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563 Commits

Author SHA1 Message Date
Kirk McKusick
e04a020067 Unconditionally reset vp->v_vnlock back to the default in the
vclean() function (e.g., vp->v_vnlock = &vp->v_lock) rather
than requiring filesystems that use alternate locks to do so
in their vop_reclaim functions. This change is a further cleanup
of the vop_stdlock interface.

Submitted by:	Poul-Henning Kamp <phk@critter.freebsd.dk>
Sponsored by:	DARPA & NAI Labs.
2002-10-14 19:44:51 +00:00
Kirk McKusick
a5b65058d5 Regularize the vop_stdlock'ing protocol across all the filesystems
that use it. Specifically, vop_stdlock uses the lock pointed to by
vp->v_vnlock. By default, getnewvnode sets up vp->v_vnlock to
reference vp->v_lock. Filesystems that wish to use the default
do not need to allocate a lock at the front of their node structure
(as some still did) or do a lockinit. They can simply start using
vn_lock/VOP_UNLOCK. Filesystems that wish to manage their own locks,
but still use the vop_stdlock functions (such as nullfs) can simply
replace vp->v_vnlock with a pointer to the lock that they wish to
have used for the vnode. Such filesystems are responsible for
setting the vp->v_vnlock back to the default in their vop_reclaim
routine (e.g., vp->v_vnlock = &vp->v_lock).

In theory, this set of changes cleans up the existing filesystem
lock interface and should have no function change to the existing
locking scheme.

Sponsored by:	DARPA & NAI Labs.
2002-10-14 03:20:36 +00:00
Kirk McKusick
192e439ed4 When considering a vnode for reuse in getnewvnode, we call
vcanrecycle to check a free vnode's availability. If it is
available, vcanrecycle returns an error code of zero and the
vnode in question locked. The getnewvnode routine then used
to call vn_start_write with the V_NOWAIT flag. If the filesystem
was suspended while taking a snapshot, the vn_start_write would
fail but getnewvnode would fail to unlock the vnode, instead
leaving it locked on the freelist. The result would be that the
vnode would be locked forever and would eventually hang the
system with a race to the root when it was attempted to recycle
it. This fix moves the vn_start_write check into vcanrecycle
where it will properly unlock the vnode if it is unavailable
for recycling due to filesystem suspension.

Sponsored by:	DARPA & NAI Labs.
2002-10-11 01:04:14 +00:00
Maxim Sobolev
790a8088d0 Fix problem introduced in rev.1.406, which can cause already unlocked
mutex being unlocked again causing system panic.
2002-10-05 12:56:10 +00:00
Poul-Henning Kamp
8d3574c7a4 Fix some harmless mis-indents.
Spotted by:	FlexeLint
2002-10-01 15:48:31 +00:00
Robert Watson
0626774f08 Move vnode MAC label initialization to after the release of the vnode
interlock in getnewvnode() to avoid possible sleeps while holding
the mutex.  Note that the warning from Witness is a slight false
positive since we know there will be no contention on the interlock
since we haven't made the vnode available for use yet, but the theory
is not a bad one.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-09-30 20:51:48 +00:00
Poul-Henning Kamp
37c841831f Be consistent about "static" functions: if the function is marked
static in its prototype, mark it static at the definition too.

Inspired by:    FlexeLint warning #512
2002-09-28 17:15:38 +00:00
Jeff Roberson
6423c9433c - Move ASSERT_VOP_*LOCK* functionality into functions in vfs_subr.c
- Make the VI asserts more orthogonal to the rest of the asserts by using a
   new, common vfs_badlock() function and adding a 'str' arg.
 - Adjust generated ASSERTS to match the new prototype.
 - Adjust explicit ASSERTS to match the new prototype.
2002-09-26 04:48:44 +00:00
Jeff Roberson
6cb8bf2027 - Lock down the syncer with sync_mtx.
- Enable vfs_badlock_mutex by default.
 - Assert that the vp is locked in VOP_UNLOCK.
 - Use standard interlock macros in remaining code.
 - Correct a race in getnewvnode().
 - Lock access to v_numoutput with interlock.
 - Lock access to buf lists and splay tree with interlock.
 - Add VOP and VI asserts.
 - Lock b_vnbufs with the vnode interlock.
 - Add vrefcnt() for callers who want to retreive the vnode ref without
   holding a lock.  Add a comment that describes when this is safe.
 - Add vholdl() and vdropl() so that callers who already own the interlock
   can avoid race conditions and unnecessary unlocking.
 - Move the VOP_GETATTR() in vflush() into the WRITECLOSE conditional case.
 - Hold the interlock before droping the mntlist_mtx in vflush() to avoid
   a race.
 - Fix locking in vfs_msync().
2002-09-25 02:22:21 +00:00
Nate Lawson
86ed6d45ac Remove any VOP_PRINT that redundantly prints the tag.
Move lockmgr_printinfo() into vprint() for everyone's benefit.

Suggested by: bde
2002-09-18 20:42:04 +00:00
Nate Lawson
06be2aaa83 Remove all use of vnode->v_tag, replacing with appropriate substitutes.
v_tag is now const char * and should only be used for debugging.

Additionally:
1. All users of VT_NTS now check vfsconf->vf_type VFCF_NETWORK
2. The user of VT_PROCFS now checks for the new flag VV_PROCDEP, which
is propagated by pseudofs to all child vnodes if the fs sets PFS_PROCDEP.

Suggested by:   phk
Reviewed by:    bde, rwatson (earlier version)
2002-09-14 09:02:28 +00:00
Julian Elischer
85e40eaf26 Indentation does not make a block.. need curly braces too.
Submitted by: Eagle-eyes evans <bde@freebsd.org>
2002-09-11 18:15:26 +00:00
Julian Elischer
71fad9fdee Completely redo thread states.
Reviewed by:	davidxu@freebsd.org
2002-09-11 08:13:56 +00:00
Poul-Henning Kamp
f8b663614d Fix an inherited style bug: compare with NOCRED instead of NULL.
Sponsored by:	DARPA & NAI Labs.
2002-09-05 20:46:19 +00:00
Poul-Henning Kamp
c1a925a637 Introduce new extattr_check_cred() function which implements the canonical
crential washing for extended attributes.

Sponsored by:	DARPA & NAI Labs.
2002-09-05 20:38:57 +00:00
Philippe Charnier
93b0017f88 Replace various spelling with FALLTHROUGH which is lint()able 2002-08-25 13:23:09 +00:00
Jeff Roberson
ad32f726db - Fix a mistake in my last few commits. The PDROP flag stops msleep from
re-acquiring the mutex.

Pointy hat to:	me
Noticed by:	tegge
2002-08-23 00:32:03 +00:00
Jeff Roberson
9abf54f032 - Make vn_lock() vget() and VOP_LOCK() all behave the same way WRT
LK_INTERLOCK.  The interlock will never be held on return from these
   functions even when there is an error.  Errors typically only occur when
   the XLOCK is held which means this isn't the vnode we want anyway.  Almost
   all users of these interfaces expected this behavior even though it was
   not provided before.
2002-08-22 07:44:45 +00:00
Jeff Roberson
183158485a - Fix interlock handling in vn_lock(). Previously, vn_lock() could return
with interlock held in error conditions when the caller did not specify
   LK_INTERLOCK.
 - Add several comments to vn_lock() describing the rational behind the code
   flow since it was not immediately obvious.
2002-08-22 06:51:06 +00:00
Jeff Roberson
0b600db425 - Document two cases, one in vget and the other in vn_lock, where the state
of interlock on exit is not consistent.  There are probably several bugs
   relating to this.
2002-08-21 08:34:48 +00:00
Jeff Roberson
88cf6b94bd - If vn_lock fails with the LK_INTERLOCK flag set, interlock will not be
released.  vcanrecycle() failed to unlock interlock under this condition.
 - Remove an extra VOP_UNLOCK from a failure case in vcanrecycle().

Pointed out by:	rwatson
2002-08-21 06:40:34 +00:00
Jeff Roberson
71ea4ba57c - Add two new debugging macros: ASSERT_VI_LOCKED and ASSERT_VI_UNLOCKED
- Use the new VI asserts in place of the old mtx_assert checks.
 - Add the VI asserts to the automated lock checking in the VOP calls.  The
   interlock should not be held across vops with a few exceptions.
 - Add the vop_(un)lock_{pre,post} functions to assert that interlock is held
   when LK_INTERLOCK is set.
2002-08-21 06:19:29 +00:00
Jeff Roberson
055c012332 - Extend the vnode_free_list_mtx to cover numvnodes and freevnodes. This
was done only some of the time before, and now it is uniformly applied.
2002-08-13 05:29:48 +00:00
Maxime Henrion
5965373e69 - Introduce a new struct xvfsconf, the userland version of struct vfsconf.
- Make getvfsbyname() take a struct xvfsconf *.
- Convert several consumers of getvfsbyname() to use struct xvfsconf.
- Correct the getvfsbyname.3 manpage.
- Create a new vfs.conflist sysctl to dump all the struct xvfsconf in the
  kernel, and rewrite getvfsbyname() to use this instead of the weird
  existing API.
- Convert some {set,get,end}vfsent() consumers to use the new vfs.conflist
  sysctl.
- Convert a vfsload() call in nfsiod.c to kldload() and remove the useless
  vfsisloadable() and endvfsent() calls.
- Add a warning printf() in vfs_sysctl() to tell people they are using
  an old userland.

