Commit Graph

224 Commits

Author SHA1 Message Date
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
Kirk McKusick
ad8ac923fa These changes appear to give us benefits with both small (32MB) and
large (1G) memory machine configurations.  I was able to run 'dbench 32'
on a 32MB system without bring the machine to a grinding halt.

    * buffer cache hash table now dynamically allocated.  This will
      have no effect on memory consumption for smaller systems and
      will help scale the buffer cache for larger systems.

    * minor enhancement to pmap_clearbit().  I noticed that
      all the calls to it used constant arguments.  Making
      it an inline allows the constants to propogate to
      deeper inlines and should produce better code.

    * removal of inherent vfs_ioopt support through the emplacement
      of appropriate #ifdef's, with John's permission.  If we do not
      find a use for it by the end of the year we will remove it entirely.

    * removal of getnewbufloops* counters & sysctl's - no longer
      necessary for debugging, getnewbuf() is now optimal.

    * buffer hash table functions removed from sys/buf.h and localized
      to vfs_bio.c

    * VFS_BIO_NEED_DIRTYFLUSH flag and support code added
      ( bwillwrite() ), allowing processes to block when too many dirty
      buffers are present in the system.

    * removal of a softdep test in bdwrite() that is no longer necessary
      now that bdwrite() no longer attempts to flush dirty buffers.

    * slight optimization added to bqrelse() - there is no reason
      to test for available buffer space on B_DELWRI buffers.

    * addition of reverse-scanning code to vfs_bio_awrite().
      vfs_bio_awrite() will attempt to locate clusterable areas
      in both the forward and reverse direction relative to the
      offset of the buffer passed to it.  This will probably not
      make much of a difference now, but I believe we will start
      to rely on it heavily in the future if we decide to shift
      some of the burden of the clustering closer to the actual
      I/O initiation.

    * Removal of the newbufcnt and lastnewbuf counters that Kirk
      added.  They do not fix any race conditions that haven't already
      been fixed by the gbincore() test done after the only call
      to getnewbuf().  getnewbuf() is a static, so there is no chance
      of it being misused by other modules.  ( Unless Kirk can think
      of a specific thing that this code fixes.  I went through it
      very carefully and didn't see anything ).

    * removal of VOP_ISLOCKED() check in flushbufqueues().  I do not
      think this check is necessary, the buffer should flush properly
      whether the vnode is locked or not. ( yes? ).

    * removal of extra arguments passed to getnewbuf() that are not
      necessary.

    * missed cluster_wbuild() that had to be a cluster_wbuild_wb() in
      vfs_cluster.c

    * vn_write() now calls bwillwrite() *PRIOR* to locking the vnode,
      which should greatly aid flushing operations in heavy load
      situations - both the pageout and update daemons will be able
      to operate more efficiently.

    * removal of b_usecount.  We may add it back in later but for now
      it is useless.  Prior implementations of the buffer cache never
      had enough buffers for it to be useful, and current implementations
      which make more buffers available might not benefit relative to
      the amount of sophistication required to implement a b_usecount.
      Straight LRU should work just as well, especially when most things
      are VMIO backed.  I expect that (even though John will not like
      this assumption) directories will become VMIO backed some point soon.

Submitted by:	Matthew Dillon <dillon@backplane.com>
Reviewed by:	Kirk McKusick <mckusick@mckusick.com>
1999-07-08 06:06:00 +00:00
Kirk McKusick
e929c00d23 The buffer queue mechanism has been reformulated. Instead of having
QUEUE_AGE, QUEUE_LRU, and QUEUE_EMPTY we instead have QUEUE_CLEAN,
QUEUE_DIRTY, QUEUE_EMPTY, and QUEUE_EMPTYKVA.  With this patch clean
and dirty buffers have been separated.  Empty buffers with KVM
assignments have been separated from truely empty buffers.  getnewbuf()
has been rewritten and now operates in a 100% optimal fashion.  That is,
it is able to find precisely the right kind of buffer it needs to
allocate a new buffer, defragment KVM, or to free-up an existing buffer
when the buffer cache is full (which is a steady-state situation for
the buffer cache).

Buffer flushing has been reorganized.  Previously buffers were flushed
in the context of whatever process hit the conditions forcing buffer
flushing to occur.  This resulted in processes blocking on conditions
unrelated to what they were doing.  This also resulted in inappropriate
VFS stacking chains due to multiple processes getting stuck trying to
flush dirty buffers or due to a single process getting into a situation
where it might attempt to flush buffers recursively - a situation that
was only partially fixed in prior commits.  We have added a new daemon
called the buf_daemon which is responsible for flushing dirty buffers
when the number of dirty buffers exceeds the vfs.hidirtybuffers limit.
This daemon attempts to dynamically adjust the rate at which dirty buffers
are flushed such that getnewbuf() calls (almost) never block.

