NFS packets, mainly initializing structure pointers to NULL which
are conditionally freed prior to return.
PR: kern/15249
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
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>
* 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
a 0 error code. The problem occured with NFSv2 mounts and also with
any NFSv3 mount returning an EEXIST error (which is translated to 0
prior to return). The reply to the rpc only contains the file handle
for the no-error case under NFSv3. The error case under NFSv3 and
all cases under NFSv2 do *not* return the file handle. The fix is
to do a secondary lookup to obtain the file handle and thus be able
to generate a return vnode for the situations where the rpc reply
does not contain the required information.
The bug was originally introduced when VOP_SYMLINK semantics were
changed for -CURRENT. The NFS symlink implementation was not properly
modified to go along with the change despite the fact that three
people reviewed the code. It took four attempts to get the current
fix correct with five people. Is NFS obfuscated? Ha!
Reviewed by: Alfred Perlstein <bright@wintelcom.net>
Testing and Discussion: "Viren R.Shah" <viren@rstcorp.com>, Eivind Eklund <eivind@FreeBSD.ORG>, Ian Dowse <iedowse@maths.tcd.ie>
of element [4] in both, which goes beyond the end of the array, leaving
[0], [1], [2], and [3]. This bug did not cause any problems since
the overrun fields are initialized after the bogus array init but
needs to be fixed anyway.
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
Note: Previous commit to these files (except coda_vnops and devfs_vnops)
that claimed to remove WILLRELE from VOP_RENAME actually removed it from
VOP_MKNOD.
when returning an error. Bug fix was extracted from the PR. The PR
is not yet entirely resolved by this commit.
PR: kern/13049
Reviewed by: Matt Dillon <dillon@freebsd.org>
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
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.
error for a directory. I have made this change after a great deal of
review although I cannot be absolutely sure that this meets the spec.
The issue devolves into whether changes in an underlying (UFS) directory
can cause NFS directory blocks to be renumbered. My read of the code
indicates that NFS directory blocks will not be renumbered, which means
that the cookies should still remain valid after a change is made to
the underlying directory. This being the case, a cookie error should
not be returned when a change is made to the underlying directory and,
instead, the NFS client should rely on mtime detection to invalidate and
reload the directory.
The use of mtime is problematic in of itself, due to insufficient
resolution, which is why I believe the original conservative error
handling was done. Still, there have been dozens of bug reports by
people needing solaris<->FreeBSD interoperability and these have to
be accomodated.
-----------------------------
The core of the signalling code has been rewritten to operate
on the new sigset_t. No methodological changes have been made.
Most references to a sigset_t object are through macros (see
signalvar.h) to create a level of abstraction and to provide
a basis for further improvements.
The NSIG constant has not been changed to reflect the maximum
number of signals possible. The reason is that it breaks
programs (especially shells) which assume that all signals
have a non-null name in sys_signame. See src/bin/sh/trap.c
for an example. Instead _SIG_MAXSIG has been introduced to
hold the maximum signal possible with the new sigset_t.
struct sigprop has been moved from signalvar.h to kern_sig.c
because a) it is only used there, and b) access must be done
though function sigprop(). The latter because the table doesn't
holds properties for all signals, but only for the first NSIG
signals.
signal.h has been reorganized to make reading easier and to
add the new and/or modified structures. The "old" structures
are moved to signalvar.h to prevent namespace polution.
Especially the coda filesystem suffers from the change, because
it contained lines like (p->p_sigmask == SIGIO), which is easy
to do for integral types, but not for compound types.
NOTE: kdump (and port linux_kdump) must be recompiled.
Thanks to Garrett Wollman and Daniel Eischen for pressing the
importance of changing sigreturn as well.
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>
reasonable defaults.
This avoids confusing and ugly casting to eopnotsupp or making dummy functions.
Bogus casting of filesystem sysctls to eopnotsupp() have been removed.
This should make *_vfsops.c more readable and reduce bloat.
Reviewed by: msmith, eivind
Approved by: phk
Tested by: Jeroen Ruigrok/Asmodai <asmodai@wxs.nl>
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;
works correctly in if/else etc. egcs had probably picked up most of the
problems here before with "ambiguous braces" etc, but this should
increase the robustness a bit. Based on an idea from Eivind Eklund.
correct the pointers afterwards.
It's kinda bogus that we generate a 24 (?) byte filehandle (2 x int32
fsid and 16 byte VFS fhandle) and pad it out to 64 bytes for NFSv3 with
garbage. The whole point of NFSv3's variable filehandle length was
to allow for shorter handles, both in memory and over the wire. I plan
on taking a shot at fixing this shortly.
I did some tcpdumping the other day and noticed that GETATTR calls
were frequently followed by an ACCESS call to the same file. The
attached patch changes nfs_getattr to fill the access cache as a side
effect. This is accomplished by calling ACCESS rather than
GETATTR. This implies a modest overhead of 4 bytes in the request and
8 bytes in the response compared to doing a vanilla GETATTR.
...
[The patch comprises two parts] The first
is the "real" patch, the second counts misses and hits rather than
fills and hits. The difference is subtle but important because both
nfs_getattr and nfs_access now fill the cache. It also changes the
default value of nfsaccess_cache_timeout to better match the attribute
cache. IMHO, file timestamps change much more frequently than
protection bits.
Submitted by: Bjoern Groenvall <bg@sics.se>
Reviewed by: dillon (partially)
vnodes are locked and never unlocked, which leads to processes starting
to wedge up after doing a mount -o nfsv3,tcp,rdirplus foo:/fs /fs; ls /fs.
The second is that sometimes cnp is accessed without having been
properly initialized: cnp->cn_nameptr points to an earlier name while
"len" contains the length of a current name of different size. This
leads to an attempt to dereference *(cn->cn_nameptr + len) which will
sometimes cause a page fault and a panic.
With these two fixes, client side readdirplus works correctly with
FreeBSD, IRIX 6.5.4 and Solaris 2.5.1 and 2.6 servers.
Submitted by: Matthew Dillon <dillon@backplane.com>
being incremented by 4 bytes too few each time through the loop, which
allows more data into the mbuf chain that we really want. In the worst
case, when we're using 32K read/write sizes with a TCP client, this causes
readdirplus replies to sometimes exceed NFS_MAXPACKET which leads to a
panic. This problem cropped up for me using an IRIX 6.5.4 NFSv3 TCP client
with 32K read/write sizes, however supposedly it can be triggered by
WinNT NFS servers too. In theory, it can probably be triggered by any
NFS v3 implementation using TCP as long as it's using the maxiumum block
size.
Reviewed by: Matthew Dillon <dillon@backplane.com>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
The following ugly hack to the exit path of nfs_readlinkrpc() circumvents
an Auspex bug: for symlinks longer than 112 (0x70) they return a 1024 byte
xdr string - the correct data with many nulls appended. Without this fix
namei returns ENAMETOOLONG, at least it does on our source base and on
FreeBSD 3.0. Note we do not (and should not) rely upon their null padding.
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.
mount point for seeing whether or not the new nfsnode is already in the
hash queue. We're pretty much guaranteed that the old nfsnode is already
in the hash queue. Wank! Infinite Loop! Looks like just a minor typo....
(ah the influence of fortran ... np && np2... why not nfsnode_the_first &&
nfsnode_the_second???)...
make sure we've freed any allocated resources (to avoid a memory leak)
and and do the right thing with respect to the nfs node hash lock we'd
acquired.
