Commit Graph

164 Commits

Author SHA1 Message Date
Jeff Roberson
3bbd6d8ae6 - Release the references acquired by VOP_GETWRITEMOUNT and vfs_getvfs().
Discussed with:	tegge
Tested by:	kris
Sponsored by:	Isilon Systems, Inc.
2006-03-31 03:54:20 +00:00
Jeff Roberson
e64df05c33 - Reorder vrele calls after vput calls to prevent lock order reversals
between leaf and directory locks.

Found by:	kris
Sponsored by:	Isilon Systems, Inc.
2006-03-12 04:59:04 +00:00
Jeff Roberson
89b0e10910 - Reorder calls to vrele() after calls to vput() when the vrele is a
directory.  vrele() may lock the passed vnode, which in these cases would
   give an invalid lock order of child -> parent.  These situations are
   deadlock prone although do not typically deadlock because the vrele
   is typically not releasing the last reference to the vnode.  Users of
   vrele must consider it as a call to vn_lock() and order it appropriately.

MFC After: 	1 week
Sponsored by:	Isilon Systems, Inc.
Tested by:	kkenn
2006-02-01 00:25:26 +00:00
Christian S.J. Peron
7a3e891951 Manage the ucred for the NFS server using the crget/crfree API defined in
kern_prot.c. This API handles reference counting among many other things.
Notably, if MAC is compiled into the kernel, it will properly initialize the
MAC labels when the ucred is allocated.

This work is in preparation for a new MAC entry point which will be responsible
for properly initializing policy specific labels for the NFS server credential.
Utilization of the crfree/crget APIs reduce the complexity associated with
this label's management.

Submitted by:	green (with changes) [1]
Obtained from:	TrustedBSD Project
Discussed with:	rwatson, alfred

[1] I moved the ucred allocation outside the scope of the NFS server lock to
    prevent M_WAIKOK allocations from occurring with non-sleep-able locks held.
    Additionally, to reduce complexity, the ucred persist as long as the NFS
    server descriptor.
2006-01-28 19:24:40 +00:00
Tom Rhodes
129518ec2c Revert my previous commit.
Proved I'm not that bright at times:	jhb
2006-01-23 21:06:22 +00:00
Tom Rhodes
cb5c1ec725 Fix indentation.
Prodded by:	stefanf, ru, njl (in that order)
2006-01-23 17:41:43 +00:00
Tom Rhodes
9c013503bb Remove some dead code.
Found with:     Coverity Prevent(tm)
2006-01-21 12:10:33 +00:00
Gleb Smirnoff
19bf94288f Keep locks consistent before goto.
Reported by:	pho
Reviewed by:	mohans
2005-10-27 19:02:34 +00:00
Robert Watson
ad77d81512 NFS write gathering defers execution of NFS server write requests to wait
to see if additional write requests will arrive that can be coalesced and
clustered with earlier ones.  When doing so, it must determine whether
the two requests are made by credentials with the same access writes, so
as not to coalesce improperly.  NFSW_SAMECRED() implements a test of two
credentials using a binary compare.

Replace NFSW_SAMECRED() macro with nfsrv_samecred() function, which is
aware of the contents and layout of a struct ucred, rather than a simple
binary compare.  While the binary compare works when ucred is simply a
zero'd and embedded 'struct ucred' in the NFS descriptor, it will work
less well when the ucred associated with an NFS descriptor is "real", so
has defined and populated reference count, mutex, etc.

MFC after:	1 week
Obtained from:	TrustedBSD Project
2005-04-17 16:25:36 +00:00
Poul-Henning Kamp
c62801a7f8 Don't try to create vnode_pager objects on other filesystems vnodes,
either they did it themselves or it won't happen.
2005-01-24 22:09:13 +00:00
Paul Saab
f1b3bfb348 Now that we have a non blocking version of nfsm_dissect(), change all the
nfsm_dissect() calls (done under the NFSD lock) to nfsm_dissect_nonblock().

Submitted by:	Mohan Srinivasan
2005-01-19 22:53:40 +00:00
Poul-Henning Kamp
8df6bac4c7 Remove the unused credential argument from VOP_FSYNC() and VFS_SYNC().
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:

	The credentials for syncing a file (ability to write to the
	file) should be checked at the system call level.

	Credentials for syncing one or more filesystems ("none")
	should be checked at the system call level as well.

	If the filesystem implementation needs a particular credential
	to carry out the syncing it would logically have to the
	cached mount credential, or a credential cached along with
	any delayed write data.