After these changes, it's possible to modify struct vfsconf without
breaking the binary compatibility.  Please note that these changes don't
break this compatibility either.

When bp will have updated mount_smbfs(8) with the patch I sent him, there
will be no more consumers of the {set,get,end}vfsent(), vfsisloadable()
and vfsload() API, and I will promptly delete it.
2002-08-10 20:19:04 +00:00
Jeff Roberson
8947be9ba0 - Move some logic from getnewvnode() to a new function vcanrecycle()
- Unlock the free list mutex around vcanrecycle to prevent a lock order
   reversal.
2002-08-05 10:15:56 +00:00
Jeff Roberson
e6e370a7fe - Replace v_flag with v_iflag and v_vflag
- v_vflag is protected by the vnode lock and is used when synchronization
   with VOP calls is needed.
 - v_iflag is protected by interlock and is used for dealing with vnode
   management issues.  These flags include X/O LOCK, FREE, DOOMED, etc.
 - All accesses to v_iflag and v_vflag have either been locked or marked with
   mp_fixme's.
 - Many ASSERT_VOP_LOCKED calls have been added where the locking was not
   clear.
 - Many functions in vfs_subr.c were restructured to provide for stronger
   locking.

Idea stolen from:	BSD/OS
2002-08-04 10:29:36 +00:00
Robert Watson
f9d0d52459 Include file cleanup; mac.h and malloc.h at one point had ordering
relationship requirements, and no longer do.

Reminded by:	bde
2002-08-01 17:47:56 +00:00
Dag-Erling Smørgrav
3072197229 Nit in previous commit: the correct sysctl type is "S,xvnode" 2002-07-31 12:25:28 +00:00
Dag-Erling Smørgrav
217b2a0b61 Initialize v_cachedid to -1 in getnewvnode().
Reintroduce the kern.vnode sysctl and make it export xvnodes rather than
vnodes.

Sponsored by:	DARPA, NAI Labs
2002-07-31 12:24:35 +00:00
Robert Watson
07bdba7e2d Note that the privilege indicating flag to vaccess() originally used
by the process accounting system is now deprecated.
2002-07-31 02:05:12 +00:00
Robert Watson
a0ee6ed1c0 Introduce support for Mandatory Access Control and extensible
kernel access control.

Invoke the necessary MAC entry points to maintain labels on vnodes.
In particular, initialize the label when the vnode is allocated or
reused, and destroy the label when the vnode is going to be released,
or reused.  Wow, an object where there really is exactly one place
where it's allocated, and one other where it's freed.  Amazing.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-07-31 02:03:46 +00:00
Jeff Roberson
a562685f65 - Backout the patch made in revision 1.75 of vfs_mount.c. The vputs here
were hiding the real problem of the missing unlock in sync_inactive.
 - Add the missing unlock in sync_inactive.

Submitted by:	iedowse
2002-07-29 06:26:55 +00:00
Don Lewis
5c38b6dbce Wire the sysctl output buffer before grabbing any locks to prevent
SYSCTL_OUT() from blocking while locks are held.  This should
only be done when it would be inconvenient to make a temporary copy of
the data and defer calling SYSCTL_OUT() until after the locks are
released.
2002-07-28 19:59:31 +00:00
Robert Watson
b02aac465d Teach discretionary access control methods for files about VAPPEND
and VALLPERM.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-07-22 03:57:07 +00:00
Kirk McKusick
7aca6291e3 Add support to UFS2 to provide storage for extended attributes.
As this code is not actually used by any of the existing
interfaces, it seems unlikely to break anything (famous
last words).

The internal kernel interface to manipulate these attributes
is invoked using two new IO_ flags: IO_NORMAL and IO_EXT.
These flags may be specified in the ioflags word of VOP_READ,
VOP_WRITE, and VOP_TRUNCATE. Specifying IO_NORMAL means that
you want to do I/O to the normal data part of the file and
IO_EXT means that you want to do I/O to the extended attributes
part of the file. IO_NORMAL and IO_EXT are mutually exclusive
for VOP_READ and VOP_WRITE, but may be specified individually
or together in the case of VOP_TRUNCATE. For example, when
removing a file, VOP_TRUNCATE is called with both IO_NORMAL
and IO_EXT set. For backward compatibility, if neither IO_NORMAL
nor IO_EXT is set, then IO_NORMAL is assumed.

Note that the BA_ and IO_ flags have been `merged' so that they
may both be used in the same flags word. This merger is possible
by assigning the IO_ flags to the low sixteen bits and the BA_
flags the high sixteen bits. This works because the high sixteen
bits of the IO_ word is reserved for read-ahead and help with
write clustering so will never be used for flags. This merge
lets us get away from code of the form:

        if (ioflags & IO_SYNC)
                flags |= BA_SYNC;

For the future, I have considered adding a new field to the
vattr structure, va_extsize. This addition could then be
exported through the stat structure to allow applications to
find out the size of the extended attribute storage and also
would provide a more standard interface for truncating them
(via VOP_SETATTR rather than VOP_TRUNCATE).

I am also contemplating adding a pathconf parameter (for
concreteness, lets call it _PC_MAX_EXTSIZE) which would
let an application determine the maximum size of the extended
atribute storage.

Sponsored by:	DARPA & NAI Labs.
2002-07-19 07:29:39 +00:00
Kirk McKusick
fb36a3d847 Change utimes to set the file creation time (for filesystems that
support creation times such as UFS2) to the value of the
modification time if the value of the modification time is older
than the current creation time. See utimes(2) for further details.

Sponsored by:	DARPA & NAI Labs.
2002-07-17 02:03:19 +00:00
Matthew Dillon
d331c5d43f Replace the global buffer hash table with per-vnode splay trees using a
methodology similar to the vm_map_entry splay and the VM splay that Alan
Cox is working on.  Extensive testing has appeared to have shown no
increase in overhead.

Disadvantages
    Dirties more cache lines during lookups.

    Not as fast as a hash table lookup (but still N log N and optimal
    when there is locality of reference).

Advantages
    vnode->v_dirtyblkhd is now perfectly sorted, making fsync/sync/filesystem
    syncer operate more efficiently.

    I get to rip out all the old hacks (some of which were mine) that tried
    to keep the v_dirtyblkhd tailq sorted.

    The per-vnode splay tree should be easier to lock / SMPng pushdown on
    vnodes will be easier.

    This commit along with another that Alan is working on for the VM page
    global hash table will allow me to implement ranged fsync(), optimize
    server-side nfs commit rpcs, and implement partial syncs by the
    filesystem syncer (aka filesystem syncer would detect that someone is
    trying to get the vnode lock, remembers its place, and skip to the
    next vnode).

Note that the buffer cache splay is somewhat more complex then other splays
due to special handling of background bitmap writes (multiple buffers with
the same lblkno in the same vnode), and B_INVAL discontinuities between the
old hash table and the existence of the buffer on the v_cleanblkhd list.

Suggested by: alc
2002-07-10 17:02:32 +00:00
Jeff Roberson
25b286d6db - Use standard locking functions in syncer's opv
- vput instead of vrele syncer vnodes in vfs_mount
 - Add vop_lookup_{pre,post} to verify locking in VOP_LOOKUP
2002-07-09 19:54:20 +00:00
Jeff Roberson
18c48f437f - Don't hold the vn lock while calling VOP_CLOSE in vclean(). 2002-07-07 06:38:22 +00:00
Jeff Roberson
bed75d4627 - BUF_REFCNT() seems to be the preferred method for verifying a locked buf.
Tell vop_strategy_pre() to use this instead.
 - Ignore B_CLUSTER bufs.  Their components are locked but they don't really
   exist so they don't have to be.  This isn't ideal but it is safe.
2002-07-07 05:29:45 +00:00
Jeff Roberson
c031d11bb4 Fix a mistake in my last commit. Don't grab an extra reference to the object
in bp->b_object.
2002-07-06 21:27:20 +00:00
Jeff Roberson
9a236af3ad Fixup uses of GETVOBJECT.
- Cache a pointer to the vnode's object in the buf.
 - Hold a reference to that object in addition to the vnode's reference just
   to be consistent.
 - Cleanup code that got the object indirectly through the vp and VOP calls.

