branches: 1.1.2; 1.1.12;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.2.2; 1.2.12;
Additional documentation on extents and some artificial limitations SGI
has introduced (and changed in backwards-incompatible ways) over the years.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

KNF. Remove extra spaces. No functional change.

branches: 1.2.2; 1.2.12; 1.2.82; 1.2.102;
Additional documentation on extents and some artificial limitations SGI
has introduced (and changed in backwards-incompatible ways) over the years.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

KNF. Remove extra spaces. No functional change.

branches: 1.1.2; 1.1.12; 1.1.82; 1.1.102;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.3.2; 1.3.12;
Additional fixes/enhancements:
1) Comply with the way buffercache(9) is intended to be used. Now we
read in single blocks of EFS_BB_SIZE, never taking in variable
length extents with a single bread() call.

2) Handle symlinks with more than one extent. There's no reason for
this to ever happen, but it's handled now.

3) Finally, add a hint to our iteration initialiser so we can start
from the desired offset, rather than naively looping through from
the beginning each time. Since we can binary search the correct
location quickly, this improves large sequential reads by about
40% with 128MB files. Improvement should increase with file size.

Additional documentation on extents and some artificial limitations SGI
has introduced (and changed in backwards-incompatible ways) over the years.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

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

branches: 1.1.2; 1.1.12; 1.1.124;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.1.2; 1.1.12;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

Change efs from hashlist to vcache.

branches: 1.10.2;
The current implementation of vn_lock() is racy. Modification of
the vnode operations vector for active vnodes is unsafe because it
is not known whether deadfs or the original file system will be
called.

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

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

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

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

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

Discussed on tech-kern.

Welcome to 6.99.33

branches: 1.9.2; 1.9.4;
Remove everything to do with 'struct malloc_type' and the malloc link_set.
To make code in 'external' (etc) still compile, MALLOC_DECLARE() still
has to generate something of type 'struct malloc_type *', with
normal optimisation gcc generates a compile-time 0.
MALLOC_DEFINE() and friends have no effect.
Fix one or two places where the code would no longer compile.

extending vmem(9) to be able to allocated resources for it's own needs.
simplifying uvm_map handling (no special kernel entries anymore no relocking)
make malloc(9) a thin wrapper around kmem(9)
(with private interface for interrupt safety reasons)

releng@ acknowledged

branches: 1.7.2; 1.7.6;
Welcome to 5.99.53! Merge rmind-uvmplock branch:

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

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

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

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

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

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

branches: 1.6.6;
Make holding v_interlock mandatory for callers of vget().

Announced some time ago on tech-kern.

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

Welcome to 5.99.34.

Discussed on tech-kern.

branches: 1.4.20; 1.4.22;
- Convert hashinit() to use kmem_alloc(). The hash tables can be large
and it's better to not have them in kmem_map.
- Convert a couple of minor items along the way to kmem_alloc().
- Fix some memory leaks.

branches: 1.3.6; 1.3.8; 1.3.10;
Replace struct lock on vnodes with a simpler lock object built on
krwlock_t. This is a step towards removing lockmgr and simplifying
vnode locking. Discussed on tech-kern.

Merge vmlocking2 to head.

branches: 1.1.2; 1.1.10; 1.1.12; 1.1.18; 1.1.20; 1.1.24;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

Change efs from hashlist to vcache.

branches: 1.1.2; 1.1.12; 1.1.82; 1.1.98;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.1.2; 1.1.12;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.1.2; 1.1.12;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.1.2; 1.1.12;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

s/occured/occurred/ in comments, log messages and man pages.

fix unaligned access

Curious typo. Harmless. Found by Brainy

Remove the 'cred' argument from bread(). Remove a now unused var in
ffs_snapshot.c. Update the man page accordingly.

ok hannken@

branches: 1.10.6;
use __diagused where appropriate.

Now that KASSERT will always consume its arguments, move a KASSERT inside
a DIAGNOSTIC, because the function used is only defined with DIAGNOSTIC.

branches: 1.8.2;
Change bread() and breadn() to never return a buffer on
error and modify all callers to not brelse() on error.

Welcome to 6.99.16

PR kern/46282 (6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread)

branches: 1.7.32; 1.7.42;
Make sure all cached buffers with valid, not yet written data have been
run through copy-on-write. Call fscow_run() with valid data where possible.

The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.

- Add a flag B_MODIFY to bread(), breada() and breadn(). If set the caller
intends to modify the buffer returned.

