Now remove cn_consume from struct componentname.

This change requires a kernel bump.

Note though that I'm not going to version the VOP_LOOKUP args
structure (or any other args structure) as code that doesn't touch
cn_consume doesn't need attention and code that does will fail on it
without further intervention.

Add ACL support for FFS. From FreeBSD.

Revert the changes made in February to make cwdinfo use mostly lockless,
which relied on taking extra vnode refs.

Having benchmarked various experimental changes over the past few months it
seems that it's better to avoid vnode refs as much as possible. cwdi_lock
as a RW lock already did that to some extent for getcwd() and will permit
the same for namei() too.

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

branches: 1.57.2;
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.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

branches: 1.52.4;
Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

Add ACL support for FFS. From FreeBSD.

Revert the changes made in February to make cwdinfo use mostly lockless,
which relied on taking extra vnode refs.

Having benchmarked various experimental changes over the past few months it
seems that it's better to avoid vnode refs as much as possible. cwdi_lock
as a RW lock already did that to some extent for getcwd() and will permit
the same for namei() too.

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

branches: 1.57.2;
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.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

branches: 1.52.4;
Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

Revert the changes made in February to make cwdinfo use mostly lockless,
which relied on taking extra vnode refs.

Having benchmarked various experimental changes over the past few months it
seems that it's better to avoid vnode refs as much as possible. cwdi_lock
as a RW lock already did that to some extent for getcwd() and will permit
the same for namei() too.

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

branches: 1.57.2;
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.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

branches: 1.52.4;
Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

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

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.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

branches: 1.52.4;
Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

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.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

Merge vfs_cache.c from the ad-namecache branch. With this the namecache
index becomes per-directory (initially, a red-black tree). The remaining
changes on the branch to namei()/getcwd() will be merged in the future.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.

branches: 1.32.4; 1.32.6;
Use the LWP cached credentials where sane.

integrate kauth.

branches: 1.30.2; 1.30.4; 1.30.6;
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: 1.29.2; 1.29.4; 1.29.6;
merge ktrace-lwp.

64 bit inode changes.

branches: 1.27.2;
Use ANSI function decls.

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

Nuke __P().

Some whitespace fix.

The vnode capability id is gone.

Rewind the `bp' advanced backward by cache_revlookup() if getcwd_getcache()
finally returns cache miss.

# Slightly modified from posted version so that it is cleanly patchable
# at least on 1.6 branch.

eliminate v_id.

branches: 1.20.2;
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

move declaration of getcwd_common and constant to the header file.

Merge the nathanw_sa branch.

branches: 1.15.10;
add RCSIDs

branches: 1.14.2; 1.14.4; 1.14.8;
Jump out of the scandir loop if VOP_READDIR returns an error, avoiding
running around in circles.

branches: 1.13.4;
Get rid of register declarations.

Make getcwd_common() available to COMPAT_NETBSD32 code as well.

g/c redundant vn_isunder() prototype (it.s in <sys/vnode.h>)
minor KNF changes

branches: 1.10.2; 1.10.8;
Fix kern/7944: getcwd permission checking was overly restrictive.
(Don't require start directory to have read permission).

Housecleaning time:

Fix and document naming convention for vnode variables (always use
lvp/lvpp and uvp/uvpp instead of a hash of cvp, vpp, dvpp, pvp, pvpp).

Delete old stale #if 0'ed code at the end.

Change error path code in getcwd_getcache() slightly (merge common
cleanup code; shouldn't affect behavior any).

Fix PR7373 for real: Rearrange locking to avoid need for LOCKPARENT in lookup

Fix PR7761: clip overly large length rather than failing

Break cdir/rdir/cmask info out of struct filedesc, and put it in a new
substructure, `cwdinfo'. Implement optional sharing of this substructure.

This is required for clone(2).

Fix adosfs's locking panic

Fix compile warning (not seen with egcs, but...)

branches: 1.3.2;
Disallow tracing of processes unless tracer's root directory is at or
above tracee's root directory.

Garbage collect a non-useful variable in getcwd_scandir().

Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling
back to reading the filesystem on a cache miss.
Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating
that a reclaim is being done, so only a "shallow" fsync is needed.

Merge from ad-namecache:

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

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

- Make cwdinfo use mostly lockless.

- options NAMECACHE_ENTER_REVERSE is no more.

- Partially sort the list of per-vnode namecache entries by using a TAILQ.
Put the real name to the head, and put dot and dotdot to the tail so that
cache_lookup_reverse() doesn't have to consider them.

branches: 1.53.2;
- add missing error check
- use '\0' for char const

Don't walk off the end of the dirent buffer.

From Ilja Van Sprundel.

branches: 1.51.2;
remove checks for failure after memory allocation calls that cannot fail:

kmem_alloc() with KM_SLEEP
kmem_zalloc() with KM_SLEEP
percpu_alloc()
pserialize_create()
psref_class_create()

all of these paths include an assertion that the allocation has not failed,
so callers should not assert that again.

branches: 1.50.4; 1.50.6; 1.50.8; 1.50.16;
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: 1.49.2;
Stick UFS_ in front of these symbols:
DIRBLKSIZ
DIRECTSIZ
DIRSIZ
OLDDIRFMT
NEWDIRFMT

Part of PR 47909.

(two stragglers in this commit; oops)

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: 1.47.8; 1.47.14; 1.47.18; 1.47.20; 1.47.22;
Abolish struct componentname's cn_pnbuf. Use the path buffer in the
pathbuf object passed to namei as work space instead. (For now a pnbuf
pointer appears in struct nameidata, to support certain unclean things
that haven't been fixed yet, but it will be going away in the future.)

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

Using cache_revlookup() leads to vnode races as it returns an unreferenced
vnode that may disappear before the caller has a chance to reference it.

Reference the vnode while the name cache is locked.

No objections on tech-kern.

Clean up vnode lock operations pass 2:

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

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.44.2; 1.44.4;
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

malloc -> kmem_alloc.

branches: 1.42.2; 1.42.8;
Remove clause 3 and 4 from TNF licenses

branches: 1.41.6; 1.41.8; 1.41.10;
Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.40.4;
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: 1.39.2;
- add an elf aux vector entry for implementing $ORIGIN.
- the code to convert from a vnode to a path is commented out now until
a better solution is implemented. Only absolute paths work for now
(which is most of the cases).

requested by core

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: 1.37.4;
Merge from vmlocking:

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

Merge file descriptor locking, cwdi locking and cross-call changes
from the vmlocking branch.

branches: 1.35.6; 1.35.18; 1.35.20; 1.35.22;
Merge newlock2 to head.

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: 1.33.2;
Defer the vnode test for directory until after the cache lookup. This makes
getcwd work with plain files too, if we allow plain files in the vnode->name
cache.