Commit Graph

120 Commits

Author SHA1 Message Date
Alan Cox
aec774abec Lock the vm object when freeing a page. 2003-06-17 05:17:00 +00:00
Poul-Henning Kamp
17a1391990 The IO_NOWDRAIN and B_NOWDRAIN hacks are no longer needed to prevent
deadlocks with vnode backed md(4) devices because md now uses a
kthread to run the bio requests instead of doing it directly from
the bio down path.
2003-05-31 16:42:45 +00:00
Robert Watson
7042ac8cd7 This change grabs the vnode lock for NFS client vnodes when calling
VOP_SETATTR() or VOP_GETATTR(); without these locks (a) VFS_DEBUG_LOCKS
will panic, and (b) it may be possible to corrupt entries in the cached
vnode attributes in the nfsnode, since nfsnode attribute cache data is
also protected by the vnode lock.

Approved by:	re (jhb)
Pointed out by:	VFS_DEBUG_LOCKS
2003-05-15 21:12:08 +00:00
Jeff Roberson
7261f5f68e - Add a new 'flags' parameter to getblk().
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
   flag to the initial BUF_LOCK().  This will eventually be used in cases
   were we want to use a buffer only if it is not currently in use.
 - Convert all consumers of the getblk() api to use this extra parameter.

Reviwed by:	arch
Not objected to by:	mckusick
2003-03-04 00:04:44 +00:00
Dag-Erling Smørgrav
521f364b80 More low-hanging fruit: kill caddr_t in calls to wakeup(9) / [mt]sleep(9). 2003-03-02 16:54:40 +00:00
Matthew Dillon
3a3d82ec0a Abstract-out the constants for the sequential heuristic.
No operational changes.

MFC after:	1 day
2002-12-28 20:37:50 +00:00
Jeff Roberson
8926aed697 - Lock access to the buf lists.
- Use vrefcnt() where appropriate.
 - Add some locking asserts.
2002-09-25 02:38:43 +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
Alan Cox
e0c9fdb50e o Lock page queue accesses in nfs_getpages(). 2002-07-21 20:01:32 +00:00
Matthew Dillon
8e0619c6b0 Fix a bug nfs_write() related to ^C'ing during a file write on an
interruptable mount.  We were returning from inside the loop without
releasing the rslock.

Submitted by:	Mike Junk <junk@isilon.com>
MFC after:	3 days
2002-07-16 19:43:59 +00:00
Matthew Dillon
3d8f797ac1 Convert old style (type foo *)0 casts to NULLs
PR:		kern/40360
Requested by:	Hiten PAndya via direct email
2002-07-11 17:54:58 +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
John Baldwin
56e9ce41a5 In namei(), we use a NULL thread for uio_td when doing a VOP_READLINK().
nfs_readlink() calls nfs_bioread() which passes in uio_td as the thread
argument to nfs_getcacheblk().  In nfs_getcacheblk() we dereference the
thread pointer to get a process pointer to pass to nfs_sigintr().  This
obviously results in a panic. :)

Rather than change nfs_getcacheblk() to check if the thread pointer is
NULL when calling nfs_sigintr() like other callers do, change
nfs_sigintr() to take a thread as the last argument instead of a
process so none of the callers have to care if the thread is NULL or not.
2002-06-28 21:53:08 +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
Peter Wemm
1bde568682 Revise the nfsiod auto tuning code. Now both the upper and lower limits
are specifyable by sysctl and are respected.

Submitted by:	Maxime Henrion <mux@sneakerz.org>
2002-01-15 20:57:21 +00:00
Peter Wemm
117f61374c Implement vfs.nfs.iodmin (minimum number of nfsiod's) and
vfs.nfs.iodmaxidle (idle time before nfsiod's exit).  Make it adaptive
so that we create nfsiod's on demand and they go away after not being
used for a while.  The upper limit is NFS_MAXASYNCDAEMON (currently 20).
More will be done here, but this is a useful checkpoint.

Submitted by:	Maxime Henrion <mux@qualys.com>
2002-01-14 02:13:46 +00:00
Matthew Dillon
3ebeaf5984 This fixes a large number of bugs in our NFS client side code. A recent
commit by Kirk also fixed a softupdates bug that could easily be triggered
by server side NFS.

	* An edge case with shared R+W mmap()'s and truncate whereby
	  the system would inappropriately clear the dirty bits on
	  still-dirty data.  (applicable to all filesystems)

	  THIS FIX TEMPORARILY DISABLED PENDING FURTHER TESTING.
	  see vm/vm_page.c line 1641

	* The straddle case for VM pages and buffer cache buffers when
	  truncating.  (applicable to NFS client side)

	* Possible SMP database corruption due to vm_pager_unmap_page()
	  not clearing the TLB for the other cpu's.  (applicable to NFS
	  client side but could effect all filesystems).  Note: not
	  considered serious since the corruption occurs beyond the file
	  EOF.