- Always run copy-on-write on buffers returned from ffs_balloc().

- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
may clear the buffer and runs copy-on-write. Process possible errors
from getblk() or fscow_run(). Part of PR kern/38664.

Welcome to 4.99.63

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

branches: 1.6.18; 1.6.20; 1.6.22; 1.6.24;
Merge brelse() changes from the vmlocking branch.

branches: 1.5.2; 1.5.4; 1.5.6; 1.5.8;
Fix a parenthesis bug that would nearly always make the superblock magic
check evaluate to true.

branches: 1.4.4;
When computing the superblock checksum, use an unsigned short to avoid an
undesired sign-extension. Now EFS works on big endian machines, too.

branches: 1.3.2; 1.3.4;
Clamp down tigher on the bound around 'numextents'. Add a few comments
to make it clearer what we're tracking.

Additional fixes/enhancements:
1) Comply with the way buffercache(9) is intended to be used. Now we
read in single blocks of EFS_BB_SIZE, never taking in variable
length extents with a single bread() call.

2) Handle symlinks with more than one extent. There's no reason for
this to ever happen, but it's handled now.

3) Finally, add a hint to our iteration initialiser so we can start
from the desired offset, rather than naively looping through from
the beginning each time. Since we can binary search the correct
location quickly, this improves large sequential reads by about
40% with 128MB files. Improvement should increase with file size.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

branches: 1.2.2; 1.2.12;
Additional fixes/enhancements:
1) Comply with the way buffercache(9) is intended to be used. Now we
read in single blocks of EFS_BB_SIZE, never taking in variable
length extents with a single bread() call.

2) Handle symlinks with more than one extent. There's no reason for
this to ever happen, but it's handled now.

3) Finally, add a hint to our iteration initialiser so we can start
from the desired offset, rather than naively looping through from
the beginning each time. Since we can binary search the correct
location quickly, this improves large sequential reads by about
40% with 128MB files. Improvement should increase with file size.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

Remove now unused VV_LOCKSWORK, all file systems support locking.

Remove unused predicates vn_locked() and vn_anylocked().

Welcome to 9.99.95

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

branches: 1.28.14; 1.28.20;
Add generic genfs_suspendctl() and use it for all file systems.
Layered file systems need work.

branches: 1.27.2; 1.27.4;
KNF. Remove extra spaces. No functional change.

branches: 1.26.4;
Change efs from hashlist to vcache.

An (un)privileged user can easily make the kernel dereference a NULL
pointer.

The kernel allows 'data' to be NULL; it's the fs's responsibility to
ensure that it isn't NULL (if the fs actually needs data).

ok christos@

branches: 1.24.2; 1.24.10;
Change bread() and breadn() to never return a buffer on
error and modify all callers to not brelse() on error.

Welcome to 6.99.16

PR kern/46282 (6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread)

branches: 1.23.2;
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: 1.22.2; 1.22.6; 1.22.8; 1.22.12; 1.22.14;
Welcome to 5.99.53! Merge rmind-uvmplock branch:

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

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

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

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

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

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

branches: 1.21.6;
Introduce struct pathbuf. This is an abstraction to hold a pathname
and the metadata required to interpret it. Callers of namei must now
create a pathbuf and pass it to NDINIT (instead of a string and a
uio_seg), then destroy the pathbuf after the namei session is
complete.

Update all namei call sites accordingly. Add a pathbuf(9) man page and
update namei(9).

The pathbuf interface also now appears in a couple of related
additional places that were passing string/uio_seg pairs that were
later fed into NDINIT. Update other call sites accordingly.

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: 1.19.2; 1.19.4;
Add genfs_can_mount() and use it to prevent some more code duplication of
the security checks when mounting a device (VOP_ACCESS() + kauth(9) call)).

Proposed with no objections on tech-kern@:

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

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

Pass VREAD instead of FREAD to VOP_ACCESS().

Okay christos@.

branches: 1.17.4;
Add specfs/fifofs support. Not really fully tested, but at least
vfs routines don't crash now.
(didn't have an image with matching device node numbers)

fixes PR kern/40055 by myself

branches: 1.16.2; 1.16.4;
Don't assign vnode::v_mount. getnewvnode() does it.

branches: 1.15.4;
Convert file systems to dynamically attach with the new module interface.
Make VFS hooks dynamic while we're here and say farewell to VFS_ATTACH and
VFS_HOOKS_ATTACH linksets.

As a consequence, most of the file systems can now be loaded as new style
modules.

