 1.6V

Add 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.

eliminate i_ino from in-core inode
and use local variable instead.

ok'ed by Frank van der Linden.

Avoid strict-alias warnings.

remove trailing \n in panic(). approved perry.

Spell '[Rr]ight' correctly. From Jim Bernard.

#if 0 a test that is always false (and the XXX comment above it
indicates so).

branches: 1.18.8; 1.18.10;
add RCSID

remove #include <ufs/ufs/quota.h> where it was just to appease
<ufs/ufs/inode.h>, since the latter now includes the former. leave the former
in source that obviously uses specific bits of it (for completeness.)

branches: 1.16.2; 1.16.6; 1.16.10;
MALLOC()/FREE() are not to be used for variable sized allocations.

Remove register declarations.

Correct (minor) bogons in filetype option support, and add support
for sparse_super option

First cut at ext2fs rev 1 support (as of mke2fs 1.18): supports the filetype
option read/write and the sparse option read-only.

branches: 1.12.2;
Adapt to cache_lookup() changes.

Tested by: jdolecek
Rewieved by: wrstuden

Pull in changes which parallel rev 1.22 -> 1.25 of ufs_lookup().

Add PDIRUNLOCK support.

branches: 1.9.4;
- intentation
- sync LK_* flags with ffs/ufs

Fix copyright '\t' -> ' '

bzero->memset, bcopy->memcpy, bcmp->memcmp

fix to accomodate change in vn_rdwr prototype

Merge with Lite2 + local changes

Update for 64 bits directory cookies.

Add byte-swapping functions (bswap16, bswap32, bswap64) to libkern.
Only assembly version for i386 bswap16 and bswap32 for now (bswap64 uses
bswap32). Contribution of assembly versions of these are welcome.
Add byte-swapping of ext2fs metadata for big-endian systems.
Tested on i386 and sparc.

Fix bad cut&paste from ufs code: we can't align uio_resid to a directory
block size boundary, because size of the returned dir entry may be bigger than
the one read.

branches: 1.1.4;
The ext2fs layer, based on the ffs/ufs one. Uses a few functions from
sys/ufs/ufs/

s/blity/bility/ in various words, mainly in comments.

Add ACL support for FFS. From FreeBSD.

Merge the remaining changes from the ad-namecache branch, affecting namei()
and getcwd():

- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.

Possible future enhancements:

- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.

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

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

branches: 1.88.16; 1.88.22;
KNF, no functional change

fix bug introduced in rev 1.82 of ext2fs_lookup.c, when ext2fs_add_entry()
was introduced splitting code from ext2fs_direnter() - code used
incorrect new entry size, leading to incomplete entry copy or buffer
overflow; fixed by passing the right size from ext2fs_direnter()

when converting on-disk direntry, only use the on-disk filetype if the feature flag is present

switch code to use the EXT2_HAS_{COMPAT|ROCOMPAT|INCOMPAT}_FEATURE() macros instead of open coding the checks

KNF, no functional changes...

sync with hrishi's git

merge missing function.

actually pass the d_type from the on-disk directory entry to the lookup results

GSoC 2016 (Hrishikesh Goyal): Htree index support from FreeBSD

Use buffer cache, not page cache, to expand directories in ext2fs.

Candidate fix for PR kern/50607, PR port-evbmips/50059.

Formerly VOP_WRITE-->ext2fs_write would automatically dispatch to
this code path for writes to directories, but I broke that in
ext2fs_lookup.c rev. 1.78 when disentangling page-cached and
buffer-cached writes.

This was not a problem in ufs, and I didn't notice it in ext2fs,
because ufs consistently used buffercache(9) directly instead of
using VOP_WRITE sometimes as ext2fs did.

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.

branches: 1.77.4;
Introduce two helper functions to centralise the namecache statistics
in vfs_cache.c. Use consistent locking around the per-cpu data.

Remove ext2fs_checkpath(). It is a relic from the pre-genfs_rename era.

Add a global vnode cache:

- vcache_get() retrieves a referenced and initialised vnode / fs node pair.
- vcache_remove() removes a vnode / fs node pair from the cache.