Discussed with:	rwatson
2005-01-11 07:36:22 +00:00
Warner Losh
c398230b64 /* -> /*- for license, minor formatting changes 2005-01-07 01:45:51 +00:00
Robert Watson
29af382686 Correct a bug in nfsrv_create() where a call to nfsrv_access() might
be made holding the NFS server mutex.  To clean this up, introduce a
version of the function, nfsrv_access_withgiant(), that expects the
NFS server mutex to already have been dropped and Giant acquired.
Wrap nfsrv_access() around this.  This permits callers to more
efficiently check access if they're in a code block performing VFS
operations, and can be substitited for the nfsrv_access() call that
triggered this bug.

PR:		73807, 73208
MFC after:	1 week
2004-11-11 21:30:52 +00:00
Poul-Henning Kamp
494eb176e7 Add b_bufobj to struct buf which eventually will eliminate the need for b_vp.
Initialize b_bufobj for all buffers.

Make incore() and gbincore() take a bufobj instead of a vnode.

Make inmem() local to vfs_bio.c

Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj)
also VI_MTX() to BO_MTX(),

Make buf_vlist_add() take a bufobj instead of a vnode.

Eliminate other uses of bp->b_vp where bp->b_bufobj will do.

Various minor polishing: remove "register", turn panic into KASSERT,
use new function declarations, TAILQ_FOREACH_SAFE() etc.
2004-10-22 08:47:20 +00:00
Robert Watson
ae8c2fa228 Correct several instances where calls to vfs_getvfs() resulting in
failure in the NFS server would result in a leaked instance of the NFS
server subsystem lock.  Liberally sprinkle assertions in all target
labels for error unwinding to assert the desired locking state.

RELENG_5_3 candidate.

MFC after:	3 days
Reported by:	Wilkinson, Alex <alex dot wilkinson at dsto dot defence dot gov dot au>
2004-10-18 11:23:11 +00:00
Robert Watson
e2d2098653 Convert a mtx_lock(&Giant) to a mtx_unlock(&Giant) in nfsrv_link() to
prevent leakage of Giant.  With INVARIANTS, this results in an
assertion failure following execution of the RPC.  Without INVARIANTS,
it could result in problems if the NFS server is killed causing nfsd
to return to user space holding Giant.

Feet provided by:	brueffer
2004-08-25 16:52:59 +00:00
Poul-Henning Kamp
f3732fd15b Second half of the dev_t cleanup.
The big lines are:
	NODEV -> NULL
	NOUDEV -> NODEV
	udev_t -> dev_t
	udev2dev() -> findcdev()

Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
2004-06-17 17:16:53 +00:00
Robert Watson
69af1dccdc Release NFS subsystem lock and acquire Giant when calling into
vn_start_write().
2004-05-31 19:08:22 +00:00
Robert Watson
73a4c21f28 One more case where we want to drop the NFS server lock and acquire
Giant when entering VFS.  Discovered by code inspection; still not
hit without debug.mpsafenet=1.

Reported by:	bmilekic
2004-05-30 22:59:54 +00:00
Robert Watson
53f137e9d3 Acquire Giant around two more cases when calling into VFS to vput()
a vnode.  Not bumped into with asserts in the main tree because we
run the NFS server with Giant by default.  Discovered by inspection.

Complete annotations of Giant acquisition/release to note that it's
only because of VFS that we acquire Giant in most places in the NFS
server.
2004-05-30 22:41:43 +00:00
Robert Watson
e95fb8576b Don't release Giant until after the call to vput() in nfsrv_setattr().
Unless running with debug.mpsafenet=1, this was not actually a problem.
2004-05-29 15:52:39 +00:00
Robert Watson
9a7563cf2d Call nfsm_clget_nolock() instead of nfsm_clget() when holding the NFS
subsystem lock to avoid tripping over an assertion regarding whether
the lock is held or not.  This is likely to be the cause of a panic
tripped over by Andrea Campi.
2004-05-27 20:34:04 +00:00
Robert Watson
1ee624b31d The socket code upcalls into the NFS server using the so_upcall
mechanism so that early processing on mbufs can be performed before
a context switch to the NFS server threads.  Because of this, if
the socket code is running without Giant, the NFS server also needs
to be able to run the upcall code without relying on the presence on
Giant.  This change modifies the NFS server to run using a "giant
code lock" covering operation of the whole subsystem.  Work is in
progress to move to data-based locking as part of the NFSv4 server
changes.