The number of nbufs and amount of buffer space is now scaled past the
8MB limit that was previously imposed for systems with over 64MB of
memory, and the vfs.{lo,hi}dirtybuffers limits have been relaxed
somewhat.  The number of physical buffers has been increased with the
intention that we will manage physical I/O differently in the future.

reassignbuf previously attempted to keep the dirtyblkhd list sorted which
could result in non-deterministic operation under certain conditions,
such as when a large number of dirty buffers are being managed.  This
algorithm has been changed.  reassignbuf now keeps buffers locally sorted
if it can do so cheaply, and otherwise gives up and adds buffers to
the head of the dirtyblkhd list.  The new algorithm is deterministic but
not perfect.  The new algorithm greatly reduces problems that previously
occured when write_behind was turned off in the system.

The P_FLSINPROG proc->p_flag bit has been replaced by the more descriptive
P_BUFEXHAUST bit.  This bit allows processes working with filesystem
buffers to use available emergency reserves.  Normal processes do not set
this bit and are not allowed to dig into emergency reserves.  The purpose
of this bit is to avoid low-memory deadlocks.

A small race condition was fixed in getpbuf() in vm/vm_pager.c.

Submitted by:	Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by:	Kirk McKusick <mckusick@mckusick.com>
1999-07-04 00:25:38 +00:00
Poul-Henning Kamp
8947a90a90 Make sure that stat(2) and friends always return a valid st_dev field.
Pseudo-FS need not fill in the va_fsid anymore, the syscall code
will use the first half of the fsid, which now looks like a udev_t
with major 255.
1999-07-02 16:29:47 +00:00
Peter Wemm
9c8b8baa38 Slight reorganization of kernel thread/process creation. Instead of using
SYSINIT_KT() etc (which is a static, compile-time procedure), use a
NetBSD-style kthread_create() interface.  kproc_start is still available
as a SYSINIT() hook.  This allowed simplification of chunks of the
sysinit code in the process.  This kthread_create() is our old kproc_start
internals, with the SYSINIT_KT fork hooks grafted in and tweaked to work
the same as the NetBSD one.

One thing I'd like to do shortly is get rid of nfsiod as a user initiated
process.  It makes sense for the nfs client code to create them on the
fly as needed up to a user settable limit.  This means that nfsiod
doesn't need to be in /sbin and is always "available".  This is a fair bit
easier to do outside of the SYSINIT_KT() framework.
1999-07-01 13:21:46 +00:00
Kirk McKusick
67812eacd7 Convert buffer locking from using the B_BUSY and B_WANTED flags to using
lockmgr locks. This commit should be functionally equivalent to the old
semantics. That is, all buffer locking is done with LK_EXCLUSIVE
requests. Changes to take advantage of LK_SHARED and LK_RECURSIVE will
be done in future commits.
1999-06-26 02:47:16 +00:00
Kirk McKusick
f9c8cab591 Add a vnode argument to VOP_BWRITE to get rid of the last vnode
operator special case. Delete special case code from vnode_if.sh,
vnode_if.src, umap_vnops.c, and null_vnops.c.
1999-06-16 23:27:55 +00:00
Kirk McKusick
e4ab40bcb6 Get rid of the global variable rushjob and replace it with a function in
kern/vfs_subr.c named speedup_syncer() which handles the speedup request.
Change the various clients of rushjob to use the new function.
1999-06-15 23:37:29 +00:00
Poul-Henning Kamp
2447bec829 Simplify cdevsw registration.
The cdevsw_add() function now finds the major number(s) in the
struct cdevsw passed to it.  cdevsw_add_generic() is no longer
needed, cdevsw_add() does the same thing.

cdevsw_add() will print an message if the d_maj field looks bogus.

Remove nblkdev and nchrdev variables.  Most places they were used
bogusly.  Instead check a dev_t for validity by seeing if devsw()
or bdevsw() returns NULL.

Move bdevsw() and devsw() functions to kern/kern_conf.c

Bump __FreeBSD_version to 400006

This commit removes:
        72 bogus makedev() calls
        26 bogus SYSINIT functions

if_xe.c bogusly accessed cdevsw[], author/maintainer please fix.