This fixes at least one case where we were calling GETVOBJECT without a lock.
It also avoids an expensive layered call at the cost of another pointer in
struct buf.
2002-07-06 08:59:52 +00:00
Jeff Roberson
302c7aaab9 - Add vop_strategy_pre to validate VOP_STRATEGY locking.
- Disable original vop_strategy lock specification.
 - Switch to the new vop_strategy_pre for lock validation.

VOP_STRATEGY requires only that the buf is locked UNLESS the block numbers need
to be translated.  There may be other reasons, but as long as the underlying
layer uses a VOP to perform the operations they will be caught later.
2002-07-06 05:21:12 +00:00
Jeff Roberson
cc8662b0f9 Add "vop_rename_pre" to do pre rename lock verification. This is enabled only
with DEBUG_VFS_LOCKS.
2002-07-06 04:39:48 +00:00
Maxime Henrion
d7f9ecc86b Move vfs_rootmountalloc() in vfs_mount.c and remove lite2_vfs_mountroot()
which was #if 0'd and is not likely to be used now.
2002-07-03 09:27:24 +00:00
Maxime Henrion
2b4edb69f1 Move every code related to mount(2) in a new file, vfs_mount.c.
The file vfs_conf.c which was dealing with root mounting has
been repo-copied into vfs_mount.c to preserve history.
This makes nmount related development easier, and help reducing
the size of vfs_syscalls.c, which is still an enormous file.

Reviewed by:	rwatson
Repo-copy by:	peter
2002-07-02 17:09:22 +00:00
Ian Dowse
6bd521df93 Use indirect function pointer hooks instead of #ifdef SOFTUPDATES
direct calls for the two places where the kernel calls into soft
updates code. Set up the hooks in softdep_initialize() and NULL
them out in softdep_uninitialize(). This change allows soft updates
to function correctly when ufs is loaded as a module.

Reviewed by:	mckusick
2002-07-01 17:59:40 +00:00
David E. O'Brien
87e1503e2c Rename the db command lockedvnodes to lockedvnods so that it fits on the
help screen and one doens't think we have a lockedvnodesmap command.
2002-06-29 04:45:09 +00:00
Alfred Perlstein
210a5a7169 nuke caddr_t. 2002-06-28 23:17:36 +00:00
Jeff Roberson
90769c9ed0 Improve the VOP locking asserts
- Add vfs_badlock_print to control whether or not we print lock violations
 - Add vfs_badlock_panic to control whether we panic on lock violations

Both default to on to mimic the original behavior if DEBUG_VFS_LOCKS is on.
2002-06-28 20:58:14 +00:00
Brian Feldman
aac12bcfbc Fix a case where a vnode got explicitly unlocked after the pointer to it
got set to NULL.

Revision 1.355: in the box
2002-06-28 16:17:47 +00:00
Maxime Henrion
7d2d440991 Change the way we internally store the mount options to
a linked list.  This is to allow the merging of the mount
options in the MNT_UPDATE case, as the current data structure
is unsuitable for this.

There are no functional differences in this commit.

Reviewed by:	phk
2002-06-20 20:03:42 +00:00
Maxime Henrion
fe93750656 Change vfs_copyopt() so that the length argument passed to it
must be the exact same size as the mount option.  This makes
vfs_copyopt() much more useful.
2002-06-14 20:04:21 +00:00
Dag-Erling Smørgrav
edad3af28d Move some sysctls from the debug tree to the vfs tree. 2002-06-06 15:50:22 +00:00
Dag-Erling Smørgrav
4a357a32e0 Gratuitous whitespace cleanup. 2002-06-06 15:46:38 +00:00
Tom Rhodes
d394511de3 More s/file system/filesystem/g 2002-05-16 21:28:32 +00:00
Maxime Henrion
34e53231d0 o Fix vfs_copyopt(), the first argument to bcopy() is the source,
not the destination.
o Remove some code from vfs_getopt() which was making the interface
  more complicated to use for a very slight gain.
2002-05-16 17:09:41 +00:00
Jeff Roberson
f0d73b3e5f Switch from just holding the interlock to holding the standard lock throughout
getnewvnode().  This is safer.  In the future, we should investigate requiring
only the interlock to get the vnode object.
2002-05-07 02:44:06 +00:00
Jeff Roberson
6953f5da1a Hold the currently selected vnode's lock across the call to VOP_GETVOBJECT.
Don't try to create a vm object before the file system has a chance to finish
initializing it.  This is incorrect for a number of reasons.  Firstly, that
VOP requires a lock which the file system may not have initialized yet. Also,
open and others will create a vm object if it is necessary later.
2002-05-06 04:47:43 +00:00
Poul-Henning Kamp
81e017430a Expand the one-line function pbreassignbuf() the only place it is or could
be used.
2002-05-05 20:37:08 +00:00
Matthew Dillon
9f9435545b Remove obsolete code (that was already #if 0'd out).
Requested by: Hiten Pandya <hitmaster2k@yahoo.com>
2002-05-04 17:10:15 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
John Baldwin
44731cab3b Change the suser() API to take advantage of td_ucred as well as do a
general cleanup of the API.  The entire API now consists of two functions
similar to the pre-KSE API.  The suser() function takes a thread pointer
as its only argument.  The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0.  The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on:	smp@
2002-04-01 21:31:13 +00:00
Maxime Henrion
17594b936b As discussed in -arch, add the new nmount(2) system call and the
new vfs_getopt()/vfs_copyopt() API.  This is intended to be used
later, when there will be filesystems implementing the VFS_NMOUNT
operation.  The mount(2) system call will disappear when all
filesystems will be converted to the new API.  Documentation will
be committed in a while.

Reviewed by:	phk
2002-03-26 15:33:44 +00:00
Jeff Roberson
c897b81311 Remove references to vm_zone.h and switch over to the new uma API.
Also, remove maxsockets.  If you look carefully you'll notice that the old
zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
Alfred Perlstein
4d77a549fe Remove __P. 2002-03-19 21:25:46 +00:00
Robert Watson
89e1164ee2 Three p_ucred -> td_ucred's missed in jhb's earlier pass; all appear to
be safe.
2002-03-05 19:45:45 +00:00
John Baldwin
a854ed9893 Simple p_ucred -> td_ucred changes to start using the per-thread ucred
reference.
2002-02-27 18:32:23 +00:00
Poul-Henning Kamp
68edc1b939 Make v_addpollinfo() visible and non-inline.
Have callers only call it as needed.
Add necessary call in ufs_kqfilter().

Test-case found by:	Andrew Gallatin <gallatin@cs.duke.edu>
2002-02-18 16:18:02 +00:00
Poul-Henning Kamp
90737495aa Remove yet a redundant VN_KNOTE() macro. 2002-02-18 08:24:48 +00:00
Poul-Henning Kamp
4b55dbe36b Move the stuff related to select and poll out of struct vnode.
The use of the zone allocator may or may not be overkill.
There is an XXX: over in ufs/ufs/ufs_vnops.c that jlemon may need
to revisit.

This shaves about 60 bytes of struct vnode which on my laptop means
600k less RAM used for vnodes.
2002-02-17 21:15:36 +00:00
Peter Wemm
2b8a08af6b Fix a couple of style bugs introduced (or touched by) previous commit. 2002-02-07 23:06:26 +00:00
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
Kirk McKusick
64011154e5 In the routines vrele() and vput(), we must lock the vnode and
call VOP_INACTIVE before placing the vnode back on the free list.
Otherwise there is a race condition on SMP machines between
getnewvnode() locking the vnode to reclaim it and vrele()
locking the vnode to inactivate it. This window of vulnerability
becomes exaggerated in the presence of filesystems that have
been suspended as the inactive routine may need to temporarily
release the lock on the vnode to avoid deadlock with the syncer
process.
2002-02-02 01:49:18 +00:00
Matthew Dillon
c73df808a0 Remove 'VXLOCK: interlock avoided' warnings. This can now occur in normal
operation.  The vgonel() code has always called vclean() but until we
started proactively freeing vnodes it would never actually be called with
a dirty vnode, so this situation did not occur prior to the vnlru() code.
Now that we proactively free vnodes when kern.maxvnodes is hit, however,
vclean() winds up with work to do and improperly generates the warnings.

Reviewed by:	peter
Approved by:	re (for MFC)
MFC after:	1 day
2002-01-19 02:14:45 +00:00
Kirk McKusick
cd6005961f When downgrading a filesystem from read-write to read-only, operations
involving file removal or file update were not always being fully
committed to disk. The result was lost files or corrupted file data.
This change ensures that the filesystem is properly synced to disk
before the filesystem is down-graded.