	* When flusing a dirty buffer due to B_CACHE getting cleared,
	  we were accidently setting B_CACHE again (that is, bwrite() sets
	  B_CACHE), when we really want it to stay clear after the write
	  is complete.  This resulted in a corrupt buffer.  (applicable
	  to all filesystems but probably only triggered by NFS)

	* We have to call vtruncbuf() when ftruncate()ing to remove
	  any buffer cache buffers.  This is still tentitive, I may
	  be able to remove it due to the second bug fix.  (applicable
	  to NFS client side)

	* vnode_pager_setsize() race against nfs_vinvalbuf()... we have
	  to set n_size before calling nfs_vinvalbuf or the NFS code
	  may recursively vnode_pager_setsize() to the original value
	  before the truncate.  This is what was causing the user mmap
	  bus faults in the nfs tester program.  (applicable to NFS
	  client side)

	* Fix to softupdates (see ufs/ffs/ffs_inode.c 1.73, commit made
	  by Kirk).

Testing program written by: Avadis Tevanian, Jr.
Testing program supplied by: jkh / Apple (see Dec2001 posting to freebsd-hackers with Subject 'NFS: How to make FreeBS fall on its face in one easy step')
MFC after:	1 week
2001-12-14 01:16:57 +00:00
Matthew Dillon
7e76bb562e Implement IO_NOWDRAIN and B_NOWDRAIN - prevents the buffer cache from blocking
in wdrain during a write.  This flag needs to be used in devices whos
strategy routines turn-around and issue another high level I/O, such as
when MD turns around and issues a VOP_WRITE to vnode backing store, in order
to avoid deadlocking the dirty buffer draining code.

Remove a vprintf() warning from MD when the backing vnode is found to be
in-use.  The syncer of buf_daemon could be flushing the backing vnode at
the time of an MD operation so the warning is not correct.

MFC after:	1 week
2001-11-05 18:48:54 +00:00
John Baldwin
bd78cece5d Change the kernel's ucred API as follows:
- crhold() returns a reference to the ucred whose refcount it bumps.
- crcopy() now simply copies the credentials from one credential to
  another and has no return value.
- a new crshared() primitive is added which returns true if a ucred's
  refcount is > 1 and false (0) otherwise.
2001-10-11 23:38:17 +00:00
Peter Wemm
891a092764 Sigh, Last minute pre-merge typo. (missing quotes) 2001-09-18 23:49:33 +00:00
Peter Wemm
eb25edbda3 Cleanup and split of nfs client and server code.
This builds on the top of several repo-copies.
2001-09-18 23:32:09 +00:00
Warner Losh
976a26437e nfs_strategy calls nfs_asyncio with td as NULL. So add a bandaid that
will pass NULL as the struct proc when td is NULL.  This has stopped
crashing on my machine.

Note: The passing of NULL may be bogus, but I'll let others fix that
problem.

Reviewed by: jhb
2001-09-18 18:37:52 +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
John Baldwin
617e358cdf - Sort includes.
- Update vmmeter statistics for vnode pagein/pageouts in getpages/putpages.
2001-07-04 20:14:59 +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
ce70e0a964 Assert Giant is held by the caller rather than getting it and releasing
it in getpages/putpages.
2001-05-23 22:26:05 +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
Greg Lehey
60fb0ce365 Revert consequences of changes to mount.h, part 2.
Requested by:	bde
2001-04-29 02:45:39 +00:00
Greg Lehey
d98dc34f52 Correct #includes to work with fixed sys/mount.h. 2001-04-23 09:05:15 +00:00
Alfred Perlstein
d8d5fa8805 vnode_pager_freepage() is really vm_page_free() in disguise,
nuke vnode_pager_freepage() and replace all calls to it with vm_page_free()
2001-04-19 06:18:23 +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
John Baldwin
19eb87d22a Grab the process lock while calling psignal and before calling psignal. 2001-03-07 03:37:06 +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
8177437d85 Complete the bio/buf divorce for all code below devfs::strategy
Exceptions:
        Vinum untouched.  This means that it cannot be compiled.
        Greg Lehey is on the case.

        CCD not converted yet, casts to struct buf (still safe)

        atapi-cd casts to struct buf to examine B_PHYS
2000-04-15 05:54:02 +00:00
Poul-Henning Kamp
c244d2de43 Move B_ERROR flag to b_ioflags and call it BIO_ERROR.
(Much of this done by script)

Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.

Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.

Add bio_queue field for struct bio aware disksort.

Address a lot of stylistic issues brought up by bde.
2000-04-02 15:24:56 +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
Poul-Henning Kamp
21144e3bf1 Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new
field in struct buf: b_iocmd.  The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue.  It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users:  Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +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
Matthew Dillon
b7303db36e Fix two problems: First, fix the append seek position race that can
occur due to np->n_size potentially changing if nfs_getcacheblk()
    blocks in nfs_write().