On cache miss vcache_get() calls new vfs operation vfs_loadvnode() to
initialise a vnode / fs node pair. This call is guaranteed exclusive,
no other thread will try to load this vnode / fs node pair.

Convert ufs/ext2fs, ufs/ffs and ufs/mfs to use this interface.

Remove now unused ufs/ufs_ihash

Discussed on tech-kern.

Welcome to 6.99.41

branches: 1.74.2;
Change vnode operation lookup to return the resulting vnode *vpp unlocked.
Change cache_lookup() to return an unlocked vnode.

Discussed on tech-kern@

Welcome to 6.99.31

branches: 1.73.2;
Stuff UFS_ in front of a few of ufs's symbols to reduce namespace
pollution. Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN -> UFS_MAXSYMLINKLEN
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Sort out ext2fs's misuse of NDADDR and NIADDR; fortunately, these have
the same values in ext2fs and ffs.

No functional change intended.

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

Disentangle the namecache from the internals of namei.

- Move the namecache's hash computation to inside the namecache code,
instead of being spread out all over the place. Remove cn_hash from
struct componentname and delete all uses of it.

- It is no longer necessary (if it ever was) for cache_lookup and
cache_lookup_raw to clear MAKEENTRY from cnp->cn_flags for the cases
that cache_enter already checks for.

- Rearrange the interface of cache_lookup (and cache_lookup_raw) to
make it somewhat simpler, to exclude certain nonexistent error
conditions, and (most importantly) to make it not require write access
to cnp->cn_flags.

This change requires a kernel bump.

branches: 1.70.2;
Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Fix last commit that broke lookup for dot with op DELETE.

Reviewed by: David Holland <dholland@netbsd.org>

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

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

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

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

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

branches: 1.67.2;
converting readdir in ffs ext2fs from malloc(9) to kmem(9)
while there allocate ufs mount structs from kmem(9) too
preceding kmem-vmem-pool-patch

releng@ acknowledged

branches: 1.66.2; 1.66.6;
Pass the ufs_lookup_results pointer around instead of fetching it from
the inode in the guts of ufs. Now, in VOPs where i_crap is used it is
used (directly) only immediately on entry to the VOP call and then
passed around by reference.

Except for rename, which needs explicit sorting out. The code in
ufs_wapbl_rename is unchanged in behavior but I'm increasingly
inclined to think it's wrong.

Currently, ufs_lookup produces five auxiliary results that are left in
the vnode when lookup returns and fished out again later.

1. Create struct ufs_lookup_results to hold these.

2. Call the ufs_lookup_results instance in struct inode "i_crap" to be
clear about exactly what's going on, and to distinguish the lookup
results from respectable members of struct inode.

3. Update references to these members in the directory access
subroutines.

4. Include preliminary infrastructure for checking that the i_crap
being used is still valid when it's used. This doesn't actually do
anything yet.

5. Update the way ufs_wapbl_rename manipulates these elements to use
the new data structures. I have not changed the manipulation; it may
or may not be correct but I continue to suspect that it is not.

The word of the day is "stigmergy".

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

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

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

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

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.61.2; 1.61.4;
The VATTR_NULL/VREF/VHOLD/HOLDRELE() macros lost their will to live
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.

no functional change

Whitespace nits.

Migrate from u_intNN_t to uintNN_t.

kill MALLOC and FREE macros.

Remove an extra semicolon.

add support for 32 bit uid/gid fields in ext2, but only do so for
when the revision is > REV0.

branches: 1.55.12; 1.55.16; 1.55.22; 1.55.24; 1.55.26;
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: 1.54.2;
Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.53.4;
Merge ffs locking & brelse changes from the vmlocking branch.

Avoid stack allocation of large dirent structures in foo_readdir().

branches: 1.51.4; 1.51.6; 1.51.8; 1.51.10;
Don't depend on uvm_extern.h pulling in proc.h.

branches: 1.50.2; 1.50.10;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.49.2;
Merge newlock2 to head.

Consistent usage of KAUTH_GENERIC_ISSUSER.

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

branches: 1.46.2;
__unused removal on arguments; approved by core.