Quick sanity check by ad@.

branches: 1.14.12; 1.14.14; 1.14.16; 1.14.18;
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: 1.13.2;
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: 1.12.4;
Merge from vmlocking:

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

Merge brelse() changes from the vmlocking branch.

branches: 1.10.2;
Don't explicitly set vp->v_size and then call uvm_vnp_setsize(). This is
not only unnecessary, but trips a kernel assertion introduced in r1.85 of
uvm/uvm_vnode.c.

branches: 1.9.2; 1.9.4; 1.9.6;
Make VFS_SYNC always succeed instead of always fail.
Fixes non-forced unmount.

branches: 1.8.2;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

Use eopnotsupp() instead of vfs_stdsuspendctl() and retire the latter.

Don't depend on uvm_extern.h pulling in proc.h.

branches: 1.5.2;
Make set_statvfs_info() take a parameter for the vfs name instead
of always retrieving it from mp->mnt_op->vfs_name

christos ok

branches: 1.4.2;
Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

Additional fixes/enhancements:
1) Comply with the way buffercache(9) is intended to be used. Now we
read in single blocks of EFS_BB_SIZE, never taking in variable
length extents with a single bread() call.

2) Handle symlinks with more than one extent. There's no reason for
this to ever happen, but it's handled now.

3) Finally, add a hint to our iteration initialiser so we can start
from the desired offset, rather than naively looping through from
the beginning each time. Since we can binary search the correct
location quickly, this improves large sequential reads by about
40% with 128MB files. Improvement should increase with file size.

Remove a superfluous pasted structure definition, permitting ALL to
build again.

Caught by Hisashi T Fujinaka.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

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

Use macros for the canned parts of device and fifo vnode op tables.

Add GENFS_SPECOP_ENTRIES and GENFS_FIFOOP_ENTRIES macros that contain
the portion of the vnode ops table declaration that is
(conservatively) the same in every fs. Use these in every fs that
supports devices and/or fifos with separate ops tables.

Note that ptyfs works differently (it has one type of vnode with
open-coded dispatch to the specfs code, which I haven't changed in
this commit) and rump/librump/rumpvfs/rumpfs.c has an indirect dynamic
dispatch that already does more or less the same thing, which I also
haven't changed.

Also note that this anticipates a few bits in the next changeset here
and there, and adds missing but unreachable calls in some cases (e.g.
most fses weren't defining whiteout on devices and fifos, but it isn't
reachable there), and it changes parsepath on devices and fifos to
genfs_badop from genfs_parsepath (but it's not reachable there
either).

It appears that devices in kernfs were missing kqfilter, so it's
possible that if you try to use kqueue on /kern/rootdev that it'll
explode.

And finally note that the ops declaration tables aren't
order-dependent. (Other than vop_default_desc has to come first.)
Otherwise this wouldn't work.

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

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

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

branches: 1.41.6;
Introduce genfs_pathconf() and use it for the default case in all filesystems.

Add ACL support for FFS. From FreeBSD.

PR kern/54759 (vm.ubc_direct deadlock when read()/write() into mapping of itself)

- Add new flag UBC_ISMAPPED which tells ubc_uiomove() the object is mmap()ed
somewhere. Use it to decide whether to do direct-mapped copy, rather than
poking around directly in the vnode in ubc_uiomove(), which is ugly and
doesn't work for tmpfs. It would be nicer to contain all this in UVM but
the filesystem provides the needed locking here (VV_MAPPED) and to
reinvent that would suck more.

- Rename UBC_UNMAP_FLAG() to UBC_VNODE_FLAGS(). Pass in UBC_ISMAPPED where
appropriate.

branches: 1.38.20;
Make VOP_RECLAIM do the last unlock of the vnode.

VOP_RECLAIM naturally has exclusive access to the vnode, so having it
locked on entry is not strictly necessary -- but it means if there
are any final operations that must be done on the vnode, such as
ffs_update, requiring exclusive access to it, we can now kassert that
the vnode is locked in those operations.

We can't just have the caller release the last lock because some file
systems don't use genfs_lock, and require the vnode to remain valid
for VOP_UNLOCK to work, notably unionfs.

Make VOP_INACTIVE preserve vnode lock on return.

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

Ride 7.99.68, a bumpy bus of incremental vfs improvements!

branches: 1.36.2;
Remove now obsolete operation vcache_remove().

Welcome to 7.99.36

branches: 1.35.2;
KNF. Remove extra spaces. No functional change.