This delta also fixes a long standing bug in which a file open for
reading has been unlinked. When the last open reference to the file
is closed, the inode is reclaimed by the filesystem. Previously,
if the filesystem had been down-graded to read-only, the inode could
not be reclaimed, and thus was lost and had to be later recovered
by fsck.  With this change, such files are found at the time of the
down-grade.  Normally they will result in the filesystem down-grade
failing with `device busy'. If a forcible down-grade is done, then
the affected files will be revoked causing the inode to be released
and the open file descriptors to begin failing on attempts to read.

Submitted by:	"Sam Leffler" <sam@errno.com>
2002-01-15 07:17:12 +00:00
Matthew Dillon
e61ab5fce9 Add vlruvp() routine - implements LRU operation for vnode recycling.
We calculate a trigger point that both guarentees we will find a
sufficient number of vnodes to recycle and prevents us from recycling
vnodes with lots of resident pages.  This particular section of
code is designed to recycle vnodes, not do unnecessary frees of
cached VM pages.
2002-01-10 18:31:53 +00:00
Matthew Dillon
9dd4281db8 Fix type-o in previous commit (tsleep was using wrong rendezvous point) 2001-12-25 01:23:25 +00:00
Matthew Dillon
23b590188f Fix a BUF_TIMELOCK race against BUF_LOCK and fix a deadlock in vget()
against VM_WAIT in the pageout code.  Both fixes involve adjusting
the lockmgr's timeout capability so locks obtained with timeouts do not
interfere with locks obtained without a timeout.

Hopefully MFC: before the 4.5 release
2001-12-20 22:42:27 +00:00
Peter Wemm
9f2f52d695 Do not initialize static/global variables to 0. Use bss instead of
taking up space in the data section.
2001-12-19 01:35:18 +00:00
Peter Wemm
8f0d41d324 Use a different mechanism to get the vnlru process to wake up and notice
the shutdown request at reboot/halt time.
Disable the printf 'vnlru process getting nowhere, pausing...' and instead
export the count to the debug.vnlru_nowhere sysctl.
2001-12-19 01:31:12 +00:00
Matthew Dillon
fdb33f08ef This is a forward port of Peter's vlrureclaim() fix, with some minor mods
by me to make it more efficient.  The original code had serious balancing
problems and could also deadlock easily.  This code relegates the vnode
reclamation to its own kproc and relaxes the vnode reclamation requirements
to better maintain kern.maxvnodes.  This code still doesn't balance as well
as it could, but it does a much better job then the original code.

Approved by:	re@freebsd.org
Obtained from:	ps, peter, dillon
MFS Assuming:	Assuming no problems crop up in Yahoo testing
MFC after:	7 days
2001-12-18 20:48:54 +00:00
Matthew Dillon
873a490449 A slightly different version of the vlrureclaim fix.
Reported by: peter, ps
2001-12-14 07:18:31 +00:00
Peter Wemm
9446b36bab If we were called to allocate a vnode that is not associated with a
mount point, do not dereference the NULL mp argument.
2001-12-13 23:46:01 +00:00
Matthew Dillon
6b8bd2efc1 Add mnt_reservedvnlist so we can MFC to 4.x, in order to make all mount
structure changes now rather then piecemeal later on.  mnt_nvnodelist
currently holds all the vnodes under the mount point.  This will eventually
be split into a 'dirty' and 'clean' list.  This way we only break kld's once
rather then twice.  nvnodelist will eventually turn into the dirty list
and should remain compatible with the klds.
2001-11-04 18:55:42 +00:00
Robert Watson
bcc0dc3dc7 Merge from POSIX.1e Capabilities development tree:
o POSIX.1e capabilities authorize overriding of VEXEC for VDIR based
  on CAP_DAC_READ_SEARCH, but of !VDIR based on CAP_DAC_EXECUTE.  Add
  appropriate conditionals to vaccess() to take that into account.
o Synchronization cap_check_xxx() -> cap_check() change.

Obtained from:	TrustedBSD Project
2001-11-02 15:16:59 +00:00
Matthew Dillon
4ffa210b94 syncdelay, filedelay, dirdelay, metadelay are ints, not time_t's,
and can also be made static.
2001-10-27 19:58:56 +00:00
Matthew Dillon
245df27cee Implement kern.maxvnodes. adjusting kern.maxvnodes now actually has a
real effect.

Optimize vfs_msync().  Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list.  Improves looping case by 500%.

Optimize ffs_sync().  Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list.  This makes a couple of assumptions,
which I believe are ok, in regards to vnode stability when the mount list
mutex is held.  Improves looping case by 500%.

(more optimization work is needed on top of these fixes)

MFC after:	1 week
2001-10-26 00:08:05 +00:00
Matthew Dillon
f92dcd3e4a Add missing TAILQ_INSERT_TAIL's which somehow didn't get comitted with
the recent vnode cleanup.
2001-10-25 23:13:56 +00:00
Matthew Dillon
c72ccd014d Change the vnode list under the mount point from a LIST to a TAILQ
in preparation for an implementation of limiting code for kern.maxvnodes.

MFC after:	3 days
2001-10-23 01:21:29 +00:00
Matthew Dillon
2210e5d9fa fix minor bug in kern.minvnodes sysctl. Use OID_AUTO. 2001-10-16 23:08:09 +00:00
Matthew Dillon
917efbaaba WS Cleanup 2001-10-08 19:51:13 +00:00
Matthew Dillon
845bd795c9 vinvalbuf() was only waiting for write-I/O to complete. It really has to
wait for both read AND write I/O to complete.  Only NFS calls vinvalbuf()
on an active vnode (when the server indicates that the file is stale), so
this bug fix only effects NFS clients.

MFC after:	3 days
2001-10-05 20:10:32 +00:00
Matthew Dillon
b5810bab2d After extensive testing it has been determined that adding complexity
to avoid removing higher level directory vnodes from the namecache has
no perceivable effect and will be removed.  This is especially true
when vmiodirenable is turned on, which it is by default now.  ( vmiodirenable
makes a huge difference in directory caching ).  The vfs.vmiodirenable and
vfs.nameileafonly sysctls have been left in to allow further testing, but
I expect to rip out vfs.nameileafonly soon too.

I have also determined through testing that the real problem with numvnodes
getting too large is due to the VM Page cache preventing the vnode from
being reclaimed.  The directory stuff made only a tiny dent relative
to Poul's original code, enough so that some tests succeeded.  But tests
with several million small files show that the bigger problem is the VM Page
cache.  This will have to be addressed by a future commit.

MFC after:	3 days
2001-10-01 04:33:35 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Peter Wemm
0f7289022b If a file has been completely unlinked, stop automatically syncing the
file.  ffs will discard any pending dirty pages when it is closed,
so we may as well not waste time trying to clean them.  This doesn't
stop other things from writing it out, eg: pageout, fsync(2) etc.
2001-08-27 06:09:56 +00:00
Peter Wemm
b219758f94 Revert previous accidental commit. FWIW, it was part of enabling
VM caching of disks through mmap() and stopping syncing of open files
that had their last reference in the fs removed (ie: their unsync'ed
pages get discarded on close already, so I made it stop syncing too).
2001-07-27 15:57:17 +00:00
Peter Wemm
24a590a074 Fix cut/paste blunder. Serves me right for doing a last minute tweak
to what I had for some time.

Submitted by:	bde
2001-07-27 15:52:49 +00:00
Matthew Dillon
0cddd8f023 With Alfred's permission, remove vm_mtx in favor of a fine-grained approach
(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
2001-07-04 16:20:28 +00:00
John Baldwin
cd2f721557 - Fix a mntvnode and vnode interlock reversal.
- Protect the mnt_vnode list with the mntvnode lock.
2001-06-28 04:05:54 +00:00
Alfred Perlstein
2395531439 Introduce a global lock for the vm subsystem (vm_mtx).
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
Ian Dowse
0864ef1e8a Change the second argument of vflush() to an integer that specifies
the number of references on the filesystem root vnode to be both
expected and released. Many filesystems hold an extra reference on
the filesystem root vnode, which must be accounted for when
determining if the filesystem is busy and then released if it isn't
busy. The old `skipvp' approach required individual filesystem
xxx_unmount functions to re-implement much of vflush()'s logic to
deal with the root vnode.

All 9 filesystems that hold an extra reference on the root vnode
got the logic wrong in the case of forced unmounts, so `umount -f'
would always fail if there were any extra root vnode references.
Fix this issue centrally in vflush(), now that we can.

This commit also fixes a vnode reference leak in devfs, which could
result in idle devfs filesystems that refuse to unmount.