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

branches: 1.44.8; 1.44.10;
integrate kauth.

Coverity CID 1169: Add KASSERT before deref.

Remove dead code, fixing coverity ID 745. nameiop can only be CREATE
or DELETE here. This code got cut-n-pasted from ufs_loolup.c, but
is only used in whiteout support. ext2fs doesn't support whiteout.

don't use MALLOC with a non-constant size; use malloc instead.

branches: 1.40.2; 1.40.4; 1.40.6;
merge yamt-uio_vmspace branch.

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

branches: 1.39.2; 1.39.4; 1.39.6;
merge ktrace-lwp.

branches: 1.38.2;
merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.37.2;
* Remove __P()
* Use ANSI function declarations on ext2fs and mfs

Don't overload MAXNAMLEN, use a separate constant for each filesystem type.

64 bit inode changes.

branches: 1.34.2;
Ensure that we change the size of the vnode at the same time as
we change the size of the inode, and use ext2fs_size uniformly.
This fixes a crash that occurs when I create a directory, then
move it, all on an ext2 filesystem.

- sprinkle const
- avoid shadow variables.

nuke trailing whitespace

Add support for large files (>2GB).
Like Linux, automagically convert old filesystem to use this,
if they are already at revision 1.
For revision 0, just punt (unlike Linux; makes me a bit too nervous.)

There should be an option to fsck_ext2fs to upgrade revision 0 to revision 1.

Reviewd by Manuel (bouyer@).

branches: 1.30.4; 1.30.6;
There's no need to pass a proc value when using UIO_SYSSPACE with
vn_rdwr(9) and uiomove(9).

OK'd by Jason Thorpe

Fixing age old cruft:
* Rather than using mnt_maxsymlinklen to indicate that a file systems returns
d_type fields(!), add a new internal flag, IMNT_DTYPE.

Add 3 new elements to ufsmount:
* um_maxsymlinklen, replaces mnt_maxsymlinklen (which never should have existed
in the first place).
* um_dirblksiz, which tracks the current directory block size, eliminating the
FS-specific checks littered throughout the code. This may be used later to
make the block size variable.
* um_maxfilesize, which is the maximum file size, possibly adjusted lower due
to implementation issues.

Sync some bug fixes from FFS into ext2fs, particularly:
* ffs_lookup.c 1.21, 1.28, 1.33, 1.48
* ffs_inode.c 1.43, 1.44, 1.45, 1.66, 1.67
* ffs_vnops.c 1.84, 1.85, 1.86

Clean up some crappy pointer frobnication.

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

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

branches: 1.27.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

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

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

Bump the kernel rev up to 1.6V

Add 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.

eliminate i_ino from in-core inode
and use local variable instead.

ok'ed by Frank van der Linden.

Avoid strict-alias warnings.

remove trailing \n in panic(). approved perry.

Spell '[Rr]ight' correctly. From Jim Bernard.

#if 0 a test that is always false (and the XXX comment above it
indicates so).

branches: 1.18.8; 1.18.10;
add RCSID

remove #include <ufs/ufs/quota.h> where it was just to appease
<ufs/ufs/inode.h>, since the latter now includes the former. leave the former
in source that obviously uses specific bits of it (for completeness.)

branches: 1.16.2; 1.16.6; 1.16.10;
MALLOC()/FREE() are not to be used for variable sized allocations.

Remove register declarations.

Correct (minor) bogons in filetype option support, and add support
for sparse_super option

First cut at ext2fs rev 1 support (as of mke2fs 1.18): supports the filetype
option read/write and the sparse option read-only.

branches: 1.12.2;
Adapt to cache_lookup() changes.

Tested by: jdolecek
Rewieved by: wrstuden

Pull in changes which parallel rev 1.22 -> 1.25 of ufs_lookup().

Add PDIRUNLOCK support.

branches: 1.9.4;
- intentation
- sync LK_* flags with ffs/ufs

Fix copyright '\t' -> ' '

bzero->memset, bcopy->memcpy, bcmp->memcmp

fix to accomodate change in vn_rdwr prototype

Merge with Lite2 + local changes

Update for 64 bits directory cookies.