    Second, under -current we must supply the proper bufsize when obtaining
    buffers that straddle the EOF, but due to the fact that np->n_size can
    change out from under us it is possible that we may specify the wrong
    buffer size and wind up truncating dirty data written by another
    process.

    Both problems are solved by implementing nfs_rslock(), which allows us
    to lock around sensitive buffer cache operations such as those that
    occur when appending to a file.

    It is believed that this race is responsible for causing dirtyoff/dirtyend
    and (in stable) validoff/validend to exceed the buffer size.  Therefore
    we have now added a warning printf for the dirtyoff/end case in current.

    However, we have introduced a new problem which we need to fix at some
    point, and that is that soft or intr NFS mounts may become
    uninterruptable from the point of view of process A which is stuck waiting
    on rslock while process B is stuck doing the rpc.  To unstick process A,
    process B would have to be interrupted first.

Reviewed by:	Alfred Perlstein <bright@wintelcom.net>
1999-12-14 19:07:54 +00:00
Matthew Dillon
ea94c7b968 Synopsis of problem being fixed: Dan Nelson originally reported that
blocks of zeros could wind up in a file written to over NFS by a client.
    The problem only occurs a few times per several gigabytes of data.   This
    problem turned out to be bug #3 below.

    bug #1:

        B_CLUSTEROK must be cleared when an NFS buffer is reverted from
        stage 2 (ready for commit rpc) to stage 1 (ready for write).
        Reversions can occur when a dirty NFS buffer is redirtied with new
        data.

        Otherwise the VFS/BIO system may end up thinking that a stage 1
        NFS buffer is clusterable.  Stage 1 NFS buffers are not clusterable.

    bug #2:

        B_CLUSTEROK was inappropriately set for a 'short' NFS buffer (short
        buffers only occur near the EOF of the file).  Change to only set
        when the buffer is a full biosize (usually 8K).  This bug has no
        effect but should be fixed in -current anyway.  It need not be
        backported.

    bug #3:

        B_NEEDCOMMIT was inappropriately set in nfs_flush() (which is
	typically only called by the update daemon).  nfs_flush()
        does a multi-pass loop but due to the lack of vnode locking it
        is possible for new buffers to be added to the dirtyblkhd list
        while a flush operation is going on.  This may result in nfs_flush()
        setting B_NEEDCOMMIT on a buffer which has *NOT* yet gone through its
        stage 1 write, causing only the commit rpc to be made and thus
        causing the contents of the buffer to be thrown away (never sent to
        the server).

    The patch also contains some cleanup, which only applies to the commit
    into -current.

Reviewed by:	dg, julian
Originally Reported by: Dan Nelson <dnelson@emsphone.com>
1999-12-12 06:09:57 +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
Matthew Dillon
8fdd2461b3 Add comment to clarify a commit rpc optimization already being performed. 1999-09-20 19:10:28 +00:00
Matthew Dillon
b5acbc8b9c Asynchronized client-side nfs_commit. NFS commit operations were
previously issued synchronously even if async daemons (nfsiod's) were
    available.  The commit has been moved from the strategy code to the doio
    code in order to asynchronize it.

    Removed use of lastr in preparation for removal of vnode->v_lastr.  It
    has been replaced with seqcount, which is already supported by the system
    and, in fact, gives us a better heuristic for sequential detection then
    lastr ever did.

    Made major performance improvements to the server side commit.  The
    server previously fsync'd the entire file for each commit rpc.  The
    server now bawrite()s only those buffers related to the offset/size
    specified in the commit rpc.

    Note that we do not commit the meta-data yet.  This works still needs
    to be done.

    Note that a further optimization can be done (and has not yet been done)
    on the client: we can merge multiple potential commit rpc's into a
    single rpc with a greater file offset/size range and greatly reduce
    rpc traffic.

Reviewed by:	Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:57:57 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Alan Cox
2c28a10540 Add the (inline) function vm_page_undirty for clearing the dirty bitmask
of a vm_page.

Use it.

Submitted by:	dillon
1999-08-17 04:02:34 +00:00
Dmitrij Tejblum
e868365294 nfs_getcacheblk() can return 0 if the mount is interruptible. It need to be
checked by the caller.

Broken in: rev. 1.70 (1999/05/02)
1999-08-12 18:04:39 +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
Peter Wemm
adbde675ee Don't mistake a non-async block that needs to be committed for an
interrupted write.

Obtained from: fvdl@NetBSD.org via OpenBSD.
1999-06-05 05:25:37 +00:00
Poul-Henning Kamp
b0eeea2042 remove b_proc from struct buf, it's (now) unused.
Reviewed by:	dillon, bde
1999-05-06 20:00:34 +00:00