Commit Graph

357 Commits

Author SHA1 Message Date
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no longer valid, by returning EV_EOF.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
Poul-Henning Kamp
698bfad7f2 Now a dev_t is a pointer to struct specinfo which is shared by all specdev
vnodes referencing this device.

Details:
        cdevsw->d_parms has been removed, the specinfo is available
        now (== dev_t) and the driver should modify it directly
        when applicable, and the only driver doing so, does so:
        vn.c.  I am not sure the logic in checking for "<" was right
        before, and it looks even less so now.

        An intial pool of 50 struct specinfo are depleted during
        early boot, after that malloc had better work.  It is
        likely that fewer than 50 would do.

        Hashing is done from udev_t to dev_t with a prime number
        remainder hash, experiments show no better hash available
        for decent cost (MD5 is only marginally better)  The prime
        number used should not be close to a power of two, we use
        83 for now.

        Add new checkalias2() to get around the loss of info from
        dev2udev() in bdevvp();

        The aliased vnodes are hung on a list straight of the dev_t,
        and speclisth[SPECSZ] is unused.  The sharing of struct
        specinfo means that the v_specnext moves into the vnode
        which grows by 4 bytes.

        Don't use a VBLK dev_t which doesn't make sense in MFS, now
        we hang a dummy cdevsw on B/Cmaj 253 so that things look sane.

	Storage overhead from all of this is O(50k).

        Bump __FreeBSD_version to 400009

The next step will add the stuff needed so device-drivers can start to
hang things from struct specinfo
1999-07-20 09:47:55 +00:00
Poul-Henning Kamp
3de280c443 [click] Now all dev_t's in the kernel have their char device major.
Only know casualy of this is swapinfo/pstat which should be fixes
the right way:  Store the actual pathname in the kernel like mount
does.  [Volounteers sought for this task]

The road map from here is roughly:  expand struct specinfo into struct
based dev_t.  Add dev_t registration facilities for device drivers and
start to use them.
1999-07-19 09:37:59 +00:00
Poul-Henning Kamp
6ca5486476 Introduce the vn_todev(struct vnode*) function, which returns the dev_t
corresponding to a VBLK or VCHR node, or NODEV.
1999-07-18 14:30:37 +00:00
Poul-Henning Kamp
c7119ea7dd Fix 2nd arg to udev2dev(). 1999-07-17 19:38:00 +00:00
Poul-Henning Kamp
f008cfcc1a I have not one single time remembered the name of this function correctly
so obviously I gave it the wrong name.  s/umakedev/makeudev/g
1999-07-17 18:43:50 +00:00
Kris Kennaway
e7647e6c20 Correct a couple of spelling errors in comments. 1999-07-12 15:02:51 +00:00