Add byte-swapping functions (bswap16, bswap32, bswap64) to libkern.
Only assembly version for i386 bswap16 and bswap32 for now (bswap64 uses
bswap32). Contribution of assembly versions of these are welcome.
Add byte-swapping of ext2fs metadata for big-endian systems.
Tested on i386 and sparc.

Fix bad cut&paste from ufs code: we can't align uio_resid to a directory
block size boundary, because size of the returned dir entry may be bigger than
the one read.

branches: 1.1.4;
The ext2fs layer, based on the ffs/ufs one. Uses a few functions from
sys/ufs/ufs/

Add ACL support for FFS. From FreeBSD.

Merge the remaining changes from the ad-namecache branch, affecting namei()
and getcwd():

- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.

Possible future enhancements:

- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.

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

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

branches: 1.88.16; 1.88.22;
KNF, no functional change

fix bug introduced in rev 1.82 of ext2fs_lookup.c, when ext2fs_add_entry()
was introduced splitting code from ext2fs_direnter() - code used
incorrect new entry size, leading to incomplete entry copy or buffer
overflow; fixed by passing the right size from ext2fs_direnter()

when converting on-disk direntry, only use the on-disk filetype if the feature flag is present

switch code to use the EXT2_HAS_{COMPAT|ROCOMPAT|INCOMPAT}_FEATURE() macros instead of open coding the checks

KNF, no functional changes...

sync with hrishi's git

merge missing function.

actually pass the d_type from the on-disk directory entry to the lookup results

GSoC 2016 (Hrishikesh Goyal): Htree index support from FreeBSD

Use buffer cache, not page cache, to expand directories in ext2fs.

Candidate fix for PR kern/50607, PR port-evbmips/50059.

Formerly VOP_WRITE-->ext2fs_write would automatically dispatch to
this code path for writes to directories, but I broke that in
ext2fs_lookup.c rev. 1.78 when disentangling page-cached and
buffer-cached writes.

This was not a problem in ufs, and I didn't notice it in ext2fs,
because ufs consistently used buffercache(9) directly instead of
using VOP_WRITE sometimes as ext2fs did.

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.

branches: 1.77.4;
Introduce two helper functions to centralise the namecache statistics
in vfs_cache.c. Use consistent locking around the per-cpu data.

Remove ext2fs_checkpath(). It is a relic from the pre-genfs_rename era.

Add a global vnode cache:

- vcache_get() retrieves a referenced and initialised vnode / fs node pair.
- vcache_remove() removes a vnode / fs node pair from the cache.

On cache miss vcache_get() calls new vfs operation vfs_loadvnode() to
initialise a vnode / fs node pair. This call is guaranteed exclusive,
no other thread will try to load this vnode / fs node pair.

Convert ufs/ext2fs, ufs/ffs and ufs/mfs to use this interface.

Remove now unused ufs/ufs_ihash

Discussed on tech-kern.

Welcome to 6.99.41

branches: 1.74.2;
Change vnode operation lookup to return the resulting vnode *vpp unlocked.
Change cache_lookup() to return an unlocked vnode.

Discussed on tech-kern@

Welcome to 6.99.31

branches: 1.73.2;
Stuff UFS_ in front of a few of ufs's symbols to reduce namespace
pollution. Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN -> UFS_MAXSYMLINKLEN
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Sort out ext2fs's misuse of NDADDR and NIADDR; fortunately, these have
the same values in ext2fs and ffs.

No functional change intended.

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

Disentangle the namecache from the internals of namei.

- Move the namecache's hash computation to inside the namecache code,
instead of being spread out all over the place. Remove cn_hash from
struct componentname and delete all uses of it.

- It is no longer necessary (if it ever was) for cache_lookup and
cache_lookup_raw to clear MAKEENTRY from cnp->cn_flags for the cases
that cache_enter already checks for.

- Rearrange the interface of cache_lookup (and cache_lookup_raw) to
make it somewhat simpler, to exclude certain nonexistent error
conditions, and (most importantly) to make it not require write access
to cnp->cn_flags.

This change requires a kernel bump.

branches: 1.70.2;
Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Fix last commit that broke lookup for dot with op DELETE.

