Commit Graph

88 Commits

Author SHA1 Message Date
Attilio Rao
628f51d275 Introduce some functions in the vnode locks namespace and in the ffs
namespace in order to handle lockmgr fields in a controlled way instead
than spreading all around bogus stubs:
- VN_LOCK_AREC() allows lock recursion for a specified vnode
- VN_LOCK_ASHARE() allows lock sharing for a specified vnode

In FFS land:
- BUF_AREC() allows lock recursion for a specified buffer lock
- BUF_NOREC() disallows recursion for a specified buffer lock

Side note: union_subr.c::unionfs_node_update() is the only other function
directly handling lockmgr fields. As this is not simple to fix, it has
been left behind as "sole" exception.
2008-02-24 16:38:58 +00:00
Attilio Rao
0e9eb108f0 Cleanup lockmgr interface and exported KPI:
- Remove the "thread" argument from the lockmgr() function as it is
  always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
  Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
  present

Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
  curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h

KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.

Tested by: matteo
2008-01-24 12:34:30 +00:00
Tor Egge
61b9d89ff0 Make insmntque() externally visibile and allow it to fail (e.g. during
late stages of unmount).  On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque().  Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode.  The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup.  Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by:	re (kensmith)
Reviewed by:	kib
In collaboration with:	kib
2007-03-13 01:50:27 +00:00
Mohan Srinivasan
594ece53bc In nfs_nget(), we must initialize the fh in the nfsnode before inserting the
vnode into the vfs hash. Otherwise, another thread walking the hash can trip
on an nfsnode with an uninitialized or partially initialized fh.
Thanks to ups@ for spotting this race.
2006-11-29 02:21:40 +00:00
Mohan Srinivasan
88d5725c38 Fix for a bug caused by a race when 2 threads lookup the same
file. Leave the loser's lock(s) initialized, so the reclaim logic can
unconditionally destroy them when that race occurs (or if the vfs hash
insert happened to fail for some other reason). Thanks to ups@ for a
careful review of the code.
Reported by : Kris Kennaway
2006-11-27 19:06:43 +00:00
Mohan Srinivasan
3c2fcc3c92 vfs_hash_insert() vputs() the losing vnode before returning, in the event of
a race where a duplicate vnode is entered into the vfs hash. nfs_nget() shouldn't
be releasing the vnode in that case.
2006-11-16 23:03:46 +00:00
Mohan Srinivasan
7d7d9e2242 Fixes up the handling of shared vnode lock lookups in the NFS client,
adds a FS type specific flag indicating that the FS supports shared
vnode lock lookups, adds some logic in vfs_lookup.c to test this flag
and set lock flags appropriately.

- amd on 6.x is a non-starter (without this change). Using amd under
  heavy load results in a deadlock (with cascading vnode locks all the
  way to the root) very quickly.
- This change should also fix the more general problem of cascading
  vnode deadlocks when an NFS server goes down.

Ideally, we wouldn't need these changes, as enabling shared vnode lock
lookups globally would work. Unfortunately, UFS, for example isn't
ready for shared vnode lock lookups, crashing pretty quickly.

This change is the result of discussions with Stephan Uphoff (ups@).

Reviewed by:	ups@
2006-09-13 18:39:09 +00:00
Mohan Srinivasan
f2c48228fe Vnode locks are recursive and the NFS client support shared vnode locks.
Found by: Kris Kennaway.
2006-05-23 16:07:23 +00:00
Mohan Srinivasan
f1cdf89911 Changes to make the NFS client MP safe.
Thanks to Kris Kennaway for testing and sending lots of bugs my way.
2006-05-19 00:04:24 +00:00
Alfred Perlstein
92e73f5711 I ran into an nfs client panic a couple of times in a row over the
last few days.  I tracked it down to the fact that nfs_reclaim()
is setting vp->v_data to NULL _before_ calling vnode_destroy_object().
After silence from the mailing list I checked further and discovered
that ufs_reclaim() is unique among FreeBSD filesystems for calling
vnode_destroy_object() early, long before tossing v_data or much
of anything else, for that matter.  The rest, including NFS, appear
to be identical, as if they were just clones of one original routine.

The enclosed patch fixes all file systems in essentially the same
way, by moving the call to vnode_destroy_object() to early in the
routine (before the call to vfs_hash_remove(), if any).  I have
only tested NFS, but I've now run for over eighteen hours with the
patch where I wouldn't get past four or five without it.

Submitted by: Frank Mayhar
Requested by: Mohan Srinivasan
MFC After: 1 week
2006-01-17 17:29:03 +00:00
Paul Saab
4fb48d10b0 In nfs_nget() if two threads race on the same filehandle, the loser should
cause the nfsnode to get freed. This fixes a potential vnode (and nfsnode)
leak in that path.