Introduce an NFS server subsystem lock, 'nfsd_mtx', and a set of
macros to operate on the lock:

  NFSD_LOCK_ASSERT()    Assert nfsd_mtx owned by current thread
  NFSD_UNLOCK_ASSERT()  Assert nfsd_mtx not owned by current thread
  NFSD_LOCK_DONTCARE()  Advisory: this function doesn't care
  NFSD_LOCK()           Lock nfsd_mtx
  NFSD_UNLOCK()         Unlock nfsd_mtx

Constify a number of global variables/structures in the NFS server
code, as they are not modified and contain constants only:

  nfsrvv2_procid       nfsrv_nfsv3_procid      nonidempotent
  nfsv2_repstat        nfsv2_type              nfsrv_nfsv3_procid
  nfsrvv2_procid       nfsrv_v2errmap          nfsv3err_null
  nfsv3err_getattr     nfsv3err_setattr        nfsv3err_lookup
  nfsv3err_access      nfsv3err_readlink       nfsv3err_read
  nfsv3err_write       nfsv3err_create         nfsv3err_mkdir
  nfsv3err_symlink     nfsv3err_mknod          nfsv3err_remove
  nfsv3err_rmdir       nfsv3err_rename         nfsv3err_link
  nfsv3err_readdir     nfsv3err_readdirplus    nfsv3err_fsstat
  nfsv3err_fsinfo      nfsv3err_pathconf       nfsv3err_commit
  nfsrv_v3errmap

There are additional structures that should be constified but due
to their being passed into general purpose functions without const
arguments, I have not yet converted.

In general, acquire nfsd_mtx when accessing any of the global NFS
structures, including struct nfssvc_sock, struct nfsd, struct
nfsrv_descript.

Release nfsd_mtx whenever calling into VFS, and acquire Giant for
calls into VFS.  Giant is not required for any part of the
operation of the NFS server with the exception of calls into VFS.
Giant will never by acquired in the upcall code path.  However, it
may operate entirely covered by Giant, or not.  If debug.mpsafenet
is set to 0, the system calls will acquire Giant across all
operations, and the upcall will assert Giant.  As such, by default,
this enables locking and allows us to test assertions, but should not
cause any substantial new amount of code to be run without Giant.
Bugs should manifest in the form of lock assertion failures for now.

This approach is similar (but not identical) to modifications to the
BSD/OS NFS server code snapshot provided by BSDi as part of their
SMPng snapshot.  The strategy is almost the same (single lock over
the NFS server), but differs in the following ways:

- Our NFS client and server code bases don't overlap, which means
  both fewer bugs and easier locking (thanks Peter!).  Also means
  NFSD_*() as opposed to NFS_*().

- We make broad use of assertions, whereas the BSD/OS code does not.

- Made slightly different choices about how to handle macros building
  packets but operating with side effects.

- We acquire Giant only when entering VFS from the NFS server daemon
  threads.

- Serious bugs in BSD/OS implementation corrected -- the snapshot we
  received was clearly a work in progress.

Based on ideas from:	BSDi SMPng Snapshot
Reviewed by:		rick@snowhite.cis.uoguelph.ca
Extensive testing by:	kris
2004-05-24 04:06:14 +00:00
Maxime Henrion
7cc35e41e7 Don't send the available space as is in the FSSTAT call. Under
FreeBSD, we can have a negative available space value, but the
corresponding fields in the NFS protocol are unsigned.  So
trnucate the value to 0 if it's negative, so that the client
doesn't receive absurdly high values.

Tested by:	cognet
2004-04-12 13:02:21 +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
Poul-Henning Kamp
4d453ef101 Properly vector all bwrite() and BUF_WRITE() calls through the same path
and s/BUF_WRITE()/bwrite()/ since it now does the same as bwrite().
2004-03-11 18:02:36 +00:00
Poul-Henning Kamp
63b92d134e When grabbing vnodes to service NFS requests, make sure to call
vn_start_write() early to avoid snapshot deadlocks.

By:	mckusick
2003-10-24 18:36:49 +00:00
Ian Dowse
92daf89227 Fix a bug in nfsrv_read() that caused the replies to certain NFSv3
short read operations at the end of a file to not have the "eof"
flag set as they should. The problem is that the requested read
count was compared against the rounded-up reply data length instead
of the actual reply data length. This bug appears to have been
introduced in revision 1.78 (June 1999). It causes first-time reads
of certain file sizes (e.g 4094 bytes) to fail with EIO on a RedHat
9.0 NFSv3 client.

MFC after:	1 week
2003-06-24 19:04:26 +00:00
Kirk McKusick
98530110a2 Increase the size of the NFS server hash table to improve performance
when serving up more than about 32 active files. For details see
section 6.3 (pg 111) of Daniel Ellard and Margo Seltzer, ``NFS
Tricks and Benchmarking Traps'' in the Proceedings of the Usenix
2003 Freenix Track, June 9-14, 2003 pg 101-114.

Obtained from:	Daniel Ellard <ellard@eecs.harvard.edu>
Sponsored by:   DARPA & NAI Labs.
2003-06-21 21:01:44 +00:00
Don Lewis
263c8abeb9 Beat vnode locking in the NFS server code into submission. This change
is not pretty, but it fixes the code so that it no longer violates the
vnode locking rules in the VFS API and doesn't trip any of the locking
assertions enabled by the DEBUG_VFS_LOCKS kernel configuration option.
There is one report that this patch fixed a "locking against myself"
panic on an NFS server that was tripped by a diskless client.