Reviewed by: David Holland <dholland@netbsd.org>

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

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

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

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

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

branches: 1.67.2;
converting readdir in ffs ext2fs from malloc(9) to kmem(9)
while there allocate ufs mount structs from kmem(9) too
preceding kmem-vmem-pool-patch

releng@ acknowledged

branches: 1.66.2; 1.66.6;
Pass the ufs_lookup_results pointer around instead of fetching it from
the inode in the guts of ufs. Now, in VOPs where i_crap is used it is
used (directly) only immediately on entry to the VOP call and then
passed around by reference.

Except for rename, which needs explicit sorting out. The code in
ufs_wapbl_rename is unchanged in behavior but I'm increasingly
inclined to think it's wrong.

Currently, ufs_lookup produces five auxiliary results that are left in
the vnode when lookup returns and fished out again later.

1. Create struct ufs_lookup_results to hold these.

2. Call the ufs_lookup_results instance in struct inode "i_crap" to be
clear about exactly what's going on, and to distinguish the lookup
results from respectable members of struct inode.

3. Update references to these members in the directory access
subroutines.

4. Include preliminary infrastructure for checking that the i_crap
being used is still valid when it's used. This doesn't actually do
anything yet.

5. Update the way ufs_wapbl_rename manipulates these elements to use
the new data structures. I have not changed the manipulation; it may
or may not be correct but I continue to suspect that it is not.

The word of the day is "stigmergy".

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

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

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

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

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.61.2; 1.61.4;
The VATTR_NULL/VREF/VHOLD/HOLDRELE() macros lost their will to live
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.

no functional change

Whitespace nits.

Migrate from u_intNN_t to uintNN_t.

kill MALLOC and FREE macros.

Remove an extra semicolon.

add support for 32 bit uid/gid fields in ext2, but only do so for
when the revision is > REV0.

branches: 1.55.12; 1.55.16; 1.55.22; 1.55.24; 1.55.26;
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: 1.54.2;
Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.53.4;
Merge ffs locking & brelse changes from the vmlocking branch.

Avoid stack allocation of large dirent structures in foo_readdir().

branches: 1.51.4; 1.51.6; 1.51.8; 1.51.10;
Don't depend on uvm_extern.h pulling in proc.h.

branches: 1.50.2; 1.50.10;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.49.2;
Merge newlock2 to head.

Consistent usage of KAUTH_GENERIC_ISSUSER.

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

branches: 1.46.2;
__unused removal on arguments; approved by core.

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

branches: 1.44.8; 1.44.10;
integrate kauth.

Coverity CID 1169: Add KASSERT before deref.

Remove dead code, fixing coverity ID 745. nameiop can only be CREATE
or DELETE here. This code got cut-n-pasted from ufs_loolup.c, but
is only used in whiteout support. ext2fs doesn't support whiteout.

don't use MALLOC with a non-constant size; use malloc instead.

branches: 1.40.2; 1.40.4; 1.40.6;
merge yamt-uio_vmspace branch.

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

branches: 1.39.2; 1.39.4; 1.39.6;
merge ktrace-lwp.

branches: 1.38.2;
merge yamt-vop branch. remove following VOPs.

VOP_BLKATOFF
VOP_VALLOC
VOP_BALLOC
VOP_REALLOCBLKS
VOP_VFREE
VOP_TRUNCATE
VOP_UPDATE

branches: 1.37.2;
* Remove __P()
* Use ANSI function declarations on ext2fs and mfs

Don't overload MAXNAMLEN, use a separate constant for each filesystem type.

64 bit inode changes.

branches: 1.34.2;
Ensure that we change the size of the vnode at the same time as
we change the size of the inode, and use ext2fs_size uniformly.
This fixes a crash that occurs when I create a directory, then
move it, all on an ext2 filesystem.

- sprinkle const
- avoid shadow variables.

nuke trailing whitespace

Add support for large files (>2GB).
Like Linux, automagically convert old filesystem to use this,
if they are already at revision 1.
For revision 0, just punt (unlike Linux; makes me a bit too nervous.)

There should be an option to fsck_ext2fs to upgrade revision 0 to revision 1.