I4b and vinum not changed.  Patches emailed to authors.  LINT
probably broken until they catch up.
1999-05-31 11:29:30 +00:00
John Birrell
02013ff886 Remove the test for bdevsw(dev) == NULL from bdevvp() because it fails
if there is no character device associated with the block device. In this
case that doesn't matter because bdevvp() doesn't use the character
device structure.

I can use the pointy bit of the axe too.
1999-05-24 00:34:10 +00:00
Luoqi Chen
0ce54cbb0c Legally acquire a major number for mfs. 1999-05-14 20:40:23 +00:00
Kirk McKusick
eaea7a9e9f Previously directories were sync'ed every 10 seconds while bitmaps &
inodes were synced every 15 seconds. This is now reversed as during
directory create, we cannot commit the directory entry until its
inode has been written. With this switch, the inodes will be more
likely to be written by the time that the directory is written thus
reducing the number of directory rollbacks that are needed.
1999-05-14 01:29:21 +00:00
Peter Wemm
cc5881cff5 Fix (?) SPECHASH dev_t/major/minor/etc args 1999-05-12 19:06:40 +00:00
Poul-Henning Kamp
8bee45c44e Don't peek into dev_t 1999-05-12 11:06:07 +00:00
Poul-Henning Kamp
bfbb9ce670 Divorce "dev_t" from the "major|minor" bitmap, which is now called
udev_t in the kernel but still called dev_t in userland.

Provide functions to manipulate both types:
        major()         umajor()
        minor()         uminor()
        makedev()       umakedev()
        dev2udev()      udev2dev()

For now they're functions, they will become in-line functions
after one of the next two steps in this process.

Return major/minor/makedev to macro-hood for userland.

Register a name in cdevsw[] for the "filedescriptor" driver.

In the kernel the udev_t appears in places where we have the
major/minor number combination, (ie: a potential device: we
may not have the driver nor the device), like in inodes, vattr,
cdevsw registration and so on, whereas the dev_t appears where
we carry around a reference to a actual device.

In the future the cdevsw and the aliased-from vnode will be hung
directly from the dev_t, along with up to two softc pointers for
the device driver and a few houskeeping bits.  This will essentially
replace the current "alias" check code (same buck, bigger bang).

A little stunt has been provided to try to catch places where the
wrong type is being used (dev_t vs udev_t), if you see something
not working, #undef DEVT_FASCIST in kern/kern_conf.c and see if
it makes a difference.  If it does, please try to track it down
(many hands make light work) or at least try to reproduce it
as simply as possible, and describe how to do that.

Without DEVT_FASCIST I belive this patch is a no-op.

Stylistic/posixoid comments about the userland view of the <sys/*.h>
files welcome now, from userland they now contain the end result.

Next planned step: make all dev_t's refer to the same devsw[] which
means convert BLK's to CHR's at the perimeter of the vnodes and
other places where they enter the game (bootdev, mknod, sysctl).
1999-05-11 19:55:07 +00:00
Poul-Henning Kamp
1637aa4b1c Fix some of the places where too much inside knowledge about major/minor
layout and dev_t structure is being (ab)used.
1999-05-08 07:02:41 +00:00
Poul-Henning Kamp
4be2eb8c49 I got tired of seeing all the cdevsw[major(foo)] all over the place.
Made a new (inline) function devsw(dev_t dev) and substituted it.

Changed to the BDEV variant to this format as well: bdevsw(dev_t dev)

DEVFS will eventually benefit from this change too.
1999-05-08 06:40:31 +00:00
Poul-Henning Kamp
46eede0058 Continue where Julian left off in July 1998:
Virtualize bdevsw[] from cdevsw.  bdevsw() is now an (inline)
        function.

        Join CDEV_MODULE and BDEV_MODULE to DEV_MODULE (please pay attention
        to the order of the cmaj/bmaj arguments!)

        Join CDEV_DRIVER_MODULE and BDEV_DRIVER_MODULE to DEV_DRIVER_MODULE
        (ditto!)

(Next step will be to convert all bdev dev_t's to cdev dev_t's
before they get to do any damage^H^H^H^H^H^Hwork in the kernel.)
1999-05-07 10:11:40 +00:00
Bill Fumerola
3d177f465a Add sysctl descriptions to many SYSCTL_XXXs
PR:		kern/11197
Submitted by:	Adrian Chadd <adrian@FreeBSD.org>
Reviewed by:	billf(spelling/style/minor nits)
Looked at by:	bde(style)
1999-05-03 23:57:32 +00:00
Julian Elischer
4ef2094e45 Reviewed by: Many at differnt times in differnt parts,
including alan, john, me, luoqi, and kirk
Submitted by:	Matt Dillon <dillon@frebsd.org>

This change implements a relatively sophisticated fix to getnewbuf().
There were two problems with getnewbuf(). First, the writerecursion
can lead to a system stack overflow when you have NFS and/or VN
devices in the system. Second, the free/dirty buffer accounting was
completely broken. Not only did the nfs routines blow it trying to
manually account for the buffer state, but the accounting that was
done did not work well with the purpose of their existance: figuring
out when getnewbuf() needs to sleep.