Submitted by:	Mohan Srinivasan
Reviewed by:	phk
2005-07-27 15:05:31 +00:00
Paul Saab
865b5cc7fd Remove the NFS client rslock. The rslock was used to serialize
writers that want to extend the file. It was also used to serialize
readers that might want to read the last block of the file (with a
writer extending the file).  Now that we support vnode locking for
NFS, the rslock is unnecessary. Writers grab the exclusive vnode
lock before writing and readers grab the shared (or in some cases
the exclusive) lock.

Submitted by:	Mohan Srinivasan
2005-07-21 22:46:56 +00:00
Jeff Roberson
f247a5240d - LK_NOPAUSE is a nop now.
Sponsored by:   Isilon Systems, Inc.
2005-03-31 04:37:09 +00:00
Poul-Henning Kamp
8b5505c013 Use vfs_hash. 2005-03-16 11:28:19 +00:00
Jeff Roberson
8d8d331063 - VOP_INACTIVE should no longer drop the vnode lock.
Sponsored by:	Isilon Systems, Inc.
2005-03-13 12:15:36 +00:00
Poul-Henning Kamp
a369f34d76 Make filesystems get rid of their own vnodes vnode_pager object in
VOP_RECLAIM().
2005-01-28 14:42:17 +00:00
Poul-Henning Kamp
56dd36b1a6 Remove unused cred arg from nfs_vinvalbuf() and many bogus arguments
passed for it.
2005-01-24 12:31:06 +00:00
Warner Losh
c398230b64 /* -> /*- for license, minor formatting changes 2005-01-07 01:45:51 +00:00
Paul Saab
d54d263a79 Serialize NFS vinvalbuf operations by acquiring/upgrading to the
vnode EXCLUSIVE lock. This prevents threads from adding pages to
the vnode while an invalidation is in progress, closing potential
races. In the bioread() path, callers acquire the SHARED vnode lock
- so while an invalidate was in progress, it was possible to fault
in new pages onto the vnode causing the invalidation to take a while
or fail. We saw these races at Yahoo! with very large files+heavy
concurrent access. Forcing an upgrade to EXCLUSIVE lock before doing
the invalidation closes all these races.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
2004-12-06 18:52:28 +00:00
Poul-Henning Kamp
aec0fb7b40 Back when VOP_* was introduced, we did not have new-style struct
initializations but we did have lofty goals and big ideals.

Adjust to more contemporary circumstances and gain type checking.

	Replace the entire vop_t frobbing thing with properly typed
	structures.  The only casualty is that we can not add a new
	VOP_ method with a loadable module.  History has not given
	us reason to belive this would ever be feasible in the the
	first place.

	Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.

	Give coda correct prototypes and function definitions for
	all vop_()s.

	Generate a bit more data from the vnode_if.src file:  a
	struct vop_vector and protype typedefs for all vop methods.

	Add a new vop_bypass() and make vop_default be a pointer
	to another struct vop_vector.

	Remove a lot of vfs_init since vop_vector is ready to use
	from the compiler.

	Cast various vop_mumble() to void * with uppercase name,
	for instance VOP_PANIC, VOP_NULL etc.

	Implement VCALL() by making vdesc_offset the offsetof() the
	relevant function pointer in vop_vector.  This is disgusting
	but since the code is generated by a script comparatively
	safe.  The alternative for nullfs etc. would be much worse.

	Fix up all vnode method vectors to remove casts so they
	become typesafe.  (The bulk of this is generated by scripts)
2004-12-01 23:16:38 +00:00
Poul-Henning Kamp
b792bebeea Move the buffer method vector (buf->b_op) to the bufobj.
Extend it with a strategy method.

Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.

Rename ibwrite to bufwrite().

Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.

Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().

Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
2004-10-24 20:03:41 +00:00
Peter Edwards
1630ff08a3 Clean up properly when unloading NFS client module.
This includes a modified form of some code from Thomas Moestl (tmm@)
to properly clean up the UMA zone and the "nfsnodehashtbl" hash
table.