Reviewed by:	phk, bp
2001-05-16 18:04:37 +00:00
Ian Dowse
1feb7a6efa In vrele() and vput(), avoid triggering the confusing "missed vn_close"
KASSERT when vp->v_usecount is zero or negative. In this case, the
"v*: negative ref cnt" panic that follows is much more appropriate.

Reviewed by:	mckusick
2001-05-11 20:42:41 +00:00
Poul-Henning Kamp
8ee8b21b48 vfs_subr.c is getting rather fat. The underlying repocopy and this
commit moves the filesystem export handling code to vfs_export.c
2001-04-26 20:47:14 +00:00
Poul-Henning Kamp
a13234bb35 Move the netexport structure from the fs-specific mountstructure
to struct mount.

This makes the "struct netexport *" paramter to the vfs_export
and vfs_checkexport interface unneeded.

Consequently that all non-stacking filesystems can use
vfs_stdcheckexp().

At the same time, make it a pointer to a struct netexport
in struct mount, so that we can remove the bogus AF_MAX
and #include <net/radix.h> from <sys/mount.h>
2001-04-25 07:07:52 +00:00
Greg Lehey
d98dc34f52 Correct #includes to work with fixed sys/mount.h. 2001-04-23 09:05:15 +00:00
Seigo Tanimura
759cb26335 Reclaim directory vnodes held in namecache if few free vnodes are
available.

Only directory vnodes holding no child directory vnodes held in
v_cache_src are recycled, so that directory vnodes near the root of
the filesystem hierarchy remain in namecache and directory vnodes are
not reclaimed in cascade.

The period of vnode reclaiming attempt and the number of vnodes
attempted to reclaim can be tuned via sysctl(2).

Suggested by:	tegge
Approved by:	phk
2001-04-18 11:19:50 +00:00
Poul-Henning Kamp
f84e29a06c This patch removes the VOP_BWRITE() vector.
VOP_BWRITE() was a hack which made it possible for NFS client
side to use struct buf with non-bio backing.

This patch takes a more general approach and adds a bp->b_op
vector where more methods can be added.

The success of this patch depends on bp->b_op being initialized
all relevant places for some value of "relevant" which is not
easy to determine.  For now the buffers have grown a b_magic
element which will make such issues a tiny bit easier to debug.
2001-04-17 08:56:39 +00:00
Jonathan Lemon
7df2842dee Add a NOTE_REVOKE flag for vnodes, which is triggered from within vclean().
Use this to tell a filter attached to a vnode that the underlying vnode is
no longer valid, by returning EV_EOF.

PR: kern/25309, kern/25206
2001-02-23 20:06:01 +00:00
Brian Feldman
c0511d3b58 Switch to using a struct xucred instead of a struct xucred when not
actually in the kernel.  This structure is a different size than
what is currently in -CURRENT, but should hopefully be the last time
any application breakage is caused there.  As soon as any major
inconveniences are removed, the definition of the in-kernel struct
ucred should be conditionalized upon defined(_KERNEL).

This also changes struct export_args to remove dependency on the
constantly-changing struct ucred, as well as limiting the bounds
of the size fields to the correct size.  This means: a) mountd and
friends won't break all the time, b) mountd and friends won't crash
the kernel all the time if they don't know what they're doing wrt
actual struct export_args layout.

Reviewed by:	bde
2001-02-18 13:30:20 +00:00
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
Poul-Henning Kamp
fc2ffbe604 Mechanical change to use <sys/queue.h> macro API instead of
fondling implementation details.

Created with: sed(1)
Reviewed by: md5(1)
2001-02-04 13:13:25 +00:00
Boris Popov
f3f1af390d Properly lock new vnode.
Reminded by:	tegge
2001-01-31 04:54:23 +00:00
Jason Evans
1b367556b5 Convert all simplelocks to mutexes and remove the simplelock implementations. 2001-01-24 12:35:55 +00:00
Robert Watson
02b65ffb64 o The move to using VADMIN under vaccess() resulted in some system
calls returning EACCES instead of EPERM.  This patch modifies vaccess()
  to return EPERM instead of EACCES if VADMIN is among the requested
  rights.  This affects functions normally limited to the owners of
  a file, such as chmod(), as EPERM is the error indicating that
  privilege would allow the operation, rather than a chance in mandatory
  or discretionary rights.

Reported by:	bde
2001-01-23 04:15:19 +00:00
John Baldwin
ffc831da27 Stick the kthread API in a kthread_* namespace, and the specialized kproc
functions in a kproc_* namespace.

Reviewed by:	-arch
2000-12-15 20:08:20 +00:00
Kirk McKusick
0bf3b91d8a Use proper mutex locking when calling setrunnable from speedup_syncer().
Submitted by:	Tor.Egge@fast.no
2000-12-13 01:06:53 +00:00
David Malone
7cc0979fd6 Convert more malloc+bzero to malloc+M_ZERO.
Submitted by:	josh@zipperup.org
Submitted by:	Robert Drehmel <robd@gmx.net>
2000-12-08 21:51:06 +00:00
Peter Wemm
138e514cb5 Untangle vfsinit() a bit. Use seperate sysinit functions rather than
having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
Andrew Gallatin
19f085228f Correct int/long type mismatch in the proper place this time. freevnodes
and numvnodes are longs in the kernel.  They should remain longs in systat,
what really needs to change is that they should be using SYSCTL_LONG rather
than SYSCTL_INT.   I also changed wantfreevnodes to SYSCTL_LONG because I
happened to notice it.

I wish there was a way to find all of these automatically..

Pointed out by: bde
2000-12-02 20:08:33 +00:00
John Baldwin
2191340786 Use msleep() instead of mtx_exit()/tsleep() so that we release the lock and
go to sleep as an "atomic" operation.
2000-12-01 03:43:33 +00:00
Kirk McKusick
6d984dfa6a Get rid of a bogus mtx_exit (it was attempting to release an
already released mutex).

Submitted by:	"Chris Knight" <chris@aims.com.au>
2000-11-30 19:09:29 +00:00
Matthew Dillon
936524aa02 Implement a low-memory deadlock solution.
Removed most of the hacks that were trying to deal with low-memory
    situations prior to now.

    The new code is based on the concept that I/O must be able to function in
    a low memory situation.  All major modules related to I/O (except
    networking) have been adjusted to allow allocation out of the system
    reserve memory pool.  These modules now detect a low memory situation but
    rather then block they instead continue to operate, then return resources
    to the memory pool instead of cache them or leave them wired.

    Code has been added to stall in a low-memory situation prior to a vnode
    being locked.

    Thus situations where a process blocks in a low-memory condition while
    holding a locked vnode have been reduced to near nothing.  Not only will
    I/O continue to operate, but many prior deadlock conditions simply no
    longer exist.

Implement a number of VFS/BIO fixes

	(found by Ian): in biodone(), bogus-page replacement code, the loop
        was not properly incrementing loop variables prior to a continue
        statement.  We do not believe this code can be hit anyway but we
        aren't taking any chances.  We'll turn the whole section into a
        panic (as it already is in brelse()) after the release is rolled.

	In biodone(), the foff calculation was incorrectly
        clamped to the iosize, causing the wrong foff to be calculated
        for pages in the case of an I/O error or biodone() called without
        initiating I/O.  The problem always caused a panic before.  Now it
        doesn't.  The problem is mainly an issue with NFS.

	Fixed casts for ~PAGE_MASK.  This code worked properly before only
        because the calculations use signed arithmatic.  Better to properly
        extend PAGE_MASK first before inverting it for the 64 bit masking
        op.

	In brelse(), the bogus_page fixup code was improperly throwing
        away the original contents of 'm' when it did the j-loop to
        fix the bogus pages.  The result was that it would potentially
        invalidate parts of the *WRONG* page(!), leading to corruption.

	There may still be cases where a background bitmap write is
        being duplicated, causing potential corruption.  We have identified
        a potentially serious bug related to this but the fix is still TBD.
        So instead this patch contains a KASSERT to detect the problem
  	and panic the machine rather then continue to corrupt the filesystem.
	The problem does not occur very often..  it is very hard to
	reproduce, and it may or may not be the cause of the corruption
	people have reported.