PR/50883: David Binderman: Remove redundant code.

branches: 1.33.4;
Change efs from hashlist to vcache.

Add VOP_FALLOCATE and VOP_FDISCARD to every vnode ops table I can
find.

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

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

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

branches: 1.31.2;
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: 1.30.6;
C99 section 6.7.2.3 (Tags) Note 3 states that:

A type specifier of the form

enum identifier

without an enumerator list shall only appear after the type it
specifies is complete.

which means that we cannot pass an "enum vtype" argument to
kauth_access_action() without fully specifying the type first.
Unfortunately there is a complicated include file loop which
makes that difficult, so convert this minimal function into a
macro (and capitalize it).

(ok elad@)

Change bread() and breadn() to never return a buffer on
error and modify all callers to not brelse() on error.

Welcome to 6.99.16

PR kern/46282 (6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread)

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: 1.26.2;
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@.

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: 1.24.4; 1.24.8; 1.24.10;
Remove cache_purge(9) calls from reclamation routines in the file systems,
as vclean(9) performs it for us since Lite2 merge.

branches: 1.23.2;
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.

Stop exposing fifofs internals and leave only fifo_vnodeop_p visible.

branches: 1.20.2; 1.20.4;
Fix utterly botched previous commit. efs compiles now and apprears
to work, but the person doing the original change should verify
that it actually works like before the change.

(hi, elad!)

Where possible, extract the file-system's access() routine to two internal
functions: the first checking if the operation is possible (regardless of
permissions), the second checking file-system permissions, ACLs, etc.

Mailing list reference:

http://mail-index.netbsd.org/tech-kern/2009/06/21/msg005311.html

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

Adjust file-system code to use it.

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

No objections on tech-kern@:

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

branches: 1.17.4;
Add specfs/fifofs support. Not really fully tested, but at least
vfs routines don't crash now.
(didn't have an image with matching device node numbers)

fixes PR kern/40055 by myself

Rototill all remaining file systems to use ubc_uiomove() instead
of the ubc_alloc() - uiomove() - ubc_release() dance.

more <sys/buf.h> police

branches: 1.14.6; 1.14.10; 1.14.16; 1.14.18; 1.14.20;
Remove VOP_LEASE. Discussed on tech-kern.

Merge vmlocking2 to head.

branches: 1.12.2; 1.12.6;
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: 1.11.4;
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 brelse() changes from the vmlocking branch.

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

branches: 1.8.2;
In efs_readdir don't foolishly allocate and free dirents for each entry
before copying them out, rather just use a single one. Further, follow
the example of tmpfs and others by simply allocating on the stack.

This should have the side-effect of silencing false Coverity reports like
CID 4559 and 4554.

CID 4553:

In efs_lookup, when checking whether a CREATE or RENAME operation would
succeed, be sure to pass the appropriate vnode pointer to VOP_ACCESS.

branches: 1.6.4; 1.6.6; 1.6.8; 1.6.10;
Only set *ap->a_cookies when we're returning success. Also, do not hard-
code 16, but rather use _DIRENT_MINSIZE as the divisor when determining
the number of cookies to allocate.

Noticed by pooka@.

Support NFS cookies and the eofflag in efs_readdir. Also, be sure to
update uio->uio_offset as not doing so would cause large directory reads
to misbehave.

EFS is now properly NFS-exportable.

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

branches: 1.3.2; 1.3.4;
Additional fixes/enhancements:
1) Comply with the way buffercache(9) is intended to be used. Now we
read in single blocks of EFS_BB_SIZE, never taking in variable
length extents with a single bread() call.

2) Handle symlinks with more than one extent. There's no reason for
this to ever happen, but it's handled now.

3) Finally, add a hint to our iteration initialiser so we can start
from the desired offset, rather than naively looping through from
the beginning each time. Since we can binary search the correct
location quickly, this improves large sequential reads by about
40% with 128MB files. Improvement should increase with file size.

Fix a significant performance bug in efs_read:

When reading a file, we would erroneously iterate to the next extent
before having filled the entire uio request. This lead to unnecessary
extent iteration and excessive calls to efs_read.

Sequential read performance has doubled in the uncached case and
quadrupled when data is buffered.

Add read-only support for SGI's Extent File System.

Reviewed by pooka@.

Define filesystem attributes with vfs dependency.

Change efs from hashlist to vcache.

branches: 1.1.2; 1.1.12; 1.1.82; 1.1.98;
Add read-only support for SGI's Extent File System.

Reviewed by pooka@.