Approved by:	re (scottl)
2003-05-25 06:17:33 +00:00
Alan Cox
b6e48e0372 - Acquire the vm_object's lock when performing vm_object_page_clean().
- Add a parameter to vm_pageout_flush() that tells vm_pageout_flush()
   whether its caller has locked the vm_object.  (This is a temporary
   measure to bootstrap vm_object locking.)
2003-04-24 04:31:25 +00:00
Jeff Roberson
c033bdc013 - Lock bufs before inspecting their flags. 2003-03-13 07:05:22 +00:00
Jeff Roberson
17661e5ac4 - Add an interlock argument to BUF_LOCK and BUF_TIMELOCK.
- Remove the buftimelock mutex and acquire the buf's interlock to protect
   these fields instead.
 - Hold the vnode interlock while locking bufs on the clean/dirty queues.
   This reduces some cases from one BUF_LOCK with a LK_NOWAIT and another
   BUF_LOCK with a LK_TIMEFAIL to a single lock.

Reviewed by:	arch, mckusick
2003-02-25 03:37:48 +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
Jens Schweikhardt
9d5abbddbf Correct typos, mostly s/ a / an / where appropriate. Some whitespace cleanup,
especially in troff files.
2003-01-01 18:49:04 +00:00
Matthew Dillon
45587e2514 Abstract-out the constants for the sequential heuristic.
No operational changes.

MFC after:	1 day
2002-12-28 20:28:10 +00:00
Ian Dowse
2f07688e82 In the NFSv3 `fsinfo' procedure reply, don't claim that we support
32k read and write operations on datagram sockets when in fact we
reject requests larger than 16k. It must be the case that virtually
all clients use data sizes of 16k or less for UDP transport (FreeBSD's
client defaults to 8k and never exceeds 16k), as this bug has been
present ever since NFSv3 support was added.

Reported by:	Senthil <lihtnes78@netscape.net>
Reviewed by:	dillon
Approved by:	re
MFC-after:	1 week
2002-12-05 16:58:11 +00:00
Jeff Roberson
24b50116ed - Introduce a new macro, since that's what nfs loves, called
nfsm_srvpathsiz.  This macro plucks a length out of an rpc request and
   verifies that its size does not exceed NFS_MAXPATHLEN.  If it does
   it generates an ENAMETOOLONG response.
 - Use this macro, and the existing nfsm_srvnamsiz macro in two places
   where we deal with paths passed in by the client.

This fixes a linux interoperability bug.  Linux was sending oversized path
components which would cause us to ignore the request all together.  This
causes linux to hang indefinitly while it waits for a response.  This
could still happen in other cases where we error out with EBADRPC.

Sponsored by:	Isilon Systems, Inc.
Reviewed by:	alfred, fabbri@isilon.com, neal@isilon.com
2002-10-31 22:35:03 +00:00
Robert Watson
60cfb7c64a Correct a problem wherein NFS servers running NFSv2 would not return
certain classes of failure responses to the client during a failed
remove operation.

Submitted by:	Ian Dowse <iedowse@maths.tcd.ie>
2002-10-03 21:50:37 +00:00
Jeff Roberson
d3b85e1c8b - Use incore() instead of gbincore() so we don't have to acquire the
vnode interlock.
2002-09-25 02:39:39 +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
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
Tom Rhodes
d394511de3 More s/file system/filesystem/g 2002-05-16 21:28:32 +00:00
Ian Dowse
3aed248695 Limit to the maximum allowed reply size the amount of data that
nfsrv_readdir and nfsrv_readdirplus can return. A client request
containing an over-large `count' field could trigger the "Bad nfs
svc reply" panic in nfs_syscalls.c.

Spotted while trying to reproduce kern/37304, which turned out to
be fixed in FreeBSD a long time ago.

MFC after:	1 week
2002-04-21 16:14:54 +00:00
John Baldwin
44731cab3b Change the suser() API to take advantage of td_ucred as well as do a
general cleanup of the API.  The entire API now consists of two functions
similar to the pre-KSE API.  The suser() function takes a thread pointer
as its only argument.  The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0.  The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on:	smp@
2002-04-01 21:31:13 +00:00
Kirk McKusick
a0595d0249 Add a flags parameter to VFS_VGET to pass through the desired
locking flags when acquiring a vnode. The immediate purpose is
to allow polling lock requests (LK_NOWAIT) needed by soft updates
to avoid deadlock when enlisting other processes to help with
the background cleanup. For the future it will allow the use of
shared locks for read access to vnodes. This change touches a
lot of files as it affects most filesystems within the system.
It has been well tested on FFS, loopback, and CD-ROM filesystems.
only lightly on the others, so if you find a problem there, please
let me (mckusick@mckusick.com) know.
2002-03-17 01:25:47 +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