Review by: (VFS/BIO: mckusick, Ian Dowse <iedowse@maths.tcd.ie>)
Testing by: (VM/Deadlock) Paul Saab <ps@yahoo-inc.com>
2000-11-18 23:06:26 +00:00
Tor Egge
a2d1480cf8 Clear the VFREE flag when the vnode is removed from the free list in
getnewvnode().  Otherwise routines called from VOP_INACTIVE() might
attempt to remove the vnode from a free list the vnode isn't on,
causing corruption.
PR:		18012
2000-11-02 21:42:54 +00:00
Poul-Henning Kamp
1d7e3e42e7 Take VBLK devices further out of their missery.
This should fix the panic I introduced in my previous commit on this topic.
2000-11-02 21:14:13 +00:00
John Baldwin
35e0e5b311 Catch up to moving headers:
- machine/ipl.h -> sys/ipl.h
- machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
Robert Watson
47460a23a0 o Introduce new VOP_ACCESS() flag VADMIN, allowing file systems to perform
"administrative" authorization checks.  In most cases, the VADMIN test
  checks to make sure the credential effective uid is the same as the file
  owner.
o Modify vaccess() to set VADMIN as an available right if the uid is
  appropriate.
o Modify references to uid-based access control operations such that they
  now always invoke VOP_ACCESS() instead of using hard-coded policy checks.
o This allows alternative UFS policies to be implemented by replacing only
  ufs_access() (such as mandatory system policies).
o VOP_ACCESS() requires the caller to hold an exclusive vnode lock on the
  vnode: I believe that new invocations of VOP_ACCESS() are always called
  with the lock held.
o Some direct checks of the uid remain, largely associated with the QUOTA
  and SUIDDIR code.

Reviewed by:	eivind
Obtained from:	TrustedBSD Project
2000-10-19 07:53:59 +00:00
Eivind Eklund
7eb9fca557 Blow away the v_specmountpoint define, replacing it with what it was
defined as (rdev->si_mountpoint)
2000-10-09 17:31:39 +00:00
Jason Evans
39df86086f Do not call lockdestroy() for v_vnlock, which may point to a lock in a
deeper vfs stacking layer.

Submitted by:	bp
2000-10-06 08:04:48 +00:00
Eivind Eklund
a863c0fb2f Style fixes based on comments by bde 2000-10-05 18:22:46 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Boris Popov
f8be809e0f Move KASSERTs which checks value of v_usecount after vnode locking, so
it will not produce wrong alarms.
2000-10-02 09:57:06 +00:00
Kirk McKusick
02a1e48f02 Do the right thing if bdevvp is called twice for the same device.
Obtained from:	Poul-Henning Kamp <phk@freebsd.org>
2000-09-27 18:03:17 +00:00
Boris Popov
67e871664b Add a lock structure to vnode structure. Previously it was either allocated
separately (nfs, cd9660 etc) or keept as a first element of structure
referenced by v_data pointer(ffs). Such organization leads to known problems
with stacked filesystems.

From this point vop_no*lock*() functions maintain only interlock lock.
vop_std*lock*() functions maintain built-in v_lock structure using lockmgr().
vop_sharedlock() is compatible with vop_stdunlock(), but maintains a shared
lock on vnode.

If filesystem wishes to export lockmgr compatible lock, it can put an address
of this lock to v_vnlock field. This indicates that the upper filesystem
can take advantage of it and use single lock structure for entire (or part)
of stack of vnodes. This field shouldn't be examined or modified by VFS code
except for initialization purposes.

Reviewed in general by:	mckusick
2000-09-25 15:24:04 +00:00
Eivind Eklund
453aaa0dff Style fixes:
* Add lots of comments
* Convert a couple of assertions to KASSERT()
* Minimal whitespace & misapplied {} fixes
* Convert #if 0 to #if COMPILING_LINT for code we presently do not
  support, but want to keep available.

Reviewed by:	adrian, markm
2000-09-22 12:22:36 +00:00
Eivind Eklund
bba25953af Staticize addalias() 2000-09-22 11:54:48 +00:00
Alfred Perlstein
21a9039725 comment vfs_export functions, requested by: eivind 2000-09-21 15:55:55 +00:00
Robert Watson
e084835893 o Add additional comment describing vaccess() behavior.
Requested by:	eivind
Reviewed by:	eivind, adrian
2000-09-20 17:18:12 +00:00
Poul-Henning Kamp
b0d17ba69e Rename lminor() to dev2unit(). This function gives a linear unit number
which hides the 'hole' in the minor bits.

Introduce unit2minor() to do the reverse operation.

Fix some some make_dev() calls which didn't use UID_* or GID_* macros.

Kill the v_hashchain alias macro, it hides the real relationship.

Introduce experimental SI_CHEAPCLONE flag set it on cloned bpfs.
2000-09-19 10:28:44 +00:00
Boris Popov
9ff5ce6baf Add three new VOPs: VOP_CREATEVOBJECT, VOP_DESTROYVOBJECT and VOP_GETVOBJECT.
They will be used by nullfs and other stacked filesystems to support full
cache coherency.

Reviewed in general by:	mckusick, dillon
2000-09-12 09:49:08 +00:00
Jason Evans
0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Robert Watson
728783c27a o Synchronize vaccess() capability access control checks with TrustedBSD
tree.

Obtained from:	TrustedBSD Project
2000-09-06 12:18:24 +00:00
Poul-Henning Kamp
64dc16df4a Move extern declaration of dead_vnodeop_p to a .h file.
Remove race condition in vn_isdisk().
2000-09-05 21:09:56 +00:00
Robert Watson
012c643d3e o Restructure vaccess() so as to check for DAC permission to modify the
object before falling back on privilege.  Make vaccess() accept an
  additional optional argument, privused, to determine whether
  privilege was required for vaccess() to return 0.  Add commented
  out capability checks for reference.  Rename some variables to make
  it more clear which modes/uids/etc are associated with the object,
  and which with the access mode.
o Update file system use of vaccess() to pass NULL as the optional
  privused argument.  Once additional patches are applied, suser()
  will no longer set ASU, so privused will permit passing of
  privilege information up the stack to the caller.

Reviewed by:	bde, green, phk, -security, others
Obtained from:	TrustedBSD Project
2000-08-29 14:45:49 +00:00
Poul-Henning Kamp
4fe6d43729 Fix typo in last commit. 2000-08-20 11:46:39 +00:00
Poul-Henning Kamp
e39c53eda5 Centralize the canonical vop_access user/group/other check in vaccess().
Discussed with: bde
2000-08-20 08:36:26 +00:00
Kirk McKusick
9b97113391 This patch corrects the first round of panics and hangs reported
with the new snapshot code.

Update addaliasu to correctly implement the semantics of the old
checkalias function. When a device vnode first comes into existence,
check to see if an anonymous vnode for the same device was created
at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than
creating a new vnode for the device. This corrects a problem which
caused the kernel to panic when taking a snapshot of the root
filesystem.

Change the calling convention of vn_write_suspend_wait() to be the
same as vn_start_write().

Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue when suspending filesystem
operations.

Access to buffers becomes recursive so that snapshots can recursively
traverse their indirect blocks using ffs_copyonwrite() when checking
for the need for copy on write when flushing one of their own indirect
blocks. This eliminates a deadlock between the syncer daemon and a
process taking a snapshot.

Ensure that softdep_process_worklist() can never block because of a
snapshot being taken. This eliminates a problem with buffer starvation.

Cleanup change in ffs_sync() which did not synchronously wait when
MNT_WAIT was specified. The result was an unclean filesystem panic
when doing forcible unmount with heavy filesystem I/O in progress.

Return a zero'ed block when reading a block that was not in use at
the time that a snapshot was taken. Normally, these blocks should
never be read. However, the readahead code will occationally read
them which can cause unexpected behavior.

Clean up the debugging code that ensures that no blocks be written
on a filesystem while it is suspended. Snapshots must explicitly
label the blocks that they are writing during the suspension so that
they do not cause a `write on suspended filesystem' panic.

Reorganize ffs_copyonwrite() to eliminate a deadlock and also to
prevent a race condition that would permit the same block to be
copied twice. This change eliminates an unexpected soft updates
inconsistency in fsck caused by the double allocation.

Use bqrelse rather than brelse for buffers that will be needed
soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
Kirk McKusick
f2a2857bb3 Add snapshots to the fast filesystem. Most of the changes support
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.

Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
Boris Popov
3660ebc2c0 Fix support for more than 256 simultaneous mounts. Theoretical limit
is 2^16 mounts per fs type.

Reported by:	Troy Arie Cobb <tcobb@staff.circle.net> via phk
Reviewed by:	bde
2000-07-07 14:01:08 +00:00
Poul-Henning Kamp
77978ab8bc Previous commit changing SYSCTL_HANDLER_ARGS violated KNF.
Pointed out by:	bde
2000-07-04 11:25:35 +00:00
Kirk McKusick
c904bbbdd8 Simplify and rationalise the management of the vnode free list
(preparing the code to add snapshots).
2000-07-04 04:32:40 +00:00
Kirk McKusick
3764219663 If a buffer flush fails when trying to reclaim a vnode, it is too
late to save the vnode, so just toss any remaining unwritten buffers
rather than leaving them lying around to make trouble in the future.
2000-07-04 03:23:29 +00:00
Poul-Henning Kamp
3275cf7379 Make the two calls from kern/* into softupdates #ifdef SOFTUPDATES,
that is way cleaner than using the softupdates_stub stunt, which
should be killed when convenient.