Reviewed By:	iedowse
PR:		16299
2004-04-11 13:30:20 +00:00
Warner Losh
2fcbca0d85 Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson
2004-04-07 05:00:01 +00:00
Alfred Perlstein
1bf8720450 University of Michigan's Citi NFSv4 kernel client code.
Submitted by: Jim Rees <rees@umich.edu>
2003-11-14 20:54:10 +00:00
Ian Dowse
d94f8c66b8 Since the addition of the VI_DOINGINACT flag some time ago,
VOP_INACTIVE routines need not worry about their vnode getting
recycled if they block. Remove the code from nfs_inactive() that
used vget() to get an extra vnode reference that was held during
the nfs_vinvalbuf() call.
2003-10-05 12:41:35 +00:00
Jeff Roberson
4b1a52f639 - We don't need to cache_purge() in nfs_reclaim(), vclean() does it for us. 2003-10-05 06:46:02 +00:00
Poul-Henning Kamp
2a3d23acc6 Name the vnode method vectors consistently with the rest of the filesystems.
This improves the output of src/tools/tools/vop_table
2003-09-12 16:44:40 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Poul-Henning Kamp
0c183c5a56 Remove extern declarations of stuff which is static in nfs_node.c
Move related macro to nfs_node.c

Spotted by:	FlexeLint
2002-10-20 21:40:55 +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
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
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
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
Ian Dowse
10632e44cc Remove the nfs_{lock,unlock,islocked} functions and the associated
definitions; they have been unused and #if 0'd out since the Lite/2
merge and we are unlikely to want them in the future.
2002-04-27 22:10:16 +00:00
Jeff Roberson
ab426dc822 Remove references to vm_zone.h and switch over to the new uma API. 2002-03-20 10:07:52 +00:00
Matthew Dillon
885d36ce36 nfs_nget() does no locking whatsoever when looking up a vnode. If the
vget() sleeps we have to retry the operation to avoid racing against
a deletion.

MFC maybe: submitted to re's
2001-12-27 19:40:34 +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
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
Mark Murray
fb919e4d5a Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by:	bde (with reservations)
2001-05-01 08:13:21 +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
Peter Wemm
9d10eb0c0c Create debug.hashstat.[raw]nchash and debug.hashstat.[raw]nfsnode to
enable easy access to the hash chain stats.  The raw prefixed versions
dump an integer array to userland with the chain lengths.  This cheats
and calls it an array of 'struct int' rather than 'int' or sysctl -a
faithfully dumps out the 128K array on an average machine.  The non-raw
versions return 4 integers: count, number of chains used, maximum chain
length, and percentage utilization (fixed point, multiplied by 100).
The raw forms are more useful for analyzing the hash distribution, while
the other form can be read easily by humans and stats loggers.
2001-04-11 00:39:20 +00:00
Peter Wemm
439fea92c2 Use the same API as the example code.
Allow the initial hash value to be passed in, as the examples do.
Incrementally hash in the dvp->v_id (using the official api) rather than
add it.  This seems to help power-of-two predictable filename trees
where the filenames repeat on a power-of-two cycle and the directory trees
have power-of-two components in it.  The simple add then mask was causing
things like 12000+ entry collision chains while most other entries have
between 0 and 3 entries each.  This way seems to improve things.
2001-03-20 02:10:18 +00:00
Peter Wemm
6eb39ac8fc Use a generic implementation of the Fowler/Noll/Vo hash (FNV hash).
Make the name cache hash as well as the nfsnode hash use it.

As a special tweak, create an unsigned version of register_t.  This allows
us to use a special tweak for the 64 bit versions that significantly
speeds up the i386 version (ie: int64 XOR int64 is slower than int64
XOR int32).

The code layout is a little strange for the string function, but I was
able to get between 5 to 10% improvement over the original version I
started with. The layout affects gcc code generation choices and this way
was fastest on x86 and alpha.

Note that 'CPUTYPE=p3' etc makes a fair difference to this.  It is
around 45% faster with -march=pentiumpro on a p6 cpu.
2001-03-17 09:31:06 +00:00
Peter Wemm
be1d4058eb Dramatically improve the **lame** nfs_hash(). This is based on the
Fowler / Noll / Vo Hash (http://www.isthe.com/chongo/tech/comp/fnv/).

This improves hash coverage a *massive* amount.  We were seeing one
set of machines that were using 0.84% of their 131072 entry nfsnode
hash buckets with maximum chain lengths of up to ~500 entries.  The
machine was spending nearly 100% of its time in 'system'.
A test with this has pushed the coverage from a few perCent up to 91%
utilization with a max chain length of 11.

Submitted by:  David Filo
2001-03-17 05:43:01 +00:00
Kirk McKusick
d6514f21d7 In preparation for deprecating CIRCLEQ macros in favor of TAILQ
macros which provide the same functionality and are a bit more
efficient, convert use of CIRCLEQ's in NFS to TAILQ's.
2000-11-14 08:00:39 +00:00
Poul-Henning Kamp
53ce36d17a Remove unneeded #include <sys/proc.h> lines. 2000-10-29 13:57:19 +00:00
Boris Popov
823548e131 Add missed vop_stdunlock() for fifo's vnops (this affects only v2 mounts).
Give nfs's node lock its own name.
2000-10-15 08:01:28 +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