Reviewd by Manuel (bouyer@).

branches: 1.30.4; 1.30.6;
There's no need to pass a proc value when using UIO_SYSSPACE with
vn_rdwr(9) and uiomove(9).

OK'd by Jason Thorpe

Fixing age old cruft:
* Rather than using mnt_maxsymlinklen to indicate that a file systems returns
d_type fields(!), add a new internal flag, IMNT_DTYPE.

Add 3 new elements to ufsmount:
* um_maxsymlinklen, replaces mnt_maxsymlinklen (which never should have existed
in the first place).
* um_dirblksiz, which tracks the current directory block size, eliminating the
FS-specific checks littered throughout the code. This may be used later to
make the block size variable.
* um_maxfilesize, which is the maximum file size, possibly adjusted lower due
to implementation issues.

Sync some bug fixes from FFS into ext2fs, particularly:
* ffs_lookup.c 1.21, 1.28, 1.33, 1.48
* ffs_inode.c 1.43, 1.44, 1.45, 1.66, 1.67
* ffs_vnops.c 1.84, 1.85, 1.86

Clean up some crappy pointer frobnication.

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

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

branches: 1.27.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

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

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

Bump the kernel rev up to 1.6V

Add 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.

eliminate i_ino from in-core inode
and use local variable instead.

ok'ed by Frank van der Linden.

Avoid strict-alias warnings.

remove trailing \n in panic(). approved perry.

Spell '[Rr]ight' correctly. From Jim Bernard.

#if 0 a test that is always false (and the XXX comment above it
indicates so).

branches: 1.18.8; 1.18.10;
add RCSID

remove #include <ufs/ufs/quota.h> where it was just to appease
<ufs/ufs/inode.h>, since the latter now includes the former. leave the former
in source that obviously uses specific bits of it (for completeness.)

branches: 1.16.2; 1.16.6; 1.16.10;
MALLOC()/FREE() are not to be used for variable sized allocations.

Remove register declarations.

Correct (minor) bogons in filetype option support, and add support
for sparse_super option

First cut at ext2fs rev 1 support (as of mke2fs 1.18): supports the filetype
option read/write and the sparse option read-only.

branches: 1.12.2;
Adapt to cache_lookup() changes.

Tested by: jdolecek
Rewieved by: wrstuden

Pull in changes which parallel rev 1.22 -> 1.25 of ufs_lookup().

Add PDIRUNLOCK support.

branches: 1.9.4;
- intentation
- sync LK_* flags with ffs/ufs

Fix copyright '\t' -> ' '

bzero->memset, bcopy->memcpy, bcmp->memcmp

fix to accomodate change in vn_rdwr prototype

Merge with Lite2 + local changes

Update for 64 bits directory cookies.

Add byte-swapping functions (bswap16, bswap32, bswap64) to libkern.
Only assembly version for i386 bswap16 and bswap32 for now (bswap64 uses
bswap32). Contribution of assembly versions of these are welcome.
Add byte-swapping of ext2fs metadata for big-endian systems.
Tested on i386 and sparc.

Fix bad cut&paste from ufs code: we can't align uio_resid to a directory
block size boundary, because size of the returned dir entry may be bigger than
the one read.

branches: 1.1.4;
The ext2fs layer, based on the ffs/ufs one. Uses a few functions from
sys/ufs/ufs/

Merge the remaining changes from the ad-namecache branch, affecting namei()
and getcwd():

- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.

Possible future enhancements:

- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.

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

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

branches: 1.88.22;
KNF, no functional change

fix bug introduced in rev 1.82 of ext2fs_lookup.c, when ext2fs_add_entry()
was introduced splitting code from ext2fs_direnter() - code used
incorrect new entry size, leading to incomplete entry copy or buffer
overflow; fixed by passing the right size from ext2fs_direnter()

when converting on-disk direntry, only use the on-disk filetype if the feature flag is present

switch code to use the EXT2_HAS_{COMPAT|ROCOMPAT|INCOMPAT}_FEATURE() macros instead of open coding the checks

KNF, no functional changes...

sync with hrishi's git

merge missing function.