Discussed with:	mckusick
2000-07-03 13:26:54 +00:00
Poul-Henning Kamp
82d9ae4e32 Style police catches up with rev 1.26 of src/sys/sys/sysctl.h:
Sanitize SYSCTL_HANDLER_ARGS so that simplistic tools can grog our
sources:

        -sysctl_vm_zone SYSCTL_HANDLER_ARGS
        +sysctl_vm_zone (SYSCTL_HANDLER_ARGS)
2000-07-03 09:35:31 +00:00
Poul-Henning Kamp
a8b1f9d2c9 Move prtactive to vfs from ufs. It is used all over the place. 2000-06-27 07:46:22 +00:00
Poul-Henning Kamp
a2e7a027a7 Virtualizes & untangles the bioops operations vector.
Ref: Message-ID: <18317.961014572@critter.freebsd.dk> To: current@
2000-06-16 08:48:51 +00:00
Jake Burkholder
e39756439c Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by:		msmith and others
2000-05-26 02:09:24 +00:00
Jake Burkholder
740a1973a6 Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by:	phk
Reviewed by:	phk
Approved by:	mdodd
2000-05-23 20:41:01 +00:00
Jeroen Ruigrok van der Werven
01f76720fb Fix the rootmount code for now.
This function will probably rewritten/renamed to devpp.

Submitted by:	Assar Westerlund <assar@sics.se> on -current
Confirmed to work:	Steinar Haug <sthaug@nethelp.no>,
			Manfred Antar <mantar@pacbell.net>
Reviewed by:	phk
2000-05-14 07:43:12 +00:00
Poul-Henning Kamp
9626b608de Separate the struct bio related stuff out of <sys/buf.h> into
<sys/bio.h>.

<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.

Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.

Still a few bogus uses of struct buf to track down.

Repocopy by:    peter
2000-05-05 09:59:14 +00:00
Poul-Henning Kamp
b99c307a21 Rename the existing BUF_STRATEGY() to DEV_STRATEGY()
substitute BUF_WRITE(foo) for VOP_BWRITE(foo->b_vp, foo)

substitute BUF_STRATEGY(foo) for VOP_STRATEGY(foo->b_vp, foo)

This patch is machine generated except for the ccd.c and buf.h parts.
2000-03-20 11:29:10 +00:00
Chris Costello
b081a64afb In vn_isdisk(), check whether vp->v_rdev is NULL. If it is, then
return ENXIO (Device not configured).  Without this, vn_isdisk()
could (and did in the case of lstat() under fdesc) pass a NULL pointer
to devsw(), which caused a page fault.

Reviewed by:	alfred
2000-03-18 01:27:44 +00:00
Poul-Henning Kamp
db5f635acc Eliminate the undocumented, experimental, non-delivering and highly
dangerous MAX_PERF option.
2000-03-16 08:51:55 +00:00
Bruce Evans
05ecdd7037 Don't try so hard to make the lower 16 bits of fsids unique. It tended
to recycle full fsids after only 16 mount/unmount's.  This is probably
too often for exported fsids.  Now we recycle the full fsids only
after 2^16 mount/ umount's and only ensure uniqueness in the lower 16
bits if there have been <= 256 calls to vfs_getnewfsid() since the
system started.
2000-03-14 14:19:49 +00:00
Bruce Evans
61214975da Try harder to make the lower 16 bits of fsids unique. The vfs type
number was packed very wastefully, giving perfect non-uniqeness in
the lower 16 bits of fsids for filesystems with the same vfs type.
This made linux_stat() return perfectly non-unique (broken) 16-bit
st_dev's for nfs mount points, and effectively reduced mntid_base to
8 bits so that the vfs_getnewfsid() looped endlessly when there are
already 256 mounted filesystems with the required vfs type.

Approved by:	jkh
2000-03-12 14:23:21 +00:00
Søren Schmidt
e8359a57de Do refcounting of open devices (more) correctly.
count_dev funtion by phk.
2000-02-07 23:05:40 +00:00
Robert Watson
b7a5f3ca1b Remove static qualifier from vgonel, as it is needed by the Arla folk
outside of vfs_subr.c.

Submitted by:	Assar Westerlund <assar@sics.se>
Reviewed by:	rwatson
Approved by:	jkh
2000-02-02 07:07:17 +00:00
Robert Watson
9a2b8fca80 This patch fixes a locking bug that can result in deadlock if
the codepath is followed.

From the PR:

  vclean calls vrele leading to deadlock (if usecount > 0)

  vclean() calls vrele() if v_usecount of the node was higher than one.
  But before calling it, it sets the VXLOCK flag, which will make
  vn_lock called from vrele dead-lock.

PR:		kern/15117
Submitted by:	Assar Westerlund <assar@stacken.kth.se>
Reviewed by:	rwatson
Obtained from:	NetBSD
2000-01-29 15:22:58 +00:00
Poul-Henning Kamp
ba4ad1fcea Give vn_isdisk() a second argument where it can return a suitable errno.
Suggested by:	bde
2000-01-10 12:04:27 +00:00
Kirk McKusick
411e1480fd Remove the P_BUFEXHAUST flag from the syncer process (leaving
it only on the buf_daemon process). The problem is that when the
syncer process starts running the worklist, it wants to delete
lots of files. It does this by VFS_VGET'ing the vnodes, clearing
the blocks in them and bdwrite'ing the buffer. It can process close
to a thousand files per second which generates a large number of
dirty buffers. So, giving it special priviledge at the buffer trough
leads to trouble as the buf_daemon does occationally need a free
buffer to proceed and if the syncer has used every last one up,
we are toast.
2000-01-10 00:07:24 +00:00
Eivind Eklund
e12d97d239 Change NDFREE() from a macro to a function for the time being; the macro
version caused intolerable bloat (30k).  I'm likely to revisit this with an
attempt at a smarter macro.

Bloat noticed by:       bde
2000-01-08 16:20:06 +00:00
Luoqi Chen
5e95083920 Introduce a mechanism to suspend/resume system processes. Suspend syncer
and bufdaemon prior to disk sync during system shutdown.
2000-01-07 08:36:44 +00:00
Matthew Dillon
c37c9620cd Enhance reassignbuf(). When a buffer cannot be time-optimally inserted
into vnode dirtyblkhd we append it to the list instead of prepend it to
    the list in order to maintain a 'forward' locality of reference, which
    is arguably better then 'reverse'.  The original algorithm did things this
    way to but at a huge time cost.

    Enhance the append interlock for NFS writes to handle intr/soft mounts
    better.

    Fix the hysteresis for NFS async daemon I/O requests to reduce the
    number of unnecessary context switches.

    Modify handling of NFS mount options.  Any given user option that is
    too high now defaults to the kernel maximum for that option rather then
    the kernel default for that option.

Reviewed by:	 Alfred Perlstein <bright@wintelcom.net>
2000-01-05 05:11:37 +00:00
Kirk McKusick
02b0085406 Prettyness police: Identify flags in b_xflags with BX_ to distinguish
them from flags in b_flags which are prefixed with B_
1999-12-22 03:11:04 +00:00
Matthew Dillon
4f79d873c1 Add MAP_NOSYNC feature to mmap(), and MADV_NOSYNC and MADV_AUTOSYNC to
madvise().

    This feature prevents the update daemon from gratuitously flushing
    dirty pages associated with a mapped file-backed region of memory.  The
    system pager will still page the memory as necessary and the VM system
    will still be fully coherent with the filesystem.  Modifications made
    by other means to the same area of memory, for example by write(), are
    unaffected.  The feature works on a page-granularity basis.

    MAP_NOSYNC allows one to use mmap() to share memory between processes
    without incuring any significant filesystem overhead, putting it in
    the same performance category as SysV Shared memory and anonymous memory.

Reviewed by: julian, alc, dg
1999-12-12 03:19:33 +00:00
Eivind Eklund
6bdfe06ad9 Lock reporting and assertion changes.
* lockstatus() and VOP_ISLOCKED() gets a new process argument and a new
  return value: LK_EXCLOTHER, when the lock is held exclusively by another
  process.
* The ASSERT_VOP_(UN)LOCKED family is extended to use what this gives them
* Extend the vnode_if.src format to allow more exact specification than
  locked/unlocked.

This commit should not do any semantic changes unless you are using
DEBUG_VFS_LOCKS.

Discussed with:	grog, mch, peter, phk
Reviewed by:	peter
1999-12-11 16:13:02 +00:00
Matthew Dillon
245efbba4d Remove vfs_getrootfsid() function (a temporary hack added a few months
ago to make BOOTP work again).  It is no longer required by BOOTP and
    no longer used.
1999-11-29 22:25:36 +00:00
Poul-Henning Kamp
38224dcd59 Convert various pieces of code to use vn_isdisk() rather than checking
for vp->v_type == VBLK.