The meat of the change is to kern/vfs_bio.c. The remaining diffs are
all minor except for NFS, which includes both the fixes for bp
interaction AND fixes for a 'biodone(): buffer already done' lockup.
Sys/buf.h also contains a chaining structure which is not used by
this patchset but is used by other patches that are coming soon.
This patch deliniated by tags PRE_MAT_GETBUF and POST_MAT_GETBUF.
(sorry for the missing T matt)
1999-03-12 02:24:58 +00:00
Matthew Dillon
155f87daf2 Reviewed by: Julian Elischer <julian@whistle.com>
Add d_parms() to {c,b}devsw[].  If non-NULL this function points to
    a device routine that will properly fill in the specinfo structure.
    vfs_subr.c's checkalias() supplies appropriate defaults.  This change
    should be fully backwards compatible with existing devices.
1999-02-25 05:22:30 +00:00
Matthew Dillon
42e26d47bd Protect vn worklist and vn->v_{clean,dirty}blkhd at splbio().
Get rid of extra LIST_REMOVE()

Reviewed by:	hsu@FreeBSD.ORG (Jeffrey Hsu), mckusick@McKusick.COM
Submitted by:	hsu@FreeBSD.ORG (Jeffrey Hsu), dillon@backplane.com ( Matthew Dillon )
1999-02-19 17:36:58 +00:00
Matthew Dillon
82b23b5384 vp->v_object must be valid after normal flow of vfs_object_create()
completes, change if() to KASSERT().  This is not a bug, we are
    simplify clarifying and optimizing the code.

    In if/else in vfs_object_create(), the failure of both conditionals
    will lead to a NULL object.  Exit gracefully if this case occurs.
    ( this case does not normally occur, but needed to be handled ).

Obtained from: Eivind Eklund <eivind@FreeBSD.org>
1999-02-04 18:25:39 +00:00
Matthew Dillon
bc81493155 More const fixes for -Wall, -Wcast-qual 1999-01-29 23:18:50 +00:00
Matthew Dillon
8aef171243 Fix warnings in preparation for adding -Wall -Wcast-qual to the
kernel compile
1999-01-28 00:57:57 +00:00
Matthew Dillon
1c7c3c6a86 This is a rather large commit that encompasses the new swapper,
changes to the VM system to support the new swapper, VM bug
    fixes, several VM optimizations, and some additional revamping of the
    VM code.  The specific bug fixes will be documented with additional
    forced commits.  This commit is somewhat rough in regards to code
    cleanup issues.

Reviewed by:	"John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Eivind Eklund
219cbf59f2 KNFize, by bde. 1999-01-10 01:58:29 +00:00
Eivind Eklund
5526d2d920 Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as
discussed on -hackers.

Introduce 'KASSERT(assertion, ("panic message", args))' for simple
check + panic.

Reviewed by:	msmith
1999-01-08 17:31:30 +00:00
Eivind Eklund
fb1167777a Remove the 'waslocked' parameter to vfs_object_create(). 1999-01-05 18:50:03 +00:00
Eivind Eklund
0df45b5a31 Finish staticization. 1999-01-05 18:12:29 +00:00
Bruce Evans
289bdf33d3 Ifdefed conditionally used simplock variables. 1999-01-02 11:34:57 +00:00
Bruce Evans
4d94881342 Restored rev.1.31 which was clobbered by rev.1.69 (the big Lite2
merge).  This fixes at least hanging in revoke(2) when a somewhat
active slave pty is revoked.  The hang made the window for the
null pointer bug in ufsspec_{read,write} much larger.

There are many other bugs in this area (revoke of an active fifo
at best leaks memory...).
1998-12-24 12:07:16 +00:00
Eivind Eklund
29c98cd8bf Check return value of tsleep(). I've checked of all call points -
there does not seem to be a problem with this.

PR:		kern/8732
Analysis by:	David G Andersen <danderse@cs.utah.edu>
Tested by:	Alfred Perlstein <bright@hotjobs.com>
1998-12-22 00:44:11 +00:00
Eivind Eklund
db878ba480 Staticize. 1998-12-21 23:38:33 +00:00