In ccd: we don't need to call VOP_GETATTR to find the type of a vnode.

Reviewed by:    sos
1999-11-22 10:33:55 +00:00
Poul-Henning Kamp
0429e37ade struct mountlist and struct mount.mnt_list have no business being
a CIRCLEQ.  Change them to TAILQ_HEAD and TAILQ_ENTRY respectively.

This removes ugly  mp != (void*)&mountlist  comparisons.

Requested by:   phk
Submitted by:   Jake Burkholder jake@checker.org
PR:             14967
1999-11-20 10:00:46 +00:00
Poul-Henning Kamp
1b7277516b Commit the remaining part of PR14914:
Alot of the code in sys/kern directly accesses the *Q_HEAD and *Q_ENTRY
   structures for list operations.  This patch makes all list operations
   in sys/kern use the queue(3) macros, rather than directly accessing the
   *Q_{HEAD,ENTRY} structures.

Reviewed by:    phk
Submitted by:   Jake Burkholder <jake@checker.org>
PR:     14914
1999-11-16 16:28:58 +00:00
Poul-Henning Kamp
698f9cf828 Next step in the device cleanup process.
Correctly lock vnodes when calling VOP_OPEN() from filesystem mount code.

Unify spec_open() for bdev and cdev cases.

Remove the disabled bdev specific read/write code.
1999-11-09 14:15:33 +00:00
Poul-Henning Kamp
923502ff91 useracc() the prequel:
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>.  This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.

This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
1999-10-29 18:09:36 +00:00
Peter Wemm
d1f088dab5 Trim unused options (or #ifdef for undoc options).
Submitted by:	phk
1999-10-11 15:19:12 +00:00
Poul-Henning Kamp
aa4f4b695e Move the buffered read/write code out of spec_{read|write} and into
two new functions spec_buf{read|write}.

Add sysctl vfs.bdev_buffered which defaults to 1 == true.  This
sysctl can be used to experimentally turn buffered behaviour for
bdevs off.  I should not be changed while any blockdevices are
open.  Remove the misplaced sysctl vfs.enable_userblk_io.

No other changes in behaviour.
1999-10-04 11:23:10 +00:00
Poul-Henning Kamp
1b5464ef9d Remove v_maxio from struct vnode.
Replace it with mnt_iosize_max in struct mount.

Nits from:	bde
1999-09-29 20:05:33 +00:00
Matthew Dillon
40360b1bbb Final commit to remove vnode->v_lastr. vm_fault now handles read
clustering issues (replacing code that used to be in
    ufs/ufs/ufs_readwrite.c).  vm_fault also now uses the new VM page counter
    inlines.

    This completes the changeover from vnode->v_lastr to vm_entry_t->v_lastr
    for VM, and fp->f_nextread and fp->f_seqcount (which have been in the
    tree for a while).  Determination of the I/O strategy (sequential, random,
    and so forth) is now handled on a descriptor-by-descriptor basis for
    base I/O calls, and on a memory-region-by-memory-region and
    process-by-process basis for VM faults.

Reviewed by:	David Greenman <dg@root.com>, Alan Cox <alc@cs.rice.edu>
1999-09-21 00:36:16 +00:00
Poul-Henning Kamp
552f337f1f Initialize vp->v_maxio to its default in getnetvnode() rather than
four different places in vfs_cluster.c
1999-09-20 19:53:23 +00:00
Matthew Dillon
e6f7111170 Fix BOOTP root FS mounts. Also cleanup vfs_getnewfsid() and collapse
addaliasu() into addalias() (no operational change) and clarify comments
    relating to a trick that vclean() uses.

    The fix to BOOTP is yet another hack.  Actually, rootfsid handling
    is already a major hack.  The whole thing needs to be cleaned up.

Reviewed by:	David Greenman <dg@root.com>, Alan Cox <alc@cs.rice.edu>
1999-09-19 06:24:21 +00:00
Matthew Dillon
bb01f28e97 Add vfs.enable_userblk_io sysctl to control whether user reads and writes
to buffered block devices are allowed.  The default is to be backwards
    compatible, i.e. reads and writes are allowed.

    The idea is for a larger crowd to start running with this disabled and
    see what problems, if any, crop up, and then to change the default to
    off and see if any problems crop up in the next 6 months prior to
    potentially removing support entirely.  There are still a few people,
    Julian and myself included, who believe the buffered block device
    access from usermode to be useful.

    Remove use of vnode->v_lastr from buffered block device I/O in
    preparation for removal of vnode->v_lastr field, replacing it with
    the already existing seqcount metric to detect sequential operation.

Reviewed by:	Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 06:10:27 +00:00
Poul-Henning Kamp
d137accc89 Add dev_t freeing code. Controlled by sysctl debug.free_devt, default
is off.
1999-08-29 09:09:12 +00:00
Poul-Henning Kamp
9626728875 remove unused variables. 1999-08-28 19:21:03 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Poul-Henning Kamp
dbafb3660f Simplify the handling of VCHR and VBLK vnodes using the new dev_t:
Make the alias list a SLIST.

        Drop the "fast recycling" optimization of vnodes (including
        the returning of a prexisting but stale vnode from checkalias).
        It doesn't buy us anything now that we don't hardlimit
        vnodes anymore.

        Rename checkalias2() and checkalias() to addalias() and
        addaliasu() - which takes dev_t and udev_t arg respectively.

        Make the revoke syscalls use vcount() instead of VALIASED.

        Remove VALIASED flag, we don't need it now and it is faster
        to traverse the much shorter lists than to maintain the
        flag.

        vfs_mountedon() can check the dev_t directly, all the vnodes
        point to the same one.

Print the devicename in specfs/vprint().

Remove a couple of stale LFS vnode flags.

Remove unimplemented/unused LK_DRAINED;
1999-08-26 14:53:31 +00:00
Poul-Henning Kamp
41d2e3e09e Introduce vn_isdisk(struct vnode *vp) function, and use it to test for diskness. 1999-08-25 12:24:39 +00:00
Julian Elischer
0ff7b13acd Make DEVFS use PHK's specinfo struct as the source of dev_t and devsw.
In lookup() however it's the other way around as we need to supply the
dev_t for the vnode, so devfs still has a copy of it stashed away.

Sourcing it from the vnode in the vnops however is useful as it makes
a lot of the code almost the same as that in specfs.
1999-08-25 04:55:20 +00:00
John Polstra
a2801b7731 Support full-precision file timestamps. Until now, only the seconds
have been maintained, and that is still the default.  A new sysctl
variable "vfs.timestamp_precision" can be used to enable higher
levels of precision:

      0 = seconds only; nanoseconds zeroed (default).
      1 = seconds and nanoseconds, accurate within 1/HZ.
      2 = seconds and nanoseconds, truncated to microseconds.
    >=3 = seconds and nanoseconds, maximum precision.

Level 1 uses getnanotime(), which is fast but can be wrong by up
to 1/HZ.  Level 2 uses microtime().  It might be desirable for
consistency with utimes() and friends, which take timeval structures
rather than timespecs.  Level 3 uses nanotime() for the higest
precision.

I benchmarked levels 0, 1, and 3 by copying a 550 MB tree with
"cpio -pdu".  There was almost negligible difference in the system
times -- much less than 1%, and less than the variation among
multiple runs at the same level.  Bruce Evans dreamed up a torture
test involving 1-byte reads with intervening fstat() calls, but
the cpio test seems more realistic to me.

This feature is currently implemented only for the UFS (FFS and
MFS) filesystems.  But I think it should be easy to support it in
the others as well.

An earlier version of this was reviewed by Bruce.  He's not to
blame for any breakage I've introduced since then.

Reviewed by:	bde (an earlier version of the code)
1999-08-22 00:15:16 +00:00
Poul-Henning Kamp
7dc5cd047f The bdevsw() and cdevsw() are now identical, so kill the former. 1999-08-13 10:29:38 +00:00
Poul-Henning Kamp
4d4f932326 s/v_specinfo/v_rdev/ 1999-08-13 10:10:12 +00:00
Poul-Henning Kamp
0ef1c82630 Decommision miscfs/specfs/specdev.h. Most of it goes into <sys/conf.h>,
a few lines into <sys/vnode.h>.

Add a few fields to struct specinfo, paving the way for the fun part.
1999-08-08 18:43:05 +00:00
Alan Cox
6745299365 Add sysctl and support code to allow directories to be VMIO'd. The default
setting for the sysctl is OFF, which is the historical operation.

Submitted by:	dillon
1999-07-26 06:25:53 +00:00